1
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Xia W, Veeragandham P, Cao Y, Xu Y, Rhyne TE, Qian J, Hung CW, Zhao P, Jones Y, Gao H, Liddle C, Yu RT, Downes M, Evans RM, Rydén M, Wabitsch M, Wang Z, Hakozaki H, Schöneberg J, Reilly SM, Huang J, Saltiel AR. Obesity causes mitochondrial fragmentation and dysfunction in white adipocytes due to RalA activation. Nat Metab 2024; 6:273-289. [PMID: 38286821 PMCID: PMC10896723 DOI: 10.1038/s42255-024-00978-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 05/17/2023] [Accepted: 01/04/2024] [Indexed: 01/31/2024]
Abstract
Mitochondrial dysfunction is a characteristic trait of human and rodent obesity, insulin resistance and fatty liver disease. Here we show that high-fat diet (HFD) feeding causes mitochondrial fragmentation in inguinal white adipocytes from male mice, leading to reduced oxidative capacity by a process dependent on the small GTPase RalA. RalA expression and activity are increased in white adipocytes after HFD. Targeted deletion of RalA in white adipocytes prevents fragmentation of mitochondria and diminishes HFD-induced weight gain by increasing fatty acid oxidation. Mechanistically, RalA increases fission in adipocytes by reversing the inhibitory Ser637 phosphorylation of the fission protein Drp1, leading to more mitochondrial fragmentation. Adipose tissue expression of the human homolog of Drp1, DNM1L, is positively correlated with obesity and insulin resistance. Thus, chronic activation of RalA plays a key role in repressing energy expenditure in obese adipose tissue by shifting the balance of mitochondrial dynamics toward excessive fission, contributing to weight gain and metabolic dysfunction.
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Affiliation(s)
- Wenmin Xia
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Preethi Veeragandham
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Yu Cao
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Yayun Xu
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Torrey E Rhyne
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Jiaxin Qian
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Chao-Wei Hung
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Peng Zhao
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Ying Jones
- Electron Microscopy Core, Cellular and Molecular Medicine, University of California San Diego, San Diego, CA, USA
| | - Hui Gao
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Christopher Liddle
- Storr Liver Centre, Westmead Institute for Medical Research and Westmead Hospital, University of Sydney School of Medicine, Sydney, New South Wales, Australia
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, San Diego, CA, USA
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, San Diego, CA, USA
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, San Diego, CA, USA
| | - Mikael Rydén
- Department of Medicine (H7), Karolinska Institute (C2-94), Karolinska University Hospital, Stockholm, Sweden
| | - Martin Wabitsch
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Endocrinology and Diabetes, Ulm University Medical Center, Ulm, Germany
| | - Zichen Wang
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA, USA
| | - Hiroyuki Hakozaki
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA, USA
| | - Johannes Schöneberg
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA, USA
| | - Shannon M Reilly
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA
- Weill Center for Metabolic Health, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Jianfeng Huang
- Gene Expression Laboratory, Salk Institute for Biological Studies, San Diego, CA, USA
| | - Alan R Saltiel
- Division of Endocrinology and Metabolism, Department of Medicine, University of California San Diego, San Diego, CA, USA.
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA.
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2
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Bridge-Comer PE, Reilly SM. Measuring the Rate of Lipolysis in Ex vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro. J Vis Exp 2023:10.3791/65106. [PMID: 37010285 PMCID: PMC10583296 DOI: 10.3791/65106] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023] Open
Abstract
Adipocytes store energy in the form of triglycerides in lipid droplets. This energy can be mobilized via lipolysis, where the fatty acid side chains are sequentially cleaved from the glycerol backbone, resulting in the release of free fatty acids and glycerol. Due to the low expression of glycerol kinase in white adipocytes, glycerol re-uptake rates are negligible, while fatty acid re-uptake is dictated by the fatty acid binding capacity of media components such as albumin. Both glycerol and fatty acid release into media can be quantified by colorimetric assays to determine the lipolytic rate. By measuring these factors at multiple time points, one can determine the linear rate of lipolysis with high confidence. Here, we provide a detailed protocol for the measurement of lipolysis in in vitro differentiated adipocytes and ex vivo adipose tissue from mice. This protocol may also be optimized for other preadipocyte cell lines or adipose tissue from other organisms; considerations and optimization parameters are discussed. This protocol is designed to be useful in determining and comparing the rate of adipocyte lipolysis between mouse models and treatments.
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Affiliation(s)
- Pania E Bridge-Comer
- Weill Center for Metabolic Health, Department of Medicine, Weill Cornell Medicine
| | - Shannon M Reilly
- Weill Center for Metabolic Health, Department of Medicine, Weill Cornell Medicine;
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3
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Luan D, Dadpey B, Zaid J, Bridge-Comer PE, DeLuca JH, Xia W, Castle J, Reilly SM. Adipocyte-Secreted IL-6 Sensitizes Macrophages to IL-4 Signaling. Diabetes 2023; 72:367-374. [PMID: 36449000 PMCID: PMC9935493 DOI: 10.2337/db22-0444] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
Complex bidirectional cross talk between adipocytes and adipose tissue immune cells plays an important role in regulating adipose function, inflammation, and insulin responsiveness. Adipocytes secrete the pleiotropic cytokine IL-6 in response to both inflammatory and catabolic stimuli. Previous studies have suggested that IL-6 secretion from adipocytes in obesity may promote adipose tissue inflammation. Here, we investigated catabolic stimulation of adipocyte IL-6 secretion and its impact on adipose tissue immune cells. In obesity, catecholamine resistance reduces cAMP-driven adipocyte IL-6 secretion in response to catabolic signals. By restoring adipocyte catecholamine sensitivity in obese adipocytes, amlexanox stimulates adipocyte-specific IL-6 secretion. We report that in this context, adipocyte-secreted IL-6 activates local macrophage STAT3 to promote Il4ra expression, thereby sensitizing them to IL-4 signaling and promoting an anti-inflammatory gene expression pattern. Supporting a paracrine adipocyte to macrophage mechanism, these effects could be recapitulated using adipocyte conditioned media to pretreat bone marrow-derived macrophages prior to polarization with IL-4. The effects of IL-6 signaling in adipose tissue are complex and context specific. These results suggest that cAMP-driven IL-6 secretion from adipocytes sensitizes adipose tissue macrophages to IL-4 signaling.
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Affiliation(s)
- Danny Luan
- Division of Nephrology and Hypertension, Department of Medicine/NewYork-Presbyterian Hospital, Weill Cornell Medicine, New York, NY
- Life Sciences Institute, University of Michigan, Ann Arbor, MI
| | - Benyamin Dadpey
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Jessica Zaid
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Pania E. Bridge-Comer
- Weill Center for Metabolic Health, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Julia H. DeLuca
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wenmin Xia
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Joshua Castle
- Life Sciences Institute, University of Michigan, Ann Arbor, MI
| | - Shannon M. Reilly
- Life Sciences Institute, University of Michigan, Ann Arbor, MI
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA
- Weill Center for Metabolic Health, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Weill Cornell Medicine, New York, NY
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4
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DeLuca JH, Reilly SM. Culture and Differentiation of Primary Preadipocytes from Mouse Subcutaneous White Adipose Tissue. Methods Mol Biol 2023; 2662:11-24. [PMID: 37076667 PMCID: PMC10583291 DOI: 10.1007/978-1-0716-3167-6_2] [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] [Indexed: 04/21/2023]
Abstract
Adipocytes are terminally differentiated cells derived from fibroblastic preadipocyte precursors. Here, we describe a method for the isolation and proliferation of preadipocytes from murine subcutaneous white adipose tissue, followed by differentiation in culture to mature adipocytes; we refer to these cells as primary preadipocytes differentiated in vitro (PPDIVs). Compared to adipogenic cell lines, PPDIV metabolism and adipokine secretion more closely resemble in vivo adipocyte biology. While primary mature adipocytes have the greatest in vivo relevance, their fragility and buoyancy make them unsuitable for many cell culture-based methods. PPDIVs can also take advantage of transgenic and knockout mouse models to produce genetically modified adipocytes. Thus, PPDIVs are a valuable resource for studying adipocyte biology in cell culture.
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Affiliation(s)
- Julia H DeLuca
- Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Shannon M Reilly
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Weill Center for Metabolic Health, Weill Cornell Medicine, New York, NY, USA.
