1
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Walker JT, Saunders DC, Rai V, Chen HH, Orchard P, Dai C, Pettway YD, Hopkirk AL, Reihsmann CV, Tao Y, Fan S, Shrestha S, Varshney A, Petty LE, Wright JJ, Ventresca C, Agarwala S, Aramandla R, Poffenberger G, Jenkins R, Mei S, Hart NJ, Phillips S, Kang H, Greiner DL, Shultz LD, Bottino R, Liu J, Below JE, Parker SCJ, Powers AC, Brissova M. Genetic risk converges on regulatory networks mediating early type 2 diabetes. Nature 2023; 624:621-629. [PMID: 38049589 DOI: 10.1038/s41586-023-06693-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 09/28/2023] [Indexed: 12/06/2023]
Abstract
Type 2 diabetes mellitus (T2D), a major cause of worldwide morbidity and mortality, is characterized by dysfunction of insulin-producing pancreatic islet β cells1,2. T2D genome-wide association studies (GWAS) have identified hundreds of signals in non-coding and β cell regulatory genomic regions, but deciphering their biological mechanisms remains challenging3-5. Here, to identify early disease-driving events, we performed traditional and multiplexed pancreatic tissue imaging, sorted-islet cell transcriptomics and islet functional analysis of early-stage T2D and control donors. By integrating diverse modalities, we show that early-stage T2D is characterized by β cell-intrinsic defects that can be proportioned into gene regulatory modules with enrichment in signals of genetic risk. After identifying the β cell hub gene and transcription factor RFX6 within one such module, we demonstrated multiple layers of genetic risk that converge on an RFX6-mediated network to reduce insulin secretion by β cells. RFX6 perturbation in primary human islet cells alters β cell chromatin architecture at regions enriched for T2D GWAS signals, and population-scale genetic analyses causally link genetically predicted reduced RFX6 expression with increased T2D risk. Understanding the molecular mechanisms of complex, systemic diseases necessitates integration of signals from multiple molecules, cells, organs and individuals, and thus we anticipate that this approach will be a useful template to identify and validate key regulatory networks and master hub genes for other diseases or traits using GWAS data.
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Affiliation(s)
- John T Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Diane C Saunders
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Vivek Rai
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Hung-Hsin Chen
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Peter Orchard
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Chunhua Dai
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yasminye D Pettway
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Alexander L Hopkirk
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Conrad V Reihsmann
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yicheng Tao
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Simin Fan
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Shristi Shrestha
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Arushi Varshney
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Lauren E Petty
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jordan J Wright
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christa Ventresca
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Samir Agarwala
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Radhika Aramandla
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Greg Poffenberger
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Regina Jenkins
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shaojun Mei
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nathaniel J Hart
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sharon Phillips
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Dale L Greiner
- Department of Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Rita Bottino
- Imagine Pharma, Devon, PA, USA
- Institute of Cellular Therapeutics, Allegheny-Singer Research Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Jie Liu
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Jennifer E Below
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Stephen C J Parker
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA.
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA.
| | - Alvin C Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- VA Tennessee Valley Healthcare System, Nashville, TN, USA.
| | - Marcela Brissova
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
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2
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Hart NJ, Weber C, Price N, Banuelos A, Schultz M, Huey B, Harnois E, Gibson C, Steyn LV, Papas KK, Lynch RM. Insulinoma-derived pseudo-islets for diabetes research. Am J Physiol Cell Physiol 2021; 321:C247-C256. [PMID: 34106785 DOI: 10.1152/ajpcell.00466.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The islets of Langerhans of the pancreas are the primary endocrine organ responsible for regulating whole body glucose homeostasis. The use of isolated primary islets for research development and training requires organ resection, careful digestion, and isolation of the islets from nonendocrine tissue. This process is time consuming, expensive, and requires substantial expertise. For these reasons, we sought to develop a more rapidly obtainable and consistent model system with characteristic islet morphology and function that could be employed to train personnel and better inform experiments prior to using isolated rodent and human islets. Immortalized β cell lines reflect several aspects of primary β cells, but cell propagation in monolayer cell culture limits their usefulness in several areas of research, which depend on islet morphology and/or functional assessment. In this manuscript, we describe the propagation and characterization of insulinoma pseudo-islets (IPIs) from a rat insulinoma cell line INS832/3. IPIs were generated with an average diameter of 200 μm, consistent with general islet morphology. The rates of oxygen consumption and mitochondrial oxidation-reduction changes in response to glucose and metabolic modulators were similar to isolated rat islets. In addition, the dynamic insulin secretory patterns of IPIs were similar to primary rat islets. Thus, INS832/3-derived IPIs provide a valuable and convenient model for accelerating islet and diabetes research.
