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Kim K, Nist KM, Puleo F, McKenna J, Wainford RD. Sex differences in dietary sodium evoked NCC regulation and blood pressure in male and female Sprague-Dawley, Dahl salt-resistant, and Dahl salt-sensitive rats. Am J Physiol Renal Physiol 2024; 327:F277-F289. [PMID: 38813592 DOI: 10.1152/ajprenal.00150.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 05/07/2024] [Accepted: 05/15/2024] [Indexed: 05/31/2024] Open
Abstract
Hypertension affects approximately one in two United States adults and sex plays an important role in the pathogenesis of hypertension. The Na+-Cl- cotransporter (NCC), regulated by a kinase network including with-no-lysine kinase (WNK)1 and WNK4, STE20/SPS1-related proline alanine-rich kinase (SPAK), and oxidative stress response 1 (OxSR1), is critical to Na+ reabsorption and blood pressure regulation. Dietary salt differentially modulates NCC in salt-sensitive and salt-resistant rats, in part by modulation of WNK/SPAK/OxSR1 signaling. In this study, we tested the hypothesis that sex-dependent differences in NCC regulation contribute to the development of the salt sensitivity of blood pressure using male and female Sprague-Dawley (SD), Dahl salt-resistant (DSR), and Dahl salt-sensitive (DSS) rats. In normotensive salt-resistant SD and DSR rats, a high-salt diet evoked significant decreases in NCC activity, expression, and phosphorylation. In males, these changes were associated with no change in WNK1 expression, a decrease in WNK4 levels, and suppression of SPAK/OxSR1 expression and phosphorylation. In contrast, in females, there was decreased NCC activity associated with suppression of SPAK/OxSR1 expression and phosphorylation. In hypertensive DSS rats, the ability of females to suppress NCC (in opposition to males) via a SPAK/OxSR1 mechanism likely contributes to their lower magnitude of salt-sensitive hypertension. Collectively, our findings support the existence of sex differences in male versus female rats with NCC regulation during dietary salt intake involving suppression of WNK4 expression in male rats only and the involvement of SPAK/OxSR1 signaling in both males and females.NEW & NOTEWORTHY NCC regulation is sex dependent. In normotensive male and female Sprague-Dawley and Dahl salt-resistant rats, which exhibit dietary Na+-evoked NCC suppression, male rats exhibit decreased WNK4 expression and decreased SPAK and OxSR1 levels, whereas female rats only suppress SPAK and OxSR1. In hypertensive Dahl salt-sensitive rats, the ability of females to suppress NCC (in opposition to males) via a SPAK/OxSR1 mechanism likely contributes to their lower magnitude of salt-sensitive hypertension.
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Affiliation(s)
- Kiyoung Kim
- Department of Pharmacology and Experimental Therapeutics, Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Kayla M Nist
- Department of Anatomy and Neurobiology, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Franco Puleo
- Department of Pharmacology and Experimental Therapeutics, Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - James McKenna
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Richard D Wainford
- Department of Pharmacology and Experimental Therapeutics, Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
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Grano de Oro A, Kumariya S, Mell B, Zubcevic J, Joe B, Osman I. Spontaneous vascular dysfunction in Dahl salt-sensitive male rats raised without a high-salt diet. Physiol Rep 2024; 12:e16165. [PMID: 39048525 PMCID: PMC11268988 DOI: 10.14814/phy2.16165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/09/2024] [Accepted: 07/17/2024] [Indexed: 07/27/2024] Open
Abstract
Dahl salt-sensitive (SS) rats fed a high-salt diet, but not low-salt, exhibit vascular dysfunction. Several substrains of SS rats exist that differ in their blood pressure phenotypes and salt sensitivity. The goal of this study was to investigate whether the John-Rapp-derived SS rat (SS/Jr), which exhibits spontaneous hypertension on a low-salt diet, presents with hallmarks of vascular dysfunction observed in another experimental model of hypertension independent of dietary salt, the spontaneously hypertensive rat (SHR). Endothelium-intact aortic rings and mesenteric resistance arteries were isolated from low-salt fed adult male SS/Jr rats and SHRs, or their respective controls, for isometric wire myography. Vessels were challenged with cumulative concentrations of various vasoactive substances, in the absence or presence of nitric oxide synthase or cyclooxygenase inhibitors. Despite showing some differences in their responses to various vasoactive substances, both SS/Jr rats and SHRs exhibited key features of vascular dysfunction, including endothelial dysfunction and hyperresponsiveness to vasocontractile agonists. In conclusion, this study provides evidence to support the utility of the SS/Jr rat strain maintained on a low-salt diet as a valid experimental model for vascular dysfunction, a key feature of human hypertension.
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Affiliation(s)
- Arturo Grano de Oro
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized MedicineUniversity of Toledo, College of Medicine and Life SciencesToledoOhioUSA
| | - Sanjana Kumariya
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized MedicineUniversity of Toledo, College of Medicine and Life SciencesToledoOhioUSA
| | - Blair Mell
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized MedicineUniversity of Toledo, College of Medicine and Life SciencesToledoOhioUSA
| | - Jasenka Zubcevic
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized MedicineUniversity of Toledo, College of Medicine and Life SciencesToledoOhioUSA
| | - Bina Joe
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized MedicineUniversity of Toledo, College of Medicine and Life SciencesToledoOhioUSA
| | - Islam Osman
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized MedicineUniversity of Toledo, College of Medicine and Life SciencesToledoOhioUSA
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Ferrari LF, Wilkinson A, Cahoon C, Ramirez A, Rey C, Donaldson GW, Taylor NE. Descending Control of Nociception Poorly Predicts the Development of Persistent Postsurgical Pain-like Behavior in Consomic Dahl S Rat Strains. Anesthesiology 2023; 139:476-491. [PMID: 37351557 PMCID: PMC10530067 DOI: 10.1097/aln.0000000000004662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
BACKGROUND Chronic postsurgical pain is a poorly recognized outcome of surgery where patients experience pain long after healing from the surgical insult. Descending control of nociception, a phenomenon whereby application of a strong nociceptive stimulus to one part of the body of animals inhibits pain in remote body regions, offers one strategy to identify a propensity to develop chronic postsurgical pain-like behavior. Here, consomic rat panel was used to test the hypothesis that pain persistence is mechanistically linked to ineffective descending control of nociception. METHODS Male and female Brown Norway, Dahl S, and eight consomic strains (SS-xBN) were used to determine the presence of chronic postsurgical pain-like behaviors by using paw-withdrawal threshold evaluation (von Frey method) in the area adjacent to a hind paw plantar incision. Descending control of nociception was assessed by measuring hind paw-withdrawal thresholds (Randall-Selitto method) after capsaicin (125 µg) injection into a forepaw. Consomic rats were developed by introgressing individual Brown Norway chromosomes on the Dahl S rat genetic background, as Dahl S rats lack preoperative descending control of nociception. RESULTS Substitution of several chromosomes from the "pain-resistant" Brown Norway to the "pain-prone" Dahl S/Medical College of Wisconsin reduced mechanical nociceptive sensitivity and increased endogenous pain modulation capacity by differing degrees. Statistical modeling of these data revealed that descending control of nociception is a poor general predictor of the propensity to develop chronic postsurgical pain-like behavior (poor fit for model 1). However, a significant strain-by-descending control of nociception interaction was revealed (model 3, -2*log likelihood; 550.668, -2ll change; 18.093, P = 0.034) with SS-13BN and SS-15BN strains showing a negative descending control of nociception relationship with chronic postsurgical pain-like behavior. CONCLUSIONS Descending control of nociception poorly predicted which rat strains developed chronic postsurgical pain-like behavior despite controlling for genetic, environmental, and sex differences. Two consomic strains that mimic clinical chronic postsurgical pain criteria and display a strong negative correlation with descending control of nociception were identified, offering novel candidates for future experiments exploring mechanisms that lead to chronic postsurgical pain. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Luiz F. Ferrari
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
| | - Ashley Wilkinson
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
| | - Christian Cahoon
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
| | - Anna Ramirez
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
| | - Charles Rey
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
| | - Gary W. Donaldson
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
| | - Norman E. Taylor
- Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, 84108
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Lukaszewicz K, Falck JR, Lombard J. Effect of Chronically Suppressed Plasma Angiotensin II on Regulation of the CYP4A/20-HETE Pathway in the Dahl Salt-Sensitive Rat. Antioxidants (Basel) 2023; 12:antiox12040783. [PMID: 37107157 PMCID: PMC10135295 DOI: 10.3390/antiox12040783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 04/29/2023] Open
Abstract
In Dahl salt-sensitive (SS) rats, impaired vascular relaxation can be restored by: (1) minipump infusion of a low (sub-pressor) dose of angiotensin II (ANG II) to restore physiological levels of plasma ANG II, (2) inhibition of 20-HETE production, and (3) introgression of a normally functioning renin allele from the Brown Norway rat (SS-13BN consomic rat). Unlike SS rats, SS-13BN rats have normal levels of ANG II on a normal-salt diet and suppressed ANG II on a high-salt (HS) diet. This study tested whether chronically low ANG II levels in SS rats upregulate cytochrome P450-4A (CYP4A) increasing the production of the vasoconstrictor 20-HETE. Although salt-induced suppression of ANG II levels increased reactive oxygen species (ROS) in basilar arteries from SS-13BN rats in previous studies, this study showed no change in vascular 20-HETE levels in response to ANGII suppression. CYP4A inhibition significantly reduced vascular ROS levels and restored endothelium-dependent relaxation in response to acetylcholine in the middle cerebral artery (MCA) of SS rats and HS-fed SS-13BN rats. These data demonstrate that both the renin-angiotensin system and the CYP4A/20-HETE pathway play a direct role in the vascular dysfunction of the Dahl SS rat but are independent of each other, even though they may both contribute to vascular dysfunction through ROS production.
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Affiliation(s)
| | - John R Falck
- Department of Biochemistry, University of Texas Southwestern Medical School, Dallas, TX 75390, USA
| | - Julian Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Chivers JM, Whiles SA, Miles CB, Biederman BE, Ellison MF, Lovingood CW, Wright MH, Hoover DB, Raafey MA, Youngberg GA, Venkatachalam MA, Zheleznova NN, Yang C, Liu P, Kriegel AJ, Cowley AW, O'Connor PM, Picken MM, Polichnowski AJ. Brown-Norway chromosome 1 mitigates the upregulation of proinflammatory pathways in mTAL cells and subsequent age-related CKD in Dahl SS/JrHsdMcwi rats. Am J Physiol Renal Physiol 2023; 324:F193-F210. [PMID: 36475869 PMCID: PMC9886360 DOI: 10.1152/ajprenal.00145.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 12/13/2022] Open
Abstract
Chronic kidney disease (CKD) has a strong genetic component; however, the underlying pathways are not well understood. Dahl salt-sensitive (SS)/Jr rats spontaneously develop CKD with age and are used to investigate the genetic determinants of CKD. However, there are currently several genetically diverse Dahl SS rats maintained at various institutions and the extent to which some exhibit age-related CKD is unclear. We assessed glomerulosclerosis (GS) and tubulointerstitial fibrosis (TIF) in 3- and 6-mo-old male and female SS/JrHsdMcwi, BN/NHsd/Mcwi [Brown-Norway (BN)], and consomic SS-Chr 1BN/Mcwi (SS.BN1) rats, in which chromosome 1 from the BN rat was introgressed into the genome of the SS/JrHsdMcwi rat. Rats were fed a 0.4% NaCl diet. GS (31 ± 3% vs. 7 ± 1%) and TIF (2.3 ± 0.2 vs. 0.5 ± 0.1) were significantly greater in 6-mo-old compared with 3-mo-old SS/JrHsdMcwi rats, and CKD was exacerbated in males. GS was minimal in 6- and 3-mo-old BN (3.9 ± 0.6% vs. 1.2 ± 0.4%) and SS.BN1 (2.4 ± 0.5% vs. 1.0 ± 0.3%) rats, and neither exhibited TIF. In SS/JrHsdMcwi and SS.BN1 rats, mean arterial blood pressure was significantly greater in 6-mo-old compared with 3-mo-old SS/JrHsdMcwi (162 ± 4 vs. 131 ± 2 mmHg) but not SS.BN1 (115 ± 2 vs. 116 ± 1 mmHg) rats. In 6-mo-old SS/JrHsdMcwi rats, blood pressure was significantly greater in females. RNA-sequencing analysis revealed that inflammatory pathways were upregulated in isolated medullary thick ascending tubules in 7-wk-old SS/JrHsdMcwi rats, before the development of tubule pathology, compared with SS.BN1 rats. In summary, SS/JrHsdMcwi rats exhibit robust age-related progression of medullary thick ascending limb abnormalities, CKD, and hypertension, and gene(s) on chromosome 1 have a major pathogenic role in such changes.NEW & NOTEWORTHY This study shows that the robust age-related progression of kidney disease in Dahl SS/JrHsdMcw rats maintained on a normal-salt diet is abolished in consomic SS.BN1 rats. Evidence that medullary thick ascending limb segments of SS/JrHsdMcw rats are structurally abnormal and enriched in proinflammatory pathways before the development of protein casts provides new insights into the pathogenesis of kidney disease in this model.
