Human erythrocyte membranes metabolize inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4] to inositol 1,3,4-trisphosphate [Ins(1,3,4)P3] in the presence of Mg2+. In the absence of Mg2+ a less rapid conversion of Ins(1,3,4,5)P4 into Ins(1,4,5)P3 was revealed. Such an enzyme activity, if present in hormonally sensitive cells, could provide a mechanism for maintaining constant concentrations of I...

Astroglial cells isolated from the rodent postnatal cerebral cortex are particularly susceptible to lineage reprogramming into neurons. However, it remains unknown whether other astroglial populations retain the same potential. Likewise, little is known about the fate of induced neurons (iNs) in vivo. In this study we addressed these questions using two different astroglial populations isolated...

Type 2 diabetes seriously affects human health and burdens public health systems. Pancreatic β‑cell apoptosis contributes to a reduction in β‑cell mass, which is responsible for the occurrence of type 2 diabetes. However, the mechanism that underlies this effect remains unclear. In the present study, the role of forkhead box O1 (Foxo1) was investigated (which is a key regulatory factor in β‑cel...

Polymorphisms located at microRNA (miRNA) binding sites may affect the expression of genes. The present study aimed to identify the association between an insertion/deletion (Ins/Del) polymorphism (rs3783553) in the 3'‑untranslated region (3'‑UTR) of interleukin‑1α (IL‑1A) and the risk for osteoarthritis (OA). Using a luciferase reporter system, IL‑1A was identified in the present study as an e...

Chronic free fatty acid (FFA) exposure induces pancreatic beta-cell death, which may contribute to the development of type 2 diabetes. The mechanisms involved in FFA-induced cell death are not completely understood. Here we have investigated the effect of FFA on endoplasmic reticulum (ER) stress pathways in INS-1 pancreatic beta-cells. INS-1 cells exposed to palmitate for 16-24 h under serum-fr...

OBJECTIVE Diabetes is caused by a deficiency of pancreatic beta-cells that produce insulin. Approaches to enhance beta-cell mass by increasing proliferation and survival are desirable. We determined whether stromal cell-derived factor (SDF)-1/CXCL12 and its receptor, CX chemokine receptor (CXCR)4, are important for the survival of beta-cells. RESEARCH DESIGN AND METHODS Mouse pancreata and cl...

K cells are a subpopulation of enteroendocrine cells that secrete glucose-dependent insulinotropic polypeptide (GIP), a hormone that promotes glucose homeostasis and obesity. Therefore, it is important to understand how GIP secretion is regulated. GIP-producing (GIP/Ins) cell lines secreted hormones in response to many GIP secretagogues except glucose. In contrast, glyceraldehyde and methyl pyr...

The role nitric oxide (NO) plays in physiological insulin secretion has been controversial. Here we present evidence that exogenous NO stimulates insulin secretion, and that endogenous NO production occurs and is involved in the regulation of insulin release. Radioimmunoassay measurement of insulin release and a dynamic assay of exocytosis using the dye FM1-43 demonstrated that three different ...

Ca(2+) signalling in exocrine acinar cells has been shown to be both polarized and pulsatile in all cell types tested, except acutely isolated mouse lacrimal acinar cells. Lacrimal cells are also unusual in that they display a very low sensitivity to Ins(1,4,5) P (3) (Ins P (3)) that may be enhanced by placing the cells in primary culture for 12-72 h or by intracellular infusion of a low concen...