Cynata’s MSC Technology Produces Significant Relief of Asthma in Preclinical Study


An Australian stem cell company called Cynata Therapeutics Limited is in the process of developing a therapeutic stem cell platform technology that they called “Cymerus.” The idea for Cymerus originated at the University of Wisconsin-Madison, but Cymerus would generate a protocol by which clinical laboratories could produce very immature mesenchymal stem cells from induced pluripotent stem cells. Such cells would be personalized for patients and their needs, and Cynata’s goal is to produce a platform that is economically feasible and relatively fast so that patients can receive infusions of the cells they so badly need in a timely fashion. These are very ambitious goals to say the least, but Cynata has been hacking away at this problem for some time, and we certainly wish them the best.

Cynata has recently released some very encouraging data in which their personalized mesenchymal stem cells were used to treat laboratory animals with a laboratory-induces form of asthma. Briefly, female mice (BALB/c mice for those who are interested) were injected with a yolk-protein called “ovalbumin.” Ovalbumin is a protein found in egg whites, and because it is an egg-specific protein, mice do not have it and their immune systems have never seen it before. Such an injection causes the mice to mount an immune response to the ovalbumin, and these mice are then administered aerosolized ovalbumin by means of a nebulizer. This causes the animals to develop a rather severe asthmatic attack against ovalbumin.

In this study, Cynata scientists and their collaborators used 48 mice that were divided into six different groups. The first group was untreated animals that did not suffer from ovalbumin asthma. The second group contained eight animals that had no asthma but were treated intravenously with one million mesenchymal stem cells. The third group also had no asthma, but were treated with an intranasal infusions of one million mesenchymal stem cells. The fourth group contain eight asthmatic animals that were untreated during the course of the experiment. The fifth group contain eight asthmatic animals that were treated intravenously with one million mesenchymal stem cells. The final group contained eight asthmatic animals that were treated with intranasal infusions of one million mesenchymal stem cells. As a note, all animals that were treated mesenchymal stem cells were treated three times. So-called airway hyperresponsiveness (AHR) is a measure of the sensitivity and irritability of the bronchial tissues. AHR is an important measure of the tendency of the lungs to undergo constriction during an asthma attack and AHR is usually measured by administering a drug that can cause bronchoconstriction. The greater the degree of bronchoconstriction in such an experiment is indicative of great AHR. The successful treatment of asthma results in reduction in AHR.

The results of this experiment were wonderfully successful. Exposing mice to the ovalbumin caused them to exhibit significantly increased AHR. However, intravenous administration of Cynata’s MSCs in asthmatic animals caused a statistically significant (60-70%) decrease in AHR compared to untreated, sensitized animals. Additionally, intranasal administration of Cynata’s MSCs completely normalized AHR. The AHR in these asthmatic mice was brought down to a level that was largely the same as the non-asthmatic mice. Also, importantly, no adverse side effects were observed during the study.

This study was conducted under the supervision of Associate Professor Chrishan Samuel and Dr. Simon Royce from the Department of Pharmacology at Monash University, Melbourne, Australia. Because the features of this model asthma system closely resemble the clinical manifestations of asthma in humans, these results provide excellent evidence that such a treatment stands a chance of working in human patients.

“We are very excited by these results, which indicate that Cymerus™ MSCs could have a profound effect in the treatment of asthma. This is a debilitating condition, which affects about 10% of the population, resulting in close to 40,000 hospitalizations and several hundred deaths each year, in Australia alone,” said Cynata Vice President of Product Development, Dr. Kilian Kelly. “Although a number of drugs are approved for the treatment of asthma, studies have shown that conventional treatments result in as few as 5% of asthma patients achieving full control of their condition. Consequently, there is a widely recognized need for novel treatments that address – and potentially eliminate – the underlying disease”, added Dr. Kelly.

