Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report the cDNA cloning and subsequent characterization of a novel antigen implicated in antibody-mediated human infertility. This antigen, designated AgX (unknown antigen), was identified originally by screening a human testis lambda gt11 cDNA expression library with infertile patients' sera known to contain anti-sperm antibodies. AgX cDNAs isolated from testis and placenta cDNA libraries (AgX-1 and AgX-2, respectively) differed by a 48-bp deletion in the open-reading frame (ORF). The AgX-1 and AgX-2 ORFs encoded putative peptide chains of 505 and 521 amino acids (approximately 55.5 and approximately 57.3 kDa), respectively. The AgX amino acid sequences contained consensus motifs indicative of NTP binding. However, computer homology searches did not identify any significant similarity with known sequences. Quantitative analysis using the reverse transcriptase-polymerase chain reaction (RT-PCR) indicated that the AgX-1 mRNA was fiftyfold more abundant than AgX-2 in the testis, while AgX-2 was more abundant than AgX-1 in somatic tissues. An anti-AgX peptide antiserum identified two AgX isoforms on Western blots of human tissue extracts. An abundant 56-kDa isoform was detected only in testis and sperm. These data suggest that the 56- and 58-kDa isoforms are AgX-1 and AgX-2, respectively. AgX was localized by immunofluorescence to the principal piece of the sperm tail. Therefore, antibodies against an AgX isoform may reduce fertility by affecting sperm function.
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PMID:Characterization of a human antigen with sera from infertile patients. 802 65

The present study was conducted to examine the expression of tumor necrosis factor-alpha (TNF-alpha) and its receptors (types I and II, designated TNFR-I and TNFR-II, respectively) in human oocytes and cumulus cells at the mRNA and protein levels. mRNA expression was investigated using a reverse transcriptase-polymerase chain reaction (PCR)/Southern hybridization procedure. DNA-free RNA was isolated from the oocytes/cumulus cells, reverse-transcribed, and PCR-amplified using specific oligonucleotide primers based upon genomic/cDNA sequences. The expected bands of 303 bp and 513 bp were observed in oocytes and cumulus cells using primers based on genomic/cDNA sequences of TNF-alpha and TNFR-II, respectively, that hybridized with specific cDNA probes in Southern blot hybridization procedure. The expected band of 368 bp was not observed in oocytes and cumulus cells using primers based on the TNFR-I cDNA sequence. Similar results were observed for expression at the protein level, as seen by the immunoreactivity of the specific antibodies with the paraformaldehyde-fixed oocytes and cumulus cells in the indirect immunofluorescence technique (IFT). These results indicate that human oocytes and cumulus cells express TNF-alpha and its receptor type II (TNFR-II), and not type I (TNFR-I), both at the mRNA and protein levels. These findings provide further evidence and substantiate the proposed physiologic role of TNF-alpha in ovarian function, and may lead to clinical applications in in vitro fertilization programs and in diagnosis and treatment of infertility in women, especially in cases attributed to ovarian dysfunction.
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PMID:Expression of tumor necrosis factor-alpha and its receptors type I and type II in human oocytes. 913 12

