501
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Kim M, Yoo G, Randy A, Kim HS, Nho CW. Chicoric acid attenuate a nonalcoholic steatohepatitis by inhibiting key regulators of lipid metabolism, fibrosis, oxidation, and inflammation in mice with methionine and choline deficiency. Mol Nutr Food Res 2017; 61. [DOI: 10.1002/mnfr.201600632] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/29/2016] [Accepted: 12/05/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Myungsuk Kim
- Natural Products Research Center; Korea Institute of Science and Technology; Gangneung Republic of Korea
- Convergence Research Center for Smart Farm Solution; Korea Institute of Science and Technology; Gangneung Republic of Korea
| | - GyHye Yoo
- Natural Products Research Center; Korea Institute of Science and Technology; Gangneung Republic of Korea
- Convergence Research Center for Smart Farm Solution; Korea Institute of Science and Technology; Gangneung Republic of Korea
| | - Ahmad Randy
- Natural Products Research Center; Korea Institute of Science and Technology; Gangneung Republic of Korea
- Department of Biological Chemistry, Korea; University of Science and Technology; Daejeon Republic of Korea
| | - Hyoung Seok Kim
- Natural Products Research Center; Korea Institute of Science and Technology; Gangneung Republic of Korea
- Convergence Research Center for Smart Farm Solution; Korea Institute of Science and Technology; Gangneung Republic of Korea
| | - Chu Won Nho
- Natural Products Research Center; Korea Institute of Science and Technology; Gangneung Republic of Korea
- Convergence Research Center for Smart Farm Solution; Korea Institute of Science and Technology; Gangneung Republic of Korea
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502
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Branchu J, Boutry M, Sourd L, Depp M, Leone C, Corriger A, Vallucci M, Esteves T, Matusiak R, Dumont M, Muriel MP, Santorelli FM, Brice A, El Hachimi KH, Stevanin G, Darios F. Loss of spatacsin function alters lysosomal lipid clearance leading to upper and lower motor neuron degeneration. Neurobiol Dis 2017; 102:21-37. [PMID: 28237315 PMCID: PMC5391847 DOI: 10.1016/j.nbd.2017.02.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/10/2017] [Accepted: 02/20/2017] [Indexed: 12/12/2022] Open
Abstract
Mutations in SPG11 account for the most common form of autosomal recessive hereditary spastic paraplegia (HSP), characterized by a gait disorder associated with various brain alterations. Mutations in the same gene are also responsible for rare forms of Charcot-Marie-Tooth (CMT) disease and progressive juvenile-onset amyotrophic lateral sclerosis (ALS). To elucidate the physiopathological mechanisms underlying these human pathologies, we disrupted the Spg11 gene in mice by inserting stop codons in exon 32, mimicking the most frequent mutations found in patients. The Spg11 knockout mouse developed early-onset motor impairment and cognitive deficits. These behavioral deficits were associated with progressive brain atrophy with the loss of neurons in the primary motor cortex, cerebellum and hippocampus, as well as with accumulation of dystrophic axons in the corticospinal tract. Spinal motor neurons also degenerated and this was accompanied by fragmentation of neuromuscular junctions and muscle atrophy. This new Spg11 knockout mouse therefore recapitulates the full range of symptoms associated with SPG11 mutations observed in HSP, ALS and CMT patients. Examination of the cellular alterations observed in this model suggests that the loss of spatacsin leads to the accumulation of lipids in lysosomes by perturbing their clearance from these organelles. Altogether, our results link lysosomal dysfunction and lipid metabolism to neurodegeneration and pinpoint a critical role of spatacsin in lipid turnover. Spg11 knockout mouse recapitulates the motor and cognitive symptoms observed in patients. Spg11 knockout mouse presents neurodegeneration in cortex, cerebellum, hippocampus and spinal cord. Loss of spatacsin, the product of Spg11, leads to early lysosomal dysfunction. Loss of spatacsin promotes lipid accumulation in lysosomes.
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Affiliation(s)
- Julien Branchu
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France
| | - Maxime Boutry
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France
| | - Laura Sourd
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Marine Depp
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Céline Leone
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Alexandrine Corriger
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Maeva Vallucci
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Typhaine Esteves
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Raphaël Matusiak
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France
| | - Magali Dumont
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France
| | - Marie-Paule Muriel
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France
| | - Filippo M Santorelli
- Molecular Medicine, IRCCS Stella Maris Foundation, Calambronne, I-56100 Pisa, Italy
| | - Alexis Brice
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France
| | - Khalid Hamid El Hachimi
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France
| | - Giovanni Stevanin
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Laboratoire de Neurogénétique, F-75013 Paris, France.
| | - Frédéric Darios
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France.
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503
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Irshad Z, Dimitri F, Christian M, Zammit VA. Diacylglycerol acyltransferase 2 links glucose utilization to fatty acid oxidation in the brown adipocytes. J Lipid Res 2017; 58:15-30. [PMID: 27836993 PMCID: PMC5234708 DOI: 10.1194/jlr.m068197] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 10/18/2016] [Indexed: 01/03/2023] Open
Abstract
Brown adipose tissue uptake of glucose and fatty acids is very high during nonshivering thermogenesis. Adrenergic stimulation markedly increases glucose uptake, de novo lipogenesis, and FA oxidation simultaneously. The mechanism that enables this concerted response has hitherto been unknown. Here, we find that in primary brown adipocytes and brown adipocyte-derived cell line (IMBAT-1), acute inhibition and longer-term knockdown of DGAT2 links the increased de novo synthesis of fatty acids from glucose to a pool of TAG that is simultaneously hydrolyzed, providing FA for mitochondrial oxidation. DGAT1 does not contribute to this pathway, but uses exogenous FA and glycerol to synthesize a functionally distinct pool of TAG to which DGAT2 also contributes. The DGAT2-dependent channelling of 14C from glucose into TAG and CO2 was reproduced in β3-agonist-stimulated primary brown adipocytes. Knockdown of DGAT2 in IMBAT-1 affected the mRNA levels of UCP1 and genes important in FA activation and esterification. Therefore, in β3-agonist activated brown adipocytes, DGAT2 specifically enables channelling of de novo synthesized FA into a rapidly mobilized pool of TAG, which is simultaneously hydrolyzed to provide substrates for mitochondrial fatty acid oxidation.
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Affiliation(s)
- Zehra Irshad
- Translational and Experimental Medicine, Division of Biomedical Sciences, Warwick Medical School, CV4 7AL, United Kingdom
| | - Federica Dimitri
- Translational and Experimental Medicine, Division of Biomedical Sciences, Warwick Medical School, CV4 7AL, United Kingdom
| | - Mark Christian
- Translational and Experimental Medicine, Division of Biomedical Sciences, Warwick Medical School, CV4 7AL, United Kingdom
| | - Victor A Zammit
- Translational and Experimental Medicine, Division of Biomedical Sciences, Warwick Medical School, CV4 7AL, United Kingdom
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504
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Karatas OF, Suer I, Yuceturk B, Yilmaz M, Oz B, Guven G, Cansiz H, Creighton CJ, Ittmann M, Ozen M. Identification of microRNA profile specific to cancer stem-like cells directly isolated from human larynx cancer specimens. BMC Cancer 2016; 16:853. [PMID: 27816053 PMCID: PMC5097853 DOI: 10.1186/s12885-016-2863-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 10/04/2016] [Indexed: 12/14/2022] Open
Abstract
Background Emerging evidences proposed that microRNAs are associated with regulation of distinct physio-pathological processes including development of normal stem cells and carcinogenesis. In this study we aimed to investigate microRNA profile of cancer stem-like cells (CSLCs) isolated form freshly resected larynx cancer (LCa) tissue samples. Methods CD133 positive (CD133+) stem-like cells were isolated from freshly resected LCa tumor specimens. MicroRNA profile of 12 pair of CD133+ and CD133− cells was determined using microRNA microarray and differential expressions of selvected microRNAs were validated by quantitative real time PCR (qRT-PCR). Results MicroRNA profiling of CD133+ and CD133− LCa samples with microarray revealed that miR-26b, miR-203, miR-200c, and miR-363-3p were significantly downregulated and miR-1825 was upregulated in CD133+ larynx CSLCs. qRT-PCR analysis in a total of 25 CD133+/CD133− sample pairs confirmed the altered expressions of these five microRNAs. Expressions of miR-26b, miR-200c, and miR-203 were significantly correlated with miR-363-3p, miR-203, and miR-363-3p expressions, respectively. Furthermore, in silico analysis revealed that these microRNAs target both cancer and stem-cell associated signaling pathways. Conclusions Our results showed that certain microRNAs in CD133+ cells could be used as cancer stem cell markers. Based on these results, we propose that this panel of microRNAs might carry crucial roles in LCa pathogenesis through regulating stem cell properties of tumor cells. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2863-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Omer Faruk Karatas
- Molecular Biology and Genetics Department, Erzurum Technical University, Erzurum, Turkey
| | - Ilknur Suer
- Department of Medical Genetics, Istanbul University Cerrahpasa Medical School, Istanbul, Turkey
| | - Betul Yuceturk
- Department of Medical Genetics, Istanbul University Cerrahpasa Medical School, Istanbul, Turkey.,Advanced Genomics and Bioinformatics Research Center, The Scientific and Technological Research Council of Turkey (TUBITAK), Gebze, Kocaeli, Turkey
| | - Mehmet Yilmaz
- Department of Otorhinolaryngology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Buge Oz
- Department of Pathology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Gulgun Guven
- Department of Medical Genetics, Istanbul University Cerrahpasa Medical School, Istanbul, Turkey
| | - Harun Cansiz
- Department of Otorhinolaryngology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Chad J Creighton
- Department of Medicine and Dan L. Duncan Cancer Center Division of Biostatistics, Baylor College of Medicine, Houston, TX, USA
| | - Michael Ittmann
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, 77030, USA.,Michael E. DeBakey VAMC, Houston, TX, 77030, USA
| | - Mustafa Ozen
- Department of Medical Genetics, Istanbul University Cerrahpasa Medical School, Istanbul, Turkey. .,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, 77030, USA.
