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Slane EG, Tambrini SJ, Cummings BS. Therapeutic potential of lipin inhibitors for the treatment of cancer. Biochem Pharmacol 2024; 222:116106. [PMID: 38442792 DOI: 10.1016/j.bcp.2024.116106] [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: 12/18/2023] [Revised: 01/28/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024]
Abstract
Lipins are phosphatidic acid phosphatases (PAP) that catalyze the conversion of phosphatidic acid (PA) to diacylglycerol (DAG). Three lipin isoforms have been identified: lipin-1, -2 and -3. In addition to their PAP activity, lipin-1 and -2 act as transcriptional coactivators and corepressors. Lipins have been intensely studied for their role in regulation of lipid metabolism and adipogenesis; however, lipins are hypothesized to mediate several pathologies, such as those involving metabolic diseases, neuropathy and even cognitive impairment. Recently, an emerging role for lipins have been proposed in cancer. The study of lipins in cancer has been hampered by lack of inhibitors that have selectivity for lipins, that differentiate between lipin family members, or that are suitable for in vivo studies. Such inhibitors have the potential to be extremely useful as both molecular tools and therapeutics. This review describes the expression and function of lipins in various tissues and their roles in several diseases, but with an emphasis on their possible role in cancer. The mechanisms by which lipins mediate cancer cell growth are discussed and the potential usefulness of selective lipin inhibitors is hypothesized. Finally, recent studies reporting the crystallization of lipin-1 are discussed to facilitate rational design of novel lipin inhibitors.
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Affiliation(s)
- Elizabeth G Slane
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Samantha J Tambrini
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Brian S Cummings
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA.
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2
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Wang F, Liu Y, Dong Y, Zhao M, Huang H, Jin J, Fan L, Xiang R. Haploinsufficiency of Lipin3 leads to hypertriglyceridemia and obesity by disrupting the expression and nucleocytoplasmic localization of Lipin1. Front Med 2024; 18:180-191. [PMID: 37776435 DOI: 10.1007/s11684-023-1003-0] [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: 12/16/2022] [Accepted: 04/27/2023] [Indexed: 10/02/2023]
Abstract
Lipin proteins including Lipin 1-3 act as transcriptional co-activators and phosphatidic acid phosphohydrolase enzymes, which play crucial roles in lipid metabolism. However, little is known about the function of Lipin3 in triglyceride (TG) metabolism. Here, we identified a novel mutation (NM_001301860: p.1835A>T/p.D612V) of Lipin3 in a large family with hypertriglyceridemia (HTG) and obesity through whole-exome sequencing and Sanger sequencing. Functional studies revealed that the novel variant altered the half-life and stability of the Lipin3 protein. Hence, we generated Lipin3 heterozygous knockout (Lipin3-heKO) mice and cultured primary hepatocytes to explore the pathophysiological roles of Lipin3 in TG metabolism. We found that Lipin3-heKO mice exhibited obvious obesity, HTG, and non-alcoholic fatty liver disorder. Mechanistic study demonstrated that the haploinsufficiency of Lipin3 in primary hepatocytes may induce the overexpression and abnormal distribution of Lipin1 in cytosol and nucleoplasm. The increased expression of Lipin1 in cytosol may contribute to TG anabolism, and the decreased Lipin1 in nucleoplasm can reduce PGC1α, further leading to mitochondrial dysfunction and reduced TG catabolism. Our study suggested that Lipin3 was a novel disease-causing gene inducing obesity and HTG. We also established a relationship between Lipin3 and mitochondrial dysfunction.
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Affiliation(s)
- Fang Wang
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, 410013, China
| | - Yuxing Liu
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, 410013, China
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China
| | - Yi Dong
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China
| | - Meifang Zhao
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China
| | - Hao Huang
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China
| | - Jieyuan Jin
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China
| | - Liangliang Fan
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, 410013, China.
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China.
| | - Rong Xiang
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, 410013, China.
- Department of Cellular Biology, School of Life Sciences, Key Laboratory of Pediatric Rare Diseases, Ministry of Education, Central South University, Changsha, 410013, China.
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3
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Li Z, Zhang G, Pan K, Niu X, Shu-Chien AC, Chen T, Zhang X, Wu X. Functional transcriptome reveals hepatopancreatic lipid metabolism during the molting cycle of the Chinese mitten crab Eriocheir sinensis. Comp Biochem Physiol A Mol Integr Physiol 2023; 284:111474. [PMID: 37406959 DOI: 10.1016/j.cbpa.2023.111474] [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: 02/08/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023]
Abstract
Crustacean molting is highly related to energy and lipid metabolism. This study was conducted to detect the changes of total lipids (TL), triacylglyceride (TAG), phospholipid (PL) and lipid droplets in hepatopancreas, and then to investigate the gene expression patterns related to hepatopancreatic lipid metabolism during the molting cycle of Chinese mitten crab Eriocheir sinensis. Hepatopancreatic TL and TAG increased significantly from post-molt stage to pre-molt stage, then decreased significantly from pre-molt stage to ecdysis stage, which is consistent to the changes of neutral lipid-rich adipocytes in hepatopancreas. By transcriptomic analysis, 65,325 transcripts were sequenced and assembled, and 28,033 transcripts were annotated. Most genes were related to energy metabolism, and the enriched genes were involved in carbohydrate and lipid metabolism and biosynthesis, especially in de novo synthesis of fatty acids and TAG, and ketone body production. Compared to the inter-molt stages, acetyl-CoA carboxylase, fatty acid synthase and other genes related to the synthesis of fatty acids were upregulated in the pre-molt stage. TAG synthesis related genes, including Glycerol-3-phosphate acyltransferase and 1-acylglycerol-3-phosphate acyltransferases, were upregulated in the post-molt stage compared to the inter-molt stage. The expression of ketone body-related genes had no significant changes during the molting cycle. Compared to the TAG synthetic pathway, ketone body biosynthesis may contribute less/secondarily to fatty acid metabolic processes, which could be involved in the other physiological processes or metabolism. In conclusion, these results showed that TAG is the major lipid deposition during inter- and pre-molt stages, and the most genes are related to the fatty acids and TAG metabolism in the hepatopancreas during the molting cycle of E. sinensis.
