Critical appraisal of the chorioallantoic membrane model for studying angiogenesis in preclinical research.

BACKGROUND: Angiogenesis, the biological mechanism by which new blood vessels are generated from existing ones, plays a vital role in growth and development. Effective preclinical screening is necessary for the development of medications that may enhance or inhibit angiogenesis in the setting of different disorders. Traditional in vitro and, in vivo models of angiogenesis are laborious and time-consuming, necessitating advanced infrastructure for embryo culture. MAIN BODY: A challenge encountered by researchers studying angiogenesis is the lack of appropriate techniques to evaluate the impact of regulators on the angiogenic response. An ideal test should possess reliability, technical simplicity, easy quantifiability, and, most importantly, physiological relevance. The CAM model, leveraging the extraembryonic membrane of the chicken embryo, offers a unique combination of accessibility, low cost, and rapid development, making it an attractive option for angiogenesis assays. This review evaluates the strengths and limitations of the CAM model in the context of its anatomical and physiological properties, and its relevance to human pathophysiological conditions. Its abundant capillary network makes it a common choice for studying angiogenesis. The CAM assay serves as a substitute for animal models and offers a natural setting for developing blood vessels and the many elements involved in the intricate interaction with the host. Despite its advantages, the CAM model's limitations are notable. These include species-specific responses that may not always extrapolate to humans and the ethical considerations of using avian embryos. We discuss methodological adaptations that can mitigate some of these limitations and propose future directions to enhance the translational relevance of this model. This review underscores the CAM model's valuable role in angiogenesis research and aims to guide researchers in optimizing its use for more predictive and robust preclinical studies. CONCLUSION: The highly vascularized chorioallantoic membrane (CAM) of fertilized chicken eggs is a cost-effective and easily available method for screening angiogenesis, in comparison to other animal models.

Dilemma of Epigenetic Changes Causing or Reducing Metabolic Disorders in Offsprings of Obese Mothers.

Maternal obesity is associated with fetal complications predisposing later to the development of metabolic syndrome during childhood and adult stages. High-fat diet seems to influence individuals and their subsequent generations in mediating weight gain, insulin resistance, obesity, high cholesterol, diabetes, and cardiovascular disorder. Research evidence strongly suggests that epigenetic alteration is the major contributor to the development of metabolic syndrome through DNA methylation, histone modifications, and microRNA expression. In this review, we have discussed the outcome of recent studies on the adverse and beneficial effects of nutrients and vitamins through epigenetics during pregnancy. We have further discussed about the miRNAs altered during maternal obesity. Identification of new epigenetic modifiers such as mesenchymal stem cells condition media (MSCs-CM)/exosomes for accelerating the reversal of epigenetic abnormalities for the development of new treatments is yet another aspect of the present review.

Long-term cryopreservation of whole gingival tissue.

Stem cells obtained from the body tissue, such as adipose tissue, dental pulp and gingival tissue. Fresh tissue is often used to isolate and culture for regenerative medicine. However, availability of tissue as and when required is one of the measure issue in regenerative medicine. Cryopreservation of tissue provides benefit over tissue availability, storage for significant amount of period and helps preserve the original cell structures. The effects of cryopreservation of gingival tissue for mesenchymal stem cell (MSC) are not well documented; however this process is of increasing importance for regenerative therapies. This study examined the effect of cryopreservation on the long term survival the whole gingival biopsy tissue. We studied cell outgrowth, cell morphology, MSC surface-markers and differentiation of mesenchymal stem cells derived from cryopreserved gingiva. In this study, gingival tissue was cryopreserved for 3, 6, 9 months. Cryopreserved tissue has been thawed and cells were isolated by using explant culture method. The fresh and cryopreserved gingival tissue cells were cultured and characterized for surface marker analysis, CFU-f, population doubling time, and osteogenic, chondrogenic and adipogenic differentiation. The fresh and cryopreserved tissue has similar stem cell properties. Results indicate that cryopreservation of the entire gingival tissue does not affect the properties of stem cells. This opens door for gingival tissue banking for future use in periodontology and regenerative medicine.