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505
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Mammalian knock out cells reveal prominent roles for atlastin GTPases in ER network morphology. Exp Cell Res 2016; 349:32-44. [DOI: 10.1016/j.yexcr.2016.09.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/19/2016] [Accepted: 09/22/2016] [Indexed: 12/28/2022]
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506
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Modeling Axonal Defects in Hereditary Spastic Paraplegia with Human Pluripotent Stem Cells. ACTA ACUST UNITED AC 2016; 11:339-354. [PMID: 27956894 DOI: 10.1007/s11515-016-1416-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Cortical motor neurons, also known as upper motor neurons, are large projection neurons whose axons convey signals to lower motor neurons to control the muscle movements. Degeneration of cortical motor neuron axons is implicated in several debilitating disorders, including hereditary spastic paraplegia (HSP) and amyotrophic lateral sclerosis (ALS). Since the discovery of the first HSP gene, SPAST that encodes spastin, over 70 distinct genetic loci associated with HSP have been identified. How the mutations of these functionally diverse genes result in axonal degeneration and why certain axons are affected in HSP remains largely unknown. The development of induced pluripotent stem cell (iPSC) technology has provided researchers an excellent resource to generate patient-specific human neurons to model human neuropathologic processes including axonal defects. METHODS In this article, we will frst review the pathology and pathways affected in the common forms of HSP subtypes by searching the PubMed database. We will then summurize the findings and insights gained from studies using iPSC-based models, and discuss the challenges and future directions. RESULTS HSPs, a heterogeneous group of genetic neurodegenerative disorders, are characterized by lower extremity weakness and spasticity that result from retrograde axonal degeneration of cortical motor neurons. Recently, iPSCs have been generated from several common forms of HSP including SPG4, SPG3A, and SPG11 patients. Neurons derived from HSP iPSCs exhibit disease-relevant axonal defects, such as impaired neurite outgrowth, increased axonal swellings, and reduced axonal transport. CONCLUSION These patient-derived neurons offer unique tools to study the pathogenic mechanisms and explore the treatments for rescuing axonal defects in HSP, as well as other diseases involving axonopathy.
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507
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Wang L, Xu F, Wang G, Wang X, Liang A, Huang H, Sun F. C30F12.4 influences oogenesis, fat metabolism, and lifespan in C. elegans. Protein Cell 2016; 7:714-721. [PMID: 27638466 PMCID: PMC5055490 DOI: 10.1007/s13238-016-0308-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/19/2016] [Indexed: 11/25/2022] Open
Abstract
Reproduction, fat metabolism, and longevity are intertwined regulatory axes; recent studies in C. elegans have provided evidence that these processes are directly coupled. However, the mechanisms by which they are coupled and the reproductive signals modulating fat metabolism and lifespan are poorly understood. Here, we find that an oogenesis-enriched gene, c30f12.4, is specifically expressed and located in germ cells and early embryos; when the gene is knocked out, oogenesis is disrupted and brood size is decreased. In addition to the reproductive phenotype, we find that the loss of c30f12.4 alters fat metabolism, resulting in decreased fat storage and smaller lipid droplets. Meanwhile, c30f12.4 mutant worms display a shortened lifespan. Our results highlight an important role for c30f12.4 in regulating reproduction, fat homeostasis, and aging in C. elegans, which helps us to better understand the relationship between these processes.
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Affiliation(s)
- Lu Wang
- International Peace Maternity & Child Health Hospital, Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiaotong University, Shanghai, 200030, China
| | - Fei Xu
- School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Guishuan Wang
- International Peace Maternity & Child Health Hospital, Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiaotong University, Shanghai, 200030, China
| | - Xiaorong Wang
- International Peace Maternity & Child Health Hospital, Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiaotong University, Shanghai, 200030, China
| | - Ajuan Liang
- International Peace Maternity & Child Health Hospital, Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiaotong University, Shanghai, 200030, China
| | - Hefeng Huang
- International Peace Maternity & Child Health Hospital, Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiaotong University, Shanghai, 200030, China.
| | - Fei Sun
- International Peace Maternity & Child Health Hospital, Shanghai Key laboratory for Reproductive Medicine, School of Medicine, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiaotong University, Shanghai, 200030, China.
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508
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Rao K, Stone MC, Weiner AT, Gheres KW, Zhou C, Deitcher DL, Levitan ES, Rolls MM. Spastin, atlastin, and ER relocalization are involved in axon but not dendrite regeneration. Mol Biol Cell 2016; 27:3245-3256. [PMID: 27605706 PMCID: PMC5170858 DOI: 10.1091/mbc.e16-05-0287] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/31/2016] [Indexed: 12/19/2022] Open
Abstract
A Drosophila model system is used to show that the hereditary spastic paraplegia proteins spastin and atlastin help axons but not dendrites regenerate. The endoplasmic reticulum concentrates at tips of regenerating axons but not dendrites, and this depends on spastin and atlastin. Mutations in >50 genes, including spastin and atlastin, lead to hereditary spastic paraplegia (HSP). We previously demonstrated that reduction of spastin leads to a deficit in axon regeneration in a Drosophila model. Axon regeneration was similarly impaired in neurons when HSP proteins atlastin, seipin, and spichthyin were reduced. Impaired regeneration was dependent on genetic background and was observed when partial reduction of HSP proteins was combined with expression of dominant-negative microtubule regulators, suggesting that HSP proteins work with microtubules to promote regeneration. Microtubule rearrangements triggered by axon injury were, however, normal in all genotypes. We examined other markers to identify additional changes associated with regeneration. Whereas mitochondria, endosomes, and ribosomes did not exhibit dramatic repatterning during regeneration, the endoplasmic reticulum (ER) was frequently concentrated near the tip of the growing axon. In atlastin RNAi and spastin mutant animals, ER accumulation near single growing axon tips was impaired. ER tip concentration was observed only during axon regeneration and not during dendrite regeneration. In addition, dendrite regeneration was unaffected by reduction of spastin or atlastin. We propose that the HSP proteins spastin and atlastin promote axon regeneration by coordinating concentration of the ER and microtubules at the growing axon tip.
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Affiliation(s)
- Kavitha Rao
- Biochemistry and Molecular Biology and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
| | - Michelle C Stone
- Biochemistry and Molecular Biology and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
| | - Alexis T Weiner
- Biochemistry and Molecular Biology and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802.,Molecular, Cellular and Integrative Biosciences Graduate Program, Pennsylvania State University, University Park, PA 16802
| | - Kyle W Gheres
- Biochemistry and Molecular Biology and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802.,Molecular, Cellular and Integrative Biosciences Graduate Program, Pennsylvania State University, University Park, PA 16802
| | - Chaoming Zhou
- Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261
| | | | - Edwin S Levitan
- Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Melissa M Rolls
- Biochemistry and Molecular Biology and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802 .,Molecular, Cellular and Integrative Biosciences Graduate Program, Pennsylvania State University, University Park, PA 16802
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509
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A Genetic Screen for Mutants with Supersized Lipid Droplets in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2016; 6:2407-19. [PMID: 27261001 PMCID: PMC4978895 DOI: 10.1534/g3.116.030866] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To identify genes that regulate the dynamics of lipid droplet (LD) size, we have used the genetically tractable model organism Caenorhabditis elegans, whose wild-type LD population displays a steady state of size with an upper limit of 3 μm in diameter. From a saturated forward genetic screen of 6.7 × 105 mutagenized haploid genomes, we isolated 118 mutants with supersized intestinal LDs often reaching 10 μm. These mutants define nine novel complementation groups, in addition to four known genes (maoc-1, dhs-28, daf-22, and prx-10). The nine groups are named drop (lipid droplet abnormal) and categorized into four classes. Class I mutants drop-5 and drop-9, similar to prx-10, are up-regulated in ACS-22-DGAT-2-dependent LD growth, resistant to LD hydrolysis, and defective in peroxisome import. Class II mutants drop-2, drop-3, drop-6, and drop-7 are up-regulated in LD growth, are resistant to LD hydrolysis, but are not defective in peroxisome import. Class III mutants drop-1 and drop-8 are neither up-regulated in LD growth nor resistant to LD hydrolysis, but seemingly up-regulated in LD fusion. Class IV mutant drop-4 is cloned as sams-1 and, different to the other three classes, is ACS-22-independent and hydrolysis-resistant. These four classes of supersized LD mutants should be valuable for mechanistic studies of LD cellular processes including growth, hydrolysis, and fusion.
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510
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Wang S, Wang J, Zhang X, Hu L, Fang Z, Huang Z, Shi P. Trivalent chromium alleviates oleic acid induced steatosis in SMMC-7721 cells by decreasing fatty acid uptake and triglyceride synthesis. Biometals 2016; 29:881-92. [DOI: 10.1007/s10534-016-9960-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/28/2016] [Indexed: 12/23/2022]
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511
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Lemieux GA, Ashrafi K. Investigating Connections between Metabolism, Longevity, and Behavior in Caenorhabditis elegans. Trends Endocrinol Metab 2016; 27:586-596. [PMID: 27289335 PMCID: PMC4958586 DOI: 10.1016/j.tem.2016.05.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 01/19/2023]
Abstract
An overview of Caenorhabditis elegans as an experimental organism for studying energy balance is presented. Some of the unresolved questions that complicate the interpretation of lipid measurements from C. elegans are highlighted. We review studies that show that both lipid synthesis and lipid breakdown pathways are activated and needed for the longevity of hermaphrodites that lack their germlines. These findings illustrate the heterogeneity of triglyceride-rich lipid particles in C. elegans and reveal specific lipid signals that promote longevity. Finally, we provide a brief overview of feeding behavioral responses of C. elegans to varying nutritional conditions and highlight an unanticipated metabolic pathway that allows the incorporation of experience in feeding behavior.
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Affiliation(s)
| | - Kaveh Ashrafi
- University of California, San Francisco, San Francisco, CA, USA.
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512
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Li Y, Zhu Y, Prochownik EV. MicroRNA-based screens for synthetic lethal interactions with c-Myc. RNA & DISEASE 2016; 3:e1330. [PMID: 27975083 PMCID: PMC5152767 DOI: 10.14800/rd.1330] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
microRNAs (miRs) are small, non-coding RNAs, which play crucial roles in the development and progression of human cancer. Given that miRs are stable, easy to synthetize and readily introduced into cells, they have been viewed as having potential therapeutic benefit in cancer. c-Myc (Myc) is one of the most commonly deregulated oncogenic transcription factors and has important roles in the pathogenesis of cancer, thus making it an important, albeit elusive therapeutic target. Here we review the miRs that have been identified as being both positive and negative targets for Myc and how these participate in the complex phenotypes that arise as a result of Myc-driven transformation. We also discussseveral recent reports of Myc-synthetic lethal interactions with miRs.These highlight the importance and complexity of miRs in Myc-mediated biological functions and the opportunities for Myc-driven human cancer therapies.
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Affiliation(s)
- Youjun Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China
- Medical Research Institute, Wuhan University, Wuhan 430071, China
| | - Yahui Zhu
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Edward V. Prochownik
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC and The Department of Microbiology and Molecular Genetics, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15224, USA
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513
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D'Aquila T, Hung YH, Carreiro A, Buhman KK. Recent discoveries on absorption of dietary fat: Presence, synthesis, and metabolism of cytoplasmic lipid droplets within enterocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:730-47. [PMID: 27108063 DOI: 10.1016/j.bbalip.2016.04.012] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/16/2016] [Accepted: 04/16/2016] [Indexed: 02/07/2023]
Abstract
Dietary fat provides essential nutrients, contributes to energy balance, and regulates blood lipid concentrations. These functions are important to health, but can also become dysregulated and contribute to diseases such as obesity, diabetes, cardiovascular disease, and cancer. Within enterocytes, the digestive products of dietary fat are re-synthesized into triacylglycerol, which is either secreted on chylomicrons or stored within cytoplasmic lipid droplets (CLDs). CLDs were originally thought to be inert stores of neutral lipids, but are now recognized as dynamic organelles that function in multiple cellular processes in addition to lipid metabolism. This review will highlight recent discoveries related to dietary fat absorption with an emphasis on the presence, synthesis, and metabolism of CLDs within this process.