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Affiliation(s)
- Jacqueline M Chivers
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Shannon A Whiles
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Conor B Miles
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Brianna E Biederman
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Megan F Ellison
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Connor W Lovingood
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Marie H Wright
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - Donald B Hoover
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
- Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, Tennessee
| | - Muhammad A Raafey
- Department of Pathology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - George A Youngberg
- Department of Pathology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | | | | | - Chun Yang
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Pengyuan Liu
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Alison J Kriegel
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Paul M O'Connor
- Department of Physiology, Augusta University, Augusta, Georgia
| | - Maria M Picken
- Department of Pathology, Loyola University Medical Center, Maywood, Illinois
| | - Aaron J Polichnowski
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
- Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, Tennessee
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Henry Dasinger J, Joe B, Abais-Battad JM. Microbiota-associated mechanisms underlying sexual dimorphism in hypertension. MICROBIOTA AND HOST 2023; 1:e230016. [PMID: 38107627 PMCID: PMC10723812 DOI: 10.1530/mah-23-0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Consistent research over the last 20 years has shown that there are clear sex differences in the pathogenesis of hypertension, the leading risk factor for the development of cardiovascular diseases. More recently, there is evidence in both humans and experimental animal models that causally implicates the gut microbiota in hypertension. It therefore follows that sex differences in the gut microbiota may mediate the extent of disease between sexes. This new field is rapidly changing and advancing, and the purpose of this review is to cover the most up-to-date evidence regarding the sexual dimorphism of the gut microbiota and its potential influence on the differential manifestation of hypertension in males versus females. Emphasis will be placed on the mechanisms thought to contribute to these sex differences in both the gut microbiota and hypertension, including sex steroid hormones, gut-derived metabolites, the immune system, and pregnancy.
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Affiliation(s)
| | - Bina Joe
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences
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Ashraf UM, Atari E, Alasmari F, Waghulde H, Kumar V, Sari Y, Najjar SM, Jose PA, Kumarasamy S. Intrarenal Dopaminergic System Is Dysregulated in SS- Resp18mutant Rats. Biomedicines 2023; 11:111. [PMID: 36672619 PMCID: PMC9855394 DOI: 10.3390/biomedicines11010111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
The genetic and molecular basis of developing high blood pressure and renal disease are not well known. Resp18mutant Dahl salt-sensitive (SS-Resp18mutant) rats fed a 2% NaCl diet for six weeks have high blood pressure, increased renal fibrosis, and decreased mean survival time. Impairment of the dopaminergic system also leads to hypertension that involves renal and non-renal mechanisms. Deletion of any of the five dopamine receptors may lead to salt-sensitive hypertension. Therefore, we investigated the interaction between Resp18 and renal dopamine in SS-Resp18mutant and Dahl salt-sensitive (SS) rats. We found that SS-Resp18mutant rats had vascular dysfunction, as evidenced by a decrease in vasorelaxation in response to sodium nitroprusside. The pressure-natriuresis curve in SS-Resp18mutant rats was shifted down and to the right of SS rats. SS-Resp18mutant rats had decreased glomerular filtration rate and dopamine receptor subtypes, D1R and D5R. Renal dopamine levels were decreased, but urinary dopamine levels were increased, which may be the consequence of increased renal dopamine production, followed by secretion into the tubular lumen. The increased renal dopamine production in SS-Resp18mutant rats in vivo was substantiated by the increased dopamine production in renal proximal tubule cells treated with L-DOPA. Overall, our study provides evidence that targeted disruption of the Resp18 locus in the SS rat dysregulates the renal dopaminergic system.
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Affiliation(s)
- Usman M. Ashraf
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Ealla Atari
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Fawaz Alasmari
- Department of Pharmacology and Experimental Therapeutics, University of Toledo College of Pharmacy & Pharmaceutical Sciences, Toledo, OH 43614, USA
| | - Harshal Waghulde
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Vikash Kumar
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Youssef Sari
- Department of Pharmacology and Experimental Therapeutics, University of Toledo College of Pharmacy & Pharmaceutical Sciences, Toledo, OH 43614, USA
| | - Sonia M. Najjar
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Pedro A. Jose
- Department of Medicine, Division of Kidney Diseases & Hypertension, The George Washington University School of Medicine & Health Sciences, Washington, DC 20052, USA
- Department of Pharmacology and Physiology, The George Washington University School of Medicine & Health Sciences, Washington, DC 20052, USA
| | - Sivarajan Kumarasamy
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
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Nutrigenetic Interaction of Spontaneously Hypertensive Rat Chromosome 20 Segment and High-Sucrose Diet Sensitizes to Metabolic Syndrome. Nutrients 2022; 14:nu14163428. [PMID: 36014934 PMCID: PMC9416443 DOI: 10.3390/nu14163428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/16/2022] Open
Abstract
Several corresponding regions of human and mammalian genomes have been shown to affect sensitivity to the manifestation of metabolic syndrome via nutrigenetic interactions. In this study, we assessed the effect of sucrose administration in a newly established congenic strain BN.SHR20, in which a limited segment of rat chromosome 20 from a metabolic syndrome model, spontaneously hypertensive rat (SHR), was introgressed into Brown Norway (BN) genomic background. We mapped the extent of the differential segment and compared the genomic sequences of BN vs. SHR within the segment in silico. The differential segment of SHR origin in BN.SHR20 spans about 9 Mb of the telomeric portion of the short arm of chromosome 20. We identified non-synonymous mutations e.g., in ApoM, Notch4, Slc39a7, Smim29 genes and other variations in or near genes associated with metabolic syndrome in human genome-wide association studies. Male rats of BN and BN.SHR20 strains were fed a standard diet for 18 weeks (control groups) or 16 weeks of standard diet followed by 14 days of high-sucrose diet (HSD). We assessed the morphometric and metabolic profiles of all groups. Adiposity significantly increased only in BN.SHR20 after HSD. Fasting glycemia and the glucose levels during the oral glucose tolerance test were higher in BN.SHR20 than in BN groups, while insulin levels were comparable. The fasting levels of triacylglycerols were the highest in sucrose-fed BN.SHR20, both compared to the sucrose-fed BN and the control BN.SHR20. The non-esterified fatty acids and total cholesterol concentrations were higher in BN.SHR20 compared to their respective BN groups, and the HSD elicited an increase in non-esterified fatty acids only in BN.SHR20. In a new genetically defined model, we have isolated a limited genomic region involved in nutrigenetic sensitization to sucrose-induced metabolic disturbances.
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Cīrulis A, Hansson B, Abbott JK. Sex-limited chromosomes and non-reproductive traits. BMC Biol 2022; 20:156. [PMID: 35794589 PMCID: PMC9261002 DOI: 10.1186/s12915-022-01357-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 06/22/2022] [Indexed: 12/03/2022] Open
Abstract
Sex chromosomes are typically viewed as having originated from a pair of autosomes, and differentiated as the sex-limited chromosome (e.g. Y) has degenerated by losing most genes through cessation of recombination. While often thought that degenerated sex-limited chromosomes primarily affect traits involved in sex determination and sex cell production, accumulating evidence suggests they also influence traits not sex-limited or directly involved in reproduction. Here, we provide an overview of the effects of sex-limited chromosomes on non-reproductive traits in XY, ZW or UV sex determination systems, and discuss evolutionary processes maintaining variation at sex-limited chromosomes and molecular mechanisms affecting non-reproductive traits.
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Affiliation(s)
- Aivars Cīrulis
- Department of Biology, Lund University, 223 62, Lund, Sweden.
| | - Bengt Hansson
- Department of Biology, Lund University, 223 62, Lund, Sweden
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10
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Amraei R, Moreira JD, Wainford RD. Central Gαi 2 Protein Mediated Neuro-Hormonal Control of Blood Pressure and Salt Sensitivity. Front Endocrinol (Lausanne) 2022; 13:895466. [PMID: 35837296 PMCID: PMC9275552 DOI: 10.3389/fendo.2022.895466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
Hypertension, a major public health issue, is estimated to contribute to 10% of all deaths worldwide. Further, the salt sensitivity of blood pressure is a critical risk factor for the development of hypertension. The hypothalamic paraventricular nucleus (PVN) coordinates neuro-hormonal responses to alterations in plasma sodium and osmolality and multiple G Protein-Coupled Receptors (GPCRs) are involved in fluid and electrolyte homeostasis. In acute animal studies, our laboratory has shown that central Gαi/o subunit protein signal transduction mediates hypotensive and bradycardic responses and that Gz/q, proteins mediate the release of arginine vasopressin (AVP) and subsequent aquaretic responses to acute pharmacological stimuli. Extending these studies, our laboratory has shown that central Gαi2 proteins selectively mediate the hypotensive, sympathoinhibitory and natriuretic responses to acute pharmacological activation of GPCRs and in response to acute physiological challenges to fluid and electrolyte balance. In addition, following chronically elevated dietary sodium intake, salt resistant rats demonstrate site-specific and subunit-specific upregulation of Gαi2 proteins in the PVN, resulting in sympathoinhibition and normotension. In contrast, chronic dietary sodium intake in salt sensitive animals, which fail to upregulate PVN Gαi2 proteins, results in the absence of dietary sodium-evoked sympathoinhibition and salt sensitive hypertension. Using in situ hybridization, we observed that Gαi2 expressing neurons in parvocellular division of the PVN strongly (85%) colocalize with GABAergic neurons. Our data suggest that central Gαi2 protein-dependent responses to an acute isotonic volume expansion (VE) and elevated dietary sodium intake are mediated by the peripheral sensory afferent renal nerves and do not depend on the anteroventral third ventricle (AV3V) sodium sensitive region or the actions of central angiotensin II type 1 receptors. Our translational human genomic studies have identified three G protein subunit alpha I2 (GNAI2) single nucleotide polymorphisms (SNPs) as potential biomarkers in individuals with salt sensitivity and essential hypertension. Collectively, PVN Gαi2 proteins-gated pathways appear to be highly conserved in salt resistance to counter the effects of acute and chronic challenges to fluid and electrolyte homeostasis on blood pressure via a renal sympathetic nerve-dependent mechanism.
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Affiliation(s)
- Razie Amraei
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Jesse D. Moreira
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States
- Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Richard D. Wainford
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
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11
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Kravtsova O, Bohovyk R, Levchenko V, Palygin O, Klemens CA, Rieg T, Staruschenko A. SGLT2 inhibition effect on salt-induced hypertension, RAAS, and Na + transport in Dahl SS rats. Am J Physiol Renal Physiol 2022; 322:F692-F707. [PMID: 35466690 PMCID: PMC9142161 DOI: 10.1152/ajprenal.00053.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/08/2022] [Accepted: 04/21/2022] [Indexed: 12/27/2022] Open
Abstract
Na+-glucose cotransporter-2 (SGLT2) inhibitors are the new mainstay of treatment for diabetes mellitus and cardiovascular diseases. Despite the remarkable benefits, the molecular mechanisms mediating the effects of SGLT2 inhibitors on water and electrolyte balance are incompletely understood. The goal of this study was to determine whether SGLT2 inhibition alters blood pressure and kidney function via affecting the renin-angiotensin-aldosterone system (RAAS) and Na+ channels/transporters along the nephron in Dahl salt-sensitive rats, a model of salt-induced hypertension. Administration of dapagliflozin (Dapa) at 2 mg/kg/day via drinking water for 3 wk blunted the development of salt-induced hypertension as evidenced by lower blood pressure and a left shift of the pressure natriuresis curve. Urinary flow rate, glucose excretion, and Na+- and Cl--to-creatinine ratios increased in Dapa-treated compared with vehicle-treated rats. To define the contribution of the RAAS, we measured various hormones. Despite apparent effects on Na+- and Cl--to-creatinine ratios, Dapa treatment did not affect RAAS metabolites. Subsequently, we assessed the effects of Dapa on renal Na+ channels and transporters using RT-PCR, Western blot analysis, and patch clamp. Neither mRNA nor protein expression levels of renal transporters (SGLT2, Na+/H+ exchanger isoform 3, Na+-K+-2Cl- cotransporter 2, Na+-Cl- cotransporter, and α-, β-, and γ-epithelial Na+ channel subunits) changed significantly between groups. Furthermore, electrophysiological experiments did not reveal any difference in Dapa treatment on the conductance and activity of epithelial Na+ channels. Our data suggest that SGLT2 inhibition in a nondiabetic model of salt-sensitive hypertension blunts the development of salt-induced hypertension by causing glucosuria and natriuresis without changes in the RAAS or the expression or activity of the main Na+ channels and transporters.NEW & NOTEWORTHY The present study indicates that Na+-glucose cotransporter-2 (SGLT2) inhibition in a nondiabetic model of salt-sensitive hypertension blunts the development and magnitude of salt-induced hypertension. Chronic inhibition of SGLT2 increases glucose and Na+ excretion without secondary effects on the expression and function of other Na+ transporters and channels along the nephron and hormone levels in the renin-angiotensin-aldosterone system. These data provide novel insights into the effects of SGLT2 inhibitors and their potential use in hypertension.
