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Igoshin AV, Mishakova TM, Aitnazarov RB, Ilina AV, Larkin DM, Yudin NS. Association of three single nucleotide polymorphisms in the LPIN1 gene with milk production traits in cows of the Yaroslavl breed. Vavilovskii Zhurnal Genet Selektsii 2024; 28:117-125. [PMID: 38465251 PMCID: PMC10917680 DOI: 10.18699/vjgb-24-14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/15/2024] [Accepted: 01/15/2024] [Indexed: 03/12/2024] Open
Abstract
Lipin-1 is a member of the evolutionarily conserved family of proteins and is expressed predominantly in adipose tissue and skeletal muscle. On the one hand, lipin-1 is an enzyme that catalyzes the dephosphorylation of phosphatidic acid to diacylglycerol (DAG) and thus participates in the metabolic pathways of biosynthesis of storage lipids in the cell, membrane phospholipids, and intracellular signaling molecules. On the other hand, lipin-1 is able to be transported from the cytoplasm to the nucleus and is a coactivator of lipid metabolism gene transcription. It was shown, using the analysis of single nucleotide polymorphism (SNP) associations, that the lipin-1 coding gene (LPIN1) is a promising candidate gene for milk production traits in Holstein and Brown Swiss cows. However, it is unclear how much of its effect depends on the breed. The Yaroslavl dairy cattle breed was created in the 18-19 centuries in Russia by breeding northern Great Russian cattle, which were short and poor productive, but well adapted to local climatic conditions and bad food base. It was shown by whole genome genotyping and sequencing that the Yaroslavl breed has unique genetics compared to Russian and other cattle breeds. The aim of the study was to assess the frequency of alleles and genotypes of three SNPs in the LPIN1 gene and to study the association of these SNPs with milk production traits in Yaroslavl cows. Blood samples from 142 cows of the Yaroslavl breed were obtained from two farms in the Yaroslavl region. Genotyping of SNPs was carried out by polymerase chain reaction-restriction fragment length polymorphism method. Associations of SNPs with 305-day milk yield, fat yield, fat percentages, protein yield, and protein percentages were studied from the first to the fourth lactation. Statistical tests were carried out using a mixed linear model, taking into account the relationship between individuals. We identified three SNPs - rs110871255, rs207681322 and rs109039955 with a frequency of a rare allele of 0.042-0.261 in Yaroslavl cows. SNP rs110871255 was associated with fat yield during the third and fourth lactations. SNP rs207681322 was associated with milk yield for the second, third and fourth lactations, as well as protein yield for the third lactation. Thus, we identified significant associations of SNPs rs207681322 and rs110871255 in the LPIN1 gene with a number of milk production traits during several lactations in Yaroslavl cows.
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Affiliation(s)
- A V Igoshin
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - T M Mishakova
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - R B Aitnazarov
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A V Ilina
- Federal Williams Research Center for Forage Production and Agroecology, Scientific Research Institute of Livestock Breeding and Forage Production, Yaroslavl Region, Russia
| | - D M Larkin
- Royal Veterinary College, University of London, London, United Kingdom
| | - N S Yudin
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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2
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Chen R, Liao K, Liao H, Zhang L, Zhao H, Sun J. Screening and functional validation of lipid metabolism-related lncRNA-46546 based on the transcriptome analysis of early embryonic muscle tissue in chicken. Anim Biosci 2023; 36:175-190. [PMID: 35073667 PMCID: PMC9834732 DOI: 10.5713/ab.21.0440] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 01/07/2022] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE The study was conducted to screen differentially expressed long noncoding RNA (lncRNA) in chickens by high-throughput sequencing and explore its mechanism of action on intramuscular fat deposition. METHODS Herein, Rose crown and Cbb broiler chicken embryo breast and leg muscle lncRNA and mRNA expression profiles were constructed by RNA sequencing. A total of 96 and 42 differentially expressed lncRNAs were obtained in Rose crown vs Cobb broiler chicken breast and leg muscle, respectively. lncRNA-ENSGALT00000046546, with high interspecific variability and a potential regulatory role in lipid metabolism, and its predicted downstream target gene 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), were selected for further study on the preadipocytes. RESULTS lncRNA-46546 overexpression in chicken preadipocyte 2 cells significantly increased (p<0.01) the expression levels of AGPAT2 and its downstream genes diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 and those of the fat metabolism-related genes peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein α, fatty acid synthase, sterol regulatory element-binding transcription factor 1, and fatty acid binding protein 4. The lipid droplet concentration was higher in the overexpression group than in the control cells, and the triglyceride content in cells and medium was also significantly increased (p<0.01). CONCLUSION This study preliminarily concludes that lncRNA-46546 may promote intramuscular fat deposition in chickens, laying a foundation for the study of lncRNAs in chicken early embryonic development and fat deposition.
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Affiliation(s)
- Ruonan Chen
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China
| | - Kai Liao
- College of Pharmacy, Shihezi University, Shihezi, 832000,
China
| | - Herong Liao
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China
| | - Li Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China
| | - Haixuan Zhao
- College of Medical, Shihezi University, Shihezi, 832000,
China
| | - Jie Sun
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China,Corresponding Author: Jie Sun, Tel: +86-135-7974-2370, E-mail:
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3
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Wang M, Xie M, Yu S, Shang P, Zhang C, Han X, Fan C, Chen L, Zhuang X, Chen S. Lipin1 Alleviates Autophagy Disorder in Sciatic Nerve and Improves Diabetic Peripheral Neuropathy. Mol Neurobiol 2021; 58:6049-6061. [PMID: 34435332 DOI: 10.1007/s12035-021-02540-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 08/17/2021] [Indexed: 01/10/2023]
Abstract
Diabetic peripheral neuropathy (DPN) is a chronic complication of diabetes, and its neural mechanisms underlying the pathogenesis remain unclear. Autophagy plays an important role in neurodegenerative diseases and nerve tissue injury. Lipin1 is a phosphatidic acid phosphatase enzyme that converts phosphatidic acid (PA) into diacylglycerol (DAG), a precursor of triacylglycerol and phospholipids which plays an important role in maintaining normal peripheral nerve conduction function. However, whether Lipin1 involved in the pathogenesis of DPN via regulation of autophagy is not elucidated. Here, we show that the Lipin1 expression was downregulated in streptozotocin (STZ)-induced DPN rat model. Interestingly, STZ prevented DAG synthesis, and resulted in autophagic hyperactivity, effects which may increase the apoptosis of Schwann cells and lead to demyelination in sciatic nerve in DPN rats. More importantly, upregulation of lipin1 in the DPN rats ameliorated autophagy disorders and pathological changes of the sciatic nerve, which associated with the increase of the motor nerve conductive velocity (MNCV) in DPN rats. In contrast, knockdown of lipin1 exacerbates neuronal abnormalities and facilitates the genesis of DPN phenotypes in rats. In addition, overexpression of lipin1 in RSC96 cells also significantly decreased the autophagic hyperactivity and apoptosis induced by hyperglycemia. These results suggest that lipin1 may exert neuroprotection within the sciatic nerve anomalies and may serve as a potential therapeutic target for the treatment of DPN.
