1
|
Parlakgül G, Pang S, Artico LL, Min N, Cagampan E, Villa R, Goncalves RLS, Lee GY, Xu CS, Hotamışlıgil GS, Arruda AP. Spatial mapping of hepatic ER and mitochondria architecture reveals zonated remodeling in fasting and obesity. Nat Commun 2024; 15:3982. [PMID: 38729945 PMCID: PMC11087507 DOI: 10.1038/s41467-024-48272-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 04/26/2024] [Indexed: 05/12/2024] Open
Abstract
The hepatocytes within the liver present an immense capacity to adapt to changes in nutrient availability. Here, by using high resolution volume electron microscopy, we map how hepatic subcellular spatial organization is regulated during nutritional fluctuations and as a function of liver zonation. We identify that fasting leads to remodeling of endoplasmic reticulum (ER) architecture in hepatocytes, characterized by the induction of single rough ER sheet around the mitochondria, which becomes larger and flatter. These alterations are enriched in periportal and mid-lobular hepatocytes but not in pericentral hepatocytes. Gain- and loss-of-function in vivo models demonstrate that the Ribosome receptor binding protein1 (RRBP1) is required to enable fasting-induced ER sheet-mitochondria interactions and to regulate hepatic fatty acid oxidation. Endogenous RRBP1 is enriched around periportal and mid-lobular regions of the liver. In obesity, ER-mitochondria interactions are distinct and fasting fails to induce rough ER sheet-mitochondrion interactions. These findings illustrate the importance of a regulated molecular architecture for hepatocyte metabolic flexibility.
Collapse
Affiliation(s)
- Güneş Parlakgül
- Department of Molecular Metabolism and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA
| | - Song Pang
- HHMI Janelia Research Campus, Ashburn, VA, USA
- Yale School of Medicine, New Haven, CT, USA
| | - Leonardo L Artico
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA
| | - Nina Min
- Department of Molecular Metabolism and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Erika Cagampan
- Department of Molecular Metabolism and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Reyna Villa
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA
| | - Renata L S Goncalves
- Department of Molecular Metabolism and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Grace Yankun Lee
- Department of Molecular Metabolism and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - C Shan Xu
- HHMI Janelia Research Campus, Ashburn, VA, USA
- Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
| | - Gökhan S Hotamışlıgil
- Department of Molecular Metabolism and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Ana Paula Arruda
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
| |
Collapse
|
2
|
Pang L, Cui M, Wu S, Kong J. Cav-1 regulates the bile salt export pump on the canalicular membrane of hepatocytes by PKCα-associated signalling under cholesterol stimulation. J Cell Mol Med 2024; 28:e18110. [PMID: 38164042 PMCID: PMC10844719 DOI: 10.1111/jcmm.18110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/25/2023] [Accepted: 11/22/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND AND AIMS The secretion of bile salts transported by the bile salt export pump (BSEP) is the primary driving force for the generation of bile flow; thus, it is closely related to the formation of cholesterol stones. Caveolin-1 (Cav-1), an essential player in cell signalling and endocytosis, is known to co-localize with cholesterol-rich membrane domains. This study illustrates the role of Cav-1 and BSEP in cholesterol stone formation. METHODS Adult male C57BL/6 mice were used as an animal model. HepG2 cells were cultured under different cholesterol concentrations and BSEP, Cav-1, p-PKCα and Hax-1 expression levels were determined via Western blotting. Expression levels of BSEP and Cav-1 mRNA were detected using real-time PCR. Immunofluorescence and immunoprecipitation assays were performed to study BSEP and Hax-1 distribution. Finally, an ATPase activity assay was performed to detect BSEP transport activity under different cholesterol concentrations in cells. RESULTS Under low-concentration stimulation with cholesterol, Cav-1 and BSEP protein and mRNA expression levels significantly increased, PKCα phosphorylation significantly decreased, BSEP binding capacity to Hax-1 weakened, and BSEP function increased. Under high-concentration stimulation with cholesterol, Cav-1 and BSEP protein and mRNA expression levels decreased, PKCα phosphorylation increased, BSEP binding capacity to Hax-1 rose, and BSEP function decreased. CONCLUSION Cav-1 regulates the bile salt export pump on the canalicular membrane of hepatocytes via PKCα-associated signalling under cholesterol stimulation.
