Cell-based interventions to halt autoimmunity in type 1 diabetes mellitus

Stem Cell Therapy for the Management of Type 1 Diabetes: Advances and Perspectives

Due to insulin resistance and excessive blood sugar levels, type 1 diabetes mellitus (T1DM) is characterized by pancreatic cell loss. This condition affects young people at a higher rate than any other chronic autoimmune disease. Regardless of the method, exogenous insulin cannot substitute for insulin produced by a healthy pancreas. An emerging area of medicine is pancreatic and islet transplantation for type 1 diabetics to restore normal blood sugar regulation. However, there are still obstacles standing in the way of the widespread use of these therapies, including very low availability of pancreatic and islets supplied from human organ donors, challenging transplantation conditions, high expenses, and a lack of easily accessible methods. Efforts to improve Type 1 Diabetes treatment have been conducted in response to the disease's increasing prevalence. Type 1 diabetes may one day be treated with stem cell treatment. Stem cell therapy has proven to be an effective treatment for type 1 diabetes. Recent progress in stem cell-based diabetes treatment is summarised, and the authors show how to isolate insulin-producing cells (IPCs) from a variety of progenitor cells.

Cotransplantation of marginal mass allogeneic islets with 3D culture-derived adult human skin cells improves glycemia in diabetic mice

Islet transplantation represents a therapeutic option for type 1 diabetes (T1D). Long-term viability of transplanted islets requires improvement. Mesenchymal stromal cells (MSCs) have been proposed as adjuvants for islet transplantation facilitating grafting and functionality. Stem cell aggregation provides physiological interactions between cells and enhances the in situ concentration of modulators of inflammation and immunity. We established a hanging-drop culture of adult human skin fibroblast-like cells as spheroids, and skin spheroid-derived cells (SphCs) were characterized. We assessed the potential of SphCs in improving islet functionality by cotransplantation with a marginal mass of allogeneic islets in an experimental diabetic mouse model and characterized the secretome of SphCs by mass spectrometry-based proteomics. SphCs were characterized as multipotent progenitors and their coculture with anti-CD3 stimulated mouse splenocytes decreased CD4+ T cell proliferation with skewed cytokine secretion through an increase in the Th2/Th1 ratio profile. SphCs-conditioned media attenuated apoptosis of islets induced by cytokine challenge in vitro and importantly, intratesticular SphCs administration did not show tumorigenicity in immune-deficient mice. Moreover, SphCs improved glycemic control when cotransplanted with a marginal mass of allogeneic islets in a diabetic mouse model without pharmacological immunosuppression. SphCs' protein secretome differed from its paired skin fibroblast-like counterpart in containing 70% of up- and downregulated proteins and biological processes that overall positively influenced islets such as cytoprotection, cellular stress, metabolism, and survival. In summary, SphCs improved the performance of transplanted allogeneic islets in an experimental T1D model, without pharmacological immunosuppression. Future research is warranted to identify SphCs-secreted factors responsible for islets' endurance.

Advances in surface-modified nanometal-organic frameworks for drug delivery

Nanometal-organic frameworks (NMOFs) are porous network structures composed of metal ions or metal clusters through self-assembly. NMOFs have been considered as a promising nano-drug delivery system due to their unique properties such as pore and flexible structures, large specific surface areas, surface modifiability, non-toxic and degradable properties. However, NMOFs face a series complex environment during in vivo delivery. Therefore, surface functionalization of NMOFs is vital to ensure that the structure of NMOFs remain stable during delivery, and can overcome physiological barriers to deliver drugs more accurately to specific sites, and achieve controllable release. In this review, the first part summarizes the physiological barriers that NMOFs faced during drug delivery after intravenous injection and oral administration. The second part summarizes the current main ways to load drugs into NMOFs, mainly including pore adsorption, surface attachment, formation of covalent/coordination bonds between drug molecules and NMOFs, and in situ encapsulation. The third part is the main review part of this paper, which summarizes the surface modification methods of NMOFs used in recent years to overcome the physiological barriers and achieve effective drug delivery and disease therapy, which are mainly divided into physical modifications and chemical modifications. Finally, the full text is summarized and prospected, with the hope to provide ideas for the future development of NMOFs as drug delivery.

