From the Clinical to the Bench: Exploring the Insulin Modulation Effects of Tacrolimus and Belatacept.

Calcineurin inhibitors (CNIs) are critical in preventing rejection posttransplantation but pose an increased risk of post-transplant diabetes (PTD). Recent studies show that late conversion from CNIs to belatacept, a costimulation blocker, improves HbA1c in kidney transplant recipients with PTD or de novo diabetes. This study investigates whether the observed effects on PTD stem solely from CNI withdrawal or if belatacept influences PTD independently. The study assessed the impact of tacrolimus and belatacept on insulin secretion in MIN6 cells (a beta cell line) and rat islets. Tacrolimus and belatacept were administered to the cells and islets, followed by assessments of cell viability and insulin secretion. Tacrolimus impaired insulin secretion without affecting cell viability, while belatacept showed no detrimental effects on either parameter. These findings support clinical observations of improved HbA1c upon switching from tacrolimus to belatacept. Belatacept holds promise in islet or pancreas transplantation, particularly in patients with unstable diabetes. Successful cases of islet transplantation treated with belatacept without severe hypoglycemia highlight its potential in managing PTD. Further research is needed to fully understand the metabolic changes accompanying the transition from CNIs to belatacept. Preserving insulin secretion emerges as a promising avenue for investigation in this context.

Diabetes in spotlight: current knowledge and perspectives of photobiomodulation utilization.

Introduction: Diabetes is a global health concern characterized by chronic hyperglycemia resulting from insulinopenia and/or insulin resistance. The rising prevalence of diabetes and its associated complications (ulcers, periodontitis, healing of bone defect, neuropathy, retinopathy, cardiopathy and nephropathy) necessitate innovative therapeutic approaches. Photobiomodulation (PBM), involves exposing tissues and cells to low-energy light radiation, leading to biological effects, largely via mitochondrial activation. Methods: This review evaluates preclinical and clinical studies exploring the potential of PBM in diabetes and its complications, as well all clinical trials, both planned and completed, available on ClinicalTrials database. Results: This review highlights the variability in PBM parameters across studies, hindering consensus on optimal protocols. Standardization of treatment parameters and rigorous clinical trials are needed to unlock PBM's full therapeutic potential. 87 clinical trials were identified that investigated PBM in diabetes mellitus (with 5,837 patients planned to be treated with PBM). Clinical trials assessing PBM effects on diabetic neuropathy revealed pain reduction and potential quality of life improvement. Studies focusing on wound healing indicated encouraging results, with PBM enhancing angiogenesis, fibroblast proliferation, and collagen density. PBM's impact on diabetic retinopathy remains inconclusive however, requiring further investigation. In glycemic control, PBM exhibits positive effects on metabolic parameters, including glucose tolerance and insulin resistance. Conclusion: Clinical studies have reported PBM-induced reductions in fasting and postprandial glycemia without an increased hypoglycemic risk. This impact of PBM may be related to its effects on the beta cells and islets in the pancreas. Notwithstanding challenges, PBM emerges as a promising adjunctive therapy for managing diabetic neuropathy, wound healing, and glycemic control. Further investigation into its impact on diabetic retinopathy and muscle recovery is warranted.

Effect of a lifestyle intervention to prevent weight gain at initiation of insulin pump therapy in type 2 diabetes: A randomized, controlled, multicentre trial.

Insulin pump therapy improves glycaemic control in individuals with type 2 diabetes. However, it may be associated with weight gain. AIM: To test the effectiveness of a six-month dietary and physical activity intervention, compared to usual care, on weight gain prevention after initiation of insulin pump. METHODS: Multicentre randomized, controlled trial of 54 individuals. Primary endpoint was between group difference in weight gain at six-months. RESULTS: Weight gain after 6 months of insulin pump treatment did not differ between groups: mean 3.2 (3.9) kg in the control group and 3.9 (3.8) kg in the intervention group, (p = 0.56). HbA1c improved without difference between groups. Post-hoc multivariate analysis of all participants found that weight gain was independently associated with younger age, active smoking, and the magnitude of HbA1c reduction. A 1 % decrease in HbA1c was associated with an increase of 0.94 kg [95 % Confidence Interval 0.47; 1.41], p < 0.001. CONCLUSIONS: Treatment intensification by insulin pump therapy in patients with type 2 diabetes is effective to improve glycaemic control. A gain of about 1 kg per 1 % drop in HbA1c can be expected after insulin treatment intensification. This weight gain was not prevented by a home-base, individualized, 6-months lifestyle intervention program.