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5
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Guma M, Dadpey B, Coras R, Mikuls TR, Hamilton B, Quehenberger O, Thorisdottir H, Bittleman D, Lauro K, Reilly SM, Liu-Bryan R, Terkeltaub R. Xanthine oxidase inhibitor urate-lowering therapy titration to target decreases serum free fatty acids in gout and suppresses lipolysis by adipocytes. Arthritis Res Ther 2022; 24:175. [PMID: 35879786 PMCID: PMC9310412 DOI: 10.1186/s13075-022-02852-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 06/26/2022] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE Linked metabolic and cardiovascular comorbidities are prevalent in hyperuricemia and gout. For mechanistic insight into impact on inflammatory processes and cardiometabolic risk factors of xanthine oxidase inhibitor urate-lowering therapy (ULT) titration to target, we performed a prospective study of gout serum metabolomes from a ULT trial. METHODS Sera of gout patients meeting the 2015 ACR/EULAR gout classification criteria (n = 20) and with hyperuricemia were studied at time zero and weeks 12 and 24 of febuxostat or allopurinol dose titration ULT. Ultrahigh performance liquid chromatography-tandem mass spectroscopy acquired the serum spectra. Data were assessed using the Metabolon and Metaboloanalyst software. Lipolysis validation assays were done in febuxostat and/or colchicine-treated 3T3-L1 differentiated adipocytes. RESULTS Serum urate decreased from time zero (8.21 ±1.139 SD) at weeks 12 (5.965 ± 1.734 SD) and 24 (5.655 ±1.763 SD). Top metabolites generated by changes in nucleotide and certain amino acid metabolism and polyamine pathways were enriched at 12 and 24 weeks ULT, respectively. Decreases in multiple fatty acid metabolites were observed at 24 weeks, linked with obesity. In cultured adipocytes, febuxostat significantly decreased while colchicine increased the lipolytic response to β-adrenergic-agonism or TNF. CONCLUSION Metabolomic profiles linked xanthine oxidase inhibitor-based ULT titration to target with reduced serum free fatty acids. In vitro validation studies revealed that febuxostat, but not colchicine, reduced lipolysis in cultured adipocytes. Since soluble urate, xanthine oxidase inhibitor treatment, and free fatty acids modulate inflammation, our findings suggest that by suppressing lipolysis, ULT could regulate inflammation in gout and comorbid metabolic and cardiovascular disease.
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Affiliation(s)
- Monica Guma
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA ,grid.7080.f0000 0001 2296 0625Department of Medicine, Autonomous University of Barcelona, Plaça Cívica, 08193 Bellaterra, Barcelona Spain
| | - Benyamin Dadpey
- grid.217200.60000 0004 0627 2787Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093 USA
| | - Roxana Coras
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA ,grid.7080.f0000 0001 2296 0625Department of Medicine, Autonomous University of Barcelona, Plaça Cívica, 08193 Bellaterra, Barcelona Spain
| | - Ted R. Mikuls
- grid.266813.80000 0001 0666 4105University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - Bartlett Hamilton
- grid.266813.80000 0001 0666 4105University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - Oswald Quehenberger
- grid.217200.60000 0004 0627 2787Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093 USA
| | - Hilda Thorisdottir
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - David Bittleman
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - Kimberly Lauro
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - Shannon M. Reilly
- grid.217200.60000 0004 0627 2787Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093 USA ,grid.5386.8000000041936877XWeill Center for Metabolic Health, Department of Medicine, Weill Cornell Medicine, New York, NY 10021 USA
| | - Ru Liu-Bryan
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - Robert Terkeltaub
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
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6
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Yong J, Parekh VS, Reilly SM, Nayak J, Chen Z, Lebeaupin C, Jang I, Zhang J, Prakash TP, Sun H, Murray S, Guo S, Ayala JE, Satin LS, Saltiel AR, Kaufman RJ. Chop/ Ddit3 depletion in β cells alleviates ER stress and corrects hepatic steatosis in mice. Sci Transl Med 2021; 13:13/604/eaba9796. [PMID: 34321322 DOI: 10.1126/scitranslmed.aba9796] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/07/2021] [Accepted: 06/23/2021] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes (T2D) is a metabolic disorder characterized by hyperglycemia, hyperinsulinemia, and insulin resistance (IR). During the early phase of T2D, insulin synthesis and secretion by pancreatic β cells is enhanced, which can lead to proinsulin misfolding that aggravates endoplasmic reticulum (ER) protein homeostasis in β cells. Moreover, increased circulating insulin may contribute to fatty liver disease. Medical interventions aimed at alleviating ER stress in β cells while maintaining optimal insulin secretion are therefore an attractive therapeutic strategy for T2D. Previously, we demonstrated that germline Chop gene deletion preserved β cells in high-fat diet (HFD)-fed mice and in leptin receptor-deficient db/db mice. In the current study, we further investigated whether targeting Chop/Ddit3 specifically in murine β cells conferred therapeutic benefits. First, we showed that Chop deletion in β cells alleviated β cell ER stress and delayed glucose-stimulated insulin secretion (GSIS) in HFD-fed mice. Second, β cell-specific Chop deletion prevented liver steatosis and hepatomegaly in aged HFD-fed mice without affecting basal glucose homeostasis. Third, we provide mechanistic evidence that Chop depletion reduces ER Ca2+ buffering capacity and modulates glucose-induced islet Ca2+ oscillations, leading to transcriptional changes of ER chaperone profile ("ER remodeling"). Last, we demonstrated that a GLP1-conjugated Chop antisense oligonucleotide strategy recapitulated the reduction in liver triglycerides and pancreatic insulin content. In summary, our results demonstrate that Chop depletion in β cells provides a therapeutic strategy to alleviate dysregulated insulin secretion and consequent fatty liver disease in T2D.
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Affiliation(s)
- Jing Yong
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA. .,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Vishal S Parekh
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.,Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Shannon M Reilly
- Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.,Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jonamani Nayak
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Zhouji Chen
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Cynthia Lebeaupin
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.,Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Insook Jang
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Jiangwei Zhang
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Thazha P Prakash
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Hong Sun
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Sue Murray
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Shuling Guo
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Julio E Ayala
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Leslie S Satin
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.,Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Alan R Saltiel
- Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.,Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
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7
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Abu-Odeh M, Zhang Y, Reilly SM, Ebadat N, Keinan O, Valentine JM, Hafezi-Bakhtiari M, Ashayer H, Mamoun L, Zhou X, Zhang J, Yu RT, Dai Y, Liddle C, Downes M, Evans RM, Kliewer SA, Mangelsdorf DJ, Saltiel AR. FGF21 promotes thermogenic gene expression as an autocrine factor in adipocytes. Cell Rep 2021; 35:109331. [PMID: 34192547 PMCID: PMC8293281 DOI: 10.1016/j.celrep.2021.109331] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/04/2021] [Accepted: 06/09/2021] [Indexed: 12/14/2022] Open
Abstract
The contribution of adipose-derived FGF21 to energy homeostasis is unclear. Here we show that browning of inguinal white adipose tissue (iWAT) by β-adrenergic agonists requires autocrine FGF21 signaling. Adipose-specific deletion of the FGF21 co-receptor β-Klotho renders mice unresponsive to β-adrenergic stimulation. In contrast, mice with liver-specific ablation of FGF21, which eliminates circulating FGF21, remain sensitive to β-adrenergic browning of iWAT. Concordantly, transgenic overexpression of FGF21 in adipocytes promotes browning in a β-Klotho-dependent manner without increasing circulating FGF21. Mechanistically, we show that β-adrenergic stimulation of thermogenic gene expression requires FGF21 in adipocytes to promote phosphorylation of phospholipase C-γ and mobilization of intracellular calcium. Moreover, we find that the β-adrenergic-dependent increase in circulating FGF21 occurs through an indirect mechanism in which fatty acids released by adipocyte lipolysis subsequently activate hepatic PPARα to increase FGF21 expression. These studies identify FGF21 as a cell-autonomous autocrine regulator of adipose tissue function. Abu-Odeh et al. demonstrate that autocrine action of FGF21 is a required second signal promoting thermogenic gene expression in catecholamine-stimulated adipocytes. Hepatic FGF21 secretions, secondary to catecholamine-stimulated adipocyte lipolysis, are dispensable for adipose tissue browning. These studies identify FGF21 as a cell-autonomous autocrine regulator of adipose tissue function.
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Affiliation(s)
- Mohammad Abu-Odeh
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Yuan Zhang
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shannon M Reilly
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Nima Ebadat
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Omer Keinan
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Joseph M Valentine
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | | | - Hadeel Ashayer
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Lana Mamoun
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Xin Zhou
- Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA; Moores Cancer Center at UC San Diego Health, La Jolla, CA 92037, USA; Department of Bioengineering, University of California San Diego, San Diego, CA 92093; Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093, USA
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Yang Dai
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Christopher Liddle
- Storr Liver Centre, Westmead Institute for Medical Research and Sydney Medical School, University of Sydney, Westmead, NSW, Australia
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Steven A Kliewer
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - David J Mangelsdorf
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute
| | - Alan R Saltiel
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA; Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA.
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8
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Reilly SM, Abu-Odeh M, Ameka M, DeLuca JH, Naber MC, Dadpey B, Ebadat N, Gomez AV, Peng X, Poirier B, Walk E, Potthoff MJ, Saltiel AR. FGF21 is required for the metabolic benefits of IKKε/TBK1 inhibition. J Clin Invest 2021; 131:145546. [PMID: 33822771 DOI: 10.1172/jci145546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/23/2021] [Indexed: 12/15/2022] Open
Abstract
The protein kinases IKKε and TBK1 are activated in liver and fat in mouse models of obesity. We have previously demonstrated that treatment with the IKKε/TBK1 inhibitor amlexanox produces weight loss and relieves insulin resistance in obese animals and patients. While amlexanox treatment caused a transient reduction in food intake, long-term weight loss was attributable to increased energy expenditure via FGF21-dependent beiging of white adipose tissue (WAT). Amlexanox increased FGF21 synthesis and secretion in several tissues. Interestingly, although hepatic secretion determined circulating levels, it was dispensable for regulating energy expenditure. In contrast, adipocyte-secreted FGF21 may have acted as an autocrine factor that led to adipose tissue browning and weight loss in obese mice. Moreover, increased energy expenditure was an important determinant of improved insulin sensitivity by amlexanox. Conversely, the immediate reductions in fasting blood glucose observed with acute amlexanox treatment were mediated by the suppression of hepatic glucose production via activation of STAT3 by adipocyte-secreted IL-6. These findings demonstrate that amlexanox improved metabolic health via FGF21 action in adipocytes to increase energy expenditure via WAT beiging and that adipocyte-derived IL-6 has an endocrine role in decreasing gluconeogenesis via hepatic STAT3 activation, thereby producing a coordinated improvement in metabolic parameters.
