[Effect of StarD7 and Wnt/β-catenin signal pathway on the testosterone secretion stimulated by Annexin 5 in rat Leydig cells].
OBJECTIVE
This research aims to study the internal mechanism that promotes the testosterone synthesis by StarD7 and Wnt/β-catenin, and explores a  new regulatory pathway of testosterone synthesis.


METHODS
After treated with 1 nmol/L Annexin 5 for 24 h, the culture media were collected for  testosterone measurement by chemiluminescence assay. The expressions of StarD7 and β-catenin at mRNA and protein levels were detected by RT-PCR and western blot respectively. The cellular location of β-catenin was identified by immunofluorescence.


RESULTS
Comparing with the control  groups, under the treatment with Annexin 5, the level of testosterone raised 176%[(7.83±0.32)vs.(21.6±1.1), P<0.05], StarD7 mRNA in the experimental  groups increased 55%[(1.12±0.08)vs.(1.74±0.11), P<0.05], and β-catenin mRNA increased 48%[(1.15±0.08)vs.(1.70±0.05), P<0.05]. At the level of  protein, the expression of StarD7 in the experimental groups increased 42%[(1.06±0.09)vs.(1.51±0.07), P<0.05], and β-catenin increased 55%[(1.02± 0.01)vs.(1.58±0.02), P<0.05]. Immunofluorescence identified that β-catenin was accumulation in the nuclear of the rat Leydig cells in the experiment  groups cultured with Annexin 5.


CONCLUSIONS
StarD7 and β-catenin have both increased significantly at the mRNA and protein levels under treatment  with the Annexin 5, and β-catenin were accumulation in the nuclear of the rat Leydig cells. It suggests that StarD7 and β-catenin both regulate the effect of  Annexin 5 in testosterone production of rat Leydig cells. This regulation may active the Wnt/β-catenin signal pathway, then increase the expression of the  StarD7, eventually raise the progress of the testosterone secretion in rat Leydig cells.
Reproductive Medical Center, Nanjing General Hospital of Nanjing Military Command, Nanjing, China.
Hai-yan
HY
Fu
Jun
J
Jing
Nan
N
Yi
Shi-chao
SC
Yu
Shi-feng
SF
Yun
Yuan-jiao
YJ
Liang
Bing
B
Yao
D000818:Animals; D017304:Annexin A5 / Q000494:pharmacology*; D007985:Leydig Cells / Q000166:cytology / Q000378:metabolism*; D008297:Male; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000096:biosynthesis*; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D000098682:Steroidogenic Acute Regulatory Protein
D017304:Annexin A5; C495268:Ctnnb1 protein, rat; D010750:Phosphoproteins; D012333:RNA, Messenger; D051176:beta Catenin; D000098682:Steroidogenic Acute Regulatory Protein; D013739:Testosterone