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Steinhauser S, Estoppey D, Buehler DP, Xiong Y, Pizzato N, Rietsch A, Wu F, Leroy N, Wunderlin T, Claerr I, Tropberger P, Müller M, Davison LM, Sheng Q, Bergling S, Wild S, Moulin P, Liang J, English WJ, Williams B, Knehr J, Altorfer M, Reyes A, Mickanin C, Hoepfner D, Nigsch F, Frederiksen M, Flynn CR, Fodor BD, Brown JD, Kolter C. The transcription factor ZNF469 regulates collagen production in liver fibrosis. bioRxiv 2024:2024.04.25.591188. [PMID: 38712281 PMCID: PMC11071482 DOI: 10.1101/2024.04.25.591188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Non-alcoholic fatty liver disease (NAFLD) - characterized by excess accumulation of fat in the liver - now affects one third of the world's population. As NAFLD progresses, extracellular matrix components including collagen accumulate in the liver causing tissue fibrosis, a major determinant of disease severity and mortality. To identify transcriptional regulators of fibrosis, we computationally inferred the activity of transcription factors (TFs) relevant to fibrosis by profiling the matched transcriptomes and epigenomes of 108 human liver biopsies from a deeply-characterized cohort of patients spanning the full histopathologic spectrum of NAFLD. CRISPR-based genetic knockout of the top 100 TFs identified ZNF469 as a regulator of collagen expression in primary human hepatic stellate cells (HSCs). Gain- and loss-of-function studies established that ZNF469 regulates collagen genes and genes involved in matrix homeostasis through direct binding to gene bodies and regulatory elements. By integrating multiomic large-scale profiling of human biopsies with extensive experimental validation we demonstrate that ZNF469 is a transcriptional regulator of collagen in HSCs. Overall, these data nominate ZNF469 as a previously unrecognized determinant of NAFLD-associated liver fibrosis.
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Chiusa M, Lee YA, Zhang MZ, Harris RC, Sherrill T, Lindner V, Brooks CR, Yu G, Fogo AB, Flynn CR, Zienkiewicz J, Hawiger J, Zent R, Pozzi A. Cytoplasmic retention of the DNA/RNA-binding protein FUS ameliorates organ fibrosis in mice. J Clin Invest 2024; 134:e175158. [PMID: 38488009 PMCID: PMC10940094 DOI: 10.1172/jci175158] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 01/17/2024] [Indexed: 03/18/2024] Open
Abstract
Uncontrolled accumulation of extracellular matrix leads to tissue fibrosis and loss of organ function. We previously demonstrated in vitro that the DNA/RNA-binding protein fused in sarcoma (FUS) promotes fibrotic responses by translocating to the nucleus, where it initiates collagen gene transcription. However, it is still not known whether FUS is profibrotic in vivo and whether preventing its nuclear translocation might inhibit development of fibrosis following injury. We now demonstrate that levels of nuclear FUS are significantly increased in mouse models of kidney and liver fibrosis. To evaluate the direct role of FUS nuclear translocation in fibrosis, we used mice that carry a mutation in the FUS nuclear localization sequence (FUSR521G) and the cell-penetrating peptide CP-FUS-NLS that we previously showed inhibits FUS nuclear translocation in vitro. We provide evidence that FUSR521G mice or CP-FUS-NLS-treated mice showed reduced nuclear FUS and fibrosis following injury. Finally, differential gene expression analysis and immunohistochemistry of tissues from individuals with focal segmental glomerulosclerosis or nonalcoholic steatohepatitis revealed significant upregulation of FUS and/or collagen genes and FUS protein nuclear localization in diseased organs. These results demonstrate that injury-induced nuclear translocation of FUS contributes to fibrosis and highlight CP-FUS-NLS as a promising therapeutic option for organ fibrosis.
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Affiliation(s)
- Manuel Chiusa
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Youngmin A. Lee
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ming-Zhi Zhang
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Raymond C. Harris
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Veterans Affairs, Nashville, Tennessee, USA
| | - Taylor Sherrill
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Volkhard Lindner
- Center for Molecular Medicine, Maine Health Institute for Research, Scarborough, Maine, USA
| | - Craig R. Brooks
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Gang Yu
- Department of Neuroscience, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Agnes B. Fogo
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Charles R. Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jozef Zienkiewicz
- Department of Veterans Affairs, Nashville, Tennessee, USA
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jacek Hawiger
- Department of Veterans Affairs, Nashville, Tennessee, USA
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Roy Zent
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Veterans Affairs, Nashville, Tennessee, USA
| | - Ambra Pozzi
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Veterans Affairs, Nashville, Tennessee, USA
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Wang L, O’Brien MT, Zhang X, Chen Y, English WJ, Williams B, Spann M, Albaugh V, Shu XO, Flynn CR, Yu D. Cardiometabolic Improvements After Metabolic Surgery and Related Presurgery Factors. J Endocr Soc 2024; 8:bvae027. [PMID: 38487212 PMCID: PMC10939051 DOI: 10.1210/jendso/bvae027] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Indexed: 03/17/2024] Open
Abstract
Context Metabolic surgery remains the most effective and durable treatment for severe obesity and related metabolic diseases. Objective We examined cardiometabolic improvements after metabolic surgery and associated presurgery demographic and clinical factors in a large multiracial cohort. Methods Included were 7804 patients (20-79 years) undergoing first-time metabolic surgery at Vanderbilt University Medical Center from 1999 to 2022. Pre- and 1-year postsurgery cardiometabolic profiles were extracted from medical records, including body mass index (BMI), blood pressure, blood lipids, glucose, and hemoglobin A1c. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk was estimated per American College of Cardiology/American Heart Association equations. Pre- to postsurgery cardiometabolic profiles were compared by paired t-test, and associated factors were identified by multivariable linear and logistic regression. Results Among 7804 patients, most were women and White, while 1618 were men and 1271 were Black; median age and BMI were 45 years [interquartile range (IQR): 37-53] and 46.4 kg/m2 (IQR: 42.1-52.4). At 1-year postsurgery, patients showed significant decreases in systolic blood pressure (10.5 [95% confidence interval: 10.1, 10.9] mmHg), total cholesterol (13.5 [10.3, 16.7] mg/dL), glucose (13.6 [12.9, 14.4] mg/dL), hemoglobin A1c (1.13% [1.06, 1.20]), and 10-year ASCVD risk (absolute reduction: 1.58% [1.22, 1.94]; relative reduction: 34.4% [29.4, 39.3]); all P < .0001. Older, male, or Black patients showed less reduction in 10-year ASCVD risk and lower odds of diabetes/hypertension/dyslipidemia remission than younger, female, or White patients. Patients with a history of diabetes, hypertension, dyslipidemia, or cardiovascular disease showed less cardiometabolic improvements than those without. Results were similar with or without further adjusting for weight loss and largely sustained at 2-year postsurgery. Conclusion Metabolic surgery results in significant cardiometabolic improvements, particularly among younger, female, or White patients and those without comorbidities.
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Affiliation(s)
- Lei Wang
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | | | - Xinmeng Zhang
- Department of Computer Science, Vanderbilt University, Nashville, TN 37203, USA
| | - You Chen
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | - Wayne J English
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | - Brandon Williams
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | - Matthew Spann
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | - Vance Albaugh
- Metamor Institute, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Xiao-Ou Shu
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37203, USA
| | - Danxia Yu
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37203, USA
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Zhang X, Kang K, Yan C, Feng Y, Vandekar S, Yu D, Rosenbloom ST, Samuels J, Srivastava G, Williams B, Albaugh VL, English WJ, Flynn CR, Chen Y. Enhanced Patient Portal Engagement Associated with Improved Weight Loss Outcomes in Post-Bariatric Surgery Patients. medRxiv 2024:2024.01.20.24301550. [PMID: 38293039 PMCID: PMC10827275 DOI: 10.1101/2024.01.20.24301550] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Background Bariatric surgery is an effective intervention for obesity, but it requires comprehensive postoperative self-management to achieve optimal outcomes. While patient portals are generally seen as beneficial in engaging patients in health management, the link between their use and post-bariatric surgery weight loss remains unclear. Objective This study investigated the association between patient portal engagement and postoperative body mass index (BMI) reduction among bariatric surgery patients. Methods This retrospective longitudinal study included patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at Vanderbilt University Medical Center (VUMC) between January 2018 and March 2021. Using generalized estimating equations, we estimated the association between active days of postoperative patient portal use and the reduction of BMI percentage (%BMI) at 3, 6, and 12 months post-surgery. Covariates included duration since surgery, the patient's age at the time of surgery, gender, race and ethnicity, type of bariatric surgery, severity of comorbid conditions, and socioeconomic disadvantage. Results The study included 1,415 patients, mostly female (80.9%), with diverse racial and ethnic backgrounds. 805 (56.9%) patients underwent RYGB and 610 (43.1%) underwent SG. By one-year post-surgery, the mean (SD) %BMI reduction was 31.1% (8.3%), and the mean (SD) number of patient portal active days was 61.0 (41.2). A significantly positive association was observed between patient portal engagement and %BMI reduction, with variations revealed over time. Each 10-day increment of active portal use was associated with a 0.57% ([95% CI: 0.42- 0.72], P < .001) and 0.35% ([95% CI: 0.22- 0.49], P < .001) %BMI reduction at 3 and 6 months postoperatively. The association was not statistically significant at 12 months postoperatively (β=-0.07, [95% CI: -0.24- 0.09], P = .54). Various portal functions, including messaging, visits, my record, medical tools, billing, resources, and others, were positively associated with %BMI reduction at 3- and 6-months follow-ups. Conclusions Greater patient portal engagement, which may represent stronger adherence to postoperative instructions, better self-management of health, and enhanced communication with care teams, was associated with improved postoperative weight loss. Future investigations are needed to identify important portal features that contribute to the long-term success of weight loss management.
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Affiliation(s)
- Xinmeng Zhang
- Department of Computer Science, Vanderbilt University, Nashville, TN
| | - Kaidi Kang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN
| | - Chao Yan
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
| | - Yubo Feng
- Department of Computer Science, Vanderbilt University, Nashville, TN
| | - Simon Vandekar
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN
| | - Danxia Yu
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - S. Trent Rosenbloom
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jason Samuels
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Gitanjali Srivastava
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
- Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Weight Loss Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Brandon Williams
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Weight Loss Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Vance L. Albaugh
- Metamor Institute, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Wayne J. English
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Weight Loss Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Charles R. Flynn
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Weight Loss Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - You Chen
- Department of Computer Science, Vanderbilt University, Nashville, TN
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN
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Rathmacher JA, Fuller JC, Abumrad NN, Flynn CR. Inflammation Biomarker Response to Oral 2-Hydroxybenzylamine (2-HOBA) Acetate in Healthy Humans. Inflammation 2023; 46:1343-1352. [PMID: 36935449 PMCID: PMC10025056 DOI: 10.1007/s10753-023-01801-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 03/21/2023]
Abstract
Inflammation is associated with the formation of reactive oxygen species (ROS) and the formation of lipid-derived compounds, such as isolevuglandins (IsoLGs), malondialdehyde, 4-hydroxy-nonenal, and 4-oxo-nonenal. The most reactive of these are the IsoLGs, which form covalent adducts with lysine residues and other cellular primary amines leading to changes in protein function, immunogenicity, and epigenetic alterations and have been shown to contribute to a number of inflammatory diseases. 2-Hydroxybenzylamine (2-HOBA) is a natural compound found in buckwheat seeds and reacts with all IsoLG adducts preventing adduct formation with proteins and DNA. Therefore, 2-HOBA is well positioned as an agent for the prevention of inflammatory-prone diseases. In this study, we examined the potential beneficial effects of 2-HOBA on oxidative stress and inflammatory biomarkers in two cohorts of healthy younger and older adults. We utilized the Olink® targeted inflammation panel before and after an oral 15-day treatment regimen with 2-HOBA. We found significant relative changes in the plasma concentration of 15 immune proteins that may reflect the in vivo immune targets of 2-HOBA. Treatment of 2-HOBA resulted in significant increased levels of CCL19, IL-12β, IL-20Rα, and TNFβ, whereas levels of TWEAK significantly decreased. Ingenuity Pathway Analysis identified canonical pathways regulated by the differentially secreted cytokines, chemokines, and growth factors upon 2-HOBA treatment and further points to biofunctions related to the recruitment, attraction, and movement of different immune cell types. In conclusion, 2-HOBA significantly altered the protein biomarkers CCL19, IL-12β, IL-20Rα, TNFβ, and TWEAK, and these may be responsible for the protective effects of 2-HOBA against reactive electrophiles, such as IsoLGs, commonly expressed in conditions of excessive oxidative stress. 2-HOBA has a role as a IsoLG scavenger to proactively improve immune health in a variety of conditions.