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Affiliation(s)
- Meijian Wang
- Department of Endocrinology, The Second Hospital, Cheeloo College of Medicine, Shandong University, 247 Beiyuan Street, Ji'nan, Shandong, 250033, People's Republic of China.,Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Qingdao, 758 Hefei Road, Qingdao, Shandong, 266035, People's Republic of China
| | - Min Xie
- Department of Endocrinology, The Second Hospital, Cheeloo College of Medicine, Shandong University, 247 Beiyuan Street, Ji'nan, Shandong, 250033, People's Republic of China.,Department of Endocrinology, Binzhou Medical University Hospital, 661 Huanghe Second Road, Binzhou, Shandong, 256603, People's Republic of China
| | - Shuyan Yu
- Department of Physiology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Pan Shang
- Department of Endocrinology, The Second Hospital, Cheeloo College of Medicine, Shandong University, 247 Beiyuan Street, Ji'nan, Shandong, 250033, People's Republic of China
| | - Cong Zhang
- Department of School of Biological & Chemical Engineering, Qingdao Technical College, 369 Qiantangjiang Road, Qingdao, Shandong, 266555, People's Republic of China
| | - Xiaolin Han
- Department of Endocrinology, The Second Hospital, Cheeloo College of Medicine, Shandong University, 247 Beiyuan Street, Ji'nan, Shandong, 250033, People's Republic of China
| | - Cuiqin Fan
- Department of Physiology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Li Chen
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Qingdao, 758 Hefei Road, Qingdao, Shandong, 266035, People's Republic of China
| | - Xianghua Zhuang
- Department of Endocrinology, The Second Hospital, Cheeloo College of Medicine, Shandong University, 247 Beiyuan Street, Ji'nan, Shandong, 250033, People's Republic of China.
| | - Shihong Chen
- Department of Endocrinology, The Second Hospital, Cheeloo College of Medicine, Shandong University, 247 Beiyuan Street, Ji'nan, Shandong, 250033, People's Republic of China.
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4
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Lu S, Lyu Z, Wang Z, Kou Y, Liu C, Li S, Hu M, Zhu H, Wang W, Zhang C, Kuan YS, Liu YW, Chen J, Tian J. Lipin 1 deficiency causes adult-onset myasthenia with motor neuron dysfunction in humans and neuromuscular junction defects in zebrafish. Theranostics 2021; 11:2788-2805. [PMID: 33456573 PMCID: PMC7806489 DOI: 10.7150/thno.53330] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/12/2020] [Indexed: 12/03/2022] Open
Abstract
Lipin 1 is an intracellular protein acting as a phosphatidic acid phosphohydrolase enzyme controlling lipid metabolism. Human recessive mutations in LPIN1 cause recurrent, early-onset myoglobinuria, a condition normally associated with muscle pain and weakness. Whether and how lipin 1 deficiency in humans leads to peripheral neuropathy is yet unclear. Herein, two novel compound heterozygous mutations in LPIN1 with neurological disorders, but no myoglobinuria were identified in an adult-onset syndromic myasthenia family. The present study sought to explore the pathogenic mechanism of LPIN1 in muscular and neural development. Methods: The clinical diagnosis of the proband was compared to the known 48 cases of LPIN1 recessive homozygous mutations. Whole-exome sequencing was carried out on the syndromic myasthenia family to identify the causative gene. The pathogenesis of lipin 1 deficiency during somitogenesis and neurogenesis was investigated using the zebrafish model. Whole-mount in situ hybridization, immunohistochemistry, birefringence analysis, touch-evoke escape response and locomotion assays were performed to observe in vivo the changes in muscles and neurons. The conservatism of the molecular pathways regulated by lipin 1 was evaluated in human primary glioblastoma and mouse myoblast cells by siRNA knockdown, drug treatment, qRT-PCR and Western blotting analysis. Results: The patient exhibited adult-onset myasthenia accompanied by muscle fiber atrophy and nerve demyelination without myoglobinuria. Two novel heterozygous mutations, c.2047A>C (p.I683L) and c.2201G>A (p.R734Q) in LPIN1, were identified in the family and predicted to alter the tertiary structure of LPIN1 protein. Lipin 1 deficiency in zebrafish embryos generated by lpin1 morpholino knockdown or human LPIN1 mutant mRNA injections reproduced the myotomes defects, a reduction both in primary motor neurons and secondary motor neurons projections, morphological changes of post-synaptic clusters of acetylcholine receptors, and myelination defects, which led to reduced touch-evoked response and abnormalities of swimming behaviors. Loss of lipin 1 function in zebrafish and mammalian cells also exhibited altered expression levels of muscle and neuron markers, as well as abnormally enhanced Notch signaling, which was partially rescued by the specific Notch pathway inhibitor DAPT. Conclusions: These findings pointed out that the compound heterozygous mutations in human LPIN1 caused adult-onset syndromic myasthenia with peripheral neuropathy. Moreover, zebrafish could be used to model the neuromuscular phenotypes due to the lipin 1 deficiency, where a novel pathological role of over-activated Notch signaling was discovered and further confirmed in mammalian cell lines.
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5
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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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6
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Maemoto Y, Maruyama T, Nemoto K, Baba T, Motohashi M, Ito A, Tagaya M, Tani K. DDHD1, but Not DDHD2, Suppresses Neurite Outgrowth in SH-SY5Y and PC12 Cells by Regulating Protein Transport From Recycling Endosomes. Front Cell Dev Biol 2020; 8:670. [PMID: 32850804 PMCID: PMC7396612 DOI: 10.3389/fcell.2020.00670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/02/2020] [Indexed: 12/02/2022] Open
Abstract
DDHD1 and DDHD2 are both intracellular phospholipases A1 and hydrolyze phosphatidic acid in vitro. Given that phosphatidic acid participates in neurite outgrowth, we examined whether DDHD1 and DDHD2 regulate neurite outgrowth. Depletion of DDHD1 from SH-SY5Y and PC12 cells caused elongation of neurites, whereas DDHD2 depletion prevented neurite elongation. Rescue experiments demonstrated that the enzymatic activity of DDHD1 is necessary for the prevention of neurite elongation. Depletion of DDHD1 caused enlargement of early endosomes and stimulated tubulation of recycling endosomes positive for phosphatidic acid-binding proteins syndapin2 and MICAL-L1. Knockout of DDHD1 enhanced transferrin recycling from recycling endosomes to the cell surface. Our results suggest that DDHD1 negatively controls the formation of a local phosphatidic acid-rich domain in recycling endosomes that serves as a membrane source for neurite outgrowth.
