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Diabetes mellitus may cause tau protein hyperphosphorylation and neurodegeneration, but the exact mechanism by which diabetic conditions induce tau pathology remains unclear. Tau protein hyperphosphorylation is considered a major pathological hallmark of neurodegeneration and can be triggered by diabetes. Various tau-directed kinases, including P38, can be activated upon diabetic stress and induce tau hyperphosphorylation. Despite extensive research efforts, the exact tau specie(s) and kinases driving neurodegeneration in diabetes mellitus have not been clearly elucidated. We herein employed different techniques to determine the exact molecular mechanism of tau pathology triggered by diabetes in in vivo and in vitro models. We showed that diabetes-related stresses and glucose metabolism deficiency could induce cis P-tau (an early driver of the tau pathology) accumulation in the midbrain and corpus callosum of the diabetic mice models and cells treated with 2-deoxy-D-glucose, respectively. We found that the active phosphorylated level of P38 was increased in the treated cells and diabetic mice models. We observed that oxidative stress activated P38, which directly and indirectly drove tau pathology in the GABAergic and glutamatergic neurons of the midbrain of the diabetic mice after 96 h, which accumulated in the other neighboring brain areas after 2 months. Notably, P38 inhibition suppressed tau pathogenicity and risk-taking behaviors in the animal models after 96 h. The data establish P38 as a central mediator of diabetes mellitus-induced tau pathology. Our findings provide mechanistic insight into the consequences of this metabolic disorder on the nervous system.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease of unknown cause. The interaction of immune system cells and the secretion of inflammatory cytokines with synovial cells leads to severe inflammation in the affected joints. Currently, medications, including non-steroidal anti-inflammatory drugs, glucocorticoids, and more recently, disease-modifying anti-rheumatic drugs, are used to reduce inflammation. However, long-term use of these drugs causes adverse effects or resistance in a considerable number of RA patients. Recent findings revealed the safety and efficacy of mesenchymal stromal cells (MSCs)-based therapies both in RA animal models and clinical trials. Here, the beneficial effects of bone marrow-derived heterogeneous MSCs (BM-hMSCs) and Wharton jelly-derived MSCs (WJ-MSCs) at early passages were compared to BM-derived clonal MSCs (BM-cMSCs) at high passage number on a rat model of collagen-induced arthritis. Results showed that systemic delivery of MSCs significantly reversed adverse changes in body weight, paw swelling, and arthritis score in all MSC-treated groups. Radiological images and histological evaluation demonstrated the therapeutic effects of MSCs. There was a decrease in serum level of anti-collagen type II immunoglobulin G and the inflammatory cytokines interleukin (IL)-1β, IL-6, IL-17, and tumor necrosis factor-α in all MSC-treated groups. In contrast, an increase in inhibitory cytokines transforming growth factor-β and IL-10 was seen. Notably, the long-term passages of BM-cMSCs could alleviate RA symptoms similar to the early passages of WJ-MSCs and BM-hMSCs. The importance of BM-cMSCs is the potential to establish cell banks with billions of cells derived from a single donor that could be a competitive cell-based therapy to treat RA.

The therapeutic potential of naturally secreted micro- and nanoscale extracellular vesicles (EVs) makes them attractive candidates for regenerative medicine and pharmaceutical science applications. To date, the results of numerous publications have shown the practicality of using EVs to replace mesenchymal stromal cells (MSCs) or liposomes. This article presents a systematic review of pre-clinical studies conducted over the past decade of MSC-derived EVs (MSC-EVs) used in animal models of disease. The authors searched the relevant literature in the PubMed and Scopus databases (9358 articles), and 690 articles met the inclusion criteria. The eligible articles were placed in the following disease categories: autoimmune, brain, cancer, eye, gastrointestinal, heart, inflammation/transplantation, liver, musculoskeletal, pancreas, spinal cord and peripheral nervous system, respiratory system, reproductive system, skin, urinary system and vascular-related diseases. Next, the eligible articles were assessed for the rate of publication and global distribution, methodology of EV isolation and characterization, route of MSC-EV administration, length of follow-up, source of MSCs and animal species. The current review classifies and critically discusses the technical aspects of these MSC-EV animal studies and discusses potential relationships between methodological details and the effectiveness of MSC-EVs as reported by these pre-clinical studies.

Allogeneic mesenchymal stromal cells (MSCs) have been used extensively in various clinical trials. Nevertheless, there are concerns about their efficacy, attributed mainly to the heterogeneity of the applied populations. Therefore, producing a consistent population of MSCs is crucial to improve their therapeutic efficacy. This study presents a good manufacturing practice (GMP)-compatible and cost-effective protocol for manufacturing, banking, and lot-release of a homogeneous population of human bone marrow-derived clonal MSCs (cMSCs).Here, cMSCs were isolated based on the subfractionation culturing method. Afterward, isolated clones that could reproduce up to passage three were stored as the seed stock. To select proliferative clones, we used an innovative, cost-effective screening strategy based on lengthy serial passaging. Finally, the selected clones re-cultured from the seed stock to establish the following four-tired cell banking system: initial, master, working, and end of product cell banks (ICB, MCB, WCB, and EoPCB).Through a rigorous screening strategy, three clones were selected from a total of 21 clones that were stored during the clonal isolation process. The selected clones met the identity, quality, and safety assessments criteria. The validated clones were stored in the four-tiered cell bank system under GMP conditions, and certificates of analysis were provided for the three-individual ready-to-release batches. Finally, a stability study validated the EoPCB, release, and transport process of the frozen final products.Collectively, this study presents a technical and translational overview of a GMP-compatible cMSCs manufacturing technology that could lead to the development of similar products for potential therapeutic applications.

Introduction Mesenchymal stromal cells (MSCs) have opened a new window to treat inflammatory and non-inflammatory diseases. Nonetheless, their clinical applications require rigorous control and monitoring procedures to ensure full compliance with the principles of good manufacturing practice (GMP). Various evaluations should be passed in conjunction with the development of these newly emerging therapeutic products from bench-to-bedside. These evaluations include in vitro characterization, preclinical studies, and clinical trials to ensure product safety and efficacy. Therefore, a robust and well-designed preclinical study is critical to confirm product safety. This study aims to determine the probable toxicity effects of local and systemic injections of cryopreserved human bone marrow-derived clonal MSCs (BM-cMSCs) during subacute and subchronic periods of time. Methods BM-cMSCs were characterized according to the International Society for Cell and Gene Therapy (ISCT) criteria for MSCs. Both safety and toxicity of the BM-cMSCs population produced under GMP-compatible conditions were assessed in both sexes of Sprague Dawley (SD) rats via systemic intravenous (IV) administration and local injection in intervertebral disc (IVD). Behavioral changes, clinical signs of toxicity, and changes in body weight, water and food consumption were the important variables for product toxicity testing over 14 consecutive days during the subacute period and 90 consecutive days during the subchronic period. At the end of the assessment periods, the rats were killed for histopathology analysis of the target tissues. The BM-cMSCs potential for tumorigenicity was checked in nude mice. Results Single IV and IVD injections of BM-cMSCs did not cause significant signs of clinical toxicity, or changes in laboratory and histopathology data during the subacute (14 day) and subchronic (90 day) periods. Ex vivo-expanded and cryopreserved BM-cMSCs did not induce tumor formation in nude mice. Conclusion The results suggest that local and systemic administrations of xenogeneic BM-cMSCs in both sexes of SD rats do not cause toxicity during the subacute and subchronic periods of time. Also, BM-cMSCs were non-tumorigenic in nude mice.

Type 1 diabetes (T1D) is caused by low insulin production and chronic hyperglycemia due to destruction of pancreatic β-cells. Cell transplantation is an attractive alternative approach compared to insulin injection. However, cell therapy has been limited by major challenges, including life-long requirement for immunosuppressive drugs to prevent host immune responses. Encapsulation of the transplanted cells can solve the problem of immune rejection, by providing a physical barrier between the transplanted cells and the recipient's immune cells. Despite current disputes in cell encapsulation approaches, thanks to recent advances in the fields of biomaterials and transplantation immunology, extensive effort has been dedicated to immunoengineering strategies, in combination with encapsulation technologies, to overcome the problem of host's immune responses. This review summarizes the most commonly used encapsulation and immunoengineering strategies combined with cell therapy, which have been applied as a novel approach to improve cell replacement therapies for management of T1D. Recent advances in the fields of biomaterial design, nanotechnology, as well as deeper knowledge about immune modulation had significantly improved cell encapsulation strategies. However, further progress requires combined application of novel immunoengineering approaches and islet/β-cell transplantation. Impact statement Cell encapsulation shows promising potential in preventing host's immune responses and rejection of islets or β-cells by providing a selectively permeable barrier between the host and the transplanted cells. Innovative materials, conformal nanocoatings, and immunomodulation have provided promising approaches in the field of encapsulation technology. Novel nanocarriers have been synthesized to release and deliver immunosuppressive agents to islets/β-cells within the capsules in a controlled manner. The immunoengineering approach (immunosuppressive and immunomodulatory agents) could overcome the challenges of cell replacement therapy in type 1 diabetes.