Collapse
Affiliation(s)
- Liwei Pang
- Department of General SurgeryShengjing Hospital of China Medical UniversityShenyangLiaoningChina
| | - Meiying Cui
- Department of Anesthesiology, Shengjing HospitalChina Medical UniversityShenyangChina
| | - Shuodong Wu
- Department of General SurgeryShengjing Hospital of China Medical UniversityShenyangLiaoningChina
| | - Jing Kong
- Department of General SurgeryShengjing Hospital of China Medical UniversityShenyangLiaoningChina
| |
Collapse
|
3
|
Maury EA, Sherman MA, Genovese G, Gilgenast TG, Kamath T, Burris S, Rajarajan P, Flaherty E, Akbarian S, Chess A, McCarroll SA, Loh PR, Phillips-Cremins JE, Brennand KJ, Macosko EZ, Walters JT, O’Donovan M, Sullivan P, Sebat J, Lee EA, Walsh CA. Schizophrenia-associated somatic copy-number variants from 12,834 cases reveal recurrent NRXN1 and ABCB11 disruptions. CELL GENOMICS 2023; 3:100356. [PMID: 37601975 PMCID: PMC10435376 DOI: 10.1016/j.xgen.2023.100356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/21/2022] [Accepted: 06/09/2023] [Indexed: 08/22/2023]
Abstract
While germline copy-number variants (CNVs) contribute to schizophrenia (SCZ) risk, the contribution of somatic CNVs (sCNVs)-present in some but not all cells-remains unknown. We identified sCNVs using blood-derived genotype arrays from 12,834 SCZ cases and 11,648 controls, filtering sCNVs at loci recurrently mutated in clonal blood disorders. Likely early-developmental sCNVs were more common in cases (0.91%) than controls (0.51%, p = 2.68e-4), with recurrent somatic deletions of exons 1-5 of the NRXN1 gene in five SCZ cases. Hi-C maps revealed ectopic, allele-specific loops forming between a potential cryptic promoter and non-coding cis-regulatory elements upon 5' deletions in NRXN1. We also observed recurrent intragenic deletions of ABCB11, encoding a transporter implicated in anti-psychotic response, in five treatment-resistant SCZ cases and showed that ABCB11 is specifically enriched in neurons forming mesocortical and mesolimbic dopaminergic projections. Our results indicate potential roles of sCNVs in SCZ risk.
Collapse
Affiliation(s)
- Eduardo A. Maury
- Division of Genetics and Genomics, Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Bioinformatics & Integrative Genomics Program and Harvard/MIT MD-PHD Program, Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Maxwell A. Sherman
- Brigham and Women’s Hospital, Division of Genetics & Center for Data Sciences, Boston, MA, USA
| | - Giulio Genovese
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Thomas G. Gilgenast
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Tushar Kamath
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Harvard Graduate Program in Biophysics, Harvard University, Cambridge, MA, USA
| | - S.J. Burris
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Prashanth Rajarajan
- Nash Family Department of Neuroscience, Friedman Brain Institute, Department of Genetics & Genomics, Icahn Institute of Genomics and Multiscale Biology, Department of Psychiatry, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine of Mount Sinai, New York, NY, USA
| | - Erin Flaherty
- Nash Family Department of Neuroscience, Friedman Brain Institute, Department of Genetics & Genomics, Icahn Institute of Genomics and Multiscale Biology, Department of Psychiatry, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine of Mount Sinai, New York, NY, USA
| | - Schahram Akbarian
- Nash Family Department of Neuroscience, Friedman Brain Institute, Department of Genetics & Genomics, Icahn Institute of Genomics and Multiscale Biology, Department of Psychiatry, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine of Mount Sinai, New York, NY, USA
| | - Andrew Chess
- Nash Family Department of Neuroscience, Friedman Brain Institute, Department of Genetics & Genomics, Icahn Institute of Genomics and Multiscale Biology, Department of Psychiatry, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine of Mount Sinai, New York, NY, USA
| | - Steven A. McCarroll
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Po-Ru Loh
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Brigham and Women’s Hospital, Division of Genetics & Center for Data Sciences, Boston, MA, USA
| | | | - Kristen J. Brennand
