Monitoring C-Peptide Storage and Secretion in Islet β-Cells In Vitro and In Vivo
نویسندگان
چکیده
Human proinsulin with C-peptide-bearing Superfolder Green Fluorescent Protein (CpepSfGFP) has been expressed in transgenic mice, driven by the Ins1 promoter. The protein, expressed exclusively in β-cells, is processed and stored as CpepSfGFP and human insulin comprising only ∼0.04% of total islet proinsulin plus insulin, exerting no metabolic impact. The kinetics of the release of insulin and CpepSfGFP from isolated islets appear identical. Upon a single acute stimulatory challenge in vitro, fractional release of insulin does not detectably deplete islet fluorescence. In vivo, fluorescence imaging of the pancreatic surface allows, for the first time, visual assessment of pancreatic islet insulin content, and we demonstrate that CpepSfGFP visibly declines upon diabetes progression in live lepR(db/db) mice. In anesthetized mice, after intragastric or intravenous saline delivery, pancreatic CpepSfGFP (insulin) content remains undiminished. Remarkably, however, within 20 min after acute intragastric or intravenous glucose delivery (with blood glucose concentrations reaching >15 mmol/L), a small subset of islets shows rapid dispossession of a major fraction of their stored CpepSfGFP (insulin) content, whereas most islets exhibit no demonstrable loss of CpepSfGFP (insulin). These studies strongly suggest that there are "first responder" islets to an in vivo glycemic challenge, which cannot be replicated by islets in vitro.
منابع مشابه
بررسی القای تمایز سلولهای بنیادی به سلولهای بتای پانکراس بهوسیله عصاره متانولی یونجه
Background and Objective: β cell replacement therapy by pancreatic islet transplantation has become a promising treatment for type 1 diabetes. Medicago sativa L (Lucerne) from leguminosae family is known to exhibit hypoglycaemic activity both in animal and human studies. Most of these studies were concentrated on the effects of plant extracts on fasting glucose levels. Until now no researches h...
متن کاملCo-Transplantation of VEGF-Expressing Human Embryonic Stem Cell Derived Mesenchymal Stem Cells to Enhance Islet Revascularization in Diabetic Nude Mice
Background: Pancreatic islet transplantation has emerged as a promising treatment for type I diabetes. However, its efficacy is severely hampered due to poor islet engraftment and revascularization, which have been resulted to partially loss of transplanted islets. It has been shown that local delivery of vascular endothelial growth factor (VEGF) could accelerate transplanted islet revasculari...
متن کاملPancreatic Differentiation of Sox 17 Knock-in Mouse Embryonic Stem Cells in Vitro
The way to overcome current limitations in the generation of glucose-responsive insulin-producing cells is selective enrichment of the number of definitive endoderm (DE) progenitor cells. Sox17 is the marker of mesendoderm and definitive endoderm. The aim of the present research was to study the potential of Sox17 knock-in CGR8 mouse embryonic stem (ES) cells to differentiate into insulin produ...
متن کاملIn-vitro Differentiation of Human Umbilical Cord Wharton’s Jelly Mesenchymal Stem Cells to Insulin-Producing Cells
Background & Objective: Diabetes is a major chronic metabolic disease in the world. Islet transplantation is a way to treat diabetes. Unfortunately, this method is restricted due to graft rejection and lack of donor islets. Mesenchymal Stem Cells (MSCS) have the ability to differentiate into Insulin-Producing Cells (IPCs). In this study, Human Umbilical Mesenchymal Stem Cells (HUMSCS) were in...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 65 شماره
صفحات -
تاریخ انتشار 2016