Biomedical subjects

Rong Nie

Publications and source records attributed to Rong Nie.

7 recordsLinked to original sources

PubMed2004

Androgen-regulated transcripts in the neonatal mouse testis as determined through microarray analysis.

Androgens are required for normal spermatogenesis in mammalian testes. These hormones directly regulate testicular somatic cells that, in turn, support germ cell differentiation. However, the identity of genes under androgen regulation in the testis are not well known. In the present study, neonatal male mice (8 days postpartum) treated by testosterone propionate (TP) were used to study androgen action in the testis as evidenced by alterations in gene expression. Mice were treated with 0.5 mg of TP or dihydrotestosterone (DHT) or vehicle (oil), and testes were harvested 4, 8, and 16 h after treatment. Global gene expression was monitored by microarray analysis. Real-time reverse transcription-polymerase chain reaction was performed to confirm the microarray results. The methodology was verified by confirming the presence of previously characterized TP-regulated genes, including Pem in Sertoli cells and Cyp17a1 in Leydig cells. No significant differences in gene expression were found between TP- and DHT-treated samples. Microarray analysis identified 141, 119, and 109 up-regulated genes at 4, 8 and 16 h after TP treatment, respectively, and 83, 99, and 111 down-regulated genes at the same corresponding time points. The androgen regulation of the selected gene was verified further using testes from flutamide-treated adult mice and isolated Sertoli cells in culture. The data generated in the present study may serve as a foundation for hypothesis-driven research and provide insights regarding gene networks and pathways under androgen control in the testis.

Androgen Antagonists↗

PubMed2004

Human KIT ligand promoter is positively regulated by HMGA1 in breast and ovarian cancer cells.

KIT ligand (KL) and its receptor, c-kit, are coexpressed in many types of cancer cells and have been implicated in tumor growth and angiogenesis. While Sertoli cell-specific regulation of the KL promoter has been well characterized, regulation in cancer cells remains to be elucidated. We recently reported microarray results demonstrating that increased high-mobility group (HMG) A1a protein expression correlates with increased KL transcription in MCF-7 human breast cancer cells. Sequence analysis indicates a potential for multiple HMGA1 binding sites within the human KL promoter. In order to better define the underlying molecular mechanisms that HMGA1 uses to facilitate malignant transformation of cancer cells, we have used a variety of methods to determine whether HMGA1a directly regulates the human KL promoter in breast and ovarian cancer cells. Our results indicate that: (i) KL promoter activity is significantly higher in MCF-7 cells overexpressing HMGA1a; (ii) HMGA1a protein binds to AT-rich regions of the KL promoter DNA both in vitro and in vivo; (iii) mutation of the AT-rich regions inhibits HMGA1a binding in vitro; and (iv) HMGA1a-specific inhibition significantly decreases transcription of KL in OCC1 human ovarian cancer cells. In addition, MCF-7 cells with transgenic HMGA1 overexpression stained positive for the KL protein by immunocytochemistry and immunohistochemistry, and were growth-inhibited by KL neutralization. The cumulative evidence indicates that HMGA1 positively regulates the human KL promoter in breast and ovarian cancer cells and implicates serum KL as a diagnostic marker for HMGA1-positive carcinomas.

Animals↗

PubMed2003

The antiestrogen ICI 182,780 decreases the expression of estrogen receptor-alpha but has no effect on estrogen receptor-beta and androgen receptor in rat efferent ductules.