In sheep, as in other mammalian species, the pronounced reduction in GnRH and gonadotropin secretion that characterizes stages of infertility is normally associated with a conspicuous increase in the secretion of PRL. A possible role of PRL in modulating gonadotropin release implies the presence and activation of specific receptors in target tissues (i.e. pituitary, hypothalamus). In this study, we investigated the expression of PRL receptor (PRL-R) messenger RNA (mRNA) in the sheep pituitary and the distribution of the translated product in specific pituitary cell types. Using primers designed to flank different regions of the extracellular and cytoplasmic domains of the PRL-R, two complementary DNA (cDNA) fragments, one of which was specific for the long-form PRL-R, were amplified by reverse transcriptase-PCR. Sequencing revealed more than 95% identity with nucleotides 267-1272 of the bovine PRL-R cDNA. When these cDNA fragments were used as probes for the detection of PRL-R mRNA expression by Northern analysis, three major transcripts of approximately 13, 10, and 3.5 kb were identified in the pituitary. Both probes detected identical transcripts, suggesting that primarily the long form of PRL-R is expressed in the sheep pituitary gland. No difference in the abundance of pituitary PRL-R mRNA transcripts was observed between anestrous and breeding season ewes (P > 0.05). Additional RT-PCR studies revealed the existence of a cDNA variant bearing a 39-bp insert with a premature stop codon. Translation of the PRL-R mRNA was confirmed by Western blot analysis. The identification of PRL-R in specific pituitary cell types was carried out by immunocytochemistry. Double immunofluorescent staining, using antibodies to the rat liver PRL-R and specific monoclonal antibodies to the LHbeta-subunit, FSHbeta-subunit, free alpha-subunit, PRL, or GH, revealed that in both the pars distalis and pars tuberalis, all pituitary cells expressing PRL-R immunoreactivity were positive for LHbeta, although only 53% of LHbeta-positive cells expressed PRL-R. A small proportion (2%) of gonadotrophs expressing PRL-R immunoreactivity were negative for FSHbeta, indicating the specific localization of PRL-R in LH (or LH/FSH) secreting cells. Further, a selective cytological association was detected in the pars distalis where LH gonadotrophs appeared surrounded by lactotrophs. In contrast to these observations, PRL-R immunoreactivity was completely absent in lactotrophs and in the vast majority (>98%) of somatotrophs. In conclusion, here we show the expression of PRL-R mRNA in the sheep pituitary and the specific translation of the signal in LH (or LH/FSH) gonadotrophs. These results support the hypothesis that PRL may be involved in the regulation of gonadotropin secretion through a paracrine mechanism within the pituitary gland and that this action does not seem to be mediated by changes in PRL-R mRNA expression.
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PMID:Detection of prolactin receptor gene expression in the sheep pituitary gland and visualization of the specific translation of the signal in gonadotrophs. 983 62

Molecular biology is being increasingly used to address the complex problem of bovine infertility. One common concern shared by many of these studies is the postmortem delay in obtaining reproductive tissues and the effect this may have on RNA dependent studies. To address this concern, bovine ovarian, oviduct and uterine tissue samples, collected over intervals ranging from 0 to 96 h postmortem to freeze storage, were analysed to determine the potential effects on RNA quantity and quality. The analysis showed that total RNA yields were not changed significantly by postmortem interval up to 96 h while 28S ribosomal RNA remained intact up to 24 h postmortem. Specific messenger RNA transcripts encoding beta-actin, GAPDH and transforming growth factor-beta were detected in all tissues up to 96 h postmortem using reverse transcriptase-polymerase chain reaction and Northern analysis indicated no detectable mRNA degradation up to 24 h postmortem. Finally, using poly(A)(+) mRNA isolated from ovarian tissues frozen 2 h postmortem, we constructed corpus luteum and ovarian cortex cDNA libraries containing 7.65x10(4) and 1.9x10(6) primary transformants with average cDNA lengths of 2.3 and 1.6 kb respectively. Taken together, these data show that a postmortem delay of up to 24 h does not significantly affect the yield or quality of RNA prepared from bovine reproductive tissues.
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PMID:Postmortem stability of RNA isolated from bovine reproductive tissues. 1195 9

The Fas system is involved in the regulation of germ cell apoptosis associated with testicular injury in experimental animals exposed to various insults. We tested the hypothesis that enhanced germ cell apoptosis mediated by the up-regulation of the Fas system and the activation of caspases may be involved in ethanol-induced testicular injury. Adult Wistar rats were fed either ethanol in Lieber-DeCarli liquid diet or an isocaloric control diet for 12 weeks. Marked Sertoli cell vacuolization and germ cell degeneration were observed in the testes of ethanol-treated rats (ETR) by both light and electron microscopy. Enhanced apoptosis of germ cells in ETR was detected by the terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labelling (TUNEL) method, transmission electron microscopy, and was associated with elevated activity of caspase-3, -8 and -9. The expression levels of the Fas ligand (FasL) in Sertoli cells and of both Fas and caspase-3 in germ cells of ETR detected immunohistochemically were higher than those of the control testes. Furthermore, reverse transcriptase-polymerase chain reaction analysis demonstrated an increase in both Fas and FasL mRNA levels in ETR. Fas system up-regulation and the elevated activity of caspases in the testes of ETR may be a reflection of ethanol-induced testicular injury resulting in enhanced germ cells apoptosis, which may be involved in infertility associated with alcohol abuse.
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PMID:Involvement of Fas system and active caspases in apoptotic signalling in testicular germ cells of ethanol-treated rats. 1203 Oct 44

