Producing dopamine-making neurons from stem cells for transplantation into Parkinson’s disease patients remains challenging. Differentiating stem cells into dopaminergic neurons is not as efficient a process as we would like it to be. While several laboratories have managed to make pretty good batches of dopaminergic neurons, reliably producing large and pure batches of dopamine-making neurons from pluripotent stem cells is still somewhat problematic. Secondly, transplanting dopamine-making neurons into either the midbrain or the striatum of the brain represents another patch of problems because the production of too much dopamine can cause unwanted, uncontrollable movements. Preclinical assessments of stem cell-derived dopamine neurons in laboratory animals have produced positive, but highly varied results, even though the transplanted cells are very similar at the time of transplantation.
“This has been frustrating and puzzling, and has significantly delayed the establishment of clinical cell production protocols,” said Malin Parmar, who led the study at Lund University.
To address this issue, Parmar and his colleagues used modern global gene expression studies to gain a better understand the molecular changes that drive the differentiation of stem cells into dopamine-making neurons. Parmar conducted these experiments in collaboration with a team of scientists at Karolinska Institute. In their paper, which appeared in the journal Cell Stem Cell, Parmar and his colleagues used single-cell RNA seq to construct the neuronal development of dopaminergic neurons.
These neurons are characterized by the expression of a gene called LMX1a. However, it turns out that LMX1a-expressing neurons includes not only midbrain dopaminergic neurons (see below at the substantia nigra), but also subthalamic nuclear neurons.
These findings reveal that markers used to identify midbrain dopaminergic neurons do not specifically isolate midbrain dopaminergic neurons, but isolate a mixture of cells. Is there a way to separate these two populations?
Indeed, there is. Parmar and his colleagues in the laboratory of Thomas Perlmann showed that although dopaminergic neurons from the midbrain and subthalamic nuclear neurons are related, they do express a distinct profile of genes that are specific to the two cell types. The authors argue that the application of these distinct marker genes can help optimize those protocols that differentiate dopaminergic neurons from pluripotent stem cells.
See Nigel Kee and others, “Single-Cell Analysis Reveals a Close Relationship between Differentiating Dopamine and Subthalamic Nucleus Neuronal Lineages,” Cell Stem Cell, 2016; DOI: 10.1016/j.stem.2016.10.003.
Accidents happen and sometimes really bad accidents happen; especially if they injure your head. Traumatic brain injuries or TBIs can result from automobile accidents, explosions or other events that result from severe blows to the head. TBIs an adversely affect a patient and his/her family for long periods of time. TBI patients can experience cognitive deficits that prevent them from thinking or speaking straight, and sensory deficits that prevent them from seeing, hearing or smelling properly. Psychological problems can also result. Essentially, TBIs represent a major challenge for modern medicine.
According to data from the Centers for Disease Control (CDC), 1.7 million Americans suffer from TBIs each year (of varying severity). Of these, 275,000 are hospitalized for their injuries and approximately 52,000 of these patients die from their injuries. In fact, TBIs contribute to one-third of all injury-related deaths in the United States each year. More than 6.5 million patients are burdened by the deleterious effects of TBIs, and this leads to an economic burden of approximately $60 billion each year.
Currently, treatments for TBI are few and far between. Neurosurgeons can use surgery to repair damaged blood vessels and tissues, and diminish swelling in the brain. Beyond these rather invasive techniques, the options for clinicians are poor.
A new study by Charles S. Cox, professor of Pediatric Surgery and co-director of the Memorial Hermann Red Duke Trauma Institute, and his colleagues suggest that stem cell treatments might benefit TBI patients. The results of this study were published in the journal Stem Cells.
This study enrolled 25 TBI patients. Five of them received no treatment and served as controls, but the remaining 20 received gradually increasing dosages of their own bone marrow stem cells. The harvesting, processing and infusion of the bone marrow cells occurred within 48 hours of injury. Functional and cognitive results were measured with standard tests and brain imaging with magnetic resonance imaging and diffusion tensor imaging.
This work is an extension of extensive preclinical work done by Cox and his coworkers in laboratory animals and a phase I study that established that such stem cell transplantation are safe for human patients. The implanted stem cells seem to quell brain inflammation and lessen the damage to the brain by the TBI.
Despite the fact that those TBI patients who received the stem cell treatments had greater degrees of brain damage, the treatment group showed better structural preservation of the brain and better functional outcomes than the control group. Of particular interest was the decrease in indicators of inflammation as a result of the bone marrow cell-based infusions.
Cox said of this trial, “The data derived from this trial moves beyond just testing safety of this approach.” He continued: “We now have a hint of a treatment effect that mirrors our pre-clinical work, and were are now pursuing this approach in a phase IIb clinical trial sponsored by the Joint Warfighter Program within the US Army Medical Research Acquisition Activity, as well as our ongoing phase IIb pediatric severe TBI clinical trial; both using the same autonomous cell therapy.”
This an exciting study, but it is a small study. While the safety of this procedure has been established, the precise dosage and long-term benefits will require further examination. However it is a fine start to what may become the flowering of new strategies to treat TBI patients.
International Stem Cell Corporation (OTCQB:ISCO) announced that the company’s proprietary ISC-hpNSC readily expandable neural stem cells improved cognitive performance and motor coordination in laboratory afflicted with traumatic brain injuries. ISC-hpNSCs consists of a highly pure population of neural stem cells derived from human parthenogenetic stem cells.
This preclinical study was conducted by scientists at the University of South Florida Morsani College of Medicine. The study examined rodents that had suffered from controlled cortical impact injury (rather well-known to be an established model of traumatic brain injury model).
The University of South Florida researchers divided their laboratory animals into four different cohorts. One group was treated with vehicle (the buffer in which the stem cells were delivered). This group of animals were the control group for this experiment. The next three groups were treated with ISC-hpNSCs, but the animals were given these cells in three different ways. Interestingly, laboratory animals that had received injections of ISC-hpNSCs showed the highest levels of improvements in cognitive performance and motor coordination when compared to those animals injected with only vehicle. Improvements in cognitive tests in animals transplanted with ISC-hpNSCs appeared only a few days after implantation.
ISCO’s new traumatic brain injury program will use the same cellular product (ISC-hpNSC) as their ongoing Parkinson’s disease program, which is presently in clinical trials. The safety data from the Parkinson’s disease trial can be used for future trials in patients with traumatic brain injuries.
Cell banks of ISC-hpNSCs were made under so-called “Good Manufacturing Practices,” which means that they are clean enough to be used in human patients. All of these stem cells have been extensively tested for sterility, purity, identity and safety. These extensive preclinical studies conducted during the development of the Parkinson’s disease program nicely demonstrate the safety of ISC-hpNSCs, even at high doses.
There is no approved treatment for traumatic brain injuries, and these injuries can cause long-term neurological disability. However, transplantation of neural stem cells may improve some of the symptoms of traumatic brain injury. Over 1.7 million people in North America suffer annually from traumatic brain injury, with associated medical costs exceeding $70 billion. According to the World Health Organization, the global incidence for traumatic brain injury is approximately 10 million people annually.
Preclinical studies in rodents and non-human primates have shown improvement in Parkinson’s disease symptoms and increase in brain dopamine levels following the intracranial administration of ISC-hpNSCs.
Researchers from the Harvard T.H. Chan School of Public Health have elucidated the potential molecular mechanism by which lead, a pervasive environmental toxin, harms neural stem cells and neurodevelopment in children.
The results of this study by Quan Lu and his colleagues suggest that exposure to lead leads to oxidative stress, which perturbs cell behavior. However, Lu and his coworkers found that lead also seems to disrupt the function of certain proteins within neural stem cells.
This study resulted from a collaboration between the Departments of Environmental Health, Biostatistics, and Genetics and Complex Diseases and the T.H. Chan School of Public Health, and the Department of Environmental Health Sciences at Columbia University Mailman School of Public Health, and Department of Preventative Medicine, Mount Sinai School of Medicine.
