A unique human blood-derived cell population displays high potential for producing insulin

Revisiting the Pathogenesis of Type 1 Diabetes: Importance of Neural Input to Pancreatic Islets and the Therapeutic Capability of Stem Cell Educator TM Therapy to Restore Their Integrity

Type 1 diabetes (T1D) is an autoimmune disease with a shortage of islet β cells. To date, the etiology of T1D remains elusive. Increasing clinical evidence and animal studies demonstrate that autoimmune cells are directed against the nervous system of pancreatic islets, contributing to the development of T1D. Therefore, it highlights the necessity to explore novel clinical approaches to fundamentally correct the T1D autoimmunity not only focusing on islet β cells but also on protecting the islet nervous system. This allows the restoration of the integrity of islet innervation and the normal islet β-cell function. To address these issues, we developed a novel technology designated the Stem Cell Educator ^TM therapy, based on immune education by human cord-blood-derived multipotent stem cells (CB-SC). International amulticenter clinical trials demonstrated its clinical safety and efficacy to treat T1D and other autoimmune diseases. Stem Cell Educator ^TM therapy may have the potential to revolutionize the treatment of T1D, without the safety and ethical concerns associated with conventional immune and/or stem cell-based therapies.

Higher NADH Dehydrogenase [Ubiquinone] Iron–Sulfur Protein 8 (NDUFS8) Serum Levels Correlate with Better Insulin Sensitivity in Type 1 Diabetes

Objective: The aim of the study was to evaluate NADH dehydrogenase [ubiquinone] iron–sulfur protein 8 (NDUFS8) serum concentration as a marker of Complex I, and the relationship with insulin resistance in type 1 diabetes mellitus (T1DM). Design and methods: Participants were adults with T1DM, recruited over the course of 1 year (2018–2019). NDUFS8 protein serum concentration was measured using the ELISA test. Insulin resistance was evaluated with indirect marker estimated glucose disposal rate (eGDR). The group was divided on the base of median value of eGDR (higher eGDR—better insulin sensitivity). Results: The study group consists of 12 women and 24 men. Medians of eGDR and NDUFS8 protein concentration are 7.6 (5.58–8.99) mg/kg/min and 2.25 (0.72–3.81) ng/mL, respectively. The group with higher insulin sensitivity has higher NDUFS8 protein serum concentration, lower waist to hip ratio (WHR), body mass index (BMI), and they are younger. A negative correlation is observed between NDUFS8 protein serum concentration and WHR (rs = −0.35, p = 0.03), whereas a positive correlation is observed between NDUFS8 protein serum concentration and eGDR (rs = 0.43, p = 0.008). Univariate logistic regression shows a significant association between insulin sensitivity and lower age, as well as a higher NDUFS8 serum level. A multivariate logistic regression model confirms the significance (AOR 2.38 (1.04–5.48). p = 0.042). Multivariate linear regression confirms a significant association between insulin sensitivity and better mitochondrial function (beta = 0.54, p = 0.003), independent of age, duration of diabetes, and smoking. Conclusions: Higher NDUFS8 protein serum concentration is associated with higher insulin sensitivity among adults with T1DM.

Notch-HEY2 signaling pathway contributes to the differentiation of CD34+ hematopoietic-like stem cells from adult peripheral blood insulin-producing cells after the treatment with platelet-derived mitochondria

Previous works characterized a novel cell population from adult human peripheral blood, designated peripheral blood insulin-producing cells (PB-IPC). PB-IPC displayed the pluripotent potential of differentiations after the treatment with platelet-derived mitochondria and gave rise to three germ layer-derived cells such as the mitochondrion-induced CD34⁺ hematopoietic stem cells (HSC)-like cells (miCD34⁺ HSC). To determine the molecular mechanism underlying the differentiation of miCD34⁺ cells, mechanistic studies established that MitoTracker Deep Red-labeled mitochondria could enter into the PB-IPC in a dose-dependent manner. Blocking Notch signaling pathway with a γ-secretase inhibitor, DAPT, markedly inhibited the proliferation of PB-IPC and improved the differentiation of miCD34⁺ HSC. Additionally, treatment with platelet-derived mitochondria can reprogram the differentiation of PB-IPC into miCD34⁺ HSC through inhibition of the Notch/HEY2 signaling pathway, as demonstrated by blocking experiments with HEY2 small interfering RNA (siRNA). The data indicated that Notch signaling pathway contributes to the miCD34⁺ HSC differentiation, thus advancing our understanding of the mitochondrial reprogramming and the potential treatment of human hematopoietic disease.