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Affiliation(s)
- Theresa D'Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Yu-Han Hung
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Alicia Carreiro
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA.
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514
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Abstract
Lipid droplets are the intracellular sites for neutral lipid storage. They are critical for lipid metabolism and energy homeostasis, and their dysfunction has been linked to many diseases. Accumulating evidence suggests that the roles lipid droplets play in biology are significantly broader than previously anticipated. Lipid droplets are the source of molecules important in the nucleus: they can sequester transcription factors and chromatin components and generate the lipid ligands for certain nuclear receptors. Lipid droplets have also emerged as important nodes for fatty acid trafficking, both inside the cell and between cells. In immunity, new roles for droplets, not directly linked to lipid metabolism, have been uncovered, with evidence that they act as assembly platforms for specific viruses and as reservoirs for proteins that fight intracellular pathogens. Until recently, knowledge about droplets in the nervous system has been minimal, but now there are multiple links between lipid droplets and neurodegeneration: many candidate genes for hereditary spastic paraplegia also have central roles in lipid-droplet formation and maintenance, and mitochondrial dysfunction in neurons can lead to transient accumulation of lipid droplets in neighboring glial cells, an event that may, in turn, contribute to neuronal damage. As the cell biology and biochemistry of lipid droplets become increasingly well understood, the next few years should yield many new mechanistic insights into these novel functions of lipid droplets.
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515
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Han H, Li W, Shen H, Zhang J, Zhu Y, Li Y. microRNA-129-5p, a c-Myc negative target, affects hepatocellular carcinoma progression by blocking the Warburg effect. J Mol Cell Biol 2016; 8:400-410. [PMID: 27001970 DOI: 10.1093/jmcb/mjw010] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 12/03/2015] [Accepted: 12/25/2015] [Indexed: 01/09/2023] Open
Abstract
Deregulation of microRNAs (miRNAs) and c-Myc (Myc) contributes to hepatocellular carcinoma (HCC) progression, but how miRNAs and Myc regulate each other in hepatocarcinogenesis is still poorly understood. Using a functional screen, we identified miR-129-5p as a miRNA that inhibits HCC cell growth. miR-129-5p targets the mitochondrial matrix protein pyruvate dehydrogenase kinase 4 (PDK4), which leads to decreased phosphorylation of the E1α subunit of pyruvate dehyrogenase (PDH) complex, inhibition of glycolysis, retarded tumor growth, and impaired lung colonization. Enforced expression of PDK4 refractory to inhibition by miR-129-5p rescued all of these phenotypes. Targeting PDK4 by shRNA recapitulated the effects caused by miR-129-5p. miR-129-5p is transcriptionally repressed by a complex comprised of Myc, histone deacetylase 3 (HDAC3), and enhancer of zeste 2 polycomb repressive complex 2 (EZH2). Levels of miR-129-5p negatively correlated with clinical stages in human HCC. Restoring miR-129-5p expression suppressed the diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. Thus, we concluded that miR-129-5p, which is a negative target of Myc, blocks glycolysis to retard hepatocarcinogenesis via targeting PDK4. The critical link between miR-129-5p and PDK4 in the progression of HCC suggests potential points of therapeutic intervention for this disease.
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Affiliation(s)
- Han Han
- College of Life Sciences, Medical Research Institute, Wuhan University, Wuhan 430072, China
| | - Wenjuan Li
- College of Life Sciences, Medical Research Institute, Wuhan University, Wuhan 430072, China
| | - Hongxing Shen
- College of Life Sciences, Medical Research Institute, Wuhan University, Wuhan 430072, China
| | - Jinxiang Zhang
- Department of Surgery, Wuhan Union Hospital, Wuhan 430022, China
| | - Yahui Zhu
- College of Life Sciences, Medical Research Institute, Wuhan University, Wuhan 430072, China
| | - Youjun Li
- College of Life Sciences, Medical Research Institute, Wuhan University, Wuhan 430072, China
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516
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Angrish MM, Kaiser JP, McQueen CA, Chorley BN. Tipping the Balance: Hepatotoxicity and the 4 Apical Key Events of Hepatic Steatosis. Toxicol Sci 2016; 150:261-8. [PMID: 26980302 DOI: 10.1093/toxsci/kfw018] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Hepatic steatosis is a condition were fat accumulates in the liver and it is associated with extra-hepatic diseases related to metabolic syndrome and systemic energy metabolism. If not reversed, steatosis can progress to steatohepatitis and irreversible stages of liver disease including fibrosis, cirrhosis, hepatocellular carcinoma, and death. From a public health standpoint, identifying chemical exposures that may be factors in steatosis etiology are important for preventing hepatotoxicity and liver disease progression. It is therefore important to identify the biological events that are key for steatosis pathology mediated by chemical exposure. In this review, we give a current overview of the complex biological cascades that can disrupt lipid homeostasis in hepatocytes in the context of 4 apical key events central to hepatic lipid retention: hepatic fatty acid (FA) uptake,de novoFA and lipid synthesis, FA oxidation, and lipid efflux. Our goal is to review these key cellular events and visually summarize them using a network for application in pathway-based toxicity testing. This effort provides a foundation to improve next-generation chemical screening efforts that may be used to prevent and ultimately reverse the growing incidence of fatty liver disease in our population.
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Affiliation(s)
- Michelle M Angrish
- *National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), United States Environmental Protection Agency (US EPA), Research Triangle Park, North Carolina 27709
| | - Jonathan Phillip Kaiser
- United States Environmental Protection Agency (US EPA), National Center for Environmental Assessment, Office of Research and Development (ORD), Cincinnati, Ohio 45268
| | - Charlene A McQueen
- *National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), United States Environmental Protection Agency (US EPA), Research Triangle Park, North Carolina 27709
| | - Brian N Chorley
- *National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), United States Environmental Protection Agency (US EPA), Research Triangle Park, North Carolina 27709;
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517
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Feng G, Shi H, Li J, Yang Z, Fang R, Ye L, Zhang W, Zhang X. MiR-30e suppresses proliferation of hepatoma cells via targeting prolyl 4-hydroxylase subunit alpha-1 (P4HA1) mRNA. Biochem Biophys Res Commun 2016; 472:516-22. [PMID: 26966067 DOI: 10.1016/j.bbrc.2016.03.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/05/2016] [Indexed: 12/12/2022]
Abstract
Aberrant microRNA expression has been shown to be characteristic of many cancers. It has been reported that the expression levels of miR-30e are decreased in liver cancer tissues. However, the role of miR-30e in hepatocellular carcinoma remains poorly understood. In the present study, we investigated the significance of miR-30e in hepatocarcinogenesis. Bioinformatics analysis reveals a putative target site of miR-30e in the 3'-untranslated region (3'UTR) of prolyl 4-hydroxylase subunit alpha-1 (P4HA1) mRNA. Moreover, luciferase reporter gene assays verified that miR-30e directly targeted 3'UTR of P4HA1 mRNA. Then, we demonstrated that miR-30e was able to reduce the expression of P4HA1 at the levels of mRNA and protein using reverse transcription-polymerase chain reaction and Western blot analysis. Enforced expression of miR-30e suppressed proliferation of HepG2 cells by 5-ethynyl-2-deoxyuridine (EdU) assay and reduced colony formation of these cells by colony formation analysis. Conversely, anti-miR-30e enhanced the proliferation of hepatoma cells in vitro. Interestingly, the ectopic expression of P4HA1 could efficiently rescue the inhibition of cell proliferation mediated by miR-30e in HepG2 cells. Meanwhile, silencing of P4HA1 abolished the anti-miR-30e-induced proliferation of cells. Clinically, quantitative real-time PCR showed that miR-30e was down-regulated in liver tumor tissues relative to their peritumor tissues. The expression levels of miR-30e were negatively correlated to those of P4HA1 mRNA in clinical liver tumor tissues. Thus, we conclude that miR-30e suppresses proliferation of hepatoma cells through targeting P4HA1 mRNA. Our finding provides new insights into the mechanism of hepatocarcinogenesis.
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Affiliation(s)
- Guoxing Feng
- State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Hui Shi
- State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Jiong Li
- State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Zhe Yang
- State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Runping Fang
- State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Lihong Ye
- State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Weiying Zhang
- State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Xiaodong Zhang
- State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, PR China.
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518
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Van Keuren‐Jensen KR, Malenica I, Courtright AL, Ghaffari LT, Starr AP, Metpally RP, Beecroft TA, Carlson EW, Kiefer JA, Pockros PJ, Rakela J. microRNA changes in liver tissue associated with fibrosis progression in patients with hepatitis C. Liver Int 2016; 36:334-43. [PMID: 26189820 PMCID: PMC5049661 DOI: 10.1111/liv.12919] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/12/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Accumulating evidence indicates that microRNAs play a role in a number of disease processes including the pathogenesis of liver fibrosis in hepatitis C infection. Our goal is to add to the accruing information regarding microRNA deregulation in liver fibrosis to increase our understanding of the underlying mechanisms of pathology and progression. METHODS We used next generation sequencing to profile all detectable microRNAs in liver tissue and serum from patients with hepatitis C, stages F1-F4 of fibrosis. RESULTS We found altered expression of several microRNAs, in particular, miR-182, miR199a-5p, miR-200a-5p and miR-183 were found to be significantly upregulated in tissue from liver biopsies of hepatitis C patients with advanced fibrosis, stage F3 and F4, when compared with liver biopsies from patients with early fibrosis, stages F1 and F2. We also found miR-148-5p, miR-1260b, miR-122-3p and miR-378i among the microRNAs most significantly down-regulated from early to advanced fibrosis of the liver. We also sequenced the serum microRNAs; however, we were not able to detect significant changes in circulating microRNAs associated with fibrosis stage after adjusting for multiple tests. CONCLUSIONS Adding measurements of tissue microRNAs acquired during routine biopsies will continue to increase our knowledge of underlying mechanisms of fibrosis. Our goal is that these data, in combination with studies from other researchers and future long-term studies, could be used to enhance the staging accuracy of liver biopsies and expand the surveillance of patients at increased risk for cancer and progression to advanced fibrosis.
