Bone marrow-derived stem cell transplantation for the treatment of insulin-dependent diabetes

The efficiency of stem cell differentiation into functional beta cells for treating insulin-requiring diabetes: Recent advances and current challenges

In recent years, the potential of stem cells (SCs) to differentiate into various types of cells, including β-cells, has led to a significant boost in development. The efficiency of this differentiation process and the functionality of the cells post-transplantation are crucial factors for the success of stem cell therapy in diabetes. Herein, this article reviews the current advances and challenges faced by stem cell differentiation into functional β-cells for diabetes treatment. In vitro, researchers have sought to enhance the differentiation efficiency of functional β-cells by mimicking the normal pancreatic development process, using gene manipulation, pharmacological and culture conditions stimulation, three-dimensional (3D) and organoid culture, or sorting for functional β-cells based on mature islet cell markers. Furthermore, in vivo studies have also looked at suitable transplantation sites, the enhancement of the transplantation microenvironment, immune modulation, and vascular function reconstruction to improve the survival rate of functional β-cells, thereby enhancing the treatment of diabetes. Despite these advancements, developing stem cells to produce functional β-cells for efficacious diabetes treatment is a continuous research endeavor requiring significant multidisciplinary collaboration, for the stem-cell-derived beta cells to evolve into an effective cellular therapy.

Ectopic expression of insulin in a type 1 diabetic rat model by injection of manipulated mesenchymal stem cells with an insulin construct driven by a glucose-sensitive promoter in the port vein

The treatment of type 1 diabetes through islet cell transplantation is a complex process, facing challenges such as allograft rejections and a limited supply of donors. One potential solution is to utilize the liver as an alternative for natural insulin production, as hepatocytes can secrete proteins and respond to glucose levels. Recent research has shown promising results in using mesenchymal stem cells as a potential cure for diabetes. The study utilized a diabetic rat model, confirmed through blood sugar measurement. A plasmid vector was designed with specific genetic components, synthesized by biotech company, and then Inserted vector into a plasmid with resistance genes and bacterial origin. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were cultured and transfected with the plasmid using Lipofectamine 3000. Polymerase chain reaction was employed to confirm successful transfection using specific primers. For the animal study, 30 male Wistar rats were divided into six groups, each comprising five rats. The control group did not receive any treatment, while the second group received MSCs via Portal Vein Injection. The third group received MSCs transfected with a specific construct via Portal Vein Injection. The fourth group was induced to develop diabetes through streptozotocin (STZ) injection, the fifth group developed diabetes and received untransfected MSCs via Portal Vein Injection, and the sixth group received MSCs transfected with the specific construct via Portal Vein Injection. To manage Pain, appropriate pain control was administered to the rats for 3 days after the surgery. Fixed liver tissues obtained from the euthanized rats were utilized for immunohistochemistry. In this study, immunohistochemical techniques were used to examine insulin expression in different groups of rats. The control groups showed high levels of insulin expression, while the diabetic groups exhibited lower expression. However, there was a significant difference between the diabetic groups treated with MSC and transgenic MSC cells. All groups had similar baseline glucose levels, but the diabetic groups showed a significant increase after STZ injection, whereas the control and MSC groups did not. Postintervention, both the control and MSC groups had similar glucose levels to the post-STZ levels. However, diabetes-induced groups experienced a significant decrease in glucose levels, with the transfected MSCs showing a greater decrease than the untransfected MSCs. The study suggested that treatment with MSCs, especially transfected ones, can effectively reduce glucose levels in rats with diabetes. In this research, rat BM-MSCs were utilized to create insulin-producing mesenchymal cells with glucose-sensitive insulin expression. The cells were transferred to the liver of diabetic rats via portal vein injection, leading to an increase in insulin expression. This study proposes a novel approach for cell therapy and delivery in the treatment of type 1 diabetes.

Therapeutic Benefits of Mesenchymal Stem Cells in Acute Respiratory Distress Syndrome: Potential Mechanisms and Challenges

Acute respiratory distress syndrome (ARDS) presents as a form of acute respiratory failure resulting from non-cardiogenic pulmonary edema due to excessive alveolocapillary permeability, which may be pulmonary or systemic in origin. In the last 3 years, the coronavirus disease 2019 pandemic has resulted in an increase in ARDS cases and highlighted the challenges associated with this syndrome, as well as the unacceptably high mortality rates and lack of effective treatments. Currently, clinical treatment remains primarily supportive, including mechanical ventilation and drug-based therapy. Mesenchymal stem cell (MSC) therapies are emerging as a promising intervention in patients with ARDS and have promising therapeutic effects and safety. The therapeutic mechanisms include modifying the immune response and assisting with tissue repair. This review provides an overview of the general properties of MSCs and outlines their role in mitigating lung injury and promoting tissue repair in ARDS. Finally, we summarize the current challenges in the study of translational MSC research and identify avenues by which the discipline may progress in the coming years.

Delivery of therapeutic agents and cells to pancreatic islets: Towards a new era in the treatment of diabetes

