Controlling Mesenchymal Stem Cell Activity With Microparticles Loaded With Small Molecules

Mesenchymal stem cells are the subject of many clinical trials and show a potent ability to down-regulate unwanted immune responses and quell inflammation. A genuine challenge with mesenchymal stem cells (MSCs) is controlling the genes they express and the proteins they secrete.

A new publication details the strategy of one enterprising laboratory to control MSC function. Work by Jeffery Karp from the Harvard Stem Cell Institute and Maneesha Inamdar from the Institute for Stem Cell Biology and Regenerative Medicine in Bangalore, India and their colleagues had use microparticles that are loaded with small molecules and are readily taken up by cultures MSCs.

In this paper, which appeared in Stem Cell Reports (DOI:, human MSCs were stimulated with a small signaling protein called Tumor Necrosis Factor-alpha (TNF-alpha). TNF-alpha makes MSCs “angry” and they pour out pro-inflammatory molecules upon stimulation with TNF-alpha. However, to these TNF-alpha-stimulated, MSC, Karp and others added tiny microparticles loaded with a small molecule called TPCA-1. TPCA-1 inhibits the NF-κB signaling pathway, which is one of the major signal transduction pathways involved in inflammation.

fx1 (7)

Delivery of these TPCA-1-containing microparticles thinned-out the production of pro-inflammatory molecules by these TNF-alpha-treated MSCs for at least 6 days. When the culture medium from TPCA-1-loaded MSCs was given to different cell types, the molecules secreted by these cells reduced the recruitment of white blood cells called monocytes. This is indicative of the anti-inflammatory nature of TPCA-1-treated MSCs. The culture medium from these cells also prevented the differentiation of human cardiac fibroblasts into collagen-making cells called “myofibroblasts.” Myofibroblasts lay down the collagen that produces the heart scar after a heart attack. This is a further indication of the anti-inflammatory nature of the molecules made by these TPCA-1-treated MSCs.

These results are important because it shows that MSC activities can be manipulated without gene therapy. It is possible that such non-gene therapy-based approached can be used to fine-tune MSC activity and the types of molecules secreted by implanted MSCs. Furthermore, given the effect of these cells on monocytes and cardiac fibroblasts, perhaps microparticle-treated MSCs can prevent the adverse remodeling that occurs in the heart after a heart attack.


Individual Cells of Four Cell-Stage Embryos Show Distinct Genetic Signatures

University of Cambridge and EMBL-EBI researchers have revealed that differences in gene expression begin emerge earlier in human development than originally thought.  According to the Cambridge and EMBL teams, genetic differences arrive as early as the second day after the completion of fertilization.  These four cell-stage embryos consist of four “blastomeres” that appear identical in size and shape.  However, even at these early stages, these four blastomeres are already beginning to display subtle differences in gene expression.

Fertilization of an egg (oocyte) by a sperm is a multistep process that begins with the contact of the sperm with the jelly layer that surrounds the egg (zona pellucida), and the acrosomal reaction of the sperm, contact of the egg and sperm membranes, followed by fusion of the egg and sperm membranes, egg activation, disassembly of the sperm and remodeling of the sperm and egg pronuclei, contact of the sperm and egg pronuclei, and culminating in the initiation of the first mitotic division.  The first cell division or “cleavage” occurs approximately 24 hours after the initiation of fertilization, and forms the two-cell embryo.  The next cleavage occurs about 12 hours later, and the blastomeres initially divide synchromously (at the same time), but eventually divide asynchronously (at different times).  During these early cleavages of the zygote, special embryonic cell cycles and include S phases and M phases that alternate without any intervening G1 or G2 phases.  Therefore individual cell volume decreases.  About day 4, the embryo is a solid ball of 16-20 cells with peripheral cells flattened against the zona pellucida, and compaction occurs forming a cavity that leads to the next blastocyst stage, which is a large free-floating ball of stem cells.

At first, the blastomeres of the early embryo are “totipotent,” which means that each blastomere can potentially divide and grow and produce every single cell of the whole body and the placenta.  After compaction, two cell populations emerge that include, round, slow-dividing cells in the center and fast-growing flatter cells on the outside.  The central cells of the inner cell mass have a “pluripotent” status, which means that they can generate the cells of the whole body, but not the placenta.  However, the point during development at which cells begin to show a preference for becoming a specific cell type is unclear.

At this point, the new study, which was published in the journal Cell, presents rather convincing data that even as early as the four-cell embryo stage, the cells are indeed different.

The EMBL/Cambridge teams utilized the latest sequencing technologies to model embryo development in mice and examined the activity of individual genes at a single cell level.  This analysis showed that some genes in each of the four blastomeres showed distinct genetic signatures.  The expression of one gene in particular, Sox21, differed the most between cells.  Sox21 is part of the so-called “pluripotency network.”  The pluripotency network consists of a cascade of genes that are essential both in culture (in vivo) and in vitro (in the organism) for early development and maintenance of pluripotency.  The EMBL/Cambridge teams discovered that when the activity of Sox21 was reduced, the activity of a master regulator that directs cells to develop into the placenta increased.