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Affiliation(s)
- Zhi Li
- Shanghai Collaborative Innovation Centre for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China; CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Guangbao Zhang
- Shanghai Collaborative Innovation Centre for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China
| | - Kewu Pan
- Shanghai Collaborative Innovation Centre for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China
| | - Xingjian Niu
- Shanghai Collaborative Innovation Centre for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China
| | | | - Ting Chen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Xin Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
| | - Xugan Wu
- Shanghai Collaborative Innovation Centre for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China; School of Biological Sciences, Universiti Sains Malaysia, Minden, 11800, Penang, Malaysia; Centre for Research on Environmental Ecology and Fish Nutrition of the Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China.
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4
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Elkhawaga SY, Ismail A, Elsakka EGE, Doghish AS, Elkady MA, El-Mahdy HA. miRNAs as cornerstones in adipogenesis and obesity. Life Sci 2023; 315:121382. [PMID: 36639051 DOI: 10.1016/j.lfs.2023.121382] [Citation(s) in RCA: 59] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/12/2023]
Abstract
In recent decades, obesity has extensively emerged to the level of pandemics. It's significantly associated with serious co-morbidities that could decrease life quality and even life expectancy. Obesity has several determinants, such as age, sex, endocrine, and genetic factors. The miRNAs have emerged as genetic factors affecting obesity. The miRNAs are small noncoding nucleic acids that can modify gene expression and hence, control biological processes. The miRNAs can greatly affect many biological processes in obesity, such as adipogenesis, lipid metabolism, and homeostasis. As a result, the entry of miRNAs in obesity therapeutic approaches has been strongly advised as miRNAs mimics, inhibitors, and stimulators. Hence, this review aims to point out a summarized and updated overview of miRNAs and their roles in obesity and its included processes, such as adipogenesis and lipid metabolism. Besides, we also review recent applications of miRNAs as a treatment approach for obesity.
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Affiliation(s)
- Samy Y Elkhawaga
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
| | - Ahmed Ismail
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
| | - Elsayed G E Elsakka
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt.
| | - Ahmed S Doghish
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt.
| | - Mohamed A Elkady
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
| | - Hesham A El-Mahdy
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
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5
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Yan B, Yuan S, Cao J, Fung K, Lai PM, Yin F, Sze KH, Qin Z, Xie Y, Ye ZW, Yuen TTT, Chik KKH, Tsang JOL, Zou Z, Chan CCY, Luo C, Cai JP, Chan KH, Chung TWH, Tam AR, Chu H, Jin DY, Hung IFN, Yuen KY, Kao RYT, Chan JFW. Phosphatidic acid phosphatase 1 impairs SARS-CoV-2 replication by affecting the glycerophospholipid metabolism pathway. Int J Biol Sci 2022; 18:4744-4755. [PMID: 35874954 PMCID: PMC9305268 DOI: 10.7150/ijbs.73057] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/27/2022] [Indexed: 11/08/2022] Open
Abstract
Viruses exploit the host lipid metabolism machinery to achieve efficient replication. We herein characterize the lipids profile reprogramming in vitro and in vivo using liquid chromatography-mass spectrometry-based untargeted lipidomics. The lipidome of SARS-CoV-2-infected Caco-2 cells was markedly different from that of mock-infected samples, with most of the changes involving downregulation of ceramides. In COVID-19 patients' plasma samples, a total of 54 lipids belonging to 12 lipid classes that were significantly perturbed compared to non-infected control subjects' plasma samples were identified. Among these 12 lipid classes, ether-linked phosphatidylcholines, ether-linked phosphatidylethanolamines, phosphatidylcholines, and ceramides were the four most perturbed. Pathway analysis revealed that the glycerophospholipid, sphingolipid, and ether lipid metabolisms pathway were the most significantly perturbed host pathways. Phosphatidic acid phosphatases (PAP) were involved in all three pathways and PAP-1 deficiency significantly suppressed SARS-CoV-2 replication. siRNA knockdown of LPIN2 and LPIN3 resulted in significant reduction of SARS-CoV-2 load. In summary, these findings characterized the host lipidomic changes upon SARS-CoV-2 infection and identified PAP-1 as a potential target for intervention for COVID-19.
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Affiliation(s)
- Bingpeng Yan
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Shuofeng Yuan
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Jianli Cao
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kingchun Fung
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Pok-Man Lai
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Feifei Yin
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, Hainan, China.,Academician Workstation of Hainan Province, Hainan Medical University, Haikou, Hainan, China.,Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Pathogen Biology, Hainan Medical University, Haikou, Hainan, China
| | - Kong-Hung Sze
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
| | - Zhenzhi Qin
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Yubin Xie
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Zi-Wei Ye
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Terrence Tsz-Tai Yuen
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kenn Ka-Heng Chik
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
| | - Jessica Oi-Ling Tsang
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
| | - Zijiao Zou
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Chris Chun-Yiu Chan
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Cuiting Luo
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Jian-Piao Cai
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kwok-Hung Chan
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
| | - Tom Wai-Hing Chung
- Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China
| | - Anthony Raymond Tam
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Hin Chu
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China.,Department of Infectious Disease and Microbiology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Dong-Yan Jin
- Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China.,School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Guangzhou Laboratory, Guangdong Province, China
| | - Ivan Fan-Ngai Hung
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Infectious Disease and Microbiology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Academician Workstation of Hainan Province, Hainan Medical University, Haikou, Hainan, China.,Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China.,Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Infectious Disease and Microbiology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China.,Guangzhou Laboratory, Guangdong Province, China
| | - Richard Yi-Tsun Kao
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
| | - Jasper Fuk-Woo Chan
- State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Academician Workstation of Hainan Province, Hainan Medical University, Haikou, Hainan, China.,Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China.,Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Infectious Disease and Microbiology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China.,Guangzhou Laboratory, Guangdong Province, China
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6
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Ghanem M, Lewis GF, Xiao C. Recent advances in cytoplasmic lipid droplet metabolism in intestinal enterocyte. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159197. [PMID: 35820577 DOI: 10.1016/j.bbalip.2022.159197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022]
Abstract
Processing of dietary fats in the intestine is a highly regulated process that influences whole-body energy homeostasis and multiple physiological functions. Dysregulated lipid handling in the intestine leads to dyslipidemia and atherosclerotic cardiovascular disease. In intestinal enterocytes, lipids are incorporated into lipoproteins and cytoplasmic lipid droplets (CLDs). Lipoprotein synthesis and CLD metabolism are inter-connected pathways with multiple points of regulation. This review aims to highlight recent advances in the regulatory mechanisms of lipid processing in the enterocyte, with particular focus on CLDs. In-depth understanding of the regulation of lipid metabolism in the enterocyte may help identify therapeutic targets for the treatment and prevention of metabolic disorders.
