HepaCAM knockdown impairs learning and memory in mice by regulating cholesterol synthesis pathway
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PROVIDER: PRJNA1177475 | ENA |
REPOSITORIES: ENA
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Project description:Astrocytes engage in metabolic interactions with nearby neurons by supplying various substances. However, how they regulate learning and memory through changes in the metabolic state of neurons is still unclear. In this study, we show that knocking down astrocytic hepaCAM silences genes related to cholesterol biosynthesis in astrocytes, leading to a decrease in cholesterol levels. Additionally, astrocytes play a crucial role in synapse development and function by releasing signals that guide neurons. Consequently, without enough cholesterol, the level of neuronal synaptic proteins and the density of dendritic spines decrease. Then we demonstrate that knocking down hepaCAM leads to impaired learning and memory in mice. Collectively, hepaCAM, a cell adhesion molecules specifically expressed in astrocytes, regulates learning and memory by regulating the cholesterol synthesis pathway.
2025-07-01 | GSE280264 | GEO
Project description:Thyrotropin Receptor Signaling Deficiency Impairs Spatial Learning and Memory
| PRJNA608876 | ENA
Project description:An improved mechanistic understanding of the thyroid hormone (TH) action on bile acid (BA) synthetic pathway, the major route for cholesterol elimination, will facilitate the identification of novel therapeutic targets for hypercholesterolemia. Here, we show that hepatic miR-378 is positively regulated by TH. Transient overexpression of miR-378 in the liver of mice reduces the serum cholesterol levels, which is accompanied with an upregulation of key enzymes involved in the intrahepatic conversion of cholesterol to BAs. Importantly, transgenic mice with liver-specific and moderate overexpression of miR-378 also display a decrease in serum cholesterol levels accompanied with an enhanced BA synthesis and are resistant to diet-induced hypercholesterolemia. In contrast, mice lacking miR-378 exhibit an elevation of serum cholesterol levels accompanied with an impaired BA synthesis. Mechanistic studies reveal that hepatic miR-378 regulates BA synthesis and cholesterol homeostasis through its direct target gene MAFG, which is a transcriptional repressor of BA synthetic genes. We also show that miR-378 serves as an essential component in either incoherent or coherent feed-forward loop to confer robust and precise controls on BA synthesis in response to TH signalling. Together, we identify a previously undescribed miR-378-mediated mechanism underlying the cholesterol-lowering effect of TH. Our findings not only add a new dimension to our understanding the regulation of BA synthesis by TH, but also provide new therapeutic regimens to manage serum cholesterol levels
2019-10-29 | GSE139491 | GEO
Project description:Subclinical hyperthyroidism, a disease characterized by decreased thyroid-stimulating hormone (TSH) and normal concentration of thyroid hormone, is associated with an elevated risk for cognitive impairment. TSH is the major endogenous ligand of TSH receptor (TSHR) and its role dependent on the process of signal transduction of TSHR. It has not, however, been established whether TSHR signaling are involved in the regulation of cognition. In the current study, Tshr deletion leads to significantly compromised performance in hippocampus-dependent tasks, along with reduced dendritic spine density and excitatory synaptic density as well as altered synaptic structure in CA1 subfield of the hippocampus. Furthermore, the synapse-related gene expression was altered in the hippocampus of Tshr-/- mice. These findings suggest the ablation of TSHR signaling impairs spatial learning and memory, which reveals a fresh role of TSHR signaling in brain.