“We know that life starts when a sperm fertilizes an egg, but we’re interested in when the important decisions that determine our future development occur,” says Professor Magdalena Zernicka-Goetz from the Department of Physiology, Development and Neuroscience at the University of Cambridge. “We now know that even as early as the four-stage embryo – just two days after fertilization – the embryo is being guided in a particular direction and its cells are no longer identical.”

Dr John Marioni of EMBL-EBI, the Wellcome Trust Sanger Institute and the Cancer Research UK Cambridge Institute, adds: “We can make use of powerful sequencing tools to deepen our understanding of the molecular mechanisms that drive development in individual cells. Because of these high-resolution techniques, we are now able to see the genetic and epigenetic signatures that indicate the direction in which early embryonic cells will tend to travel.”

This research tends to diffuse one of the arguments embryonic stem cell proponents use to justify the destruction of human embryos.  Namely, the early human embryos consist of cells that are all the same and have no interactions with each other.  The embryo is, then, not an individual organism, but a collection of many potential organisms that eventually becomes as unified organism.  This turns out to be incorrect, since the cells of the early blastomere are not all equivalent.  Instead, the blastomeres are interacting with each other and using these interactions to figure what kind of cells their progeny will form.  This is the hallmark of an entity with a unified purpose that has a distinct goal.  Folks, that sounds like a unified organism.  It is simply young.

Gladstone Institute Scientists Devise New Way to Make Heart Cells from Skin Cells Opening the Door to the Possibility of Personalized Medicine for Heart Attack Patients

Gladstone Institute research scientists have devised a new way to make heart replacement cells. This novel protocol generates cells that lie in between embryonic stem cells and adult heart cells. These induced expandable cardiovascular progenitor cells (ieCPCs) might very well hold the key to treating heart disease. Even though ieCPCs can develop into heart cells, they still have the ability to grow and expand in culture to produce the large numbers of cells required for clinical purposes. When these ieCPCs are injected directly into the hearts of laboratory mice that have recently suffered a heart attack, they formed heart muscle cells and other heart-specific cell types and significantly improved heart function.

Yu Zhang, MD, PhD, lead author on the study and a postdoctoral scholar at the Gladstone Institutes said, “Scientists have tried for decades to treat heart failure by transplanting adult heart cells, but these cells cannot reproduce themselves, and so they do not survive in the damaged heart.” Zhang continued, “Our generated ieCPCs can prolifically replicate and reliably mature into the three types of cells in the heart, which makes them a very promising potential treatment for heart failure.”

CPCs or cardiovascular progenitor cells are the result of embryonic development and help form the embryonic heart. In the embryo, CPCs can differentiate into a wide variety of different heart-specific cells. This Gladstone Institute study, which was published in the journal Cell Stem Cell, Zhang and his colleagues reprogrammed mouse embryonic fibroblasts into CPCs in the laboratory. Once the mouse embryonic fibroblasts had been reprogrammed into CPCs, Zhang and others used a special medium to keep the cells from differentiating into fully-mature, functional heart cells that no longer were able to divide.

CPCs constitute so-called “organ-specific stem cells.” Organ-specific stem cells are special because they can differentiate into adult cells and, under the right conditions, grow, expand and proliferate in culture indefinitely. Zhang and his colleagues were able to expand their ieCPC cultures for over a dozen generations. This generated more than enough cells to treat several patients.

The importance of the ability of these cells to expand in the laboratory cannot be undersold. When a patient suffers a heart attack, over one billion heart cells can die off. Robust cell renewal means ieCPCs can play the role of a sustainable source of cells that can replace the cells that died as a result of the heat attack. Furthermore, ieCPCs can also develop into each of the three different types of heart cells: cardiomyocytes (heart muscle cells), endothelial cells (blood vessel cells), and smooth muscle cells (that surround the blood vessels and regulate their diameter).. When ieCPCs were injected into a mouse hearts, they spontaneously differentiated into each of these heart-specific cell types without requiring any further coaxing or signals.

Previous attempts to treat heart failure by transplanting adult heart cells have produced, for the most part, modest results. Implanted cells tend to survive poorly and do not self-renew, which seriously compromises their ability to repopulate and heal a damaged heart. An additional caveat is that regenerating the heart after a heart attack requires that the heart be supplied with more than just heart muscle cells (cardiomyocytes). Instead the heart needs all three cell types;

Clinical trials that have tested the ability of non-cardiac stem cells to heal the heart after a heart attack have also shown modest, though limited success. In this case, the implanted cells only differentiate into heart-specific cells types rather poorly. Such transdifferentiation events require complex signals that are absent in an adult heart. ieCPCs circumvent these issues since they are already heart-specific progenitor cells that are committed to forming heart-specific cell types.