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Affiliation(s)
- Olha Kravtsova
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
| | - Ruslan Bohovyk
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
| | - Vladislav Levchenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
| | - Oleg Palygin
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Christine A Klemens
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- James A. Haley Veterans' Hospital, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
| | - Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- James A. Haley Veterans' Hospital, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
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12
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Hoffman MJ, Takizawa A, Jensen ES, Schilling R, Grzybowski M, Geurts AM, Dwinell MR. Btg2 mutation induces renal injury and impairs blood pressure control in female rats. Physiol Genomics 2022; 54:231-241. [PMID: 35503009 DOI: 10.1152/physiolgenomics.00167.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypertension (HTN) is a complex disease influenced by heritable genetic elements and environmental interactions. Dietary salt is among the most influential modifiable factors contributing to increased blood pressure (BP). It is well established that men and women develop BP impairment in different patterns and a recent emphasis has been placed on identifying mechanisms leading to the differences observed between the sexes in HTN development. The current work reported here builds on an extensive genetic mapping experiment which sought to identify genetic determinants of salt sensitive (SS) HTN using the Dahl SS rat. BTG anti-proliferation factor 2 (Btg2) was previously identified by our group as a candidate gene contributing to SS HTN in female rats. In the current study, Btg2 was mutated using TALEN targeted gene disruption on the SSBN congenic rat background. The Btg2 mutated rats exhibited impaired BP and proteinuria responses to a high salt diet compared to wild type rats. Differences in body weight, mutant pup viability, skeletal morphology, and adult nephron density suggest a potential role for Btg2 in developmental signaling pathways. Subsequent cell cycle gene expression assessment provides several additional signaling pathways that Btg2 may function through during salt handling in the kidney. The expression analysis also identified several potential upstream targets that can be explored to further isolate therapeutic approaches for SS HTN.
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Affiliation(s)
- Matthew J Hoffman
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Akiko Takizawa
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Eric S Jensen
- Biomedical Research Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Rebecca Schilling
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Michael Grzybowski
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Aron M Geurts
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Melinda R Dwinell
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
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13
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Belanger KM, Mohamed R, Webb RC, Sullivan JC. Sex Differences in TLR4 Expression in SHR Do Not Contribute to Sex Differences in Blood Pressure or the Renal T cell Profile. Am J Physiol Regul Integr Comp Physiol 2022; 322:R319-R325. [PMID: 35107023 PMCID: PMC8917934 DOI: 10.1152/ajpregu.00237.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypertension is a primary risk factor for the development of cardiovascular disease. Mechanisms controlling blood pressure (BP) in men and women are still being investigated, however, there is increasing evidence supporting a role for the innate immune system. Specifically, Toll-like receptors (TLR), and TLR4 in particular, have been implicated in the development of hypertension in male spontaneously hypertensive rats (SHR). Despite established sex differences in BP control and inflammatory markers in hypertensive males and females, little is known regarding the role of TLR4 in hypertension in females. Our hypotheses were that male SHR have greater TLR4 expression compared to females, and that sex differences in TLR4 contribute to sex differences in BP and the T cell profile. To test these hypotheses, initial studies measured renal TLR4 protein expression in 13-week old male and female SHR. Additional SHR were implanted with telemetry devices and randomized to treatment with either IgG or TLR4 neutralizing antibodies. Untreated control male SHR have greater TLR4 protein expression in the kidney compared to females. However, treatment with TLR4 neutralizing antibody for 2 weeks did not significantly alter BP in either male or female SHR. Interestingly, neutralization of TLR4 increased renal CD3+ T cells in female SHR, with no alteration in CD4+ T cells or CD8+ T cells in either sex. Taken together, our data indicates that although male SHR have greater renal TLR4 expression than females, TLR4 does not contribute to the higher BP and more pro-inflammatory renal T cell prolife in males vs. females.
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Affiliation(s)
- Kasey M Belanger
- Department of Physiology Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Riyaz Mohamed
- Department of Physiology Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - R Clinton Webb
- Department of Pharmacology, Physiology, and Neuroscience University of South Carolina, Columbia, South Carolina, United States
| | - Jennifer C Sullivan
- Department of Physiology Medical College of Georgia at Augusta University, Augusta, GA, United States
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14
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Potter JC, Whiles SA, Miles CB, Whiles JB, Mitchell MA, Biederman BE, Dawoud FM, Breuel KF, Williamson GA, Picken MM, Polichnowski AJ. Salt-Sensitive Hypertension, Renal Injury, and Renal Vasodysfunction Associated With Dahl Salt-Sensitive Rats Are Abolished in Consomic SS.BN1 Rats. J Am Heart Assoc 2021; 10:e020261. [PMID: 34689582 PMCID: PMC8751849 DOI: 10.1161/jaha.120.020261] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Abnormal renal hemodynamic responses to salt‐loading are thought to contribute to salt‐sensitive (SS) hypertension. However, this is based largely on studies in anesthetized animals, and little data are available in conscious SS and salt‐resistant rats. Methods and Results We assessed arterial blood pressure, renal function, and renal blood flow during administration of a 0.4% NaCl and a high‐salt (4.0% NaCl) diet in conscious, chronically instrumented 10‐ to 14‐week‐old Dahl SS and consomic SS rats in which chromosome 1 from the salt‐resistant Brown‐Norway strain was introgressed into the genome of the SS strain (SS.BN1). Three weeks of high salt intake significantly increased blood pressure (20%) and exacerbated renal injury in SS rats. In contrast, the increase in blood pressure (5%) was similarly attenuated in Brown‐Norway and SS.BN1 rats, and both strains were completely protected against renal injury. In SS.BN1 rats, 1 week of high salt intake was associated with a significant decrease in renal vascular resistance (−8%) and increase in renal blood flow (15%). In contrast, renal vascular resistance failed to decrease, and renal blood flow remained unchanged in SS rats during high salt intake. Finally, urinary sodium excretion and glomerular filtration rate were similar between SS and SS.BN1 rats during 0.4% NaCl and high salt intake. Conclusions Our data support the concept that renal vasodysfunction contributes to blood pressure salt sensitivity in Dahl SS rats, and that genes on rat chromosome 1 play a major role in modulating renal hemodynamic responses to salt loading and salt‐induced hypertension.
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Affiliation(s)
- Jacqueline C Potter
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Shannon A Whiles
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Conor B Miles
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Jenna B Whiles
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Mark A Mitchell
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Brianna E Biederman
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Febronia M Dawoud
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Kevin F Breuel
- Department of Obstetrics and Gynecology Quillen College of MedicineEast Tennessee State University Johnson City TN
| | - Geoffrey A Williamson
- Department of Electrical and Computer Engineering Illinois Institute of Technology Chicago IL
| | - Maria M Picken
- Department of Pathology Loyola University Medical Center Maywood IL
| | - Aaron J Polichnowski
- Department of Biomedical Sciences Quillen College of MedicineEast Tennessee State University Johnson City TN.,Center of Excellence in Inflammation, Infectious Disease and Immunity East Tennessee State University Johnson City TN
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15
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Wang Z, Cheng C, Yang X, Zhang C. L-phenylalanine attenuates high salt-induced hypertension in Dahl SS rats through activation of GCH1-BH4. PLoS One 2021; 16:e0250126. [PMID: 33857222 PMCID: PMC8049246 DOI: 10.1371/journal.pone.0250126] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/31/2021] [Indexed: 02/07/2023] Open
Abstract
Amino acid metabolism plays an important role in controlling blood pressure by regulating the production of NO and ROS. The present study examined amino acid levels in the serum of Dahl SS rats and SS.13BN rats fed a low or high salt diet. We observed that 8 of 27 amino acids responded to a high salt diet in SS rats. Thus, we hypothesized that a defect in amino acids may contribute to the development of salt-induced hypertension. L-phenylalanine was used to treat SS rats with a low or high salt diet. The results demonstrated that L-phenylalanine supplementation significantly enhanced the serum nitrite levels and attenuated the high salt-induced hypertension in SS rats. Low levels of BH4 and nitrite and the impaired vascular response to acetylcholine were rescued by L-phenylalanine supplementation. Moreover, increased GTP cyclohydrolase (GCH1) mRNA, levels of BH4 and nitrite, and reduced superoxide production were observed in the kidneys of hypertensive SS rats with L-phenylalanine. The antihypertensive effects of L-phenylalanine might be mediated by enhancing BH4 biosynthesis and decreasing superoxide production from NO synthase, thereby protecting vascular and kidney function with reduced ROS and elevated NO levels. The present study demonstrated that L-phenylalanine supplementation restored vascular function, suggesting L-phenylalanine represented a potential target to attenuate high salt-sensitive hypertension through GCH1-BH4.
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Affiliation(s)
- Zhengjun Wang
- School of Psychology, Shaanxi Normal University and Key Laboratory for Behavior and Cognitive Neuroscience of Shaanxi Province, Xi’an, China
- * E-mail: (ZW); (CZ)
| | - Chen Cheng
- School of Psychology, Shaanxi Normal University and Key Laboratory for Behavior and Cognitive Neuroscience of Shaanxi Province, Xi’an, China
| | - Xiaoyu Yang
- School of Life Science, Shaanxi Normal University, Xi’an, China
| | - Chen Zhang
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
- * E-mail: (ZW); (CZ)
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16
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Kumar RK, Yang Y, Contreras AG, Garver H, Bhattacharya S, Fink GD, Rockwell CE, Watts SW. Phenotypic Changes in T Cell and Macrophage Subtypes in Perivascular Adipose Tissues Precede High-Fat Diet-Induced Hypertension. Front Physiol 2021; 12:616055. [PMID: 33815135 PMCID: PMC8010306 DOI: 10.3389/fphys.2021.616055] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/22/2021] [Indexed: 01/03/2023] Open
Abstract
Perivascular adipose tissue (PVAT) may connect adiposity to hypertension because of its vasoactive functions and proximity to blood vessels. We hypothesized that immune cell changes in PVATs precede the development of high fat diet (HFD)-induced hypertension. Both sexes of Dahl S rat become equally hypertensive when fed a HFD. Further, both sexes would have similar immune cell composition in PVATs with the development and progression of hypertension. Male and female Dahl S rats were fed a regular (10% calories from fat; CD) diet or a HFD (60%) from weaning. PVATs from around the thoracic aorta (APVAT) and small mesenteric vessels (MRPVAT) were harvested at 10 weeks (pre-hypertensive), 17 weeks (onset), or 24 (hypertensive) weeks on diet. RNA-sequencing in MRPVAT at 24 weeks indicated sex-differences with HFD (>CD) and diet-differences in males (>females). The top 2 out of 7 immune processes with the maximum number of differentially expressed genes (DEGs) were associated with immune effector processes and leukocyte activation. Macrophages and T cells (and their activation status), neutrophils, mast, B and NK cells were measured by flow cytometry. Sex-specific changes in the number of CD4 memory T cells (males > females) and M2-like macrophages (females > males) in PVATs occur with a HFD before hypertension developed. Sex-differences became more prominent with the development and progression of hypertension, driven by the diet (HFD > CD). These findings suggest that though the magnitudes of increased blood pressure were equivalent in both sexes, the associated phenotypic changes in the immune subsets within the PVATs were different in the male vs. the female with the development and progression of hypertension.
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Affiliation(s)
- Ramya Kalyana Kumar
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Yongliang Yang
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States.,Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Andres G Contreras
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States.,Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI, United States
| | - Hannah Garver
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Sudin Bhattacharya
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States.,Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States.,Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States.,Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
| | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Cheryl E Rockwell
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
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17
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Berillo O, Ouerd S, Idris-Khodja N, Rehman A, Richer C, Sinnett D, Kwitek AE, Paradis P, Schiffrin EL. Chromosome 2 Fragment Substitutions in Dahl Salt-Sensitive Rats and RNA Sequencing Identified Enpep and Hs2st1 as Vascular Inflammatory Modulators. Hypertension 2020; 77:178-189. [PMID: 33161775 DOI: 10.1161/hypertensionaha.120.15690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chromosome 2 introgression from normotensive Brown Norway (BN) rats into hypertensive Dahl salt-sensitive (SS) background (SS-chromosome 2BN/Mcwi; consomic S2B) reduced blood pressure and vascular inflammation under a normal-salt diet (NSD). We hypothesized that BN chromosome 2 contains anti-inflammatory genes that could reduce blood pressure and vascular inflammation in rats fed NSD or high-salt diet (HSD). Four- to 6-week old male SS and congenic rats containing the BN chromosome 2 distal portion (SS.BN-[rs13453786-rs66377062]/Aek; S2Ba) and middle segment (SS.BN-[rs106982173-rs65057186]/Aek; S2Bb) were fed NSD or HSD (4% NaCl) up to age 12 to 13 weeks. Systolic blood pressure determined by telemetry was higher in SS rats fed HSD versus NSD. Systolic blood pressure was lower in both congenic rats than in SS under NSD, but similar under HSD versus SS. Reactive oxygen species generation using dihydroethidium staining, expression of vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, and immune cell infiltration by immunofluorescence demonstrated that S2Ba rats present less inflammation under NSD and more under HSD versus SS rats. RNA sequencing and reverse transcription-quantitative PCR identified 2 differentially expressed genes encoded within BN chromosome 2 distal portion that could act as regulators of vascular inflammation. These were downregulated glutamyl aminopeptidase (Enpep) that was anti-inflammatory under NSD and upregulated heparan sulfate 2-O-sulfotransferase 1 (Hs2st1) that was proinflammatory under HSD. In conclusion, 2 differentially expressed genes encoded within introgressed BN chromosome 2 distal fragment were identified: Enpep associated with reduced vascular inflammation under NSD, and Hs2st1, associated with increased vascular inflammation under HSD.
