TGF-β engineered mesenchymal stem cells (TGF-β/MSCs) for treatment of Type 1 diabetes (T1D) mice model

Stem cells therapy for diabetes: from past to future

Diabetes mellitus is a chronic disease of carbohydrate metabolism characterized by uncontrolled hyperglycemia due to the body's impaired ability to produce or respond to insulin. Oral or injectable exogenous insulin and its analogs cannot mimic endogenous insulin secreted by healthy individuals, and pancreatic and islet transplants face a severe shortage of sources and transplant complications, all of which limit the widespread use of traditional strategies in diabetes treatment. We are now in the era of stem cells and their potential in ameliorating human disease. At the same time, the rapid development of gene editing and cell-encapsulation technologies has added to the wings of stem cell therapy. However, there are still many unanswered questions before stem cell therapy can be applied clinically to patients with diabetes. In this review, we discuss the progress of strategies to obtain insulin-producing cells from different types of stem cells, the application of gene editing in stem cell therapy for diabetes, as well as summarize the current advanced cell encapsulation technologies in diabetes therapy and look forward to the future development of stem cell therapy in diabetes.

Leverage biomaterials to modulate immunity for type 1 diabetes

The pathogeny of type 1 diabetes (T1D) is mainly provoked by the β-cell loss due to the autoimmune attack. Critically, autoreactive T cells firsthand attack β-cell in islet, that results in the deficiency of insulin in bloodstream and ultimately leads to hyperglycemia. Hence, modulating immunity to conserve residual β-cell is a desirable way to treat new-onset T1D. However, systemic immunosuppression makes patients at risk of organ damage, infection, even cancers. Biomaterials can be leveraged to achieve targeted immunomodulation, which can reduce the toxic side effects of immunosuppressants. In this review, we discuss the recent advances in harness of biomaterials to immunomodulate immunity for T1D. We investigate nanotechnology in targeting delivery of immunosuppressant, biological macromolecule for β-cell specific autoreactive T cell regulation. We also explore the biomaterials for developing vaccines and facilitate immunosuppressive cells to restore immune tolerance in pancreas.

Hope for bone regeneration: The versatility of iron oxide nanoparticles

Although bone tissue has the ability to heal itself, beyond a certain point, bone defects cannot rebuild themselves, and the challenge is how to promote bone tissue regeneration. Iron oxide nanoparticles (IONPs) are a magnetic material because of their excellent properties, which enable them to play an active role in bone regeneration. This paper reviews the application of IONPs in bone tissue regeneration in recent years, and outlines the mechanisms of IONPs in bone tissue regeneration in detail based on the physicochemical properties, structural characteristics and safety of IONPs. In addition, a bibliometric approach has been used to analyze the hot spots and trends in the field in order to identify future directions. The results demonstrate that IONPs are increasingly being investigated in bone regeneration, from the initial use as magnetic resonance imaging (MRI) contrast agents to later drug delivery vehicles, cell labeling, and now in combination with stem cells (SCs) composite scaffolds. In conclusion, based on the current research and development trends, it is more inclined to be used in bone tissue engineering, scaffolds, and composite scaffolds.

Strategies for the induction of anti-inflammatory mesenchymal stem cells and their application in the treatment of immune-related nephropathy

Mesenchymal stem cells (MSCs) have potent immunomodulatory functions. Animal studies and clinical trials have demonstrated that MSCs can inhibit immune/inflammatory response in tissues and have good therapeutic effects on a variety of immune-related diseases. However, MSCs currently used for treatment are a mixed, undefined, and heterogeneous cell population, resulting in inconsistent clinical treatment effects. MSCs have dual pro-inflammatory/anti-inflammatory regulatory functions in different environments. In different microenvironments, the immunomodulatory function of MSCs has plasticity; therefore, MSCs can transform into pro-inflammatory MSC1 or anti-inflammatory MSC2 phenotypes. There is an urgent need to elucidate the molecular mechanism that induces the phenotypic transition of MSCs to pro-inflammatory or anti-inflammatory MSCs and to develop technical strategies that can induce the transformation of MSCs to the anti-inflammatory MSC2 phenotype to provide a theoretical basis for the future clinical use of MSCs in the treatment of immune-related nephropathy. In this paper, we summarize the relevant strategies and mechanisms for inducing the transformation of MSCs into the anti-inflammatory MSC2 phenotype and enhancing the immunosuppressive function of MSCs.