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Affiliation(s)
- John A Rathmacher
- MTI BioTech, Inc, Iowa State University Research Park, Ames, IA, USA
- Department of Animal Science, Iowa State University, Ames, IA, USA
| | | | - Naji N Abumrad
- MTI BioTech, Inc, Iowa State University Research Park, Ames, IA, USA
- Metabolic Technologies, LLC, Missoula, MT, USA
- Department of Surgery, Vanderbilt University Medical Center, MRBIV Room 8465A, Nashville, TN, 37232, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, MRBIV Room 8465A, Nashville, TN, 37232, USA.
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Ukita R, Wu WK, Liang J, Talackine JR, Patel YJ, Francois SA, Cardwell NL, Flynn CR, Shingina A, Washington MK, Trinh VQH, Bacchetta M, Alexopoulos SP. Pulmonary artery banding in sheep: a novel large animal model for congestive hepatopathy. J Appl Physiol (1985) 2023; 134:840-845. [PMID: 36759164 PMCID: PMC10042593 DOI: 10.1152/japplphysiol.00473.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Congestive hepatopathy is becoming increasingly recognized among Fontan-palliated patients. Elevated central venous pressure is thought to drive the pathologic progression, characterized by sinusoidal dilatation, congestion, and fibrosis. A clinically relevant large animal model for congestive hepatopathy would provide a valuable platform for researching novel biomarkers, treatment, and prevention. Here, we report on a titratable, sheep pulmonary artery banding model for this disease application. Pulmonary artery banding was achieved by progressively inflating the implanted pulmonary artery cuff. Right ventricular catheter was implanted to draw venous blood samples and measure pressure. The pulmonary artery cuff pressure served as a surrogate for the intensity of pulmonary artery banding and was measured weekly. After about 9 wk, animals were euthanized, and the liver was harvested for histopathological assessment. Nine animal subjects received pulmonary artery banding for 64 ± 8 days. Four of the nine subjects exhibited moderate to severe liver injury, and three of those four exhibited bridging fibrosis. Increasing pulmonary artery cuff pressure significantly correlated with declining mixed venous oxygen saturation (P = 3.29 × 10-5), and higher congestive hepatic fibrosis score (P = 0.0238), suggesting that pulmonary artery banding strategy can be titrated to achieve right-sided congestion and liver fibrosis. Blood analyses demonstrated an increase in plasma bile acids, aspartate aminotransferase, and γ-glutamyltransferase among subjects with moderate to severe injury, further corroborating liver tissue findings. Our large animal pulmonary artery banding model recapitulates congestive hepatopathy and provides a basis to bridge the current gaps in scientific and clinical understanding about the disease.NEW & NOTEWORTHY We present here a large animal platform for congestive hepatopathy, a disease growing in clinical prevalence due to the increasing number of Fontan-palliated patients. Further data are needed to develop a better clinical management strategy for this poorly characterized patient population. Previous reports of animal models to study this disease have mostly been in small animals with limited fidelity. We show that congestive hepatopathy can be replicated in a chronic, progressive pulmonary artery banding model in sheep. We also show that the banding strategy can be controlled to titrate the level of liver injury. To date, we do not know of any other large animal model that can achieve this level of control over disease phenotype and clinical relevance.
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Affiliation(s)
- Rei Ukita
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Wei Kelly Wu
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Division of Hepatobiliary Surgery and Liver Transplantation, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Jiancong Liang
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Jennifer R Talackine
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Yatrik J Patel
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Sean A Francois
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Nancy L Cardwell
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Alexandra Shingina
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Mary Kay Washington
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Vincent Quoc-Huy Trinh
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Matthew Bacchetta
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - Sophoclis P Alexopoulos
- Division of Hepatobiliary Surgery and Liver Transplantation, Vanderbilt University Medical Center, Nashville, Tennessee, United States
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Jacobse J, Brown RE, Li J, Pilat JM, Pham L, Short SP, Peek CT, Rolong A, Washington MK, Martinez-Barricarte R, Byndloss MX, Shelton C, Markle JG, Latour YL, Allaman MM, Cassat JE, Wilson KT, Choksi YA, Williams CS, Lau KS, Flynn CR, Casanova JL, Rings EHHM, Samsom JN, Goettel JA. Interleukin-23 receptor signaling impairs the stability and function of colonic regulatory T cells. Cell Rep 2023; 42:112128. [PMID: 36807140 PMCID: PMC10432575 DOI: 10.1016/j.celrep.2023.112128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/29/2022] [Accepted: 01/31/2023] [Indexed: 02/19/2023] Open
Abstract
The cytokine interleukin-23 (IL-23) is involved in the pathogenesis of inflammatory and autoimmune conditions including inflammatory bowel disease (IBD). IL23R is enriched in intestinal Tregs, yet whether IL-23 modulates intestinal Tregs remains unknown. Here, investigating IL-23R signaling in Tregs specifically, we show that colonic Tregs highly express Il23r compared with Tregs from other compartments and their frequency is reduced upon IL-23 administration and impairs Treg suppressive function. Similarly, colonic Treg frequency is increased in mice lacking Il23r specifically in Tregs and exhibits a competitive advantage over IL-23R-sufficient Tregs during inflammation. Finally, IL-23 antagonizes liver X receptor pathway, cellular cholesterol transporter Abca1, and increases Treg apoptosis. Our results show that IL-23R signaling regulates intestinal Tregs by increasing cell turnover, antagonizing suppression, and decreasing cholesterol efflux. These results suggest that IL-23 negatively regulates Tregs in the intestine with potential implications for promoting chronic inflammation in patients with IBD.
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Affiliation(s)
- Justin Jacobse
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Willem-Alexander Children's Hospital, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA
| | - Rachel E Brown
- Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jing Li
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jennifer M Pilat
- Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Ly Pham
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sarah P Short
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christopher T Peek
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Andrea Rolong
- Department of Cell and Developmental Biology and Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - M Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ruben Martinez-Barricarte
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Medicine, Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mariana X Byndloss
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Catherine Shelton
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Janet G Markle
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Medicine, Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yvonne L Latour
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Margaret M Allaman
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA
| | - James E Cassat
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Keith T Wilson
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA; Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yash A Choksi
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA; Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christopher S Williams
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ken S Lau
- Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Cell and Developmental Biology and Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jean-Laurent Casanova
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale (INSERM) U1163, Necker Hospital for Sick Children, Paris, France; The Center for Stem Cell Biology, Sloan-Kettering Institute for Cancer Research, New York, NY, USA; Developmental Biology Program, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY, USA; Howard Hughes Medical Institute, New York, NY, USA
| | - Edmond H H M Rings
- Willem-Alexander Children's Hospital, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands; Sophia Children's Hospital, Department of Pediatrics, Erasmus University, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Janneke N Samsom
- Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Jeremy A Goettel
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
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8
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Noto JM, Piazuelo MB, Shah SC, Romero-Gallo J, Hart JL, Di C, Carmichael JD, Delgado AG, Halvorson AE, Greevy RA, Wroblewski LE, Sharma A, Newton AB, Allaman MM, Wilson KT, Washington MK, Calcutt MW, Schey KL, Cummings BP, Flynn CR, Zackular JP, Peek RM. Iron deficiency linked to altered bile acid metabolism promotes Helicobacter pylori-induced inflammation-driven gastric carcinogenesis. J Clin Invest 2022; 132:e147822. [PMID: 35316215 PMCID: PMC9106351 DOI: 10.1172/jci147822] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/16/2022] [Indexed: 12/24/2022] Open
Abstract
Gastric carcinogenesis is mediated by complex interactions among Helicobacter pylori, host, and environmental factors. Here, we demonstrate that H. pylori augmented gastric injury in INS-GAS mice under iron-deficient conditions. Mechanistically, these phenotypes were not driven by alterations in the gastric microbiota; however, discovery-based and targeted metabolomics revealed that bile acids were significantly altered in H. pylori-infected mice with iron deficiency, with significant upregulation of deoxycholic acid (DCA), a carcinogenic bile acid. The severity of gastric injury was further augmented when H. pylori-infected mice were treated with DCA, and, in vitro, DCA increased translocation of the H. pylori oncoprotein CagA into host cells. Conversely, bile acid sequestration attenuated H. pylori-induced injury under conditions of iron deficiency. To translate these findings to human populations, we evaluated the association between bile acid sequestrant use and gastric cancer risk in a large human cohort. Among 416,885 individuals, a significant dose-dependent reduction in risk was associated with cumulative bile acid sequestrant use. Further, expression of the bile acid receptor transmembrane G protein-coupled bile acid receptor 5 (TGR5) paralleled the severity of carcinogenic lesions in humans. These data demonstrate that increased H. pylori-induced injury within the context of iron deficiency is tightly linked to altered bile acid metabolism, which may promote gastric carcinogenesis.
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Affiliation(s)
- Jennifer M Noto
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M Blanca Piazuelo
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Shailja C Shah
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Judith Romero-Gallo
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Chao Di
- Division of Protective Immunity, and
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - James D Carmichael
- Department of Biochemistry, Mass Spectrometry Research Center Laboratory, Vanderbilt University, Nashville, Tennessee, USA
| | - Alberto G Delgado
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alese E Halvorson
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Robert A Greevy
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lydia E Wroblewski
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ayushi Sharma
- Creighton University School of Medicine, Omaha, Nebraska, USA
| | | | - Margaret M Allaman
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Keith T Wilson
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M Wade Calcutt
- Department of Biochemistry, Mass Spectrometry Research Center Laboratory, Vanderbilt University, Nashville, Tennessee, USA
| | - Kevin L Schey
- Department of Biochemistry, Mass Spectrometry Research Center Laboratory, Vanderbilt University, Nashville, Tennessee, USA
| | - Bethany P Cummings
- Department of Surgery, University of California, Davis, Davis, California, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Joseph P Zackular
- Division of Protective Immunity, and
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Richard M Peek
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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9
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Breier NC, Paranjape SY, Scudder S, Mehr SE, Diedrich A, Flynn CR, Okamoto LE, Hartmann B, Gasbjerg LS, Shibao CA. Worsening Postural Tachycardia Syndrome Is Associated With Increased Glucose-Dependent Insulinotropic Polypeptide Secretion. Hypertension 2022; 79:e89-e99. [PMID: 35232225 PMCID: PMC9010371 DOI: 10.1161/hypertensionaha.121.17852] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Postural tachycardia syndrome (POTS) is characterized by excessive upright tachycardia and disabling presyncopal symptoms, which are exacerbated after consuming a high-carbohydrate meal; it is unknown, however, what is the precise underlying mechanism. We seek to investigate the effect of glucose intake on orthostatic hemodynamic changes and gastrointestinal hormone secretion in POTS. METHODS Prospective, case-control study, 12 women with POTS who reported a postprandial worsening of their POTS symptoms and 13 age-matched female controls received 75-g oral glucose and 20 mg/kg acetaminophen to assess nutrient absorption. Hemodynamic, gastrointestinal hormone and acetaminophen levels were measured for up to 120 minutes postingestion while supine and standing. RESULTS Patients with POTS had significant orthostatic tachycardia, 48.7±11.2 versus 23.3±8.1 bpm, P=0.012 and elevated upright norepinephrine levels, 835.2±368.4 versus 356.9±156.7 pg/mL, P=0.004. After oral glucose, upright heart rate significantly increased in POTS, 21.2±11.9% versus 6.0±19.9%, P=0.033 with a concomitant decline in upright stroke volume, -10.3±11.90% versus 3.3±13.7%, P=0.027; total peripheral resistance, blood pressure and cardiac output remained unaltered. Acetaminophen rate of appearance was similar between groups (P=0.707), indicating comparable nutrient absorption rates. POTS had increased plasma levels of C-peptide (P=0.001), GIP (glucose-dependent insulinotropic polypeptide; P=0.001), peptide YY (P=0.016), and pancreatic polypeptide (P=0.04) following glucose consumption, but only GIP had a time-dependent association with the worsening upright tachycardia and stroke volume fall. CONCLUSIONS The glucose-induced worsening orthostatic tachycardia in POTS was associated with a decline in SV; these changes occurred while GIP, a splanchnic vasodilator, was maximally elevated.