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Affiliation(s)
- Murooj Ghanem
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Gary F Lewis
- Departments of Medicine and Physiology, University of Toronto, and University Health Network, Toronto, ON, Canada
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
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7
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Güldür T. Potential linkages between circadian rhythm and membrane lipids: timekeeper and bilayer. BIOL RHYTHM RES 2022. [DOI: 10.1080/09291016.2022.2096756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Tayfun Güldür
- Medical Biochemistry Department, Faculty of Medicine, Inönü University, Malatya, Turkey
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8
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Seok S, Kim YC, Zhang Y, Kong B, Guo G, Ma J, Kemper B, Kemper JK. Feeding activates FGF15-SHP-TFEB-mediated lipophagy in the gut. EMBO J 2022; 41:e109997. [PMID: 35686465 PMCID: PMC9434102 DOI: 10.15252/embj.2021109997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 01/18/2023] Open
Abstract
Lysosome‐mediated macroautophagy, including lipophagy, is activated under nutrient deprivation but is repressed after feeding. We show that, unexpectedly, feeding activates intestinal autophagy/lipophagy in a manner dependent on both the orphan nuclear receptor, small heterodimer partner (SHP/NR0B2), and the gut hormone, fibroblast growth factor‐15/19 (FGF15/19). Furthermore, postprandial intestinal triglycerides (TGs) and apolipoprotein‐B48 (ApoB48), the TG‐rich chylomicron marker, were elevated in SHP‐knockout and FGF15‐knockout mice. Genomic analyses of the mouse intestine indicated that SHP partners with the key lysosomal activator, transcription factor‐EB (TFEB) to upregulate the transcription of autophagy/lipolysis network genes after feeding. FGF19 treatment activated lipophagy, reducing TG and ApoB48 levels in HT29 intestinal cells, which was dependent on TFEB. Mechanistically, feeding‐induced FGF15/19 signaling increased the nuclear localization of TFEB and SHP via PKC beta/zeta‐mediated phosphorylation, leading to increased transcription of the TFEB/SHP target lipophagy genes, Ulk1 and Atgl. Collectively, these results demonstrate that paradoxically after feeding, FGF15/19‐activated SHP and TFEB activate gut lipophagy, limiting postprandial TGs. As excess postprandial lipids cause dyslipidemia and obesity, the FGF15/19‐SHP‐TFEB axis that reduces intestinal TGs via lipophagic activation provides promising therapeutic targets for obesity‐associated metabolic disease.
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Affiliation(s)
- Sunmi Seok
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Young-Chae Kim
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yang Zhang
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Bo Kong
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Grace Guo
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Jian Ma
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Byron Kemper
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jongsook Kim Kemper
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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9
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卞 京, 陈 平, 卞 读, 贺 晓, Mutamba AK, 王 涛. [Correlation of Lipin gene expression with hepatic fat content in rats with intrauterine growth retardation]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2022; 24:440-446. [PMID: 35527422 PMCID: PMC9044995 DOI: 10.7499/j.issn.1008-8830.2110130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/01/2022] [Indexed: 01/24/2023]
Abstract
OBJECTIVES To study the correlation of the expression of Lipin1 in visceral adipose tissue and Lipin2 in liver tissue with hepatic fat content in rats with intrauterine growth retardation (IUGR). METHODS Pregnant rats were given a low-protein (10% protein) diet during pregnancy to establish a model of IUGR in neonatal rats. The pregnant rats in the control group were given a normal-protein (21% protein) diet during pregnancy. The neonatal rats were weighed and liver tissue was collected on day 1 and at weeks 3, 8, and 12 after birth, and visceral adipose tissue was collected at weeks 3, 8, and 12 after birth. The 3.0T 1H-magnetic resonance spectroscopy was used to measure hepatic fat content at weeks 3, 8, and 12 after birth. Real-time PCR was used to measure mRNA expression levels of Lipin2 in liver tissue and Lipin1 in visceral adipose tissue. Western blot was used to measure protein levels of Lipin2 in liver tissue and Lipin1 in visceral adipose tissue. A Pearson correlation analysis was performed to investigate the correlation of mRNA and protein expression of Lipin with hepatic fat content. RESULTS The IUGR group had significantly higher mRNA and protein expression levels of Lipin1 in visceral adipose tissue than the control group at weeks 3, 8, and 12 after birth (P<0.05). Compared with the control group, the IUGR group had significantly lower mRNA and protein expression levels of Lipin2 in liver tissue on day 1 after birth and significantly higher mRNA and protein expression levels of Lipin2 at weeks 1, 3, 8, and 12 after birth (P<0.05). At week 3 after birth, there was no significant difference in hepatic fat content between the IUGR and control groups (P>0.05), while at weeks 8 and 12 after birth, the IUGR group had a significantly higher hepatic fat content than the control group (P<0.05). The protein and mRNA expression levels of Lipin1 were positively correlated with hepatic fat content (r=0.628 and 0.521 respectively; P<0.05), and the protein and mRNA expression levels of Lipin2 were also positively correlated with hepatic fat content (r=0.601 and 0.524 respectively; P<0.05). CONCLUSIONS Upregulation of the mRNA and protein expression levels of Lipin1 in visceral adipose tissue and Lipin2 in liver tissue can increase hepatic fat content in rats with IUGR and may be associated with obesity in adulthood.