BackgroundType-1 diabetes (T1D) occurs following autoimmune-induced pancreatic beta cells death. Among several treatment modalities, Mesenchymal Stem Cells (MSCs) transplantation is promising for autoimmune disorders due to immunomodulation, regeneration, and migration to damaged tissue upon systemic injection. This study assessed the safety and efficacy of intravenous injection of autologous bone marrow-derived MSCs in newly diagnosed T1D patients. MethodsAfter receiving informed consent, 21 patients who met the study criteria were enrolled and randomly assigned to receive either MSCs or placebo. Each patient in the experimental group received two doses of MSCs and followed for at least one year post-transplantation. ResultsThe results have shown that this transplantation is safe and significantly reduces the number of hypoglycemic episodes. MSCs transplantation improved glycated hemoglobin (HbA1c), shifted serum cytokine patterns from pro-inflammatory to anti-inflammatory, increased the number of regulatory T-cells in the peripheral blood, and improved quality of life. Early transplantation of MSCs significantly improved HbA1c and C-peptide levels and shifted pro-inflammatory cytokines to anti-inflammatory cytokines. Also, exercise combined with MSCs transplantation improved glycemic and immunologic indices. ConclusionsIn conclusion, autologous MSC transplantation is safe and effective, and its early transplantation is a promising treatment in newly-diagnosed T1D children suffering from hypoglycemic episodes. Trial registrationThis clinical trial was registered at the Iranian Registry of Clinical Trials (IRCT) with the identifier IRCT ID: IRCT2016070428786N1 registered on August 20, 2016 (Retrospectively registered) (https://en.irct.ir/trial/23256) and at the U.S. National Institutes of Health (ClinicalTrials.gov) with the related identifier NCT04078308 registered on September 6, 2019 (Retrospectively registered). (https://clinicaltrials.gov/ct2/show/NCT04078308)

BackgroundType-1 diabetes (T1D) occurs following autoimmune-induced pancreatic beta cells death. Among several treatment modalities, mesenchymal stem cells (MSCs) transplantation is promising for autoimmune disorders due to immunomodulation, regeneration, and migration to damaged tissue upon systemic injection. This study assessed the safety and efficacy of intravenous injection of autologous bone marrow-derived MSCs in newly diagnosed T1D patients.MethodsAfter receiving informed consent, 21 patients who met the study criteria were enrolled and randomly assigned to receive either MSCs or placebo. Each patient in the experimental group received two doses of MSCs and was followed for at least one-year post-transplantation.ResultsThe results have shown that this transplantation is safe and significantly reduces the number of hypoglycemic episodes. MSCs transplantation improved glycated hemoglobin (HbA1c), shifted serum cytokine patterns from pro-inflammatory to anti-inflammatory, increased the number of regulatory T-cells in the peripheral blood, and improved quality of life. Early transplantation of MSCs significantly improved HbA1c and C-peptide levels and shifted pro-inflammatory cytokines to anti-inflammatory cytokines. Also, exercise combined with MSCs transplantation improved glycemic and immunologic indices.ConclusionsTaken together, autologous MSC transplantation is safe and effective, and its early transplantation is a promising treatment in newly diagnosed T1D children suffering from hypoglycemic episodes.Trial registration: This clinical trial was registered at the Iranian Registry of Clinical Trials (IRCT) with the identifier IRCT ID: IRCT2016070428786N1 registered on August 20, 2016 (Retrospectively registered) (https://en.irct.ir/trial/23256) and at the U.S. National Institutes of Health (ClinicalTrials.gov) with the related identifier NCT04078308 registered on September 6, 2019 (Retrospectively registered). (https://clinicaltrials.gov/ct2/show/NCT04078308).