“This study has clearly demonstrated that Cynata’s MSCs have a dramatic effect on AHR in our model, particularly when directly administered into the allergic lung. We look forward to continuing our analysis of the effects of these unique cells on markers of inflammation and airway remodeling, and we are optimistic of building on the very positive data we have generated so far,” said Associate Professor Samuel.

Asthma is a condition characterized by the inflammation, narrowing, and swelling of the airways, accompanied by excessive mucous production that makes it difficult to breathe. According to the Global Asthma Network, asthma affects over 330 million people globally. Cynata had partnered with Monash University to examine the potential of its Cymerus technology as an alternate treatment for asthma sufferers.

Cymerus™ makes us of induced pluripotent stem cells (iPSCs) that are then differentiated into a specific type of mesenchymal stem cell precursor known as a “mesenchymoangioblast” or MCA. Cymerus potentially provides a source of MSCs that can be made for so-called “off-the-shelf” therapeutic uses.

Advertisements

Fat-Based Mesenchymal Stem Cell-Seeded Matrix Heals Bronchopleural Fistula in Female Cancer Patient


Bronchopleural fistulae, mercifully abbreviated as BPF, refers to an opening or hole in the respiratory tree that causes continuity between the pleural space that surrounds the lungs and the bronchial tree. BPH is a highly feared complication of surgery on the respiratory system.

BPH can complicate surgical resection of the pulmonary system. Patients with lung cancers may require lung resection in order to remove tumorous lung tissue. The rate of BPH incidence after lung surgery varies widely, with reported incidences ranging from 1.5 to 28%. Necrosis or death of lung tissue as a result of infection can also cause BPH, as can tuberculosis. Chemotherapy or radiation therapy for lung cancers can also result in BPF. Finally, BPF may caused by persistent spontaneous pneumothorax, which refers to an abnormal build up of air or other gases in the pleural space, which causes an uncoupling of the lung from the chest wall.

To date, treatment for BPF is only partially effectively. The main treatment includes surgery, but the rate of recurrence of the fistulae remains rather high as do the rate of mortality. Can stem cells show us a better way?

Perhaps they can. Dennis A. Wigle, a surgeon at Mayo Clinic, and his collaborators used a synthetic bioabsorbable matrix seeded with the patients one fat-based mesenchymal stem cells to heal a BPF in a 63-yr old woman. Mind you, this is a case study (the lowest quality clinical evidence) and not a controlled study,. However, the success of this case study is at least suggestive that such an approach might prove useful for patients who suffer from BPFs.

Microscopic assessment of matrix cell seeding. (A): Ethidium bromide (red) and Syto-13 (green) costain demonstrating live and dead cells on mesenchymal stem cell seeding on matrix. (B): Confocal microscopy with CD90 (Thy-1) fluorescein isothiocyanate (green) and Hoechst 33342 (trihydrochloride trihydrate) (blue) fluorescent nuclear staining. These images were captured using a ×20 objective and a ×10 eyepiece, for a combined magnification of ×200. Scale bar = 150 µm.
Microscopic assessment of matrix cell seeding. (A): Ethidium bromide (red) and Syto-13 (green) costain demonstrating live and dead cells on mesenchymal stem cell seeding on matrix. (B): Confocal microscopy with CD90 (Thy-1) fluorescein isothiocyanate (green) and Hoechst 33342 (trihydrochloride trihydrate) (blue) fluorescent nuclear staining. These images were captured using a ×20 objective and a ×10 eyepiece, for a combined magnification of ×200. Scale bar = 150 µm.

A 63-yr old woman who had surgical resection of the lung in order to treat her lung cancer had, as a consequence of her surgery, a BPF. Some 30 different surgical attempts were made to repair the BPF, but all of them failed. The woman’s health declined and her medical team started to think of alternative treatments.

Fortunately, Mayo Clinic has been participating in an ongoing clinical trial to use fat-based mesenchymal stem cells to treat anal fistulae in Crohn’s disease patients. Therefore Dr. Wigle and his team considered using the protocol utilized with Crohn’s patients to repair this woman’s BPF.