Nicotinamide attenuates streptozotocin-induced diabetes complications and increases survival rate in rats: role of autonomic nervous system

BACKGROUND

To evaluate the effect of nicotinamide prior to streptozotocin-induced (STZ) diabetes in baroreflex sensitivity and cardiovascular autonomic modulation, and its association with hemodynamics and metabolic parameters.

METHODS

Methods: Male Wistar rats were divided into control (Cont) and STZ-induced diabetes (Diab). Half of the rats from each group received a single dose of nicotinamide (100 mg/Kg) before STZ injection (Cont+NicA and Diab+NicA). All groups were followed-up for 5 weeks.

RESULTS

Body weight loss of more than 40% was observed in Diab throughout the period (Diab: 271.00 ± 12.74 g; Diab+NicA: 344.62 ± 17.82). Increased glycemia was seen in Diab rats (541.28 ± 18.68 mg/dl) while Diab+NicA group had a slight decrease (440.87 ± 20.96 mg/dl). However, insulin resistance was observed only in Diab. In relation to Cont, heart rate, mean blood pressure and diastolic function were reduced when compared to Diab, together with parasympathetic modulation and baroreflex sensitivity. All of these parameters were improved in Diab+NicA when compared to Diab. Improved baroreflex sensitivity and parasympathetic modulation were correlated with glycemia, insulin resistance, and body weight mass. Additionally, Diab+NicA group increased survival rate.

CONCLUSIONS

Results suggest that the association of nicotinamide in STZ-induced diabetic rats prevents most of the expected derangements mainly by preserving parasympathetic and baroreflex parameters.

Modeling Type 1 Diabetes Using Pluripotent Stem Cell Technology

Induced pluripotent stem cell (iPSC) technology is increasingly being used to create in vitro models of monogenic human disorders. This is possible because, by and large, the phenotypic consequences of such genetic variants are often confined to a specific and known cell type, and the genetic variants themselves can be clearly identified and controlled for using a standardized genetic background. In contrast, complex conditions such as autoimmune Type 1 diabetes (T1D) have a polygenic inheritance and are subject to diverse environmental influences. Moreover, the potential cell types thought to contribute to disease progression are many and varied. Furthermore, as HLA matching is critical for cell-cell interactions in disease pathogenesis, any model that seeks to test the involvement of particular cell types must take this restriction into account. As such, creation of an in vitro model of T1D will require a system that is cognizant of genetic background and enables the interaction of cells representing multiple lineages to be examined in the context of the relevant environmental disease triggers. In addition, as many of the lineages critical to the development of T1D cannot be easily generated from iPSCs, such models will likely require combinations of cell types derived from in vitro and in vivo sources. In this review we imagine what an ideal in vitro model of T1D might look like and discuss how the required elements could be feasibly assembled using existing technologies. We also examine recent advances towards this goal and discuss potential uses of this technology in contributing to our understanding of the mechanisms underlying this autoimmune condition.

Advances in Understanding the Roles of CD244 (SLAMF4) in Immune Regulation and Associated Diseases

Proteins in the signaling lymphocytic activating molecule (SLAM) family play crucial roles in regulating the immune system. CD244 (SLAMF4) is a protein in this family, and is also a member of the CD2 subset of the immunoglobulin (Ig) superfamily. CD244 is a cell surface protein expressed by NK cells, T cells, monocytes, eosinophils, myeloid-derived suppressor cells, and dendritic cells. CD244 binds to the ligand CD48 on adjacent cells and transmits stimulatory or inhibitory signals that regulate immune function. In-depth studies reported that CD244 functions in many immune-related diseases, such as autoimmune diseases, infectious diseases, and cancers, and its action is essential for the onset and progression of these diseases. The discovery of these essential roles of CD244 suggests it has potential as a prognostic indicator or therapeutic target. This review describes the molecular structure and function of CD244 and its roles in various immune cells and immune-related diseases.

