Non-Genomic Action of Androgens is Mediated by Rapid Phosphorylation and Regulation of Androgen Receptor Trafficking.

BACKGROUND: Testosterone is critical for maintaining spermatogenesis and male fertility. The accomplishment of these processes requires the synergistic actions of the classical and non-classical signaling pathways of androgens. METHODS: A murine testicular Sertoli cell line, TM4 cell was used to examine androgen actions in Sertoli cells. Western blot analysis and immunofluorescence assay were employed to study the testosterone-induced Androgen receptor (AR) translocation. Protein phosphorylation antibody array was applied to identify the phosphorylation sites under testosterone treatment, and these findings were verified by Western blot analysis. RESULTS: We found that a physiological dose of testosterone induced fast membrane association of AR. By using a phosphorylation antibody array, several phosphorylation sites, such as MEK1/2 (Ser217/221), Akt (Ser473), and Erk1/2 (Thr202/Tyr204) were rapidly phosphorylated within 5 min of testosterone treatment. Inhibition of the MEK and Akt signaling pathways prevented AR trafficking. Blocking of AR by flutamide eliminated the stimulation effect of testosterone on kinase phosphorylation. Testosterone induced kinase Src phosphorylation, and inhibition of Src restricted AR translocation to the membrane and the nucleus. CONCLUSION: Findings suggested that the membrane association of AR was mediated by the MEK and Akt phosphorylation signaling pathways, which resulted in Src activation and was initiated by testosterone binding to the membrane-localized AR. This study provides new insights into the testosterone signaling pathway in Sertoli cells, which mediate spermatogenesis. In addition, the study can be used in the diagnosis and treatment of male infertility caused by disorders in spermatogenesis.

[Expression characteristics of the Daxx gene in the mouse testis during spermatogenesis].

OBJECTIVE: To investigate the expression characteristic of the Daxx gene in the mouse testis and its role in spermatogenesis. METHODS: Real-time PCR, Western blot and immunofluorescence were used in examining the expression characteristics of DAXX in the testis tissue from wild-type, Sertoli cell-specific androgen receptor knockout (SCARKO) and androgen receptor knockout (ARKO) mice at different postnatal weeks . RESULTS: The Daxx gene was highly expressed in the testis tissue and mainly in the nuclei of the wild-type mice at 4 postnatal weeks. Compared with the wild-type, the ARKO mice showed a markedly decreased expression of DAXX (0.299±0.026), which displayed a polar distribution in the spermatogenic cells (0.853±0.058) and exhibited no significant difference in the SCARKO mice (1.000±0.015). CONCLUSIONS: The Daxx gene expression is the highest in the middle-stage development of the mouse testis, significantly decreased in ARKO mice as compared with the wild-type, and its location influenced by specific AR knockout in Sertoli cells. DAXX may be involved in the regulation of spermatogenesis in mice.

[Expression characteristics of the 1700008O03Rik gene in the mouse testis during spermatogenesis and results of bioinformatic analysis].

OBJECTIVE: To investigate the characteristics of the expression of the RIKEN cDNA 1700008O03 (1700008O03Rik) gene in the testis of the mouse from birth to sexual maturity and its potential role in regulating spermatogenesis. METHODS: Using mouse gene expression profile microarray, we screened the testis-specific gene 1700008O03Rik from the mouse. We studied the expression characteristics of the gene in the development of the mouse testis by reverse transcription PCR, quantitative real-time PCR, Western-blot, immunohistochemistry and immunofluorescence, and analyzed the structure of the 1700008O03Rik protein and its homology with other species using the bioinformatic software. RESULTS: 1700008O03Rik gene was highly expressed in the testis of the mouse, increasing in an age-dependent manner, and mainly in the endochylema of oblong spermatozoa. Bioinformatic analysis revealed a high homology of the 1700008O03Rik protein between human and mice, and phylogenetic tree analysis showed it to be highly conserved in mammalian evolution. CONCLUSIONS: 1700008O03Rik is a highly expressed gene in the mouse testis, mainly in the endochylema of oblong spermatozoa, which may be involved in the regulation of spermatogenesis in mice.

Identification of NR0B1 as a novel androgen receptor co-repressor in mouse Sertoli cells.