Epidemiological studies that conclusively linked lead exposure to specific health problems. Lu used these valuable studies are married the epidemiological data with the molecular data from his own work. In fact, this paper by Lu and others, is one of the first to integrate genetic analysis in the lab with genomic data from participants in an epidemiological study.
Lead exposure affects the early stages of neurodevelopment, but the underlying molecular mechanisms by which lead affects early childhood development remain poorly understood.
Lu and others in his laboratory identified one key mechanism that might lead to new therapeutic approaches to treat the neurotoxicity associated with lead exposure.
Numerous studies have suggested that lead exposure can harm the cognitive, language, and psychomotor development of children. Lead exposure also increases the risk that children will later engage in antisocial and delinquent behavior.
Although regulatory limits on the use of lead have definitely reduced blood lead levels in U.S., half a million children aged 1-5 in the U.S. have lead blood levels that are twice those deemed safe by the U.S. Centers for Disease Control. Recent incidents of lead contamination in drinking water in Flint, Mich., and several U.S. cities highlight the continued threat.
Outside the U.S., environmental levels of lead remain high in many countries where lead has not, or has only recently, been phased out from gasoline, paint, and other materials.
Lu and his coworkers explored the molecular mechanisms through which exposure to lead may impact neural stem cells. Neural stem cells can differentiate into other kinds of cells in the central nervous system and play a key role in shaping the developing brain.
In this paper, scientists in Lu’s laboratory and his collaborators conducted a genome-wide screen in neural stem cells for genes whose expression is changed during lead exposure. 19 different genes were identified, and many of these 19 genes are known to be regulated by a protein called NRF2. This is a significant finding, since the NRF2 proteins is known to control the oxidative stress response in cells. This led Lu and others to hypothesize that lead exposure induces an oxidative stress response in cells. However, the Lu group and their collaborators identified a new target of NRF2; a gene designated as SPP1 (also known as osteopontin).
Others involved in this work also conducted genetic analyses on blood samples from a group of infants who were part of the Early Life Exposures in Mexico and NeuroToxicology (ELEMENT) prospective birth cohort. The ELEMENT study was designed to assess the roles of environmental and social factors in birth outcomes and in infant and child development.
Data from the ELEMENT study showed that genetic variants in SPP1 in some blood samples that were statistically linked to abnormal cognition development in those children, whose neurodevelopmental progress was followed through age two. This suggests that lead exerts its deleterious effects, in part, through SPP1. Therefore, drugs that target SPP1 might provide protection against lead exposure in at-risk children.
This paper appeared here: Peter Wagner et al., “In Vitro Effects of Lead on Gene Expression in Neural Stem Cells and Associations between Upregulated Genes and Cognitive Scores in Children,” Environmental Health Perspectives, 2016; DOI: 10.1289/EHP265.
The choroid plexus is a network of blood vessels in each ventricle of the brain. It is derived from the pia mater and produces the cerebrospinal fluid. The choroid plexus, unfortunately, has been ignored to some degree when it comes to brain research. However, CSF turns to be an important regulator of adult neural stem cells, research indicates.
A new study led by Prof. Fiona Doetsch at the Biozentrum of the University of Basel, Switzerland has shown that signals secreted by the choroid plexus dynamically change during aging, and these different signals affect the behavior of aged stem cells.
In the adult brain, neural stem cell populations in various places throughout the central nervous system divide to give rise to neurons and glial cells throughout our lives. These stem cells reside in unique micro-environments (known as niches) that provide key signals that regulate stem cell self-renewal and differentiation. Stem cells in the adult brain contact the ventricles, which are cavities in the brain filled with CSF. CSF bathes and protects the brain and is produced by the cells of the choroid plexus.
Doetsch and her coworkers have shown that the choroid plexus is a key component of the stem cell niche, and that the properties of this stem cell niche change throughout life and affect stem cell behavior.
Doetsch’s group discovered that the choroid plexus secretes a cocktail of important signaling factors into the CSF. These CSF-secreted growth factors are important in stem cell regulation throughout life. As we age, the levels of stem cell division and formation of new neurons decrease. They also showed that although stem cells are still present in the aged brain, and have the capacity to divide, their ability to do so have significantly decreased.
“One reason is that signals in the old choroid plexus are different. As a consequence, stem cells receive different messages and are less capable to form new neurons during aging. In other words, compromising the fitness of stem cells in this brain region,” said Violeta Silva Vargas, first author of the paper that appeared in the journal Cell Stem Cell. “But what is really amazing is that when you cultivate old stem cells with signals from young fluid, they can still be stimulated to divide, behaving like the young stem cells.”
In the future, Doetsch and her group plans to tease out the composition of the signaling factors secreted by the choroid plexus. They would also like to know how the composition of this growth factor cocktail changes as a result of changes in brain states and how these changes affect neural stem cells. This could provide new ways to understand brain function in health and disease.
“We can imagine the choroid plexus as a watering can that provides signals to the stem cells. Our investigations also open a new route for understanding how different physiological states of the body influence stem cells in the brain during health and disease, and opens new ways for thinking about therapy,” said Doetsch.
The brains of some people with autism spectrum disorder grow faster than usual early on in life, often before diagnosis. Now new research from scientists at the Salk Institute has used cutting-edge stem cell-based techniques to elucidate those mechanisms that drive excess brain growth, which affects as many as 30 percent of people with autism.
These findings show that it is possible to use stem cell reprogramming technologies to model the earliest stages of complex disorders and to evaluate potential therapeutic drugs. The Salk team, led by Alysson Muotri, discovered that stem cell-derived neurons, derived from stem cells that had been made from cells taken from autism patients, made fewer connections in culture compared to cells from healthy individuals. These same scientists also restored cell-cell communication between these cells by adding a growth factor called IGF-1 (insulin-like growth factor-1). IGF-1 is in the process of being evaluated in clinical trials of autism.
“This technology allows us to generate views of neuron development that have historically been intractable,” said senior investigator Fred H. Gage. “We’re excited by the possibility of using stem cell methods to unravel the biology of autism and to possibly screen for new drug treatments for this debilitating disorder.”
In the United States alone, autism affects approximately one out of every 68 children. Autistic children have problems communicating, show an inhibited ability to interact with others, and usually engage in repetitive behaviors. Mind you, the symptomatic manifestations in autistic children can vary dramatically in type and severity. Autism, to date, has no known, identified cause.
In 2010, Gage and collaborators recreated features of Rett syndrome (a rare disorder that shares features of autism but is caused by mutations in a single gene; MECP2) in a cell culture system. They extracted skin cells from Rett Syndrome patients and converted those cells into induced pluripotent stem cells (iPSCs). Then Gage and others differentiated those Rett-Syndrome-specific iPSCs into neurons, which they grew in culture. These neurons were then studied in detail in a neuron-specific culture system. “In that study, induced pluripotent stem cells gave us a window into the birth of a neuron that we would not otherwise have,” said Marchetto, the study’s first author. “Seeing features of Rett syndrome in a dish gave us the confidence to next study classical autism.”
In this new study, Gage and others created iPSCs from autism patients whose brains had grown up to 23 percent faster than usual during toddlerhood but had subsequently normalized. These iPSCs were then differentiated into neuron precursor cells (NPCs). Examinations of these NPCs revealed that the NPCs made from iPSCs derived from autism patients proliferated faster than those derived from typically developing individuals. This finding supports a theory advanced by some experts that brain enlargement is caused by disruptions to the cell’s normal cycle of division, according to Marchetto.
In addition, the neurons derived from autism-specific iPSCs behaved abnormally in culture. They fired less often compared with those cells derived from healthy people. The activity of these neurons, however, improved if they were treated with IGF-1. IGF-1 enhances the formation of cell-cell connections between neurons, and the establishment and stabilization of these connections seem to normalize neuronal function.
Muotri and Gage and others plan to use these patient-derived cells to elucidate the molecular mechanisms behind IGF-1’s effects. They will examine changes in gene expression and attempt to correlate them with changes in neuronal function. Although the newly derived cells are far from the patients’ brains, a brain cell by itself may, hopefully, reveal important clues about a person and their brain.