Estrogen Facilitates the Healing of Diabetic Wounds via Ameliorating the Function of Bone Marrow Mesenchymal Stem Cells

We inted to elucidate the impacts of estrogen on the bone marrow-originated endothelial progenitor cells (BM-EPC) and mesenchymal stem cells (BM-MSC) as well as on diabetic wound healing. The skin injury models were established using the diabetic mice (db+/db+) and non-diabetic vector mice and then treated with estrogen-based or placebo-based cream. On the 5th day following injury, BM cells were collected for quantification of EPCs and MSCs and colony-forming units along with analysis of wound healing rate and densities of blood vessels and scars following whole-body perfusion. EPCs were identified through staining of VEGFR1 and CD34 by immunohistochemistrical analyses. In contrast to placebo, treatment with estrogen significantly intensified the colony formation of EPC and MSC, and further promoted the viability and proliferation potential of cells. Meanwhile, estrogen-treated mice exhibited increased recruitment of EPC to the diabetic wounds along with increased vascular density. Additionally, on day 6 after injury, estrogen significantly accelerated wound healing, which was mediated by the enhanced collagen deposition through boosting MSC activation and differentiation, resulting in elevated scar density. In conclusion, estrogen prompts wound healing of diabetic mice via ameliorating the function of BM-derived EPC and MSC, so as to accelerate the neovascularization at the sites of wounds in diabetic mice.

Stem Cell Transplantation in the Treatment of Type 1 Diabetes Mellitus: From Insulin Replacement to Beta-Cell Replacement

Type 1 diabetes mellitus (T1DM) is an autoimmune disease that attacks pancreatic β-cells, leading to the destruction of insulitis-related islet β-cells. Islet β-cell transplantation has been proven as a curative measure in T1DM. However, a logarithmic increase in the global population with diabetes, limited donor supply, and the need for lifelong immunosuppression restrict the widespread use of β-cell transplantation. Numerous therapeutic approaches have been taken to search for substitutes of β-cells, among which stem cell transplantation is one of the most promising alternatives. Stem cells have demonstrated the potential efficacy to treat T1DM by reconstitution of immunotolerance and preservation of islet β-cell function in recent research. cGMP-grade stem cell products have been used in human clinical trials, showing that stem cell transplantation has beneficial effects on T1DM, with no obvious adverse reactions. To better achieve remission of T1DM by stem cell transplantation, in this work, we explain the progression of stem cell transplantation such as mesenchymal stem cells (MSCs), human embryonic stem cells (hESCs), and bone marrow hematopoietic stem cells (BM-HSCs) to restore the immunotolerance and preserve the islet β-cell function of T1DM in recent years. This review article provides evidence of the clinical applications of stem cell therapy in the treatment of T1DM.

Effects of 15-Lipoxygenase Overexpressing Adipose Tissue Mesenchymal Stem Cells on The Th17 / Treg Plasticity

15-lipoxygenase (15-LOX) is a critical enzyme that allows the direction of arachidonic acid metabolism to change from inflammation into the resolution. This study aims to reveal how the immunomodulation properties of mesenchymal stem cells (MSC) alter by the 15-LOX overexpression. For this purpose, peripheral blood mononuclear cells (PBMCs) isolated from seven healthy volunteers, and both MSCs and 15-LOX overexpressing MSCs (^15-LOXMSCs) were co-cultured at different cell ratios (1/1, 1/5 and 1/10). Alterations of CD4⁺Tbet⁺, CD4⁺Gata3⁺, CD4⁺RoRC2⁺, and CD4⁺FoxP3⁺ lymphocyte frequencies were detected by flow cytometry, and IFN-γ, IL-4, IL-6, IL-10, IL-17a, TGF-β and LXA₄ levels of medium supernatants were measured by ELISA method. According to our findings, MSC and ^15-LOXMSCs have a suppressive effect on PHA activated PBMCs. However, as the ratio of PBMCs increased, the effects of ^15-LOXMSCs increased significantly, while the effects of MSCs decreased. The most notable effect of the 15-LOX modification was the significant reduction in IL-6, IL-10 and IL-17a expression and the accompanying increase in TGF-β and LXA₄ levels. We also observed a similar situation between CD4⁺RoRC2⁺ and CD4⁺FoxP3⁺ cell frequencies. These data suggested that the effects of MSCs on the balance of Th17 / Treg could change by the 15-LOX overexpression, and this might be in favor of the Treg cells.