Pancreatic islet cells, and in particular insulin-producing beta cells, are centrally involved in the pathogenesis of diabetes mellitus. These cells are of paramount importance for the endocrine control of glycemia and glucose metabolism. In Type 1 Diabetes, islet beta cells are lost due to an autoimmune attack. In Type 2 Diabetes, beta cells become dysfunctional and insufficient to counterbalance insulin resistance in peripheral tissues. Therapeutic agents have been developed to support the function of islet cells, as well as to inhibit deleterious immune responses and inflammation. Most of these agents have undesired effects due to systemic administration and off-target effects. Typically, only a small fraction of therapeutic agent reaches the desired niche in the pancreas. Because islets and their beta cells are scattered throughout the pancreas, access to the niche is limited. Targeted delivery to pancreatic islets could dramatically improve the therapeutic effect, lower the dose requirements, and lower the side effects of agents administered systemically. Targeted delivery is especially relevant for those therapeutics for which the manufacturing is difficult and costly, such as cells, exosomes, and microvesicles. Along with therapeutic agents, imaging reagents intended to quantify the beta cell mass could benefit from targeted delivery. Several methods have been developed to improve the delivery of agents to pancreatic islets. Intra-arterial administration in the pancreatic artery is a promising surgical approach, but it has inherent risks. Targeted delivery strategies have been developed based on ligands for cell surface molecules specific to islet cells or inflamed vascular endothelial cells. Delivery methods range from nanocarriers and vectors to deliver pharmacological agents to viral and non-viral vectors for the delivery of genetic constructs. Several strategies demonstrated enhanced therapeutic effects in diabetes with lower amounts of therapeutic agents and lower off-target side effects. Microvesicles, exosomes, polymer-based vectors, and nanocarriers are gaining popularity for targeted delivery. Notably, liposomes, lipid-assisted nanocarriers, and cationic polymers can be bioengineered to be immune-evasive, and their advantages to transport cargos into target cells make them appealing for pancreatic islet-targeted delivery. Viral vectors have become prominent tools for targeted gene delivery. In this review, we discuss the latest strategies for targeted delivery of therapeutic agents and imaging reagents to pancreatic islet cells.

Potential roles of mesenchymal stromal cells in islet allo- and xenotransplantation for type 1 diabetes mellitus

Islet transplantation is poised to play an important role in the treatment of type 1 diabetes mellitus (T1DM). However, there are several challenges limiting its widespread use, including the instant blood-mediated inflammatory reaction, hypoxic/ischemic injury, and the immune response. Mesenchymal stem/stromal cells (MSCs) are known to exert regenerative, immunoregulatory, angiogenic, and metabolic properties. Here, we review recent reports on the application of MSCs in islet allo- and xenotransplantation. We also document the clinical trials that have been undertaken or are currently underway, relating to the co-transplantation of islets and MSCs. Increasing evidence indicates that co-transplantation of MSCs prolongs islet graft survival by locally secreted protective factors that reduce immune reactivity and promote vascularization, cell survival, and regeneration. MSC therapy may be a promising option for islet transplantation in patients with T1DM.

Role of bone marrow-derived mesenchymal stem cells on the parotid glands of streptozotocin induced diabetes rats

The functional insufficiency of salivary glands constitute the common oral complaints in both type 1 and type 2 diabetes mellitus. The treatment with stem cell could decrease diabetic-induced hyposalivation and improve the quality of life for patients.

OBJECTIVE

The current study designed to assess the biological outcome of systemic injection of stem cells on the parotid salivary gland in streptozotocin induced diabetic.

METHODS

Twenty-four albino rats received intra-peritoneal injection of 50 mg/kg streptozotocin for induction of diabetes and were divided into two groups (n = 12): Group I (control) were kept without any manipulation, Group II received intravenous injection of 1×106 of mesenchymal stem cells of bone marrow derived for two days. All rats were sacrificed at 1, 3 weeks, then the parotid glands were isolated, fixed and processed for Heamatoxylin and Eosin examination, immunohistochemical staining for aquaporin-5.

RESULTS

group I groups showed intracellular cytoplasmic vacuoles and focal loss of salivary architecture, while group II showed maintenance of gland architecture. Immunohistochemical examination of aquaporin-5 showed significant difference between the two groups.

CONCLUSION

bone marrow derived stem cell treatment considers as an improved methods in prevention and treatment of diabeticinduced hyposalivation.

Efficacy of Autologous Bone Marrow Mononuclear Cell Transplantation Therapy for Type 2 Diabetes Mellitus: An Updated Meta-Analysis

INTRODUCTION

Studies of the effects of stem cell therapy on type 2 diabetes mellitus (T2DM) have not reached consistent results. Our meta-analysis aimed to systematically evaluate the efficacy of autologous bone marrow-derived stem cells (ABM-MNCs) on T2DM.

METHODS

We systematically searched PubMed, EMBASE, Web of Science, and the Cochrane Library for studies published between 1980 and May 2018. Two researchers screened the literature independently following the inclusion and exclusion criteria. Meta-analysis of the pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated based on either a fixed- or random-effects model.

RESULTS

We identified six studies with 206 participants investigating the effects of autologous bone marrow stem cell therapy on T2DM after screening 102 studies found after the initial search. According to the pooled estimates, compared with the control group, after 12-month follow-up the ABM-MNC therapy group had a lower level of HbA1c (MD, - 1.18; 95% CI, - 1.40 to 0.95) and lower required insulin dose (MD, - 2.05; 95% CI, - 3.55 to - 0.55). HbA1c decreased after ABM-MNC therapy compared with before (12 months: MD, - 1.22; 95% CI, - 1.43 to - 1.0). We also observed a significant decrease in insulin requirement after 3-, 6-, 9-, and 12-month follow-up in the ABM-MNC group, respectively.

CONCLUSION

Autologous stem cell therapy showed a beneficial effect on T2DM.

Adipose stem cells from chronic pancreatitis patients improve mouse and human islet survival and function

BACKGROUND

Chronic pancreatitis has surgical options including total pancreatectomy to control pain. To avoid surgical diabetes, the explanted pancreas can have islets harvested and transplanted. Immediately following total pancreatectomy with islet autotransplantation (TP-IAT), many islet cells die due to isolation and transplantation stresses. The percentage of patients remaining insulin free after TP-IAT is therefore low. We determined whether cotransplantation of adipose-derived mesenchymal stem cells (ASCs) from chronic pancreatitis patients (CP-ASCs) would protect islets after transplantation.