2022-02-28 | GSE145958 | GEO
Project description:HepG2 cell line CRISPR-Cas9 generated Knock-out in 4 cholesterol synthesis gene: CYP51, DHCR24, SC5D and HSD17B7 Excess of cholesterol associates with a variety of diseases so its synthesis must be under tight homeostatic control. The early part of cholesterol synthesis with rate-limiting HMGCR and SQLE steps is proceeded by the sterol part where numerous non-polar sterols with poorly defined biological functions are produced. To illuminate their role we developed knockouts (KO) for the consecutive enzymes that metabolize sterols towards cholesterol CYP51A1, DHCR24, SC5D resulted in the accumulation of specific set of sterols in each KO cell. Despite that, we targeted three steps of the cholesterol synthesis housekeeping pathway, the overlap of de-regulated genes was only 9%, suggesting that each set of sterols modulated the hepatic cell transcriptome uniquely. Lanosterol and 24,25-dihydrolanosterol, but not other non-polar sterols, provoked higher cell proliferation, cell cycle changes, and upregulation of metabolic pathways and transcription factors (TFs) associated with cancer progression and immune response like NFKB, SMAD, ESR1 and highly elevated LEF1 a protein from WNT signalling. In contrast, lathosterol and desmosterol caused slower proliferation and apoptosis promotion, through TFs like HNF1A and E2F. We were able to show how sterols from early part of synthesis can promote cell proliferation as sterols from end of synthesis suppress proliferation. These findings challenge the current dogma that sterols produced during cholesterol synthesis have similar biological functions
2024-08-08 | GSE221582 | GEO
Project description:Cholesterol is essential for membrane biogenesis, cell proliferation and differentiation. The role of cholesterol in cancer development and the regulation of cholesterol synthesis are still under active investigation. Here we show that under normal-sterol conditions，p53 directly represses the expression of SQLE, a rate-limiting and the first oxygenation enzyme in cholesterol synthesis，in a SREBP2-independent manner. Through transcriptional downregulation of SQLE, p53 represses cholesterol production in vivo and in vitro, leading to tumor growth suppression. Inhibition of SQLE using small interfering RNA (siRNA) or terbinafine (a SQLE inhibitor) reverses the increased cell proliferation caused by p53 deficiency. Conversely, SQLE overexpression or cholesterol addition promotes cell proliferation, particularly in p53 wild-type cells. More importantly, pharmacological inhibition or shRNA-mediated silencing of SQLE restricts nonalcoholic fatty liver disease (NAFLD) -induced liver tumorigenesis in p53 knockout mice. Therefore, our findings reveal a role for p53 in regulating SQLE and cholesterol biosynthesis, and further demonstrate that downregulation of SQLE is critical for p53-mediated tumor suppression.
2021-07-18 | GSE176112 | GEO
Project description:Cholesterol performs multiple essential roles in cells. Enhanced cholesterol synthesis and storage in lipid droplets have been linked to cancer aggressiveness, particularly in lipid-rich and hormone-sensitive cancers such as prostate cancer . Cholesterol anabolism and catabolism are finely regulated in tumor cells in response to various nutritional states. Mitochondria have increasingly been recognized as a signal transduction organelle, particularly concerning metabolites derived from mitochondrial activity. The link between mitochondrial regulation and cholesterol synthesis remains inadequately understood. Here, we show that propionyl-CoA promotes cholesterol synthesis, storage, and further progression in prostate cancer cells. We found that propionyl-CoA, mainly produced by isoleucine and valine metabolism in the mitochondria, can translocate through the mitochondrial membrane and serves as a substrate for modifying cleaved SREBP2, stabilizing it and thereby promoting cholesterol synthesis and storage in lipid droplets. This process facilitates cancer metastasis and castration resistant partially through enhancing androgen synthesis in prostate cancer cells. Our results demonstrate that branched-chain amino acid (BCAA) catabolism and propionate metabolism in mitochondria are involved in the regulation of cholesterol synthesis and utilization through metabolite-mediated protein modification. We anticipate that our findings provide a critical link between amino acid metabolism and cholesterol anabolism, highlighting a mechanism that plays a crucial role in the development of castration resistance in prostate cancer patients. This study offers a theoretical rationale for targeting the production of propionyl-CoA, particularly through the metabolism of isoleucine and valine, as an effective strategy to inhibit cholesterol synthesis and its related diseases.
2025-07-11 | GSE272086 | GEO
Project description:Recent developments in genome sequencing have expanded the knowledge of genetic factors associated with late-onset Alzheimer’s disease (AD). Among them, genetic variant e4 of the APOE gene (ApoE4) confers the greatest disease risk. Dysregulated glucose metabolism is an early pathological feature of AD. Using isogenic ApoE3 and ApoE4 astrocytes derived from human-induced pluripotent stem cells, we find that ApoE4 increases glycolytic activity but impairs mitochondrial respiration in astrocytes. Ultrastructural and autophagic flux analyses show that ApoE4-induced cholesterol accumulation impairs lysosome-dependent removal of damaged mitochondria. Acute treatment with cholesterol-depleting agents restores autophagic activity, mitochondrial dynamics, and associated proteomes, and extended treatment rescues mitochondrial respiration in ApoE4 astrocytes. Taken together, our study provides a direct link between ApoE4-induced lysosomal cholesterol accumulation and abnormal oxidative phosphorylation.
2023-09-12 | PXD045298 | Pride
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
2011-08-30 | E-GEOD-31752 | biostudies-arrayexpress
Project description:Thyroid hormone-responsive miR-378 modulates cholesterol homeostasis by regulating hepatic bile acid synthesis
| PRJNA579974 | ENA