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Affiliation(s)
- Yuki Maemoto
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Tomohiro Maruyama
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Kazuaki Nemoto
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Takashi Baba
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan.,Department of Biological Informatics and Experimental Therapeutics, Graduate School of Medicine and Faculty of Medicine, Akita University, Akita, Japan
| | - Manae Motohashi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Akihiro Ito
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Mitsuo Tagaya
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Katsuko Tani
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
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7
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Szpirer C. Rat models of human diseases and related phenotypes: a systematic inventory of the causative genes. J Biomed Sci 2020; 27:84. [PMID: 32741357 PMCID: PMC7395987 DOI: 10.1186/s12929-020-00673-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
The laboratory rat has been used for a long time as the model of choice in several biomedical disciplines. Numerous inbred strains have been isolated, displaying a wide range of phenotypes and providing many models of human traits and diseases. Rat genome mapping and genomics was considerably developed in the last decades. The availability of these resources has stimulated numerous studies aimed at discovering causal disease genes by positional identification. Numerous rat genes have now been identified that underlie monogenic or complex diseases and remarkably, these results have been translated to the human in a significant proportion of cases, leading to the identification of novel human disease susceptibility genes, helping in studying the mechanisms underlying the pathological abnormalities and also suggesting new therapeutic approaches. In addition, reverse genetic tools have been developed. Several genome-editing methods were introduced to generate targeted mutations in genes the function of which could be clarified in this manner [generally these are knockout mutations]. Furthermore, even when the human gene causing a disease had been identified without resorting to a rat model, mutated rat strains (in particular KO strains) were created to analyze the gene function and the disease pathogenesis. Today, over 350 rat genes have been identified as underlying diseases or playing a key role in critical biological processes that are altered in diseases, thereby providing a rich resource of disease models. This article is an update of the progress made in this research and provides the reader with an inventory of these disease genes, a significant number of which have similar effects in rat and humans.
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Affiliation(s)
- Claude Szpirer
- Université Libre de Bruxelles, B-6041, Gosselies, Belgium.
- , Waterloo, Belgium.
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8
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Kwiatek JM, Carman GM. Yeast phosphatidic acid phosphatase Pah1 hops and scoots along the membrane phospholipid bilayer. J Lipid Res 2020; 61:1232-1243. [PMID: 32540926 DOI: 10.1194/jlr.ra120000937] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/09/2020] [Indexed: 01/01/2023] Open
Abstract
PA phosphatase, encoded by PAH1 in the yeast Saccharomyces cerevisiae, catalyzes the Mg2+-dependent dephosphorylation of PA, producing DAG at the nuclear/ER membrane. This enzyme plays a major role in triacylglycerol synthesis and in the regulation of phospholipid synthesis. As an interfacial enzyme, PA phosphatase interacts with the membrane surface, binds its substrate, and catalyzes its reaction. The Triton X-100/PA-mixed micellar system has been utilized to examine the activity and regulation of yeast PA phosphatase. This system, however, does not resemble the in vivo environment of the membrane phospholipid bilayer. We developed an assay system that mimics the nuclear/ER membrane to assess PA phosphatase activity. PA was incorporated into unilamellar phospholipid vesicles (liposomes) composed of the major nuclear/ER membrane phospholipids, PC, PE, PI, and PS. We optimized this system to support enzyme-liposome interactions and to afford activity that is greater than that obtained with the aforementioned detergent system. Activity was regulated by phospholipid composition, whereas the enzyme's interaction with liposomes was insensitive to composition. Greater activity was attained with large (≥100 nm) versus small (50 nm) vesicles. The fatty-acyl moiety of PA had no effect on this activity. PA phosphatase activity was dependent on the bulk (hopping mode) and surface (scooting mode) concentrations of PA, suggesting a mechanism by which the enzyme operates along the nuclear/ER membrane in vivo.
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Affiliation(s)
- Joanna M Kwiatek
- Department of Food Science and Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901
| | - George M Carman
- Department of Food Science and Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901
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9
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Rashid T, Nemazanyy I, Paolini C, Tatsuta T, Crespin P, de Villeneuve D, Brodesser S, Benit P, Rustin P, Baraibar MA, Agbulut O, Olivier A, Protasi F, Langer T, Chrast R, de Lonlay P, de Foucauld H, Blaauw B, Pende M. Lipin1 deficiency causes sarcoplasmic reticulum stress and chaperone-responsive myopathy. EMBO J 2019; 38:e99576. [PMID: 30420558 PMCID: PMC6315296 DOI: 10.15252/embj.201899576] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/21/2018] [Accepted: 10/02/2018] [Indexed: 12/20/2022] Open
Abstract
As a consequence of impaired glucose or fatty acid metabolism, bioenergetic stress in skeletal muscles may trigger myopathy and rhabdomyolysis. Genetic mutations causing loss of function of the LPIN1 gene frequently lead to severe rhabdomyolysis bouts in children, though the metabolic alterations and possible therapeutic interventions remain elusive. Here, we show that lipin1 deficiency in mouse skeletal muscles is sufficient to trigger myopathy. Strikingly, muscle fibers display strong accumulation of both neutral and phospholipids. The metabolic lipid imbalance can be traced to an altered fatty acid synthesis and fatty acid oxidation, accompanied by a defect in acyl chain elongation and desaturation. As an underlying cause, we reveal a severe sarcoplasmic reticulum (SR) stress, leading to the activation of the lipogenic SREBP1c/SREBP2 factors, the accumulation of the Fgf21 cytokine, and alterations of SR-mitochondria morphology. Importantly, pharmacological treatments with the chaperone TUDCA and the fatty acid oxidation activator bezafibrate improve muscle histology and strength of lipin1 mutants. Our data reveal that SR stress and alterations in SR-mitochondria contacts are contributing factors and potential intervention targets of the myopathy associated with lipin1 deficiency.
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Affiliation(s)
- Talha Rashid
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Sanofi R&D, Translational Sciences Unit, In Silico Biology, Chilly-Mazarin, France
| | - Ivan Nemazanyy
- Platform for Metabolic Analyses, Institut Necker-Enfants Malades, Paris, France
| | - Cecilia Paolini
- Center for Research on Ageing and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging, and Clinical Sciences (DNICS), University G. d' Annunzio of Chieti, Chieti, Italy
| | - Takashi Tatsuta
- Max-Planck-Institute for Biology of Ageing, Cologne, Germany
| | - Paul Crespin
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Delphine de Villeneuve
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Susanne Brodesser
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Paule Benit
- INSERM, UMR 1141, Hôpital Robert Debré, Paris, France
| | - Pierre Rustin
- INSERM, UMR 1141, Hôpital Robert Debré, Paris, France
| | | | - Onnik Agbulut
- CNRS, Institut de Biologie Paris-Seine (IBPS), Biological Adaptation and Ageing, Sorbonne Université, Paris, France
| | - Anne Olivier
- Sanofi R&D, Translational Sciences Unit, In Silico Biology, Chilly-Mazarin, France
| | - Feliciano Protasi
- Center for Research on Ageing and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging, and Clinical Sciences (DNICS), University G. d' Annunzio of Chieti, Chieti, Italy
| | - Thomas Langer
- Max-Planck-Institute for Biology of Ageing, Cologne, Germany
| | - Roman Chrast
- Department of Neuroscience and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Pascale de Lonlay
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Helene de Foucauld
- Sanofi R&D, Translational Sciences Unit, In Silico Biology, Chilly-Mazarin, France
| | - Bert Blaauw
- Department of Biomedical Sciences, Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy
| | - Mario Pende
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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10
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Starr ML, Fratti RA. The Participation of Regulatory Lipids in Vacuole Homotypic Fusion. Trends Biochem Sci 2018; 44:546-554. [PMID: 30587414 DOI: 10.1016/j.tibs.2018.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/27/2018] [Accepted: 12/03/2018] [Indexed: 12/28/2022]
Abstract
In eukaryotes, organelles and vesicles modulate their contents and identities through highly regulated membrane fusion events. Membrane trafficking and fusion are carried out through a series of stages that lead to the formation of SNARE complexes between cellular compartment membranes to trigger fusion. Although the protein catalysts of membrane fusion are well characterized, their response to their surrounding microenvironment, provided by the lipid composition of the membrane, remains to be fully understood. Membranes are composed of bulk lipids (e.g., phosphatidylcholine), as well as regulatory lipids that undergo constant modifications by kinases, phosphatases, and lipases. These lipids include phosphoinositides, diacylglycerol, phosphatidic acid, and cholesterol/ergosterol. Here we describe the roles of these lipids throughout the stages of yeast vacuole homotypic fusion.