METHODS

In a marginal mass islet transplantation model, islets from C57BL/6 mice were cotransplanted with CP-ASCs into syngeneic streptozotocin-treated diabetic mice. Treatment response was defined by the percentage of recipients reaching normoglycemia, and by the area under the curve for glucose and c-peptide in a glucose tolerance test. Macrophage infiltration, β-cell apoptosis, and islet graft vasculature were measured in transplanted islet grafts by immunohistochemistry. mRNA expression profiling of 84 apoptosis-related genes in islet grafts transplanted alone or with CP-ASCs was measured by the RT² Profiler™ Apoptosis PCR Array. The impact of insulin-like growth factor-1 (IGF-1) on islet apoptosis was determined in islets stimulated with cytokines (IL-1β and IFN-γ) in the presence and absence of CP-ASC conditioned medium.

RESULTS

CP-ASC-treated mice were more often normoglycemic compared to mice receiving islets alone. ASC cotransplantation reduced macrophage infiltration, β-cell death, suppressed expression of TNF-α and Bcl-2 modifying factor (BMF), and upregulated expressions of IGF-1 and TNF Receptor Superfamily Member 11b (TNFRSF11B) in islet grafts. Islets cultured in conditioned medium from CP-ASCs showed reduced cell death. This protective effect was diminished when IGF-1 was blocked in the conditioned medium by the anti-IGF-1 antibody.

CONCLUSION

Cotransplantation of islets with ASCs from the adipose of chronic pancreatitis patients improved islet survival and islet function after transplantation. The effects are in part mediated by paracrine secretion of IGF-1, suppression of inflammation, and promotion of angiogenesis. ASCs from chronic pancreatitis patients have the potential to be used as a synergistic therapy to enhance the efficacy of islet transplantation following pancreatectomy.

Basic Fibroblast Growth Factor Inhibits Apoptosis and Promotes Proliferation of Adipose-Derived Mesenchymal Stromal Cells Isolated from Patients with Type 2 Diabetes by Reducing Cellular Oxidative Stress

Type 2 diabetes (T2D) is a chronic metabolic disorder affecting increasing number of people in developed countries. Therefore new strategies for treatment of T2D and its complications are of special interest. Nowadays, cellular therapies involving mesenchymal stromal cells that reside in adipose tissue (ASCs) constitute a promising approach; however, there are still many obstacles concerning safety and effectiveness that need to be overcome before ASCs could be engaged for the treatment of diabetes mellitus. One of the challenges is preventing ASCs from deterioration caused by elevated oxidative stress present in diabetes milieu. In the current study we investigated the effect of basic fibroblast growth factor (bFGF) treatment on ASCs isolated from patients with diagnosed T2D. We demonstrate here that cell exposition to bFGF in 5 and 10 ng/mL dosages results in improved morphology, increased proliferative activity, reduced cellular senescence and apoptosis, and decreased oxidative stress, indicating recovery of ASCs' function impaired by T2D. Therefore our results provide a support for bFGF as a potential therapeutic agent for improving stem cell-based approaches for the treatment of diabetes mellitus and its complications.

Applications of Cell Microencapsulation

The goal of this chapter is to provide an overview of the different purposes for which the cell microencapsulation technology can be used. These include immunoisolation of non-autologous cells used for cell therapy; immobilization of cells for localized (targeted) delivery of therapeutic products to ablate, repair, or regenerate tissue; simultaneous delivery of multiple therapeutic agents in cell therapy; spatial compartmentalization of cells in complex tissue engineering; expansion of cells in culture; and production of different probiotics and metabolites for industrial applications. For each of these applications, specific examples are provided to illustrate how the microencapsulation technology can be utilized to achieve the purpose. However, successful use of the cell microencapsulation technology for whatever purpose will ultimately depend upon careful consideration for the choice of the encapsulating polymers, the method of fabrication (cross-linking) of the microbeads, which affects the permselectivity, the biocompatibility and the mechanical strength of the microbeads as well as environmental parameters such as temperature, humidity, osmotic pressure, and storage solutions.The various applications discussed in this chapter are illustrated in the different chapters of this book and where appropriate relevant images of the microencapsulation products are provided. It is hoped that this outline of the different applications of cell microencapsulation would provide a good platform for tissue engineers, scientists, and clinicians to design novel tissue constructs and products for therapeutic and industrial applications.

Beneficial effects of urine-derived stem cells on fibrosis and apoptosis of myocardial, glomerular and bladder cells

Urine-derived stem cells (USCs) are isolated from voided urine and display high proliferative activity and multiple differentiation potentials. The applicability of USCs in the treatment of bladder dysfunction and in cell-based urological tissue engineering has been demonstrated. Whether they could serve as a potential stem cell source for the treatment of diabetes mellitus (DM) and its complications has not been investigated. Here, we report the repairing and protective effects of USCs on pancreatic islets, the myocardium, the renal glomerulus and the bladder detrusor in diabetic rat models. Type 2 diabetic rat models were induced by means of a high fat diet and intraperitoneal injection with streptozotocin. USCs isolated from voided urine were administered via tail veins. The functional changes of pancreatic islets, left ventricle, glomerulus and bladder micturition were assessed by means of insulin tolerance tests, echocardiography, urine biochemical indexes and cystometry. The histologic changes were evaluated by hematoxylin and eosin staining, Masson's trichrome staining and TUNEL staining. Treatment with USCs significantly alleviated the histological destruction and functional decline. Although the USC treatment did not decrease fasting blood glucose to a significantly different level, the fibrosis and apoptosis of the myocardium, glomerulus and detrusor were significantly inhibited. This study indicates that administration of USCs may be useful for the treatment of the complications of DM.