Mesenchymal Stem Cells Influence Activation of Hepatic Stellate Cells, and Constitute a Promising Therapy for Liver Fibrosis

Liver fibrosis is a common feature of chronic liver disease. Activated hepatic stellate cells (HSCs) are the main drivers of extracellular matrix accumulation in liver fibrosis. Hence, a strategy for regulating HSC activation is crucial in treating liver fibrosis. Mesenchymal stem cells (MSCs) are multipotent stem cells derived from various post-natal organs. Therapeutic approaches involving MSCs have been studied extensively in various diseases, including liver disease. MSCs modulate hepatic inflammation and fibrosis and/or differentiate into hepatocytes by interacting directly with immune cells, HSCs, and hepatocytes and secreting modulators, thereby contributing to reduced liver fibrosis. Cell-free therapy including MSC-released secretomes and extracellular vesicles has elicited extensive attention because they could overcome MSC transplantation limitations. Herein, we provide basic information on hepatic fibrogenesis and the therapeutic potential of MSCs. We also review findings presenting the effects of MSC itself and MSC-based cell-free treatments in liver fibrosis, focusing on HSC activation. Growing evidence supports the anti-fibrotic function of either MSC itself or MSC modulators, although the mechanism underpinning their effects on liver fibrosis has not been established. Further studies are required to investigate the detailed mechanism explaining their functions to expand MSC therapies using the cell itself and cell-free treatments for liver fibrosis.

Differences and similarities between mesenchymal stem cell and endothelial progenitor cell immunoregulatory properties against T cells

Bone-marrow-derived mesenchymal stem cells and endothelial progenitor cells have some interesting biological properties that make them unique for cell therapy of degenerative and cardiovascular disorders. Although both cell populations have been already studied and used for their regenerative potentials, recently their special immunoregulatory features have brought much more attention. Mesenchymal stem cells and endothelial progenitor cells have both proangiogenic functions and have been shown to suppress the immune response, particularly T cell proliferation, activation, and cytokine production. This makes them suitable choices for allogeneic stem cell transplantation. Nevertheless, these two cells do not have equal immunoregulatory activities. Many elements including their extraction sources, age/passage, expression of different markers, secretion of bioactive mediators, and some others could change the efficiency of their immunosuppressive function. However, to our knowledge, no publication has yet compared mesenchymal stem cells and endothelial progenitor cells for their immunological interaction with T cells. This review aims to specifically compare the immunoregulatory effect of these two populations including their T cell suppression, deactivation, cytokine production, and regulatory T cells induction capacities. Moreover, it evaluates the implications of the tumor necrosis factor alpha-tumor necrosis factor receptor 2 axis as an emerging immune checkpoint signaling pathway controlling most of their immunological properties.

Regulatory Effect of Mesenchymal Stem Cells on T Cell Phenotypes in Autoimmune Diseases

Research on mesenchymal stem cells (MSCs) starts from the earliest assumption that cells derived from the bone marrow have the ability to repair tissues. Several scientists have since documented the crucial role of bone marrow-derived MSCs (BM-MSCs) in processes such as embryonic bone and cartilage formation, adult fracture and tissue repair, and immunomodulatory activities in therapeutic applications. In addition to BM-MSCs, several sources of MSCs have been reported to possess tissue repair and immunoregulatory abilities, making them potential treatment options for many diseases. Therefore, the therapeutic potential of MSCs in various diseases including autoimmune conditions has been explored. In addition to an imbalance of T cell subsets in most patients with autoimmune diseases, they also exhibit complex disease manifestations, overlapping symptoms among diseases, and difficult treatment. MSCs can regulate T cell subsets to restore their immune homeostasis toward disease resolution in autoimmune conditions. This review summarizes the role of MSCs in relieving autoimmune diseases via the regulation of T cell phenotypes.