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Affiliation(s)
- Shannon M Reilly
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Mohammad Abu-Odeh
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA
| | - Magdalene Ameka
- Department of Neuroscience and Pharmacology and.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Julia H DeLuca
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA
| | - Meghan C Naber
- Department of Neuroscience and Pharmacology and.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Benyamin Dadpey
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA
| | - Nima Ebadat
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA
| | - Andrew V Gomez
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA
| | - Xiaoling Peng
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - BreAnne Poirier
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Elyse Walk
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA
| | - Matthew J Potthoff
- Department of Neuroscience and Pharmacology and.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Alan R Saltiel
- Division of Metabolism and Endocrinology, Department of Medicine, UCSD, La Jolla, California, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
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9
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Huh JY, Reilly SM, Abu-Odeh M, Murphy AN, Mahata SK, Zhang J, Cho Y, Seo JB, Hung CW, Green CR, Metallo CM, Saltiel AR. TANK-Binding Kinase 1 Regulates the Localization of Acyl-CoA Synthetase ACSL1 to Control Hepatic Fatty Acid Oxidation. Cell Metab 2020; 32:1012-1027.e7. [PMID: 33152322 PMCID: PMC7710607 DOI: 10.1016/j.cmet.2020.10.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/20/2020] [Accepted: 10/12/2020] [Indexed: 12/12/2022]
Abstract
Hepatic TANK (TRAF family member associated NFκB activator)-binding kinase 1 (TBK1) activity is increased during obesity, and administration of a TBK1 inhibitor reduces fatty liver. Surprisingly, liver-specific TBK1 knockout in mice produces fatty liver by reducing fatty acid oxidation. TBK1 functions as a scaffolding protein to localize acyl-CoA synthetase long-chain family member 1 (ACSL1) to mitochondria, which generates acyl-CoAs that are channeled for β-oxidation. TBK1 is induced during fasting and maintained in the unphosphorylated, inactive state, enabling its high affinity binding to ACSL1 in mitochondria. In TBK1-deficient liver, ACSL1 is shifted to the endoplasmic reticulum to promote fatty acid re-esterification in lieu of oxidation in response to fasting, which accelerates hepatic lipid accumulation. The impaired fatty acid oxidation in TBK1-deficient hepatocytes is rescued by the expression of kinase-dead TBK1. Thus, TBK1 operates as a rheostat to direct the fate of fatty acids in hepatocytes, supporting oxidation when inactive during fasting and promoting re-esterification when activated during obesity.
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Affiliation(s)
- Jin Young Huh
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Shannon M Reilly
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Mohammad Abu-Odeh
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Anne N Murphy
- Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA
| | - Sushil K Mahata
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA; VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Jinyu Zhang
- Division of Biological Sciences, University of California, San Diego, San Diego, CA 92093, USA
| | - Yoori Cho
- Division of Biological Sciences, University of California, San Diego, San Diego, CA 92093, USA
| | - Jong Bae Seo
- Department of Biosciences, Mokpo National University, Jeonnam 58554, Republic of Korea
| | - Chao-Wei Hung
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Courtney R Green
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA
| | - Christian M Metallo
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA
| | - Alan R Saltiel
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA; Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA.
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10
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Reilly SM, Hung CW, Ahmadian M, Zhao P, Keinan O, Gomez AV, DeLuca JH, Dadpey B, Lu D, Zaid J, Poirier B, Peng X, Yu RT, Downes M, Liddle C, Evans RM, Murphy AN, Saltiel AR. Catecholamines suppress fatty acid re-esterification and increase oxidation in white adipocytes via STAT3. Nat Metab 2020; 2:620-634. [PMID: 32694788 PMCID: PMC7384260 DOI: 10.1038/s42255-020-0217-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 04/30/2020] [Indexed: 12/12/2022]
Abstract
Catecholamines stimulate the mobilization of stored triglycerides in adipocytes to provide fatty acids (FAs) for other tissues. However, a large proportion is taken back up and either oxidized or re-esterified. What controls the disposition of these FAs in adipocytes remains unknown. Here, we report that catecholamines redirect FAs for oxidation through the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Adipocyte STAT3 is phosphorylated upon activation of β-adrenergic receptors, and in turn suppresses FA re-esterification to promote FA oxidation. Adipocyte-specific Stat3 KO mice exhibit normal rates of lipolysis, but exhibit defective lipolysis-driven oxidative metabolism, resulting in reduced energy expenditure and increased adiposity when they are on a high-fat diet. This previously unappreciated, non-genomic role of STAT3 explains how sympathetic activation can increase both lipolysis and FA oxidation in adipocytes, revealing a new regulatory axis in metabolism.
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Affiliation(s)
- Shannon M Reilly
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
| | - Chao-Wei Hung
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Maryam Ahmadian
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA, USA
| | - Peng Zhao
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Omer Keinan
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Andrew V Gomez
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Julia H DeLuca
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Benyamin Dadpey
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Donald Lu
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jessica Zaid
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - BreAnne Poirier
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaoling Peng
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA, USA
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA, USA
| | - Christopher Liddle
- Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA, USA
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA, USA
| | - Anne N Murphy
- Department of Pharmacology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Cytokinetics, South San Francisco, CA, USA
| | - Alan R Saltiel
- Division of Metabolism and Endocrinology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
- Department of Pharmacology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
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11
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Wang L, Mazagova M, Pan C, Yang S, Brandl K, Liu J, Reilly SM, Wang Y, Miao Z, Loomba R, Lu N, Guo Q, Liu J, Yu RT, Downes M, Evans RM, Brenner DA, Saltiel AR, Beutler B, Schnabl B. YIPF6 controls sorting of FGF21 into COPII vesicles and promotes obesity. Proc Natl Acad Sci U S A 2019; 116:15184-15193. [PMID: 31289229 PMCID: PMC6660779 DOI: 10.1073/pnas.1904360116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [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] [Indexed: 12/12/2022] Open
Abstract
Fibroblast growth factor 21 (FGF21) is an endocrine hormone that regulates glucose, lipid, and energy homeostasis. While gene expression of FGF21 is regulated by the nuclear hormone receptor peroxisome proliferator-activated receptor alpha in the fasted state, little is known about the regulation of trafficking and secretion of FGF21. We show that mice with a mutation in the Yip1 domain family, member 6 gene (Klein-Zschocher [KLZ]; Yipf6KLZ/Y ) on a high-fat diet (HFD) have higher plasma levels of FGF21 than mice that do not carry this mutation (controls) and hepatocytes from Yipf6KLZ/Y mice secrete more FGF21 than hepatocytes from wild-type mice. Consequently, Yipf6KLZ/Y mice are resistant to HFD-induced features of the metabolic syndrome and have increased lipolysis, energy expenditure, and thermogenesis, with an increase in core body temperature. Yipf6KLZ/Y mice with hepatocyte-specific deletion of FGF21 were no longer protected from diet-induced obesity. We show that YIPF6 binds FGF21 in the endoplasmic reticulum to limit its secretion and specifies packaging of FGF21 into coat protein complex II (COPII) vesicles during development of obesity in mice. Levels of YIPF6 protein in human liver correlate with hepatic steatosis and correlate inversely with levels of FGF21 in serum from patients with nonalcoholic fatty liver disease (NAFLD). YIPF6 is therefore a newly identified regulator of FGF21 secretion during development of obesity and could be a target for treatment of obesity and NAFLD.
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Affiliation(s)
- Lirui Wang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China;
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
- Department of Medicine, VA San Diego Healthcare System, San Diego, CA 92161
| | - Magdalena Mazagova
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Chuyue Pan
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China
| | - Song Yang
- Department of Hepatology, Beijing Ditan Hospital, Capital Medical University, Chaoyang District, 100015 Beijing, China
| | - Katharina Brandl
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Jun Liu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China
| | - Shannon M Reilly
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Yanhan Wang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Zhaorui Miao
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China
| | - Rohit Loomba
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Na Lu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China
| | - Qinglong Guo
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China
| | - Jihua Liu
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, 211198 Nanjing, Jiang Su, China
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037
| | - David A Brenner
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Alan R Saltiel
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Bruce Beutler
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, La Jolla, CA 92093;
- Department of Medicine, VA San Diego Healthcare System, San Diego, CA 92161
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12
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Beyett TS, Gan X, Reilly SM, Gomez AV, Chang L, Tesmer JJG, Saltiel AR, Showalter HD. Design, synthesis, and biological activity of substituted 2-amino-5-oxo-5H-chromeno[2,3-b]pyridine-3-carboxylic acid derivatives as inhibitors of the inflammatory kinases TBK1 and IKKε for the treatment of obesity. Bioorg Med Chem 2018; 26:5443-5461. [PMID: 30270002 PMCID: PMC6252132 DOI: 10.1016/j.bmc.2018.09.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [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: 08/14/2018] [Revised: 09/12/2018] [Accepted: 09/18/2018] [Indexed: 12/30/2022]
Abstract
The non-canonical IκB kinases TANK-binding kinase 1 (TBK1) and inhibitor of nuclear factor kappa-B kinase ε (IKKε) play a key role in insulin-independent pathways that promote energy storage and block adaptive energy expenditure during obesity. Utilizing docking calculations and the x-ray structure of TBK1 bound to amlexanox, an inhibitor of these kinases with modest potency, a series of analogues was synthesized to develop a structure activity relationship (SAR) around the A- and C-rings of the core scaffold. A strategy was developed wherein R7 and R8 A-ring substituents were incorporated late in the synthetic sequence by utilizing palladium-catalyzed cross-coupling reactions on appropriate bromo precursors. Analogues display IC50 values as low as 210 nM and reveal A-ring substituents that enhance selectivity toward either kinase. In cell assays, selected analogues display enhanced phosphorylation of p38 or TBK1 and elicited IL-6 secretion in 3T3-L1 adipocytes better than amlexanox. An analogue bearing a R7 cyclohexyl modification demonstrated robust IL-6 production in 3T3-L1 cells as well as a phosphorylation marker of efficacy and was tested in obese mice where it promoted serum IL-6 response, weight loss, and insulin sensitizing effects comparable to amlexanox. These studies provide impetus to expand the SAR around the amlexanox core toward uncovering analogues with development potential.
