1
|
Kuzmina IV, Ovchinnikova NV, Tolpygo SM. Serum Activity of Proteolytic Enzyme Trypsin in Rats under Conditions of Water and Food Deprivation. Bull Exp Biol Med 2023; 175:608-611. [PMID: 37861909 DOI: 10.1007/s10517-023-05910-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Indexed: 10/21/2023]
Abstract
Trypsin is mainly regarded as a digestive enzyme, but there is evidence that activation of protease-activated receptor-2 (PAR-2) leads to behavioral changes. There are no data on trypsin activity in the serum of animals under conditions of thirst and starvation in the available literature. In our experiments, water deprivation led to a significant (p⩽0.05) increase in trypsin activity in rats, and food deprivation led to its decrease in comparison with controls (free access to water and food). After deprived rats received water and food, a decrease in trypsin activity was observed in both experimental groups. Changes in trypsin activity under conditions of water or food deprivation and after satiation were accompanied by shifts in some biochemical parameters of the bloods. Under conditions of metabolic stress (starvation and thirst), opposite changes in trypsin activity seem to indicate its participation in the mechanisms of adequate restructuring of metabolism and maintenance of vital processes in the body.
Collapse
Affiliation(s)
- I V Kuzmina
- P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia.
| | - N V Ovchinnikova
- P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia
| | - S M Tolpygo
- P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia
| |
Collapse
|
2
|
Wang AN, Carlos J, Singh KK, Fraser GM, McGuire JJ. Endothelium dysfunction in hind limb arteries of male Zucker Diabetic-Sprague Dawley rats. Biochem Pharmacol 2022; 206:115319. [PMID: 36279920 DOI: 10.1016/j.bcp.2022.115319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022]
Abstract
Endothelium dysfunction produces peripheral vascular disease comorbidities in type 2 diabetes, including hypertension, and critical limb ischemia. In this study we aimed to test endothelial dysfunction, the vasodilator effects of a proteinase-activated receptor 2 (PAR2) agonist (2fLIGRLO), and thromboxane A2 synthase inhibitor (ozagrel) on PAR2 vasodilation in hind limb arteries ex vivo, using Zucker Diabetic-Sprague Dawley (ZDSD) rats, a model of type 2 diabetes. Male Sprague Dawley rats (SD) and ZDSD were fed a high-fat content 'Western diet' from 16 to 20 weeks of age (wks) then fed a standard laboratory diet. We identified diabetic ZDSD rats by two consecutive blood glucose measurements > 12.5 mM, based on weekly monitoring. We used acetylcholine, 2fLIGRLO, and nitroprusside with wire-myograph methods to compare relaxations of femoral, and saphenous arteries from diabetic ZDSD (21-23 wks) to age-matched normoglycemic SD. All arteries showed evidence of endothelium dysfunction using acetylcholine (reduced maximum relaxations, reduced sensitivity), and higher sensitivities to 2fLIGRLO, and nitroprusside in ZDSD vs SD. Ozagrel treatment of ZDSD distal segments, and end-branches of saphenous arteries decreased their sensitivities to 2fLIGRLO. We tested aortas for altered expression of endothelium-specific gene targets using PCR array and qPCR. PAR2, and placental growth factor gene transcripts were 1.5, and 4-times higher in ZDSD than SD aortas. Hind limb arteries of ZDSD exhibit endothelium dysfunction having less GPCR agonist induced vasodilation by endothelial NO-release. Different expression of several endothelial genes in ZDSD vs SD aortas, including PAR2, suggests altered inflammatory, and angiogenesis signaling pathways in the endothelium of ZDSD.