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Affiliation(s)
| | - Craig Weber
- Department of Physiology, University of Arizona, Tucson, Arizona
| | - Nicholas Price
- Department of Surgery, University of Arizona, Tucson, Arizona
| | - Alma Banuelos
- Department of Surgery, University of Arizona, Tucson, Arizona
| | - Madison Schultz
- Department of Surgery, University of Arizona, Tucson, Arizona
| | - Barry Huey
- Department of Surgery, University of Arizona, Tucson, Arizona
| | - Emily Harnois
- Department of Physiology, University of Arizona, Tucson, Arizona
| | - Cyonna Gibson
- Department of Surgery, University of Arizona, Tucson, Arizona
| | - Leah V Steyn
- Department of Surgery, University of Arizona, Tucson, Arizona
| | - Klearchos K Papas
- Department of Surgery, University of Arizona, Tucson, Arizona.,Department of Biomedical Engineering, University of Arizona, Tucson, Arizona.,The BIO5 Institute, University of Arizona, Tucson, Arizona
| | - Ronald M Lynch
- Department of Physiology, University of Arizona, Tucson, Arizona.,Department of Biomedical Engineering, University of Arizona, Tucson, Arizona.,The BIO5 Institute, University of Arizona, Tucson, Arizona
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3
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Dai C, Walker JT, Shostak A, Bouchi Y, Poffenberger G, Hart NJ, Jacobson DA, Calcutt MW, Bottino R, Greiner DL, Shultz LD, McGuinness OP, Dean ED, Powers AC. Dapagliflozin Does Not Directly Affect Human α or β Cells. Endocrinology 2020; 161:bqaa080. [PMID: 32428240 PMCID: PMC7375801 DOI: 10.1210/endocr/bqaa080] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/14/2020] [Indexed: 02/06/2023]
Abstract
Selective inhibitors of sodium glucose cotransporter-2 (SGLT2) are widely used for the treatment of type 2 diabetes and act primarily to lower blood glucose by preventing glucose reabsorption in the kidney. However, it is controversial whether these agents also act on the pancreatic islet, specifically the α cell, to increase glucagon secretion. To determine the effects of SGLT2 on human islets, we analyzed SGLT2 expression and hormone secretion by human islets treated with the SGLT2 inhibitor dapagliflozin (DAPA) in vitro and in vivo. Compared to the human kidney, SLC5A2 transcript expression was 1600-fold lower in human islets and SGLT2 protein was not detected. In vitro, DAPA treatment had no effect on glucagon or insulin secretion by human islets at either high or low glucose concentrations. In mice bearing transplanted human islets, 1 and 4 weeks of DAPA treatment did not alter fasting blood glucose, human insulin, and total glucagon levels. Upon glucose stimulation, DAPA treatment led to lower blood glucose levels and proportionally lower human insulin levels, irrespective of treatment duration. In contrast, after glucose stimulation, total glucagon was increased after 1 week of DAPA treatment but normalized after 4 weeks of treatment. Furthermore, the human islet grafts showed no effects of DAPA treatment on hormone content, endocrine cell proliferation or apoptosis, or amyloid deposition. These data indicate that DAPA does not directly affect the human pancreatic islet, but rather suggest an indirect effect where lower blood glucose leads to reduced insulin secretion and a transient increase in glucagon secretion.
