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Glucagon, secreted from pancreatic alpha-cells integrated within the islets of Langerhans, is involved in the regulation of glucose metabolism by enhancing the synthesis and mobilization of glucose in the liver. In addition, it has other extrahepatic effects ranging from lipolysis in adipose tissue to the control of satiety in the central nervous system. In(More)
Developmental genes are silenced in embryonic stem cells by a bivalent histone-based chromatin mark. It has been proposed that this mark also confers a predisposition to aberrant DNA promoter hypermethylation of tumor suppressor genes (TSGs) in cancer. We report here that silencing of a significant proportion of these TSGs in human embryonic and adult stem(More)
Extracellular signalling cues play a major role in the activation of differentiation programmes. Mouse embryonic stem (ES) cells are pluripotent and can differentiate into a wide variety of specialized cells. Recently, protocols designed to induce endocrine pancreatic differentiation in vitro have been designed but little information is currently available(More)
Glucose homeostasis in blood is mainly maintained by insulin released from beta-cells and glucagon released from alpha-cells, both integrated within the pancreatic islet of Langerhans. The secretory processes in both types of cells are triggered by a rise in intracellular calcium concentration ([Ca2+](i)). In this study, rapid effects of the natural hormone(More)
Cell-attached and inside-out patch clamp recording was used to compare the functional expression of membrane ion channels in mouse and human embryonic stem cells (ESCs). Both ESCs express mechanosensitive Ca2+ permeant cation channels (MscCa) and large conductance (200 pS) Ca2+-sensitive K+ (BKCa2+) channels but with markedly different patch densities.(More)
In mammalian visceral organs, vascular smooth muscle cells (VSMCs) originate from an epithelial-to-mesenchymal transition (EMT) of embryonic mesothelial cells (MCs). The ability of adult MCs to recapitulate EMT and to acquire smooth muscle (SM) markers upon provasculogenic culture suggested they might retain embryonic vasculogenic differentiation potential.(More)
17beta-Estradiol elicits a rapid opposite effect on [Ca2+]i in alpha- and beta-cells within intact islets of Langerhans. In beta-cells, physiological concentrations of the gonadal hormone decreases KATP channel activity in synergy with glucose, leading to a membrane depolarization that opens voltage-gated Ca2+ channels, potentiating Ca2+ signals. As a(More)
Pancreatic beta-cells constitute a well-communicating multicellular network that permits a coordinated and synchronized signal transmission within the islet of Langerhans that is necessary for proper insulin release. Gap junctions are the molecular keys that mediate functional cellular connections, which are responsible for electrical and metabolic coupling(More)
Recent developments in the effort to understand the metabolism and function of the intra-cellular dinucleoside polyphosphates were described by nine speakers from some of the world's leading laboratories in this field in a workshop at the Purines 2000 International Symposium on Nucleosides and Nucleotides held in Madrid in July, 2000. Topics were(More)
Stem cells have been successfully used for the treatment of critical limb ischemia (CLI). We conducted a clinical trial to determine the feasibility of using autologous adipose-derived mesenchymal stromal cells (AdMSCs) for the treatment of CLI. Unexpectedly, two diabetic patients developed peripheral microthrombosis. This adverse effect, which contrasts(More)