26 research outputs found

    Loss of Cx43 in Murine Sertoli Cells Leads to Altered Prepubertal Sertoli Cell Maturation and Impairment of the Mitosis-Meiosis Switch.

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    Male factor infertility is a problem in today's society but many underlying causes are still unknown. The generation of a conditional Sertoli cell (SC)-specific connexin 43 (Cx43) knockout mouse line (SCCx43KO) has provided a translational model. Expression of the gap junction protein Cx43 between adjacent SCs as well as between SCs and germ cells (GCs) is known to be essential for the initiation and maintenance of spermatogenesis in different species and men. Adult SCCx43KO males show altered spermatogenesis and are infertile. Thus, the present study aims to identify molecular mechanisms leading to testicular alterations in prepubertal SCCx43KO mice. Transcriptome analysis of 8-, 10- and 12-day-old mice was performed by next-generation sequencing (NGS). Additionally, candidate genes were examined by qRT-PCR and immunohistochemistry. NGS revealed many significantly differentially expressed genes in the SCCx43KO mice. For example, GCspecific genes were mostly downregulated and found to be involved in meiosis and spermatogonial differentiation (e.g., Dmrtb1, Sohlh1). In contrast, SC-specific genes implicated in SC maturation and proliferation were mostly upregulated (e.g., Amh, Fshr). In conclusion, Cx43 in SCs appears to be required for normal progression of the first wave of spermatogenesis, especially for the mitosis-meiosis switch, and also for the regulation of prepubertal SC maturation

    Histamine 2 Receptor Agonism and Histamine 4 Receptor Antagonism Ameliorate Inflammation in a Model of Psoriasis

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    Psoriasis is a chronic inflammatory skin disorder characterized by hyperproliferative keratinocytes and immune cell infiltration into the skin, often accompanied by itch. Histamine, acting via histamine 1–4 receptors, is known to modulate immune responses in the skin and to induce itch. The aim of this study was to test the role of histamine 2 receptors and histamine 4 receptors in the imiquimod-induced psoriasis-like skin inflammation model. BALB/c mice were treated intraperitoneally with amthamine (histamine 2 receptor agonist), JNJ-39758979 (histamine 4 receptor antagonist), a combination of both, or vehicle twice daily in a preventive manner. Imiquimod was applied once daily onto the back skin for 10 consecutive days. Stimulation of histamine 2 receptors and blockade of histamine 4 receptors ameliorated imiquimod-induced skin inflammation. The combination of amthamine and JNJ-39758979 reduced skin inflammation even more pronounced, diminished epidermal hyperproliferation, and inhibited spontaneous scratching behaviour. A combination of histamine 2 receptor agonist and histamine 4 receptor antagonists could represent a new strategy for the treatment of psoriasis

    Analysis of connexin 43, connexin 45 and N-cadherin in the human sertoli cell line FS1 and the human seminoma-like cell line TCam-2 in comparison with human testicular biopsies

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    Background: Germ cell tumors are relatively common in young men. They derive from a non-invasive precursor, called germ cell neoplasia in situ, but the exact pathogenesis is still unknown. Thus, further understanding provides the basis for diagnostics, prognostics and therapy and is therefore paramount. A recently developed cell culture model consisting of human FS1 Sertoli cells and human TCam-2 seminoma-like cells offers new opportunities for research on seminoma. Since junctional proteins within the seminiferous epithelium are involved in cell organization, differentiation and proliferation, they represent interesting candidates for investigations on intercellular adhesion and communication in context with neoplastic progression. Methods: FS1 and TCam-2 cells were characterized regarding gap-junction-related connexin 43 (Cx43) and connexin 45 (Cx45), and adherens-junction-related N-cadherin using microarray, PCR, Western blot, immunocytochemistry and immunofluorescence. Results were compared to human testicular biopsies at different stages of seminoma development via immunohistochemistry to confirm the cell lines’ representativeness. Furthermore, dye-transfer measurements were performed to investigate functional cell coupling. Results: Cx43, Cx45 and N-cadherin mRNA and protein were generally detectable in both cell lines via qualitative RT-PCR and Western blot. Immunocytochemistry and immunofluorescence revealed a mainly membrane-associated expression of N-cadherin in both cell lines, but gene expression values were higher in FS1 cells. Cx43 expression was also membrane-associated in FS1 cells but barely detectable in TCam-2 cells. Accordingly, a high gene expression value of Cx43 was measured for FS1 and a low value for TCam-2 cells. Cx45 was primary located in the cytoplasm of FS1 and TCam-2 cells and revealed similar low to medium gene expression values in both cell lines. Overall, results were comparable with corresponding biopsies. Additionally, both FS1 and TCam-2 cells showed dye diffusion into neighboring cells. Conclusion: The junctional proteins Cx43, Cx45 and N-cadherin are expressed in FS1 and TCam-2 cells at mRNA and/or protein level in different amounts and localizations, and cells of both lines are functionally coupled among each other. Concerning the expression of these junctional proteins, FS1 and TCam-2 cells are largely representative for Sertoli and seminoma cells, respectively. Thus, these results provide the basis for further coculture experiments evaluating the role of junctional proteins in context with seminoma progression

    Carfilzomib and dexamethasone maintenance following salvage ASCT in multiple myeloma: A randomised phase 2 trial by the Nordic Myeloma Study Group