Impact of a Remote Monitoring Programme Including Lifestyle Education Software in Type 2 Diabetes: Results of the Educ@dom Randomised Multicentre Study.

INTRODUCTION: Telemonitoring in type 2 diabetes (T2D) is mainly based on glucose monitoring. A new type of connected device which routinely gathers data on weight, physical activity and food intake could improve patients' diabetes control. The main aim of this study was to assess the efficacy of an at-home interventional programme incorporating such devices and lifestyle education software on diabetes control, i.e., change in HbA1c, compared to standard care. METHODS: This multicentre study randomly assigned 282 people with T2D to either a telemonitoring group (TMG) or a control group (CG) for a 1-year intervention period. While routine follow-up was maintained in the CG, TMG subjects were provided with interactive lifestyle educational software (with artificial intelligence algorithms) and connected objects (blood glucose meters, scales and actimeters) for use in their own homes and were remotely monitored by their diabetologists. Changes in HbA1c were compared between groups using a mixed linear model. RESULTS: The mean HbA1c dropped from 7.8 ± 0.8% (62 mmol/mol) to 7.4 ± 1.0% (57 mmol/mol) in the TMG and from 7.8 ± 0.8% (62 mmol/mol) to 7.6 ± 1.0% (60 mmol/mol) in the CG, resulting in an intergroup difference of - 0.16 (p = 0.06) in favour of TMG, after adjustment for confounding factors. Within TMG, the decrease in HbA1c was greater in frequent users: - 0.23% (p = 0.03) in the case of connections to telemonitoring synthesis above the median and - 0.21% (p = 0.05) in the case of connections to tele-education software above the median compared to the CG. Significant weight loss was observed in the TMG but only in women (p = 0.01). FINDINGS: The EDUC@DOM telemonitoring and tele-education device did not highlight a significant decrease in HbA1c levels compared to routine management although a slight, albeit significant improvement in glycaemic control was observed in the frequent user subgroup as well as significant weight loss but only in women. A high level of satisfaction with the connected device was recorded amongst all participants. TRIAL REGISTRATION: This trial was registered in the Clinical Trials Database on September 27, 2013, under no. NCT01955031 and bears ID-RCB number 2013-A00391-44.

Improved human islets' viability and functionality with mesenchymal stem cells and arg-gly-asp tripeptides supplementation of alginate micro-encapsulated islets in vitro.

INTRODUCTION: The extension of islet transplantation to a wider number of type 1 diabetes patients is compromised by severe adverse events related to the immunosuppressant therapy required for allogenic islet transplantation. In this context, microencapsulation offers the prospects of immunosuppressive-free therapy by physically isolating islets from the immune system. However, current biomaterials need to be optimized to: improve biocompatibility, guaranty the maintenance of graft viability and functionality, and prevent fibrosis overgrowth around the capsule in vivo. Accumulating evidence suggest that mesenchymal stem cells (MSCs) and anchor points consisting of tripeptides arg-gly-asp (RGD) have cytoprotective effects on pancreatic islets. Here, we investigated the effect of supplementing reference M-rich alginate microcapsules with MSCs and RGD-G rich alginate on bioprocessing as well as on human pancreatic islets viability and functionality. METHODS: We characterized the microcapsules components, and then for the new microcapsule composite product: we analyzed the empty capsules biocompatibility and then investigated the benefits of MSCs and RGD-G rich alginate on viability and functionality on the encapsulated human pancreatic islets in vitro. We performed viability tests by confocal microscopy and glucose stimulated insulin secretion (GSIS) test in vitro to assess the functionality of naked and encapsulated islets. RESULTS: Encapsulation in reference M-rich alginate capsules induced a reduction in viability and functionality compared to naked islets. This side-effect of encapsulation was in part counteracted by the presence of MSCs but the restoration was complete with the combination of both MSCs and the RGD-G rich alginate. CONCLUSIONS: The present findings show that bioprocessing a favorable composite environment inside the M-rich alginate capsule with both MSCs and RGD-G rich alginate improves human islets survival and functionality in vitro.

Human mesenchymal stem cells improve rat islet functionality under cytokine stress with combined upregulation of heme oxygenase-1 and ferritin.

