Embryonic Decellularized Cardiac Scaffold Supports Embryonic Stem Cell Differentiation to Produce Beating Cardiac Tissue

Regenerative medicine offers a curative approach to treating heart disease through multiple emerging therapeutic concepts. Decellularized organ scaffolds are being optimized to guide and spatially organize stem cell differentiation in efforts to rebuild functional tissues. Additionally, pluripotent stem cells offer a transformative cell source to differentiate into the full spectrum of cellular building blocks. Adult cardiac tissues have been used as extracellular scaffolds as a proof of principle; however, matching the developmental stages of embryonic scaffold with primitive cardiac progenitors may be used to optimize the differentiation and maturation of bioengineered cardiac tissues. Our novel approach uses embryo-derived decellularized hearts as scaffolds to promote embryonic stem cell differentiation. Further, we determined that agitation with 0.25% sodium dodecyl sulfate (SDS) solution was the most effective protocol to maintain matrix integrity while eliminating endogenous cells. The scaffolds were successfully reseeded with different cellular sources derived from pluripotent stem cells to achieve beating cardiac tissues characterized by endothelial, cardiac, and smooth muscle markers. Therefore, embedding stem cells within a tissue-specific environment matched to the developmental stage of the progenitors may offer a practical solution for stem-cell-derived applications such as disease modeling, pharmaceutical safety testing, and screening of novel therapeutic targets.

The States of Pluripotency: Pluripotent Lineage Development in the Embryo and in the Dish

The pluripotent cell lineage of the embryo comprises a series of temporally and functionally distinct intermediary cell states, the epiblast precursor cell of the newly formed blastocyst, the epiblast population of the inner cell mass, and the early and late epiblast of the postimplantation embryo, referred to here as early and late primitive ectoderm. Pluripotent cell populations representative of the embryonic populations can be formed in culture. Although multiple pluripotent cell states are now recognised, little is known about the signals and pathways that progress cells from the epiblast precursor cell to the late primitive ectoderm in the embryo or in culture. The characterisation of cell states is most advanced in mouse where conditions for culturing distinct pluripotent cell states are well established and embryonic material is accessible. This review will focus on the pluripotent cell states present during embryonic development in the mouse and what is known of the mechanisms that regulate the progression of the lineage from the epiblast precursor cell and the ground state of pluripotency to the late primitive ectoderm present immediately prior to cell differentiation.

Total Ischemic Time as an Independent Predictor of Response to Stem Cell Therapy in Patients with ST Segment Elevation Myocardial Infarction

The selection criteria for bone marrow stem cell (BMSC) therapy are not well established for ST segment elevation myocardial infarction (STEMI) patients. This investigation seeks to utilize total ischemic time (TIT), time of symptom onset to percutaneous coronary intervention (PCI), as a criterion for giving BMSC to STEMI patients. A meta-analysis and metaregression were conducted to evaluate improvement of LVEF with BMSC and its association with TIT (<6 and ≥6 hours) and baseline LVEF (<45% and ≥45%) at short (3–6 months) and long term (>6 months) followup. At short term, BMSC allowed improvement of LVEF with prolonged TIT (6.62%, 95% CI, 2.26 to 10.98 for <45%; 6.13%, 95% CI, 2.59 to 9.67 for ≥45%). Similarly, for long term, receiving BMSC allowed significant improvement of LVEF for prolonged TIT (9.19%, 95% CI, 2.34 to 16.05 for <45%; 7.64%, 95% CI, 3.72 to 11.56 for ≥45%). Additionally, TIT was a significant predictor of LVEF improvement independent of baseline LVEF in both short (4.96%, 95% CI, 0.72 to 9.19, P=0.02) and long term (6.24%, 95% CI, 0.46 to 12.02, P=0.03) followup. Consequently, BMSC therapy allows LVEF improvement in prolonged TIT and future studies for BMSC should include TIT ≥ 6 hours as an inclusion criterion.