This work was published in the journal Molecular Psychiatry: M. C. Marchetto et al., “Altered proliferation and networks in neural cells derived from idiopathic autistic individuals,” Molecular Psychiatry, 2016; DOI: 10.1038/mp.2016.95.
SanBio, Inc., has announced the randomization of the first patient in their STEMTRA Phase 2 clinical trial study for traumatic brain injury. The STEMTRA trial is presently enrolling patients in both the United States and Japan, and the first patient was randomized at Emory University Hospital in Atlanta, Ga.
STEMTRA stands for “Stem cell therapy for traumatic brain injury,” and this trial will examine the effects of SB623 stem cells to treat patients with chronic motor deficits that result from traumatic brain injury (TBI).
SB623, a proprietary product of SanBio, are bone marrow-derived mesenchymal stem cells that have been genetically engineered to express the intracellular domain of Notch-1. When injected into neural tissue, SB623 cells seem to reverse neural damage. Since SB623 cells come from donors, a single donor’s cells can be used to treat thousands of patients. In cell culture and animal models, SB623 cells restore function to neurons damaged by strokes, spinal cord injury and Parkinson’s disease. There have been no serious adverse events attributable to the cell therapy product and patients benefit on all three stroke scales.
Traumatic brain injuries (TBIs) can be caused by a wide range of events, including falls, fights, car accidents, gunshot wounds to the head, blows to the head from falling objects, and battlefield injuries. These events often result in permanent damage, including significant motor deficits; leaving more than 5.3 million people living with disabilities in the United States alone.
Damien Bates of SanBio, said, “This modified stem cell treatment has improved outcomes in patients with persistent limb weakness secondary to ischemic stroke. Our preclinical data suggest it may also help TBI patients. For people suffering from the often debilitating effects of TBI, this milestone brings us one step closer to proving whether it’s an effective treatment option.”
The STEMTRA trial follows a Phase 1/2a clinical trial in patients afflicted with chronic motor deficit secondary as a result of an ischemic stroke were treated with SB623 cells. In this trial, SB623 cells statistically significantly improved motor function following implantation. The STEMTRA study will evaluate the tolerability, efficacy, and safety of the SB623 cell treatment and the administration process in those patients who have suffered a TBI. As a Phase 2 trial, STEMTRA will evaluate the clinical efficacy and safety of intracranial administration of SB623 cells in patients with chronic motor deficit from TBI.
STEMTRA will be conducted across approximately 25 clinical trial sites throughout the United States and five sites in Japan. Total enrollment is expected to reach 52 patients in total, and all enrolled patients must have suffered their TBI at least 12 months ago.
BrainStorm Cell Therapeutics Inc. (BCLI) has developed a cell-based product they call “NurOwn.” NurOwn consists of mesenchymal stem cells that have been cultured to secrete a variety of neurotrophic factors (NTFs). These NTFs are a collection of different growth factors that promote the survival of neurons. NurOwn cells were originally developed in the laboratories of Professor Dani Offen and the late Professor Eldad Melamed, at Tel Aviv University. NurOwn cells have been studied extensively and they clearly have the capacity to migrate to damaged areas in the central nervous system (Sadan O, et al., Stem Cells. 2008 Oct;26(10):2542-51), decrease dopamine depletion in a Parkinson’s disease model system (Barhum Y, et al., J Mol Neurosci. 2010 May;41(1):129-37), can promote the survival of photoreceptors in the retina of animals who optic nerves were damaged (Levkovitch-Verbin H, et al., Invest Ophthalmol Vis Sci. 2010 Dec;51(12):6394-400), decrease quinolinic acid toxicity in an animal model of Huntington’s disease (Sadan O, et al., Exp Neurol. 2012 Apr;234(2):417-27), and improve motor function and survival in a genetic model of Huntington’s disease.
On the strength of these experiments, NurOwn cells have also been tested in clinical trials. Because NTF-secreting MSCs (or, MSC-NTF cells) are designed specifically to treat neurodegenerative diseases, most of the clinical trials, to date, have examined of safety and efficacy of MSC-NTFs in patients with neurological disorders. The safety of NurOwn cells was established in a small phase I/II trial with amyotrophic lateral sclerosis (ALS) patients. This was a small study (12 patients), but showed that, at least in this patients population, intrathecal (injected into the central nervous system) and intramuscular administration of MSC-NTF cells in ALS patients with is safe and patients even showed some indications of clinical benefits, but the study was too small to be definitive about the efficacy of these cells.
Now a recently completed randomized, double-blind, placebo-controlled phase 2 study of NurOwn in ALS patients has found that NurOwn is safe and well tolerated and may also confer clinical benefits upon ALS patients.
According to BrainStorm, this phase 2 study achieved its primary objective (safety and tolerability). No deaths were reported in the study and no patients discontinued participation because of an adverse event. All patients in both active treatment and placebo groups experienced at least one treatment-emergent adverse event that tended to be mild-to-moderate in intensity in both groups. Treatment-related adverse events, as determined by a blinded investigator, occurred slightly more frequently in active-treated patients than in placebo-treated patients (97.2 percent vs. 75.0 percent). The largest differences in frequencies were for the localized reactions of injection site pain and back pain, and fever, headache, and joint pain.
However, NurOwn also achieved multiple secondary efficacy endpoints in this trial. NurOwn showed clear evidence of a clinically significant benefit. Most significantly, the response rates were higher for NurOwn-treated subjects compared to placebo at all time points in the 24 weeks during which when the study was conducted.
This clinical trial conducted at three sites in the U.S: Massachusetts General Hospital, UMass Medical School and the Mayo Clinic. 48 patients were randomized to receive NurOwn cells administered via combined intramuscular and intrathecal injection (n= 36), or placebo (n=12). They were followed monthly for approximately three months before treatment and six months following treatment, and were assessed at 2, 4, 8, 12, 16 and 24 weeks.
The primary investigator in this trial, Robert H. Brown of the University of Massachusetts Medical Center and Medical School said, “These exciting findings clearly indicate that it is appropriate to conduct a longer study with repetitive dosing.”
Subjects treated with NurOwn in this trial showed slowing of progression of ALS and no safety concerns. NurOwn-treated patients also displayed increased levels of growth factors in the cerebrospinal fluid and decreased signs of inflammation after two weeks. These are good indicators that the MSC-NTF cells are orchestrating some kind of beneficial biological effect.
Based on these results, new trials are warranted that will examine repeat dosing at 8 to 12 weeks and employ a larger number of subjects.
Jonathan Glass, professor of neurology at Emory University in School of Medicine, is the principal investigator of a phase 2 clinical trial that examined the safety of intraspinal injection of human spinal cord–derived neural stem cells in people with amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease.
This clinical trial was not designed to determine whether the treatment was effective, which is odd given that the trial was a phase 2 trial. Glass and his collaborators noted that the transplanted stem cells did not slow down the progression of the disease. However, given that the trial was not designed to detect efficacy, it is difficult to draw any hard-and-fast conclusions.
ALS is a disorder in which the motor neurons of the brain and spinal cord degenerate. Motor neuron degeneration causes progressive loss of muscle control, which includes breathing and swallowing (leading to death). There are no treatments that can stop ALS.
“Though there were two serious complications related to the treatment, the level of acceptable risk for treating patients with ALS, where the prognosis is poor and treatments are limited, is arguably higher than that for more benign disorders,” said Dr. Glass.
In this study, 15 ALS patients who manifested their first signs and symptoms of the disease within two years of the start of the study, were treated at three different university hospitals.
The participants were divided into five treatment groups that received increasing doses of stem cells. This trial was an “open-label” trial, which means that the participants knew they were getting active stem cell treatments.
Participants received bilateral (both sides) injections into the cervical spinal cord between the C3 and C5 regions. The final group received injections into both the lumbar (L2-L4) and cervical cord through two separate surgical procedures.
