title: Characterization of activation of MAP kinase superfamily in vasculature from diabetic rats.
abstract: OBJECTIVE
  This study was investigated to characterize the activation mechanism of a mitogen-activated protein (MAP) kinase superfamily in diabetes in aortae and cultured vascular smooth muscle cells (VSMCs) from rats.
  
  
  METHODS
  Male Sprague-Dawley rats were used for this procedure, and diabetes was induced by streptozotocin injection at 50 mg/kg. After 6 weeks, the thoracic aortae from normal and diabetic rats were removed for detection of the MAP kinase superfamily by immunoblot analysis.
  
  
  RESULTS
  In aortae, the protein levels of extracellular signal-regulated protein kinase (ERK)-1, c-jun NH2-terminal protein kinase (JNK)-1 and -2, and p38 increased significantly more in diabetic rats than in normal rats. In contrast, phosphorylated protein levels of ERK-1 and -2, JNK-1, and p38 were significantly more elevated in diabetic rats than in normal rats. In VSMCs from normal rats, a high concentration of glucose cultured for three days significantly increased the phosphorylated protein levels of ERKs and p38, but not JNKs, without any change of these protein levels. Serum interleukin (IL)-1beta was significantly higher in diabetic rats than in normal rats. Several types of proinflammatory cytokine dose-dependently phosphorylated the levels of ERKs, JNK-1, and p38, but not JNK-2, in VSMCs from normal rats. In cells from diabetic rats, phosphorylated protein levels of ERKs and p38 were significantly elevated by IL-1beta. In addition, interferon-gamma phosphorylated the levels of ERKs in diabetic cells more than in normal cells.
  
  
  CONCLUSIONS
  Our results suggest that, under diabetic conditions, the MAP kinase superfamily was activated by different pathways in the vasculature; i.e., ERKs and p38 might be mainly phosphorylated by a complex of high concentrations of glucose and of several types of proinflammatory cytokines, but the phosphorylation of JNK-1 might depend on the concentration of proinflammatory cytokines such as IL-1beta, and/or additional unknown factors, except glucose.
authors.affiliation: Department of Laboratory Medicine, Yamagata University School of Medicine, Yamagata, Japan. migarasi@med.id.yamagata-u.ac.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Igarashi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hirata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Naoko
authors.initials: N
authors.lastname: Sugae
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kadomoto-Antsuki
authors.forename: Hisae
authors.initials: H
authors.lastname: Nozaki
authors.forename: Yumi
authors.initials: Y
authors.lastname: Jimbu
authors.forename: Makoto
authors.initials: M
authors.lastname: Tominaga
mesh_terms: D000818:Animals; D001011:Aorta / Q000201:enzymology; D015153:Blotting, Western; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D004789:Enzyme Activation / Q000502:physiology*; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D032389:Myocytes, Smooth Muscle / Q000201:enzymology; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D020928:Mitogen-Activated Protein Kinases