Fat biopsies were taken from the patient and the fat was washed, minced, digested with enzymes, and then grown in special culture media. The adipose tissue-derived mesenchymal stem cells (AD-MSCs) grew and were isolated, characterized and shown to be MSCs.

These cells were then seeded on a matrix of synthetic bioabsorbable poly(glycolide-trimethylene carbonate) copolymer and then placed in a bioreactor to grow. After about 4 days, the matrix was flush with AD-MSCs, and this cell-seeded patch was then used in a subsequent surgery to seal the opening in the respiratory tree. This time the surgery worked. The patient was discharged 25 days after the surgery and sent home.

MRIs of the respiratory system showed that the BPF had indeed closed and properly resolved.

Preoperative imaging showing size and location of fistula, and postoperative imaging demonstrating disease resolution. (A): Preoperative bronchoscopy demonstrating large bronchopleural fistula (BPF) cavity and lateral extension of fistula tracts. (B): Postoperative bronchoscopy (3 months) demonstrating progressive healing of BPF site. (C): Preoperative computed tomography scan demonstrating large BPF with connection to atmosphere (additional axial slices inferiorly). (D): Postoperative computed tomography scan (16 months) demonstrating resolution of BPF.
Preoperative imaging showing size and location of fistula, and postoperative imaging demonstrating disease resolution. (A): Preoperative bronchoscopy demonstrating large bronchopleural fistula (BPF) cavity and lateral extension of fistula tracts. (B): Postoperative bronchoscopy (3 months) demonstrating progressive healing of BPF site. (C): Preoperative computed tomography scan demonstrating large BPF with connection to atmosphere (additional axial slices inferiorly). (D): Postoperative computed tomography scan (16 months) demonstrating resolution of BPF.

This case study might confirm what was previously observed in large animal studies by Petrella and others, namely that AD-MSCs can be used to heal BPF. Petrella and others theorized that implanted MSCs induce the proliferation of fibroblasts that then deposit collagen, which seals the BPF (see Ann Thorac Surg 97:480483.  Alternatively, AD-MSCs might differentiate into cell types  required for regeneration of the airways (Dominici M, and others, Cytotherapy 8:315317).  Either way, this paper seems to suggest that AD-MSCs can be isolated from a patient’s fat (even a very sick patient like this one) without incident and used for tissue engineering applications that can repair very serious wound like BPF. 

This paper was published in: Johnathon M., Aho, et Al., “Closure of a Recurrent Bronchopleural Fistula Using a Matrix Seeded With Patient-Derived Mesenchymal Stem Cells.” Stem Cells Trans Med October 2016 vol. 5 no. 10 1375-1379. 

New Stem Cell Treatment for Bronchopleural Fistulas


Mayo Clinic researchers have made history by using a patient’s own stem cells to heal an open wound on the upper chest of a patient that had been caused by postoperative complications of lung removal.

A hole in the chest that opens to the outside is called a bronchopleural fistulae. Such wounds are holes that lead from large airways in the lungs to the membrane that lines the lungs.

Unfortunately, present treatments for bronchopulmonary fistulae tend to be terribly successful and death from such injuries are all too common.

According to Dr. Dennis Wigle, a Mayo Clinch Researcher, “Current management is not reliably successful. After exhausting therapeutic options, and with declining health of the patient, we moved toward a new approach. The protocol and approach were based on an ongoing trial investigating this method to treat anal fistulas in Cohn’s disease”.

So Dr. Wigle and his colleagues harvested stem cells from the belly fat of their patient and seeded onto a bioabsorbable mesh that was surgically implanted at the site of the fistula.

Follow-up imaging of the patient showed that the fistula had closed and remained healed. More than a year-and-a-half later, the patient remains asymptomatic and has been able to resume activities of daily living.