Microneedle patches have been widely used as transdermal transport systems because of their painless and easy application. Marked rigidity, strength, biocompatibility, and physiological stability are unique features of microneedles fabricated from ceramic materials to be used as microneedle patches. However, the conventional ceramic microneedles are typically dense structures with limited free space for biomolecule loading. A facile method is required for fabrication of biocompatible ceramic microneedles with interconnected porosity. Herein, the simple method of centrifugal casting was developed for fabrication of microporous microneedles from alumina suspensions. The slurry or resin-based alumina suspensions were casted into micromolds under centrifugal force, followed by sintering at high temperatures. The effects of particle size, solvent type, binder amount, resin content and sintering temperature on the microstructure and mechanical properties of microneedles were investigated. By optimizing the process parameters, highly porous (up to 60%) microneedles with interconnected micropores (of diameter ∼1–1.5 μm) were produced. The microporous microneedles were biocompatible and mechanically strong for skin penetration. The potential use of the microneedles for transdermal transportation of biomolecules was shown by fast and accurate extraction of glucose from a skin model and efficient loading and fast release of insulin under physiological conditions. The results suggested that the microporous alumina microneedles may serve as molecular transport systems in transdermal biosensing and drug delivery.

Isolated pancreatic islets are valuable resources for a wide range of research, including cell replacement studies and cell-based platforms for diabetes drug discovery and disease modeling. Islet isolation is a complex and stepwise procedure aiming to obtain pure, viable, and functional islets for in vitro and in vivo studies. It should be noted that differences in rodent strains, gender, weight, and density gradients may affect the isolated islet's properties. We evaluated the variables affecting the rat islet isolation procedure to reach the maximum islet yield and functionality, which would be critical for further studies on islet regenerative biology.The present experimental study compared the yield and purity of isolated islets from nondiabetic rats of two different strains. Next, islet particle number (IPN) and islet equivalent (IEQ) were compared between males and females, and the weight range that yields the highest number of islets was investigated. Moreover, the influence of three different density gradients, namely Histopaque, Pancoll, and Lymphodex, on final isolated islets purity and yield were assessed. Finally, the viability and functionality of isolated islets were measured.The IEQ, IPN, and purity of isolated islets in 15 Lister hooded rats (LHRs) were significantly (P≤0.05) higher than those of the other strains. Male LHRs resulted in significantly higher IEQ compared to females (P≤0.05). Moreover, IPN and IEQ did not significantly vary among different weight groups. Also, the utilization of Histopaque and Pancoll leads to higher yield and purity. In vivo assessments of the isolated islets presented significantly reduced blood glucose percentage in the transplanted group on days 2-5 following transplantation.Based on these results, an optimal protocol for isolating high-quality rat islets with a constant yield, purity, and function has been established as an essential platform for developing diabetes research.

Additional file 1: Figure S1. Flow cytometric characterization of UC-MSCs. The cells were negative for (A) CD31 (endothelial marker), (B) CD45, (C) CD34 (hematopoietic stem cell markers), (D) CD11b (leukocyte marker), and (E) HLD-R (MHC-II). They displayed positive expression for MSCs markers; (F) CD105, (G) CD90, (H) CD73, and (I) CD29.

Additional file 2: Figure S2. Timeline for ICU admitted the patients treated with MSCs. (A) Survivors. (B) Non-survivors. Nine patients received three intravenous (IV) infusions. The course of cell therapy of patient number #8 was interrupted following frequent hemodialysis as a result of acute renal failure that developed on day 4. This patient took 12 days to complete the three doses. Patient number #1 was intubated and did not complete the course of his cell therapy and died on day 4. CRRT performed for both patients (#5 and 9) late during the course of disease and at least 48 h after completion of the cell infusion. ICU: Intensive care unit, ARDS: Acute respiratory distress syndrome, MSCs: Mesenchymal stem cells; ECMO: Extracorporeal membrane oxygenation, CRRT: Continuous renal replacement therapies, MOF: Multi-organ failure, #: Patient number.

Additional file 4: Table S2. Laboratory findings before the first and after the last cell infusions.

Additional file 3: Table S1. Clinical data before the first (day one) and last (day 5) cell infusions.