The numbers of injections ranged from 10 to 40, and the number of cells injected ranged from two million to 16 million. Because of the large range of injections and stem cells injected, determining the safety of these treatments was probably more important that the efficacy of the treatments.
During the nine months of follow-up, patients were assessed for side effects from the intraspinal injections and progression of the disease, according to the functional rating scale. Most of the side effects were related to temporary pain associated with surgery and to medications that suppress the immune system.
Two people developed serious complications related to the treatment. One patient developed spinal cord swelling that caused pain, sensory loss and partial paralysis, and another patient developed central pain syndrome; a neurological condition caused by damage to or dysfunction of the central nervous system (CNS), which includes the brain, brainstem, and spinal cord. This syndrome can be caused by stroke, multiple sclerosis, tumors, epilepsy, brain or spinal cord trauma, or Parkinson’s disease.
The participants’ functioning was compared to three historical control groups, and there was no difference in how fast the disease progressed between those
who received stem cells and those who did not. This is a significant finding because injecting cells into the spinal cord might actually accelerate the progression of the disease. However, this study seemed to show that 10-40 injections into the spinal do not affect the progression of ALS.
However, Glass cautioned that no conclusions can be draw about effectiveness of the treatment from such a small, non-blinded, non-placebo-controlled study.
“This study was not designed, nor was it large enough, to determine the effectiveness of slowing or stopping the progression of ALS. The importance of this study is that it will allow us to move forward to a larger trial specifically designed to test whether transplantation of human stem cells into the spinal cord will be a positive treatment for patients with ALS,” Dr. Glass said.
These results were published in Jonathan D. Glass et al., “Transplantation of spinal cord–derived neural stem cells for ALS: Analysis of phase 1 and 2 trials,” Neurology, June 2016 DOI:10.1212/WNL.0000000000002889.
Neuralstem, Inc. has announced the enrollment of its first patient in its double-blind, placebo-controlled multi-center Phase 2 study of a compound called NSI-189 for the treatment of MDD (major depressive disorder).
MDD usually consists of a persistent feeling of sadness or loss of interest. MDD can also include an inability to sleep or concentrate on tasks, changes in appetite, decreased energy level, and even thoughts of suicide.
MDD is treated with a variety of psychological therapies, such as
cognitive behavioral therapy, Behavior therapy, and Psychotherapy. Cognitive behavioral therapy is a type of talk therapy that focuses on changing a person’s thoughts in order to change their behavior and feelings. Behavior therapy focuses on changing behavior to help people break unhealthy habits. Psychotherapy treats mental or behavioral disorders through talk therapy. A medical procedure called electroconvulsive therapy is also used for some patients. Medications include antipsychotic medicines such as Aripiprazole (Abilify), anxiolytics like buspirone (Buspar), and antidepressants such as Trazodone (Oleptro), Bupropion (Wellbutrin), Duloxetine (Cymbalta) and a host of others.
The medications used to treat MDD regulate the levels of particular neurotransmitters (small molecules used neurons use to communicate with each other) in the brain.
NSI-189 works rather different from these other medications. NSI-189 activates neurogenesis, or the production of new neurons. The drug also activates the formation of new synapses and increases the volume of the hippocampus. All of these processes are thought to play a role in reversing depression. Such neurological outcomes can also enhance cognition and promote neuroregeneration.
This phase 2 trial will randomize 220 patients, in three cohorts, two of whom will receive the drug (40 mg twice a day or 40 mg once a day) and another of which will receive the placebo. Twelve different sites will participate in this MDD trial, all under the direction of Maurizio Fava.
The primary efficacy endpoint is a reduction in depression symptoms. The Montgomery-Asberg Depression Rating Scale (MADRS) will be used to assess thee severity of depression symptoms. Other endpoints will examine cognitive improvement measures.
The trial will last for 12 weeks, with an additional observational follow-up period of six months in order to assess NSI-189 long-lasting durability of benefits.
Neuralstem expects to report the results of this trial in the second half of 2017.
“A new class of treatment is needed in major depression, where existing compounds are not effective for all patients and have high side effect profile, so patients discontinue treatment,” said Fava. “We were encouraged by the signs of improvement in the depression and cognitive symptoms of MDD patients, as witnessed in Phase I with NSI-189, and look forward to validating in Phase 2.”
As mentioned in this statement to the press by Fava, NSI-189 successfully completed a phase I clinical trial for MDD in 2011. In this trial, NSI-189 was administered to 41 healthy volunteers. A phase Ib clinical trial for treating MDD in 24 patients was started in 2012 and completed in July 2014, and the results of this trial were published in December 2015.
NSI-189 works via a new pathway that is different from current antidepressants in that it appears to create long-lasting, positive structural changes in the brain.
In animal experiments, rodents treated with NSI-189 showed significant increases in synaptogenesis, neurogenesis, and hippocampal volume.
In the Phase 1b trial, therapeutic effects were observed in patients after completion of the 28-day dosing, and these improvements persisted for an additional 56 days without the drug. This seems to support the hypothesis of a new mechanism of action that induces long-lasting structural changes in key areas of the brain. In this trial, NSU-189 was shown to be safe and demonstrated large treatment effects in two key depression outcome measures.
The Phase 1b study also showed significant improvement in cognitive symptoms (as measured by the Cognitive and Physical Functioning Questionnaire), compared to placebo.
Brain imaging with quantitative EEGs showed an increase in alpha brain waves in two parts of the brain (left posterior temporal and left parietal region), both of which are involved in depression and cognition, compared to placebo.
No significant adverse effects were observed.
This new clinical trial will test the efficacy of this new drug to treat moderate to severe clinical depression.
Traumatic brain injuries can result from a variety of causes, ranging from car accidents, falls, occupational hazards, and sports injuries. The cause of traumatic brain injury (TBI) differs from that of ischemic stroke, but many of the clinical manifestations are somewhat similar (motor deficits). Such injuries can cause lifelong motor deficits, and there are currently no approved medicines for the treatment of persistent disability from traumatic brain injury.
SanBio, Inc., has completed the regulatory requirements to conduct a clinical trial using their proprietary SB623 regenerative cell therapy to treat patients who suffer from TBI. The obligatory 30-day review period of clinical trial notification by the Japanese Pharmaceuticals and Medical Devices Agency (PMDA) was completed on March 7, 2016. No safety concerns were voiced, and the trial can proceed.
SanBio’s clinical trial is entitled “Stem cell therapy for traumatic brain injury” or STEMTRA, and it will study the safety and efficacy of SB623 cell therapy in treating patients who suffer from chronic motor impairments following a TBI.
Enrollment in this clinical trial started in the United States in October, 2015. The trial will include clinical sites and patients in Japan and will enroll ~52 patients. The enrollment of Japanese patients is expected to accelerate the overall enrollment of human subjects.
SanBio spokesperson, Damien Bates, the Chief Medical Officer and Head of Medical Research at SanBio, said: “SanBio’s regenerative cell medicine, SB623, has improved outcomes in patients with persistent motor deficits due to ischemic stroke, and our preclinical data suggest that it may also help TBI patients. This is the first global Phase 2 clinical trial for TBI allogeneic stem cells, and the approval to conduct the trial in Japan, as well as in the United States, brings us one step closer to determining SB623’s efficacy for treatment whose who suffer from the effects of traumatic brain injury.”
SB623 are modified mesenchymal stem cells that transiently express a modified human Notch1 gene that only contains the intracellular domain of the Notch1 protein. This activated gene drives mesenchymal stem cells to form a cell type that habitually supports neural cells and promotes their health, survival, and healing. When administered into damaged neural tissue, SB623 reverses neural damage. Since SB623 cells are allogeneic (from a donor), a single donor’s cells can be used to treat many patients. In cell culture and animal models, SB623 cells restore function to damaged neurons associated with stroke, traumatic brain injury, retinal diseases, and Parkinson’s disease. SB623 cells function by promoting the body’s natural regenerative process.