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    Objective: We investigated the efficacy and safety of carfilzomib-containing induction before salvage high-dose melphalan with autologous stem-cell transplantation (salvage ASCT) and maintenance with carfilzomib and dexamethasone after salvage ASCT in multiple myeloma.Methods: This randomised, open-label, phase 2 trial included patients with first relapse of multiple myeloma after upfront ASCT who were re-induced with four cycles of carfilzomib, cyclophosphamide and dexamethasone. Two months after salvage, ASCT patients were randomised to either observation or maintenance therapy with iv carfilzomib 27 -> 56 mg/sqm and p.o. dexamethasone 20 mg every second week. The study enrolled 200 patients of which 168 were randomised to either maintenance with carfilzomib and dexamethasone (n = 82) or observation (n = 86).Results: Median time to progression (TTP) after randomisation was 25.1 months (22.5-NR) in the carfilzomib-dexamethasone maintenance group and 16.7 months (14.4-21.8) in the control group (HR 0.46, 95% CI 0.30-0.71; P = .0004). The most common adverse events during maintenance were thrombocytopenia, anaemia, hypertension, dyspnoea and bacterial infections.Conclusion: In summary, maintenance therapy with carfilzomib and dexamethasone after salvage ASCT prolonged TTP with 8 months. The maintenance treatment was in general well-tolerated with manageable toxicity.</p

    Better Few than Hungry: Flexible Feeding Ecology of Collared Lemurs Eulemur collaris in Littoral Forest Fragments

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    Frugivorous primates are known to encounter many problems to cope with habitat degradation, due to the fluctuating spatial and temporal distribution of their food resources. Since lemur communities evolved strategies to deal with periods of food scarcity, these primates are expected to be naturally adapted to fluctuating ecological conditions and to tolerate a certain degree of habitat changes. However, behavioral and ecological strategies adopted by frugivorous lemurs to survive in secondary habitats have been little investigated. Here, we compared the behavioral ecology of collared lemurs (Eulemur collaris) in a degraded fragment of littoral forest of south-east Madagascar, Mandena, with that of their conspecifics in a more intact habitat, Sainte Luce.Lemur groups in Mandena and in Sainte Luce were censused in 2004/2007 and in 2000, respectively. Data were collected via instantaneous sampling on five lemur groups totaling 1,698 observation hours. The Shannon index was used to determine dietary diversity and nutritional analyses were conducted to assess food quality. All feeding trees were identified and measured, and ranging areas determined via the minimum convex polygon. In the degraded area lemurs were able to modify several aspects of their feeding strategies by decreasing group size and by increasing feeding time, ranging areas, and number of feeding trees. The above strategies were apparently able to counteract a clear reduction in both food quality and size of feeding trees.Our findings indicate that collared lemurs in littoral forest fragments modified their behavior to cope with the pressures of fluctuating resource availability. The observed flexibility is likely to be an adaptation to Malagasy rainforests, which are known to undergo periods of fruit scarcity and low productivity. These results should be carefully considered when relocating lemurs or when selecting suitable areas for their conservation

    Establishment and functional characterization of a murine primary Sertoli cell line deficient of connexin43

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    The Sertoli cell (SC) specific connexin43 (Cx43) knockout (SCCx43KO) mouse line is ideal to gain insight into the mechanistic gap junction formation in SC and the seminiferous epithelium. A method for developing primary SC cultures from these mice was established, validated and successfully characterized via polymerase chain reaction, immunohistochemistry, immunofluorescence (IF), and Western blots (WB). It was evident that both knockout (KO) and wild-type (WT) primary cell cultures were similar in morphology. These highly pure SC cultures were subjected to cell proliferation assays indicating no notable proliferation in cultures of both genotypes. Measurements of cell monolayer integrity indicated significant increases in transepithelial electrical resistance and consequently in tight junction expression of the KO cultures. Using semi-quantitative WB and IF, tight junction protein claudin-11 was analyzed. These results support a role for Cx43 in regulating blood-testis barrier (BTB) function, composition, and dynamics in vitro. Thus, the SC deficient Cx43 cell cultures may provide a valuable in vitro tool for a better understanding of the mechanistic role of Cx43 in spermatogenesis and BTB assembly

    Impaired spermatogenesis, tubular wall disruption, altered blood-testis barrier composition and intratubular lymphocytes in an infertile Beagle dog – a putative case of autoimmune orchitis

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    Impairment of blood-testis barrier integrity can be observed during inflammation, infection, trauma and experimental autoimmune orchitis, which is inducible in rodents. In the present study, an initially fertile two-year-old Beagle dog was presented with a decline in total sperm number resulting in azoospermia within five months, verified by twice-monthly semen analyses. The dog was clinically healthy with bilateral small testes and showed normal thyroid function. Bacterial cultures of semen were negative and serum biochemical analyses showed no abnormal findings. To determine causes of azoospermia, the dog was castrated. Histological examinations of hematoxylin-eosin stained testicular sections revealed impaired spermatogenesis, seminiferous tubules with spermatogenic arrest or Sertoli-cell-only syndrome as well as focal interstitial and even intratubular lymphocytic infiltrations. Germ cell sloughing, apoptosis and giant cells were also observed in some tubules. Subsequent immunostainings of smooth-muscle-actin, claudin3, claudin11 and connexin43 demonstrated, for the first time, a mechanical and functional disruption of the tubular wall and alterations of blood-testis barrier proteins in these tubules. Presence of claudin3 and claudin11 in canine testis was confirmed using RT-PCR and sequencing and/ or Western-blot analyses. All findings suggested a possible spontaneous autoimmune orchitis to be the underlying cause for the observed azoospermia
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