Stem cell therapy to cure type 1 diabetes: from hype to hope

Stem Cells Reprogramming in Diabetes Mellitus and Diabetic Complications: Recent Advances

BACKGROUND

The incidence of diabetes mellitus (DM) is dramatically increasing worldwide, and it is expected to affect 700 million cases by 2045. Diabetes influences health care economics, human quality of life, morbidity, and mortality, which were primarily seen extensively in developing countries. Uncontrolled DM, which results in consistent hyperglycemia, may lead to severe life-threatening complications such as nephropathy, retinopathy, neuropathy, and cardiovascular complications.

METHODOLOGY

In addition to traditional therapies with insulin and oral anti-diabetics, researchers have developed new approaches for treatment, including stem cell (SC) therapy, which exhibits promising outcomes. Besides its significant role in treating type one DM (T1DM) and type two DM (T2DM), it can also attenuate diabetic complications. Furthermore, the development of insulin- producing cells can be achieved by using the different types of SCs, such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and multiple types of adult stem cells, such as pancreatic, hepatic, and mesenchymal stem cells (MSC). All these types have been extensively studied and proved their ability to develop insulin-producing cells, but every type has limitations.

CONCLUSION

This review aims to enlighten researchers about recent advances in stem cell research and their potential benefits in DM and diabetic complications.

Cell Therapies and Gene Therapy for Diabetes: Current Progress

The epidemic of diabetes continues to be an increasing problem, and there is a need for new therapeutic strategies. There are several promising drugs and molecules in synthetic medicinal chemistry that are developing for diabetes. In addition to this approach, extensive studies with gene and cell therapies are being conducted. Gene therapy is an existing approach in treating several diseases, such as cancer, autoimmune diseases, heart disease and diabetes. Several reports have also suggested that stem cells have the differentiation capability to functional pancreatic beta cell development in vitro and in vivo, with the utility to treat diabetes and prevent the progression of diabetes-related complications. In this current review, we have focused on the different types of cell therapies and vector-based gene therapy in treating or preventing diabetes.

Microfluidic Mechanoporation: Current Progress and Applications in Stem Cells

Intracellular delivery, the process of transporting substances into cells, is crucial for various applications, such as drug delivery, gene therapy, cell imaging, and regenerative medicine. Among the different approaches of intracellular delivery, mechanoporation stands out by utilizing mechanical forces to create temporary pores on cell membranes, enabling the entry of substances into cells. This method is promising due to its minimal contamination and is especially vital for stem cells intended for clinical therapy. In this review, we explore various mechanoporation technologies, including microinjection, micro-nano needle arrays, cell squeezing through physical confinement, and cell squeezing using hydrodynamic forces. Additionally, we highlight recent research efforts utilizing mechanoporation for stem cell studies. Furthermore, we discuss the integration of mechanoporation techniques into microfluidic platforms for high-throughput intracellular delivery with enhanced transfection efficiency. This advancement holds potential in addressing the challenge of low transfection efficiency, benefiting both basic research and clinical applications of stem cells. Ultimately, the combination of microfluidics and mechanoporation presents new opportunities for creating comprehensive systems for stem cell processing.

MSC exosomes attenuate sterile inflammation and necroptosis associated with TAK1-pJNK-NFKB mediated cardiomyopathy in diabetic ApoE KO mice

Introduction

Diabetes is a debilitating disease that leads to complications like cardiac dysfunction and heart failure. In this study, we investigated the pathophysiology of diabetes-induced cardiac dysfunction in mice with dyslipidemia. We hypothesize diabetes in ApoE knockout (ApoE-/-) mice induces cardiac dysfunction by increasing inflammation and necroptosis.

Methods

ApoE-/- mice were divided into experimental groups: Control, Streptozotocin (STZ), STZ + MSC-Exo (mesenchymal stem cell-derived exosomes), and STZ+MEF-Exo (Mouse embryonic fibroblast derived exosomes). At Day 42, we assessed cardiac function, collected blood and heart tissues. Heart tissue samples were analyzed for inflammation, necroptosis, signaling mechanism, hypertrophy and adverse structural remodeling using histology, immunohistochemistry, western blotting, RT-PCR, cytokine array and TF array.

Results and Discussion

STZ treated ApoE-/- mice developed diabetes, with significantly (p<0.05) increased blood glucose and body weight loss. These mice developed cardiac dysfunction with significantly (p<0.05) increased left ventricular internal diameter end diastole and end systole, and decreased ejection fraction, and fractional shortening. We found significant (p<0.05) increased expression of inflammatory cytokines TNF- a, IL-6, IL-1a, IL-33 and decreased IL-10 expression. Diabetic mice also exhibited significantly (p<0.05) increased necroptosis marker expression and infiltration of inflammatory monocytes and macrophages. MSC-Exos treated mice showed recovery of diabetes associated pathologies with significantly reduced blood glucose, recovered body weight, increased IL-10 secretion and M2 polarized macrophages in the heart. These mice showed reduced TAK1-pJNK-NFKB inflammation associated expression and improved cardiac function with significantly reduced cardiac hypertrophy and fibrosis compared to diabetic mice. Treatment with MEF-Exos did not play a significant role in attenuating diabetes-induced cardiomyopathy as these treatment mice presented with cardiac dysfunction and underlying pathologies observed in STZ mice.

Conclusion

Thus, we conclude that cardiac dysfunction develops in diabetic ApoE-/- mice, arising from inflammation, necroptosis, and adverse tissue remodeling, which is ameliorated by MSC-Exos, a potential therapeutic for diabetes-induced cardiomyopathy.

Epigallocatechin-3-gallate maintains Th1/Th2 response balance and mitigates type-1 autoimmune diabetes induced by streptozotocin through promoting the effect of bone-marrow-derived mesenchymal stem cells

Stem-cell-based therapy is one of the most promising therapeutic strategies owing to its regenerative and immunomodulatory properties. Epigallocatechin-3-gallate (EGCG), a known antioxidant and anti-inflammatory agent, has beneficial effects on cellular protection. We aimed to elucidate the feasibility of using EGCG, along with bone marrow-derived mesenchymal stem cells (BM-MSCs), to improve pancreatic damage through their immune regulatory functions in an experimental model of type 1 diabetes mellitus (T1DM) induced by multiple injections of streptozotocin (STZ). BM-MSCs were isolated from C57BL/6 mice and characterized. The diabetic groups were treated intraperitoneally with PBS, MSCs, EGCG, and a combination of MSCs and EGCG. Real-time PCR assays showed that MSCs with EGCG modulated T-bet and GATA-3 expression and upregulated the mRNA levels of Foxp-3 more efficiently. Analyses of spleen-isolated lymphocytes revealed that combinational treatment pronouncedly increased regulatory cytokines and decreased pro-inflammatory cytokines and splenocyte proliferation. The histopathological assessment demonstrated that co-treatment significantly reduced insulitis and recovered pancreatic islet morphology. Furthermore, the combination of MSCs and EGCG is associated with downregulated blood glucose and enhanced insulin levels. Therefore, combined therapy with EGCG and MSCs holds clinical potential for treating T1DM through synergetic effects in maintaining the Th1/Th2 response balance and promoting the regeneration of damaged pancreatic tissues.

Newer therapeutic approaches towards the management of diabetes mellitus: an update

Diabetes mellitus is a chronic metabolic condition characterized by an elevation of blood glucose levels, resulting from defects in insulin secretion, insulin action, or both. The prevalence of the disease has been rapidly rising all over the globe at an alarming rate. Despite advances in the management of diabetes mellitus, it remains a growing epidemic that has become a significant public health burden due to its high healthcare costs and its complications. There is no cure has yet been found for the disease, however, treatment modalities include insulin and antidiabetic agents along with lifestyle modifications are still the mainstay of therapy for diabetes mellitus. The treatment spectrum for the management of diabetes mellitus has rapidly developed in recent years, with new class of therapeutics and expanded indications. This article focused on the emerging therapeutic approaches other than the conventional pharmacological therapies, which include stem cell therapy, gene therapy, siRNA, nanotechnology and theranostics.