In their paper, Wigle and others describe their patient, a 63-year-old female patient, who was referred to Mayo Clinic for treatment of a large bronchopleural fistula.

Because present therapies offer little relief, Wigle and his team turned to regenerative therapies in order to try a more innovative treatment.

“To our knowledge, this case represents the first in human report of surgically placed stem cells to repair a large, multiple recurrent bronchopleural fistula. The approach was well tolerated suggesting the potential for expanded use,” said Dr. Wigle.

While this procedure was successful in this case, it is unclear if this treatment was the main contributor to the healing of the wound. Since this is a single-patient case study and not a double blinded, placebo-controlled study, it is lower-quality evidence.

However, Wigle and others hope to further examine this technique, and in particular, the use a patient’s own stem cells, to treat fistulae in the respiratory system.

This case study was published in Stem Cells Translational Medicine, June 2016 DOI:10.5966/sctm.2016-0078.

Alveolar Macrophages Derived from Stem Cells Help Lung-Damaged Mice Recover and Survive from Airway Disease


Within the tiny alveolar sacs of our lungs is an immune cell that surveys and directs the immune response within the lung. This immune cell is called an “alveolar macrophage,” and this cell is an actively phagocytic cell. It gobbles up invading bacteria and foreign material in order to keep the lungs clean. When these cells work normally, they help our lungs function properly. When, however, they go rogue, they can fill the lungs with cells that clog the lungs and prevent you from breathing.

Alveolar Macrophages
Alveolar Macrophages

Certain diseases like chronic obstructive pulmonary disease, asthma, and lung fibrosis, have abnormal alveolar macrophages and no specific treatments can appropriately compensate for these abnormalities.

Since alveolar macrophages (AMs) can be made from pluripotent stem cells, perhaps transplanting exogenous AMs derived from pluripotent stem cells can clean up messy lungs.

Martin Post, from the University of Toronto, in Ontario, Canada, and his colleagues tested this very hypothesis in mice. Post and his coworkers differentiated mouse embryonic stem cells by using factor-defined media in order to generate embryonic macrophages that could be grown in culture. Then they conditioned their cells into an alveolar-like phenotype by treating them with the cytokine GM-CSF. The cells were surprisingly like normal AMs, at least in culture.

To test these cells in mice, Post and his group created mice that lacked the ADA (adenine deaminase) gene and these mice lacked proper AM activity and suffered chronic lung damage.

Next, Post’s team transplanted their embryonic stem cell-derived alveolar-like macrophages into the tracheas (windpipes) of these injured animals in order to view their therapeutic potential.

What Post and others saw truly amazed them. Not only was their differentiation protocol wonderfully efficient and adaptable to human pluripotent stem cells, but their PSC-derived macrophages essentially “walked and talked” like regular, normal AMs. These cells made all the right cell surface proteins to be identified as AMs and they engulfed bacteria and dying cells. In fact, they were better phagocytes than bone marrow-derived macrophages.

The implanted macrophages stayed in the airways of the recipient mice for at least 4 weeks, and were able to gobble up other types of rogue white blood cells (i.e., neutrophils) during acute lung injury. Thus, the implanted cells were able to protect the lung from further damage under conditions of lung injury. Additionally, the implanted AMs enhanced tissue repair in the lungs and promoted survival of these mice. Interestingly, the mice did not develop abnormal pathology or teratomas as a result of the implanted macrophages.

Thus, this work from Post and his colleagues shows that pluripotent stem cells are a viable source of therapeutically effective alveolar-like macrophages that can be implanted into the lungs and treat airway diseases. Further experiments in larger animals should prepare this strategy for clinical trials.

This study was published in the American Journal of Respiratory and Critical Care Medicine. published online 05 Jan 2016 as DOI: 10.1164/rccm.201509-1838OC.