Stem Cell Secretome Modulated by Arsenicum album 30C Ameliorates Lipopolysaccharide-induced Cytokine Storm in Blood Mononuclear Cells in vitro.

BACKGROUND: The therapeutic effectiveness of mesenchymal stem cells (MSCs) and their secretome can be enhanced by means of physical, chemical and biological preconditioning. Arsenicum album 30C (AA30) has been one of the leading homeopathic medicines used in prophylaxis against SARS-CoV-2 infection. AIMS: This study aimed to investigate whether AA30 preconditioning could influence the growth factors and cytokine profile of the human dental pulp-derived MSC (DPD-MSC) secretome. Also, to test the efficacy of the AA30-preconditioned DPD-MSC secretome in ameliorating the lipopolysaccharide (LPS)-induced cytokine storm in human peripheral blood mononuclear cells (PBMCs) as an in-vitro cellular model. METHODS: The cytotoxicity of AA30 was assessed in DPD-MSCs by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Growth factors and cytokine levels in the AA30-preconditioned DPD-MSC secretome were analysed by fluorescence-activated cell sorting (FACS) analysis. The angiogenic potential of the AA30-preconditioned DPD-MSC secretome was assessed by chick yolk-sac membrane (YSM) assay. Culture medium with 0.001% ethanol was used as vehicle control. The efficacy of the AA30-preconditioned DPD-MSC secretome in ameliorating the cytokine storm was assessed in LPS pre-treated PBMCs. The mRNA and protein expression of inflammatory markers such as IL-1ß, IL-6 and IL-10 were analysed by using RT-PCR and FACS analysis respectively. RESULTS: AA30 did not exhibit cytotoxicity in the concentration range of 1% to 50%. Furthermore, the AA30-preconditioned DPD-MSC secretome exhibited a significant increase in the levels of angiogenic factors, such as human angiopoietin-2, EPO and PDGF-AA, and decreased levels of cytokines, such as TNF-α, CXCL-8 and IL-6. The AA30-preconditioned DPD-MSC secretome showed augmented angiogenesis compared to vehicle controls. The DPD-MSC secretome ameliorated LPS-induced mRNA and protein expression of IL-1ß, IL-6 and IL-10 in PBMCs. CONCLUSION: The AA30-preconditioned DPD-MSC secretome augmented angiogenesis and ameliorated the LPS-induced cytokine storm in human PBMCs in vitro. Our data demonstrate that AA30 preconditioning enhances the therapeutic potency of MSCs and their secretome.

Recovery of Human Embryonic Stem Cells-Derived Neural Progenitors Exposed to Hypoxic-Ischemic-Reperfusion Injury by Indirect Exposure to Wharton's Jelly Mesenchymal Stem Cells Through Phosphatidyl-inositol-3-Kinase Pathway.

Increasing evidence suggests that mesenchymal stem cells(MSCs) have beneficial effects in hypoxic ischemic reperfusion injury, but the underlying mechanisms are unclear. Here, we first examined the effect of OGD reperfusion injury on the vulnerability of human NPs derived from human embryonic stem cells (hESCs) with regard to cell survival and oxidative stress. Cellular deregulation was assessed by measuring glutathione levels, basal calcium and intracellular calcium [Ca2+]i response under KCl stimulation, as well as the key parameters of proliferation, glial progenitor marker expression and migration. Next, the influence of WJ-MSCs in recovering these parameters was evaluated, and the role of Phosphatidyl-inositol-3-Kinase(PI3K) pathway in actuating the protective effect was assessed. OGD reperfusion injury induced significant increases in cell death, ROS generation, oxidative stress susceptibility and decreased glutathione levels in NPs, accompanied by rises in basal [Ca2+]i, KCl-induced [Ca2+]i, expression of K+ leak channel(TASK1), and declines in proliferation, migration potential and glial progenitor population. The introduction of WJ-MSCs(after 2 h of reperfusion) through a non-contact method brought about significant improvement in all these cellular parameters as observed after 24hrs, and the PI3K pathway played an important role in the neuroprotection process. Presence of WJ-MSCs increased the expression of survival signals like phosphorylated Akt/Akt and PI3K in the OGD-reperfused NPs. Our data clearly demonstrate for the first time that soluble factors from WJ-MSCs can not only ameliorate survival, proliferation, migration and glial progenitor expression of OGD-reperfused NPs, but also regulate their intracellular Ca2+ response to KCl stimulation and expression of TASK1 through the PI3K pathway.

