Increased expression of HOXA10 и HOXA11 in endometrial stroma cells under hypoxia depends on activity of the DNA demethylation system

Abstract

Aim. The work was aimed to test whether the expression levels of endometrial-specific Hoxa10 and Hoxa11 genes in the mouse uterus change after endometrial injury caused by giving birth, and to suggest a mechanism by which these genes can be upregulated in endometrial stromal cells after injury.Methods. The study was performed using young (8–10 weeks old) wild-type mice of the C57BL6 line; Hoxa10 and Hoxa11 gene expression in uterine tissues was assessed before delivery, as well as 4 hours and 24 hours after delivery were also used in the work. Hypoxia was modeled in vitro using human endometrial stromal cells by adding 200 mM CoCl2. Inhibition of DNA active demethylation system was performed using the Bobcat339 inhibitor. The level of expression of the Hoxa10 (HOXA10) and Hoxa11 (HOXA11) genes was assessed by real-time PCR coupled with reverse transcription, as well as by Western blotting.Results. During the first day after birth, both Hoxa10 and Hoxa11 gene expression increases in mouse uterine tissues. In the stromal cells of the human endometrium, during hypoxia modeling, HOXA10 and HOXA11 gene expression increases, and inhibition of the active DNA demethylation system prevents noted increase in the hypoxia model.Conclusion. We have shown for the first time that the Hoxa10 and Hoxa11 gene expression increases in vivo in the mouse uterus after endometrial damage, and also demonstrated in in vitro experiments that upregulation of these genes in endometrial stromal cells after damage can be caused by hypoxia-induced epigenetic changes associated with the operation of the active DNA demethylation system.