We present a new technique for analyzing the three-dimensional structure of intact isolated islets of Langerhans. Adult rat and human islets were stained with whole-mount immunofluorescence techniques and optically sectioned with a confocal microscope. This has several advantages over traditional methods: 1) the technical difficulties in serial sectioning and handling the large numbers of secti...

Regenerating (REG) proteins are associated with islet development, β-cell damage, diabetes and pancreatitis. Particularly, REG-1 and REG-3-beta are involved in cell growth/survival and/or inflammation and the Reg1 promoter contains interleukin-6 (IL-6)-responsive elements. We showed by transcriptome analysis that islets of Goto-Kakizaki (GK) rats, a model of spontaneous type 2 diabetes, overexp...

OBJECTIVE It is generally admitted that the endocrine cell organization in human islets is different from that of rodent islets. However, a clear description of human islet architecture has not yet been reported. The aim of this work was to describe our observations on the arrangement of human islet cells. RESEARCH DESIGN AND METHODS Human pancreas specimens and isolated islets were processed...

Studies in vivo indicate that IRS2 plays an important role in maintaining functional beta-cell mass. To investigate if IRS2 autonomously affects beta-cells, we have studied proliferation, apoptosis, and beta-cell function in isolated rat and human islets after overexpression of IRS2 or IRS1. We found that beta-cell proliferation was significantly increased in rat islets overexpressing IRS2 whil...

The collagenase digestion phase of islet isolation is variable and unpredictable. This results partly from the vagaries of collagenase itself but also from the complex effects of organ retrieval and storage on collagenase digestion. Improvements in the purification of islets by density gradient centrifugation will not result from the production of new density gradient media, but rather from the...

Context The B islets isolated from 3-5 day old chick respond well to glucose challenge in a similar fashion to those isolated from mouse pancreas. Objective To compare insulin secretory response of chick B islets with that of human Islet Equivalents (hIEqs) generated from stem cells. Methods Human Umbilical Cord Mesenchymal Stem Cells (UC-MSCs) were differentiated into hIEqs employing three ste...

Pancreatic islet transplantation has emerged as a therapy for type 1 diabetes and is today performed using both freshly isolated and cultured islets. Islet blood vessels are disrupted during islet isolation; therefore, proper revascularization of the transplanted islets is of great importance for islet graft function and survival. We have studied intraislet endothelial cells after islet isolati...

The voltage-gated potassium channels Kv2.1 and Kv2.2 are highly expressed in pancreatic islets, yet their contribution to islet hormone secretion is not fully understood. Here we investigate the role of Kv2 channels in pancreatic islets using a combination of genetic and pharmacologic approaches. Pancreatic b-cells from Kv2.1 mice possess reduced Kv current and display greater glucose-stimulate...

In wild-type mice, a single injection of streptozotocin (STZ, 200 mg/kg body wt) caused within 4 days severe hyperglycemia, hypoinsulinemia, significant glucose intolerance, loss of body weight, and the disappearance of pancreatic beta-cells. However, in ATP-sensitive K(+) channel (K(ATP) channel)-deficient mice (Kir6.2(-/-) mice), STZ had none of these effects. Exposing isolated pancreatic isl...