1
|
Jarasvaraparn C, Vilar-Gomez E, Yates KP, Wilson LA, Neuschwander-Tetri B, Loomba R, Cummings O, Vos M, Xanthakos S, Schwimmer J, Molleston JP, Sanyal A, Tonascia J, Chalasani N. Age, BMI, and Type 2 Diabetes Modify the Relationship Between PNPLA3 and Advanced Fibrosis in Children and Adults With NAFLD. Clin Gastroenterol Hepatol 2024; 22:1024-1036.e2. [PMID: 38145725 PMCID: PMC11045318 DOI: 10.1016/j.cgh.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/23/2023] [Accepted: 12/04/2023] [Indexed: 12/27/2023]
Abstract
BACKGROUND & AIMS PNPLA3 G-allele is an important determinant of disease severity in nonalcoholic fatty liver disease (NAFLD). Here, we investigated the effect of age, body mass index (BMI), and type 2 diabetes mellitus (T2DM) on the relationship between PNPLA3 G-allele and advanced fibrosis in adults and children with histologically characterized NAFLD. METHODS A total of 1047 children and 2057 adults were included. DNA was genotyped for rs738409 in duplicate. Primary outcome of interest was advanced fibrosis (fibrosis stage ≥3). Regression analyses were performed after controlling for relevant covariates. An additive model was used to assess the effect of PNPLA3 G-allele (CC vs CG vs GG). RESULTS PNPLA3 G-allele was significantly associated with advanced fibrosis in children (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.16-2.09) and adults (OR, 1.55; 95% CI, 1.16-1.54). Across the cohort, older age significantly increased the risk for advanced fibrosis for PNPLA3 CC (OR, 1.019; 95% CI, 1.013-1.026), CG (OR, 1.024; 95% CI, 1.018-1.030), and GG (OR, 1.03; 95% CI, 1.023-1.037) genotypes. BMI significantly increased the relationship between PNPLA3 genotypes and advanced fibrosis in children and adults. A BMI of 30 kg/m2 was the cutoff beyond which PNPLA3 G-allele had exponential effect on the risk for advanced fibrosis in children and adults. T2DM significantly worsened the relationship between PNPLA3 G-allele and advanced fibrosis in children and adults (interaction P < .01 for both). CONCLUSIONS Age, BMI, and T2DM modify the risk of advanced fibrosis associated with PNPLA3 G-allele. Preventing or reversing T2DM and obesity in persons carrying PNPLA3 G-allele may lower the risk for advanced fibrosis in NAFLD.
Collapse
Affiliation(s)
- Chaowapong Jarasvaraparn
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Indiana University School of Medicine, Indianapolis, Indiana
| | - Eduardo Vilar-Gomez
- Division of Gastroenterology, and Hepatology, Indiana University School of Medicine, Indiana University Health, Indianapolis, Indiana
| | - Katherine P Yates
- Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland
| | - Laura A Wilson
- Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland
| | | | - Rohit Loomba
- Division of Gastroenterology, Hepatology, and Nutrition, University of California, San Diego School of Medicine, La Jolla, California
| | - Oscar Cummings
- Division of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Miriam Vos
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia
| | - Stavra Xanthakos
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Jeffrey Schwimmer
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California, San Diego School of Medicine, La Jolla, California; Department of Gastroenterology, Rady Children's Hospital San Diego, San Diego, California
| | - Jean P Molleston
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Indiana University School of Medicine, Indianapolis, Indiana
| | - Arun Sanyal
- Division of Gastroenterology, and Hepatology, Virginia Commonwealth University, Richmond, Virginia
| | - James Tonascia
- Department of Biostatistics and Epidemiology, Johns Hopkins University, Baltimore, Maryland
| | - Naga Chalasani
- Division of Gastroenterology, and Hepatology, Indiana University School of Medicine, Indiana University Health, Indianapolis, Indiana.
| |
Collapse
|
2
|
Hehl L, Creasy KT, Vitali C, Scorletti E, Seeling KS, Vell MS, Rendel MD, Conlon D, Vujkovic M, Zandvakili I, Trautwein C, Schneider KM, Rader DJ, Schneider CV. A genome-first approach to variants in MLXIPL and their association with hepatic steatosis and plasma lipids. Hepatol Commun 2024; 8:e0427. [PMID: 38668731 DOI: 10.1097/hc9.0000000000000427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/01/2024] [Indexed: 05/01/2024] Open
Abstract
BACKGROUND Common variants of the max-like protein X (MLX)-interacting protein-like (MLXIPL) gene, encoding the transcription factor carbohydrate-responsive element-binding protein, have been shown to be associated with plasma triglyceride levels. However, the role of these variants in steatotic liver disease (SLD) is unclear. METHODS We used a genome-first approach to analyze a variety of metabolic phenotypes and clinical outcomes associated with a common missense variant in MLXIPL, Gln241His, in 2 large biobanks: the UK Biobank and the Penn Medicine Biobank. RESULTS Carriers of MLXIPL Gln241His were associated with significantly lower serum levels of triglycerides, apolipoprotein-B, gamma-glutamyl transferase, and alkaline phosphatase. Additionally, MLXIPL Gln241His carriers were associated with significantly higher serum levels of HDL cholesterol and alanine aminotransferase. Carriers homozygous for MLXIPL Gln241His showed a higher risk of SLD in 2 unrelated cohorts. Carriers of MLXIPL Gln241His were especially more likely to be diagnosed with SLD if they were female, obese, and/or also carried the PNPLA3 I148M variant. Furthermore, the heterozygous carriage of MLXIPL Gln241His was associated with significantly higher all-cause, liver-related, and cardiovascular mortality rates. Nuclear magnetic resonance metabolomics data indicated that carriage of MLXIPL Gln241His was significantly associated with lower serum levels of VLDL and increased serum levels of HDL cholesterol. CONCLUSIONS Analyses of the MLXIPL Gln241His polymorphism showed a significant association with a higher risk of SLD diagnosis and elevated serum alanine aminotransferase as well as significantly lower serum triglycerides and apolipoprotein-B levels. MLXIPL might, therefore, be a potential pharmacological target for the treatment of SLD and hyperlipidemia, notably for patients at risk. More mechanistic studies are needed to better understand the role of MLXIPL Gln241His on lipid metabolism and steatosis development.
Collapse
Affiliation(s)
- Leonida Hehl
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Kate T Creasy
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Cecilia Vitali
- Department of Medicine, Division of Translational Medicine and Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eleonora Scorletti
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Institute for Translational Medicine and Therapeutics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katharina S Seeling
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Mara S Vell
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Miriam D Rendel
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Donna Conlon
- Department of Medicine, Division of Translational Medicine and Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Marijana Vujkovic
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Inuk Zandvakili
- Department of Medicine, Division of Gastroenterology and Hepatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Internal Medicine, Division of Digestive Diseases, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Christian Trautwein
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Kai M Schneider
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel J Rader
- Department of Medicine, Division of Translational Medicine and Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Carolin V Schneider
- Department of Medicine III, Gastroenterology, Metabolic diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Institute for Translational Medicine and Therapeutics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
3
|
Mukhopadhyay B, Marietta C, Shen PH, Oiseni A, Mirshahi F, Mazzu M, Hodgkinson C, Winkler E, Yuan Q, Miranda D, Kunos G, Sanyal AJ, Goldman D. A patient-based iPSC-derived hepatocyte model of alcohol-associated cirrhosis reveals bioenergetic insights into disease pathogenesis. Nat Commun 2024; 15:2869. [PMID: 38693144 PMCID: PMC11063145 DOI: 10.1038/s41467-024-47085-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 03/15/2024] [Indexed: 05/03/2024] Open
Abstract
Only ~20% of heavy drinkers develop alcohol cirrhosis (AC). While differences in metabolism, inflammation, signaling, microbiome signatures and genetic variations have been tied to the pathogenesis of AC, the key underlying mechanisms for this interindividual variability, remain to be fully elucidated. Induced pluripotent stem cell-derived hepatocytes (iHLCs) from patients with AC and healthy controls differ transcriptomically, bioenergetically and histologically. They include a greater number of lipid droplets (LDs) and LD-associated mitochondria compared to control cells. These pre-pathologic indicators are effectively reversed by Aramchol, an inhibitor of stearoyl-CoA desaturase. Bioenergetically, AC iHLCs have lower spare capacity, slower ATP production and their mitochondrial fuel flexibility towards fatty acids and glutamate is weakened. MARC1 and PNPLA3, genes implicated by GWAS in alcohol cirrhosis, show to correlate with lipid droplet-associated and mitochondria-mediated oxidative damage in AC iHLCs. Knockdown of PNPLA3 expression exacerbates mitochondrial deficits and leads to lipid droplets alterations. These findings suggest that differences in mitochondrial bioenergetics and lipid droplet formation are intrinsic to AC hepatocytes and can play a role in its pathogenesis.
Collapse
Affiliation(s)
- Bani Mukhopadhyay
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Cheryl Marietta
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Pei-Hong Shen
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Abdul Oiseni
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Faridoddin Mirshahi
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Maria Mazzu
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Colin Hodgkinson
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Eli Winkler
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Qiaoping Yuan
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Daniel Miranda
- Aivia Machine Learning Team, Leica Microsystems, Inc, Deerfield, IL, USA
| | - George Kunos
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Arun J Sanyal
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - David Goldman
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA.
- Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA.
| |
Collapse
|
4
|
Sherman DJ, Liu L, Mamrosh JL, Xie J, Ferbas J, Lomenick B, Ladinsky MS, Verma R, Rulifson IC, Deshaies RJ. The fatty liver disease-causing protein PNPLA3-I148M alters lipid droplet-Golgi dynamics. Proc Natl Acad Sci U S A 2024; 121:e2318619121. [PMID: 38657050 PMCID: PMC11067037 DOI: 10.1073/pnas.2318619121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/16/2024] [Indexed: 04/26/2024] Open
Abstract
Nonalcoholic fatty liver disease, recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD), is a progressive metabolic disorder that begins with aberrant triglyceride accumulation in the liver and can lead to cirrhosis and cancer. A common variant in the gene PNPLA3, encoding the protein PNPLA3-I148M, is the strongest known genetic risk factor for MASLD. Despite its discovery 20 y ago, the function of PNPLA3, and now the role of PNPLA3-I148M, remain unclear. In this study, we sought to dissect the biogenesis of PNPLA3 and PNPLA3-I148M and characterize changes induced by endogenous expression of the disease-causing variant. Contrary to bioinformatic predictions and prior studies with overexpressed proteins, we demonstrate here that PNPLA3 and PNPLA3-I148M are not endoplasmic reticulum-resident transmembrane proteins. To identify their intracellular associations, we generated a paired set of isogenic human hepatoma cells expressing PNPLA3 and PNPLA3-I148M at endogenous levels. Both proteins were enriched in lipid droplet, Golgi, and endosomal fractions. Purified PNPLA3 and PNPLA3-I148M proteins associated with phosphoinositides commonly found in these compartments. Despite a similar fractionation pattern as the wild-type variant, PNPLA3-I148M induced morphological changes in the Golgi apparatus, including increased lipid droplet-Golgi contact sites, which were also observed in I148M-expressing primary human patient hepatocytes. In addition to lipid droplet accumulation, PNPLA3-I148M expression caused significant proteomic and transcriptomic changes that resembled all stages of liver disease. Cumulatively, we validate an endogenous human cellular system for investigating PNPLA3-I148M biology and identify the Golgi apparatus as a central hub of PNPLA3-I148M-driven cellular change.
Collapse
Affiliation(s)
| | - Lei Liu
- Amgen Research, South San Francisco, CA94080
| | | | | | | | - Brett Lomenick
- Proteome Exploration Laboratory, Beckman Institute, California Institute of Technology, Pasadena, CA91125
| | - Mark S. Ladinsky
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | | | | | | |
Collapse
|
5
|
Lee Y, Cho EJ, Choe EK, Kwak MS, Yang JI, Oh SW, Yim JY, Chung GE. Genome-wide association study of metabolic dysfunction-associated fatty liver disease in a Korean population. Sci Rep 2024; 14:9753. [PMID: 38679617 PMCID: PMC11056367 DOI: 10.1038/s41598-024-60152-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 04/19/2024] [Indexed: 05/01/2024] Open
Abstract
Genome-wide association studies have identified several genetic variants associated with nonalcoholic fatty liver disease. To emphasize metabolic abnormalities in fatty liver, metabolic (dysfunction)-associated fatty liver disease (MAFLD) has been introduced; thus, we aimed to investigate single-nucleotide polymorphisms related to MAFLD and its subtypes. A genome-wide association study was performed to identify genetic factors related to MAFLD. We used a Korean population-based sample of 2282 subjects with MAFLD and a control group of 4669. We replicated the results in a validation sample which included 639 patients with MAFLD and 1578 controls. Additionally, we categorized participants into three groups, no MAFLD, metabolic dysfunction (MD)-MAFLD, and overweight/obese-MAFLD. After adjusting for age, sex, and principal component scores, rs738409 [risk allele G] and rs3810622 [risk allele T], located in the PNPLA3 gene, showed significant associations with MAFLD (P-values, discovery set = 1.60 × 10-15 and 4.84 × 10-10; odds ratios, 1.365 and 1.284, validation set = 1.39 × 10-4, and 7.15 × 10-4, odds ratios, 1.299 and 1.264, respectively). An additional SNP rs59148799 [risk allele G] located in the GATAD2A gene showed a significant association with MAFLD (P-values, discovery set = 2.08 × 10-8 and validation set = 0.034, odds ratios, 1.387 and 1.250). rs738409 was significantly associated with MAFLD subtypes ([overweight/obese-MAFLD; odds ratio (95% confidence interval), P-values, 1.515 (1.351-1.700), 1.43 × 10-12 and MD-MAFLD: 1.300 (1.191-1.416), 2.90 × 10-9]. There was a significant relationship between rs3810622 and overweight/obese-MAFLD and MD-MAFLD [odds ratios (95% confidence interval), P-values, 1.418 (1.258, 1.600), 1.21 × 10-8 and 1.225 (1.122, 1.340), 7.06 × 10-6, respectively]; the statistical significance remained in the validation set. PNPLA3 was significantly associated with MAFLD and MAFLD subtypes in the Korean population. These results indicate that genetic factors play an important role in the pathogenesis of MAFLD.
Collapse
Affiliation(s)
- Young Lee
- Veterans Medical Research Institute, Veterans Health Service Medical Center, Seoul, Republic of Korea
- Department of Applied Statistics, Chung-Ang University, Seoul, Republic of Korea
| | - Eun Ju Cho
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Eun Kyung Choe
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, 39FL., Gangnam Finance Center 737, Yeoksam-Dong, Gangnam-Gu, Seoul, 135-984, South Korea
| | - Min-Sun Kwak
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, 39FL., Gangnam Finance Center 737, Yeoksam-Dong, Gangnam-Gu, Seoul, 135-984, South Korea
| | - Jong In Yang
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, 39FL., Gangnam Finance Center 737, Yeoksam-Dong, Gangnam-Gu, Seoul, 135-984, South Korea
| | - Seung-Won Oh
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, 39FL., Gangnam Finance Center 737, Yeoksam-Dong, Gangnam-Gu, Seoul, 135-984, South Korea
| | - Jeong Yoon Yim
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, 39FL., Gangnam Finance Center 737, Yeoksam-Dong, Gangnam-Gu, Seoul, 135-984, South Korea
| | - Goh Eun Chung
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, 39FL., Gangnam Finance Center 737, Yeoksam-Dong, Gangnam-Gu, Seoul, 135-984, South Korea.
| |
Collapse
|
6
|
Buscemi C, Randazzo C, Barile AM, Bo S, Ponzo V, Caldarella R, Malavazos AE, Caruso R, Colombrita P, Lombardo M, Buscemi S. Factors associated with body weight gain and insulin-resistance: a longitudinal study. Nutr Diabetes 2024; 14:21. [PMID: 38649714 PMCID: PMC11035547 DOI: 10.1038/s41387-024-00283-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND Obesity is the result of energy intake (EI) chronically exceeding energy expenditure. However, the potential metabolic factors, including insulin resistance, remain unclear. This study longitudinally investigated factors associated with changes in body weight. SUBJECTS A cohort of 707 adults without diabetes were investigated at the 4-year follow-up visit. The habitual intake of energy and macronutrients during the past 12 months was assessed using a validated Food Frequency Questionnaire for the local population. Homeostatic model assessment of β-cell function and insulin resistance (HOMA-IR) was used as a surrogate measure of insulin resistance. Additionally, PNPLA3 was genotyped. RESULTS Eighty-seven participants were weight gainers (G; cutoff value = 5 kg), and 620 were non-gainers (NG). Initial anthropometric (G vs. NG: age, 44 ± 13 vs 51 ± 13 years, P < 0.001; body mass index, 27.8 ± 6.5 vs 28.1 ± 5.1 kg/m2, P = ns; body weight, 76.7 ± 22.1 vs 74.2 ± 14.7 kg, P = ns; final body weight, 86.3 ± 23.7 vs 72.9 ± 14.2 kg, P < 0.001) and diet characteristics, as well as insulin concentrations and HOMA-IR values, were similar in both groups. Four years later, G showed significantly increased EI, insulin concentrations, and HOMA-IR values. G had a higher prevalence of the PNPLA3 CG and GG alleles than NG (P < 0.05). The presence of G was independently associated with age (OR = 1.031), EI change (OR = 2.257), and unfavorable alleles of PNPLA3 gene (OR = 1.700). Final body mass index, waist circumference, and EI were independently associated with final HOMA-IR (P < 0.001). CONCLUSIONS EI is associated with body weight gain, and genetic factors may influence the energy balance. Insulin resistance is a consequence of weight gain, suggesting a possible intracellular protective mechanism against substrate overflow. CLINICAL TRIAL REGISTRATION ISRCTN15840340.
Collapse
Affiliation(s)
- Carola Buscemi
- Unit of Internal Medicine, "V. Cervello Hospital", Palermo, Italy
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
| | - Cristiana Randazzo
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy.
- Unit of Clinical Nutrition, Obesity and Metabolic Diseases; AOU Policlinico "P. Giaccone", Palermo, Italy.
| | - Anna Maria Barile
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
- Unit of Clinical Nutrition, Obesity and Metabolic Diseases; AOU Policlinico "P. Giaccone", Palermo, Italy
| | - Simona Bo
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - Valentina Ponzo
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - Rosalia Caldarella
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
- Unit of Laboratory Medicine, AOU Policlinico "P. Giaccone", Palermo, Italy
| | - Alexis Elias Malavazos
- Endocrinology Unit, Clinical Nutrition and Cardiovascular Prevention Service, IRCCS Policlinico San Donato, San Donato Milanese, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Roberta Caruso
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
| | - Piero Colombrita
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
| | - Martina Lombardo
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
| | - Silvio Buscemi
- Dipartimento di Promozione della Salute, Materno-Infantile, Medicina Interna e Specialistica di Eccellenza (PROMISE), University of Palermo, Palermo, Italy
- Unit of Clinical Nutrition, Obesity and Metabolic Diseases; AOU Policlinico "P. Giaccone", Palermo, Italy
| |
Collapse
|
7
|
Liu M, Park S. The Role of PNPLA3_rs738409 Gene Variant, Lifestyle Factors, and Bioactive Compounds in Nonalcoholic Fatty Liver Disease: A Population-Based and Molecular Approach towards Healthy Nutrition. Nutrients 2024; 16:1239. [PMID: 38674929 PMCID: PMC11054963 DOI: 10.3390/nu16081239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024] Open
Abstract
This study aimed to investigate the impact of a common non-synonymous gene variant (C>G, rs738409) in patatin-like phospholipase domain-containing 3 (PNPLA3), leading to the substitution of isoleucine with methionine at position 148 (PNPLA3-I148M), on susceptibility to nonalcoholic fatty liver disease (NAFLD) and explore potential therapeutic nutritional strategies targeting PNPLA3. It contributed to understanding sustainable dietary practices for managing NAFLD, recently referred to as metabolic-dysfunction-associated fatty liver. NAFLD had been diagnosed by ultrasound in a metropolitan hospital-based cohort comprising 58,701 middle-aged and older Korean individuals, identifying 2089 NAFLD patients. The interaction between PNPLA3 and lifestyle factors was investigated. In silico analyses, including virtual screening, molecular docking, and molecular dynamics simulations, were conducted to identify bioactive compounds from foods targeting PNPLA3(I148M). Subsequent cellular experiments involved treating oleic acid (OA)-exposed HepG2 cells with selected bioactive compounds, both in the absence and presence of compound C (AMPK inhibitor), targeting PNPLA3 expression. Carriers of the risk allele PNPLA3_rs738409G showed an increased association with NAFLD risk, particularly with adherence to a plant-based diet, avoidance of a Western-style diet, and smoking. Delphinidin 3-caffeoyl-glucoside, pyranocyanin A, delta-viniferin, kaempferol-7-glucoside, and petunidin 3-rutinoside emerged as potential binders to the active site residues of PNPLA3, exhibiting a reduction in binding energy. These compounds demonstrated a dose-dependent reduction in intracellular triglyceride and lipid peroxide levels in HepG2 cells, while pretreatment with compound C showed the opposite trend. Kaempferol-7-glucoside and petunidin-3-rutinoside showed potential as inhibitors of PNPLA3 expression by enhancing AMPK activity, ultimately reducing intrahepatic lipogenesis. In conclusion, there is potential for plant-based diets and specific bioactive compounds to promote sustainable dietary practices to mitigate NAFLD risk, especially in individuals with genetic predispositions.
Collapse
Affiliation(s)
- Meiling Liu
- Department of Chemical Engineering, Shanxi Institute of Science and Technology, Jincheng 048000, China;
| | - Sunmin Park
- Department of Bioconvergence, Hoseo University, Asan 31499, Republic of Korea
- Department of Food and Nutrition, Institute of Basic Science, Obesity/Diabetes Research Center, Hoseo University, Asan 31499, Republic of Korea
| |
Collapse
|
8
|
Elmansoury N, Megahed AA, Kamal A, El-Nikhely N, Labane M, Abdelmageed M, Daly AK, Wahid A. Relevance of PNPLA3, TM6SF2, HSD17B13, and GCKR Variants to MASLD Severity in an Egyptian Population. Genes (Basel) 2024; 15:455. [PMID: 38674389 PMCID: PMC11049340 DOI: 10.3390/genes15040455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 03/28/2024] [Accepted: 04/01/2024] [Indexed: 04/28/2024] Open
Abstract
Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a frequent clinical condition globally. Single nucleotide polymorphisms (SNPs) associated with NAFLD have been proposed in the literature and based on bioinformatic screening. The association between NAFLD and genetic variants in Egyptians is still unclear. Hence, we sought to investigate the association of some genetic variants with NAFLD in Egyptians. Egyptians have been categorized into either the MASLD group (n = 205) or the healthy control group (n = 187). The severity of hepatic steatosis and liver fibrosis was assessed by a Fibroscan device. TaqMan-based genotyping assays were employed to explore the association of selected SNPs with MASLD. PNPLA3 rs738409 C>G variant is associated with the presence of MASLD with liver fibrosis, the severity of both hepatic steatosis and liver fibrosis, increased systolic and diastolic blood pressure and increased alanine aminotransferase (all p < 0.05), while the TM6SF2 rs58542926 C>T, HSD17B13 rs9992651 G>A, and GCKR rs1260326 T>C variants were not (all p > 0.05). The TM6SF2 rs58542926 T allele is associated with increased fasting blood glucose and a decreased waist circumference. The GCKR rs1260326 C allele is associated with decreased aspartate transaminase and diastolic blood pressure (all p < 0.05). Only after adjusting for the risk factors (age, sex, BMI, WC, HDL, TG, diabetes mellitus, and hypertension) F2 liver fibrosis score is negatively correlated with the HSD17B13 rs9992651 GA genotype. This study offers evidence for the association of the PNPLA3 rs738409 C>G variant with MASLD among Egyptians and for the association of the PNPLA3 rs738409 G allele, the TM6SF2 rs58542926 T allele, and the GCKR rs1260326 C allele with some parameters of cardiometabolic criteria.
Collapse
Affiliation(s)
- Nehal Elmansoury
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt;
| | - Ahmed A. Megahed
- Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt; (A.A.M.); (M.L.)
| | - Ahmed Kamal
- Department of Internal Medicine and Hepatology, Faculty of Medicine, Alexandria University, Alexandria 21131, Egypt;
| | - Nefertiti El-Nikhely
- Institute of Graduate Studies and Research, Alexandria University, Alexandria 21526, Egypt;
| | - Marina Labane
- Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt; (A.A.M.); (M.L.)
| | - Manal Abdelmageed
- Department of Experimental and Clinical Internal Medicine, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt;
| | - Ann K. Daly
- Translational and Clinical Research Institute, Faculty of Medical Sciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK;
| | - Ahmed Wahid
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt;
| |
Collapse
|
9
|
Klement L, Jansakun C, Yan B, Staffer S, Tuma-Kellner S, Altamura S, Muckenthaler M, Merle U, Chamulitrat W. Myeloid-specific deletion of group VIA calcium-independent phospholipase A2 induces pro-inflammatory LPS response predominantly in male mice via MIP-1α activation. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167016. [PMID: 38198970 DOI: 10.1016/j.bbadis.2024.167016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 12/15/2023] [Accepted: 12/31/2023] [Indexed: 01/12/2024]
Abstract
Polymorphisms of group VIA calcium-independent phospholipase A2 (PLA2G6) are associated with blood C-reactive protein suggesting its role in inflammation. We showed that myeloid-specific Pla2g6-deficiency in Pla2g6M-/- mice led to exaggerated inflammation and fibrosis in a lean fatty liver model. We here investigated whether these mutants display alteration in immune response after treatment with E. coli lipopolysaccharides (LPS) under acute (a single dose) and persistent (four doses) conditions. Without LPS treatment, male Pla2g6M-/- (but not Flox) mice at 12 months of age exhibited splenomegaly and hepatic necrosis, and ~ 30 % of them exhibited autoimmune hepatitis showing lymphoplasma cells with CD3(+) and CD45R(+) staining. Under acute LPS, male mutants showed an elevation of plasma MIP-1α and immunoglobulinA as well as upregulation of hepatic apoptosis and fibrosis PARP-1, Bax, MCP-1, α-SMA, and collagen I proteins. Their bone-marrow-derived macrophages also showed an elevation of MIP-1α release upon LPS stimulation in vitro. Female mutants under acute LPS showed a moderate increase in plasma KC/CXCL1, MCP-1, and IL10, and they showed no remarkable increase in hepatic fibrosis under acute or persistent LPS. Male mutants under persistent LPS displayed an elevation of aspartate aminotransferase, blood eosinophils, and hepatic apoptosis. Moreover, ~30 % of these mutants exhibited eosinophilic sclerosing portal hepatitis associated with an upregulated protein expression of hepatic CD8α, CD68, eosinophilic cationic protein, and Ly6G. Thus, myeloid-PLA2G6 deficiency led to an autoimmune and LPS-induced inflammatory liver disease via MIP-1α in a male-predominant manner. Our results may be applicable to patients with PLA2G6 mutations who undergo bacterial infection and sepsis.
Collapse
Affiliation(s)
- Lukas Klement
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Chutima Jansakun
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80161, Thailand
| | - Bin Yan
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Simone Staffer
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sandro Altamura
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
| | - Martina Muckenthaler
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), German Centre for Cardiovascular Research, Partner Site, University of Heidelberg, Germany
| | - Uta Merle
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
| |
Collapse
|
10
|
Chen Y, Shi HB, Le WL, Tang QN. [Effect of calcium-independent phospholipase A2 on the expression of glycerol 3-phosphate dehydrogenase in human non-alcoholic fatty liver disease cells]. Zhonghua Gan Zang Bing Za Zhi 2023; 31:1063-1067. [PMID: 38016771 DOI: 10.3760/cma.j.cn501113-20220724-00394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Objective: To explore the effect of calcium-independent phospholipase A2 (iPLA2) on the expression of mitochondrial glycerol 3-phosphate dehydrogenase (mGPDH) in human non-alcoholic fatty liver disease cells. Methods: Oleic acid was used to construct a non-alcoholic fatty liver disease cell model by inducing lipid deposition in THLE-2 cells in vitro. Simultaneously, intracellular triglyceride content, iPLA2 expression levels, and mGPDH levels were determined at various induction times (0, 24, 48, and 72 h) using a triglyceride assay kit, quantitative RT-PCR, and western blotting. The model cells were treated with bromelenol lactone, an iPLA2 inhibitor, and N-acetylcysteine, a ROS inhibitor, respectively. Following continuous culture for 24 and 48 hours, the cells were harvested, and the mRNA and protein expression levels of mGPDH were measured. Statistical analysis was performed using the t-test, one-way analysis of variance, and linear correlation. Results: The intracellular triglyceride content gradually increased (P < 0.01), the mGPDH mRNA and protein expression decreased (P < 0.01), and the iPLA2 mRNA and protein expression increased (P < 0.01) in THLE-2 cells with the prolonging time effect of oleic acid therapy. In addition, the mGPDH mRNA expression level was negatively correlated with the iPLA2 mRNA level (r = -0.878, P = 0.002). The expression levels of mGPDH mRNA and protein in the iPLA2 inhibitor group and ROS inhibitor group were increased compared with the model control group (P < 0.01). The expression of mGPDH mRNA was increased at 24 h compared with 48 h in the iPLA2 inhibitor group (P < 0.01). The expression of mGPDH mRNA was gradually increased in the ROS inhibitor group with the prolongation of inhibitor action time (P < 0.01). Compared with the two inhibitor groups, the increase in mGPDH mRNA was significantly higher in the ROS inhibitor group than that in the iPLA2 inhibitor group, and the difference was statistically significant (P < 0.01). Conclusion: iPLA2 can inhibit the expression of mGPDH in non-alcoholic fatty liver cells to a certain extent.
Collapse
Affiliation(s)
- Y Chen
- Ningbo Medical Center Lihuili Hospital, Ningbo 315000, China
| | - H B Shi
- Ningbo Medical Center Lihuili Hospital, Ningbo 315000, China
| | - W L Le
- Ningbo Medical Center Lihuili Hospital, Ningbo 315000, China
| | - Q N Tang
- Ningbo Medical Center Lihuili Hospital, Ningbo 315000, China
| |
Collapse
|
11
|
Hayashi D, Dennis EA. Molecular basis of unique specificity and regulation of group VIA calcium-independent phospholipase A 2 (PNPLA9) and its role in neurodegenerative diseases. Pharmacol Ther 2023; 245:108395. [PMID: 36990122 PMCID: PMC10174669 DOI: 10.1016/j.pharmthera.2023.108395] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023]
Abstract
Glycerophospholipids are major components of cell membranes and consist of a glycerol backbone esterified with one of over 30 unique fatty acids at each of the sn-1 and sn-2 positions. In addition, in some human cells and tissues as much as 20% of the glycerophospholipids contain a fatty alcohol rather than an ester in the sn-1 position, although it can also occur in the sn-2 position. The sn-3 position of the glycerol backbone contains a phosphodiester bond linked to one of more than 10 unique polar head-groups. Hence, humans contain thousands of unique individual molecular species of phospholipids given the heterogeneity of the sn-1 and sn-2 linkage and carbon chains and the sn-3 polar groups. Phospholipase A2 (PLA2) is a superfamily of enzymes that hydrolyze the sn-2 fatty acyl chain resulting in lyso-phospholipids and free fatty acids that then undergo further metabolism. PLA2's play a critical role in lipid-mediated biological responses and membrane phospholipid remodeling. Among the PLA2 enzymes, the Group VIA calcium-independent PLA2 (GVIA iPLA2), also referred to as PNPLA9, is a fascinating enzyme with broad substrate specificity and it is implicated in a wide variety of diseases. Especially notable, the GVIA iPLA2 is implicated in the sequelae of several neurodegenerative diseases termed "phospholipase A2-associated neurodegeneration" (PLAN) diseases. Despite many reports on the physiological role of the GVIA iPLA2, the molecular basis of its enzymatic specificity was unclear. Recently, we employed state-of-the-art lipidomics and molecular dynamics techniques to elucidate the detailed molecular basis of its substrate specificity and regulation. In this review, we summarize the molecular basis of the enzymatic action of GVIA iPLA2 and provide a perspective on future therapeutic strategies for PLAN diseases targeting GVIA iPLA2.
Collapse
Affiliation(s)
- Daiki Hayashi
- Department of Applied Chemistry in Bioscience, Graduate School of Agricultural Science, Faculty of Agriculture, Kobe University, Kobe 657-8501, Japan.
| | - Edward A Dennis
- Department of Pharmacology, Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0601, USA
| |
Collapse
|
12
|
Manson A, Winter T, Aukema HM. Phospholipase A 2 enzymes differently impact PUFA release and oxylipin formation ex vivo in rat hearts. Prostaglandins Leukot Essent Fatty Acids 2023; 191:102555. [PMID: 36878084 DOI: 10.1016/j.plefa.2023.102555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 03/04/2023]
Abstract
Phospholipase A2 (PLA2) enzymes cleave cell membrane phospholipids and release polyunsaturated fatty acids (PUFA), which can be converted into oxylipins. However, little is known about PLA2 preference for PUFA, and even less is known about how this further impacts oxylipin formation. Therefore, we investigated the role of different PLA2 groups in PUFA release and oxylipin formation in rat hearts. Sprague-Dawley rat heart homogenates were incubated without or with varespladib (VAR), methyl arachidonyl fluorophosphonate (MAFP) or EDTA. Free PUFA and oxylipins were determined by HPLC-MS/MS, and isoform expressions by RT-qPCR. Inhibition of sPLA2 IIA and/or V by VAR reduced the release of ARA and DHA, but only DHA oxylipins were inhibited. MAFP reduced the release of ARA, DHA, ALA, and EPA, and the formation of ARA, LA, DGLA, DHA, ALA, and EPA oxylipins. Interestingly, cyclooxygenase and 12-lipoxygenase oxylipins were not inhibited. mRNA expression levels of sPLA2 and iPLA2 isoforms were highest whereas levels of cPLA2 were low, consistent with activity. In conclusion, sPLA2 enzymes lead to the formation of DHA oxylipins, while iPLA2 is likely responsible for the formation of most other oxylipins in healthy rat hearts. Oxylipin formation cannot be implied from PUFA release, thus, both should be evaluated in PLA2 activity studies.
Collapse
Affiliation(s)
- Anne Manson
- Food and Human Nutritional Sciences, University of Manitoba, Winnipeg MB, Canada; Canadian Centre for Agri-Food Research in Health and Medicine (CCARM), Winnipeg MB, Canada
| | - Tanja Winter
- Food and Human Nutritional Sciences, University of Manitoba, Winnipeg MB, Canada; Canadian Centre for Agri-Food Research in Health and Medicine (CCARM), Winnipeg MB, Canada
| | - Harold M Aukema
- Food and Human Nutritional Sciences, University of Manitoba, Winnipeg MB, Canada; Canadian Centre for Agri-Food Research in Health and Medicine (CCARM), Winnipeg MB, Canada.
| |
Collapse
|
13
|
McHenry S, Davidson NO. Missense Mutant Patatin-Like Phospholipase Domain Containing 3 Alters Lipid Droplet Turnover in Partnership With CGI-58. Hepatology 2019; 69:2323-2325. [PMID: 30901101 PMCID: PMC6545590 DOI: 10.1002/hep.30620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 03/13/2019] [Indexed: 12/16/2022]
|
14
|
Ren X, Lin J, Jin C, Xia B. 1H, 13C and 15N resonance assignments of human H-REV107 N-terminal domain. Biomol NMR Assign 2010; 4:175-178. [PMID: 20526701 DOI: 10.1007/s12104-010-9238-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 05/20/2010] [Indexed: 05/29/2023]
Abstract
Human H-REV107 protein is the representative of a novel class II tumor suppressor family, which is lost in tumor cells and can induce cell death after restoration. The NMR assignments of the H-REV107 N-terminal domain are essential for its solution structure determination.
Collapse
Affiliation(s)
- Xiaobai Ren
- Beijing Nuclear Magnetic Resonance Center, Peking University, 100871, Beijing, China
| | | | | | | |
Collapse
|
15
|
Yanatatsaneejit P, Chalermchai T, Kerekhanjanarong V, Shotelersuk K, Supiyaphun P, Mutirangura A, Sriuranpong V. Promoter hypermethylation of CCNA1, RARRES1, and HRASLS3 in nasopharyngeal carcinoma. Oral Oncol 2008; 44:400-6. [PMID: 17689134 DOI: 10.1016/j.oraloncology.2007.05.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 05/15/2007] [Accepted: 05/17/2007] [Indexed: 10/23/2022]
Abstract
In search for putative tumor suppressor genes critical of nasopharyngeal carcinoma (NPC), we analyzed the available information from the expression profiling in conjunction with the comprehensive alleotyping published data relevant to this malignancy. Integration of this information suggested eight potential candidate tumor suppressor genes, CCNA1, HRASLS3, RARRES1, CLMN, EML1, TSC22, LOH11CR2A and MCC. However, to confirm the above observations, we chose to investigate if promoter hypermethylation of these candidate genes would be one of the mechanisms responsible for the de-regulation of gene expression in NPC in addition to the loss of genetic materials. In this study, we detected consistent hypermethylation of the 5' element of CCNA1, RARRES1, and HRASLS in NPC tissues with prevalence of 48%, 51%, and 17%, respectively. Moreover, we found a similar profile of promoter hypermethylation in primary cultured NPC cells but none in normal nasopharyngeal epithelium or leukocytes, which further substantiate our hypothesis. Our data indicate that CCNA1, RARRES1, and HRASLS3 may be the putative tumor suppressor genes in NPC.
Collapse
|
16
|
Abstract
HRSL3 (also known as H-REV107-1) belongs to a class II tumor suppressor gene family and is downregulated in several human tumors including ovarian carcinomas. To unravel the mechanism of HRSL3 tumor suppressor action, we performed a yeast two-hybrid screen and identified the alpha-isoform of the regulatory subunit A of protein phosphatase 2A (PR65alpha) as a new interaction partner of HRSL3. Interaction between HRSL3 and PR65alpha was confirmed in vitro and by co-immunoprecipitation in mammalian cells. We demonstrate that HRSL3 binds to the endogenous PR65alpha, thereby partially sequestering the catalytic subunit PR36 from the PR65 protein complex, and inhibiting PP2A catalytic activity. Furthermore, binding of HRSL3 to PR65 induces apoptosis in ovarian carcinoma cells in a caspase-dependent manner. Using several mutant HRSL3 constructs, we identified the N-terminal proline-rich region within the HRSL3 protein as the domain that is relevant for both binding of PR65alpha and induction of programmed cell death. This suggests that the negative impact of HRSL3 onto PP2A activity is important for the HRSL3 pro-apoptotic function and indicates a role of PP2A in survival of human ovarian carcinomas. The analysis of distinct PP2A target molecules revealed PKCzeta as being involved in HRSL3 action. These data implicate HRSL3 as a signaling regulatory molecule, which is functionally involved in the oncogenic network mediating growth and survival of ovarian cancer cells.
Collapse
Affiliation(s)
- Irina Nazarenko
- Molecular Tumor Pathology, Institute of Pathology, University Medicine Charité Berlin, Schumannstrasse 20/21, 10117 Berlin, Germany
| | | | | |
Collapse
|
17
|
Nazarenko I, Kristiansen G, Fonfara S, Guenther R, Gieseler C, Kemmner W, Schafer R, Petersen I, Sers C. H-REV107-1 stimulates growth in non-small cell lung carcinomas via the activation of mitogenic signaling. Am J Pathol 2006; 169:1427-39. [PMID: 17003497 PMCID: PMC1698850 DOI: 10.2353/ajpath.2006.051341] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/17/2006] [Indexed: 01/02/2023]
Abstract
H-REV107-1, a known member of the class II tumor suppressor gene family, is involved in the regulation of differentiation and survival. We analyzed H-REV107-1 in non-small cell lung carcinomas, in normal lung, and in immortalized and tumor-derived cell lines. Sixty-eight percent of lung tumors revealed positive H-REV107-1-specific staining. Furthermore, survival analysis demonstrated a significant association of cytoplasmic H-REV107-1 with decreased patient survival. This suggested that H-REV107-1, known as a tumor suppressor, plays a different role in non-small cell lung carcinomas. Knock-down of H-REV107-1 expression in lung carcinoma cells inhibited anchorage-dependent and anchorage-independent growth whereas overexpression of H-REV107-1 induced tumor cell proliferation. Consistent with results of the survival analysis, cytoplasmic localization of the protein was essential for this growth-inducing function. Analysis of signaling pathways potentially involved in this process demonstrated that overexpression of H-REV107-1 stimulated RAS-GTPase activity, ERK1,2 phosphorylation, and caveolin-1 expression in the cell lines analyzed. These results indicate that H-REV107-1 is deficient in its function as a tumor suppressor in non-small cell lung carcinomas and is required for proliferation and anchorage-independent growth in cells expressing high levels of the protein, thus contributing to tumor progression in a subset of non-small cell lung carcinomas.
Collapse
Affiliation(s)
- Irina Nazarenko
- Institute of Pathology, Charité Universitaetsmedizin Berlin Schumannstr. 20/21, D-10117 Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Tsai FM, Shyu RY, Jiang SY. RIG1 inhibits the Ras/mitogen-activated protein kinase pathway by suppressing the activation of Ras. Cell Signal 2006; 18:349-58. [PMID: 16005186 DOI: 10.1016/j.cellsig.2005.05.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Accepted: 05/06/2005] [Indexed: 01/17/2023]
Abstract
The retinoid-inducible gene 1 (RIG1) protein is a retinoid-inducible growth regulator. Previous studies have shown that the RIG1 protein inhibits the signaling pathways of Ras/mitogen-activated protein kinases. However, neither the mode of action nor the site of inhibition of RIG1 is known. This study investigated the effects of RIG1, and the mechanisms responsible for these effects, on the activation of Ras proteins in HtTA cervical cancer cells. RIG1 reduced the levels of activated Ras (Ras-GTP) and total Ras protein in cells transfected with mutated H-, N-, or K-Ras(G12V), or in cells transfected with the wild type H- or N-Ras followed by stimulation with epidermal growth factor. The half-life of Ras protein decreased from more than 36 h in control cells to 18 h in RIG1-transfected cells. RIG1 immunoprecipitated with the Ras protein in co-transfected cellular lysates. In contrast to the predominant plasma membrane localization in control cells, the H-Ras fusion protein EGFP-H-Ras was localized within a discrete cytoplasmic compartment where it co-localized with RIG1. RIG1 inhibited more than 93% of the Elk- and CHOP-mediated transactivation induced by H- or K-Ras(G12V). However, RIG1 did not inhibit the transactivation induced by MEK1 or MEK3, and failed to suppress the phosphorylation of extracellular signal-regulated kinases 1 and 2 induced by the constitutively activated B-Raf(V599E). The RIG1 with carboxyl terminal truncation (RIG1DeltaC) did not immunoprecipitate with Ras and had no effect on Ras activation or transactivation of the downstream signal pathways. These data indicate that RIG1 exerts its inhibitory effect at the level of Ras activation, which is independent of Ras subtype but dependent on the membrane localization of the RIG1 protein. This inhibition of Ras activation may be mediated through downregulation of Ras levels and alteration of Ras subcellular distribution.
Collapse
Affiliation(s)
- Fu-Ming Tsai
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan
| | | | | |
Collapse
|
19
|
Abstract
H-rev107 is a tumor suppressor originally isolated in revertants of H-ras-transformed cell lines. The gene is ubiquitously expressed in normal tissues but down-regulated in primary carcinomas or in many cell lines derived from tumors, including WEHI 7.1 lymphoma cells. Here, we show that unlike in H-rev107-expressing cells or tissues the 5'-end of H-rev107 containing a CpG-rich region of 421 bp is highly methylated in WEHI 7.1 lymphoma cells, correlating with silencing of this gene. Repression of H-rev107 transcription in these cells could be relieved by chemically induced hypomethylation with 5-aza-dC. In addition, upon in vitro methylation, expression of the luciferase reporter gene driven by the H-rev107 promoter decreased by 80% in WEHI 7.1 and 293 cells. Furthermore, co-transfection of the methyl-CpG binding proteins, MeCP2 and MBD2, inhibited H-rev107 promoter activity up to 70% in SL2 cells when the promoter was methylated. By chromatin immunoprecipitation assays, we observed in vivo binding of MeCP2 and MBD2 to the 5'-end of H-rev107 in WEHI 7.1 cells, which was reduced to undetectable levels upon 5-aza-dC treatment, concluding that MeCP2 and MBD2 might be involved in silencing the methylated H-rev107 gene in lymphoma cells and probably certain tumors.
Collapse
Affiliation(s)
- Karim Roder
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | | | | |
Collapse
|
20
|
Roder K, Kim KH, Sul HS. Induction of murine H-rev107 gene expression by growth arrest and histone acetylation: involvement of an Sp1/Sp3-binding GC-box. Biochem Biophys Res Commun 2002; 294:63-70. [PMID: 12054741 DOI: 10.1016/s0006-291x(02)00440-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
H-rev107 is downregulated in many carcinomas and tumor cell lines. Using postconfluent NIH3T3 cells, we demonstrated that growth arrest caused by contact inhibition, but not serum deprivation, increased H-rev107 expression. Furthermore, histone deacetylase inhibitors induced H-rev107 expression in NIH3T3 cells and allowed its reexpression in H-rev107-deficient WEHI 7.1 lymphoma cells. In contrast, no effect of the postconfluent stage or histone deacetylase inhibitors on H-rev107 levels was observed in tumorigenic H-rev107-expressing cell lines, HepG2, HeLa, and SKBR3. Transfections showed that TSA treatment increased luciferase activity 20-fold in NIH3T3 cells. We found that the GC-box at -83/-75 is a key element for H-rev107 induction by TSA and growth arrest, although there were no changes in the pattern and intensity of Sp1/Sp3-binding after induction. These data suggest that contact inhibition of growth and growth arrest caused by histone deacetylase inhibitors probably use the same mechanism to stimulate H-rev107 expression via histone acetylation in NIH3T3 cells and this might contribute to the development of drugs that can induce H-rev107 expression in certain tumors.
Collapse
Affiliation(s)
- Karim Roder
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | | | | |
Collapse
|
21
|
Roder K, Latasa MJ, Sul HS. Murine H-rev107 gene encoding a class II tumor suppressor: gene organization and identification of an Sp1/Sp3-binding GC-box required for its transcription. Biochem Biophys Res Commun 2002; 293:793-9. [PMID: 12054540 DOI: 10.1016/s0006-291x(02)00274-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
H-rev107, which belongs to class II tumor suppressor genes, is ubiquitously expressed in normal cells, but is downregulated in many carcinomas and tumor cell lines. Sequence analysis showed that the murine H-rev107 gene is composed of five exons and four introns. Transfections revealed that 7.6 kb of the H-rev107 promoter directed a high level expression of the reporter gene. There were no significant differences in promoter activity when various 5'-deletion promoter constructs from -7.6 kb to -113 bp were employed. By further deletion and mutation analysis, we found that the region between -83 and -75 containing a GC-box was essential for promoter activity in NIH3T3 or REF52 fibroblasts expressing H-rev107 at moderate to high levels. Gelshifts demonstrated in vitro binding of Sp1 and Sp3 to this GC-box. Cotransfection of Sp1 and Sp3 functionally stimulated promoter activity in SL2 cells. By chromatin immunoprecipitation assays, we observed in vivo binding of Sp1 and Sp3 to the proximal promoter region in NIH3T3 cells and liver, concluding that the transcription of the H-rev107 gene is dependent on Sp1/Sp3-binding to the -83/-75 GC-box.
Collapse
Affiliation(s)
- Karim Roder
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | | | | |
Collapse
|
22
|
Sers C, Husmann K, Nazarenko I, Reich S, Wiechen K, Zhumabayeva B, Adhikari P, Schröder K, Gontarewicz A, Schäfer R. The class II tumour suppressor gene H-REV107-1 is a target of interferon-regulatory factor-1 and is involved in IFNgamma-induced cell death in human ovarian carcinoma cells. Oncogene 2002; 21:2829-39. [PMID: 11973642 DOI: 10.1038/sj.onc.1205377] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2001] [Revised: 01/29/2002] [Accepted: 01/31/2002] [Indexed: 01/18/2023]
Abstract
H-rev107-1 is a growth inhibitory RAS target gene capable of suppressing anchorage independent growth in vitro and in vivo. Using a tumour tissue array with 241 matched tumour and normal tissue cDNA pools, we found down-regulation of H-REV107-1 in 7 out of 14 ovary-derived cDNAs. RT-PCR analysis and immunohistochemical investigation confirmed expression of H-REV107-1 in normal ovarian epithelial cells but down-regulation in high grade ovarian carcinomas. H-REV107-1 is also strongly expressed in immortalized rat and human ovarian epithelial cells in vitro, but suppressed in transformed cells by two different mechanisms. KRAS-transformed rat ovarian cells and PA1 teratocarcinoma cells, reversibly repress H-REV107-1 via MAP/ERK signaling. In contrast, treatment of A27/80 and OVCAR-3 epithelial ovarian cancer cells with IFNgamma stimulated H-REV107-1 expression. In NIH3T3 cells harbouring an estrogen-inducible IRF-1, H-rev107-1 is directly induced after activation of IRF-1, indicating that H-rev107-1 is a target of IRF-1. Stimulation of H-REV107-1 expression was also observed in ovarian epithelial cells suggesting that IRF-1 is involved in H-REV107-1 regulation in human ovarian epithelium. In the IFNgamma-sensitive cell line A27/80, H-REV107-1 suppresses colony formation. A27/80 and OVCAR-3 cells overexpressing H-REV107-1 protein underwent apoptosis. These results demonstrate down-regulation of the class II tumour suppressor H-REV107-1 in human ovarian carcinomas and suggest an involvement of H-REV107-1 in interferon-dependent cell death.
Collapse
Affiliation(s)
- Christine Sers
- Institute of Pathology, University Hospital Charité, Schumannstr. 20/21, D-10117 Berlin, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Siegrist S, Féral C, Chami M, Solhonne B, Mattéi MG, Rajpert-De Meyts E, Guellaën G, Bulle F. hH-Rev107, a class II tumor suppressor gene, is expressed by post-meiotic testicular germ cells and CIS cells but not by human testicular germ cell tumors. Oncogene 2001; 20:5155-63. [PMID: 11526504 PMCID: PMC1865474 DOI: 10.1038/sj.onc.1204658] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2001] [Revised: 05/16/2001] [Accepted: 05/23/2001] [Indexed: 11/08/2022]
Abstract
By systematic analysis of a human testis library, we have isolated the hH-Rev107-3 cDNA, identical to hH-Rev107-1 cDNA, which was previously described as a class II tumor suppressor gene. In this study, two transcripts (1 and 0.8 kb) were detected by Northern blot in all human tissues, excepted in thymus. The strongest expression was found in testis, skeletal muscle and heart. These two mRNA are probably transcribed from only one gene that we mapped to the q12-q13 region of the chromosome 11. In human testis, hH-Rev107 gene expression was localized, by in situ hybridization, within the round spermatids. To investigate a possible role for hH-Rev107 protein in testicular malignant growth, we examined the expression of this gene in germ cell tumors. A strong hH-Rev107 gene expression was observed in normal testis as well as in samples with preinvasive carcinoma in situ but was completely absent in overt tumors, both seminomas and non-seminomas. By in situ hybridization, CIS was found hH-Rev107 positive and tumor negative. A semi-quantitative assessment of hH-Rev107 mRNA level in testicular germ cell tumors, by RT-PCR, exhibited a ninefold decrease in the gene expression. No gross structural aberrations of hH-Rev107 gene were detected in these human primary tumors. The results suggest that down-regulation of hH-Rev107 may be associated with invasive progression of testicular germ cell tumors.
Collapse
Affiliation(s)
- Sylvie Siegrist
- Régulation des gènes et signalisation cellulaire
INSERM : U99Hôpital Henri Mondor 51, avenue Maréchal de Lattre de Tassigny 94010 CRETEIL CEDEX,FR
| | - Chloé Féral
- Régulation des gènes et signalisation cellulaire
INSERM : U99Hôpital Henri Mondor 51, avenue Maréchal de Lattre de Tassigny 94010 CRETEIL CEDEX,FR
| | - Mounia Chami
- Régulation des gènes et signalisation cellulaire
INSERM : U99Hôpital Henri Mondor 51, avenue Maréchal de Lattre de Tassigny 94010 CRETEIL CEDEX,FR
| | - Brigitte Solhonne
- Régulation des gènes et signalisation cellulaire
INSERM : U99Hôpital Henri Mondor 51, avenue Maréchal de Lattre de Tassigny 94010 CRETEIL CEDEX,FR
| | - Marie-Geneviève Mattéi
- Génétique médicale et développement
INSERM : U491Université de la Méditerranée - Aix-Marseille IIFaculte de Médecine Secteur Timone 27, Boulevard Jean Moulin 13385 MARSEILLE CEDEX 05,FR
| | - Ewa Rajpert-De Meyts
- Department of Growth and Reproduction
Copenhagen UniversityRigshospitalet, Copenhagen, Denmark,DK
| | - Georges Guellaën
- Régulation des gènes et signalisation cellulaire
INSERM : U99Hôpital Henri Mondor 51, avenue Maréchal de Lattre de Tassigny 94010 CRETEIL CEDEX,FR
| | - Frédérique Bulle
- Régulation des gènes et signalisation cellulaire
INSERM : U99Hôpital Henri Mondor 51, avenue Maréchal de Lattre de Tassigny 94010 CRETEIL CEDEX,FR
- * Correspondence should be adressed to:
| |
Collapse
|
24
|
Abstract
Retinoids exert wide-spectrum anti-tumor activities, which are mediated via the induction of growth arrest, differentiation or apoptosis. To determine whether the effects of retinoids are mediated by specific gene activation or repression, SC-M1 CL23 gastric cancer cells, pretreated with either vehicle alone or all-trans retinoic acid (10 microM) for 1 day, were analyzed using the technique of differential display. A novel retinoid-inducible gene 1 (RIG1) was isolated. The full-length RIG1 cDNA contained 768 base pairs and encoded a protein of 164 amino acids with a molecular weight of 18 kDa. The RIG1 gene was ubiquitously expressed in normal tissue, and its expression was positively associated with cellular density. Nucleotide sequence analysis demonstrated that the RIG1 gene was similar to a recently-isolated TIG3 gene, and displayed 54% nucleotide sequence homology with a type II tumor suppressor gene H-REV-107-1. RIG1 cDNA, however, contained an extra 32 base pairs located at its 5' end and revealed three base pair differences for the remaining sequences leading to two amino acids substitution between the two encoded proteins. All-trans retinoic acid increased the level of RIG1 mRNA in a time- and concentration-dependent manner in SC-M1 CL23 gastric cancer cells. This was not observed for the H-REV-107-1 gene. The RIG1 regulation was related to cellular retinoid sensitivity. Both retinoic acid receptor alpha- and retinoic acid receptor gamma-selective agonists increased RIG1 mRNA level, and the retinoid x receptor-selective agonist potentiated this regulation. In conclusion, the cDNA of a novel retinoid-inducible gene RIG1 has been cloned. This gene is regulated by retinoic acid through the heterodimer of retinoic acid receptor and retinoid x receptor.
Collapse
MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Base Sequence
- Carrier Proteins/genetics
- Cloning, Molecular
- DNA Primers/genetics
- DNA, Complementary/genetics
- DNA, Neoplasm/genetics
- Gene Expression/drug effects
- Genes, Tumor Suppressor/drug effects
- Humans
- Intracellular Signaling Peptides and Proteins
- Molecular Sequence Data
- Phospholipases A2, Calcium-Independent
- Proteins/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Receptors, Retinoic Acid
- Retinoids/pharmacology
- Sequence Homology, Amino Acid
- Signal Transduction
- Stomach Neoplasms/genetics
- Stomach Neoplasms/metabolism
- Tissue Distribution
- Tumor Cells, Cultured
- Tumor Suppressor Proteins
Collapse
Affiliation(s)
- S L Huang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
| | | | | | | |
Collapse
|
25
|
Hughes PJ, Stanway G. The 2A proteins of three diverse picornaviruses are related to each other and to the H-rev107 family of proteins involved in the control of cell proliferation. J Gen Virol 2000; 81:201-7. [PMID: 10640559 DOI: 10.1099/0022-1317-81-1-201] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 2A protein appears to be diverse among picornaviruses, in contrast to the other non-structural proteins, which have homologous structures and functions. In enteroviruses and rhinoviruses, 2A is a trypsin-like protease involved in protein processing and in shut-off of host-cell macromolecular synthesis. The aphthovirus and cardiovirus 2A is associated with an unusual processing event at the 2A/2B junction. It is shown here that the 2A protein of several diverse picornaviruses, the human parechoviruses, Aichi virus and avian encephalomyelitis virus, possess previously unrecognized conserved motifs and are likely to have a common function. Moreover, these motifs, a conserved histidine and flanking amino acids, an asparagine-cysteine dipeptide and a putative transmembrane domain, are characteristic of a family of cellular proteins, at least two of which are involved in the control of cell growth. These observations have important implications for an understanding of picornavirus genome structure and evolution, as well as pointing to possible functions of 2A in these viruses.
Collapse
Affiliation(s)
- P J Hughes
- Department of Biological Sciences, John Tabor Laboratories, University of Essex, Colchester CO4 3SQ, UK
| | | |
Collapse
|
26
|
Husmann K, Sers C, Fietze E, Mincheva A, Lichter P, Schäfer R. Transcriptional and translational downregulation of H-REV107, a class II tumour suppressor gene located on human chromosome 11q11-12. Oncogene 1998; 17:1305-12. [PMID: 9771974 DOI: 10.1038/sj.onc.1202060] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The H-rev107 tumour suppressor was isolated as a gene specifically expressed in rat fibroblasts resistant toward malignant transformation by the activated HRAS gene (Sers et al., 1997; Hajnal et al., 1994). Here we describe the human homologue of the rat H-rev107 gene. The predicted rat and human proteins are highly conserved exhibiting an overall amino acid identity of 83%. The H-REV107-1 gene is ubiquitously expressed with the exception of haematopoetic cells and tissues. In contrast, H-REV107-1 mRNA was found only in eight of 27 cell lines derived from mammary carcinoma, lung carcinoma, gastric carcinoma, kidney carcinoma, melanoma, neuroblastoma and other tumours. The H-REV107-1 protein was not detectable in any of these tumour cells. Loss of H-REV107-1 expression was not restricted to cultured human tumour cell lines, but also found in primary squamous cell carcinomas. Gross structural aberrations of the H-REV107-1 gene were absent in tumorigenic cell lines. Thus, the block to H-REV107-1 expression is achieved both at the level of transcription and translation. By fluorescence in situ hybridisation the human H-REV107-1 gene was localised to chromosome 11q11-12.
Collapse
Affiliation(s)
- K Husmann
- Department of Pathology, University of Zürich, Switzerland
| | | | | | | | | | | |
Collapse
|
27
|
Sers C, Emmenegger U, Husmann K, Bucher K, Andres AC, Schäfer R. Growth-inhibitory activity and downregulation of the class II tumor-suppressor gene H-rev107 in tumor cell lines and experimental tumors. J Cell Biol 1997; 136:935-44. [PMID: 9049257 PMCID: PMC2132501 DOI: 10.1083/jcb.136.4.935] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The H-rev107 gene is a new class II tumor suppressor, as defined by its reversible downregulation and growth-inhibiting capacity in HRAS transformed cell lines. Overexpression of the H-rev107 cDNA in HRAS-transformed ANR4 hepatoma cells or in FE-8 fibroblasts resulted in 75% reduction of colony formation. Cell populations of H-rev107 transfectants showed an attenuated tumor formation in nude mice. Cells explanted from tumors or maintained in cell culture for an extended period of time no longer exhibited detectable levels of the H-rev107 protein, suggesting strong selection against H-rev107 expression in vitro and in vivo. Expression of the truncated form of H-rev107 lacking the COOH-terminal membrane associated domain of 25 amino acids, had a weaker inhibitory effect on proliferation in vitro and was unable to attenuate tumor growth in nude mice. The H-rev107 mRNA is expressed in most adult rat tissues, and immunohistochemical analysis showed expression of the protein in differentiated epithelial cells of stomach, of colon and small intestine, in kidney, bladder, esophagus, and in tracheal and bronchial epithelium. H-rev107 gene transcription is downregulated in rat cell lines derived from liver, kidney, and pancreatic tumors and also in experimental mammary tumors expressing a RAS transgene. In colon carcinoma cell lines only minute amounts of protein were detectable. Thus, downregulation of H-rev107 expression may occur at the level of mRNA or protein.
Collapse
Affiliation(s)
- C Sers
- Department of Pathology, University of Zurich, Switzerland.
| | | | | | | | | | | |
Collapse
|
28
|
Hajnal A, Klemenz R, Schäfer R. Subtraction cloning of H-rev107, a gene specifically expressed in H-ras resistant fibroblasts. Oncogene 1994; 9:479-90. [PMID: 8290259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have isolated by subtractive hybridization a novel gene, called H-rev107, which is specifically expressed in a phenotypic revertant of H-ras transformed 208F rat fibroblasts. Apart from oncogene revertants, strong expression of H-rev107 was found in REF52 and EK-3 cells, two fibroblast lines resistant to transformation by activated H-ras oncogenes. In contrast, transformation-sensitive fibroblasts like 208F or NIH3T3 cells expressed only very little H-rev107 RNA. In H-ras or v-src transformed fibroblasts, H-rev107 RNA was undetectable. Introduction of the adenovirus E1A nuclear oncogene into ras-resistant REF52 cells abolished their transformation resistance and repressed the H-rev107 gene. H-rev107 encodes a protein with a molecular weight of 18 kDa without any structural similarity to known proteins. p18H-rev107 exists in two forms which can be distinguished by their electrophoretic mobility; one is localized predominantly in cell membranes, the other in the cytoplasm. In confluent contact-inhibited 208F cells, p18H-rev107 accumulated in cell membranes, while growth arrest induced by serum starvation did not induce H-rev107. In REF52, cell density had no influence on the expression or localization of p18H-rev107. Repression of the H-rev107 gene may be closely associated with the loss of density-dependent growth inhibition and with the expression of the neoplastic phenotype.
Collapse
MESH Headings
- Adenovirus E1A Proteins/physiology
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Blotting, Western
- Cell Line
- Cell Membrane/chemistry
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/pathology
- Cloning, Molecular
- Cytoplasm/chemistry
- DNA/analysis
- DNA/genetics
- Down-Regulation/physiology
- Fibroblasts/chemistry
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Genes, ras/genetics
- Genes, ras/physiology
- Molecular Sequence Data
- Molecular Weight
- Phenotype
- Phospholipases A2, Calcium-Independent
- Proteins/analysis
- Proteins/genetics
- Proteins/metabolism
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Rats
- Tumor Suppressor Proteins
Collapse
Affiliation(s)
- A Hajnal
- Department of Pathology, University of Zürich, Switzerland
| | | | | |
Collapse
|