Multipotent stromal cells from human marrow home to and promote repair of pancreatic islets and renal glomeruli in diabetic NOD/scid mice

Therapeutic potential: The role of mesenchymal stem cells from diverse sources and their derived exosomes in diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common microvascular complications in diabetic patients, with its incidence continuously increasing in recent years. DN causes renal tissue damage and functional decline, expedites the aging process of the kidneys, and may ultimately progress leading to end-stage renal disease, severely impacting the patient's quality of life and prognosis. Mesenchymal stem cells (MSCs) are highly valued for their multipotent differentiation, paracrine functions, immunomodulatory effects, and capacity for tissue repair. Particularly, exosomes (Exo) derived from MSCs (MSCs-Exo) are rich in bioactive molecules and facilitate intercellular communication, participating in various physiological and pathological processes. MSCs and MSCs-Exo, in particular, have been demonstrated to have therapeutic effects in DN treatment research by encouraging tissue repair, fibrosis inhibition, and inflammation reduction. Research has shown that MSCs and MSCs-Exo have therapeutic effects in DN treatment by promoting tissue repair, inhibiting fibrosis, and reducing inflammation. Recent studies underscore the potential of MSCs and MSCs-Exo, highlighting their broad applicability in DN treatment. This review aims to provide a comprehensive summary of the scientific developments in treating DN using MSCs and MSCs-Exo from diverse sources, while also exploring their future therapeutic possibilities in detail.

Mouse islet-derived stellate cells are similar to, but distinct from, mesenchymal stromal cells and influence the beta cell function

AIMS

Evidence is accumulating of the therapeutic benefits of mesenchymal stromal cells (MSCs) in diabetes-related conditions. We have identified a novel population of stromal cells within islets of Langerhans - islet stellate cells (ISCs) - which have a similar morphology to MSCs. In this study we characterize mouse ISCs and compare their morphology and function to MSCs to determine whether ISCs may also have therapeutic potential in diabetes.

METHODS

ISCs isolated from mouse islets were compared to mouse bone marrow MSCs by analysis of cell morphology; expression of cell-surface markers and extracellular matrix (ECM) components; proliferation; apoptosis; paracrine activity; and differentiation into adipocytes, chondrocytes and osteocytes. We also assessed the effects of co-culture with ISCs or MSCs on the insulin secretory capacity of islet beta cells.

RESULTS

Although morphological similar, ISCs were functionally distinct from MSCs. Thus, ISCs were less proliferative and more apoptotic; they had different expression levels of important paracrine factors; and they were less efficient at differentiation down multiple lineages. Co-culture of mouse islets with ISCs enhanced glucose induced insulin secretion more effectively than co-culture with MSCs.

CONCLUSIONS

ISCs are a specific sub-type of islet-derived stromal cells that possess biological behaviors distinct from MSCs. The enhanced beneficial effects of ISCs on islet beta cell function suggests that they may offer a therapeutic target for enhancing beta cell functional survival in diabetes.

Novel lipid mediator 7S,14R-docosahexaenoic acid: biogenesis and harnessing mesenchymal stem cells to ameliorate diabetic mellitus and retinal pericyte loss

Introduction: Stem cells can be used to treat diabetic mellitus and complications. ω3-docosahexaenoic acid (DHA) derived lipid mediators are inflammation-resolving and protective. This study found novel DHA-derived 7S,14R-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-docosahexaenoic acid (7S,14R-diHDHA), a maresin-1 stereoisomer biosynthesized by leukocytes and related enzymes. Moreover, 7S,14R-diHDHA can enhance mesenchymal stem cell (MSC) functions in the amelioration of diabetic mellitus and retinal pericyte loss in diabetic db/db mice. Methods: MSCs treated with 7S,14R-diHDHA were delivered into db/db mice i.v. every 5 days for 35 days. Results: Blood glucose levels in diabetic mice were lowered by 7S,14R-diHDHA-treated MSCs compared to control and untreated MSC groups, accompanied by improved glucose tolerance and higher blood insulin levels. 7S,14R-diHDHA-treated MSCs increased insulin+ β-cell ratio and decreased glucogan+ α-cell ratio in islets, as well as reduced macrophages in pancreas. 7S,14R-diHDHA induced MSC functions in promoting MIN6 β-cell viability and insulin secretion. 7S,14R-diHDHA induced MSC paracrine functions by increasing the generation of hepatocyte growth factor and vascular endothelial growth factor. Furthermore, 7S,14R-diHDHA enhanced MSC functions to ameliorate diabetes-caused pericyte loss in diabetic retinopathy by increasing their density in retina in db/db mice. Discussion: Our findings provide a novel strategy for improving therapy for diabetes and diabetic retinopathy using 7S,14R-diHDHA-primed MSCs.

Extracellular vesicles from adipose mesenchymal stem cells target inflamed lymph nodes in experimental autoimmune encephalomyelitis

BACKGROUND AIMS

Adipose mesenchymal stem cells (ASCs) represent a promising therapeutic approach in inflammatory neurological disorders, including multiple sclerosis (MS). Recent lines of evidence indicate that most biological activities of ASCs are mediated by the delivery of soluble factors enclosed in extracellular vesicles (EVs). Indeed, we have previously demonstrated that small EVs derived from ASCs (ASC-EVs) ameliorate experimental autoimmune encephalomyelitis (EAE), a murine model of MS. The precise mechanisms and molecular/cellular target of EVs during EAE are still unknown.

METHODS

To investigate the homing of ASC-EVs, we intravenously injected small EVs loaded with ultra-small superparamagnetic iron oxide nanoparticles (USPIO) at disease onset in EAE-induced C57Bl/6J mice. Histochemical analysis and transmission electron microscopy were carried out 48 h after EV treatment. Moreover, to assess the cellular target of EVs, flow cytometry on cells extracted ex vivo from EAE mouse lymph nodes was performed.

RESULTS

Histochemical and ultrastructural analysis showed the presence of labeled EVs in lymph nodes but not in lungs and spinal cord of EAE injected mice. Moreover, we identified the cellular target of EVs in EAE lymph nodes by flow cytometry: ASC-EVs were preferentially located in macrophages, with a consistent amount also noted in dendritic cells and CD4+ T lymphocytes.

CONCLUSIONS

This represents the first direct evidence of the privileged localization of ASC-EVs in draining lymph nodes of EAE after systemic injection. These data provide prominent information on the distribution, uptake and retention of ASC-EVs, which may help in the development of EV-based therapy in MS.

Predictive factors that influence the clinical efficacy of umbilical cord-derived mesenchymal stromal cells in the treatment of type 2 diabetes mellitus

BACKGROUND

Our previous single-center, randomized, double-blinded, placebo-controlled phase 2 study evaluated the safety and effectiveness of human umbilical cord mesenchymal stromal cell (UC-MSC) transfusion for treating patients with type 2 diabetes mellitus (T2DM). Indeed, this potential treatment strategy was able to reduce insulin use by half in a considerable number of patients. However, many other patients' responses to UC-MSC transfusion were insignificant. The selection of patients who might benefit from UC-MSC treatment is crucial from a clinical standpoint.

METHODS

In this post hoc analysis, 37 patients who received UC-MSC transfusions were divided into two groups based on whether their glycated hemoglobin (hemoglobin A1c, or HbA1c) level was less than 7% after receiving UC-MSC treatment. The baseline differences between the two groups were summarized, and potential factors influencing efficacy of UC-MSCs for T2DM were analyzed by univariate and multivariate logistic regression. The correlations between the relevant hormone levels and the treatment effect were further analyzed.

RESULTS

At the 9-week follow-up, 59.5% of patients achieved their targeted HbA1c level. Male patients with lower baseline HbA1c and greater C-peptide area under the curve (AUCC-pep) values responded favorably to UC-MSC transfusion, according to multivariate analysis. The effectiveness of UC-MSCs transfusion was predicted by AUCC-pep (cutoff value: 14.22 ng/h/mL). Further investigation revealed that AUCC-pep was increased in male patients with greater baseline testosterone levels.

CONCLUSIONS

Male patients with T2DM with greater AUCC-pep may be more likely to respond clinically to UC-MSC therapy, and further large-scale multi-ethnic clinical studies should be performed to confirm the conclusion.

Bone marrow-derived c-kit positive stem cell administration protects against diabetes-induced nephropathy in a rat model by reversing PI3K/AKT/GSK-3β pathway and inhibiting cell apoptosis

Stem cell-based therapy has been proposed as a novel therapeutic strategy for diabetic nephropathy. This study was designed to evaluate the effect of systemic administration of rat bone marrow-derived c-kit positive (c-kit+) cells on diabetic nephropathy in male rats, focusing on PI3K/AKT/GSK-3β pathway and apoptosis as a possible therapeutic mechanism. Twenty-eight animals were randomly classified into four groups: Control group (C), diabetic group (D), diabetic group, intravenously received 50 μl phosphate-buffered saline (PBS) containing 3 × 105 c-kit- cells (D + ckit-); and diabetic group, intravenously received 50 μl PBS containing 3 × 105 c-Kit positive cells (D + ckit+). Control and diabetic groups intravenously received 50 μl PBS. C-kit+ cell therapy could reduce renal fibrosis, which was associated with attenuation of inflammation as indicated by decreased TNF-α and IL-6 levels in the kidney tissue. In addition, c-kit+ cells restored the expression levels of PI3K, pAKT, and GSK-3β proteins. Furthermore, renal apoptosis was decreased following c-kit+ cell therapy, evidenced by the lower apoptotic index in parallel with the increased Bcl-2 and decreased Bax and Caspase-3 levels. Our results showed that in contrast to c-kit- cells, the administration of c-kit+ cells ameliorate diabetic nephropathy and suggested that c-kit+ cells could be an alternative cell source for attenuating diabetic nephropathy.