Fcγ1 fragment of IgG1 as a powerful affinity tag in recombinant Fc-fusion proteins: immunological, biochemical and therapeutic properties

Affinity tags are vital tools for the production of high-throughput recombinant proteins. Several affinity tags, such as the hexahistidine tag, maltose-binding protein, streptavidin-binding peptide tag, calmodulin-binding peptide, c-Myc tag, glutathione S-transferase and FLAG tag, have been introduced for recombinant protein production. The fragment crystallizable (Fc) domain of the IgG1 antibody is one of the useful affinity tags that can facilitate detection, purification and localization of proteins and can improve the immunogenicity, modulatory effects, physicochemical and pharmaceutical properties of proteins. Fcγ recombinant forms a group of recombinant proteins called Fc-fusion proteins (FFPs). FFPs are widely used in drug discovery, drug delivery, vaccine design and experimental research on receptor-ligand interactions. These fusion proteins have become successful alternatives to monoclonal antibodies for drug developments. In this review, the physicochemical, biochemical, immunological, pharmaceutical and therapeutic properties of recombinant FFPs were discussed as a new generation of bioengineering strategies.

Bone marrow-derived mesenchymal stem cells for the treatment of heart failure

Heart failure remains a major cause of death and disability, requiring rapid development of new therapies. Bone marrow-derived mesenchymal stem cell (MSC)-based therapy is an emerging approach for the treatment of both acute and chronic heart failure. Following successful experimental studies in a range of models, more than 40 clinical trials of MSC-based therapy for heart failure have now been registered, and the results of completed clinical trials so far have shown feasibility and safety of this approach with therapeutic potential suggested (though preliminarily). However, there appear to be several critical issues to be solved before this treatment could become a widespread standard therapy for heart failure. In this review, we comprehensively and systemically summarize a total of 73 preclinical studies and 11 clinical trial reports published to date. By analyzing the data in these reports, (1) improvement in the cell delivery method to the heart in order to enhance donor cell engraftment, (2) elucidation of mechanisms underpinning the therapeutic effects of the treatment differentiation and/or treatment secretion, and (3) validation of the utility of allogeneic MSCs which could enhance the efficacy and expand the application/indication of this therapeutic approach are highlighted as future perspectives. These important respects are further discussed in this review article with referencing latest scientific and clinical information.

Characterization of Insulin-Secreting Porcine Bone Marrow Stromal Cells Ex Vivo and Autologous Cell Therapy in Vivo

Cell therapy could potentially meet the need for pancreas and islet transplantations in diabetes mellitus that far exceeds the number of available donors. Bone marrow stromal cells are widely used in clinical trials mainly for their immunomodulatory effects with a record of safety. However, less focus has been paid to developing these cells for insulin secretion by transfection. Although murine models of diabetes have been extensively used in gene and cell therapy research, few studies have shown efficacy in large preclinical animal models. Here we report optimized conditions for ex vivo expansion and characterization of porcine bone marrow stromal cells and their permissive expression of a transfected insulin gene. Our data show that these cells resemble human bone marrow stromal cells in surface antigen expression, are homogeneous, and can be reproducibly isolated from outbred Yorkshire–Landrace pigs. Porcine bone marrow stromal cells were efficiently expanded in vitro to >1010 cells from 20 ml of bone marrow and remained karyotypically normal during expansion. These cells were electroporated with an insulin expression plasmid vector with high efficiency and viability, and secreted human insulin and C-peptide indicating appropriate processing of proinsulin. We showed that autologous insulin-secreting bone marrow stromal cells implanted and engrafted in the liver of a streptozotocin-diabetic pig that modeled type 1 diabetes resulted in partial, but significant, improvement in hyperglycemia that could not be ascribed to regeneration of endogenous β-cells. Glucose-stimulated insulin secretion in vivo from implanted cells in the treated pig was documented by a rise in serum human C-peptide levels during intravenous glucose tolerance tests. Compared to a sham-treated control pig, this resulted in significantly reduced fasting hyperglycemia, a slower rise in serum fructosamine, and prevented weight loss. Taken together, this study suggests that bone marrow stromal cells merit further development as autologous cell therapy for diabetes.

Synergy of bone marrow transplantation and curcumin ensue protective effects at early onset of diabetes in mice

BACKGROUND

The aim of this study was to investigate the early onset effects of diabetes on pro-angiogenic signaling pathway, total number of bone marrow cells, organs (pancreas and kidney) damage and the reversal effect of diabetes by combinatorial treatment of curcumin and bone marrow transplantation in streptozotocin (STZ) induced diabetic mice.

METHODS

In the present study, Streptozotocin induced diabetic mice were transplanted with bone marrow cells (2 × 10(6) ) followed by the administration of curcumin (80 mg/kg bodyweight). Effect of diabetes on the different organs was studied by H&E, Western blotting and immunofluorescence using vascular endothelial growth factor (VEGF), platelet/endothelial cell adhesion molecule (PECAM), insulin, Caspase-9 and Caspase-3 antibodies.

RESULTS

The effect of diabetes results in the reduction of the total cell number and viability of the bone marrow cells, organ degeneration and lower VEGF/PECAM expression. However, transplantation with normal bone marrow cells significantly reduced the blood glucose levels (above normal range) and initiated the organ regeneration via the VEGF/PECAM mediated manner. Curcumin treatment further reduced the blood glucose level (near normal); and accelerated the organ regeneration, enhanced VEGF/PECAM expression and decreased caspase expression level in the organs. Curcumin also had a protective role against the glucotoxicity test performed on the bone marrow cells.

CONCLUSION

This study suggests that bone marrow transplantation and curcumin administration is an effective treatment in reversing the early onset effects of diabetes via the VEGF/PECAM signaling pathway.

Immuno-metabolism and adipose tissue: The key role of hematopoietic stem cells

The field of immunometabolism has come a long way in the past decade, leading to the emergence of a new role for white adipose tissue (WAT) that is now recognized to stand at the junction of immune and metabolic regulations. Interestingly, a crucial role of the abundant and heterogeneous immune population present in WAT has been proposed in the induction and development of metabolic diseases. Although a large body of data focused on mature immune cells, only few scattered studies are dedicated to leukocyte production, and the activity of hematopoietic stem cells (HSC) in these pathological states. Considering that blood cell production and the differentiation of HSCs and their progeny is orchestrated, in part, by complex interacting signals emanating from their microenvironment, it thus seems worth to better understand the relationships between metabolism and HSC. This review discusses the alterations of hematopoietic process described in metabolic diseases and focused on the emerging data concerning HSC present in WAT.

