detergent-free-decellularization-human-pancreas-for-soluble

Detergent-Free Decellularization of the Human Pancreas for Soluble Extracellular Matrix (ECM) Production

Islet transplantation (ITx) has the potential to become the standard of care in beta cell replacement medicine but its results remain inferior to those ...

Grenoble Alps University

Malignant insulinoma may arise during the course of type 1 diabetes mellitus: A case report.

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. 

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

To describe the 5-year outcomes of islet transplantation within the Swiss-French GRAGIL Network.

Five-Year Metabolic, Functional, and Safety Results of Patients With Type 1 Diabetes Transplanted With Allogenic Islets Within the Swiss-French GRAGIL Network.

Islet transplantation is indicated for patients with type 1 diabetes with severe hypoglycaemia or after kidney transplantation. We did a randomised trial to assess the efficacy and safety of islet transplantation compared with insulin therapy in these patients.

Islet transplantation versus insulin therapy in patients with type 1 diabetes with severe hypoglycaemia or poorly controlled glycaemia after kidney transplantation (TRIMECO): a multicentre, randomised controlled trial.

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 ( = 0.894;  < 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.

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

This analysis from the SMILE randomized study was performed to identify predictive factors associated with the greatest reductions in hypoglycemia with the Medtronic MiniMed™ 640G Suspend before low feature in adults with type 1 diabetes at high risk of severe hypoglycemia.

Predicting factors associated with hypoglycemia reduction with automated predictive insulin suspension in patients at high risk of severe hypoglycemia: an analysis from the SMILE randomized trial.

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.

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

Article	Year
Malignant insulinoma may arise during the course of type 1 diabetes mellitus: A case report. Diabetes & metabolism\| PubMed ID: 25451188	2015
Respective effects of oxygen and energy substrate deprivation on beta cell viability. Biochimica et biophysica acta\| PubMed ID: 25868875	2015
Five-Year Metabolic, Functional, and Safety Results of Patients With Type 1 Diabetes Transplanted With Allogenic Islets Within the Swiss-French GRAGIL Network. Diabetes care\| PubMed ID: 26068866	2015
Islet transplantation versus insulin therapy in patients with type 1 diabetes with severe hypoglycaemia or poorly controlled glycaemia after kidney transplantation (TRIMECO): a multicentre, ... The lancet. Diabetes & endocrinology\| PubMed ID: 29776895	2018
New Automatized Method of 3D Multiculture Viability Analysis Based on Confocal Imagery: Application to Islets and Mesenchymal Stem Cells Co-Encapsulation. Frontiers in endocrinology\| PubMed ID: 29887835	2018
Predicting factors associated with hypoglycemia reduction with automated predictive insulin suspension in patients at high risk of severe hypoglycemia: an analysis from the SMILE randomized ... Diabetes technology & therapeutics\| PubMed ID: 32412858	2020
Improved human islets' viability and functionality with mesenchymal stem cells and arg-gly-asp tripeptides supplementation of alginate micro-encapsulated islets in vitro. Biochemical and biophysical research communications\| PubMed ID: 32513541	2020

Sandrine Lablanche

Biography

JoVE Journal Publications

Other Publications