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Affiliation(s)
| | - 平洋 陈
- 中南大学湘雅二医院儿童医学中心新生儿专科, 湖南长沙 410011
| | | | - 晓日 贺
- 中南大学湘雅二医院儿童医学中心新生儿专科, 湖南长沙 410011
| | | | - 涛 王
- 中南大学湘雅二医院儿童医学中心新生儿专科, 湖南长沙 410011
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10
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Li Y, Du Y, Xu Z, He Y, Yao R, Jiang H, Ju W, Qiao J, Xu K, Liu TM, Zeng L. Intravital lipid droplet labeling and imaging reveals the phenotypes and functions of individual macrophages in vivo. J Lipid Res 2022; 63:100207. [PMID: 35398040 PMCID: PMC9117931 DOI: 10.1016/j.jlr.2022.100207] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 01/06/2023] Open
Abstract
Macrophages play pivotal roles in the maintenance of tissue homeostasis. However, the reactivation of macrophages toward proinflammatory states correlates with a plethora of inflammatory diseases, including atherosclerosis, obesity, neurodegeneration, and bone marrow (BM) failure syndromes. The lack of methods to reveal macrophage phenotype and function in vivo impedes the translational research of these diseases. Here, we found that proinflammatory macrophages accumulate intracellular lipid droplets (LDs) relative to resting or noninflammatory macrophages both in vitro and in vivo, indicating that LD accumulation serves as a structural biomarker for macrophage phenotyping. To realize the staining and imaging of macrophage LDs in vivo, we developed a fluorescent fatty acid analog-loaded poly(lactic-co-glycolic acid) nanoparticle to label macrophages in mice with high efficiency and specificity. Using these novel nanoparticles, we achieved in situ functional identification of single macrophages in BM, liver, lung, and adipose tissues under conditions of acute or chronic inflammation. Moreover, with this intravital imaging platform, we further realized in vivo phenotyping of individual macrophages in the calvarial BM of mice under systemic inflammation. In conclusion, we established an efficient in vivo LD labeling and imaging system for single macrophage phenotyping, which will aid in the development of diagnostics and therapeutic monitoring. Moreover, this method also provides new avenues for the study of lipid trafficking and dynamics in vivo.
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11
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Doerfler AM, Han J, Jarrett KE, Tang L, Jain A, Saltzman A, De Giorgi M, Chuecos M, Hurley AE, Li A, Morand P, Ayala C, Goodlett DR, Malovannaya A, Martin JF, de Aguiar Vallim TQ, Shroyer N, Lagor WR. Intestinal Deletion of 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Promotes Expansion of the Resident Stem Cell Compartment. Arterioscler Thromb Vasc Biol 2022; 42:381-394. [PMID: 35172604 PMCID: PMC8957608 DOI: 10.1161/atvbaha.122.317320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The intestine occupies the critical interface between cholesterol absorption and excretion. Surprisingly little is known about the role of de novo cholesterol synthesis in this organ, and its relationship to whole body cholesterol homeostasis. Here, we investigate the physiological importance of this pathway through genetic deletion of the rate-limiting enzyme. METHODS Mice lacking 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) in intestinal villus and crypt epithelial cells were generated using a Villin-Cre transgene. Plasma lipids, intestinal morphology, mevalonate pathway metabolites, and gene expression were analyzed. RESULTS Mice with intestine-specific loss of Hmgcr were markedly smaller at birth, but gain weight at a rate similar to wild-type littermates, and are viable and fertile into adulthood. Intestine lengths and weights were greater relative to body weight in both male and female Hmgcr intestinal knockout mice. Male intestinal knockout had decreased plasma cholesterol levels, whereas fasting triglycerides were lower in both sexes. Lipidomics revealed substantial reductions in numerous nonsterol isoprenoids and sterol intermediates within the epithelial layer, but cholesterol levels were preserved. Hmgcr intestinal knockout mice also showed robust activation of SREBP-2 (sterol-regulatory element binding protein-2) target genes in the epithelium, including the LDLR (low-density lipoprotein receptor). At the cellular level, loss of Hmgcr is compensated for quickly after birth through a dramatic expansion of the stem cell compartment, which persists into adulthood. CONCLUSIONS Loss of Hmgcr in the intestine is compatible with life through compensatory increases in intestinal absorptive surface area, LDLR expression, and expansion of the resident stem cell compartment.
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Affiliation(s)
- Alexandria M. Doerfler
- Molecular Physiology and Biophysics Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - Jun Han
- University of Victoria - Genome British Columbia Proteomics Centre, Victoria, British Columbia, Canada.,Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Kelsey E. Jarrett
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Department of Medicine, Division of Cardiology, University of California Los Angeles, Los Angeles, USA
| | - Li Tang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.,Hunan Provincial Key Lab on Bioinformatics, School of Computer Science and Engineering, Central South University, Changsha 410083, China
| | - Antrix Jain
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, Texas, USA
| | - Alexander Saltzman
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, Texas, USA
| | - Marco De Giorgi
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - Marcel Chuecos
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.,Translational Biology and Molecular Medicine Graduate Program, Baylor College of Medicine, Houston, Texas, USA
| | - Ayrea E. Hurley
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - Ang Li
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.,Department of Bioengineering, Rice University, Houston, Texas, USA
| | - Pauline Morand
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, USA
| | - Claudia Ayala
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - David R. Goodlett
- University of Victoria - Genome British Columbia Proteomics Centre, Victoria, British Columbia, Canada.,Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Anna Malovannaya
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, Texas, USA.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.,Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - James F. Martin
- Molecular Physiology and Biophysics Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Translational Biology and Molecular Medicine Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Cardiomyocyte Renewal Laboratory, Texas Heart Institute, Houston, Texas, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas USA
| | - Thomas Q. de Aguiar Vallim
- Department of Medicine, Division of Cardiology, University of California Los Angeles, Los Angeles, USA.,Department of Biological Chemistry, University of California Los Angeles, Los Angeles, USA.,Molecular Biology Institute, University of California Los Angeles, Los Angeles, USA.,Johnsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, USA
| | - Noah Shroyer
- Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Translational Biology and Molecular Medicine Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Department of Medicine, Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, Texas, USA
| | - William R. Lagor
- Molecular Physiology and Biophysics Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Translational Biology and Molecular Medicine Graduate Program, Baylor College of Medicine, Houston, Texas, USA.,Department of Bioengineering, Rice University, Houston, Texas, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas USA
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12
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Stone SJ. Mechanisms of intestinal triacylglycerol synthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159151. [PMID: 35296424 DOI: 10.1016/j.bbalip.2022.159151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/13/2022] [Accepted: 02/16/2022] [Indexed: 02/07/2023]
Abstract
Triacylglycerols are a major source of stored energy that are obtained either from the diet or can be synthesized to some extent by most tissues. Alterations in pathways of triacylglycerol metabolism can result in their excessive accumulation leading to obesity, insulin resistance, cardiovascular disease and nonalcoholic fatty liver disease. Most tissues in mammals synthesize triacylglycerols via the glycerol 3-phosphate pathway. However, in the small intestine the monoacylglycerol acyltransferase pathway is the predominant pathway for triacylglycerol biosynthesis where it participates in the absorption of dietary triacylglycerol. In this review, the enzymes that are part of both the glycerol 3-phosphate and monoacylglycerol acyltransferase pathways and their contributions to intestinal triacylglycerol metabolism are reviewed. The potential of some of the enzymes involved in triacylglycerol synthesis in the small intestine as possible therapeutic targets for treating metabolic disorders associated with elevated triacylglycerol is briefly discussed.