Since the therapeutic mechanism of action of SB623 cells and the proposed route of administration are similar in the two trials (the stroke and TBI trials), the results of the TBI trial should be similar to those of the stroke trial.
The Japanese regulatory agencies grant marketing approval for regenerative medicines earlier countries as a result of an amendment to the Pharmaceutical Affairs Law in 2014. This particular amendment defined regenerative medicine products as a new category in addition to conventional drugs and medical devices, and the conditional and term-limited accelerated approval system for regenerative medicine products has started.
Two regenerative medicine products have already gained marketing approval under this new system, and the government-led industrialization of regenerative medicine products has gradually been realized.
SanBio has begun the preparation of clinical trial facilities in Japan and expects the launch of the clinical trial in 2016. the company hopes to market the medicine in Japan by taking advantage of the accelerated approval system.
Stem Cells, Inc., has released the six-month results from cohort I of an ongoing Phase 2 clinical trial of human neural stem cells for the treatment of chronic cervical spinal cord injuries. The data displayed significant improvements in muscle strength had occurred in five of the six patients treated. Of these five patients, four of them also showed improved performance on functional tasks that assesses dexterity and fine motor skills. Furthermore, these four patients improved in the level of spinal cord injury according to the classification system provided by the International Standards for Neurological Classification of Spinal Cord Injury or ISNCSCI.
Stem Cells, Inc., expects to release their detailed final 12-month results on this first open-cohort later this quarter.
Chief medical officer, Stephen Huhn, presented these data at the American Spinal Injury Association annual meeting in Philadelphia, on Friday, April 15. Dr. Huhn also believes that the interim results are very encouraging and reason to be quite hopeful.
“The emerging data continue to be very encouraging,” said Dr. Huhn. “We believe that these types of motor changes will improve the independence and quality of life of patients and are the first demonstration that a cellular therapy has the ability to impact recovery in chronic spinal cord injury. We currently have thirteen sites in the United States and Canada that are actively recruiting patients. We have enrolled and randomized 19 of the 40 total patients in the statistically powered, single-blind, randomized controlled, Cohort II. We are projecting to complete enrollment by the end of September so that we can have final results in 2017.”
The present Phase 2 clinical trial is a multi-center enterprise that includes physicians and scientists at 13 different sites in the united States and Canada. Incidentally, these sites are presently actively recruiting patients.
Stem Cells, Inc., has enrolled and randomized 19 of the 40 total patients in this statistically powered, single-blind, randomized controlled, cohort II.
The Phase 2 study, “Study of Human Central Nervous System (CNS) Stem Cell Transplantation in Cervical Spinal Cord Injury,” will determine the safety and efficacy of transplanting the company’s proprietary human neural stem cells (HuCNS-SC cells) into patients with traumatic injury of the cervical region of the spinal cord.
Cohort I is an open label dose-ranging cohort in six AIS-A or AIS-B subjects. For those of you not familiar with the American Spinal Injury Impairment Scale (ASI A-E scale), here is a summary of the classification scheme:
ASI – A = Complete paralysis; No sensory or motor function is preserved in the sacral segments S4-5.
ASI – B = Sensory Incomplete; Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-5 (light touch or pin prick at S4-5 or deep anal pressure) AND no motor function is preserved more than three levels below the motor level on either side of the body.
ASI – C = Motor Incomplete; Motor function is preserved below the neurological level**, and more than half of key muscle functions below the neurological level of injury (NLI) have a muscle grade less than 3 (Grades 0-2).
ASI – D = Motor Incomplete; Motor function is preserved below
the neurological level**, and at least half (half or more) of key muscle functions below the NLI have a muscle grade > 3.
ASI – E = Normal; If sensation and motor function as tested with the ISNCSCI are graded as normal in all segments, and the patient had prior deficits, then the AIS grade is E. Someone without an initial SCI does not receive an AIS grade.
Cohort II is a randomized, controlled, single-blinded cohort in forty AIS-B subjects. Cohort III, which will only be conducted at the discretion of the sponsor, is an open-label arm that involves six AIS-C subjects.
The primary efficacy outcome will focus on changes in the upper extremity strength as measured in the hands, arms, and shoulders. This trial will enroll up to 52 subjects.
StemCells, Inc. has demonstrated the safety and efficacy of their HuCNS-SC cell in preclinical studies in laboratory rodents. Additional Phase I studies yielded positive human safety data. Furthermore, completed and ongoing clinical studies in which its proprietary HuCNS-SC cells have been transplanted directly into all three components of the central nervous system: the brain, the spinal cord and the retina of the eye, have further demonstrated the safety of HuCNS SC cells in human patients.
StemCells, Inc. clinicians and scientists believe that HuCNS-SC cells may have broad therapeutic application for many diseases and disorders of the CNS. Because the transplanted HuCNS-SC cells have been shown to engraft and survive long-term, there is the possibility of a durable clinical effect following a single transplantation.
The HuCNS-SC platform technology is a highly purified composition of human neural stem cells (tissue-derived or “adult” stem cells). Manufactured under cGMP standards, the Company’s HuCNS-SC cells are purified, expanded in culture, cryopreserved, and then stored as banks of cells, ready to be made into individual patient doses when needed.
Tariq Rana, Professor of Pediatrics, University of California, San Diego, and his colleagues have used human embryonic stem cells to make neural stem cells that form spherical, neural organoids that can be infected with Zika virus. By using this elegant experimental system, Rana and his coworkers discovered how Zika virus causes brain abnormalities in babies unfortunate enough to be infected by the virus while there are in their mother’s wombs.
Zika virus is a member of the “flavivirus” group of viruses. Because this virus was first recognized in the Zika forest of Uganda, the name of this forest was applied to the virus. Zika virus causes a disease that is spread by mosquitoes. The most common symptoms of Zika virus disease are a mild fever, skin rashes, muscle and joint pain, and pink eye (conjunctivitis). These symptoms normally last for 2-7 days, but the disease is self-limiting in the vast majority of cases. The more severe cases occur if the patient is a pregnant woman. The virus caused a significant outbreak in Brazil in 2015, and many pregnant women who had been infected with Zika virus gave birth to babies with abnormally small heads, a condition known as “microcephaly.”
Work with laboratory animals has established that the Zika virus-induced microcephaly is due to a smaller brain that contains fewer neurons. How does Zika virus do this?
Dr Rana and his group seem to have made a major contribution to understanding the pathology of Zika virus on unborn babies. In a paper published in the journal Cell Stem Cell, Rana and his fellow researchers report that the neural organoids made in the Rana lab from embryonic stem cell-derived neural stem cells recapitulate fetal brain development to a large extent. While these organoids are limited in what they can model, they divide and differentiate into various sets of neurons and glial cells that roughly resemble the tissue elaboration in the fetal brain.
Secondly, infecting these neural organiods with Zika virus caused activation of Toll-like receptor 3 (TLR3). While this might seem like a foreign language to some of my readers, please hang with me and I will try to explain.
TLRs or Toll-Like Receptors bind to bits and pieces of invading fungi, bacteria, viruses, and parasites and alert the immune system to their presence. Pathogenic organisms have particular molecules collectively known as “Pathogen-Associated-Molecular-Patterns” or PAMPs and TLRs bind to various types of PAMPs.
Many non-immune cells, when their TLRs are activated, tend to give up the ghost and die, and that is precisely what happens to the neural progenitor cells in the neural organiods when they are infected by Zika virus. The infected neural stem cells kick the bucket (undergo programmed cell death) and the formation of new neurons and glial cells ceases.
The reduced formation of new neural cells means fewer neural tissues in the brain and smaller brains overall. Smaller brains also lead to smaller heads (microcephaly) and reduced mental capacity, sadly.
This article, by Jason Dang and others, shows that Zika virus might very well affect neural stem cells in the brain of the developing baby, which causes the deleterious effects on the brain of the new-born.