Efficacy and Safety of Stem Cell Therapy for T1DM: An Updated Systematic Review and Meta-Analysis

BACKGROUND

The long-term insulin therapy for type 1 diabetes mellitus (T1DM) fails to achieve optimal glycemic control and avoid adverse events simultaneously. Stem cells have unique immunomodulatory capacities and have been considered as a promising interventional strategy for T1DM. Stem cell therapy in T1DM has been tried in many studies. However, the results were controversial. We thus performed a meta-analysis to update the efficacy and safety of stem cell therapy in patients with T1DM.

METHODS

We systematically searched the Medline, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Web of Science, Wan Fang Data, China National Knowledge Infrastructure, VIP database, and the Chinese Biomedical Literature Database (SinoMed) for relevant studies published before March 19, 2019. The outcomes included parameters for glycemic control (i.e., glycosylated hemoglobin (HbA1c) levels and insulin dosages), β cell function (i.e., fasting C-peptide levels and area-under-curve of C-peptide concentration (AUCC)), and relative risk of adverse events. Statistical analysis was conducted by using RevMan 5.3 and Stata 12.0.

RESULTS

Five randomized controlled trials (RCTs) and eight nonrandomized concurrent control trials (NRCCTs) with a total of 396 individuals were finally included into the meta-analysis. Among RCTs, stem cell therapy could significantly reduce HbA1c levels (MD = -1.20, 95% CI -1.91 to -0.49, P = 0.0009) and increase fasting C-peptide levels (MD = 0.25, 95% CI 0.04 to 0.45, P = 0.02) and AUCC (SMD = 0.66, 95% CI 0.13 to 1.18, P = 0.01). Stem cell therapy could also reduce insulin dosages (SMD = -2.65, 95% CI -4.86 to -0.45, P = 0.02) at 6 months after treatment. NRCCTs also had consistent results. Furthermore, RCTs showed stem cell therapy did not increase relative risk of gastrointestinal symptom (RR = 0.69, 95% CI 0.14 to 3.28, P = 0.64) and infection (RR = 0.97, 95% CI 0.40 to 2.34, P = 0.95). However, NRCCTs showed stem cell therapy increased relative risk of gastrointestinal symptom (RR = 44.49, 95% CI 9.20 to 215.18, P < 0.00001).

CONCLUSION

Stem cell therapy for T1DM may improve glycemic control and β cell function without increasing the risk of serious adverse events. Stem cell therapy may also have a short-term (3-6 months) effect on reducing insulin dosages.

Stem Cell Therapy and Type 1 Diabetes Mellitus: Treatment Strategies and Future Perspectives

Type 1 diabetes mellitus (T1DM) is classified as an autoimmune disease which progressively results in the depletion of insulin-secreting β-cells. Consequently, the insulin secretion stops leading to hyperglycemic situations within the body. Under severe conditions, it also causes multi-organ diabetes-associated dysfunctionalities notably hypercoagulability, neuropathy, nephropathy, retinopathy, and sometimes organ failures. The prevalence of this disease has been noticed about 3% that has highlighted the serious concerns for healthcare professionals around the globe. For the treatment of this disease, the cell therapy is considered as an important therapeutic approach for the replacement of damaged β-cells. However, the development of autoantibodies unfortunately reduces their effectiveness with the passage of time and finally with the recurrence of diabetes mellitus. The development of new techniques for extraction and transplantation of islets failed to support this approach due to the issues related to major surgery and lifelong dependence on immunosuppression. For T1DM, such cells are supposed to produce, store, and supply insulin to maintain glucose homeostasis. The urgent need of much-anticipated substitute for insulin-secreting β-cells directed the researchers to focus on stem cells (SCs) to produce insulin-secreting β-cells. For being more specific and targeted therapeutic approaches, SC-based strategies opened up the new horizons to cure T1DM. This cell-based therapy aimed to produce functional insulin-secreting β-cells to cure diabetes on forever basis. The intrinsic regenerative potential along with immunomodulatory abilities of SCs highlights the therapeutic potential of SC-based strategies. In this article, we have comprehensively highlighted the role of SCs to treat diabetes mellitus.