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Affiliation(s)
- Chunhua Dai
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - John T Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Alena Shostak
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Yasir Bouchi
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Greg Poffenberger
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Nathaniel J Hart
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - M Wade Calcutt
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny-Singer Research Institute, Allegheny Health Network, Pittsburgh, Pennsylvania
| | - Dale L Greiner
- Department of Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, Massachusetts
| | | | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - E Danielle Dean
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Alvin C Powers
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
- VA Tennessee Valley Healthcare System, Nashville Tennessee
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4
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Prentice BM, Hart NJ, Phillips N, Haliyur R, Judd A, Armandala R, Spraggins JM, Lowe CL, Boyd KL, Stein RW, Wright CV, Norris JL, Powers AC, Brissova M, Caprioli RM. Imaging mass spectrometry enables molecular profiling of mouse and human pancreatic tissue. Diabetologia 2019; 62:1036-1047. [PMID: 30955045 PMCID: PMC6553460 DOI: 10.1007/s00125-019-4855-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [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: 06/22/2018] [Accepted: 02/20/2019] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS The molecular response and function of pancreatic islet cells during metabolic stress is a complex process. The anatomical location and small size of pancreatic islets coupled with current methodological limitations have prevented the achievement of a complete, coherent picture of the role that lipids and proteins play in cellular processes under normal conditions and in diseased states. Herein, we describe the development of untargeted tissue imaging mass spectrometry (IMS) technologies for the study of in situ protein and, more specifically, lipid distributions in murine and human pancreases. METHODS We developed matrix-assisted laser desorption/ionisation (MALDI) IMS protocols to study metabolite, lipid and protein distributions in mouse (wild-type and ob/ob mouse models) and human pancreases. IMS allows for the facile discrimination of chemically similar lipid and metabolite isoforms that cannot be distinguished using standard immunohistochemical techniques. Co-registration of MS images with immunofluorescence images acquired from serial tissue sections allowed accurate cross-registration of cell types. By acquiring immunofluorescence images first, this serial section approach guides targeted high spatial resolution IMS analyses (down to 15 μm) of regions of interest and leads to reduced time requirements for data acquisition. RESULTS MALDI IMS enabled the molecular identification of specific phospholipid and glycolipid isoforms in pancreatic islets with intra-islet spatial resolution. This technology shows that subtle differences in the chemical structure of phospholipids can dramatically affect their distribution patterns and, presumably, cellular function within the islet and exocrine compartments of the pancreas (e.g. 18:1 vs 18:2 fatty acyl groups in phosphatidylcholine lipids). We also observed the localisation of specific GM3 ganglioside lipids [GM3(d34:1), GM3(d36:1), GM3(d38:1) and GM3(d40:1)] within murine islet cells that were correlated with a higher level of GM3 synthase as verified by immunostaining. However, in human pancreas, GM3 gangliosides were equally distributed in both the endocrine and exocrine tissue, with only one GM3 isoform showing islet-specific localisation. CONCLUSIONS/INTERPRETATION The development of more complete molecular profiles of pancreatic tissue will provide important insight into the molecular state of the pancreas during islet development, normal function, and diseased states. For example, this study demonstrates that these results can provide novel insight into the potential signalling mechanisms involving phospholipids and glycolipids that would be difficult to detect by targeted methods, and can help raise new hypotheses about the types of physiological control exerted on endocrine hormone-producing cells in islets. Importantly, the in situ measurements afforded by IMS do not require a priori knowledge of molecules of interest and are not susceptible to the limitations of immunohistochemistry, providing the opportunity for novel biomarker discovery. Notably, the presence of multiple GM3 isoforms in mouse islets and the differential localisation of lipids in human tissue underscore the important role these molecules play in regulating insulin modulation and suggest species, organ, and cell specificity. This approach demonstrates the importance of both high spatial resolution and high molecular specificity to accurately survey the molecular composition of complex, multi-functional tissues such as the pancreas.
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Affiliation(s)
- Boone M Prentice
- 9160 MRB III, Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA
| | - Nathaniel J Hart
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Neil Phillips
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Rachana Haliyur
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Audra Judd
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA
| | - Radhika Armandala
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey M Spraggins
- 9160 MRB III, Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Cindy L Lowe
- Translational Pathology Shared Resource, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kelli L Boyd
- Translational Pathology Shared Resource, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Roland W Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Christopher V Wright
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Jeremy L Norris
- 9160 MRB III, Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Alvin C Powers
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Marcela Brissova
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Richard M Caprioli
- 9160 MRB III, Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA.