Scientists Grow New Diaphragm Tissue In Laboratory Animals


The diaphragm is a parachute-shaped muscle that separates the thoracic cavity from the abdominopelvic cavity and facilitates breathing. Contraction of the diaphragm increases the volume of the lungs, thus dropping the pressure in the lungs below the pressure of the surrounding air and causing air to rush into the lungs (inhalation). Relaxation of the diaphragm decreases the volume of the lungs and increases the pressure in the lungs so that it exceeds the pressure of the air, and air leaves the lungs (exhalation). The diaphragm is also important for swallowing. One in 2,500 babies are born with malformations or perforations in their diaphragms, and this condition is usually fatal.

The usual treatment for this condition involves the construction of an artificial patch that properly covers the lesion, but has no ability to grow with the infant and is not composed of contractile tissue. Therefore, it does not assist in contraction of the diaphragm to assist in breathing.

A new study might change the prospects for these newborn babies. Tissue engineering teams from laboratories in Sweden, Russia and the United States have successfully grown new diaphragm tissue in rats by applying a mixture of stem cells embedded in a 3D scaffold made from donated diaphragm tissue. Transplantation of this stem cell/diaphragm matrix concoction into rats allowed the animals to regrow new diaphragm tissue that possessed the same biological characteristics as diaphragm muscle.
The techniques designed by this study might provide the means for repairing defective diaphragms or even hearts.

Doris Taylor, who serves as the director of regenerative medicine research at the Texas Heart Institute and participated in this revolutionary study, said: “So far, attempts to grow and transplant such new tissues have been conducted in the relatively simple organs of the bladder, windpipe and esophagus. The diaphragm, with its need for constant muscle contraction and relaxation puts complex demands on any 3D scaffold. Until now, no one knew whether it would be possible to engineer.”

Paolo Macchiarini, the director of the Advanced Center for Regenerative Medicine and senior scientist at Karolinska Institutet, who also participated in this study, said: “This bioengineered muscle tissue is a truly exciting step in our journey towards regenerating whole and complex organs. You can see the muscle contracting and doing its job as well as any naturally grown tissue.”

To make their tissue engineered diaphragms, the team used diaphragm tissue that had been taken from donor rats. They stripped these diaphragms of all their cells, but maintained all the connective tissue. This removed anything in these diaphragms that might cause the immune systems of recipient animals to reject the implanted tissue, while at the same time keeping all the things that give the diaphragm its shape and form. In the laboratory, the decellularized diaphragms had lost all their elasticity. However, once these diaphragm matrices were seeded with bone marrow-derived stem cells and transplanted into recipient laboratory animals, the diaphragm scaffolds began to function as well as normal, undamaged diaphragms.

If this new technique can be successfully adapted to human patients, it could replace the damaged diaphragm tissue of the patient with tissue that would constantly contract and grow with the child. Additionally, the diaphragm could be repaired by utilizing a child’s own stem cells. As a bonus, this technique might also provide a new way to

Next, the team must test this technique on larger animals before it can be tested in a human clinical trial.

The study was published in the journal Biomaterials.

Lung Spheroidal Cells Superior to Mesenchymal Stem Cells When Treating Pulmonary Fibrosis in Mice


Lung diseases are no fun for anyone. The constant feeling of suffocation, withering weakness, and significant limitations on human activity are indicative of a loss of lung capacity. Chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis are among the top five causes of mortality, according to the World Health Organization (Cottin Eur Respir Rev 22:2632).  Regenerating damaged lungs, therefore, represent one of the Holy Grails of regenerative medicine.

Animal studies have used infusions of mesenchymal stem cells (MSCs) from isolated from human bone marrow, adipose tissue, placental tissue, or cord blood to treat animals with various types of lung disease (Moodley Y, et al.Am J Pathol 175:303313; Ortiz LA, et al. Proc Natl Acad Sci USA 104:1100211007; Ortiz LA, et al. Proc Natl Acad Sci USA 100:84078411). Also, a Phase I clinical trial has assessed the safety of fat-based MSCs as a treatment for lung damage in human patients. Because this study was only designed to test the safety of this procedure, little to nothing can be said of the efficacy of this test (Tzouvelekis A, J Transl Med. 2013 Jul 15;11:171).

