Genetic male infertility and mutation of CATSPER ion channels.

A clinically significant proportion of couples experience difficulty in conceiving a child. In about half of these cases male infertility is the cause and often genetic factors are involved. Despite advances in clinical diagnostics ∼50% of male infertility cases remain idiopathic. Based on this, further analysis of infertile males is required to identify new genetic factors involved in male infertility. This review focuses on cation channel of sperm (CATSPER)-related male infertility. It is based on PubMed literature searches using the keywords 'CATSPER', 'male infertility', 'male contraception', 'immunocontraception' and 'pharmacologic contraception' (publication dates from January 1979 to December 2009). Previously, contiguous gene deletions including the CATSPER2 gene implicated the sperm-specific CATSPER channel in syndromic male infertility (SMI). Recently, we identified insertion mutations of the CATSPER1 gene in families with recessively inherited nonsyndromic male infertility (NSMI). The CATSPER channel therefore represents a novel human male fertility factor. In this review we summarize the genetic and clinical data showing the role of CATSPER mutation in human forms of NSMI and SMI. In addition, we discuss clinical management and therapeutic options for these patients. Finally, we describe how the CATSPER channel could be used as a target for development of a male contraceptive.

Actualités en gastroentérologie et hépatologie [Highlights in gastroenterology and hepatology 2010].

This review highlights recent advances in gastroenterology and hepatology, including the treatment of Crohn's disease, of eosinophilic esophagitis, of chronic hepatitis C, and of hepatic encephalopathy as well as the role of high resolution manometry in the investigation of esophageal motility disorders. These new developments will be summarized and discussed critically, with a particular emphasis on their potential implications for current and future clinical practice.

Growth, cysts and kinetics of Borrelia garinii (Spirochaetales: Spirochaetacea) in different culture media

The aim of the present paper was to evaluate cyst formation and growth parameters of Borrelia garinii in a range of media differing in formulation and cost. A qualitative assessment of morphology and motility of B. garinii was conducted. All media were prepared aseptically and used in test tubes or Petri dishes. For each medium, the initial spirochete concentration was standardized to 10³ spirochets/mL. The following culture media were suitable to grow B. garinii: Barbour-Stoenner-Kelly, brain heart infusion and PMR. Growth was minimal at six weeks post-inoculation and maximum spirochete density was observed between 9-12 weeks. Often, the cultures developed cysts of different sizes, isolated or in groups, with a spiraled portion of variable sizes, mainly in unfavorable culture media. Brazilian Lyme disease-like illness, also known as Baggio-Yoshinari syndrome (BYS), is a new and interesting emerging tick-borne disease, caused by Borrelia burgdorferi sensu lato spirochetes, only during its cystic forms. It has been assumed that the peculiar clinical and laboratory features of BYS are consequential to the absence of a human sucker Ixodes ricinus complex tick at risk areas in Brazil, supporting the concept that the borrelia phenotypic expression pattern is modified as it is transmitted through the host.

Tumor necrosis-like weak inducer of apoptosis as a proinflammatory cytokine in human adipocyte cells: up-regulation in severe obesity is mediated by inflammation but not hypoxia.

CONTEXT Adipose tissue hypoxia and endoplasmic reticulum (ER) stress may link the presence of chronic inflammation and macrophage infiltration in severely obese subjects. We previously reported the up-regulation of TNF-like weak inducer of apoptosis (TWEAK)/fibroblast growth factor-inducible 14 (Fn14) axis in adipose tissue of severely obese type 2 diabetic subjects. OBJECTIVES The objective of the study was to examine TWEAK and Fn14 adipose tissue expression in obesity, severe obesity, and type 2 diabetes in relation to hypoxia and ER stress. DESIGN In the obesity study, 19 lean, 28 overweight, and 15 obese nondiabetic subjects were studied. In the severe obesity study, 23 severely obese and 35 control subjects were studied. In the type 2 diabetes study, 11 type 2 diabetic and 36 control subjects were studied. The expression levels of the following genes were analyzed in paired samples of sc and visceral adipose tissue: Fn14, TWEAK, VISFATIN, HYOU1, FIAF, HIF-1a, VEGF, GLUT-1, GRP78, and XBP-1. The effect of hypoxia, inflammation, and ER stress on the expression of TWEAK and Fn14 was examined in human adipocyte and macrophage cell lines. RESULTS Up-regulation of TWEAK/Fn14 and hypoxia and ER stress surrogate gene expression was observed in sc and visceral adipose tissue only in our severely obese cohort. Hypoxia modulates TWEAK or Fn14 expression in neither adipocytes nor macrophages. On the contrary, inflammation up-regulated TWEAK in macrophages and Fn14 expression in adipocytes. Moreover, TWEAK had a proinflammatory effect in adipocytes mediated by the nuclear factor-kappaB and ERK but not JNK signaling pathways. CONCLUSIONS Our data suggest that TWEAK acts as a pro-inflammatory cytokine in the adipose tissue and that inflammation, but not hypoxia, may be behind its up-regulation in severe obesity.