Adipose-derived Mesenchymal Stem Cells Therapy as a new Treatment Option for Diabetes Mellitus

The worldwide increase in the prevalence of diabetes mellitus has raised the demand for new therapeutic strategies targeting diabetic symptoms and its chronic complications. Among different treatment options for diabetes, adipose-derived mesenchymal stem cells (ADMSCs) therapy attract the most attention. The therapeutic effects of ADMSCs are based primarily on their paracrine release of immunomodulatory, anti-inflammatory, and trophic factors. Animal models of diabetes as well as human clinical trials have shown that ADMSCs can effectively facilitate endogenous β cell regeneration, preserve residual β cell mass, reduce islet graft rejection, regulate the immune system, and ultimately improve insulin sensitivity or ameliorate insulin resistance in peripheral tissues. Nevertheless, transplantation of mesenchymal stem cells is associated with certain risks; therefore recently much attention has been devoted to ADMSCs derivatives, such as exosomes or conditioned media, as therapeutic agents for the treatment of diabetes. Compared to ADMSCs, cell-free therapy has even better therapeutic potential. This narrative review summarizes recent outcomes and molecular mechanisms of ADMSCs action in the treatment for both type 1 DM and type 2 DM, as well as shows their feasibility, benefits, and current limitations.

Tissue engineering approaches and generation of insulin-producing cells to treat type 1 diabetes

Tissue engineering (TE) has become a new effective solution to a variety of medical problems, including diabetes. Mesenchymal stem cells (MSCs), which have the ability to differentiate into endodermal and mesodermal cells, appear to be appropriate for this function. The purpose of this review was to evaluate the outcomes of various researches on the insulin-producing cells (IPCs) generation from MSCs with TE approaches to increase efficacy of type 1 diabetes treatments. The search was performed in PubMed/Medline, Scopus and Embase databases until 2021. Studies revealed that MSCs could also differentiate into IPCs under certain conditions. Therefore, a wide range of protocols have been used for this differentiation, but their effectiveness is very different. Scaffolds can provide a microenvironment that enhances the MSCs to IPCs differentiation, improves their metabolic activity and up-regulate pancreatic-specific transcription factors. They also preserve IPCs architecture and enhance insulin production as well as protect against cell death. This systematic review offers a framework for prospective research based on data. In vitro and in vivo evidence suggests that scaffold-based TE can improve the viability and function of IPCs.

Co-treatment with grape seed extract and mesenchymal stem cells in vivo regenerated beta cells of islets of Langerhans in pancreas of type I-induced diabetic rats

BACKGROUND

Nowadays, diabetes mellitus is known as a silent killer because individual is not aware that he has the disease till the development of its complications. Many researchers have studied the use of stem cells in treatment of both types of diabetes. Mesenchymal stem cells (MSCs) hold a lot of potential for regenerative therapy. MSCs migrate and home at the damaged site, where they can aid in the repair of damaged tissues and restoring their function. Oxidative stress and inflammation represent a huge obstacle during MSCs transplantation. Therefore, the present study aimed to evaluate the role of grape seed extract (GSE) administration during MSCs transplantation in streptozotocin (STZ)-induced type I diabetes. Furthermore, testing some of GSE components [procyanidins(P)-B1 and P-C1] in conjunction with MSCs, in vivo, was performed to determine if one of them was more effective in relieving the measured attributes of diabetes more than the whole GSE.

METHODS

Firstly, GSE was prepared from the seeds of Muscat of Alexandria grapes and characterized to identify its phytochemical components. Experimental design was composed of control group I, untreated diabetic group II, GSE (300 mg/kg)-treated diabetic group III, MSCs (2 × 106 cells/rat)-treated diabetic group IV and GSE (300 mg/kg)/MSCs (2 × 106 cells/rat)-treated diabetic group V. Type I diabetes was induced in rats by intravenous injection with 65 mg/kg of STZ. Treatment started when fasting blood glucose (FBG) level was more than 200 mg/dl; GSE oral administration started in the same day after MSCs intravenous injection and continued daily for 30 consecutive days.

RESULTS

The results showed that GSE/MSCs therapy in type I-induced diabetic rats has dramatically managed homeostasis of glucose and insulin secretion; together with, improvement in levels of inflammatory markers and oxidative stress.

CONCLUSION

Co-treatment with GSE and MSCs in vivo regenerates beta cells in type I-induced diabetic rats.

Fas Ligand-Modified Scaffolds Protect Stem Cell Derived β-Cells by Modulating Immune Cell Numbers and Polarization

Stem cell derived β-cells have demonstrated the potential to control blood glucose levels and represent a promising treatment for Type 1 diabetes (T1D). Early engraftment post-transplantation and subsequent maturation of these β-cells are hypothesized to be limited by the initial inflammatory response, which impacts the ability to sustain normoglycemia for long periods. We investigated the survival and development of immature hPSC-derived β-cells transplanted on poly(lactide-co-glycolide) (PLG) microporous scaffolds into the peritoneal fat, a site being considered for clinical translation. The scaffolds were modified with biotin for binding of a streptavidin-FasL (SA-FasL) chimeric protein to modulate the local immune cell responses. The presence of FasL impacted infiltration of monocytes and neutrophils and altered the immune cell polarization. Conditioned media generated from SA-FasL scaffolds explanted at day 4 post-transplant did not impact hPSC-derived β-cell survival and maturation in vitro, while these responses were reduced with conditioned media from control scaffolds. Following transplantation, β-cell viability and differentiation were improved with SA-FasL modification. A sustained increase in insulin positive cell ratio was observed with SA-FasL-modified scaffolds relative to control scaffolds. These results highlight that the initial immune response can significantly impact β-cell engraftment, and modulation of cell infiltration and polarization may be a consideration for supporting long-term function at an extrahepatic site.

Insulitis in Human Type 1 Diabetic Pancreas: From Stem Cell Grafting to Islet Organoids for a Successful Cell-Based Therapy

Type 1 diabetes (T1D) is an autoimmune disease with immune cells' islet infiltration (called "insulitis"), which leads to beta cell loss. Despite being the critical element of T1D occurrence and pathogenesis, insulitis is often present in a limited percentage of islets, also at diagnosis. Therefore, it is needed to define reproducible methods to detect insulitis and beta-cell decline, to allow accurate and early diagnosis and to monitor therapy. However, this goal is still far due to the morphological aspect of islet microvasculature, which is rather dense and rich, and is considerably rearranged during insulitis. More studies on microvasculature are required to understand if contrast-enhanced ultrasound sonography measurements of pancreatic blood-flow dynamics may provide a clinically deployable predictive marker to predict disease progression and therapeutic reversal in pre-symptomatic T1D patients. Therefore, it is needed to clarify the relation between insulitis and the dynamics of β cell loss and with coexisting mechanisms of dysfunction, according to clinical stage, as well as the micro vessels' dynamics and microvasculature reorganization. Moreover, the ideal cell-based therapy of T1D should start from an early diagnosis allowing a sufficient isolation of specific Procr+ progenitors, followed by the generation and expansion of islet organoids, which could be transplanted coupled to an immune-regulatory therapy which will permit the maintenance of pancreatic islets and an effective and long-lasting insulitis reversal.

The Therapeutic Potential of Mesenchymal Stem Cells in the Treatment of Diabetes Mellitus

Mesenchymal stem cells (MSCs) exist in many tissues and can differentiate into cells of multiple lineages, such as adipocytes, osteoblasts, or chondrocytes. MSC administration has demonstrated therapeutic potential in various degenerative and inflammatory diseases (e.g., graft-vs.-host disease, multiple sclerosis, Crohn's disease, organ fibrosis, and diabetes mellitus [DM]). The mechanisms involved in the therapeutic effects of MSCs are multifaceted. Generally, implanted MSCs can migrate to sites of injury, where they establish an anti-inflammatory and regenerative microenvironment in damaged tissues. In addition, MSCs can modulate innate and adaptive immune responses through immunosuppressive mechanisms that involve immune cells, inflammatory cytokines, chemokines, and immunomodulatory factors. DM has a high prevalence worldwide; it also contributes to a high rate of mortality worldwide. MSCs offer a promising therapeutic agent to prevent or repair damage from DM and diabetic complications through properties such as multilineage differentiation, homing, promotion of angiogenesis, and immunomodulation (e.g., prevention of oxidative stress, fibrosis, and cell death). In this study, we review current findings regarding the immunomodulatory and regenerative mechanisms of MSCs, as well as their therapeutic applications in DM and DM-related complications.

