Histone H4 acetylation and AZFc involvement in germ cells of specimens of impaired spermatogenesis.

OBJECTIVE

To measure histone-H4 acetylation and involvement of the AZFc region in testicular mixed atrophy.

DESIGN

Prospective study.

SETTING

University-affiliated medical center.

PATIENT(S): Azoospermic men (n = 23) who underwent testicular sperm extraction and preparation for intracytoplasmic sperm injection (ICSI) divided into obstructive azoospermia with complete spermatogenesis (group A), testicular mixed atrophy (group B), and testicular mixed atrophy associated with AZFc deletion (group C).

INTERVENTION(S): Testicular biopsy evaluation by Western blotting and quantitative immunohistochemistry of histone-H4 hyperacetylation (Hypac-H4) and lysine-12 acetylation (Lys12ac-H4).

MAIN OUTCOME MEASURE(S): Percentage of spermatogonia and spermatids stained by Hypac-H4 and Lys12ac-H4 antibodies in retrieved specimens.

RESULT(S): The percentage of spermatogonia stained for Hypac-H4 and Lys12ac-H4 in groups B and C was statistically significantly reduced. The percentage of elongated spermatids showing positive staining to Hypac-H4 was statistically significantly lower in group B than group A. The percentage of Lys12ac-H4-labeled spermatids was similar for all groups. Hypac-H4 and Lys12ac-H4 processes were highly correlated in spermatogonia but not in spermatids.

CONCLUSION(S): The reduced percentage of spermatogonia with Hypac-H4 and Lys12ac-H4 in groups B and C may contribute to lower sperm production in mixed atrophy. Spermatids Hypac-H4 impairment in mixed atrophy did not deteriorate further by AZFc region deletion.