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Affiliation(s)
| | - Ivana Malenica
- NeurogenomicsTranslational Genomics Research InstitutePhoenixAZUSA
| | | | | | - Alex P. Starr
- NeurogenomicsTranslational Genomics Research InstitutePhoenixAZUSA
| | | | | | | | | | | | - Jorge Rakela
- Gastroenterology and HepatologyMayo ClinicScottsdaleAZUSA
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519
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Peng Y, Croce CM. The role of MicroRNAs in human cancer. Signal Transduct Target Ther 2016; 1:15004. [PMID: 29263891 PMCID: PMC5661652 DOI: 10.1038/sigtrans.2015.4] [Citation(s) in RCA: 1512] [Impact Index Per Article: 189.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 11/25/2015] [Accepted: 11/29/2015] [Indexed: 02/07/2023] Open
Abstract
MicroRNAs (miRNAs) are endogenous, small non-coding RNAs that function in regulation of gene expression. Compelling evidences have demonstrated that miRNA expression is dysregulated in human cancer through various mechanisms, including amplification or deletion of miRNA genes, abnormal transcriptional control of miRNAs, dysregulated epigenetic changes and defects in the miRNA biogenesis machinery. MiRNAs may function as either oncogenes or tumor suppressors under certain conditions. The dysregulated miRNAs have been shown to affect the hallmarks of cancer, including sustaining proliferative signaling, evading growth suppressors, resisting cell death, activating invasion and metastasis, and inducing angiogenesis. An increasing number of studies have identified miRNAs as potential biomarkers for human cancer diagnosis, prognosis and therapeutic targets or tools, which needs further investigation and validation. In this review, we focus on how miRNAs regulate the development of human tumors by acting as tumor suppressors or oncogenes.
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Affiliation(s)
- Yong Peng
- Department of Thoracic Surgery, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.,Collaborative Innovation Center of Biotherapy, Chengdu, China
| | - Carlo M Croce
- Department of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
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520
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Musso G, Cassader M, Gambino R. Non-alcoholic steatohepatitis: emerging molecular targets and therapeutic strategies. Nat Rev Drug Discov 2016; 15:249-74. [PMID: 26794269 DOI: 10.1038/nrd.2015.3] [Citation(s) in RCA: 321] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Non-alcoholic fatty liver disease - the most common chronic liver disease - encompasses a histological spectrum ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Over the next decade, NASH is projected to be the most common indication for liver transplantation. The absence of an effective pharmacological therapy for NASH is a major incentive for research into novel therapeutic approaches for this condition. The current focus areas for research include the modulation of nuclear transcription factors; agents that target lipotoxicity and oxidative stress; and the modulation of cellular energy homeostasis, metabolism and the inflammatory response. Strategies to enhance resolution of inflammation and fibrosis also show promise to reverse the advanced stages of liver disease.
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Affiliation(s)
- Giovanni Musso
- Gradenigo Hospital, Corso Regina Margherita 8, 10132 Turin, Italy
| | - Maurizio Cassader
- Department of Medical Sciences, University of Turin, Corso A.M. Dogliotti 14, 10126, Turin, Italy
| | - Roberto Gambino
- Department of Medical Sciences, University of Turin, Corso A.M. Dogliotti 14, 10126, Turin, Italy
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521
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Li Y, Chen D, Li Y, Jin L, Liu J, Su Z, Qi Z, Shi M, Jiang Z, Ni L, Yang S, Gui Y, Mao X, Chen Y, Lai Y. Oncogenic cAMP responsive element binding protein 1 is overexpressed upon loss of tumor suppressive miR-10b-5p and miR-363-3p in renal cancer. Oncol Rep 2016; 35:1967-78. [PMID: 26796749 DOI: 10.3892/or.2016.4579] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 09/09/2015] [Indexed: 11/05/2022] Open
Abstract
Renal cell carcinoma (RCC) is the most common kidney cancer in adults and has a poor prognosis. cAMP responsive element binding protein 1 (CREB1) is a proto‑oncogenic transcription factor involved in malignancies of various organs. However, its functional role(s) have not yet been elucidated in RCC. We investigated the expression pattern, function and regulation of CREB1 in RCC. CREB1 was overexpressed in the RCC tissues and cell lines. Downregulation of CREB1 inhibited RCC tumorigenesis by affecting cell proliferation, migration and apoptosis. Multiple computational algorithms predicted that the 3'‑untranslated region (3'‑UTR) of human CREB1 mRNA is a target for miR‑10b‑5p and miR‑363‑3p. Luciferase reporter assay, qPCR and western blot analysis confirmed that miR‑10b‑5p and miR‑363‑3p bind directly to the 3'‑UTR of CREB1 mRNA and inhibit mRNA and protein expression of CREB1. qPCR data also revealed a significantly lower expression of miR‑10b‑5p and miR‑363‑3p in RCC tissues. Introduction of miR‑10b‑5p and miR‑363‑3p mimics led to suppressed expression of CREB1 and inhibited cell proliferation, migration and apoptosis reduction. Taken together, we propose that CREB1 is an oncogene in RCC and that upregulation of CREB1 by loss of tumor suppressive miR‑10b‑5p and miR‑363‑3p plays an important role in the tumorigenesis of RCC.
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Affiliation(s)
- Yifan Li
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Duqun Chen
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Yuchi Li
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Lu Jin
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Jiaju Liu
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Zhengming Su
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Zhengyu Qi
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Min Shi
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Zhimao Jiang
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Liangchao Ni
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Shangqi Yang
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Yaoting Gui
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Xiangming Mao
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Yun Chen
- Department of Ultrasound Division, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Yongqing Lai
- Department of Urology, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
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522
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Cheng Q, Yuan F, Lu F, Zhang B, Chen T, Chen X, Cheng Y, Li N, Ma L, Tong T. CSIG promotes hepatocellular carcinoma proliferation by activating c-MYC expression. Oncotarget 2016; 6:4733-44. [PMID: 25749381 PMCID: PMC4467111 DOI: 10.18632/oncotarget.2900] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 12/15/2014] [Indexed: 12/11/2022] Open
Abstract
Cellular senescence-inhibited gene (CSIG) protein significantly prolongs the progression of replicative senescence, but its role in tumorigenesis is unclear. To reveal the role of CSIG in HCC, we determined its expression in HCC tissues and surrounding tissues and its functions in tumor cell proliferation in vitro and in vivo. CSIG protein was overexpressed in 86.4% of the human HCC cancerous tissues as compared with matched surrounding tissues, and its protein expression was greater in HCC cells than the non-transformed hepatic cell line L02. Furthermore, upregulation of CSIG significantly increased the colony formation of SMMC7721 and HepG2 cells, and silencing CSIG could induce cell cycle arrest and cell apoptosis. The tumorigenic ability of CSIG was confirmed in vivo in a mouse xenograft model. Our results showed that CSIG promoted the proliferation of HepG2 and SMMC7721 cells in vivo. Finally, CSIG protein directly interacted with c-MYC protein and increased c-MYC protein levels; the ubiquitination and degradation of c-MYC protein was increased with knockdown of CSIG. CSIG could also increase the expression of c-MYC protein in SMMC7721 cells in vivo, and it was noted that the level of c-MYC protein was also elevated in most human cancerous tissues with high level of CSIG.
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Affiliation(s)
- Qian Cheng
- The Peking University Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
| | - Fuwen Yuan
- The Peking University Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
| | - Fengmin Lu
- Department of Microbiology, Peking University Health Science Center, Beijing, China
| | - Bo Zhang
- Department of Pathology, Peking University Health Science Center, Beijing, China
| | - Tianda Chen
- The Peking University Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
| | - Xiangmei Chen
- Department of Microbiology, Peking University Health Science Center, Beijing, China
| | - Yuan Cheng
- Department of Histology and Embryology, Peking University Health Science Center, Beijing, China
| | - Na Li
- The Peking University Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
| | - Liwei Ma
- The Peking University Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
| | - Tanjun Tong
- The Peking University Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
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523
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Khuu C, Utheim TP, Sehic A. The Three Paralogous MicroRNA Clusters in Development and Disease, miR-17-92, miR-106a-363, and miR-106b-25. SCIENTIFICA 2016; 2016:1379643. [PMID: 27127675 PMCID: PMC4834410 DOI: 10.1155/2016/1379643] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/16/2016] [Accepted: 03/17/2016] [Indexed: 05/06/2023]
Abstract
MicroRNAs (miRNAs) form a class of noncoding RNA genes whose products are small single-stranded RNAs that are involved in the regulation of translation and degradation of mRNAs. There is a fine balance between deregulation of normal developmental programs and tumor genesis. An increasing body of evidence suggests that altered expression of miRNAs is entailed in the pathogenesis of human cancers. Studies in mouse and human cells have identified the miR-17-92 cluster as a potential oncogene. The miR-17-92 cluster is often amplified or overexpressed in human cancers and has recently emerged as the prototypical oncogenic polycistron miRNA. The functional analysis of miR-17-92 is intricate by the existence of two paralogues: miR-106a-363 and miR-106b-25. During early evolution of vertebrates, it is likely that the three clusters commenced via a series of duplication and deletion occurrences. As miR-106a-363 and miR-106b-25 contain miRNAs that are very similar, and in some cases identical, to those encoded by miR-17-92, it is feasible that they regulate a similar set of genes and have overlapping functions. Further understanding of these three clusters and their functions will increase our knowledge about cancer progression. The present review discusses the characteristics and functions of these three miRNA clusters.
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Affiliation(s)
- Cuong Khuu
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0372 Oslo, Norway
- *Cuong Khuu:
| | - Tor Paaske Utheim
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0372 Oslo, Norway
- Department of Medical Biochemistry, Oslo University Hospital, 0407 Oslo, Norway
- Department of Ophthalmology, Drammen Hospital, Vestre Viken Hospital Trust, 3004 Drammen, Norway
- Faculty of Health Sciences, University College of South East Norway, 3614 Kongsberg, Norway
| | - Amer Sehic
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0372 Oslo, Norway
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524
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Lipid droplets, lipophagy, and beyond. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1861:793-805. [PMID: 26713677 DOI: 10.1016/j.bbalip.2015.12.010] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/06/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023]
Abstract
Lipids are essential components for life. Their various structural and physical properties influence diverse cellular processes and, thereby, human health. Lipids are not genetically encoded but are synthesized and modified by complex metabolic pathways, supplying energy, membranes, signaling molecules, and hormones to affect growth, physiology, and response to environmental insults. Lipid homeostasis is crucial, such that excess fatty acids (FAs) can be harmful to cells. To prevent such lipotoxicity, cells convert excess FAs into neutral lipids for storage in organelles called lipid droplets (LDs). These organelles do not simply manage lipid storage and metabolism but also are involved in protein quality management, pathogenesis, immune responses, and, potentially, neurodegeneration. In recent years, a major trend in LD biology has centered around the physiology of lipid mobilization via lipophagy of fat stored within LDs. This review summarizes key findings in LD biology and lipophagy, offering novel insights into this rapidly growing field. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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525
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Carnitine palmitoyltransferase 1C: From cognition to cancer. Prog Lipid Res 2015; 61:134-48. [PMID: 26708865 DOI: 10.1016/j.plipres.2015.11.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 11/18/2015] [Accepted: 11/23/2015] [Indexed: 11/21/2022]
Abstract
Carnitine palmitoyltransferase 1 (CPT1) C was the last member of the CPT1 family of genes to be discovered. CPT1A and CPT1B were identified as the gate-keeper enzymes for the entry of long-chain fatty acids (as carnitine esters) into mitochondria and their further oxidation, and they show differences in their kinetics and tissue expression. Although CPT1C exhibits high sequence similarity to CPT1A and CPT1B, it is specifically expressed in neurons (a cell-type that does not use fatty acids as fuel to any major extent), it is localized in the endoplasmic reticulum of cells, and it has minimal CPT1 catalytic activity with l-carnitine and acyl-CoA esters. The lack of an easily measurable biological activity has hampered attempts to elucidate the cellular and physiological role of CPT1C but has not diminished the interest of the biomedical research community in this CPT1 isoform. The observations that CPT1C binds malonyl-CoA and long-chain acyl-CoA suggest that it is a sensor of lipid metabolism in neurons, where it appears to impact ceramide and triacylglycerol (TAG) metabolism. CPT1C global knock-out mice show a wide range of brain disorders, including impaired cognition and spatial learning, motor deficits, and a deregulation in food intake and energy homeostasis. The first disease-causing CPT1C mutation was recently described in humans, with Cpt1c being identified as the gene causing hereditary spastic paraplegia. The putative role of CPT1C in the regulation of complex-lipid metabolism is supported by the observation that it is highly expressed in certain virulent tumor cells, conferring them resistance to glucose- and oxygen-deprivation. Therefore, CPT1C may be a promising target in the treatment of cancer. Here we review the molecular, biochemical, and structural properties of CPT1C and discuss its potential roles in brain function, and cancer.