BACKGROUND: The antiestrogen ICI 182,780 has been used successfully as an alternative experimental model for the study of estrogen action in the rodent adult male reproductive tract. Although ICI 182,780 causes severe alterations in testicular and efferent ductule morphology and function, the effects on the expression of estrogen and androgen receptors in the male have not been shown. METHODS: In the present study, adult male rats were treated with ICI 182,780 for 7 to 150 days, to evaluate the time-response effects of the treatment on the pattern of ERalpha, ERbeta and AR protein expression in the efferent ductules. The receptors were localized using immunohistochemistry. RESULTS: ERalpha, ERbeta and AR have distinct cellular distribution in the testis and efferent ductules. Staining for ERalpha is nearly opposite of that for ERbeta, as ERalpha shows an increase in staining intensity from proximal to distal efferent ductules, whereas ERbeta shows the reverse. Androgen receptor follows that of ERalpha. ICI 182,780 caused a gradual but dramatic decrease in ERalpha expression in the testis and efferent ductules, but no change in ERbeta and AR expression. CONCLUSIONS: The differential response of ERalpha and ERbeta proteins to ICI 182,780 indicates that these receptors are regulated by different mechanisms in the male reproductive tract.

Animals↗

PubMed2003

The antiestrogen ICI 182,780 induces early effects on the adult male mouse reproductive tract and long-term decreased fertility without testicular atrophy.

BACKGROUND: Estrogen receptors (ER) have important physiological roles in both the female and male reproductive systems. Previous studies using the estrogen receptor-alpha knockout mouse (alphaERKO) or antiestrogen treatment in adult rodents have shown that ERalpha is essential for normal function of the male reproductive tract. In the present study, time-response effects of the antiestrogen ICI 182,780 were determined to better understand ERalpha function in the adult male. METHODS: Adult male mice, 30 days old, were injected subcutaneously with ICI 182,780 (5 mg) once per week for 17 weeks. Tissues were fixed by vascular perfusion to study the time responses from day 2 to 125 post treatment. RESULTS: No difference was seen in body weight due to treatment. Testis weight was decreased 18% on day 59 and 21.4% on day 125. Other significant treatment-related effects included the following: 1) dilation of rete testis and efferent ductule lumen; 2) decreased height of the rete testis and efferent ductule epithelium; 3) decreased height of the supranuclear epithelial cytoplasm in efferent ductules; 4) decreased height of the efferent ductule epithelial microvilli, particularly in the proximal ductules; 5) decrease in the PAS-positive granules and endocytotic vesicles in nonciliated epithelial cells of efferent ductules; 6) capping and vesiculation of narrow cells in the initial segment of the epididymis; 7) accumulation of PAS-positive granules in apical cells of the caput epididymis; 8) increase in lysosomal granules in clear cells of the corpus and cauda epididymis; 9) limited induction of atrophic seminiferous tubules and abnormal spermatogenesis; and 10) decreases in the concentration of cauda sperm, progressive sperm motility and decreased fertility. CONCLUSIONS: Antiestrogen treatment of the pubertal male mouse resulted in reproductive effects similar to those observed in the alphaERKO mouse as early as day 4; however, testis weight did not increase substantially and total atrophy was not observed with extended treatment.

Animals↗

PubMed2002

Differential expression of estrogen receptors alpha and beta in the reproductive tracts of adult male dogs and cats.

Expression of estrogen receptors (ERs) in the reproductive tracts of adult male dogs and cats has not been reported. In the present study, ERalpha and ERbeta were localized by immunohistochemistry using ER-specific antibodies. ERalpha was found in interstitial cells and peritubular myoid cells in the dog testis, but only in interstitial cells of the cat. In rete testis of the dog, epithelial cells were positive for ERalpha staining, but in the cat, rete testis epithelium was only weakly positive. In efferent ductules of the dog, both ciliated and nonciliated cells stained intensely positive. In the cat, ciliated epithelial cells were less stained than nonciliated epithelial cells. Epithelial cells in dog epididymis and vas deferens were negative for ERalpha. In the cat, except for the initial region of caput epididymis, ERalpha staining was positive in the epithelial cells of epididymis and vas deferens. Multiple cell types of dog and cat testes stained positive for ERbeta. In rete testis and efferent ductules, epithelial cells were weakly positive for ERbeta. Most epithelial cells of the epididymis and vas deferens exhibited a strong positive staining in both species. In addition, double staining was used to demonstrate colocalization of both ERalpha and ERbeta in efferent ductules of both species. The specificity of antibodies was demonstrated by Western blot analysis. This study reveals a differential localization of ERalpha and ERbeta in male dog and cat reproductive tracts, demonstrating more intensive expression of ERbeta than ERalpha. However, as in other species, the efferent ductules remained the region of highest concentration of ERalpha.

