Gene Expression Analysis Implicates a Death Receptor Pathway in Schizophrenia Pathology
PLOS ONE
Authors: Catts, Vibeke Sorensen; Weickert, Cynthia Shannon
Abstract
An increase in apoptotic events may underlie neuropathology in schizophrenia. By data-mining approaches, we identified significant expression changes in death receptor signaling pathways in the dorsolateral prefrontal cortex (DLPFC) of patients with schizophrenia, particularly implicating the Tumor Necrosis Factor Superfamily member 6 (FAS) receptor and the Tumor Necrosis Factor [ ligand] Superfamily member 13 (TNFSF13) in schizophrenia. We sought to confirm and replicate in an independent tissue collection the noted mRNA changes with quantitative real-time RT-PCR. To test for regional and diagnostic specificity, tissue from orbital frontal cortex (OFC) was examined and a bipolar disorder group included. In schizophrenia, we confirmed and replicated significantly increased expression of TNFSF13 mRNA in the DLPFC. Also, a significantly larger proportion of subjects in the schizophrenia group had elevated FAS receptor expression in the DLPFC relative to unaffected controls. These changes were not observed in the bipolar disorder group. In the OFC, there were no significant differences in TNFSF13 or FAS receptor mRNA expression. Decreases in BH3 interacting domain death agonist (BID) mRNA transcript levels were found in the schizophrenia and bipolar disorder groups affecting both the DLPFC and the OFC. We tested if TNFSF13 mRNA expression correlated with neuronal mRNAs in the DLPFC, and found significant negative correlations with interneuron markers, parvalbumin and somatostatin, and a positive correlation with PPP1R9B (spinophilin), but not DLG4 (PSD-95). The expression of TNFSF13 mRNA in DLPFC correlated negatively with tissue pH, but decreasing pH in cultured cells did not cause increased TNFSF13 mRNA nor did exogenous TNFSF13 decrease pH. We concluded that increased TNFSF13 expression may be one of several cell-death cytokine abnormalities that contribute to the observed brain pathology in schizophrenia, and while increased TNFSF13 may be associated with lower brain pH, the change is not necessarily causally related to brain pH.
Excess of de novo variants in genes involved in chromatin remodelling in patients with marfanoid habitus and intellectual disability
JOURNAL OF MEDICAL GENETICS
Authors: Chevarin, Martin; Duffourd, Yannis; A. Barnard, Rebecca; Moutton, Sebastien; Lecoquierre, Francois; Daoud, Fatma; Kuentz, Paul; Cabret, Caroline; Thevenon, Julien; Gautier, Elodie; Callier, Patrick; St-Onge, Judith; Jouan, Thibaud; Lacombe, Didier; Delrue, Marie Ange; Goizet, Cyril; Morice-Picard, Fanny; Van-Gils, Julien; Munnich, Arnold; Lyonnet, Stanislas; Cormier-Daire, Valerie; Baujat, Genevieve; Holder, Muriel; Petit, Florence; Leheup, Bruno; Odent, Sylvie; Jouk, Pierre-Simon; Lopez, Gipsy; Genevieve, David; Collignon, Patrick; Martin-Coignard, Dominique; Jacquette, Aurelia; Perrin, Laurence; Putoux, Audrey; Sarrazin, Elisabeth; Amarof, Khadija; Missotte, Isabelle; Coubes, Christine; Jagadeesh, Sujatha; Lapi, Elisabetta; Demurger, Florence; Goldenberg, Alice; Doco-Fenzy, Martine; Mignot, Cyril; Heron, Delphine; Jean-Marcais, Nolwenn; Masurel, Alice; El Chehadeh, Salima; Marle, Nathalie; Huet, Frederic; Binquet, Christine; Collod-Beroud, Gwenaelle; Arnaud, Pauline; Hanna, Nadine; Boileau, Catherine; Jondeau, Guillaume; Olaso, Robert; Lechner, Doris; Poe, Charlotte; Assoum, Mirna; Carmignac, Virginie; Duplomb, Laurence; Tran Mau-Them, Frederic; Philippe, Christophe; Vitobello, Antonio; Bruel, Ange-Line; Boland, Anne; Deleuze, Jean-Francois; Thauvin-Robinet, Christel; Riviere, Jean-Baptiste; O'Roak, Brian J.; Faivre, Laurence
Abstract
Purpose Marfanoid habitus (MH) combined with intellectual disability (ID) (MHID) is a clinically and genetically heterogeneous presentation. The combination of array CGH and targeted sequencing of genes responsible for Marfan or Lujan-Fryns syndrome explain no more than 20% of subjects. Methods To further decipher the genetic basis of MHID, we performed exome sequencing on a combination of trio-based (33 subjects) or single probands (31 subjects), of which 61 were sporadic. Results We identified eight genes with de novo variants (DNVs) in at least two unrelated individuals (ARID1B, ATP1A1, DLG4, EHMT1, NFIX, NSD1, NUP205andZEB2). Using simulation models, we showed that five genes (DLG4, NFIX, EHMT1, ZEB2andATP1A1) met conservative Bonferroni genomewide significance for an excess of the observed de novo point variants. Overall, at least one pathogenic or likely pathogenic variant was identified in 54.7% of subjects (35/64). These variants fell within 27 genes previously associated with Mendelian disorders, includingNSD1andNFIX, which are known to be mutated in overgrowth syndromes. Conclusion We demonstrated that DNVs were enriched in chromatin remodelling (p=2x10(-4)) and genes regulated by the fragile X mental retardation protein (p=3x10(-8)), highlighting overlapping genetic mechanisms between MHID and related neurodevelopmental disorders.