title: Down-regulation of alpha-2u globulin in renal mitochondria of STZ-induced diabetic rats observed by a proteomic method.
abstract: OBJECTIVE
  To identify the changes of mitochondrial protein expression in diabetic renal parenchyma and to characterize their molecular functions and biological processes in diabetes.
  
  
  METHODS
  Mitochondrial proteins extracted from renal parenchyma mitochondria of streptozotocin-induced diabetic rats and normal rats were separated by two-dimensional polyacrylamide gel electrophoresis and identified by matrix-assisted laser desorption/ionization tandem time-of-ﬂight mass spectrometry.
  
  
  RESULTS
  Eleven proteins from 533 visualized protein spots displayed significant different expressions in mitochondria of diabetic kidneys compared with those in normal ones. Among these altered proteins, two proteins with the most obvious changes in protein expression were identified as alpha-2u globulin (mature protein, named A2) and its proteolytically modified form (named A2-fragment) respectively. These proteins were found in mitochondria of male rat renal parenchyma and were proved to be down-regulated in diabetic rats simultaneously.
  
  
  CONCLUSIONS
  Our results suggest that down-regulation of alpha-2u globulin may be associated with an abnormal β-oxidation of long-chain fatty acids during diabetes. The decreased expression of A2-fragment in renal mitochondria of diabetic nephropathy may reduce fatty acid β-oxidation, which leads to a diminished energy supply from mitochondria to kidney tissue and the deposition of a large number of fatty acids in the kidney, ultimately causing and aggravating kidney damage. In conclusion, these findings may be helpful for understanding the molecular mechanism of diabetic nephropathy.
authors.affiliation: Department of Anatomy, North Sichuan Medical College, Nangchong, 234, Fujiang Road, Nangchong, Sichuan, 637007, China.
authors.forename: Shi-He
authors.initials: SH
authors.lastname: Sun
authors.forename: Shang-Qing
authors.initials: SQ
authors.lastname: Liu
authors.forename: Chang-Ping
authors.initials: CP
authors.lastname: Cai
authors.forename: Rong
authors.initials: R
authors.lastname: Cai
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.forename: Quan-Bo
authors.initials: QB
authors.lastname: Zhang
mesh_terms: D000510:Alpha-Globulins / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D003928:Diabetic Nephropathies / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D007668:Kidney / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D024101:Mitochondrial Proteins / Q000032:analysis / Q000378:metabolism; D020543:Proteome / Q000032:analysis / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin; D054928:Validation Studies as Topic
chemical_list: D000510:Alpha-Globulins; D024101:Mitochondrial Proteins; D020543:Proteome; C013803:alpha 2u globulin; D013311:Streptozocin