Animals↗

PubMed2002

ER function in the adult male rat: short- and long-term effects of the antiestrogen ICI 182,780 on the testis and efferent ductules, without changes in testosterone.

Male rats, 30 d old, were treated with the antiestrogen ICI 182,780 (3-150 d) to determine sequences of events leading to testicular atrophy and infertility. Plasma testosterone and LH concentrations were unchanged. ICI 182,780 induced dilation of efferent ductules as early as 3 d post treatment, and the dilation increased over time, resulting in an overall increase of 200% in tubule diameter. A gradual reduction in height of the ductule epithelium was observed; however, the microvilli height increased up to d 73 but subsequently decreased. A transient increase in lysosomes in nonciliated cells was seen from d 15 to d 100. Testicular weight increased by d 45 and seminiferous tubules were dilated by d 52. These effects on testes persisted until d 100, but on d 150 the weight decreased and severe atrophy was observed. These testicular effects were probably owing to accumulation of fluid following inhibition of reabsorption in the efferent ductules, similar to the ER-alpha knockout mouse. In agreement with this conclusion, there was a decrease in Na+-H+ exchanger-3 mRNA and protein, which is consistent with previous studies showing that ER is required for expression of Na+-H+ exchanger-3 and ultimately fluid reabsorption in the efferent ductules.

Acid Phosphatase↗

PubMedDate not supplied

Localization of androgen and estrogen receptors in adult male mouse reproductive tract.

There is considerable variation, both within and between species, in reports of nuclear steroid receptor localizations in the male reproductive tract. In this study, androgen receptor (AR) and estrogen receptors ERalpha and ERbeta were visualized by immunohistochemistry in adult male mice reproductive tracts, including testes, efferent ductules; initial segment, caput, corpus, and cauda epididymides; and vas deferens. Antibody specificity was demonstrated by Western blot and antibody competition. In testis, AR was expressed in Leydig cells, Sertoli cells, and most peritubular cells, but not in germ cells; Sertoli cells showed more intense staining in stages VI-VII; ERalpha was present in Leydig and some peritubular cells; ERbeta was in Leydig, some peritubular, all Sertoli and germ cells except in spermatids and meiotic spermatocytes. In efferent ductules, AR was strongly expressed in ciliated and nonciliated epithelial cells and in stromal cells; ERalpha was strongly expressed in ciliated and nonciliated epithelial cells; stromal cells were negative; and ERbeta was strongly expressed in ciliated and nonciliated epithelial cells and also in stromal cells. In epididymis, AR was strongly expressed in all epithelial cells (not in intraepithelial lymphocytes); ERalpha was strongly expressed in apical, narrow, and some basal cells of the initial segment, and in caput, principal cells of the caput, clear cells of the distal caput through cauda; stromal cells were negative in the initial segment, but more stromal cells were stained from caput to cauda; ERbeta was strongly expressed in most of epithelial cells of the epididymis, but stromal cells were inconsistently stained. In vas deferens, AR was weakly expressed or absent in principal cells but moderately stained in basal cells, smooth muscle cells of stroma were stained intensely, ERalpha was absent in epithelial cells but present in a subepithelial smooth muscle layer, and ERbeta was strongly expressed in all epithelial cells and most stromal cells. This study demonstrates that the reproductive tracts of male mice differ considerably from those of rats in expression of ARs and ERs and that caution is needed when extrapolating nuclear steroid receptor data across mammalian species.

Animals↗