Challenges with Cell-based Therapies for Type 1 Diabetes Mellitus

Type 1 diabetes (T1D) is a chronic, lifelong metabolic disease. It is characterised by the autoimmune-mediated loss of insulin-producing pancreatic β cells in the islets of Langerhans (β-islets), resulting in disrupted glucose homeostasis. Administration of exogenous insulin is the most common management method for T1D, but this requires lifelong reliance on insulin injections and invasive blood glucose monitoring. Replacement therapies with beta cells are being developed as an advanced curative treatment for T1D. Unfortunately, this approach is limited by the lack of donated pancreatic tissue, the difficulties in beta cell isolation and viability maintenance, the longevity of the transplanted cells in vivo, and consequently high costs. Emerging approaches to address these limitations are under intensive investigations, including the production of insulin-producing beta cells from various stem cells, and the development of bioengineered devices including nanotechnologies for improving islet transplantation efficacy without the need for recipients taking toxic anti-rejection drugs. These emerging approaches present promising prospects, while the challenges with the new techniques need to be tackled for ultimately clinical treatment of T1D. This review discussed the benefits and limitations of the cell-based therapies for beta cell replacement as potential curative treatment for T1D, and the applications of bioengineered devices including nanotechnology to overcome the challenges associated with beta cell transplantation.

Nanobiotechnology-Modified Cellular and Molecular Therapy as a Novel Approach for Autoimmune Diabetes Management

Several cellular and molecular therapies such as stem cell therapy, cell replacement therapy, gene modification therapy, and tolerance induction therapy have been researched to procure a permanent cure for Type 1 Diabetes. However, due to the induction of undesirable side effects, their clinical utility is questionable. These anti-diabetic therapies can be modified with nanotechnological tools for reducing adverse effects by selectively targeting genes and/or receptors involved directly or indirectly in diabetes pathogenesis, such as the glucagon-like peptide 1 receptor, epidermal growth factor receptor, human leukocyte antigen (HLA) gene, miRNA gene and hepatocyte growth factor (HGF) gene. This paper will review the utilities of nanotechnology in stem cell therapy, cell replacement therapy, beta-cell proliferation strategies, immune tolerance induction strategies, and gene therapy for type 1 diabetes management.

AMFR and DCTN2 genes cause transplantation resistance of adipose-derived mesenchymal stem cells in type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is characterized by pancreatic beta cell destruction by autoantibodies and other factors, resulting in insulin secretion deficiency. Therefore, beta cell regeneration would be necessary to cure the disease. Nevertheless, the impact of type 1 diabetes on the stemness and transplantation efficiency of stem cells has not been previously described. In this study, we used next-generation sequencing to identify genes differentially expressed in T1DM adipose-derived stem cells (T1DM ADSCs) that originate from patients with type 1 diabetes. Furthermore, we evaluated their effects on transplantation efficiency following xenotransplantation into immunodeficient mice. In the T1DM ADSCs transplant group, the volume and weight of the graft were significantly reduced and the transplant efficiency was reduced. Next-generation sequencing and quantitative PCR results showed that T1DM ADSCs had significantly increased expression of AMFR and DCTN2. AMFR and DCTN2 gene knockdown in T1DM ADSC significantly restored cell proliferation and stem cell marker expression. Therefore, transplantation of T1DM ADSCs, in which AMFR and DCTN2 were knocked down, into immunodeficient mice improved transplant efficiency. This study revealed that AMFR and DCTN2 can reduce transplantation efficiency of T1DM ADSCs. Focusing on AMFR and DCTN2 is expected to increase the efficiency of stem cell transplantation therapy for diabetic patients.

Xeno-free protocol for GMP-compliant manufacturing of human fetal pancreas-derived mesenchymal stem cells

BACKGROUND

Mesenchymal stem cells (MSCs) have been suggested as an appropriate source for diabetes cell-based therapies. The high proliferation and differentiation capacity of fetal MSCs and the role of fetal pancreatic-derived MSCs (FPMSCs) in islet generation make them good candidates for diabetes treatment. To manufacture clinical-grade MSCs, animal-free culture protocols are preferred. The current study aimed to establish a xeno-free/GMP-compliant protocol for FPMSCs manufacturing. The focus was on the effects of fetal bovine serum (FBS) replacement with pooled human serum (HS).

MATERIAL AND METHODS

FPMSCs were isolated and expanded from the pancreas of legally aborted fetuses with few modifications in our previously established protocol. The cells were expanded in two different culture media, including DMEM supplemented with 10% FBS or 10% pooled HS. A side-by-side comparison was made to evaluate the effect of each serum on proliferation rate, cell cycle, senescence, multi-lineage differentiation capacity, immunophenotype, and tumorigenesis of FPMSCs.

RESULTS

Flow cytometry analysis and three-lineage differentiation ability demonstrated that fibroblast-like cells obtained from primary culture had MSCs' characteristics. The FPMSCs displayed similar morphology and CD markers expression in both sera. HS had a higher proliferative effect on FPMSCs than FBS. In FBS, the cells reached senescence earlier. In addition to normal karyotypes and anchorage-dependent growth, in vivo tumor formation was not seen.

CONCLUSION

Our results demonstrated that HS was a better serum alternative than FBS for in vitro expansion of FPMSCs. Compared with FBS, HS increased FPMSCs' proliferation rate and decreased their senescence. In conclusion, HS can effectively replace FBS for clinical-grade FPMSCs manufacturing.

Nanotechnology in Immunotherapy for Type 1 Diabetes: Promising Innovations and Future Advances

Diabetes is a chronic condition which affects the glucose metabolism in the body. In lieu of any clinical "cure," the condition is managed through the administration of pharmacological aids, insulin supplements, diet restrictions, exercise, and the like. The conventional clinical prescriptions are limited by their life-long dependency and diminished potency, which in turn hinder the patient's recovery. This necessitated an alteration in approach and has instigated several investigations into other strategies. As Type 1 diabetes (T1D) is known to be an autoimmune disorder, targeting the immune system in activation and/or suppression has shown promise in reducing beta cell loss and improving insulin levels in response to hyperglycemia. Another strategy currently being explored is the use of nanoparticles in the delivery of immunomodulators, insulin, or engineered vaccines to endogenous immune cells. Nanoparticle-assisted targeting of immune cells holds substantial potential for enhanced patient care within T1D clinical settings. Herein, we summarize the knowledge of etiology, clinical scenarios, and the current state of nanoparticle-based immunotherapeutic approaches for Type 1 diabetes. We also discuss the feasibility of translating this approach to clinical practice.

Critical Considerations in Bioluminescence Imaging of Transplanted Islets: Dynamic Signal Change in Early Posttransplant Phase and Signal Absorption by Tissues

OBJECTIVES

In pancreatic islet transplantation studies, bioluminescence imaging enables quantitative and noninvasive tracking of graft survival. Amid the recent heightened interest in extrahepatic sites for islet and stem cell-derived beta-like cell transplantations, proper understanding the nature of bioluminescence imaging in these sites is important.

METHODS

Islets isolated from Firefly rats ubiquitously expressing luciferase reporter gene in Lewis rats were transplanted into subcutaneous or kidney capsule sites of wild-type Lewis rats or immunodeficient mice. Posttransplant changes of bioluminescence signal curves and absorption of bioluminescence signal in transplantation sites were examined.

RESULTS

The bioluminescence signal curve dynamically changed in the early posttransplantation phase; the signal was low within the first 5 days after transplantation. A substantial amount of bioluminescence signal was absorbed by tissues surrounding islet grafts, correlating to the depth of the transplanted site from the skin surface. Grafts in kidney capsules were harder to image than those in the subcutaneous site. Within the kidney capsule, locations that minimized depth from the skin surface improved the graft detectability.

CONCLUSIONS

Posttransplant phase and graft location/depth critically impact the bioluminescence images captured in islet transplantation studies. Understanding these parameters is critical for reducing experimental biases and proper interpretation of data.

Gymnemic Acid Ameliorates Pancreatic β-Cell Dysfunction by Modulating Pdx1 Expression: A Possible Strategy for β-Cell Regeneration

BACKGROUND

Endogenous pancreatic β-cell regeneration is a promising therapeutic approach for enhancing β-cell function and neogenesis in diabetes. Various findings have reported that regeneration might occur via stimulating β-cell proliferation, neogenesis, or conversion from other pancreatic cells to β-like cells. Although the current scenario illustrates numerous therapeutic strategies and approaches that concern endogenous β-cell regeneration, all of them have not been successful to a greater extent because of cost effectiveness, availability of suitable donors and rejection in case of transplantation, or lack of scientific evidence for many phytochemicals derived from plants that have been employed in traditional medicine. Therefore, the present study aims to investigate the effect of gymnemic acid (GA) on β-cell regeneration in streptozotocin-induced type 1 diabetic rats and high glucose exposed RIN5-F cells.