Efficacy and safety of autologous bone marrow-derived stem cell transplantation in patients with type 2 diabetes mellitus: a randomized placebo-controlled study

There is a growing interest in cell-based therapies in T2DM as β-cell failure is progressive and inexorable with the advancing duration of disease. This prospective, randomized, single-blinded placebo-controlled study evaluates the efficacy and safety of autologous bone marrow-derived stem cell transplantation (ABMSCT) in T2DM. Twenty-one patients with triple oral antidiabetic drug failure and requiring insulin ≥0.4 IU per kg per day with HbA1c <7.5% were randomly assigned to an intervention (n = 11) and control group (n = 10) and followed for 12 months. Patients in the intervention group received ABMSCT through a targeted approach, and after 12 weeks, a second dose of stem cells was administered through the antecubital vein after mobilization with G-CSF, while the control group underwent a sham procedure. The primary end point was a reduction in insulin requirement by ≥50% from baseline while maintaining HbA1c <7%. Nine out of the 11 (82%) patients in the intervention group achieved the primary end point, whereas none of the patients in the control group did over the study period (p = 0.002). The insulin requirement decreased by 66.7% in the intervention group from 42.0 (31.0‐64.0) IU per day to 14.0 (0.0‐30.0) IU per day (p = 0.011), while in controls it decreased by 32.1% from 40.5 (31.8‐44.3) IU per day to 27.5 (23.5‐33.3) IU per day (p = 0.008) at 12 months. The reduction in insulin requirement was significantly more in the intervention group compared to controls at both 6 (p = 0.001) and 12 months (p = 0.004). There was a modest but nonsignificant increase in HbA1c (%) in cases from 6.9% (6.4‐7.2%) to 7.1% (6.6‐7.5%) as well as in controls from 6.9% (6.2‐7.0%) to 7.0% (6.9‐7.5%). Ten out of 11 (91%) patients could maintain HbA1c <7% in the intervention group, whereas 6 out of 10 did (60%) in the control group (p = 0.167). The glucagon-stimulated C-peptide significantly increased in treated cases compared to controls (p = 0.036). The decrease in insulin requirement positively correlated with stimulated C-peptide (r = 0.8, p = 0.001). In conclusion, ABMSCT results in a significant decrease in the insulin dose requirement along with an improvement in the stimulated C-peptide levels in T2DM. However, a greater number of patients with a longer duration of follow-up are required to substantiate these observations.

Mesenchymal stem cells in the treatment of type 1 diabetes mellitus

Diabetes mellitus type 1 is a form of diabetes mellitus that results from the autoimmune destruction of insulin-producing beta cells in the pancreas. The current gold standard therapy for pancreas transplantation has limitations because of the long list of waiting patients and the limited supply of donor pancreas. Mesenchymal stem cells (MSCs), a relatively new potential therapy in various fields, have already made their mark in the young field of regenerative medicine. Recent studies have shown that the implantation of MSCs decreases glucose levels through paracrine influences rather than through direct transdifferentiation into insulin-producing cells. Therefore, these cells may use pro-angiogenic and immunomodulatory effects to control diabetes following the cotransplantation with pancreatic islets. In this review, we present and discuss new approaches of using MSCs in the treatment of diabetes mellitus type 1.

Re-engineering islet cell transplantation

We are living exciting times in the field of beta cell replacement therapies for the treatment of diabetes. While steady progress has been recorded thus far in clinical islet transplantation, novel approaches are needed to make cell-based therapies more reproducible and leading to long-lasting success. The multiple facets of diabetes impose the need for a transdisciplinary approach to attain this goal, by targeting immunity, promoting engraftment and sustained functional potency. We discuss herein the emerging technologies applied to this rapidly evolving field.

Karyotype stability of human umbilical cord-derived mesenchymal stem cells during in vitro culture

The aim of this study was to investigate whether the chromosomes of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) change following in vitro culture for several generations. In the present study, umbilical cords from two healthy infants following cesarean delivery were collected aseptically and hUCMSCs were isolated by digestion with collagenase and trypsin, and then cultured in vitro. hUCMSCs with fibroblastic morphology were presented from the human umbilical cord tissue after 7 days of adherent culture. When cultured for 6 passages in vitro, the hUCMSCs maintained a stable spindle-shaped morphology. Cells reached the logarithmic growth phase after 3–4 days of culture. In addition, CD13, CD29, CD44, CD90 and CD105 were highly expressed in generations P3-P6. The expression of CD31, CD34, CD45 and HLA-DR was negative. Furthermore, karyotype analysis revealed a normal diploid karyotype with 46 chromosomes and no abnormal changes were found in chromosome structure. These findings suggest that when cultured for 6 passages in vitro, hUCMSCs maintain a stable immunophenotype and chromosome structure, which provides an experimental basis for the safety of hUCMSC cytotherapy.

Transdisciplinary approach to restore pancreatic islet function

The focus of our research is on islet immunobiology. We are exploring novel strategies that could be of assistance in the treatment and prevention of type 1 diabetes, as well as in the restoration of metabolic control via transplantation of insulin producing cells (i.e., islet cells). The multiple facets of diabetes and β-cell replacement encompass different complementary disciplines, such as immunology, cell biology, pharmacology, and bioengineering, among others. Through their interaction and integration, a transdisciplinary dimension is needed in order to address and overcome all aspects of the complex puzzle toward a successful clinical translation of a biological cure for diabetes.

Tracing type 1 diabetic Tibet miniature pig's bone marrow mesenchymal stem cells in vitro by magnetic resonance imaging (1)

BACKGROUND

Traditional cell-tracking methods fail to meet the needs of preclinical or clinical research. Thus, the aim of the present study was to establish a new method of double labeling bone marrow mesenchymal stem cells (BMSCs) from type 1 diabetic (T1D) minipigs with super-paramagnetic iron oxide (SPIO) and enhanced green fluorescent protein (eGFP) and tracing them using MRI in vitro.

