Detection of Morphological Abnormalities in Schizophrenia: An Important Step to Identify Associated Genetic Disorders or Etiologic Subtypes.

Current research suggests that alterations in neurodevelopmental processes, involving gene X environment interactions during key stages of brain development (prenatal period and adolescence), are a major risk for schizophrenia. First, epidemiological studies supporting a genetic contribution to schizophrenia are presented in this article, including family, twin, and adoption studies. Then, an extensive literature review on genetic disorders associated with schizophrenia is reviewed. These epidemiological findings and clinical observations led researchers to conduct studies on genetic associations in schizophrenia, and more specifically on genomics (CNV: copy-number variant, and SNP: single nucleotide polymorphism). The main structural (CNV) and sequence (SNP) variants found in individuals with schizophrenia are reported here. Evidence of genetic contributions to schizophrenia and current knowledge on genetic syndromes associated with this psychiatric disorder highlight the importance of a clinical genetic examination to detect minor physical anomalies in individuals with ultra-high risk of schizophrenia. Several dysmorphic features have been described in schizophrenia, especially in early onset schizophrenia, and can be viewed as neurodevelopmental markers of vulnerability. Early detection of individuals with neurodevelopmental abnormalities is a fundamental issue to develop prevention and diagnostic strategies, therapeutic intervention and follow-up, and to ascertain better the underlying mechanisms involved in the pathophysiology of schizophrenia.

Hypogonadism Associated with Cyp19a1 (Aromatase) Posttranscriptional Upregulation in Celf1 Knockout Mice.

CELF1 is a multifunctional RNA-binding protein that controls several aspects of RNA fate. The targeted disruption of the Celf1 gene in mice causes male infertility due to impaired spermiogenesis, the postmeiotic differentiation of male gametes. Here, we investigated the molecular reasons that underlie this testicular phenotype. By measuring sex hormone levels, we detected low concentrations of testosterone in Celf1-null mice. We investigated the effect of Celf1 disruption on the expression levels of steroidogenic enzyme genes, and we observed that Cyp19a1 was upregulated. Cyp19a1 encodes aromatase, which transforms testosterone into estradiol. Administration of testosterone or the aromatase inhibitor letrozole partly rescued the spermiogenesis defects, indicating that a lack of testosterone associated with excessive aromatase contributes to the testicular phenotype. In vivo and in vitro interaction assays demonstrated that CELF1 binds to Cyp19a1 mRNA, and reporter assays supported the conclusion that CELF1 directly represses Cyp19a1 translation. We conclude that CELF1 downregulates Cyp19a1 (Aromatase) posttranscriptionally to achieve high concentrations of testosterone compatible with spermiogenesis completion. We discuss the implications of these findings with respect to reproductive defects in men, including patients suffering from isolated hypogonadotropic hypogonadism and myotonic dystrophy type I.

Inactivation of the Celf1 gene that encodes an RNA-binding protein delays the first wave of spermatogenesis in mice.

BACKGROUND: The first wave of spermatogenesis in mammals is characterized by a sequential and synchronous appearance of germ cells in the prepubertal testis. Post-transcriptional controls of gene expression play important roles in this process but the molecular actors that underlie them are poorly known. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the requirement for the RNA-binding protein CELF1 during the first wave of spermatogenesis in mice. Mice inactivated for Celf1 gene were not viable on pure genetic backgrounds. On a mixed background, we observed by histology and gene profiling by RT-qPCR that the testes of inactivated prepubertal mice were characterized by several features. (i) Spermiogenesis (differentiation of post-meiotic cells) was blocked in a subset of prepubertal inactivated mice. (ii) The appearance of the different stages of germ cell development was delayed by several days. (iii) The expression of markers of Leydig cells functions was similarly delayed. CONCLUSIONS/SIGNIFICANCE: Celf1 disruption is responsible for a blockage of spermiogenesis both in adults and in prepubertal males. Hence, the spermiogenesis defects found in Celf1-inactivated adults appear from the first wave of spermiogenesis. The disruption of Celf1 gene is also responsible for a fully penetrant delayed first wave of spermatogenesis, and a delay of steroidogenesis may be the cause for the delay of germ cells differentiation.

Combination of Temsirolimus and tyrosine kinase inhibitors in renal carcinoma and endothelial cell lines.

PURPOSE: Multitargeted tyrosine kinase inhibitors (TKIs) (such as Sunitinib and Sorafenib) and mTOR inhibitors (such as Temsirolimus) are effective in treating metastatic clear-cell renal cell carcinoma (CCRCC), by acting on different pathways in both tumour and endothelial cells. A study of their combined effect could be of major interest. METHODS: We studied endothelial and CCRCC cell lines treated with Sunitinib, Sorafenib, Temsirolimus and 2 drug combinations: Sunitinib-Temsirolimus and Sorafenib-Temsirolimus. We studied inhibition of proliferation with an MTT assay under normoxia and hypoxia, VEGF expression by quantitative RT-PCR and ELISA, and angiogenesis with a Matrigel assay. RESULTS: TKIs and Temsirolimus inhibited proliferation of endothelial and tumour cell lines and inhibited angiogenesis. Anti-proliferative effects were more significant on cell lines with VHL gene inactivation and under hypoxic conditions. VEGF expression was induced by TKIs, but inhibited by Temsirolimus. The Sunitinib/Temsirolimus combination had synergistic or additive effects on the proliferation of tumour and endothelial cell lines. The Sorafenib-Temsirolimus combination had additive effects on the proliferation of most tumour cell lines, but not endothelial cell lines. Both combinations had additive effects on the inhibition of angiogenesis. CONCLUSION: In our model, Sunitinib, Sorafenib and Temsirolimus had anti-tumour and anti-angiogenic effects. The combinations of Sunitinib or Sorafenib with Temsirolimus had additive or synergistic effects on the inhibition of tumour and endothelial cell proliferation, and on the inhibition of angiogenesis. This work could lead to new trials with lower-dose combinations to prevent side effects and enhance efficacy.