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA.
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA.
- Department of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, USA.
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5
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Abstract
Over the last two decades, improved access to human islets and the development of human islet distribution networks have enabled the use of millions of human islets in hundreds of scientific research projects, leading to a dramatic increase in our understanding of human islet biology. Here we discuss recent scientific advances as well as methodological and experimental challenges that impact human islet quality, experimental outcomes and the reporting of human islets used in scientific publications. In a survey of over 200 scientific publications with human islet experimentation, we found that the reporting of critical information was quite variable, sometimes obscure, and often failed to adequately outline the experiments and results using human islets. As the complexity of human islet research grows, we propose that members of the human islet research ecosystem work together to develop procedures and approaches for accessible and transparent collecting and reporting of crucial human islet characteristics and, through this, enhance collaboration, reproducibility and rigour, leading to further advances in our understanding of human islet biology.
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Affiliation(s)
- Nathaniel J Hart
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, 7465 Medical Research Bldg IV, Vanderbilt University Medical Center, 2215 Garland Avenue, Nashville, TN, 37232-0475, USA
- Institute for Cellular Transplantation, College of Medicine, Department of Surgery, Arizona Health Sciences Center, Tucson, AZ, USA
| | - Alvin C Powers
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, 7465 Medical Research Bldg IV, Vanderbilt University Medical Center, 2215 Garland Avenue, Nashville, TN, 37232-0475, USA.
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
- VA Tennessee Valley Healthcare, Nashville, TN, USA.
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6
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Hart NJ, Weber C, Papas KK, Limesand SW, Vagner J, Lynch RM. Multivalent activation of GLP-1 and sulfonylurea receptors modulates β-cell second-messenger signaling and insulin secretion. Am J Physiol Cell Physiol 2018; 316:C48-C56. [PMID: 30404557 DOI: 10.1152/ajpcell.00209.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Linking two pharmacophores that bind different cell surface receptors into a single molecule can enhance cell-targeting specificity to cells that express the complementary receptor pair. In this report, we developed and tested a synthetic multivalent ligand consisting of glucagon-like peptide-1 (GLP-1) linked to glibenclamide (Glb) (GLP-1/Glb) for signaling efficacy in β-cells. Expression of receptors for these ligands, as a combination, is relatively specific to the β-cell in the pancreas. The multivalent GLP-1/Glb increased both intracellular cAMP and Ca2+, although Ca2+ responses were significantly depressed compared with the monomeric Glb. Moreover, GLP-1/Glb increased glucose-stimulated insulin secretion in a dose-dependent manner. However, unlike the combined monomers, GLP-1/Glb did not augment insulin secretion at nonstimulatory glucose concentrations in INS 832/13 β-cells or human islets of Langerhans. These data suggest that linking two binding elements, such as GLP-1 and Glb, into a single bivalent ligand can provide a unique functional agent targeted to β-cells.
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Affiliation(s)
| | - Craig Weber
- Department of Physiology, University of Arizona , Tucson, Arizona
| | | | - Sean W Limesand
- School of Animal and Comparative Biomedical Sciences, University of Arizona , Tucson, Arizona.,BIO5 Institute, University of Arizona , Tucson, Arizona
| | - Josef Vagner
- BIO5 Institute, University of Arizona , Tucson, Arizona
| | - Ronald M Lynch
- Department of Physiology, University of Arizona , Tucson, Arizona.,Department of Pharmacology, University of Arizona , Tucson, Arizona.,BIO5 Institute, University of Arizona , Tucson, Arizona
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7
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Hart NJ, Aramandla R, Poffenberger G, Fayolle C, Thames AH, Bautista A, Spigelman AF, Babon JAB, DeNicola ME, Dadi PK, Bush WS, Balamurugan AN, Brissova M, Dai C, Prasad N, Bottino R, Jacobson DA, Drumm ML, Kent SC, MacDonald PE, Powers AC. Cystic fibrosis-related diabetes is caused by islet loss and inflammation. JCI Insight 2018; 3:98240. [PMID: 29669939 PMCID: PMC5931120 DOI: 10.1172/jci.insight.98240] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/14/2018] [Indexed: 12/20/2022] Open
Abstract
Cystic fibrosis-related (CF-related) diabetes (CFRD) is an increasingly common and devastating comorbidity of CF, affecting approximately 35% of adults with CF. However, the underlying causes of CFRD are unclear. Here, we examined cystic fibrosis transmembrane conductance regulator (CFTR) islet expression and whether the CFTR participates in islet endocrine cell function using murine models of β cell CFTR deletion and normal and CF human pancreas and islets. Specific deletion of CFTR from murine β cells did not affect β cell function. In human islets, CFTR mRNA was minimally expressed, and CFTR protein and electrical activity were not detected. Isolated CF/CFRD islets demonstrated appropriate insulin and glucagon secretion, with few changes in key islet-regulatory transcripts. Furthermore, approximately 65% of β cell area was lost in CF donors, compounded by pancreatic remodeling and immune infiltration of the islet. These results indicate that CFRD is caused by β cell loss and intraislet inflammation in the setting of a complex pleiotropic disease and not by intrinsic islet dysfunction from CFTR mutation.