Advances and complications of regenerative medicine in diabetes therapy

The rapid development of technologies in regenerative medicine indicates clearly that their common application is not a matter of if, but of when. However, the regeneration of beta-cells for diabetes patients remains a complex challenge due to the plurality of related problems. Indeed, the generation of beta-cells masses expressing marker genes is only a first step, with maintaining permanent insulin secretion, their protection from the immune system and avoiding pathological modifications in the genome being the necessary next developments. The prospects of regenerative medicine in diabetes therapy were promoted by the emergence of promising results with embryonic stem cells (ESCs). Their pluripotency and proliferation in an undifferentiated state during culture have ensured the success of ESCs in regenerative medicine. The discovery of induced pluripotent stem cells (iPSCs) derived from the patients’ own mesenchymal cells has provided further hope for diabetes treatment. Nonetheless, the use of stem cells has significant limitations related to the pluripotent stage, such as the risk of development of teratomas. Thus, the direct conversion of mature cells into beta-cells could address this issue. Recent studies have shown the possibility of such transdifferentiation and have set trends for regeneration medicine, directed at minimizing genome modifications and invasive procedures. In this review, we will discuss the published results of beta-cell regeneration and the advantages and disadvantages illustrated by these experiments.

Generation of Hematopoietic-Like Stem Cells from Adult Human Peripheral Blood Following Treatment with Platelet-Derived Mitochondria

Adult stem cells represent a potential source for cellular therapy to treat serious human diseases. We characterized the insulin-producing cells from adult peripheral blood (designated PB-IPC), which displayed a unique phenotype. Mitochondria are normally located in the cellular cytoplasm, where they generate ATP to power the cell’s functions. Ex vivo and in vivo functional studies established that treatment with platelet-derived mitochondria can reprogram the transformation of adult PB-IPC into functional CD34⁺ hematopoietic stem cells (HSC)-like cells, leading to the production of blood cells such as T cells, B cells, monocytes/macrophages, granulocytes, red blood cells, and megakaryocytes (MKs)/platelets. These findings revealed a novel function of mitochondria in directly contributing to cellular reprogramming, thus overcoming the limitations and safety concerns of using conventional technologies to reprogram embryonic stem (ES) and induced pluripotent stem (iPS) cells in regenerative medicine.

Generation of Multipotent Stem Cells from Adult Human Peripheral Blood Following the Treatment with Platelet-Derived Mitochondria

Autologous stem cells are highly preferred for cellular therapy to treat human diseases. Mitochondria are organelles normally located in cytoplasm. Our recent studies demonstrated the differentiation of adult peripheral blood-derived insulin-producing cells (designated PB-IPC) into hematopoietic-like cells after the treatment with platelet-derived mitochondria. To further explore the molecular mechanism and their therapeutic potentials, through confocal and electron microscopy, we found that mitochondria enter cells and directly penetrate the nucleus of PB-IPC after the treatment with platelet-derived mitochondria, where they can produce profound epigenetic changes as demonstrated by RNA-seq and PCR array. Ex vivo functional studies established that mitochondrion-induced PB-IPC (miPB-IPC) can give rise to retinal pigment epithelium (RPE) cells and neuronal cells in the presence of different inducers. Further colony analysis highlighted the multipotent capability of the differentiation of PB-IPC into three-germ layer-derived cells. Therefore, these data indicate a novel function of mitochondria in cellular reprogramming, leading to the generation of autologous multipotent stem cells for clinical applications.