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Affiliation(s)
- Olga Berillo
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Sofiane Ouerd
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Noureddine Idris-Khodja
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Asia Rehman
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Chantal Richer
- Sainte-Justine University Hospital, Montreal, QC, Canada (C.R., D.S.)
| | - Daniel Sinnett
- Sainte-Justine University Hospital, Montreal, QC, Canada (C.R., D.S.)
| | - Anne E Kwitek
- Department of Physiology, Medical College of Wisconsin, Milwaukee (A.E.K.)
| | - Pierre Paradis
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Ernesto L Schiffrin
- Department of Medicine (E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University
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18
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Cowley AW, Dwinell MR. Chromosomal Substitution Strategies to Localize Genomic Regions Related to Complex Traits. Compr Physiol 2020; 10:365-388. [PMID: 32163204 DOI: 10.1002/cphy.c180029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chromosomal substitution strategies provide a powerful tool to anonymously reveal the relationship between DNA sequence variants and a normal or disease phenotype of interest. Even in this age of CRISPR-Cas9 genome engineering, the knockdown or overexpression of a gene provides relevant information to our understanding of complex disease only when a close association of an allelic variant with the phenotype has first been established. Limitations of genetic linkage approaches led to the development of more efficient breeding strategies to substitute chromosomal segments from one animal strain into the genetic background of a different strain, enabling a direct comparison of the phenotypes of the strains with variant(s) that differ only at a defined locus. This substitution can be a whole chromosome (consomic), a part of a chromosome (congenic), or as small as only a single or several alleles (subcongenics). In contrast to complete knockout of a specific candidate gene of interest, which simply studies the effects of complete elimination of the gene, the substitution of naturally occurring variants can provide special insights into the functional actions of wild-type alleles. Strategies for production of these inbred strains are reviewed, and a number of examples are used to illustrate the utility of these model systems. Consomic/congenic strains provide a number of experimental advantages in the study of functions of genes and their variants, which are emphasized in this article, such as replication of experimental studies; determination of temporal relationships throughout a life; rigorously controlled experiments in which relations between genotype and phenotype can be tested with the confounding effects of heterogeneous genetic backgrounds, both targeted and multilayered; and "omic" studies performed at many levels of functionality, from molecules to organelles, cells to organs, and organs to organismal behavior across the life span. The application of chromosomal substitution strategies and development of consomic/congenic rat and mouse strains have greatly expanded our knowledge of genomic variants and their phenotypic relationship to physiological functions and to complex diseases such as hypertension and cancer. © 2020 American Physiological Society. Compr Physiol 10:365-388, 2020.
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Affiliation(s)
- Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Melinda R Dwinell
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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19
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Schlaak RA, Frei A, SenthilKumar G, Tsaih SW, Wells C, Mishra J, Flister MJ, Camara AKS, Bergom C. Differences in Expression of Mitochondrial Complexes Due to Genetic Variants May Alter Sensitivity to Radiation-Induced Cardiac Dysfunction. Front Cardiovasc Med 2020; 7:23. [PMID: 32195269 PMCID: PMC7066205 DOI: 10.3389/fcvm.2020.00023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 02/11/2020] [Indexed: 01/02/2023] Open
Abstract
Radiation therapy is received by over half of all cancer patients. However, radiation doses may be constricted due to normal tissue side effects. In thoracic cancers, including breast and lung cancers, cardiac radiation is a major concern in treatment planning. There are currently no biomarkers of radiation-induced cardiotoxicity. Complex genetic modifiers can contribute to the risk of radiation-induced cardiotoxicities, yet these modifiers are largely unknown and poorly understood. We have previously reported the SS (Dahl salt-sensitive/Mcwi) rat strain is a highly sensitized model of radiation-induced cardiotoxicity compared to the more resistant Brown Norway (BN) rat strain. When rat chromosome 3 from the resistant BN rat strain is substituted into the SS background (SS.BN3 consomic), it significantly attenuates radiation-induced cardiotoxicity, demonstrating inherited genetic variants on rat chromosome 3 modify radiation sensitivity. Genes involved with mitochondrial function were differentially expressed in the hearts of SS and SS.BN3 rats 1 week after radiation. Here we further assessed differences in mitochondria-related genes between the sensitive SS and resistant SS.BN3 rats. We found mitochondrial-related gene expression differed in untreated hearts, while no differences in mitochondrial morphology were seen 1 week after localized heart radiation. At 12 weeks after localized cardiac radiation, differences in mitochondrial complex protein expression in the left ventricles were seen between the SS and SS.BN3 rats. These studies suggest that differences in mitochondrial gene expression caused by inherited genetic variants may contribute to differences in sensitivity to cardiac radiation.
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Affiliation(s)
- Rachel A Schlaak
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Anne Frei
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Gopika SenthilKumar
- Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Shirng-Wern Tsaih
- Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Clive Wells
- Electron Microscope Facility, Department of Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Jyotsna Mishra
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Michael J Flister
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Amadou K S Camara
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Carmen Bergom
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, United States
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20
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Fehrenbach DJ, Mattson DL. Inflammatory macrophages in the kidney contribute to salt-sensitive hypertension. Am J Physiol Renal Physiol 2020; 318:F544-F548. [PMID: 31984790 DOI: 10.1152/ajprenal.00454.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This review will highlight recent studies that have investigated the relationship between Na+, renal macrophage polarization, and renal damage. A hyperosmotic environment drives the macrophage toward a proinflammatory phenotype and away from an anti-inflammatory phenotype. Animal models of salt-sensitive hypertension demonstrate a characteristic infiltration of macrophages into the kidney that is greatly reduced when blood pressure is lowered. Because general immunosuppression or macrophage depletion leads to a host of adverse side effects, more recent studies have modulated the interaction of specific signaling molecules, including NOD-like receptor family pyrin domain-containing 3, chemokine (C-X-C motif) ligand 16, and VEGF, to prevent the end-organ renal damage that accumulates in salt-sensitive disease.
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Affiliation(s)
- Daniel J Fehrenbach
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Physiology, Augusta University and the Medical College of Georgia, Augusta, Georgia
| | - David L Mattson
- Department of Physiology, Augusta University and the Medical College of Georgia, Augusta, Georgia
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21
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Dasinger JH, Alsheikh AJ, Abais-Battad JM, Pan X, Fehrenbach DJ, Lund H, Roberts ML, Cowley AW, Kidambi S, Kotchen TA, Liu P, Liang M, Mattson DL. Epigenetic Modifications in T Cells: The Role of DNA Methylation in Salt-Sensitive Hypertension. Hypertension 2019; 75:372-382. [PMID: 31838911 DOI: 10.1161/hypertensionaha.119.13716] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The SS (Dahl salt sensitive) rat is an established model of hypertension and renal damage that is accompanied with immune system activation in response to a high-salt diet. Investigations into the effects of sodium-independent and dependent components of the diet were shown to affect the disease phenotype with SS/MCW (JrHsdMcwi) rats maintained on a purified diet (AIN-76A) presenting with a more severe phenotype relative to grain-fed SS/CRL (JrHsdMcwiCrl) rats. Since contributions of the immune system, environment, and diet are documented to alter this phenotype, this present study examined the epigenetic profile of T cells isolated from the periphery and the kidney from these colonies. T cells isolated from kidneys of the 2 colonies revealed that transcriptomic and functional differences may contribute to the susceptibility of hypertension and renal damage. In response to high-salt challenge, the methylome of T cells isolated from the kidney of SS/MCW exhibit a significant increase in differentially methylated regions with a preference for hypermethylation compared with the SS/CRL kidney T cells. Circulating T cells exhibited similar methylation profiles between colonies. Utilizing transcriptomic data from T cells isolated from the same animals upon which the DNA methylation analysis was performed, a predominant negative correlation was observed between gene expression and DNA methylation in all groups. Lastly, inhibition of DNA methyltransferases blunted salt-induced hypertension and renal damage in the SS/MCW rats providing a functional role for methylation. This study demonstrated the influence of epigenetic modifications to immune cell function, highlighting the need for further investigations.
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Affiliation(s)
- John Henry Dasinger
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Ammar J Alsheikh
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Justine M Abais-Battad
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Xiaoqing Pan
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Daniel J Fehrenbach
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Hayley Lund
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Michelle L Roberts
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Allen W Cowley
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Srividya Kidambi
- Medicine (S.K., T.A.K.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Theodore A Kotchen
- Medicine (S.K., T.A.K.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Pengyuan Liu
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - Mingyu Liang
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
| | - David L Mattson
- From the Departments of Physiology (J.H.D., A.J.A., J.M.A.-B., X.P., D.J.F., H.L., M.L.R., A.W.C., P.L., M.L., D.L.M.), Medical College of Wisconsin Milwaukee, Wisconsin, USA
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22
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Rapp JP, Garrett MR. Will the real Dahl S rat please stand up? Am J Physiol Renal Physiol 2019; 317:F1231-F1240. [PMID: 31545925 DOI: 10.1152/ajprenal.00359.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- John P Rapp
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio
| | - Michael R Garrett
- Department of Pharmacology, University of Mississippi Medical Center, Jackson, Mississippi
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23
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Rapp JP, Joe B. Dissecting Epistatic QTL for Blood Pressure in Rats: Congenic Strains versus Heterogeneous Stocks, a Reality Check. Compr Physiol 2019; 9:1305-1337. [PMID: 31688958 DOI: 10.1002/cphy.c180038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Advances in molecular genetics have provided well-defined physical genetic maps and large numbers of genetic markers for both model organisms and humans. It is now possible to gain a fundamental understanding of the genetic architecture underlying quantitative traits, of which blood pressure (BP) is an important example. This review emphasizes analytical techniques and results obtained using the Dahl salt-sensitive (S) rat as a model of hypertension by presenting results in detail for three specific chromosomal regions harboring genetic elements of increasing complexity controlling BP. These results highlight the critical importance of genetic interactions (epistasis) on BP at all levels of structure, intragenic, intergenic, intrachromosomal, interchromosomal, and across whole genomes. In two of the three examples presented, specific DNA structural variations leading to biochemical, physiological, and pathological mechanisms are well defined. This proves the usefulness of the techniques involving interval mapping followed by substitution mapping using congenic strains. These classic techniques are compared to newer approaches using sophisticated statistical analysis on various segregating or outbred model-organism populations, which in some cases are uniquely useful in demonstrating the existence of higher-order interactions. It is speculated that hypertension as an outlier quantitative phenotype is dependent on higher-order genetic interactions. The obstacle to the identification of genetic elements and the biochemical/physiological mechanisms involved in higher-order interactions is not theoretical or technical but the lack of future resources to finish the job of identifying the individual genetic elements underlying the quantitative trait loci for BP and ascertaining their molecular functions. © 2019 American Physiological Society. Compr Physiol 9:1305-1337, 2019.
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Affiliation(s)
- John P Rapp
- Physiological Genomics Laboratory, Department of Physiology and Pharmacology, Center for Hypertension and Precision Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Bina Joe
- Physiological Genomics Laboratory, Department of Physiology and Pharmacology, Center for Hypertension and Precision Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
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24
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Fehrenbach DJ, Abais-Battad JM, Dasinger JH, Lund H, Mattson DL. Salt-sensitive increase in macrophages in the kidneys of Dahl SS rats. Am J Physiol Renal Physiol 2019; 317:F361-F374. [PMID: 31215801 DOI: 10.1152/ajprenal.00096.2019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Studies of Dahl salt-sensitive (SS) rats have shown that renal CD3+ T cells and ED-1+ macrophages are involved in the development of salt-sensitive hypertension and renal damage. The present study demonstrated that the increase in renal immune cells, which accompanies renal hypertrophy and albuminuria in high-salt diet-fed Dahl SS rats, is absent in Sprague-Dawley and SSBN13 rats that are protected from the SS disease phenotype. Flow cytometric analysis demonstrated that >70% of the immune cells in the SS kidney are M1 macrophages. PCR profiling of renal myeloid cells showed a salt-induced upregulation in 9 of 84 genes related to Toll-like receptor signaling, with notable upregulation of the Toll-like receptor 4/CD14/MD2 complex. Because of the prominent increase in macrophages in the SS kidney, we used liposome-encapsulated clodronate (Clod) to deplete macrophages and assess their contribution to salt-sensitive hypertension and renal damage. Dahl SS animals were administered either Clod-containing liposomes (Clod-Lipo), Clod, or PBS-containing liposomes as a vehicle control. Clod-Lipo treatment depleted circulating and splenic macrophages by ∼50%; however, contrary to our hypothesis, Clod-Lipo-treated animals developed an exacerbated salt-sensitive response with respect to blood pressure and albuminuria, which was accompanied by increased renal T and B cells. Interestingly, those treated with Clod also demonstrated an exacerbated phenotype, but it was less severe than Clod-Lipo-treated animals and independent of changes to the number of renal immune cells. Here, we have shown that renal macrophages in Dahl SS animals sustain a M1 proinflammatory phenotype in response to increased dietary salt and highlighted potential adverse effects of Clod-Lipo macrophage depletion.