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Affiliation(s)
- Nathaniel J. Hart
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Radhika Aramandla
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Gregory Poffenberger
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Cody Fayolle
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ariel H. Thames
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Austin Bautista
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Aliya F. Spigelman
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jenny Aurielle B. Babon
- Department of Medicine, Division of Diabetes, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Megan E. DeNicola
- Department of Medicine, Division of Diabetes, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Prasanna K. Dadi
- School of Medicine, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - William S. Bush
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Appakalai N. Balamurugan
- Center for Cellular Transplantation, Department of Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, Kentucky, USA
| | - Marcela Brissova
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Chunhua Dai
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Nripesh Prasad
- Hudson Alpha Institute of Biotechnology, Huntsville, Alabama, USA
| | - Rita Bottino
- Allegheny Singer Research Institute, Pittsburgh, Pennsylvania, USA
| | - David A. Jacobson
- School of Medicine, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Mitchell L. Drumm
- School of Medicine, Department of Genetics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sally C. Kent
- Department of Medicine, Division of Diabetes, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Patrick E. MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Alvin C. Powers
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- School of Medicine, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
- VA Tennessee Valley Healthcare, Nashville, Tennessee, USA
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8
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Westacott MJ, Farnsworth NL, St Clair JR, Poffenberger G, Heintz A, Ludin NW, Hart NJ, Powers AC, Benninger RKP. Age-Dependent Decline in the Coordinated [Ca 2+] and Insulin Secretory Dynamics in Human Pancreatic Islets. Diabetes 2017; 66:2436-2445. [PMID: 28588099 PMCID: PMC5566297 DOI: 10.2337/db17-0137] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/30/2017] [Indexed: 12/25/2022]
Abstract
Aging is associated with increased risk for type 2 diabetes, resulting from reduced insulin sensitivity and secretion. Reduced insulin secretion can result from reduced proliferative capacity and reduced islet function. Mechanisms underlying altered β-cell function in aging are poorly understood in mouse and human islets, and the impact of aging on intraislet communication has not been characterized. Here, we examine how β-cell [Ca2+] and electrical communication are impacted during aging in mouse and human islets. Islets from human donors and from mice were studied using [Ca2+] imaging, static and perifusion insulin secretion assays, and gap junction permeability measurements. In human islets, [Ca2+] dynamics were coordinated within distinct subregions of the islet, invariant with islet size. There was a marked decline in the coordination of [Ca2+] dynamics, gap junction coupling, and insulin secretion dynamics with age. These age-dependent declines were reversed by pharmacological gap junction activation. These results show that human islet function declines with aging, which can reduce insulin action and may contribute to increased risk of type 2 diabetes.