Collapse
Affiliation(s)
- Andrea N Wang
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Joselia Carlos
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Krishna K Singh
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Graham M Fraser
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St. John's, Newfoundland and Labrador, Canada
| | - John J McGuire
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.
| |
Collapse
|
3
|
Vertiprakhov VG, Ovchinnikova NV. The activity of trypsin in the pancreatic juice and blood of poultry increases simultaneously in the postprandial period. Front Physiol 2022; 13:874664. [PMID: 36388123 PMCID: PMC9641294 DOI: 10.3389/fphys.2022.874664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 10/13/2022] [Indexed: 10/21/2023] Open
Abstract
Modern literature data indicate that the role of trypsin goes far beyond its digestive function. Once in the blood, trypsin is involved as part of the kallikrein-kinin system in the regulation of blood pressure, regulates pancreatic function by activating PAR receptors, and influences inflammation and immunity in the cell. The interaction of trypsin in the intestine and serum in the living healthy organism has been insufficiently studied. On the basis of our own studies and literature data, we concluded that after overnight fasting the increase of trypsin activity in pancreatic juice and blood serum in the postprandial period occurs in parallel, which determines not only digestion of food protein but also the level of metabolism. Consequently, determining the optimal amount of crude protein in the diet during the morning meal is a paramount task for physiologists.
Collapse
Affiliation(s)
| | - Natalya V. Ovchinnikova
- Timiryazev Russian State Agrarian University Moscow Agrarian Academy, Moscow, Russia
- Physiology of Motivation Laboratory, Anokhin Research Institute of Normal Physiology, Moscow, Russia
| |
Collapse
|
4
|
Wang AN, Fraser GM, McGuire JJ. Characterization of Endothelium-Dependent Relaxation in the Saphenous Artery and Its Caudal Branches in Young and Old Adult Sprague Dawley Rats. Biomolecules 2022; 12:biom12070889. [PMID: 35883445 PMCID: PMC9312764 DOI: 10.3390/biom12070889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 12/11/2022] Open
Abstract
Ageing is associated with reduced endothelium-derived nitric oxide (NO) production in the femoral artery of Sprague Dawley (SD) rats. In the current study, we examined endothelium-dependent relaxation (EDR) in the saphenous artery and its caudal branches. We used acetylcholine and the Proteinase-Activated receptor-2 (PAR2)-specific agonist (2fLIGRLO) with nitroarginine methylester (L-NAME) to assess EDR in two groups of male SD rats (age in weeks: young, 10–12; old, 27–29). Acetylcholine and 2fLIGRLO were potent NO-dependent relaxant agents in all arteries. For all arteries, EDR by acetylcholine decreased significantly in old compared to young SD rats. Interestingly, PAR2-induced EDR of proximal saphenous artery segments and caudal branches decreased significantly in old compared to young, but did not differ for the in-between middle and distal ends of the saphenous artery. L-NAME treatment increased subsequent contractions of proximal and middle segments of saphenous arteries by phenylephrine and U46619 in young, but not in old, SD rats. We conclude the SD saphenous artery and caudal branches exhibit regional characteristics that differ in response to specific EDR agonists, endothelial NO synthase inhibitor, and changes to endothelium function with increased age, which are, in part, attributed to decreased sensitivity of vascular smooth muscle to the gaseous transmitter NO.
Collapse
Affiliation(s)
- Andrea N. Wang
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5C1, Canada;
| | - Graham M. Fraser
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NL A1B 3V6, Canada;
| | - John J. McGuire
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5C1, Canada;
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5C1, Canada
- Correspondence:
| |
Collapse
|
5
|
Myrie SB, McKnight LL, King JC, McGuire JJ, Van Vliet BN, Cheema SK, Bertolo RF. Intrauterine growth-restricted Yucatan miniature pigs experience early catch-up growth, leading to greater adiposity and impaired lipid metabolism as young adults. Appl Physiol Nutr Metab 2017; 42:1322-1329. [PMID: 28813611 DOI: 10.1139/apnm-2017-0311] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2023]
Abstract
Early nutrition has critical influences on cardiovascular disease risk in adulthood. The study objectives were to evaluate the impact of low birth weight on fasting and postprandial lipid metabolism and endothelium function in Yucatan miniature pigs. Intrauterine growth-restricted (IUGR) piglets (n = 6; 3 days old, 0.73 ± 0.04 kg) were paired with normal-weight (NW) same-sex littermates (n = 6; 1.11 ± 0.05 kg) and fed milk replacer ad libitum for 4 weeks. Thereafter, all pigs were fed a standard diet ad libitum for 5 h/day with growth, intakes, and blood samples collected for 8 months. At 9 months old, pigs were surgically fitted with venous catheters and an oral fat tolerance test was performed. At 10 months old, pigs were killed and endothelium-dependent and -independent vasodilations of isolated coronary arteries were measured using wire-myographs. IUGR pigs demonstrated catch-up growth (P < 0.05) in body weight and abdominal circumference prior to sexual maturity (<7 months old) and had more (P < 0.05) subcutaneous fat at 10 months old compared with NW pigs. IUGR pigs had consistently higher fasting plasma triglyceride concentrations from 5 to 10 months old and higher liver triglyceride and total cholesterol concentrations at 10 months old (P < 0.05). The fat tolerance test revealed delayed postprandial triglyceride clearance in IUGR pigs, but no differences in plaque formation or vascular reactivity. To conclude, IUGR and early postnatal catch-up growth are associated with increased overall body fat deposition and altered triglyceride metabolism in adult Yucatan miniature swine.