Current status of stem cell therapy for type 1 diabetes: a critique and a prospective consideration

Over the past decade, there had been progress in the development of cell therapy for insulin-dependent diabetes. Nevertheless, important hurdles that need to be overcome still remain. Protocols for the differentiation of pluripotent stem cells into pancreatic progenitors or fully differentiated β-cells have been developed. The resulting insulin-producing cells can control chemically induced diabetes in rodents and were the subject of several clinical trials. However, these cells are immunogenic and possibly teratogenic for their transplantation, and an immunoisolation device and/or immunosuppression is needed. A growing number of studies have utilized genetic manipulations to produce immune evasive cells. Evidence must be provided that in addition to the expected benefit, gene manipulations should not lead to any unforeseen complications. Mesenchymal stem/stromal cells (MSCs) can provide a viable alternative. MSCs are widely available from many tissues. They can form insulin-producing cells by directed differentiation. Experimentally, evidence has shown that the transplantation of allogenic insulin-producing cells derived from MSCs is associated with a muted allogeneic response that does not interfere with their functionality. This can be explained by the immunomodulatory functions of the MSC subpopulation that did not differentiate into insulin-producing cells. Recently, exosomes derived from naive MSCs have been used in the experimental domain to treat diabetes in rodents with varying degrees of success. Several mechanisms for their beneficial functions were proposed including a reduction in insulin resistance, the promotion of autophagy, and an increase in the T regulatory population. However, euglycemia was not achieved in any of these experiments. We suggest that exosomes derived from β-cells or insulin-producing cells (educated) can provide a better therapeutic effect than those derived from undifferentiated cells.

Embryonic-stem-cell-derived mesenchymal stem cells relieve experimental contact urticaria by regulating the functions of mast cells and T cells

Contact urticaria (CU) is an inflammatory skin disorder triggered by specific substances upon skin contact, leading to immediate acute or chronic manifestations characterized by swelling and redness. While mesenchymal stem cells (MSCs) are increasingly recognized for their therapeutic potential in immune diseases, research on the efficacy and mechanisms of stem cell therapy for urticaria remains scarce. This study investigates the regulatory role of embryonic-stem-cell-derived multipotent MSCs (M-MSCs) administered in a CU mouse model. Therapeutic effects of M-MSC administration were assessed in a Trimellitic anhydride-induced contact urticaria model, revealing significant inhibition of urticarial reactions, including ear swelling, itchiness, and skin lesion. Moreover, M-MSC administration exerted control over effector T cell activities in major lymphoid and peripheral tissues, while also suppressing mast cell degranulation in peripheral tissues. Notably, the inhibitory effects mediated by M-MSCs were found to be TGF-β-dependent. Our study demonstrates the capacity of M-MSCs to regulate contact urticaria in a murine model, harmonizing the activation of inflammatory T cells and mast cells. Additionally, we suggest that TGF-β derived from M-MSCs could play a pivotal role as an inhibitory mechanism in contact urticaria.

Bone marrow mesenchymal stem cell-derived exosomal miR-30e-5p ameliorates high-glucose induced renal proximal tubular cell pyroptosis by inhibiting ELAVL1

BACKGROUND

The rapid increase in the prevalence of diabetes has resulted in more cases of diabetic kidney disease (DKD). Treatment with bone marrow mesenchymal stem cells (BMSCs) may represent an alternative strategy to manage DKD.

METHODS

HK-2 cells were treated with 30 mM high glucose (HG). Bone marrow MSC-derived exosomes (BMSC-exos) were isolated and internalized into HK-2 cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) and lactate dehydrogenase (LDH) assays were used to measure viability and cytotoxicity. The secretion of IL-1β and IL-18 was measured by ELISA. Pyroptosis was assessed by flow cytometry. Quantitative RT-PCR was used to measure the levels of miR-30e-5p, ELAV like RNA binding protein 1 (ELAVL1), IL-1β, and IL-18. The expression of ELAVL1 and pyroptosis-associated cytokine proteins was determined by western blot analysis. A dual-luciferase reporter gene assay was conducted to confirm the relationship between miR-30e-5p and ELAVL1.

RESULTS

BMSC-exos decreased LDH, IL-1β, and IL-18 secretion and inhibited the expression of the pyroptosis-related factors (IL-1β, caspase-1, GSDMD-N, and NLRP3) in HG-induced HK-2 cells. Moreover, miR-30e-5p depletion derived from BMSC-exos promoted HK-2 cell pyroptosis. Besides, miR-30e-5p over-expression or ELVAL1 knockdown could directly inhibit pyroptosis. ELAVL1 was a target of miR-30e-5p and knocking down ELAVL1 reversed the effect of miR-30e-5p inhibition in BMSC-exos-treated HK-2 cells.

CONCLUSIONS

BMSC-derived exosomal miR-30e-5p inhibits caspase-1-mediated pyroptosis by targeting ELAVL1 in HG-induced HK-2 cells, which might provide a new strategy for treating DKD.

Mesenchymal Stem/Stromal Cells Therapy for Metabolic Syndrome: Potential Clinical Application?

Mesenchymal stem/stromal cells (MSCs), a class of cells with proliferative, immunomodulatory, and reparative functions, have shown therapeutic potential in a variety of systemic diseases, including metabolic syndrome (MetS). The cluster of morbidities that constitute MetS might be particularly amenable for the application of MSCs, which employ an arsenal of reparative actions to target multiple pathogenic pathways simultaneously. Preclinical studies have shown that MSCs can reverse pathological changes in MetS mainly by inhibiting inflammation, improving insulin resistance, regulating glycolipid metabolism, and protecting organ function. However, several challenges remain to overcome before MSCs can be applied for treating MetS. For example, the merits of autologous versus allogeneic MSCs sources remain unclear, particularly with autologous MSCs obtained from the noxious MetS milieu. The distinct characteristics and relative efficacy of MSCs harvested from different tissue sources also require clarification. Moreover, to improve the therapeutic efficacy of MSCs, investigators have explored several approaches that improved therapeutic efficacy but may involve potential safety concerns. This review summarized the potentially useful MSCs strategy for treating MetS, as well as some hurdles that remain to be overcome. In particular, larger-scale studies are needed to determine the therapeutic efficacy and safety of MSCs for clinical application.

Safety and Preliminary Efficacy of Mesenchymal Stromal Cell (ORBCEL-M) Therapy in Diabetic Kidney Disease: A Randomized Clinical Trial (NEPHSTROM)

SIGNIFICANCE STATEMENT

Mesenchymal stromal cells (MSCs) may offer a novel therapy for diabetic kidney disease (DKD), although clinical translation of this approach has been limited. The authors present findings from the first, lowest dose cohort of 16 adults with type 2 diabetes and progressive DKD participating in a randomized, placebo-controlled, dose-escalation phase 1b/2a trial of next-generation bone marrow-derived, anti-CD362 antibody-selected allogeneic MSCs (ORBCEL-M). A single intravenous (iv) infusion of 80×10 6 cells was safe and well-tolerated, with one quickly resolved infusion reaction in the placebo group and no subsequent treatment-related serious adverse events (SAEs). Compared with placebo, the median annual rate of decline in eGFR was significantly lower with ORBCEL-M, although mGFR did not differ. The results support further investigation of ORBCEL-M in this patient population in an appropriately sized phase 2b study.

BACKGROUND

Systemic therapy with mesenchymal stromal cells may target maladaptive processes involved in diabetic kidney disease progression. However, clinical translation of this approach has been limited.

METHODS

The Novel Stromal Cell Therapy for Diabetic Kidney Disease (NEPHSTROM) study, a randomized, placebo-controlled phase 1b/2a trial, assesses safety, tolerability, and preliminary efficacy of next-generation bone marrow-derived, anti-CD362-selected, allogeneic mesenchymal stromal cells (ORBCEL-M) in adults with type 2 diabetes and progressive diabetic kidney disease. This first, lowest dose cohort of 16 participants at three European sites was randomized (3:1) to receive intravenous infusion of ORBCEL-M (80×10 6 cells, n =12) or placebo ( n =4) and was followed for 18 months.

RESULTS

At baseline, all participants were negative for anti-HLA antibodies and the measured GFR (mGFR) and estimated GFR were comparable between groups. The intervention was safe and well-tolerated. One placebo-treated participant had a quickly resolved infusion reaction (bronchospasm), with no subsequent treatment-related serious adverse events. Two ORBCEL-M recipients died during follow-up of causes deemed unrelated to the trial intervention; one recipient developed low-level anti-HLA antibodies. The median annual rate of kidney function decline after ORBCEL-M therapy compared with placebo did not differ by mGFR, but was significantly lower by eGFR estimated by the Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease equations. Immunologic profiling provided evidence of preservation of circulating regulatory T cells, lower natural killer T cells, and stabilization of inflammatory monocyte subsets in those receiving the cell therapy compared with placebo.

CONCLUSIONS

Findings indicate safety and tolerability of intravenous ORBCEL-M cell therapy in the trial's lowest dose cohort. The rate of decline in eGFR (but not mGFR) over 18 months was significantly lower among those receiving cell therapy compared with placebo. Further studies will be needed to determine the therapy's effect on CKD progression.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrial.gov NCT02585622 .

A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome

Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.

Umbilical cord-derived mesenchymal stromal cells preserve endogenous insulin production in type 1 diabetes: a Phase I/II randomised double-blind placebo-controlled trial

AIM/HYPOTHESIS

This study aimed to investigate the safety and efficacy of treatment with allogeneic Wharton's jelly-derived mesenchymal stromal cells (MSCs) in recent-onset type 1 diabetes.