Recently, several laboratories have identified resident stem cells in the lung and some researchers have even managed to isolate them and growth them in culture (Desai TJ, et al., (2014) Alveolar progenitor and stem cells in lung development, renewal and cancer. Nature 507:190–194; Kajstura J, et al., (2011) Evidence for human lung stem cells. N Engl J Med 364:1795–1806; Kim CF, et al., (2005) Identification of bronchioalveolar stem cells in normal lung and lung cancer. Cell 121:823–835; Wansleeben C, et al. (2013) Stem cells of the adult lung: Their development and role in homeostasis, regeneration, and disease. Wiley Interdiscip Rev Dev Biol 2:131–148; Barkauskas CE, et al. (2013) Type 2 alveolar cells are stem cells in adult lung. J Clin Invest 123:3025–3036; Hogan BL, et al. (2014) Repair and regeneration of the respiratory system: Complexity, plasticity, and mechanisms of lung stem cell function. Cell Stem Cell 15:123–138). Could such cells work better than MSCs?

At this point it is difficult to say, since there are a fair amount known about isolating and growing MSCs in culture, but there is relatively little known about resident lung stem cell populations. However, a new paper might change that feature of the debate.

Ke Cheng and his colleagues from North Carolina State University have developed a rapid, reproducible, and scalable method to generate clinically applicable amounts of resident lung progenitor cells. This technique capitalizes on the “Spheroid method” used for tumor cells. Spheroids are three-dimensional structures that grow as small balls of cells in culture. Cheng and others applied the spheroid culture method to lung cells with great success.

Lung cells were acquired from lung biopsies taken from human patients. The tissues were appropriately minced, treated with enzymes to disintegrate the structural components, and then grown in culture. The cells that grew were eventually seeded onto a special culture system for growing spheroids. In this culture system, spheroids formed, consisting of internal clumps of lung progenitor cells surrounded by a shell of stroma-like cells. These cells expressed the cadre of genes you would expect them to. Cheng and his coworkers called these cells “lung spheroid cells” or LSCs.

Generation of lung spheroids and lung spheroid cells. (A): Schematic showing the protocol to grow lung spheroids and lung spheroid cells. (B-I): Edge of lung tissue explants with outgrowth cells becoming confluent and ready to harvest. (B-II): Lung spheroids formed from outgrowth cells in suspension culture. (B-III): Plated lung spheroids onto fibronectin-coated surfaces to generate lung spheroid cells. (B-IV): Expansion of LSCs in suspension cultures. (C): Cumulative doubling for LSCs from three different donors. (D): Immunocytochemistry on lung spheroids. Scale bars = 50 µm. Abbreviations: LSCs, lung spheroid cells; PF, pulmonary fibrosis; SCID, severe combined immunodeficiency.
Generation of lung spheroids and lung spheroid cells. (A): Schematic showing the protocol to grow lung spheroids and lung spheroid cells. (B-I): Edge of lung tissue explants with outgrowth cells becoming confluent and ready to harvest. (B-II): Lung spheroids formed from outgrowth cells in suspension culture. (B-III): Plated lung spheroids onto fibronectin-coated surfaces to generate lung spheroid cells. (B-IV): Expansion of LSCs in suspension cultures. (C): Cumulative doubling for LSCs from three different donors. (D): Immunocytochemistry on lung spheroids. Scale bars = 50 µm. Abbreviations: LSCs, lung spheroid cells; PF, pulmonary fibrosis; SCID, severe combined immunodeficiency.