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Affiliation(s)
- Tyler S Beyett
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, United States; Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Xinmin Gan
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, United States
| | - Shannon M Reilly
- Departments of Medicine and Pharmacology, Institute for Diabetes and Metabolic Health, University of California, San Diego, La Jolla, CA 92093-0912, United States
| | - Andrew V Gomez
- Departments of Medicine and Pharmacology, Institute for Diabetes and Metabolic Health, University of California, San Diego, La Jolla, CA 92093-0912, United States
| | - Louise Chang
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - John J G Tesmer
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Alan R Saltiel
- Departments of Medicine and Pharmacology, Institute for Diabetes and Metabolic Health, University of California, San Diego, La Jolla, CA 92093-0912, United States
| | - Hollis D Showalter
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, United States.
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13
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Beyett TS, Gan X, Reilly SM, Chang L, Gomez AV, Saltiel AR, Showalter HD, Tesmer JJG. Carboxylic Acid Derivatives of Amlexanox Display Enhanced Potency toward TBK1 and IKK ε and Reveal Mechanisms for Selective Inhibition. Mol Pharmacol 2018; 94:1210-1219. [PMID: 30082428 DOI: 10.1124/mol.118.112185] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 08/01/2018] [Indexed: 12/21/2022] Open
Abstract
Chronic low-grade inflammation is a hallmark of obesity, which is a risk factor for the development of type 2 diabetes. The drug amlexanox inhibits IκB kinase ε (IKKε) and TANK binding kinase 1 (TBK1) to promote energy expenditure and improve insulin sensitivity. Clinical studies have demonstrated efficacy in a subset of diabetic patients with underlying adipose tissue inflammation, albeit with moderate potency, necessitating the need for improved analogs. Herein we report crystal structures of TBK1 in complex with amlexanox and a series of analogs that modify its carboxylic acid moiety. Removal of the carboxylic acid or mutation of the adjacent Thr156 residue significantly reduces potency toward TBK1, whereas conversion to a short amide or ester nearly abolishes the inhibitory effects. IKKε is less affected by these modifications, possibly due to variation in its hinge that allows for increased conformational plasticity. Installation of a tetrazole carboxylic acid bioisostere improved potency to 200 and 400 nM toward IKKε and TBK1, respectively. Despite improvements in the in vitro potency, no analog produced a greater response in adipocytes than amlexanox, perhaps because of altered absorption and distribution. The structure-activity relationships and cocrystal structures described herein will aid in future structure-guided inhibitor development using the amlexanox pharmacophore for the treatment of obesity and type 2 diabetes.
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Affiliation(s)
- Tyler S Beyett
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - Xinmin Gan
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - Shannon M Reilly
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - Louise Chang
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - Andrew V Gomez
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - Alan R Saltiel
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - Hollis D Showalter
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
| | - John J G Tesmer
- Program in Chemical Biology (T.S.B.), Life Sciences Institute (T.S.B., L.C., J.J.G.T.), Departments of Medicinal Chemistry (X.G., H.D.S., J.J.G.T.), Pharmacology (J.J.G.T.), Biological Chemistry (J.J.G.T.), and Vahlteich Medicinal Chemistry Core, College of Pharmacy (X.G., H.D.S.), University of Michigan, Ann Arbor, Michigan; Institute for Diabetes and Metabolic Health (S.M.R., A.V.G., A.R.S.), Departments of Medicine (S.M.R., A.R.S.) and Pharmacology (A.V.G., A.R.S.), University of California, San Diego, La Jolla, California; and Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (J.J.G.T.)
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14
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Skorobogatko Y, Dragan M, Cordon C, Reilly SM, Hung CW, Xia W, Zhao P, Wallace M, Lackey DE, Chen XW, Osborn O, Bogner-Strauss JG, Theodorescu D, Metallo CM, Olefsky JM, Saltiel AR. RalA controls glucose homeostasis by regulating glucose uptake in brown fat. Proc Natl Acad Sci U S A 2018; 115:7819-7824. [PMID: 29915037 PMCID: PMC6065037 DOI: 10.1073/pnas.1801050115] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [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] [Indexed: 11/18/2022] Open
Abstract
Insulin increases glucose uptake into adipose tissue and muscle by increasing trafficking of the glucose transporter Glut4. In cultured adipocytes, the exocytosis of Glut4 relies on activation of the small G protein RalA by insulin, via inhibition of its GTPase activating complex RalGAP. Here, we evaluate the role of RalA in glucose uptake in vivo with specific chemical inhibitors and by generation of mice with adipocyte-specific knockout of RalGAPB. RalA was profoundly activated in brown adipose tissue after feeding, and its inhibition prevented Glut4 exocytosis. RalGAPB knockout mice with diet-induced obesity were protected from the development of metabolic disease due to increased glucose uptake into brown fat. Thus, RalA plays a crucial role in glucose transport in adipose tissue in vivo.
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Affiliation(s)
- Yuliya Skorobogatko
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Morgan Dragan
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
| | - Claudia Cordon
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Shannon M Reilly
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Chao-Wei Hung
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
| | - Wenmin Xia
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
- Institute of Biochemistry, Graz University of Technology, 8010 Graz, Austria
| | - Peng Zhao
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Martina Wallace
- Jacobs School of Engineering, University of California, San Diego, La Jolla, CA 92093
| | - Denise E Lackey
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
| | - Xiao-Wei Chen
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Olivia Osborn
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
| | | | - Dan Theodorescu
- Department of Surgery, University of Colorado, Aurora, CO 80045
| | - Christian M Metallo
- Jacobs School of Engineering, University of California, San Diego, La Jolla, CA 92093
| | - Jerrold M Olefsky
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093
| | - Alan R Saltiel
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, CA 92093;
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
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15
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Zhao P, Wong KI, Sun X, Reilly SM, Uhm M, Liao Z, Skorobogatko Y, Saltiel AR. TBK1 at the Crossroads of Inflammation and Energy Homeostasis in Adipose Tissue. Cell 2018; 172:731-743.e12. [PMID: 29425491 PMCID: PMC5808582 DOI: 10.1016/j.cell.2018.01.007] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [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: 09/20/2017] [Revised: 11/17/2017] [Accepted: 01/04/2018] [Indexed: 12/22/2022]
Abstract
The noncanonical IKK family member TANK-binding kinase 1 (TBK1) is activated by pro-inflammatory cytokines, but its role in controlling metabolism remains unclear. Here, we report that the kinase uniquely controls energy metabolism. Tbk1 expression is increased in adipocytes of HFD-fed mice. Adipocyte-specific TBK1 knockout (ATKO) attenuates HFD-induced obesity by increasing energy expenditure; further studies show that TBK1 directly inhibits AMPK to repress respiration and increase energy storage. Conversely, activation of AMPK under catabolic conditions can increase TBK1 activity through phosphorylation, mediated by AMPK's downstream target ULK1. Surprisingly, ATKO also exaggerates adipose tissue inflammation and insulin resistance. TBK1 suppresses inflammation by phosphorylating and inducing the degradation of the IKK kinase NIK, thus attenuating NF-κB activity. Moreover, TBK1 mediates the negative impact of AMPK activity on NF-κB activation. These data implicate a unique role for TBK1 in mediating bidirectional crosstalk between energy sensing and inflammatory signaling pathways in both over- and undernutrition.
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Affiliation(s)
- Peng Zhao
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kai In Wong
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA
| | - Xiaoli Sun
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA
| | - Shannon M Reilly
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Maeran Uhm
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zhongji Liao
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA
| | - Yuliya Skorobogatko
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alan R Saltiel
- Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA.
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16
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Abstract
Adipose tissue not only has an important role in the storage of excess nutrients but also senses nutrient status and regulates energy mobilization. An overall positive energy balance is associated with overnutrition and leads to excessive accumulation of fat in adipocytes. These cells respond by initiating an inflammatory response that, although maladaptive in the long run, might initially be a physiological response to the stresses obesity places on adipose tissue. In this Review, we characterize adipose tissue inflammation and review the current knowledge of what triggers obesity-associated inflammation in adipose tissue. We examine the connection between adipose tissue inflammation and the development of insulin resistance and catecholamine resistance and discuss the ensuing state of metabolic inflexibility. Finally, we review the current and potential new anti-inflammatory treatments for obesity-associated metabolic disease.
