Project description:Expression array analysis of mice livers with conditional deletion of autophagy related protein 7 (Atg7). Whole RNA from mice livers of 2 month old control (Atg7 FF), Olig1-CRE:Atg7 FF (conditional deletion in hepatocytes) and Alb-CRE:Atg7 FF (conditional deletion in hepatocytes/cholangiocytes) were analyzed. The results provide insight into the gene expression profile and role of autophagy in hepatocytes or hepatocytes/cholangiocytes in hepatic growth regulation and hepatocarcinogenesis.
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice. Eight week old Atg7F/F:Mx1-Cre mice and Atg7F/F:Mx1-Cre:Nrf2-/- together with control mice were injected with pIpC. At 4 weeks after pIpC injection, total RNAs were purified from each mouse liver.
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice.
Project description:Engrams are considered to be substrates for memory storage, and the functional dysregulation of the engrams leads to cognition impairment.However, the cellular basis for these maladaptive changes lead to the forgetting of memories remains unclear. Here we found that the expression of autophagy protein 7 (Atg7) mRNA was dramatically upregulated in aged DG engrams, and led to the forgetting of contextual fear memory and the activation of surrounding microglia.To determine mechanism by which autophagy in DG engrams activates the surrounding microglia, mice were co-injected AAV-RAM-Cre either with AAV-Dio-Atg7-Flag or AAV-Dio- EYFP in dorsal dentate gyrus to overexpress ATG7 in the DG memory engrams. Microglia were separated using magnetic-activated cell sorting and subjected to RNA-Seq in dorsal hippocampus .Bioinformatics analysis shown overexpression of Atg7 in dorsal DG memory engrams caused an increase in the expression of Tlr2 in the surrounding microglia.Depletion of Toll-like receptor 2/4 (TLR2/4) in DG microglia prohibited excessive microglial activation and synapse elimination induced by the overexpression of ATG7 in DG engrams, and thus prevented forgetting. Furthermore, the expression of Rac1, a Rho-GTPases which regulates active forgetting in both fly and mice, was upregulated in aged engrams. Optogentic activation of Rac1 in DG engrams promoted the autophagy of the engrams, the activation of microglia, and the forgetting of fear memory. Invention of the Atg7 expression and microglia activation attenuated forgetting induced by activation of Rac1 in DG engrams. Together, our findings revealed autophagy-dependent synapse elimination of DG engrams by microglia as a novel forgetting mechanism.
Project description:Emergency myelopoiesis (EM) is critical for immune defense against pathogens, which requires rapid replenishing of mature myeloid cells. The EM process involves a rapid cell cycle switch from the quiescent hematopoietic stem cells (HSCs) to highly proliferative myeloid progenitors (MPs). How this cell cycle switch is regulated remains poorly understood. Here, we reveal that ATG7, a critical autophagy factor is essential for the rapid proliferation of MPs during human myelopoiesis. Peripheral blood (PB) mobilized HSPCs with ATG7 knock-down or HSPCs derived from ATG7-/- human embryonic stem cells (hESCs) exhibit severe defect in proliferation at MP stage during myeloid/granulocytes differentiation. ATG7 deficient MPs show substantially elevated P53 protein and up-regulation of P53 signaling pathway genes. Mechanistically, ATG7 dependent autophagy mediates P53 degradation in lysosome that allows normal proliferation of MPs. Together, we reveal an essential role of autophagy for P53 degradation in cell cycle switch during human myelopoiesis
Project description:Transcriptome analysis of NesCre:Atg7 conditional knockout mice. Autophagy plays an important role in regulating protein metabolism and tissue homeostasis. Recent studies have reported that neural stem cell-specific Atg7 knockout mice (NesCre:Atg7f/f cKO mice) exhibit neonatal lethal due to severe neurodegeneration. However, the precise mechanisms of how neuronal fate is regulated by the autophagic pathway have not been elucidated. Here, we performed microarray experiments to analyze the changes in gene expression patterns in NesCre:Atg7 cKO mice. As a result, we could find a lot of candidate genes changed by Atg7 deficiency.
Project description:Autophagy is a lysosomal degradation process involved in the turnover of organelles or other cell constituents, in providing sources for energy production under starving conditions, and in cell metabolism. A key protein in the macroautophagic machinery is the autophagy related protein (Atg) 7. Constitutive deletion of Atg7 is lethal at birth. A conditional deletion of Atg7 in hepatocytes leads to hepatomegaly and in aged animals to liver tumors. With this study, we aimed at analyzing the hepatomegaly development more detailed. The 3- to 4-fold enlargement of the liver takes place between day 25 and 35 after birth (P25-P35) and persists at least until P90. This is accompanied by a change in the expression of enzymes involved in the glycogen/glucose metabolism. While glycogen synthesis is inhibited, glucose is preferentially kept as glucose-6-phosphate inside the cells, inducing a swelling of the cells caused by hyperosmolarity. An increase of lipogenic enzymes suggests that glucose-6-phosphate is delivered to lipogenic pathways, which is supported by the occurrence of a steatosis around P30. The development of hepatomegaly is accompanied by a polyploidisation of hepatocytes, an enhanced expression of genes related to inflammatory processes, and an infiltration of macrophages. Our data provide evidence that the attenuation of macroautophagy in hepatocytes leads to a glucose retention which causes cell swelling. The resulting hepatomegaly, which develops in a time interval of about 10 days, perturbs liver perfusion and induces an inflammatory reaction together with polyploidisation.
Project description:we carried out microarray experiments to undestand how the inhibition of autophagy mediated by Atg7 deletion acts as tumor suppresion mechanism cDNA from duodenum of each genotype were prepared