Antischistosomal activity of a calcium channel antagonist on schistosomula and adult Schistosoma mansoni worms

Current schistosomiasis control strategies are largely based on chemotherapeutic agents and a limited number of drugs are available today. Praziquantel (PZQ) is the only drug currently used in schistosomiasis control programs. Unfortunately, this drug shows poor efficacy in patients during the earliest infection phases. The effects of PZQ appear to operate on the voltage-operated Ca2+channels, which are located on the external Schistosoma mansoni membrane. Because some Ca2+channels have dihydropyridine drug class (a class that includes nifedipine) sensitivity, an in vitro analysis using a calcium channel antagonist (clinically used for cardiovascular hypertension) was performed to determine the antischistosomal effects of nifedipine on schistosomula and adult worm cultures. Nifedipine demonstrated antischistosomal activity against schistosomula and significantly reduced viability at all of the concentrations used alone or in combination with PZQ. In contrast, PZQ did not show significant efficacy when used alone. Adult worms were also affected by nifedipine after a 24 h incubation and exhibited impaired motility, several lesions on the tegument and intense contractility. These data support the idea of Ca2+channels subunits as drug targets and favour alternative therapeutic schemes when drug resistance has been reported. In this paper, strong arguments encouraging drug research are presented, with a focus on exploring schistosomal Ca2+channels.

Cells derived from the coelomic epithelium contribute to multiple gastrointestinal tissues in mouse embryos.

Gut mesodermal tissues originate from the splanchnopleural mesenchyme. However, the embryonic gastrointestinal coelomic epithelium gives rise to mesenchymal cells, whose significance and fate are little known. Our aim was to investigate the contribution of coelomic epithelium-derived cells to the intestinal development. We have used the transgenic mouse model mWt1/IRES/GFP-Cre (Wt1(cre)) crossed with the Rosa26R-EYFP reporter mouse. In the gastrointestinal duct Wt1, the Wilms' tumor suppressor gene, is specific and dynamically expressed in the coelomic epithelium. In the embryos obtained from the crossbreeding, the Wt1-expressing cell lineage produces the yellow fluorescent protein (YFP) allowing for colocalization with differentiation markers through confocal microscopy and flow cytometry. Wt1(cre-YFP) cells were very abundant throughout the intestine during midgestation, declining in neonates. Wt1(cre-YFP) cells were also transiently observed within the mucosa, being apparently released into the intestinal lumen. YFP was detected in cells contributing to intestinal vascularization (endothelium, pericytes and smooth muscle), visceral musculature (circular, longitudinal and submucosal) as well as in Cajal and Cajal-like interstitial cells. Wt1(cre-YFP) mesenchymal cells expressed FGF9, a critical growth factor for intestinal development, as well as PDGFRα, mainly within developing villi. Thus, a cell population derived from the coelomic epithelium incorporates to the gut mesenchyme and contribute to a variety of intestinal tissues, probably playing also a signaling role. Our results support the origin of interstitial cells of Cajal and visceral circular muscle from a common progenitor expressing anoctamin-1 and SMCα-actin. Coelomic-derived cells contribute to the differentiation of at least a part of the interstitial cells of Cajal.

Relationship of mating systems and metabolic rate with cycle length of spermatogenesis and sperm production rate in shrews