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Affiliation(s)
- Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
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13
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Papagiannidis D, Bircham PW, Lüchtenborg C, Pajonk O, Ruffini G, Brügger B, Schuck S. Ice2 promotes ER membrane biogenesis in yeast by inhibiting the conserved lipin phosphatase complex. EMBO J 2021; 40:e107958. [PMID: 34617598 PMCID: PMC8591542 DOI: 10.15252/embj.2021107958] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 11/30/2022] Open
Abstract
Cells dynamically adapt organelle size to current physiological demand. Organelle growth requires membrane biogenesis and therefore needs to be coordinated with lipid metabolism. The endoplasmic reticulum (ER) can undergo massive expansion, but the underlying regulatory mechanisms are largely unclear. Here, we describe a genetic screen for factors involved in ER membrane expansion in budding yeast and identify the ER transmembrane protein Ice2 as a strong hit. We show that Ice2 promotes ER membrane biogenesis by opposing the phosphatidic acid phosphatase Pah1, called lipin in metazoa. Specifically, Ice2 inhibits the conserved Nem1‐Spo7 complex and thus suppresses the dephosphorylation and activation of Pah1. Furthermore, Ice2 cooperates with the transcriptional regulation of lipid synthesis genes and helps to maintain cell homeostasis during ER stress. These findings establish the control of the lipin phosphatase complex as an important mechanism for regulating ER membrane biogenesis.
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Affiliation(s)
- Dimitrios Papagiannidis
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Peter W Bircham
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany
| | | | - Oliver Pajonk
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Giulia Ruffini
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Sebastian Schuck
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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14
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Gu W, Gao S, Wang H, Fleming KD, Hoffmann RM, Yang JW, Patel NM, Choi YM, Burke JE, Reue K, Airola MV. The middle lipin domain adopts a membrane-binding dimeric protein fold. Nat Commun 2021; 12:4718. [PMID: 34354069 PMCID: PMC8342540 DOI: 10.1038/s41467-021-24929-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023] Open
Abstract
Phospholipid synthesis and fat storage as triglycerides are regulated by lipin phosphatidic acid phosphatases (PAPs), whose enzymatic PAP function requires association with cellular membranes. Using hydrogen deuterium exchange mass spectrometry, we find mouse lipin 1 binds membranes through an N-terminal amphipathic helix, the Ig-like domain and HAD phosphatase catalytic core, and a middle lipin (M-Lip) domain that is conserved in mammalian and mammalian-like lipins. Crystal structures of the M-Lip domain reveal a previously unrecognized protein fold that dimerizes. The isolated M-Lip domain binds membranes both in vitro and in cells through conserved basic and hydrophobic residues. Deletion of the M-Lip domain in lipin 1 reduces PAP activity, membrane association, and oligomerization, alters subcellular localization, diminishes acceleration of adipocyte differentiation, but does not affect transcriptional co-activation. This establishes the M-Lip domain as a dimeric protein fold that binds membranes and is critical for full functionality of mammalian lipins.
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Affiliation(s)
- Weijing Gu
- grid.36425.360000 0001 2216 9681Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY USA
| | - Shujuan Gao
- grid.36425.360000 0001 2216 9681Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY USA
| | - Huan Wang
- grid.19006.3e0000 0000 9632 6718Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA USA
| | - Kaelin D. Fleming
- grid.143640.40000 0004 1936 9465Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC Canada
| | - Reece M. Hoffmann
- grid.143640.40000 0004 1936 9465Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC Canada
| | - Jong Won Yang
- grid.36425.360000 0001 2216 9681Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY USA
| | - Nimi M. Patel
- grid.36425.360000 0001 2216 9681Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY USA
| | - Yong Mi Choi
- grid.36425.360000 0001 2216 9681Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY USA
| | - John E. Burke
- grid.143640.40000 0004 1936 9465Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC Canada
| | - Karen Reue
- grid.19006.3e0000 0000 9632 6718Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA USA
| | - Michael V. Airola
- grid.36425.360000 0001 2216 9681Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY USA
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15
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Clifford BL, Sedgeman LR, Williams KJ, Morand P, Cheng A, Jarrett KE, Chan AP, Brearley-Sholto MC, Wahlström A, Ashby JW, Barshop W, Wohlschlegel J, Calkin AC, Liu Y, Thorell A, Meikle PJ, Drew BG, Mack JJ, Marschall HU, Tarling EJ, Edwards PA, de Aguiar Vallim TQ. FXR activation protects against NAFLD via bile-acid-dependent reductions in lipid absorption. Cell Metab 2021; 33:1671-1684.e4. [PMID: 34270928 PMCID: PMC8353952 DOI: 10.1016/j.cmet.2021.06.012] [Citation(s) in RCA: 166] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/12/2021] [Accepted: 06/21/2021] [Indexed: 12/24/2022]
Abstract
FXR agonists are used to treat non-alcoholic fatty liver disease (NAFLD), in part because they reduce hepatic lipids. Here, we show that FXR activation with the FXR agonist GSK2324 controls hepatic lipids via reduced absorption and selective decreases in fatty acid synthesis. Using comprehensive lipidomic analyses, we show that FXR activation in mice or humans specifically reduces hepatic levels of mono- and polyunsaturated fatty acids (MUFA and PUFA). Decreases in MUFA are due to FXR-dependent repression of Scd1, Dgat2, and Lpin1 expression, which is independent of SHP and SREBP1c. FXR-dependent decreases in PUFAs are mediated by decreases in lipid absorption. Replenishing bile acids in the diet prevented decreased lipid absorption in GSK2324-treated mice, suggesting that FXR reduces absorption via decreased bile acids. We used tissue-specific FXR KO mice to show that hepatic FXR controls lipogenic genes, whereas intestinal FXR controls lipid absorption. Together, our studies establish two distinct pathways by which FXR regulates hepatic lipids.
