Project description:First, we determined the gene expression profile of WT mouse lacrimal gland tissue and organoids in expansion and in differentiation. Then, we sought the differences between WT and Pax6-KO mouse lacrimal gland organoids in expansion and in differentiation.
Project description:DJ1 KO was generated in BJsips iPSC and differentiated into midbrain organoids with the respective iPSC controls. The midbrain organoids were collected at day 40, 100 and 200 after differentiation.
Project description:Mex3a is an RNA binding protein of unknown function. To elucidate the contribution of Mex3a to tumoral heterogeneity, Mex3a KO organoids engineered by CRISPR were sequenced in three different conditions. Live organoids (DAPI negative) were sorted in Control, after 2 days of FOLFIRI and after 5 days of treatment. Two WT organoids (parental and a derived clone) and two KO (KO1 and KO2, two independent clones) were used for this experiment.
Project description:Glutathione (GSH) is a critical endogenous antioxidant that protects against intracellular oxidative stress. As such, pathological alterations in GSH levels are linked to a myriad of diseases including cancer, neurodegeneration and cataract. The rate limiting step in GSH biosynthesis is catalyzed by the glutamate cysteine ligase catalytic subunit (GCLC). The high expression of GCLC in the lens supports the synthesis of millimolar concentrations of GSH in this tissue. Herein, we describe the morphological consequences of deleting (knocking out) Gclc from surface ectoderm-derived ocular tissues (using the Le-Cre transgene; Gclc KO) which includes an overt microphthalmia phenotype and severely disrupted formation of multiple ocular structures (i.e., cornea, iris, lens, retina). Controlling for the Le-Cre transgene revealed that the deletion of Gclc significantly exacerbated the microphthalmia phenotype in Le-Cre hemizygous mice and resulted in dysregulated gene expression that was unique to only the lenses of KO mice. We further characterized the impaired lens development by conducting an RNA-seq experiment on KO and Gclc control (CON) mouse lens at the day of birth. RNA-sequencing revealed significant differences between Gclc knockout (KO) and Gclc control (CON) lenses, including down-regulation of crystallins and lens fiber cell identity genes, and up-regulation of lens epithelial cell identity genes. In addition, genes related to the immune system (e.g., immune system process, inflammatory response, neutrophil chemotaxis) were upregulated, and genes related to eye/lens development were downregulated. TRANSFAC analysis of differentially expressed genes (DEGs) in the lens of Gclc KO mice implicated PAX6 as a key upstream regulator of Gclc KO sensitive genes. This was further supported by a strong positive correlation between the transcriptomes of the lenses of Gclc KO and Pax6 KO mice. Strikingly, the dysregulation of PAX6-regulated genes in Gclc KO mice was observed despite no change in the ocular localization of PAX6 or decrease in the expression of PAX6 in the lens. In vitro experiments demonstrated that suppression of intracellular GSH concentrations resulted in impairment of PAX6 transactivation activity. Taken together, the present results elucidate a novel mechanism wherein intracellular GSH concentrations may modulate PAX6 activity.
Project description:Lineage-specific transcription factors (TFs) play key roles in maintaining the unique properties of cells, but the molecular mechanism that regulates the homeostasis of human corneal epithelial cells (CECs) is still poorly understood. We aimed to modulate KLF4 and PAX6 in human CECs using gene knockout system to clarify the regulatory network of KLF4, and then elucidate how KLF4 regulates the transcriptional genes of human CECs compared with PAX6. We performed a functional analysis of KLF4 via gene knockout using a lentivirus vector that carries both Cas9 and guide RNAs. We designed guide RNAs targeted for KLF4 and PAX6, and created KLF4-, PAX6-, and both KLF4- and PAX6-depleted CECs (KLF4-KO, PAX6-KO, and DKO, respectively). An empty vector was used as a control. The morphology of KLF4-KO CECs displayed an epithelial-mesenchymal transition (EMT)-like change, including upregulation of mesenchymal genes and downregulation of epithelial genes, as well as downregulation of keratin (KRT) 3 and KRT12. Global analyses using NGS revealed that the downregulated genes in KLF4-KO CECs were enriched in more widely keratin-related genes than PAX6-KO CECs. DKO cells showed disruption of the epithelial barrier due to downregulation of epithelial genes and showed more increase of KRT1 and KRT10 than PAX6-KO and KLF4-KO CECs, respectively. In conclusion, KLF4 modulates keratin-related genes as well as EMT-related genes and, together with PAX6, co-regulates the human CEC identity.