Insulin-producing cell clusters derived from human gingival mesenchymal stem cells as a model for diabetes research.

BACKGROUND: The human gingiva-derived mesenchymal stem cells (hGMSCs) possess a great potential to develop the cell-based therapy for diabetes due to its unscarred healing capacity and reparative potential. In this current study, we isolated, cultured and characterised the GMSCs and explored their potential to differentiate into Insulin Producing Cell Clusters (IPCCs). METHODS: The cells derived from gingival tissues exhibited fibroblast-like morphology. The flow cytometric analysis revealed positive expression of CD73(97.43%), CD90(95.05%), and CD105(93.17%) and negative expression of CD34(0.05%), CD45(0.09%), and HLA-DR (0.025) surface markers. We then converted this adherent fibroblast-like GMSCs into floating IPCCs using a sequential three-step protocol containing a different combination of differentiating agents. Initially, the presence of insulin in IPCCs was confirmed by dithizone staining. Glucose-stimulated insulin secretion (GSIS) assay confirmed that IPCCs secrete insulin in response to glucose. RESULTS: Generated IPCCs express pancreatic markers such as insulin, pdx1, glucagon, GLUT4 and GLUT2 as evidenced by RT-PCR analysis. Our results unequivocally showed that IPCCs can be generated from gingiva which is a potential source of postnatal MSCs. Our results offer the IPCCs generated from hGMSCs a platform for screening anti-diabetic drugs and a new autologous source of tissue for islet transplantation for the treatment of diabetes. CONCLUSIONS: Our results unequivocally demonstrate for the first time that hGMSCs can be used as an attractive non-invasive tissue source for generating IPCCs, which can be employed in diabetes research for screening antidiabetic agents and also for transplantation in type 1 diabetic patients as autologous source without the need of immunosuppression.

Neuronal and cardiac toxicity of pharmacological compounds identified through transcriptomic analysis of human pluripotent stem cell-derived embryoid bodies.

Concurrent with the '3R' principle, the embryonic stem cell test (EST) using mouse embryonic stem cells, developed in 2000, remains the solely accepted in vitro method for embryotoxicity testing. However, the scope and implementation of EST for embryotoxicity screening, compliant with regulatory requirements, are limited. This is due to its technical complexity, long testing period, labor-intensive methodology, and limited endpoint data, leading to misclassification of embryotoxic potential. In this study, we used human induced pluripotent stem cell (hiPSC)-derived embryoid bodies (EB) as an in vitro model to investigate the embryotoxic effects of a carefully selected set of pharmacological compounds. Morphology, viability, and differentiation potential were investigated after exposing EBs to folic acid, all-trans-retinoic acid, dexamethasone, and valproic acid for 15 days. The results showed that the compounds differentially repressed cell growth, compromised morphology, and triggered apoptosis in the EBs. Further, transcriptomics was employed to compare subtle temporal changes between treated and untreated cultures. Gene ontology and pathway analysis revealed that dysregulation of a large number of genes strongly correlated with impaired neuroectoderm and cardiac mesoderm formation. This aberrant gene expression pattern was associated with several disorders of the brain like mental retardation, multiple sclerosis, stroke and of the heart like dilated cardiomyopathy, ventricular tachycardia, and ventricular arrhythmia. Lastly, these in vitro findings were validated using in ovo chick embryo model. Taken together, pharmacological compound or drug-induced defective EB development from hiPSCs could potentially be used as a suitable in vitro platform for embryotoxicity screening.

Placental mesenchymal stromal cells as an alternative tool for therapeutic angiogenesis.

