Overexpression of the steroidogenic acute regulatory protein increases the expression of ATP-binding cassette transporters in microvascular endothelial cells(bEnd.3)

Objective:To determine the effect of steroidogenic acute regulatory protein(StAR) overexpression on the levels of adenosine triphosphate(ATP)-binding cassette transporter A1(ABCA1) and ATP-binding cassette transporter G1(ABCG1) in an endothelial cell line(bEnd.3).Methods:The StAR gene was induced in bEnd.3 cells with adenovirus infection.The infection efficiency was detected by fluorescence activated cell sorter(FACS) and fluorescence microscopy.The expressions of StAR gene and protein levels were detected by real-time polymerase chain reaction(PCR) and Western blot.The gene and protein levels of ABCA1 and ABCG1 were detected by real-time PCR and Western blot after StAR overexpression.Results:The result shows that StAR was successfully overexpressed in bEnd.3 cells by adenovirus infection.The mRNA and protein expressions of ABCA1 and ABCG1 were greatly increased by StAR overexpression in bEnd.3 cells.Conclusion:Overexpression of StAR increases ABCA1 and ABCG1 expressions in endothelial cells.

Adiponectin orchestrates testosterone suppression in biological pathways

This current review highlights adiponectin engagement with AdipoR1 and AdipoR2 which subsequently triggers pathways such as AMPK,PPARα,and MAPK,thereby modulating testicular steroidogenesis.Adiponectin's actions on Leydig and adrenal cells inhibit androgen secretion by suppressing the steroidogenic acute regulatory protein(StAR).Given that StAR facilitates cholesterol to testosterone conversion,AMPK inhibits this process by modulating cholesterol transport and suppressing StAR expression through multiple avenues.Furthermore,adiponectin-induced PPARαactivation impedes mitochondrial cholesterol influx,further modulating androgen biosynthesis.The suppressive influence of PPARαon steroidogenic genes,notably StAR,is evident.Collectively,adiponectin signalling predominantly attenuates androgen production,ensuring metabolic and reproductive equilibrium.Imbalances,as seen in conditions like hypogonadism and obesity-related infertility,highlight their crucial roles and potential clinical interventions for reproductive disorders.

Effects of varicocele on testosterone, apoptosis and expression of StAR mRNA in rat Leydig cells

The aim of this study was to explore the effects of varicocele on the morphology and function of Leydig cells in the rat testis. Forty male Sprague-Dawley rats were divided into two groups： the experimental group underwent surgery to create a left varicocele （VC）, and the control group underwent a sham operation. Serum testosterone and intratesticular testosterone levels were measured using a radioimmunoassay after 4 and 8 weeks of operation. Leydig cells were studied for apoptosis and expression of steroidogenetic acute regulatory （STAR） protein mRNA levels. Serum testosterone levels declined after 4 and 8 weeks of operation but were not significant （P〉0.05）. However, the intratesticular testosterone levels after 8 weeks were significantly decreased compared with the control group （P〈0.01）. The mean apoptosis index of Leydig cells in the experimental group was significantly higher than that in the control group after 4 or 8 weeks （P〈0.01）. StAR mRNA levels in the Leydig cells of the experimental group were significantly lower compared to those of the control group （P〈0.01）. Our data show that varicocele did impair Leydig cell function by increasing apoptosis and suppressing the expression of the StAR protein.

Cox7a2 mediates steroidogenesis in TM3 mouse Leydig cells

Aim： To investigate the regulatory function of Cox7a2 on steroidogenesis and the mechanism involved in TM3 mouse Leydig cells. Methods： The cDNA of Cox7a2 was cloned from TM3 mouse Leydig cells. It was subcloned to pDsRed- Express-N 1 and transfected back into TM3 mouse Leydig cells for Cox7a2 overexpression by transient gene transfection. Steroidogenesis affected by overexpressed Cox7a2 was studied by ELISA. To elicit the mechanism of this effect, expression of steroidogenic acute regulatory （STAR） protein and reactive oxygen species （ROS） were examined by Western blot and fluorometer, respectively. Results： The cDNA of Cox7a2 （249 bp） was cloned from Leydig cells and confirmed by DNA sequencing. After constructed pDsRed-Express-N1-Cox7a2 was transfected back into TM3 mouse Leydig cells, Cox7a2 inhibited not only luteinizing hormone （LH）-induced secretion of testosterone but also the expression of StAR protein. At the same time, Cox7a2 increased the activity of ROS in TM3 mouse Leydig cells. Conclusion： Cox7a2 inhibited LH-induced StAR protein expression, and consequent testosterone production, at least in part, by increasing ROS activity in TM3 mouse Leydig cells.

Blepharis persica increases testosterone biosynthesis by modulating StAR and 3β-HSD expression in rat testicular tissues