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Affiliation(s)
- Daniel J Fehrenbach
- Department of Physiology, Medical College of Wisconsin, Wauwatosa, Wisconsin
| | | | - John Henry Dasinger
- Department of Physiology, Medical College of Wisconsin, Wauwatosa, Wisconsin
| | - Hayley Lund
- Department of Physiology, Medical College of Wisconsin, Wauwatosa, Wisconsin
| | - David L Mattson
- Department of Physiology, Medical College of Wisconsin, Wauwatosa, Wisconsin
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25
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Schlaak RA, Frei A, Schottstaedt AM, Tsaih SW, Fish BL, Harmann L, Liu Q, Gasperetti T, Medhora M, North PE, Strande JL, Sun Y, Rui H, Flister MJ, Bergom C. Mapping genetic modifiers of radiation-induced cardiotoxicity to rat chromosome 3. Am J Physiol Heart Circ Physiol 2019; 316:H1267-H1280. [PMID: 30848680 PMCID: PMC6620678 DOI: 10.1152/ajpheart.00482.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 02/08/2023]
Abstract
Radiation therapy is used in ~50% of cancer patients to reduce the risk of recurrence and in some cases improve survival. Despite these benefits, doses can be limited by toxicity in multiple organs, including the heart. The underlying causes and biomarkers of radiation-induced cardiotoxicity are currently unknown, prompting the need for experimental models with inherent differences in sensitivity and resistance to the development of radiation-induced cardiotoxicity. We have identified the parental SS (Dahl salt-sensitive/Mcwi) rat strain to be a highly-sensitized model of radiation-induced cardiotoxicity. In comparison, substitution of rat chromosome 3 from the resistant BN (Brown Norway) rat strain onto the SS background (SS-3BN consomic) significantly attenuated radiation-induced cardiotoxicity. SS-3BN rats had less radiation-induced cardiotoxicity than SS rats, as measured by survival, pleural and pericardial effusions, echocardiogram parameters, and histological damage. Mast cells, previously shown to have predominantly protective roles in radiation-induced cardiotoxicity, were increased in the more resistant SS-3BN hearts postradiation. RNA sequencing from SS and SS-3BN hearts at 1 wk postradiation revealed 5,098 differentially expressed candidate genes across the transcriptome and 350 differentially expressed genes on rat chromosome 3, which coincided with enrichment of multiple pathways, including mitochondrial dysfunction, sirtuin signaling, and ubiquitination. Upstream regulators of enriched pathways included the oxidative stress modulating transcription factor, Nrf2, which is located on rat chromosome 3. Nrf2 target genes were also differentially expressed in the SS vs. SS-3BN consomic hearts postradiation. Collectively, these data confirm the existence of heritable modifiers in radiation-induced cardiotoxicity and provide multiple biomarkers, pathways, and candidate genes for future analyses. NEW & NOTEWORTHY This novel study reveals that heritable genetic factors have the potential to modify normal tissue sensitivity to radiation. Gene variant(s) on rat chromosome 3 can contribute to enhanced cardiotoxicity displayed in the SS rats vs. the BN and SS-3BN consomic rats. Identifying genes that lead to understanding the mechanisms of radiation-induced cardiotoxicity represents a novel method to personalize radiation treatment, as well as predict the development of radiation-induced cardiotoxicity.
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Affiliation(s)
- Rachel A Schlaak
- Department of Pharmacology and Toxicology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Anne Frei
- Department of Radiation Oncology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | | | - Shirng-Wern Tsaih
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Brian L Fish
- Department of Radiation Oncology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Leanne Harmann
- Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Qian Liu
- Interdisciplinary Program in Biomedical Sciences, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Tracy Gasperetti
- Department of Radiation Oncology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Meetha Medhora
- Department of Radiation Oncology, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cardiovascular Center, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Paula E North
- Department of Pathology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Jennifer L Strande
- Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cardiovascular Center, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Yunguang Sun
- Department of Pathology, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cancer Center, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Hallgeir Rui
- Department of Pathology, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cancer Center, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Michael J Flister
- Department of Medicine, Case Western Reserve University , Cleveland, Ohio
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cardiovascular Center, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cancer Center, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Carmen Bergom
- Department of Radiation Oncology, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cardiovascular Center, Medical College of Wisconsin , Milwaukee, Wisconsin
- Cancer Center, Medical College of Wisconsin , Milwaukee, Wisconsin
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26
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Fernandes R, Garver H, Harkema JR, Galligan JJ, Fink GD, Xu H. Sex Differences in Renal Inflammation and Injury in High-Fat Diet-Fed Dahl Salt-Sensitive Rats. Hypertension 2019; 72:e43-e52. [PMID: 30354819 DOI: 10.1161/hypertensionaha.118.11485] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We examined the impact of sex on high-fat diet (HFD)-induced renal alterations in Dahl salt-sensitive and Sprague Dawley rats. In Dahl rats, HFD (60% kcal from fat for 24-26 weeks starting at weaning) significantly and equally increased blood pressure in males and females when compared with rats fed a control diet (10% kcal from fat). Male Dahl rats on HFD exhibited progressive renal histological injury and moderately increased renal macrophage infiltration at 10 and 24 weeks of feeding when compared with males on control diet. Female Dahl rats had lower grade renal injury and less macrophage infiltration (except at 17 weeks) than males regardless of diet. Male Dahl rats on both diets showed progressively increasing numbers of renal T-cells, a pattern not observed in females. HFD per se did not significantly affect renal T-cell number. Male Dahl rats had lower renal regulatory T-cells cell ratio than females at 24 weeks. Renal macrophage and T-cell infiltrations were highly correlated to final mean arterial pressure levels in males but not in females. Sprague Dawley rats fed HFD were normotensive without significant renal injury/inflammation after 24 weeks of feeding. In summary, HFD feeding fails to increase arterial blood pressure in Sprague Dawley rats but strongly promotes hypertension in both male and female Dahl salt-sensitive rats. Only Dahl males, however, exhibited blood pressure-associated renal inflammation and injury. Maintenance of regulatory T-cells ratio may protect against hypertension-associated renal injury/inflammation but not HFD-induced hypertension.
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Affiliation(s)
- Roxanne Fernandes
- From the Department of Pharmacology and Toxicology, Michigan State University, East Lansing (R.F., H.G., J.J.G., G.D.F., H.X.)
| | - Hannah Garver
- From the Department of Pharmacology and Toxicology, Michigan State University, East Lansing (R.F., H.G., J.J.G., G.D.F., H.X.)
| | - Jack R Harkema
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing (J.R.H.)
| | - James J Galligan
- From the Department of Pharmacology and Toxicology, Michigan State University, East Lansing (R.F., H.G., J.J.G., G.D.F., H.X.).,Neuroscience Program, Michigan State University, East Lansing (J.J.G., G.D.F., H.X.)
| | - Gregory D Fink
- From the Department of Pharmacology and Toxicology, Michigan State University, East Lansing (R.F., H.G., J.J.G., G.D.F., H.X.).,Neuroscience Program, Michigan State University, East Lansing (J.J.G., G.D.F., H.X.)
| | - Hui Xu
- From the Department of Pharmacology and Toxicology, Michigan State University, East Lansing (R.F., H.G., J.J.G., G.D.F., H.X.).,Neuroscience Program, Michigan State University, East Lansing (J.J.G., G.D.F., H.X.)
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27
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Regal JF, Laule CF, McCutcheon L, Root KM, Lund H, Hashmat S, Mattson DL. The complement system in hypertension and renal damage in the Dahl SS rat. Physiol Rep 2019; 6:e13655. [PMID: 29595916 PMCID: PMC5875537 DOI: 10.14814/phy2.13655] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/25/2018] [Accepted: 02/26/2018] [Indexed: 11/24/2022] Open
Abstract
Evidence indicates the immune system is important in development of hypertension and kidney disease. In the Dahl Salt-Sensitive (SS) rat model, lymphocytes play a role in development of hypertension and kidney damage after increased sodium intake. Recent transcriptomic analyses demonstrate upregulation of the innate immune complement system in the kidney of Dahl SS rat fed a high-salt diet, leading us to hypothesize that inhibition of complement activation would attenuate development of hypertension and kidney damage. Male Dahl SS rats on a low salt (0.4% NaCl) diet were instrumented with telemeters for continuous monitoring of arterial blood pressure. Animals received saline vehicle (Control) or sCR1, a soluble form of endogenous Complement Receptor 1 (CR1; CD35) that inhibits complement activation. At Day 0, rats were switched to high salt (4.0% NaCl) diet and assigned to sCR1 (15 mg/kg per day) or Control groups with daily ip injections either days 1-7 or days 14-18. Urine was collected overnight for determination of albumin excretion. Treatment with sCR1, either immediately after high-salt diet was initiated, or at days 14-18, did not alter development of hypertension or albuminuria. The sCR1 dose effectively inhibited total hemolytic complement activity as well as C3a generation. High salt caused an increase in message for complement regulator Cd59, with minimal change in Crry that controls the C3 convertase. Thus, innate immune complement activation in the circulation is not critical for development of hypertension and kidney damage due to increased sodium intake, and therapeutic manipulation of the complement system is not indicated in salt-sensitive hypertension.
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Affiliation(s)
- Jean F Regal
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Connor F Laule
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Luke McCutcheon
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Kate M Root
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Hayley Lund
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Shireen Hashmat
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - David L Mattson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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28
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Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
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Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
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29
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Sandoval RM, Molitoris BA, Palygin O. Fluorescent Imaging and Microscopy for Dynamic Processes in Rats. Methods Mol Biol 2019; 2018:151-175. [PMID: 31228156 PMCID: PMC6693343 DOI: 10.1007/978-1-4939-9581-3_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The rat is a favored model organism to study physiological function in vivo. This is largely due to the fact that it has been used for decades and is often more comparable to corresponding human conditions (both normal and pathologic) than mice. Although the development of genetic manipulations in rats has been slower than in mice, recent advances of new genomic editing tools allow for the generation of targeted global and specific cell type mutations in different rat strains. The rat is an ideal model for advancing imaging techniques like intravital multi-photon microscopy or IVMPM. Multi-photon excitation microscopy can be applied to visualize real-time physiologic events in multiple organs including the kidney. This imaging modality can generate four-dimensional high resolution images that are inherently confocal due to the fact that the photon density needed to excite fluorescence only occurs at the objective focal plane, not above or below. Additionally, longer excitation wavelengths allow for deeper penetration into tissue, improved excitation, and are inherently less phototoxic than shorter excitation wavelengths. Applying imaging tools to study physiology in rats has become a valuable scientific technique due to the relatively simple surgical procedures, improved quality of reagents, and reproducibility of established assays. In this chapter, the authors provide an example of the application of fluorescent techniques to study cardio-renal functions in rat models. Use of experimental procedures described here, together with multiple available genetically modified animal models, provide new prospective for the further application of multi-photon microscopy in basic and translational research.
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Affiliation(s)
- Ruben M Sandoval
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Center for Biological Microscopy, Indianapolis, IN, USA
| | - Bruce A Molitoris
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Center for Biological Microscopy, Indianapolis, IN, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.
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30
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Gallo LA, Walton SL, Mazzuca MQ, Tare M, Parkington HC, Wlodek ME, Moritz KM. Uteroplacental insufficiency temporally exacerbates salt-induced hypertension associated with a reduced natriuretic response in male rat offspring. J Physiol 2018; 596:5859-5872. [PMID: 29604087 PMCID: PMC6265551 DOI: 10.1113/jp275655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 03/21/2018] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Low weight at birth increases the risk of developing chronic diseases in adulthood A diet that is high in salt is known to elevate blood pressure, which is a major risk factor for cardiovascular and kidney diseases The present study demonstrates that growth restricted male rats have a heightened sensitivity to high dietary salt, in the context of raised systolic blood pressure, reduced urinary sodium excretion and stiffer mesenteric resistance vessels Other salt-induced effects, such as kidney hyperfiltration, albuminuria and glomerular damage, were not exacerbated by being born small The present study demonstrates that male offspring born small have an increased cardiovascular susceptibility to high dietary salt, such that that minimizing salt intake is probably of particular benefit to this at-risk population ABSTRACT: Intrauterine growth restriction increases the risk of developing chronic diseases in adulthood. Lifestyle factors, such as poor dietary choices, may elevate this risk. We determined whether being born small increases the sensitivity to a dietary salt challenge, in the context of hypertension, kidney disease and arterial stiffness. Bilateral uterine vessel ligation or sham surgery (offspring termed Restricted and Control, respectively) was performed on 18-day pregnant Wistar Kyoto rats. Male offspring were allocated to receive a diet high in salt (8% sodium chloride) or remain on standard rat chow (0.52% sodium chloride) from 20 to 26 weeks of age for 6 weeks. Systolic blood pressure (tail-cuff), renal function (24 h urine excretions) and vascular stiffness (pressure myography) were assessed. Restricted males were born 15% lighter than Controls and remained smaller throughout the study. Salt-induced hypertension was exacerbated in Restricted offspring, reaching a peak systolic pressure of ∼175 mmHg earlier than normal weight counterparts. The natriuretic response to high dietary salt in Restricted animals was less than in Controls and may explain the early rise in arterial pressure. Growth restricted males allocated to a high salt diet also had increased passive arterial stiffness of mesenteric resistance arteries. Other aspects of renal function, including salt-induced hyperfiltration, albuminuria and glomerular damage, were not exacerbated by uteroplacental insufficiency. The present study demonstrates that male offspring exposed to uteroplacental insufficiency and born small have an increased sensitivity to salt-induced hypertension and arterial remodelling.