Collapse
Affiliation(s)
- Semone B Myrie
- a Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
| | - Leslie L McKnight
- a Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
| | - J Christopher King
- b Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - John J McGuire
- b Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Bruce N Van Vliet
- b Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Sukhinder K Cheema
- a Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
| | - Robert F Bertolo
- a Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
| |
Collapse
|
6
|
Characterization and Functions of Protease-Activated Receptor 2 in Obesity, Diabetes, and Metabolic Syndrome: A Systematic Review. BIOMED RESEARCH INTERNATIONAL 2016; 2016:3130496. [PMID: 27006943 PMCID: PMC4781943 DOI: 10.1155/2016/3130496] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/26/2016] [Indexed: 12/16/2022]
Abstract
Proteinase-activated receptor 2 (PAR2) is a cell surface receptor activated by serine proteinases or specific synthetic compounds. Interest in PAR2 as a pharmaceutical target for various diseases is increasing. Here we asked two questions relevant to endothelial dysfunction and diabetes: How is PAR2 function affected in blood vessels? What role does PAR2 have in promoting obesity, diabetes, and/or metabolic syndrome, specifically via the endothelium and adipose tissues? We conducted a systematic review of the published literature in PubMed and Scopus (July 2015; search terms: par2, par-2, f2lr1, adipose, obesity, diabetes, and metabolic syndrome). Seven studies focused on PAR2 and vascular function. The obesity, diabetes, or metabolic syndrome animal models differed amongst studies, but each reported that PAR2-mediated vasodilator actions were preserved in the face of endothelial dysfunction. The remaining studies focused on nonvascular functions and provided evidence supporting the concept that PAR2 activation promoted obesity. Key studies showed that PAR2 activation regulated cellular metabolism, and PAR2 antagonists inhibited adipose gain and metabolic dysfunction in rats. We conclude that PAR2 antagonists for treatment of obesity indeed show early promise as a therapeutic strategy; however, endothelial-specific PAR2 functions, which may offset mechanisms that produce vascular dysfunction in diabetes, warrant additional study.
Collapse
|
7
|
Maruyama K, Kagota S, McGuire JJ, Wakuda H, Yoshikawa N, Nakamura K, Shinozuka K. Enhanced Nitric Oxide Synthase Activation via Protease-Activated Receptor 2 Is Involved in the Preserved Vasodilation in Aortas from Metabolic Syndrome Rats. J Vasc Res 2016; 52:232-43. [DOI: 10.1159/000442415] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 11/09/2015] [Indexed: 11/19/2022] Open
|
8
|
Hennessey JC, Stuyvers BD, McGuire JJ. Small caliber arterial endothelial cells calcium signals elicited by PAR2 are preserved from endothelial dysfunction. Pharmacol Res Perspect 2015; 3:e00112. [PMID: 25729579 PMCID: PMC4324686 DOI: 10.1002/prp2.112] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 10/24/2014] [Indexed: 12/05/2022] Open
Abstract
Endothelial cell (EC)-dependent vasodilation by proteinase-activated receptor 2 (PAR2) is preserved in small caliber arteries in disease states where vasodilation by muscarinic receptors is decreased. In this study, we identified and characterized the PAR2-mediated intracellular calcium (Ca2+)-release mechanisms in EC from small caliber arteries in healthy and diseased states. Mesenteric arterial EC were isolated from PAR2 wild-type (WT) and null mice, after saline (controls) or angiotensin II (AngII) infusion, for imaging intracellular calcium and characterizing the calcium-release system by immunofluorescence. EC Ca2+ signals comprised two forms of Ca2+-release events that had distinct spatial-temporal properties and occurred near either the plasmalemma (peripheral) or center of EC. In healthy EC, PAR2-dependent increases in the densities and firing