Objective:To evaluate the effect of methanolic extract and ethyl acetate fraction of methanol extract prepared from the seeds of Blepharis(B.)persica on testosterone biosynthesis and also to elucidate the underlying mechanism.Methods:Forty-eight male Wistar rats were divided into eight groups(n=6 per group).GroupⅠreceived 0.3%w/w gum acacia suspension p.o.and served as the normal control group.GroupⅡwas administered testosterone propionate in arachis oil i.m.as the positive control group.GroupⅢtoⅣreceived B.persica methanolic extract p.o.at doses of 50,100 and 200 mg/kg body weight.GroupⅥtoⅦreceived B.persica ethyl acetate fraction p.o.at doses of 50,100 and 200 mg/kg body weight.The testis was used for biochemical estimation and histological studies.The effects of methanolic extract and ethyl acetate fraction of B.persica on testicular testosterone,mRNA expression corresponding to steroidogenic acute regulatory protein(StAR)and 3β-hydroxysteroid dehydrogenase(3β-HSD)along with 3β-HSD enzyme assay were evaluated in testicular tissues and sperm concentration.Ethyl acetate fraction of B.persica was subjected to column chromatography.Invitro studies were performed using TM3 cell line at three dose levels(50,100,200μg/mL),each for methanolic extract,ethyl acetate fraction and 2-benzoxazolinone for evaluation of their comparative effect on testosterone production.Results:Ethyl acetate fraction and methanolic extract of B.persica could elevate the testicular testosterone content compared to the normal control group.The treatment with methanolic extract and ethyl acetate fraction of B.persica increased the expression of mRNA corresponding to StAR by 6.7 fold and 10.6 fold,respectively,whereas the mRNA expression of 3β-HSD increased by 5.7 fold and 7.3 fold,respectively.Moreover,fraction and extract treatment exhibited increased 3β-HSD activity in the testicular tissues and were found to elevate sperm concentration in seminal fluid.The spermatogenic potential was further ensured by histological observations.2-benzoxazolinone was isolated from ethyl acetate fraction and identified using spectral studies.It showed the ability to increase the testosterone content in the TM3 Leydig cells.Conclusions:Methanolic extract and ethyl acetate fraction of B.persica are able to increase the testicular testosterone in rats by elevating mRNA expression of StAR and 3β-HSD in testicular tissues,leading to increase the sperm concentration.

Congenital lipoid adrenal hyperplasia with Graves'disease:A case report

BACKGROUND Congenital adrenal hyperplasia(CAH),which is caused by a mutation of the steroidogenic acute regulatory(StAR)gene.Affected patients are usually characterized by adrenal insufficiency in the first year of life,salt loss,glucocorticoid and mineralocorticoid deficiency,and female external genitalia,regardless of chromosomal karyotype.Patients with non-classical lipoid CAH usually develop glucocorticoid deficiency and mild mineralocorticoid deficiency at 2-4 years of age.CASE SUMMARY Herein,We report the case of a woman with non-classic lipoid CAH combined with Graves’disease.Her chromosome karyotype was 46,XX,and highthroughput sequencing revealed two missense variants in the StAR gene:c.229C>T(p.Q77X)and c.814C>T(p.R272C),which were inherited from both parents(non-close relatives).The patient was treated for Graves’disease in a timely manner and the dosage of glucocorticoid was adjusted during the treatment of Graves’disease.CONCLUSION This is the first case of non-classic lipoid CAH combined with Graves’disease reported in the Chinese population.In addition to conventional glucocorticoid replacement therapy,timely adjustments were made to the dosages of thyroid hormone and glucocorticoid to avoid adrenal crisis as a consequence of the increased demand and accelerated metabolism of glucocorticoids when the patient was diagnosed with Graves’disease.

Changes of testicular phosphorylated proteins in response to restraint stress in male rats

Objective： To investigate male reproductive parameters via changes of potential testicular protein markers in restraint-stress rats. Methods： Male Sprague-Dawley rats were divided into two groups （non-immobilized control and restraint-immobilized/stress groups, n=8 each group）. The stress animals were immobilized （12 h/d） by a restraint cage for 7 consecutive days. All reproductive parameters, morphology and histology were observed and compared between groups. In addition, the expression of steroidogenic acute regulatory （STAR） and phosphotyrosine proteins （previously localized in Sertoli and late spermatid cells） in testicular lysate was assayed by immuno-Western blotting. Results： Testosterone level, sperm concentration and sperm head normality of stress rats were significantly decreased while the corticosterone level was increased as compared with the control （P〈0.05）. Histologically, stress rats showed low sperm mass in epididymal lumen and some atrophy of seminiferous tubules. Although the expression of testicular STAR protein was not significantly different between groups, changed patterns of the 131, 95, and 75 kDa testicular phosphorylated proteins were observed in the stress group compared with the control group. The intensity of a tes- ticular 95-kDa phosphorylated protein was significantly decreased in stress rats. Conclusions： This study has demonstrated the alteration of testicular phosphorylated protein patterns, associated with adverse male reproductive parameters in stress rats. It could be an explanation of some infertility in stress males.

Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs

The effects of equine chorionic gonadotropin （eCG） on follicular development and ovulation in cyclic guinea pigs were investigated by histological and immunohistochemical analyses. Three groups of guinea pigs （n=12） were administrated subcutaneously with saline, 20 or 50 IU of eCG, respectively, on cyclic Day 12 （Day 1=vaginal openings）. Ovaries were collected at 4 and 8 d after administration （6 animals per group each time）. The eCG administration induced significant and distinct morphological changes in the ovaries, as it promoted the luteinization of granulosa cells, but not follicular development. In addition, proliferating cell nuclear antigen （PCNA） and steroidogenic acute regulatory protein （STAR） were immunolocalized specifically in luteinized follicles. Our experiments together indicate that eCG administration can induce follicular luteinization but not superovulation in guinea pigs. The eCG in cyclic guinea pigs functions similar to that of luteinizing hormone （LH）, but not follicle-stimulating hormone （FSH）.

Estrogen Biosynthesis and Its Regulation in Endometriosis

Endometriosis is a common benign gynecological disorder with an enigmatic etiology and pathogenesis.It affects approximately 10%women of reproductive age.Although its etiology and pathogenesis remain poorly understood,it is characterized by the elevated local production of estrogen in the endometriotic tissues.In this paper,we review the mechanisms of estrogen biosynthesis and its regulation in endometriosis.