METHODS

The study involves histopathological and immunohistochemical analysis to examine the islet's architecture. Quantitative polymerase chain reaction (qPCR) and/or immunoblot were employed to quantify the β-cell regeneration markers and cell cycle proliferative markers.

RESULTS

The immunoexpression of E-cadherin, β-catenin, and phosphoinositide 3-kinases/protein kinase B were significantly increased in GA-treated diabetic rats. On the other hand, treatment with GA upregulated the pancreatic regenerative transcription factor viz. pancreatic duodenal homeobox 1, Neurogenin 3, MafA, NeuroD1, and β-cells proliferative markers such as CDK4, and Cyclin D1, with a simultaneous downregulation of the forkhead box O, glycogen synthase kinase-3, and p21^cip1 in diabetic treated rats. Adding to this, we noticed increased nuclear localization of Pdx1 in GA treated high glucose exposed RIN5-F cells.

CONCLUSION

Our results suggested that GA acts as a potential therapeutic candidate for endogenous β-cell regeneration in treating type 1 diabetes.

Integrated stem cells from apical papilla in a 3D culture system improve human embryonic stem cell derived retinal organoid formation

AIM

Eye organoids are 3D models of the retina that provide new possibilities for studying retinal development, drug toxicity and the molecular mechanisms of diseases. Although there are several protocols that can be used to generate functional tissues, none have been used to assemble human retinal organoids containing mesenchymal stem cells (MSCs).

MAIN METHODS

In this study we intend to assess the effective interactions of MSCs and human embryonic stem cells (hESCs) during retinal organoid formation. We evaluated the inducing activities of bone marrow MSCs (BM-MSCs), trabecular meshwork (TM), and stem cells from apical papilla (SCAP)-derived MSCs in differentiation of hESCs in a three-dimensional (3D) direct co-culture system.

KEY FINDINGS

In comparison with the two other MSC sources, the induction potential of SCAP was confirmed in the co-culture system. Although the different SCAP cell ratios did not show any significant morphology changes during the first seven days, increasing the number of SCAPs improved formation of the optic vesicle (OV) structure, which was confirmed by assessment of specific markers. The OVs subsequently developed to an optic cup (OC), which was similar to the in vivo environment. These arrangements expressed MITF in the outer layer and CHX10 in the inner layer.

SIGNIFICANCE

We assessed the inducing activity of SCAP during differentiation of hESCs towards a retinal fate in a 3D organoid system. However, future studies be conducted to gather additional details about the development of the eye field, retinal differentiation, and the molecular mechanisms of diseases.

New hope for intervertebral disc degeneration: bone marrow mesenchymal stem cells and exosomes derived from bone marrow mesenchymal stem cell transplantation

Bone marrow mesenchymal stem cells (BMSCs), multidirectional cells with self-renewal capacity, can differentiate into many cell types and play essential roles in tissue healing and regenerative medicine. Cell experiments and in vivo research in animal models have shown that BMSCs can repair degenerative discs by promoting cell proliferation and expressing extracellular matrix (ECM) components, such as type II collagen and protein-polysaccharides. Delaying or reversing the intervertebral disc (IVD) degeneration (IDD) process at an etiological level may be an effective strategy. However, despite increasingly in-depth research, some deficiencies in cell transplantation timing and strategy remain, preventing the clinical application of cell transplantation. Exosomes exhibit the characteristics of the mother cells from which they were secreted and can inhibit nucleus pulposus (NP) cell (NPC) apoptosis and delay IDD through intercellular communication. Furthermore, the use of exosomes effectively avoids problems associated with cell transplantation, such as immune rejection. This manuscript introduces almost all of the BMSCs and exosomes derived from BMSCs (BMSCs-Exos) described in the IDD literature. Many challenges regarding the use of cell transplantation and therapeutic exosome intervention for IDD remain to be overcome.

Exosome Degeneration in Mesenchymal Stem Cells Derived from Patients with Type 1 Diabetes Mellitus

Type 1 diabetes mellitus is characterized by the destruction of pancreatic β-cells and requires the regeneration of these destroyed pancreatic β-cells for radical treatment. The degeneration of organelles in stem cells compromises stem cell quality; however, organelles in the mesenchymal stem cells of patients with type 1 diabetes mellitus have not been characterized previously. In this study, we use transmission electron microscopy to evaluate the degeneration of organelles in adipose-derived stem cells of patients with type 1 diabetes mellitus (T1DM ADSCs). Compared to adipose-derived stem cells from healthy humans, T1DM ADSCs degenerate differently, characterized by prominent enlarged spherical vesicles. The exosomes of T1DM ADSCs are found to be enlarged, reduced in number, and increased in the percentage of those positive for tetraspanin CD9. The findings of this study provide insight into the characteristics of stem cells in patients with type 1 diabetes mellitus.

The Synergistic Beneficial Effect of Thyme Honey and Olive Oil against Diabetes and Its Complications Induced by Alloxan in Wistar Rats

Diabetes is a metabolic disorder characterized by a chronic increase in blood glucose. Owing to the limitations observed with antidiabetics in modern medicine, medicinal plants and bee products are known as good matrices for the search for new antidiabetic molecules. The present study focused on the evaluation of the hypoglycemic and the protective properties of two natural products widely used in complementary and alternative medicine (thyme honey and olive oil). To achieve this, the study was carried out on Wistar rats rendered diabetic by the injection of a single dose of alloxan monohydrate (65 mg/kg body weight (BW)). First, the physicochemical characterization and the phytochemical analysis of thyme honey and olive oil were carried out, and then in vivo study was conducted on 42 Wistar rats divided into seven groups: three groups were normal, one group was untreated diabetic, and three groups were diabetic rats treated with thyme honey (2 g/kg BW) or olive oil (10 mL/kg BW) or their combination ((1 g/kg BW of thyme honey) and (5 mL/kg BW of olive oil)). During the experiment, the glycemia was measured regularly every 10 days. After 30 days of treatment, the rats were sacrificed. The serum and urine were analyzed to determine hepatic enzymes levels (AST, ALT, ALP, and LDH), lipidic profile (total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein), and kidney parameters (urea, uric acid, creatinine, total protein, sodium, potassium, and chloride). The liver, pancreas, and kidneys were analyzed to evaluate their histological changes and to determine their enzymatic antioxidant content (catalase, GSH, and GPx) and the levels of MDA. The results obtained showed that thyme honey or olive oil, and especially their combination, improved significantly the blood glucose levels and they protect against metabolic changes and the complications induced by diabetes.

Regenerative Medicine in South Korea: Bridging the Gap Between Authorization and Reimbursement

Regenerative medicine (RM) has considerable potential to address the needs of aging-related and uncurable diseases. However, its incorporation into reimbursement of health insurance benefits poses many challenges, including uncertain evidence and insufficient investment. This paper examines the wide gap between manufacturers, regulatory bodies, and health technology bodies regarding reimbursements for RMs focused cell therapy products. In this mixed-methods study, we first analyzed the sales of RMs approved in South Korea. In addition to exploring beliefs related to the market value of RMs, in-depth interviews were conducted with 24 experts (17 from bio-industries, two from the regulatory body, three from a health technology assessment (HTA) body, and two from the Pharmaceutical Benefit Coverage Assessment Committee [PBCAC]). Lastly, we surveyed PBCAC members about the market value of RMs. In total, 15 of the 20 developed cell therapy products are on the market in South Korea, and amounted to 0.24% of total pharmaceutical expenditures in 2018. We identified a wide gap between stakeholders and regulators regarding the market value and pricing of RMs. The interviewees from the pharmaceutical manufacturer association raised the issue of rising manufacturing costs and proposed a specific pricing policy for RMs. To bridge the gap between approval and reimbursement, stakeholders demand an alternative framework of value-based pricing. Conditional health insurance reimbursement may be an alternative to the traditional process in order to generate evidence of the effects of RMs using “risk-based” or “outcome-based” approaches.