METHODS

Isolated BMSCs from T1D minipigs were labeled with eGFP and different concentrations of SPIO. The effects of lentivirus (LV)-eGFP transfection and SPIO on the viability and growth curves of BMSCs were determined by Trypan blue exclusion, the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry. Cellular ultrastructure was evaluated by transmission electron microscopy. Magnetic resonance imaging was used to evaluate BMSCs labeled with SPIO-eGFP complexes 6 weeks after labeling.

RESULTS

Expression of eGFP in BMSCs peaked 96 h after transfection with LV-eGFP. Prussian blue staining revealed scattered blue granules in the cytoplasm of SPIO-labeled cells. Transmission electron microscopy revealed that the dense granules aggregated mainly in secondary lysosomes. On MRI, T2* -weighted imaging was far more sensitive for SPIO-labeled BMSCs than other image sequences 3 and 6 weeks after the cells had been labeled with SPIO-eGFP.

CONCLUSIONS

We have developed a relatively simple and safe method for double labeling of BMSCs from T1D minipigs using SPIO and LV-eGFP and tracing them in vitro by MRI for 6 weeks.

B6.g7 mice reconstituted with BDC2·5 non-obese diabetic (BDC2·5NOD) stem cells do not develop autoimmune diabetes

In BDC2·5 non-obese diabetic (BDC2·5NOD) mice, a spontaneous model of type 1 diabetes, CD4(+) T cells express a transgene-encoded T cell receptor (TCR) with reactivity against a pancreatic antigen, chromogranin. This leads to massive infiltration and destruction of the pancreatic islets and subsequent diabetes. When we reconstituted lethally irradiated, lymphocyte-deficient B6.g7 (I-A(g7+)) Rag(-/-) mice with BDC2·5NOD haematopoietic stem and progenitor cells (HSPC; ckit(+)Lin(-)Sca-1(hi)), the recipients exhibited hyperglycaemia and succumbed to diabetes. Surprisingly, lymphocyte-sufficient B6.g7 mice reconstituted with BDC2·5NOD HSPCs were protected from diabetes. In this study, we investigated the factors responsible for attenuation of diabetes in the B6.g7 recipients. Analysis of chimerism in the B6.g7 recipients showed that, although B cells and myeloid cells were 98% donor-derived, the CD4(+) T cell compartment contained ∼50% host-derived cells. These host-derived CD4(+) T cells were enriched for conventional regulatory T cells (Tregs ) (CD25(+) forkhead box protein 3 (FoxP3)(+)] and also for host- derived CD4(+)CD25(-)FoxP3(-) T cells that express markers of suppressive function, CD73, FR4 and CD39. Although negative selection did not eliminate donor-derived CD4(+) T cells in the B6.g7 recipients, these cells were functionally suppressed. Thus, host-derived CD4(+) T cells that emerge in mice following myeloablation exhibit a regulatory phenoytpe and probably attenuate autoimmune diabetes. These cells may provide new therapeutic strategies to suppress autoimmunity.

MRI tracking of transplanted iron-labeled mesenchymal stromal cells in an immune-compromised mouse model of critical limb ischemia

Peripheral arterial disease is a clinical problem in which mesenchymal stromal cell (MSC) transplantation may offer substantial benefit by promoting the generation of new blood vessels and improving limb ischemia and wound healing via their potent paracrine activities. MRI allows for the noninvasive tracking of cells over time using iron oxide contrast agents to label cells before they are injected or transplanted. However, a major limitation of the tracking of iron oxide-labeled cells with MRI is the possibility that dead or dying cells will transfer the iron oxide label to local bystander macrophages, making it very difficult to distinguish between viable transplanted cells and endogenous macrophages in the images. In this study, a severely immune-compromised mouse, with limited macrophage activity, was investigated to examine cell tracking in a system in which bystander cell uptake of dead, iron-labeled cells or free iron particles was minimized. MRI was used to track the fate of MSCs over 21 days after their intramuscular transplantation in mice with a femoral artery ligation. In all mice, a region of signal loss was observed at the injection site and the volume of signal hypointensity diminished over time. Fluorescence and light microscopy showed that iron-positive MSCs persisted at the transplant site and often appeared to be integrated in perivascular niches. This was compared with MSC transplantation in immune-competent mice with femoral artery ligation. In these mice, the regions of signal loss caused by iron-labeled MSC cleared more slowly, and histology revealed iron particles trapped at the site of cell transplantation and associated with areas of inflammation.

The antidiabetic effect of mesenchymal stem cells is unrelated to their transdifferentiation potential but to their capability to restore Th1/Th2 balance and to modify the pancreatic microenvironment

Type 1 diabetes mellitus (T1DM) is a chronic metabolic disease that results from cell-mediated autoimmune destruction of insulin-producing cells. In T1DM animal models, it has been shown that the systemic administration of multipotent mesenchymal stromal cells, also referred as to mesenchymal stem cells (MSCs), results in the regeneration of pancreatic islets. Mechanisms underlying this effect are still poorly understood. Our aims were to assess whether donor MSCs (a) differentiate into pancreatic β-cells and (b) modify systemic and pancreatic pathophysiologic markers of T1DM. After the intravenous administration of 5 × 10(5) syngeneic MSCs, we observed that mice with T1DM reverted their hyperglycemia and presented no donor-derived insulin-producing cells. In contrast, 7 and 65 days post-transplantation, MSCs were engrafted into secondary lymphoid organs. This correlated with a systemic and local reduction in the abundance of autoaggressive T cells together with an increase in regulatory T cells. Additionally, in the pancreas of mice with T1DM treated with MSCs, we observed a cytokine profile shift from proinflammatory to antinflammatory. MSC transplantation did not reduce pancreatic cell apoptosis but recovered local expression and increased the circulating levels of epidermal growth factor, a pancreatic trophic factor. Therefore, the antidiabetic effect of MSCs intravenously administered is unrelated to their transdifferentiation potential but to their capability to restore the balance between Th1 and Th2 immunological responses along with the modification of the pancreatic microenvironment. Our data should be taken into account when designing clinical trials aimed to evaluate MSC transplantation in patients with T1DM since the presence of endogenous precursors seems to be critical in order to restore glycemic control.