Background: Diabetes mellitus may cause neurodegeneration, but the exact mechanism by which diabetic conditions induce neuronal cell death remains unclear. Tau protein hyperphosphorylation is considered to be a major pathological hallmark of neurodegeneration and can be triggered by diabetes. Various tau-directed kinases, including P38, can be activated upon diabetic stress and induce tau hyperphosphorylation. Despite extensive research efforts and the known importance of tau pathology in neurodegeneration, the exact tau specie(s) and kinases driving neurodegeneration in diabetes mellitus have not been clearly elucidated. Methods: We herein employed protein expression data analysis as well as immunofluorescence and immunoblotting techniques to determine the exact molecular mechanism of tau pathology triggered by diabetes in both in vitro and in vivo systems.Results: We found that P38, a major tau kinase, was increased in Glutamatergic & GABAergic neuron subtypes under diabetic conditions. This rendered them more responsive to oxidative stress caused by diabetes. We observed that oxidative stress activated P38, which in turn directly and indirectly drove tau pathology in the brainstem (enriched by Glutamatergic & GABAergic neurons), which gradually spread to neighboring brain areas. Notably, P38 inhibition suppressed tau pathogenicity and neurodegeneration in diabetic mouse models. Conclusion: The data establish P38 as a central mediator of diabetes mellitus induced tau pathology. Furthermore, the inhibition of P38 at early stages of diabetes-induced stress can inhibit tau pathology. Our findings provide mechanistic insight on the consequences of this metabolic disorder on the nervous system.

Organoids can be regarded as a beneficial tool for discovery of new therapeutics for diabetes and/or maturation of pancreatic progenitors (PP) towards β cells. Here, we devised a strategy to enhance maturation of PP by assembly of three-dimensional (3D) pancreatic organoids (PO) containing human embryonic stem (ES) cell derivatives including ES-derived pancreatic duodenal homeobox 1 (PDX1) + early PP, mesenchymal stem cells, and endothelial cells at an optimized cell ratio, on Matrigel. The PO was placed in a 3D-printed tissue trapper and heterotopically implanted into the peritoneal cavity of immunodeficient mice where it remained for 90 days. Our results indicated that, in contrast to corresponding early PP transplants, 3D PO developed more vascularization as indicated by greater area and number of vessels, a higher number of insulin-positive cells and improvement of human C-peptide secretions. Based on our findings, PO-derived β cells could be considered a novel strategy to study human β-cell development, novel therapeutics, and regenerative medicine for diabetes.

Exosomes are required for the regenerative effects of human cardiosphere-derived cells (CDCs). Studies show that they mimic the cardioprotective benefits of CDCs in rodents and porcine myocardial infarction (MI) models. Hypoxic preconditioning of stem cells increases the cardioprotective effects of exosomes in MI models by enhancing angiogenesis. Several exosomal microRNAs (miRNAs) up-regulate in response to hypoxia and play a role in cardioprotective and pro-angiogenic effects. In this study, we have demonstrated that human CDCs secreted exosomes under hypoxic conditions (1% O2 for 2 days) enhanced tube formation by human umbilical vein endothelial cells (HUVECs) at a concentration of 25 µg/mL. Pro-angiogenic exosomal miRNAs including miR-126, miR-130a, and miR-210 showed a substantial increase (>2-, >2-, and >4-fold, respectively) in the hypoxic exosomes compared to normoxic CDC-derived exosomes. Our study suggested a significant benefit of hypoxic CDC exosomes for the treatment of cardiac diseases by induction of angiogenesis via enrichment of pro-angiogenic exosomal miRNAs.

Glucose-responsive microneedle (MN) patches are of great interest for painless self-regulated insulin delivery in diabetic patients to improve their quality of life. This work is aimed to develop a smart MN-based insulin delivery system with potential for post-fabrication loading of insulin and a fast, repeatable response to glucose fluctuations without sacrificing its structural constituents. A hierarchically porous inorganic MN array is developed, consisting of a macroporous alumina core to provide an external access and a large capacity for insulin loading and a mesoporous shell to control insulin release by glucose-responsive gating of its nanopores that are dynamically capped with an enzyme-loaded chitosan (CS) hydrogel. The capped MNs doff their caps to blood sugar quickly and reversibly via swelling/deswelling of the CS cap. As a result, insulin release can be repeatedly regulated during sequential cycles of hyperglycemia/normoglycemia with short intervals of 40 min. In a type 1 diabetic mouse model, application of the smart MN system quickly causes normoglycemia within 1 h, which is prolonged for 5 h. Diabetic mice treated by the smart MN system behave similarly to the healthy mice in terms of controlled blood glucose levels during the in vivo glucose tolerance test. The “cap doffing” approach can aid the development of more safe, long-lasting MN systems for smart transdermal delivery of insulin and other drugs.

