15 research outputs found

    Sperm glyceraldehyde 3-phosphate dehydrogenase gene expression in asthenozoospermic spermatozoa

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    It has been suggested that the energy required for sperm motility is produced by oxidative phosphorylation while glycolysis seems to be an important source for ATP transmission along the flagellum. Some studies have investigated the chemical and kinetic properties of the enzyme glyceraldehyde 3‐phosphate dehydrogenase to identify any changes in the regulation of glycolysis and sperm motility. In contrast, there are few studies analyzing the genetic basis of hypokinesis. For this reason, we investigated the glyceraldehyde 3‐phosphate dehydrogenase gene in human sperm to evaluate whether asthenozoospermia was correlated with any changes in its expression. Semen examination and glyceraldehyde 3‐phosphate dehydrogenase gene expression studies were carried out on 116 semen samples divided into two groups – Group A consisted of 58 normokinetic samples and Group B of 58 hypokinetic samples. Total RNA was extracted from spermatozoa, and real‐time PCR quantification of mRNA was carried out using specific primers and probes. The expression profiles for the Groups A and B were very similar. The mean delta Ct was as follows – Group A, 5.79 ± 1.04; Group B, 5.47 ± 1.27. Our study shows that in human sperm, there is no difference in glyceraldehyde 3‐phosphate dehydrogenase gene expression between samples with impaired motility and samples with normal kinetics. We believe that this study could help in the understanding of the molecular mechanisms of sperm kinetics, suggesting that hypomotility may be due to a possible posttranscriptional impairment of the control mechanism, such as mRNA splicing, or to posttranslational changes

    Mechanisms of Testicular Disruption from Exposure to Bisphenol A and Phtalates

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    Great attention has been paid in recent years to the harmful effects of various chemicals that interfere with our natural hormone balance, collectively known as endocrine-disrupting chemicals (EDCs) or endocrine disruptors. The effects on the reproductive system of bisphenol A (BPA) and phthalates have received particular attention: while they have a short half-life, they are so widespread that human exposure can be considered as continuous. Evidence is often limited to the animal model, disregarding the likelihood of human exposure to a mixture of contaminants. Data from animal models show that maternal exposure probably has harmful effects on the male fetus, with an increased risk of urogenital developmental abnormalities. After birth, exposure is associated with changes in the hypothalamic-pituitary-testicular axis, hindering the development and function of the male genital pathways through the mediation of inflammatory mechanisms and oxidative stress. The epidemiological and clinical evidence, while generally confirming the association between reproductive abnormalities and some phthalate esters and BPA, is more contradictory, with wildly different findings. The aim of this review is therefore to provide an update of the potential mechanisms of the damage caused by BPA and phthalates to reproductive function and a review of the clinical evidence currently available in the literature

    Differential expression of miRNAs in the seminal plasma and serum of testicular cancer patients

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    Various microRNAs from the miR-371-3 and miR-302a–d clusters have recently been proposed as markers for testicular germ cell tumours. Upregulation of these miRNAs has been found in both the tissue and serum of testicular cancer patients, but they have never been studied in human seminal plasma. The aim of this study was, therefore, to assess the differences in the expression of miR-371-3 and miR-302a–d between the seminal plasma and serum of testicular cancer patients, and to identify new potential testicular cancer markers in seminal plasma. We investigated the serum and seminal plasma of 28 pre-orchiectomy patients subsequently diagnosed with testicular cancer, the seminal plasma of another 20 patients 30 days post-orchiectomy and a control group consisting of 28 cancer-free subjects attending our centre for an andrological check-up. Serum microRNA expression was analysed using RT-qPCR. TaqMan Array Card 3.0 platform was used for microRNA profiling in the seminal plasma of cancer patients. Results for both miR-371-3 and the miR-302 cluster in the serum of testicular cancer patients were in line with literature reports, while miR-371and miR-372 expression in seminal plasma showed the opposite trend to serum. On array analysis, 37 miRNAs were differentially expressed in the seminal plasma of cancer patients, and the upregulated miR-142 and the downregulated miR-34b were validated using RT-qPCR. Our study investigated the expression of miRNAs in the seminal plasma of patients with testicular cancer for the first time. Unlike in serum, miR-371-3 cannot be considered as markers in seminal plasma, whereas miR-142 levels in seminal plasma may be a potential marker for testicular cancer

    Inhibin B: are modified ranges needed for orchiectomised testicular cancer patients?

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    Inhibin B is a gonadal hormone that downregulates the pituitary production of follicle-stimulating hormone (FSH). In recent years, inhibin B has proved to be an excellent marker of spermatogenesis and even a predictive factor for the recovery of fertility in patients undergoing orchiectomy and antineoplastic treatments. We propose to study inhibin B levels in orchiectomised testicular cancer patients, in order to identify a minimum value representative of normal semen quality. This retrospective study evaluates hormonal and semen parameters of 290 normozoospermic patients attending the Laboratory of Seminology - Sperm Bank “Loredana Gandini” (Rome, Italy) for cryopreservation of seminal fluid following a diagnosis of testicular cancer (TC group) and 117 healthy, normozoospermic men as a control group (CTR group). The percentile distribution of gonadotropin and inhibin B values in the TC and CTR groups was analyzed. There was a statistically significant difference between the two groups in the levels of all hormones (P ≀ 0.001) and in all semen parameters (P < 0.05). About 20% of TC patients revealed inhibin B levels below the 5th percentile of CTR group, despite normozoospermia, and 31.4% had normal spermatogenesis in the presence of FSH values >95th percentile of CTR group. Orchiectomised patients for testicular cancer presented inhibin B levels lower than healthy patients, despite normozoospermia. Our study revealed the poor sensitivity of the current inhibin B reference range when applied to monorchidic patients, suggesting the need to establish more representative ranges to enable more appropriate counseling in relation to the patient’s new endocrine condition