Treatment of diabetic mice by microfluidic system-assisted transplantation of stem cells-derived insulin-producing cells transduced with miRNA

AIMS

Cell-based therapy is a promising approach for the treatment of type-1 diabetes mellitus. Identifying stem cells with differentiation potential to Insulin-producing cells (IPCs) and their application is an emerging issue. Different strategies have been used to support cell survival and their specific functions to control hyperglycemia conditions. Novel technologies using appropriate materials/fibers can improve cell transplantation.

MAIN METHODS

In the present study, IPCs were differentiated from adipose-derived stem cells transduced with miR-375 and anti-miR-7. The cells' survival rate was also improved using a microfluidic system before their in vivo transplantation.

KEY FINDINGS

After adopting a stable, functional condition of the IPCs, the cells were used for in vivo grafting to diabetic mice, which resulted in a substantial drop in blood glucose during four weeks of grafting compared to the control group (p < 0.0001). The pattern of blood glucose levels in the mice receiving fiber entrapped IPCs, was similar to that of non-diabetic mice. Blood insulin was elevated in diabetic mice which received a transplant of fiber-entrapped-IPCs carrying miR-375 and anti-miR-7 after five weeks of transplantation compared to the diabetic mice (p < 0.014).

SIGNIFICANCE

For the first time, this study showed that the two-component microfluidic system is useful for supporting the Collagen-Alginate fiber-entrapped IPCs and the miRNA-based cell therapy. Overall, our data show that the IPC encapsulation using a microfluidic system can support the cells in terms of morphology and biological function and their efficiency for controlling the hyperglycemia condition in diabetic mice.

TNFR2 Is a Crucial Hub Controlling Mesenchymal Stem Cell Biological and Functional Properties

Mesenchymal stem cells (MSCs) have drawn lots of attention as gold standard stem cells in fundamental and clinical researches during the last 20 years. Due to their tissue and vascular repair capacities, MSCs have been used to treat a variety of degenerative disorders. Moreover, MSCs are able to modulate immune cells’ functions, particularly T cells while inducing regulatory T cells (iTregs). MSCs are very sensitive to inflammatory signals. Their biological functions could remarkably vary after exposure to different pro-inflammatory cytokines, notably TNFα. In this article, we have explored the importance of TNFR2 expression in a series of MSCs’ biological and functional properties. Thus, MSCs from wild-type (WT) and TNFR2 knockout (TNFR2 KO) mice were isolated and underwent several ex vivo experiments to investigate the biological significance of TNFR2 molecule in MSC main functions. Hampering in TNFR2 signaling resulted in reduced MSC colony-forming units and proliferation rate and diminished the expression of all MSC characteristic markers such as stem cell antigen-1 (Sca1), CD90, CD105, CD44, and CD73. TNFR2 KO-MSCs produced more pro-inflammatory cytokines like TNFα, IFNγ, and IL-6 and less anti-inflammatory mediators such as IL-10, TGFβ, and NO and induced Tregs with less suppressive effect. Furthermore, the TNFR2 blockade remarkably decreased MSC regenerative functions such as wound healing, complex tube formation, and endothelial pro-angiogenic support. Therefore, our results reveal the TNFα–TNFR2 axis as a crucial regulator of MSC immunological and regenerative functions.

Efficacy of Fe3O4@polydopamine nanoparticle-labeled human umbilical cord Wharton's jelly-derived mesenchymal stem cells in the treatment of streptozotocin-induced diabetes in rats

Diabetes mellitus (DM) is characterized by the irreversible destruction of insulin-secreting pancreatic β-islet cells and requires life-long exogenous insulin therapy. Umbilical cord Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) have been shown to improve islet function in animal models of diabetes. However, inadequate MSC homing to injured sites has limited their efficacy. Since efficient cell therapy heavily relies on appropriate homing to target tissues, increasing the specificity to the target organ and the extent of homing of the injected WJ-MSCs is paramount to successful clinical outcomes. Therefore, in this study, we synthesized Fe₃O₄@polydopamine nanoparticle (NP)-labeled MSCs and evaluated their therapeutic efficacy in a clinically relevant rat model of streptozotocin-induced diabetes using an external magnetic field. We found that NPs were successfully incorporated into WJ-MSCs and did not negatively affect stem cell properties. Magnetic targeting of WJ-MSCs contributed to long-term cell retention in pancreatic tissue and improved the islet function of diabetic rats, compared to injection of WJ-MSC alone. In addition, anti-inflammatory effects and the anti-apoptotic capacity of WJ-MSCs appeared to play a major role in the functional and structural recovery of the pancreas. Thus, therapy relying on the magnetic targeting of WJ-MSCs may serve as an effective approach for DM treatment.