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Affiliation(s)
- Nicholas C Breier
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
| | - Sachin Y Paranjape
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
| | - Shea Scudder
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
| | - Shahram E Mehr
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
| | - Andre' Diedrich
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
| | - Charles R Flynn
- Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Luis E Okamoto
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
| | - Bolette Hartmann
- Novo Nordisk Foundation Center for Basic Metabolic Research (B.H.), University of Copenhagen, Denmark
| | - Lærke Smidt Gasbjerg
- Department of Biomedical Science (B.H., L.S.G.), University of Copenhagen, Denmark
| | - Cyndya A Shibao
- Department of Medicine, Division of Clinical Pharmacology (N.C.B., S.Y.P., S.S., S.E.M., A.D., L.E.O., C.A.S.), Vanderbilt University Medical Center, Nashville, TN
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10
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Wu WK, Tumen A, Stokes JW, Ukita R, Hozain A, Pinezich M, O'Neill JD, Lee MJ, Reimer JA, Flynn CR, Talackine JR, Cardwell NL, Benson C, Vunjak-Novakovic G, Alexopoulos SP, Bacchetta M. Cross-Circulation for Extracorporeal Liver Support in a Swine Model. ASAIO J 2022; 68:561-570. [PMID: 34352819 PMCID: PMC9984766 DOI: 10.1097/mat.0000000000001543] [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: 11/26/2022] Open
Abstract
Although machine perfusion has gained momentum as an organ preservation technique in liver transplantation, persistent organ shortages and high waitlist mortality highlight unmet needs for improved organ salvage strategies. Beyond preservation, extracorporeal organ support platforms can also aid the development and evaluation of novel therapeutics. Here, we report the use of veno-arterial-venous (V-AV) cross-circulation (XC) with a swine host to provide normothermic support to extracorporeal livers. Functional, biochemical, and morphological analyses of the extracorporeal livers and swine hosts were performed over 12 hours of support. Extracorporeal livers maintained synthetic function through alkaline bile production and metabolic activity through lactate clearance and oxygen consumption. Beyond initial reperfusion, no biochemical evidence of hepatocellular injury was observed. Histopathologic injury scoring showed improvements in sinusoidal dilatation and composite acute injury scores after 12 hours. Swine hosts remained hemodynamically stable throughout XC support. Altogether, these outcomes demonstrate the feasibility of using a novel V-AV XC technique to provide support for extracorporeal livers in a swine model. V-AV XC has potential applications as a translational research platform and clinical biotechnology for donor organ salvage.
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Affiliation(s)
- Wei Kelly Wu
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
- Division of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Andrew Tumen
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - John W Stokes
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rei Ukita
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ahmed Hozain
- Department of Surgery, Columbia University Medical Center, New York, New York
- Department of Biomedical Engineering, Columbia University, New York, New York
| | - Meghan Pinezich
- Department of Biomedical Engineering, Columbia University, New York, New York
| | - John D O'Neill
- Department of Biomedical Engineering, Columbia University, New York, New York
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York City
| | - Michael J Lee
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Jonathan A Reimer
- Department of Surgery, Columbia University Medical Center, New York, New York
- Department of Biomedical Engineering, Columbia University, New York, New York
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jennifer R Talackine
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Nancy L Cardwell
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Clayne Benson
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Gordana Vunjak-Novakovic
- Department of Biomedical Engineering, Columbia University, New York, New York
- Department of Medicine, Columbia University, New York, New York
| | - Sophoclis P Alexopoulos
- Division of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Matthew Bacchetta
- From the Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cardiac Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
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11
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Zhu L, An J, Chinnarasu S, Luu T, Pettway YD, Fahey K, Litts B, Kim HYH, Flynn CR, Linton MF, Stafford JM. Expressing the Human Cholesteryl Ester Transfer Protein Minigene Improves Diet-Induced Fatty Liver and Insulin Resistance in Female Mice. Front Physiol 2022; 12:799096. [PMID: 35082691 PMCID: PMC8784660 DOI: 10.3389/fphys.2021.799096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 10/22/2021] [Accepted: 12/16/2021] [Indexed: 01/22/2023] Open
Abstract
Mounting evidence has shown that CETP has important physiological roles in adapting to chronic nutrient excess, specifically, to protect against diet-induced insulin resistance. However, the underlying mechanisms for the protective roles of CETP in metabolism are not yet clear. Mice naturally lack CETP expression. We used transgenic mice with a human CETP minigene (huCETP) controlled by its natural flanking region to further understand CETP-related physiology in response to obesity. Female huCETP mice and their wild-type littermates were fed a high-fat diet for 6 months. Blood lipid profile and liver lipid metabolism were studied. Insulin sensitivity was analyzed with euglycemic-hyperinsulinemic clamp studies combined with 3H-glucose tracer techniques. While high-fat diet feeding induced obesity for huCETP mice and their wild-type littermates lacking CETP expression, insulin sensitivity was higher for female huCETP mice than for their wild-type littermates. There was no difference in insulin sensitivity for male huCETP mice vs. littermates. The increased insulin sensitivity in females was largely caused by the better insulin-mediated suppression of hepatic glucose production. In huCETP females, CETP in the circulation decreased HDL-cholesterol content and increased liver cholesterol uptake and liver cholesterol and oxysterol contents, which was associated with the upregulation of LXR target genes in long-chain polyunsaturated fatty acid biosynthesis and PPARα target genes in fatty acid β-oxidation in the liver. The upregulated fatty acid β-oxidation may account for the improved fatty liver and liver insulin action in female huCETP mice. This study provides further evidence that CETP has beneficial physiological roles in the metabolic adaptation to nutrient excess by promoting liver fatty acid oxidation and hepatic insulin sensitivity, particularly for females.
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Affiliation(s)
- Lin Zhu
- VA Tennessee Valley Healthcare System, Nashville, TN, United States.,Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Julia An
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Sivaprakasam Chinnarasu
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Thao Luu
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Yasminye D Pettway
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Kelly Fahey
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Bridget Litts
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Hye-Young H Kim
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Charles R Flynn
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - MacRae F Linton
- Atherosclerosis Research Unit, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - John M Stafford
- VA Tennessee Valley Healthcare System, Nashville, TN, United States.,Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, United States.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States
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12
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Shi J, Yang Y, Xu W, Cai H, Wu J, Long J, Cai Q, Zheng W, Flynn CR, Shu XO, Yu D. Sex-Specific Associations between Gut Microbiome and Non-Alcoholic Fatty Liver Disease among Urban Chinese Adults. Microorganisms 2021; 9:microorganisms9102118. [PMID: 34683439 PMCID: PMC8537656 DOI: 10.3390/microorganisms9102118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) has been linked to altered gut microbiome; however, evidence from large population-based studies is limited. We compared gut microbiome profiles of 188 male and 233 female NAFLD cases with 571 male and 567 female controls from two longitudinal studies of urban Chinese adults. History of NAFLD was assessed during surveys administered in 2004-2017. Microbiota were assessed using 16S rRNA sequencing of stool samples collected in 2015-2018. Associations of NAFLD with microbiome diversity and composition were evaluated by generalized linear or logistic regression models. Compared with controls, male cases had lower microbial α-diversity, higher abundance of genera Dialister and Streptococcus and Bifidobacterium species, lower abundance of genus Phascolarctobacterium, and lower prevalence of taxa including order RF39 (all p < 0.05). In contrast, female cases had higher α-diversity, higher abundance of genus Butyricimonas and a family of order Clostridiales, lower abundance of Dialister and Bifidobacterium species, and higher prevalence of RF39. Significant NAFLD-sex interactions were found for α-diversity and above taxa (all false discovery rate < 0.1). In conclusion, we observed sex-specific gut microbiome features related to history of NAFLD. Further studies are needed to validate our findings and evaluate the health effects of NAFLD-related gut microbiota.
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Affiliation(s)
- Jiajun Shi
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Yaohua Yang
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Wanghong Xu
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai 200433, China;
| | - Hui Cai
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Jie Wu
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Jirong Long
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Qiuyin Cai
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Wei Zheng
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Charles R. Flynn
- Department of Surgery, Division of General Surgery, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA;
| | - Xiao-Ou Shu
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
| | - Danxia Yu
- Department of Medicine, Division of Epidemiology, Vanderbilt University Medical Center, Suite 600, Nashville, TN 37232, USA; (J.S.); (Y.Y.); (H.C.); (J.W.); (J.L.); (Q.C.); (W.Z.); (X.-O.S.)
- Correspondence: ; Tel.: +1-615-936-7389; Fax: +1-615-936-8291
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13
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Breier N, Diedrich A, Okamoto LE, Mehr SE, Flynn CR, Shibao CA. Abstract P196: Exacerbation Of Postural Tachycardia Syndrome After An Oral Glucose Challenge: Role Of Incretins. Hypertension 2021. [DOI: 10.1161/hyp.78.suppl_1.p196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Postural Tachycardia Syndrome (POTS) is characterized by excessive upright tachycardia and disabling pre-syncopal symptoms, which are exacerbated after consuming a high-carbohydrate meal. The purpose of this study is to investigate the effect of oral glucose on orthostatic hemodynamic changes and gastrointestinal hormone secretion in POTS. We studied 12 women with POTS and 13 age-matched controls, all subjects received 75-gr oral glucose and 20 mg/kg acetaminophen for nutrient absorption measurement. Hemodynamic, GI hormone secretion and acetaminophen levels were measured at different time-points up to 120-min post-ingestion and while supine and standing. POTS patients had significant upright tachycardia ( delta HR: 48.7 ± 11.2 vs. 23.3 ± 8.1 bpm, P=0.012) and norepinephrine levels (835.2 ± 368.4 vs. 356.9 ± 156.7 pg/mL, P= 0.004). After oral glucose, upright HR significantly increased in POTS (92±15.5 vs. 112± 26 bpm, P=0.002) with a concomitant decline in upright stroke volume (P=0.027); total peripheral resistance, blood pressure and cardiac output remained unaltered. Acetaminophen rate of appearance was similar between groups (P=0.707). POTS patients had increased secretion of C-peptide (P=0.001), Glucose Dependent Insulinotropic Peptide (GIP) (P=0.001), peptide YY (P=0.016) and pancreatic polypeptide (P=0.04), but not GLP-1 (p=0.658) or Glucagon (P=0.836). Only GIP had a time-dependent association with the worsening upright tachycardia and SV fall, figure.