Sry in some varieties of Mus musculus domesticus fails to form normal testis when introduced into the C57BL/6J (B6) strain. We studied the developmental pattern of pre-Sertoli cells that express Sox9 by immunofluorescence and the profile levels of Sox9 transcripts by semiquantitative reverse transcriptase polymerase chain reaction and in situ hybridization in developing gonads of B6-Ytir mice. Sox9-positive cells (pre-Sertoli cells) appeared in all B6.Ytir genital ridges at 11.5 and 12.5 days postcoitum (dpc). However, at 13.5 dpc, Sox9-positive cells were not detected only in 50% of the B6.Ytir gonads compared with 100% of B6 gonads. Although pre-Sertoli cells formed the seminiferous cords after 14.5 dpc in the medial region of the B6.Ytir gonad, the cranial and caudal regions formed ovarian tissue. Further, B6.Ytir ovaries have lower levels of Sox9 than ovotestes at all fetal stages. These results suggest that although the pre-Sertoli cell lineage forms in B6.Ytir genital ridges, its further differentiation into Sertoli cells is apparently prevented. The cause may be the low levels of Sox9 and down-regulation of its product. Results suggest that inhibitory signals of Sox9 acting along the whole genital ridge or only at its cranial and/or caudal regions underlie formation of B6.Ytir ovaries or ovotestes, respectively. Furthermore, our results suggest that infertility of B6.Ytir females may be due to the abnormal presence of Sox9 transcripts in their ovaries.
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PMID:Disturbed expression of Sox9 in pre-sertoli cells underlies sex-reversal in mice b6.Ytir. 1367 20

Summary Apoptosis is a common phenomenon during spermatogenesis, and its dysregulation has been associated with male infertility. Survivin is an inhibitor of apoptosis protein that regulates apoptosis at cell division and is overexpressed in common human cancers. We investigated whether survivin mRNA expression is detectable in testicular biopsies from patients with infertility of varying aetiology. The aim of this study was to examine the testicular survivin expression in azoospermic men with normal spermatogenesis and in those with specific spermatogenic disorders. Survivin mRNA expression was detected by reverse transcriptase-polymerase chain reaction in histologically classified testicular biopsy specimens from 30 azoospermic men. Survivin was found to be expressed in normal spermatogenesis (n = 10), in post-meiotic spermatogenic arrest (n = 6), and in specimens showing a mixed picture of pre-meiotic maturation arrest with sparse islands of post-meiotic arrest (n = 2). In contrast, a lack of survivin expression was seen in specimens without haploid germ cells (pre-meiotic maturation arrest, n = 2) and in those with Sertoli-cell-only syndrome (SCOS, n = 10). These data indicate for the first time that survivin is expressed in human testis. Moreover, its expression seems to correlate with the stage of maturation arrest in patients presenting with spermatogenic disorders. Survivin mRNA expression was not found in SCOS specimens, possibly indicating germ-cell-specific expression in human testicular tissue. Thus, survivin is a potential molecular marker of spermatogenesis, whose expression is altered in specific spermatogenic disorders.
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PMID:Expression of the apoptosis inhibitor survivin in testicular tissue of infertile patients. 1513 71