Drug delivery to macrophages: A review of targeting drugs and drug carriers to macrophages for inflammatory diseases

Macrophages play a key role in defending against foreign pathogens, healing wounds, and regulating tissue homeostasis. Driving this versatility is their phenotypic plasticity, which enables macrophages to respond to subtle cues in tightly coordinated ways. However, when this coordination is disrupted, macrophages can aid the progression of numerous diseases, including cancer, cardiovascular disease, and autoimmune disease. The central link between these disorders is aberrant macrophage polarization, which misguides their functional programs, secretory products, and regulation of the surrounding tissue microenvironment. As a result of their important and deterministic roles in both health and disease, macrophages have gained considerable attention as targets for drug delivery. Here, we discuss the role of macrophages in the initiation and progression of various inflammatory diseases, summarize the leading drugs used to regulate macrophages, and review drug delivery systems designed to target macrophages. We emphasize strategies that are approved for clinical use or are poised for clinical investigation. Finally, we provide a prospectus of the future of macrophage-targeted drug delivery systems.

Immunobiology of Uveal Melanoma: State of the Art and Therapeutic Targets

Uveal Melanoma (UM) represents the most common primary intraocular malignant tumor in adults. Although it originates from melanocytes as cutaneous melanoma, it shows significant clinical and biological differences with the latter, including high resistance to immune therapy. Indeed, UM can evade immune surveillance via multiple mechanisms, such as the expression of inhibitory checkpoints (e.g., PD-L1, CD47, CD200) and the production of IDO-1 and soluble FasL, among others. More in-depth understanding of these mechanisms will suggest potential targets for the design of novel and more effective management strategies for UM patients.

Research Status of Mesenchymal Stem Cells in Liver Transplantation

Liver transplantation has been deemed the best choice for end-stage liver disease patients but immune rejection after surgery is still a serious problem. Patients have to take immunosuppressive drugs for a long time after liver transplantation, and this often leads to many side effects. Mesenchymal stem cells (MSCs) gradually became of interest to researchers because of their powerful immunomodulatory effects. In the past, a large number of in vitro and in vivo studies have demonstrated the great potential of MSCs for participation in posttransplant immunomodulation. In addition, MSCs also have properties that may potentially benefit patients undergoing liver transplantation. This article aims to provide an overview of the current understanding of the immunomodulation achieved by the application of MSCs in liver transplantation, to discuss the problems that may be encountered when using MSCs in clinical practice, and to describe some of the underlying capabilities of MSCs in liver transplantation. Cell–cell contact, soluble molecules, and exosomes have been suggested to be critical approaches to MSCs’ immunoregulation in vitro; however, the exact mechanism, especially in vivo, is still unclear. In recent years, the clinical safety of MSCs has been proven by a series of clinical trials. The obstacles to the clinical application of MSCs are decreasing, but large sample clinical trials involving MSCs are still needed to further study their clinical effects.

The Role of Monocytes and Macrophages in Autoimmune Diseases: A Comprehensive Review

Monocytes (Mo) and macrophages (Mϕ) are key components of the innate immune system and are involved in regulation of the initiation, development, and resolution of many inflammatory disorders. In addition, these cells also play important immunoregulatory and tissue-repairing roles to decrease immune reactions and promote tissue regeneration. Several lines of evidence have suggested a causal link between the presence or activation of these cells and the development of autoimmune diseases. In addition, Mo or Mϕ infiltration in diseased tissues is a hallmark of several autoimmune diseases. However, the detailed contributions of these cells, whether they actually initiate disease or perpetuate disease progression, and whether their phenotype and functional alteration are merely epiphenomena are still unclear in many autoimmune diseases. Additionally, little is known about their heterogeneous populations in different autoimmune diseases. Elucidating the relevance of Mo and Mϕ in autoimmune diseases and the associated mechanisms could lead to the identification of more effective therapeutic strategies in the future.

Iron oxide nanoparticles promote the migration of mesenchymal stem cells to injury sites

Background

Developing new methods to deliver cells to the injured tissue is a critical factor in translating cell therapeutics research into clinical use; therefore, there is a need for improved cell homing capabilities.