When Cheng and his group implanted LSCs into Matrigel, the cell appropriately differentiated into lung-specific cell types and formed structures that greatly resembled the tiny air sacs in lungs, known as alveoli. These structures, based on their expression patterns of particular genes are where specific proteins were found in the cells, seemed for a mature lung structure. Interestingly, when the culture medium that had been used to grow the LSCs (conditioned media) was given to other cultured cells, it promoted survival or proliferation of human lung epithelial cells and tube formation of human endothelial cells on Matrigel.

In vitro differentiation and paracrine assays of lung spheroid cells. (A): LSCs grown on Matrigel and displaying alveoli-like structures (inset). (B): LSCs grown on Matrigel expressed aquaporin 5 (red). (C): Human lung epithelial cells cultured in control media and LSC-CM and stained for live (green)/dead (red) assay. (D): HUVEC tube formation assay on Matrigel surface in control or conditioned media from LSCs. Data are presented as mean ± SD. All experiments were run in triplicate, unless noted otherwise. Scale bars = 50 µm. ∗, p < .05 compared with the control media group. (E): Representative antibody array images showing the proteins presenting in the CM from LSCs and NHDF cells. Abbreviations: AQ5, aquaporin 5; BDNF, brain-derived neurotrophic factor; CM, conditioned media; DAPI, 4′,6-diamidino-2-phenylindole; EGFP, enhanced green fluorescent protein; GRO, growth-regulated protein; HGF, hepatocyte growth factor; HUVEC, human umbilical vein endothelial cell; IGFBP2, insulin-like growth factor binding protein 2; IL, interleukin; LSCs, lung spheroid cells; POS, positive; NHDF, normal human dermal fibroblast cell.
In vitro differentiation and paracrine assays of lung spheroid cells. (A): LSCs grown on Matrigel and displaying alveoli-like structures (inset). (B): LSCs grown on Matrigel expressed aquaporin 5 (red). (C): Human lung epithelial cells cultured in control media and LSC-CM and stained for live (green)/dead (red) assay. (D): HUVEC tube formation assay on Matrigel surface in control or conditioned media from LSCs. Data are presented as mean ± SD. All experiments were run in triplicate, unless noted otherwise. Scale bars = 50 µm. ∗, p < .05 compared with the control media group. (E): Representative antibody array images showing the proteins presenting in the CM from LSCs and NHDF cells. Abbreviations: AQ5, aquaporin 5; BDNF, brain-derived neurotrophic factor; CM, conditioned media; DAPI, 4′,6-diamidino-2-phenylindole; EGFP, enhanced green fluorescent protein; GRO, growth-regulated protein; HGF, hepatocyte growth factor; HUVEC, human umbilical vein endothelial cell; IGFBP2, insulin-like growth factor binding protein 2; IL, interleukin; LSCs, lung spheroid cells; POS, positive; NHDF, normal human dermal fibroblast cell.

Now the $64,000 question is this: “How do LSCs stack up against MSCs at treating lung damage?”

To address this question, Cheng and others used a mouse model of pulmonary fibrosis. To induce pulmonary fibrosis in mice, Severe Combined Immune Deficient (SCID) mice were given intratracheal washes of the anticancer drug bleomycin, which induces a condition in mice that, to some degree, resembles human pulmonary fibrosis. Different groups of mice with this lung damage were given either intravenous infusions of LSCs, MSCs or saline as a control.

The administered LSCs reduced the amount of cell death and scarring observed in the lungs. LSCs also increased the formation of new blood vessels and decreased the expression of pro-fibrotic genes. While the infusion of MSCs did improve the lung tissue in these mice, the LSCs were clearly superior.