Co-transplantation of Human Fetal Mesenchymal and Hematopoietic Stem Cells in Type 1 Diabetic Mice Model

Introduction: Cell therapy can overcome the limitation of conventional treatments (including different medications and β cell replacement) for type 1 diabetes. Based- on several studies human fetal mesenchymal and hematopoietic stem cells are ideal candidates for stem cell therapy. On the other hand, co-transplantation of them can improve their effects. Accordingly, the aim of this research is co-transplantation of human fetal mesenchymal and hematopoietic stem cells in type 1 diabetes. Materials and Methods: The liver of legally aborted fetus was harvested. Then, mononuclear cells were isolated and extracted mesenchymal stromal cells and CD34⁺ hematopoietic stem cells were cultured. Expression of pluripotency markers were evaluated. For molecular imaging, mesenchymal stromal cells were labeled using GFP- vector. BALB/c inbred male mice were modeled by injection a single dose of Streptozotocin. Diabetic animals were received stem cells. After stem cell transplantation, in vivo imaging was performed and blood glucose levels were measured weekly. Results: Fetal mesenchymal stromal cells were demonstrated differentiation potential. Expression of pluripotency markers were positive. The mean of blood glucose levels were reduced in mixed mesenchymal and hematopoietic stem cells transplantation. A lot of GFP-labeled mesenchymal stem cells were engrafted in the pancreas of animal models that received a mixed suspension of hematopoietic and mesenchymal stromal cells. Conclusions: Human fetal stem cells are valuable source for cell therapy and co-transplantation of mesenchymal stromal cells can improve therapeutic effects of hematopoietic stem cells.

Clinical variables and ethnicity may influenced by polymorphism of CAT -262C/T and MnSOD 47C/T antioxidant enzymes in Algerian type1 diabetes without complications

The latest studies in Algeria show that the frequency of type 1 diabetes (T1D) without complications is lower than that with complications and represents a significant burden in terms of cost and treatment. For this reason, we are interested in uncomplicated type1 diabetes and risk factors that are related to polymorphisms of antioxidant enzymes in order to prevent its complications. A total of 260 blood samples of young Algerian adults were examined. The genotypic analysis of Catalase gene (CAT -262C/T, rs1001179) and the superoxide dismutase gene (MnSOD 47C/T, rs4880) was performed by real-time PCR using TaqMan technology. The genotypic distribution of the CAT -262C/T promoter gene's polymorphism showed a significant difference between control and T1D patients for the CC genotype (p = 0.009; OR = 0.30) and for the T allele (p = 0.002; OR = 2.82). In addition, the genotypic distribution of the MnSOD 47C/T gene showed an association with T1D for the CT genotype (p = 0.040; OR = 2.37). Our results revealed that polymorphisms of CAT and MnSOD may be associated with physiopathology causing the onset of T1D. Our data, suggest that the genotypic frequencies of these SNPs appear to be influenced by clinical variables and by the Arab-Berber ethnic origin of the Algerian population.

Hepatitis B vaccine non response: A predictor of latent autoimmunity?

Unresponsiveness to Hepatitis B virus (HBV) vaccine has been associated with interleukins involved with Th1 functioning including Interleukin-8 (IL-18) and Interferon-γ (IFN-γ). IL-18 and IFN-γ have also been implicated in the onset of different types of immune-mediate inflammatory conditions such as Type 1 Diabetes (T1D), Celiac disease (CD), rheumatoid arthritis (RA), obesity and systemic lupus erythematosus (SLE). Taking into account that HBV vaccination is provided in the 1st year of life worldwide, I propose that all babies should be tested for anti-HBs response after completion of the vaccine series. And I suggest that children with undetectable anti-HBs titers after recommended immunization schedule as well as the additional booster doses should be followed up over time because they may be at risk of developing a number of autoimmune disorders. In this light, the non-responsiveness to HBV vaccine might be a predictor of latent autoimmunity. For that reason, research studies are needed in order to verify the existence of potential IL-18 and IFN-γ gene polymorphisms to utilize as biomarkers of latent autoimmunity. As a final point, administration of neutralizing antibodies against IFN-γ and/or IL-18 might represent a future target for immune-modulatory therapeutic approach to halt or even reverse autoimmune phenomena.

Microvascular Complications in Type 1 Diabetes: A Comparative Analysis of Patients Treated with Autologous Nonmyeloablative Hematopoietic Stem-Cell Transplantation and Conventional Medical Therapy

OBJECTIVE

To explore the impact on microvascular complications, long-term preservation of residual B-cell function and glycemic control of patients with type 1 diabetes treated with autologous nonmyeloablative hematopoietic stem-cell transplantation (AHST) compared with conventional medical therapy (CT).