Materials and methods

In this study, we demonstrated the effects of labeling rat bone marrow-derived mesenchymal stem cells (MSCs) with fabricated polydopamine (PDA)-capped Fe₃O₄ (Fe₃O₄@PDA) superparticles employing preassembled Fe₃O₄ nanoparticles as the cores.

Results

We found that the Fe₃O₄@PDA composite superparticles exhibited no adverse effects on MSC characteristics. Moreover, iron oxide nanoparticles increased the number of MSCs in the S-phase, their proliferation index and migration ability, and their secretion of vascular endothelial growth factor relative to unlabeled MSCs. Interestingly, nanoparticles not only promoted the expression of C-X-C chemokine receptor 4 but also increased the expression of the migration-related proteins c-Met and C-C motif chemokine receptor 1, which has not been reported previously. Furthermore, the MSC-loaded nanoparticles exhibited improved homing and anti-inflammatory abilities in the absence of external magnetic fields in vivo.

Conclusion

These results indicated that iron oxide nanoparticles rendered MSCs more favorable for use in injury treatment with no negative effects on MSC properties, suggesting their potential clinical efficacy.

Current status of stem cell therapy, scaffolds for the treatment of diabetes mellitus

Diabetes mellitus (DM) remains the 7th leading cause of death in the world. Daily insulin injection is one component of a treatment plan for people with Diabetes mellitus type 1 (T1DM) that restores normal or near-normal blood sugar levels. However, Insulin treatment depends upon a variety of individual factors and leads to poor and drastic glycemic control. The need for an effective cell replacement strategy will be the aim of future clinical trials. Therefore, the aim of this systematic review is to outline the latest advances in scaffolding and stem cell therapy as a non-pharmacologic treatment for T1DM. It also emphasizes on some pancreas differentiation protocols and the clinical trials associated with stem cell therapy regarding T1DM in vitro and in vivo.

The Role of the TGFβ Receptor Signaling Pathway in Adult Beta Cell Proliferation

Diabetes is a global epidemic and affects millions of individuals in the United States. Devising novel treatments for diabetes continues to be a great medical challenge. Postnatal beta cell growth or compensation is largely attributed to beta cell proliferation, which declines continuously with age. To boost beta cell proliferation to regenerate an adequate functional mass, there is a need to understand the signaling pathways that regulate beta cell proliferation for creating practical strategies to promote the process. Transforming growth factor β (TGFβ) belongs to a signaling superfamily that governs pancreatic development and the regeneration of beta cells after pancreatic diseases. TGFβ exerts its functions by activation of downstream Smad proteins and through its crosstalk with other pathways. Accumulating data demonstrate that the TGFβ receptor signaling pathway also participates in the control of beta cell proliferation. This review details the role of the TGFβ receptor signaling pathway in beta cell proliferation physiologically and in the pathogenesis of diabetes.

Gene therapy and type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder characterized by T cell-mediated self-destruction of insulin-secreting islet β cells. Management of T1DM is challenging and complicated especially with conventional medications. Gene therapy has emerged as one of the potential therapeutic alternatives to treat T1DM. This review primarily focuses on the current status and the future perspectives of gene therapy in the management of T1DM. A vast number of the studies which are reported on gene therapy for the management of T1DM are done in animal models and in preclinical studies. In addition, the safety of such therapies is yet to be established in humans. Currently, there are several gene level interventions that are being investigated, notably, overexpression of genes and proteins needed against T1DM, transplantation of cells that express the genes against T1DM, stem-cells mediated gene therapy, genetic vaccination, immunological precursor cell-mediated gene therapy and vectors.

METHODS

We searched the current literature through searchable online databases, journals and other library sources using relevant keywords and search parameters. Only relevant publications in English, between the years 2000 and 2018, with evidences and proper citations, were considered. The publications were then analyzed and segregated into several subtopics based on common words and content. A total of 126 studies were found suitable for this review.

FINDINGS

Generally, the pros and cons of each of the gene-based therapies have been discussed based on the results collected from the literature. However, there are certain interventions that require further detailed studies to ensure their effectiveness. We have also highlighted the future direction and perspectives in gene therapy, which, researchers could benefit from.

