Extracellular ATP (eATP) induces an intracellular Ca(2+) transient by activating phospholipase C (PLC)-associated P2X4 purinergic receptors, leading to production of inositol 1,4,5-trisphosphate (IP3) and subsequent Ca(2+) release from intracellular stores in mouse pancreatic beta-cells. Using laser scanning confocal microscopy, Ca(2+) indicator fluo-4 AM, and the cell permeable nuclear indicat...

Transforming growth factor-beta (TGF-beta) suppresses tumor formation by blocking cell cycle progression and maintaining tissue homeostasis. In pancreatic carcinomas, this tumor suppressive activity is often lost by inactivation of the TGF-beta-signaling mediator, Smad4. We found that human pancreatic carcinoma cell lines that have undergone deletion of MADH4 constitutively expressed high endog...

The effect of glucose on growth of the beta cell population was characterized in rat pancreatic organ culture. The effect was monitored by measuring [3H]thymidine labelling indices of beta cells during the culture period and by quantitation of beta cell population size at the end of the culture period. Foetal and neonatal pancreases and different glucose levels were compared. Glucose was found ...

The pancreatic beta-cell adapts to increased nutrient availability and insulin resistance by increasing its function and mass. These processes are orchestrated by signals derived from nutrient metabolism, hormones and cytokines. Their end-result is the regulation of insulin secretion and biosynthesis, and beta-cell proliferation and apoptosis. This review focuses on the mechanisms involved in b...

BACKGROUND AND OBJECTIVES Type 1 Diabetes Mellitus (T1DM) is an autoimmune disorder resulting out of T cell mediated destruction of pancreatic beta cells. Immunomodulatory properties of mesenchymal stem cells may help to regenerate beta cells and/or prevent further destruction of remnant, unaffected beta cells in diabetes. We have assessed the ability of umbilical cord derived MSCs (UCMSCs) to ...

An ectopic pancreas is defined as pancreatic tissue outside its normal location, anatomically separated from the pancreas.The transcription factor pancreas/duodenum homeobox protein 1 (PDX1) involved in maintaining and functions early development, beta cell differentiation, endocrine non cells. Pancreatic subunit alpha (PTF1A) affects exocrine formation regulation of acinar identity, expressed ...

Non-coding variation within TCF7L2 remains the strongest genetic determinant of type 2 diabetes risk in humans. A considerable effort has been placed in understanding the functional roles of TCF7L2 in pancreatic beta cells, despite evidence of TCF7L2 expression in various peripheral tissues important in glucose homeostasis. Here, we use a humanized mouse model overexpressing Tcf7l2, resulting i...

BACKGROUND A limitation in the number of insulin-producing pancreatic beta-cells is a special feature of diabetes. The identification of alternative sources for the induction of insulin-producing surrogate beta-cells is a matter of profound importance. PDX-1/VP16, BETA2/NeuroD, and MafA overexpression have been shown to influence the differentiation and proliferation of pancreatic stem cells. H...

The local synthesis of dopamine and its effects on insulin release have been described in isolated islets. Thus, it may be accepted that dopamine exerts an auto-paracrine regulation of insulin secretion from pancreatic beta cells. The aim of the present study is to analyze whether dopamine is a regulator of the proliferation and apoptosis of rat pancreatic beta cells after glucose-stimulated in...