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Affiliation(s)
- Matthew J Westacott
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, CO
| | - Nikki L Farnsworth
- Barbara Davis Center for Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, CO
| | - Joshua R St Clair
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, CO
| | - Greg Poffenberger
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN
- VA Tennessee Valley Healthcare System, Nashville, TN
| | - Audrey Heintz
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, CO
| | - Nurin W Ludin
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, CO
| | - Nathaniel J Hart
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Alvin C Powers
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN
- VA Tennessee Valley Healthcare System, Nashville, TN
| | - Richard K P Benninger
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, CO
- Barbara Davis Center for Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, CO
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Kelly AC, Steyn LV, Kitzmann JP, Anderson MJ, Mueller KR, Hart NJ, Lynch RM, Papas KK, Limesand SW. Function and expression of sulfonylurea, adrenergic, and glucagon-like peptide 1 receptors in isolated porcine islets. Xenotransplantation 2014; 21:385-91. [PMID: 24801676 DOI: 10.1111/xen.12101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 03/14/2014] [Indexed: 11/29/2022]
Abstract
The scarcity of human cadaveric pancreata limits large-scale application of islet transplantation for patients with diabetes. Islets isolated from pathogen-free pigs provide an economical and abundant alternative source assuming immunologic barriers are appropriate. Membrane receptors involved in insulin secretion that also have potential as imaging targets were investigated in isolated porcine islets. Quantitative (q)PCR revealed that porcine islets express mRNA transcripts for sulfonylurea receptor 1 (Sur1), inward rectifying potassium channel (Kir6.2, associated with Sur1), glucagon-like peptide 1 receptor (GLP1R), and adrenergic receptor alpha 2A (ADRα2A). Receptor function was assessed in static incubations with stimulatory glucose concentrations, and in the presence of receptor agonists. Glibenclamide, an anti-diabetic sulfonylurea, and exendin-4, a GLP-1 mimetic, potentiated glucose-stimulated insulin secretion >2-fold. Conversely, epinephrine maximally reduced insulin secretion 72 ± 9% (P < 0.05) and had a half maximal inhibitory concentration of 60 nm in porcine islets (95% confidence interval of 45-830 nm). The epinephrine action was inhibited by the ADRα2A antagonist yohimbine. Our findings demonstrate that porcine islets express and are responsive to both stimulatory and inhibitory membrane localized receptors, which can be used as imaging targets after transplantation or to modify insulin secretion.
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Affiliation(s)
- Amy C Kelly
- School of Comparative Animal and Biomedical Sciences, University of Arizona, Tucson, AZ, USA
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Hart NJ, Chung WJ, Weber C, Ananthakrishnan K, Anderson M, Patek R, Zhang Z, Limesand SW, Vagner J, Lynch RM. Hetero-bivalent GLP-1/glibenclamide for targeting pancreatic β-cells. Chembiochem 2013; 15:135-45. [PMID: 24259278 DOI: 10.1002/cbic.201300375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Indexed: 01/15/2023]
Abstract
G protein-coupled receptor (GPCR) cell signalling cascades are initiated upon binding of a specific agonist ligand to its cell surface receptor. Linking multiple heterologous ligands that simultaneously bind and potentially link different receptors on the cell surface is a unique approach to modulate cell responses. Moreover, if the target receptors are selected based on analysis of cell-specific expression of a receptor combination, then the linked binding elements might provide enhanced specificity of targeting the cell type of interest, that is, only to cells that express the complementary receptors. Two receptors whose expression is relatively specific (in combination) to insulin-secreting pancreatic β-cells are the sulfonylurea-1 (SUR1) and the glucagon-like peptide-1 (GLP-1) receptors. A heterobivalent ligand was assembled from the active fragment of GLP-1 (7-36 GLP-1) and glibenclamide, a small organic ligand for SUR1. The synthetic construct was labelled with Cy5 or europium chelated in DTPA to evaluate binding to β-cells, by using fluorescence microscopy or time-resolved saturation and competition binding assays, respectively. Once the ligand binds to β-cells, it is rapidly capped and presumably removed from the cell surface by endocytosis. The bivalent ligand had an affinity approximately fivefold higher than monomeric europium-labelled GLP-1, likely a result of cooperative binding to the complementary receptors on the βTC3 cells. The high-affinity binding was lost in the presence of either unlabelled monomer, thus demonstrating that interaction with both receptors is required for the enhanced binding at low concentrations. Importantly, bivalent enhancement was accomplished in a cell system with physiological levels of expression of the complementary receptors, thus indicating that this approach might be applicable for β-cell targeting in vivo.
