Cytoprotective actions of clusterin on beta cells

초록

Clusterin is a heterodimeric glycoprotein and ubiquitously expressed in a variety of tissues, although its physiological actions has not been clearly elucidated. The glycoprotein has been known to be involved in apoptosis, whereas its cytoprotective action was ascertained even in the same tissue. Recently we reported clusterin expression in α cells and its diverse biological actions in pancreatic tissue including its β cell protection. In the present study, we examined the role of clusterin in pancreatic tissues using a transgenic mouse model with β cell-targeted overexpression of clusterin (CLU-TG), and the clusterin-deficient mice (CLU-KO). Depletion and overexpression of clusterin were confirmed by RT-PCR and immunocytochemistry. Diabetes and hyperglycemia were not developed in the CLU-TG mice by multiple and low dose injection of streptozotocin (MLDS). Pancreatic islets of these mice demonstrated a normal profile without destruction or loss of insulin-secreting beta cells.