A research effort led by Dr. Sheng Ding from the Gladstone Institute and scientists from the Roddenberry Center for Stem Cell Biology and Medicine has successfully transformed skin cells into heart cells and brain cells using little more than a cocktail of chemicals. Previous work that sought to transdifferentiate mature, adult cells into another cell type used gene vectors (such as viruses) that genetically engineered the cells to express new genes at high levels. Because this new protocol uses no genetic engineering techniques, these results are nothing short of unprecedented. This work lays the foundation for, hopefully, being able to regenerate lost or damaged cells with pharmaceutical agents.
In two publications that appeared in the journals Scienceand Cell Stem Cell, Ding and his collaborators utilized chemical cocktails to drive skin cells to differentiate into organ-specific stem cell-like cells and, then into terminally differentiated heart or brain cells. These results were achieved without genetically engineering cells.
Ding, who was the senior author on both studies, said: “This method brings us closer to being able to generate new cells at the site of injury in patients. Our hope is to one day treat diseases like heart failure or Parkinson’s disease with drugs that help the heart and brain regenerate damaged areas from their own existing tissue cells. This process is much closer to the natural regeneration that happens in animals like newts and salamanders, which has long fascinated us.”
Mature heart muscle cells have very little regenerative ability. Once a patient has suffered a heart attack, the cells that have died are, for the most part, not replaced. Therefore, stem cell scientists have left no stone unturned to find a way to replace dead and dying heart muscle cells. Several clinical trials have transplanted mature adult heart cells or various types of stem cells into the damaged heart. However, such procedures have either not improved heart function or have only modestly improved heart function (with a few exceptions). Typically, transplanted cells do not survive in the hostile environment of the heart after a heart attack and even those cells that do survive fail to properly integrate into the heart. Also, the ability of transplanted cells to differentiate into heart cells is not stellar. Alternatively, Deepak Srivastava, director of cardiovascular and stem cell research at the Gladstone Institute, and his team pioneered a distinctly novel approach in which scar-forming cells in the heart of animals were genetically engineered to differentiate into heart new muscle that greatly improved heart function. Genetic engineering brings its own safety issues to the table and, for these reasons, chemical reprogramming protocols that can do the same thing might provide an easier way to drive heart muscle to regenerate local lesions.
In the Science study, Dr. Nan Cao (a postdoctoral research fellow at Gladstone, and others applied a cocktail of nine chemicals to reprogram human skin cells into beating heart cells. By using a kind of trial-and-error strategy, they discovered the best combination of chemicals to transdifferentiate skin cells into multipotent stem cells. Multipotent stem cells have the ability to differentiate into several distinct cell types from several different types of organs. A second-growth factor/small molecule cocktail drove the multipotent stem cells to differentiate into heart muscle cells.
Perhaps the most surprising result of this protocol is its efficiency. Typically, chemically-induced differentiation is relatively inefficient, but with Ding’s method, over 97% of the cells began beating. These chemically-derived heart muscle cells also responded appropriately to hormones, and they also molecularly resembled heart muscle cells (and not skin cells). Upon transplantation into a mouse heart, these cells developed into healthy-looking heart muscle cells within the heart of the laboratory animal.
“The ultimate goal in treating heart failure is a robust, reliable way for the heart to create new muscle cells,” said Srivastava, co-senior author on the Science paper. “Reprogramming a patient’s own cells could provide the safest and most efficient way to regenerate dying or diseased heart muscle.”
In the second study, published in Cell Stem Cell, which was authored by Gladstone postdoctoral scholar Dr. Mingliang Zhang, PhD, the Gladstone team created neural stem cells from mouse skin cells using a similar approach.
Once again, the chemical cocktail that transdifferentiated skin cells into neural stem cells contained nine different chemicals. Some of the molecules used in the neural stem cell experiment overlapped with those employed in the heart muscle study. Treatment of the skin cells for about ten days with the cocktail transdifferentiated the skins cells into neural-like cells. Virtually all the skin cell-specific genes were shut off and the neural stem cell-specific genes were gradually activated. When these chemical-differentiated cells were transplanted into mice, the cells spontaneously differentiated into neurons, oligodendrocytes, and astrocytes (three basic nerve cells). The neural stem cells were also able to self-replicate, which makes them ideal for treating neurodegenerative diseases or brain injury.
“With their improved safety, these neural stem cells could one day be used for cell replacement therapy in neurodegenerative diseases like Parkinson’s disease and Alzheimer’s disease,” said co-senior author Dr. Yadong Huang, who is a senior investigator at Gladstone. “In the future, we could even imagine treating patients with a drug cocktail that acts on the brain or spinal cord, rejuvenating cells in the brain in real-time.”
In the March 28th, 2016 issue of the journal Nature Medicine, Mark Tuszynski and his colleagues from the University of California, San Diego, in collaboration with colleagues from Japan and Wisconsin, report that they were able to successfully coax stem cell-derived neurons to regenerate damaged corticospinal tracts in rats. Furthermore, this regeneration produced observable, functional benefits.
What is the “corticospinal tract” you ask? The corticospinal tracts are part of the “pyramidal tracts” that include the corticospinal and corticobulbar tracts. The pyramidal tracts are the main controllers of voluntary movement and connect their nerve fibers eventually to cells that serve voluntary muscles and allow them to contract. We call such nerves “motor nerves,” and the corticospinal nerve tracts are among the most important of the motor nerve tracts.
These neural tracts are collectively called “pyramidal tracts” because they pass through a small area of the brain stem known as the pyramids, which lie on the ventral side of the medulla oblongata. Both pyramidal tracts originate in the forebrain; specifically from the so-called “motor cortex” of the forebrain. The motor cortex lies just in front of the central sulcus of the forebrain. In the motor cortex, lies thousands of “upper motor neurons” that extend their axons down to the brain stem and spinal cord.
In the brain stem, the majority of these corticospinal tracts crossover (or decussate) to the other side of the brain stem and travel down the opposite side of the spinal cord. The corticospinal axons extend all the way down the spinal cord, until they make a connection (synapse) with a “lower motor neuron” that extends its axon to the skeletal muscles that it will direct to contract. The corticobulbar tract contains nerves that conduct nerve impulses from cranial nerves and these help the muscles of the face and neck contract, and are involved in facial expressions, swallowing, chewing, and so on.
Damage to the upper motor neurons as a result of a stroke can rob a person of the ability to move, since the muscles that are attached to the upper motor neurons cannot receive any signals to contract. Likewise, damage to the axonal tracts (also known as nerve fibers) can paralyze a patient and rob them of their ability to move.
Dr. Tuszynski continued, “The new thing here was that we used neural stem cells for the first time to determine whether they, unlike any other cell type tested, would support regeneration. And to our surprise, they did.”
In this experiment, Tuszynski, and his colleagues and collaborators used rats that had suffered spinal cord injuries and had trouble moving their forelimbs. Then they implanted grafted multipotent neural progenitor cells (MNPCs) into those sites within the spinal cord that had suffered injury, where corticospinal axonal tracts had been severed or damaged. The MNPCs had been previously treated to differentiate into spinal cord-specific motor neurons. Fortunately, the MNPCs prodigiously formed lower motor neurons that made good, solid, functional synapses with interneurons and upper motor neurons that improved forelimb movements in the rats. This work put the lie to previous beliefs about corticospinal neurons; namely that they lacked any of the internal mechanisms required to regenerate severed or damaged connections.
Even though several previous studies have demonstrated functional recovery in spinal cord-injured rats through the use of stem cell-based treatments, none of these studies has convincingly demonstrated regeneration of corticospinal axons.
“We humans use corticospinal axons for voluntary movement,” said Tuszynski. “In the absence of regeneration of this system in previous studies, I was doubtful that most therapies taken to humans would improve function. Now that we can regenerate the most important motor system for humans, I think that the potential for translation is more promising.”
This is certainly exciting work, but even though it worked in rats, it may not yet work in humans. The road from pre-clinical studies in animals to clinical trials in humans is a long, tedious, frustrating, and uncertain pathway, pockmarked with the failures of past therapies that worked well in animals but failed to translate into successes in human patients.