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Affiliation(s)
- Bethan L Clifford
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Leslie R Sedgeman
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Kevin J Williams
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Lipidomics Core Facility, Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Pauline Morand
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Angela Cheng
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Kelsey E Jarrett
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Alvin P Chan
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Madelaine C Brearley-Sholto
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Annika Wahlström
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Julianne W Ashby
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - William Barshop
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Anna C Calkin
- Lipid Metabolism & Cardiometabolic Disease Laboratory, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Yingying Liu
- Lipid Metabolism & Cardiometabolic Disease Laboratory, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Molecular Metabolism & Ageing Laboratory, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Anders Thorell
- Karolinska Institutet, Department of Clinical Science, Danderyd Hospital and Department of Surgery, Ersta Hospital, Stockholm, Sweden
| | - Peter J Meikle
- Metabolomics Laboratory, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Brian G Drew
- Central Clinical School, Monash University, Melbourne, VIC, Australia; Molecular Metabolism & Ageing Laboratory, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Julia J Mack
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Hanns-Ulrich Marschall
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Elizabeth J Tarling
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Peter A Edwards
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Thomas Q de Aguiar Vallim
- Department of Medicine, Division of Cardiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
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16
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Link JC, Wiese CB, Chen X, Avetisyan R, Ronquillo E, Ma F, Guo X, Yao J, Allison M, Chen YDI, Rotter JI, El-Sayed Moustafa JS, Small KS, Iwase S, Pellegrini M, Vergnes L, Arnold AP, Reue K. X chromosome dosage of histone demethylase KDM5C determines sex differences in adiposity. J Clin Invest 2021; 130:5688-5702. [PMID: 32701509 DOI: 10.1172/jci140223] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/16/2020] [Indexed: 12/29/2022] Open
Abstract
Males and females differ in body composition and fat distribution. Using a mouse model that segregates gonadal sex (ovaries and testes) from chromosomal sex (XX and XY), we showed that XX chromosome complement in combination with a high-fat diet led to enhanced weight gain in the presence of male or female gonads. We identified the genomic dosage of Kdm5c, an X chromosome gene that escapes X chromosome inactivation, as a determinant of the X chromosome effect on adiposity. Modulating Kdm5c gene dosage in XX female mice to levels that are normally present in males resulted in reduced body weight, fat content, and food intake to a degree similar to that seen with altering the entire X chromosome dosage. In cultured preadipocytes, the levels of KDM5C histone demethylase influenced chromatin accessibility (ATAC-Seq), gene expression (RNA-Seq), and adipocyte differentiation. Both in vitro and in vivo, Kdm5c dosage influenced gene expression involved in extracellular matrix remodeling, which is critical for adipocyte differentiation and adipose tissue expansion. In humans, adipose tissue KDM5C mRNA levels and KDM5C genetic variants were associated with body mass. These studies demonstrate that the sex-dependent dosage of Kdm5c contributes to male/female differences in adipocyte biology and highlight X-escape genes as a critical component of female physiology.
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Affiliation(s)
| | | | - Xuqi Chen
- Integrative Biology and Physiology, and
| | | | | | - Feiyang Ma
- Molecular, Cellular and Developmental Biology, UCLA, Los Angeles, California, USA
| | - Xiuqing Guo
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Jie Yao
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Matthew Allison
- Division of Preventive Medicine, School of Medicine, UCSD, San Diego, California, USA
| | - Yii-Der Ida Chen
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | | | - Kerrin S Small
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Shigeki Iwase
- Human Genetics, Medical School, University of Michigan, Ann Arbor, Michigan, USA
| | - Matteo Pellegrini
- Molecular, Cellular and Developmental Biology, UCLA, Los Angeles, California, USA
| | | | | | - Karen Reue
- Molecular Biology Institute.,Human Genetics, David Geffen School of Medicine
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17
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Gil-Zamorano J, Tomé-Carneiro J, Lopez de Las Hazas MC, Del Pozo-Acebo L, Crespo MC, Gómez-Coronado D, Chapado LA, Herrera E, Latasa MJ, Ruiz-Roso MB, Castro-Camarero M, Briand O, Dávalos A. Intestinal miRNAs regulated in response to dietary lipids. Sci Rep 2020; 10:18921. [PMID: 33144601 PMCID: PMC7642330 DOI: 10.1038/s41598-020-75751-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 10/08/2020] [Indexed: 02/07/2023] Open
Abstract
The role of miRNAs in intestinal lipid metabolism is poorly described. The small intestine is constantly exposed to high amounts of dietary lipids, and it is under conditions of stress that the functions of miRNAs become especially pronounced. Approaches consisting in either a chronic exposure to cholesterol and triglyceride rich diets (for several days or weeks) or an acute lipid challenge were employed in the search for intestinal miRNAs with a potential role in lipid metabolism regulation. According to our results, changes in miRNA expression in response to fat ingestion are dependent on factors such as time upon exposure, gender and small intestine section. Classic and recent intestinal in vitro models (i.e. differentiated Caco-2 cells and murine organoids) partially mirror miRNA modulation in response to lipid challenges in vivo. Moreover, intestinal miRNAs might play a role in triglyceride absorption and produce changes in lipid accumulation in intestinal tissues as seen in a generated intestinal Dicer1-deletion murine model. Overall, despite some variability between the different experimental cohorts and in vitro models, results show that some miRNAs analysed here are modulated in response to dietary lipids, hence likely to participate in the regulation of lipid metabolism, and call for further research.