BACKGROUND: Islets of Langerhans transplantation is a promising therapy for type 1 diabetes mellitus, but this technique is compromised by transplantation stresses including inflammation. In other tissues, co-transplantation with mesenchymal stem cells has been shown to reduce damage by improving anti-inflammatory and anti-oxidant defences. Therefore, we probed the protection afforded by bone marrow mesenchymal stem cells to islets under pro-inflammatory cytokine stress. METHODS: In order to evaluate the cytoprotective potential of mesenchymal stem cells on rat islets, co-cultures were exposed to the interleukin-1, tumour necrosis factor α and interferon γ cocktail for 24 h. Islet viability and functionality tests were performed. Reactive oxygen species and malondialdehyde were measured. Expression of stress-inducible genes acting as anti-oxidants and detoxifiers, such as superoxide dismutases 1 and 2, NAD(P)H quinone oxidoreductase 1, heme oxygenase-1 and ferritin H, was compared to non-stressed cells, and the corresponding proteins were measured. Data were analysed by a two-way ANOVA followed by a Holm-Sidak post hoc analysis. RESULTS: Exposure of rat islets to cytokines induces a reduction in islet viability and functionality concomitant with an oxidative status shift with an increase of cytosolic ROS production. Mesenchymal stem cells did not significantly increase rat islet viability under exposure to cytokines but protected islets from the loss of insulin secretion. A drastic reduction of the antioxidant factors heme oxygenase-1 and ferritin H protein levels was observed in islets exposed to the cytokine cocktail with a prevention of this effect by the presence of mesenchymal stem cells. CONCLUSIONS: Our data evidenced that MSCs are able to preserve islet insulin secretion through a modulation of the oxidative imbalance mediated by heme and iron via heme oxygenase-1 and ferritin in a context of cytokine exposure.

New Automatized Method of 3D Multiculture Viability Analysis Based on Confocal Imagery: Application to Islets and Mesenchymal Stem Cells Co-Encapsulation.

Co-encapsulation of pancreatic islets with mesenchymal stem cells in a three-dimensional biomaterial's structure is a promising technique to improve transplantation efficacy and to decrease immunosuppressant therapy. Currently, evaluation of graft quality after co-encapsulation is only based on insulin secretion. Viability measurement in a 3D conformation structure involving two different cell types is complex, mainly performed manually, highly time consuming and examiner dependent. Standardization of encapsulated graft viability analysis before transplantation is a key point for the translation of the method from the bench side to clinical practice. In this study, we developed an automated analysis of islet viability based on confocal pictures processing of cells stained with three probes (Hoechst, propidium iodide, and PKH67). When compared with results obtained manually by different examiners, viability results show a high degree of similarity (under 3% of difference) and a tight correlation (r = 0.894; p < 0.001) between these two techniques. The automated technique offers the advantage of reducing the analysis time by 6 and avoids the examiner's dependent variability factor. Thus, we developed a new efficient tool to standardize the analysis of islet viability in 3D structure involving several cell types, which is a key element for encapsulated graft analysis in clinical practice.

Respective effects of oxygen and energy substrate deprivation on beta cell viability.

Deficit in oxygen and energetic substrates delivery is a key factor in islet loss during islet transplantation. Permeability transition pore (PTP) is a mitochondrial channel involved in cell death. We have studied the respective effects of oxygen and energy substrate deprivation on beta cell viability as well as the involvement of oxidative stress and PTP opening. Energy substrate deprivation for 1h followed by incubation in normal conditions led to a cyclosporin A (CsA)-sensitive-PTP-opening in INS-1 cells and human islets. Such a procedure dramatically decreased INS-1 cells viability except when transient removal of energy substrates was performed in anoxia, in the presence of antioxidant N-acetylcysteine (NAC) or when CsA or metformin inhibited PTP opening. Superoxide production increased during removal of energy substrates and increased again when normal energy substrates were restored. NAC, anoxia or metformin prevented the two phases of oxidative stress while CsA prevented the second one only. Hypoxia or anoxia alone did not induce oxidative stress, PTP opening or cell death. In conclusion, energy substrate deprivation leads to an oxidative stress followed by PTP opening, triggering beta cell death. Pharmacological prevention of PTP opening during islet transplantation may be a suitable option to improve islet survival and graft success.