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Affiliation(s)
- Matthew L Starr
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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11
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Pelosi M, Testet E, Le Lay S, Dugail I, Tang X, Mabilleau G, Hamel Y, Madrange M, Blanc T, Odent T, McMullen TPW, Alfò M, Brindley DN, de Lonlay P. Normal human adipose tissue functions and differentiation in patients with biallelic LPIN1 inactivating mutations. J Lipid Res 2017; 58:2348-2364. [PMID: 28986436 PMCID: PMC5711497 DOI: 10.1194/jlr.p075440] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 08/23/2017] [Indexed: 12/22/2022] Open
Abstract
Lipin-1 is a Mg2+-dependent phosphatidic acid phosphatase (PAP) that in mice is necessary for normal glycerolipid biosynthesis, controlling adipocyte metabolism, and adipogenic differentiation. Mice carrying inactivating mutations in the Lpin1 gene display the characteristic features of human familial lipodystrophy. Very little is known about the roles of lipin-1 in human adipocyte physiology. Apparently, fat distribution and weight is normal in humans carrying LPIN1 inactivating mutations, but a detailed analysis of adipose tissue appearance and functions in these patients has not been available so far. In this study, we performed a systematic histopathological, biochemical, and gene expression analysis of adipose tissue biopsies from human patients harboring LPIN1 biallelic inactivating mutations and affected by recurrent episodes of severe rhabdomyolysis. We also explored the adipogenic differentiation potential of human mesenchymal cell populations derived from lipin-1 defective patients. White adipose tissue from human LPIN1 mutant patients displayed a dramatic decrease in lipin-1 protein levels and PAP activity, with a concomitant moderate reduction of adipocyte size. Nevertheless, the adipose tissue develops without obvious histological signs of lipodystrophy and with normal qualitative composition of storage lipids. The increased expression of key adipogenic determinants such as SREBP1, PPARG, and PGC1A shows that specific compensatory phenomena can be activated in vivo in human adipocytes with deficiency of functional lipin-1.
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Affiliation(s)
- Michele Pelosi
- Centre de Référence des Maladies Héréditaires du Métabolisme, Institut Imagine des Maladies Génétiques, Laboratoire de génétique des maladies autoinflammatoires monogéniques, INSERM UMR1163, Université Paris Descartes et Hôpital Necker-Enfants malades (Assistance publique - Hôpitaux de Paris), Paris, France
| | - Eric Testet
- Laboratoire de Biogenèse Membranaire-UMR 5200, CNRS, Université de Bordeaux, Villenave d'Ornon, France
| | - Soazig Le Lay
- INSERM, UMR1063, Université d'Angers, UBL, Angers, France
| | - Isabelle Dugail
- INSERM, U1166, Equipe 6, Université Pierre et Marie Curie, Paris, France
| | - Xiaoyun Tang
- Department of Biochemistry, Signal Transduction Research Group, University of Alberta, Edmonton, Alberta, Canada
| | | | - Yamina Hamel
- Centre de Référence des Maladies Héréditaires du Métabolisme, Institut Imagine des Maladies Génétiques, Laboratoire de génétique des maladies autoinflammatoires monogéniques, INSERM UMR1163, Université Paris Descartes et Hôpital Necker-Enfants malades (Assistance publique - Hôpitaux de Paris), Paris, France
| | - Marine Madrange
- Centre de Référence des Maladies Héréditaires du Métabolisme, Institut Imagine des Maladies Génétiques, Laboratoire de génétique des maladies autoinflammatoires monogéniques, INSERM UMR1163, Université Paris Descartes et Hôpital Necker-Enfants malades (Assistance publique - Hôpitaux de Paris), Paris, France
| | - Thomas Blanc
- Department of Pediatric Surgery and Urology, Hôpital Necker-Enfants malades-Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Thierry Odent
- Department of Pediatric Orthopedics, Hôpital Necker-Enfants malades-Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Todd P W McMullen
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Marco Alfò
- Dipartimento di Scienze Statistiche, Sapienza Università di Roma, Rome, Italy
| | - David N Brindley
- Department of Biochemistry, Signal Transduction Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Pascale de Lonlay
- Centre de Référence des Maladies Héréditaires du Métabolisme, Institut Imagine des Maladies Génétiques, Laboratoire de génétique des maladies autoinflammatoires monogéniques, INSERM UMR1163, Université Paris Descartes et Hôpital Necker-Enfants malades (Assistance publique - Hôpitaux de Paris), Paris, France
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12
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Qiu Y, Hassaninasab A, Han GS, Carman GM. Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae. J Biol Chem 2016; 291:26455-26467. [PMID: 27834677 DOI: 10.1074/jbc.m116.763839] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/08/2016] [Indexed: 11/06/2022] Open
Abstract
In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1-77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1-77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA.
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Affiliation(s)
- Yixuan Qiu
- From the 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 08901
| | - Azam Hassaninasab
- From the 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 08901
| | - Gil-Soo Han
- From the 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 08901
| | - George M Carman
- From the 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 08901
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13
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Temprano A, Sembongi H, Han GS, Sebastián D, Capellades J, Moreno C, Guardiola J, Wabitsch M, Richart C, Yanes O, Zorzano A, Carman GM, Siniossoglou S, Miranda M. Redundant roles of the phosphatidate phosphatase family in triacylglycerol synthesis in human adipocytes. Diabetologia 2016; 59:1985-94. [PMID: 27344312 PMCID: PMC4969345 DOI: 10.1007/s00125-016-4018-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/23/2016] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS In mammals, the evolutionary conserved family of Mg(2+)-dependent phosphatidate phosphatases (PAP1), involved in phospholipid and triacylglycerol synthesis, consists of lipin-1, lipin-2 and lipin-3. While mutations in the murine Lpin1 gene cause lipodystrophy and its knockdown in mouse 3T3-L1 cells impairs adipogenesis, deleterious mutations of human LPIN1 do not affect adipose tissue distribution. However, reduced LPIN1 and PAP1 activity has been described in participants with type 2 diabetes. We aimed to characterise the roles of all lipin family members in human adipose tissue and adipogenesis. METHODS The expression of the lipin family was analysed in adipose tissue in a cross-sectional study. Moreover, the effects of lipin small interfering RNA (siRNA)-mediated depletion on in vitro human adipogenesis were assessed. RESULTS Adipose tissue gene expression of the lipin family is altered in type 2 diabetes. Depletion of every lipin family member in a human Simpson-Golabi-Behmel syndrome (SGBS) pre-adipocyte cell line, alters expression levels of adipogenic transcription factors and lipid biosynthesis genes in early stages of differentiation. Lipin-1 knockdown alone causes a 95% depletion of PAP1 activity. Despite the reduced PAP1 activity and alterations in early adipogenesis, lipin-silenced cells differentiate and accumulate neutral lipids. Even combinatorial knockdown of lipins shows mild effects on triacylglycerol accumulation in mature adipocytes. CONCLUSIONS/INTERPRETATION Overall, our data support the hypothesis of alternative pathways for triacylglycerol synthesis in human adipocytes under conditions of repressed lipin expression. We propose that induction of alternative lipid phosphate phosphatases, along with the inhibition of lipid hydrolysis, contributes to the maintenance of triacylglycerol content to near normal levels.