Dysregulation of angiogenesis is a phenomenon observed in several disorders such as diabetic foot, critical limb ischemia and myocardial infarction. Mesenchymal stromal cells (MSCs) possess angiogenic potential and have recently emerged as a powerful tool for cell therapy to promote angiogenesis. Although bone marrow-derived MSCs are the primary cell of choice, obtaining them has become a challenge. The placenta has become a popular alternative as it is a highly vascular organ, easily available and ethically more favorable with a rich supply of MSCs. Comparatively, placenta-derived MSCs (PMSCs) are clinically promising due to their proliferative, migratory, clonogenic and immunomodulatory properties. PMSCs release a plethora of cytokines and chemokines key to angiogenic signaling and facilitate the possibility of delivering PMSC-derived exosomes as a targeted therapy to promote angiogenesis. However, there still remains the challenge of heterogeneity in the isolated populations, questions on the maternal or fetal origin of these cells and the diversity in previously reported isolation and culture conditions. Nonetheless, the growing rate of clinical trials using PMSCs clearly indicates a shift in favor of PMSCs. The overall aim of the review is to highlight the importance of this rather poorly understood cell type and emphasize the need for further investigations into their angiogenic potential as an alternative source for therapeutic angiogenesis.

Genetic and epigenetic stability of stem cells: Epigenetic modifiers modulate the fate of mesenchymal stem cells.

Stem cell research has progressed widely and has been receiving a considerable attention for its advantages and drawbacks. Despite their extensive therapeutic potential in regenerative medicine, they are debatable for their genetic and epigenetic stability. In fact lineage specific differentiation is mediated via epigenetic changes in DNA methylation, acetylation, histone modifications etc. Thus epigenetics plays an important role in stem cell biology. For therapeutic interventions stem cells need to be genetically and epigenetically stable for their maximum paracrine secretions for bringing about expected tissue repair and regeneration. In this review we have focused on the current status of genetic and epigenetic stability in stem cells and their importance in regenerative medicine. We have also touched upon the possibility of considering tissue resident mesenchymal stem cells as epigenetic modifiers. This is likely to open a new era in stem cell therapeutic intervention by reversing disease inducing epigenetic changes.

Human adipose tissue mesenchymal stem cells as a novel treatment modality for correcting obesity induced metabolic dysregulation.

OBJECTIVE: Obesity induced metabolic dysregulation results in cluster of chronic conditions mainly hyperglycemia, hyperinsulinemia, dyslipidemia, diabetes, cardiovascular complications and insulin resistance. To investigate the effect of i.m. injection of human adipose tissue derived mesenchymal stem cells and its secretome in correcting obesity induced metabolic dysregulation in high fat diet fed obese model of mice and understand its mechanism of action. SUBJECTS: We injected human adipose tissue derived mesenchymal stem cells (ADMSCs) suspension (CS), conditioned medium (CM) and the cell lysate (CL) intramuscularly in high fat diet (HFD)-induced C57BL/6 mice. Metformin was used as a positive control. ADMSCs were traced in vivo for its bio distribution after injection at different time points. RESULTS: ADMSCs-treated mice exhibited remarkable decrease in insulin resistance as quantified by HOMA-IR and triglyceride glucose index with concomitant decrease in oxidized LDL and IL6 as compared with the untreated control. CS injection showed improvement in glucose tolerance and reduction in fatty infiltration in the liver, macrophage infiltration in adipose and hypertrophy of the islets resulting from HFD. Upregulation of miRNA-206, MyoD and increase in protein content of the skeletal muscle in CS-treated mice indicates plausible mechanism of action of ADMSCs treatment in ameliorating IR in HFD mice. CONCLUSION: Of all the three treatments, CS was found to be the best. ADMSCs were found to have migrated to different organs in order to bring about the correction in dysregulated metabolism induced by obesity. Our results open up a novel treatment modality for possible therapeutic usage in human subjects by employing autologous or allogeneic ADMSCs for the better management of obesity induced metabolic dysregulation.

Reprogramming mouse embryo fibroblasts to functional islets without genetic manipulation.

