Project description:LIS1 mutations are known to cause lissencephaly, a neurological disorder characterized by the absence of cerebral cortical convolutions. Here we show that brain organoids with LIS1 mutations exhibit increased expression of extracellular matrix (ECM) proteins, which are less organized. The mechanical properties of the mutant organoids demonstrated increased stiffness and steady-state stiffness. These changes are associated with dysregulated mRNA and microRNA. Short-term treatment of the mutant organoids, but not the control ones, with the catalytic subunit of MMP2, which proteolytically cleaves ECM, reduced stiffness. The changes were associated with changes in water diffusion measured by MRI (Magnetic Resonance Imaging) and gene expression. We generated a model incorporating the differences in the mutant's and control brain organoid composition and organization that matches and explains our findings. Our study provides insights into the importance of the composition and organization of the ECM during human brain development and the role of LIS1 in brain structure.
Project description:We generated cortical organoids from four FCD patients. To generate cortical organoids, we used induced pluriplotent stem cells (iPSCs) obtained from skin biopsy from these FCD selected patients and healthy controls. We extrated RNA samples from the cortical organoids to do customized panel of gene expression. Gene expression using NanoString Human Neuropathology Panel from four FCD patients and four controls
Project description:Here we used human cortical brain organoids to probe the longitudinal impact of GSK3 inhibition through multiple developmental stages. Chronic GSK3 inhibition increased the proliferation of neural progenitors and caused massive derangement of cortical tissue architecture. Cortical organoids were differentiated as previously described (Paşca et al., 2015, doi: 10.1038/nmeth.3415.).Chronic GSK3 inhibition was performed by adding CHIR99021 (Merck SML1046) to the medium at day 0 (1 microM) and kept throughout the differentiation process until reaching the respective collection timepoints (day 18, day 50, day 100).
Project description:A method was developed to reproducibly produce neural retina and cortical brain regions from confluent cultures of stem cells. The spontaneously generated cortical organoids were isolated and cultured in suspension conditions for maturation. Proteomic analysis of both the original induced pluripotent stem cells and the cortical organoids demonstrated the increased presence of synaptic components, indicating maturity.
Project description:Mutations in Lissencephaly 1 (LIS1) result in various human brain developmental diseases, such as changes in brain structure, lissencephaly, and epilepsy. RNA-sequencing data from on-chip organoids derived from human embryonic stem cells (hESCs) revealed significant changes in the expression of extracellular matrix (ECM) – related genes in LIS1+/- samples. This project examined the biomechanical properties of LIS1+/- mutated and healthy hESCs-derived cortical organoids. A rheological test using the pipette aspiration technique revealed that LIS1+/- cortical organoids are stiffer than control organoids. The increased stiffness of the LIS1+/- cortices was proportional to an increased expression of the nuclear mechano-sensing protein, Lamin A, highlighting the adverse cellular and nuclear changes underlying the stiffening of LIS1+/- organoids. To delineate the ECM composition associated with the stiffening effect in LIS1+/-, healthy and mutated hippocampal and cortical organoids were examined at the protein, mRNA, and miRNA levels. Whole RNA sequencing showed altered expression of multiple collagen-related pathways, including the 'collagens containing ECM' and the 'Collagen trimer' pathways. Differential mRNA expression has inversely correlated with the expression of their targeting miRNAs in the LIS1+/- organoids. This inverse miRNA-mRNA expression was most pronounced in genes associated with the ECM-receptor signalling pathway. At the protein level, the mutated hippocampal organoids showed unilateral, substantial increased expression of collagens and proteins involved in collagen synthesis, modification, and remodelling. Following a collagenolytic treatment with the catalytic domain of the MMP9 enzyme, the stiffness levels in the LIS1+/- organoids were reduced to control values. Overall, this work provides new information about the role of LIS1 in controlling collagen expression and the abnormal mechanical properties associated with mutation to the LIS1 gene in the development of the human cortex and hippocampus.
Project description:Here we used human cortical brain organoids to probe the longitudinal impact of GSK3 inhibition through multiple developmental stages. Chronic GSK3 inhibition increased the proliferation of neural progenitors and caused massive derangement of cortical tissue architecture. Cortical organoids were differentiated as previously described (Paşca et al., 2015, doi: 10.1038/nmeth.3415.). Chronic GSK3 inhibition was performed by adding CHIR99021 (Merck SML1046) to the medium at day 0 (1 microM) and kept throughout the differentiation process until reaching the respective collection timepoints (day 50, day 100).