Therapeutic benefits of human LSCs in mice with bleomycin-induced pulmonary fibrosis. (A): Schematic showing the design of the mouse studies. (B): Macroscopic views of explanted lungs 14 days after LSC or saline treatment. H&E staining (C) and Masson’s trichrome staining (D) were performed on the lungs. (E): Quantitation of fibrous thickening by Ashcroft score from the H&E staining images (n = 6–7 animals per group). (F): Quantitation of tissue infiltrates from the H&E staining images (n = 6–7 animals per group). Data are presented as mean ± SD. Scale bars = 100 µm. ∗, p < .05 compared with the sham group; #, p < .05 compared with the Bleo + saline group. Abbreviations: Bleo, bleomycin; H&E, hematoxylin and eosin; LSCs, lung spheroid cells.
Therapeutic benefits of human LSCs in mice with bleomycin-induced pulmonary fibrosis. (A): Schematic showing the design of the mouse studies. (B): Macroscopic views of explanted lungs 14 days after LSC or saline treatment. H&E staining (C) and Masson’s trichrome staining (D) were performed on the lungs. (E): Quantitation of fibrous thickening by Ashcroft score from the H&E staining images (n = 6–7 animals per group). (F): Quantitation of tissue infiltrates from the H&E staining images (n = 6–7 animals per group). Data are presented as mean ± SD. Scale bars = 100 µm. ∗, p < .05 compared with the sham group; #, p < .05 compared with the Bleo + saline group. Abbreviations: Bleo, bleomycin; H&E, hematoxylin and eosin; LSCs, lung spheroid cells.

Can LSCs provide the kind regenerative “OOMPH” damaged lungs need? The culture system that was developed by Cheng and others can produce large quantities of cells from even small biopsies. This makes the procedure suitable and efficacious for clinical situations in which a patient is receiving infusions of their own cells or someone else’s cells. An added advantage to this system in the absence of any need for cell sorting, which is expensive, and requires highly-trained technicians who operate large, expensive machines. Also, none of the mice treated in this study showed any signs of tumors, which underscores the clinical safety of LSCs.

Cultured MSCs might also provide an excellent model system to study lung pathologies. Making LSCs from patients with cystic fibrosis, inherited versions of emphysema, or other pulmonary diseases could provide an accessible and effective model system for drug testing and pathological studies.

This work was published in the journal Stem Cells and Translational Medicine.

New Way to Improve Stem Cell Production May Improve IPF Treatment


North Carolina State University researcher have tested a faster, cheaper way to harvest and grow lung stem cells that have been extracted from patients’ own bodies. That makes such cells a perfect match for lung patients, according to a small proof-of-concept trial.

Ke Cheng, an associate professor of regenerative medicine at NC State, and his team tested this method with, a view toward eventually treating people with idiopathic pulmonary fibrosis, or IPF, a disease that causes inflammation in lung tissue that over time becomes thick and stiff. This scarring of tissue negatively affects lung function over time.

“In current stem cell harvesting, just the process of sorting the stem cells can damage them, wasting not only the cells, but also time and money,” said Cheng. “We wanted to see if we could take healthy stem cells from an organ while they were still in a supportive environment, recreate and enhance that environment outside the body to encourage stem cell reproduction, then reintroduce those cells into a damaged organ to treat disease.”

Cheng and others placed healthy, human adult lung stem cells in a multicellular spheroid, a three-dimensional structure with stem cells in the middle surrounded by layers of support cells. Spheroids are typically used in the laboratory to culture cancer or embryonic cells.

They then used mice with IPF and injected cultured human stem cells into the animals. These injected stem cells produced decreases in inflammation and fibrosis, which Cheng said matched the condition of lungs in the study’s control group that did not have IPF.

Cheng hopes that stem cells isolated from biopsies in human patients can be used to grow and harvest additional cells. Such a procedure should be able to decrease the number of invasive procedures necessary for treatment.

“Picture the lung as a garden and the stem cells as seeds,” Cheng said. “In an IPF environment, with inflammation, the soil is bad, but the seeds are still there. We take the seeds out and give them a protected place to grow. Then when we put them back into the lung, they can grow into mature lung cells to replace the damaged lung tissues in IPF. They can also wake the other seeds up, telling them to help fight the inflammation and ‘improving’ the soil.”

The study was published in the journal STEM CELLS Translational Medicine.