In this study, 90% of the injected ieCPCs were retained in a mouse heart after a heart attack and successfully differentiated into functioning heart cells. The ieCPCs formed cardiomyocytes that integrated into the myocardium and formed functional connections with existing, surviving cardiomyocytes. The ability to connect with existing heart muscle cells is also crucial to minimize the risk of arrhythmias after a heart attack. The implanted ieCPCs also created new blood vessels that pumped blood and oxygen to newly-forming heart tissues. The ieCPCs significantly improved heart function. The mouse hearts pumped more efficiently, and the benefits lasted for at least three months. Because these cells are generated from skin cells, this procedure also opens the door for personalized medicine in which a heart patient’s own cells are used to treat their heart disease.


ieCPCs Give Rise to CMs, ECs, and SMCs In Vivo and Improve Cardiac Function after MI

(A–E) Immunofluorescence analyses of RFP and CM (A), EC (B and C), and SMC (D and E) markers in tissue sections collected 2 weeks after transplanting RFP-labeled ieCPCs at passage 10 into infarcted hearts of immunodeficient mice. Scale bars represent 100 μm.

(F and G) Ejection fraction and fractional shortening of the left ventricle (LV) quantified by echocardiography. Results from two independent experiments were shown. D, days; W, weeks.

(H–J) Cardiac fibrosis was evaluated at eight levels (L1–L8) by Masson’s trichrome staining 12 weeks after coronary ligation. The ligation site is marked as X. Sections of representative hearts are shown in (I) with quantification in (J). Scar tissue (%) = (the sum of fibrotic area or length at L1–L8/the sum of LV area or circumference at L1–L8) × 100. Scale bars represent 500 μm.

(K) Quantification of LV circumference of mouse hearts 12 weeks after transplantation of 2nd MEFs or ieCPCs. Data were summarized from 48 sections for each group. Data are mean ± SE. p < 0.05.

“Cardiac progenitor cells could be ideal for heart regeneration,” said senior author Sheng Ding, PhD, a senior investigator at Gladstone. “They are the closest precursor to functional heart cells, and, in a single step, they can rapidly and efficiently become heart cells, both in a dish and in a live heart. With our new technology, we can quickly create billions of these cells in a dish and then transplant them into damaged hearts to treat heart failure.”


Did the city of Nazareth exist at the time of the birth of Jesus?

I was discussing a recent debate that a friend attended between an atheist musician named Dan Barker and a Christian with a doctorate in New Testament Studies named Justin Bass. According to my friend’s report, the atheist questioned the existence of Nazareth, and then went on from there to assert that everything we know about Jesus is legendary. This […]

Scientists Create Injectable Foam To Repair Degenerating Bones

Researchers in France have developed a self-setting foam that can repair defects in bones and assist growth. Eventually, this advanced biomaterial could be used to quickly regenerate bone growth and treat degenerative diseases such as osteoporosis. Sourced through from: See on – Cardiovascular Disease: PHARMACO-THERAPY

Merry Christmas to all my readers!!!

From Luke 2:1-20

1 In those days Caesar Augustus issued a decree that a census should be taken of the entire Roman world. 2 (This was the first census that took place while Quirinius was governor of Syria.) 3 And everyone went to their own town to register.

4 So Joseph also went up from the town of Nazareth in Galilee to Judea, to Bethlehem the town of David, because he belonged to the house and line of David. 5 He went there to register with Mary, who was pledged to be married to him and was expecting a child. 6 While they were there, the time came for the baby to be born, 7 and she gave birth to her firstborn, a son. She wrapped him in cloths and placed him in a manger, because there was no guest room available for them.

8 And there were shepherds living out in the fields nearby, keeping watch over their flocks at night. 9 An angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were terrified. 10 But the angel said to them, “Do not be afraid. I bring you good news that will cause great joy for all the people. 11 Today in the town of David a Savior has been born to you; he is the Messiah, the Lord. 12 This will be a sign to you: You will find a baby wrapped in cloths and lying in a manger.”

13 Suddenly a great company of the heavenly host appeared with the angel, praising God and saying,

“Glory to God in the highest heaven,
and on earth peace to those on whom his favor rests.”

15 When the angels had left them and gone into heaven, the shepherds said to one another, “Let’s go to Bethlehem and see this thing that has happened, which the Lord has told us about.”

16 So they hurried off and found Mary and Joseph, and the baby, who was lying in the manger. 17 When they had seen him, they spread the word concerning what had been told them about this child, 18 and all who heard it were amazed at what the shepherds said to them. 19 But Mary treasured up all these things and pondered them in her heart. 20 The shepherds returned, glorifying and praising God for all the things they had heard and seen, which were just as they had been told.