rates of both forms of Ca2+-release were abolished by inositol 1,4,5- trisphosphate receptor (IP3R) inhibitor, but partially reduced by transient potential vanilloid channels inhibitor ruthenium red (RR). Acetylcholine (ACh)-induced less overall Ca2+-release than PAR2 activation, but enhanced selectively the incidence of central events. PAR2-dependent Ca2+-activity, inhibitors sensitivities, IP3R, small- and intermediate-conductance Ca2+-activated potassium channels expressions were unchanged in EC from AngII WT. However, the same cells exhibited decreases in ACh-induced Ca2+-release, RR sensitivity, and endothelial nitric oxide synthase expression, indicating AngII-induced dysfunction was differentiated by receptor, Ca2+-release, and downstream targets of EC activation. We conclude that PAR2 and muscarinic receptors selectively elicit two elementary Ca2+ signals in single EC. PAR2-selective IP3R-dependent peripheral Ca2+-release mechanisms are identical between healthy and diseased states. Further study of PAR2-selective Ca2+-release for eliciting pathological and/or normal EC functions is warranted.
Collapse
Affiliation(s)
- John C Hennessey
- Cardiovascular Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University St. John's, Newfoundland, Canada
| | - Bruno D Stuyvers
- Cardiovascular Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University St. John's, Newfoundland, Canada
| | - John J McGuire
- Cardiovascular Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University St. John's, Newfoundland, Canada
| |
Collapse
|
9
|
Antoniak S, Sparkenbaugh E, Pawlinski R. Tissue factor, protease activated receptors and pathologic heart remodelling. Thromb Haemost 2014; 112:893-900. [PMID: 25104210 DOI: 10.1160/th14-03-0243] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 05/30/2014] [Indexed: 12/13/2022]
Abstract
Tissue factor is the primary initiator of coagulation cascade and plays an essential role in haemostasis and thrombosis. In addition, tissue factor and coagulation proteases contribute to many cellular responses via activation of protease activated receptors. The heart is an organ with high levels of constitutive tissue factor expression. This review focuses on the role of tissue factor, coagulation proteases and protease activated receptors in heart haemostasis and the pathological heart remodelling associated with myocardial infarction, viral myocarditis and hypertension.
Collapse
Affiliation(s)
| | | | - Rafal Pawlinski
- Rafal Pawlinski, PhD, Division of Hematology/Oncology, Department of Medicine, McAllister Heart Institute, University of North Carolina, 320A Mary Ellen Jones Bldg, 98 Manning Drive, Chapel Hill, NC 27599, USA, Tel: 919 843 8387, Fax: 919 843 4896, E-mail:
| |
Collapse
|
10
|
Yau MK, Liu L, Fairlie DP. Toward drugs for protease-activated receptor 2 (PAR2). J Med Chem 2013; 56:7477-97. [PMID: 23895492 DOI: 10.1021/jm400638v] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PAR2 has a distinctive functional phenotype among an unusual group of GPCRs called protease activated receptors, which self-activate after cleavage of their N-termini by mainly serine proteases. PAR2 is the most highly expressed PAR on certain immune cells, and it is activated by multiple proteases (but not thrombin) in inflammation. PAR2 is expressed on many types of primary human cells and cancer cells. PAR2 knockout mice and PAR2 agonists and antagonists have implicated PAR2 as a promising target in inflammatory conditions; respiratory, gastrointestinal, metabolic, cardiovascular, and neurological dysfunction; and cancers. This article summarizes salient features of PAR2 structure, activation, and function; opportunities for disease intervention via PAR2; pharmacological properties of published or patented PAR2 modulators (small molecule agonists and antagonists, pepducins, antibodies); and some personal perspectives on limitations of assessing their properties and on promising new directions for PAR2 modulation.