Adipose tissue-derived stromal/stem cells + cholecalciferol: a pilot study in recent-onset type 1 diabetes patients

Objective

Adipose tissue-derived stromal/stem cells (ASCs) and vitamin D have immunomodulatory actions that could be useful for type 1 diabetes (T1D). We aimed in this study to investigate the safety and efficacy of ASCs + daily cholecalciferol (VIT D) for 6 months in patients with recent-onset T1D.

Methods

In this prospective, dual-center, open trial, patients with recent onset T1D received one dose of allogenic ASC (1 × 10⁶ cells/kg) and cholecalciferol 2,000 UI/day for 6 months (group 1). They were compared to patients who received chol-ecalciferol (group 2) and standard treatment (group 3). Adverse events were recorded; C-peptide (CP), insulin dose and HbA1c were measured at baseline (T0), after 3 (T3) and 6 months (T6).

Results

In group 1 (n = 7), adverse events included transient headache (all), mild local reactions (all), tachycardia (n = 4), abdominal cramps (n = 1), thrombophlebitis (n = 4), scotomas (n = 2), and central retinal vein occlusion at T3 (n = 1, resolution at T6). Group 1 had an increase in basal CP (p = 0.018; mean: 40.41+/-40.79 %), without changes in stimulated CP after mixed meal (p = 0.62), from T0 to T6. Basal CP remained stable in groups 2 and 3 (p = 0.58 and p = 0.116, respectively). Group 1 had small insulin requirements (0.31+/- 0.26 UI/kg) without changes at T6 (p = 0.44) and HbA1c decline (p = 0.01). At T6, all patients (100%; n = 7) in group 1 were in honeymoon vs 75% (n = 3/4) and 50% (n = 3/6) in groups 2 and 3, p = 0.01.

Conclusion

Allogenic ASC + VIT D without immunosuppression was safe and might have a role in the preservation of β-cells in patients with recent-onset T1D. ClinicalTrials.gov: NCT03920397.

A signature of 24 aging‑related gene pairs predict overall survival in gastric cancer

BACKGROUND

Aging is the major risk factor for most human cancers. We aim to develop and validate a reliable aging-related gene pair signature (ARGPs) to predict the prognosis of gastric cancer (GC) patients.

METHODS

The mRNA expression data and clinical information were obtained from two public databases, The Cancer Genome Atlas (TCGA) dataset, and Gene Expression Omnibus (GEO) dataset, respectively. The best prognostic signature was established using Cox regression analysis (univariate and least absolute shrinkage and selection operator). The optimal cut-off value to distinguish between high- and low-risk patients was found by time-dependent receiver operating characteristic (ROC). The prognostic ability of the ARGPS was evaluated by a log-rank test and a Cox proportional hazards regression model.

RESULTS

The 24 ARGPs were constructed for GC prognosis. Using the optimal cut-off value - 0.270, all patients were stratified into high risk and low risk. In both TCGA and GEO cohorts, the results of Kaplan-Meier analysis showed that the high-risk group has a poor prognosis (P < 0.001, P = 0.002, respectively). Then, we conducted a subgroup analysis of age, gender, grade and stage, and reached the same conclusion. After adjusting for a variety of clinical and pathological factors, the results of multivariate COX regression analysis showed that the ARGPs is still an independent prognostic factor of OS (HR, 4.919; 95% CI 3.345-7.235; P < 0.001). In comparing with previous signature, the novel signature was superior, with an area under the receiver operating characteristic curve (AUC) value of 0.845 vs. 0.684 vs. 0.695. The results of immune infiltration analysis showed that the abundance of T cells follicular helper was significantly higher in the low-risk group, while the abundance of monocytes was the opposite. Finally, we identified and incorporated independent prognostic factors and developed a superior nomogram to predict the prognosis of GC patients.

CONCLUSION

Our study has developed a robust prognostic signature that can accurately predict the prognostic outcome of GC patients.

Early-Phase Luciferase Signals of Islet Grafts Predicts Successful Subcutaneous Site Transplantation in Rats

PURPOSE

The transplantation of pancreatic islets is a promising cell replacement therapy for type 1 diabetes. Subcutaneous islet transplantation is currently under investigation as a means to circumvent problems associated with standard intra-hepatic islet transplantation. As modifications are being developed to improve the efficacy of subcutaneous islet transplantation, it is important to have robust methods to assess engraftment. Experimentally, ATP-dependent bioluminescence imaging using luciferase reporter genes has been effective for non-invasively tracking engraftment. However, it was heretofore unknown if the bioluminescence of subcutaneously transplanted luciferase-expressing islet grafts correlates with diabetes reversal, a primary outcome of transplantation.

PROCEDURES

A retrospective analysis was conducted using data obtained from subcutaneous islet transplantations in Lewis rats. The analysis included transplantations from our laboratory in which islet donors were transgenic rats ubiquitously expressing luciferase and recipients were wild type, streptozotocin-induced diabetic rats. Data from 79 bioluminescence scans were obtained from 27 islet transplantations during the post-transplant observation period (up to 6 weeks). The bioluminescence intensity of the subcutaneously transplanted grafts, captured after the intravenous administration of luciferin, was correlated with diabetes reversal.

RESULTS

After subcutaneous transplantation, islet bioluminescence decreased over time, dropping > 50 % from 1 to 3 weeks post-transplant. Bioluminescence intensity in the early post-transplant phase (1-2 weeks) correlated with the subsequent reversal of diabetes; based on optimized bioluminescence cutoff values, the bioluminescence intensity of islets at 1 and 2 weeks predicted successful transplantations. However, intensity in the late post-transplant phase (≥ 4 weeks) did not reflect transplantation outcomes.

CONCLUSIONS

Early-phase bioluminescence imaging of luciferase-expressing islets could serve as a useful tool to predict the success of subcutaneous islet transplantations by preceding changes in glucose homeostasis.

Therapeutic potential of mesenchymal stem cells in treating both types of diabetes mellitus and associated diseases

Diabetes mellitus is a common lifestyle disease which can be classified into type 1 diabetes mellitus and type 2 diabetes mellitus. While both result in hyperglycemia due to lack of insulin action and further associated chronic ailments, there is a marked distinction in the cause for each type due to which both require a different prophylaxis. As observed, type 1 diabetes is caused due to the autoimmune action of the body resulting in the destruction of pancreatic islet cells. On the other hand, type 2 diabetes is caused either due to insulin resistance of target cells or lack of insulin production as per physiological requirements. Attempts to cure the disease have been made by bringing drastic changes in the patients' lifestyle; parenteral administration of insulin; prescription of drugs such as biguanides, meglitinides, and amylin; pancreatic transplantation; and immunotherapy. While these attempts cause a certain degree of relief to the patient, none of these can cure diabetes mellitus. However, a new treatment strategy led by the discovery of mesenchymal stem cells and their unique immunomodulatory and multipotent properties has inspired therapies to treat diabetes by essentially reversing the conditions causing the disease. The current review aims to enumerate the role of various mesenchymal stem cells and the different approaches to treat both types of diabetes and its associated diseases as well.

Generation of Insulin-Producing Cells from Canine Adipose Tissue-Derived Mesenchymal Stem Cells

The potential of mesenchymal stem cells (MSCs) to differentiate into nonmesodermal cells such as pancreatic beta cells has been reported. New cell-based therapy using MSCs for diabetes mellitus is anticipated as an alternative treatment option to insulin injection or islet transplantation in both human and veterinary medicine. Several protocols were reported for differentiation of MSCs into insulin-producing cells (IPCs), but no studies have reported IPCs generated from canine MSCs. The purpose of this study was to generate IPCs from canine adipose tissue-derived MSCs (AT-MSCs) in vitro and to investigate the effects of IPC transplantation on diabetic mice in vivo. Culturing AT-MSCs with the differentiation protocol under a two-dimensional culture system did not produce IPCs. However, spheroid-like small clusters consisting of canine AT-MSCs and human recombinant peptide μ-pieces developed under a three-dimensional (3D) culture system were successfully differentiated into IPCs. The generated IPCs under 3D culture condition were stained with dithizone and anti-insulin antibody. Canine IPCs also showed gene expression typical for pancreatic beta cells and increased insulin secretion in response to glucose stimulation. The blood glucose levels in streptozotocin-induced diabetic mice were decreased after injection with the supernatant of canine IPCs, but the hyperglycemic states of diabetic mice were not improved after transplanting IPCs subcutaneously or intramesenterically. The histological examination showed that the transplanted small clusters of IPCs were successfully engrafted to the mice and included cells positive for insulin by immunofluorescence. Several factors, such as the transplanted cell number, the origin of AT-MSCs, and the differentiation protocol, were considered potential reasons for the inability to improve the hyperglycemic state after IPC transplantation. These findings suggest that canine AT-MSCs can be differentiated into IPCs under a 3D culture system and IPC transplantation may be a new treatment option for dogs with diabetes mellitus.

