Project description:Urea cycle disorders with hyperammonemia remain difficult to treat and eventually necessitate liver transplantation. An ornithine transcarbamylase defect (Otcspf-ash) mouse model, a model of urea cycle disorder, was used to test whether knockdown of a key glutamine metabolism enzyme glutaminase 2 (Gls2) or glutamine dehydrogenase 1 (Glud1) could rescue the hyperammonemia and associated lethality induced by a high protein diet. Reduced hepatic expression of Gls2, but not Glud1, by AAV8-mediated delivery of a short hairpin RNA in Otcspf-ash mice diminished hyperammonemia, reduced body weight loss, and reduced lethality. These data suggest that Gls2 hepatic knockdown could help alleviate risk for hyperammonemia and other clinical manifestations of patients suffering from defects in the urea cycle.
Project description:<p>Individuals with Urea Cycle Disorders (UCD) cannot remove ammonia, a waste product, from the blood. The purpose of this study is to conduct a longitudinal investigation of the natural history, morbidity, and mortality in people with UCD. This study will look at how people with a UCD grow and develop over time and how often they get sick.</p> <p>The research questions are: <ol> <li>What is the prevalence of specific morbid indicators of disease severity, including hyperammonemia, developmental disabilities, and various long-term kidney and liver effects? What is the fatality rate associated with the various forms of UCD?</li> <li>What are the correlations between various biomarkers and disease severity and progression?</li> <li>What is the safety and efficacy of currently used and new UCD therapies?</li> </ol> </p> <p>This is a longitudinal study of individuals with urea cycle disorders. Those participating in this study will be evaluated every three to twelve months, depending age and time of diagnosis. Participants two years of age and younger that were diagnosed with UCD within the first four weeks of life will be evaluated every three months. Those who are over two years of age or were diagnosed after four weeks of age will be evaluated every six months. Participants older than 18 years of age will be evaluated once every year.</p>
Project description:Purpose: Nuclear Factor I B (NFIB) has been reported to promote tumor growth, metastasis, and liver regeneration, but its mechanism in liver cancer is not fully elucidated. The present study aims to reveal the role of NFIB in hepatocellular carcinogenesis Methods:In our study, we constructed hepatocyte-specific NFIB gene knockout mice with CRISPR/Cas9 technology (Nfib-/-; Alb-cre), and induced liver cancer mouse model by intraperitoneal injection of DEN/CCl4 Results: First, we found that Nfib-/-; Alb-cre mice developed more tumor nodules and had heavier livers than wild-type mice. H&E staining indicated that the liver histological severity of Nfib-/- group was more serious than that of WT group. Then we found that the differentially expressed genes in the tumor tissue between Nfib-/- mice and wild type mice were enriched in urea cycle. Furthermore, ASS1 and CPS1, the core enzymes of the urea cycle, were significantly upregulated in Nfib-/- tumors. Subsequently, we validated that the expression of ASS1 and CPS1 increased after knockdown of NFIB by lentivirus in normal hepatocytes and also promoted cell proliferation in vitro. In addition, ChIP assay confirmed that NFIB can bind with promoter region of both ASS1 and CPS1 gene Conclusions:Our study reveals for the first time that hepatocyte-specific knock-out of Nfib aggravates hepatocellular tumor development by enhancing the urea cycle.
Project description:Excess/residual urea is a pervasion problem in wine and Sake fermentation. We sought to reduce residual urea levels (to reduce ethyl carbamate leves) by engineering the Sake yeast strain K7 to constitutively express either the urea amidolyase (Dur1,2) or urea importer (Dur3). We sought to then compare the gene expression profiles of the metabolically engineered yeast strains to the parental strain during fermentation. Engineered strains would hopefully have gene expression profiles that were minimally different from the parental strain. Yeast strains were used to ferment Chardonnay grape must and total RNA harvested at 24 hrs into fermentation. 10 ug of total RNA was made into cDNA, and then labelled cRNA, with the Affymetrix GeneChip one cycle target amplification and labelling system. Fragmented cRNA was then hybridized to an Affymetrix YGS98 array in biological duplicate.
Project description:Longitudinal Study of Immune Mediated Disorders after Allogeneic HCT Protocol (Immune Mediated Disorders after Allo-HCT) - cGVHD 6501
Project description:Ammonia production via glutamate dehydrogenase is inhibited by SIRT4, a sirtuin that displays both amidase and non-amidase activities. The processes underlying the regulation of ammonia removal by amino acids remain unclear. Here, we report that SIRT4 acts as a decarbamylase that responds to amino acid sufficiency and regulates ammonia removal. Amino acids promote lysine 307 carbamylation (OTCCP-K307) of ornithine transcarbamylase (OTC), which activates OTC and the urea cycle. Proteomic and interactome screening identified OTC as a substrate of SIRT4. SIRT4 decarbamylates OTCCP-K307 and inactivates OTC in a NAD+-dependent manner. SIRT4 expression was transcriptionally upregulated by the amino acid insufficiency-activated GCN2–eIF2a–ATF4 axis. SIRT4 knockout in cultured cells caused higher OTCCP-K307 levels, activated OTC, elevated urea cycle intermediates, and urea production via amino acid catabolism. Sirt4 ablation decreased mouse blood ammonia levels and ameliorated CCl4-induced hepatic encephalopathy phenotypes. We reveal that SIRT4 safeguards cellular ammonia toxicity during amino acid catabolism.
Project description:Lung adenocarcinoma (LUAD) remains the leading cause of cancer deaths worldwide. Apurinic/apyrimidinic endonuclease 1 (APE1), an enzyme integral to DNA repair and redox signaling, is notably upregulated in various cancers, including LUAD. Here we reveal that APE1 amplification, primarily via allele duplication, correlates with poor prognosis in LUAD patients strongly. Using human LUAD cell models and a KRAS-driven genetically engineered mouse model (GEMM), we show that APE1 deletion hampers cell proliferation and tumor growth, highlighting its role in tumorigenesis. Mechanistically, APE1 promoted the transcription of urea cycle genes CPS1 and ARG2 by modulating the presence of G-quadruplex (G4) structures in their promoter regions. Loss of APE1 disrupts the urea cycle and pyrimidine metabolism, inducing metabolic reprogramming and growth arrest, which can be rescued by CPS1 or pyrimidine restoration. These findings uncover APE1’s role in metabolic regulation via G4-mediated transcription, providing a potential therapeutic target LUAD patients with elevated APE1 expression.
Project description:Lung adenocarcinoma (LUAD) remains the leading cause of cancer deaths worldwide. Apurinic/apyrimidinic endonuclease 1 (APE1), an enzyme integral to DNA repair and redox signaling, is notably upregulated in various cancers, including LUAD. Here we reveal that APE1 amplification, primarily via allele duplication, correlates with poor prognosis in LUAD patients strongly. Using human LUAD cell models and a KRAS-driven genetically engineered mouse model (GEMM), we show that APE1 deletion hampers cell proliferation and tumor growth, highlighting its role in tumorigenesis. Mechanistically, APE1 promoted the transcription of urea cycle genes CPS1 and ARG2 by modulating the presence of G-quadruplex (G4) structures in their promoter regions. Loss of APE1 disrupts the urea cycle and pyrimidine metabolism, inducing metabolic reprogramming and growth arrest, which can be rescued by CPS1 or pyrimidine restoration. These findings uncover APE1’s role in metabolic regulation via G4-mediated transcription, providing a potential therapeutic target LUAD patients with elevated APE1 expression.