METHODS

A combined Phase I/II trial, composed of a dose escalation followed by a randomised double-blind placebo-controlled study in parallel design, was performed in which treatment with allogeneic MSCs produced as an advanced therapy medicinal product (ProTrans) was compared with placebo in adults with newly diagnosed type 1 diabetes. Inclusion criteria were a diagnosis of type 1 diabetes <2 years before enrolment, age 18-40 years and a fasting plasma C-peptide concentration >0.12 nmol/l. Randomisation was performed with a web-based randomisation system, with a randomisation code created prior to the start of the study. The randomisation was made in blocks, with participants randomised to ProTrans or placebo treatment. Randomisation envelopes were kept at the clinic in a locked room, with study staff opening the envelopes at the baseline visits. All participants and study personnel were blinded to group assignment. The study was conducted at Karolinska University Hospital, Stockholm, Sweden.

RESULTS

Three participants were included in each dose cohort during the first part of the study. Fifteen participants were randomised in the second part of the study, with ten participants assigned to ProTrans treatment and five to placebo. All participants were analysed for the primary and secondary outcomes. No serious adverse events related to treatment were observed and, overall, few adverse events (mainly mild upper respiratory tract infections) were reported in the active treatment and placebo arms. The primary efficacy endpoint was defined as Δ-change in C-peptide AUC for a mixed meal tolerance test at 1 year following ProTrans/placebo infusion compared with baseline performance prior to treatment. C-peptide levels in placebo-treated individuals declined by 47%, whereas those in ProTrans-treated individuals declined by only 10% (p<0.05). Similarly, insulin requirements increased in placebo-treated individuals by a median of 10 U/day, whereas insulin needs of ProTrans-treated individuals did not change over the follow-up period of 12 months (p<0.05).

CONCLUSIONS/INTERPRETATION

This study suggests that allogeneic Wharton's jelly-derived MSCs (ProTrans) is a safe treatment for recent-onset type 1 diabetes, with the potential to preserve beta cell function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03406585 FUNDING: The sponsor of the clinical trial is NextCell Pharma AB, Stockholm, Sweden.

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.

Sustainable Approach of Functional Biomaterials-Tissue Engineering for Skin Burn Treatment: A Comprehensive Review

Burns are a widespread global public health traumatic injury affecting many people worldwide. Non-fatal burn injuries are a leading cause of morbidity, resulting in prolonged hospitalization, disfigurement, and disability, often with resulting stigma and rejection. The treatment of burns is aimed at controlling pain, removing dead tissue, preventing infection, reducing scarring risk, and tissue regeneration. Traditional burn wound treatment methods include the use of synthetic materials such as petroleum-based ointments and plastic films. However, these materials can be associated with negative environmental impacts and may not be biocompatible with the human body. Tissue engineering has emerged as a promising approach to treating burns, and sustainable biomaterials have been developed as an alternative treatment option. Green biomaterials such as collagen, cellulose, chitosan, and others are biocompatible, biodegradable, environment-friendly, and cost-effective, which reduces the environmental impact of their production and disposal. They are effective in promoting wound healing and reducing the risk of infection and have other benefits such as reducing inflammation and promoting angiogenesis. This comprehensive review focuses on the use of multifunctional green biomaterials that have the potential to revolutionize the way we treat skin burns, promoting faster and more efficient healing while minimizing scarring and tissue damage.

Recent advances in molecular mechanisms of acute kidney injury in patients with diabetes mellitus

Several insults can lead to acute kidney injury (AKI) in native kidney and transplant patients, with diabetes critically contributing as pivotal risk factor. High glucose per se can disrupt several signaling pathways within the kidney that, if not restored, can favor the instauration of mechanisms of maladaptive repair, altering kidney homeostasis and proper function. Diabetic kidneys frequently show reduced oxygenation, vascular damage and enhanced inflammatory response, features that increase the kidney vulnerability to hypoxia. Importantly, epidemiologic data shows that previous episodes of AKI increase susceptibility to diabetic kidney disease (DKD), and that patients with DKD and history of AKI have a generally worse prognosis compared to DKD patients without AKI; it is therefore crucial to monitor diabetic patients for AKI. In the present review, we will describe the causes that contribute to increased susceptibility to AKI in diabetes, with focus on the molecular mechanisms that occur during hyperglycemia and how these mechanisms expose the different types of resident renal cells to be more vulnerable to maladaptive repair during AKI (contrast- and drug-induced AKI). Finally, we will review the list of the existing candidate biomarkers of diagnosis and prognosis of AKI in patients with diabetes.

Extracellular vesicles from mesenchymal stem cells reduce neuroinflammation in hippocampus and restore cognitive function in hyperammonemic rats

Chronic hyperammonemia, a main contributor to hepatic encephalopathy (HE), leads to neuroinflammation which alters neurotransmission leading to cognitive impairment. There are no specific treatments for the neurological alterations in HE. Extracellular vesicles (EVs) from mesenchymal stem cells (MSCs) reduce neuroinflammation in some pathological conditions. The aims were to assess if treatment of hyperammonemic rats with EVs from MSCs restores cognitive function and analyze the underlying mechanisms. EVs injected in vivo reach the hippocampus and restore performance of hyperammonemic rats in object location, object recognition, short-term memory in the Y-maze and reference memory in the radial maze. Hyperammonemic rats show reduced TGFβ levels and membrane expression of TGFβ receptors in hippocampus. This leads to microglia activation and reduced Smad7-IkB pathway, which induces NF-κB nuclear translocation in neurons, increasing IL-1β which alters AMPA and NMDA receptors membrane expression, leading to cognitive impairment. These effects are reversed by TGFβ in the EVs from MSCs, which activates TGFβ receptors, reducing microglia activation and NF-κB nuclear translocation in neurons by normalizing the Smad7-IkB pathway. This normalizes IL-1β, AMPA and NMDA receptors membrane expression and, therefore, cognitive function. EVs from MSCs may be useful to improve cognitive function in patients with hyperammonemia and minimal HE.

Immunomodulatory Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Allergic Airway Disease

Mesenchymal stem cells (MSCs) have been reported as promising candidates for the treatment of various diseases, especially allergic diseases, as they have the capacity to differentiate into various cells. However, MSCs itself have several limitations such as creating a risk of aneuploidy, difficulty in handling them, immune rejection, and tumorigenicity, so interest in the extracellular vesicles (EVs) released from MSCs are increasing, and many studies have been reported. Previous studies have shown that extracellular vesicles (EVs) produced by MSCs are as effective as the MSCs themselves in suppression of allergic airway inflammation through the suppression of Th2 cytokine production and the induction of regulatory T cells (Treg) expansion. EVs are one of the substances secreted by paracrine induction from MSCs, and because it exerts its effect by delivering contents such as mRNA, microRNA, and proteins to the receptor cell, it can reduce the problems or risks related to stem cell therapy. This article reviews the immunomodulatory properties of MSCs-derived EVs and their therapeutic implications for allergic airway disease.

Maintaining Myofibroblastic-Like Cancer-Associated Fibroblasts by Cancer Stemness Signal Transduction Feedback Loop

Background: Myofibroblast-like cancer-associated fibroblasts (myCAF) in the tumor microenvironment (TME) promote cancer stemness, growth, and metastasis. Cancer cell-derived osteopontin (OPN) has been reported as a biomarker related to malignant cancer growth. In this study, we confirm that cancer cell stemness is required for the maintenance of an OPN-induced myCAF phenotype. Methods: MDA-MB-231 or HepG2 cells and Sox2 knockout variants were co-cultured with human mesenchymal stem cells (MSC). In selected instances, the OPN bioactivity inhibitor OPN-R3 aptamer (APT), OPN-R3 mutant aptamer (MuAPT), or cancer cell stemness inhibitor BBI-608 were added separately. MDA-MB-231 cancer stemness and myCAF markers were quantified by real-time PCR. Stemness-lacking cancer cell mice models were created to confirm that stemness is required for the maintenance of the OPN-induced myCAF phenotype in vivo. Results: In an MDA-MB-231 co-culture system, myCAF and stemness markers increased. Osteopontin and stemness blockade in this co-culture system decreased both myCAF and stemness marker expression, but OPN blockade after 72 hours had no effect. In contrast, when BBI608 was added at 72 hours, myCAF markers were abated after 36-hour treatment. Replacing wildtype with MDA-MB-231(-/-sox2) in co-cultures at 72 hours decreased myCAF marker expression to baseline despite the Western blot confirming the presence of OPN. Conversely, replacing MDA-MB-231(-/-sox2) cells with wildtype increased myCAF marker expression to a level equivalent to the MDA-MB-231+MSC co-culture system. In vivo osteopontin blockade diminished stemness and myCAF marker expression and stemness lacking cancer cell models, indicated by decreasing myCAF presence. Experiments were repeated in a HepG2 cell line with identical results. Conclusions: Cancer and myCAF crosstalk increases myCAF maintenance and cancer cell stemness. In this study using human breast and liver cancer cell lines, maintenance of the OPN-induced myCAF phenotype also requires cancer stemness. This indicates that the myCAF phenotype requires two distinct signaling pathways: initiation and maintenance.

Reprogramming adipose mesenchymal stem cells into islet β-cells for the treatment of canine diabetes mellitus

BACKGROUND

Islet transplantation is an excellent method for the treatment of type I diabetes mellitus. However, due to the limited number of donors, cumbersome isolation and purification procedures, and immune rejection, the clinical application is greatly limited. The development of a simple and efficient new method to obtain islet β-cells is a key problem that urgently requires a solution for the treatment of type I diabetes mellitus.