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526
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Abstract
PURPOSE OF REVIEW Gene-based therapies are designed to modulate gene expression in specific tissues by introducing into cells transgenes, antisense oligonucleotides, RNA interference, microRNAs, or a variety of other oligonucleotide-based compounds and their delivery systems. Several types of gene-based therapies are already available or in clinical development to treat severe lipid-related disorders and associated risk. The review briefly presents the current status and future challenges of these therapies in clinical lipidology, focusing on most advanced and promising agents or mechanisms. RECENT FINDINGS Gene-based agents address several unmet medical needs in lipidology such as homozygous familial hypercholesterolemia, familial or multifactorial chylomicronemia, severe hypertriglyceridemia, elevated lipoprotein (a), familial partial lipodystrophy, nonalcoholic fatty liver disease, and hypoalphalipoproteinemia. Most advanced antisense oligonucleotide drugs target apolipoprotein C-III, apolipoprotein (a), angiopoietin-like 3, and diacylglycerol o-acyltransferase-2. Long-term efficacy and safety data are now available for two gene-based agents, mipomersen, approved in the USA for homozygous familial hypercholesterolemia and Glybera, AAV1-LPLS447X gene therapy, conditionally approved in Europe for lipoprotein lipase deficiency. SUMMARY Although positive to date, the overall benefit-risk ratio of gene-based therapies is yet to be documented long term across additional patients and conditions. The next generation of such therapies might improve their therapeutic index.
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Affiliation(s)
- Daniel Gaudet
- Lipidology Unit, Community genomic medicine Center, Department of Medicine, Université de Montréal and ECOGENE-21, Chicoutimi, Quebec, Canada
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527
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Vallerie SN, Bornfeldt KE. Metabolic Flexibility and Dysfunction in Cardiovascular Cells. Arterioscler Thromb Vasc Biol 2015; 35:e37-42. [PMID: 26310811 DOI: 10.1161/atvbaha.115.306226] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Sara N Vallerie
- From the Division of Metabolism, Endocrinology and Nutrition, Departments of Medicine (S.N.V., K.E.B.) and Pathology (K.E.B.), Diabetes and Obesity Center of Excellence, University of Washington School of Medicine, Seattle
| | - Karin E Bornfeldt
- From the Division of Metabolism, Endocrinology and Nutrition, Departments of Medicine (S.N.V., K.E.B.) and Pathology (K.E.B.), Diabetes and Obesity Center of Excellence, University of Washington School of Medicine, Seattle.
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528
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Abstract
The compact nervous system of Caenorhabditis elegans and its genetic tractability are features that make this organism highly suitable for investigating energy balance in an animal system. Here, we focus on molecular components and organizational principles emerging from the investigation of pathways that largely originate in the nervous system and regulate feeding behavior but also peripheral fat regulation through neuroendocrine signaling. We provide an overview of studies aimed at understanding how C. elegans integrate internal and external cues in feeding behavior. We highlight some of the similarities and differences in energy balance between C. elegans and mammals. We also provide our perspective on unresolved issues, both conceptual and technical, that we believe have hampered critical evaluation of findings relevant to fat regulation in C. elegans.
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Affiliation(s)
- George A Lemieux
- Department of Physiology, University of California, San Francisco, California 94158;
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, California 94158;
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529
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Green CJ, Johnson D, Amin HD, Sivathondan P, Silva MA, Wang LM, Stevanato L, McNeil CA, Miljan EA, Sinden JD, Morten KJ, Hodson L. Characterization of lipid metabolism in a novel immortalized human hepatocyte cell line. Am J Physiol Endocrinol Metab 2015; 309:E511-22. [PMID: 26126685 PMCID: PMC4572456 DOI: 10.1152/ajpendo.00594.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/15/2015] [Indexed: 02/06/2023]
Abstract
The development of hepatocyte cell models that represent fatty acid partitioning within the human liver would be beneficial for the study of the development and progression of nonalcoholic fatty liver disease (NAFLD). We sought to develop and characterize a novel human liver cell line (LIV0APOLY) to establish a model of lipid accumulation using a physiological mixture of fatty acids under low- and high-glucose conditions. LIV0APOLY cells were compared with a well-established cell line (HepG2) and, where possible, primary human hepatocytes. LIV0APOLY cells were found to proliferate and express some mature liver markers and were wild type for the PNPLA3 (rs738409) gene, whereas HepG2 cells carried the Ile(148)Met variant that is positively associated with liver fat content. Intracellular triglyceride content was higher in HepG2 than in LIV0APOLY cells; exposure to high glucose and/or exogenous fatty acids increased intracellular triglyceride in both cell lines. Triglyceride concentrations in media were higher from LIV0APOLY compared with HepG2 cells. Culturing LIV0APOLY cells in high glucose increased a marker of endoplasmic reticulum stress and attenuated insulin-stimulated Akt phosphorylation whereas low glucose and exogenous fatty acids increased AMPK phosphorylation. Although LIV0APOLY cells and primary hepatocytes stored similar amounts of exogenous fatty acids as triglyceride, more exogenous fatty acids were partitioned toward oxidation in the LIV0APOLY cells than in primary hepatocytes. LIV0APOLY cells offer the potential to be a renewable cellular model for studying the effects of exogenous metabolic substrates on fatty acid partitioning; however, their usefulness as a model of lipoprotein metabolism needs to be further explored.
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Affiliation(s)
- Charlotte J Green
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | | | - Harsh D Amin
- ReNeuron Group, Guildford, Surrey, United Kingdom
| | - Pamela Sivathondan
- Nuffield Department of Obstetrics and Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Michael A Silva
- Department of Hepatobiliary and Pancreatic Surgery, Oxford University Hospital NHS Trust, Churchill Hospital, Oxford, United Kingdom; and
| | - Lai Mun Wang
- Department of Cellular Pathology, Oxford University Hospitals, Oxford, United Kingdom
| | | | - Catriona A McNeil
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | | | | | - Karl J Morten
- Nuffield Department of Obstetrics and Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom;
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530
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Shi HB, Yu K, Luo J, Li J, Tian HB, Zhu JJ, Sun YT, Yao DW, Xu HF, Shi HP, Loor JJ. Adipocyte differentiation-related protein promotes lipid accumulation in goat mammary epithelial cells. J Dairy Sci 2015; 98:6954-64. [PMID: 26298750 DOI: 10.3168/jds.2015-9452] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 05/21/2015] [Indexed: 12/16/2022]
Abstract
Milk fat originates from the secretion of cytosolic lipid droplets (CLD) synthesized within mammary epithelial cells. Adipocyte differentiation-related protein (ADRP; gene symbol PLIN2) is a CLD-binding protein that is crucial for synthesis of mature CLD. Our hypothesis was that ADRP regulates CLD production and metabolism in goat mammary epithelial cells (GMEC) and thus plays a role in determining milk fat content. To understand the role of ADRP in ruminant milk fat metabolism, ADRP (PLIN2) was overexpressed or knocked down in GMEC using an adenovirus system. Immunocytochemical staining revealed that ADRP localized to the surface of CLD. Supplementation with oleic acid (OA) enhanced its colocalization with CLD surface and enhanced lipid accumulation. Overexpression of ADRP increased lipid accumulation and the concentration of triacylglycerol in GMEC. In contrast, morphological examination revealed that knockdown of ADRP decreased lipid accumulation even when OA was supplemented. This response was confirmed by the reduction in mass of cellular TG when ADRP was knocked down. The fact that knockdown of ADRP did not completely eliminate lipid accumulation at a morphological level in GMEC without OA suggests that some other compensatory factors may also aid in the process of CLD formation. The ADRP reversed the decrease of CLD accumulation induced by adipose triglyceride lipase. This is highly suggestive of ADRP promoting triacylglycerol stability within CLD by preventing access to adipose triglyceride lipase. Collectively, these data provide direct in vitro evidence that ADRP plays a key role in CLD formation and stability in GMEC.
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Affiliation(s)
- H B Shi
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100; College of Life Science, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, P. R. China 310018
| | - K Yu
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - J Luo
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100.
| | - J Li
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - H B Tian
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - J J Zhu
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - Y T Sun
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - D W Yao
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - H F Xu
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - H P Shi
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China 712100
| | - J J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801.
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531
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Sarkar N, Chakravarty R. Hepatitis B Virus Infection, MicroRNAs and Liver Disease. Int J Mol Sci 2015; 16:17746-62. [PMID: 26247932 PMCID: PMC4581219 DOI: 10.3390/ijms160817746] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 12/16/2022] Open
Abstract
Hepatitis B virus (HBV) attacks the liver and can cause both acute as well as chronic liver diseases which might lead to liver cirrhosis and hepatocellular carcinoma. Regardless of the availability of a vaccine and numerous treatment options, HBV is a major cause of morbidity and mortality across the world. Recently, microRNAs (miRNAs) have emerged as important modulators of gene function. Studies on the role of miRNA in the regulation of hepatitis B virus gene expression have been the focus of modern antiviral research. miRNAs can regulate viral replication and pathogenesis in a number of different ways, which includefacilitation, direct or indirect inhibition, activation of immune response, epigenetic modulation, etc. Nevertheless, these mechanisms can appropriately be used with a diagnosticand/or therapeutic approach. The present review is an attempt to classify specific miRNAs that are reported to be associated with various aspects of hepatitis B biology, in order to precisely present the participation of individual miRNAs in multiple aspects relating to HBV.
