2,194 research outputs found

    Neuroendocrine effects of carnitines on reproductive impairments

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    Carnitines are quaternary amines involved in various cellular processes such as fatty acid uptake, β‐oxidation and glucose metabolism regulation. Due to their neurotrophic activities, their integrative use has been studied in several different physio‐pathological conditions such as anorexia nervosa, chronic fatigue, vascular diseases, Alzheimer’s disease and male infertility. Being metabol-ically active, carnitines have also been proposed to treat reproductive impairment such as functional hypothalamic amenorrhea (FHA) and polycystic ovary syndrome (PCOS) since they improve both hormonal and metabolic parameters modulating the neuroendocrine impairments of FHA. Moreo-ver, they are capable of improving the lipid profile and the insulin sensitivity in patients with PCOS

    The Expression of the PDZ Protein MALS-1/Velis Is Regulated by Calcium and Calcineurin in Cerebellar Granule Cells

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    Activity-dependent gene expression is thought to be important in shaping neuronal development and in modifying the protein content of neurons. Ca(2+) entry into neurons appears to be one of the key effectors of activity-dependent gene expression. Among the possible downstream targets of calcium, the protein phosphatase calcineurin represents a prime candidate. We hereby report that in cultured cerebellar granule cells the activation of the Ca(2+)/calcineurin pathway via either voltage- or ligand- operated Ca(2+) channels regulates MALS-1 and MALS-2 expression at the transcriptional level. These proteins are integral parts of the post-synaptic density and are also involved in receptor trafficking. MALS regulation is not at the level of mRNA stability and does not require de novo protein synthesis, thereby suggesting a direct pathway. These data suggest that Ca(2+) entry by means of calcineurin is capable of controlling the structure of the post-synaptic density by controlling the expression of key components at the transcriptional level

    Inositol supplementation in women with polycystic ovary syndrome undergoing intracytoplasmic sperm injection: a systematic review and meta-analysis of randomized controlled trials

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    Polycystic ovary syndrome (PCOS) is a complex and heterogeneous disease that involves menstrual dysfunction and reproductive difficulty, as well as metabolic problems. The aim of this study was to assess the effectiveness of myo-inositol (MYO) and d-chiro-inositol (DCI) on improving oocyte or embryo quality and pregnancy rates for women with PCOS undergoing intracytoplasmic sperm injection (ICSI). We searched the Web of Knowledge, MEDLINE, EMBASE, Pubmed, Scopus and Cochrane databases for all articles published in any language up to March 2017. The selection criteria were as follows: (population) patients with PCOS; (intervention) treatment with inositol (MYO, DCI, or both, with any dose and any duration) in conjunction with an ovulation-inducing agent versus the ovulation-inducing agent alone; (outcome) oocyte and embryo quality; (study design) randomized controlled trials. Of 76 identified studies, eight RCTs were included for analysis comprising 1019 women with PCOS. MYO supplementation was insufficient to improve oocyte quality (OR 2.2051; 95% CI 0.8260 to 5.8868), embryo quality (OR 1.6231, 95% CI 0.3926 to 6.7097), or pregnancy rate (OR 1.2832, 95% CI 0.8692 to 1.8944). Future studies of appropriate dose, size and duration of DCI are vital to clarify its the role in the management of PCOS

    NAADP receptors are present and functional in the heart

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    AbstractAlongside the well-studied inositol 1,4,5 trisphosphate and ryanodine receptors, evidence is gathering that a new intracellular release mechanism, gated by the pyridine nucleotide nicotinic acid adenine dinucleotide phosphate (NAADP), is present in numerous organisms, ranging from plant to mammalian cells (reviewed in [1]). Most cells have been shown to express at least two Ca2+-release mechanisms controlled by different messengers, and this can lead to redundancy, convergence, or divergence of responses. One exception appears to be muscle and heart contractile tissues. Here, it is thought that the dominant intracellular channel is the ryanodine receptor, while IP3 receptors are poorly expressed and their role appears to be negligible. We now report that NAADP receptors are functional and abundant in cardiac microsomes. NAADP binds specifically and with high affinity (130 pM and 4 nM) to two sites on cardiac microsomes and releases Ca2+ with an apparent EC50 of 323 ± 14 nM. Furthermore, binding experiments show that this receptor displays both positive and negative cooperativity, a peculiarity unique among intracellular Ca2+ channels. Therefore, we show that the heart possesses multiple mechanisms to increase the complexity of Ca2+ signaling and that NAADP may be integral in the functioning of this organ

    Celecoxib inhibits proliferation and survival of chronic myelogeous leukemia (CML) cells via AMPK-dependent regulation of β-catenin and mTORC1/2.