Existence of Circulating Mitochondria in Human and Animal Peripheral Blood

Mitochondria are usually located in the cytoplasm of cells where they generate adenosine triphosphate (ATP) to empower cellular functions. However, we found circulating mitochondria in human and animal blood. Electron microscopy confirmed the presence of mitochondria in adult human blood plasma. Flow cytometry analyses demonstrated that circulating mitochondria from the plasma of human cord blood and adult peripheral blood displayed the immune tolerance-associated membrane molecules such as CD270 and PD-L1 (programmed cell death-ligand 1). Similar data were obtained from fetal bovine serum (FBS) and horse serum of different vendors. Mitochondria remained detectable even after 56 °C heat inactivation. A real-time PCR array revealed purified mitochondria from animal sera expressed several genes that contribute to human T- and B-cell activation. Transwell experiments confirmed the migration capability of mitochondria through their expression of the chemokine receptor CXCR4 in responses to its ligand stromal-derived factor-1α (SDF-1α). Functional analysis established that human plasma mitochondria stimulated the proliferation of anti-CD3/CD28 bead-activated PBMC, up-regulated the percentage of activated CD4⁺ T and CD8⁺ T cells, and reduced the production of inflammatory cytokines. These findings suggested that the existence of circulating mitochondria in blood may function as a novel mediator for cell-cell communications and maintenance of homeostasis. Plasma-related products should be cautiously utilized in cell cultures due to the mitochondrial contamination.

CD45 in human physiology and clinical medicine

CD45 is an evolutionary highly conserved receptor protein tyrosine phosphatase exclusively expressed on all nucleated cells of the hematopoietic system. It is characterized by the expression of several isoforms, specific to a certain cell type and the developmental or activation status of the cell. CD45 is one of the key players in the initiation of T cell receptor signaling by controlling the activation of the Src family protein-tyrosine kinases Lck and Fyn. CD45 deficiency results in T- and B-lymphocyte dysfunction in the form of severe combined immune deficiency. It also plays a significant role in autoimmune diseases and cancer as well as in infectious diseases including fungal infections. The knowledge collected on CD45 biology is rather vast, but it remains unclear whether all findings in rodent immune cells also apply to human CD45. This review focuses on human CD45 expression and function and provides an overview on its ligands and role in human pathology.

CD44 fucosylation on mesenchymal stem cell enhances homing and macrophage polarization in ischemic kidney injury

The lack of homing ability possibly reduces the healing potential of bone-marrow-derived mesenchymal stem cells (MSCs). Therefore, transforming native CD44 on MSCs into a hematopoietic cell E-/L-selectin ligand (HCELL) that possesses potent E-selectin affinity might enhance the homing and regenerative abilities of MSCs. Through fucosyltransferase VI (FTVI) transfection, MSCs were fucosylated on N-glycans of CD44 to become HCELL positive, thus interacting with E-selectin on injured endothelial cells. HCELL expression facilitated MSC homing in kidneys within 24h after injury and reduced lung stasis. An in vitro adhesion assay revealed that transfection enhanced the association between MSCs and hypoxic endothelial cells. In mice treated with HCELL-positive MSCs, the injured kidneys exhibited clusters of homing MSCs, whereas MSCs were rarely observed in mouse kidneys treated with HCELL-negative MSCs. Most MSCs were initially localized at the renal capsule, and some MSCs later migrated inward between tubules. Most homing MSCs were in close contact with inflammatory cells without tubular transdifferentiation. Furthermore, HCELL-positive MSCs substantially alleviated renal injury, partly by enhancing the polarization of infiltrating macrophages. In conclusion, engineering the glycan of CD44 on MSCs through FTVI transfection might enhance renotropism and the regenerating ability of MSCs in ischemic kidney injury.

Genome-wide pathway analysis for diabetic nephropathy in type 1 diabetes

OBJECTIVE

The aim of this study was to identify candidate single-nucleotide polymorphisms (SNPs) that might play a role in susceptibility to diabetic nephropathy (DN) in type 1 diabetes, elucidate their potential mechanisms, and generate SNP-to-gene-to-pathway hypotheses.

