Korean J Urol.  2009 May;50(5):498-504.

Proteomic Analysis of Penile Protein Alterations in a Rat Model of Cavernous Nerve Injury

• Chung H
• Lee CK
• Kim B
• Kim HS
• Kim TW
• Paick SH
• Jeon HS
• Yang SK

Abstract

PURPOSE: Cavernous nerve resection (CNR) in rats is a standard model of animal experiments on erectile dysfunction (ED) that occurs after radical prostatectomy (RP). Injured cavernous nerves after surgery can cause fibrosis and apoptosis that lead to penile structural changes that may be accompanied by alterations of protein expression. This study aimed to analyze the changes in protein after CNR in Wistar Kyoto rats.
MATERIALS AND METHODS
Using 8-week-old male Wistar Kyoto rats, sham and CNR operation under a microscope were performed. Two and 8 weeks after surgery, we applied 2-DE and MALDI-TOF/TOF (AB 4700) to identify differently expressed penile proteins after CNR. 2-DE gels were stained with silver nitrate and were analyzed with PDQuest. After in-gel digestion, peptide mass spectra were obtained by MALDI-TOF/TOF mass spectrometry in the positive ion reflector mode. The obtained data were screened with a rat database from both the NCBI and the Swiss-Prot/TrFMBL home page.
RESULTS
The proteins that were changed more than 1.5-fold compared with the sham group were annexin A4 and pyruvate kinase (PK). Annexin A4 was increased by 1.75-fold after 2 weeks, whereas PK was decreased by 4.16 after 8 weeks. These results were confirmed by immunohistochemistry.
CONCLUSIONS
Annexin A4 in the CNR group was increased, which may be related to emiocytosis during apoptosis. The decrease in PK of the CNR group is assumed to be related to a decrease in efficacy during glycolysis. Further study will be needed to elucidate the molecular pathophysiology of ED after cavernous nerve injury.

Keyword

Cavernous nerve; Erectile dysfunction; Proteomics

MeSH Terms

Animal Experimentation
Animals
Annexin A4
Apoptosis
Caves
Digestion
Erectile Dysfunction
Fibrosis
Gels
Glycolysis
Humans
Immunohistochemistry
Male
Mass Spectrometry
Prostatectomy
Proteins
Proteomics
Pyruvate Kinase
Rats
Rats, Inbred WKY
Salicylamides
Silver Nitrate
Annexin A4
Gels
Proteins
Pyruvate Kinase
Salicylamides
Silver Nitrate

Figure

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  Fig. 1 Two-dimension electrophoresis image of the rat penile cavernosum tissue. (A) after 2 weeks, (B) after 8 weeks (1: Annexin A4, 2: Pyruvate kinase, WKY: Wistar Kyoto rats, CNR: cavernous nerves resection).

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  Fig. 2 Two-dimension electrophoresis patterns showing up- and down-regulation of important proteins in penile tissues by cavernous nerve resection (CNR) as compared with sham operation (a: p<0.05).

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  Fig. 3 Immunohistochemical staining of annexin A4 in cavernous sections obtained from the penile tissue 2 weeks after sham or cavernous nerve resection (CNR) operation ((A) sham ×200, (B) CNR ×200, arrow: endothelial cells, arrow head: smooth muscle cells).

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