SUMMARY : The shrews are among the most ancient of living eutherian mammals. They represent an interesting comparative model because of their extreme divergent species. The two shrew subfamilies, Soricinae and Crocidurinae are characterized by fundamental differences concerning their metabolic rates, litter size, period of gestation and different mating pattern. In this study we established and compared the sperm characteristics in four species of different genera of shrews (Sorex araneus, Neomys fodiens, Crocidura russula and Suncus murinus) in the context of the sperm competition hypothesis. The sperm competition concerns the competition between ejaculates of different males for fertilization of ova of a female within a single estrus period. As expected, a greater relative testis size (indicating the importance of polyandry) was associated with a higher number of cauda epididymal spermatozoa, higher level of circulating testosterone and a higher percentage of progressive sperm motility. In addition, we investigated if the basal metabolic rate (BMR) and relative testis size (RTS) may be correlated with the cycle length of spermatogenesis. In this purpose, we determined and compared the cycle length of spermatogenesis in six species of shrews belonging to two subfamilies: Soiricinae (Sorex araneus, Sorex coronatus, Sorex minutus, Neomys fodiens) and Crocidurinae (Crocidura russula, Sunctes murinus). Our results indicate that sperm competition and metabolic rate may act independently or together reducing cycle length of spermatogenesis and thus increase sperm production. We finally investigated this correlation across 32 mammalian species. After testing the data for phylogenetic independence, our results showed that BMR explained only 21 % of the variation, while the RTS explained 44% of the variation of the cycle length of spermatogenesis. The level of the sperm competition, indicated by RTS, is thus to our knowledge the most important factor influencing the speed of spermatogenesis in mammals. RESUME : Les musaraignes sont parmi les plus anciens mammifères vivants. Grâce à leurs extrêmes divergences, ils sont souvent utilisés comme modèles dans des études comparatives. Les deux sous-familles Soricinae et Crocidurinae sont caractérisées par des différences fondamentales, notamment en termes d'intensité du métabolisme, des stratégies de reproduction et du comportement social. Dans la première partie de cette étude, nous avons établi et comparé certaines "caractéristiques des spermatozoïdes chez quatre espèces de musaraignes appartenant à des genres différents (Sorex araneus, Neomys fodiens, Crocidura russula et Suncus murinus). Les résultats ont été interprétés dans le contexte de la théorie de la compétition spermatique, c'est-à-dire la compétition entre le sperme de deux ou plusieurs mâles pour féconder un maximum d'ovules de la même femelle. Cette compétition spermatique peut amener à certaines adaptations biologiques afin de produire plus de sperme. Comme attendu, une grande taille relative des testicules est associée à un nombre élevé de spermatozoïdes, dont la majorité présente une mobilité progressive. Un taux élévé de testostérone a également été observé. De plus, nous avons étudié l'influence du métabolisme basal ainsi que l'intensité de la compétition spermatique sur la durée du cycle de la spermatogenèse. Dans ce but, nous avons déterminé et comparé les durées de la spermatogenèse chez six espèces de musaraignes appartenant à deux sous-familles : Soricinae (Sorex araneus, Sorex coronatus, Sorex minutus, Neomys fodiens) et Crocidurinae (Crocidura russula, Suncus murinus). Les résultats obtenus indiquent que ces deux facteurs (l'intensité du métabolisme basal et de la compétition spermatique) agissent d'une manière dépendante ou indépendante dans le même sens. La conséquence de ces actions est une diminution de la durée de la spermatogenèse entraînant une augmentation de la production de spermatozoïdes. Nous avons finalement étudié ce phénomène dans l'ensemble des mammifères. Après avoir testé l'indépendance phylogénétique, nos résultats montrent que l'intensité de la compétition spermatique indiquée par le RTS est mieux corrélée avec la régulation de la durée de la spermatogenèse qu'avec l'intensité du métabolisme.

Genetic dysregulation of glutathione synthesis predicts alteration of plasma thiol redox status in schizophrenia.

Abstract Genetic studies have shown an association between schizophrenia and a GAG trinucleotide repeat (TNR) polymorphism in the catalytic subunit (GCLC) of the glutamate cysteine ligase (GCL), the key enzyme for glutathione (GSH) synthesis. The present study was aimed at analyzing the influence of a GSH dysregulation of genetic origin on plasma thiols (total cysteine, homocysteine, and cysteine-glycine) and other free amino acid levels as well as fibroblast cultures GSH levels. Plasma thiols levels were also compared between patients and controls. As compared with patients with a low-risk GCLC GAG TNR genotype, patients with a high-risk genotype, having an impaired GSH synthesis, displayed a decrease of fibroblast GSH and plasma total cysteine levels, and an increase of the oxidized form of cysteine (cystine) content. Increased levels of plasma free serine, glutamine, citrulline, and arginine were also observed in the high-risk genotype. Taken together, the high-risk genotypes were associated with a subgroup of schizophrenia characterized by altered plasma thiols and free amino acid levels that reflect a dysregulation of redox control and an increased susceptibility to oxidative stress. This altered pattern potentially contributes to the development of a biomarker profile useful for early diagnosis and monitoring the effectiveness of novel drugs targeting redox dysregulation in schizophrenia. Antioxid. Redox Signal. 15, 2003-2010.

