title: ER stress and ER stress-induced apoptosis are activated in gastric SMCs in diabetic rats.
abstract: OBJECTIVE
  To investigate the gastric muscle injury caused by endoplasmic reticulum (ER) stress in rats with diabetic gastroparesis.
  
  
  METHODS
  Forty rats were randomly divided into two groups: a control group and a diabetic group. Diabetes was induced by intraperitoneal injection of 60 mg/kg of streptozotocin. Gastric emptying was determined at the 4(th) and 12(th) week. The ultrastructural changes in gastric smooth muscle cells (SMCs) were investigated by transmission electron microscopy. TdT-mediated dUTP nick end labeling (TUNEL) assay was performed to assess apoptosis of SMCs. Expression of the ER stress marker, glucose-regulated protein 78 (GRP78), and the ER-specific apoptosis mediator, caspase-12 protein, was determined by immunohistochemistry.
  
  
  RESULTS
  Gastric emptying was significantly lower in the diabetic rats than in the control rats at the 12(th) wk (40.71% ± 2.50%, control rats vs 54.65% ± 5.22%, diabetic rats; P < 0.05). Swollen and distended ER with an irregular shape was observed in gastric SMCs in diabetic rats. Apoptosis of gastric SMCs increased in the diabetic rats in addition to increased expression of GRP78 and caspase-12 proteins.
  
  
  CONCLUSIONS
  ER stress and ER stress-mediated apoptosis are activated in gastric SMCs in diabetic rats with gastroparesis.
authors.affiliation: Xia Chen, Xiang-Sheng Fu, Chang-Ping Li, Department of Gastroenterology, Affiliated Hospital of Luzhou Medical College, Luzhou 646000, Sichuan Province, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.affiliation: Xia Chen, Xiang-Sheng Fu, Chang-Ping Li, Department of Gastroenterology, Affiliated Hospital of Luzhou Medical College, Luzhou 646000, Sichuan Province, China.
authors.forename: Xiang-Sheng
authors.initials: XS
authors.lastname: Fu
authors.affiliation: Xia Chen, Xiang-Sheng Fu, Chang-Ping Li, Department of Gastroenterology, Affiliated Hospital of Luzhou Medical College, Luzhou 646000, Sichuan Province, China.
authors.forename: Chang-Ping
authors.initials: CP
authors.lastname: Li
authors.affiliation: Xia Chen, Xiang-Sheng Fu, Chang-Ping Li, Department of Gastroenterology, Affiliated Hospital of Luzhou Medical College, Luzhou 646000, Sichuan Province, China.
authors.forename: Hong-Xian
authors.initials: HX
authors.lastname: Zhao
mesh_terms: D000818:Animals; D017209:Apoptosis; D053454:Caspase 12 / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure*; D059865:Endoplasmic Reticulum Stress; D005746:Gastric Emptying; D005753:Gastric Mucosa / Q000378:metabolism; D018589:Gastroparesis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D006360:Heat-Shock Proteins; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D046529:Microscopy, Electron, Transmission; D032389:Myocytes, Smooth Muscle / Q000378:metabolism / Q000648:ultrastructure*; D017208:Rats, Wistar; D013270:Stomach / Q000503:physiopathology / Q000648:ultrastructure*; D013997:Time Factors; D000091342:Endoplasmic Reticulum Chaperone BiP
chemical_list: D053454:Caspase 12; D006360:Heat-Shock Proteins; C051684:GRP78 protein, rat; D000091342:Endoplasmic Reticulum Chaperone BiP; C506443:Casp12 protein, rat
keywords: Apoptosis; Caspase-12; Diabetic gastroparesis; Endoplasmic reticulum stress; glucose-regulated protein 78 kD