54 research outputs found

    Detection of estrogen receptors ER-alpha and ER-beta in human ejaculated immature spermatozoa with excess residual cytoplasm

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    BACKGROUND: A key role of estrogens in human sperm biology has been recently suggested by aromatase and estrogen receptor detection in human testicular germ cells and ejaculated spermatozoa. However, the involvement of these hormones in the sperm maturation process is still not defined. The aim of this work was to investigate the expression of estrogen receptors, ER-alpha and ER-beta, in human ejaculated immature spermatozoa with excess residual cytoplasm. METHODS: Immunofluorescence labelling has been used to localize ER-alpha and ER-beta proteins in immature spermatozoa isolated by Percoll gradient, while Western blot analysis was carried out on sperm protein extracts. RESULTS: Both estrogen receptors were localized in excess residual cytoplasm of immature sperm, while sperm tails showed only ER-beta. Furthermore, in the same cells, immunoblots detected the presence of the full-length (~67 kDa) ER-alpha and (~59 kDa) ER-beta proteins, together with a ~50 kDa ER-beta species, lacking in mature sperm. CONCLUSION: The present investigation demonstrated ER-alpha and ER-beta presence in excess residual cytoplasm of human abnormal sperm cells, suggesting the hypothesis that both the 'classical' ERs could be able to mediate estrogen action in spermatogenetic cells. Furthermore, the presence of the short ER-beta form in abnormal germ cells and its disappearance in mature sperm, support estrogen modulation via different ER forms during sperm maturation

    Cytochrome P450arom, androgen and estrogen receptors in pig sperm

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    <p>Abstract</p> <p>Background</p> <p>Androgens and estrogens are crucial for mammalian sperm differentiation but their role in biology of mature male gamete is not still defined. The expression of proteins involved in the biosynthesis and action of these steroid hormones has been demonstrated in human spermatozoa, but very few data have been reported in mature sperm from non human species. The purpose of the current study was to investigate the expression of aromatase (P450arom), estrogen (ERalpha/ERbeta) and androgen (AR) receptors in ejaculated spermatozoa of pig.</p> <p>Methods</p> <p>The immunfluorescence experiments were carried out treating pig sperm with anti-P450arom, anti-ERalpha, anti-ERbeta and anti-AR as primary antibodies, while Texas-Red/FITC conjugated IgG were applied as secondary antibodies. Furthermore, Western blot analysis was performed on sperm lysates.</p> <p>Results</p> <p>Aromatase was immunolocalized in the sperm tail, ERalpha and AR were localised in the sperm midpiece, while ERbeta was confined in the acrosomal region of the male gamete. Immunoblots detected a ~52 kDa aromatase band, a ~110 kDa AR band, a ~67 kDa ERalpha and two ERbeta bands, at ~50 kDa and ~59 kDa.</p> <p>Conclusion</p> <p>This is the first report demonstrating that pig ejaculated spermatozoa express aromatase, estrogen and androgen receptors with a differential intra-cellular localization revealing a specie-specific expression pattern. Therefore, pig sperm could be considered as a potential estrogen source while the different hormone cellular sites suggest distinct roles of androgens and estrogens in pig sperm physiology.</p

    Identification of the estrogen receptor GPER in neoplastic and non-neoplastic human testes

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    <p>Abstract</p> <p>Background</p> <p>Estrogen signaling is mediated by estrogen receptor beta isoforms in normal and neoplastic human testes. Recently, a G-protein-coupled-receptor (GPER) has been suggested as being involved in rapid responses to estrogens in different normal and tumor cells.</p> <p>Methods</p> <p>This study investigated the GPER expression in paraffin-embedded samples from non neoplastic and neoplastic human testes (sex-cord stromal and germ cell tumors) by immunohistochemical and Western Blot analyses.</p> <p>Results</p> <p>In control testes, a positive GPER immunoreactivity was detected in Leydig and in Sertoli cells while all germ cells were immunonegative. Furthermore, neoplastic cells of the Sertoli cell tumor, Leydig cell tumor, seminoma and embryonal carcinoma samples were all immunopositive. The immunoblots of testis extracts confirmed the results.</p> <p>Conclusions</p> <p>These findings suggest that GPER could mediate estrogen signaling in both normal and transformed somatic cells of human testis, but they reveal a differential expression of the novel estrogen receptor in non neoplastic and neoplastic germ cells.</p

    Nitric oxide involvement in the acrosome reaction triggered by leptin in pig sperm