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Affiliation(s)
- Shannon M Reilly
- Department of Medicine, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Alan R Saltiel
- Department of Medicine, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, California 92093, USA
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17
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Abstract
The current obesity epidemic has focused a great deal of attention on mechanisms controlling energy balance. While diet and nutrient absorption affect energy intake, on the other side of the equation, energy expenditure is determined by basal metabolism, physical activity, and adaptive thermogenesis. Given various challenges in modulating these energy balance mechanisms to combat human obesity, many efforts have concentrated on how it might be possible to achieve weight loss through increased thermogenesis. In this issue of Cell, Kazak et al. describe a previously unrecognized molecular pathway for thermogenesis in fat cells.
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Affiliation(s)
- Shannon M Reilly
- Department of Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Alan R Saltiel
- Department of Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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18
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Fang S, Suh JM, Reilly SM, Yu E, Osborn O, Lackey D, Yoshihara E, Perino A, Jacinto S, Lukasheva Y, Atkins AR, Khvat A, Schnabl B, Yu RT, Brenner DA, Coulter S, Liddle C, Schoonjans K, Olefsky JM, Saltiel AR, Downes M, Evans RM. Intestinal FXR agonism promotes adipose tissue browning and reduces obesity and insulin resistance. Nat Med 2015; 21:159-65. [PMID: 25559344 DOI: 10.1038/nm.3760] [Citation(s) in RCA: 516] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/21/2014] [Indexed: 12/14/2022]
Abstract
The systemic expression of the bile acid (BA) sensor farnesoid X receptor (FXR) has led to promising new therapies targeting cholesterol metabolism, triglyceride production, hepatic steatosis and biliary cholestasis. In contrast to systemic therapy, bile acid release during a meal selectively activates intestinal FXR. By mimicking this tissue-selective effect, the gut-restricted FXR agonist fexaramine (Fex) robustly induces enteric fibroblast growth factor 15 (FGF15), leading to alterations in BA composition, but does so without activating FXR target genes in the liver. However, unlike systemic agonism, we find that Fex reduces diet-induced weight gain, body-wide inflammation and hepatic glucose production, while enhancing thermogenesis and browning of white adipose tissue (WAT). These pronounced metabolic improvements suggest tissue-restricted FXR activation as a new approach in the treatment of obesity and metabolic syndrome.
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Affiliation(s)
- Sungsoon Fang
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Jae Myoung Suh
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Shannon M Reilly
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Elizabeth Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Olivia Osborn
- Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Denise Lackey
- Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Eiji Yoshihara
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Alessia Perino
- Metabolic Signaling, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Federale de Lausanne, Switzerland
| | - Sandra Jacinto
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Yelizaveta Lukasheva
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Annette R Atkins
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | | | - Bernd Schnabl
- Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - David A Brenner
- Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Sally Coulter
- Storr Liver Unit, Westmead Millennium Institute, Sydney Medical School, University of Sydney, Australia
| | - Christopher Liddle
- Storr Liver Unit, Westmead Millennium Institute, Sydney Medical School, University of Sydney, Australia
| | - Kristina Schoonjans
- Metabolic Signaling, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Federale de Lausanne, Switzerland
| | - Jerrold M Olefsky
- Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Alan R Saltiel
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Ronald M Evans
- 1] Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA. [2] Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, California, USA
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19
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Affiliation(s)
- Shannon M Reilly
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Alan R Saltiel
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
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20
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Affiliation(s)
- Shannon M Reilly
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Alan R Saltiel
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA
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21
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Mowers J, Uhm M, Reilly SM, Simon J, Leto D, Chiang SH, Chang L, Saltiel AR. Inflammation produces catecholamine resistance in obesity via activation of PDE3B by the protein kinases IKKε and TBK1. eLife 2013; 2:e01119. [PMID: 24368730 PMCID: PMC3869376 DOI: 10.7554/elife.01119] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Obesity produces a chronic inflammatory state involving the NFκB pathway, resulting in persistent elevation of the noncanonical IκB kinases IKKε and TBK1. In this study, we report that these kinases attenuate β-adrenergic signaling in white adipose tissue. Treatment of 3T3-L1 adipocytes with specific inhibitors of these kinases restored β-adrenergic signaling and lipolysis attenuated by TNFα and Poly (I:C). Conversely, overexpression of the kinases reduced induction of Ucp1, lipolysis, cAMP levels, and phosphorylation of hormone sensitive lipase in response to isoproterenol or forskolin. Noncanonical IKKs reduce catecholamine sensitivity by phosphorylating and activating the major adipocyte phosphodiesterase PDE3B. In vivo inhibition of these kinases by treatment of obese mice with the drug amlexanox reversed obesity-induced catecholamine resistance, and restored PKA signaling in response to injection of a β-3 adrenergic agonist. These studies suggest that by reducing production of cAMP in adipocytes, IKKε and TBK1 may contribute to the repression of energy expenditure during obesity. DOI:http://dx.doi.org/10.7554/eLife.01119.001 Obesity is a complex metabolic disorder that is caused by increased food intake and decreased expenditure of energy. Obesity also increases the risk of developing type 2 diabetes, heart disease, stroke, arthritis, and certain cancers. There is considerable evidence to suggest that adipose tissue becomes less sensitive to catecholamines such as adrenaline in states of obesity, and that this reduced sensitivity in turn reduces energy expenditure. However, the details of this process are not fully understood. It is well established that obesity generates a state of chronic, low-grade inflammation in liver and adipose tissue, accompanied by the secretion of signaling proteins that prevent fat cells from responding to insulin, which leads to type 2 diabetes. Activation of the NFκB pathway is thought to have a central role in causing this inflammation. Now Mowers et al. have investigated whether inflammation caused by activation of the NFκB pathway also has a role in producing catecholamine resistance in fat cells. Obesity-dependent activation of the NFκB pathway increases the levels of a pair of enzymes, IKKε and TBK1. Mowers et al. found that elevated levels of these two enzymes reduced the ability of certain receptors (called β-adrenergic receptors) in the fat cells of obese mice to respond to catecholamines. High levels of the two enzymes also resulted in lower levels of a second messenger molecule called cAMP, which increases energy expenditure by elevating fat burning. However, treating the fat cells with drugs that interfere with the two enzymes restored sensitivity to catecholamine, allowing the fat cells to burn energy. Mowers et al. also treated obese mice with amlexanox, a drug that inhibits these enzymes, and found that this treatment made the mice sensitive to a synthetic catecholamine that triggered the release of energy from fat. Mowers et al. suggest, therefore, that IKKε and TBK1 respond to inflammation in the body by reducing catecholamine signaling, thus preventing energy expenditure. Drugs targeting these enzymes may be useful for treating conditions like obesity or type 2 diabetes. DOI:http://dx.doi.org/10.7554/eLife.01119.002
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Affiliation(s)
- Jonathan Mowers
- Life Sciences Institute, University of Michigan, Ann Arbor, United States
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22
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Liu S, Reilly SM, Lee CH. Transcriptional repression of mitochondrial function in aging: a novel role for the silencing mediator of retinoid and thyroid hormone receptors co-repressor. Antioxid Redox Signal 2013; 19:299-309. [PMID: 22703297 PMCID: PMC3691917 DOI: 10.1089/ars.2011.4413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE Mitochondrial function plays an important role in metabolic homeostasis and has been implicated in aging. Although there is still ongoing debate regarding whether mitochondrion-derived oxidative stress is causative to the aging process, interventions that increase oxidative metabolism and antioxidant pathways in animal models protect against age-related deterioration, such as metabolic diseases and neurodegenerative disorders. RECENT ADVANCES One of the well-characterized transcriptional networks known to improve mitochondrial activity is mediated by transcriptional co-activator peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α), which is activated by AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), two of the major energy sensing molecules that are responsible for the longevity effect of caloric restriction in certain model systems. PGC-1α co-activates several nuclear receptors, notably members of the peroxisome proliferator-activated receptor (PPAR) family, which are key regulators of mitochondrial oxidative metabolism. CRITICAL ISSUES Although the AMPK/SIRT1-PGC-1α-PPAR axis plays a prominent role in activating mitochondrial functions, their activities are down-regulated in older animals, suggesting the involvement of dominant negative regulatory mechanisms in the process of aging. FUTURE DIRECTIONS In this review, we will discuss the role of a transcriptional co-repressor, silencing mediator of retinoid and thyroid hormone receptors (SMRT), whose activity and expression are increased with age, as a negative regulator of mitochondrial function that promotes aging and age-related metabolic diseases.
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Affiliation(s)
- Sihao Liu
- Division of Biological Sciences, Department of Genetics and Complex Diseases, Harvard University School of Public Health, Boston, Massachusetts, USA
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23
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Jorgensen ME, Reilly SM. Phylogenetic patterns of skeletal morphometrics and pelvic traits in relation to locomotor mode in frogs. J Evol Biol 2013; 26:929-43. [PMID: 23510149 DOI: 10.1111/jeb.12128] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/18/2012] [Accepted: 01/02/2013] [Indexed: 11/28/2022]
Abstract
Frogs are one of the most speciose groups of vertebrate tetrapods (> 6200sp) with a diverse array of locomotor behaviours. Despite the impressive diversity in frog locomotor behaviours, there remains a paucity of information on the relationship between skeletal variation and locomotor mode in frogs and the evolutionary patterns in which these relationships are framed across the frog phylogeny. Our current understanding of the evolution of frog locomotion shows that hopping transitioned into jumping within the Neobatrachia where a variety of pelvic/hindlimb length patterns and locomotor niches have appeared, but this has yet to be studied over a broad taxonomic sample of frogs. Although limb length remains as the primary predictor of leaping performance, pelvic and sacral morphometrics have not been quantified in relation to limb proportions, body size and locomotor mode and previous studies have not sampled more than 24 families. We present a large-scale phylogenetic comparison of skeletal morphometrics in relation to locomotor mode in 188 genera from 37 families. Osteological variation in limb/pelvic girdle morphometrics and pelvic traits that are posited to be associated with locomotor mode were analysed to identify which aspects of the frog skeleton are the best descriptors of locomotor mode. Our results, contrary to previous work, reveal that the greatest axis of variation in frogs is represented by the shape of the sacrum with two pelvic morphologies evident in qualitative and quantitative ancestral trait reconstructions. Limb morphology was not significantly different across most locomotor modes, but we identified several outliers in hindlimb phylomorphospace. Patterns of sacral evolution together with hindlimb length outliers reveal how the general bauplan of this successful group of vertebrate tetrapods is constrained, has radiated and has converged on certain phenotypes to fill an array of locomotor modes.