Nuclear receptor subfamily 0 group B member 1 (Nr0b1) is an atypical member of the nuclear receptor family that is predominantly expressed in mouse Sertoli cells (SCs). Mutations of NR0B1 in humans cause adrenal failure and hypogonadotropic hypogonadism. The targeted mutagenesis of Nr0b1 in mice has revealed a primary gonadal defect characterized by the overexpression of aromatase and cellular obstruction of the seminiferous tubules and efferent ductules, leading to germ cell death and infertility. The transgenic expression of Nr0b1 under the control of the Müllerian-inhibiting substance promoter (MIS-Nr0b1), which is selectively expressed in SCs, improves fertility. Testicular androgen receptor (AR) was also expressed in SCs. Many genes are directly regulated by androgen and its AR, which are involved in spermatogenesis and male infertility. As the association between NR0B1 and AR remains unclear in mouse SCs, we decided to further explore the relationship between them. In the present study, we have identified NR0B1 as a novel AR co-repressor in mouse SCs. Using RT­qPCR and immunofluorescence, we determined that NR0B1 was mainly expressed in mouse SCs in an age-dependent manner from 2-8 weeks of age postnatally. The inhibition of the effects of AR on AR target genes by NR0B1, in an androgen­dependent manner, was further demonstrated by western blot analysis and RT-qPCR in TM4 cells, a mouse Sertoli cell line. Finally, in vitro luciferase and co-immunoprecipitation assays validated that NR0B1, as an AR co-repressor, significantly inhibited the transcriptional activation of its target genes. These results suggest that novel inhibitory mechanisms underlie the effects of NR0B1 in modulating androgen-dependent gene transcription in mouse SCs.

Identification and characteristics of the testes-specific gene, Ccdc38, in mice.

Distinguishing the testes-specific genes in different species may disclose key genes associated with testes-specific functions and provide sufficient information for the study and treatment of male infertility. A testes­specific gene, coiled-coil domain containing 38 (Ccdc38), was identified by screening UniGene libraries. Systematic bioinformatics analysis demonstrated that the CCDC38 protein was conserved in various mammalian species. It was determined that CCDC38 was exclusively expressed in testes and its expression increased from 2­8 weeks of age. Additional immunohistochemical analysis indicated that CCDC38 was mainly expressed in spermatogonia and spermatocytes. It is of note that, immunofluorescence and co-immunoprecipitation assays demonstrated that CCDC38 interacted with ubiquitinated histone H2A in mouse testes. Therefore, these results suggest that Ccdc38 is a testes-specific gene, which may be important for mouse spermatogenesis.

[Expression characteristics of the Ccdc70 gene in the mouse testis during spermatogenesis].

OBJECTIVE: To investigate the expression characteristics of the gene of coiled-coil domain-containing protein 70 (Ccdc70) in the mouse testis and its potential role in spermatogenesis. METHODS: Using expression profile microarray, we screened the mouse testis-specific gene Ccdc70, studied its expression characteristics in the mouse testis by RT-PCR, real-time PCR, Western blot and immunohistochemistry, followed by bioinformatic analysis of the Ccdc70 protein. RESULTS: The Ccdc70 gene was expressed highly in the testis but lowly in the epididymis of the mice. The Ccdc70 protein was expressed mainly in the spermatocytes and round spermatids of the testis and in the epithelial cells of the epididymis. Bioinformatic analysis showed a structural domain in the Ccdc70 protein, which was highly conserved in mammalian evolution. CONCLUSION: The Ccdc70 gene is highly expressed in the mouse testis and mainly in the spermatocytes, round spermatids, and epididymal epithelial cells, which indicates that it is involved in the regulation of spermatogenesis and epididymal sperm maturation.

[Expression of a testis-specific gene 1700001022RIK in mice and its bioinformatic analysis].