In people infected with the human immunodeficiency virus (HIV) both the CD4 T-cell count and the viral load are used to monitor disease progression to acquired immunodeficiency syndrome (AIDS). CD4 counts of <500/mm(3) are associated with opportunistic infections and certain malignancies, so-called 'AIDS-defining' conditions. Highly active antiretroviral therapy, using combinations of reverse transcriptase inhibitors and/or protease inhibitors, can improve considerably the prognosis of people who are HIV-positive, but such therapy is not yet widely available in many developing countries. People with AIDS are predisposed to urinary tract infection (UTI) by uncommon bacteria and pathogens, e.g. fungi, parasites and viruses, which may affect any urogenital organ; treatment should be culture-specific and long-term, because there is a tendency to recurrence, infection with multiple organisms and resistant isolates. Voiding dysfunction in patients with AIDS is usually a result of neurological complications caused by opportunistic infections, and has a poor prognosis. Of patients with AIDS, 30-50% develop a cancer, especially Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL). KS may involve any urogenital organ, but is usually part of systemic disease. Small lesions on the external genitalia can be treated with laser, cryotherapy or surgical excision, larger lesions with radiotherapy, and disseminated or visceral KS with multidrug chemotherapy. NHL may involve the kidneys, testes and retroperitoneal lymph nodes, thus obstructing the ureters, which may require ureteric stenting or percutaneous nephrostomy. NHL can be treated with radiotherapy and combination chemotherapy. Urolithiasis in patients with AIDS may be caused by indinavir, a protease inhibitor, but the more common types of stones may also occur. Fluid-electrolyte and acid-base disturbances are common in patients with advanced AIDS, secondary to vomiting, diarrhoea, malnutrition or septicaemia. HIV-associated nephropathy occurs in 10-30% of patients, and often leads to renal failure. Testicular atrophy is common, leading to infertility, erectile dysfunction (ED) and decreased libido. Treatment for ED must include counselling about strategies to reduce the transmission of HIV. The risk of HIV transmission after parenteral exposure to blood from an HIV-positive patient is relatively low (0.2-0.4%); the urologist can reduce the risk of transmission during surgery by adopting certain precautions. After occupational exposure to HIV, chemoprophylaxis with antiretroviral medication can significantly reduce the probability of HIV transmission.
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PMID:The urological management of the patient with acquired immunodeficiency syndrome. 1692 74

In this article, we describe the use of a caprine beta-lactoglobulin (betaLG) expression cassette previously obtained by our group to target the expression of the human follicle-stimulating hormone (hFSH) to the mammary gland of transgenic mice. The hFSH is a pituitary glycoprotein composed of two subunits (alpha and beta). At present, this protein is obtained from mammalian cellular fermentors, and it is extensively used in the treatment of human infertility. Four lines of double (hFSHalpha/beta) transgenic mice that stably transmitted the transgenes were obtained, and hFSHalpha and hFSHbeta mRNA was detected by reverse transcriptase-polymerase chain reaction in the mammary gland of lactating females from all four transgenic lines. The hFSH protein was present in the mammary gland of the lactating females, but could not be detected in the milk by Western blot, probably as a result of low levels of transgene expression.
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PMID:Expression of recombinant human follicle-stimulating hormone in the mammary gland of transgenic mice. 1694 69

RFamide related peptides (RFRPs) have been extensively implicated in the neuroendocrine control of reproduction. While steroid hormones strongly regulate the closely-related kisspeptin gene and protein expression, the regulation of RFRPs or their receptor by steroid hormones is almost unknown. The present study aimed to quantify relative levels of RFRP and Kiss1 gene expression and their G protein-coupled receptors (GPR147 and GPR54, respectively) in various brain areas and the pituitary gland, and to determine the effects of differing levels of oestradiol and pubertal development on levels of these gene products. In Experiment 1, the treatment groups examined were: dioestrus, ovariectomised and ovariectomised with replacement oestradiol to induce a preovulatory-like luteinising hormone surge. Micropunched brain regions and whole pituitary glands were processed for measurement of RFRP, Kiss1, GPR147 and GPR54 mRNA by quantitative reverse transcriptase-polymerase chain reaction. As expected, Kiss1 gene expression was low in the rostral periventricular area of the third ventricle of ovariectomised animals, whereas levels were highest in the arcuate nucleus in this situation. No such oestrogenic effects were observed for RFRP gene expression. GPR147 gene expression was highest in the rostral periventricular region of the third ventricle. The levels of GPR147 and GPR54 mRNA were markedly lower in the pituitary gland than in the hypothalamic regions, and RFRP and Kiss1 mRNA were virtually undetectable in the pituitary gland. These data imply that the actions of RFamides are likely to be predominantly central in nature. In Experiment 2, hypothalamic RFRP and GPR147 mRNA levels were measured in male and female rats aged 2, 4, 6 and 8 weeks. In females, RFRP gene expression increased with developmental age, peaking around the time of puberty, whereas in males gene expression increased between 2 and 4 weeks of age. These results suggest a role in the regulation of adult reproduction rather that prepubertal infertility.
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PMID:Developmental and steroidogenic effects on the gene expression of RFamide related peptides and their receptor in the rat brain and pituitary gland. 2013 94


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