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Affiliation(s)
- M E Jorgensen
- Ohio Center for Ecology and Evolutionary Studies, Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
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24
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Reilly SM, Bhargava P, Liu S, Gangl MR, Gorgun C, Nofsinger RR, Evans RM, Qi L, Hu FB, Lee CH. Nuclear receptor corepressor SMRT regulates mitochondrial oxidative metabolism and mediates aging-related metabolic deterioration. Cell Metab 2010; 12:643-53. [PMID: 21109196 PMCID: PMC3033658 DOI: 10.1016/j.cmet.2010.11.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Revised: 07/10/2010] [Accepted: 10/12/2010] [Indexed: 02/01/2023]
Abstract
The transcriptional corepressor SMRT utilizes two major receptor-interacting domains (RID1 and RID2) to mediate nuclear receptor (NR) signaling through epigenetic modification. The physiological significance of such interaction remains unclear. We find SMRT expression and its occupancy on peroxisome proliferator-activated receptor (PPAR) target gene promoters are increased with age in major metabolic tissues. Genetic manipulations to selectively disable RID1 (SMRT(mRID1)) demonstrate that shifting SMRT repression to RID2-associated NRs, notably PPARs, causes premature aging and related metabolic diseases accompanied by reduced mitochondrial function and antioxidant gene expression. SMRT(mRID1) cells exhibit increased susceptibility to oxidative damage, which could be rescued by PPAR activation or antioxidant treatment. In concert, several human Smrt gene polymorphisms are found to nominally associate with type 2 diabetes and adiponectin levels. These data uncover a role for SMRT in mitochondrial oxidative metabolism and the aging process, which may serve as a drug target to improve health span.
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Affiliation(s)
- Shannon M Reilly
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA
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25
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Liu S, Hatano B, Zhao M, Yen CC, Kang K, Reilly SM, Gangl MR, Gorgun C, Balschi JA, Ntambi JM, Lee CH. Role of peroxisome proliferator-activated receptor {delta}/{beta} in hepatic metabolic regulation. J Biol Chem 2010; 286:1237-47. [PMID: 21059653 DOI: 10.1074/jbc.m110.138115] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pharmacological activation of peroxisome proliferator-activated receptor δ/β (PPARδ/β) improves glucose handling and insulin sensitivity. The target tissues of drug actions remain unclear. We demonstrate here that adenovirus-mediated liver-restricted PPARδ activation reduces fasting glucose levels in chow- and high fat-fed mice. This effect is accompanied by hepatic glycogen and lipid deposition as well as up-regulation of glucose utilization and de novo lipogenesis pathways. Promoter analyses indicate that PPARδ regulates hepatic metabolic programs through both direct and indirect transcriptional mechanisms partly mediated by its co-activator, PPARγ co-activator-1β. Assessment of the lipid composition reveals that PPARδ increases the production of monounsaturated fatty acids, which are PPAR activators, and reduces that of saturated FAs. Despite the increased lipid accumulation, adeno-PPARδ-infected livers exhibit less damage and show a reduction in JNK stress signaling, suggesting that PPARδ-regulated lipogenic program may protect against lipotoxicity. The altered substrate utilization by PPARδ also results in a secondary effect on AMP-activated protein kinase activation, which likely contributes to the glucose-lowering activity. Collectively, our data suggest that PPARδ controls hepatic energy substrate homeostasis by coordinated regulation of glucose and fatty acid metabolism, which provide a molecular basis for developing PPARδ agonists to manage hyperglycemia and insulin resistance.
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Affiliation(s)
- Sihao Liu
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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26
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Kang K, Reilly SM, Karabacak V, Gangl MR, Fitzgerald K, Hatano B, Lee CH. Adipocyte-derived Th2 cytokines and myeloid PPARdelta regulate macrophage polarization and insulin sensitivity. Cell Metab 2008; 7:485-95. [PMID: 18522830 PMCID: PMC2586840 DOI: 10.1016/j.cmet.2008.04.002] [Citation(s) in RCA: 546] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 03/05/2008] [Accepted: 04/01/2008] [Indexed: 12/14/2022]
Abstract
The polarization of adipose tissue-resident macrophages toward the alternatively activated, anti-inflammatory M2 phenotype is believed to improve insulin sensitivity. However, the mechanisms controlling tissue macrophage activation remain unclear. Here we show that adipocytes are a source of Th2 cytokines, including IL-13 and to a lesser extent IL-4, which induce macrophage PPARdelta/beta (Ppard/b) expression through a STAT6 binding site on its promoter to activate alternative activation. Coculture studies indicate that Ppard ablation renders macrophages incapable of transition to the M2 phenotype, which in turns causes inflammation and metabolic derangement in adipocytes. Remarkably, a similar regulatory mechanism by hepatocyte-derived Th2 cytokines and macrophage PPARdelta is found to control hepatic lipid metabolism. The physiological relevance of this paracrine pathway is demonstrated in myeloid-specific PPARdelta(-/-) mice, which develop insulin resistance and show increased adipocyte lipolysis and severe hepatosteatosis. These findings provide a molecular basis to modulate tissue-resident macrophage activation and insulin sensitivity.
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Affiliation(s)
- Kihwa Kang
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Shannon M. Reilly
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Volkan Karabacak
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Matthew R. Gangl
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Kelly Fitzgerald
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Ben Hatano
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Chih-Hao Lee
- Department of Genetics and Complex Diseases, Division of Biological Sciences, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
- *Correspondence should be addressed to C.-H. L. e-mail: Chih-Hao Lee, PhD, Department of Genetics and Complex Diseases, Harvard School of Public Health, 665 Huntington Ave, Bldg2, Rm 119, Boston, MA 02115, USA Phone: (617) 432-5778, Fax (617) 432-5236
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27
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Kang K, Karabacak V, Reilly SM, Fitzgerald K, Hatano B, Lee C. PPAR delta regulates adipose tissue macrophage activation and insulin sensitivity. Critical roles of PPAR delta in macrophage‐adipocyte crosstalk and insulin sensitivity. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1018.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kihwa Kang
- Genetics and Complex DiseasesHarvard School of Public HealthBostonMA
| | - Volkan Karabacak
- Genetics and Complex DiseasesHarvard School of Public HealthBostonMA
| | - Shannon M Reilly
- Genetics and Complex DiseasesHarvard School of Public HealthBostonMA
| | - Kelly Fitzgerald
- Genetics and Complex DiseasesHarvard School of Public HealthBostonMA
| | - Ben Hatano
- Genetics and Complex DiseasesHarvard School of Public HealthBostonMA
| | - Chih‐Hao Lee
- Genetics and Complex DiseasesHarvard School of Public HealthBostonMA
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28
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Abstract
PPAR delta is the only member in the PPAR subfamily of nuclear receptors that is not a target of current drugs. Animal studies demonstrate PPAR delta activation exerts many favorable effects, including reducing weight gain, increasing skeletal muscle metabolic rate and endurance, improving insulin sensitivity and cardiovascular function and suppressing atherogenic inflammation. These activities stem largely from the ability of PPAR delta to control energy balance, reduce fat burden and protect against lipotoxicity caused by ectopic lipid deposition. Therefore, PPAR delta represents a novel therapeutic target and the development of PPAR delta gonists/modulators may be useful for treating the whole spectrum of metabolic syndrome.
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Affiliation(s)
- Shannon M Reilly
- Department of Genetics and Complex Diseases, Harvard University School of Public Health, 665 Huntington Avenue, Bldg 2, Room 119, Boston, MA 02115-5818, USA
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Zajicek JP, Sanders HP, Wright DE, Vickery PJ, Ingram WM, Reilly SM, Nunn AJ, Teare LJ, Fox PJ, Thompson AJ. Cannabinoids in multiple sclerosis (CAMS) study: safety and efficacy data for 12 months follow up. J Neurol Neurosurg Psychiatry 2005; 76:1664-9. [PMID: 16291891 PMCID: PMC1739436 DOI: 10.1136/jnnp.2005.070136] [Citation(s) in RCA: 195] [Impact Index Per Article: 10.3] [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] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To test the effectiveness and long term safety of cannabinoids in multiple sclerosis (MS), in a follow up to the main Cannabinoids in Multiple Sclerosis (CAMS) study. METHODS In total, 630 patients with stable MS with muscle spasticity from 33 UK centres were randomised to receive oral Delta(9)-tetrahydrocannabinol (Delta(9)-THC), cannabis extract, or placebo in the main 15 week CAMS study. The primary outcome was change in the Ashworth spasticity scale. Secondary outcomes were the Rivermead Mobility Index, timed 10 metre walk, UK Neurological Disability Score, postal Barthel Index, General Health Questionnaire-30, and a series of nine category rating scales. Following the main study, patients were invited to continue medication, double blinded, for up to 12 months in the follow up study reported here. RESULTS Intention to treat analysis of data from the 80% of patients followed up for 12 months showed evidence of a small treatment effect on muscle spasticity as measured by change in Ashworth score from baseline to 12 months (Delta(9)-THC mean reduction 1.82 (n = 154, 95% confidence interval (CI) 0.53 to 3.12), cannabis extract 0.10 (n = 172, 95% CI -0.99 to 1.19), placebo -0.23 (n = 176, 95% CI -1.41 to 0.94); p = 0.04 unadjusted for ambulatory status and centre, p = 0.01 adjusted). There was suggestive evidence for treatment effects of Delta(9)-THC on some aspects of disability. There were no major safety concerns. Overall, patients felt that these drugs were helpful in treating their disease. CONCLUSIONS These data provide limited evidence for a longer term treatment effect of cannabinoids. A long term placebo controlled study is now needed to establish whether cannabinoids may have a role beyond symptom amelioration in MS.