- Nash Family Department of Neuroscience, Friedman Brain Institute, Department of Genetics & Genomics, Icahn Institute of Genomics and Multiscale Biology, Department of Psychiatry, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine of Mount Sinai, New York, NY, USA
- Departments of Psychiatry and Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Evan Z. Macosko
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Massachusetts General Hospital, Department of Psychiatry, Boston, MA, USA
| | - James T.R. Walters
- MRC Centre for Neuropsychiatric Genetics and Genomics, Division of Psychiatry and Clinical Neurosciences, Cardiff University, Cardiff, Wales
| | - Michael O’Donovan
- MRC Centre for Neuropsychiatric Genetics and Genomics, Division of Psychiatry and Clinical Neurosciences, Cardiff University, Cardiff, Wales
| | - Patrick Sullivan
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jonathan Sebat
- University of California San Diego, Department of Psychiatry, Department of Cellular & Molecular Medicine, Beyster Center of Psychiatric Genomics, San Diego, CA, USA
| | - Eunjung A. Lee
- Division of Genetics and Genomics, Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
| |
Collapse
|
4
|
Stacpoole PW, McCall CE. The pyruvate dehydrogenase complex: Life's essential, vulnerable and druggable energy homeostat. Mitochondrion 2023; 70:59-102. [PMID: 36863425 DOI: 10.1016/j.mito.2023.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/30/2023] [Accepted: 02/13/2023] [Indexed: 03/04/2023]
Abstract
Found in all organisms, pyruvate dehydrogenase complexes (PDC) are the keystones of prokaryotic and eukaryotic energy metabolism. In eukaryotic organisms these multi-component megacomplexes provide a crucial mechanistic link between cytoplasmic glycolysis and the mitochondrial tricarboxylic acid (TCA) cycle. As a consequence, PDCs also influence the metabolism of branched chain amino acids, lipids and, ultimately, oxidative phosphorylation (OXPHOS). PDC activity is an essential determinant of the metabolic and bioenergetic flexibility of metazoan organisms in adapting to changes in development, nutrient availability and various stresses that challenge maintenance of homeostasis. This canonical role of the PDC has been extensively probed over the past decades by multidisciplinary investigations into its causal association with diverse physiological and pathological conditions, the latter making the PDC an increasingly viable therapeutic target. Here we review the biology of the remarkable PDC and its emerging importance in the pathobiology and treatment of diverse congenital and acquired disorders of metabolic integration.
Collapse
Affiliation(s)
- Peter W Stacpoole
- Department of Medicine (Division of Endocrinology, Metabolism and Diabetes), and Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL, United States.
| | - Charles E McCall
- Department of Internal Medicine and Translational Sciences, and Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| |
Collapse
|
5
|
Arruda AP, Parlakgül G. Endoplasmic Reticulum Architecture and Inter-Organelle Communication in Metabolic Health and Disease. Cold Spring Harb Perspect Biol 2023; 15:cshperspect.a041261. [PMID: 35940911 PMCID: PMC9899651 DOI: 10.1101/cshperspect.a041261] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The endoplasmic reticulum (ER) is a key organelle involved in the regulation of lipid and glucose metabolism, proteostasis, Ca2+ signaling, and detoxification. The structural organization of the ER is very dynamic and complex, with distinct subdomains such as the nuclear envelope and the peripheral ER organized into ER sheets and tubules. ER also forms physical contact sites with all other cellular organelles and with the plasma membrane. Both form and function of the ER are highly adaptive, with a potent capacity to respond to transient changes in environmental cues such as nutritional fluctuations. However, under obesity-induced chronic stress, the ER fails to adapt, leading to ER dysfunction and the development of metabolic pathologies such as insulin resistance and fatty liver disease. Here, we discuss how the remodeling of ER structure and contact sites with other organelles results in diversification of metabolic function and how perturbations to this structural flexibility by chronic overnutrition contribute to ER dysfunction and metabolic pathologies in obesity.
