|
1
|
Dong Y, Wang J, Yang C, Bao J, Liu X, Chen H, Zhang X, Shi W, Zhang L, Qi Q, Li Y, Wang S, Ma R, Cong B, Zhang G. Phosphorylated CPI-17 and MLC2 as Biomarkers of Coronary Artery Spasm-Induced Sudden Cardiac Death. Int J Mol Sci 2024; 25:2941. [PMID: 38474189 PMCID: PMC10932290 DOI: 10.3390/ijms25052941] [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: 01/04/2024] [Revised: 02/19/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
Coronary artery spasm (CAS) plays an important role in the pathogeneses of various ischemic heart diseases and has gradually become a common cause of life-threatening arrhythmia. The specific molecular mechanism of CAS has not been fully elucidated, nor are there any specific diagnostic markers for the condition. Therefore, this study aimed to examine the specific molecular mechanism underlying CAS, and screen for potential diagnostic markers. To this end, we successfully constructed a rat CAS model and achieved in vitro culture of a human coronary-artery smooth-muscle cell (hCASMC) contraction model. Possible molecular mechanisms by which protein kinase C (PKC) regulated CAS through the C kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa (CPI-17)/myosin II regulatory light chain (MLC2) pathway were studied in vivo and in vitro to screen for potential molecular markers of CAS. We performed hematoxylin and eosin staining, myocardial zymogram, and transmission electron microscopy to determine myocardial and coronary artery injury in CAS rats. Then, using immunohistochemical staining, immunofluorescence staining, and Western blotting, we further demonstrated a potential molecular mechanism by which PKC regulated CAS via the CPI-17/MLC2 pathway. The results showed that membrane translocation of PKCα occurred in the coronary arteries of CAS rats. CPI-17/MLC2 signaling was observably activated in coronary arteries undergoing CAS. In addition, in vitro treatment of hCASMCs with angiotensin II (Ang II) increased PKCα membrane translocation while consistently activating CPI-17/MLC2 signaling. Conversely, GF-109203X and calphostin C, specific inhibitors of PKC, inactivated CPI-17/MLC2 signaling. We also collected the coronary artery tissues from deceased subjects suspected to have died of CAS and measured their levels of phosphorylated CPI-17 (p-CPI-17) and MLC2 (p-MLC2). Immunohistochemical staining was positive for p-CPI-17 and p-MLC2 in the tissues of these subjects. These findings suggest that PKCα induced CAS through the CPI-17/MLC2 pathway; therefore, p-CPI-17 and p-MLC2 could be used as potential markers for CAS. Our data provide novel evidence that therapeutic strategies against PKC or CPI-17/MLC2 signaling might be promising in the treatment of CAS.
Collapse
Affiliation(s)
- Yiming Dong
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Jianfeng Wang
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Chenteng Yang
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Junxia Bao
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Xia Liu
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Hao Chen
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Xiaojing Zhang
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Weibo Shi
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Lihua Zhang
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Qian Qi
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Yingmin Li
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Songjun Wang
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Rufei Ma
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Bin Cong
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
| | - Guozhong Zhang
- Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China; (Y.D.); (J.W.); (C.Y.); (J.B.); (X.L.); (H.C.); (X.Z.); (W.S.); (L.Z.); (Q.Q.); (Y.L.); (S.W.); (R.M.); (B.C.)