Collapse
Affiliation(s)
- Mei-Kwan Yau
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland , Brisbane, Queensland 4072, Australia
| | | | | |
Collapse
|
11
|
Agarwal JJ, Zhu Y, Zhang QY, Mongin AA, Hough LB. TRAM-34, a putatively selective blocker of intermediate-conductance, calcium-activated potassium channels, inhibits cytochrome P450 activity. PLoS One 2013; 8:e63028. [PMID: 23667566 PMCID: PMC3646888 DOI: 10.1371/journal.pone.0063028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 03/27/2013] [Indexed: 11/25/2022] Open
Abstract
TRAM-34, a clotrimazole analog characterized as a potent and selective inhibitor of intermediate-conductance, calcium-activated K+ (IKCa) channels, has been used extensively in vitro and in vivo to study the biological roles of these channels. The major advantage of TRAM-34 over clotrimazole is the reported lack of inhibition of the former drug on cytochrome P450 (CYP) activity. CYPs, a large family of heme-containing oxidases, play essential roles in endogenous signaling and metabolic pathways, as well as in xenobiotic metabolism. However, previously published work has only characterized the effects of TRAM-34 on a single CYP isoform. To test the hypothesis that TRAM-34 may inhibit some CYP isoforms, the effects of this compound were presently studied on the activities of four rat and five human CYP isoforms. TRAM-34 inhibited recombinant rat CYP2B1, CYP2C6 and CYP2C11 and human CYP2B6, CYP2C19 and CYP3A4 with IC50 values ranging from 0.9 µM to 12.6 µM, but had no inhibitory effects (up to 80 µM) on recombinant rat CYP1A2, human CYP1A2, or human CYP19A1. TRAM-34 also had both stimulatory and inhibitory effects on human CYP3A4 activity, depending on the substrate used. These results show that low micromolar concentrations of TRAM-34 can inhibit several rat and human CYP isoforms, and suggest caution in the use of high concentrations of this drug as a selective IKCa channel blocker. In addition, in vivo use of TRAM-34 could lead to CYP-related drug-drug interactions.
Collapse
Affiliation(s)
- Jay J. Agarwal
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Yi Zhu
- Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, Albany, New York, United States of America
| | - Qing-Yu Zhang
- Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, Albany, New York, United States of America
| | - Alexander A. Mongin
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Lindsay B. Hough
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
- * E-mail:
| |
Collapse
|
12
|
Hughes KH, Wijekoon EP, Valcour JE, Chia EW, McGuire JJ. Effects of chronic in-vivo treatments with protease-activated receptor 2 agonist on endothelium function and blood pressures in mice. Can J Physiol Pharmacol 2013; 91:295-305. [DOI: 10.1139/cjpp-2012-0266] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Short-term treatments with protease-activated receptor 2-activating peptides (PAR2-AP) induce endothelium-dependent vasodilation and decrease blood pressure. In this study, we tested the effect of chronic in-vivo treatment with PAR2-AP on the blood pressure and endothelium function of mice. Male PAR2 wild-type (WT) and par2-deficient (KO) mice received subcutaneous infusions of either saline, low (PAR2-LD), or high (PAR2-HD) doses of 2-furoyl-LIGRLO-amide for 1 or 2 weeks. In each treatment group, endothelium function was assessed in isolated arteries. Blood pressure, heart rate, and locomotor activity were recorded by radiotelemetry, and levels of tumour nercrosis factor α (TNF-α) and interkeukin 1β (IL-1β) were measured in plasma samples by ELISA. The relaxation of WT aortas and mesenteric arteries induced by PAR2-AP was decreased by PAR2-LD and PAR2-HD. In mesenteric arteries, PAR2-LD and PAR2-HD decreased the relaxation induced by acetylcholine, but not by nitroprusside; in aortas, PAR2-LD and PAR2-HD caused differential decreases in the relaxations induced by acetylcholine and nitroprusside. Only PAR2-HD lowered systolic arterial pressures in WT, when compared with all of the other groups. TNF-α and IL-1β plasma concentrations were not different among the groups. We conclude that the systolic blood pressure of unrestrained mice can be lowered by chronic in-vivo activation of PAR2; however, this effect is countered by receptor desensitization and the concomitant development of endothelium and vascular dysfunction.