Objective: Pancreatic β cells are recognized as central players in the pathogenesis of types 1 and 2 diabetes. Efficient and robust primary culture methods are required to interrogate β cell biology and screen potential anti-diabetic therapeutics. The aim of this study was to refine monolayer culture of beta cells and to investigate potential inducers of beta cell proliferation. Materials and Methods: In this experimental study, we compared different culture methods to optimize conditions required for a monolayer culture of rat pancreatic islet cells in order to facilitate image analysis-based assays. We also used the refined culture method to screen a group of rationally selected candidate small molecules and their combinations to determine their potential proliferative effects on the β cells. Results: Ham’s F10 medium supplemented with 2% foetal bovine serum (FBS) in the absence of any surface coating provided a superior monolayer β cell culture, while other conditions induced fibroblast-like cell growth or multilayer cell aggregation over two weeks. Evaluation of candidate small molecules showed that a menin inhibitor MI-2 and a combination of transforming growth factor-β (TGF-β) inhibitor SB481542 and protein kinase C (PKC) activator indolactam V (IndV) significantly induced replication of pancreatic β cells. Conclusion: Overall, our optimized culture condition provided a convenient approach to study the cultured pancreatic islet cells and enabled us to detect the proliferative effect of menin inhibition and combined TGF-β inhibition and PKC activation, which could be considered as potential strategies for inducing β cell proliferation and regeneration.

Additional file 1: Supplementery Table 1. Ethical guideline for research on stem cells and regenerative medicine in the Islamic Republic of Iran.

Chimeric immune receptors (CIRs) are functionally pleiotropic because they are artificially expressed on diverse cell types, which gives specificity to their function to anergize, kill, or protect cognate target cells. CIRs consist of chimeric antigen receptors (CARs) and B-cell antibody receptor (BAR) or chimeric autoantibody receptors (CAARs). Approval of CAR-T cell therapy by the Food and Drug Administration (FDA) has encouraged investigators to search for autoimmune therapies that are CIR-based. Both T effector cells, particularly CD8+, and T CD4+ regulatory cells (Tregs) can be engineered through CIR expression. Recently, natural killer cells have been included to increase efficiency. Unwanted antibody producer B cells are effectively prevented by CAAR-T cells, B-cell antibody receptor (BAR)-T CD8+, and BAR-Treg, which represents an advantage in antibody-mediated diseases such as pemphigus vulgaris (PV) and hemophilia A. Although CAAR and BAR-T cells may have curative benefits for autoantibody-mediated immune diseases, verification of long-term efficacy and safety are a priority before clinical use. Effective CIR-T cell therapy largely depends on the reliability and stability of the receptor. Based on CIR functionality, factors that explicitly determine effectiveness of the treatment should be considered. These factors include antigen/autoantibody specificity, single chain variable fragment (scFv) affinity, and autoantibody masking. Herein, we review the current evidence of CIR therapy with a focus on their therapeutic potential for autoimmune diseases and their challenges.

Several antiepileptic drugs (AEDs) are administrated during pregnancy according to recent therapeutic protocols. Ten percent of pregnant women with epilepsy give birth to offspring with malformations and teratogenic defects. Since the mechanism of action of AEDs is not yet completely understood, therefore, it could be hypothesized that they may cause cyto- or genotoxicity in embryonic fetus cells. To investigate this hypothesis, the genotoxicity and cell survival of AEDs treated human embryonic stem cells (hESCs) were investigated by single-cell gel electrophoresis (Comet assay) and MTS assay, respectively. HESCs (Royan H6 cell line) were treated in-vitro with high therapeutic doses of Carbamazepine, Gabapentin, Lamotrigine, Levetiracetam or Topiramate as monotherapy or combination therapy of each drug with Folic acid. After hESCs pluripotency confirmation, the effect of AEDs on cellular DNA damage of hESCs was investigated. levetiracetam and topiramate were found to damage the DNA significantly compared to untreated cells. The amount of DNA damage produced by carbamazepine and lamotrigine was similar while for gabapentin, the amount of DNA migration was very low and produced less DNA damage than the others. A considerable reduction in DNA damages occurred in genotoxicity in the presence of Folic acid in comparison to AEDs monotherapies. According to our results, all mentioned AEDs caused DNA damage, while Levetiracetam and topiramate caused more extensive DNA damages than the others. Noticeably, the addition of Folic acid to the treated cells decreased the DNA damages considerably.