Basic research and clinical application of islet transplantation: Current status and future prospects

Type 1 diabetes mellitus is a chronic autoimmune disease. Although treatment with insulin is effective in most patients with type 1 diabetes mellitus, it can result in severe hypoglycemia which can be even deadly in some patients. Beta cell replacement, which can be achieved by whole pancreas transplantation or isolated islet cell transplantation, is usually used to restore physiologic glucose homeostasis. Compared with pancreas transplantation, islet transplantation has certain advantages. However, there was not a great breakthrough in islet transplantation until 2000 when the Edmonton protocol was published. However, some investigators believe that progressive graft loss and lack of reproducibility are fatal flaws of the Edmonton protocol. Thus, the protocol needs some improvements. In this article, we briefly describe the Edmonton protocol and its improvements and review the current status and future prospects of islet transplantation.

Environmental Biomechanics Substantiated by Defined Pillar Micropatterns Govern Behavior of Human Mesenchymal Stem Cells

While evidence on the impact of the biomechanical environment elasticity on human mesenchymal stem cell (hMSC) behavior is growing, the aspect of micropatterning is still poorly understood. Thus, the present study aimed at investigating the influence of defined environmental micropatterning on hMSC behavior. Following characterization, hMSCs were grown on defined pillar micropatterns of 5, 7, 9, and 11 μm. With respect to cell behavior, primary hMSC adhesion was detected by indirect immunofluorescence (iIF) for paxillin, vinculin, integrin αV, and actin, while proliferation was visualized by histone H3. Morphogenesis was monitored by scanning electron microscopy and the expression of stem cell-specific biomarkers by real-time PCR. Favoritism of primary adhesion of hMSCs on pillar tops occurred at smaller pillar micropatterns, concomitant with cell flattening. While vinculin, integrin αV, and paxillin appeared initially more cytoplasmic, high pillar micropatterns favored a progressive redistribution with polarization to cell tension sites and at cell borders. Accomplishment of morphogenesis at day 3 revealed establishment of fully rotund cell somata at 5 μm, while hMSCs appeared progressively elongated at rising micropatterns. The hMSC proliferation capacity was influenced by pillar micropatterns and gene expression analysis of stem cell- and differentiation-associated biomarkers disclosed clear modulation by distinct pillar micropatterns. In response to environmental biomechanics, our results show that hMSC behavior is governed by pillar micropatterning. In turn, these findings may form the basis to prospectively direct lineage specificity of hMSCs in a customized fashion.

Harnessing the immunomodulatory and tissue repair properties of mesenchymal stem cells to restore β cell function

Islet cell transplantation has therapeutic potential to cure type 1 diabetes (T1D), which is characterized by autoimmune-mediated destruction of insulin-producing β cells. However, current success rates are limited by long-term decline in islet graft function resulting partially from poor revascularization and immune destruction. Mesenchymal stem cells (MSCs) have the potential to enhance islet transplantation and prevent disease progression by a multifaceted approach. MSCs have been shown to be effective at inhibiting inflammatory-mediated immune responses and at promoting tissue regeneration. The immunomodulatory and tissue repairing properties of MSCs may benefit β cell regeneration in the context of T1D. This review will elucidate how MSCs can minimize β cell damage by providing survival signals and simultaneously modulate the immune response by inhibiting activation, and proliferation of several immune cell types. In addition, MSCs can enhance islet graft revascularization, maintaining long-term β cell viability and function.

Unsaturated fatty acids induce mesenchymal stem cells to increase secretion of angiogenic mediators

Mesenchymal stem cells (MSC) represent emerging cell-based therapies for diabetes and associated complications. Ongoing clinical trials are using exogenous MSC to treat type 1 and 2 diabetes, cardiovascular disease and non-healing wounds due to diabetes. The majority of these trials are aimed at exploiting the ability of these multipotent mesenchymal stromal cells to release soluble mediators that reduce inflammation and promote both angiogenesis and cell survival at sites of tissue damage. Growing evidence suggests that MSC secretion of soluble factors is dependent on tissue microenvironment. Despite the contribution of fatty acids to the metabolic environment of type 2 diabetes, almost nothing is known about their effects on MSC secretion of growth factors and cytokines. In this study, human bone marrow-derived MSC were exposed to linoleic acid, an omega-6 polyunsaturated fatty acid, or oleic acid, a monounsaturated fatty acid, for seven days in the presence of 5.38 mM glucose. Outcomes measured included MSC proliferation, gene expression, protein secretion and chemotaxis. Linoleic and oleic acids inhibited MSC proliferation and altered MSC expression and secretion of known mediators of angiogenesis. Both unsaturated fatty acids induced MSC to increase secretion of interleukin-6, VEGF and nitric oxide. In addition, linoleic acid but not oleic acid induced MSC to increase production of interleukin-8. Collectively these data suggest that exposure to fatty acids may have functional consequences for MSC therapy. Fatty acids may affect MSC engraftment to injured tissue and MSC secretion of cytokines and growth factors that regulate local cellular responses to injury.