RESEARCH DESIGN AND METHODS

Cross-sectional data of patients treated with AHST were compared with patients who received conventional therapy from the Brazilian Type 1 Diabetes Study Group, the largest multicenter observational study in type 1 diabetes mellitus in Brazil. Both groups of patients had diabetes for 8 years on average. An assessment comparison was made on the presence of microvascular complications, residual function of B cell, A1c, and insulin dose of the patients.

RESULTS

After a median of 8 years of diagnosis, none of the AHST-treated patients (n = 24) developed microvascular complications, while 21.5% (31/144) had at least one (p < 0.005) complication in the CT group (n = 144). Furthermore, no case of nephropathy was reported in the AHST group, while 13.8% of CT group (p < 0.005) developed nephropathy during the same period. With regard of residual B-cell function, the percentage of individuals with predicted higher C-peptide levels (IDAA1C ≤ 9) was about 10-fold higher in the AHST group compared with CT (75 vs. 8.3%) (p < 0.001) group. Among AHST patients, 54.1% (13/24) had the HbA1c < 7.0 compared with 13.1% in the CT (p < 0.001) group.

CONCLUSION

Patients with newly diagnosed type 1 diabetes treated with AHST presented lower prevalence of microvascular complications, higher residual B-cell function, and better glycemic control compared with the CT group.

Stem cell therapy emerging as the key player in treating type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is an autoimmune disease causing progressive destruction of pancreatic β cells, ultimately resulting in loss of insulin secretion producing hyperglycemia usually affecting children. Replacement of damaged β cells by cell therapy can treat it. Currently available strategies are insulin replacement and islet/pancreas transplantation. Unfortunately these offer rescue for variable duration due to development of autoantibodies. For pancreas/islet transplantation a deceased donor is required and various shortfalls of treatment include quantum, cumbersome technique, immune rejection and limited availability of donors. Stem cell therapy with assistance of cellular reprogramming and β-cell regeneration can open up new therapeutic modalities. The present review describes the history and current knowledge of T1DM, evolution of cell therapies and different cellular therapies to cure this condition.

Fibroblast Cell-Based Therapy for Experimental Autoimmune Diabetes

Type 1 diabetes (T1D) results from autoimmune destruction of insulin producing β cells of the pancreatic islets. Curbing autoimmunity at the initiation of T1D can result in recovery of residual β cells and consequently remission of diabetes. Here we report a cell-based therapy for autoimmune diabetes in non-obese diabetic (NOD) mice using dermal fibroblasts. This was achieved by a single injection of fibroblasts, expressing the immunoregulatory molecule indoleamine 2,3 dioxygenase (IDO), into peritoneal cavity of NOD mice shortly after the onset of overt hyperglycemia. Mice were then monitored for reversal of hyperglycemia and changes in inflammatory / regulatory T cell profiles. Blood glucose levels dropped into the normal range in 82% of NOD mice after receiving IDO-expressing fibroblasts while all control mice remained diabetic. We found significantly reduced islet inflammation, increased regulatory T cells, and decreased T helper 17 cells and β cell specific autoreactive CD8+ T cells following IDO cell therapy. We further showed that some of intraperitoneal injected fibroblasts migrated to local lymph nodes and expressed co-inhibitory molecules. These findings suggest that IDO fibroblasts therapy can reinstate self-tolerance and alleviate β cell autoreactivity in NOD mice, resulting in remission of autoimmune diabetes.

Cell-based therapy approaches: the hope for incurable diseases

Cell therapies aim to repair the mechanisms underlying disease initiation and progression, achieved through trophic effect or by cell replacement. Multiple cell types can be utilized in such therapies, including stem, progenitor or primary cells. This review covers the current state of cell therapies designed for the prominent disorders, including cardiovascular, neurological (Parkinson's disease, amyotrophic lateral sclerosis, stroke, spinal cord injury), autoimmune (Type 1 diabetes, multiple sclerosis, Crohn's disease), ophthalmologic, renal, liver and skeletal (osteoarthritis) diseases. Various cell therapies have reached advanced clinical trial phases with potential marketing approvals in the near future, many of which are based on mesenchymal stem cells. Advances in pluripotent stem cell research hold great promise for regenerative medicine. The information presented in this review is based on the analysis of the cell therapy collection detailed in LifeMap Discovery(®) (LifeMap Sciences Inc., USA) the database of embryonic development, stem cell research and regenerative medicine.