OBJECTIVE: To identify the expression characteristics of the 1700001022RIK (RIKEN cDNA 1700001022) gene in mice and explore its function by bioinformatic analysis. METHODS: Using the expression profile of gene microarray, we detected the expression of a new testis-specific gene, 1700001022RIK, in mice. We analyzed its expression characteristics in the testis tissue and their changes in different developmental stages of the testis by RT-PCR, real-time RT-PCR, Western blot, and immunohistochemistry. We performed bioinformatic analysis using a bioinformatic software. RESULTS: The 1700001022RIK gene was specifically expressed in the mouse testis in an age-dependent manner, most highly in the adult mice. The 1700001022RIK protein was mainly expressed in the spermatogonia, spermatocytes, and round spermatids of the adult mice. Bioinformatic analysis showed that the 1700001022RIK protein amino acid sequence had a high similarity in human and mice, which indicated that this gene was highly conserved in mammals. CONCLUSION: 1700001022RIK is a testis-specific gene mainly expressed in the spermatogonia, spermatocytes, and round spermatids of seminiferous tubules, which might be involved in the regulation of spermatogenesis.

[UBE2B gene and male infertility: an update].

Male infertility is a worldwide problem, and about 15% of the cases are associated with spermatogenesis-related gene mutation. The mammalian gene UBE2B is the homolog of the RAD6 gene of yeast, belonging to the ubiquitin proteasome system and playing an important role in spermatogenesis. Mice lacking the UBE2B gene are infertile, with reduced sperm motility, increased morphologically abnormal sperm, and inhibited meiosis of spermatogonia. Accumulated evidence shows that UBE2B gene mutants and single nucleotide polymorphisms are associated with male infertility. This article reviews the relation between the UBE2B gene and male infertility, offering some theoretical evidence for the diagnosis and treatment of male infertility.

The Wilms tumor gene, Wt1, is critical for mouse spermatogenesis via regulation of sertoli cell polarity and is associated with non-obstructive azoospermia in humans.

Azoospermia is one of the major reproductive disorders which cause male infertility in humans; however, the etiology of this disease is largely unknown. In the present study, six missense mutations of WT1 gene were detected in 529 human patients with non-obstructive azoospermia (NOA), indicating a strong association between WT1 mutation and NOA. The Wilms tumor gene, Wt1, is specifically expressed in Sertoli cells (SCs) which support spermatogenesis. To examine the functions of this gene in spermatogenesis, Wt1 was deleted in adult testis using Wt1(flox) and Cre-ER(TM) mice strains. We found that inactivation of Wt1 resulted in massive germ cell death and only SCs were present in most of the seminiferous tubules which was very similar to NOA in humans. In investigating the potential mechanism for this, histological studies revealed that the blood-testis barrier (BTB) was disrupted in Wt1 deficient testes. In vitro studies demonstrated that Wt1 was essential for cell polarity maintenance in SCs. Further studies found that the expression of cell polarity associated genes (Par6b and E-cadherin) and Wnt signaling genes (Wnt4, Wnt11) were downregulated in Wt1 deficient SCs, and that the expression of Par6b and E-cadherin was regulated by Wnt4. Our findings suggest that Wt1 is important in spermatogenesis by regulating the polarity of SCs via Wnt signaling pathway and that WT1 mutation is one of the genetic causes of NOA in humans.

Overexpression of cyclooxygenase-1 correlates with poor prognosis in renal cell carcinoma.

The aim of this study was to evaluate expression of COX-1 in renal cell carcinoma (RCC) and its prognostic value. mRNA of COX-1 was detected in 42 paired RCC and adjacent normal tissues with quantitative real- time polymerase chain reaction (qRT-PCR). Expression of COX-1 was also evaluated in 196 RCC sections and 91 adjacent normal tissues with immunohistochemistry. Statistical analysis was performed to assess COX-1 expression in RCC and its prognostic significance. The results of qRT-PCR showed mRNA levels of COX-1 in RCC tissues to be significantly higher than that in adjacent normal tissues (p < 0.001). Immunohistochemical assays also revealed COX-1 to be overexpressed in RCC tissues (p < 0.001). Statistical analysis demonstrated high expression of COX-1 was correlated with tumour size (p = 0.002), pathological stage (p = 0.003), TNM stage (p = 0.003, 0.007, 0.027, respectively), and tumour recurrence (p < 0.001). Survival analysis indicated patients with high expression of COX-1 had shorter survival time (p < 0.001), and COX-1 was an independent predictor. This is the first study to reveal overexpression of COX-1 in RRC and point to use as a prognostic marker in affected patients.

