Project description:Primary Hyperoxaluria Type 1 (PH1) is a rare inherited metabolic disorder characterized by oxalate overproduction in the liver, resulting in renal damage. It is caused by mutations in the AGXT gene. Combined liver and kidney transplantation is currently the only permanent curative treatment. We combined locus-specific gene correction and hepatic direct cell reprogramming to generate autologous healthy induced hepatocytes (iHeps) from PH1 patient-derived fibroblasts. First, site-specific AGXT corrected cells were obtained by homology directed repair (HDR) assisted by CRISPR/Cas9, following two different strategies: accurate point mutation (c.853T>C) correction or knock-in of an enhanced version of AGXT cDNA. Then, iHeps were generated, by overexpression of hepatic transcription factors. Generated AGXT-corrected iHeps showed hepatic gene expression profile and exhibited in vitro reversion of oxalate accumulation compared to non-edited PH1-derived iHeps. This strategy set up a potential alternative cellular source for liver cell replacement therapy and a personalized PH1 in vitro disease model.
Project description:The therapeutic use of adeno-associated viral vector (AAV)-mediated gene disruption using CRISPR-Cas9 is limited by potential off-target modifications and the risk of uncontrolled integration of vector genomes into CRISPR-mediated double-strand breaks. To address these concerns, we explored the use of AAV-delivered paired Staphylococcus aureus nickases (D10ASaCas9) to target the Hao1 gene for the treatment of primary hyperoxaluria type 1 (PH1). Our study demonstrated effective Hao1 gene disruption, a significant decrease in glycolate oxidase expression, and a therapeutic effect in PH1 mice. The assessment of undesired genetic modifications through CIRCLE-seq and CAST-Seq analyses revealed neither off-target activity nor chromosomal translocations. Importantly, the use of paired-D10ASaCas9 resulted in a significant reduction in AAV integration at the target site compared to SaCas9 nuclease. Additionally, our study highlights the limitations of current analytical tools in characterizing modifications introduced by paired D10ASaCas9, necessitating the development of a custom pipeline for more accurate characterization. These results describe a positive advance towards a safe and effective potential long-term treatment for PH1 patients.
Project description:This study aims to investigate a wheat recombination hotspot (H1) in comparison with a “regular” recombination site (Rec7) on the sequence and epigenetic level in conditions with functional and non-functional Ph1 locus.
Project description:LDHA is key enzyme for tumor glycolysis metabolism and knocking down LDHA would change a lot of gene expression We used microarrays to detail the global gene expression in 4T1 cells with LDHA knocked down by shRNA
Project description:The “Warburg effect” describes the use of aerobic glycolysis by cancer cells to fuel their growth. Lactate dehydrogenase-A (LDHA) is key to this process and catalyzes the interconversion of pyruvate and lactate. Here we used a proteomic approach to identify LDHA as a binding partner of the tumor suppressor FLCN. Canonically, LDHA is thought to be a substrate-regulated enzyme, however our data show that FLCN uncompetitively inhibits LDHA activity by restricting movement of its active site loop. This inhibition appears to be critical in normal cells, as we show FLCN binds to and tightly regulates LDHA activity in order to preserve metabolic homeostasis. Pathogenic mutations of FLCN are associated with LDHA hyperactivity and kidney tumor formation, suggesting a mechanism for FLCN tumor suppressive function. We have identified a cell-permeant ten amino acid peptide based on the FLCN sequence that enters these tumors and inhibits LDHA ex vivo. In a broader context, renal cell carcinomas experience the Warburg effect and show FLCN dissociation from LDHA. Cells that experience this metabolic shift depend on the hyperactivity of LDHA, as previous work has shown attenuation or inhibition of LDHA leads to programmed cell death. Treating these cells with the FLCN-derived peptide causes apoptosis, strongly suggesting that the glycolytic shift of cancer cells is the result of FLCN inactivation or disassociation from LDHA. Taken together, FLCN-mediated inhibition of LDHA provides a new paradigm for the regulation of glycolysis.
Project description:To assess the function of LDHA in PTCs, we performed transcriptome analysis through high-throughput RNA-Seq of control and LDHA knockdown cells
Project description:Following infection or vaccination, activated B cells at extrafollicular sites or within germinal centers (GCs) undergo vigorous clonal proliferation. Proliferating lymphocytes have been shown to undertake lactate dehydrogenase A (LDHA)-dependent aerobic glycolysis; however, the specific role of this metabolic pathway in a B cell transitioning from a naïve to a highly proliferative, activated state remains poorly defined. Here, we deleted LDHA in a stage- and cell-specific manner. We find that ablation of LDHA in a naïve B cell did not profoundly affect its ability to undergo a T cell-independent extrafollicular B cell response. On the other hand, LDHA-deleted naïve B cells had a severe defect in the capacities to form GCs and mount GC-dependent antibody responses. In addition, loss of LDHA in T cells severely compromised B cell-dependent immune responses. Strikingly, when LDHA was deleted in activated, as opposed to naïve, B cells, there were only minimal effects on the GC reaction and in the generation of high-affinity antibodies. These findings strongly suggest that naïve and activated B cells have distinct metabolic requirements that are further regulated by niche and cellular interactions.
Project description:Following infection or vaccination, activated B cells at extrafollicular sites or within germinal centers (GCs) undergo vigorous clonal proliferation. Proliferating lymphocytes have been shown to undertake lactate dehydrogenase A (LDHA)-dependent aerobic glycolysis; however, the specific role of this metabolic pathway in a B cell transitioning from a naïve to a highly proliferative, activated state remains poorly defined. Here, we deleted LDHA in a stage- and cell-specific manner. We find that ablation of LDHA in a naïve B cell did not profoundly affect its ability to undergo a T cell-independent extrafollicular B cell response. On the other hand, LDHA-deleted naïve B cells had a severe defect in the capacities to form GCs and mount GC-dependent antibody responses. In addition, loss of LDHA in T cells severely compromised B cell-dependent immune responses. Strikingly, when LDHA was deleted in activated, as opposed to naïve, B cells, there were only minimal effects on the GC reaction and in the generation of high-affinity antibodies. These findings strongly suggest that naïve and activated B cells have distinct metabolic requirements that are further regulated by niche and cellular interactions.
Project description:Following infection or vaccination, activated B cells at extrafollicular sites or within germinal centers (GCs) undergo vigorous clonal proliferation. Proliferating lymphocytes have been shown to undertake lactate dehydrogenase A (LDHA)-dependent aerobic glycolysis; however, the specific role of this metabolic pathway in a B cell transitioning from a naïve to a highly proliferative, activated state remains poorly defined. Here, we deleted LDHA in a stage- and cell-specific manner. We find that ablation of LDHA in a naïve B cell did not profoundly affect its ability to undergo a T cell-independent extrafollicular B cell response. On the other hand, LDHA-deleted naïve B cells had a severe defect in the capacities to form GCs and mount GC-dependent antibody responses. In addition, loss of LDHA in T cells severely compromised B cell-dependent immune responses. Strikingly, when LDHA was deleted in activated, as opposed to naïve, B cells, there were only minimal effects on the GC reaction and in the generation of high-affinity antibodies. These findings strongly suggest that naïve and activated B cells have distinct metabolic requirements that are further regulated by niche and cellular interactions.