Conclusions:
Oral glucose exacerbated upright tachycardia in POTS, which was associated with a decline in SV; these changes occurred while GIP, a splanchnic vasodilator, is being maximally secreted.
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14
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DiCarlo GE, Mabry SJ, Cao X, McMillan C, Woynaroski TG, Harrison FE, Reddy IA, Matthies HJG, Flynn CR, Wallace MT, Wu H, Galli A. Autism-Associated Variant in the SLC6A3 Gene Alters the Oral Microbiome and Metabolism in a Murine Model. Front Psychiatry 2021; 12:655451. [PMID: 33935841 PMCID: PMC8081952 DOI: 10.3389/fpsyt.2021.655451] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/16/2021] [Indexed: 12/02/2022] Open
Abstract
Background: Altered dopamine (DA) signaling has been associated with autism spectrum disorder (ASD), a neurodevelopmental condition estimated to impact 1 in 54 children in the United States. There is growing evidence for alterations in both gastrointestinal function and oral microbiome composition in ASD. Recent work suggests that rare variants of the SLC6A3 gene encoding the DA transporter (DAT) identified in individuals with ASD result in structural and functional changes to the DAT. One such recently identified de novo mutation is a threonine to methionine substitution at position 356 of the DAT (DAT T356M). The DAT T356M variant is associated with ASD-like phenotypes in mice homozygous for the mutation (DAT T356M+/+), including social deficits, hyperactivity, and impaired DA signaling. Here, we determine the impact of this altered DA signaling as it relates to altered oral microbiota, and metabolic and gastrointestinal dysfunction. Methods: In the DAT T356M+/+ mouse, we determine the oral microbiota composition, metabolic function, and gastrointestinal (GI) function. We examined oral microbiota by 16S RNA sequencing. We measured metabolic function by examining glucose tolerance and we probed gastrointestinal parameters by measuring fecal dimensions and weight. Results: In the DAT T356M+/+ mouse, we evaluate how altered DA signaling relates to metabolic dysfunction and altered oral microbiota. We demonstrate that male DAT T356M+/+ mice weigh less (Wild type (WT) = 26.48 ± 0.6405 g, DAT T356M+/+ = 24.14 ± 0.4083 g) and have decreased body fat (WT = 14.89 ± 0.6206%, DAT T356M+/+ = 12.72 ± 0.4160%). These mice display improved glucose handling (WT = 32.60 ± 0.3298 kcal/g, DAT T356M+/+ = 36.97 ± 0.4910 kcal/g), and an altered oral microbiota. We found a significant decrease in Fusobacterium abundance. The abundance of Fusobacterium was associated with improved glucose handling and decreased body fat. Conclusions: Our findings provide new insights into how DAT dysfunction may alter gastrointestinal function, composition of the oral microbiota, and metabolism. Our data suggest that impaired DA signaling in ASD is associated with a number of metabolic and gastrointestinal changes which are common in individuals with ASD.
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Affiliation(s)
- Gabriella E. DiCarlo
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Samuel J. Mabry
- Department of Surgery, University of Alabama Birmingham, Birmingham, AL, United States
- Department of Neurobiology, University of Alabama Birmingham, Birmingham, AL, United States
| | - Xixi Cao
- School of Dentistry, Oregon Health and Science University, Portland, OR, United States
| | - Clara McMillan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Tiffany G. Woynaroski
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, United States
- Frist Center for Autism and Innovation, Vanderbilt University, Nashville, TN, United States
| | - Fiona E. Harrison
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - India A. Reddy
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | | | - Charles R. Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Mark T. Wallace
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, United States
- Frist Center for Autism and Innovation, Vanderbilt University, Nashville, TN, United States
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Hui Wu
- School of Dentistry, Oregon Health and Science University, Portland, OR, United States
| | - Aurelio Galli
- Department of Surgery, University of Alabama Birmingham, Birmingham, AL, United States
- Department of Neurobiology, University of Alabama Birmingham, Birmingham, AL, United States
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15
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Yu D, Shu XO, Howard EF, Long J, English WJ, Flynn CR. Fecal metagenomics and metabolomics reveal gut microbial changes after bariatric surgery. Surg Obes Relat Dis 2020; 16:1772-1782. [PMID: 32747219 DOI: 10.1016/j.soard.2020.06.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/06/2020] [Accepted: 06/13/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Evidence from longitudinal patient studies regarding gut microbial changes after bariatric surgery is limited. OBJECTIVE To examine intraindividual changes in fecal microbiome and metabolites among patients undergoing Roux-en-Y gastric bypass or vertical sleeve gastrectomy. SETTING Observational study. METHODS Twenty patients were enrolled and provided stool samples before and 1 week, 1 month, and/or 3 months after surgery. Shallow shotgun metagenomics and untargeted fecal metabolomics were performed. Zero-inflated generalized additive models and linear mixed models were applied to identify fecal microbiome and metabolites changes, with adjustment for potential confounders and correction for multiple testing. RESULTS We enrolled 16 women and 4 men, including 16 white and 4 black participants (median age = 45 years; presurgery body mass index = 47.7 kg/m2). Ten patients had Roux-en-Y gastric bypass, 10 had vertical sleeve gastrectomy, and 14 patients provided postsurgery stool samples. Of 47 samples, median sequencing depth was 6.3 million reads and 1073 metabolites were identified. Microbiome alpha-diversity increased after surgery, especially at 3 months. Significant genus-level changes included increases in Odoribacter, Streptococcus, Anaerotruncus, Alistipes, Klebsiella, and Bifidobacterium, while decreases in Bacteroides, Coprocosccus, Dorea, and Faecalibacterium. Large increases in Streptococcus, Akkermansia, and Prevotella were observed at 3 months. Beta-diversity and fecal metabolites were also changed, including reduced caffeine metabolites, indoles, and butyrate. CONCLUSIONS Despite small sample size and missing repeated samples in some participants, our pilot study showed significant postsurgery changes in fecal microbiome and metabolites among bariatric surgery patients. Future large-scale, longitudinal studies are warranted to investigate gut microbial changes and their associations with metabolic outcomes after bariatric surgery.
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Affiliation(s)
- Danxia Yu
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
| | - Xiao-Ou Shu
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Eric F Howard
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jirong Long
- Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Wayne J English
- Division of General Surgery, Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Charles R Flynn
- Division of General Surgery, Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
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16
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Coutts AW, Webster DA, Chen J, Liang T, Dasgupta D, Ferreira M, Alloosh M, Flynn CR, Cummings O, Carlson DF, Malhi H, Sturek MS, Chalasani N, Melkamu T. A PNPLA3
I148M
gene‐edited Ossabaw swine model of Nonalcoholic steatohepatitis (NASH). FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.07238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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]
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17
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Smith NK, Hackett TA, Galli A, Flynn CR. GLP-1: Molecular mechanisms and outcomes of a complex signaling system. Neurochem Int 2019; 128:94-105. [PMID: 31002893 PMCID: PMC7081944 DOI: 10.1016/j.neuint.2019.04.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/26/2019] [Accepted: 04/15/2019] [Indexed: 12/15/2022]
Abstract
Meal ingestion provokes the release of hormones and transmitters, which in turn regulate energy homeostasis and feeding behavior. One such hormone, glucagon-like peptide-1 (GLP-1), has received significant attention in the treatment of obesity and diabetes due to its potent incretin effect. In addition to the peripheral actions of GLP-1, this hormone is able to alter behavior through the modulation of multiple neural circuits. Recent work that focused on elucidating the mechanisms and outcomes of GLP-1 neuromodulation led to the discovery of an impressive array of GLP-1 actions. Here, we summarize the many levels at which the GLP-1 signal adapts to different systems, with the goal being to provide a background against which to guide future research.
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Affiliation(s)
- Nicholas K Smith
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Troy A Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
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18
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Flynn CR, Albaugh VL, Abumrad NN. Metabolic Effects of Bile Acids: Potential Role in Bariatric Surgery. Cell Mol Gastroenterol Hepatol 2019; 8:235-246. [PMID: 31075353 PMCID: PMC6664228 DOI: 10.1016/j.jcmgh.2019.04.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 02/08/2023]
Abstract
Bariatric surgery is the most effective and durable treatment for morbid obesity, with an unexplained yet beneficial side effect of restoring insulin sensitivity and improving glycemia, often before weight loss is observed. Among the many contributing mechanisms often cited, the altered handling of intestinal bile acids is of considerable therapeutic interest. Here, we review a growing body of literature examining the metabolic effects of bile acids ranging from their physical roles in dietary fat handling within the intestine to their functions as endocrine and paracrine hormones in potentiating responses to bariatric surgery. The roles of 2 important bile acid receptors, Takeda G-protein coupled receptor (also known as G-protein coupled bile acid receptor) and farnesoid X receptor, are highlighted as is downstream signaling through glucagon-like polypeptide 1 and its cognate receptor. Additional improvements in other phenotypes and potential contributions of commensal gut bacteria, such as Akkermansia muciniphila, which are manifest after Roux-en-Y gastric bypass and other emulations, such as gallbladder bile diversion to the ileum, are also discussed.
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Affiliation(s)
- Charles R. Flynn
- Correspondence Address correspondence to: Charles R. Flynn, PhD, 1161 21st Avenue S, CCC-2308 MCN, Nashville, Tennessee 37232-2730. fax: (615) 343-6456.
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19
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Syring KE, Cyphert TJ, Beck TC, Flynn CR, Mignemi NA, McGuinness OP. Systemic bile acids induce insulin resistance in a TGR5-independent manner. Am J Physiol Endocrinol Metab 2019; 316:E782-E793. [PMID: 30779633 PMCID: PMC6732652 DOI: 10.1152/ajpendo.00362.2018] [Citation(s) in RCA: 5] [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: 08/28/2018] [Revised: 02/04/2019] [Accepted: 02/18/2019] [Indexed: 02/07/2023]
Abstract
Bile acids are involved in the emulsification and absorption of dietary fats, as well as acting as signaling molecules. Recently, bile acid signaling through farnesoid X receptor and G protein-coupled bile acid receptor (TGR5) has been reported to elicit changes in not only bile acid synthesis but also metabolic processes, including the alteration of gluconeogenic gene expression and energy expenditure. A role for bile acids in glucose metabolism is also supported by a correlation between changes in the metabolic state of patients (i.e., obesity or postbariatric surgery) and altered serum bile acid levels. However, despite evidence for a role for bile acids during metabolically challenging settings, the direct effect of elevated bile acids on insulin action in the absence of metabolic disease has yet to be investigated. The present study examines the impact of acutely elevated plasma bile acid levels on insulin sensitivity using hyperinsulinemic-euglycemic clamps. In wild-type mice, elevated bile acids impair hepatic insulin sensitivity by blunting the insulin suppression of hepatic glucose production. The impaired hepatic insulin sensitivity could not be attributed to TGR5 signaling, as TGR5 knockout mice exhibited a similar inhibition of insulin suppression of hepatic glucose production. Canonical insulin signaling pathways, such as hepatic PKB (or Akt) activation, were not perturbed in these animals. Interestingly, bile acid infusion directly into the portal vein did not result in an impairment in hepatic insulin sensitivity. Overall, the data indicate that acute increases in circulating bile acids in lean mice impair hepatic insulin sensitivity via an indirect mechanism.