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Affiliation(s)
- Ana Temprano
- Joan XXIII University Hospital, Pere Virgili Health Research Institut (IISPV), Modular Building, C/ Mallafre Guasch, Tarragona, 43005, Spain
- Department of Biochemistry and Molecular Biology, Rovira i Virgili University, Tarragona, Spain
| | - Hiroshi Sembongi
- Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge, CB2 0XY, UK
- , Chesterford Research Park, Little Chesterford, Saffron Walden, UK
| | - 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
| | - David Sebastián
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Jordi Capellades
- Biomedical Research Networking Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Centre for Omic Sciences, Rovira i Virgili University, Reus, Spain
| | - Cristóbal Moreno
- Joan XXIII University Hospital, Pere Virgili Health Research Institut (IISPV), Modular Building, C/ Mallafre Guasch, Tarragona, 43005, Spain
- Biomedical Research Networking Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Juan Guardiola
- Department of Pulmonary, Critical Care and Sleep Medicine, University of Louisville, Louisville, KY, USA
| | - Martin Wabitsch
- Division of Paediatric Endocrinology and Diabetes, Interdisciplinary Obesity Clinic, University Clinic for Child and Adolescent Medicine, University of Ulm, Ulm, Germany
| | - Cristóbal Richart
- Joan XXIII University Hospital, Pere Virgili Health Research Institut (IISPV), Modular Building, C/ Mallafre Guasch, Tarragona, 43005, Spain
- GEMMAIR Research Group - Applied Medicine, Department of Medicine and Surgery, Rovira i Virgili University (URV), Tarragona, Spain
| | - Oscar Yanes
- Biomedical Research Networking Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Centre for Omic Sciences, Rovira i Virgili University, Reus, Spain
- Department of Electronic Engineering, Rovira i Virgili University, Tarragona, Spain
| | - Antonio Zorzano
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - 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
| | - Symeon Siniossoglou
- Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge, CB2 0XY, UK.
| | - Merce Miranda
- Joan XXIII University Hospital, Pere Virgili Health Research Institut (IISPV), Modular Building, C/ Mallafre Guasch, Tarragona, 43005, Spain.
- Biomedical Research Networking Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain, .
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14
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Jaradat SA, Amayreh W, Al-Qa'qa' K, Krayyem J. Molecular analysis of LPIN1 in Jordanian patients with rhabdomyolysis. Meta Gene 2015; 7:90-4. [PMID: 26909335 PMCID: PMC4733219 DOI: 10.1016/j.mgene.2015.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/15/2015] [Accepted: 12/02/2015] [Indexed: 12/31/2022] Open
Abstract
Recessive mutations in LPIN1, which encodes a phosphatidate phosphatase enzyme, are a frequent cause of severe rhabdomyolysis in childhood. Hence, we sequenced the 19 coding exons of the gene in eight patients with recurrent hereditary myoglobinuria from four unrelated families in Jordan. The long-term goal is to facilitate molecular genetic diagnosis without the need for invasive procedures such as muscle biopsies. Three different mutations were detected, including the novel missense mutation c.2395G>C (Gly799Arg), which was found in two families. The two other mutations, c.2174G>A (Arg725His) and c.1162C>T (Arg388X), have been previously identified, and were found to cosegregate with the disease phenotype in the other two families. Intriguingly, patients homozygous for Arg725His were also homozygous for the c.1828C>T (Pro610Ser) polymorphism, and were exercise-intolerant between myoglobinuria episodes. Notably, patients homozygous for Arg388X were also homozygous for the c.2250G>C silent variant (Gly750Gly). Taken together, the data provide family-based evidence linking hereditary myoglobinuria to pathogenic variations in the C-terminal lipin domain of the enzyme. This finding highlights the functional significance of this domain in the absence of structural information. This is the first analysis of LPIN1 in myoglobinuria patients of Jordanian origin, and the fourth such analysis worldwide. LPIN1 mutations were cataloged in families with hereditary myoglobinuria. A novel missense Gly799Arg mutation was identified. Arg725His, the only other known missense mutation, was confirmed to be pathogenic. Arg388X, a known nonsense mutation, was the most common among Arabic patients. Patients exercise-intolerant between myoglobinuria episodes have a second mutation.
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Affiliation(s)
- Saied A Jaradat
- Princess Haya Biotechnology Center, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Wajdi Amayreh
- Department of Pediatrics, Metabolic Genetics Clinic, Queen Rania Al-Abdullah Children's Hospital, King Hussein Medical Centre, Amman 11855, Jordan
| | - Kefah Al-Qa'qa'
- Department of Pediatrics, Metabolic Genetics Clinic, Queen Rania Al-Abdullah Children's Hospital, King Hussein Medical Centre, Amman 11855, Jordan
| | - Jan Krayyem
- Princess Haya Biotechnology Center, Jordan University of Science and Technology, Irbid 22110, Jordan
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15
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Park Y, Han GS, Mileykovskaya E, Garrett TA, Carman GM. Altered Lipid Synthesis by Lack of Yeast Pah1 Phosphatidate Phosphatase Reduces Chronological Life Span. J Biol Chem 2015; 290:25382-94. [PMID: 26338708 DOI: 10.1074/jbc.m115.680314] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 01/20/2023] Open
Abstract
In Saccharomyces cerevisiae, Pah1 phosphatidate phosphatase, which catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol, plays a crucial role in the synthesis of the storage lipid triacylglycerol. This evolutionarily conserved enzyme also plays a negative regulatory role in controlling de novo membrane phospholipid synthesis through its consumption of phosphatidate. We found that the pah1Δ mutant was defective in the utilization of non-fermentable carbon sources but not in oxidative phosphorylation; the mutant did not exhibit major changes in oxygen consumption rate, mitochondrial membrane potential, F1F0-ATP synthase activity, or gross mitochondrial morphology. The pah1Δ mutant contained an almost normal complement of major mitochondrial phospholipids with some alterations in molecular species. Although oxidative phosphorylation was not compromised in the pah1Δ mutant, the cellular levels of ATP in quiescent cells were reduced by 2-fold, inversely correlating with a 4-fold increase in membrane phospholipids. In addition, the quiescent pah1Δ mutant cells had 3-fold higher levels of mitochondrial superoxide and cellular lipid hydroperoxides, had reduced activities of superoxide dismutase 2 and catalase, and were hypersensitive to hydrogen peroxide. Consequently, the pah1Δ mutant had a shortened chronological life span. In addition, the loss of Tsa1 thioredoxin peroxidase caused a synthetic growth defect with the pah1Δ mutation. The shortened chronological life span of the pah1Δ mutant along with its growth defect on non-fermentable carbon sources and hypersensitivity to hydrogen peroxide was suppressed by the loss of Dgk1 diacylglycerol kinase, indicating that the underpinning of pah1Δ mutant defects was the excess synthesis of membrane phospholipids.