METHODS

In this study, Pbx1, Rfx3, Pdx1, Ngn3, Pax4 and MafA were used to form a six-gene combination to efficiently reprogram aMSCs (adipose mesenchymal stem cells) into ra-βCs (reprogrammed aMSCs-derived islet β-cells), and the characteristics and immunogenicity of ra-βCs were detected. Feasibility of ra-βCs transplantation for the treatment of diabetes mellitus in model dogs and clinical dogs was detected.

RESULTS

In this study, aMSCs were efficiently reprogrammed into ra-βCs using a six-gene combination. The ra-βCs showed islet β-cell characteristics. The immunogenicity of ra-βCs was detected and remained low in vitro and increased after transplantation. The cotransplantation of ra-βCs and aMSCs in the treatment of a model and clinical cases of canine diabetes mellitus achieved ideal therapeutic effects.

CONCLUSIONS

The aMSCs were efficiently reprogrammed into ra-βCs using a six-gene combination. The cotransplantation of ra-βCs and aMSCs as a treatment for canine diabetes is feasible, which provides a theoretical basis and therapeutic method for the treatment of canine diabetes.

Deducing Insulin-Producing Cells from Goat Adipose Tissue-Derived Mesenchymal Stem Cells

Mesenchymal stem cell is a potent tool for regenerative medicine against control of incurable diseases in human and animals. Diabetes mellitus is one such condition marked with the blood glucose is high due to lack of insulin (INS) hormone secreted by the pancreatic cells. Rare, but sporadic, cases of dysfunctional pancreatic cells in goat as well as the promises of stem cell therapy as an off-the-shelf medicine prompted us to explore the potential of adipose-derived goat mesenchymal stem cells (AD-MSCs) to transdifferentiate into pancreatic islet-like cells. We isolated, in vitro cultured, and characterized the AD-MSCs by expression of MSC-specific markers and differentiation into multiple mesodermal lineage cells. The characterized AD-MSCs were in vitro transdifferentiated into INS-producing islet-like cells using a cocktail of glucose, nicotinamide, activin-A, exendin-4, pentagastrin, retinoic acid, and mercaptoethanol in 3 weeks. The transdifferentiated islet-like cells demonstrated the expression of pancreatic endoderm-specific transcripts PDX1, NGN3, PAX6, PAX4, ISL1, and GLUT2 as well as protein expression of pancreatic and duodenal homeobox 1 (PDX1), INS, and Islets 1 (ISL1). The islet-like cells also demonstrated the significant glucose-dependent INS release with respect to the course of transdifferentiation regime. The study envisaged to create the building material for basic research into mechanism of glucose homeostasis, which may pave road for developments in diabetes drug discovery and regenerative therapies.

Mesenchymal stem cells derived from the kidney can ameliorate diabetic nephropathy through the TGF-β/Smad signaling pathway

Diabetic nephropathy (DN) has been introduced as one of the main microvascular complications in diabetic patients, the most common cause of end-stage renal disease (ESRD). Based on the therapeutic potential of mesenchymal stem cells in tissue repair, we aimed to test the hypothesis that kidney stem cells (KSCs) might be effective in the kidney regeneration process. Stem cells from rat kidney were separated, and the surface stem cell markers were determined by flow cytometry analysis. Thirty-two Sprague Dawley rats were divided into four groups (control, control that received kidney stem cells, diabetic, diabetic treated with stem cells). To establish diabetic, model STZ (streptozotocin) (60 mg/kg) was used. The KSCs were injected into experimental groups via tail vein (2 × 10⁶ cells/rat). In order to determine the impact of stem cells on the function and structure of the kidney, biochemical and histological parameters were measured. Further, the expression of miRNA-29a, miR-192, IL-1β, and TGF-β was determined through the real-time PCR technique. Phosphorylation of Smad2/3 was evaluated by using the standard western blotting. The KSCs significantly reduced blood nitrogen (BUN), serum creatinine (Scr), and 24-h urinary proteins in DN (P < 0.05). IL-1β and TGF-β significantly increased in the kidney of diabetic rats. In addition, the expression of miR-29a is significantly increased, whereas miR-192 decreased after treatment with KSCs (P < 0.05). Diabetic rats showed an increased level of phosphorylation of both Smad2 and Smad3 (P < 0.05). Periodic acid-Schiff (PAS) staining showed improved histopathological changes in the presence of KSCs. Stem cells derived from adult rat kidney may be an option for treating the early DN to improve the functions and structure of kidneys in rats with DN.

Metabolic Syndrome-Related Kidney Injury: A Review and Update

Metabolic syndrome (MetS) includes visceral obesity, hyperglycemia, dyslipidemia, and hypertension. The prevalence of MetS is 20-25%, which is an important risk factor for chronic kidney disease (CKD). MetS causes effects on renal pathophysiology, including glomerular hyperfiltration, RAAS, microalbuminuria, profibrotic factors and podocyte injury. This review compares several criteria of MetS and analyzes their differences. MetS and the pathogenesis of CKD includes insulin resistance, obesity, dyslipidemia, inflammation, oxidative stress, and endothelial dysfunction. The intervention of MetS-related renal damage is the focus of this article and includes controlling body weight, hypertension, hyperglycemia, and hyperlipidemia, requiring all components to meet the criteria. In addition, interventions such as endoplasmic reticulum stress, oxidative stress, gut microbiota, body metabolism, appetite inhibition, podocyte apoptosis, and mesenchymal stem cells are reviewed.

Mesenchymal stem cell transplantation in newly diagnosed type-1 diabetes patients: a phase I/II randomized placebo-controlled clinical trial

Background

Type-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.

Methods

After 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.

Results

The 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.

Conclusions

Taken 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).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02941-w.

The anti-inflammatory feature of glucagon-like peptide-1 and its based diabetes drugs—Therapeutic potential exploration in lung injury

Since 2005, GLP-1 receptor (GLP-1R) agonists (GLP-1RAs) have been developed as therapeutic agents for type 2 diabetes (T2D). GLP-1R is not only expressed in pancreatic islets but also other organs, especially the lung. However, controversy on extra-pancreatic GLP-1R expression still needs to be further resolved, utilizing different tools including the use of more reliable GLP-1R antibodies in immune-staining and co-immune-staining. Extra-pancreatic expression of GLP-1R has triggered extensive investigations on extra-pancreatic functions of GLP-1RAs, aiming to repurpose them into therapeutic agents for other disorders. Extensive studies have demonstrated promising anti-inflammatory features of GLP-1RAs. Whether those features are directly mediated by GLP-1R expressed in immune cells also remains controversial. Following a brief review on GLP-1 as an incretin hormone and the development of GLP-1RAs as therapeutic agents for T2D, we have summarized our current understanding of the anti-inflammatory features of GLP-1RAs and commented on the controversy on extra-pancreatic GLP-1R expression. The main part of this review is a literature discussion on GLP-1RA utilization in animal models with chronic airway diseases and acute lung injuries, including studies on the combined use of mesenchymal stem cell (MSC) based therapy. This is followed by a brief summary.

Extracellular Vesicles Released from Stem Cells as a New Therapeutic Strategy for Primary and Secondary Glomerulonephritis

Current treatment of primary and secondary glomerulopathies is hampered by many limits and a significant proportion of these disorders still evolves towards end-stage renal disease. A possible answer to this unmet challenge could be represented by therapies with stem cells, which include a variety of progenitor cell types derived from embryonic or adult tissues. Stem cell self-renewal and multi-lineage differentiation ability explain their potential to protect and regenerate injured cells, including kidney tubular cells, podocytes and endothelial cells. In addition, a broad spectrum of anti-inflammatory and immunomodulatory actions appears to interfere with the pathogenic mechanisms of glomerulonephritis. Of note, mesenchymal stromal cells have been particularly investigated as therapy for Lupus Nephritis and Diabetic Nephropathy, whereas initial evidence suggest their beneficial effects in primary glomerulopathies such as IgA nephritis. Extracellular vesicles mediate a complex intercellular communication network, shuttling proteins, nucleic acids and other bioactive molecules from origin to target cells to modulate their functions. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, reparative and immunomodulatory properties of parental cells and are increasingly recognized as a cell-free alternative to stem cell-based therapies for different diseases including glomerulonephritis, also considering the low risk for potential adverse effects such as maldifferentiation and tumorigenesis. We herein summarize the renoprotective potential of therapies with stem cells and extracellular vesicles derived from progenitor cells in glomerulonephritis, with a focus on their different mechanisms of actions. Technological progress and growing knowledge are paving the way for wider clinical application of regenerative medicine to primary and secondary glomerulonephritis: this multi-level, pleiotropic therapy may open new scenarios overcoming the limits and side effects of traditional treatments, although the promising results of experimental models need to be confirmed in the clinical setting.

Mesenchymal Stem Cell-Derived Extracellular Vesicles as Non-Coding RNA Therapeutic Vehicles in Autoimmune Diseases

Autoimmune diseases (ADs) are characterized by the activation of the immune system against self-antigens. More common in women than in men and with an early onset, their incidence is increasing worldwide, and this, combined with their chronic nature, is contributing to an enlarged medical and economic burden. Conventional immunosuppressive agents are designed to alleviate symptoms but do not constitute an effective therapy, highlighting a need to develop new alternatives. In this regard, mesenchymal stem cells (MSCs) have demonstrated powerful immunosuppressive and regenerative effects. MSC-derived extracellular vesicles (MSC-EVs) have shown some advantages, such as less immunogenicity, and are proposed as novel therapies for ADs. In this review, we summarize current perspectives on therapeutic options for ADs based on MSCs and MSC-EVs, focusing particularly on their mechanism of action exerted through their non-coding RNA (ncRNA) cargo. A complete state-of-the-art review was performed, centralized on some of the most severe ADs (rheumatoid arthritis, autoimmune type 1 diabetes mellitus, and systemic lupus erythematosus), giving evidence that a promising field is evolving to overcome the current knowledge and provide new therapeutic possibilities centered on MSC-EVs and their role as ncRNA delivery vehicles for AD gene therapy.