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Affiliation(s)
- Judit Gil-Zamorano
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain
| | - João Tomé-Carneiro
- Laboratory of Functional Foods, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM CSIC, 28049, Madrid, Spain
| | - María-Carmen Lopez de Las Hazas
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain
| | - Lorena Del Pozo-Acebo
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain
| | - M Carmen Crespo
- Laboratory of Functional Foods, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM CSIC, 28049, Madrid, Spain
| | - Diego Gómez-Coronado
- Servicio de Bioquímica-Investigación, Hospital Universitario Ramón y Cajal, IRYCIS, 28034, Madrid, Spain.,Centre of Biomedical Research in Physiopathology of Obesity and Nutrition (CIBEROBN), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Luis A Chapado
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain
| | - Emilio Herrera
- Department of Biochemistry and Chemistry, Faculties of Pharmacy and Medicine, Universidad San Pablo CEU, 28668, Madrid, Spain
| | - María-Jesús Latasa
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain
| | - María Belén Ruiz-Roso
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain
| | - Mónica Castro-Camarero
- Servicio de Cirugía Experimental, Hospital Universitario Ramón y Cajal, IRYCIS, 28034, Madrid, Spain
| | - Olivier Briand
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, Lille, 59000, France
| | - Alberto Dávalos
- Laboratory of Epigenetics of Lipid Metabolism, Madrid Institute for Advanced Studies Food (IMDEA Food), CEI UAM + CSIC, Carretera de Canto Blanco, 8, 28049, Madrid, Spain.
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18
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Abstract
Phosphatidate phosphatase (PAP) catalyzes the penultimate step in the synthesis of triacylglycerol and regulates the synthesis of membrane phospholipids. There is much interest in this enzyme because it controls the cellular levels of its substrate, phosphatidate (PA), and product, DAG; defects in the metabolism of these lipid intermediates are the basis for lipid-based diseases such as obesity, lipodystrophy, and inflammation. The measurement of PAP activity is required for studies aimed at understanding its mechanisms of action, how it is regulated, and for screening its activators and/or inhibitors. Enzyme activity is determined through the use of radioactive and nonradioactive assays that measure the product, DAG, or Pi However, sensitivity and ease of use are variable across these methods. This review summarizes approaches to synthesize radioactive PA, to analyze radioactive and nonradioactive products, DAG and Pi, and discusses the advantages and disadvantages of each PAP assay.
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Affiliation(s)
- Prabuddha Dey
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, USA
| | - Gil-Soo Han
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, USA
| | - George M Carman
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, USA.
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19
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Mirheydari M, Dey P, Stukey GJ, Park Y, Han GS, Carman GM. The Spo7 sequence LLI is required for Nem1-Spo7/Pah1 phosphatase cascade function in yeast lipid metabolism. J Biol Chem 2020; 295:11473-11485. [PMID: 32527729 DOI: 10.1074/jbc.ra120.014129] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/09/2020] [Indexed: 11/06/2022] Open
Abstract
The Nem1-Spo7 complex in the yeast Saccharomyces cerevisiae is a protein phosphatase that catalyzes the dephosphory-lation of Pah1 phosphatidate phosphatase, required for its translocation to the nuclear/endoplasmic reticulum membrane. The Nem1-Spo7/Pah1 phosphatase cascade plays a major role in triacylglycerol synthesis and in the regulation of phospholipid synthesis. In this work, we examined Spo7, a regulatory subunit required for Nem1 catalytic function, to identify residues that govern formation of the Nem1-Spo7 complex. By deletion analysis of Spo7, we identified a hydrophobic Leu-Leu-Ile (LLI) sequence comprising residues 54-56 as being required for the protein to complement the temperature-sensitive phenotype of an spo7Δ mutant strain. Mutational analysis of the LLI sequence with alanine and arginine substitutions showed that its overall hydrophobicity is crucial for the formation of the Nem1-Spo7 complex as well as for the Nem1 catalytic function on its substrate, Pah1, in vivo Consistent with the role of the Nem1-Spo7 complex in activating the function of Pah1, we found that the mutational effects of the Spo7 LLI sequence were on the Nem1-Spo7/Pah1 axis that controls lipid synthesis and related cellular processes (e.g. triacylglycerol/phospholipid synthesis, lipid droplet formation, nuclear/endoplasmic reticulum membrane morphology, vacuole fusion, and growth on glycerol medium). These findings advance the understanding of Nem1-Spo7 complex formation and its role in the phosphatase cascade that regulates the function of Pah1 phosphatidate phosphatase.
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Affiliation(s)
- Mona Mirheydari
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Prabuddha Dey
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Geordan J Stukey
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Yeonhee Park
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Gil-Soo Han
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - George M Carman
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
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20
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Crystal structure of a lipin/Pah phosphatidic acid phosphatase. Nat Commun 2020; 11:1309. [PMID: 32161260 PMCID: PMC7066176 DOI: 10.1038/s41467-020-15124-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Lipin/Pah phosphatidic acid phosphatases (PAPs) generate diacylglycerol to regulate triglyceride synthesis and cellular signaling. Inactivating mutations cause rhabdomyolysis, autoinflammatory disease, and aberrant fat storage. Disease-mutations cluster within the conserved N-Lip and C-Lip regions that are separated by 500-residues in humans. To understand how the N-Lip and C-Lip combine for PAP function, we determined crystal structures of Tetrahymena thermophila Pah2 (Tt Pah2) that directly fuses the N-Lip and C-Lip. Tt Pah2 adopts a two-domain architecture where the N-Lip combines with part of the C-Lip to form an immunoglobulin-like domain and the remaining C-Lip forms a HAD-like catalytic domain. An N-Lip C-Lip fusion of mouse lipin-2 is catalytically active, which suggests mammalian lipins function with the same domain architecture as Tt Pah2. HDX-MS identifies an N-terminal amphipathic helix essential for membrane association. Disease-mutations disrupt catalysis or destabilize the protein fold. This illustrates mechanisms for lipin/Pah PAP function, membrane association, and lipin-related pathologies. Lipin/Pah phosphatidic acid phosphatases generate diacylglycerol to regulate triglyceride synthesis and cellular signaling. Here authors determine structures of Tetrahymena thermophila Pah2 and identify an N-terminal amphipathic helix essential for membrane association.
