Dynamic Expression and Chromatin Incorporation of ACT and CREM Transcription Factors in Testis Tissues of Infertile Men.

OBJECTIVE

Activator of CREM in the testis (ACT) is a tissue specific transcription factor which activates cAMP responsive element modulator (CREM), a key transcription factor in differentiation of round spermatids into mature spermatozoa. They bind to CRE region in the promoters of transition protein genes () and protamine genes ( and ), which are essential for sperm chromatin compaction, and regulates their transcription. This study was conducted to consider the expression of ACT and CREM and their regulatory roles on the expression of and genes in testis tissues of infertile men.

MATERIALS AND METHODS

In this case-control study, testicular biopsies were collected from 40 infertile men and classified into three groups: obstructive azoospermia (OA, n=10, positive control), round spermatid maturation arrest (SMA, n=20), Sertoli cell-only syndrome (SCOS, n=10, negative control group). Using quantitative real-time polymerase chain reaction (PCR), the expression profile of and genes were assessed in testicular samples and incorporation of ACT and CREM proteins on the promoters of and genes were also evaluated by ChIP-real time PCR.

RESULTS

Our results demonstrated significant decrease in the expression levels of ACT, CREM and in their incorporations on their target genes in SMA group in comparison to control groups (P≤0.05).

CONCLUSION

These data confirm that there is low expression and incorporation of ACT and CREM and of their target genes in infertilities which are associated with post-meiotic arrest.