- Hebei Province Laboratory of Experimental Animal, Shijiazhuang 050017, China
| |
Collapse
|
|
2
|
Álvarez-Maestro M, Eguibar A, Chanca P, Klett-Mingo M, Gómez Rivas J, Buño-Soto A, de Bethencourt FR, Ferrer M. Androgen Deprivation Therapy in Patients With Prostate Cancer Increases Serum Levels of Thromboxane A 2: Cardiovascular Implications. Front Cardiovasc Med 2021; 8:653126. [PMID: 33928136 PMCID: PMC8076684 DOI: 10.3389/fcvm.2021.653126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/15/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Androgens have been described as important players in the regulation of vascular function/structure through their action on the release and effect of vasoactive factors, such as prostanoids. Patients with prostate cancer (PCa) under androgen deprivation therapies (ADTs) present increased risk of cardiovascular mortality. Since thromboxane A2 (TXA2) is one of the most studied prostanoids and its involvement in different cardiovascular diseases has been described, the aim of this study was to investigate: (i) the effect of ADT on the serum levels of TXA2 in PCa patients and its possible link to the redox status and (ii) the effect of the non-hydrolyzable TXA2 analog U-46619 on the function of the aorta of male rats. Methods: The levels of TXA2 and total antioxidant status in 50 healthy subjects, 54 PCa patients, and 57 PCa under ADT were evaluated. These determinations were accompanied by levels of testosterone and C-reactive protein as an inflammation marker. In aortic segments from male rats, the U46619-induced effects on: (i) the vasomotor responses to acetylcholine (ACh), to the NO donor sodium nitroprusside (SNP), to the carbon monoxide-releasing molecule-3 (CORM-3), and to noradrenaline (NA) and (ii) the expression of cyclooxygenase-2 (COX-2), heme oxygenase-1 (HO-1), and phosphorylated ERK1/2 were analyzed. Results: The serum level of TXA2 in patients with PCa was increased with respect to healthy subjects, which was further increased by ADT. There was no modification in the total antioxidant status among the three experimental groups. In aortic segments from male rats, the TXA2 analog decreased the endothelium-dependent relaxation and the sensitivity of smooth muscle cells to NO, while it increased the vasoconstriction induced by NA; the expression of COX-2, HO-1, and pERK1/2 was also increased. Conclusions: ADT increased, along with other inflammatory/oxidative markers, the serum levels of TXA2. The fact that TXA2 negatively impacts the vascular function of the aorta of healthy male rats suggests that inhibition of TXA2-mediated events could be considered a potential strategy to protect the cardiovascular system.
Collapse
Affiliation(s)
- Mario Álvarez-Maestro
- Servicio de Urología, Hospital Universitario La Paz, Madrid, Spain.,Grupo de Investigación en Urología, IdiPAZ, Madrid, Spain
| | - Aritz Eguibar
- Servicio de Urología, Hospital Universitario La Paz, Madrid, Spain
| | - Patricia Chanca
- Servicio de Análisis Clínicos, Hospital Universitario La Paz, Madrid, Spain
| | | | - Juan Gómez Rivas
- Departamento de Urología, Hospital Clínico San Carlos, Madrid, Spain
| | - Antonio Buño-Soto
- Servicio de Análisis Clínicos, Hospital Universitario La Paz, Madrid, Spain.,Grupo de Investigación en Neonatología, IdiPAZ, Madrid, Spain
| | - Fermín R de Bethencourt
- Servicio de Urología, Hospital Universitario La Paz, Madrid, Spain.,Grupo de Investigación en Urología, IdiPAZ, Madrid, Spain
| | - Mercedes Ferrer
- Grupo de Investigación en Urología, IdiPAZ, Madrid, Spain.,Departamento de Fisiología, Facultad de Medicina, UAM, Madrid, Spain
| |
Collapse
|
|
3
|
Blædel M, Sams A, Boonen HCM, Sheykhzade M. Increased Contractile Response to Noradrenaline Induced By Factors Associated with the Metabolic Syndrome in Cultured Small Mesenteric Arteries. Pharmacology 2015; 97:48-56. [PMID: 26587661 DOI: 10.1159/000442259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/04/2015] [Indexed: 11/19/2022]
Abstract
UNLABELLED This study investigated the effect of the metabolic syndrome associated risk factors hyperglycemia (glucose [Glc]), hyperinsulinemia (insulin [Ins]) and low-grade inflammation (tumor necrosis factor α [TNFα]) on the vasomotor responses of resistance arteries. Isolated small mesenteric arteries from 3-month-old Sprague-Dawley rats, were suspended for 21-23 h in tissue cultures containing either elevated Glc (30 mmol/l), Ins (100 nmol/l), TNFα (100 ng/ml) or combinations thereof. After incubation, the vascular response to noradrenaline (NA), phenylephrine, isoprenaline and NA in the presence of propranolol (10 µmol/l) was measured by wire myography. RESULTS Arteries exposed only to combinations of the risk factors showed a significant 1.6-fold increase in the contractile NA sensitivity, which suggests that complex combinations of metabolic risk factors might lead to changes in vascular tone.