    Sperm DNA fragmentation in Italian couples with recurrent pregnancy loss

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    The aetiopathogenesis of recurrent pregnancy loss (RPL) is heterogeneous. The aim of this study was to investigate the male factor in Italian couples experiencing RPL following natural conception. The study investigated 112 men from RPL couples and two control groups: 114 infertile men with one or more impaired semen parameters and 114 fertile men with high-quality semen parameters. Semen parameters were examined according to WHO criteria. Sperm DNA fragmentation (SDF) was evaluated using TdT-mediated dUDP nick-end labelling (TUNEL) assay. With the exception of ejaculate volume, the seminal profile of patients with RPL was similar to that of fertile patients and better than the infertile ones. Despite good spermatogenesis, however, sperm DNA integrity was impaired in the RPL group, with SDF values significantly higher than in fertile controls (18.8 ± 7.0 versus 12.8 ± 5.3, P < 0.001) and similar to those of infertile patients. SDF also showed a positive correlation with the age of patients with RPL and number of miscarriages. The results suggest a correlation between increased SDF and impaired reproductive capacity in terms of both fertilization and pregnancies carried to term, but high SDF cannot yet be considered a predictive factor for the risk of RPL

    Semen quality and fertility before and after therapy in patients affected by non Hodgkin Lymphoma

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    Non hodgkin lymphoma represent phatology in men in fertile age and includes about 8% of all cancer diagnosis in men aver 15-45 years. In recent years overall survival of these patients has improved remarkably. Thus, new challenges regarding reproductive outcome have emerged as many antineoplastic regimens utilised as chemotherapy (CH) and radiotherapy (RT), stem cell transplantation (SCT), are known to alter semen qualit

    Concerted microRNA control of Hedgehog signalling in cerebellar neuronal progenitor and tumour cells

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    MicroRNAs (miRNA) are crucial post-transcriptional regulators of gene expression and control cell differentiation and proliferation. However, little is known about their targeting of specific developmental pathways. Hedgehog (Hh) signalling controls cerebellar granule cell progenitor development and a subversion of this pathway leads to neoplastic transformation into medulloblastoma (MB). Using a miRNA high-throughput profile screening, we identify here a downregulated miRNA signature in human MBs with high Hh signalling. Specifically, we identify miR-125b and miR-326 as suppressors of the pathway activator Smoothened together with miR-324-5p, which also targets the downstream transcription factor Gli1. Downregulation of these miRNAs allows high levels of Hh-dependent gene expression leading to tumour cell proliferation. Interestingly, the downregulation of miR-324-5p is genetically determined by MB-associated deletion of chromosome 17p. We also report that whereas miRNA expression is downregulated in cerebellar neuronal progenitors, it increases alongside differentiation, thereby allowing cell maturation and growth inhibition. These findings identify a novel regulatory circuitry of the Hh signalling and suggest that misregulation of specific miRNAs, leading to its aberrant activation, sustain cancer development

    Identification and Characterization of KCASH2 and KCASH3, 2 Novel Cullin3 Adaptors Suppressing Histone Deacetylase and Hedgehog Activity in Medulloblastoma12

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    Medulloblastoma is the most common pediatric malignant brain tumor, arising from aberrant cerebellar precursors' development, a process mainly controlled by Hedgehog (Hh) signaling pathway. Histone deacetylase HDAC1 has been recently shown to modulate Hh signaling, deacetylating its effectors Gli1/2 and enhancing their transcriptional activity. Therefore, HDAC may represent a potential therapeutic target for Hh-dependent tumors, but still little information is available on the physiological mechanisms of HDAC regulation. The putative tumor suppressor RENKCTD11 acts through ubiquitination-dependent degradation of HDAC1, thereby affecting Hh activity and medulloblastoma growth. We identify and characterize here two RENKCTD11 homologues, defining a new family of proteins named KCASH, as “KCTD containing, Cullin3 adaptor, suppressor of Hedgehog.” Indeed, the novel genes (KCASH2KCTD21 and KCASH3KCTD6) share with RENKCTD11 a number of features, such as a BTB domain required for the formation of a Cullin3 ubiquitin ligase complex and HDAC1 ubiquitination and degradation capability, suppressing the acetylation-dependent Hh/Gli signaling. Expression of KCASH2 and -3 is observed in cerebellum, whereas epigenetic silencing and allelic deletion are observed in human medulloblastoma. Rescuing KCASHs expression reduces the Hedgehog-dependent medulloblastoma growth, suggesting that loss of members of this novel family of native HDAC inhibitors is crucial in sustaining Hh pathway-mediated tumorigenesis. Accordingly, they might represent a promising class of endogenous “agents” through which this pathway may be targeted
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