Collapse
Affiliation(s)
- Ana Paula Arruda
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California 94720, USA.,Chan Zuckerberg Biohub, San Francisco, California 94158, USA
| | - Güneş Parlakgül
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California 94720, USA.,Sabri Ülker Center for Metabolic Research and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA
| |
Collapse
|
6
|
Song C, Li W, Wang Z. The Landscape of Liver Chromatin Accessibility and Conserved Non-coding Elements in Larimichthys crocea, Nibea albiflora, and Lateolabrax maculatus. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:763-775. [PMID: 35895229 DOI: 10.1007/s10126-022-10142-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Large yellow croaker (Larimichthys crocea), yellow drum (Nibea albiflora), and Chinese seabass (Lateolabrax maculatus) are important economic marine fishes in China. The conserved non-coding elements (CNEs) in the liver tissues of the three kinds of fish are directly or indirectly involved in the regulation of gene expression and affect liver functions. However, the fishes' CNEs and even chromatin accessibility landscape have not been effectively investigated. Hence, this study established the landscapes of the fishes' genome-wide chromatin accessibility and CNEs by detecting regions of the open chromatin in their livers using an assay for transposase-accessible chromatin by high-throughput sequencing (ATAC-seq) and comparative genomics approach. The results showed that Smad1, Sp1, and Foxl1 transcription factor binding motifs were considerably enriched in the chromatin accessibility landscape in the liver of the three species, and the three transcription factors (TFs) had a wide range of common targets. The hypothetical gene set was targeted by one, two, or all three TFs, which was much higher than would be expected for an accidental outcome. The gene sets near the CNEs were mainly enriched through processes such as a macromolecule metabolic process and ribonucleoprotein complex biogenesis. The active CNEs were found in the promoter regions of genes such as ap1g1, hax1, and ndufs2. And 5 CNEs were predicted to be highly conserved active enhancers. These results demonstrated that Smad1, Sp1, and Foxl1 might be related to the liver function in the three fishes. In addition, we found a series of ATAC-seq-labeled CNEs located in the gene promoter regions, and highly conserved H3k27ac + -labeled CNEs located in the liver function genes. The highly conserved nature of these regulatory elements suggests that they play important roles in the liver in fish. This study mined the landscape of chromatin accessibility and CNEs of three important economic fishes to fill the knowledge gaps in this field. Moreover, the work provides useful data for the industrial application and theoretical research of these three fish species.
Collapse
Affiliation(s)
- Chaowei Song
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Jimei University, Xiamen, China
| | - Wanbo Li
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Jimei University, Xiamen, China
| | - Zhiyong Wang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Jimei University, Xiamen, China.
- Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology, Qingdao, China.
| |
Collapse
|
7
|
Lin J, Wang Y, Lin Z. HAX1 maintains the glioma progression in hypoxia through promoting mitochondrial fission. J Cell Mol Med 2021; 25:11170-11184. [PMID: 34755451 PMCID: PMC8650040 DOI: 10.1111/jcmm.17038] [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: 08/17/2021] [Revised: 10/06/2021] [Accepted: 10/12/2021] [Indexed: 12/24/2022] Open
Abstract
HCLS1‐associated protein X‐1 (HAX1), an anti‐apoptotic molecular, overexpresses in glioma. However, the role of HAX1 in glioma cell surviving in hypoxic environment remains unclear. Western blotting, qRT‐PCR, Transwell assay, TUNEL assay, wounding healing assay, clone formation, tumour xenograft model and immunohistochemical staining were used to investigate the role of HAX1 in glioma. HAX1 regulated by HIF‐1α was increased in glioma cells cultured in hypoxia. Silencing of HAX1 could cause an increased apoptosis of glioma cells cultured in hypoxia. Silencing of HAX1 also decreased the proliferation, migration and invasion of glioma cells cultured in hypoxia. Increased mitochondrial fission could prevent glioma cells from the damage induced by HAX1 knockdown in hypoxia. Furthermore, HAX1 was found to regulate glioma cells through phosphorylated AKT/Drp signal pathway. In conclusion, our study suggested that HAX1 promoted survival of glioma cells in hypoxic environment via AKT/Drp signal pathway. Our study also provided a potential therapeutic target for glioma.