Hypoxia preconditioning increases the ability of healthy but not diabetic rat-derived adipose stromal/stem cells (ASC) to improve histological lesions of streptozotocin-induced diabetic nephropathy

BACKGROUND

Mesenchymal stromal cells (MSC) have demonstrated ability to improve diabetic nephropathy (DN) in experimental models, as well as by improving kidney endogenous progenitor cells proliferation and differentiation. Many studies have demonstrated the effect of hypoxia on MSC improving their functionality but the potential enhancement of the nephroprotective properties of MSC cultured under low oxygen concentration has been explored in few studies, none of them in the context of DN. On the other hand, diabetes is associated with abnormalities in MSCs functionality. These findings related to the hypoxia preconditioning ability to enhance adipose-tissue derived-MSC (ASC) performance have led us to wonder if hypoxia could increase the known beneficial effect of normal ASC in DN and if it could correct the expected inability of diabetic rat-derived ASC to exert this effect in vivo. To answer these questions, in the present study we have used ASC from healthy and diabetic-induced rats, cultured under standard conditions or hypoxia preconditioned, in a DN rat model induced by streptozotocin (STZ).

METHODS

Diabetes was induced in Wistar-rats by 60 mg/kg streptozotocin (STZ) intraperitoneal injection. Fifteen days thereafter, five diabetic-induced rats and five healthy, previously injected with saline, were sacrificed and used as ASC donors . Both healthy and diabetic rat-derived ASC (cASC and dASC, respectively) were cultured under standard conditions (21%O2)(N) or were subjected to a 48 h conditioning period in hypoxia (3%O2)(H). Thus, four types of cells were generated depending on their origin (healthy or diabetic-induced rats) and the culture conditions(N or H):cASC-N, cASC-H, dASC-N and dASC-H. DN experimental study were carried out fifteen days after STZ induction of diabetes in fifty-two healthy rats. DN-induced-animals were randomly assigned to be injected with 200 µL saline as placebo or with 3 × 106 cASC-N, cASC-H, dASC-N or dASC-H, according to the study group. Serum glucose, urea and creatinine, and urine albumin levels were measured at 2-weeks intervals until day+ 45 after ND-induction.Animals were sacrificed and kidneys extracted for histopathological and transmission electron microcopy analysis RESULTS: None of the four study groups that received cell treatment showed significant changes in serum glucose, urea and creatinine levels, urine albumin concentration and body weight compared to placebo ND-induced group. Interestingly, only the group that received cASC-H showed a reduction in glucose and creatinine levels although it did not reach statistical significance.All DN-induced groups treated with ASC reduced significantly renal lesions such as mesangial expansion, mesangiolysis, microaneurysms and acute tubular necrosis compared to ND-induced placebo group (p ≤ 0.05). Renal injuries such as clear tubular cell changes, thickening of tubular basement membrane, tubular cysts and interstitial fibrosis significantly showed reduction in ND-induced rats treated with cASC-H regarding to their received cASCN (p ≤ 0.05). Non statistical differences were observed in the improvement capacity of cASC and dASC culture under standard condition.However, hypoxia preconditioning reduces the presence of tubular cysts (p ≤ 0.01).

CONCLUSIONS

Hypoxia preconditioning enhances the ability of healthy rat-derived ASC to improve kidney injury in a rat model of DN. Moreover, diabetic-derived ASC exhibits a similar ability to healthy ASC which is clearly more than expected, but it is not significantly modified by hypoxia preconditioning.

Mesenchymal Stem Cell-Based COVID-19 Therapy: Bioengineering Perspectives

The novel pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). Mesenchymal stem cells (MSCs) are currently utilized in clinics for pulmonary inflammatory diseases, including acute respiratory distress syndrome and acute lung injury. Given that MSCs offer a promising treatment against COVID-19, they are being used against COVID-19 in more than 70 clinical trials with promising findings. Genetically engineered MSCs offer promising therapeutic options in pulmonary diseases. However, their potential has not been explored yet. In this review, we provide perspectives on the functionally modified MSCs that can be developed and harnessed for COVID-19 therapy. Options to manage the SARS-CoV-2 infection and its variants using various bioengineering tools to increase the therapeutic efficacy of MSCs are highlighted.

Recent Progress of Research Regarding the Applications of Stem Cells for Treating Diabetes Mellitus

At present, the number of diabetes patients has exceeded 537 million worldwide and this number continues to increase. Stem cell therapy represents a new direction for the treatment of diabetes; the use of stem cells overcomes some shortcomings associated with traditional therapies. Functional β-cells play an important role in the pathogenesis of diabetes. As therapeutic targets, functional β-cells are restored by a variety of stem cells, including pluripotent stem cells, mesenchymal cells, and urine-derived stem cells. Although all types of stem cells have their own characteristics, they mainly promote the repair and regeneration of β-cells through directional differentiation, immunomodulation, and paracrine signaling after homing to the injured site. However, stem cell therapy still faces many obstacles, such as low long-term cell survival rate after transplantation, low maintenance time of blood glucose homeostasis, immune rejection, and tumorigenesis. Recently, genetically edited pluripotent stem cells and the co-transplantation of mesenchymal stem cells and islet cells have made significant progress in improving the efficacy of stem cell transplantation processes, also providing powerful tools for the study of the mechanisms underlying diabetes and disease modeling. In this review, we first focused on: (1) stem cells as a pool for the differentiation of insulin-producing cells; (2) stem cells as a source for regenerative repair of damaged islets and as a potential co-transplanted population with islets; (3) the potential of combining gene editing with stem cell therapy; and (4) selection of the stem cell transplantation approach. Based on these topics, we discuss the challenges within the field of adapting stem cell-supported and stem cell-derived transplantations, and the promising routes for overcoming these problems.

Mesenchymal stem cells: A new therapeutic tool for chronic kidney disease

Chronic kidney disease (CKD) has a major impact on public health, which could progress to end-stage kidney disease (ESRD) and consume many medical resources. Currently, the treatment for CKD has many flaws, so more effective treatment tools are urgently required for CKD. Mesenchymal stem cells (MSCs) are primitive cells with self-renewal and proliferation capacity and differentiation potential. Extensive preclinical and clinical data has shown that cell-based therapies using MSCs can modulate immunity, inhibit inflammatory factors, and improve renal function in CKD, suggesting that MSCs have the potential to be a new, effective therapeutic tool for CKD. In this review, we will describe different kinds of MSCs and MSCs products for the treatment of CKD in experimental models and clinical trials, potential signaling pathways, therapeutic efficacy, and critical issues that need to be addressed before therapeutic application in humans.

Biodistribution studies for cell therapy products: Current status and issues

Information on the biodistribution (BD) of cell therapy products (CTPs) is essential for prediction and assessment of their efficacy and toxicity profiles in non-clinical and clinical studies. To conduct BD studies, it is necessary to understand regulatory requirements, implementation status, and analytical methods. This review aimed at surveying international and Japanese trends concerning the BD study for CTPs and the following subjects were investigated, which were considered particularly important: 1) comparison of guidelines to understand the regulatory status of BD studies in a global setting; 2) case studies of the BD study using databases to understand its current status in cell therapy; 3) case studies on quantitative polymerase chain reaction (qPCR) used primarily in non-clinical BD studies for CTPs; and 4) survey of imaging methods used for non-clinical and clinical BD studies. The results in this review will be a useful resource for implementing BD studies.

Therapeutic effects of stem cells in different body systems, a novel method that is yet to gain trust: A comprehensive review

Stem cell therapy has been used to treat several types of diseases, and it is expected that its therapeutic uses shall increase as novel lines of evidence begin to appear. Furthermore, stem cells have the potential to make new tissues and organs. Thus, some scientists propose that organ transplantation will significantly rely on stem cell technology and organogenesis in the future. Stem cells and its robust potential to differentiate into specific types of cells and regenerate tissues and body organs, have been investigated by numerous clinician scientists and researchers for their therapeutic effects. Degenerative diseases in different organs have been the main target of stem cell therapy. Neurodegenerative diseases such as Alzheimer's, musculoskeletal diseases such as osteoarthritis, congenital cardiovascular diseases, and blood cell diseases such as leukemia are among the health conditions that have benefited from stem cell therapy advancements. One of the most challenging parts of the process of incorporating stem cells into clinical practice is controlling their division and differentiation potentials. Sometimes, their potential for  uncontrolled growth will make these cells tumorigenic. Another caveat in this process is the ability to control the differentiation process. While stem cells can easily differentiate into a wide variety of cells,  a paracrine effect controlled activity, being in an appropriate medium will cause abnormal differentiation leading to treatment failure. In this review, we aim to provide an overview of the therapeutic effects of stem cells in diseases of various organ systems. In order to advance this new treatment to its full potential, researchers should focus on establishing methods to control the differentiation process, while policymakers should take an active role in providing adequate facilities and equipment for these projects. Large population clinical trials are a necessary tool that will help build trust in this method. Moreover, improving social awareness about the advantages and adverse effects of stem cell therapy is required to develop a rational demand in the society, and consequently, healthcare systems should consider established stem cell-based therapeutic methods in their treatment algorithms.

