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Hao L, Wang L, Ju M, Feng W, Guo Z, Sun X, Xiao R. 27-Hydroxycholesterol impairs learning and memory ability via decreasing brain glucose uptake mediated by the gut microbiota. Biomed Pharmacother 2023; 168:115649. [PMID: 37806088 DOI: 10.1016/j.biopha.2023.115649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/25/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023] Open
Abstract
Brain glucose hypometabolism is a significant manifestation of Alzheimer's disease (AD). 27-hydroxycholesterol (27-OHC) and the gut microbiota have been recognized as factors possibly influencing the pathogenesis of AD. This study aimed to investigate the link between 27-OHC, the gut microbiota, and brain glucose uptake in AD. Here, 6-month-old male C57BL/6 J mice were treated with sterile water or antibiotic cocktails, with or without 27-OHC and/or 27-OHC synthetic enzyme CYP27A1 inhibitor anastrozole (ANS). The gut microbiota, brain glucose uptake levels, and memory ability were measured. We observed that 27-OHC altered microbiota composition, damaged brain tissue structures, decreased the 2-deoxy-2-[18 F] fluorodeoxyglucose (18F-FDG) uptake value, downregulated the gene expression of glucose transporter type 4 (GLUT4), reduced the colocalization of GLUT1/glial fibrillary acidic protein (GFAP) in the hippocampus, and impaired spatial memory. ANS reversed the effects of 27-OHC. The antibiotic-treated mice did not exhibit similar results after 27-OHC treatment. This study reveals a potential molecular mechanism wherein 27-OHC-induced memory impairment might be linked to reduced brain glucose uptake, mediated by the gut microbiota.
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Affiliation(s)
- Ling Hao
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China
| | - Lijing Wang
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China
| | - Mengwei Ju
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China
| | - Wenjing Feng
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China
| | - Zhiting Guo
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China
| | - Xuejing Sun
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China
| | - Rong Xiao
- School of Public Health, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, No.10 Xitoutiao, You An Men Wai, Beijing 100069, China.
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Kakiyama G, Rodriguez-Agudo D, Pandak WM. Mitochondrial Cholesterol Metabolites in a Bile Acid Synthetic Pathway Drive Nonalcoholic Fatty Liver Disease: A Revised "Two-Hit" Hypothesis. Cells 2023; 12:1434. [PMID: 37408268 DOI: 10.3390/cells12101434] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 07/07/2023] Open
Abstract
The rising prevalence of nonalcoholic fatty liver disease (NAFLD)-related cirrhosis highlights the need for a better understanding of the molecular mechanisms responsible for driving the transition of hepatic steatosis (fatty liver; NAFL) to steatohepatitis (NASH) and fibrosis/cirrhosis. Obesity-related insulin resistance (IR) is a well-known hallmark of early NAFLD progression, yet the mechanism linking aberrant insulin signaling to hepatocyte inflammation has remained unclear. Recently, as a function of more distinctly defining the regulation of mechanistic pathways, hepatocyte toxicity as mediated by hepatic free cholesterol and its metabolites has emerged as fundamental to the subsequent necroinflammation/fibrosis characteristics of NASH. More specifically, aberrant hepatocyte insulin signaling, as found with IR, leads to dysregulation in bile acid biosynthetic pathways with the subsequent intracellular accumulation of mitochondrial CYP27A1-derived cholesterol metabolites, (25R)26-hydroxycholesterol and 3β-Hydroxy-5-cholesten-(25R)26-oic acid, which appear to be responsible for driving hepatocyte toxicity. These findings bring forth a "two-hit" interpretation as to how NAFL progresses to NAFLD: abnormal hepatocyte insulin signaling, as occurs with IR, develops as a "first hit" that sequentially drives the accumulation of toxic CYP27A1-driven cholesterol metabolites as the "second hit". In the following review, we examine the mechanistic pathway by which mitochondria-derived cholesterol metabolites drive the development of NASH. Insights into mechanistic approaches for effective NASH intervention are provided.
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Affiliation(s)
- Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, VA 23249, USA
| | - Daniel Rodriguez-Agudo
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, VA 23249, USA
| | - William M Pandak
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, VA 23249, USA
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27-Hydroxycholesterol-Induced Dysregulation of Cholesterol Metabolism Impairs Learning and Memory Ability in ApoE ε4 Transgenic Mice. Int J Mol Sci 2022; 23:ijms231911639. [PMID: 36232940 PMCID: PMC9569856 DOI: 10.3390/ijms231911639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/18/2022] [Accepted: 09/20/2022] [Indexed: 11/09/2022] Open
Abstract
Dysregulated brain cholesterol metabolism is one of the characteristics of Alzheimer’s disease (AD). 27-Hydroxycholesterol (27-OHC) is a cholesterol metabolite that plays an essential role in regulating cholesterol metabolism and it is suggested that it contributes to AD-related cognitive deficits. However, the link between 27-OHC and cholesterol homeostasis, and how this relationship relates to AD pathogenesis, remain elusive. Here, 12-month-old ApoE ε4 transgenic mice were injected with saline, 27-OHC, 27-OHC synthetase inhibitor (anastrozole, ANS), and 27-OHC+ANS for 21 consecutive days. C57BL/6J mice injected with saline were used as wild-type controls. The indicators of cholesterol metabolism, synaptic structure, amyloid β 1-42 (Aβ1-42), and learning and memory abilities were measured. Compared with the wild-type mice, ApoE ε4 mice had poor memory and dysregulated cholesterol metabolism. Additionally, damaged brain tissue and synaptic structure, cognitive decline, and higher Aβ1-42 levels were observed in the 27-OHC group. Moreover, cholesterol transport proteins such as ATP-binding cassette transporter A1 (ABCA1), apolipoprotein E (ApoE), low-density lipoprotein receptor (LDLR), and low-density lipoprotein receptor-related protein1 (LRP1) were up-regulated in the cortex after the 27-OHC treatment. The levels of cholesterol metabolism-related indicators in the hippocampus were not consistent with those in the cortex. Additionally, higher serum apolipoprotein A1 (ApoA1) levels and lower serum ApoE levels were observed in the 27-OHC group. Notably, ANS partially reversed the effects of 27-OHC. In conclusion, the altered cholesterol metabolism induced by 27-OHC was involved in Aβ1-42 deposition and abnormalities in both the brain tissue and synaptic structure, ultimately leading to memory loss in the ApoE ε4 transgenic mice.
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