Collapse
Affiliation(s)
- Jinghui Lin
- Department of Neurosurgery, Ningbo First Hospital, Ningbo, China
| | - Yang Wang
- Department of Neurosurgery, Ningbo First Hospital, Ningbo, China
| | - Zhiqing Lin
- Department of Neurosurgery, Ningbo First Hospital, Ningbo, China
| |
Collapse
|
8
|
Ren T, Pang L, Dai W, Wu S, Kong J. Regulatory mechanisms of the bile salt export pump (BSEP/ABCB11) and its role in related diseases. Clin Res Hepatol Gastroenterol 2021; 45:101641. [PMID: 33581308 DOI: 10.1016/j.clinre.2021.101641] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/03/2021] [Accepted: 01/21/2021] [Indexed: 02/04/2023]
Abstract
The bile salt export pump (BSEP/ABCB11) is located on the apical membrane and mediates the secretion of bile salts from hepatocytes into the bile. BSEP-mediated bile salt efflux is the rate-limiting step of bile salt secretion and the main driving force of bile flow. BSEP drives and maintains the enterohepatic circulation of bile salts. In recent years, research efforts have been focused on understanding the physiological and pathological functions and regulatory mechanisms of BSEP. These studies elucidated the roles of farnesoid X receptor (FXR), AMP-activated protein kinase (AMPK), liver receptor homolog-1(LRH-1) and nuclear factor erythroid 2-related factor 2 (Nrf-2) in BSEP expression and discovered some regulatory factors which participate in its post-transcriptional regulation. A series of liver diseases have also been shown to be related to BSEP expression and dysfunction, such as cholestasis, drug-induced liver injury, and gallstones. Here, we systematically review and summarize recent literature on BSEP structure, physiological functions, regulatory mechanisms, and related diseases.
Collapse
Affiliation(s)
- Tengqi Ren
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Liwei Pang
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Wanlin Dai
- Innovation Institute of China Medical University, Shenyang, Liaoning, China
| | - Shuodong Wu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Jing Kong
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China.
| |
Collapse
|
9
|
Inositol hexanicotinate self-micelle solid dispersion is an efficient drug delivery system in the mouse model of non-alcoholic fatty liver disease. Int J Pharm 2021; 602:120576. [PMID: 33839223 DOI: 10.1016/j.ijpharm.2021.120576] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 03/24/2021] [Accepted: 04/03/2021] [Indexed: 12/12/2022]
Abstract
Inositol hexanicotinate (IHN) self-micelle solid dispersion (SD) with glycyrrhizic acid (GA) and arabic gum (AG) was prepared by mechanical ball milling process to improve the solubility, stability of amorphous state, and bioavailability of IHN, which enhanced the treatment of IHN on hyperlipidemia and nonalcoholic fatty liver disease (NAFLD). The physicochemical properties of IHN/GA/AG SDs in solid state were characterized by differential scanning calorimetry, X-ray diffraction studies, and scanning electron microscopy. The characteristics of the sample solutions were analyzed by reverse-phase HPLC, particle characterization, critical micelle concentration, and transmission electron microscopy. Further pharmacokinetic study of this SD formulation in rats showed a significant 3.3-fold increase in bioavailability compared to pure IHN. Moreover, biomarkers in serum and liver of NAFLD mice were significantly ameliorated after oral administration of IHN/GA/AG SDs for 15 days. Altogether, these results establish the mechanochemically prepared IHN/GA/AG SDs as an efficacious formulation for the treatment of hyperlipidemia and NAFLD.