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Affiliation(s)
- Neelakshi Sarkar
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata-700010, India.
| | - Runu Chakravarty
- ICMR Virus Unit, Kolkata, ID & BG Hospital Campus, Kolkata-700010, India.
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532
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Ding N, Wang S, Yang Q, Li Y, Cheng H, Wang J, Wang D, Deng Y, Yang Y, Hu S, Zhao H, Fang X. Deep sequencing analysis of microRNA expression in human melanocyte and melanoma cell lines. Gene 2015; 572:135-145. [PMID: 26164755 DOI: 10.1016/j.gene.2015.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 06/28/2015] [Accepted: 07/02/2015] [Indexed: 12/19/2022]
Abstract
Melanoma is a type of skin cancer that is highly aggressive, and is considered the most deadly of all skin cancers. Currently, there are no effective therapies for melanomas once they undergo metastasis. MicroRNAs (miRNAs) are small, single-stranded, non-coding RNA molecules that can post-transcriptionally regulate gene expression. They have been reported to be associated with the occurrence of many diseases, including human melanoma. However, the mechanisms by which miRNAs exert their effects remain unclear; therefore, a systematic analysis of the miRNAome in human melanoma is necessary. We investigated the miRNAome in human melanocyte and melanoma cell lines using high-throughput RNA sequencing. We identified a group of dysregulated miRNAs by comparing the miRNA expression profiles among the melanoma cell lines. Target genes of these miRNAs encode proteins whose functions are associated with the cell cycle and apoptosis. Gene networks were built to investigate the interactions of genes during melanoma progression. We identified that the key genes that regulate melanoma cell proliferation were regulated by miRNAs. In summary, our investigation of the human melanoma miRNAome using high-throughput sequencing revealed a number of previously unreported miRNAs associated with malignant progression of melanoma. Our findings add to existing knowledge regarding the mechanisms of melanoma development.
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Affiliation(s)
- Nan Ding
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shaobin Wang
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiong Yang
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongjun Li
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hua Cheng
- Institute of Biology, Hebei Academy of Sciences, Shijiazhuang 050081, China
| | - Junyun Wang
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Wang
- Department of Dermatology, General Hospital of People's Liberation Army, Beijing 100853, China
| | - Youhui Deng
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yadong Yang
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Songnian Hu
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hua Zhao
- Department of Dermatology, General Hospital of People's Liberation Army, Beijing 100853, China.
| | - Xiangdong Fang
- CAS Key Laboratory of Genome Science and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
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533
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Lipidomic and proteomic analysis of Caenorhabditis elegans lipid droplets and identification of ACS-4 as a lipid droplet-associated protein. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1337-45. [PMID: 26121959 DOI: 10.1016/j.bbalip.2015.06.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 06/08/2015] [Accepted: 06/25/2015] [Indexed: 01/08/2023]
Abstract
Lipid droplets are cytoplasmic organelles that store neutral lipids for membrane synthesis and energy reserves. In this study, we characterized the lipid and protein composition of purified Caenorhabditis elegans lipid droplets. These lipid droplets are composed mainly of triacylglycerols, surrounded by a phospholipid monolayer composed primarily of phosphatidylcholine and phosphatidylethanolamine. The fatty acid composition of the triacylglycerols is rich in fatty acid species obtained from the dietary Escherichia coli, including cyclopropane fatty acids and cis-vaccenic acid. Unlike other organisms, C. elegans lipid droplets contain very little cholesterol or cholesterol esters. Comparison of the lipid droplet proteomes of wild type and high-fat daf-2 mutant strains shows a very similar proteome in both strains, except that the most abundant protein in the C. elegans lipid droplet proteome, MDT-28, is relatively less abundant in lipid droplets isolated from daf-2 mutants. Functional analysis of lipid droplet proteins identified in our proteomic studies indicated an enrichment of proteins required for growth and fat homeostasis in C. elegans. Finally, we confirmed the localization of one of the newly identified lipid droplet proteins, ACS-4. We found that ACS-4 localizes to the surface of lipid droplets in the C. elegans intestine and skin. This study bolsters C. elegans as a model to study the dynamics and functions of lipid droplets in a multicellular organism.
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534
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Shen H, Li W, Tian Y, Xu P, Wang H, Zhang J, Li Y. Upregulation of miR-362-3p Modulates Proliferation and Anchorage-Independent Growth by Directly Targeting Tob2 in Hepatocellular Carcinoma. J Cell Biochem 2015; 116:1563-73. [PMID: 25649327 DOI: 10.1002/jcb.25110] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 01/23/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Hongxing Shen
- College of Life Sciences; Wuhan University; Wuhan 430072 China
| | - Wenjuan Li
- College of Life Sciences; Wuhan University; Wuhan 430072 China
| | - Yuan Tian
- College of Life Sciences; Wuhan University; Wuhan 430072 China
| | - Peng Xu
- Department of Surgery; Wuhan Union Hospital; Wuhan 430022 China
| | - Hui Wang
- Department of Medical Genetics, Tongji Medical College; Huazhong University of Science and Technology; Wuhan 430022 China
| | - Jinxiang Zhang
- Department of Surgery; Wuhan Union Hospital; Wuhan 430022 China
| | - Youjun Li
- College of Life Sciences; Wuhan University; Wuhan 430072 China
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535
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Ghidini M, Braconi C. Non-Coding RNAs in Primary Liver Cancer. Front Med (Lausanne) 2015; 2:36. [PMID: 26131450 PMCID: PMC4469108 DOI: 10.3389/fmed.2015.00036] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/19/2015] [Indexed: 12/12/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a primary malignancy of the liver with poor prognosis and limited therapeutic options. Over the past few years, many studies have evaluated the role of non-coding RNAs (ncRNAs) in hepatocarcinogenesis and tumor progression. ncRNAs were shown to have diagnostic, prognostic, and therapeutic potential in HCC. In this manuscript, we review the latest major discoveries concerning microRNAs and long ncRNAs in HCC pathogenesis, and discuss the potentials and the limitations for their use in clinical practice.
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Affiliation(s)
- Michele Ghidini
- Division of Cancer Therapeutics, The Institute of Cancer Research , London , UK ; Cancer Center, Humanitas Clinical and Research Center , Milano , Italy
| | - Chiara Braconi
- Division of Cancer Therapeutics, The Institute of Cancer Research , London , UK ; The Royal Marsden NHS Foundation Trust , London , UK
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536
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Rinaldi C, Schmidt T, Situ AJ, Johnson JO, Lee PR, Chen KL, Bott LC, Fadó R, Harmison GH, Parodi S, Grunseich C, Renvoisé B, Biesecker LG, De Michele G, Santorelli FM, Filla A, Stevanin G, Dürr A, Brice A, Casals N, Traynor BJ, Blackstone C, Ulmer TS, Fischbeck KH. Mutation in CPT1C Associated With Pure Autosomal Dominant Spastic Paraplegia. JAMA Neurol 2015; 72:561-70. [PMID: 25751282 PMCID: PMC5612424 DOI: 10.1001/jamaneurol.2014.4769] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
IMPORTANCE The family of genes implicated in hereditary spastic paraplegias (HSPs) is quickly expanding, mostly owing to the widespread availability of next-generation DNA sequencing methods. Nevertheless, a genetic diagnosis remains unavailable for many patients. OBJECTIVE To identify the genetic cause for a novel form of pure autosomal dominant HSP. DESIGN, SETTING, AND PARTICIPANTS We examined and followed up with a family presenting to a tertiary referral center for evaluation of HSP for a decade until August 2014. Whole-exome sequencing was performed in 4 patients from the same family and was integrated with linkage analysis. Sanger sequencing was used to confirm the presence of the candidate variant in the remaining affected and unaffected members of the family and screen the additional patients with HSP. Five affected and 6 unaffected participants from a 3-generation family with pure adult-onset autosomal dominant HSP of unknown genetic origin were included. Additionally, 163 unrelated participants with pure HSP of unknown genetic cause were screened. MAIN OUTCOME AND MEASURE Mutation in the neuronal isoform of carnitine palmitoyl-transferase (CPT1C) gene. RESULTS We identified the nucleotide substitution c.109C>T in exon 3 of CPT1C, which determined the base substitution of an evolutionarily conserved Cys residue for an Arg in the gene product. This variant strictly cosegregated with the disease phenotype and was absent in online single-nucleotide polymorphism databases and in 712 additional exomes of control participants. We showed that CPT1C, which localizes to the endoplasmic reticulum, is expressed in motor neurons and interacts with atlastin-1, an endoplasmic reticulum protein encoded by the ATL1 gene known to be mutated in pure HSPs. The mutation, as indicated by nuclear magnetic resonance spectroscopy studies, alters the protein conformation and reduces the mean (SD) number (213.0 [46.99] vs 81.9 [14.2]; P < .01) and size (0.29 [0.01] vs 0.26 [0.01]; P < .05) of lipid droplets on overexpression in cells. We also observed a reduction of mean (SD) lipid droplets in primary cortical neurons isolated from Cpt1c-/- mice as compared with wild-type mice (1.0 [0.12] vs 0.44 [0.05]; P < .001), suggesting a dominant negative mechanism for the mutation. CONCLUSIONS AND RELEVANCE This study expands the genetics of autosomal dominant HSP and is the first, to our knowledge, to link mutation in CPT1C with a human disease. The association of the CPT1C mutation with changes in lipid droplet biogenesis supports a role for altered lipid-mediated signal transduction in HSP pathogenesis.