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    <p>Abstract</p> <p>Background</p> <p>Nitric oxide (NO) is a signaling molecule produced by intracellular nitric oxide synthase (NOS) enzymes. This free radical appears to affect sperm capacitation, a maturation step preceding acrosome reaction. Recent studies have reported leptin ability to promote capacitation and acrosome reaction in pig male gametes.</p> <p>Methods</p> <p>This study has investigated nitric oxide production in leptin-treated pig spermatozoa by fluorescence-activated cell sorting, while the intracellular NOS isoforms were assessed by Western blot analysis. In addition, acrosome status of treated-spermatozoa was evaluated by FITC-PNA staining.</p> <p>Results</p> <p>Significant increases of nitric oxide levels and acrosome reaction extent were detected in leptin-treated spermatozoa, but both the effects were reversed in presence of <it>L</it>-NAME. Furthermore, the immunoblots of sperm extracts have evidenced three bands of ~160 Kd(bNOS), ~130 Kd (iNOS) and ~135 Kd (eNOS).</p> <p>Conclusions</p> <p>The identification of the three intracellular NOS isoforms suggests that pig spermatozoa could produce NO, while the augmented nitric oxide levels in leptin-treated male gametes indicates the capacity of the hormone to induce nitric oxide production. Furthermore, the inhibitory effect of <it>L</it>-NAME and of Ab-ObR on the promotion of acrosome reaction triggered by leptin suggests a possible involvement of NO in the hormone action.</p

    Cytochrome P450 aromatase expression in human seminoma

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    BACKGROUND: The enzyme cytochrome P450 aromatase, catalysing the conversion of androgens into estrogens, has been detected in normal human testicular cells suggesting a physiological role of local estrogen biosynthesis on spermatogenesis control. Estrogens, regulating cell growth and apoptosis, can also be involved in tumorigenesis process, but the possible link between estrogens and testicular neoplastic process is, up to now, scarcely known. This study examined aromatase expression in human seminoma, which is the most common germ cell tumour of the testis. METHODS: The tumour-bearing testes were obtained from 20 patients with classic seminoma undergoing to therapeutic orchidectomy. Paraffin embedded tissues were processed for immunohistochemistry using a mouse monoclonal antibody generated against human placental cytochrome P450 arom, as primary antibody, and a biotinylated goat-anti-mouse IgG, as secondary antibody. Furthermore, Western blot analysis of seminoma extracts was carried out. RESULTS: Intense P450 arom immunoreactivity was observed in the seminoma cells and Western blot analysis confirmed the immunodetection. A strong immunostaining was also detected in cells of intratubular germ cell neoplasia (IGCN), adjacent to seminoma. CONCLUSION: The present study demonstrated, for the first time in human, aromatase expression in neoplastic cells of seminoma suggesting a relation between local estrogen biosynthesis and germ cell tumorigenesis. The P450 arom immunolocalization in the cells of IGCN, representing the common precursor of most germ cell tumors, seems to support these findings

    Evaluation of the In Vitro Wound-Healing Activity of Calabrian Honeys

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    The healing of skin wounds and particularly chronic wounds, such as diabetic foot ulcers, is still a clinical emergency. Despite the many therapeutic tools that are available so far, none seems to be really effective and safe. In this context, we highlighted the renewed wound healing activity of honey, a viscous aromatic and sweet food, by way of in vitro wound-healing assays, using the HaCaT cell line. Specifically, we investigated five monofloral or multifloral honeys from different Calabrian provinces using them as such or extracted (by Amberlite® or n-hexane and ethyl acetate). The chemical composition of honeys was ascertained by ¹H NMR spectroscopy and by the gas chromatography/mass spectrometry (GC/MS) method for volatile organic compounds (VOCs). Amongst the five tested honeys, BL1 and BL5 honeys showed the most promising healing properties. Pinocembrin, which was revealed in BL1 (multifloral) and BL5 (orange) honey samples, is a flavanol that is already known to possess interesting biological activities, including healing. This study aims to investigate how a traditional food such as honey, which is appreciated for its nutritional value and used in folk medicine, can be enhanced as an effective modern remedial to promote a multifaceted and safe healing activity for all skin wounds

    Leptin and leptin receptor in pig spermatozoa: evidence of their involvement in sperm capacitation and survival

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    Several studies have recently investigated the role of leptin, the adipocyte-secreted hormone, in the growth and reproduction of rodents, humans, and domestic animals. The present study was designed to explore the expression of leptin and its receptor in pig spermatozoa. Successful Western blot evidenced a 16 kDa band for leptin and six isoforms, ranging from 120 to 40 kDa, for the leptin receptor. Both leptin and leptin receptor were interestingly located at sperm acrosomal level, suggesting their involvement in the oocyte fertilization events. In fact, both capacitation indexes and acrosin activity were enhanced by leptin, and these effects were reduced by the anti-leptin receptor antibody. Afterwards, we investigated the main transduction pathways regulated by the hormone. Our results showed that, in pig sperm, leptin can trigger the signal transducer and activator of transcription 3, a classical component of cytokine signal transduction pathways, whose expression has not been previously reported in male gamete; in addition it was found constitutively activated. Besides, leptin was able to induce the activation of phosphatidylinositol phosphate kinase 3 and MAP kinase pathways as well as of BCL2, a known antiapoptotic protein. These data address to a role of leptin and its receptor on pig sperm survival. The presence of leptin and its receptor in pig sperm suggests that they, through an autocrine short loop, may induce signal transduction and molecular changes associated with sperm capacitation and survival