“There is more work to do prior to moving to humans,” Tuszynski said. We must establish long-term safety and long-term functional benefit in animals. We must devise methods for transferring this technology to humans in larger animal models. And we must identify the best type of human neural stem cell to bring to the clinic.”
SanBio, a regenerative medicine company in Mountain View, California, has announced the randomization of the first enrolled patient in the ACTIsSIMA Phase 2B clinical trial. This trial will examine the efficacy of SanBio’s proprietary SB623 product in patients who suffer from chronic motor deficits as a result of strokes. SB623 consists of modified adult bone-marrow-derived stem cells. A secondary purpose of this trial is to evaluate the safety of SB623 in these patients.
Ischemic strokes account for about 87 percent of all strokes in the United States. Ischemic strokes occur when there is an obstruction in one or more of the blood vessels that provide blood and oxygen to the brain. On the order of 800,000 cases of ischemic stroke occur in the United States every year, and it is the leading cause of acquired disability in the United States. Present drug treatments for stroke either try to prevent strokes or address patients who have recently suffered a stroke. Unfortunately, there are no medical treatments currently available for people who live with the effects of stroke, months or even years after suffering a stroke.
SB623 cells are derived from bone marrow mesenchymal stem cells extracted from healthy donors. These cells are designed to promote recovery from injury by triggering the brain’s natural regenerative ability. SB623 cells have been genetically engineered to express a modified version of the Notch gene (NICD) that conveys upon the cells the ability to promote the formation of new blood vessels and the survival of endothelial cells that form these new blood vessels (see J Transl Med. 2013, 11:81. doi: 10.1186/1479-5876-11-81).
SB623 was tested in a Phase 1/2A clinical trial in which SB623 was implanted into stroke patients and produced some improved motor function.
This follow-up trial, ACTIsSIMA, will treat stroke patients with SB623 cells in order to examine the safety and efficacy of SB623 cells. All patients in this trial have suffered from a stroke anywhere from six months to five years. Also, all patients must exhibit chronic motor impairments.
Damien Bates, M.D., Chief Medical Officer & Head of Research at SanBio, said, “Our previous trial suggested there was potential for SB623 to improve outcomes for patients with lasting motor deficits following an ischemic stroke. Randomization of the first subject marks an exciting step toward further evaluating this treatment as a promising new option for patients.”
For this trial, SanBio is collaborating with Sunovion Pharmaceuticals, Inc. Sunovion is a wholly owned subsidiary of Sumitomo Dainippon Pharma Co., Ltd., and SanBio and Sumitomo Dainippon Pharma have entered into a joint development and license agreement for exclusive marketing rights in North America for SB623 for chronic stroke.
The ACTIsSIMA trial will include approximately 60 clinical trial sites throughout the United States, and total enrollment is expected to reach 156 patients.
In an article published in the Journal of Neuroinflammation (2015 12(1):241), Dr. Reint Jellema, in collaboration with scientists from Maastricht University, Maastricht University Medical Center and Máxima Medical Center Veldhoven in the Netherlands, and Athersys scientists described the results of experiments designed to evaluate the potential for Multipotent Adult Progenitor Cells (MAPCs) to stroke patients.
In the series of experiments described in this publication, Jellema and others examined pre-term sheep that suffered strokes while still in the womb. Such injuries in human babies are one of the main causes of cerebral palsy. In the case of these pre-term sheep, the intravenous administration of MAPCs reduced both the number and duration of seizures compared to placebo-treated animals.
Seizures commonly follow strokes in new born babies and these strokes usually cause several detrimental neurodevelopmental outcomes. MAPC treatment significantly reduced inflammation in the injured brain. The implanted cells reduced activation and proliferation of immune cells in the brain. In general the immune response after the onset of the stroke was tamped down.
This paper provides further evidence that multipotent adult progenitor cells (MAPCs) have can provide benefit following strokes. Such injuries are caused by oxygen deprivation to the brain before or during birth and are a leading cause of cerebral palsy.
“This study in a large animal model of pre-term hypoxic-ischemic injury further demonstrates the potential for MultiStem therapy to provide benefit to patients suffering from an acute neurological injury,” said Dr. Robert Mays, Vice President and Head of Neuroscience Research at Athersys. “These results are consistent with those from previous studies testing our cells in rodent models of hypoxic ischemia and ischemic stroke, and confirm our previous findings supporting the biological mechanisms through which MAPC treatment provides benefit following acute neurological injury. The results strengthen the biologic rationale for our ongoing clinical and preclinical research in ischemic stroke and hypoxic-ischemic injury, as well as traumatic brain and spinal cord injury.”
A growth factor called Glial cell line-derived neurotrophic factor (GDNF) has the remarkable ability to supports the growth and survival of dopamine-using neurons. Dopamine-using neurons are the cells that die off in Parkinson’s disease (PD). Providing GDNF to dopamine-using neurons can help them survive , but getting GDNF genes into the central nervous system relies on invasive intracerebral injections in order to pass through the blood-brain barrier.
Typically, genes are placed into the central nervous system by means of genetically engineered viruses. Viruses, however, are often recognized by the immune system and are destroyed before they can deliver their genetic payload. Therefore, non-viral gene delivery that can pass through the blood-brain barrier is an attractive alternative, since it is non-invasive. Unfortunately, such a high-yield technique is not yet available.
A new study by workers in the laboratories of Hao-Li Liu from Chang Gung University and Chih-Kuang Yeh from National Tsing Hua University, Taiwan has utilized a novel, non-viral gene delivery system to deliver genes into the central nervous system.
In this study, Lui and Yeh and their research teams used tiny bubbles made from positively-charged molecules to carry genes across the blood brain barrier. These bubbles formed stable complexes with GDNF genes, and when the skulls of laboratory animals were exposed to focused ultrasound, the bubble-gene complexes permeated the blood brain barrier and induced local GDNF expression.
In fact, this technique outperformed intracerebral injection in terms of targeted GDNF delivery. The amount of GDNF expressed in these laboratory animals that received the GDNF gene/microbubbles + ultrasound protocol was significantly higher than those animals that had genes directly injected into their brains. Furthermore, these higher levels of GDNF genes increased the levels of neuroprotection from PD. Animals that had a form of PD and had received nonviral GDNF gene therapy showed reduced disease progression and restored behavioral function.
This interesting study explores the potential of using ultrasound-induced passage through the blood brain barrier to bring genes into the central nervous system. This noninvasive technique successfully delivered genes into the brain to delay the effects of, and possibly treat, a neurodegenerative disease.
This study was published in Scientific Reports6, Article number: 19579 (2016), doi:10.1038/srep19579.
Jan Nolta and her colleagues at the Stem Cell Program and Institute for Regenerative Cures at UC Davis have published a remarkable paper in the journal Molecular Therapy regarding Huntington’s disease and a potential stem cell-based strategy to delay the ravages of this disease.
Huntington’s disease (HD) is an inherited neurodegenerative disease. It is inherited as an autosomal dominant disease, which means that someone need only inherit one copy of the disease-causing allele of the HTT gene to have this disease. HD is characterized by progressive cell death in the brain, particularly in a portion of the brain known as the striatum and by widespread brain atrophy.
The portion of the brain known as the striatum lies underneath the surface of the forebrain (subcortical) and it receives neural inputs from the cerebral cortex and is the primary source of neural inputs to the basal ganglia system. The basal ganglia system (BGS) is located underneath the surface of the brain but even deeper within the cerebral hemispheres. The BGS is part of the corpus striatum, it consists of the subthalamic nucleus and the substantia nigra. The BGS help with voluntary motor control, procedural learning relating to routine behaviors. otherwise known as “habits,” eye movements, and cognitive, and emotional functions. The ventral striatum is very important in addiction because it is the reward center on consists of the nucleus accumbens, olfactory tubercle, and islands of Calleja.