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Affiliation(s)
- Nathaniel J Hart
- Department of Physiological Sciences, University of Arizona, 1656 E. Mabel St., Tucson, AZ 85721 (USA)
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Ananthakrishnan K, Penrod LV, Hart NJ, Weber CS, Anderson M, Vagner J, Limesand SW, Lynch RM. Multivalent GLP‐1/Yhb for targeted therapy and imaging of pancreatic β‐cells. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1154.18] [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)
| | | | | | | | | | | | | | - Ronald M. Lynch
- Physiological SciencesUniversity of ArizonaTucsonAZ
- BIO5 InstituteUniversity of ArizonaTucsonAZ
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Green AS, Chen X, Macko AR, Anderson MJ, Kelly AC, Hart NJ, Lynch RM, Limesand SW. Chronic pulsatile hyperglycemia reduces insulin secretion and increases accumulation of reactive oxygen species in fetal sheep islets. J Endocrinol 2012; 212:327-42. [PMID: 22182602 PMCID: PMC3516619 DOI: 10.1530/joe-11-0300] [Citation(s) in RCA: 12] [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] [Indexed: 01/21/2023]
Abstract
Children from diabetic pregnancies have a greater incidence of type 2 diabetes. Our objective was to determine if exposure to mild-moderate hyperglycemia, by modeling managed diabetic pregnancies, affects fetal β-cell function. In sheep fetuses, β-cell responsiveness was examined after 2 weeks of sustained hyperglycemia with 3 pulses/day, mimicking postprandial excursions, and compared to saline-infused controls (n = 10). Two pulsatile hyperglycemia (PHG) treatments were studied: mild (mPHG, n = 5) with +15% sustained and +55% pulse; and moderate (PHG, n = 10) with +20% sustained and +100% pulse. Fetal glucose-stimulated insulin secretion and glucose-potentiated arginine insulin secretion were lower (P < 0.05) in PHG (0.86 ± 0.13 and 2.91 ± 0.39 ng/ml plasma insulin) but not in mPHG fetuses (1.21 ± 0.08 and 4.25 ± 0.56 ng/ml) compared to controls (1.58 ± 0.25 and 4.51 ± 0.56 ng/ml). Islet insulin content was 35% lower in PHG and 35% higher in mPHG vs controls (P < 0.01). Insulin secretion and maximally stimulated insulin release were also reduced (P < 0.05) in PHG islets due to lower islet insulin content. Isolated PHG islets also had 63% greater (P < 0.01) reactive oxygen species (ROS) accumulation at 11.1 mmol/l glucose than controls (P < 0.01), but oxidative damage was not detected in islet proteins. PHG fetuses showed evidence of oxidative damage to skeletal muscle proteins (P < 0.05) but not insulin resistance. Our findings show that PHG induced dysregulation of islet ROS handling and decreased islet insulin content, but these outcomes are independent. The β-cell outcomes were dependent on the severity of hyperglycemia because mPHG fetuses had no distinguishable impairments in ROS handling or insulin secretion but greater insulin content.
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Affiliation(s)
- Alice S. Green
- Department of Animal Sciences, University of Arizona, Tucson AZ
| | - Xiaochuan Chen
- Department of Animal Sciences, University of Arizona, Tucson AZ
| | - Antoni R. Macko
- Department of Animal Sciences, University of Arizona, Tucson AZ
| | | | - Amy C. Kelly
- Department of Animal Sciences, University of Arizona, Tucson AZ
| | - Nathaniel J. Hart
- Departments of Pharmacology and Physiology, University of Arizona, Tucson AZ
| | - Ronald M. Lynch
- Departments of Pharmacology and Physiology, University of Arizona, Tucson AZ
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Smith PH, Hadfield J, Hart NJ, Koebner RMD, Boyd LA. STS markers for the wheat yellow rust resistance geneYr5suggest a NBS–LRR-type resistance gene cluster. Genome 2007; 50:259-65. [PMID: 17502899 DOI: 10.1139/g07-004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two sequence-tagged site (STS) markers for the wheat yellow rust resistance (R) gene Yr5 have been derived through the identification and characterization of linked amplified fragment length polymorphisms (AFLPs). The sequences of the 2 AFLP markers partially overlap with one another, but belong to discrete loci: S19M93-140 completely cosegregates with Yr5, whereas S23M41-310 maps at a distance of 0.7 cM. The DNA sequence of S23M41-310 shows significant homology with the 3′ end of nucleotide-binding site (NBS) - leucine-rich repeat (LRR) - type R-genes, in particular with orthologues of the rice bacterial blight R-gene Xa-I. The distinct genetic location of the 2 AFLP loci suggests that Yr5 falls within an R-gene cluster. Because neither sequence forms part of a detectable transcription product, we propose that the Yr5 R-gene cluster includes R-gene analogues and pseudogenes. A Yr5 flanking simple sequence repeat (SSR) marker has also been identified, which allows Yr5 to be effectively incorporated, along with other R-genes for yellow rust, into elite wheat genetic backgrounds, through marker-assisted selection.