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Affiliation(s)
- Kristen E Syring
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Travis J Cyphert
- Department of Biological Sciences, Marshall University College of Science, Huntington, West Virginia
| | - Thomas C Beck
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Nicholas A Mignemi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee
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20
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Abstract
Bariatric surgery, specifically Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), are the most effective and durable treatments for morbid obesity and potentially a viable treatment for type 2 diabetes (T2D). The resolution rate of T2D following these procedures is between 40 and 80% and far surpasses that achieved by medical management alone. The molecular basis for this improvement is not entirely understood, but has been attributed in part to the altered enterohepatic circulation of bile acids. In this review we highlight how bile acids potentially contribute to improved lipid and glucose homeostasis, insulin sensitivity and energy expenditure after these procedures. The impact of altered bile acid levels in enterohepatic circulation is also associated with changes in gut microflora, which may further contribute to some of these beneficial effects. We highlight the beneficial effects of experimental surgical procedures in rodents that alter bile secretory flow without gastric restriction or altering nutrient flow. This information suggests a role for bile acids beyond dietary fat emulsification in altering whole body glucose and lipid metabolism strongly, and also suggests emerging roles for the activation of the bile acid receptors farnesoid x receptor (FXR) and G-protein coupled bile acid receptor (TGR5) in these improvements. The limitations of rodent studies and the current state of our understanding is reviewed and the potential effects of bile acids mediating the short- and long-term metabolic improvements after bariatric surgery is critically examined.
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MESH Headings
- Animals
- Bile Acids and Salts/metabolism
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/microbiology
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/surgery
- Enterohepatic Circulation
- Gastrectomy
- Gastric Bypass
- Gastrointestinal Microbiome/physiology
- Gene Expression Regulation
- Glucose/metabolism
- Homeostasis/physiology
- Humans
- Insulin Resistance
- Obesity, Morbid/metabolism
- Obesity, Morbid/microbiology
- Obesity, Morbid/pathology
- Obesity, Morbid/surgery
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Rodentia
- Signal Transduction
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Affiliation(s)
- Vance L Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Babak Banan
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Hana Ajouz
- American University of Beirut, Beirut, Lebanon
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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21
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Dikalova AE, Itani HA, Nazarewicz RR, McMaster WG, Flynn CR, Uzhachenko R, Fessel JP, Gamboa JL, Harrison DG, Dikalov SI. Sirt3 Impairment and SOD2 Hyperacetylation in Vascular Oxidative Stress and Hypertension. Circ Res 2017; 121:564-574. [PMID: 28684630 DOI: 10.1161/circresaha.117.310933] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [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: 03/03/2017] [Revised: 07/01/2017] [Accepted: 07/05/2017] [Indexed: 01/21/2023]
Abstract
RATIONALE Clinical studies have shown that Sirt3 (Sirtuin 3) expression declines by 40% by 65 years of age paralleling the increased incidence of hypertension and metabolic conditions further inactivate Sirt3 because of increased NADH (nicotinamide adenine dinucleotide, reduced form) and acetyl-CoA levels. Sirt3 impairment reduces the activity of a key mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2) because of hyperacetylation. OBJECTIVE In this study, we examined whether the loss of Sirt3 activity increases vascular oxidative stress because of SOD2 hyperacetylation and promotes endothelial dysfunction and hypertension. METHODS AND RESULTS Hypertension was markedly increased in Sirt3-knockout (Sirt3-/-) and SOD2-depleted (SOD2+/-) mice in response to low dose of angiotensin II (0.3 mg/kg per day) compared with wild-type C57Bl/6J mice. Sirt3 depletion increased SOD2 acetylation, elevated mitochondrial O2· -, and diminished endothelial nitric oxide. Angiotensin II-induced hypertension was associated with Sirt3 S-glutathionylation, acetylation of vascular SOD2, and reduced SOD2 activity. Scavenging of mitochondrial H2O2 in mCAT mice expressing mitochondria-targeted catalase prevented Sirt3 and SOD2 impairment and attenuated hypertension. Treatment of mice after onset of hypertension with a mitochondria-targeted H2O2 scavenger, mitochondria-targeted hydrogen peroxide scavenger ebselen, reduced Sirt3 S-glutathionylation, diminished SOD2 acetylation, and reduced blood pressure in wild-type but not in Sirt3-/- mice, whereas an SOD2 mimetic, (2-[2,2,6,6-tetramethylpiperidin-1-oxyl-4-ylamino]-2-oxoethyl) triphenylphosphonium (mitoTEMPO), reduced blood pressure and improved vasorelaxation both in Sirt3-/- and wild-type mice. SOD2 acetylation had an inverse correlation with SOD2 activity and a direct correlation with the severity of hypertension. Analysis of human subjects with essential hypertension showed 2.6-fold increase in SOD2 acetylation and 1.4-fold decrease in Sirt3 levels, whereas SOD2 expression was not affected. CONCLUSIONS Our data suggest that diminished Sirt3 expression and redox inactivation of Sirt3 lead to SOD2 inactivation and contributes to the pathogenesis of hypertension.
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Affiliation(s)
- Anna E Dikalova
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Hana A Itani
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Rafal R Nazarewicz
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - William G McMaster
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Charles R Flynn
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Roman Uzhachenko
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Joshua P Fessel
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Jorge L Gamboa
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - David G Harrison
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Sergey I Dikalov
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN.
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22
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Sharifnia T, Antoun J, Verriere TGC, Suarez G, Wattacheril J, Wilson KT, Peek RM, Abumrad NN, Flynn CR. Hepatic TLR4 signaling in obese NAFLD. Am J Physiol Gastrointest Liver Physiol 2015; 309:G270-8. [PMID: 26113297 PMCID: PMC4537925 DOI: 10.1152/ajpgi.00304.2014] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [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: 08/12/2014] [Accepted: 06/11/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease occurs frequently in the setting of metabolic syndrome, but the factors leading to nonalcoholic steatohepatitis (NASH) are not fully understood. This study investigated Toll-like receptor 4 (TLR4) signaling in human liver with the goal of delineating whether activation of this pathway segregates those with nonalcoholic fatty liver from those with NASH. Experiments were performed using liver biopsy tissue obtained from class III obese subjects undergoing bariatric surgery, and extended to an immortalized human hepatocyte HepaRG cell line and primary human hepatocytes. The bacterial endotoxin lipopolysaccharide (LPS) and total free fatty acid levels were significantly increased in plasma of NASH patients. TLR4 mRNA levels were significantly increased in subjects with NASH compared with NAFL as was interferon regulatory factor (IRF) 3 in the myeloid differentiation factor 88-independent signaling pathway. In HepaRG cells, nuclear factor-κB (NF-κB) nuclear translocation and functional activity increased following treatment with the fatty acid, palmitate, and following exposure to LPS compared with hepatocytes stimulated with a lipogenic treatment that induced de novo lipogenesis. Palmitate and LPS induction of NF-κB activity was partially attenuated by chemical- or small-interfering RNA-mediated inhibition of TLR4. Expression of TLR4 and its downstream mediators was upregulated with palmitate and LPS. Similar results were observed using primary human hepatocytes from a lean donor. Interestingly, NF-κB activity assays showed obese donor hepatocytes were resistant to chemical TLR4 inhibition. In conclusion, TLR4 expression is upregulated in a large cohort of NASH patients, compared with those with NAFL, and this occurs within the setting of increased LPS and fatty acids.
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Affiliation(s)
- Torfay Sharifnia
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Joseph Antoun
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Thomas G. C. Verriere
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Giovanni Suarez
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Julia Wattacheril
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Keith T. Wilson
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; ,3Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Richard M. Peek
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Naji N. Abumrad
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Charles R. Flynn
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
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23
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Cheung-Flynn JO, Flynn CR, Brophy CM. PC234. Metabolic Response to Graft Preparation-Induced Injury in Saphenous Veins. J Vasc Surg 2015. [DOI: 10.1016/j.jvs.2015.04.340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Kim SH, Wu SY, Baek JI, Choi SY, Su Y, Flynn CR, Gamse JT, Ess KC, Hardiman G, Lipschutz JH, Abumrad NN, Rockey DC. A post-developmental genetic screen for zebrafish models of inherited liver disease. PLoS One 2015; 10:e0125980. [PMID: 25950913 PMCID: PMC4423964 DOI: 10.1371/journal.pone.0125980] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [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] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization), we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease.
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Affiliation(s)
- Seok-Hyung Kim
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
- * E-mail:
| | - Shu-Yu Wu
- Department of Biology, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Jeong-In Baek
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Soo Young Choi
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Yanhui Su
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Charles R. Flynn
- Department of Surgery, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Joshua T. Gamse
- Department of Biology, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Kevin C. Ess
- Department of Pediatrics, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Gary Hardiman
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
| | - Joshua H. Lipschutz
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
- Department of Medicine, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, 29401, the United States of America
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University, Nashville, TN, 37232, the United States of America
| | - Don C. Rockey
- Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, the United States of America
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25
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Fessel JP, Flynn CR, Robinson LJ, Penner NL, Gladson S, Kang CJ, Wasserman DH, Hemnes AR, West JD. Hyperoxia synergizes with mutant bone morphogenic protein receptor 2 to cause metabolic stress, oxidant injury, and pulmonary hypertension. Am J Respir Cell Mol Biol 2013; 49:778-87. [PMID: 23742019 DOI: 10.1165/rcmb.2012-0463oc] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) has been associated with a number of different but interrelated pathogenic mechanisms. Metabolic and oxidative stresses have been shown to play important pathogenic roles in a variety of model systems. However, many of these relationships remain at the level of association. We sought to establish a direct role for metabolic stress and oxidant injury in the pathogenesis of PAH. Mice that universally express a disease-causing mutation in bone morphogenic protein receptor 2 (Bmpr2) were exposed to room air or to brief daily hyperoxia (95% oxygen for 3 h) for 6 weeks, and were compared with wild-type animals undergoing identical exposures. In both murine tissues and cultured endothelial cells, the expression of mutant Bmpr2 was sufficient to cause oxidant injury that was particularly pronounced in mitochondrial membranes. With the enhancement of mitochondrial generation of reactive oxygen species by hyperoxia, oxidant injury was substantially enhanced in mitochondrial membranes, even in tissues distant from the lung. Hyperoxia, despite its vasodilatory actions in the pulmonary circulation, significantly worsened the PAH phenotype (elevated right ventricular systolic pressure, decreased cardiac output, and increased pulmonary vascular occlusion) in Bmpr2 mutant animals. These experiments demonstrate that oxidant injury and metabolic stress contribute directly to disease development, and provide further evidence for PAH as a systemic disease with life-limiting cardiopulmonary manifestations.
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Affiliation(s)
- Joshua P Fessel
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine
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Osgood MJ, Flynn CR, Komalavilas P, Brophy C. Cell-permeant peptide inhibitors of vasospasm and intimal hyperplasia. Vascular 2012; 21:46-53. [PMID: 23104826 DOI: 10.1258/vasc.2011.201203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Outcomes from vein graft bypass are limited by graft failure, leading causes of which include intimal hyperplasia and vasospasm. Intimal hyperplasia remains the most common cause of graft failure, but no therapeutic modalities have been shown to prevent intimal hyperplasia in humans. The small heat shock proteins are a class of naturally occurring proteins in vascular smooth muscle. These proteins have an integral role in maintenance of vascular tone and in cellular defense against various stressors. Transduction domains have enabled intracellular therapeutic delivery of peptide analogs of heat shock proteins, as well as peptide inhibitors of the kinases that phosphorylate these proteins. These cell-permeant peptides have been shown to prevent vasospasm and intimal hyperplasia in vitro. Since vascular bypass using vein grafts is analogous to autologous organ transplantation, ex vivo treatment of the vein graft with cell-permeant peptide inhibitors of vasospasm and intimal hyperplasia prior to implantation provides a unique opportunity for targeted treatment of the graft to improve patency.