Potential clinical applications of adult human mesenchymal stem cell (Prochymal®) therapy

In vitro, in vivo animal, and human clinical data show a broad field of application for mesenchymal stem cells (MSCs). There is overwhelming evidence of the usefulness of MSCs in regenerative medicine, tissue engineering, and immune therapy. At present, there are a significant number of clinical trials exploring the use of MSCs for the treatment of various diseases, including myocardial infarction and stroke, in which oxygen suppression causes widespread cell death, and others with clear involvement of the immune system, such as graft-versus-host disease, Crohn’s disease, and diabetes. With no less impact, MSCs have been used as cell therapy to treat defects in bone and cartilage and to help in wound healing, or in combination with biomaterials in tissue engineering development. Among the MSCs, allogeneic MSCs have been associated with a regenerative capacity due to their unique immune modulatory properties. Their immunosuppressive capability without evidence of immunosuppressive toxicity at a global level define their application in the treatment of diseases with a pathogenesis involving uncontrolled activity of the immune system. Until now, the limitation in the number of totally characterized autologous MSCs available represents a major obstacle to their use for adult stem cell therapy. The use of premanufactured allogeneic MSCs from controlled donors under optimal conditions and their application in highly standardized clinical trials would lead to a better understanding of their real applications and reduce the time to clinical translation.

Mesenchymal Stromal Cells as a Therapeutic Strategy to Support Islet Transplantation in Type 1 Diabetes Mellitus

Type 1 diabetes is an autoimmune disorder that leads to destruction of pancreatic β islet cells and is a growing global health issue. While insulin replacement remains the standard therapy for type 1 diabetes, exogenous insulin does not mimic the physiology of insulin secretion. Transplantation of pancreatic islets has the potential to cure this disease; however, there are several major limitations to widespread implementation of islet transplants. The use of mesenchymal stromal cells (MSCs) in the treatment of type 1 diabetes has been investigated as an adjunct therapy during islet graft administration to prevent initial islet loss and promote engraftment and revascularization of islets. In this review we will discuss the results of recent MSC studies in animal models of diabetes with a focus on islet transplantation and explore the potential for these findings to be extended to clinical use for the treatment of type 1 diabetes.

Moving from the laboratory bench to patients' bedside: considerations for effective therapy with stem cells

Although stem cell therapy is not a new field, the field was limited to transplantation of hematopoietic stem cells. Such transplantation has provided invaluable information for the emerging field with new stem cells. Mesenchymal stem cells (MSCs) are an attractive source for therapy; reduced ethical concern, ease in expansion, as off-the-shelf stem cells. MSCs exert immune suppressive properties, providing them with the potential for immune suppressive therapy such as autoimmunity, asthma, allergic rhinitis and graft versus host disease. In addition, MSCs, as well as other stem cells, can be applied for bone and cartilage repair, cardiovascular disease, and neural repair/protection. The data thus far with MSCs are mixed. This review discusses the immune-enhancing properties of MSCs to explain the possible confounds of inflammatory microenvironment in the MSCs therapy. Although this review focuses on MSCs, the information can be extrapolated to other stem cells. The review summarizes the biology of MSCs, including multilineage differentiation potential, transdifferentiation capability, and immunological effects. We emphasize the key concepts that may predict the use of these cells in medicine, namely, the application of these cells from the bench to the bedside. Prospects on immunotherapy, neuroregeneration, and cardiovascular repair are used as examples of tissue repair.

Human placenta-derived mesenchymal stem cells and islet-like cell clusters generated from these cells as a novel source for stem cell therapy in diabetes

Placental tissue holds great promise as a source of cells for regenerative medicine due to its plasticity, and easy availability. Human placenta-derived mesenchymal stem cells (hPDMSCs) have the potential to differentiate into insulin-producing cells. Upon transplantation, they can reverse experimental diabetes in mice. However, it is not known whether culture-expanded undifferentiated hPDMSCs are capable of restoring normoglycemia upon transplantation in streptozotocin (STZ)-induced diabetic mice. Hence we prepared long-term cultures of hPDMSCs from the chorionic villi of full-term human placenta. Flow cytometry analyses and immunocytochemistry study revealed bonafide mesenchymal nature of the isolated hPDMSCs. These cultures could differentiate into adipogenic, oesteogenic, chondrogenic, and neuronal lineages on exposure to lineage-specific cocktails. Furthermore, we showed that hPDMSCs can form islet-like cell clusters (ILCs) on stepwise exposure to serum-free defined media containing specific growth factors and differentiating agents. qRT-PCR showed the expression of insulin, glucagon, and somatostatin in undifferentiated hPDMSCs and in ILCs. Differentiated ILCs were found to express human insulin, glucagon, and somatostatin by immunocytochemistry. Additionally, ILCs also showed abundance of pancreatic transcription factors ngn3 and isl1. Both undifferentiated hPDMSCs and ILCs exihibited insulin secretion in response to glucose. Transplantation of hPDMSCs or ILCs derived from hPDMSCs in STZ-induced diabetic mice led to restoration of normoglycemia. Our results demonstrate, for the first time, reversal of hyperglycemia by undifferentiated hPDMSCs and ILCs derived from hPDMSCs. These results suggest human placenta-derived MSCs as an alternative source for cell replacement therapy in diabetes.

The quest for tissue stem cells in the pancreas and other organs, and their application in beta-cell replacement

Adult stem cell research has drawn a lot of attention by many researchers, due to its medical hope of cell replacement or regenerative therapy for diabetes patients. Despite the many research efforts to date, there is no consensus on the existence of stem cells in adult pancreas. Genetic lineage tracing experiments have put into serious doubt whether β-cell neogenesis from stem/progenitor cells takes place postnatally. Different in vitro experiments have suggested centroacinar, ductal, acinar, stellate, or yet unidentified clonigenic cells as candidate β-cell progenitors. As in the rest of the adult stem cell field, sound and promising observations have been made. However, these observations still need to be replicated. As an alternative to committed stem/progenitor cells in the pancreas, transdifferentiation or lineage reprogramming of exocrine acinar and endocrine α-cells may be used to generate new β-cells. At present, it is unclear which approach is most medically promising. This article highlights the progress being made in knowledge about tissue stem cells, their existence and availability for therapy in diabetes. Particular attention is given to the assessment of methods to verify the existence of tissue stem cells.