The constant quest for generation of large number of islets aimed us to explore the differentiation potential of mouse embryo fibroblast cells. Mouse embryo fibroblast cells isolated from 12- to 14-day-old pregnant mice were characterized for their surface markers and tri-lineage differentiation potential. They were subjected to serum-free media containing a cocktail of islet differentiating reagents and analyzed for the expression of pancreatic lineage transcripts. The islet-like cell aggregates (ICAs) was confirmed for their pancreatic properties via immunofluorecence for C-peptide, glucagon, and somatostain. They were positive for CD markers-Sca1, CD44, CD73, and CD90 and negative for hematopoietic markers-CD34 and CD45 at both transcription and translational levels. The transcriptional analysis of the ICAs at different day points exhibited up-regulation of islet markers (Insulin, PDX1, HNF3, Glucagon, and Somatostatin) and down-regulation of MSC-markers (Vimentin and Nestin). They positively stained for dithizone, C-peptide, insulin, glucagon, and somatostatin indicating intact insulin producing machinery. In vitro glucose stimulation assay revealed three-fold increase in insulin secretion as compared to basal glucose with insulin content being the same in both the conditions. The preliminary in vivo data on ICA transplantation showed reversal of diabetes in streptozotocin induced diabetic mice. Our results demonstrate for the first time that mouse embryo fibroblast cells contain a population of MSC-like cells which could differentiate into insulin producing cell aggregates. Hence, our study could be extrapolated for isolation of MSC-like cells from human, medically terminated pregnancies to generate ICAs for treating type 1 diabetic patients.

Omega-3 polyunsaturated fatty acids promote angiogenesis in placenta derived mesenchymal stromal cells.

Enhancement of angiogenesis is solicited in wound repair and regeneration. Mesenchymal stromal cells derived from the placenta (P-MSCs) have an inherent angiogenic potential. Polyunsaturated fatty acids (PUFAs) in turn, specifically the omega-3 (N-3) are essential for growth and development. They are also recommended as dietary supplements during pregnancy. We therefore hypothesized that addition of N-3 PUFAs in P-MSC culture media may enhance their angiogenic potential. Hence, we treated P-MSCs with omega-3 (N-3) fatty acids -Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) at different concentrations and tested their angiogenic potential. We saw an upregulation of both bFGF and VEGFA. We also found enhanced in vitro tube formation ability of P-MSCs treated with DHA: EPA. We then looked at the influence of the conditioned medium (CM) collected from P-MSCs exposed to DHA: EPA on the key effector cells -HUVECs (Human Umbilical Vein derived endothelial cells and their functionality was further confirmed on chick yolk sac membrane. We found that the CM of P-MSCs exposed to DHA: EPA could enhance angiogenesis in both cases. These result were finally validated in an in vivo matrigel plug assay which revealed enhanced migration and vessel formation in CM treated with DHA: EPA. Our data thus reveals for the first time that supplementation with lower concentration of PUFA enhances the angiogenic potential of P-MSCs making them suitable for chronic wound healing applications.

Establishment of an in ovo chick embryo yolk sac membrane (YSM) assay for pilot screening of potential angiogenic and anti-angiogenic agents.

Angiogenesis, the process of new blood vessel formation from pre-existing vessels, is essential for growth and development. Development of drugs that can accelerate or decelerate angiogenesis in the context of various diseases requires appropriate preclinical screening. As angiogenesis involves complex cellular and molecular processes, in vivo studies are superior to in vitro investigations. Conventional in vitro, in vivo, and ex ovo models of angiogenesis are time consuming and tedious, and require sophisticated infrastructure for embryo culture. In the present study, we established an in ovo chick embryo yolk sac membrane (YSM) assay for angiogenesis and tested the angiogenic potential of arginine, conditioned medium (CM) from human adipose tissue and placenta-derived mesenchymal stem cells (ADMSCs-CM and PDMSCs-CM), avastin and vitamin C. The obtained results were confirmed with the routinely employed chick embryo Chorioallantoic Membrane (CAM) assay. Both assays revealed the pro-angiogenic nature of arginine, ADMSCs-CM, and PDMSCs-CM, and the anti-angiogenic effect of avastin and vitamin C. This novel in ovo YSM model is simple, reproducible, and highly economic in terms of the time frame and cost incurred. The proposed model is thus a suitable substitute to the CAM model for pilot screening of potential angiogenic and anti-angiogenic agents.