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21
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Rewiring Neuronal Glycerolipid Metabolism Determines the Extent of Axon Regeneration. Neuron 2019; 105:276-292.e5. [PMID: 31786011 PMCID: PMC6975164 DOI: 10.1016/j.neuron.2019.10.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 09/11/2019] [Accepted: 10/03/2019] [Indexed: 12/21/2022]
Abstract
How adult neurons coordinate lipid metabolism to regenerate axons remains elusive. We found that depleting neuronal lipin1, a key enzyme controlling the balanced synthesis of glycerolipids through the glycerol phosphate pathway, enhanced axon regeneration after optic nerve injury. Axotomy elevated lipin1 in retinal ganglion cells, which contributed to regeneration failure in the CNS by favorably producing triglyceride (TG) storage lipids rather than phospholipid (PL) membrane lipids in neurons. Regrowth induced by lipin1 depletion required TG hydrolysis and PL synthesis. Decreasing TG synthesis by deleting neuronal diglyceride acyltransferases (DGATs) and enhancing PL synthesis through the Kennedy pathway promoted axon regeneration. In addition, peripheral neurons adopted this mechanism for their spontaneous axon regeneration. Our study reveals a critical role of lipin1 and DGATs as intrinsic regulators of glycerolipid metabolism in neurons and indicates that directing neuronal lipid synthesis away from TG synthesis and toward PL synthesis may promote axon regeneration. Injury-elevated Lipin1 and DGAT in retinal ganglion cells suppress regeneration Neuronal lipin1 and DGATs increase triglyceride and decrease phospholipids Redirecting triacylglyceride to phospholipid synthesis promotes axon regeneration
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22
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Lee J, Ridgway ND. Substrate channeling in the glycerol-3-phosphate pathway regulates the synthesis, storage and secretion of glycerolipids. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158438. [PMID: 30959116 DOI: 10.1016/j.bbalip.2019.03.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 01/16/2023]
Abstract
The successive acylation of glycerol-3-phosphate (G3P) by glycerol-3-phosphate acyltransferases and acylglycerol-3-phosphate acyltransferases produces phosphatidic acid (PA), a precursor for CDP-diacylglycerol-dependent phospholipid synthesis. PA is further dephosphorylated by LIPINs to produce diacylglycerol (DG), a substrate for the synthesis of triglyceride (TG) by DG acyltransferases and a precursor for phospholipid synthesis via the CDP-choline and CDP-ethanolamine (Kennedy) pathways. The channeling of fatty acids into TG for storage in lipid droplets and secretion in lipoproteins or phospholipids for membrane biogenesis is dependent on isoform expression, activity and localization of G3P pathway enzymes, as well as dietary and hormonal and tissue-specific factors. Here, we review the mechanisms that control partitioning of substrates into lipid products of the G3P pathway.
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Affiliation(s)
- Jonghwa Lee
- Atlantic Research Center, Depts. of Pediatrics and Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Neale D Ridgway
- Atlantic Research Center, Depts. of Pediatrics and Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, Canada.
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23
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Reue K, Wang H. Mammalian lipin phosphatidic acid phosphatases in lipid synthesis and beyond: metabolic and inflammatory disorders. J Lipid Res 2019; 60:728-733. [PMID: 30804008 PMCID: PMC6446709 DOI: 10.1194/jlr.s091769] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/15/2019] [Indexed: 12/12/2022] Open
Abstract
The regulation of cellular lipid storage and membrane lipid composition plays a critical role in metabolic homeostasis, and dysregulation may contribute to disorders such as obesity, fatty liver, type 2 diabetes, and cardiovascular disease. The mammalian lipin proteins (lipin 1, lipin 2, and lipin 3) are phosphatidic acid phosphatase (PAP) enzymes that modulate levels of cellular triacylglycerols and phospholipids, and also regulate lipid intermediates in cellular signaling pathways. Lipin proteins also have the ability to coactivate/corepress transcription. In humans and mice, lipin gene mutations cause severe metabolic phenotypes including rhabdomyolysis (lipin 1), autoinflammatory disease (lipin 2), and impaired intestinal lipoprotein assembly (lipin 2/lipin 3). Characterization of these diseases has revealed roles for lipin PAP activity in fundamental cellular processes such as autophagy, inflammasome activation, and lipoprotein assembly. Lipin protein activity is regulated at pre- and posttranscriptional levels, which suggests a need for their ordered response to specific physiological stimuli. Challenges for the future include better elucidation of the unique biochemical and physiological properties of individual lipin family members and determination of lipin protein structure-function relationships. Further research may propel exploration of lipin proteins as viable therapeutic targets in metabolic or inflammatory disorders.
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Affiliation(s)
- Karen Reue
- Department of Human Genetics, David Geffen School of Medicine, and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Huan Wang
- Department of Human Genetics, David Geffen School of Medicine, and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095.
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24
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Abstract
Lipins play important roles in adipogenesis, insulin sensitivity, and gene regulation, and mutations in these genes cause lipodystrophy, myoglobinuria, and inflammatory disorders. While all lipins (lipin 1, 2, and 3) act as phosphatidic acid phosphatase (PAP) enzymes, which are required for triacylglycerol (TAG) synthesis from glycerol 3-phosphate, lipin 1 has been the focus of most of the lipin-related research. In the current issue of the JCI, Zhang et al. show that while lipin 2 and 3 are expendable for the incorporation of dietary fatty acids into triglycerides, lipin 2/3 PAP activity has a critical role in phospholipid homeostasis and chylomicron assembly in enterocytes.
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Affiliation(s)
- Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, New York University School of Medicine, New York, New York, USA
| | - M Mahmood Hussain
- Diabetes and Obesity Research Center, NYU Winthrop Hospital, Mineola, New York, USA
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