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    CML is effectively treated with tyrosine kinase inhibitors (TKIs). However, the efficacy of these drugs is confined to the chronic phase of the disease and development of resistance to TKIs remains a pressing issue. The anti-inflammatory COX2 inhibitor celecoxib has been utilized as anti-tumour drug due to its anti-proliferative activity. However, its effects in hematological malignancies, in particular CML, have not been investigated yet. Thus, we tested biological effects and mechanisms of action of celecoxib in Philadelphia-positive (Ph+) CML and ALL cells.We show here that celecoxib suppresses the growth of Ph+ cell lines by increasing G1-phase and apoptotic cells and reducing S- and G2-phase cells. These effects were independent of COX2 inhibition but required the rapid activation of AMP-activated protein kinase (AMPK) and the consequent inhibition mTORC1 and 2. Treatment with celecoxib also restored GSK3β function and led to down-regulation of β-catenin activity through transcriptional and post-translational mechanisms, two effects likely to contribute to Ph+ cell growth suppression by celecoxib.Celecoxib inhibited colony formation of TKI-resistant Ph+ cell lines including those with the T315I BCR-ABL mutation and acted synergistically with imatinib in suppressing colony formation of TKI-sensitive Ph+ cell lines. Finally, it suppressed colony formation of CD34+ cells from CML patients, while sparing most CD34+ progenitors from healthy donors, and induced apoptosis of primary Ph+ ALL cells.Together, these findings indicate that celecoxib may serve as a COX2-independent lead compound to simultaneously target the mTOR and β-catenin pathways, key players in the resistance of CML stem cells to TKIs

    DPYD IVS14+1G>A and 2846A>T genotyping for the prediction of severe fluoropyrimidine-related toxicity: a meta-analysis.

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    Aim: In the present study we conducted a systematic review and meta-analysis of published data to quantify the impact of the DPYD IVS14+1G>A and 2846A>T variants on the risk of fluoropyrimidine-related toxicities and to determine sensitivity and specificity testing for DPYD variants. Methods: Relevant studies were identified through PubMed and Web of Knowledge databases, studies included were those published up until to May 2012. Study quality was assessed according to the HuGENET guidelines and Strengthening the Reporting of Genetic Association (STREGA) recommendations. Results: Random-effects meta-analysis provided evidence that carriers of DPYD IVS14+1G>A are at higher risk of ≥3 degrees of overall grade toxicity, hematological toxicity, mucositis and diarrhea. In addition, a strong association was also found between carriers of the DPYD 2846T allele and overall grade ≥3 toxicity or grade ≥3 diarrhea. An inverse linear relationship was found in prospective studies between the odds ratio of DPYD IVS14+1G>A and the incidence of overall grade ≥3 toxicity, indicating an higher impact in cohorts in which the incidence of severe toxicity was lower. Conclusion: The results of this meta-analysis confirm clinical validity of DPYD IVS14+1G>A and 2846A>T as risk factors for the development of severe toxicities following fluoropyrimidine treatment. Furthermore, the sensitivity and specificity estimates obtained could be useful in establishing the cost-effectiveness of testing for DPYD variants. Original submitted 4 March 2013; Revision submitted 17 June 2013

    Calcineurin Controls the Expression of Isoform 4CII of the Plasma Membrane Ca2+ Pump in Neurons *

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    Abstract The expression of the CII splice variant of the plasma membrane Ca2+ ATPase 4 (PMCA4) was down-regulated in granule neurons when they were cultured under conditions of partial membrane depolarization (25 mm KCl), which are required for long term in vitro survival of the neurons. These conditions, which cause a chronic increase of the resting free Ca2+ concentration in the neurons, have recently been shown to promote up-regulation of the PMCA2, 3, and 1CII isoforms. Whereas the chronic, i.e. >3 days, Ca2+ increase was necessary for the up-regulation of the PMCA1CII, 2, and 3, the down-regulation of the PMCA4CII mRNA was already evident 1–2 h after the start of culturing in 25 mm KCl. The immunosuppressant calcineurin inhibitor FK506 inhibited the down-regulation of the PMCA4CII at both the protein and the mRNA level but did not affect the changes of the other PMCA pumps. Direct evidence for the involvement of calcineurin in the down-regulation of the PMCA4CII was obtained by overexpressing a truncated, constitutively active, and Ca2+-independent form of calcineurin; under these conditions, depolarization was not required for the down-regulation of the PMCA4CII pump. De novosynthesis of (transcription) factors was required for the down-regulation of the PMCA4CII mRNA. Calcineurin, therefore, controls the neuronal transcription of PMCA4CII, a splice variant of the pump isoforms that is found almost exclusively in brain
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