Expression pattern of circadian genes and steroidogenesis-related genes after testosterone stimulation in the human ovary.
BACKGROUND
Previous studies have shown that circadian genes might be involved in the development of polycystic ovarian syndrome (PCOS). Hyperandrogenism is a hallmark feature of PCOS. However, the effect of hyperandrogenism on circadian gene expression in human granulosa cells is unknown, and the general expression pattern of circadian genes in the human ovary is unclear.


METHODS
Expression of the circadian proteins CLOCK and PER2 in human ovaries was observed by immunohistochemistry. The mRNA expression patterns of the circadian genes CLOCK, PER2, and BMAL1, and the steroidogenesis-related genes STAR, CYP11A1, HSD3B2, and CYP19A1 in cultured human luteinized granulosa cells were analyzed over the course of 48 h after testosterone treatment by quantitative polymerase chain reaction.


RESULTS
Immunostaining of CLOCK and PER2 protein was detected in the granulosa cells of dominant antral follicles but was absent in the primordial, primary, or preantral follicles of human ovaries. After testosterone stimulation, expression of PER2 showed an oscillating pattern, with two peaks occurring at the 24th and 44th hours; expression of CLOCK increased significantly to the peak at the 24th hour, whereas expression of BMAL1 did not change significantly over time in human luteinized granulosa cells. Among the four steroidogenesis-related genes evaluated, only STAR displayed an oscillating expression pattern with two peaks occurring at the 24th and 40th hours after testosterone stimulation.


CONCLUSIONS
Circadian genes are expressed in the dominant antral follicles of the human ovary. Oscillating expression of the circadian gene PER2 can be induced by testosterone in human granulosa cells in vitro. Expression of STAR also displayed an oscillating pattern after testosterone stimulation. Our results indicate a potential relationship between the circadian clock and steroidogenesis in the human ovary, and demonstrate the effect of testosterone on circadian gene expression in granulosa cells.
Reproductive Medicine Center, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.|Guangdong Provincial Key Laboratory of Reproductive Medicine, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.
Minghui
M
Chen
Reproductive Medicine Center, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.|Guangdong Provincial Key Laboratory of Reproductive Medicine, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.
Yanwen
Y
Xu
Reproductive Medicine Center, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.|Guangdong Provincial Key Laboratory of Reproductive Medicine, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.
Benyu
B
Miao
Department of Hepatic Surgery, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, GD510630, People's Republic of China.
Hui
H
Zhao
Reproductive Medicine Center, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.|Guangdong Provincial Key Laboratory of Reproductive Medicine, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.
Lu
L
Luo
Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China.
Huijuan
H
Shi
Reproductive Medicine Center, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China. zhoucanquan@hotmail.com.|Guangdong Provincial Key Laboratory of Reproductive Medicine, The First Affiliated Hospital of Sun Yat-sen University, 58 2nd Zhongshan Road, Guangzhou, GD510080, People's Republic of China. zhoucanquan@hotmail.com.
Canquan
C
Zhou
D000328:Adult; D056926:CLOCK Proteins / Q000096:biosynthesis* / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006107:Granulosa Cells / Q000473:pathology; D006801:Humans; D006080:Ovarian Follicle / Q000378:metabolism / Q000473:pathology; D010053:Ovary / Q000378:metabolism* / Q000473:pathology; D056950:Period Circadian Proteins / Q000096:biosynthesis* / Q000235:genetics; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000235:genetics; D011085:Polycystic Ovary Syndrome / Q000235:genetics* / Q000473:pathology; D013739:Testosterone / Q000008:administration & dosage; D000098682:Steroidogenic Acute Regulatory Protein
C421902:PER2 protein, human; D056950:Period Circadian Proteins; D010750:Phosphoproteins; D000098682:Steroidogenic Acute Regulatory Protein; D013739:Testosterone; D056926:CLOCK Proteins; C538943:CLOCK protein, human
Circadian rhythm; Granulosa cells; Human; Ovary; Testosterone