title: Apurinic/apyrimidinic endonuclease immunoreactivity in germ cells of experimental varicocele-induced rat testes.
abstract: Increased germ cell apoptosis is related to oxidative DNA damage; therefore, we investigated whether there was a significant change in apurinic/apyrimidinic endonuclease (APE) in varicoceles. Experimental varicoceles were created by partial ligation of the left renal vein of adult male Sprague-Dawley rats, which were sacrificed at 1, 3 and 6 weeks after varicocele creation. Testicular tissues were sampled for TUNEL, Western blotting and immunohistochemistry. There was a significant increase in apoptotic germ cells in the ipsilateral testes 6 weeks after varicocele creation. Increased activation of p53, Bax and cleaved caspase-3 in the left testes was also noted. APE increased activation until 3 weeks after varicocele creation, and then decreased at 6 weeks after varicocele surgery. The spermatocytes were immunostained for both 8-hydroxy-2'-deoxyguanosine and APE, but the spermatogonia revealed only APE immunopositivity in the defective tubules. These results suggest that repression of APE is an underlying mechanism of augmented p53-dependent apoptosis in varicocele-induced rat testes and that remaining APE in the spermatogonia plays a decisive role in regaining testicular spermatogenic function after varicocelectomy.
authors.affiliation: Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea. Electronic address: spyoon@jejunu.ac.kr.
authors.forename: Sang Pil
authors.initials: SP
authors.lastname: Yoon
mesh_terms: D000818:Animals; D017209:Apoptosis; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000032:analysis / Q000378:metabolism*; D005854:Germ Cells / Q000201:enzymology* / Q000473:pathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000201:enzymology / Q000473:pathology*; D014646:Varicocele / Q000201:enzymology / Q000473:pathology*
chemical_list: D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase
keywords: 8-OHdG; 8-hydroxy-2′-deoxyguanosine; APE; Apoptosis; BER; Base excision repair; ROS; Rat; Spermatogenesis; TUNEL; Testis; Varicocelectomy; apurinic/apyrimidinic endonuclease; base excision repair; phosphorylated H2AX; reactive oxygen species; terminal deoxyuridine nick-end labeling; γ-H2AX