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Affiliation(s)
- Linda A. Gallo
- Department of PhysiologyThe University of MelbourneVICAustralia
- School of Biomedical SciencesThe University of QueenslandQLDAustralia
- Mater Research Institute‐The University of QueenslandTranslational Research InstituteQLDAustralia
| | - Sarah L. Walton
- School of Biomedical SciencesThe University of QueenslandQLDAustralia
- Child Health Research CentreThe University of QueenslandQLDAustralia
| | - Marc Q. Mazzuca
- Department of PhysiologyThe University of MelbourneVICAustralia
| | - Marianne Tare
- Department of PhysiologyMonash UniversityVICAustralia
- Monash Rural HealthMonash UniversityVICAustralia
| | | | - Mary E. Wlodek
- Department of PhysiologyThe University of MelbourneVICAustralia
| | - Karen M. Moritz
- School of Biomedical SciencesThe University of QueenslandQLDAustralia
- Child Health Research CentreThe University of QueenslandQLDAustralia
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Prokop JW, May T, Strong K, Bilinovich SM, Bupp C, Rajasekaran S, Worthey EA, Lazar J. Genome sequencing in the clinic: the past, present, and future of genomic medicine. Physiol Genomics 2018; 50:563-579. [PMID: 29727589 PMCID: PMC6139636 DOI: 10.1152/physiolgenomics.00046.2018] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genomic sequencing has undergone massive expansion in the past 10 yr, from a rarely used research tool into an approach that has broad applications in a clinical setting. From rare disease to cancer, genomics is transforming our knowledge of biology. The transition from targeted gene sequencing, to whole exome sequencing, to whole genome sequencing has only been made possible due to rapid advancements in technologies and informatics that have plummeted the cost per base of DNA sequencing and analysis. The tools of genomics have resolved the etiology of disease for previously undiagnosable conditions, identified cancer driver gene variants, and have impacted the understanding of pathophysiology for many diseases. However, this expansion of use has also highlighted research's current voids in knowledge. The lack of precise animal models for gene-to-function association, lack of tools for analysis of genomic structural changes, skew in populations used for genetic studies, publication biases, and the "Unknown Proteome" all contribute to voids needing filled for genomics to work in a fast-paced clinical setting. The future will hold the tools to fill in these voids, with new data sets and the continual development of new technologies allowing for expansion of genomic medicine, ushering in the days to come for precision medicine. In this review we highlight these and other points in hopes of advancing and guiding precision medicine into the future for optimal success.
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Affiliation(s)
- Jeremy W Prokop
- HudsonAlpha Institute for Biotechnology , Huntsville, Alabama
- Department of Pediatrics and Human Development, Michigan State University , East Lansing, Michigan
- Department of Pharmacology and Toxicology, Michigan State University , East Lansing, Michigan
| | - Thomas May
- HudsonAlpha Institute for Biotechnology , Huntsville, Alabama
- Institute for Health and Aging, University of California San Francisco , San Francisco, California
- Elson S. Floyd College of Medicine, Washington State University , Spokane, Washington
| | - Kim Strong
- HudsonAlpha Institute for Biotechnology , Huntsville, Alabama
| | - Stephanie M Bilinovich
- Department of Pediatrics and Human Development, Michigan State University , East Lansing, Michigan
| | - Caleb Bupp
- Department of Pediatrics and Human Development, Michigan State University , East Lansing, Michigan
- Department of Genetics, Helen DeVos Children's Hospital, Spectrum Health, Grand Rapids, Michigan
| | - Surender Rajasekaran
- Department of Pediatrics and Human Development, Michigan State University , East Lansing, Michigan
- Department of Pediatric Critical Care Medicine, Helen DeVos Children's Hospital, Spectrum Health, Grand Rapids, Michigan
| | | | - Jozef Lazar
- HudsonAlpha Institute for Biotechnology , Huntsville, Alabama
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Spires D, Poudel B, Shields CA, Pennington A, Fizer B, Taylor L, McPherson KC, Cornelius DC, Williams JM. Prevention of the progression of renal injury in diabetic rodent models with preexisting renal disease with chronic endothelin A receptor blockade. Am J Physiol Renal Physiol 2018; 315:F977-F985. [PMID: 29846112 DOI: 10.1152/ajprenal.00182.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The endothelin (ET) system has emerged as a therapeutic target for the treatment of diabetic nephropathy (DN). The present study examined whether chronic endothelin A (ETA) receptor blockade with atrasentan prevents the progression of renal injury in two models of DN with preexisting renal disease that exhibit an increased renal ET-1 system compared with nondiabetic rats: streptozotocin-treated Dahl salt-sensitive (STZ-SS) and type 2 diabetic nephropathy (T2DN) rats. Nine week-old SS rats were treated with (STZ; 50 mg/kg ip) to induce diabetes. After 3 wk of diabetes, proteinuria increased to 353 ± 34 mg/day. The rats were then separated into two groups: 1) vehicle and 2) atrasentan (5 mg·kg-1·day-1) via drinking water. After 6 wk of treatment with atrasentan, mean arterial pressure (MAP) and proteinuria decreased by 12 and 40%, respectively, in STZ-SS rats. The degree of glomerulosclerosis and renal fibrosis was significantly reduced in the kidneys of atrasentan-treated STZ-SS rats compared with vehicle STZ-SS rats. Interestingly, treatment with atrasentan did not affect GFR but significantly increased renal blood flow by 33% and prevented the elevations in filtration fraction and renal vascular resistance by 23 and 20%, respectively, in STZ-SS rats. In contrast to the STZ-SS study, atrasentan had no effect on MAP or proteinuria in T2DN rats. However, treatment with atrasentan significantly decreased glomerular injury and renal fibrosis and prevented the decline in renal function in T2DN rats. These data indicate that chronic ETA blockade produces advantageous changes in renal hemodynamics that slow the progression of renal disease and also reduces renal histopathology in the absence of reducing arterial pressure and proteinuria.
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Affiliation(s)
- Denisha Spires
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Bibek Poudel
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Corbin A Shields
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Alyssa Pennington
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Brianca Fizer
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Lateia Taylor
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Kasi C McPherson
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Denise C Cornelius
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
| | - Jan M Williams
- Departments of Pharmacology and Emergency Medicine, University of Mississippi Medical Center , Jackson, Mississippi
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Lukaszewicz KM, Paudyal MP, Falck JR, Lombard JH. Role of vascular reactive oxygen species in regulating cytochrome P450-4A enzyme expression in Dahl salt-sensitive rats. Microcirculation 2018; 23:540-548. [PMID: 27537772 DOI: 10.1111/micc.12304] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/15/2016] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The potential contribution of CYP4A enzymes to endothelial dysfunction in Dahl salt-sensitive rats was determined by comparison to SS-5BN consomic rats having chromosome 5 carrying CYP4A alleles from the BN rat introgressed into the SS genetic background. METHODS The following experiments were performed in cerebral arteries from HS-fed SS and SS-5BN rats ± the SOD inhibitor DETC and/or the superoxide scavenger Tempol: (i) endothelial function was determined via video microscopy ± acute addition of the CYP4A inhibitor DDMS or Tempol; (ii) vascular oxidative stress was assessed with DHE fluorescence ± acute addition of DDMS, l-NAME, or PEG-SOD; and (iii) CYP4A protein levels were compared by western blotting. RESULTS In DETC-treated SS-5BN and HS-fed SS rats, (i) DDMS or Tempol ameliorated vascular dysfunction, (ii) DDMS reduced vascular oxidative stress to control levels, (iii) chronic Tempol treatment reduced vascular CYP4A protein expression, and (iv) combined treatment with Tempol and l-NAME prevented the reduction in CYP4A protein expression in MCA of HS-fed SS rats. CONCLUSION The CYP4A pathway plays a role in vascular dysfunction in SS rats and there appears to be a direct role of reduced NO availability due to salt-induced oxidant stress in upregulating CYP4A enzyme expression.
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Affiliation(s)
| | - Mahesh P Paudyal
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - John R Falck
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.
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Jensen PN, Bao TQ, Huong TTT, Heckbert SR, Fitzpatrick AL, LoGerfo JP, Ngoc TLV, Mokdad AH. The association of estimated salt intake with blood pressure in a Viet Nam national survey. PLoS One 2018; 13:e0191437. [PMID: 29346423 PMCID: PMC5773206 DOI: 10.1371/journal.pone.0191437] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 01/04/2018] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVE To evaluate the association of salt consumption with blood pressure in Viet Nam, a developing country with a high level of salt consumption. DESIGN AND SETTING Analysis of a nationally representative sample of Vietnamese adults 25-65 years of age who were surveyed using the World Health Organization STEPwise approach to Surveillance protocol. Participants who reported acute illness, pregnancy, or current use of antihypertensive medications were excluded. Daily salt consumption was estimated from fasting mid-morning spot urine samples. Associations of salt consumption with systolic blood pressure and prevalent hypertension were assessed using adjusted linear and generalized linear models. Interaction terms were tested to assess differences by age, smoking, alcohol consumption, and rural/urban status. RESULTS The analysis included 2,333 participants (mean age: 37 years, 46% male, 33% urban). The average estimated salt consumption was 10g/day. No associations of salt consumption with blood pressure or prevalent hypertension were observed at a national scale in men or women. The associations did not differ in subgroups defined by age, smoking, or alcohol consumption; however, associations differed between urban and rural participants (p-value for interaction of urban/rural status with salt consumption, p = 0.02), suggesting that higher salt consumption may be associated with higher systolic blood pressure in urban residents but lower systolic blood pressure in rural residents. CONCLUSIONS Although there was no evidence of an association at a national level, associations of salt consumption with blood pressure differed between urban and rural residents in Viet Nam. The reasons for this differential association are not clear, and given the large rate of rural to urban migration experienced in Viet Nam, this topic warrants further investigation.
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Affiliation(s)
- Paul N. Jensen
- Department of Epidemiology, University of Washington, Seattle, WA, United States of America
| | - Tran Quoc Bao
- Department of Preventive Medicine, Viet Nam Ministry of Health, Hanoi, Viet Nam
| | - Tran Thi Thanh Huong
- Department of Ethics and Social Medicine, Hanoi Medical University, Hanoi, Viet Nam
| | - Susan R. Heckbert
- Department of Epidemiology, University of Washington, Seattle, WA, United States of America
| | - Annette L. Fitzpatrick
- Department of Epidemiology, University of Washington, Seattle, WA, United States of America
- Department of Global Health, University of Washington, Seattle, WA, United States of America
| | - James P. LoGerfo
- Department of Global Health, University of Washington, Seattle, WA, United States of America
- Department of Medicine, University of Washington, Seattle, WA, United States of America
| | - Truong Le Van Ngoc
- Department of Preventive Medicine, Viet Nam Ministry of Health, Hanoi, Viet Nam
| | - Ali H. Mokdad
- Department of Epidemiology, University of Washington, Seattle, WA, United States of America
- Department of Global Health, University of Washington, Seattle, WA, United States of America
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Lukaszewicz KM, Durand MJ, Priestley JRC, Schmidt JR, Allen LA, Geurts AM, Lombard JH. Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats. J Vis Exp 2017. [PMID: 29286398 DOI: 10.3791/56133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This protocol describes the use of in vitro television microscopy to evaluate vascular function in isolated cerebral resistance arteries (and other vessels), and describes techniques for evaluating tissue perfusion using Laser Doppler Flowmetry (LDF) and microvessel density utilizing fluorescently labeled Griffonia simplicifolia (GS1) lectin. Current methods for studying isolated resistance arteries at transmural pressures encountered in vivo and in the absence of parenchymal cell influences provide a critical link between in vivo studies and information gained from molecular reductionist approaches that provide limited insight into integrative responses at the whole animal level. LDF and techniques to selectively identify arterioles and capillaries with fluorescently-labeled GS1 lectin provide practical solutions to enable investigators to extend the knowledge gained from studies of isolated resistance arteries. This paper describes the application of these techniques to gain fundamental knowledge of vascular physiology and pathology in the rat as a general experimental model, and in a variety of specialized genetically engineered "designer" rat strains that can provide important insight into the influence of specific genes on important vascular phenotypes. Utilizing these valuable experimental approaches in rat strains developed by selective breeding strategies and new technologies for producing gene knockout models in the rat, will expand the rigor of scientific premises developed in knockout mouse models and extend that knowledge to a more relevant animal model, with a well understood physiological background and suitability for physiological studies because of its larger size.