Long term explant culture for harvesting homogeneous population of human dental pulp stem cells.

Dental pulp stem cells have emerged as a preferred source of mesenchymal stem cells, because of its easy availability and high stem cell content. Dental pulp is a specific fibrous tissue that contains heterogeneous populations of odontoblasts, fibroblasts, pericytes, progenitors, stem cells, leukocytes and neuronal cells. In this study, we propose sustained explant culture as a simple, economical and efficient process to isolate dental pulp stem cells from human Dental pulp Tissue. Historically explant cultures were used to get fibroblast cells from embryonic chick heart using plasma clot cultures. The subculture was performed by lifting mother explant (original explant) and grafting it in a new plasma clot. We modified this age old technique to suit the modern times. Here we demonstrate for the first time that the mother explant (E0) of human dental pulp tissue could be sub-cultured consecutively seven times (E7) without displacement. This technique is highly reproducible and permits growth and proliferation of dental pulp stem cells yielding an enriched homogeneous mesenchymal stem cells population in the first passage itself as revealed by surface marker expression. These dental pulp stem cells exhibit differentiation into adipogenic, chondrogenic and osteogenic lineage revealing their mesenchymal stem cell nature. We propose that dental pulp stem cells isolated by sustained explant culture are phenotypically and functionally comparable to those obtained by enzymatic method. It is a simple, inexpensive and gentle method, which may be preferred over the conventional techniques for obtaining stem cells from other tissue sources as well especially in cases of limited starting material.

Adipose tissue: A natural resource for multipotent mesenchymal stem cells with potential translation to trigerminal layers.

BACKGROUND: The article reports basic science research that establishes that adipose tissue (AT)-derived mesenchymal stem cells (MSCs) have a potential to transgerminal translation. STUDY DESIGN: MSC confirmation was obtained by phenotypic spindle-shaped cells as well as with four positive and three negative markers. The translineage translation of adipose-derived MSCs (ADMSCs) was established. MATERIALS AND METHODS: The lipoaspirate was subjected to enzymatic digestion with collagenase. Stromal vascular factor (SVF) was isolated. With two passages, pure culture of ADMSCs was obtained. They were translated to all the three germinal layers. RESULTS: AT-derived SVF contains ~30% MSCs. They are capable of being translated into endoderm, mesoderm and ectoderm. CONCLUSION: AT is a rich source for MSCs, with immense research possibilities for regeneration and rejuvenation.

Conditioned Media From Adipose Tissue Derived Mesenchymal Stem Cells Reverse Insulin Resistance in Cellular Models.

The link between insulin resistance (IR) and type 2 diabetes has been recognized for a long time. Type 2 diabetes is often associated with basal hyperinsulinemia, reduced sensitivity to insulin, and disturbances in insulin release. There are evidences showing the reversal of IR by mesenchymal stem cells. However, the effect of conditioned media from adipose derived mesenchymal stem cells (ADSCs-CM) in reversal of IR has not been established. We established an insulin resistant model of 3T3L1 and C2C12 cells and treated with ADSCs-CM. 2-NBDG (2-[N-[7-Nitrobenz-2-oxa-1,3-diazol-4-yl]Amino]-2-Deoxyglucose) uptake was performed to assess improvement in glucose uptake. Genes involved in glucose transport and in inflammation were also analysed. Western blot for glucose transporter-4 and Akt was performed to evaluate translocation of Glut4 and insulin signaling respectively. We found that the ADSCs-CM treated cells restored insulin, stimulated glucose uptake as compared to the untreated control indicating the insulin sensitizing effect of the CM. The treated cells also showed inhibition adipogenesis in 3T3L1 cells and significant reduction of intramuscular triglyceride accumulation in C2C12 cells. Gene expressions studies revealed the drastic upregulation of GLUT4 gene and significant reduction in IL6 and PAI1 gene in both 3T3L1 and C2C12 cells, indicating possible mechanism of glucose uptake with concomitant decrease in inflammation. Enhancement of GLUT4 and phospho Akt protein expression seems to be responsible for the increment in glucose uptake and enhanced insulin signaling, respectively. Our study revealed for the first time that ADSCs-CM acts as an alternative insulin sensitizer providing stem cell solution to IR. J. Cell. Biochem. 118: 2037-2043,2017. © 2016 Wiley Periodicals, Inc.