HD takes its largest toll on the striatum, which affects voluntary movement, routine behaviors, and personality. Disturbances of both involuntary and voluntary movements occur in individuals with HD. Chorea, an involuntary movement disorder consisting of nonrepetitive, non-periodic jerking of limbs, face, or trunk, is the major sign of the disease. Chorea is present in more than 90% of individuals, increasing during the first ten years. The choreic movements are continuously present during waking hours, cannot be suppressed voluntarily, and are worsened by stress. HD patients show impaired voluntary motor function early on and show a clumsiness in common daily activities.
With advancing disease duration, other involuntary movements such as slowness of movement (bradykinesia), rigidity, and involuntary muscle contractions that cause repetitive or twisting movements (dystonia) occur. Eye movement becomes progressively worse. So-called “gaze fixation” is observed in ~75% of symptomatic individuals. Unclear speech occurs early and Swallowing difficulties occur later.
Animal models of HD used in the past have injected molecules into the brain that kill off striatal cells and mimic at least some of the characteristics of HD in laboratory animals. Unfortunately, such a model system is fat too clean, since implanted cells tend to survive perfectly well. However the brains of HD patients are like unto a toxic waste dumps and implanted cells are quickly killed off. Therefore, a better animal model system was required, and it came in the form of R6/2 and YAC128 mice. R6/2 mice have a part of the human HTT gene that has 150 CAG triplets, and show the characteristic cell death in the striatum and behavioral deficits. The only problem with this mouse strain is that the neurodegenerative decline is very rapid rather than slow and progressive. YAC128 mice have a full-length copy of the HTT gene and show a slower, more progressive neurological decline that more closely approximates the human clinical condition.
In this paper from the Nolta laboratory, they used a growth factor that is known to decrease precipitously in HD brains; a growth factor called Brain-Derived Neurotrophic Factor (BDNF). BDNF is known to mediate the survival and function of striatal neurons and the reduction of BDNF in the brains of HD patients correlates with the onset of symptoms and the greater the reduction in BDNF, the greater the severity of the disease (see Her LS & Goldstein LS, J Neurosci 2008; 28, 13662-13676).
However injecting BDNF into the brain is problematic, since the protein has a very short half-life. Delivering the growth factor by means of genetically engineered viruses shows promise, but most of the viral vectors used in such experiments are recognized by the immune system as foreign invaders. Therefore, Nolta and her colleagues decided to genetically engineer mesenchymal stem cells (MSCs) to overexpress BDNF and implant these cells into the brains of R6/2 and YAC128 mice.
MSCs have an added advantage over viral vectors: these cells migrate to damaged areas where they can exert their healing properties (see Olson SD et al., Mol Neurobiol 45; 2012: 87-98).
Nolta and her coworkers actually tested human MSCs in HD model mice. After completing all the necessary control experiments to ensure that their isolated and engineered MSCs were secreting BDNF, Nolta and others implanted them into the brains of R6/2 and YAC128 mice.
HD mice show greater anxiety, which is manifested in a so-called “open field assay” by not remaining the center of the field. The control HD mice did not stay long in the center of the open field, but the normal mice did. The MSC-BDNF-implanted mice spend far more time in the center of the field. Mind you, not as much as wild-type mice, but significantly more than their HD counterparts.
Next the volume of the striata of these mice were determined and compared to the normal mice. While all the HD mice showed shrinking of the striatum, the MSC-NDNF-implanted YAC128 mice show significantly less shrinking of the striatum. Then the degree of neurogenesis (formation of new neurons) was measured in normal, HD, HD + implanted MSCs, and HS + MSC-BDNF mice. This experiment measures the degree of healing that is occurring in the brain. The brain from HD + MSC and HD + MSC-BDNF mice showed significantly more new brain cell growth. This is probably the reason for the delayed onset of symptoms and the delayed shrinking of the striatum.
Finally, Nolta and others measured the lifespans of the R6/2 mice and compared them with R6/2 mice that had been implanted with MSCs-BDNF. Animals transplanted with the MSCs that made the most BDNF lived 15% longer than the nontreated R6/2 mice.
MSCs have been shown in several experiments to promote neuronal growth, decrease cell death and decrease inflammation through the secretion of trophic factors. MSCs can modify the toxic environment that is part of the brain of an HD patient and help damaged tissue out by inducing neural regeneration and protection (see Crigler L, et al., Experimental neurology, 198; 2–6, 54-64; Kassis I, et al., Archives of Neurology 65; 2008: 753-761).
The downside of using MSCs that they will only survive in the brain for a few months. However, several studies have shown that the benefits of modified MSC implantation persist after the MSCs are gone, since the neural reconstruction wrought by the secreted BDNF stay after the MSCs have died off (see Arregui L, et al., Cell Mol Neurobiol 31; 2011: 1229-1243 and many others).
At best this treatment would delay the ravages of HD, but delaying this disease might very well be the first step towards a cure. Hopefully, clinical trials will not be fat behind.
The biotechnology company BrainStorm Cell Therapeutics Inc. has developed an autologous stem cell therapy for several neurodegenerative diseases including Amyotrophic Lateral Sclerosis (ALS, also known as Lou Gehrig’s disease), Multiple Sclerosis (MS) and Parkinson’s Disease (PD). BrainStorm has designed a proprietary product called NurOwn™ that is made from the patient’s own bone marrow mesenchymal stem cells (BM-MSCs). Essentially, the patient’s BM-MSCs are isolated, purified, and cultured in a specialized culture system that drives the BM-MSCs to differentiate into nerve-like cells that Neurotrophic Factors (NTF). These NTFs have the capacity to keep nerve cells alive and prevent moribund cells from dying.
By transplanting NurOwn cells back into the patient at or near the site of neural damage, in the spine and/or muscles, it could potentially delay or even roll back damage from neurodegeneration. NurOwn cells have proven their efficacy in animal experiments (e.g., STEM CELLS 2008;26:2542–2551), and in a few small clinical trials.
In one case, a 75-year-old man who suffered from ALS and myasthenia gravis (the immune system attacks your own receptors for acetylcholine at the neuromuscular junction, which prevents the muscle contraction), was treated with NurOwn cells, and experienced the following improvement 1 month later.
This is only a case study and involves only one patient, which is the absolute lowest-quality evidence you can have in medicine. Therefore, this study is suggestive that NurOwn cells can help ALS patients improve.
Now BrainStorm Cell Therapeutics has entered into a collaborative agreement with Hadassah Medical Center in Jerusalem, Israel, to conduct a Phase 2 clinical trial to test the ability of NurOwn cells to treatment patients with Amyotrophic Lateral Sclerosis (ALS).
This clinical trial is not BrainStorm’s first rodeo, since they have conducted two other clinical trials in collaboration with Hadassah Medical Center. BrainStorm hopes that the results of this clinical trial will provide guidance in preparing a Phase 3 clinical trial that will test their NurOwn® stem cell based therapy in patients suffering from ALS.
In this trial, BrainStorm plans to enroll up to 24 ALS patients, all of whom will receive three consecutive stem cell transplantations of their own BM-MSCs that have been genetically engineered to secrete NFTs. The goal of this trial is to establish the safety and efficacy of a treatment regimen that includes multiple doses of stem cells. Because this trial includes human subjects, it must be approved by Hadassah’s Helsinki Committee and the Israeli Ministry of Health before the study can commence.
Professor Dimitrios Karussis, MD, PhD, Head of the Unit of Neuroimmunology and Cell Therapies at Hadassah’s Department of Neurology, who served as Principal Investigator in Brainstorm’s prior ALS studies, will serve as the Principal Investigator for this trial.
“NurOwn has generated promising clinical data in ALS and has the potential to offer a new approach for the treatment of patients afflicted with this disease,” stated Professor Karussis. “We are excited to be collaborating with BrainStorm to advance this product to the next phase of development and the application of stem cell therapies in similar neurological diseases in general.”
“Evaluating multiple doses with NurOwn is an important next step in our efforts to understand the treatment effect of this investigative medicine,” stated Chaim Lebovits, CEO of Brainstorm. “We are pleased to continue our partnership with Hadassah Medical Center, which has long maintained a reputation for excellence in the treatment of neurological disorders.”