Enhanced HOXA10 sumoylation inhibits embryo implantation in women with recurrent implantation failure

Ruiwei Jiang,Jingyu Liu,Qiang Yan,Haixiang Sun,Yue Jiang,Qun Zhang,Lijun Ding,Guijun Yan,Jianjun Zhou,Xin Zhen,Jianxin Sun,Chenyang Huang

doi:10.1038/cddiscovery.2017.57

Ruiwei Jiang, Jingyu Liu + Show 10 more

Open Access

https://doi.org/10.1038/cddiscovery.2017.57

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Abstract

HOXA10 has emerged as an important molecular marker of endometrial receptivity. Recurrent implantation failure (RIF) after in vitro fertilization-embryo transplantation (IVF-ET) treatment is associated with impaired endometrial receptivity, but the exact underlying mechanism of this phenomenon remains elusive. Here we found that HOXA10 was modified by small ubiquitin like-modifier 1 (SUMO1) at the evolutionarily conserved lysine 164 residue. Sumoylation inhibited HOXA10 protein stability and transcriptional activity without affecting its subcellular localization. SUMO1-modified HOXA10 expression was decreased in estradiol- and progesterone-treated Ishikawa cells. Sumoylation inhibited the accelerant role of HOXA10 in BeWo spheroid and mouse embryo attachment to Ishikawa cells. Importantly, aberrantly high SUMO1-HOXA10 expression was detected in mid-secretory endometria of women with RIF compared with that of the control fertile women. Together, our results suggest that HOXA10 sumoylation impairs the process of embryo implantation in vitro and takes part in the development of RIF.

Highlights

Embryo implantation is a process of mutual communication between the blastocyst and the uterus primarily under the direction of ovarian estrogen and progestin
We found that HOXA10 expression increased over time in Ishikawa cells treated with estradiol and progesterone, but that expression of small ubiquitin like-modifier 1 (SUMO1) conjugates with a molecular weight of 90 kDa decreased over time (Figure 4a)
We found markedly attenuated SUMO1-HOXA10 expression in Ishikawa cells treated with estradiol and progesterone (Figure 4c)

Summary

INTRODUCTION

Embryo implantation is a process of mutual communication between the blastocyst and the uterus primarily under the direction of ovarian estrogen and progestin. We demonstrated that HOXA10 ;was modified by SUMO1 and that sumoylation inhibited HOXA10 protein stability and transcriptional activity, leading to impaired attachment rates in vitro. In the presence of SUMO1, HOXA10WT was degraded more rapidly than in HOXA10WT-expressing cells (Figure 3a, compare lanes 1–4 with lanes 5–8), whereas no change in HOXA10K164R was found, suggesting that SUMO1 modifies K164 of HOXA10 and inhibits its protein stability. We observed similar levels of ubiquitination between HOXA10WT and HOXA10K164R, whereas overexpression of SUMO1 markedly increased the ubiquitination of HOXA10, indicating that sumoylation somehow promotes ubiquitinmediated degradation (Figure 3b). Higher levels of SUMO1-HOXA10 were found in the endometria of women with RIF compared with those of the control fertile women (P o 0.05; Figure 6c), suggesting that HOXA10 sumoylation may contribute to the development of impaired endometrial receptivity and embryo implantation in RIF

DISCUSSION

Findings

MATERIALS AND METHODS