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Affiliation(s)
- Michael J Osgood
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
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27
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Xie X, Yi Z, Bowen B, Wolf C, Flynn CR, Sinha S, Mandarino LJ, Meyer C. Characterization of the Human Adipocyte Proteome and Reproducibility of Protein Abundance by One-Dimensional Gel Electrophoresis and HPLC-ESI-MS/MS. J Proteome Res 2011; 9:4521-34. [PMID: 20812759 DOI: 10.1021/pr100268f] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Abnormalities in adipocytes play an important role in various conditions, including the metabolic syndrome, type 2 diabetes mellitus and cardiovascular disease, but little is known about alterations at the protein level. We therefore sought to (1) comprehensively characterize the human adipocyte proteome for the first time and (2) demonstrate feasibility of measuring adipocyte protein abundances by one-dimensional SDS-PAGE and high performance liquid chromatography-electron spray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). In adipocytes isolated from approximately 0.5 g of subcutaneous abdominal adipose tissue of three healthy, lean subjects, we identified a total of 1493 proteins. Triplicate analysis indicated a 22.5% coefficient of variation of protein abundances. Proteins ranged from 5.8 to 629 kDa and included a large number of proteins involved in lipid metabolism, such as fatty acid transport, fatty acid oxidation, lipid storage, lipolysis, and lipid droplet maintenance. Furthermore, we found most glycolysis enzymes and numerous proteins associated with oxidative stress, protein synthesis and degradation as well as some adipokines. 22% of all proteins were of mitochondrial origin. These results provide the first detailed characterization of the human adipocyte proteome, suggest an important role of adipocyte mitochondria, and demonstrate feasibility of this approach to examine alterations of adipocyte protein abundances in human diseases.
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Affiliation(s)
- Xitao Xie
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona, USA
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Flynn CR, Cheung-flynn J, Smoke CC, Lowry D, Roberson R, Sheller MR, Brophy CM. Internalization and Intracellular Trafficking of a PTD-Conjugated Anti-Fibrotic Peptide, AZX100, in Human Dermal Keloid Fibroblasts. J Pharm Sci 2010; 99:3100-21. [DOI: 10.1002/jps.22087] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Højlund K, Bowen BP, Hwang H, Flynn CR, Madireddy L, Geetha T, Langlais P, Meyer C, Mandarino LJ, Yi Z. In vivo phosphoproteome of human skeletal muscle revealed by phosphopeptide enrichment and HPLC-ESI-MS/MS. J Proteome Res 2010; 8:4954-65. [PMID: 19764811 DOI: 10.1021/pr9007267] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein phosphorylation plays an essential role in signal transduction pathways that regulate substrate and energy metabolism, contractile function, and muscle mass in human skeletal muscle. Abnormal phosphorylation of signaling enzymes has been identified in insulin-resistant muscle using phosphoepitope-specific antibodies, but its role in other skeletal muscle disorders remains largely unknown. This may be in part due to insufficient knowledge of relevant targets. Here, we therefore present the first large-scale in vivo phosphoproteomic study of human skeletal muscle from 3 lean, healthy volunteers. Trypsin digestion of 3-5 mg human skeletal muscle protein was followed by phosphopeptide enrichment using SCX and TiO(2). The resulting phosphopeptides were analyzed by HPLC-ESI-MS/MS. Using this unbiased approach, we identified 306 distinct in vivo phosphorylation sites in 127 proteins, including 240 phosphoserines, 53 phosphothreonines, and 13 phosphotyrosines in at least 2 out of 3 subjects. In addition, 61 ambiguous phosphorylation sites were identified in at least 2 out of 3 subjects. The majority of phosphoproteins detected are involved in sarcomeric function, excitation-contraction coupling (the Ca(2+)-cycle), glycolysis, and glycogen metabolism. Of particular interest, we identified multiple novel phosphorylation sites on several sarcomeric Z-disk proteins known to be involved in signaling and muscle disorders. These results provide numerous new targets for the investigation of human skeletal muscle phosphoproteins in health and disease and demonstrate feasibility of phosphoproteomics research of human skeletal muscle in vivo.
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Affiliation(s)
- Kurt Højlund
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona 85287-3704, USA
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Hwang H, Bowen BP, Lefort N, Flynn CR, De Filippis EA, Roberts C, Smoke CC, Meyer C, Højlund K, Yi Z, Mandarino LJ. Proteomics analysis of human skeletal muscle reveals novel abnormalities in obesity and type 2 diabetes. Diabetes 2010; 59:33-42. [PMID: 19833877 PMCID: PMC2797941 DOI: 10.2337/db09-0214] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [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] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Insulin resistance in skeletal muscle is an early phenomenon in the pathogenesis of type 2 diabetes. Studies of insulin resistance usually are highly focused. However, approaches that give a more global picture of abnormalities in insulin resistance are useful in pointing out new directions for research. In previous studies, gene expression analyses show a coordinated pattern of reduction in nuclear-encoded mitochondrial gene expression in insulin resistance. However, changes in mRNA levels may not predict changes in protein abundance. An approach to identify global protein abundance changes involving the use of proteomics was used here. RESEARCH DESIGN AND METHODS Muscle biopsies were obtained basally from lean, obese, and type 2 diabetic volunteers (n = 8 each); glucose clamps were used to assess insulin sensitivity. Muscle protein was subjected to mass spectrometry-based quantification using normalized spectral abundance factors. RESULTS Of 1,218 proteins assigned, 400 were present in at least half of all subjects. Of these, 92 were altered by a factor of 2 in insulin resistance, and of those, 15 were significantly increased or decreased by ANOVA (P < 0.05). Analysis of protein sets revealed patterns of decreased abundance in mitochondrial proteins and altered abundance of proteins involved with cytoskeletal structure (desmin and alpha actinin-2 both decreased), chaperone function (TCP-1 subunits increased), and proteasome subunits (increased). CONCLUSIONS The results confirm the reduction in mitochondrial proteins in insulin-resistant muscle and suggest that changes in muscle structure, protein degradation, and folding also characterize insulin resistance.
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Affiliation(s)
- Hyonson Hwang
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
| | - Benjamin P. Bowen
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona
| | - Natalie Lefort
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
| | - Charles R. Flynn
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
| | | | - Christine Roberts
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
| | | | - Christian Meyer
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
| | - Kurt Højlund
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Diabetes Research Centre, Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Zhengping Yi
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- School of Life Sciences, Arizona State University, Tempe, Arizona
| | - Lawrence J. Mandarino
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
- School of Life Sciences, Arizona State University, Tempe, Arizona
- Corresponding author: Lawrence J. Mandarino,
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Dreiza CM, Komalavilas P, Furnish EJ, Flynn CR, Sheller MR, Smoke CC, Lopes LB, Brophy CM. The small heat shock protein, HSPB6, in muscle function and disease. Cell Stress Chaperones 2010; 15:1-11. [PMID: 19568960 PMCID: PMC2866971 DOI: 10.1007/s12192-009-0127-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 06/05/2009] [Indexed: 10/20/2022] Open
Abstract
The small heat shock protein, HSPB6, is a 17-kDa protein that belongs to the small heat shock protein family. HSPB6 was identified in the mid-1990s when it was recognized as a by-product of the purification of HSPB1 and HSPB5. HSPB6 is highly and constitutively expressed in smooth, cardiac, and skeletal muscle and plays a role in muscle function. This review will focus on the physiologic and biochemical properties of HSPB6 in smooth, cardiac, and skeletal muscle; the putative mechanisms of action; and therapeutic implications.
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Lefort N, Yi Z, Bowen B, Glancy B, De Filippis EA, Mapes R, Hwang H, Flynn CR, Willis WT, Civitarese A, Højlund K, Mandarino LJ. Proteome profile of functional mitochondria from human skeletal muscle using one-dimensional gel electrophoresis and HPLC-ESI-MS/MS. J Proteomics 2009; 72:1046-60. [PMID: 19567276 DOI: 10.1016/j.jprot.2009.06.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 06/12/2009] [Accepted: 06/20/2009] [Indexed: 10/20/2022]
Abstract
Mitochondria can be isolated from skeletal muscle in a manner that preserves tightly coupled bioenergetic function in vitro. The purpose of this study was to characterize the composition of such preparations using a proteomics approach. Mitochondria isolated from human vastus lateralis biopsies were functional as evidenced by their response to carbohydrate and fat-derived fuels. Using one-dimensional gel electrophoresis and HPLC-ESI-MS/MS, 823 unique proteins were detected, and 487 of these were assigned to the mitochondrion, including the newly characterized SIRT5, MitoNEET and RDH13. Proteins detected included 9 of the 13 mitochondrial DNA-encoded proteins and 86 of 104 electron transport chain (ETC) and ETC-related proteins. In addition, 59 of 78 proteins of the 55S mitoribosome, several TIM and TOM proteins and cell death proteins were present. This study presents an efficient method for future qualitative assessments of proteins from functional isolated mitochondria from small samples of healthy and diseased skeletal muscle.
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Affiliation(s)
- Natalie Lefort
- Center for Metabolic Biology, Arizona State University, Tempe, AZ, USA
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Komalavilas P, Lopes LB, Flynn CR, Smoke C, Seal B, Panitch A, Brophy CM. Reduction of heat shock protein 27 phosphorylation inhibits the development of intimal hyperplasia. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.902.6] [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)
- Padmini Komalavilas
- Center for Metabolic BiologyArizona State UniversityTempeAZ
- Carl T. Hayden VA Medical CenterPhoenixAZ
| | | | | | | | - Brandon Seal
- Weldon School of Biomedical EngineeringPurdue UniversityWest LafayetteIN
| | - Alyssa Panitch
- Weldon School of Biomedical EngineeringPurdue UniversityWest LafayetteIN
| | - Colleen M Brophy
- Center for Metabolic BiologyArizona State UniversityTempeAZ
- Carl T. Hayden VA Medical CenterPhoenixAZ
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Smoke CC, Morley EL, Flynn CR, Komalavilas P, Brophy CM. Transduction of recombinant heat shock protein 27 increases contractility of vascular smooth muscle. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1165.5] [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)
| | | | | | - Padmini Komalavilas
- Center for Metabolic BiologyArizona State UniversityTempeAZ
- Carl T Hayden Veterans Affairs Medical CenterPhoenixAZ
| | - Colleen M. Brophy
- Center for Metabolic BiologyArizona State UniversityTempeAZ
- Carl T Hayden Veterans Affairs Medical CenterPhoenixAZ
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35
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Komalavilas P, Penn RB, Flynn CR, Thresher J, Lopes LB, Furnish EJ, Guo M, Pallero MA, Murphy-Ullrich JE, Brophy CM. The small heat shock-related protein, HSP20, is a cAMP-dependent protein kinase substrate that is involved in airway smooth muscle relaxation. Am J Physiol Lung Cell Mol Physiol 2007; 294:L69-78. [PMID: 17993590 DOI: 10.1152/ajplung.00235.2007] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of the cAMP/cAMP-dependent PKA pathway leads to relaxation of airway smooth muscle (ASM). The purpose of this study was to examine the role of the small heat shock-related protein HSP20 in mediating PKA-dependent ASM relaxation. Human ASM cells were engineered to constitutively express a green fluorescent protein-PKA inhibitory fusion protein (PKI-GFP) or GFP alone. Activation of the cAMP-dependent signaling pathways by isoproterenol (ISO) or forskolin led to increases in the phosphorylation of HSP20 in GFP but not PKI-GFP cells. Forskolin treatment in GFP but not PKI-GFP cells led to a loss of central actin stress fibers and decreases in the number of focal adhesion complexes. This loss of stress fibers was associated with dephosphorylation of the actin-depolymerizing protein cofilin in GFP but not PKI-GFP cells. To confirm that phosphorylated HSP20 plays a role in PKA-induced ASM relaxation, intact strips of bovine ASM were precontracted with serotonin followed by ISO. Activation of the PKA pathway led to relaxation of bovine ASM, which was associated with phosphorylation of HSP20 and dephosphorylation of cofilin. Finally, treatment with phosphopeptide mimetics of HSP20 possessing a protein transduction domain partially relaxed precontracted bovine ASM strips. In summary, ISO-induced phosphorylation of HSP20 or synthetic phosphopeptide analogs of HSP20 decreases phosphorylation of cofilin and disrupts actin in ASM, suggesting that one possible mechanism by which HSP20 mediates ASM relaxation is via regulation of actin filament dynamics.