Intestinal Stem Cells: Common Signal Pathways, Human Disease Correlation, and Implications for Therapies

Enterocytes originating from gastrointestinal stem cells are basic building blocks of villi and crypts in human intestine. Little is known about intestinal stem cells (ISCs), their interaction with niche, and key pathways in their regulation. In this paper, we have reviewed the characteristics of ISC, its interaction with niche, and the understanding of key signaling pathways like Wnt. A better understanding of all of this will help to better utilize novel therapies like mesenchymal stromal cells (MSCs), R-spondin1, and sulindac in various disorders like colon cancer, graft-versus-host disease, intestinal polyposis, and radiation-related bowel injuries.

Differentiation of Human Umbilical Cord Lining Membrane-Derived Mesenchymal Stem Cells into Hepatocyte-Like Cells

Background. Mesenchymal stem cells (MSCs), isolated from bone marrow, adipose tissue, and umbilical cord tissue, have been known to differentiate into hepatocyte-like cells. MSCs can also be easily obtained from umbilical cord lining membrane (CLMSCs). CLMSCs are more primitive MSCs than those isolated from other tissue sources. Objectives. The aim of this study was to investigate the in vitro differentiation of CLMSCs into hepatocyte lineage. Materials and Methods. In this study, CLMSCs were isolated through a tissue attachment method. Cells were characterized for expression of MSC-specific markers and differentiation potency. CLMSCs were induced to differentiate into hepatocytes by a simple two-step protocol. Differentiated cells were examined for the expression of hepatocyte-specific markers and hepatocyte functions. Results. CLMSCs expressed MSC-specific markers and differentiated into adipocytes and osteoblasts. RT-PCR, real-time qRT-PCR, Western blot, and immunocytochemistry analyses demonstrated that differentiated CLMSCs, having hepatocyte-like morphology, expressed several liver-specific markers, such as ALB, AFP, CK18, and CK19, at both mRNA and protein levels following hepatocyte differentiation. Furthermore, periodic acid-Schiff staining and low-density lipoprotein (LDL) uptake assay showed that differentiated cells could store glycogen and uptake LDL. Conclusion. This study demonstrated that CLMSCs can differentiate into functional hepatocyte-like cells. CLMSCs can serve as a favorable cell source for tissue engineering in the treatment of liver disease.

Translational Research in Stem Cell Treatment of Neuromuscular Diseases

Neuromuscular diseases are a heterogeneous group of diseases that lead to significant disability in effected individuals. Pharmacological treatments failed to provide any significant improvement to date. Recently, the introduction of stem cells into the field of health sciences raised the hopes for a new treatment for neuromuscular diseases. In theory, stem cells, owing to their multilineage differentiation capacity, could differentiate into myofibers and neurons and replace the degenerated cells leading to recovery of the patients. Results obtained from the preclinical studies supported this theory. However, clinical trials with stem cells could not meet the expectations mainly because of early mortality, limited migration, and differentiation of the implanted cells. Modification of the stem cells before implantation, such as introduction of deficient genes or commitment to a precursor cell line provided little improvement. The biggest barrier to overcome for a successful of stem cell treatment, which also should be the focus of the future studies, is to increase the functional integration of the donor cells with the recipient tissues. Understanding the underlying pathogenic mechanisms of the neuromuscular diseases is essential to achieve this goal.

Characterization of Bone-Marrow-Derived Stem Cells in Osteoporotic Models of the Rat

Osteoporotic effects observed after osteoporosis induction in the rat by combining ovariectomy (OVX) either with a defined calcium-deficient diet (OVX + Diet) or by administration of a glucocorticoid (dexamethasone) (OVX + Steroid) mimic the skeletal effects observed in humans affected by osteoporosis. In the present investigation rat MSCs have been characterized in vitro after osteoporosis has been induced for twelve weeks in rats by means of OVX + Diet (n=5) and OVX + Steroid (n=5). Sham-operated animals (n=5) served as controls. MSCs were harvested from humerus and iliac crest and were cultured in standard medium and in osteogenic differentiation medium for studying the proliferation, migration, and differentiation capacity of the cells. Expression of CD90, CD105, runx2, osteocalcin (OC), and bone sialoprotein (BSP) was performed by using qrtPCR. Calcium deposits developed in the course of osteogenic differentiation were measured by using Pentra 400 Axon Lab. Taken together, the present results showed that osteoporosis induction leads to MSC in a state of senescence: proliferation and migration rates of the cells were diminished pointing to self-renewal deficiency and impaired motility of rat MSC in contrast to controls. However, the osteogenic differentiation capacity was increased after osteoporosis induction with OVX + Diet and OVX + Steroid.