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Affiliation(s)
- J P Zajicek
- Department of Mathematics and Statistics, University of Plymouth, Room N16, ITTC Building, Tamar Science Park, Plymouth, Devon PL6 8BX, UK.
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Abstract
In this paper we examine the biomechanics of prey processing behavior in the amniotes. Whether amniotes swallow prey items whole or swallow highly processed slurries or boluses of food, they share a common biomechanical system where hard surfaces (teeth or beaks) are brought together on articulated jaws by the actions of adductor muscles to grasp and process food. How have amniotes modified this basic system to increase the chewing efficiency of the system? To address this question we first examine the primitive condition for prey processing representative of many of the past and present predatory amniotes. Because herbivory is expected to be related to improved prey processing in the jaws we review patterns of food processing mechanics in past and present herbivores. Herbivory has appeared numerous times in amniotes and several solutions to the task of chewing plant matter have appeared. Birds have abandoned jaw chewing in favor of a new way to chew--with the gut--so we will detour from the jaws to examine the appearance of gut chewing in the archosaurs. We will then fill in the gaps among amniote taxa with a look at some new data on patterns of prey processing behavior and jaw mechanics in lizards. Finally, we examine evolutionary patterns of amniote feeding mechanism and how correlates of chewing relate to the need to increase the efficiency of prey processing in order to facilitate increased metabolic rate and activity.
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Affiliation(s)
- S M Reilly
- Department of Biological Sciences, Ohio University, 45701, Athens, OH, USA.
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Abstract
Volumetric trabecular bone mineral density of the lumbar spine (vTBMD) and distal radius (rTBMD) were measured in 20 prepubertal white asthmatic children treated with moderate to high doses of inhaled corticosteroids. The median standard deviation score for vTBMD (0.20, -0.56 to 2.09) and rTBMD (-0.04, -0.82 to 1.39) were within the normal range.
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Affiliation(s)
- S M Reilly
- Department of Paediatric Medicine, Saint Mary's Hospital for Women & Children, Hathersage Road, Manchester M13 0JH, UK
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Abstract
Previous kinematic analyses in Sceloporus clarkii have shown that increased speed during trotting is attained by retracting the femur relatively faster (decreasing retraction time relative to stride duration) while all other aspects of axial and limb movements occur simply faster (scaling with stride duration). Thus, most of the limb muscles must be modulated to move the joints absolutely faster, while muscles effecting femoral retraction must be modulated differently to retract the femur relatively faster to increase speed. This prediction was examined by analyzing motor patterns in several key leg muscles in the spiny lizard running over a threefold increase in speed during a trot. The prediction is borne out in the limb muscles where the limb adductor (flexor tibialis), knee extender (femorotibialis), and plantar flexor of the ankle (gastrocnemius) have similar patterns of motor modulation that are different from that of the femoral retractor (caudofemoralis). To modulate a muscle to move simply faster (scaled with speed) the offset of the motor pattern is moved relatively earlier to decrease burst duration, while the intensity of electromyographical activation is ramped up. Increasing the relative speed of action is done by activating the muscle earlier, increasing the duration of the burst, and increasing the relative level of activation. Comparisons to other studies illustrate that the confounding effects that stance and swing duration have on stride duration with speed have important consequences for functional interpretations and that scaling locomotory data to stance duration is a more appropriate and useful convention because it relates information directly to the duty cycle when the propulsive effects of motor modulation are transmitted to the substrate. The iliocostalis in Sceloporus clarkii has a pattern of activity indicating that it functions to rotate the pelvis to aid the contralateral duty cycle. This is strikingly different from the function of the iliocostalis in the monitor lizard. Differences in axial function and differences among lizards in postures of the foot and crus during locomotion indicate that there are different ways that lizards run and that the functional and anatomical diversity of modes of locomotion in lizards is greater than is recognized at present.
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Affiliation(s)
- S M Reilly
- Department of Biological Sciences, Ohio University, Athens, Ohio 45701, USA.
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Rogers HL, Reilly SM. Health problems associated with international business travel. A critical review of the literature. AAOHN J 2000; 48:376-84. [PMID: 11760300] [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] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
1. Few studies examine the travel related health problems of international business travelers (IBTs). Research exists for other travelers, such as tourists, which begins to help clinicians understand the potential health problems faced by IBTs. 2. A review of the literature reveals 36% to 54% of travelers experience physical health problems such as traveler's diarrhea, insomnia, respiratory problems, and skin problems; 6% to 18% report accidents and injuries while abroad. 3. Psychosocial data are equally limited, but support the idea that IBTs may experience stress, anxiety, culture shock, and adjustment problems while overseas. 4. Multiple factors likely contribute to the physical and psychosocial health experiences of IBTs. The historical lack of data for this population of workers combined with the trend towards globalization confirm the need for further study from an occupational health perspective.
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Affiliation(s)
- H L Rogers
- WHI, Workplace Health International Ltd., Calgary, Alberta, Canada
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Elias JA, McBrayer LD, Reilly SM. Prey transport kinematics in Tupinambis teguixin and Varanus exanthematicus: conservation of feeding behavior in ‘chemosensory-tongued’ lizards. J Exp Biol 2000; 203:791-801. [PMID: 10648221 DOI: 10.1242/jeb.203.4.791] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although lizards have been predicted to show extensive intraoral prey-processing behaviors, quantitative analyses of the types of prey-processing behavior they demonstrate and of their kinematics have been limited. The more basal lizard lineages (Iguanians) have undergone some study, but the prey-processing repertoires of crown taxa have not been thoroughly examined and quantitative comparisons of behaviors within or among species have not been made. In this study, the prey transport behavior of the savannah monitor (Varanus exanthematicus) and gold tegu (Tupinambis teguixin) are described. Although these two lineages have independently evolved tongues that are highly specialized for chemoreception, we found that they share the same three distinct types of transport behavior. These behavior patterns are (i) a purely inertial transport, (ii) an inertial transport with use of the tongue, and (iii) a non-inertial lingual transport. The tongue is used extensively in both the inertial and the purely lingual transport behaviors. More than 75 % of all transport behaviors involved tongue movements. These species appear to exhibit a conservation of feeding kinematics compared with patterns known for basal lizards. A hypothesis for the evolution of inertial feeding is proposed.
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Affiliation(s)
- J A Elias
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA
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Abstract
Hindlimb segmental kinematics and stride characteristics are quantified in several quail locomoting on a treadmill over a six-fold increase in speed. These data are used to describe the kinematics of a walking stride and to identify which limb elements are used to change stride features as speed increases. In quail, the femur does not move during locomotion and the tarsometatarsus-phalangeal joint is a major moving joint; thus, quail have lost the most proximal moving joint and added one distally. The tibiotarsus and tarsometatarsus act together as a fixed strut swinging from the knee during stance phase (the ankle angle remains constant at a given speed) and the tarsometatarsus-phalangeal joint appears to have a major role in increasing limb length during the propulsive phase of the stride. Speed is increased with greater knee extension and by lengthening the tibiotarsus/tarsometatarsus via increased ankle extension at greater speeds. Because the femur is not moved and three distal elements are, quail move the limb segments through a stride and increase speed in a way fundamentally different from other nonavian vertebrates. However, the three moving joints in quail (the knee, ankle, and tarsometatarsophangeal joint) have strikingly similar kinematics to the analogous moving joints (the hip, knee, and ankle) in other vertebrates. Comparisons to other vertebrates indicate that birds appear to have two modes of limb function (three- and four-segment modes) that vary with speed and locomotory habits.
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Affiliation(s)
- S M Reilly
- Department of Biological Sciences, Ohio University, Athens, Ohio 45701, USA.
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Abstract
Forty-seven children with non-organic failure to thrive (NOFT) were identified from a whole-population survey of children's growth and development. A significant proportion (N=17) of these 47 children were found to have oral-motor dysfunction (OMD) identified using a previously validated assessment tool. NOFT children with OMD and those with normal oral-motor function (N=30) were compared in order to ascertain whether there were any neurodevelopmental differences which might explain this finding. We hypothesized that children with OMD might have a subtle neurodevelopmental disorder. Few psychosocial variables discriminated the two groups. However, cognitive stimulation within the home and cognitive-growth fostering during mealtimes was much poorer for children with OMD. Some evidence has suggested that NOFT children with OMD may be 'biologically' more vulnerable from birth. We suggest that the continued use of the term 'non-organic' to describe failure to thrive in such children is questionable and requires redefining.
