Leptin siRNA promotes ovarian granulosa cell apoptosis and affects steroidogenesis by increasing NPY2 receptor expression.

Abstract

Leptin has been found to be involved in the ovarian granulosa cell apoptosis and steroidogenesis. Loss of neuropeptide Y (NPY) can correct the obesity syndrome of mutant mice lacking of leptin (ob/ob). However, the association of NPY and leptin in ovarian granulosa cells and ovarian steroidogenesis has not been investigated. Here, C57BL/6J ob/ob mice and C57BL/6J (control) mice were intraperitoneally injected with PBS, leptin (0.4μg/g bodyweight) or BIIE0246 (NPY2 receptor [NPY2R] antagonist, 30μg/kg bodyweight) every day for 15days. We found that NPY2R mRNA expression in mouse ovary was suppressed by leptin treatment, but increased by leptin deficiency. Leptin or BIIE0246 treatment significantly increased E2, but notably decreased progesterone in both mice. A lower level of E2 and a higher level of progesterone was observed in ob/ob mice than in control mice. Further, we then knocked down leptin expression in human ovarian granulosa cells by siRNA transfection and treated the cells with DMSO or BIIE0246. In vitro experiments confirmed the findings in mice. siLeptin treatment decreased the secretion of E2, anti-Mullerian hormone (AMH), insulin-like growth factor (IGF)-1 and transforming growth factor (TGF)-β, and the cell proliferation, but increased the secretion of progesterone and cell apoptosis. Western blotting analysis of PCNA, Bcl-2 and Bax confirmed the results of cell proliferation and apoptosis. Activation of JAK2 and STAT3 was also suppressed by knocking down leptin. All the effects of siLeptin on ovarian granulosa cells were partially reversed by BIIE0246. In conclusion, knockdown of leptin significantly affected ovarian steroidogenesis and ovarian function through NPY. siLeptin transfection impaired the activation of JAK2/STAT3 and contributed to ovarian granulosa cell apoptosis partially through up-regulating NPY2R expression.

• Authors: Xiaomeng Ding, Xinxin Kou, Ye Zhang, Xiaoli Zhang, Guomei Cheng, Tianming Jia
• Journal: Gene (Gene) Vol. 633 Pg. 28-34 (Oct 30 2017) ISSN: 1879-0038 [Electronic] Netherlands
• PMID: 28864114 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical References

• Benzazepines
• Gonadal Steroid Hormones
• Leptin
• Neuropeptide Y
• RNA, Small Interfering
• Receptors, Neuropeptide Y
• STAT3 Transcription Factor
• neuropeptide Y2 receptor
• Androstenedione
• Progesterone
• Follicle Stimulating Hormone
• Arginine
• JAK2 protein, human
• Janus Kinase 2
• Dinoprostone
• BIIE 0246

Topics

• Androstenedione (genetics)
• Animals
• Apoptosis (drug effects, genetics)
• Arginine (administration & dosage, analogs & derivatives, pharmacology)
• Benzazepines (administration & dosage, pharmacology)
• Cell Proliferation
• Dinoprostone (genetics)
• Female
• Follicle Stimulating Hormone (metabolism)
• Gene Knockdown Techniques
• Gonadal Steroid Hormones (genetics)
• Granulosa Cells (cytology, drug effects, physiology)
• Humans
• Janus Kinase 2 (biosynthesis, genetics)
• Leptin (genetics, metabolism, pharmacology)
• Mice
• Mice, Inbred C57BL
• Neuropeptide Y (antagonists & inhibitors, metabolism)
• Progesterone (biosynthesis, genetics)
• RNA, Small Interfering (metabolism)
• Receptors, Neuropeptide Y (antagonists & inhibitors, biosynthesis, genetics)
• STAT3 Transcription Factor (biosynthesis, genetics)