Intermittent normobaric oxygen inhalation enhances subcutaneous prevascularization for cell transplantation

PURPOSE

Subcutaneous tissue is a promising site for cell transplantation; advantages include minimally invasive procedures and easy post-transplant monitoring. However, limited vascularity is the major known challenge. To address this challenge, a prevascularized graft bed is prepared in recipients. We aimed to establish an improved, clinically applicable approach to promote prevascularization of the subcutaneous graft bed prior to cell transplantation.

METHODS

We applied a conventional prevascularization approach by subcutaneously implanting nylon discs into the backs of Lewis rats. After disc implantation, we treated rats with or without intermittent normobaric 100% oxygen inhalation (1 h, twice a day, for consecutive 7 days). We used histology to compare vascular density between the oxygen-treated or control groups. To assess the functional effects of prevascularization, we transplanted three hundred islets isolated from luciferase-transgenic Lewis rats into the oxygen-treated or control wild type Lewis recipients, then used bioluminescence imaging to track engraftment for 4 weeks.

RESULTS

Oxygen treatment significantly augmented prevascularization in the subcutaneous site compared to controls. Islet transplantation into prevascularized graft beds demonstrated significant improvement in engraftment efficiency in oxygen-treated recipients compared to controls at 2-4 weeks post-transplantation.

CONCLUSION

Combining intermittent normobaric 100% oxygen inhalation with a conventional vascularization approach promotes a functional vasculature within a week. A simple approach using normobaric oxygen has the potential for translation into clinical application in subcutaneous site cell transplantations.

Efficacy and safety of stem cells transplantation in patients with type 1 diabetes mellitus-a systematic review and meta-analysis

Stem cells (SCs) therapy is a new promising therapeutic modality for type 1 diabetes (T1DM). We performed a systematic review and meta-analysis to evaluate the efficacy and safety of stem cells transplantation (SCT) in patients with T1DM. We searched five literature databases (MEDLINE, EMBASE, Web of Science, WanFang and CENTRAL) up to 31 October 2019. 29 studies (487 patients with T1DM) were included in our meta-analysis. There was no substantial publication bias. Meta-analysis showed the SCT had significant effect to decrease HbA1c (SMD, 1.40; 95% CI, 0.93 to 1.86; p < 0.00001; I² = 89%) and to improve C-peptide levels (SMD, -0.62; 95% CI, -1.22 to -0.02; p = 0.04; I² = 92%) at 1 year follow-up. Subgroup analyses showed the heterogeneity level of the results was high. Significant improvement of metabolic outcomes was observed in the subgroups of mesenchymal stem cells (MSCs) combined with hematopoietic stem cells (HSCs) and HSCs. The older age showed significant association with the efficacy in HSCs subgroup. The higher GADA positive rate before treatment also significantly associated with the decrease of daily insulin requirement. The transient insulin independence rate at last follow-up was 9.6 per 100 person-years (95% CI: 5.8-13.5%). The mean length of insulin independence was 15.6 months (95% CI: 12.3-18.9). The mortality of SCT was 3.4% (95% CI: 2.1-5.5%). Therefore, SCT is an efficacious and safe method for treating patients with T1DM especially in the subgroups of MSCs + HSCs and HSCs. Well designed, double blind and randomized controlled trails with large sample size and long-term follow-up are needed for further evaluation.

The SIRT6 activator MDL-800 improves genomic stability and pluripotency of old murine-derived iPS cells

Cellular reprogramming is an emerging strategy for delaying the aging processes. However, a number of challenges, including the impaired genome integrity and decreased pluripotency of induced pluripotent stem cells (iPSCs) derived from old donors, may hinder their potential clinical applications. The longevity gene, Sirtuin 6 (SIRT6), functions in multiple biological processes such as the maintenance of genome integrity and the regulation of somatic cell reprogramming. Here, for the first time, we demonstrate that MDL‐800, a recently developed selective SIRT6 activator, improved genomic stability by activating two DNA repair pathways—nonhomologous end joining (NHEJ) and base excision repair (BER) in old murine‐derived iPSCs. More interestingly, we found that pretreating old murine iPSCs, which normally exhibit a restricted differentiation potential, with MDL‐800 promoted the formation of teratomas comprised of all three germ layers and robustly stimulated chimera generation. Our findings suggest that pharmacological activation of SIRT6 holds great promise in treating aging‐associated diseases with iPSC‐based cell therapy.

Promissory and protective imaginaries of regenerative medicine: Expectations work and scenario maintenance of disease research charities in the United Kingdom

This article draws upon recent scholarship on technoscientific imaginaries and the sociology of technology expectations to reveal the mediating roles played by a number of disease-focused research charities in the United Kingdom. We examine the expectations they deal with about regenerative medicine research, and how they develop strategies to support and 'protect' potential medical scenarios for new therapies for dread diseases. In so doing, we develop and detail a concept of scenario maintenance to denote the strategic discursive and practical work of preserving stakeholders' faith in specific disease research pathways in the face of obstacles. Semi-structured in-depth interviews (N = 10) of research managers at nine research charities were qualitatively analysed, alongside a variety of charities' documentary data. Our analysis yielded three themes: managing and moderating media expectations; specifying expectations about disease-specific appropriateness of regenerative medicine; and maintaining scenarios of possible pathways for future success taking challenges into account.

Investigating the route of administration and efficacy of adipose tissue-derived mesenchymal stem cells and conditioned medium in type 1 diabetic mice

Type 1 diabetes (T1D) is a chronic autoimmune disease destroying the insulin-producing beta cells. Recently, stem cell therapy has been tested to treat T1D. In the present study, we aim to investigate the effects of intraperitoneal and intravenous infusion of multipotent mesenchymal stem/stromal cells (MSCs) and MSC-conditioned medium (MSC-CM) in an experimental model of diabetes, induced by multiple injections of Streptozotocin (STZ). The adipose tissue-derived MSC and MSC-CM were isolated from C57Bl/6 male mice and characterized. Later, MSC and MSC-CM were injected intraperitoneally or intravenously into mice. The blood glucose, urinary glucose, and body weight were measured, and the percentages of CD4+ CD25+ FOXP3+ T cells as well as the levels of IFN-γ, TGF-β, IL-4, IL-17, and IL-10 were evaluated. Our results showed that both intraperitoneal and intravenous infusions of MSC and MSC-CM could decrease the blood glucose, recover pancreatic islets, and increase the levels of insulin-producing cells. Furthermore, the percentage of CD4+ CD25+ FOXP3+ T cells was increased after intraperitoneal injection of MSC or MSC-CM and intravenous injection of MSCs. After intraperitoneal injection of the MSC and MSC-CM, the levels of inflammatory cytokines reduced, while the levels of anti-inflammatory cytokines increased. Together current data showed that although both intraperitoneal and intravenous administration had beneficial effects on T1D animal model, but intraperitoneal injection of AD-MSC and AD-MSC-CM was more effective than systemic administration.