PARP-1 regulates metastatic melanoma through modulation of vimentin-induced malignant transformation.

PARP inhibition can induce anti-neoplastic effects when used as monotherapy or in combination with chemo- or radiotherapy in various tumor settings; however, the basis for the anti-metastasic activities resulting from PARP inhibition remains unknown. PARP inhibitors may also act as modulators of tumor angiogenesis. Proteomic analysis of endothelial cells revealed that vimentin, an intermediary filament involved in angiogenesis and a specific hallmark of EndoMT (endothelial to mesenchymal transition) transformation, was down-regulated following loss of PARP-1 function in endothelial cells. VE-cadherin, an endothelial marker of vascular normalization, was up-regulated in HUVEC treated with PARP inhibitors or following PARP-1 silencing; vimentin over-expression was sufficient to drive to an EndoMT phenotype. In melanoma cells, PARP inhibition reduced pro-metastatic markers, including vasculogenic mimicry. We also demonstrated that vimentin expression was sufficient to induce increased mesenchymal/pro-metastasic phenotypic changes in melanoma cells, including ILK/GSK3-β-dependent E-cadherin down-regulation, Snail1 activation and increased cell motility and migration. In a murine model of metastatic melanoma, PARP inhibition counteracted the ability of melanoma cells to metastasize to the lung. These results suggest that inhibition of PARP interferes with key metastasis-promoting processes, leading to suppression of invasion and colonization of distal organs by aggressive metastatic cells.

A dynamic view of hepatitis C virus replication complexes.

Hepatitis C virus (HCV) replicates its genome in a membrane-associated replication complex (RC). Specific membrane alterations, designated membranous webs, represent predominant sites of HCV RNA replication. The principles governing HCV RC and membranous web formation are poorly understood. Here, we used replicons harboring a green fluorescent protein (GFP) insertion in nonstructural protein 5A (NS5A) to study HCV RCs in live cells. Two distinct patterns of NS5A-GFP were observed. (i) Large structures, representing membranous webs, showed restricted motility, were stable over many hours, were partitioned among daughter cells during cell division, and displayed a static internal architecture without detectable exchange of NS5A-GFP. (ii) In contrast, small structures, presumably representing small RCs, showed fast, saltatory movements over long distances. Both populations were associated with endoplasmic reticulum (ER) tubules, but only small RCs showed ER-independent, microtubule (MT)-dependent transport. We suggest that this MT-dependent transport sustains two distinct RC populations, which are both required during the HCV life cycle.

The rise of soluble TWEAK levels in severely obese subjects after bariatric surgery may affect adipocyte-cytokine production induced by TNFα.

CONTEXT Soluble TNF-like weak inducer of apoptosis (sTWEAK) is generated by the intracellular proteolytic cleavage of full-length membrane-bound TNF-like weak inducer of apoptosis (mTWEAK). sTWEAK levels are reduced in diseases with an inflammatory component. Additionally, sTWEAK hampers TNFα activity in human cells. OBJECTIVES The objectives of the study were as follows: 1) to determine circulating sTWEAK in severe obesity and after bariatric surgery; 2) to study m/sTWEAK and its receptor fibroblast growth factor-inducible 14 (Fn14) protein expression in sc adipose tissue (SAT) of severely obese subjects, in SAT stromal vascular fraction (SVF), and isolated adipocytes and in human monocyte-derived macrophages; and 3) to explore, on human adipocytes, the sTWEAK effect on TNFα proinflammatory activity. DESIGN sTWEAK levels were measured in cohort 1: severely obese subjects (n = 23) and a control group (n = 35); and in cohort 2: (n = 23) severely obese subjects before and after surgery. The m/sTWEAK and Fn14 expressions were determined in SAT biopsies, SVF, and isolated adipocytes from severely obese and control subjects and in human monocyte-derived macrophages. In human primary cultured adipocytes, sTWEAK pretreated and TNFα challenged, IL-6, IL-8, and adiponectin protein and gene expressions were determined and nuclear factor-κ B and MAPK signaling analyzed. RESULTS sTWEAK levels were reduced in severely obese subjects. After surgery, sTWEAK levels rose in 69% of patients. mTWEAK protein expression was increased in SAT and SVF of severely obese subjects, whereas Fn14 was up-regulated in isolated adipocytes. M2 human monocyte-derived macrophages overexpress mTWEAK. In human adipocytes, sTWEAK down-regulates TNFα cytokine production by hampering TNFα intracellular signaling events. CONCLUSION The decrease of sTWEAK in severely obese patients may favor the proinflammatory activity elicited by TNFα.