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Affiliation(s)
- S M Reilly
- Behavioural Sciences Unit, Institute of Child Health, London, UK
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Reilly SM, Elias JA. Locomotion in alligator mississippiensis: kinematic effects of speed and posture and their relevance to the sprawling-to-erect paradigm. J Exp Biol 1998; 201 (Pt 18):2559-74. [PMID: 9716509 DOI: 10.1242/jeb.201.18.2559] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In terms of locomotory posture, amphibians and lizards are considered to be sprawlers, mammals and dinosaurs are considered to be erect, and extant crocodilians are considered to be intermediate because they use the 'high walk', a semi-erect posture where the body is held half-way between the sprawling and erect grades during locomotion. In addition, crocodilians occasionally use a sprawling posture. Extant crocodilians, therefore, provide an interesting model in which to investigate the sprawling-to-erect transition in vertebrate evolution. This study quantifies the sprawl and high walk kinematics of the alligator Alligator mississippiensis moving at different speeds on a treadmill and compares them with kinematic data available for other vertebrates. These data allow us to examine the effects of speed on crocodilian postures and to examine how crocodilian locomotion relates to the sprawling-to-erect paradigm in vertebrate locomotion. Our results show that the crocodilian sprawl is not functionally equivalent to the primitive sprawling behaviors exhibited by salamanders and lizards. In fact, although the high walks and sprawls of alligators exhibit some kinematic differences, they are actually much more similar than expected and, essentially, the crocodilian sprawl is a lower version of a high walk and could be termed a 'low walk'. In terms of the sprawling-to-erect transition, the high walk has knee kinematics intermediate between those of birds and non-archosaurian tetrapods, but alligators increase speed in a way completely different from other terrestrial vertebrates (distal rather than proximal limb elements are used to increase speed). These kinematic data viewed in the light of the fossil and phylogenetic evidence that modern crocodilians evolved from erect ancestors suggest that modern crocodilians have secondarily evolved a variable semi-erect posture and that they are problematic as an intermediate model for the evolutionary transition from sprawling to erect postures in archosaurs.
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Affiliation(s)
- SM Reilly
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
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Lang TF, Hasegawa BH, Liew SC, Brown JK, Blankespoor SC, Reilly SM, Gingold EL, Cann CE. Description of a prototype emission-transmission computed tomography imaging system. J Nucl Med 1992; 33:1881-7. [PMID: 1403162] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We have developed a prototype imaging system that can perform simultaneous x-ray transmission CT and SPECT phantom studies. This system employs a 23-element high-purity-germanium detector array. The detector array is coupled to a collimator with septa angled toward the focal spot of an x-ray tube. During image acquisition, the x-ray fan beam and the detector array move synchronously along an arc pivoted at the x-ray source. Multiple projections are obtained by rotating the object, which is mounted at the center of rotation of the system. The detector array and electronics can count up to 10(6) cps/element with sufficient energy-resolution to discriminate between x-rays at 100-120 kVp and gamma rays from 99mTc. We have used this device to acquire x-ray CT and SPECT images of a three-dimensional Hoffman brain phantom. The emission and transmission images may be superimposed in order to localize the emission image on the transmission map.
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Affiliation(s)
- T F Lang
- Department of Radiology, University of California, San Francisco
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Abstract
Bone, feathers, and liver were analyzed for lead in herring gull chicks (Larus argentatus) of two different ages. The highest levels were found in the bone, evidence of chronic exposure. No differences were found within the bones. Differences occurred between different bones, with the ribs having twice the amount of lead than any other bone. These studies indicate that type of bone affects lead levels; thus researchers should clearly state which parts of which bones are examined. It is also suggested that for humans consistent location should be used for analysis by in vivo X-ray fluorescence.
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Affiliation(s)
- J Burger
- Department of Biology, Rutgers University, Piscataway, NJ 08855
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40
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Abstract
The kinematics of aquatic prey capture were studied in species representing six salamander families (Ambystomatidae, Amphiumidae, Cryptobranchidae, Dicamptodontidae, Proteidae, and Sirenidae) to test the hypothesis that the process of aquatic prey capture is similar in these families. Seven variables were digitized from high-speed video records of prey capture, and a nested analysis of variance was performed to test for both significant individual within taxon and among taxa effects. The time-to-peak head angle and gape variables showed no taxon effect, while the other five variables exhibited highly significant differences among taxa. Cryptobranchus and Siren showed the most divergent kinematic pattern from the other taxa in a multivariate analysis of all variables, while Ambystoma, Dicamptodon, and Amphiuma tended to have similar overall patterns of head movement. These results show that kinematic patterns during aquatic feeding are not conserved across salamander taxa, and that phylogenetic differentiation in head morphology has been accompanied by novelties in feeding function. The feeding mechanisms of Cryptobranchus and Amphiuma have a bidirectional hydrodynamic design with kinematic correlates that are similar to kinematic characteristics of aquatic feeding in turtles and transformed ambystomatid salamanders. A general framework is presented as an aid to understanding the interrelationships among muscle activity patterns, morphology, and behavior (kinematic patterns). By considering the distribution of taxa in three multivariate spaces, corresponding to three of the levels at which one might analyze a behavior (kinematics, morphology, and motor pattern), it is possible to identify patterns of correspondence among the levels, which aid in understanding the evolution of behavior.
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Affiliation(s)
- S M Reilly
- School of Biological Sciences, University of California, Irvine 92717
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Jayne BC, Lauder GV, Reilly SM, Wainwright PC. The effect of sampling rate on the analysis of digital electromyograms from vertebrate muscle. J Exp Biol 1990; 154:557-65. [PMID: 2277264 DOI: 10.1242/jeb.154.1.557] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- B C Jayne
- Department of Ecology and Evolutionary Biology, University of California, Irvine 92717
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Wainwright PC, Sanford CP, Reilly SM, Lauder GV. Evolution of motor patterns: aquatic feeding in salamanders and ray-finned fishes. Brain Behav Evol 1989; 34:329-41. [PMID: 2611639 DOI: 10.1159/000116519] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Patterns of muscle activity (motor patterns) have generally been found to be strongly conserved during the evolution of aquatic feeding behavior within closely related groups of fishes and salamanders. We conducted a test of the generality of motor pattern conservation with a much broader phylogenetic scope than has been done previously. Activity patterns of three cranial muscles were quantified from electromyographic (EMG) recordings made during suction feeding in a salamander (Ambystoma mexicanum) and 4 widely divergent species of ray-finned fishes (Amia calva, Notopterus chitala, Micropterus salmoides and Lepomis macrochirus). General features of the motor pattern were the same in all species, but multivariate and univariate analyses of variance revealed highly significant differences among the 5 species in the average muscle activity pattern, indicating that the motor pattern has not been precisely conserved among these 5 taxa. Five of eight EMG variables that describe the intensity and timing of muscle activity differed among species. Only the intensity of activity of the adductor mandibulae appears to be a strongly conserved feature of the suction feeding motor pattern in anamniotes. A discriminant function analysis of the 8 EMG variables successfully classified about two thirds of the feeding incidents as belonging to the correct species. In contrast to the results of previous studies of closely related taxa, we found that numerous quantitative differences exist among species, indicating that functionally significant details of suction feeding motor patterns have changed during evolution, whereas several general features of the pattern have been conserved.
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Affiliation(s)
- P C Wainwright
- School of Biological Sciences, University of California, Irvine
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Reilly SM. Ontogeny of cranial ossification in the eastern newt, Notophthalmus viridescens (Caudata: Salamandridae), and its relationship to metamorphosis and neoteny. J Morphol 1986; 188:315-26. [PMID: 3735436 DOI: 10.1002/jmor.1051880306] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The ontogenetic sequence of cranial osteogenesis through adulthood is described in samples of newts from completely metamorphosing and partially neotenic populations. Cranial ossification proceeds in the same sequence in both samples. Seven stages of cranial development are described on the basis of conspicuous events that occur during ontogeny. These include four larval stages, metamorphs, efts, and adults. Neotenic adults have skulls that are metamorphosed completely and indistinguishable from the skulls of non-neotenic adults. Neoteny in these newts does not involve the skull and is limited to the postmetamorphic retention of some gill structures and, thus, is termed "limited neoteny." The evolution of limited neoteny in newts as a correlated response to the inhibition of land-drive behavior is discussed.
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DesGroseilliers JP, Reilly SM, Cullen AE. The importance of patient selection for photochemotherapy in psoriasis. Can Med Assoc J 1981; 124:1016-8. [PMID: 7260785 PMCID: PMC1705390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Twenty-four patients with psoriasis were treated with orally administered 8-methoxypsoralen followed by exposure to high-intensity long-wavelength ultraviolet radiation (PUVA) at a psoriasis day care centre. Among the 20 with plaque type psoriasis the condition cleared in 13 (65%), after a mean of 20.7 treatment sessions, and improved but failed to clear in 4 (20%); the treatment failed in the other 3 (15%). The other four patients had erythrodermic, pustular or inflammatory psoriasis, and all failed to respond to PUVA therapy. Factors to be considered in patient selection for this form of therapy are the type of psoriasis, the patient's skin type and th proportion of the body surface area involved.
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Reilly SM. Elective cesarean section. Can Fam Physician 1979; 25:901. [PMID: 21297780 PMCID: PMC2383185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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