TGF-β and mesenchymal stromal cells in regenerative medicine, autoimmunity and cancer

Multipotent mesenchymal stromal cells (MSCs) represent a promising cell-based therapy in regenerative medicine and for the treatment of inflammatory/autoimmune diseases. Importantly, MSCs have emerged as an important contributor to the tumor stroma with both pro- and anti-tumorigenic effects. However, the successful translation of MSCs to the clinic and the prevention of their tumorigenic and metastatic effect require a greater understanding of factors controlling their proliferation, differentiation, migration and immunomodulation in vitro and in vivo. The transforming growth factor(TGF)-β1, 2 and 3 are involved in almost every aspect of MSC function. The aim of this review is to highlight the roles that TGF-β play in the biology and therapeutic applications of MSCs. We will discuss the how TGF-β modulate MSC function as well as the paracrine effects of MSC-derived TGF-β on other cell types in the context of tissue regeneration, immune responses and cancer. Finally, taking all these aspects into consideration we discuss how modulation of TGF-β signaling/production in MSCs could be of clinical interest.

Forced expression of CD200 improves the differentiation capability and immunoregulatory functions of mesenchymal stromal cells

OBJECTIVE

In order to identify specific mesenchymal stromal cell (MSC) populations with enhanced therapeutic efficacy, we evaluated the functional changes associated with the stable expression of CD200, which is associated with immune regulatory function and osteogenic differentiation, in human bone marrow-derived MSCs (CD200/MSCs).

RESULTS

We detected significantly greater osteogenesis and chondrogenesis in CD200/MSCs than in mock-transfected MSCs. In addition, the immune regulatory function of MSCs in mixed lymphocyte reactions was enhanced by CD200 gene transfection. In CD200/MSCs, the secretion of inflammatory cytokines, i.e., IL-6 and IL-8, was reduced, and levels of the anti-inflammatory factors IL-10, FOXP3, and indoleamine 2,3-dioxygenase 1 were elevated. Finally, CD200 transfection increased the stemness of MSCs, as evidenced by greater colony numbers in colony-forming unit fibroblast assays and analyses of NANOG and OCT-4 expression.

CONCLUSIONS

These results suggest that CD200/MSCs have therapeutic applications, and further in-depth research should focus on the development of a clinically applicable cell-based therapeutic strategy.

MicroRNAs in type 1 diabetes: new research progress and potential directions

MicroRNAs (miRNAs) are a class of noncoding single-stranded RNA molecules encoded by endogenous genes of about 22 nucleotides, which are involved in post-transcriptional gene expression regulation in animals and plants. Type 1 diabetes (T1D) is an autoimmune disease that is clinically silent until the majority of β cells are destroyed, and a large number of studies have shown that miRNAs are involved in the pathological mechanism of T1D. In this review, we searched the related research in recent years and summarized the important roles of miRNAs in T1D diagnosis and treatment. Furthermore, we summarized the current understanding of miRNA-mediated regulation mechanisms of gene expression in the T1D pathogenesis as well as related signaling pathways with a focus on the important roles of miRNAs and their antagonists in T1D pathogenesis, and brought insight into the potential therapeutic value of miRNAs for T1D patients. In view of the important roles of miRNAs in T1D pathology, disordered miRNAs may be important diagnostic markers and therapeutic targets for patients with T1D.

Mesenchymal stem cell-derived factors: Immuno-modulatory effects and therapeutic potential

Stem cell-based therapy is considered to be a new hope in transplantation medicine. Among stem cells, mesenchymal stem cells (MSCs) are, due to their differentiation and immuno-modulatory characteristics, the most commonly used as therapeutic agents in the treatment of immune-mediated diseases. MSCs migrate to the site of inflammation and modulate immune response. The capacity of MSC to alter phenotype and function of immune cells are largely due to the production of soluble factors which expression varies depending on the pathologic condition to which MSCs are exposed. Under inflammatory conditions, MSCs-derived factors suppress both innate and adaptive immunity by attenuating maturation and capacity for antigen presentation of dendritic cells, by inducing polarization of macrophages towards alternative phenotype, by inhibiting activation and proliferation of T and B lymphocytes and by reducing cytotoxicity of NK and NKT cells. In this review, we emphasized current findings regarding immuno-modulatory effects of MSC-derived factors and emphasize their potential in the therapy of immune-mediated diseases. © 2017 BioFactors, 43(5):633-644, 2017.