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Affiliation(s)
- Yeonhee Park
- From the 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 08901
| | - Gil-Soo Han
- From the 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 08901
| | - Eugenia Mileykovskaya
- the Department of Biochemistry and Molecular Biology, University of Texas-Houston Medical School, Houston, Texas 77030, and
| | - Teresa A Garrett
- the Department of Chemistry, Vassar College, Poughkeepsie, New York 12604
| | - George M Carman
- From the 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 08901,
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16
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Hsieh LS, Su WM, Han GS, Carman GM. Phosphorylation regulates the ubiquitin-independent degradation of yeast Pah1 phosphatidate phosphatase by the 20S proteasome. J Biol Chem 2015; 290:11467-78. [PMID: 25809482 DOI: 10.1074/jbc.m115.648659] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Indexed: 01/08/2023] Open
Abstract
Saccharomyces cerevisiae Pah1 phosphatidate phosphatase, which catalyzes the conversion of phosphatidate to diacylglycerol for triacylglycerol synthesis and simultaneously controls phosphatidate levels for phospholipid synthesis, is subject to the proteasome-mediated degradation in the stationary phase of growth. In this study, we examined the mechanism for its degradation using purified Pah1 and isolated proteasomes. Pah1 expressed in S. cerevisiae or Escherichia coli was not degraded by the 26S proteasome, but by its catalytic 20S core particle, indicating that its degradation is ubiquitin-independent. The degradation of Pah1 by the 20S proteasome was dependent on time and proteasome concentration at the pH optimum of 7.0. The 20S proteasomal degradation was conserved for human lipin 1 phosphatidate phosphatase. The degradation analysis using Pah1 truncations and its fusion with GFP indicated that proteolysis initiates at the N- and C-terminal unfolded regions. The folded region of Pah1, in particular the haloacid dehalogenase-like domain containing the DIDGT catalytic sequence, was resistant to the proteasomal degradation. The structural change of Pah1, as reflected by electrophoretic mobility shift, occurs through its phosphorylation by Pho85-Pho80, and the phosphorylation sites are located within its N- and C-terminal unfolded regions. Phosphorylation of Pah1 by Pho85-Pho80 inhibited its degradation, extending its half-life by ∼2-fold. The dephosphorylation of endogenously phosphorylated Pah1 by the Nem1-Spo7 protein phosphatase, which is highly specific for the sites phosphorylated by Pho85-Pho80, stimulated the 20S proteasomal degradation and reduced its half-life by 2.6-fold. These results indicate that the proteolysis of Pah1 by the 20S proteasome is controlled by its phosphorylation state.
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Affiliation(s)
- Lu-Sheng Hsieh
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Wen-Min Su
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Gil-Soo Han
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - George M Carman
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
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17
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Su WM, Han GS, Carman GM. Yeast Nem1-Spo7 protein phosphatase activity on Pah1 phosphatidate phosphatase is specific for the Pho85-Pho80 protein kinase phosphorylation sites. J Biol Chem 2014; 289:34699-708. [PMID: 25359770 DOI: 10.1074/jbc.m114.614883] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pah1 is the phosphatidate phosphatase in the yeast Saccharomyces cerevisiae that produces diacylglycerol for triacylglycerol synthesis and concurrently controls the levels of phosphatidate used for phospholipid synthesis. Phosphorylation and dephosphorylation of Pah1 regulate its subcellular location and phosphatidate phosphatase activity. Compared with its phosphorylation by multiple protein kinases, Pah1 is dephosphorylated by a protein phosphatase complex consisting of Nem1 (catalytic subunit) and Spo7 (regulatory subunit). In this work, we characterized the Nem1-Spo7 phosphatase complex for its enzymological, kinetic, and regulatory properties with phosphorylated Pah1. The dephosphorylation of Pah1 by Nem1-Spo7 phosphatase resulted in the stimulation (6-fold) of phosphatidate phosphatase activity. For Pah1 phosphorylated by the Pho85-Pho80 kinase complex, maximum Nem1-Spo7 phosphatase activity required Mg(2+) ions (8 mm) and Triton X-100 (0.25 mm) at pH 5.0. The energy of activation for the reaction was 8.4 kcal/mol, and the enzyme was thermally labile at temperatures above 40 °C. The enzyme activity was inhibited by sodium vanadate, sodium fluoride, N-ethylmaleimide, and phenylglyoxal but was not significantly affected by lipids or nucleotides. Nem1-Spo7 phosphatase activity was dependent on the concentrations of Pah1 phosphorylated by Pho85-Pho80, Cdc28-cyclin B, PKA, and PKC with kcat and Km values of 0.29 s(-1) and 81 nm, 0.11 s(-1) and 127 nm, 0.10 s(-1) and 46 nm, and 0.02 s(-1) and 38 nm, respectively. Its specificity constant (kcat/Km) for Pah1 phosphorylated by Pho85-Pho80 was 1.6-, 4-, and 6-fold higher, respectively, than that phosphorylated by PKA, Cdc28-cyclin B, and PKC.
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Affiliation(s)
- Wen-Min Su
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Gil-Soo Han
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - George M Carman
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
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18
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Su WM, Han GS, Carman GM. Cross-talk phosphorylations by protein kinase C and Pho85p-Pho80p protein kinase regulate Pah1p phosphatidate phosphatase abundance in Saccharomyces cerevisiae. J Biol Chem 2014; 289:18818-30. [PMID: 24876385 DOI: 10.1074/jbc.m114.581462] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Yeast Pah1p is the phosphatidate phosphatase that catalyzes the penultimate step in triacylglycerol synthesis and plays a role in the transcriptional regulation of phospholipid synthesis genes. The enzyme is multiply phosphorylated, some of which is mediated by Pho85p-Pho80p, Cdc28p-cyclin B, and protein kinase A. Here, we showed that Pah1p is a bona fide substrate of protein kinase C; the phosphorylation reaction was time- and dose-dependent and dependent on the concentrations of ATP (Km = 4.5 μm) and Pah1p (Km = 0.75 μm). The stoichiometry of the reaction was 0.8 mol of phosphate/mol of Pah1p. By combining mass spectrometry, truncation analysis, site-directed mutagenesis, and phosphopeptide mapping, we identified Ser-677, Ser-769, Ser-773, and Ser-788 as major sites of phosphorylation. Analysis of Pah1p phosphorylations by different protein kinases showed that prephosphorylation with protein kinase C reduces its subsequent phosphorylation with protein kinase A and vice versa. Prephosphorylation with Pho85p-Pho80p had an inhibitory effect on its subsequent phosphorylation with protein kinase C; however, prephosphorylation with protein kinase C had no effect on the subsequent phosphorylation with Pho85p-Pho80p. Unlike its phosphorylations by Pho85p-Pho80p and protein kinase A, which cause a significant reduction in phosphatidate phosphatase activity, the phosphorylation of Pah1p by protein kinase C had a small stimulatory effect on the enzyme activity. Analysis of phosphorylation-deficient forms of Pah1p indicated that protein kinase C does not have a major effect on its location or its function in triacylglycerol synthesis, but instead, the phosphorylation favors loss of Pah1p abundance when it is not phosphorylated with Pho85p-Pho80p.