METHODS

A genome-wide association study (GWAS) dataset of DN in type 1 diabetes, which included 345,363 SNPs from a total of 1,705 samples (820 DN cases and 885 normoalbuminuric controls) of European ancestry, was used in this study. The Identify Candidate Causal SNPs and Pathways (ICSNPathway) analysis was applied to the GWAS dataset.

RESULTS

ICSNPathway analysis identified 14 candidate SNPs, 10 genes, and 19 pathways, which in turn revealed 10 hypothetical biological mechanisms. The strongest hypothetical biological mechanism was one in which rs4740 altered the role of EBI3 in various pathways and processes, including regulation of the cytokine biosynthetic process, cytokine metabolic process, positive regulation of the cytokine biosynthetic process, regulation of the interferon gamma biosynthetic process, and interferon gamma production (0.008 ≤ p < 0.001; 0.047 ≤ false discovery rate [FDR] ≤ 0.002). This next most strongly supported hypothesis was the modulation of NMUR2 by rs982715, rs4958531, 4958532, rs1895245, and rs4958535 to affect its role in various pathways and processes, including calcium-mediated signaling and peptide receptor activity, and G-protein activity (p < 0.001, 0.002; FDR = 0.005, 0.049, respectively).

CONCLUSIONS

By using the ICSNPathway to analyze the DN GWAS data, we identified 14 candidate SNPs, 10 genes (including EBI3, NMUR2, and EFNA1), and 19 pathways that likely contribute to the susceptibility to DN in type 1 diabetes.

Astrocyte-like cells differentiated from a novel population of CD45-positive cells in adult human peripheral blood

We have previously reported a novel CD45-positive cell population called peripheral blood insulin-producing cells (PB-IPCs) and its unique potential for releasing insulin in vitro. Despite the CD45-positive phenotype and self-renewal ability, PB-IPCs are distinguished from hemopoietic and endothelial progenitor cells (EPCs) by some characteristics, such as a CD34-negative phenotype and different culture conditions. We have further identified the gene profiles of the embryonic and neural stem cells, and these profiles include Sox2, Nanog, c-Myc, Klf4, Notch1 and Mash1. After treatment with all-trans retinoic acid (ATRA) in vitro, most PB-IPCs exhibited morphological changes that included the development of elongated and branched cell processes. In the process of induction, the mRNA expression of Hes1 was robustly upregulated, and a majority of cells acquired some astrocyte-associated specific phenotypes including anti-glial fibrillary acidic protein (GFAP), CD44, Glutamate-aspartate transporter (GLAST) and S100β. In spite of the deficiency of glutamate uptaking, the differentiated cells significantly relaxed the regulation of the expression of brain-derived neurotrophic factor (BDNF) mRNA. This finding demonstrates that PB-IPCs could be induced into a population of astrocyte-like cells and enhanced the neurotrophic potential when the state of proliferation was limited by ATRA, which implies that this unique CD45+ cell pool may have a protective role in some degenerative diseases of the central nervous system (CNS).

Regulation of lipid metabolism-related gene expression in whole blood cells of normo- and dyslipidemic men after fish oil supplementation

Background

Beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on the lipid levels of dyslipidemic subjects are widely described in the literature. However, the underlying molecular mechanisms are largely unknown. The aim of this study was to investigate the effects of n-3 PUFAs on the expression of lipid metabolism-related genes in normo- and dyslipidemic men to unveil potential genes and pathways affecting lipid metabolism.

Methods

Ten normo- and ten dyslipidemic men were supplemented for twelve weeks with six fish oil capsules per day, providing 1.14 g docosahexaenoic acid and 1.56 g eicosapentaenoic acid. The gene expression levels were determined by whole genome microarray analysis and quantitative real-time polymerase chain reaction.

Results

Several transcription factors (peroxisome proliferator-activated receptor α (PPARα), retinoid X receptor (RXR) α, RXRγ, hepatic nuclear factor (HNF) 6, and HNF1ß) as well as other genes related to triacylglycerol (TG) synthesis or high-density lipoprotein (HDL-C) and cholesterol metabolism (phospholipids transfer protein, ATP-binding cassette sub-family G member 5, 2-acylglycerol O-acyltransferase (MOGAT) 3, MOGAT2, diacylglycerol O-acyltransferase 1, sterol O-acyltransferase 1, apolipoprotein CII, and low-density lipoprotein receptor) were regulated after n-3 PUFA supplementation, especially in dyslipidemic men.