Aims Immunomodulation concurrent with the promotion of β-cell function is a strategy used to develop innovative therapies for type 1 diabetes (T1D). Here, we assessed the therapeutic potential of co-administration of human clonal mesenchymal stem (stromal) cells (hBM-cMSCs) and liraglutide as a glucagon-like peptide-1 agonist in a non-human primate model with streptozotocin (STZ)-induced diabetes. Main methods Diabetes was induced through intravenous (i.v.) multiple low-dose (MLD) infusions of STZ at a dose of 30 mg/kg body weight (b.w.) for five consecutive days, followed by two booster injections of 35 mg/kg on days 12 and 19. After 90 days, the diabetic animals were randomly allocated to two groups: The combination therapy group (n = 4) received injections of 1.5 × 106 hBM-cMSCs/kg b.w. through celiac artery by angiography on days 91 and 105 and daily subcutaneous injections of liraglutide (up to 1.8 mg/day) until day 160 while vehicle group received phosphate-buffered saline. The monkeys were assessed for functional, immunological, and histological analysis. Key findings The combined treatment group had continued reduction in FBG levels up to day 160, which was accompanied by increased b.w., C-peptide, and β-cell function, and decreased HbA1c and fructosamine levels compared to vehicle group. The combined treatment increased Tregs, IL-4, IL-10, and TGF-β1 and decreased IL-6 and IL-1β. Stereological analysis of the pancreatic tissue exhibited more total volume of insulin-secreting islets in the combined treatment group compared to vehicle group. Significance Our findings demonstrated this combined treatment impaired the clinical symptoms of diabetes in this animal model through immunomodulation and β-cell preservation.

A major hindrance in islet transplantation as a feasible therapeutic approach for patients with type 1 diabetes is the insufficient oxygenation of the grafts, which results in cell death in portions of the implant. Here we address this limitation through the application of oxygen-generating microparticles (MP) and a fibrin-conjugated heparin/VEGF collagen scaffold to support cell survival by using a β cell line and pancreatic rat islets. MP are composed of a polyvinylpyrrolidone/hydrogen peroxide (PVP/H2O2) core and poly(D,L-lactide-co-glycolide) (PLGA) shell, along with immobilized catalase on the shell. The presence of MP is sufficient to reduce hypoxia-induced cell dysfunction and death for both cell types, resulting in localization of hypoxia-inducible factor (HIF-1α) into the cytoplasm and enhanced metabolic function. After co-transplantation of MP and a reduced islet mass (250 islet equivalents) within an angiogenic scaffold in the omental pouch of streptozotocin-induced diabetic nude mice, we have observed significantly promoted graft function as evidenced by improved blood glucose levels, body weight, glucose tolerance, serum C-peptide, and graft revascularization. These results suggest that the developed platform has great potential to enhance the efficacy for implants in cases where the cell dosage is critical for efficacy, such as islet transplantation and ischemic tissues.

Although transplantation of pancreatic islets is a promising approach for treatment of type 1 diabetes mellitus, the engraftment efficiency of these islets is limited by host immune responses. Extensive efforts have been made to immunoisolate these islets by introducing barriers on the islet surface. To date, these barriers have not successfully protected islets from attack by the immune system. In addition, the inevitable permeability of an islet capsule cannot prevent filtration by proinflammatory cytokines and islet self-antigens. Thus, we have developed a surface engineering approach for localized immonumodulation of the islet microenvironment. Jagged-1 (JAG-1), as a potent immunomodulatory factor, was immobilized on the islet surface by mediation of a double-layer of heterobifunctional poly (ethylene glycol) (PEG). Immobilization and functionality of JAG-1 on PEGylated islet surfaces were established. When co-cultured with splenocytes, the JAG-1 conjugated islets induced a significant increase in regulatory T cells and regulated the cytokine levels produced by immune cells. The results demonstrated that JAG-1 immobilization could improve immunoprotection of pancreatic islets by localized modulation of the immune milieu from an inflammatory to an anti-inflammatory state. We also evaluated the effects of surface modification of these islets by JAG-1 in a xenotransplantation model. The transplanted JAG-1/PEG/islets group showed a significantly reduced blood glucose levels compared with the control group of diabetic mice during the acute phase of the immune response to the transplanted islets. Our results demonstrated that surface modification has the potential to shift the immune system from an inflammatory to anti-inflammatory milieu and may offer a new prospective for immunoprotection of pancreatic islets.