Insulin-producing cells from mesenchymal stromal cells: Protection against cognitive impairment in diabetic rats depends upon implant site

Diabetes mellitus (DM) is a serious public health problem and can cause long-term damage to the brain, resulting in cognitive impairment in these patients. Insulin therapy for type 1 DM (DM1) can achieve overall blood glucose control, but glycemic variations can occur during injection intervals, which may contribute to some complications. Among the additional therapies available for DM1 treatment is the implantation of insulin-producing cells (IPCs) to attenuate hyperglycemia and even reverse diabetes. Here, we studied the strategy of implanting IPCs obtained from mesenchymal stromal cells (MSCs) from adipose tissue, comparing two different IPC implant sites, subcapsular renal (SR) and subcutaneous (SC), to investigate their putative protection against hippocampal damage, induced by STZ, in a rat DM1 model. Both implants improved hyperglycemia and reduced the serum content of advanced-glycated end products in diabetic rats, but serum insulin was not observed in the SC group. The SC-implanted group demonstrated ameliorated cognitive impairment (evaluated by novel object recognition) and modulation of hippocampal astroglial reactivity (evaluated by S100B and GFAP). Using GFP+ cell implants, the survival of cells at the implant sites was confirmed, as well as their migration to the pancreas and hippocampus. The presence of undifferentiated MSCs in our IPC preparation may explain the peripheral reduction in AGEs and subsequent cognitive impairment recovery, mediated by autophagic depuration and immunomodulation at the hippocampus, respectively. Together, these data reinforce the importance of MSCs for use in neuroprotective strategies, and highlight the logistic importance of the subcutaneous route for their administration.

The Clinical Efficacy and Safety of Stem Cell Therapy for Diabetes Mellitus: A Systematic Review and Meta-Analysis

Diabetes mellitus (DM) is a chronic metabolic disease with high morbidity and mortality. Recently, stem cell-based therapy for DM has shown considerable promise. Here, we undertook a systematic review and meta-analysis of published clinical studies to evaluate the efficacy and safety of stem cell therapy for both type 1 DM (T1DM) and type 2 DM (T2DM). The PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and ClinicalTrials.gov databases were searched up to November 2018. We employed a fixed-effect model using 95% confidence intervals (CIs) when no statistically significant heterogeneity existed. Otherwise, a random-effects statistical model was used. Twenty-one studies met our inclusion criteria: ten T1DM studies including 226 patients and eleven T2DM studies including 386 patients. Stem cell therapy improved C-peptide levels (mean difference (MD), 0.41; 95% CI, 0.06 to 0.76) and glycosylated hemoglobin (HbA1c; MD, -3.46; 95% CI, -6.01 to -0.91) for T1DM patients. For T2DM patients, stem cell therapy improved C-peptide levels (MD, 0.33; 95% CI, 0.07 to 0.59), HbA1c (MD, -0.87; 95% CI, -1.37 to -0.37) and insulin requirements (MD, -35.76; 95% CI, -40.47 to -31.04). However, there was no significant change in fasting plasma glucose levels (MD, -0.52; 95% CI, -1.38 to 0.34). Subgroup analyses showed significant HbA1c and C-peptide improvements in patients with T1DM treated with bone marrow hematopoietic stem cells (BM-HSCs), while there was no significant change in the mesenchymal stem cell (MSC) group. In T2DM, HbA1c and insulin requirements decreased significantly after MSC transplantation, and insulin requirements and C-peptide levels were significantly improved after bone marrow mononuclear cell (BM-MNC) treatment. Stem cell therapy is a relatively safe and effective method for selected individuals with DM. The data showed that BM-HSCs are superior to MSCs in the treatment of T1DM. In T2DM, MSC and BM-MNC transplantation showed favorable therapeutic effects.

Exosomes derived from human umbilical cord mesenchymal stem cells ameliorate IL-6-induced acute liver injury through miR-455-3p

BACKGROUND

Using a toxin-induced nonhuman primate model of acute liver failure (ALF), we previously reported that peripheral infusion of human umbilical cord mesenchymal stem cells (hUC-MSCs) strongly suppresses the activation of circulating monocytes and interleukin-6 (IL-6) production, thereby disrupting the development of a cytokine storm and improving the prognosis of monkeys. MSCs are considered to play a therapeutic role under different stresses by adaptively producing specific factors, prompting us to investigate the factors that hUC-MSCs produce in response to high serum levels of IL-6, which plays a critical role in initiating and accelerating ALF.

METHODS

We stimulated hUC-MSCs with IL-6, and the hUC-MSC-derived exosomes were deeply sequenced. The miRNAs in the exosomes that have potential to suppress IL-6-associated signaling pathway were screened, and the role of one of the most possible miRNAs was tested in the mouse model of inflammatory liver injury.

RESULT

We determined that miR-455-3p, which is secreted through exosomes and potentially targets PI3K signaling, was highly produced by hUC-MSCs with IL-6 stimulation. The miR-455-3p-enriched exosomes could inhibit the activation and cytokine production of macrophages challenged with lipopolysaccharide (LPS) both in vivo and in vitro. In a chemical liver injury mouse model, enforced expression of miR-455-3p could attenuate macrophage infiltration and local liver damage and reduce the serum levels of inflammatory factors, thereby improving liver histology and systemic disorder.

CONCLUSIONS

miR-455-3p-enriched exosomes derived from hUC-MSCs are a promising therapy for acute inflammatory liver injury.

Exploring the effect of epigenetic modifiers on developing insulin-secreting cells

Diabetes is a worldwide health problem with increasing incidence. The current management modalities did not succeed to decrease comorbidities. This study aimed at enhancing the regenerative solution for diabetes by improving the differentiation of mesenchymal stromal cells (MSC) into glucose-sensitive, insulin-secreting cells through an epigenetic modification approach. A 3-day treatment protocol with the epigenetic modifiers, either decitabine (5-aza-2'-deoxycytidine; Aza); a DNA methylation inhibitor or Vorinostat (suberoylanilide hydroxamic acid; SAHA); a histone deacetylase inhibitor was added to two different human stem cell lines. The cells followed a multi-step differentiation protocol that provided the critical triggers in a temporal approach. Aza-pretreated group showed higher intracellular expression of insulin and the transcription factor 'PDX-1'. The cells responded to the high glucose challenge by secreting insulin in the media, as shown by ELISA. Gene expression showed induction of the genes for insulin, the glucose transporter 2, glucokinase, as well as the transcription factors MafA and NKX6.1. Although SAHA showed upregulation of insulin secretion, in comparison to control, the cells could not respond to the high glucose challenge. Interestingly, Aza-treated cells showed a significant decrease in the global DNA methylation level at the end of the culture. In conclusion, this additional step with Aza could enhance the response of MSC to the classical differentiation protocol for insulin-secreting cells and may help in establishing a regenerative solution for patients with diabetes.

A revealing review of mesenchymal stem cells therapy, clinical perspectives and Modification strategies

Multipotent mesenchymal stem cells (MSCs) have been considerably inspected as effective tool for cell-based therapy of inflammatory, immune-mediated, and degenerative diseases, attributed to their immunomodulatory, immunosuppressive, and regenerative potentials. In the present review, we focus on recent research findings of the clinical applications and therapeutic potential of this cell type, MSCs' mechanisms of therapy, strategies to improve their therapeutic potentials such as manipulations and preconditioning, and potential/unexpected risks which should be considered as a prerequisite step before clinical use. The potential risks would probably include undesirable immune responses, tumor formation and the transmission of incidental agents. Then, we also review some of the milestones in the field, briefly discuss challenges and highlight the new guideline suggested for future directions and perspectives.

Metabolomics and Cell Therapy in Diabetes Mellitus

Diabetes with a broad spectrum of complications has become a global epidemic metabolic disorder. Till now, several pharmaceutical and non-pharmaceutical therapeutic approaches were applied for its treatment. Cell-based therapies have become promising methods for diabetes treatment. Better understanding of diabetes pathogenesis and identification of its specific biomarkers along with evaluation of different treatments efficacy, can be possible by clarification of specific metabolic modifications during the diabetes progression. Subsequently, metabolomics technology can support this goal as an effective tool. The present review tried to show how metabolomics quantifications can be useful for diabetic monitoring before and after cell therapy. Cell therapy is an alternative approach to achieve diabetes treatments goals including insulin resistance amelioration, insulin independence reparation, and control of glycemia. OMICs approaches provide a comprehensive insight into the molecular mechanisms of cells features and functional mechanism of their genomics, transcriptomics, proteomics, and metabolomics profile which can be useful for their therapeutic application. As a modern technology for the detection and analysis of metabolites in biological samples, metabolomica can identify many of the metabolic and molecular pathways associated with diabetes and its following complications.

