Xiao-Xia Wang1, Xiao-Xiong Wang2, Xiao-Fan Jia1, Tan Guo3, Tong-Zhang Xian1, Li Liu1, Zhu-Jin Xu3, Yue Guo4, Xiang Deng5, Li-Na Zhang1, Fu-Li Man1, Xian-Bo Zhang1, Tong Chen2, Qi Pan6, Li-Xin Guo7. 1. Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Beijing, China. 2. Department of Ophthalmology, Beijing Hospital, National Center of Gerontology, Beijing, China. 3. Department of Radiology, Beijing Hospital, National Center of Gerontology, Beijing, China. 4. Department of Nuclear Medicine, Beijing Hospital, National Center of Gerontology, Beijing, China. 5. Department of Radiotherapy, Beijing Hospital, National Center of Gerontology, Beijing, China. 6. Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Beijing, China. Electronic address: panqi621@126.com. 7. Department of Endocrinology, Beijing Hospital, National Center of Gerontology, Beijing, China. Electronic address: glx1218@163.com.
Abstract
BACKGROUND/AIM: Thyroid-associated ophthalmopathy (TAO) is a chronic autoimmune disorder characterized by an increased volume of adipose/connective tissue. This study aims to explore whether steroidogenic factor 1 (SF1) is implicated in development of TAO through the adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Initially, we extracted orbital preadipocytes from 10 TAO patients for culture and identification. After differentiation, cells were inoculated with plasmids with overexpressed SF1, and plasmids with siRNA against SF1, respectively. Then fat content and PGE2 secretion were measured by using ELISA. The levels of SF1, Bax, Bcl-2, Caspase3, Pref-1, PPARγ, Leptin, Adiponectin, p-AMPKαThr172, p-mTORSer2448, and p-S6KThr389 were detected by RT-qPCR and western blot analysis. Cell proliferation and apoptosis were measured by EdU and flow cytometry. RESULTS: TAO patients showed reduced SF1 expression in orbital preadipocytes. Overexpression of SF1 led to inhibited expression of Bcl-2, PPARγ, Leptin, Adiponectin and p-AMPKαThr172, fat content, cell proliferation and differentiation, but increased levels of Bax, Caspase3, Pref-1, p-mTORSer2448 and p-S6KThr389, PGE2 secretion and apoptosis rate. CONCLUSION: Our result showed up-regulated SF1 may relieve TAO through suppressing cell proliferation and differentiation, but accelerating cell apoptosis by inhibiting the activation of the AMPK/mTOR signaling pathway.
BACKGROUND/AIM: Thyroid-associated ophthalmopathy (TAO) is a chronic autoimmune disorder characterized by an increased volume of adipose/connective tissue. This study aims to explore whether steroidogenic factor 1 (SF1) is implicated in development of TAO through the adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Initially, we extracted orbital preadipocytes from 10 TAO patients for culture and identification. After differentiation, cells were inoculated with plasmids with overexpressed SF1, and plasmids with siRNA against SF1, respectively. Then fat content and PGE2 secretion were measured by using ELISA. The levels of SF1, Bax, Bcl-2, Caspase3, Pref-1, PPARγ, Leptin, Adiponectin, p-AMPKαThr172, p-mTORSer2448, and p-S6KThr389 were detected by RT-qPCR and western blot analysis. Cell proliferation and apoptosis were measured by EdU and flow cytometry. RESULTS: TAO patients showed reduced SF1 expression in orbital preadipocytes. Overexpression of SF1 led to inhibited expression of Bcl-2, PPARγ, Leptin, Adiponectin and p-AMPKαThr172, fat content, cell proliferation and differentiation, but increased levels of Bax, Caspase3, Pref-1, p-mTORSer2448 and p-S6KThr389, PGE2 secretion and apoptosis rate. CONCLUSION: Our result showed up-regulated SF1 may relieve TAO through suppressing cell proliferation and differentiation, but accelerating cell apoptosis by inhibiting the activation of the AMPK/mTOR signaling pathway.