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Affiliation(s)
- Padmini Komalavilas
- Center for Metabolic Biology, College of Liberal Arts and Sciences, Arizona State University, PO Box 873704, Tempe, AZ 85287-3704, USA.
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36
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Højlund K, Yi Z, Hwang H, Bowen B, Lefort N, Flynn CR, Langlais P, Weintraub ST, Mandarino LJ. Characterization of the human skeletal muscle proteome by one-dimensional gel electrophoresis and HPLC-ESI-MS/MS. Mol Cell Proteomics 2007; 7:257-67. [PMID: 17911086 PMCID: PMC3836591 DOI: 10.1074/mcp.m700304-mcp200] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Changes in protein abundance in skeletal muscle are central to a large number of metabolic and other disorders, including, and perhaps most commonly, insulin resistance. Proteomics analysis of human muscle is an important approach for gaining insight into the biochemical basis for normal and pathophysiological conditions. However, to date, the number of proteins identified by this approach has been limited, with 107 different proteins being the maximum reported so far. Using a combination of one-dimensional gel electrophoresis and high performance liquid chromatography electrospray ionization tandem mass spectrometry, we identified 954 different proteins in human vastus lateralis muscle obtained from three healthy, nonobese subjects. In addition to a large number of isoforms of contractile proteins, we detected all proteins involved in the major pathways of glucose and lipid metabolism in skeletal muscle. Mitochondrial proteins accounted for 22% of all proteins identified, including 55 subunits of the respiratory complexes I-V. Moreover, a number of enzymes involved in endocrine and metabolic signaling pathways as well as calcium homeostasis were identified. These results provide the most comprehensive characterization of the human skeletal muscle proteome to date. These data hold promise for future global assessment of quantitative changes in the muscle proteome of patients affected by disorders involving skeletal muscle.
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Affiliation(s)
- Kurt Højlund
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Diabetes Research Centre, Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Zhengping Yi
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- School of Life Sciences, Arizona State University, Tempe, Arizona
- To whom correspondence should be addressed: Center for Metabolic Biology, College of Liberal Arts and Sciences, PO Box 873704, Tempe, AZ 85287–3704; Tel.: 480-727-7602; Fax: 480-727-6813;
| | - Hyonson Hwang
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
| | - Benjamin Bowen
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona
| | - Natalie Lefort
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
| | - Charles R. Flynn
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
| | - Paul Langlais
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
| | - Susan T. Weintraub
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Lawrence J. Mandarino
- Center for Metabolic Biology, Arizona State University, Tempe, Arizona
- School of Life Sciences, Arizona State University, Tempe, Arizona
- Department of Kinesiology, Arizona State University, Tempe, Arizona
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Yi Z, Langlais P, De Filippis EA, Luo M, Flynn CR, Schroeder S, Weintraub ST, Mapes R, Mandarino LJ. Global assessment of regulation of phosphorylation of insulin receptor substrate-1 by insulin in vivo in human muscle. Diabetes 2007; 56:1508-16. [PMID: 17360977 DOI: 10.2337/db06-1355] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [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] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Research has focused on insulin receptor substrate (IRS)-1 as a locus for insulin resistance. Tyrosine phosphorylation of IRS-1 initiates insulin signaling, whereas serine/threonine phosphorylation alters the ability of IRS-1 to transduce the insulin signal. Of 1,242 amino acids in IRS-1, 242 are serine/threonine. Serine/threonine phosphorylation of IRS-1 is affected by many factors, including insulin. The purpose of this study was to perform global assessment of phosphorylation of serine/threonine residues in IRS-1 in vivo in humans. RESEARCH DESIGN AND METHODS In this study, we describe our use of capillary high-performance liquid chromotography electrospray tandem mass spectrometry to identify/quantify site-specific phosphorylation of IRS-1 in human vastus lateralis muscle obtained by needle biopsy basally and after insulin infusion in four healthy volunteers. RESULTS Twenty-two serine/threonine phosphorylation sites were identified; 15 were quantified. Three sites had not been previously identified (Thr495, Ser527, and S1005). Insulin increased the phosphorylation of Ser312, Ser616, Ser636, Ser892, Ser1101, and Ser1223 (2.6 +/- 0.4, 2.9 +/- 0.8, 2.1 +/- 0.3, 1.6 +/- 0.1, 1.3 +/- 0.1, and 1.3 +/- 0.1-fold, respectively, compared with basal; P < 0.05); phosphorylation of Ser348, Thr446, Thr495, and Ser1005 decreased (0.4 +/- 0.1, 0.2 +/- 0.1, 0.1 +/- 0.1, and 0.3 +/- 0.2-fold, respectively; P < 0.05). CONCLUSIONS These results provide an assessment of IRS-1 phosphorylation in vivo and show that insulin has profound effects on IRS-1 serine/threonine phosphorylation in healthy humans.
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Affiliation(s)
- Zhengping Yi
- Center for Metabolic Biology, Arizona State University, Tempe, AZ 85287-3704, USA
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38
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Flynn CR, Smoke CC, Furnish E, Komalavilas P, Thresher J, Yi Z, Mandarino LJ, Brophy CM. Phosphorylation and activation of a transducible recombinant form of human HSP20 in Escherichia coli. Protein Expr Purif 2006; 52:50-8. [PMID: 17084643 PMCID: PMC1839877 DOI: 10.1016/j.pep.2006.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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] [Received: 07/07/2006] [Accepted: 08/19/2006] [Indexed: 10/24/2022]
Abstract
Protein-based cellular therapeutics have been limited by getting molecules into cells and the fact that many proteins require post-translational modifications for activation. Protein transduction domains (PTDs), including that from the HIV TAT protein (TAT), are small arginine rich peptides that carry molecules across the cell membrane. We have shown that the heat shock-related protein, HSP20 is a downstream-mediator of cyclic nucleotide-dependent relaxation of vascular smooth muscle and is activated by phosphorylation. In this study, we co-expressed in Escherichia coli the cDNAs encoding the catalytic subunit of protein kinase G and a TAT-HSP20 fusion protein composed of the TAT PTD (-YGRKKRRQRRR-) fused to the N-terminus of human HSP20. Immunoblot and HPLC-ESI-MS/MS analysis of the purified TAT-HSP20 demonstrated that it was phosphorylated at serine 40 (equivalent to serine 16 in wild-type human HSP20). This phosphorylated TAT-HSP20 was physiologically active in intact smooth muscles in that it inhibited 5-hydroxytryptamine-induced contractions by 57%+/-4.5. The recombinant phosphorylated protein also led to changes in actin cytoskeletal morphology in 3T3 cells. These results delineate strategies for the expression and activation of therapeutic molecules for intracellular protein based therapeutics.
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Affiliation(s)
- Charles R Flynn
- Arizona State University, Harrington Department of Bioengineering, Tempe, AZ 85287-9709, USA.
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Boles JA, Kott RW, Hatfield PG, Bergman JW, Flynn CR. Supplemental safflower oil affects the fatty acid profile, including conjugated linoleic acid, of lamb. J Anim Sci 2005; 83:2175-81. [PMID: 16100073 DOI: 10.2527/2005.8392175x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The objective of this study was to determine whether increasing levels of dietary safflower oil would alter unsaturated fat (especially CLA) and tocopherol content of lamb, animal performance, carcass characteristics, or color stability of lamb muscle tissue. Targhee x Rambouillet wethers (n = 60) were assigned to one of three diets (four pens per treatment with five lambs per pen) in a completely random design. Diets were formulated with supplemental safflower oil at 0 (control), 3, or 6% (as-fed basis) of the diet. Diets containing approximately 80% concentrate and 20% roughage were formulated, on a DM basis, to be isocaloric and isonitrogenous and to meet or exceed NRC requirements for Ca, P, and other nutrients. A subsample of 12 wethers per treatment was selected based on average BW (54 kg) and slaughtered. Carcass data (LM area, fat thickness, and internal fat content) and wholesale cut weight (leg, loin, rack, shoulder, breast, and foreshank), along with fatty acid, tocopherol, and color analysis, were determined on each carcass. The LM and infraspinatus were sampled for fatty acid profile. Increasing safflower oil supplementation from 0 to 3 or 6% increased the proportion of linoleic acid in the diet from 49.93 to 55.32 to 62.38%, respectively, whereas the percentage of oleic acid decreased from 27.94 to 23.80 to 20.73%, respectively. The percentage of oil in the diet did not (P > or = 0.11) alter the growth and carcass characteristics of lambs, nor did it alter the tocopherol content or color stability of meat. Increasing levels of safflower oil in lamb diets decreased (P < 0.01) the weight percentage of oleic acid in the infraspinatus and LM, and increased linoleic acid (P < 0.01). Oil supplementation increased (P < 0.01) the weight percentage of various isomers of CLA in muscle, with the greatest change in the cis-9,trans-11 isomer. Supplementation of sheep diets with safflower oil, up to 6% of the diet, resulted in increasing levels of unsaturated fatty acids and CLA in the lean tissue, without adversely affecting growth performance, carcass characteristics, or color stability of lamb.
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Affiliation(s)
- J A Boles
- Animal and Range Sciences Department, Montana State University, Bozeman, 59717, USA.
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40
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Lopes LB, Brophy CM, Furnish E, Flynn CR, Sparks O, Komalavilas P, Joshi L, Panitch A, Bentley MVLB. Comparative Study of the Skin Penetration of Protein Transduction Domains and a Conjugated Peptide. Pharm Res 2005; 22:750-7. [PMID: 15906170 DOI: 10.1007/s11095-005-2591-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [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] [Received: 10/04/2004] [Accepted: 01/26/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE We examined the ability of a protein transduction domain (PTD), YARA, to penetrate in the skin and carry a conjugated peptide, P20. The results with YARA were compared to those of a well-known PTD (TAT) and a control, nontransducing peptide (YKAc). The combined action of PTDs and lipid penetration enhancers was also tested. METHODS YARA, TAT, YKAc, P20, YARA-P20, and TAT-P20 were synthesized by Fmoc chemistry. Porcine ear skin mounted in a Franz diffusion cell was used to assess the topical and transdermal delivery of fluorescently tagged peptides in the presence or absence of lipid penetration enhancers (monoolein or oleic acid). The peptide concentrations in the skin (topical delivery) and receptor phase (transdermal delivery) were assessed by spectrofluorimetry. Fluorescence microscopy was used to visualize the peptides in different skin layers. RESULTS YARA and TAT, but not YKAc, penetrated abundantly in the skin and permeated modestly across this tissue. Monoolein and oleic acid did not enhance the topical and transdermal delivery of TAT or YARA but increased the topical delivery of YKAc. Importantly, YARA and TAT carried a conjugated peptide, P20, into the skin, but the transdermal delivery was very small. Fluorescence microscopy confirmed that free and conjugated PTDs reached viable layers of the skin. CONCLUSIONS YARA and TAT penetrate in the porcine ear skin in vitro and carry a conjugated model peptide, P20, with them. Thus, the use of PTDs can be a useful strategy to increase topical delivery of peptides for treatment of cutaneous diseases.