Short-Term Protocols to Obtain Insulin-Producing Cells from Rat Adipose Tissue: Signaling Pathways and In Vivo Effect

Studies using mesenchymal stromal cells (MSCs) as a source of insulin-secreting cells (IPCs) are a promising path in the pursuit for diabetes therapy. Here, we investigate three short-term differentiation protocols in order to generate IPCs from autologous adipose-derived stromal cells (ADSCs) with an expressive insulin-secreting profile in vitro and in vivo, as well as the signaling pathways involved in the chosen differentiation protocols. We extracted and cultured ADSCs and differentiated them into IPCs, using three different protocols with different inductors. Afterwards, the secretory profile was analyzed and IPCs differentiated in exendin-4/activin A medium, which presented the best secretory profile, was implanted in the kidney subcapsular region of diabetic rats. All protocols induced the differentiation, but media supplemented with exendin-4/activin A or resveratrol induced the expression and secretion of insulin more efficiently, and only the exendin-4/activin-A-supplemented medium generated an insulin secretion profile more like β-cells, in response to glucose. The PI3K/Akt pathway seems to play a negative role in IPC differentiation; however, the differentiation of ADSCs with exendin-4/activin A positively modulated the p38/MAPK pathway. Resveratrol medium activated the Jak/STAT3 pathway and generated IPCs apparently less sensitive to insulin and insulin-like receptors. Finally, the implant of IPCs with the best secretory behavior caused a decrease in hyperglycemia after one-week implantation in diabetic rats. Our data provide further information regarding the generation of IPCs from ADSCs and strengthen evidence to support the use of MSCs in regenerative medicine, specially the use of exendin-4/activin A to produce rapid and effectively IPCs with significant in vivo effects.

Impaired Bone Regenerative Effect of Exosomes Derived from Bone Marrow Mesenchymal Stem Cells in Type 1 Diabetes

Stem cell‐derived exosomes have exhibited promise for applications in tissue regeneration. However, one major problem for stem cell‐derived exosome therapies is identifying appropriate source cells. In the present study, we aimed to compare the bone regenerative effect of exosomes secreted by bone marrow mesenchymal stem cells (BMSCs) derived from type 1 diabetes rats (dBMSC‐exos) and exosomes secreted by BMSCs derived from normal rats (nBMSC‐exos). BMSCs were isolated from rats with streptozotocin‐induced diabetes and normal rats. dBMSC‐exos and nBMSC‐exos were isolated by an ultracentrifugation method and identified. The effects of dBMSC‐exos and nBMSC‐exos on the proliferation and migration of BMSCs and human umbilical vein endothelial cells (HUVECs) were investigated. The effects of exosomes on the osteogenic differentiation of BMSCs and the angiogenic activity of HUVECs were compared. Finally, a rat calvarial defect model was used to compare the effects of exosomes on bone regeneration and neovascularization in vivo. In vitro, dBMSC‐exos and nBMSC‐exos both enhanced the osteogenic differentiation of BMSCs and promoted the angiogenic activity of HUVECs, but nBMSC‐exos had a greater effect than dBMSC‐exos. Similarly, in vivo, both dBMSC‐exos and nBMSC‐exos promoted bone regeneration and neovascularization in rat calvarial defects, but the therapeutic effect of nBMSC‐exos was superior to that of dBMSC‐exos. The present study demonstrates for the first time that the bone regenerative effect of exosomes derived from BMSCs is impaired in type 1 diabetes, indicating that for patients with type 1 diabetes, the autologous transplantation of BMSC‐exos to promote bone regeneration may be inappropriate. stem cells translational medicine2019;8:593–605

Regenerative and Transplantation Medicine: Cellular Therapy Using Adipose Tissue-Derived Mesenchymal Stromal Cells for Type 1 Diabetes Mellitus

Type 1 diabetes mellitus (T1DM) is caused by the autoimmune targeting of pancreatic β-cells, and, in the advanced stage, severe hypoinsulinemia due to islet destruction. In patients with T1DM, continuous exogenous insulin therapy cannot be avoided. However, an insufficient dose of insulin easily induces extreme hyperglycemia or diabetic ketoacidosis, and intensive insulin therapy may cause hypoglycemic symptoms including hypoglycemic shock. While these insulin therapies are efficacious in most patients, some additional therapies are warranted to support the control of blood glucose levels and reduce the risk of hypoglycemia in patients who respond poorly despite receiving appropriate treatment. There has been a recent gain in the popularity of cellular therapies using mesenchymal stromal cells (MSCs) in various clinical fields, owing to their multipotentiality, capacity for self-renewal, and regenerative and immunomodulatory potential. In particular, adipose tissue-derived MSCs (ADMSCs) have become a focus in the clinical setting due to the abundance and easy isolation of these cells. In this review, we outline the possible therapeutic benefits of ADMSC for the treatment of T1DM.

Paving the way for successful islet encapsulation

Type 1 diabetes mellitus (T1DM) is a disorder that decimates pancreatic β-cells which produce insulin. Direct pancreatic islet transplantation cannot serve as a widespread therapeutic modality owing to the need for lifelong immunosuppression and donor shortage. Therefore, several encapsulation techniques have been developed to enclose the islets in semipermeable vehicles that will allow oxygen and nutrient input as well as insulin, other metabolites and waste output, while accomplishing immunoisolation. Although encapsulation technology continues to face significant obstacles, recent advances in material science, stem cell biology and immunology potentially serve as pathways to success. This review summarizes the accomplishments of the past 5 years.

Oxygen transporter for the hypoxic transplantation site

Cell transplantation is a promising treatment for complementing lost function by replacing new cells with a desired function, e.g. pancreatic islet transplantation for diabetics. To prevent cell obliteration, oxygen supply is critical after transplantation, especially until the graft is sufficiently re-vascularized. To supply oxygen during this period, we developed a chemical-/electrical-free implantable oxygen transporter that delivers oxygen to the hypoxic graft site from ambient air by diffusion potential. This device is simply structured using a biocompatible silicone-based body that holds islets, connected to a tube that opens outside the body. In computational simulations, the oxygen transporter increased the oxygen level to >120 mmHg within grafts; in contrast, a control device that did not transport oxygen showed <6.5 mmHg. In vitro experiments demonstrated similar results. To test the effectiveness of the oxygen transporter in vivo, we transplanted pancreatic islets, which are susceptible to hypoxia, subcutaneously into diabetic rats. Islets transplanted using the oxygen transporter showed improved graft viability and cellular function over the control device. These results indicate that our oxygen transporter, which is safe and easily fabricated, effectively supplies oxygen locally. Such a device would be suitable for multiple clinical applications, including cell transplantations that require changing a hypoxic microenvironment into an oxygen-rich site.

Stem cell transplantation for the treatment of patients with type 1 diabetes mellitus: A meta-analysis

The efficacy of stem cell (SC) transplantation in patients with type 1 diabetes mellitus (T1DM) has remained to be fully elucidated. In the present study, a systematic review and meta-analysis was performed to determine the clinical outcomes. Electronic databases, including PubMed, MEDLINE, WanFang and the Cochrane Library were screened for relevant studies published until January 13, 2018. The references of retrieved papers, systematic reviews and trial registries were manually screened for additional papers. Two authors were involved in screening the titles in order to select eligible studies, extract data and assess the risk of bias. Studies were pooled using a random-effects model as well as the Begg's funnel plot and subgroup analysis was performed using Stata 14.0 software. A total of 47 studies were retrieved for detailed evaluation, of which 22 met the inclusion criteria. No substantial publication bias was identified. The meta-analysis revealed that SC therapy increased C-peptide levels when compared with placebo treatment in randomized-controlled trials [RCT; standardized mean difference (SMD), 0.93; 95% confidence interval (CI) 0.23-1.63] and self-controlled trials (SMD, 0.66; 95% CI, -0.22 to 1.54). An analysis demonstrated that SC therapy was more efficient at reducing the glycated hemoglobin level compared with the control group in RCTs (SMD, 0.56; 95% CI; 0.06-1.06; and SMD, 1.63; 95% CI, 0.92-2.34, respectively). The graphs demonstrated that SC transplantation resulted in a reduction of insulin requirement. Furthermore, subgroup analyses revealed that patient age, medical history and the SC injection dose may be sources of the heterogeneity observed. The greatest benefit of SC transplantation was seen in patients aged ≥18 years or a medical history of <3 months. In addition, the SC injection dose of ≥107 IU/kg/day was more effective than <107 IU/kg/day when the cellular composition included mesenchymal SCs and hematopoietic SCs. In conclusion, SC therapy represents an efficient option for patients with T1DM. This systematic review was registered at the International prospective register of systematic reviews (no. 42018093930).