Conclusion

Gene expression analyses revealed several possible molecular pathways by which n-3 PUFAs lower the TG level and increase the HDL-C and low-density lipoprotein level, whereupon the regulation of PPARα appear to play a central role.

Trial registration

ClinicalTrials.gov (ID: NCT01089231)

Stem cell educator therapy and induction of immune balance

Type 1 diabetes (T1D) is a T cell-mediated autoimmune disease that causes the deficit of pancreatic islet β cells. A true cure has proven elusive despite intensive research pressure by using conventional approaches over the past 25 years. The situation highlights the challenges we face in conquering this disease. Alternative approaches are needed. Increasing evidence demonstrates that stem cells possess the function of immune modulation. We established the Stem Cell Educator therapy by using cord blood-derived multipotent stem cells (CB-SCs). A closed-loop system that circulates a patient's blood through a blood cell separator, briefly co-cultures the patient's lymphocytes with adherent CB-SCs in vitro, and returns the educated lymphocytes (but not the CB-SCs) to the patient's circulation. Our clinical trial reveals that a single treatment with the Stem Cell Educator provides lasting reversal of autoimmunity that allows regeneration of islet β cells and improvement of metabolic control in subjects with long-standing T1D.

Reversal of type 1 diabetes via islet β cell regeneration following immune modulation by cord blood-derived multipotent stem cells

BACKGROUND

Inability to control autoimmunity is the primary barrier to developing a cure for type 1 diabetes (T1D). Evidence that human cord blood-derived multipotent stem cells (CB-SCs) can control autoimmune responses by altering regulatory T cells (Tregs) and human islet β cell-specific T cell clones offers promise for a new approach to overcome the autoimmunity underlying T1D.

METHODS

We developed a procedure for Stem Cell Educator therapy in which a patient's blood is circulated through a closed-loop system that separates lymphocytes from the whole blood and briefly co-cultures them with adherent CB-SCs before returning them to the patient's circulation. In an open-label, phase1/phase 2 study, patients (n=15) with T1D received one treatment with the Stem Cell Educator. Median age was 29 years (range: 15 to 41), and median diabetic history was 8 years (range: 1 to 21).

RESULTS

Stem Cell Educator therapy was well tolerated in all participants with minimal pain from two venipunctures and no adverse events. Stem Cell Educator therapy can markedly improve C-peptide levels, reduce the median glycated hemoglobin A1C (HbA1C) values, and decrease the median daily dose of insulin in patients with some residual β cell function (n=6) and patients with no residual pancreatic islet β cell function (n=6). Treatment also produced an increase in basal and glucose-stimulated C-peptide levels through 40 weeks. However, participants in the Control Group (n=3) did not exhibit significant change at any follow-up. Individuals who received Stem Cell Educator therapy exhibited increased expression of co-stimulating molecules (specifically, CD28 and ICOS), increases in the number of CD4+CD25+Foxp3+ Tregs, and restoration of Th1/Th2/Th3 cytokine balance.

CONCLUSIONS

Stem Cell Educator therapy is safe, and in individuals with moderate or severe T1D, a single treatment produces lasting improvement in metabolic control. Initial results indicate Stem Cell Educator therapy reverses autoimmunity and promotes regeneration of islet β cells. Successful immune modulation by CB-SCs and the resulting clinical improvement in patient status may have important implications for other autoimmune and inflammation-related diseases without the safety and ethical concerns associated with conventional stem cell-based approaches.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT01350219.