Clinical outcomes in patients with stage I non-seminomatous germ cell cancer.

This study assesses the long-term outcomes in Han Chinese patients with clinical stage I non-seminomatous germ cell testicular cancer (CSI NSGCT) treated with surveillance, retroperitoneal lymph node dissection (RPLND) and adjuvant chemotherapy. We retrospectively evaluated 89 patients with a mean age of 26.5 years. After orchiectomy, 37 patients were treated with surveillance, 34 underwent RPLND and 18 were managed with chemotherapy. The overall survival rate, the recurrence-free survival rate and the risk factors were evaluated. The median follow-up length was 92 months (range: 6-149 months). Thirteen of the 89 patients (14.6%) had relapses, and one died by the evaluation date. The overall survival rate was 98.9%. The cumulative 4-year recurrence-free rates were 80.2%, 92.0% and 100% for the surveillance, RPLND and chemotherapy groups, respectively. The disease-free period tended to be briefer in patients with a history of cryptorchidism and those with stage Is. Therefore, surveillance, RPLND and adjuvant chemotherapy might be reliable strategies in compliant patients with CSI NSGCT. Surveillance should be recommended for patients with the lowest recurrence rate, especially those without lymphovascular invasion. This study might aid the establishment of a standard therapy for CSI NSGCT in China.

RALY RNA binding protein-like reduced expression is associated with poor prognosis in clear cell renal cell carcinoma.

The molecular mechanisms involved in the progression of clear cell renal cell carcinomas (ccRCCs) are still unclear. The aim of this study was to analyse the relationships between expression of RALYL and clinical characteristics. In 41 paired samples of ccRCCs and adjacent normal tissues, we used real-time qPCR to evaluate the expression of RALYL mRNA. RALYL protein levels were determined in 146 samples of ccRCC and 37 adjacent normal tissues by immunohistochemistry. Statistical analysis was used to explore the relationships between expression of RALYL and the clinical characteristics (gender, age, tumor size, T stage, N stage, M stage, survival times and survival outcome) in ccRCC. In addition, these patients were follow-up period 64 months (range: 4~116 months) to investigate the influence on prognosis. We found significantly differences between ccRCC tissues and normal tissues (p<0.001, paired-sample t test) in mRNA levels of RALYL. Immunohistochemistry analyses in 146 ccRCC samples and 37 adjacent normal tissues showed significantly lower RALYL protein levels in ccRCC samples (χ2-test, p<0.001), inversely correlating with tumour size (p=0.024), T stage (0.005), N stage (p<0.001) as well as M stage (p=0.019), but not age (p=0.357) and gender (p=0.348). Kaplan-Meier survival analysis demonstrated that people with lower level of RALYL expression had a poorer survival rate than those with a higher level of RALYL expression, significantly different by the log-rank test (p=0.011). Cox regression analysis indicated that RALYL expression (p=0.039), N stage (p=0.008) and distant metastasis (p<0.001) were independent prognosis factors for the overall survival of ccRCC patients. We demonstrated that the expression of RALYL was significantly low in ccRCC and correlated with a poor prognosis in a large number of clinical samples. Our findings showed that RALYL may be a potential therapeutic target as well as a poor prognostic factor.

Effect of all-trans-retinoic acid on the expression of primordial germ cell differentiation-associated genes in mESC-derived EBs.

atRA (all-trans-retinoic acid) is known to induce the differentiation of mESCs (mouse embryonic stem cells) into PGCs (primordial germ cells) in vitro. However, it is not clear as to what changes occur in PGC differentiation-associated genes or what mechanisms are involved when EBs (embryoid bodies) derived from mESCs are induced by atRA. EBs derived from mESCs were treated with 1, 2 or 5 µM atRA for 16 h, 2 days or 5 days. Real-time PCR and Western blot analysis were performed to detect the relative levels of PGC differentiation-associated genes (Lin28, Blimp1, Stra8 and Mvh) and the corresponding proteins respectively. Immunofluorescence was used to detect the protein location and distribution in EBs. The expression characteristics of genes could be divided into three categories: rapidly reached the peak value in 16 h and then decreased (Stra8, Lin28), initially low and then increased to reach the peak value in 5 days (Mvh) and relatively unchanged (Blimp1). A low level of Lin28 was expressed in EBs treated with atRA for 2 days or 5 days. The variation in the level of Lin28 mRNA did not influence the change in the level of Blimp1 mRNA. The changes in Stra8/Lin28 were consistent with the corresponding changes in the levels of their respective mRNAs, but the changes for Mvh/Blimp1 were not consistent with the corresponding changes in the levels of their respective mRNAs. Blimp1 expression may be independent of the effect of atRA on PGC differentiation. atRA may promote the start of a period in which there is a low level of Lin28 expression during PGC differentiation.

