Cytoprotective effects of polyenoylphosphatidylcholine (PPC) on beta-cells during diabetic induction by streptozotocin.
Polyenoylphosphatidylcholine (PPC), a phosphatidylcholine-rich phospholipid extracted from soybean, has been reported to protect liver cells from alloxan-induced cytotoxicity. The present study aimed to investigate whether PPC protects pancreatic beta-cells from the cytotoxic injury induced by streptozotocin, thus preserving insulin synthesis and secretion. beta-Cells of the PPC-treated rats showed a significant reduction of cell death with lesser destruction of plasma membrane on streptozotocin insult. They demonstrated a rapid recovery of GLUT-2 expression, whereas almost irreversible depletion of membrane-bound GLUT-2 was seen in beta-cells of the rats treated with only streptozotocin. A similar cytoprotective effect of PPC was also monitored in the PPC-pretreated MIN6 cells. These beta-cells retained their ability to synthesize and secrete insulin and no alteration of glucose metabolism was detected. These results strongly suggest that PPC plays important roles not only in protecting beta-cells against cytotoxicity but also in maintaining their insulin synthesis and secretion for normal glucose homeostasis.
Lee
Seung-Hee
SH
Department of Anatomy, College of Medicine, Inha University, Inchon, Korea.
Han
Yu-Mi
YM
Min
Bon-Hong
BH
Park
In-Sun
IS
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019610:Cytoprotection; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D004032:Diet; D005947:Glucose / Q000378:metabolism; D051273:Glucose Transporter Type 2; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D016253:Microscopy, Immunoelectron; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010713:Phosphatidylcholines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
D051273:Glucose Transporter Type 2; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D010713:Phosphatidylcholines; D012333:RNA, Messenger; C005152:lipostabil; D013311:Streptozocin; D005947:Glucose