The Systems Biology of Stem Cell Released Molecules—Based Therapeutics

Most therapeutics are based on the traditional method of reductionism where a clinically defined condition is broken down into a defined biochemical pathway underlying the condition, then a target in the pathway is identified, followed by developing a drug to interact with the target, modifying the target such that the disease is ameliorated. Biology acts as a system, therefore reductionist approaches to developing therapeutics are limited in therapeutic value because disease or traumatized tissue involves multiple underlying pathways, only a part of the pathways underlying the disease is manipulated by the traditional therapeutic. Much data regarding stem cells shows that their beneficial effects are not restricted to their ability to differentiate, but is more likely due in large part to their ability to release a multitude of molecules. Stem cells release potent combinations of factors that modulate the composition of the cellular milieu to evoke a multitude of responses from neighboring cells. Therefore, stem cells represent a natural systems-based biological factory for the production and release of a multitude of molecules that interact with the system of biomolecular circuits underlying an indication. Current research includes efforts to define, stimulate, enhance, and harness stem cell released molecules (SRM) to develop systems-therapeutics.

Comparative Analysis of Mesenchymal Stromal Cells Biological Properties

The stromal progenitors of mesodermal cells, mesenchymal stromal cells (MSCs), are a heterogeneous population of plastic adherent fibroblast-like cells with extensive proliferative capacity and differentiation potential. Human MSCs have now been isolated from various tissues including bone marrow, muscle, skin, and adipose tissue, the latter being one of the most suitable cell sources for cell therapy, because of its easy accessibility, minimal morbidity, and abundance of cells. Bone marrow and subcutaneous or visceral adipose tissue samples were collected, digested with collagenase if needed, and seeded in Iscove's medium containing 5% human platelet lysate. Nonadherent cells were removed after 2-3 days and the medium was replaced twice a week. Confluent adherent cells were detached, expanded, and analyzed for several biological properties such as morphology, immunophenotype, growth rate, senescence, clonogenicity, differentiation capacity, immunosuppression, and secretion of angiogenic factors. The results show significant differences between lines derived from subcutaneous fat compared to those derived from visceral fat, such as the higher proliferation rate of the first and the strong induction of angiogenesis of the latter. We are convinced that the identification of the peculiarities of MSCs isolated from different tissues will lead to their more accurate use in cell therapy.

Differentiation of Human Dermal Mesenchymal Stem Cells into Cardiomyocytes by Treatment with 5-Azacytidine: Concept for Regenerative Therapy in Myocardial Infarction

Myocardial infarction (MI) is the leading cause of death worldwide. Stem cells regenerative medicine offers a promising approach to cure such degenerative disorders. Mesenchymal stem cells are thought to be one of the important types of stem cells which can differentiate into various lineages such as neuron, hepatocytes, and cardiomyocytes. In the present study, human dermal mesenchymal stem cells (hDMSCs) have been developed from human scalp punch biopsy and characterized for their mesenchymal phenotype so that these cells can be useful for differentiating into cardiomyocytes. 5-Azacytidine induces cardiomyocyte differentiation in vitro and therefore it has been used to differentiate hDMSCs cells into cardiomyocytes. It was observed that hDMSCs differentiated into cardiomyocyte within a period of 4 days to 15 days after treatment with 10 μM and 20 μM of 5-azacytidine. The cardiomyocyte phenotype was confirmed by studying expression of α-cardiac actin, β-myosin heavy chain, and cardiac troponin T. Thus, this paper describes the differentiation of hDMSCs into cardiomyocytes which can be further be used for treatment of MI. This type of cell-based cardiac therapy will offer a new hope for millions of patients worldwide who are suffering from heart disease.