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Affiliation(s)
- Luciana B Lopes
- Biodesign Institute, Arizona State University, Tempe, Arizona, USA
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Flynn CR, Brophy CM, Furnish EJ, Komalavilas P, Tessier D, Thresher J, Joshi L. Transduction of phosphorylated heat shock-related protein 20, HSP20, prevents vasospasm of human umbilical artery smooth muscle. J Appl Physiol (1985) 2005; 98:1836-45. [PMID: 15829720 DOI: 10.1152/japplphysiol.01043.2004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of cyclic nucleotide-dependent signaling pathways inhibits agonist-induced contraction of most vascular smooth muscles except human umbilical artery smooth muscle (HUASM). This impaired vasorelaxation may contribute to complications associated with preeclampsia, intrauterine growth restriction, and preterm delivery. Cyclic nucleotide-dependent signaling pathways converge at the phosphorylation of the small heat shock-related protein HSP20, causing relaxation of vascular smooth muscle. We produced recombinant proteins containing a protein transduction domain linked to HSP20 (rTAT-HSP20). Pretreatment of HUASM with in vitro phosphorylated rTAT-HSP20 (rTAT-pHSP20) significantly inhibited serotonin-induced contraction, without a decrease in myosin light chain phosphorylation. rTAT-pHSP20 remained phosphorylated upon transduction into isolated HUASM as demonstrated by two-dimensional gel electrophoresis. Transduction of peptide analogs of phospho-HSP20 containing the phosphorylation site on HSP20 and phosphatase-resistant mimics of the phosphorylation site (S16E) also inhibited HUASM contraction. These data suggest that impaired relaxation of HUASM may result from decreased levels of phosphorylated HSP20. Protein transduction can be used to restore intracellular expression levels and the associated physiological response. Transduction of posttranslationally modified substrate proteins represents a proteomic-based therapeutic approach that may be particularly useful when the expression of downstream substrate proteins is downregulated.
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Affiliation(s)
- Charles R Flynn
- The Biodesign Institute, Arizona State Univeristy, Tempe, AZ 85287-9709, USA
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Flynn CR, Komalavilas P, Tessier D, Thresher J, Niederkofler EE, Dreiza CM, Nelson RW, Panitch A, Joshi L, Brophy CM. Transduction of biologically active motifs of the small heat shock-related protein HSP20 leads to relaxation of vascular smooth muscle. FASEB J 2003; 17:1358-60. [PMID: 12738803 DOI: 10.1096/fj.02-1028fje] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [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: 12/20/2022]
Abstract
Activation of cyclic nucleotide-dependent signaling pathways leads to phosphorylation of the small heat shock-related protein, HSP20, on serine 16, and relaxation of vascular smooth muscle. In this study, we used an enhanced protein transduction domain (PTD) sequence to deliver HSP20 phosphopeptide analogs into porcine coronary artery. The transduction of phosphoHSP20 analogs led to dose-dependent relaxation of coronary artery smooth muscle. Peptides containing the protein transduction domain coupled to a random orientation of the same amino acids did not. Direct fluorescence microscopy of arterial rings incubated with fluorescein isothiocyanate (FITC)-PTD or FITC-PTD-HSP20 peptides showed a diffuse peptide uptake. Mass spectrometric immunoassays (MSIAs) of smooth muscle homogenates were used to determine whether the phosphopeptide analogs affected the phosphorylation of endogenous HSP20. Treatment with the phosphodiesterase inhibitor papaverine led to a mass shift of 80 Da. However, there was no mass shift of HSP20 in muscles treated with phosphoHSP20 analogs. This suggests that the PTD-phosphoHSP20 peptide alone is sufficient to inhibit force maintenance and likely has a direct effect on the target of phosphorylated HSP20. These results suggest that transduction of phosphopeptide analogs of HSP20 directly alters physiological responses of intact muscles. The data also support a direct role for phosphorylated HSP20 in mediating vasorelaxation.
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Affiliation(s)
- Charles R Flynn
- Department of Bioengineering, Arizona State University, Tempe, AZ 85287-9709, USA
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Flynn CR, Michl J. .pi., .pi.-Biradicaloid hydrocarbons. o-Xylylene. Photochemical preparation from 1,4-dihydrophthalazine in rigid glass, electric spectroscopy, and calculations. J Am Chem Soc 2002. [DOI: 10.1021/ja00817a042] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Mullen RT, Lisenbee CS, Flynn CR, Trelease RN. Stable and transient expression of chimeric peroxisomal membrane proteins induces an independent "zippering" of peroxisomes and an endoplasmic reticulum subdomain. Planta 2001; 213:849-63. [PMID: 11722121 DOI: 10.1007/s004250100579] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Peroxisomal ascorbate peroxidase (APX) (EC 1.11.1.11) was shown recently to sort through a subdomain of the ER (peroxisomal endoplasmic reticulum; pER), and in certain cases, alter the distribution and/or morphology of peroxisomes and pER when overexpressed transiently in Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) cells. Our goal was to gain insight into the dynamics of peroxisomal membrane protein sorting by characterizing the structure and formation of reorganized peroxisomes and pER. Specifically, we test directly the hypothesis that the observed phenomenon is due to the oligomerization of cytosol-facing, membrane-bound polypeptides. a process referred to as membrane "zippering". Results from differential detergent permeabilization experiments confirmed that peroxisomal APX is a C-terminal "tail-anchored" (Cmatrix-Ncytosol) membrane protein with a majority of the polypeptide facing the cytosol. Transient expression of several APX chimeras whose passenger polypeptides can form dimers or trimers resulted in the progressive formation of "globular" peroxisomes and circular pER membranes. Stable expression of the trimer-capable fusion protein yielded suspension cultures that reproducibly maintained a high degree of peroxisomal globules but relatively few detectable pER membranes. Electron micrographs revealed that the globules consisted of numerous individual peroxisomes, seemingly in direct contact with other peroxisomes and/or mitochondria. These peroxisomal clusters or aggregates were not observed in cells transiently expressing monomeric versions of APX. These findings indicate that the progressive, independent "zippering" of peroxisomes and pER is due to the post-sorting oligomerization of monomeric, cytosol-facing polypeptides that are integrally inserted into the membranes of "like" organelles. The dynamics of this process are discussed, especially with respect to the involvement of the microtubule cytoskeleton.
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Affiliation(s)
- R T Mullen
- Department of Plant Biology, Arizona State University, Tempe 8528-1601, USA
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Abstract
Recent data from studies of peroxisome assembly and the subcellular sorting of peroxisomal matrix and membrane proteins have led to an expansion of the 'growth and division' and 'endoplasmic reticulum-vesiculation' models of peroxisome biogenesis into a more flexible, unified model. Within this context, we discuss the proposed role for the endoplasmic reticulum in the formation of preperoxisomes and the potential for 15 Arabidopsis peroxin homologs to function in the biogenesis of peroxisomes in plant cells.
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Affiliation(s)
- R T Mullen
- Dept Botany, University of Guelph, N1G 2W1., Guelph, Ontario, Canada.
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Flynn CR, Mullen RT, Trelease RN. Mutational analyses of a type 2 peroxisomal targeting signal that is capable of directing oligomeric protein import into tobacco BY-2 glyoxysomes. Plant J 1998; 16:709-20. [PMID: 10069077 DOI: 10.1046/j.1365-313x.1998.00344.x] [Citation(s) in RCA: 42] [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: 05/10/2023]
Abstract
In this study of the type 2 peroxisomal targeting signal (PTS2) pathway, we examined the apparent discontinuity and conservation of residues within the PTS2 nonapeptide and demonstrated that this topogenic signal is capable of directing heteromultimeric protein import in plant cells. Based on cumulative data showing that at least 26 unique, putative PTS2 nonapeptides occur within 12 diverse peroxisomal-destined proteins, the current (-R/K-L/V/I-X5-H/Q-L/A-) as well as the original (-R-L-X5-H/Q-L-) PTS2 motif appear to be oversimplified. To assess the functionality of residues within the motif, rat liver thiolase (rthio) and various chimeric chloramphenicol acetyltransferase (CAT) proteins were expressed transiently in suspension-cultured tobacco (Nicotiana tabaccum L.) cv Bright Yellow cells (BY-2), and their subcellular location was determined by immunofluoresence microscopy. Hemagglutinin (HA)-epitope-tagged-CAT subunits, lacking a PTS2 (CAT-HA), were 'piggybacked' into glyoxysomes by PTS2-bearing CAT subunits (rthio-CAT), whereas signal-depleted CAT-HA subunits that were modified to prevent oligomerization did not import into glyoxysomes. These results provided direct evidence that signal-depleted subunits imported into peroxisomes were targeted to the organelle as oligomers (heteromers) by a PTS2. Mutational analysis of residues within PTS2 nonapeptides revealed that a number of amino acid substitutions were capable of maintaining targeting function. Furthermore, functionality of residues within the PTS2 nonapeptide did not appear to require a context-specific environment conferred by adjacent residues. These results collectively suggest that the functional PTS2 is not solely defined as a sequence-specific motif, i.e. -R/K-X6-H/Q-A/L/F-, but defined also by its structural motif that is dependent upon the physiochemical properties of residues within the nonapeptide.
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Affiliation(s)
- C R Flynn
- Graduate Program in Molecular and Cellular Biology, Arizona State University, Tempe 85287-1601, USA
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Mullen RT, Lee MS, Flynn CR, Trelease RN. Diverse amino acid residues function within the type 1 peroxisomal targeting signal. Implications for the role of accessory residues upstream of the type 1 peroxisomal targeting signal. Plant Physiol 1997; 115:881-9. [PMID: 9390426 PMCID: PMC158551 DOI: 10.1104/pp.115.3.881] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The purpose of this study was to determine whether the plant type 1 peroxisomal targeting signal (PTS1) utilizes amino acid residues that do not strictly adhere to the serine-lysine-leucine (SKL) motif (small-basic-hydrophobic residues). Selected residues were appended to the C terminus of chloramphenicol acetyltransferase (CAT) and were tested for their ability to target CAT fusion proteins to glyoxysomes in tobacco (Nicotiana tabacum L.) cv Bright Yellow 2 suspension-cultured cells. CAT was redirected from the cytosol into glyoxysomes by a wide range of residues, i.e. A/C/G/S/T-H/K/ L/N/R-I/L/M/Y. Although L and N at the -2 position (-SLL, -ANL) do not conform to the SKL motif, both functioned, but in a temporally less-efficient manner. Other SKL divergent residues, however, did not target CAT to glyoxysomes, i.e. F or P at the -3 position (-FKL, -PKL), S or T at the -2 position (-SSI, STL), or D at the -1 position (-SKD). The targeting inefficiency of CAT-ANL could be ameliorated when K was included at the -4 position (-KANL). In summary, the plant PTS1 mostly conforms to the SKL motif. For those PTS1s that possess nonconforming residue(s), other residues upstream of the PTS1 appear to function as accessory sequences that enhance the temporal efficiency of peroxisomal targeting.
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Affiliation(s)
- R T Mullen
- Department of Plant Biology, Arizona State University, Tempe 85287-1601, USA
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