Project description:Schizophrenia is a complex and severe neuropsychiatric disorder, with a wide range of debilitating symptoms. Several aspects of its multifactorial complexity are still unknown, and some are accepted to be an early developmental deficiency with a more specifically neurodevelopmental origin. Understanding timepoints of disturbances during neural cell differentiation processes could lead to an insight into the development of the disorder. In this context, human brain organoids and neural cells differentiated from patient-derived induced pluripotent stem cells are of great interest as a model to study the developmental origins of the disease. Here we evaluated the differential expression of proteins of schizophrenia patient-derived neural progenitors, early neurons, and brain organoids. Using bottom-up shotgun proteomics with a label-free approach for quantitative analysis. Multiple dysregulated proteins were found in pathways related to synapses, in line with postmortem tissue studies of schizophrenia patients. However, organoids and immature neurons exhibit impairments in pathways never before found in patient-derived induced pluripotent stem cell studies, such as spliceosomes and amino acid metabolism. In conclusion, here we provide comprehensive, large-scale, protein-level data that may uncover underlying mechanisms of the developmental origins of schizophrenia.
Project description:Schizophrenia is a complex and severe neuropsychiatric disorder, with a wide range of debilitating symptoms. Several aspects of its multifactorial complexity are still unknown, and some are accepted to be an early developmental deficiency with a more specifically neurodevelopmental origin. Understanding timepoints of disturbances during neural cell differentiation processes could lead to an insight into the development of the disorder. In this context, human brain organoids and neural cells differentiated from patient-derived induced pluripotent stem cells are of great interest as a model to study the developmental origins of the disease. Here we evaluated the differential expression of proteins of schizophrenia patient-derived neural progenitors, early neurons, and brain organoids. Using bottom-up shotgun proteomics with a label-free approach for quantitative analysis. Multiple dysregulated proteins were found in pathways related to synapses, in line with postmortem tissue studies of schizophrenia patients. However, organoids and immature neurons exhibit impairments in pathways never before found in patient-derived induced pluripotent stem cell studies, such as spliceosomes and amino acid metabolism. In conclusion, here we provide comprehensive, large-scale, protein-level data that may uncover underlying mechanisms of the developmental origins of schizophrenia.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes