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Fotakis P, Kothari V, Thomas DG, Westerterp M, Molusky MM, Altin E, Abramowicz S, Wang N, He Y, Heinecke JW, Bornfeldt KE, Tall AR. Anti-Inflammatory Effects of HDL (High-Density Lipoprotein) in Macrophages Predominate Over Proinflammatory Effects in Atherosclerotic Plaques. Arterioscler Thromb Vasc Biol 2019; 39:e253-e272. [PMID: 31578081 DOI: 10.1161/atvbaha.119.313253] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE HDL (high-density lipoprotein) infusion reduces atherosclerosis in animal models and is being evaluated as a treatment in humans. Studies have shown either anti- or proinflammatory effects of HDL in macrophages, and there is no consensus on the underlying mechanisms. Here, we interrogate the effects of HDL on inflammatory gene expression in macrophages. Approach and Results: We cultured bone marrow-derived macrophages, treated them with reconstituted HDL or HDL isolated from APOA1Tg;Ldlr-/- mice, and challenged them with lipopolysaccharide. Transcriptional profiling showed that HDL exerts a broad anti-inflammatory effect on lipopolysaccharide-induced genes and proinflammatory effect in a subset of genes enriched for chemokines. Cholesterol removal by POPC (1-palmitoyl-2-oleoyl-glycero-3-phosphocholine) liposomes or β-methylcyclodextrin mimicked both pro- and anti-inflammatory effects of HDL, whereas cholesterol loading by POPC/cholesterol-liposomes or acetylated LDL (low-density lipoprotein) before HDL attenuated these effects, indicating that these responses are mediated by cholesterol efflux. While early anti-inflammatory effects reflect reduced TLR (Toll-like receptor) 4 levels, late anti-inflammatory effects are due to reduced IFN (interferon) receptor signaling. Proinflammatory effects occur late and represent a modified endoplasmic reticulum stress response, mediated by IRE1a (inositol-requiring enzyme 1a)/ASK1 (apoptosis signal-regulating kinase 1)/p38 MAPK (p38 mitogen-activated protein kinase) signaling, that occurs under conditions of extreme cholesterol depletion. To investigate the effects of HDL on inflammatory gene expression in myeloid cells in atherosclerotic lesions, we injected reconstituted HDL into Apoe-/- or Ldlr-/- mice fed a Western-type diet. Reconstituted HDL infusions produced anti-inflammatory effects in lesion macrophages without any evidence of proinflammatory effects. CONCLUSIONS Reconstituted HDL infusions in hypercholesterolemic atherosclerotic mice produced anti-inflammatory effects in lesion macrophages suggesting a beneficial therapeutic effect of HDL in vivo.
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Affiliation(s)
- Panagiotis Fotakis
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
| | - Vishal Kothari
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, UW Medicine Diabetes Institute, University of Washington, Seattle (V.K., Y.H., J.W.H., K.E.B.)
| | - David G Thomas
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
| | - Marit Westerterp
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.).,Department of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands (M.W.)
| | - Matthew M Molusky
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
| | - Elissa Altin
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
| | - Sandra Abramowicz
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
| | - Nan Wang
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
| | - Yi He
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, UW Medicine Diabetes Institute, University of Washington, Seattle (V.K., Y.H., J.W.H., K.E.B.)
| | - Jay W Heinecke
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, UW Medicine Diabetes Institute, University of Washington, Seattle (V.K., Y.H., J.W.H., K.E.B.)
| | - Karin E Bornfeldt
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, UW Medicine Diabetes Institute, University of Washington, Seattle (V.K., Y.H., J.W.H., K.E.B.).,Department of Pathology, University of Washington, Seattle (K.E.B.)
| | - Alan R Tall
- From the Division of Molecular Medicine, Department of Medicine, Columbia University, New York (P.F., D.G.T., M.W., M.M.M., E.A., S.A., N.W., A.R.T.)
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2
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The Genetic Architecture of Coronary Artery Disease: Current Knowledge and Future Opportunities. Curr Atheroscler Rep 2017; 19:6. [PMID: 28130654 DOI: 10.1007/s11883-017-0641-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE OF REVIEW We provide an overview of our current understanding of the genetic architecture of coronary artery disease (CAD) and discuss areas of research that provide excellent opportunities for further exploration. RECENT FINDINGS Large-scale studies in human populations, coupled with rapid advances in genetic technologies over the last decade, have clearly established the association of common genetic variation with risk of CAD. However, the effect sizes of the susceptibility alleles are for the most part modest and collectively explain only a small fraction of the overall heritability. By comparison, evidence that rare variants make a substantial contribution to risk of CAD has been somewhat disappointing thus far, suggesting that other biological mechanisms have yet to be discovered. Emerging data suggests that novel pathways involved in the development of CAD can be identified through complementary and integrative systems genetics strategies in mice or humans. There is also convincing evidence that gut bacteria play a previously unrecognized role in the development of CAD, particularly through metabolism of certain dietary nutrients that lead to proatherogenic metabolites in the circulation. A major effort is now underway to functionally understand the newly discovered genetic and biological associations for CAD, which could lead to the development of potentially novel therapeutic strategies. Other important areas of investigation for understanding the pathophysiology of CAD, including epistatic interactions between genes or with either sex and environmental factors, have not been studied on a broad scope and represent additional opportunities for future studies.
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Abstract
PURPOSE OF REVIEW Atherosclerosis and associated cardiovascular disease still remain the largest cause of mortality worldwide. Several recent studies have discovered that metabolism of common nutrients by gut microbes can produce a proatherogenic metabolite called trimethylamine-N-oxide (TMAO). The goal of this review is to discuss emerging evidence that the hepatic enzyme that generates TMAO, flavin monooxygenase 3 (FMO3), plays a regulatory role in maintaining whole body cholesterol balance and atherosclerosis development. RECENT FINDINGS Several independent studies have recently uncovered a link between either FMO3 itself or its enzymatic product TMAO with atherosclerosis and hepatic insulin resistance. These recent studies show that inhibition of FMO3 stimulates macrophage reverse cholesterol transport and protects against atherosclerosis in mice. SUMMARY A growing body of work demonstrates that nutrients present in high-fat foods (phosphatidylcholine, choline and L-carnitine) can be metabolized by the gut microbial enzymes to generate trimethylamine, which is then further metabolized by the host enzyme FMO3 to produce proatherogenic TMAO. Here, we discuss emerging evidence that the TMAO-producing enzyme FMO3 is centrally involved in the pathogenesis of atherosclerosis by regulating cholesterol metabolism and insulin resistance, and how these new insights provide exciting new avenues for cardiovascular disease therapies.
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Affiliation(s)
| | - J. Mark Brown
- To whom correspondence should be addressed: Cleveland Clinic Lerner Research Institute, Department of Cellular and Molecular Medicine. Tel: 216-444-8340; Fax: 216-444-9404;
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4
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Zhou X, Crow AL, Hartiala J, Spindler TJ, Ghazalpour A, Barsky LW, Bennett BJ, Parks BW, Eskin E, Jain R, Epstein JA, Lusis AJ, Adams GB, Allayee H. The Genetic Landscape of Hematopoietic Stem Cell Frequency in Mice. Stem Cell Reports 2015; 5:125-38. [PMID: 26050929 PMCID: PMC4618249 DOI: 10.1016/j.stemcr.2015.05.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 05/07/2015] [Accepted: 05/08/2015] [Indexed: 12/31/2022] Open
Abstract
Prior efforts to identify regulators of hematopoietic stem cell physiology have relied mainly on candidate gene approaches with genetically modified mice. Here we used a genome-wide association study (GWAS) strategy with the hybrid mouse diversity panel to identify the genetic determinants of hematopoietic stem/progenitor cell (HSPC) frequency. Among 108 strains, we observed ∼120- to 300-fold variation in three HSPC populations. A GWAS analysis identified several loci that were significantly associated with HSPC frequency, including a locus on chromosome 5 harboring the homeodomain-only protein gene (Hopx). Hopx previously had been implicated in cardiac development but was not known to influence HSPC biology. Analysis of the HSPC pool in Hopx−/− mice demonstrated significantly reduced cell frequencies and impaired engraftment in competitive repopulation assays, thus providing functional validation of this positional candidate gene. These results demonstrate the power of GWAS in mice to identify genetic determinants of the hematopoietic system. Genetic variation across mouse strains influences hematopoietic stem cell frequency This variation can be exploited for genome-wide association studies Hopx is a regulator of hematopoietic stem/progenitor cell function This approach can be used to identify genetic determinants of other stem cell systems
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Affiliation(s)
- Xiaoying Zhou
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Amanda L Crow
- Department of Preventive Medicine and Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jaana Hartiala
- Department of Preventive Medicine and Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Tassja J Spindler
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Anatole Ghazalpour
- Departments of Human Genetics, Medicine, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Lora W Barsky
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Brian J Bennett
- Department of Genetics and Nutrition Research Institute, University of North Carolina, Chapel Hill, Kannapolis, NC 28081, USA
| | - Brian W Parks
- Departments of Human Genetics, Medicine, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Eleazar Eskin
- Department of Computer Science and Inter-Departmental Program in Bioinformatics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rajan Jain
- Department of Cell and Developmental Biology and Penn Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jonathan A Epstein
- Department of Cell and Developmental Biology and Penn Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aldons J Lusis
- Departments of Human Genetics, Medicine, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gregor B Adams
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
| | - Hooman Allayee
- Department of Preventive Medicine and Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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5
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Gregory JC, Buffa JA, Org E, Wang Z, Levison BS, Zhu W, Wagner MA, Bennett BJ, Li L, DiDonato JA, Lusis AJ, Hazen SL. Transmission of atherosclerosis susceptibility with gut microbial transplantation. J Biol Chem 2014; 290:5647-60. [PMID: 25550161 DOI: 10.1074/jbc.m114.618249] [Citation(s) in RCA: 345] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Recent studies indicate both clinical and mechanistic links between atherosclerotic heart disease and intestinal microbial metabolism of certain dietary nutrients producing trimethylamine N-oxide (TMAO). Here we test the hypothesis that gut microbial transplantation can transmit choline diet-induced TMAO production and atherosclerosis susceptibility. First, a strong association was noted between atherosclerotic plaque and plasma TMAO levels in a mouse diversity panel (n = 22 strains, r = 0.38; p = 0.0001). An atherosclerosis-prone and high TMAO-producing strain, C57BL/6J, and an atherosclerosis-resistant and low TMAO-producing strain, NZW/LacJ, were selected as donors for cecal microbial transplantation into apolipoprotein e null mice in which resident intestinal microbes were first suppressed with antibiotics. Trimethylamine (TMA) and TMAO levels were initially higher in recipients on choline diet that received cecal microbes from C57BL/6J inbred mice; however, durability of choline diet-dependent differences in TMA/TMAO levels was not maintained to the end of the study. Mice receiving C57BL/6J cecal microbes demonstrated choline diet-dependent enhancement in atherosclerotic plaque burden as compared with recipients of NZW/LacJ microbes. Microbial DNA analyses in feces and cecum revealed transplantation of donor microbial community features into recipients with differences in taxa proportions between donor strains that were transmissible to recipients and that tended to show coincident proportions with TMAO levels. Proportions of specific taxa were also identified that correlated with plasma TMAO levels in donors and recipients and with atherosclerotic lesion area in recipients. Atherosclerosis susceptibility may be transmitted via transplantation of gut microbiota. Gut microbes may thus represent a novel therapeutic target for modulating atherosclerosis susceptibility.
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Affiliation(s)
- Jill C Gregory
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Jennifer A Buffa
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Elin Org
- the Departments of Human Genetics and Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, 90095, and
| | - Zeneng Wang
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Bruce S Levison
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Weifei Zhu
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Matthew A Wagner
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Brian J Bennett
- the Department of Genetics, Nutrition Research Institute, University of North Carolina, Chapel Hill, North Carolina 28081
| | - Lin Li
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Joseph A DiDonato
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Aldons J Lusis
- the Departments of Human Genetics and Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, 90095, and
| | - Stanley L Hazen
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio 44195,
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6
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Wu X, Davis RC, McMillen TS, Schaeffer V, Zhou Z, Qi H, Mazandarani PN, Alialy R, Hudkins KL, Lusis AJ, LeBoeuf RC. Genetic modulation of diabetic nephropathy among mouse strains with Ins2 Akita mutation. Physiol Rep 2014; 2:2/11/e12208. [PMID: 25428948 PMCID: PMC4255814 DOI: 10.14814/phy2.12208] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diabetic nephropathy (DN) is a major complication of diabetes and the leading cause of end‐stage renal disease. DN is characterized by changes in kidney structure and function but the underlying genetic and molecular factors are poorly understood. We used a mouse diversity panel to explore the genetic basis of DN traits in mice carrying the Ins2 Akita mutation. Twenty‐eight Akita strains were generated by breeding this panel to DBA/2.Akita mice. Male F1 diabetic and nondiabetic littermates were evaluated for DN‐related traits. Urine albumin‐to‐creatinine ratios (ACRs), volume and cystatin C as well as blood urea nitrogen and lipoprotein levels varied significantly among the diabetic strains. For most Akita strains, ACR values increased 2‐ to 6‐fold over euglycemic control values. However, six strains exhibited changes in ACR exceeding 10‐fold with two strains (NOD/ShiLt and CBA) showing 50‐ to 83‐ fold increases. These increases are larger than previously reported among available DN mouse models establishing these strains as useful for additional studies of renal function. ACRs correlated with cystatin C (P = 0.0286), a measure of hyperfiltration and an interstitial tubular marker associated with DN onset in humans suggesting that tubule damage as well as podocyte‐stress contributed to reduced kidney function assessed by ACR. Although large changes were seen for ACRs, severe nephropathology was absent. However, glomerular hypertrophy and collagen IV content were found to vary significantly among strains suggesting a genetic basis for early onset features of DN. Our results define the range of DN phenotypes that occur among common inbred strains of mice. Diabetic nephropathy (DN) is characterized by changes in kidney structure and function but the underlying genetic and molecular factors are poorly understood. We used a mouse diversity panel to explore the genetic basis of DN traits in mice carrying the Ins2 Akita mutation. Twenty‐eight Akita strains on different genetic backgrounds were evaluated for DN‐related traits and the results define the range of DN phenotypes that occur among common inbred strains of mice.
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Affiliation(s)
- Xiuju Wu
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Richard C Davis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Timothy S McMillen
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Valerie Schaeffer
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Zhiqiang Zhou
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Hongxiu Qi
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Parisa N Mazandarani
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Roshanak Alialy
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Kelly L Hudkins
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Aldons J Lusis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA Department of Human Genetics, University of California, Los Angeles, Los Angeles, California, USA
| | - Renée C LeBoeuf
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, Washington, USA
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7
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Shih DM, Wang Z, Lee R, Meng Y, Che N, Charugundla S, Qi H, Wu J, Pan C, Brown JM, Vallim T, Bennett BJ, Graham M, Hazen SL, Lusis AJ. Flavin containing monooxygenase 3 exerts broad effects on glucose and lipid metabolism and atherosclerosis. J Lipid Res 2014; 56:22-37. [PMID: 25378658 DOI: 10.1194/jlr.m051680] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We performed silencing and overexpression studies of flavin containing monooxygenase (FMO) 3 in hyperlipidemic mouse models to examine its effects on trimethylamine N-oxide (TMAO) levels and atherosclerosis. Knockdown of hepatic FMO3 in LDL receptor knockout mice using an antisense oligonucleotide resulted in decreased circulating TMAO levels and atherosclerosis. Surprisingly, we also observed significant decreases in hepatic lipids and in levels of plasma lipids, ketone bodies, glucose, and insulin. FMO3 overexpression in transgenic mice, on the other hand, increased hepatic and plasma lipids. Global gene expression analyses suggested that these effects of FMO3 on lipogenesis and gluconeogenesis may be mediated through the PPARα and Kruppel-like factor 15 pathways. In vivo and in vitro results were consistent with the concept that the effects were mediated directly by FMO3 rather than trimethylamine/TMAO; in particular, overexpression of FMO3 in the human hepatoma cell line, Hep3B, resulted in significantly increased glucose secretion and lipogenesis. Our results indicate a major role for FMO3 in modulating glucose and lipid homeostasis in vivo, and they suggest that pharmacologic inhibition of FMO3 to reduce TMAO levels would be confounded by metabolic interactions.
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Affiliation(s)
- Diana M Shih
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Zeneng Wang
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, OH
| | | | - Yonghong Meng
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Nam Che
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Sarada Charugundla
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Hannah Qi
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Judy Wu
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Calvin Pan
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - J Mark Brown
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, OH
| | - Thomas Vallim
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Brian J Bennett
- Department of Genetics, University of North Carolina, Chapel Hill, NC
| | | | - Stanley L Hazen
- Department of Cellular and Molecular Medicine (NC10), Cleveland Clinic Lerner Research Institute, Cleveland, OH
| | - Aldons J Lusis
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA Departments of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
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8
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Spiezio SH, Amon LM, McMillen TS, Vick CM, Houston BA, Caldwell M, Ogimoto K, Morton GJ, Kirk EA, Schwartz MW, Nadeau JH, LeBoeuf RC. Genetic determinants of atherosclerosis, obesity, and energy balance in consomic mice. Mamm Genome 2014; 25:549-63. [PMID: 25001233 DOI: 10.1007/s00335-014-9530-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/11/2014] [Indexed: 12/18/2022]
Abstract
Metabolic diseases such as obesity and atherosclerosis result from complex interactions between environmental factors and genetic variants. A panel of chromosome substitution strains (CSSs) was developed to characterize genetic and dietary factors contributing to metabolic diseases and other biological traits and biomedical conditions. Our goal here was to identify quantitative trait loci (QTLs) contributing to obesity, energy expenditure, and atherosclerosis. Parental strains C57BL/6 and A/J together with a panel of 21 CSSs derived from these progenitors were subjected to chronic feeding of rodent chow and atherosclerotic (females) or diabetogenic (males) test diets, and evaluated for a variety of metabolic phenotypes including several traits unique to this report, namely fat pad weights, energy balance, and atherosclerosis. A total of 297 QTLs across 35 traits were discovered, two of which provided significant protection from atherosclerosis, and several dozen QTLs modulated body weight, body composition, and circulating lipid levels in females and males. While several QTLs confirmed previous reports, most QTLs were novel. Finally, we applied the CSS quantitative genetic approach to energy balance, and identified three novel QTLs controlling energy expenditure and one QTL modulating food intake. Overall, we identified many new QTLs and phenotyped several novel traits in this mouse model of diet-induced metabolic diseases.
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Affiliation(s)
- Sabrina H Spiezio
- Institute for Systems Biology, 401 North Terry Ave, Seattle, WA, 98109, USA
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9
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Kayashima Y, Tomita H, Zhilicheva S, Kim S, Kim HS, Bennett BJ, Maeda N. Quantitative trait loci affecting atherosclerosis at the aortic root identified in an intercross between DBA2J and 129S6 apolipoprotein E-null mice. PLoS One 2014; 9:e88274. [PMID: 24586312 PMCID: PMC3930552 DOI: 10.1371/journal.pone.0088274] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 01/09/2014] [Indexed: 12/23/2022] Open
Abstract
Apolipoprotein E-null mice on a DBA/2J genetic background (DBA-apoE) are highly susceptible to atherosclerosis in the aortic root area compared with those on a 129S6 background (129-apoE). To explore atherosclerosis-responsible genetic regions, we performed a quantitative trait locus (QTL) analysis using 172 male and 137 female F2 derived from an intercross between DBA-apoE and 129-apoE mice. A genome-wide scan identified two significant QTL for the size of lesions at the root: one is Ath44 on Chromosome (Chr) 1 at 158 Mb, and the other Ath45 on Chr 2 at 162 Mb. Ath44 co-localizes with but appears to be independent of a previously reported QTL, Ath1, while Ath45 is a novel QTL. DBA alleles of both Ath44 and Ath45 confer atherosclerosis-susceptibility. In addition, a QTL on Chr 14 at 73 Mb was found significant only in males, and 129 allele conferring susceptibility. Further analysis detected female-specific interactions between a second QTL on Chr 1 at 73 Mb and a QTL on Chr 3 at 21 Mb, and between Chr 7 at 84 Mb and Chr 12 at 77 Mb. These loci for the root atherosclerosis were independent of QTLs for plasma total cholesterol and QTLs for triglycerides, but a QTL for HDL (Chr 1 at 126 Mb) overlapped with the Ath44. Notably, haplotype analysis among 129S6, DBA/2J and C57BL/6 genomes and their gene expression data narrowed the candidate regions for Ath44 and Ath45 to less than 5 Mb intervals where multiple genome wide associations with cardiovascular phenotypes have also been reported in humans. SNPs in or near Fmo3, Sele and Selp for Ath44, and Lbp and Pkig for Ath45 were suggested for further investigation as potential candidates underlying the atherosclerosis susceptibility.
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Affiliation(s)
- Yukako Kayashima
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Hirofumi Tomita
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Svetlana Zhilicheva
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Shinja Kim
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Hyung-Suk Kim
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Brian J. Bennett
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Nobuyo Maeda
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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10
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Smolock EM, Machleder DE, Korshunov VA, Berk BC. Identification of a genetic locus on chromosome 11 that regulates leukocyte infiltration in mouse carotid artery. Arterioscler Thromb Vasc Biol 2013; 33:1014-9. [PMID: 23448970 DOI: 10.1161/atvbaha.112.301129] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE We demonstrated that inflammatory cells and intima-media thickening are increased in carotids exposed to low-blood flow in the SJL/J (SJL) strain compared with other mouse strains. We hypothesized that the extent of inflammation associated with intima-media thickening is a genetically regulated trait. APPROACH AND RESULTS We performed a whole genome approach to measure leukocyte infiltration in the carotid intima as a quantitative trait in a genetic cross between C3HeB/FeJ (C3H/F) and SJL mice. Immunostaining for CD45(+) (a pan-specific leukocyte marker) was performed on carotids from C3H/F, SJL, F1, and N2 progeny to measure leukocyte infiltration. We identified a nearly significant quantitative trait locus for CD45(+) on chromosome (chr) 11 (17 cM, LOD=2.3; significance was considered at threshold P=0.05). Interval mapping showed that the CD45(+) locus on chr 11 accounted for 8% of the variation in the logarithm of odds backcross. Importantly, the CD45(+) locus colocalized with the intima-modifier 2 (Im2) locus, which controls 17% of intima variation. We created 2 Im2 congenic lines of mice (C3H/F.SJL.11.1 and C3H/F.SJL.11.2) to better understand the regulation of intima-media thickening by the chr 11 locus. The C3H/F.SJL.11.1 congenic mouse showed ≈30% of the SJL trait, confirming that CD45(+) cell infiltration contributed to the intima trait. CONCLUSIONS We discovered a novel locus on chr 11 that controls leukocyte infiltration in the carotid. Importantly, this locus overlaps with our previously published Im2 locus on chr 11. Our study reveals a potential mechanistic relationship between leukocyte infiltration and intima-media thickening in response to decreased blood flow.
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Affiliation(s)
- Elaine M Smolock
- University of Rochester, Aab Cardiovascular Research Institute, 601 Elmwood Ave, Box CVRI, Rochester, NY 14642, USA.
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Bennett BJ, de Aguiar Vallim TQ, Wang Z, Shih DM, Meng Y, Gregory J, Allayee H, Lee R, Graham M, Crooke R, Edwards PA, Hazen SL, Lusis AJ. Trimethylamine-N-oxide, a metabolite associated with atherosclerosis, exhibits complex genetic and dietary regulation. Cell Metab 2013; 17:49-60. [PMID: 23312283 PMCID: PMC3771112 DOI: 10.1016/j.cmet.2012.12.011] [Citation(s) in RCA: 725] [Impact Index Per Article: 65.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 10/25/2012] [Accepted: 12/17/2012] [Indexed: 12/17/2022]
Abstract
Circulating trimethylamine-N-oxide (TMAO) levels are strongly associated with atherosclerosis. We now examine genetic, dietary, and hormonal factors regulating TMAO levels. We demonstrate that two flavin mono-oxygenase family members, FMO1 and FMO3, oxidize trimethylamine (TMA), derived from gut flora metabolism of choline, to TMAO. Further, we show that FMO3 exhibits 10-fold higher specific activity than FMO1. FMO3 overexpression in mice significantly increases plasma TMAO levels while silencing FMO3 decreases TMAO levels. In both humans and mice, hepatic FMO3 expression is reduced in males compared to females. In mice, this reduction in FMO3 expression is due primarily to downregulation by androgens. FMO3 expression is induced by dietary bile acids by a mechanism that involves the farnesoid X receptor (FXR), a bile acid-activated nuclear receptor. Analysis of natural genetic variation among inbred strains of mice indicates that FMO3 and TMAO are significantly correlated, and TMAO levels explain 11% of the variation in atherosclerosis.
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Affiliation(s)
- Brian J Bennett
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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Abstract
Genome-wide association studies (GWASs) have transformed the field of human genetics and have led to the discovery of hundreds of genes that are implicated in human disease. The technological advances that drove this revolution are now poised to transform genetic studies in model organisms, including mice. However, the design of GWASs in mouse strains is fundamentally different from the design of human GWASs, creating new challenges and opportunities. This Review gives an overview of the novel study designs for mouse GWASs, which dramatically improve both the statistical power and resolution compared to classical gene-mapping approaches.
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Affiliation(s)
- Jonathan Flint
- The Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, UK
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