22 research outputs found

    Candidate CSPG4 mutations and induced pluripotent stem cell modeling implicate oligodendrocyte progenitor cell dysfunction in familial schizophrenia

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    Schizophrenia is highly heritable, yet its underlying pathophysiology remains largely unknown. Among the most well-replicated findings in neurobiological studies of schizophrenia are deficits in myelination and white matter integrity; however, direct etiological genetic and cellular evidence has thus far been lacking. Here, we implement a family-based approach for genetic discovery in schizophrenia combined with functional analysis using induced pluripotent stem cells (iPSCs). We observed familial segregation of two rare missense mutations in Chondroitin Sulfate Proteoglycan 4 (CSPG4) (c.391G > A [p.A131T], MAF 7.79 × 10−5 and c.2702T > G [p.V901G], MAF 2.51 × 10−3). The CSPG4A131T mutation was absent from the Swedish Schizophrenia Exome Sequencing Study (2536 cases, 2543 controls), while the CSPG4V901G mutation was nominally enriched in cases (11 cases vs. 3 controls, P = 0.026, OR 3.77, 95% CI 1.05–13.52). CSPG4/NG2 is a hallmark protein of oligodendrocyte progenitor cells (OPCs). iPSC-derived OPCs from CSPG4A131T mutation carriers exhibited abnormal post-translational processing (P = 0.029), subcellular localization of mutant NG2 (P = 0.007), as well as aberrant cellular morphology (P = 3.0 × 10−8), viability (P = 8.9 × 10−7), and myelination potential (P = 0.038). Moreover, transfection of healthy non-carrier sibling OPCs confirmed a pathogenic effect on cell survival of both the CSPG4A131T (P = 0.006) and CSPG4V901G (P = 3.4 × 10−4) mutations. Finally, in vivo diffusion tensor imaging of CSPG4A131T mutation carriers demonstrated a reduction of brain white matter integrity compared to unaffected sibling and matched general population controls (P = 2.2 × 10−5). Together, our findings provide a convergence of genetic and functional evidence to implicate OPC dysfunction as a candidate pathophysiological mechanism of familial schizophrenia

    Schizofrenie

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    Depressie tijdens de perimenopauze

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    FSW - Self-regulation models for health behavior and psychopathology - ou

    Acute Tryptophan Depletion in Depressed SNRI-treated Patients: Acceleration of Antidepressant Response.

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    Background: It has frequently been demonstrated that experimental lowering of serotonin (5-HT) neurotransmission by acute tryptophan depletion (ATD) induces a transient depressed mood in 50-60% of patients treated with a selective serotonin reuptake inhibitor (SSRI) who are in remission from depression. In unmedicated depressed patients, ATD has no immediate effect on symptoms. The effects in currently depressed medicated patients have not been investigated. Methods: Fourteen currently depressed patients (seven patients treated with a selective serotonin-noradrenalin reuptake inhibitor (SSNRI); seven other treatment, non-SSNRI) received ATD in a double-blind, crossover design. Different strengths of the ATD mixture (aimed at 50% and 90% reduction of tryptophan) were used on separate days. Psychiatric symptoms were assessed at both sessions prior to, at +6.5 h, and at +24 h after ATD. Results: The ATD mixtures induced the expected reductions of plasma tryptophan levels. Full but not partial depletion improved mood and other psychiatric symptoms at +24 h in patients who received SSNRI treatment, as indicated by clinical ratings and self-report. Subjective sleep quality also improved. Conclusions: The effects of ATD on psychiatric symptoms in currently depressed patients are remarkably different from the results in recently remitted SSRI-treated patients. ATD in currently depressed patients treated with scrotonergic antidepressants possibly provides important information about the mechanism of action of SSRIs
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