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Affiliation(s)
- P H Smith
- Department of Disease and Stress Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
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Abstract
In an attempt to study the possible mechanism(s) by which captopril controls resistant heart failure, sequential haemodynamic studies (radioisotope technique) and humoral measurements (plasma renin activity, plasma aldosterone and plasma catecholamines) were obtained in 11 such patients. The studies were made at the time patients became unresponsive to other vasodilators (hydralazine or prazosin); the vasodilator drug was then discontinued and five days later, the 'no-vasodilator' studies were obtained. Captopril therapy was then started. Optimum daily maintenance dose of captopril varied from 75 to 200 mg in different patients. Studies were again repeated after a period of time equal to the duration of the previous vasodilator therapy. Digitalis and diuretic doses were kept constant throughout. Captopril improved effort tolerance in ten patients. Haemodynamically, mean blood pressure and peripheral resistance were lower than during vasodilator therapy (85 +/- 3.1 v. 92 +/- 3.3 mmHg and 47 +/- 4.4 v. 59 +/- 4.4 U.M2, respectively; p less than 0.05 for both). Cardiac index was higher during captopril treatment (1.95 +/- 0.15 v. 1.63 +/- 0.10 l/m2, p less than 0.01) and pulmonary mean transit was normalized by captopril (14.6 +/- 1.7 v. 18.4 +/- 1.3 s, p less than 0.05). Humoral indices revealed a significant (p less than 0.05) reduction in plasma aldosterone during captopril therapy (25.9 +/- 5.6 ng/dl during captopril, v. 62 +/- 22 ng/dl with no vasodilators and 50.9 +/- 6.1 ng/dl with other vasodilators). Moreover, there was a decrease in circulating plasma catecholamines during captopril treatment, but differences between the three treatment periods were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
The long-term effects of captopril therapy were assessed by sequential hemodynamic studies over a 6 month period in 19 patients with resistant congestive heart failure. Initial improvement during the first week of therapy was noted only in 11 and was marked by significant (p less than 0.005) increases in cardiac output and stroke volume, slowing of heart rate, and reduction of total peripheral resistance. Of the remaining eight patients, seven improved subsequently with maintained therapy so that by the end of 3 months of treatment only one patient failed to respond significantly. The hemodynamic index that reflected response most consistently was the shortening in pulmonary mean transit time. Simultaneously with clinical improvement there was a reduction in cardiopulmonary volume that reflected a reduction in pulmonary congestion and probably systemic vasodilation. Associated with these hemodynamic changes there was an increase in plasma renin activity and a significant reduction in plasma aldosterone, but these changes did not differ significantly between patients who responded markedly and those who responded moderately to converting enzyme inhibition. These results suggest that the response of congestive heart failure to captopril can occur gradually. Improvement was related to peripheral hemodynamic changes which led to a reduction in both total peripheral resistance and cardiopulmonary volume. The reduction in the plasma aldosterone/renin activity ratio was an effective marker of compliance.
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Clairmont AA, Hart NJ, Rooker DT, Franch RH. Upper airway obstruction and ventricular septal defect. JAMA 1975; 233:813-4. [PMID: 1173882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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