Induction of Tolerogenic Dendritic Cells by a PEGylated TLR7 Ligand for Treatment of Type 1 Diabetes

Autoimmune diabetes mellitus (DM) results from the destruction of pancreatic islet cells by activated T lymphocytes, which have been primed by activated dendritic cells (DC). Individualized therapy with ex vivo DC manipulation and reinfusion has been proposed as a treatment for DM, but this treatment is limited by cost, and requires specialized facilities. A means of in situ modulation of the DC phenotype in the host would be more accessible. Here we report a novel innate immune modulator, 1Z1, generated by conjugating a TLR7 ligand to six units of polyethylene glycol (PEG), which skews DC phenotype in vivo. 1Z1 was less potent in inducing cytokine production by DC than the parent ligand in vitro and in vivo. In addition, this drug only modestly increased DC surface expression of activation markers such as MHC class II, CD80, and CD86; however, the expression of negative regulatory molecules, such as programmed death ligand 1 (PD-L1), and interleukin-1 receptor-associated kinase M (IRAK-M) were markedly increased. In vivo transfer of 1Z1 treated DC into prediabetic NOD mice delayed pancreatic insulitis. Daily administration of 1Z1 effectively prevented the clinical onset of hyperglycemia and reduced histologic islet inflammation. Daily treatment with 1Z1 increased PD-L1 expression in the CD11c⁺ population in peri-pancreatic lymph nodes; however, it did not induce an increase in regulatory T cells. Pharmaceutical modulation of DC maturation and function in situ, thus represents an opportunity to treat autoimmune disease.

Toward beta cell replacement for diabetes

The discovery of insulin more than 90 years ago introduced a life-saving treatment for patients with type 1 diabetes, and since then, significant progress has been made in clinical care for all forms of diabetes. However, no method of insulin delivery matches the ability of the human pancreas to reliably and automatically maintain glucose levels within a tight range. Transplantation of human islets or of an intact pancreas can in principle cure diabetes, but this approach is generally reserved for cases with simultaneous transplantation of a kidney, where immunosuppression is already a requirement. Recent advances in cell reprogramming and beta cell differentiation now allow the generation of personalized stem cells, providing an unlimited source of beta cells for research and for developing autologous cell therapies. In this review, we will discuss the utility of stem cell-derived beta cells to investigate the mechanisms of beta cell failure in diabetes, and the challenges to develop beta cell replacement therapies. These challenges include appropriate quality controls of the cells being used, the ability to generate beta cell grafts of stable cellular composition, and in the case of type 1 diabetes, protecting implanted cells from autoimmune destruction without compromising other aspects of the immune system or the functionality of the graft. Such novel treatments will need to match or exceed the relative safety and efficacy of available care for diabetes.

Curcumin ameliorates autoimmune diabetes. Evidence in accelerated murine models of type 1 diabetes

Type 1 diabetes (T1DM) is a T cell-mediated autoimmune disease that selectively destroys pancreatic β cells. The only possible cure for T1DM is to control autoimmunity against β cell-specific antigens. We explored whether the natural compound curcumin, with anti-oxidant and anti-inflammatory activities, might down-regulate the T cell response that destroys pancreatic β cells to improve disease outcome in autoimmune diabetes. We employed two accelerated autoimmune diabetes models: (i) cyclophosphamide (CYP) administration to non-obese diabetic (NOD) mice and (ii) adoptive transfer of diabetogenic splenocytes into NODscid mice. Curcumin treatment led to significant delay of disease onset, and in some instances prevented autoimmune diabetes by inhibiting pancreatic leucocyte infiltration and preserving insulin-expressing cells. To investigate the mechanisms of protection we studied the effect of curcumin on key immune cell populations involved in the pathogenesis of the disease. Curcumin modulates the T lymphocyte response impairing proliferation and interferon (IFN)-γ production through modulation of T-box expressed in T cells (T-bet), a key transcription factor for proinflammatory T helper type 1 (Th1) lymphocyte differentiation, both at the transcriptional and translational levels. Also, curcumin reduces nuclear factor (NF)-κB activation in T cell receptor (TCR)-stimulated NOD lymphocytes. In addition, curcumin impairs the T cell stimulatory function of dendritic cells with reduced secretion of proinflammatory cytokines and nitric oxide (NO) and low surface expression of co-stimulatory molecules, leading to an overall diminished antigen-presenting cell activity. These in-vitro effects correlated with ex-vivo analysis of cells obtained from curcumin-treated mice during the course of autoimmune diabetes. These findings reveal an effective therapeutic effect of curcumin in autoimmune diabetes by its actions on key immune cells responsible for β cell death.