    Follicle-stimulating hormone receptor (FSHR) a promising novel target for cancer diagnosis in seminoma and embryonal carcinoma

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    Adult testicular germ cell tumors (TGCTs) are the most frequent malignant tumors in male patients aged 15–45 years, their incidence is increasing in recent years. There are two main subclasses of TGCTs: seminomas (SE) and non-seminomatous germ cell tumors (NSGCTs). SE have histological features of primordial germ cells, whereas NSGCTs have varying degrees of differentiation (i.e. embryonal carcinoma, EC), they present distinctive clinical features and differ for therapy and prognosis. NSGCTs tend to be metastatic at presentation, and have a worse prognosis than seminomas at an equivalent stage of disease. Despite general advances in the management of TGCTs, the molecular bases underlying their progression remain almost unknown. The effects of the Follicle-stimulating hormone (FSH), central hormone in mammalian reproductive biology, are mediated by FSHR, which was believed to be expressed primarily in ovary and testis. Recently, FSHR expression has been shown in the blood vessels of different solid tumors, including prostate, urothelial and breast carcinomas, suggesting a role in neoangiogenesis. The expression of FSHR at the periphery of tumors, also suggests that FSHR may be of relevance to the metastatic process. In normal human testis, estrogen physiological actions are mediated by estrogen receptor (ER) β and highly variable ERβ expression has been reported in the different TGCTs. ERβ loss is associated with advanced tumor stage in several cancers and previously, we showed a higher expression of ERβ1 in SE with respect EC. In this study, we evaluated the expression of FSHR in normal and neoplastic human testis tissues. Further, we compared FSHR expression with that of ERβ1 in the same samples. In normal testes, immunohistochemical studies showed the presence of FSHR prevalently in somatic testicular cells, while ERβ1 is expressed both in somatic and germinal testicular cells. Intriguingly, we discovered that FSHR was strongly expressed in EC and absent in SE. Conversely, immunostaining for ERβ1 revealed higher intensity in SE as compared to EC. These data suggest distinct physiopathological roles for the two receptors in TGCTs progression, being ERβ1 protective and FSHR harmful. Our data report for the first time the expression of FSHR in TGCTs, suggesting its possible involvement in testicular carcinogenesis. FSHR may be considered an useful molecular marker to distinguish seminoma from embryonal carcinoma, the most common TGCTs subtypes, and this could be informative in clinical decision making and patient counseling

    The follicle-stimulating hormone receptor (FSHR) is expressed in human sperm and it may be considered as molecular marker of the detrimental effects related to the physiopathology of testicular varicocele

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    Localization of the follicle-stimulating hormone receptor (FSHR), has been always closely related to the testis and ovary. FSH/FSHR role in Sertoli cell, has been known, however, the sites of FSH action within the male reproductive system are not resolved yet. Few studies have raised the intriguing possibility that germ cells may exhibit FSHR, all the reports point to Sertoli cells as the exclusive FSH target cells in testis. Besides, the attention has been always paid on the FSHR several polymorphisms which affect receptor sensitivity and expression. The presence of FSHR in germinal cells from spermatogonia to spermatocytes, including round spermatids is controversial or excluded. The mechanisms by which testicular varicocele affects fertility remain undetermined. Recently, our studies showed that the disease causes damage in sperm at the molecular level opening a new chapter in the already multifaceted physiopathology of varicocele. Samples used in this study were from normozoospermic and from diagnosed varicocele of grade III on the left testis patients. To date four FSHR isoforms were discovered, FSHR1, FSHR2, FSHR3 and FSHR4. The activity of FSHR1 is mediated by G proteins, which activate adenylate cyclase. FSHR2 and FSHR3 also bind FSH, but this does not result in activation of adenylate cyclase. FSHR4 does not bind FSH. By western blot analysis, we showed that healthy sperm express FSHR1, FSHR2 and FSHR3 while FSHR4 is almost absent. Varicocele does not express FSHR2. Immunofluorescence assay evidences FSHR localization prevalently at the midpiece level, which was strongly reduced in varicocele sperm. Responses to different FSH concentrations on motility and survival were significantly reduced in varicocele respect to the normal sperm, probably due to the lower FSHR1 expression and FSHR2 absence. The FSHR significance in human male gamete also emerged from the acrosome reaction histochemical studies, during FSH treatment which significantly induced the process. Our data showed for the first time that human sperm express the FSHR and constrain the need of further studies on the molecular anatomy of human male gamete both in healthy and in pathological conditions related to the male genital apparatus, considering the high couple infertility linked to the male. The translation of these new researches in the clinic surgery of testicular varicocele needs to be taken into account since molecular alterations in sperm imply a decline in the acquisition of fertilizing ability, and to date controversies exist on the opportunity to intervene surgically
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