Molecular targets for diabetes mellitus-associated erectile dysfunction.
Protein expression profiles in rat corporal smooth muscle tissue were compared between animal models of streptozotocin-induced diabetes mellitus (STZ-DM) and age-matched controls (AMCs) at 1 week and 2 months after induction of hyperglycemia with STZ treatment. At each time point, protein samples from four STZ-DM and four AMC rat corpora tissues were prepared independently and analyzed together across multiple quantitative two-dimensional gels using a pooled internal standard sample to quantify expression changes with statistical confidence. A total of 170 spots were differential expressed among the four experimental groups. A subsequent mass spectrometry analysis of the 170 spots identified a total of 57 unique proteins. Network analysis of these proteins using MetaCore suggested altered activity of transcriptional factors that are of too low abundance to be detected by the two-dimensional gel method. The proteins that were down-regulated with diabetes include isoforms of collagen that are precursors to fibril-forming collagen type 1; Hsp47, which assists and mediates the proper folding of procollagen; and several proteins whose abundance is controlled by sex hormones (e.g. CRP1 and A2U). On the other hand, proteins seen or predicted to be up-regulated include proteins involved in cell apoptosis (e.g. p53, 14-3-3-gamma, Serpinf1, Cct4, Cct5, and Sepina3n), proteins that neutralize the biological activity of nerve growth factor (e.g. anti-NGF 30), and proteins involved in lipid metabolism (e.g. apoA-I and apoA-IV). Subsequent Western blot validation analysis of p53, 14-3-3-gamma, and Hsp47 confirmed increased p53 and 14-3-3-gamma and decreased Hsp47 levels in separate samples. According to the results from the Western blot analysis, Hsp47 protein showed a approximately 3-fold decrease at 1 week and was virtually undetectable at 2 months in diabetic versus control. Taken together, our results identify novel candidate proteins playing a role in erectile dysfunction in diabetes resulting from STZ treatment.
Yohannes
Elizabeth
E
Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Chang
Jinsook
J
Tar
Moses T
MT
Davies
Kelvin P
KP
Chance
Mark R
MR
D048948:14-3-3 Proteins / Q000032:analysis; D000818:Animals; D017209:Apoptosis; D003094:Collagen / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D007172:Erectile Dysfunction / Q000209:etiology* / Q000503:physiopathology; D012739:Gonadal Steroid Hormones / Q000032:analysis; D050958:HSP47 Heat-Shock Proteins / Q000032:analysis; D006943:Hyperglycemia / Q000139:chemically induced; D050356:Lipid Metabolism; D008297:Male; D020932:Nerve Growth Factor / Q000032:analysis; D010413:Penis / Q000737:chemistry* / Q000503:physiopathology; D040901:Proteomics; D051381:Rats; D011916:Rats, Inbred F344; D013311:Streptozocin; D014157:Transcription Factors / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D048948:14-3-3 Proteins; D012739:Gonadal Steroid Hormones; D050958:HSP47 Heat-Shock Proteins; C494662:Serpinh1 protein, rat; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D013311:Streptozocin; D003094:Collagen; D020932:Nerve Growth Factor