New hope for type 2 diabetics: targeting insulin resistance through the immune modulation of stem cells

The prevalence of type 2 diabetes (T2D) is increasing worldwide, highlighting the need for a better understanding of the pathogenesis of the disease and the development of innovative therapeutic approaches for the prevention and cure of the condition. Mounting evidence points to the involvement of immune dysfunction in insulin resistance in T2D, suggesting that immune modulation may be a useful tool in treating the disease. Recent advances in the use of adult stem cells from human umbilical cord blood and bone marrow for immune modulation hold promise for overcoming immune dysfunction in T2D without many of the complications associated with traditional immunosuppressive therapies. This review focuses on recent progress in the use of immune modulation in T2D and discusses the potential for future therapies. New insights are provided on the use of cord blood-derived multipotent stem cells (CB-SC) in T2D.

Selective destruction of mouse islet beta cells by human T lymphocytes in a newly-established humanized type 1 diabetic model

Type 1 diabetes (T1D) is caused by a T cell-mediated autoimmune response that leads to the loss of insulin-producing beta cells. The optimal preclinical testing of promising therapies would be aided by a humanized immune-mediated T1D model. We develop this model in NOD-scid IL2rgamma(null) mice. The selective destruction of pancreatic islet beta cells was mediated by human T lymphocytes after an initial trigger was supplied by the injection of irradiated spleen mononuclear cells (SMC) from diabetic nonobese diabetic (NOD) mice. This resulted in severe insulitis, a marked loss of total beta-cell mass, and other related phenotypes of T1D. The migration of human T cells to pancreatic islets was controlled by the beta cell-produced highly conserved chemokine stromal cell-derived factor 1 (SDF-1) and its receptor C-X-C chemokine receptor (CXCR) 4, as demonstrated by in vivo blocking experiments using antibody to CXCR4. The specificity of humanized T cell-mediated immune responses against islet beta cells was generated by the local inflammatory microenvironment in pancreatic islets including human CD4(+) T cell infiltration and clonal expansion, and the mouse islet beta-cell-derived CD1d-mediated human iNKT activation. The selective destruction of mouse islet beta cells by a human T cell-mediated immune response in this humanized T1D model can mimic those observed in T1D patients. This model can provide a valuable tool for translational research into T1D.

New type of human blood stem cell: a double-edged sword for the treatment of type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease caused by an autoimmune destruction of pancreatic islet insulin-producing cells. Autoimmunity and shortage of insulin-producing cells are 2 key issues for the treatment of T1D. To cure T1D in a comprehensive manner, both issues need to be addressed simultaneously. Not only must the islet cells be replaced, the patient's immune system also must be dealt with. Regulatory T cells (Tregs) play a crucial role in maintaining homeostasis and self-tolerance through their inhibitory impacts on autoreactive effector T cells. We identified a novel type of stem cells from human umbilical cord blood, designated cord blood stem cells (CB-SC), which may be able to address immune modulation of the autoimmune process and allow for beta-cell replacement. We are the first group using CB-SC to correct functional defects of CD4(+)CD62L(+) Tregs, leading to a reversal of overt diabetes in an autoimmune-caused diabetic NOD mouse model. Notably, treatment with CB-SC-modulated CD4(+)CD62L(+) Tregs (mCD4CD62L Tregs) simultaneously can overcome the autoimmunity via systemic and local immune modulations and the shortage of insulin-producing cells via stimulating the beta-cell regeneration. These new stem cells will offer a promising avenue for the development of powerful autologous therapeutic products for prevention and reversal of T1D.

Stem cells as a potential future treatment of pediatric intestinal disorders

All surgical disciplines encounter planned and unplanned ischemic events that may ultimately lead to cellular dysfunction and death. Stem cell therapy has shown promise for the treatment of a variety of ischemic and inflammatory disorders where tissue damage has occurred. As stem cells have proven beneficial in many disease processes, important opportunities in the future treatment of gastrointestinal disorders may exist. Therefore, this article will serve to review the different types of stem cells that may be applicable to the treatment of gastrointestinal disorders, review the mechanisms suggesting that stem cells may work for these conditions, discuss current practices for harvesting and purifying stem cells, and provide a concise summary of a few of the pediatric intestinal disorders that could be treated with cellular therapy.