Shielding Engineered Islets With Mesenchymal Stem Cells Enhance Survival Under Hypoxia.

In the present study we focused on the improvisation of islet survival in hypoxia.The Islet like cell aggregates (ICAs) derived from wharton's jelly mesenchymal stem cells (WJ MSC) were cultured with and without WJ MSC for 48 h in hypoxia and normoxia and tested for their direct trophic effect on ß cell survival. The WJ MSCs themselves secreted insulin upon glucose challenge and expressed the pancreatic markers at both transcription and translational level (C-peptide, Insulin, Glucagon, and Glut 2). Direct contact of MSCs with ICAs facilitated highest viability under hypoxia as evidenced by fluorescein diacetate/propidium iodide and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytokine analysis of the co-cultured ICAs revealed amplification of anti-inflammatory cytokine like TGFß and TNFα accompanied by depletion of pro-inflammatory cytokines. The increment in VEGF and PDGFa was also seen showing their ability to vascularize upon transplantation. This was further accompanied by reduction in total reactive oxygen species, nitric oxide, and super oxide ions and down regulation of Caspase3, Caspase8, p53, and up regulation of Bcl2 confirming prevention of apoptosis in ICAs. The western blot analysis confirmed the cytoprotective effect of WJ MSC on ICAs as they enhanced the anti-apoptotic marker BCL2 and reduced the expression of apoptotic markers, Annexin 5 and Caspase 3. There was a significant reduction in the expression of p38 protein in the presence of MSCs making the ICAs responsive to glucose. Taken together our data demonstrate for the first time that the WJ MSC expressed pancreatic markers and their supplementation protected engineered islets against hypoxia and oxidative stress. J. Cell. Biochem. 118: 2672-2683, 2017. © 2017 Wiley Periodicals, Inc.

Functional recovery upon human dental pulp stem cell transplantation in a diabetic neuropathy rat model.

Diabetic neuropathy (DN) is among the most debilitating complications of diabetes. Here, we investigated the effects of human dental pulp stem cell (DPSC) transplantation in Streptozotocin (STZ)-induced neuropathic rats. Six weeks after STZ injection, DPSCs were transplanted through two routes, intravenous (IV) or intramuscular (IM), in single or two repeat doses. Two weeks after transplantation, a significant improvement in hyperalgesia, grip-strength, motor coordination and nerve conduction velocity was observed in comparison with controls. A rapid improvement in neuropathic symptoms was observed for a single dose of DPSC IV; however, repeat dose of DPSC IV did not bring about added improvement. A single dose of DPSC IM showed steady improvement, and further recovery continued upon repeat IM administration. DPSC single dose IV showed greater improvement than DPSC single dose IM, but IM transplantation brought about better improvement in body weight. A marked reduction in tumor necrosis factor (TNF) α and C-reactive protein (CRP) levels was observed in the blood plasma for all treated groups, as compared with controls. With respect to inflammatory cytokines, repeat dose of DPSC IM showed further improvement, suggesting that a repeat dose is required to maintain the improved inflammatory state. Gene expression of inflammatory markers in liver confirmed amelioration in inflammation. Arachidonic acid level was unaffected by IV DPSC transplantation but showed noticeable increase through IM administration of a repeat dose. These results suggest that DPSC transplantation through both routes and dosage was beneficial for the retrieval of neuropathic parameters of DN; transplantation via the IM route with repeat dose was the most effective.

Differential Neuronal Plasticity of Dental Pulp Stem Cells From Exfoliated Deciduous and Permanent Teeth Towards Dopaminergic Neurons.