Stem cells as a potential therapy in managing various disorders of metabolic syndrome: a systematic review

Recent explorations on mesenchymal stem/stromal cells (MSC) have reported a promising future for cell-based therapies. MSCs are widely sourced from various tissues and express unique properties of regenerative potential and immunomodulation. Currently, there is a growing interest in utilizing MSC for treatment of chronic diseases to overcome the drawbacks of chemical drugs. Metabolic Syndrome (MetS) is described as a cluster of metabolic abnormalities categorized as abdominal obesity, dyslipidaemia, hypertension, hypertriglyceridemia, and hyperglycaemia. Patients diagnosed with MetS have a high predisposition for developing cardiovascular complications, diabetes, non-alcoholic fatty liver diseases, bone loss, cancer, and mortality. Hence, research on MSC as therapy for MetS and related diseases, is greatly valued and are advantaged by the low immunogenicity with high regenerative capacity. However, there are many obstacles to be addressed such as the safety, efficacy, and consistency of different MSC sources. Additionally, factors such as effective dose level and delivery method are equally important to achieve uniform therapeutic outcomes. This systematic review discusses the potential roles of MSC in managing the multiple clusters of MetS. Research articles during the past 20 years were systematically searched and filtered to update the progress in the field of MSC therapy in managing various components of MetS. The different sources of MSC, dosage, method of delivery and outcome measures for the stem cell therapies were compiled from the systematically selected research articles. It can be concluded from the review of the selected articles that MSCs can improve the various disorders of MetS such as abdominal obesity, hyperglycaemia, hypertriglyceridemia and hypertension, and represent a promising alternative to conventional therapy of the MetS cluster.

Where Do We Stand in Stem Cell Therapy for the Management of Diabetes Mellitus?-A Scientometric Research Trend Analysis from 1990 to 2020

Stem cell therapy has been considered a promising strategy in the management of both type I and type II diabetes mellitus (DM) because of its immunomodulatory and regenerative capability to restore the beta cell number and function. Various modalities of cellular therapy like transplantation of pancreatic islet cells, transplantation of pancreatic ductal stem cells, and mesenchymal stromal cell transplantation have been tried, and the modality is undergoing rapid advancements that may become the reality in the near future. In the course of its evolution, it is essential to have a comprehensive summary of the progress for a greater capacity to refine our future directives. With technological developments like data mining, graphic drawing, and information analytics combined with computational statistics, visualization of scientific metrology has become a reality. With a newer perspective, we intend to use scientometric tools including text mining, co-word analysis, word frequency analysis, co-citation analysis, cluster network analysis, to perform a systematic and comprehensive analysis of the research trend in stem cell therapy in the management of DM over the past three decades (1990-2020) and to identify the future research hotspots.

Chronic inflammation-induced senescence impairs immunomodulatory properties of synovial fluid mesenchymal stem cells in rheumatoid arthritis

Background

Although the immunomodulatory properties of mesenchymal stem cells (MSCs) have been highlighted as a new therapy for autoimmune diseases, including rheumatoid arthritis (RA), the disease-specific characteristics of MSCs derived from elderly RA patients are not well understood.

Methods

We established MSCs derived from synovial fluid (SF) from age-matched early (average duration of the disease: 1.7 years) and long-standing (average duration of the disease: 13.8 years) RA patients (E-/L-SF-MSCs) and then analyzed the MSC characteristics such as stemness, proliferation, cellular senescence, in vitro differentiation, and in vivo immunomodulatory properties.

Results

The presence of MSC populations in the SF from RA patients was identified. We found that L-SF-MSCs exhibited impaired proliferation, intensified cellular senescence, reduced immunomodulatory properties, and attenuated anti-arthritic capacity in an RA animal model. In particular, E-SF-MSCs demonstrated cellular senescence progression and attenuated immunomodulatory properties similar to those of L-SF-MSC in an RA joint-mimetic milieu due to hypoxia and pro-inflammatory cytokine exposure. Due to a long-term exposure to the chronic inflammatory milieu, cellular senescence, attenuated immunomodulatory properties, and the loss of anti-arthritic potentials were more often identified in SF-MSCs in a long-term RA than early RA.

Conclusion

We conclude that a chronic RA inflammatory milieu affects the MSC potential. Therefore, this work addresses the importance of understanding MSC characteristics during disease states prior to their application in patients.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02453-z.

The protective mechanism of Klotho gene-modified bone marrow mesenchymal stem cells on acute kidney injury induced by rhabdomyolysis

Background

Studies have shown that the Klotho gene has tremendous potential for future therapeutic purposes in both acute and chronic kidney diseases (CKD). This study aimed to investigate the possible protective mechanisms of the Klotho gene against acute kidney injury (AKI) induced by rhabdomyolysis (RM).

Methods

In this study, bone marrow mesenchymal stem cells (BMSCs) were transfected with recombinant adenoviruses expressing the Klotho gene (BMSCs-Klotho) and by those expressing empty vector (BMSCs-EV). After successful transfection, we tested the proliferation, secretion and migration abilities of the BMSCs-Klotho compared with those of the BMSCs-EV and BMSCs. Then, 30 male C57BL/6 mice were examined, with 6 mice randomly assigned to the control group (PBS injected into the tail vein, CON) or one of the four treatment groups treated with either BMSCs-Klotho (AKI+BMSCs-Klotho), BMSCs-EV (AKI+BMSCs-EV), BMSCs (AKI+BMSCs) or PBS (AKI+PBS) after induction of RM. Seventy-two h after treatment, serum creatinine (SCr) and blood urea nitrogen (BUN) levels were obtained to assess renal function, and renal tissue was obtained to measure kidney tissue damage. Additionally, kidney protective mechanism-related indexes, such as EPO, IGF-1, KIM-1 and HIF-1, were analysed using Western blot analysis and immunohistochemistry.

Results

The results obtained showed that the proliferation, secretory and migration abilities of the BMSCs were significantly increased after transfection with the Klotho gene. Treatment with BMSCs-Klotho, BMSCs-EV or BMSCs improved renal function compared to treatment with PBS. However, the improvement observed in renal function in the BMSCs-Klotho group was better than that of the other groups. Histological analysis demonstrated that tissue damage was significantly decreased in the mice in the AKI+BMSCs-Klotho, AKI+BMSCs-EV or AKI+BMSCs groups compared to that in the mice in the AKI+PBS group. However, the best recovery was observed in the mice treated with BMSCs-Klotho concomitantly. Furthermore, the expression of protective factors erythropoietin (EPO) and insulin-like growth factor 1 (IGF-1) increased obviously, and the injury biomarkers kidney injury molecule 1 (KIM-1) and hypoxia inducible factor 1 (HIF-1) decreased notably in the group of BMSCs-Klotho, BMSCs-EV and BMSCs. Additionally, the levels of the aforementioned protein indicators in the AKI+BMSCs-Klotho group were not different from those in the CON group.

Conclusion

Klotho overexpression exerted positive effects on BMSCs and markedly promoted recovery from RM-induced AKI. These findings suggest that the overexpression of the Klotho gene might be a good candidate for further therapy for AKI in clinical trials.

From Mesenchymal Stromal/Stem Cells to Insulin-Producing Cells: Progress and Challenges

Mesenchymal stromal cells (MSCs) are an attractive option for cell therapy for type 1 diabetes mellitus (DM). These cells can be obtained from many sources, but bone marrow and adipose tissue are the most studied. MSCs have distinct advantages since they are nonteratogenic, nonimmunogenic and have immunomodulatory functions. Insulin-producing cells (IPCs) can be generated from MSCs by gene transfection, gene editing or directed differentiation. For directed differentiation, MSCs are usually cultured in a glucose-rich medium with various growth and activation factors. The resulting IPCs can control chemically-induced diabetes in immune-deficient mice. These findings are comparable to those obtained from pluripotent cells. PD-L₁ and PD-L₂ expression by MSCs is upregulated under inflammatory conditions. Immunomodulation occurs due to the interaction between these ligands and PD-1 receptors on T lymphocytes. If this function is maintained after differentiation, life-long immunosuppression or encapsulation could be avoided. In the clinical setting, two sites can be used for transplantation of IPCs: the subcutaneous tissue and the omentum. A 2-stage procedure is required for the former and a laparoscopic procedure for the latter. For either site, cells should be transplanted within a scaffold, preferably one from fibrin. Several questions remain unanswered. Will the transplanted cells be affected by the antibodies involved in the pathogenesis of type 1 DM? What is the functional longevity of these cells following their transplantation? These issues have to be addressed before clinical translation is attempted.

Graphical Abstract

The promise(s) of mesenchymal stem cell therapy in averting preclinical diabetes: lessons from in vivo and in vitro model systems

Obesity (Ob) poses a significant risk factor for the onset of metabolic syndrome with associated complications, wherein the Mesenchymal Stem Cell (MSC) therapy shows pre-clinical success. Here, we explore the therapeutic applications of human Placental MSCs (P-MSCs) to address Ob-associated Insulin Resistance (IR) and its complications. In the present study, we show that intramuscular injection of P-MSCs homed more towards the visceral site, restored HOMA-IR and glucose homeostasis in the WNIN/GR-Ob (Ob-T2D) rats. P-MSC therapy was effective in re-establishing the dysregulated cytokines. We report that the P-MSCs activates PI3K-Akt signaling and regulates the Glut4-dependant glucose uptake and its utilization in WNIN/GR-Ob (Ob-T2D) rats compared to its control. Our data reinstates P-MSC treatment's potent application to alleviate IR and restores peripheral blood glucose clearance evidenced in stromal vascular fraction (SVF) derived from white adipose tissue (WAT) of the WNIN/GR-Ob rats. Gaining insights, we show the activation of the PI3K-Akt pathway by P-MSCs both in vivo and in vitro (palmitate primed 3T3-L1 cells) to restore the insulin sensitivity dysregulated adipocytes. Our findings suggest a potent application of P-MSCs in  pre-clinical/Ob-T2D management.