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Affiliation(s)
- Wen-Min Su
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Gil-Soo Han
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - George M Carman
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
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19
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Baba T, Kashiwagi Y, Arimitsu N, Kogure T, Edo A, Maruyama T, Nakao K, Nakanishi H, Kinoshita M, Frohman MA, Yamamoto A, Tani K. Phosphatidic acid (PA)-preferring phospholipase A1 regulates mitochondrial dynamics. J Biol Chem 2014; 289:11497-11511. [PMID: 24599962 PMCID: PMC4036285 DOI: 10.1074/jbc.m113.531921] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/04/2014] [Indexed: 12/14/2022] Open
Abstract
Recent studies have suggested that phosphatidic acid (PA), a cone-shaped phospholipid that can generate negative curvature of lipid membranes, participates in mitochondrial fusion. However, precise mechanisms underling the production and consumption of PA on the mitochondrial surface are not fully understood. Phosphatidic acid-preferring phospholipase A1 (PA-PLA1)/DDHD1 is the first identified intracellular phospholipase A1 and preferentially hydrolyzes PA in vitro. Its cellular and physiological functions have not been elucidated. In this study, we show that PA-PLA1 regulates mitochondrial dynamics. PA-PLA1, when ectopically expressed in HeLa cells, induced mitochondrial fragmentation, whereas its depletion caused mitochondrial elongation. The effects of PA-PLA1 on mitochondrial morphology appear to counteract those of MitoPLD, a mitochondrion-localized phospholipase D that produces PA from cardiolipin. Consistent with high levels of expression of PA-PLA1 in testis, PA-PLA1 knock-out mice have a defect in sperm formation. In PA-PLA1-deficient sperm, the mitochondrial structure is disorganized, and an abnormal gap structure exists between the middle and principal pieces. A flagellum is bent at that position, leading to a loss of motility. Our results suggest a possible mechanism of PA regulation of the mitochondrial membrane and demonstrate an in vivo function of PA-PLA1 in the organization of mitochondria during spermiogenesis.
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Affiliation(s)
- Takashi Baba
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yuriko Kashiwagi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Nagisa Arimitsu
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Takeshi Kogure
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Ayumi Edo
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Tomohiro Maruyama
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Kazuki Nakao
- RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Hiroki Nakanishi
- Research Center for Biosignal, Akita University, Akita 010-8543, Japan
| | - Makoto Kinoshita
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Michael A Frohman
- Department of Pharmacology and Center for Developmental Genetics, Stony Brook University, Stony Brook, New York 11794-5140, and
| | - Akitsugu Yamamoto
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan
| | - Katsuko Tani
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan,.
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Sembongi H, Miranda M, Han GS, Fakas S, Grimsey N, Vendrell J, Carman GM, Siniossoglou S. Distinct roles of the phosphatidate phosphatases lipin 1 and 2 during adipogenesis and lipid droplet biogenesis in 3T3-L1 cells. J Biol Chem 2013; 288:34502-13. [PMID: 24133206 PMCID: PMC3843065 DOI: 10.1074/jbc.m113.488445] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 10/04/2013] [Indexed: 11/06/2022] Open
Abstract
Lipins are evolutionarily conserved Mg(2+)-dependent phosphatidate phosphatase (PAP) enzymes with essential roles in lipid biosynthesis. Mammals express three paralogues: lipins 1, 2, and 3. Loss of lipin 1 in mice inhibits adipogenesis at an early stage of differentiation and results in a lipodystrophic phenotype. The role of lipins at later stages of adipogenesis, when cells initiate the formation of lipid droplets, is less well characterized. We found that depletion of lipin 1, after the initiation of differentiation in 3T3-L1 cells but before the loading of lipid droplets with triacylglycerol, results in a reciprocal increase of lipin 2, but not lipin 3. We generated 3T3-L1 cells where total lipin protein and PAP activity levels are down-regulated by the combined depletion of lipins 1 and 2 at day 4 of differentiation. These cells still accumulated triacylglycerol but displayed a striking fragmentation of lipid droplets without significantly affecting their total volume per cell. This was due to the lack of the PAP activity of lipin 1 in adipocytes after day 4 of differentiation, whereas depletion of lipin 2 led to an increase of lipid droplet volume per cell. We propose that in addition to their roles during early adipogenesis, lipins also have a role in lipid droplet biogenesis.
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Affiliation(s)
- Hiroshi Sembongi
- From the Cambridge Institute for Medical Research, University of Cambridge, CB2 0XY Cambridge, United Kingdom
| | - Merce Miranda
- the Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Institut d'Investigació Pere Virgili, Universitat Rovira i Virgili, Hospital Universitari Joan XXIII, Tarragona, Spain, and
| | - Gil-Soo Han
- the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Stylianos Fakas
- the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Neil Grimsey
- From the Cambridge Institute for Medical Research, University of Cambridge, CB2 0XY Cambridge, United Kingdom
| | - Joan Vendrell
- the Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Institut d'Investigació Pere Virgili, Universitat Rovira i Virgili, Hospital Universitari Joan XXIII, Tarragona, Spain, and
| | - George M. Carman
- the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Symeon Siniossoglou
- From the Cambridge Institute for Medical Research, University of Cambridge, CB2 0XY Cambridge, United Kingdom
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21
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Siniossoglou S. Phospholipid metabolism and nuclear function: Roles of the lipin family of phosphatidic acid phosphatases. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:575-81. [DOI: 10.1016/j.bbalip.2012.09.014] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 01/22/2023]
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22
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Michot C, Hubert L, Romero NB, Gouda A, Mamoune A, Mathew S, Kirk E, Viollet L, Rahman S, Bekri S, Peters H, McGill J, Glamuzina E, Farrar M, von der Hagen M, Alexander IE, Kirmse B, Barth M, Laforet P, Benlian P, Munnich A, JeanPierre M, Elpeleg O, Pines O, Delahodde A, de Keyzer Y, de Lonlay P. Study of LPIN1, LPIN2 and LPIN3 in rhabdomyolysis and exercise-induced myalgia. J Inherit Metab Dis 2012; 35:1119-28. [PMID: 22481384 DOI: 10.1007/s10545-012-9461-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 01/19/2012] [Accepted: 01/30/2012] [Indexed: 01/21/2023]
Abstract
BACKGROUND Recessive LPIN1 mutations were identified as a cause of severe rhabdomyolysis in pediatric patients. The human lipin family includes two other closely related members, lipin-2 and 3, which share strong homology and similar activity. The study aimed to determine the involvement of the LPIN family genes in a cohort of pediatric and adult patients (n = 171) presenting with muscular symptoms, ranging from severe (CK >10 000 UI/L) or moderate (CK <10 000 UI/L) rhabdomyolysis (n = 141) to exercise-induced myalgia (n = 30), and to report the clinical findings in patients harboring mutations. METHODS Coding regions of LPIN1, LPIN2 and LPIN3 genes were sequenced using genomic or complementary DNAs. RESULTS Eighteen patients harbored two LPIN1 mutations, including a frequent intragenic deletion. All presented with severe episodes of rhabdomyolysis, starting before age 6 years except two (8 and 42 years). Few patients also suffered from permanent muscle symptoms, including the eldest ones (≥ 40 years). Around 3/4 of muscle biopsies showed accumulation of lipid droplets. At least 40% of heterozygous relatives presented muscular myalgia. Nine heterozygous SNPs in LPIN family genes were identified in milder phenotypes (mild rhabdomyolysis or myalgia). These variants were non-functional in yeast complementation assay based on respiratory activity, except the LPIN3-P24L variant. CONCLUSION LPIN1-related myolysis constitutes a major cause of early-onset rhabdomyolysis and occasionally in adults. Heterozygous LPIN1 mutations may cause mild muscular symptoms. No major defects of LPIN2 or LPIN3 genes were associated with muscular manifestations.