Based on early occurrence in chronological age, stem-cells from human exfoliated deciduous teeth (SHED) has been reported to possess better differentiation-potential toward certain cell-lineage in comparison to stem-cells from adult teeth (DPSCs). Whether this same property between them extends for the yield of functional central nervous system neurons is still not evaluated. Hence, we aim to assess the neuronal plasticity of SHED in comparison to DPSCs toward dopaminergic-neurons and further, if the difference is reflected in a differential expression of sonic-hedgehog (SHH)-receptors and basal-expressions of tyrosine-hydroxylase [TH; through cAMP levels]. Human SHED and DPSCs were exposed to midbrain-cues [SHH, fibroblast growth-factor8, and basic fibroblast growth-factor], and their molecular, immunophenotypical, and functional characterization was performed at different time-points of induction. Though SHED and DPSCs spontaneously expressed early-neuronal and neural-crest marker in their naïve state, only SHED expressed a high basal-expression of TH. The upregulation of dopaminergic transcription-factors Nurr1, Engrailed1, and Pitx3 was more pronounced in DPSCs. The yield of TH-expressing cells decreased from 49.8% to 32.16% in SHED while it increased from 8.09% to 77.47% in DPSCs. Dopamine release and intracellular-Ca(2+) influx upon stimulation (KCl and ATP) was higher in induced DPSCs. Significantly lower-expression of SHH-receptors was noted in naïve SHED than DPSCs, which may explain the differential neuronal plasticity. In addition, unlike DPSCs, SHED showed a down-regulation of cyclic adenosine-monophosphate (cAMP) upon exposure to SHH; possibly another contributor to the lesser differentiation-potential. Our data clearly demonstrates for the first time that DPSCs possess superior neuronal plasticity toward dopaminergic-neurons than SHED; influenced by higher SHH-receptor and lower basal TH expression. J. Cell. Physiol. 231: 2048-2063, 2016. © 2016 Wiley Periodicals, Inc.

Influence of 6-Hydroxydopamine Toxicity on α-Synuclein Phosphorylation, Resting Vesicle Expression, and Vesicular Dopamine Release.

Post mortem studies on familial and sporadic Parkinson's disease patient striatal tissue have shown that nearly 90% of α-synuclein deposited in Lewy-bodies is phosphorylated at serine-129 (pSyn-129) as opposed to only 4% in normal human brain. We aimed to find the influence of endogenous neurotoxin 6-hydroxydopamine (6-OHDA) on α-synuclein phosphorylation, resting vesicles, and vesicular dopamine release. The relative distribution of pSyn-129+ cells in apoptotic and non-apoptotic populations at different 6-OHDA concentrations was assessed along with changes in oxidant-antioxidant system, mitochondrial membrane-potential, and intracellular-Ca2+ . Exposing SH-SY5Y cells to different concentrations of 6-OHDA for 48 h showed cell-death and apoptosis. Immunocytochemical analysis indicated an increase in pSyn-129 with increasing 6-OHDA concentration, and ELISA-estimation showed a significant increase in the pSyn-129 to α-synuclein ratio. FACS analysis also showed a significant increase in pSyn-129; and at sub-lethal 6-OHDA concentrations, pSyn-129+ cells were primarily distributed in the non-apoptotic population, suggesting that phosphorylation of α-synuclein precedes apoptosis. At higher 6-OHDA concentrations, the pSyn-129+ cell count significantly increased in the apoptotic population and decreased in the non-apoptotic population. Cytosolic co-localization of α-synuclein and ubiquitin was noticed at higher doses of 6-OHDA. FACS analysis showed decrease in vesicular monoamine transporter-2 (VMAT2) expression in 6-OHDA-treated cells, confirmed by reduction in functional dopamine-release on KCl and ATP stimulation. Significant decrease in VMAT2 expression and vesicular dopamine-release were observed with the lower 6-OHDA concentration, together with mild occurrence of apoptosis and significant increase in phosphorylated α-synuclein. This suggests that at sub-lethal 6-OHDA concentrations, the decrease in resting vesicles (VMAT2) and vesicular dopamine release are not attributable to apoptotic cell death and occur concomitantly with the phosphorylation of α-synuclein. J. Cell. Biochem. 117: 2719-2736, 2016. © 2016 Wiley Periodicals, Inc.