A novel posttranslational modification of histone, H3 S-sulfhydration, is down-regulated in asthenozoospermic sperm

Qi Qi,Runsheng Li,Xiaofeng Wan,Hongjie Pan,Meixin Zhang,Ning Jiang,Fangxi Zhang,Hua Diao,Lingling Zhang,Shenfei Sun,Jian Wang

doi:10.1007/s10815-021-02314-x

Abstract

Oxidative stress is one of the major causes leading to male infertility including asthenozoospermia. Hydrogen sulfide (H2S) has been widely recognized to be a potent antioxidant whose role is partially implemented by protein S-sulfhydration. However, protein S-sulfhydration has not been reported in germ cells. Therefore, we investigated whether asthenozoospermia could be associated with sperm protein S-sulfhydration. S-sulfhydrated proteins in human sperm were enriched via biotin-switch assay and analyzed using LC-MS/MS spectrometry. Two hundred forty-four S-sulfhydrated proteins were identified. Importantly, we validated that sperm histones H3.1 and H3.3 were the S-sulfhydrated proteins. Their S-sulfhydrated amino acid residue was Cysteine111. Abundances of S-sulfhydrated H3 (sH3) and S-sulfhydrated H3.3 (sH3.3) were significantly down-regulated in asthenozoospermic sperm, compared with the fertile controls, and were significantly correlated with progressive motility. Retinoic acid (RA) up-regulated level of sH3.3 in primary round spermatids and the C18-4 cells (a mouse spermatogonial stem cell line). Overexpression of the mutant H3.3 (Cysteine111 was replaced with serine) affected expression of 759 genes and raised growth rate of C18-4 cells. For the first time, S-sulfhydration H3 and H3.3 were demonstrated in the present study. Our results highlight that aberrant S-sulfhydration of H3 is a new pathophysiological basis in male infertility.

Highlights

Mammalian spermatogenesis, a precisely regulated developmental process generating sperm, consists of three distinct phases
The results showed that sperm S-sulfhydrated proteins were detected both via Western blotting assay and silver staining
In order to explore the role of sulfhydrated H3 (sH3).3 in the germ cells, we studied the effect of the H3.3 Cysteine 111 (C111) was replaced by serine (C111S) mutant on growth rate of C18-4 cells

Summary

Introduction

A precisely regulated developmental process generating sperm, consists of three distinct phases. The aberrant expression of PTMs of proteins including phosphorylation [12], sumoylation [13], glutarylation [14], and hydroxyisobutyrylation [15] was associated with poor sperm motility. Study of the global protein phosphorylation landscape of spermiogenesis showed wide phosphoregulation across a diverse range of processes during spermiogenesis [17] These proteomic studies did not show any specific protein whose function was regulated by these PTMs in germ cells. We revealed S-sulfhydrated proteome consisting of 244 proteins of human sperm in the present study. They included most of ROS-associated human sperm reported elsewhere [24].

Experimental procedures

Results

Discussion