Project description:Purpose: In recent years, the mutation of ZNF469 is considered to be one of the pathogenesis of brittle cornea syndrome(BCS). We establish a znf469 mutant zebrafish line to explore its phenotype and the possible molecular mechanism. Methods: We generated the znf469 mutant zebrafish by using the CRISPR/Cas9 system. TEM is applied to examine the phenotype of the cornea in different development stage. RNA sequencing and quantitative RT-PCR are used to reveal the molecular mechanism. Results: Macroscopically, the homozygous znf469-4del zebrafish larva exhibited a curved body from 72 hpf similar to kyphoscoliosis and a noninflated swimbladder at 7 dpf. TEM reveals the extreme reduction of corneal stroma in homozygous znf469-4del zebrafish in both central and peripheral cornea since the early development stage. RNA-seq analysis demonstrates that the znf469 mutation leads to the decreased synthesis of various ECM component like collagens and proteoglycans but increased synthesis of 26S proteasome families. Conclusion: Our work indicates that znf469 is a critical gene that encoding a transcription factor, regulating the synthesis and degradation of a large number of ECM components which is also the pathologic basis of the ocular and extraocular phenotypes in the znf469 mutant zebrafish model.
Project description:The disruption of cholesterol homeostasis leads to an increase in cholesterol levels which results in the development of cardiovascular disease. Mitogen Inducible Gene 6 (Mig-6) is an immediate early response gene that can be induced by various mitogens, stresses, and hormones. To identify the metabolic role of Mig-6 in the liver, we conditionally ablated Mig-6 in the liver using the Albumin-Cre mouse model (Albcre/+Mig-6f/f; Mig-6d/d). Mig-6d/d mice exhibit hepatomegaly and fatty liver. Serum levels of total, LDL, and HDL cholesterol and hepatic lipid were significantly increased in the Mig-6d/d mice. The daily excretion of fecal bile acids was significantly decreased in the Mig-6d/d mice. DNA microarray analysis of mRNA isolated from the livers of these mice showed alterations in genes that regulate lipid metabolism, bile acid, and cholesterol synthesis, while the expression of genes that regulate biliary excretion of bile acid and triglyceride synthesis showed no difference in the Mig-6d/d mice compared to Mig-6f/f controls. These results indicate that Mig-6 plays an important role in cholesterol homeostasis and bile acid synthesis. Mice with liver specific conditional ablation of Mig-6 develop hepatomegaly and increased intrahepatic lipid and provide a novel model system to investigate the genetic and molecular events involved in the regulation of cholesterol homeostasis and bile acid synthesis. Defining the molecular mechanisms by which Mig-6 regulates cholesterol homeostasis will provide new insights into the development of more effective ways for the treatment and prevention of cardiovascular disease. Eight week old Mig-6f/f vs Mig-6d/d male mice after undergoing a 24 hour fast
Project description:Dietary restriction (DR) is a robust environmental intervention that slows aging in various species. Changes in fat content have been associated with DR, but whether they play a causal role in mediating various responses to DR remains unknown. We demonstrate that upon DR, Drosophila melanogaster shift their metabolism towards increasing both fatty acid synthesis and breakdown. Inhibition of acetyl CoA carboxylase (ACC), a critical enzyme in fatty acid synthesis, or fatty acid oxidation genes specifically in the muscle tissue inhibited the lifespan extension observed upon DR, suggesting a critical role for intra-myocellular fatty acid metabolism. DR enhances spontaneous activity of flies which was found to be dependent on the enhanced fatty acid metabolism. Furthermore, this increase in activity upon DR was found to partially mediate the lifespan extension upon DR. Over-expression of adipokinetic hormone (dAKH) in whole flies, which increases fat metabolism, led to an increase in spontaneous activity and lifespan in a nutrient dependent manner. Together these results suggest that in Drosophila melanogaster enhanced fat metabolism in the muscle is a key metabolic adaptation in response to DR. 24 experimental samples were analyzed using Nimblegen oligo microarrays. Wild type samples (AL without RU486) were used as the Cy3 reference/control for all experimetal comparisons.
Project description:The disruption of cholesterol homeostasis leads to an increase in cholesterol levels which results in the development of cardiovascular disease. Mitogen Inducible Gene 6 (Mig-6) is an immediate early response gene that can be induced by various mitogens, stresses, and hormones. To identify the metabolic role of Mig-6 in the liver, we conditionally ablated Mig-6 in the liver using the Albumin-Cre mouse model (Albcre/+Mig-6f/f; Mig-6d/d). Mig-6d/d mice exhibit hepatomegaly and fatty liver. Serum levels of total, LDL, and HDL cholesterol and hepatic lipid were significantly increased in the Mig-6d/d mice. The daily excretion of fecal bile acids was significantly decreased in the Mig-6d/d mice. DNA microarray analysis of mRNA isolated from the livers of these mice showed alterations in genes that regulate lipid metabolism, bile acid, and cholesterol synthesis, while the expression of genes that regulate biliary excretion of bile acid and triglyceride synthesis showed no difference in the Mig-6d/d mice compared to Mig-6f/f controls. These results indicate that Mig-6 plays an important role in cholesterol homeostasis and bile acid synthesis. Mice with liver specific conditional ablation of Mig-6 develop hepatomegaly and increased intrahepatic lipid and provide a novel model system to investigate the genetic and molecular events involved in the regulation of cholesterol homeostasis and bile acid synthesis. Defining the molecular mechanisms by which Mig-6 regulates cholesterol homeostasis will provide new insights into the development of more effective ways for the treatment and prevention of cardiovascular disease.
Project description:Current therapeutic strategies, including surgery and chemotherapy, for gastric cancer improve survival; however, the survival rate for those with metastatic gastric cancer is very low. The molecular mechanisms underlying dissemination of gastric cancer cells to distant organs are unknown. Here, we show that the ELK3 gene is necessary for migration and invasion of gastric cancer cells. The ELK3 gene modulates expression of extracellular matrix (ECM) remodeling-related genes such as LOXL2, SERPINF1, COL16A1, NID1, and SNAI1 to facilitate cancer cell dissemination. Our in silico analysis indicated that ELK3 expression was positively correlated with these ECM remodeling-related genes in gastric cancer cells and human gastric cancer patients. High expression of ELK3 and other ECM remodeling-related genes was also closely associated with a worse prognosis of gastric cancer patients. These findings suggested that ELK3 acts as an important regulator of gastric cancer dissemination by regulating ECM remodeling.