The global landscape of stem cell clinical trials

AIM

To provide a comprehensive analysis of clinical trials (CTs) listed in worldwide registries involving new applications for stem cell-based treatments and account for the role of industry.

MATERIALS & METHODS

We developed a data set of 4749 stem cell CTs up to 2013 in worldwide registries. We defined 1058 novel CTs (i.e., trials that were not observational in nature; did not involve an established stem cell therapy for an established indication, such as hematopoietic stem cells for leukemia; and did not investigate supportive measures). Based on trial descriptions, we manually coded these for eight additional elements.

RESULTS

Our analysis details the characteristics of novel stem cell CTs (e.g., stem cell types being tested, disease being targeted, and whether interventions were autologous or allogeneic), geotemporal trends, and private sector involvement as sponsor or collaborator.

CONCLUSION

The field is progressing at a steady pace with emerging business models for stem cell therapeutics. However, therapeutic rhetoric must be tempered to reflect current clinical and research realities.

Progress in immune-based therapies for type 1 diabetes

Immune-based therapies that prevent type 1 diabetes or preserve metabolic function remaining at diagnosis have become a major objective for funding agencies and international trial consortia, and receive backing from notable patient advocate groups. The development of immune-based therapeutic strategies in this arena requires a careful balancing of the risks of the therapy against the potential benefits, because many individuals are diagnosed or identified as being at increased risk of disease in early childhood, a period when manipulation of the developing immune system should be undertaken with caution. In addition, a therapy exists (daily insulin injection) that is life-saving in the acute stages of disease and can be used effectively over a lifetime as maintenance. Conversely, the disease is increasing in incidence; is peaking in ever-younger age groups; carries significant risk of increased morbidity and early mortality; and remains difficult to manage effectively in many settings. With these issues in mind, in this article we review progress towards immune-based strategies for this chronic autoimmune disease.

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

Type 1 diabetes mellitus (T1D) is a chronic, multifactorial autoimmune disease that involves the progressive destruction of pancreatic β-cells, ultimately resulting in the loss of insulin production and secretion. The goal of clinical intervention is to prevent or arrest the onset and progression of autoimmunity, reverse β-cell destruction, and restore glycometabolic and immune homeostasis. Despite promising outcomes observed with islet transplantation and advancements in immunomodulatory therapies, the need for an effective cell replacement strategy for curing T1D still persists. Stem cell therapy offers a solution to the cited challenges of islet transplantation. While the regenerative potential of stem cells can be harnessed to make available a self-replenishing supply of glucose-responsive insulin-producing cells, their immunomodulatory properties may potentially be used to prevent, arrest, or reverse autoimmunity, ameliorate innate/alloimmune graft rejection, and prevent recurrence of the disease. Herein, we discuss the therapeutic potential of stem cells derived from a variety of sources for the cure of T1D, for example, embryonic stem cells, induced pluripotent stem cells, bone marrow-derived hematopoietic stem cells, and multipotent mesenchymal stromal cells derived from bone marrow, umbilical cord blood, and adipose tissue. The benefits of combinatorial approaches designed to ensure the successful clinical translation of stem cell therapeutic strategies, such as approaches combining effective stem cell strategies with islet transplantation, immunomodulatory drug regimens, and/or novel bioengineering techniques, are also discussed. To conclude, the application of stem cell therapy in the cure for T1D appears extremely promising.