Collapse
|
10
|
Hepatic LDL receptor-related protein-1 deficiency alters mitochondrial dynamics through phosphatidylinositol 4,5-bisphosphate reduction. J Biol Chem 2021; 296:100370. [PMID: 33548224 PMCID: PMC7949165 DOI: 10.1016/j.jbc.2021.100370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 11/30/2022] Open
Abstract
The LDL receptor-related protein 1 (LRP1) is a multifunctional transmembrane protein with endocytosis and signal transduction functions. Previous studies have shown that hepatic LRP1 deficiency exacerbates diet-induced steatohepatitis and insulin resistance via mechanisms related to increased lysosome and mitochondria permeability and dysfunction. The current study examined the impact of LRP1 deficiency on mitochondrial function in the liver. Hepatocytes isolated from liver-specific LRP1 knockout (hLrp1−/−) mice showed reduced oxygen consumption compared with control mouse hepatocytes. The mitochondria in hLrp1−/− mouse livers have an abnormal morphology and their membranes contain significantly less anionic phospholipids, including lower levels of phosphatidylethanolamine and cardiolipin that increase mitochondrial fission and impair fusion. Additional studies showed that LRP1 complexes with phosphatidylinositol 4-phosphate 5-kinase like protein-1 (PIP5KL1) and phosphatidylinositol 4-phosphate 5-kinase-1β (PIP5K1β). The absence of LRP1 reduces the levels of both PIP5KL1 and PIP5K1β in the plasma membrane and also lowers phosphatidylinositol(4,5) bisphosphate (PI(4,5)P2) levels in hepatocytes. These data indicate that LRP1 recruits PIP5KL1 and PIP5K1β to the plasma membrane for PI(4,5)P2 biosynthesis. The lack of LRP1 reduces lipid kinase expression, leading to lower PI(4,5)P2 levels, thereby decreasing the availability of this lipid metabolite in the cardiolipin biosynthesis pathway to cause cardiolipin reduction and the impairment in mitochondria homeostasis. Taken together, the current study identifies another signaling mechanism by which LRP1 regulates cell functions: binding and recruitment of PIP5KL1 and PIP5K1β to the membrane for PI(4,5)P2 synthesis. In addition, it highlights the importance of this mechanism for maintaining the integrity and functions of intracellular organelles.
Collapse
|
11
|
Distinct Influence of Hypercaloric Diets Predominant with Fat or Fat and Sucrose on Adipose Tissue and Liver Inflammation in Mice. Molecules 2020; 25:molecules25194369. [PMID: 32977558 PMCID: PMC7584000 DOI: 10.3390/molecules25194369] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 01/01/2023] Open
Abstract
Overfeeding of a hypercaloric diet leads to obesity, diabetes, chronic inflammation, and fatty liver disease. Although limiting fat or carbohydrate intake is the cornerstone for obesity management, whether lowering fat or reducing carbohydrate intake is more effective for health management remains controversial. This study used murine models to determine how dietary fat and carbohydrates may influence metabolic disease manifestation. Age-matched C57BL/6J mice were fed 2 hypercaloric diets with similar caloric content, one with very high fat and low carbohydrate content (VHF) and the other with moderately high fat levels with high sucrose content (HFHS) for 12 weeks. Both groups gained more weight and displayed hypercholesterolemia, hyperglycemia, hyperinsulinemia, and liver steatosis compared to mice fed a normal low-fat (LF) diet. Interestingly, the VHF-fed mice showed a more robust adipose tissue inflammation compared to HFHS-fed mice, whereas HFHS-fed mice showed liver fibrosis and inflammation that was not observed in VHF-fed mice. Taken together, these results indicate macronutrient-specific tissue inflammation with excess dietary fat provoking adipose tissue inflammation, whereas moderately high dietary fat with extra sucrose is necessary and sufficient for hepatosteatosis advancement to steatohepatitis. Hence, liver and adipose tissues respond to dietary fat and sucrose in opposite manners, yet both macronutrients are contributing factors to metabolic diseases.
Collapse
|