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Affiliation(s)
| | | | | | - James R Schmidt
- Graduate Programs of Nurse Anesthesia, Texas Wesleyan University
| | | | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin
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Palygin O, Ilatovskaya DV, Levchenko V, Endres BT, Geurts AM, Staruschenko A. Nitric oxide production by glomerular podocytes. Nitric Oxide 2017; 72:24-31. [PMID: 29128399 DOI: 10.1016/j.niox.2017.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 09/27/2017] [Accepted: 11/07/2017] [Indexed: 01/18/2023]
Abstract
Nitric Oxide (NO), a potent vasodilator and vital signaling molecule, has been shown to contribute to the regulation of glomerular ultrafiltration. However, whether changes in NO occur in podocytes during the pathogenesis of salt-sensitive hypertension has not yet been thoroughly examined. We showed here that podocytes produce NO, and further hypothesized that hypertensive animals would exhibit reduced NO production in these cells in response to various paracrine factors, which might contribute to the damage of glomeruli filtration barrier and development of proteinuria. To test this, we isolated glomeruli from the kidneys of Dahl salt-sensitive (SS) rats fed a low salt (LS; 0.4% NaCl) or high salt (HS; 4% NaCl, 3 weeks) diets and loaded podocytes with either a combination of NO and Ca2+ fluorophores (DAF-FM and Fura Red, respectively) or DAF-FM alone. Changes in fluorescence were observed with confocal microscopy in response to adenosine triphosphate (ATP), angiotensin II (Ang II), and hydrogen peroxide (H2O2). Application of Ang II resulted in activation of both NO and intracellular calcium ([Ca2+]i) transients. In contrast, ATP promoted [Ca2+]i transients, but did not have any effects on NO production. SS rats fed a HS diet for 3 weeks demonstrated impaired NO production: the response to Ang II or H2O2 in podocytes of glomeruli isolated from SS rats fed a HS diet was significantly reduced compared to rats fed a LS diet. Therefore, glomerular podocytes from hypertensive rats showed a diminished NO release in response to Ang II or oxidative stress, suggesting that podocytic NO signaling is dysfunctional in this condition and likely contributes to the development of kidney injury.
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Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Bradley T Endres
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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37
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Sullivan JC, Gillis EE. Sex and gender differences in hypertensive kidney injury. Am J Physiol Renal Physiol 2017; 313:F1009-F1017. [PMID: 28724606 PMCID: PMC5668592 DOI: 10.1152/ajprenal.00206.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 12/30/2022] Open
Abstract
Hypertension is a complex, multifaceted disorder, affecting ~1 in 3 adults in the United States. Although hypertension occurs in both men and women, there are distinct sex differences in the way in which they develop hypertension, with women having a lower incidence of hypertension until the sixth decade of life. Despite observed sex differences in hypertension, little is known about the molecular mechanisms underlying the development of hypertension in females, primarily because of their underrepresentation in both clinical and experimental animal studies. The first goal of this review is to provide a concise overview of the participation of women in clinical trials, including a discussion of the importance of including females in basic science research, as recently mandated by the National Institutes of Health. The remaining portion of the review is dedicated to identifying clinical and experimental animal studies that concentrate on gender and sex differences in hypertensive kidney disease, ending with a proposed role for T cells in mediating sex differences in blood pressure.
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Affiliation(s)
| | - Ellen E Gillis
- Department of Physiology, Augusta University, Augusta, Georgia
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38
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Wang Z, Sun Q, Sun N, Liang M, Tian Z. Mitochondrial Dysfunction and Altered Renal Metabolism in Dahl Salt-Sensitive Rats. Kidney Blood Press Res 2017; 42:587-597. [PMID: 28922660 DOI: 10.1159/000479846] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/26/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The kidney plays a critical role in the control of blood pressure and its elevation in salt-induced hypertension. Mitochondrial dysfunction, especially in energy metabolism, has been associated with hypertension. Here, we aimed to investigate mitochondrial function and metabolic features in renal mitochondria of Dahl salt-sensitive (SS) rats to gain further insight into the relationship between mitochondrial metabolism and predisposition to hypertension. METHODS In this study, SS rats fed low-salt (LS) or high-salt (HS) diets were used to investigate mitochondrial function and metabolism including mitochondrial enzyme activities, pyridine nucleotides, metabolites, and oxidative stress by biochemical analysis and gas chromatography-mass spectrometer (GC-MS). RESULTS Significantly lower activity levels of fumarase, isocitrate dehydrogenase and succinyl-CoA synthetase were observed in renal mitochondria of SS rats compared with SS.13BN control rats fed LS diets. Intra-mitochondrial pyridine nucleotide content and mitochondrial metabolism were adversely affected in SS rats. In accordance with this, reduced ATP production, Δψm, and superoxide dismutase (SOD) activity were also observed in mitochondria of the renal medulla and cortex of SS rats. Moreover, ATP production was further impaired and oxidative stress was increased, confirming that the mitochondria of SS rats fed HS diets were dysfunctional compared to those of rats fed LS diets. CONCLUSIONS Our data demonstrated that the renal mitochondria of SS rats exhibited complicated metabolic alteration and dysfunction in low-salt diets, and high-salt diets aggravated these dysfunctions. Thus, these results may be associated with renal dysfunction, which, in turn, would help in understanding the development of salt-sensitive hypertension.
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Affiliation(s)
- Zhengjun Wang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Qiong Sun
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Na Sun
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Mingyu Liang
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Zhongmin Tian
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
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Seidel E, Scholl UI. Genetic mechanisms of human hypertension and their implications for blood pressure physiology. Physiol Genomics 2017; 49:630-652. [PMID: 28887369 DOI: 10.1152/physiolgenomics.00032.2017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Hypertension, or elevated blood pressure, constitutes a major public health burden that affects more than 1 billion people worldwide and contributes to ~9 million deaths annually. Hereditary factors are thought to contribute to up to 50% of interindividual blood pressure variability. Blood pressure in the general population approximately shows a normal distribution and is thought to be a polygenic trait. In rare cases, early-onset hypertension or hypotension are inherited as Mendelian traits. The identification of the underlying Mendelian genes and variants has contributed to our understanding of the physiology of blood pressure regulation, emphasizing renal salt handling and the renin angiotensin aldosterone system as players in the determination of blood pressure. Genome-wide association studies (GWAS) have revealed more than 100 variants that are associated with blood pressure, typically with small effect sizes, which cumulatively explain ~3.5% of blood pressure trait variability. Several GWAS associations point to a role of the vasculature in the pathogenesis of hypertension. Despite these advances, the majority of the genetic contributors to blood pressure regulation are currently unknown; whether large-scale exome or genome sequencing studies will unravel these factors remains to be determined.
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Affiliation(s)
- Eric Seidel
- Department of Nephrology, Medical School, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Ute I Scholl
- Department of Nephrology, Medical School, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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40
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Endres BT, Sandoval RM, Rhodes GJ, Campos-Bilderback SB, Kamocka MM, McDermott-Roe C, Staruschenko A, Molitoris BA, Geurts AM, Palygin O. Intravital imaging of the kidney in a rat model of salt-sensitive hypertension. Am J Physiol Renal Physiol 2017; 313:F163-F173. [PMID: 28404591 DOI: 10.1152/ajprenal.00466.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 03/30/2017] [Accepted: 04/11/2017] [Indexed: 01/07/2023] Open
Abstract
Hypertension is one of the most prevalent diseases worldwide and a major risk factor for renal failure and cardiovascular disease. The role of albuminuria, a common feature of hypertension and robust predictor of cardiorenal disorders, remains incompletely understood. The goal of this study was to investigate the mechanisms leading to albuminuria in the kidney of a rat model of hypertension, the Dahl salt-sensitive (SS) rat. To determine the relative contributions of the glomerulus and proximal tubule (PT) to albuminuria, we applied intravital two-photon-based imaging to investigate the complex renal physiological changes that occur during salt-induced hypertension. Following a high-salt diet, SS rats exhibited elevated blood pressure, increased glomerular sieving of albumin (GSCalb = 0.0686), relative permeability to albumin (+Δ16%), and impaired volume hemodynamics (-Δ14%). Serum albumin but not serum globulins or creatinine concentration was decreased (-0.54 g/dl), which was concomitant with increased filtration of albumin (3.7 vs. 0.8 g/day normal diet). Pathologically, hypertensive animals had significant tubular damage, as indicated by increased prevalence of granular casts, expansion and necrosis of PT epithelial cells (+Δ2.20 score/image), progressive augmentation of red blood cell velocity (+Δ269 µm/s) and micro vessel diameter (+Δ4.3 µm), and increased vascular injury (+Δ0.61 leakage/image). Therefore, development of salt-induced hypertension can be triggered by fast and progressive pathogenic remodeling of PT epithelia, which can be associated with changes in albumin handling. Collectively, these results indicate that both the glomerulus and the PT contribute to albuminuria, and dual treatment of glomerular filtration and albumin reabsorption may represent an effective treatment of salt-sensitive hypertension.
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Affiliation(s)
- Bradley T Endres
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ruben M Sandoval
- Indiana Center for Biological Microscopy, Indiana University School of Medicine, Indianapolis, Indiana
| | - George J Rhodes
- Indiana Center for Biological Microscopy, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Malgorzata M Kamocka
- Indiana Center for Biological Microscopy, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Bruce A Molitoris
- Indiana Center for Biological Microscopy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; .,Department of Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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41
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Pavlov TS, Levchenko V, Ilatovskaya DV, Moreno C, Staruschenko A. Renal sodium transport in renin-deficient Dahl salt-sensitive rats. J Renin Angiotensin Aldosterone Syst 2016; 17:17/3/1470320316653858. [PMID: 27443990 PMCID: PMC5100984 DOI: 10.1177/1470320316653858] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 05/15/2016] [Indexed: 01/01/2023] Open
Abstract
Objective: The Dahl salt-sensitive rat is a well-established model of salt-sensitive hypertension. The goal of this study was to assess the expression and activity of renal sodium channels and transporters in the renin-deficient salt-sensitive rat. Methods: Renin knockout (Ren−/−) rats created on the salt-sensitive rat background were used to investigate the role of renin in the regulation of ion transport in salt-sensitive hypertension. Western blotting and patch-clamp analyses were utilized to assess the expression level and activity of Na+ transporters. Results: It has been described previously that Ren−/− rats exhibit severe kidney underdevelopment, polyuria, and lower body weight and blood pressure compared to their wild-type littermates. Here we found that renin deficiency led to decreased expression of sodium-hydrogen antiporter (NHE3), the Na+/H+ exchanger involved in Na+ absorption in the proximal tubules, but did not affect the expression of Na-K-Cl cotransporter (NKCC2), the main transporter in the loop of Henle. In the distal nephron, the expression of sodium chloride cotransporter (NCC) was lower in Ren−/− rats. Single-channel patch clamp analysis detected decreased ENaC activity in Ren−/− rats which was mediated via changes in the channel open probability. Conclusion: These data illustrate that renin deficiency leads to significant dysregulation of ion transporters.