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Affiliation(s)
- Carlo Rinaldi
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Thomas Schmidt
- Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles
| | - Alan J Situ
- Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles
| | - Janel O Johnson
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland
| | - Philip R Lee
- Section on Nervous System Development and Plasticity, The Eunice Kennedy Shriver National Institute of Child and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Ke-Lian Chen
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Laura C Bott
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland5Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Rut Fadó
- Basic Sciences Department, Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya, and CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Sant Cugat del Vallés, Spain
| | - George H Harmison
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Sara Parodi
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland7Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Christopher Grunseich
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Benoît Renvoisé
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Leslie G Biesecker
- Genetic Disease Research Branch, National Human Genome Research Institute, and the National Institutes of Health Intramural Sequencing Center, National Institutes of Health, Bethesda, Maryland
| | - Giuseppe De Michele
- Department of Neurosciences, Reproductive Sciences, and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Filippo M Santorelli
- Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico, Stella Maris, Pisa, Italy
| | - Alessandro Filla
- Department of Neurosciences, Reproductive Sciences, and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Giovanni Stevanin
- Institut du Cerveau et de la Moelle Épinière, Paris, France12Laboratoire de Neurogénétique, École Pratique des Hautes Études-héSam Université, Institut du Cerveau et de la Moelle Épinière, Groupe Hospitalier Pitié-Salpêtrière, Paris, France13Sorbonne Univ
| | - Alexandra Dürr
- Institut du Cerveau et de la Moelle Épinière, Paris, France13Sorbonne Universités, Université Pierre et Marie Curie, Institut du Cerveau et de la Moelle Épinière, Paris, France14Department of Genetics, Assistance Publique Hopitaux de Paris, Groupe Hospita
| | - Alexis Brice
- Institut du Cerveau et de la Moelle Épinière, Paris, France13Sorbonne Universités, Université Pierre et Marie Curie, Institut du Cerveau et de la Moelle Épinière, Paris, France14Department of Genetics, Assistance Publique Hopitaux de Paris, Groupe Hospita
| | - Núria Casals
- Basic Sciences Department, Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya, and CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Sant Cugat del Vallés, Spain
| | - Bryan J Traynor
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland
| | - Craig Blackstone
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Tobias S Ulmer
- Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles
| | - Kenneth H Fischbeck
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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537
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Papadopoulos C, Orso G, Mancuso G, Herholz M, Gumeni S, Tadepalle N, Jüngst C, Tzschichholz A, Schauss A, Höning S, Trifunovic A, Daga A, Rugarli EI. Spastin binds to lipid droplets and affects lipid metabolism. PLoS Genet 2015; 11:e1005149. [PMID: 25875445 PMCID: PMC4395272 DOI: 10.1371/journal.pgen.1005149] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 03/17/2015] [Indexed: 11/30/2022] Open
Abstract
Mutations in SPAST, encoding spastin, are the most common cause of autosomal dominant hereditary spastic paraplegia (HSP). HSP is characterized by weakness and spasticity of the lower limbs, owing to progressive retrograde degeneration of the long corticospinal axons. Spastin is a conserved microtubule (MT)-severing protein, involved in processes requiring rearrangement of the cytoskeleton in concert to membrane remodeling, such as neurite branching, axonal growth, midbody abscission, and endosome tubulation. Two isoforms of spastin are synthesized from alternative initiation codons (M1 and M87). We now show that spastin-M1 can sort from the endoplasmic reticulum (ER) to pre- and mature lipid droplets (LDs). A hydrophobic motif comprised of amino acids 57 through 86 of spastin was sufficient to direct a reporter protein to LDs, while mutation of arginine 65 to glycine abolished LD targeting. Increased levels of spastin-M1 expression reduced the number but increased the size of LDs. Expression of a mutant unable to bind and sever MTs caused clustering of LDs. Consistent with these findings, ubiquitous overexpression of Dspastin in Drosophila led to bigger and less numerous LDs in the fat bodies and increased triacylglycerol levels. In contrast, Dspastin overexpression increased LD number when expressed specifically in skeletal muscles or nerves. Downregulation of Dspastin and expression of a dominant-negative variant decreased LD number in Drosophila nerves, skeletal muscle and fat bodies, and reduced triacylglycerol levels in the larvae. Moreover, we found reduced amount of fat stores in intestinal cells of worms in which the spas-1 homologue was either depleted by RNA interference or deleted. Taken together, our data uncovers an evolutionarily conserved role of spastin as a positive regulator of LD metabolism and open up the possibility that dysfunction of LDs in axons may contribute to the pathogenesis of HSP. Hereditary spastic paraplegia (HSP) is a genetically heterogeneous neurological disease characterized by weakness and spasticity of the lower limbs, caused by progressive retrograde degeneration of the corticospinal axons, the longest in the central nervous system. The most commonly mutated gene in autosomal dominant forms of HSP, SPAST, encodes for spastin, a microtubule-severing protein. Spastin has been implicated in several processes involving remodeling of membrane structures. We now show that the longest spastin form, spastin-M1, harbors a lipid droplet targeting sequence, which allows targeting of the protein to the surface of lipid droplets, the organelles where cells store neutral lipids. Furthermore, we demonstrate that depletion of the homologous spastin proteins in both flies and worms affects lipid droplet number and triacylglycerol content. Our study adds to recent discoveries that implicate other HSP proteins in lipid droplet and lipid metabolism, and strongly suggests that lipid droplet dysfunction in neurons should be investigated to understand pathogenesis of HSP.
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Affiliation(s)
- Chrisovalantis Papadopoulos
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Genny Orso
- "E. MEDEA" Scientific Institute, Conegliano, Italy
| | - Giuseppe Mancuso
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Marija Herholz
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | | | - Nimesha Tadepalle
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Christian Jüngst
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Anne Tzschichholz
- Institute for Biochemistry I, Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Astrid Schauss
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Stefan Höning
- Institute for Biochemistry I, Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Aleksandra Trifunovic
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Andrea Daga
- "E. MEDEA" Scientific Institute, Conegliano, Italy
| | - Elena I. Rugarli
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
- * E-mail:
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538
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Tian Y, Ou JHJ. Genetic and epigenetic alterations in hepatitis B virus-associated hepatocellular carcinoma. Virol Sin 2015; 30:85-91. [PMID: 25862579 DOI: 10.1007/s12250-015-3582-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 03/25/2015] [Indexed: 12/14/2022] Open
Abstract
Hepatitis B virus (HBV) is a major cause of hepatocellular carcinoma (HCC). Its chronic infection can lead to chronic liver inflammation and the accumulation of genetic alterations to result in the oncogenic transformation of hepatocytes. HBV can also sensitize hepatocytes to oncogenic transformation by causing genetic and epigenetic changes of the host chromosomes. HBV DNA can insert into host chromosomes and recent large-scale whole-genome sequencing studies revealed recurrent HBV DNA integrations sites that may play important roles in the initiation of hepatocellular carcinogenesis. HBV can also cause epigenetic changes by altering the methylation status of cellular DNA, the post-translational modification of histones, and the expression of microRNAs. These changes can also lead to the eventual hepatocellular transformation. These recent findings on the genetic and epigenetic alterations of the host chromosomes induced by HBV opened a new avenue for the development of novel diagnosis and treatments for HBV-induced HCC.
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Affiliation(s)
- Yongjun Tian
- Department of Molecular Microbiology and Immunology, University of Southern California Keck School of Medicine, Los Angeles, 90033, USA
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539
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Sidhu K, Kapoor NR, Pandey V, Kumar V. The "Macro" World of microRNAs in Hepatocellular Carcinoma. Front Oncol 2015; 5:68. [PMID: 25859429 PMCID: PMC4373247 DOI: 10.3389/fonc.2015.00068] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 03/08/2015] [Indexed: 12/23/2022] Open
Abstract
Hepatotropic viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) are the major etiological agents associated with development of hepatocellular carcinoma (HCC). Progression of HCC is a multistep process that requires sequential or parallel deregulation of oncogenic and tumor suppressive pathways leading to chromosomal instability and neoplastic phenotype. In the recent years, microRNAs (miRNAs) have carved their own niche alongside oncogenes and tumor suppressors, owing to their innate ability to receive and relay multiple signals. Not surprisingly, miRNAs are fast emerging as central player in myriads of malignancies including HCC. miRNAs are reported to participate in initiation and progression of HCC, and have also been clinically correlated with risk assessment, disease grade, aggressiveness, and prognosis. Despite extensive data available on the role of miRNAs in HCC, there is a pressing need to integrate and evaluate these datasets to find its correlation, if any, with causal agents in order to devise novel interventional modalities. Through this review, we attempt to bridge the gap by consolidating the current knowledge and concepts in the field of HCC-related miRNAs with special emphasis on HBV and HCV. Further, we assess the potential of common as well as unique signatures that may be useful in developing novel biomarkers and therapeutics.
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Affiliation(s)
- Kaveri Sidhu
- Virology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB) , New Delhi , India
| | - Neetu Rohit Kapoor
- Virology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB) , New Delhi , India
| | - Vijaya Pandey
- Virology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB) , New Delhi , India
| | - Vijay Kumar
- Virology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB) , New Delhi , India
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540
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Ulengin I, Park JJ, Lee TH. ER network formation and membrane fusion by atlastin1/SPG3A disease variants. Mol Biol Cell 2015; 26:1616-28. [PMID: 25761634 PMCID: PMC4436774 DOI: 10.1091/mbc.e14-10-1447] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 03/03/2015] [Indexed: 12/20/2022] Open
Abstract
Atlastin catalyzes GTP-dependent membrane fusion to form the ER network. Mutations in atlastin1 cause the disease hereditary spastic paraplegia (HSP), implying that defects in ER membrane fusion cause HSP. Surprisingly, several disease variants are functional in assays for ER network formation and membrane fusion, warranting rethinking of HSP causation by atlastin1 mutations. At least 38 distinct missense mutations in the neuronal atlastin1/SPG3A GTPase are implicated in an autosomal dominant form of hereditary spastic paraplegia (HSP), a motor-neurological disorder manifested by lower limb weakness and spasticity and length-dependent axonopathy of corticospinal motor neurons. Because the atlastin GTPase is sufficient to catalyze membrane fusion and required to form the ER network, at least in nonneuronal cells, it is logically assumed that defects in ER membrane morphogenesis due to impaired fusion activity are the primary drivers of SPG3A-associated HSP. Here we analyzed a subset of established atlastin1/SPG3A disease variants using cell-based assays for atlastin-mediated ER network formation and biochemical assays for atlastin-catalyzed GTP hydrolysis, dimer formation, and membrane fusion. As anticipated, some variants exhibited clear deficits. Surprisingly however, at least two disease variants, one of which represents that most frequently identified in SPG3A HSP patients, displayed wild-type levels of activity in all assays. The same variants were also capable of co-redistributing ER-localized REEP1, a recently identified function of atlastins that requires its catalytic activity. Taken together, these findings indicate that a deficit in the membrane fusion activity of atlastin1 may be a key contributor, but is not required, for HSP causation.
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Affiliation(s)
- Idil Ulengin
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | - John J Park
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Tina H Lee
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
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541
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Delving into the complexity of hereditary spastic paraplegias: how unexpected phenotypes and inheritance modes are revolutionizing their nosology. Hum Genet 2015; 134:511-38. [PMID: 25758904 PMCID: PMC4424374 DOI: 10.1007/s00439-015-1536-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 02/23/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSP) are rare neurodegenerative diseases sharing the degeneration of the corticospinal tracts as the main pathological characteristic. They are considered one of the most heterogeneous neurological disorders. All modes of inheritance have been described for the 84 different loci and 67 known causative genes implicated up to now. Recent advances in molecular genetics have revealed clinico-genetic heterogeneity of these disorders including their clinical and genetic overlap with other diseases of the nervous system. The systematic analysis of a large set of genes, including exome sequencing, is unmasking unusual phenotypes or inheritance modes associated with mutations in HSP genes and related genes involved in various neurological diseases. A new nosology may emerge after integration and understanding of these new data to replace the current classification. Collectively, functions of the known genes implicate the disturbance of intracellular membrane dynamics and trafficking as the consequence of alterations of cytoskeletal dynamics, lipid metabolism and organelle structures, which represent in fact a relatively small number of cellular processes that could help to find common curative approaches, which are still lacking.