Identification of testosterone-/androgen receptor-regulated genes in mouse Sertoli cells.

Androgen and androgen receptor (AR) play important roles in male spermatogenesis and fertility, yet detailed androgen/AR signals in Sertoli cells remain unclear. To identify AR target genes in Sertoli cells, we analyzed the gene expression profiles of testis between mice lacking AR in Sertoli cells (S-AR(-/y)) and their littermate wild-type (WT) mice. Digital gene expression analysis identified 2276 genes downregulated and 2865 genes upregulated in the S-AR(-/y) mice testis compared to WT ones. To further nail down the difference within Sertoli cells, we first constructed Sertoli cell line TM4 with stably transfected AR (named as TM4/AR) and found androgens failed to transactivate AR in Sertoli TM4 and TM4/AR cells. Interestingly, additional transient transfection of AR-cDNA resulted in significant androgen responsiveness with TM4/AR cells showing 10 times more androgen sensitivity than TM4 cells. In the condition where maximal androgen response was demonstrated, we then analyzed gene expression and found the expression levels of 2313 genes were changed more than twofold by transient transfection of AR-cDNA in the presence of testosterone. Among these genes, 603 androgen-/AR-regulated genes, including 164 upregulated and 439 downregulated, were found in both S-AR(-/y) mice testis and TM4/AR cells. Using informatics analysis, the gene ontology was applied to analyze these androgen-/AR-regulated genes to predict the potential roles of androgen/AR in the process of spermatogenesis. Together, using gene analysis in both S-AR(-/y) mice testis and TM4/AR cells may help us to better understand the androgen/AR signals in Sertoli cells and their influences in spermatogenesis.

[Mouse-induced pluripotent stem cells have the potential to differentiate into induced primordial germ cells].

OBJECTIVE: To investigate whether mouse-induced pluripotent stem (iPS) cell line IP14D-1 has the potential to differentiate into induced primordial germ cells (iPGCs), and to explore the changes in the expression of iPGCs-differentiation associated genes and their possible mechanisms. METHODS: Undifferentiated IP14D-1 was cultured to proliferate and then differentiated to form 4-, 7- and 9-day-old induced embryoid bodies (iEBs) in vitro, respectively. RT-PCR and immunofluorescence were used to detect the expressions of Lin28, Blimpl, Stra8 and Mvh, as well as the localization of the corresponding protein in iEBs. RESULTS: The expression of Blimpl was higher than that of Lin28 in the undifferentiated IP14D-1 and mouse embryonic stem cells (mESCs). Mvh and Stra8 as well as mESCs and EBs were also expressed in IP14D-1 and iEBs, but with no significant differences. The expression of Lin28 was gradually increased in the IP14D-1-derived iEBs from 4 to 7 days, but decreased at 9 days, and the expression of Blimp1 was gradually reduced with the prolonged growing time of iEBs. CONCLUSION: A stable system was established for the culture and differentiation of IP14D-1 and IP14D-1-derived iEBs. The expressions of Lin28, Blimp1, Mvh and Stra8 were not significantly different between the undifferentiated IP14D-1 and mESCs, nor were the expressions of Mvh and Stra8 between iEBs and EBs. IP14D-1 and iEBs had the potential to differentiate into iPGCs, which increased in number in the 7-day-old iEBs, and the expression of iPGC-differentiation associated Lin28 became lower in the older iEBs.

[Abnormal expression and significance of MIR-184 in human renal carcinoma].