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Affiliation(s)
| | | | | | - Carol Moreno
- Department of Physiology, Medical College of Wisconsin, USA Cardiovascular and Metabolic Diseases, MedImmune, Cambridge, UK
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, USA Cardiovascular Center, Medical College of Wisconsin, USA
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Elijovich F, Weinberger MH, Anderson CAM, Appel LJ, Bursztyn M, Cook NR, Dart RA, Newton-Cheh CH, Sacks FM, Laffer CL. Salt Sensitivity of Blood Pressure: A Scientific Statement From the American Heart Association. Hypertension 2016; 68:e7-e46. [PMID: 27443572 DOI: 10.1161/hyp.0000000000000047] [Citation(s) in RCA: 326] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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43
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Prokop JW, Tsaih SW, Faber AB, Boehme S, Underwood AC, Troyer S, Playl L, Milsted A, Turner ME, Ely D, Martins AS, Tutaj M, Lazar J, Dwinell MR, Jacob HJ. The phenotypic impact of the male-specific region of chromosome-Y in inbred mating: the role of genetic variants and gene duplications in multiple inbred rat strains. Biol Sex Differ 2016; 7:10. [PMID: 26848384 PMCID: PMC4740989 DOI: 10.1186/s13293-016-0064-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/26/2016] [Indexed: 12/22/2022] Open
Abstract
Backgound The male-specific region of chromosome-Y (MSY) contributes to phenotypes outside of testis development and has a high rate of evolution between mammalian species. With a lack of genomic crossover, MSY is one of the few genomic areas under similar variation and evolutionary selection in inbred and outbred animal populations, allowing for an assessment of evolutionary mechanisms to translate between the populations. Methods Using next-generation sequencing, MSY consomic strains, molecular characterization, and large-scale phenotyping, we present here regions of MSY that contribute to inbred strain phenotypes. Results We have shown that (1) MSY of rat has nine autosomal gene transposition events with strain-specific selection; (2) sequence variants in MSY occur with a 1.98-fold higher number of variants than other chromosomes in seven sequenced rat strains; (3) Sry, the most studied MSY gene, has undergone extensive gene duplications, driving ubiquitous expression not seen in human or mouse; (4) the expression profile of Sry in the rat is driven by the insertion of the Sry2 copy into an intron of the ubiquitously expressed Kdm5d gene in antisense orientation, but due to several loss of function mutations in the Sry2 protein, nuclear localization and transcriptional control are decreased; (5) expression of Sry copies other than Sry2 in the rat overlaps with the expression profile for human SRY; (6) gene duplications and sequence variants (P76T) of Sry can be selected for phenotypes such as high blood pressure and androgen receptor signaling within inbred mating; and most importantly, (7) per chromosome size, MSY contributes to higher strain-specific phenotypic variation relative to all other chromosomes, with 53 phenotypes showing both a male to female and consomic cross significance. Conclusion The data presented supports a high probability of MSY genetic variation altering a broad range of inbred rat phenotypes. Electronic supplementary material The online version of this article (doi:10.1186/s13293-016-0064-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jeremy W Prokop
- HudsonAlpha Institute for Biotechnology, 601 Genome Way, Huntsville, AL 35806 USA ; Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA ; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Shirng-Wern Tsaih
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Allison B Faber
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA ; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Shannon Boehme
- Department of Biology, The University of Akron, Akron, OH 44325 USA
| | - Adam C Underwood
- Department of Mathematics and Science, Walsh University, North Canton, OH 44720 USA
| | - Samuel Troyer
- Department of Biology, The University of Akron, Akron, OH 44325 USA
| | - Lauren Playl
- Department of Biology, The University of Akron, Akron, OH 44325 USA
| | - Amy Milsted
- Department of Biology, The University of Akron, Akron, OH 44325 USA
| | - Monte E Turner
- Department of Biology, The University of Akron, Akron, OH 44325 USA
| | - Daniel Ely
- Department of Biology, The University of Akron, Akron, OH 44325 USA
| | - Almir S Martins
- Núcleo de Fisiologia Geral e Genômica Funcional-ICB-Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais Brazil
| | - Marek Tutaj
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Jozef Lazar
- HudsonAlpha Institute for Biotechnology, 601 Genome Way, Huntsville, AL 35806 USA ; Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA ; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Melinda R Dwinell
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA ; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Howard J Jacob
- HudsonAlpha Institute for Biotechnology, 601 Genome Way, Huntsville, AL 35806 USA ; Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226 USA ; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 USA
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Cowley AW, Yang C, Kumar V, Lazar J, Jacob H, Geurts AM, Liu P, Dayton A, Kurth T, Liang M. Pappa2 is linked to salt-sensitive hypertension in Dahl S rats. Physiol Genomics 2015; 48:62-72. [PMID: 26534937 DOI: 10.1152/physiolgenomics.00097.2015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/29/2015] [Indexed: 01/11/2023] Open
Abstract
A 1.37 Mbp region of chromosome 13 previously identified by exclusion mapping was consistently associated with a reduction of salt-induced hypertension in the Dahl salt-sensitive (SS) rat. This region contained five genes that were introgressed from the salt-insensitive Brown Norway (BN) rat. The goal of the present study was to further narrow that region to identify the gene(s) most likely to protect from salt-induced hypertension. The studies yielded a subcongenic SS rat strain containing a 0.71 Mbp insert from BN (26-P strain) in which salt-induced hypertension was reduced by 24 mmHg. The region contained two protein-coding genes (Astn1 and Pappa2) and a microRNA (miR-488). Pappa2 mRNA in the renal cortex of the protected 26-P was 6- to 10-fold greater than in SS fed a 0.4% NaCl diet but was reduced to levels observed in SS when fed 8.0% NaCl diet for 7 days. Compared with brain nuclei (NTS, RVLM, CVLM) and the adrenal gland, Pappa2 in the renal cortex was the only gene found to be differentially expressed between SS and 26-P and that responded to changes of salt diet. Immunohistochemistry studies found Pappa2 localized in the cytosol of the epithelial cells of the cortical thick ascending limbs. In more distal segments of the renal tubules, it was observed within tubular lumens and most notably bound to the apical membranes of the intercalated cells of collecting ducts. We conclude that we have identified a variant form of Pappa2 that can protect against salt-induced hypertension in the Dahl S rat.
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Affiliation(s)
- Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin;
| | - Chun Yang
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Vikash Kumar
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jozef Lazar
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Howard Jacob
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Pengyuan Liu
- Cancer Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Alex Dayton
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Theresa Kurth
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mingyu Liang
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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45
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Burke M, Pabbidi MR, Farley J, Roman RJ. Molecular mechanisms of renal blood flow autoregulation. Curr Vasc Pharmacol 2015; 12:845-58. [PMID: 24066938 PMCID: PMC4416696 DOI: 10.2174/15701611113116660149] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 12/18/2011] [Accepted: 07/02/2013] [Indexed: 01/10/2023]
Abstract
Diabetes and hypertension are the leading causes of chronic kidney disease and their incidence is increasing at
an alarming rate. Both are associated with impairments in the autoregulation of renal blood flow (RBF) and greater transmission
of fluctuations in arterial pressure to the glomerular capillaries. The ability of the kidney to maintain relatively
constant blood flow, glomerular filtration rate (GFR) and glomerular capillary pressure is mediated by the myogenic response
of afferent arterioles working in concert with tubuloglomerular feedback that adjusts the tone of the afferent arteriole
in response to changes in the delivery of sodium chloride to the macula densa. Despite intensive investigation, the factors
initiating the myogenic response and the signaling pathways involved in the myogenic response and tubuloglomerular
feedback remain uncertain. This review focuses on current thought regarding the molecular mechanisms underlying myogenic
control of renal vascular tone, the interrelationships between the myogenic response and tubuloglomerular feedback,
the evidence that alterations in autoregulation of RBF contributes to hypertension and diabetes-induced nephropathy and
the identification of vascular therapeutic targets for improved renoprotection in hypertensive and diabetic patients.
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Affiliation(s)
| | | | | | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA.
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46
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Carmichael CY, Wainford RD. Brain Gαi 2 -subunit proteins and the prevention of salt sensitive hypertension. Front Physiol 2015; 6:233. [PMID: 26347659 PMCID: PMC4541027 DOI: 10.3389/fphys.2015.00233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/03/2015] [Indexed: 12/19/2022] Open
Abstract
To counter the development of salt-sensitive hypertension, multiple brain G-protein-coupled receptor (GPCR) systems are activated to facilitate sympathoinhibition, sodium homeostasis, and normotension. Currently there is a paucity of knowledge regarding the role of down-stream GPCR-activated Gα-subunit proteins in these critically important physiological regulatory responses required for long-term blood pressure regulation. We have determined that brain Gαi2-proteins mediate natriuretic and sympathoinhibitory responses produced by acute pharmacological (exogenous central nociceptin/orphanin FQ receptor (NOP) and α2-adrenoceptor activation) and physiological challenges to sodium homeostasis (intravenous volume expansion and 1 M sodium load) in conscious Sprague–Dawley rats. We have demonstrated that in salt-resistant rat phenotypes, high dietary salt intake evokes site-specific up-regulation of hypothalamic paraventricular nucleus (PVN) Gαi2-proteins. Further, we established that PVN Gαi2 protein up-regulation prevents the development of renal nerve-dependent sympathetically mediated salt-sensitive hypertension in Sprague–Dawley and Dahl salt-resistant rats. Additionally, failure to up-regulate PVN Gαi2 proteins during high salt-intake contributes to the pathophysiology of Dahl salt-sensitive (DSS) hypertension. Collectively, our data demonstrate that brain, and likely PVN specific, Gαi2 protein pathways represent a central molecular pathway mediating sympathoinhibitory renal-nerve dependent responses evoked to maintain sodium homeostasis and a salt-resistant phenotype. Further, impairment of this endogenous “anti-hypertensive” mechanism contributes to the pathophysiology of salt-sensitive hypertension.
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Affiliation(s)
- Casey Y Carmichael
- The Department of Pharmacology and Experimental Therapeutics, The Whitaker Cardiovascular Institute, Boston University School of Medicine Boston, MA, USA
| | - Richard D Wainford
- The Department of Pharmacology and Experimental Therapeutics, The Whitaker Cardiovascular Institute, Boston University School of Medicine Boston, MA, USA
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47
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Prokop JW, Deschepper CF. Chromosome Y genetic variants: impact in animal models and on human disease. Physiol Genomics 2015; 47:525-37. [PMID: 26286457 DOI: 10.1152/physiolgenomics.00074.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Chromosome Y (chrY) variation has been associated with many complex diseases ranging from cancer to cardiovascular disorders. Functional roles of chrY genes outside of testes are suggested by the fact that they are broadly expressed in many other tissues and correspond to regulators of basic cellular functions (such as transcription, translation, and protein stability). However, the unique genetic properties of chrY (including the lack of meiotic crossover and the presence of numerous highly repetitive sequences) have made the identification of causal variants very difficult. Despite the prior lack of reliable sequences and/or data on genetic polymorphisms, earlier studies with animal chrY consomic strains have made it possible to narrow down the phenotypic contributions of chrY. Some of the evidence so far indicates that chrY gene variants associate with regulatory changes in the expression of other autosomal genes, in part via epigenetic effects. In humans, a limited number of studies have shown associations between chrY haplotypes and disease traits. However, recent sequencing efforts have made it possible to greatly increase the identification of genetic variants on chrY, which promises that future association of chrY with disease traits will be further refined. Continuing studies (both in humans and in animal models) will be critical to help explain the many sex-biased disease states in human that are contributed to not only by the classical sex steroid hormones, but also by chrY genetics.
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Affiliation(s)
- J W Prokop
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama; and
| | - C F Deschepper
- Institut de recherches cliniques de Montréal (IRCM) and Université de Montréal, Montreal, Quebec, Canada
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48
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Burnier M, Wuerzner G, Bochud M. Salt, blood pressure and cardiovascular risk: what is the most adequate preventive strategy? A Swiss perspective. Front Physiol 2015; 6:227. [PMID: 26321959 PMCID: PMC4535281 DOI: 10.3389/fphys.2015.00227] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/27/2015] [Indexed: 12/17/2022] Open
Abstract
Among the various strategies to reduce the incidence of non-communicable diseases reduction of sodium intake in the general population has been recognized as one of the most cost-effective means because of its potential impact on the development of hypertension and cardiovascular diseases. Yet, this strategic health recommendation of the WHO and many other international organizations is far from being universally accepted. Indeed, there are still several unresolved scientific and epidemiological questions that maintain an ongoing debate. Thus what is the adequate low level of sodium intake to recommend to the general population and whether national strategies should be oriented to the overall population or only to higher risk fractions of the population such as salt-sensitive patients are still discussed. In this paper, we shall review the recent results of the literature regarding salt, blood pressure and cardiovascular risk and we present the recommendations recently proposed by a group of experts of Switzerland. The propositions of the participating medical societies are to encourage national health authorities to continue their discussion with the food industry in order to reduce the sodium intake of food products with a target of mean salt intake of 5–6 grams per day in the population. Moreover, all initiatives to increase the information on the effect of salt on health and on the salt content of food are supported.
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Affiliation(s)
- Michel Burnier
- Service of Nephrology and Hypertension, Department of Medicine, University Hospital Lausanne, Switzerland
| | - Gregoire Wuerzner
- Service of Nephrology and Hypertension, Department of Medicine, University Hospital Lausanne, Switzerland
| | - Murielle Bochud
- Institut Universitaire de Médecine Sociale et Préventive, University Hospital Lausanne, Switzerland
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49
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Li C, Li Z, Ward BD, Dwinell MR, Lombard JH, Hudetz AG, Pawela CP. Enhancement of resting-state fcMRI networks by prior sensory stimulation. Brain Connect 2015; 4:760-8. [PMID: 25387238 DOI: 10.1089/brain.2014.0326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
It is important to consider the effect of a previous experimental condition when analyzing resting-state functional connectivity magnetic resonance imaging (fcMRI) data. In this work, a simple sensory stimulation functional MRI (fMRI) experiment was conducted between two resting-state fcMRI acquisitions in anesthetized rats using a high-field small-animal MR scanner. Previous human studies have reported fcMRI network alteration by prior task/stimulus utilizing similar experimental paradigms. An anesthetized rat preparation was used to test whether brain regions with higher level functions are involved in post-task/stimulus fcMRI network alteration. We demonstrate significant fcMRI enhancement poststimulation in the sensory cortical, limbic, and insular brain regions in rats. These brain regions have been previously implicated in vigilance and anesthetic arousal networks. We tested their experimental paradigm in several inbred strains of rats with known phenotypic differences in anesthetic susceptibility and cerebral vascular function. Brown Norway (BN), Dahl Salt-Sensitive (SS), and consomic SSBN13 strains were tested. We have previously shown significant differences in blood oxygen level-dependent fMRI activity and fcMRI networks across these strains. Here we report statistically significant interstrain differences in regional fcMRI poststimulation enhancement. In the SS strain, poststimulation enhancement occurred in posterior sensory and limbic cortical brain regions. In the BN strain, poststimulation enhancement appeared in anterior cingulate and subcortical limbic brain regions. These results imply that a prior condition has a significant impact on fcMRI networks that depend on intersubject difference in genetics and physiology.
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Affiliation(s)
- Chenxuan Li
- 1 Department of Plastic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin
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50
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Flister MJ, Prokop JW, Lazar J, Shimoyama M, Dwinell M, Geurts A. 2015 Guidelines for Establishing Genetically Modified Rat Models for Cardiovascular Research. J Cardiovasc Transl Res 2015; 8:269-77. [PMID: 25920443 PMCID: PMC4475456 DOI: 10.1007/s12265-015-9626-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/15/2015] [Indexed: 12/24/2022]
Abstract
The rat has long been a key physiological model for cardiovascular research, most of the inbred strains having been previously selected for susceptibility or resistance to various cardiovascular diseases (CVD). These CVD rat models offer a physiologically relevant background on which candidates of human CVD can be tested in a more clinically translatable experimental setting. However, a diverse toolbox for genetically modifying the rat genome to test molecular mechanisms has only recently become available. Here, we provide a high-level description of several strategies for developing genetically modified rat models of CVD.
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Affiliation(s)
- Michael J Flister
- Human and Molecular Genetics Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, 53226, WI, USA,
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