Effects of Upregulation of Hsp27 Expression on Oocyte Development and Maturation Derived from Polycystic Ovary Syndrome

Abstract

Heat shock protein 27 (Hsp27) is a heat shock protein family member which can inhibit apoptosis. Our previous studies reported down-regulated Hsp27 in ovarian tissue derived from women with polycystic ovary syndrome (PCOS) however, the exact effect of Hsp27 on oocyte maturation and developmental competence in PCOS is unclear. The effect of Hsp27 over-expression was studied in vitro using oocytes derived from PCOS patients. An artificial GFP-plasmid was injected into human oocyte to increase Hsp27 protein level. Oocyte maturation was evaluated by morphological observation. Mature oocytes were fertilized by intracytoplasmic sperm injection (ICSI) and embryonic developmental competence was evaluated. Critical apoptotic factors and cytokines were measured at both the mRNA and protein level. Our results revealed that Overexpression of HSP27 lowered the maturation rate of oocytes derived from PCOS patients. Meanwhile, fertilization rate and high quality embryo rate were similar between the Hsp27 overexpressing group and controls; however, the blastocyst formation rate in this group was significantly higher than control. Expression analysis revealed that the oocyte-secreted factors, BMP15 and GDF9, and the apoptotic-related regulators, Caspase 3, 8 and 9, were all significantly decreased in Hsp27 overexpressing oocytes. In conclusion, upregulation of Hsp27 inhibits oocyte maturation from PCOS patients, but improves embryonic developmental potential.

Small heat shock proteins: Role in cellular functions and pathology

“…Patients with polycystic ovary syndrome (PCOS) are typically characterized by increased numbers of oocytes which are often of poor quality, leading to lower fertilization, cleavage and implantation rates, and a higher miscarriage rate [352]. Hsp27 has been found to be down-regulated in ovarian tissue derived from women with PCOS [353]. Over-expression of Hsp27 in oocytes derived from PCOS patients leads to inhibition of oocyte maturation, but improves embryonic developmental potential by down-regulating oocyte-secreted factors, BMP15 and GDF9, and the apoptoticrelated regulators, Caspase 3, 8 and 9 [353].…”

“…Hsp27 has been found to be down-regulated in ovarian tissue derived from women with PCOS [353]. Over-expression of Hsp27 in oocytes derived from PCOS patients leads to inhibition of oocyte maturation, but improves embryonic developmental potential by down-regulating oocyte-secreted factors, BMP15 and GDF9, and the apoptoticrelated regulators, Caspase 3, 8 and 9 [353]. Downregulation of Hsp25 improved the maturation of mouse oocytes but increased early stage of apoptosis through the activation of extrinsic, caspase 8-mediated pathway [354].…”

Serum anti-α-crystallin antibodies in women with endocrine disorders

“…The sHSP27 is overexpressed in oocytes derived from PCOS patients and leads to inhibition of oocytes maturation, but improves embryonic developmental potential [27]. In women with PCOS, ovulation is often impossible, which leads to follicle arrest [28].…”

Construction of Polycystic Ovarian Syndrome Related lncRNA-mRNA Network Based on ceRNA to Identify Functional lncRNAs in Polycystic Ovarian Syndrome

“…Current studies con rmed that the reduction of some apoptotic markers could be one of the pathogenesis of PCOS [34]. Compared with normally ovulating women, the apoptotic-related moleculer, caspases 3, 8 and 9, were signi cantly reduced, and the anti-apoptotic regulator, cIAP-2, Hsp27 were over expressed in oocytes of women with PCOS [35,36].…”