Breast milk MSCs upregulated β-cells PDX1, Ngn3, and PCNA expression via remodeling ER stress /inflammatory /apoptotic signaling pathways in type 1 diabetic rats

Type 1 diabetes mellitus (T1DM) is one of the autoimmune diseases characterized by beta-cell dysfunction with serious health complications. Br-MSCs represent a novel valid candidate in regenerative medicine disciplines. Yet, the full potential of Br-MSCs in managing type 1 diabetes remains elusive. Indeed, this study was designed to explore a novel approach investigating the possible regenerative capacity of Br-MSCs in type1 diabetic islet on the level of the cellular mRNA expression of different molecular pathways involved in pancreatic beta-cell dysfunction. Sixty adult male Sprague-Dawley rats were randomly assigned into 3 groups (20 rats each); the control group, type1 diabetic group, and the type 1 diabetic Br-MSCs treated group. And, for the first time, our results revealed that intraperitoneally transplanted Br-MSCs homed to the diabetic islet and improved fasting blood glucose, serum insulin level, pancreatic oxidative stress, upregulated pancreatic mRNA expression for: regenerative markers (Pdx1, Ngn3, PCNA), INS, beta-cell receptors (IRS1, IRβ, PPARγ), pancreatic growth factors (IGF-1, VEGFβ1, FGFβ), anti-inflammatory cytokine (IL10) and anti-apoptotic marker (BCL2) too, Br-MSCs downregulated pancreatic mRNA expression for: inflammatory markers (NFKβ, TNFα, IL1β, IL6, IL8, MCP1), apoptotic markers for both intrinsic and extrinsic pathways (FAS, FAS-L, P53, P38, BAX, Caspase3), ER stress markers (ATF6, ATF3, ATF4, BIP, CHOP, JNK, XBP1) and autophagy inhibitor (mTOR). In conclusion, Br-MSCs could be considered as a new insight in beta cell regenerative therapy improving the deteriorated diabetic islet microenvironment via modulating; ER stress, inflammatory, and apoptotic signaling pathways besides, switching on the cellular quality control system (autophagy) thus enhancing beta-cell function.

In situ transplantation of adipose-derived stem cells via photoactivation improves glucose metabolism in obese mice

Background

Accumulating evidence suggests that enhanced adipose tissue macrophages (ATMs) are associated with metabolic disorders in obesity and type 2 diabetes. However, therapeutic persistence and reduced homing stem cell function following cell delivery remains a critical hurdle for the clinical translation of stem cells in current approaches.

Methods

We demonstrate that the effect of a combined application of photoactivation and adipose-derived stem cells (ASCs) using transplantation into visceral epididymal adipose tissue (EAT) in obesity. Cultured ASCs were derived from subcutaneous white adipose tissue isolated from mice fed a normal diet (ND).

Results

In diet-induced obesity, implantation of light-treated ASCs improved glucose tolerance and ameliorated systemic insulin resistance. Intriguingly, compared with non-light-treated ASCs, light-treated ASCs reduced monocyte infiltration and the levels of ATMs in EAT. Moreover, implantation of light-treated ASCs exerts more anti-inflammatory effects by suppressing M1 polarization and enhancing macrophage M2 polarization in EAT. Mass spectrometry revealed that light-treated human obese ASCs conditioned medium retained a more complete secretome with significant downregulation of pro-inflammatory cytokines and chemokines.

Conclusions

These data suggest that the combined application of photoactivation and ASCs using transplantation into dysfunctional adipose tissue contribute to selective suppression of inflammatory responses and protection from insulin resistance in obesity and type 2 diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02494-4.

Diabetic Kidney Disease Alters the Transcriptome and Function of Human Adipose-Derived Mesenchymal Stromal Cells but Maintains Immunomodulatory and Paracrine Activities Important for Renal Repair

Mesenchymal stem/stromal cells (MSCs) facilitate repair in experimental diabetic kidney disease (DKD). However, the hyperglycemic and uremic milieu may diminish regenerative capacity of patient-derived therapy. We hypothesized that DKD reduces human MSC paracrine function. Adipose-derived MSC from 38 participants with DKD and 16 control subjects were assessed for cell surface markers, trilineage differentiation, RNA sequencing (RNA-seq), in vitro function (coculture or conditioned medium experiments with T cells and human kidney cells [HK-2]), secretome profile, and cellular senescence abundance. The direction of association between MSC function and patient characteristics were also tested. RNA-seq analysis identified 353 differentially expressed genes and downregulation of several immunomodulatory genes/pathways in DKD-MSC versus Control-MSC. DKD-MSC phenotype, differentiation, and tube formation capacity were preserved, but migration was reduced. DKD-MSC with and without interferon-γ priming inhibited T-cell proliferation greater than Control-MSC. DKD-MSC medium contained higher levels of anti-inflammatory cytokines (indoleamine 2,3-deoxygenase 1 and prostaglandin-E2) and prorepair factors (hepatocyte growth factor and stromal cell-derived factor 1) but lower IL-6 versus control-MSC medium. DKD-MSC medium protected high glucose plus transforming growth factor-β-exposed HK-2 cells by reducing apoptotic, fibrotic, and inflammatory marker expression. Few DKD-MSC functions were affected by patient characteristics, including age, sex, BMI, hemoglobin A_1c, kidney function, and urine albumin excretion. However, senescence-associated β-galactosidase activity was lower in DKD-MSC from participants on metformin therapy. Therefore, while DKD altered the transcriptome and migratory function of culture-expanded MSCs, DKD-MSC functionality, trophic factor secretion, and immunomodulatory activities contributing to repair remained intact. These observations support testing of patient-derived MSC therapy and may inform preconditioning regimens in DKD clinical trials.

Stem Cells as a Source of Pancreatic Cells for Production of 3D Bioprinted Bionic Pancreas in the Treatment of Type 1 Diabetes

Type 1 diabetes (T1D) is the third most common autoimmune disease which develops due to genetic and environmental risk factors. Often, intensive insulin therapy is insufficient, and patients require a pancreas or pancreatic islets transplant. However, both solutions are associated with many possible complications, including graft rejection. The best approach seems to be a donor-independent T1D treatment strategy based on human stem cells cultured in vitro and differentiated into insulin and glucagon-producing cells (β and α cells, respectively). Both types of cells can then be incorporated into the bio-ink used for 3D printing of the bionic pancreas, which can be transplanted into T1D patients to restore glucose homeostasis. The aim of this review is to summarize current knowledge about stem cells sources and their transformation into key pancreatic cells. Last, but not least, we comment on possible solutions of post-transplant immune response triggered stem cell-derived pancreatic cells and their potential control mechanisms.

A systematic review and meta-analysis of cell-based interventions in experimental diabetic kidney disease

Regenerative, cell‐based therapy is a promising treatment option for diabetic kidney disease (DKD), which has no cure. To prepare for clinical translation, this systematic review and meta‐analysis summarized the effect of cell‐based interventions in DKD animal models and treatment‐related factors modifying outcomes. Electronic databases were searched for original investigations applying cell‐based therapy in diabetic animals with kidney endpoints (January 1998‐May 2019). Weighted or standardized mean differences were estimated for kidney outcomes and pooled using random‐effects models. Subgroup analyses tested treatment‐related factor effects for outcomes (creatinine, urea, urine protein, fibrosis, and inflammation). In 40 studies (992 diabetic rodents), therapy included mesenchymal stem/stromal cells (MSC; 61%), umbilical cord/amniotic fluid cells (UC/AF; 15%), non‐MSC (15%), and cell‐derived products (13%). Tissue sources included bone marrow (BM; 65%), UC/AF (15%), adipose (9%), and others (11%). Cell‐based therapy significantly improved kidney function while reducing injury markers (proteinuria, histology, fibrosis, inflammation, apoptosis, epithelial‐mesenchymal‐transition, oxidative stress). Preconditioning, xenotransplantation, and disease‐source approaches were effective. MSC and UC/AF cells had greater effect on kidney function while cell products improved fibrosis. BM and UC/AF tissue sources more effectively improved kidney function and proteinuria vs adipose or other tissues. Cell dose, frequency, and administration route also imparted different benefits. In conclusion, cell‐based interventions in diabetic animals improved kidney function and reduced injury with treatment‐related factors modifying these effects. These findings may aid in development of optimal repair strategies through selective use of cells/products, tissue sources, and dose administrations to allow for successful adaptation of this novel therapeutic in human DKD.

Impact of Syndecan-2-Selected Mesenchymal Stromal Cells on the Early Onset of Diabetic Cardiomyopathy in Diabetic db/db Mice

Background: Mesenchymal stromal cells (MSCs) are an attractive cell type for cell therapy given their immunomodulatory, anti-fibrotic, and endothelial-protective features. The heparin sulfate proteoglycan, syndecan-2/CD362, has been identified as a functional marker for MSC isolation, allowing one to obtain a homogeneous cell product that meets regulatory requirements for clinical use. We previously assessed the impact of wild-type (WT), CD362^-, and CD362⁺ MSCs on local changes in protein distribution in left ventricular (LV) tissue and on LV function in an experimental model of early-onset diabetic cardiomyopathy. The present study aimed to further explore their impact on mechanisms underlying diastolic dysfunction in this model. Materials: For this purpose, 1 × 10⁶ WT, CD362^-, or CD362⁺ MSCs were intravenously (i.v.) injected into 20-week-old diabetic BKS.Cg-m+/+Lepr^db/BomTac, i.e., db/db mice. Control animals (db+/db) were injected with the equivalent volume of phosphate-buffered saline (PBS) alone. After 4 weeks, mice were sacrificed for further analysis. Results: Treatment with all three MSC populations had no impact on blood glucose levels in db/db mice. WT, CD362^-, and CD362⁺ MSC application restored LV nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels in db/db mice, which correlated with a reduction in cardiomyocyte stiffness. Furthermore, all stromal cells were able to increase arteriole density in db/db mice. The effect of CD362⁺ MSCs on NO and cGMP levels, cardiomyocyte stiffness, and arteriole density was less pronounced than in mice treated with WT or CD362^- MSCs. Analysis of collagen I and III protein expression revealed that fibrosis had not yet developed at this stage of experimental diabetic cardiomyopathy. All MSCs reduced the number of cardiac CD3⁺ and CD68⁺ cells in db/db mice, whereas only splenocytes from CD362^-- and CD362⁺-db/db mice exhibited a lower pro-fibrotic potential compared to splenocytes from db/db mice. Conclusion: CD362⁺ MSC application decreased cardiomyocyte stiffness, increased myocardial NO and cGMP levels, and increased arteriole density, although to a lesser extent than WT and CD362^- MSCs in an experimental model of early-onset diabetic cardiomyopathy without cardiac fibrosis. These findings suggest that the degree in improvement of cardiomyocyte stiffness following CD362⁺ MSC application was insufficient to improve diastolic function.