Collapse
Affiliation(s)
- Keon H. Hughes
- Cardiovascular Research Group, Division of BioMedical Sciences, Memorial University, 300 Prince Philip Drive, St. John's, NL A1B 3V6, Canada
| | - Enoka P. Wijekoon
- Cardiovascular Research Group, Division of BioMedical Sciences, Memorial University, 300 Prince Philip Drive, St. John's, NL A1B 3V6, Canada
| | - James E. Valcour
- Division of Community Health and Humanities, Faculty of Medicine, Memorial University, 300 Prince Philip Drive, St. John's, NL A1B 3V6, Canada
| | - Elizabeth W. Chia
- Cardiovascular Research Group, Division of BioMedical Sciences, Memorial University, 300 Prince Philip Drive, St. John's, NL A1B 3V6, Canada
| | - John J. McGuire
- Cardiovascular Research Group, Division of BioMedical Sciences, Memorial University, 300 Prince Philip Drive, St. John's, NL A1B 3V6, Canada
| |
Collapse
|
13
|
Hennessey JC, McGuire JJ. Attenuated vasodilator effectiveness of protease-activated receptor 2 agonist in heterozygous par2 knockout mice. PLoS One 2013; 8:e55965. [PMID: 23409098 PMCID: PMC3567012 DOI: 10.1371/journal.pone.0055965] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/03/2013] [Indexed: 01/20/2023] Open
Abstract
Studies of homozygous PAR2 gene knockout mice have described a mix of phenotypic effects in vitro and in vivo. However, there have been few studies of PAR2 heterozygous (wild-type/knockout; PAR2-HET) mice. The phenotypes of many hemi and heterozygous transgenic mice have been described as intermediates between those of wild-type and knockout animals. In our study we aimed to determine the effects of intermediary par2 gene zygosity on vascular tissue responses to PAR2 activation. Specifically, we compared the vasodilator effectiveness of the PAR2 activating peptide 2-furoyl-LIGRLO-amide in aortas of wild-type PAR2 homozygous (PAR2-WT) and PAR2-HET mice. In myographs under isometric tension conditions, isolated aortic rings were contracted by alpha 1-adrenoeceptor agonist (phenylephrine), and thromboxane receptor agonist (U46619) and then relaxation responses by the additions of 2-furoyl-LIGRLO-amide, acetylcholine, and nitroprusside were recorded. A Schild regression analysis of the inhibition by a PAR2 antagonist (GB-83) of PAR2 agonist-induced aortic ring relaxations was used to compare receptor expression in PAR2-WT to PAR2-HET. PAR2 mRNA in aortas was measured by quantitative real-time PCR. In aortas contracted by either phenylephrine or U46619, the maximum relaxations induced by 2-furoyl-LIGRLO-amide were less in PAR2-HET than in the gender-matched PAR2-WT. GB-83 was 3- to 4-fold more potent for inhibition of 2fly in PAR2-HET than in PAR2-WT. PAR2 mRNA content of aortas from PAR2-HET was not significantly different than in PAR2-WT. Acetylcholine- and nitroprusside-induced relaxations of aortas from PAR2-HET were not significantly different than in PAR2-WT and PAR2 knockout. An interesting secondary finding was that relaxations induced by agonists of PAR2 and muscarinic receptors were larger in females than in males. We conclude that the lower PAR2-mediated responses in PAR2-HET aortas are consistent with evidence of a lower quantity of functional receptor expression, despite the apparently normal PAR2 mRNA content in PAR2-HET aortas.