OBJECTIVE: To explore the role of microRNA-184(MIR-184) in the development of renal cell carcinoma(RCC). METHODS: The expressions of MIR-184 in 51 patients with RCC Investigated, normal adjacent tissues (ADTs) matched by fluorescence quantitative PCR technology (RT-qPCR) and the correlations analyzed between MIR-184 expression and the age, gender and clinical stage of RCC patients. RESULTS: The average expression of MIR-184 in RCC was -14.664 6 ± 5.362 4, while that in ADTs was -10.408 7 ± 3.482 7(P<0.01). Bounded with the MIR-184 expression in RCC, patients were divided into lower-expression group and higher-expression group. Meanwhile, the RCC patients were divided into three groups according to the age, gender and clinical stage of the patients. Chi-square statistical analysis showed that the expression level of MIR-184 was not significantly correlated with the patient's age, gender and clinical stage (respectively: P>0.03, P>0.99, P>0.03). CONCLUSION: MIR-184 in RCC was significantly lower than that in ADTs, which may have potential significance in the occurrence and development of RCC.

[The progress of TMPRSS2-ETS gene fusions and their mechanism in prostate cancer].

The gene fusions between transmembrane protease serine 2 (TMPRSS2) and E26 (ETS) transcription factors are present in over 50% of patients with prostate cancer. TMPRSS2-ERG is the most common gene fusion type. The ERG overexpression induced by TMPRSS2-ERG gene fusion contributes to the development of prostate cancer. Both androgen receptor binding and genotoxic stress induce chromosomal proximity and TMPRSS2-ETS gene fusions. TMPRSS2-ERG gene fusion functions as a biomarker for prostate cancer, which can be easily detected in urine. This review focuses on the characteristics, oncogenic and rearranged mechanism, and clinical application of TMPRSS2-ETS gene fusions.

[Expression and location of SPAG9 in human ejaculated spermatozoa].

OBJECTIVE: SPAG9, as a member of the MAPK family, plays an important role in sperm-egg fusion. This study aimed to detect the expression of SPAG9 in human ejaculated spermatozoa. METHODS: Different human tissues (as from the muscle, liver, esophagus, lung, stomach, kidney, prostate, uterus, testis and epididymis) and semen samples were obtained from healthy volunteers, and semen analyses were performed according to the WHO criteria. Human ejaculated spermatozoa were purified by discontinuous Percoll density gradient centrifugation to rule out the contamination of germ cells and leucocytes. RT-PCR and indirect immunofluorescence were used to detect the expression of SPAG9 in human spermatozoa. RESULTS: RT-PCR showed that SPAG9 mRNA was expressed in different tissues and human ejaculated spermatozoa. Indirect immunofluorescence studies revealed the location of SPAG9 protein in the equatorial plate and flagella of human spermatozoa. CONCLUSION: SPAG9 is expressed in ejaculated spermatozoa and may play a role in sperm capacitation and motility.

[Advances in the researches of spermatogenic protein, Ropporin].

Ropporin has been identified as a spermatogenic cell-specific protein and may be involved in sperm maturation, motility, capacitation, hyperactivation and acrosome reaction. However, latest studies have shown that Ropporin is expressed weakly in normal non-testis tissues and highly in hematologic malignancies. Its highly conservative expression in mammalians demonstrates its importance to life. This paper updates the characterization, expression and its distribution, and biological function of Ropporin, and the advances in the clinical researches of the protein.

[Expression of the voltage-dependent anion channel gene in human ejaculated spermatozoa].

OBJECTIVE: To identify the genes involved in sperm motility. METHODS: We hybridized asthenospermia and normal motile sperm cDNA samples with the human whole genome Affymetrix chip to screen differentially expressed genes. Then we detected the mRNA expressions of the voltage-dependent anion channel genes (VDACs) in human organs and spermatozoa by RT-PCR and compared their expressions in the poor and normal motility spermatozoa. RESULTS: Differentially expressed genes VDACs were identified by analysis of the hybridization signals, including the 3 subtypes VDAC1, VDAC2 and VDAC3. The expression of VDAC2 mRNA was significantly decreased in the poor motility sperm (0.568 +/- 0.036), as compared with the healthy men (0.803 +/- 0.043, P < 0.01). CONCLUSION: The decreased expression of VDAC2 in the ejaculated spermatozoa is possibly associated with the reduction of sperm motility.