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542
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Lane AN, Fan TWM. Regulation of mammalian nucleotide metabolism and biosynthesis. Nucleic Acids Res 2015; 43:2466-85. [PMID: 25628363 PMCID: PMC4344498 DOI: 10.1093/nar/gkv047] [Citation(s) in RCA: 563] [Impact Index Per Article: 62.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 12/21/2014] [Accepted: 01/12/2015] [Indexed: 12/25/2022] Open
Abstract
Nucleotides are required for a wide variety of biological processes and are constantly synthesized de novo in all cells. When cells proliferate, increased nucleotide synthesis is necessary for DNA replication and for RNA production to support protein synthesis at different stages of the cell cycle, during which these events are regulated at multiple levels. Therefore the synthesis of the precursor nucleotides is also strongly regulated at multiple levels. Nucleotide synthesis is an energy intensive process that uses multiple metabolic pathways across different cell compartments and several sources of carbon and nitrogen. The processes are regulated at the transcription level by a set of master transcription factors but also at the enzyme level by allosteric regulation and feedback inhibition. Here we review the cellular demands of nucleotide biosynthesis, their metabolic pathways and mechanisms of regulation during the cell cycle. The use of stable isotope tracers for delineating the biosynthetic routes of the multiple intersecting pathways and how these are quantitatively controlled under different conditions is also highlighted. Moreover, the importance of nucleotide synthesis for cell viability is discussed and how this may lead to potential new approaches to drug development in diseases such as cancer.
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Affiliation(s)
- Andrew N Lane
- Graduate Center of Toxicology and Markey Cancer Center, University of Kentucky, Biopharm Complex, 789 S. Limestone St, Lexington, KY 40536, USA
| | - Teresa W-M Fan
- Graduate Center of Toxicology and Markey Cancer Center, University of Kentucky, Biopharm Complex, 789 S. Limestone St, Lexington, KY 40536, USA
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543
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544
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Caenorhabditis elegans Models of Hereditary Spastic Paraplegia. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00074-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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545
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Morishita A, Masaki T. miRNA in hepatocellular carcinoma. Hepatol Res 2015; 45:128-41. [PMID: 25040738 DOI: 10.1111/hepr.12386] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 06/27/2014] [Accepted: 07/01/2014] [Indexed: 12/19/2022]
Abstract
Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Despite improvements in HCC therapy, the prognosis for HCC patients remains poor due to a high incidence of recurrence. An improved understanding of the pathogenesis of HCC development would facilitate the development of more effective outcomes for the diagnosis and treatment of HCC at earlier stages. miRNA are small, endogenous, non-coding, ssRNA that are 21-30 nucleotides in length and modulate the expression of various target genes at the post-transcriptional and translational levels. Aberrant expression of miRNA is common in various human malignancies and modulates cancer-associated genomic regions or fragile sites. As for the relationship between miRNA and HCC, several studies have demonstrated that the aberrant expression of specific miRNA can be detected in HCC cells and tissues. However, little is known about the mechanisms of miRNA-related cell proliferation and development. In this review, we summarize the central and potential roles of miRNA in the pathogenesis of HCC and elucidate new possibilities that may be useful as diagnostic and prognostic markers, as well as novel therapeutic targets in HCC.
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Affiliation(s)
- Asahiro Morishita
- Department of Gastroenterology and Neurology, Kagawa University School of Medicine, Kagawa, Japan
| | - Tsutomu Masaki
- Department of Gastroenterology and Neurology, Kagawa University School of Medicine, Kagawa, Japan
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546
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Yip DKS, Pang IK, Yip KY. Systematic exploration of autonomous modules in noisy microRNA-target networks for testing the generality of the ceRNA hypothesis. BMC Genomics 2014; 15:1178. [PMID: 25539629 PMCID: PMC4367885 DOI: 10.1186/1471-2164-15-1178] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/11/2014] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND In the competing endogenous RNA (ceRNA) hypothesis, different transcripts communicate through a competition for their common targeting microRNAs (miRNAs). Individual examples have clearly shown the functional importance of ceRNA in gene regulation and cancer biology. It remains unclear to what extent gene expression levels are regulated by ceRNA in general. One major hurdle to studying this problem is the intertwined connections in miRNA-target networks, which makes it difficult to isolate the effects of individual miRNAs. RESULTS Here we propose computational methods for decomposing a complex miRNA-target network into largely autonomous modules called microRNA-target biclusters (MTBs). Each MTB contains a relatively small number of densely connected miRNAs and mRNAs with few connections to other miRNAs and mRNAs. Each MTB can thus be individually analyzed with minimal crosstalk with other MTBs. Our approach differs from previous methods for finding modules in miRNA-target networks by not making any pre-assumptions about expression patterns, thereby providing objective information for testing the ceRNA hypothesis. We show that the expression levels of miRNAs and mRNAs in an MTB are significantly more anti-correlated than random miRNA-mRNA pairs and other validated and predicted miRNA-target pairs, demonstrating the biological relevance of MTBs. We further show that there is widespread correlation of expression between mRNAs in same MTBs under a wide variety of parameter settings, and the correlation remains even when co-regulatory effects are controlled for, which suggests potential widespread expression buffering between these mRNAs, which is consistent with the ceRNA hypothesis. Lastly, we also propose a potential use of MTBs in functional annotation of miRNAs. CONCLUSIONS MTBs can be used to help identify autonomous miRNA-target modules for testing the generality of the ceRNA hypothesis experimentally. The identified modules can also be used to test other properties of miRNA-target networks in general.
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Affiliation(s)
- Danny Kit-Sang Yip
- />Department of Computer Science and Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Iris K Pang
- />School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Kevin Y Yip
- />Department of Computer Science and Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
- />Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
- />CUHK-BGI Innovation Institute of Trans-omics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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547
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Lu L, Han H, Tian Y, Li W, Zhang J, Feng M, Li Y. Aurora kinase A mediates c-Myc's oncogenic effects in hepatocellular carcinoma. Mol Carcinog 2014; 54:1467-79. [PMID: 25284017 DOI: 10.1002/mc.22223] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 08/09/2014] [Accepted: 08/13/2014] [Indexed: 12/13/2022]
Abstract
Dysregulation of c-Myc (Myc) has been shown to contribute to progression of hepatocellular carcinoma, however, the detailed molecular mechanism remains poorly understood. Here, we report that Myc binds to the Aurora kinase A (Aurka) promoter and induces expression of Aurka in HCC cells. Increased expression of Aurka correlates with that of Myc in HCC. Nuclear accumulation of Aurka was confirmed by subcellular protein fractionation and immunoblot experiments in HCC cells. Myc inhibition decreases the nuclear accumulation of Aurka in HCC cells. Also Aurka accumulating in the nucleus up-regulates Myc transcription by binding the Myc promoter containing the highly conserved CCCTCCCCA in the NHE region of the CpG islands. Inhibition of Myc or Aurka diminishes the malignant phenotypes of HCC cells by down-regulating some common target genes. Also Aurka and Myc mediates the effects of each other, at least partially, on proliferation, anchorage-independent soft agar growth, and ATP production. Blocking Aurka in an orthotopic model significantly impairs tumor growth in mice. These results identify a Myc-Aurka feedback loop in which Myc and Aurka regulate expression of each other at the transcriptional level and both play an important role in hepatocarcinogenesis.
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Affiliation(s)
- Longfeng Lu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Han Han
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yuan Tian
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wenjuan Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jinxiang Zhang
- Department of Surgery, Wuhan Union Hospital, Wuhan, China
| | - Maohui Feng
- Department of Oncology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Youjun Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
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548
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Hübner CA, Kurth I. Membrane-shaping disorders: a common pathway in axon degeneration. ACTA ACUST UNITED AC 2014; 137:3109-21. [PMID: 25281866 DOI: 10.1093/brain/awu287] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurons with long projections are particularly liable to damage, which is reflected by a large group of hereditary neurodegenerative disorders that primarily affect these neurons. In the group of hereditary spastic paraplegias motor axons of the central nervous system degenerate, while distal pure motor neuropathies, Charcot-Marie-Tooth disorders and the group of hereditary sensory and autonomic neuropathies are characterized by degeneration of peripheral nerve fibres. Because the underlying pathologies share many parallels, the disorders are also referred to as axonopathies. A large number of genes has been associated with axonopathies and one of the emerging subgroups encodes membrane-shaping proteins with a central reticulon homology domain. Association of these proteins with lipid bilayers induces positive membrane curvature and influences the architecture of cellular organelles. Membrane-shaping proteins closely cooperate and directly interact with each other, but their structural features and localization to distinct subdomains of organelles suggests mutually exclusive roles. In some individuals a mutation in a shaping protein can result in upper motor neuron dysfunction, whereas in other patients it can lead to a degeneration of peripheral neurons. This suggests that membrane-shaping disorders might be considered as a continuous disease-spectrum of the axon.
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Affiliation(s)
- Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, 07743 Jena, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Jena University Hospital, 07743 Jena, Germany
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549
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Xie KL, Zhang YG, Liu J, Zeng Y, Wu H. MicroRNAs associated with HBV infection and HBV-related HCC. Theranostics 2014; 4:1176-92. [PMID: 25285167 PMCID: PMC4183996 DOI: 10.7150/thno.8715] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 08/10/2014] [Indexed: 02/05/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a global problem and a major risk factor for hepatocellular carcinoma (HCC). microRNAs (miRNAs) comprise a group of small noncoding RNAs regulating gene expression at the posttranslational level, thereby participating in fundamental biological processes, including cell proliferation, differentiation, and apoptosis. In this review, we summarize the roles of miRNAs in HBV infection, the recently identified mechanism underlying dysregulation of miRNAs in HBV-associated HCC, and their association with hepatocarcinogenesis. Moreover, we discuss the recent advances in the use of circulating miRNAs in the early diagnosis of HCC as well as therapies based on these aberrantly expressed miRNAs.
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550
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Lemieux GA, Ashrafi K. Insights and challenges in using C. elegans for investigation of fat metabolism. Crit Rev Biochem Mol Biol 2014; 50:69-84. [PMID: 25228063 DOI: 10.3109/10409238.2014.959890] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
C. elegans provides a genetically tractable system for deciphering the homeostatic mechanisms that underlie fat regulation in intact organisms. Here, we provide an overview of the recent advances in the C. elegans fat field with particular attention to studies of C. elegans lipid droplets, the complex links between lipases, autophagy, and lifespan, and analyses of key transcriptional regulatory mechanisms that coordinate lipid homeostasis. These studies demonstrate the ancient origins of mammalian and C. elegans fat regulatory pathways and highlight how C. elegans is being used to identify and analyze novel lipid pathways that are then shown to function similarly in mammals. Despite its many advantages, study of fat regulation in C. elegans is currently faced with a number of conceptual and methodological challenges. We critically evaluate some of the assumptions in the field and highlight issues that we believe should be taken into consideration when interpreting lipid content data in C. elegans.
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Affiliation(s)
- George A Lemieux
- Department of Physiology, University of California , San Francisco, CA , USA
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