Collapse
Affiliation(s)
- John C. Hennessey
- Cardiovascular Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - John J. McGuire
- Cardiovascular Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| |
Collapse
|
14
|
Martínez-Revelles S, Avendaño MS, García-Redondo AB, Alvarez Y, Aguado A, Pérez-Girón JV, García-Redondo L, Esteban V, Redondo JM, Alonso MJ, Briones AM, Salaices M. Reciprocal relationship between reactive oxygen species and cyclooxygenase-2 and vascular dysfunction in hypertension. Antioxid Redox Signal 2013; 18:51-65. [PMID: 22671943 DOI: 10.1089/ars.2011.4335] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS This study evaluates a possible relationship between reactive oxygen species (ROS) and cyclooxygenase (COX)-2-derived products in conductance and resistance arteries from hypertensive animals. Angiotensin II (Ang II)-infused mice or spontaneously hypertensive rats treated with the NAD(P)H Oxidase inhibitor apocynin, the mitochondrion-targeted SOD2 mimetic Mito-TEMPO, the superoxide dismutase analog tempol, or the COX-2 inhibitor Celecoxib were used. RESULTS Apocynin, Mito-TEMPO, and Celecoxib treatments prevented Ang II-induced hypertension, the increased vasoconstrictor responses to phenylephrine, and the reduced acetylcholine relaxation. The NOX-2 inhibitor gp91ds-tat, the NOX-1 inhibitor ML171, catalase, and the COX-2 inhibitor NS398 abolished the ex vivo effect of Ang II-enhancing phenylephrine responses. Antioxidant treatments diminished the increased vascular COX-2 expression, prostanoid production, and/or participation of COX-derived contractile prostanoids and thromboxane A(2) receptor (TP) in phenylephrine responses, observed in arteries from hypertensive models. The treatment with the COX-2 inhibitor normalized the increased ROS production (O(2)·(-) and H(2)O(2)), NAD(P)H Oxidase expression (NOX-1, NOX-4, and p22phox) and activity, MnSOD expression, and the participation of ROS in vascular responses in both hypertensive models. Apocynin and Mito-TEMPO also normalized these parameters of oxidative stress. Apocynin, Mito-TEMPO, and Celecoxib improved the diminished nitric oxide (NO) production and the modulation by NO of phenylephrine responses in the Ang II model. INNOVATION This study provides mechanistic evidence of circuitous relationship between COX-2 products and ROS in hypertension. CONCLUSION The excess of ROS from NAD(P)H Oxidase and/or mitochondria and the increased vascular COX-2/TP receptor axis act in concert to induce vascular dysfunction and hypertension.
Collapse
Affiliation(s)
- Sonia Martínez-Revelles
- Department of Pharmacology, School of Medicine, Universidad Autónoma de Madrid, Institute for Health Research of La Paz University Hospital (IdiPAZ), Madrid, Spain
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Myrie SB, McKnight LL, King JC, McGuire JJ, Vliet BNV, Bertolo RF. Effects of a diet high in salt, fat, and sugar on telemetric blood pressure measurements in conscious, unrestrained adult Yucatan miniature swine (Sus scrofa). Comp Med 2012; 62:282-290. [PMID: 23043781 PMCID: PMC3415370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/10/2011] [Accepted: 02/15/2012] [Indexed: 06/01/2023]
Abstract
Radiotelemetry was used to evaluate diet-related elevation of blood pressure in adult Yucatan miniature swine. Systolic arterial blood pressure (SAP), diastolic atrial blood pressure (DAP), heart rate, and locomotor activity were assessed in 9- or 11-mo-old Yucatan miniature pigs fed a standard diet or a North American-type diet high in salt, fat, and sugar (HSFS). Compared with pigs fed standard diet, pigs fed HSFS diet showed markedly elevated SAP (132 ± 3 compared with 156 ± 6 mm Hg), whereas DAP was unchanged (92 ± 2 compared with 99 ± 5 mm Hg). In addition, all pigs were modestly sensitive to short-term changes in dietary salt, as indicated by a 6% to 7% response in blood pressure parameters. According to these data, the increase in SAP for pigs on the HSFS diet was too large to be explained by the NaCl content of the diet alone. We found no evidence of endothelial dysfunction, and the relaxation responses of isolated coronary arteries actually were enhanced in the HSFS group. In conclusion, in a Yucatan miniature pigs model chronically fed a HSFS diet, DAP did not increase, but SAP and pulse pressure appeared to be affected by high dietary levels of fat or sugar (or both).
Collapse
Affiliation(s)
| | | | - J Christopher King
- Division of BioMedical Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada
| | - John J McGuire
- Division of BioMedical Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada
| | - Bruce N Van Vliet
- Division of BioMedical Sciences, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada
| | | |
Collapse
|