Cardiosphere-derived cells (CDCs) have emerged as one of the most promising stem cell types for cardiac protection and repair. Exosomes are required for the regenerative effects of human CDCs and mimic the cardioprotective benefits of CDCs such as anti-apoptotic effect in animal myocardial infarction (MI) models. Here we aimed to investigate the anti-apoptotic effect of the hypoxic and normoxic human CDCs-derived exosomes on induced apoptosis in human embryonic stem cell-derived cardiomyocytes (hESC-CMs). In this study, CDCs were cultured under normoxic (18% O2) and hypoxic (1% O2) conditions and CDC-exosomes were isolated from conditioned media by differential ultracentrifugation. Cobalt chloride as hypoxia-mimetic agents at a high concentration was used to induce apoptosis in hESC-CMs. The caspase-3/7 activity was determined in apoptosis-induced hESC-CMs. The results indicated that the caspase-positive hESC-CMs were significantly decreased from 30.63 ± 1.44% (normalized against untreated cardiomyocytes) to 1.65 ± 0.1 and 1.1 ± 1.09 in the presence of normoxic exosomes (N-exo) at concentration of 25 and 50 μg/mL, respectively. Furthermore, hypoxic exosomes (H-exo) at concentration of 25 and 50 μg/mL led to 8.75 and 12.86 % reduction in caspase-positive cells, respectively. The anti-apoptotic activity of N-exo at the concentrations of 25 and 50 μg/mL was significantly higher than H-exo. These results could provide insights into optimal preparation of CDCs which would greatly influence the anti-apoptotic effect of CDC-exosomes. Totally, CDC-secreted exosomes have the potential to increase the survival of cardiomyocytes by inhibiting apoptosis. Therefore, CDC-exosomes can be developed as therapeutic strategy in ischemic cardiac disease.

The rapid expansion of immunotherapeutic approaches for treatment of various diseases, including cancers, has been greatly facilitated by the invention of new generation of antibodies. Clinical studies have indicated that anti-CD20 mAb-based therapies represent an effective treatment for various diseases with overexpression of CD20 on their cell surface, such as non-Hodgkin's lymphoma, hemolytic anemia, as well as autoimmune diseases like rheumatoid arthritis. Technically, due to a short extra membrane domain, the recombinant CD20 protein is a difficult antigen to raise immune responses. In search for new monoclonal antibodies, the authors used an antigenic polypeptide, which yielded numbers of new binders that may lead to production of anti-CD20 antibodies, with improved diagnostic or clinical attributes. Mice were immunized with extra membrane loop of human CD20 (exCD20) polypeptide. The exCD20 antigen showed a desired immune response and was able to develop a monoclonal antibody, 3B4C10, which reacted well with peptide antigen as well as native antigen on the surface of Raji B-cell line. The antibody 3B4C10 with a balanced K(on) and K(off) may be applicable in the construction of affinity columns or beads for isolation and purification of CD20-positive cells and cancer stem cells.

Islet transplantation has been hampered by loss of function due to poor revascularization. We hypothesize that co-transplantation of islets with human embryonic stem cell-derived mesenchymal stromal cells that conditionally overexpress VEGF (hESC-MSC:VEGF) may augment islet revascularization and reduce the minimal islet mass required to reverse diabetes in mice. HESC-MSCs were transduced by recombinant lentiviruses that allowed conditional (Dox-regulated) overexpression of VEGF. HESC-MSC:VEGF were characterized by tube formation assay. After co-transplantation of hESC-MSC:VEGF with murine islets in collagen-fibrin hydrogel in the omental pouch of diabetic nude mice, we measured blood glucose, body weight, glucose tolerance and serum C-peptide. As control, islets were transplanted alone or with non-transduced hESC-MSCs. Next, we compared functional parameters of 400 islets alone versus 200 islets co-transplanted with hESC-MSC:VEGF. As control, 200 islets were transplanted alone. Metabolic function of islets transplanted with hESC-MSC:VEGF significantly improved, accompanied by superior graft revascularization, compared with control groups. Transplantation of 200 islets with hESC-MSC:VEGF showed superior function over 400 islets alone. We conclude that co-transplantation of islets with VEGF-expressing hESC-MSCs allowed for at least a 50% reduction in minimal islet mass required to reverse diabetes in mice. This approach may contribute to alleviate the need for multiple donor organs per patient.

Over the past decades, tremendous efforts have been made to establish pancreatic islet transplantation as a standard therapy for type 1 diabetes. Recent advances in islet transplantation have resulted in steady improvements in the 5-year insulin independence rates for diabetic patients. Here we review the key challenges encountered in the islet transplantation field which include islet source limitation, sub-optimal engraftment of islets, lack of oxygen and blood supply for transplanted islets, and immune rejection of islets. Additionally, we discuss possible solutions for these challenges.