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Affiliation(s)
- Caroline Michot
- Paris Descartes University, INSERM U781 and Reference Center of Metabolic Diseases, Necker Hospital, Paris, France
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23
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Cell autonomous lipin 1 function is essential for development and maintenance of white and brown adipose tissue. Mol Cell Biol 2012; 32:4794-810. [PMID: 23028044 DOI: 10.1128/mcb.00512-12] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Through analysis of mice with spatially and temporally restricted inactivation of Lpin1, we characterized its cell autonomous function in both white (WAT) and brown (BAT) adipocyte development and maintenance. We observed that the lipin 1 inactivation in adipocytes of aP2(Cre/+)/Lp(fEx2)(-)(3/fEx2)(-)(3) mice resulted in lipodystrophy and the presence of adipocytes with multilocular lipid droplets. We further showed that time-specific loss of lipin 1 in mature adipocytes in aP2(Cre-ERT2/+)/Lp(fEx2)(-)(3/fEx2)(-)(3) mice led to their replacement by newly formed Lpin1-positive adipocytes, thus establishing a role for lipin 1 in mature adipocyte maintenance. Importantly, we observed that the presence of newly formed Lpin1-positive adipocytes in aP2(Cre-ERT2/+)/Lp(fEx2)(-)(3/fEx2)(-)(3) mice protected these animals against WAT inflammation and hepatic steatosis induced by a high-fat diet. Loss of lipin 1 also affected BAT development and function, as revealed by histological changes, defects in the expression of peroxisome proliferator-activated receptor alpha (PPARα), PGC-1α, and UCP1, and functionally by altered cold sensitivity. Finally, our data indicate that phosphatidic acid, which accumulates in WAT of animals lacking lipin 1 function, specifically inhibits differentiation of preadipocytes. Together, these observations firmly demonstrate a cell autonomous role of lipin 1 in WAT and BAT biology and indicate its potential as a therapeutical target for the treatment of obesity.
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Kok BPC, Venkatraman G, Capatos D, Brindley DN. Unlike two peas in a pod: lipid phosphate phosphatases and phosphatidate phosphatases. Chem Rev 2012; 112:5121-46. [PMID: 22742522 DOI: 10.1021/cr200433m] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Bernard P C Kok
- Signal Transduction Research Group, Department of Biochemistry, School of Translational Medicine, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
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25
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Xu Z, Su WM, Carman GM. Fluorescence spectroscopy measures yeast PAH1-encoded phosphatidate phosphatase interaction with liposome membranes. J Lipid Res 2011; 53:522-528. [PMID: 22180632 DOI: 10.1194/jlr.m022798] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phosphatidate (PA) phosphatase, the enzyme that catalyzes the penultimate step in triacylglycerol synthesis, is a cytosolic enzyme that must associate with the membrane where its substrate PA resides. Fluorescence spectroscopy was used to measure the interaction of yeast PAH1-encoded PA phosphatase with model liposome membranes. PA phosphatase contains five tryptophan residues and exhibited inherit fluorescence that increased upon interaction with phosphatidylcholine liposomes. The interaction was enhanced by inclusion of other phospholipids and especially the substrate PA. Interaction was dependent on both the concentration of phosphatidylcholine-PA liposomes as well as the surface concentration of PA in liposomes. Mg(2+) ions, which were required for catalysis, did not affect PA phosphatase interaction with phosphatidylcholine-PA liposomes. PA phosphatase was a substrate for protein kinase A, protein kinase C, and casein kinase II, and these phosphorylations decreased PA phosphatase interaction with phosphatidylcholine-PA liposome membranes.
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Affiliation(s)
- Zhi Xu
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ 08901
| | - Wen-Min Su
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ 08901
| | - George M Carman
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ 08901.
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26
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Zhang P, Takeuchi K, Csaki LS, Reue K. Lipin-1 phosphatidic phosphatase activity modulates phosphatidate levels to promote peroxisome proliferator-activated receptor γ (PPARγ) gene expression during adipogenesis. J Biol Chem 2011; 287:3485-94. [PMID: 22157014 DOI: 10.1074/jbc.m111.296681] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adipose tissue plays a key role in metabolic homeostasis. Disruption of the Lpin1 gene encoding lipin-1 causes impaired adipose tissue development and function in rodents. Lipin-1 functions as a phosphatidate phosphatase (PAP) enzyme in the glycerol 3-phosphate pathway for triglyceride storage and as a transcriptional coactivator/corepressor for metabolic nuclear receptors. Previous studies established that lipin-1 is required at an early step in adipocyte differentiation for induction of the adipogenic gene transcription program, including the key regulator peroxisome proliferator-activated receptor γ (PPARγ). Here, we investigate the requirement of lipin-1 PAP versus coactivator function in the establishment of Pparg expression during adipocyte differentiation. We demonstrate that PAP activity supplied by lipin-1, lipin-2, or lipin-3, but not lipin-1 coactivator activity, can rescue Pparg gene expression and lipogenesis during adipogenesis in lipin-1-deficient preadipocytes. In adipose tissue from lipin-1-deficient mice, there is an accumulation of phosphatidate species containing a range of medium chain fatty acids and an activation of the MAPK/extracellular signal-related kinase (ERK) signaling pathway. Phosphatidate inhibits differentiation of cultured adipocytes, and this can be rescued by the expression of lipin-1 PAP activity or by inhibition of ERK signaling. These results emphasize the importance of lipid intermediates as choreographers of gene regulation during adipogenesis, and the results highlight a specific role for lipins as determinants of levels of a phosphatidic acid pool that influences Pparg expression.
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Affiliation(s)
- Peixiang Zhang
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
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