Complex genetics in idiopathic hypogonadotropic hypogonadism.

Idiopathic hypogonadotropic hypogonadism (IHH) is an important human disease model. Investigations of the genetics of IHH have facilitated insights into critical pathways regulating sexual maturation and fertility. IHH has been traditionally considered a monogenic disorder. This model holds that a single gene defect is responsible for the disease in each patient. In the case of IHH, 30% of cases are explained by mutations in one of eleven genes. In recent years, several lines of evidence have challenged the monogenic paradigm in IHH. First, disease-associated mutations display striking incomplete penetrance and variable expressivity within and across IHH families. Second, each locus is responsible for only a small percentage of cases. Third, more than one disease-associated mutation seems to be segregating in some families with IHH, and their combined or separate presence in individuals accounts for the variability in disease severity. Finally, IHH is not strictly a congenital and life-long disorder; occasionally it manifests itself during adulthood (adult-onset IHH); in other cases, the disease is not permanent, as evidenced by normal activity of the hypothalamic-pituitary-gonadal axis after discontinuation of treatment in adulthood (IHH reversal). Together, these observations suggest that IHH is not strictly a monogenic mendelian disease, as previously thought. Rather, it is emerging as a digenic, and potentially oligogenic disease, in which hormonal and/or environmental factors may critically influence genetic predisposition and clinical course. Future investigations of IHH should characterize the extent of the involvement of multiple genes in disease pathogenesis, and elucidate the contributions of epigenetic factors.

A positive FGFR3/FOXN1 feedback loop underlies benign skin keratosis versus squamous cell carcinoma formation in humans.

Seborrheic keratoses (SKs) are common, benign epithelial tumors of the skin that do not, or very rarely, progress into malignancy, for reasons that are not understood. We investigated this by gene expression profiling of human SKs and cutaneous squamous cell carcinomas (SCCs) and found that several genes previously connected with keratinocyte tumor development were similarly modulated in SKs and SCCs, whereas the expression of others differed by only a few fold. In contrast, the tyrosine kinase receptor FGF receptor-3 (FGFR3) and the transcription factor forkhead box N1 (FOXN1) were highly expressed in SKs, and close to undetectable in SCCs. We also showed that increased FGFR3 activity was sufficient to induce FOXN1 expression, counteract the inhibitory effect of EGFR signaling on FOXN1 expression and differentiation, and induce differentiation in a FOXN1-dependent manner. Knockdown of FOXN1 expression in primary human keratinocytes cooperated with oncogenic RAS in the induction of SCC-like tumors, whereas increased FOXN1 expression triggered the SCC cells to shift to a benign SK-like tumor phenotype, which included increased FGFR3 expression. Thus,we have uncovered a positive regulatory loop between FGFR3 and FOXN1 that underlies a benign versus malignant skin tumor phenotype.

La revascularisation transmyocardique au laser--un risque potentiel en condition aiguë [Laser transmyocardial revascularization--a potential risk in an acute situation?]

Morphological and functional effects of transmyocardial laser revascularization (TMLR) are analyzed in an acute setting on a porcine model. Ten channels were drilled in the left lateral wall of the heart of 15 pigs (mean weight, 73 +/- 4 kg) with a Holmium-YAG laser (wavelength: 2.1 mu, probe diameter: 1.75 mm). Echocardiographic control was performed before the TMLR procedure as well as 5 min and 30 min thereafter. Echocardiographic parameters were recorded in short-axis at the level of the laser channels, and included left ventricular ejection fraction, fractional shortening and segmental wall motility of the channels' area (scale 0-3: 0 = normal, 1 = hypokinesia, 2 = akinesia, 3 = dyskinesia). After sacrifice the lased region was sliced perpendicularly to the channels for histological and morphometrical analysis. Five minutes after the drilling of the channels, all the echocardiographic index worsened significantly in comparison with baseline values (p < 0.01). All recovered after 30 min and showed no difference with baseline values. Cross-section of the channel lesions measured 8.8 +/- 2.4 mm2 which is more than three times that of the probe (p < 0.01). In acute conditions, the lesions due to the TMLR probe are significantly larger than the probe itself and cause a transient drop of the segmental wall motility on a healthy myocardium. These results suggest that TMLR should be used cautiously in the clinical setting for patients with an impaired ventricular function.