Neonatal stem cells exhibit specific characteristics in function, proliferation, and cellular signaling that distinguish them from their adult counterparts

Stem cells may be a novel treatment modality for organ ischemia, possibly through beneficial paracrine mechanisms. Stem cells from older hosts have been shown to exhibit decreased function during stress. We therefore hypothesized that 1) neonatal bone marrow mesenchymal stem cells (nBMSCs) would produce different levels of IL-6, VEGF, and IGF-1 compared with adults (aBMSCs) when stimulated with TNF or LPS; 2) differences in cytokines would be due to distinct cellular characteristics, such as proliferation or pluripotent potential; and 3) differences in cytokines would be associated with differences in p38 MAPK and ERK signaling within nBMSCs. BMSCs were isolated from adult and neonatal mice. Cells were exposed to TNF or LPS with or without p38 or ERK inhibition. Growth factors were measured via ELISA, proliferation via daily cell counts, cell surface markers via flow cytometry, and pluripotent potential via alkaline phosphatase activity. nBMSCs produced lower levels of IL-6 and VEGF, but higher levels of IGF-1 under basal conditions, as well as after stimulation with TNF, but not LPS. Neonatal and adult BMSCs had similar pluripotent potentials and cell surface markers, but nBMSCs proliferated faster. Furthermore, p38 and ERK appeared to play a more substantial role in nBMSC cytokine and growth factor production. Neonatal stem cells may aid in decreasing the local inflammatory response during ischemia, and could possibly be expanded more rapidly than adult cells prior to therapeutic use.

Blood into beta-cells: can adult stem cells be used as a therapy for Type 1 diabetes?

In the past 10 years there have been substantial developments in adult stem cell research, and the transplantation of these cells now holds great promise for regenerative medicine, such as in the treatment of Type 1 diabetes. A large proportion of studies have focused on stem cells sourced from hematopoietic tissues: bone marrow, umbilical cord blood and peripheral blood. Attempts to transdifferentiate these cells into insulin-producing cells, both in vivo and in vitro, have produced conflicting results. Although insulin production and normalization of blood glucose levels have been described in some studies, the true mechanism of stem cell plasticity remains in question - are the functional changes seen due to true transdifferentiation or do they result from cell fusion or other factors? There is evidence that stem cell plasticity is a true phenomenon, but whether it will ever be of therapeutic benefit for Type 1 diabetes remains uncertain.

Stromal cells cultured from omentum express pluripotent markers, produce high amounts of VEGF, and engraft to injured sites

When rat omentum becomes activated by intraperitoneal injection of inert polydextran particles, these particles are rapidly surrounded by cells that express markers of adult stem cells (SDF-1alpha, CXCR4, WT-1) and of embryonic pluripotent cells (Oct-4, Nanog, SSEA-1). We have cultured such cells, because they may offer a convenient source of adult stem cells, and have found that they retain stem cell markers and produce high levels of vascular endothelial growth factor for up to ten passages. After systemic or local injection of these cultured cells into rats with acute injury of various organs, the cells specifically engraft at the injured sites. Thus, our experiments show that omental stromal cells can be cultured from activated omentum, and that these cells exhibit stem cell properties enabling them to be used for repair and possibly for the regeneration of damaged tissues.

Allogeneic islet transplantation

Significant progress has been made in the field of beta-cell replacement therapies by islet transplantation in patients with unstable Type 1 diabetes mellitus (T1DM). Recent clinical trials have shown that islet transplantation can reproducibly lead to insulin independence when adequate islet numbers are implanted. Benefits include improvement of glycemic control, prevention of severe hypoglycemia and amelioration of quality of life. Numerous challenges still limit this therapeutic option from becoming the treatment of choice for T1DM. The limitations are primarily associated with the low islet yield of human pancreas isolations and the need for chronic immunosuppressive therapies. Herein the authors present an overview of the historical progress of islet transplantation and outline the recent advances of the field. Cellular therapies offer the potential for a cure for patients with T1DM. The progress in beta-cell replacement treatment by islet transplantation as well as those of emerging immune interventions for the restoration of self tolerance justify great optimism for years to come.