Combined Treatment with Bone Marrow-Derived Mesenchymal Stem Cells and Exendin-4 Promotes Islet Regeneration in Streptozotocin-Induced Diabetic Rats

This study was designed to assess whether the combination of the glucagon-like peptide-1 (GLP-1) analog exendin-4 (Ex4) and bone marrow-derived mesenchymal stem cell (BM-MSC) could enhance β-cell action in streptozotocin (STZ)-induced diabetic rats. Forty male Sprague-Dawley rats were randomly assigned to five groups: the normal control group (Normal), diabetes mellitus (DM) group, MSC-treated group (MSC), Ex4-treated group (Ex4), and MSC plus Ex4-treated group (MSC+Ex4). Body weight, blood glucose level, intraperitoneal glucose tolerance test, and in vitro glucose-stimulated insulin secretion were used to assess the treatment efficacy. The expression level of insulin, glucagon, pancreatic duodenal homeobox-1 (PDX-1), v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA), glucagon-like peptide-1 receptor (GLP-1R), and forkhead transcription factor 1 (FoxO1) was estimated by immunofluorescence analysis. Proliferation was assessed by Ki67 staining, and apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining in β-cells. Glucose-induced insulin secretion in the MSC+Ex4 group was significantly increased compared to that in the MSC group in vitro and in vivo. Compared to that of the other groups, the number of insulin-immunopositive cells was increased in both the MSC and MSC+Ex4 groups. However, β-cell proliferation and apoptosis in the MSC group and MSC+Ex4 group were not significantly different. Importantly, the expression level of PDX-1, MafA, FoxO1, and GLP-1R in β-cells in the MSC+Ex4 group was significantly higher than those in the MSC group. The numbers of insulin+ glucagon+ double positive cells and glucagon+ GLP-1+ double positive cells were significantly increased after MSC treatment and MSC+Ex4 combined treatment, suggesting the enhanced function of newly formed islet β-cells. Our findings showed that the combination of MSC and Ex4 enhanced the function of newly formed β-cells in STZ-induced diabetic rats by acting on multiple insulin transcription factors. Thus, combined MSC and Ex4 therapy provides a feasible approach for future diabetes treatments.

The Usefulness of Mesenchymal Stem Cells beyond the Musculoskeletal System in Horses

Simple Summary

The main target of mesenchymal stem cell therapy in horses has long been the locomotor system, because these athletic animals commonly suffer from tendon and joint lesions. Originally, mesenchymal stem cells were thought to act by just differentiating into the cells of the injured tissue. However, these cells are also able to regulate and stimulate the body’s own repair mechanisms, opening the door to many applications in inflammatory and immune-mediated disorders in both animals and humans. In horses, beyond their traditional application in the musculoskeletal system, these cells have been studied for ophthalmologic pathologies such as corneal ulcers or immune-mediated processes, and for reproductive disorders such as endometritis/endometrosis. Their potential has been explored for equine pathologies very similar to those affecting people, such as asthma, metabolic syndrome, aberrant wound healing, or endotoxemia, as well as for equine-specific pathologies such as laminitis. Current evidence is still preliminary, and further research is needed to clarify different aspects, although research performed so far shows the promising potential of mesenchymal stem cells to treat a wide variety of equine pathologies, some of which are analogous to human disorders. Therefore, advancements in this path will be beneficial for both animals and people.

Abstract

The differentiation ability of mesenchymal stem cells (MSCs) initially raised interest for treating musculoskeletal injuries in horses, but MSC paracrine activity has widened their scope for inflammatory and immune-mediated pathologies in both equine and human medicine. Furthermore, the similar etiopathogenesis of some diseases in both species has advanced the concept of “One Medicine, One Health”. This article reviews the current knowledge on the use of MSCs for equine pathologies beyond the locomotor system, highlighting the value of the horse as translational model. Ophthalmologic and reproductive disorders are among the most studied for MSC application. Equine asthma, equine metabolic syndrome, and endotoxemia have been less explored but offer an interesting scenario for human translation. The use of MSCs in wounds also provides a potential model for humans because of the healing particularities in both species. High-burden equine-specific pathologies such as laminitis have been suggested to benefit from MSC-therapy, and MSC application in challenging disorders such as neurologic conditions has been proposed. The available data are preliminary, however, and require further development to translate results into the clinic. Nevertheless, current evidence indicates a significant potential of equine MSCs to enlarge their range of application, with particular interest in pathologies analogous to human conditions.

Mesenchymal Stem Cells: An Overview of Their Potential in Cell-Based Therapy for Diabetic Nephropathy

Diabetic nephropathy (DN) is a devastating complication associated with diabetes mellitus, and it is the leading cause of end-stage renal diseases (ESRD). Over the last few decades, numerous studies have reported the beneficial effects of stem cell administration, specifically mesenchymal stem or stromal cells (MSCs), on tissue repair and regeneration. MSC therapy has been considered a promising strategy for ameliorating the progression of DN largely based on results obtained from several preclinical studies and recent Phase I/II clinical trials. This paper will review the recent literature on MSC treatment in DN. In addition, the roles and potential mechanisms involved in MSC treatment of DN will be summarized, which may present much needed new drug targets for this disease. Moreover, the potential benefits and related risks associated with the therapeutic action of MSCs are elucidated and may help in achieving a better understanding of MSCs.

Efficacy of Mesenchymal Stem Cell and Vitamin D in the Treatment of Diabetes Mellitus Induced in a Rat Model: Pancreatic Tissues

Treatment with mesenchyme stem cells (MSCs) plays a significant role in the therapies of many diseases such as diabetics. Vitamin D plays a significant role in the development of insulin and can increase the insulin action sensitivity of peripheral tissues. Moreover, there is limited research concerning the mechanism of the therapeutic action of MSCs with the combination of vitamin D (vit. D). Therefore, we evaluated the effect of MSC intervention in a diabetic animal model. Diabetes was induced by streptozotocin (STZ) injection at a dose of 50 mg/kg in adult male rats The diabetic rats were injected with MSCs derived from bone marrow (2 × 106 per rat), either alone or in combination with vit. D through the tail vein for four weeks. Serum insulin, glucose, C-peptide, glycosylated hemoglobin, and lipid profile levels were determined. Pancreatic oxidative stress, histology, and electron microscopy were evaluated, and the gene expression of cytokines was assessed by real-time polymerase chain reaction PCR. MSC treatment suppressed pancreatic inflammatory cytokine secretion and oxidative stress in diabetic rats, resulting in improved pancreatic histology and cellular structure, and the complication of hyperglycemia was observed. Engrafted MSCs were found inside degraded pancreatic regions and regulated inflammatory cytokines. Our results demonstrated that treatment with MSCs and vit. D in combination prevented pancreatic injury via antioxidant and immune regulation in diabetic rats, contributing to the prevention of pancreatic dysfunction, improvement of lipid metabolism, and regulation of cytokine gene expression compared with each one separately. All these mechanisms also improved the histological structure of the pancreas based on transmission electron microscopy. The combination of MSCs and vit. D appears to have contributed to a greater improvement in the diabetic pancreatic complication of rats than was observed by each one separately. Therefore, this association can be used as antidiabetic therapy.

Therapeutic potential of stem cells from human exfoliated deciduous teeth infusion into patients with type 2 diabetes depends on basal lipid levels and islet function

Mesenchymal stem cells (MSCs) hold great potential in treating patients with diabetes, but the therapeutic effects are not always achieved. Particularly, the clinical factors regulating MSC therapy in this setting are largely unknown. In this study, 24 patients with type 2 diabetes mellitus (T2DM) treated with insulin were selected to receive three intravenous infusions of stem cells from human exfoliated deciduous teeth (SHED) over the course of 6 weeks and were followed up for 12 months. We observed a significant reduction of glycosylated serum albumin level (P < .05) and glycosylated hemoglobin level (P < .05) after SHED transplantation. The total effective rate was 86.36% and 68.18%, respectively, at the end of treatment and follow‐up periods. Three patients ceased insulin injections after SHED transplantation. A steamed bread meal test showed that the serum levels of postprandial C‐peptide at 2 hours were significantly higher than those at the baseline (P < .05). Further analysis showed that patients with a high level of blood cholesterol and a low baseline level of C‐peptide had poor response to SHED transplantation. Some patients experienced a transient fever (11.11%), fatigue (4.17%), or rash (1.39%) after SHED transplantation, which were easily resolved. In summary, SHED infusion is a safe and effective therapy to improve glucose metabolism and islet function in patients with T2DM. Blood lipid levels and baseline islet function may serve as key factors contributing to the therapeutic outcome of MSC transplantation in patients with T2DM.