Collapse
Affiliation(s)
- Martin Blædel
- Diabetes Biology, Novo Nordisk A/S, Novo Nordisk Park, Mx00E5;lx00F8;v, Denmark
| | | | | | | |
Collapse
|
|
4
|
Protein Kinase C Isoforms Distinctly Regulate Propofol-induced Endothelium-dependent and Endothelium-independent Vasodilation. J Cardiovasc Pharmacol 2015; 66:276-84. [DOI: 10.1097/fjc.0000000000000275] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
|
5
|
Dippold RP, Fisher SA. Myosin phosphatase isoforms as determinants of smooth muscle contractile function and calcium sensitivity of force production. Microcirculation 2015; 21:239-48. [PMID: 24112301 DOI: 10.1111/micc.12097] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/25/2013] [Indexed: 12/14/2022]
Abstract
The dephosphorylation of myosin by the MP causes smooth muscle relaxation. MP is also a key target of signals that regulate vascular tone and thus blood flow and pressure. Here, we review studies from the past two decades that support the hypothesis that the regulated expression of MP subunits is a critical determinant of smooth muscle responses to constrictor and dilator signals. In particular, the highly regulated splicing of the regulatory subunit Mypt1 Exon 24 is proposed to tune sensitivity to NO/cGMP-mediated relaxation. The regulated transcription of the MP inhibitory subunit CPI-17 is proposed to determine sensitivity to agonist-mediated constriction. The expression of these subunits is specific in the microcirculation and varies in developmental and disease contexts. To date, the relationship between MP subunit expression and vascular function in these different contexts is correlative; confirmation of the hypothesis will require the generation of genetically engineered mice to test the role of MP subunits and their isoforms in the specificity of vascular smooth muscle responses to constrictor and dilator signals.
Collapse
Affiliation(s)
- Rachael P Dippold
- Department of Medicine (Cardiology), University of Maryland Baltimore, Baltimore, Maryland, USA
| | | |
Collapse
|
|
6
|
Dippold RP, Fisher SA. A bioinformatic and computational study of myosin phosphatase subunit diversity. Am J Physiol Regul Integr Comp Physiol 2014; 307:R256-70. [PMID: 24898838 PMCID: PMC4121627 DOI: 10.1152/ajpregu.00145.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 05/25/2014] [Indexed: 01/01/2023]
Abstract
Variability in myosin phosphatase (MP) subunits may provide specificity in signaling pathways that regulate muscle tone. We utilized public databases and computational algorithms to investigate the phylogenetic diversity of MP regulatory (PPP1R12A-C) and inhibitory (PPP1R14A-D) subunits. The comparison of exonic coding sequences and expression data confirmed or refuted the existence of isoforms and their tissue-specific expression in different model organisms. The comparison of intronic and exonic sequences identified potential expressional regulatory elements. As examples, smooth muscle MP regulatory subunit (PPP1R12A) is highly conserved through evolution. Its alternative exon E24 is present in fish through mammals with two invariant features: 1) a reading frame shift generating a premature termination codon and 2) a hexanucleotide sequence adjacent to the 3' splice site hypothesized to be a novel suppressor of exon splicing. A characteristic of the striated muscle MP regulatory subunit (PPP1R12B) locus is numerous and phylogenetically variable transcriptional start sites. In fish this locus only codes for the small (M21) subunit, suggesting the primordial function of this gene. Inhibitory subunits show little intragenic variability; their diversity is thought to have arisen by expansion and tissue-specific expression of different gene family members. We demonstrate differences in the regulatory landscape between smooth muscle enriched (PPP1R14A) and more ubiquitously expressed (PPP1R14B) family members and identify deeply conserved intronic sequence and predicted transcriptional cis-regulatory elements. This bioinformatic and computational study has uncovered a number of attributes of MP subunits that supports selection of ideal model organisms and testing of hypotheses regarding their physiological significance and regulated expression.
Collapse
Affiliation(s)
- Rachael P Dippold
- Department of Medicine, Cardiology, University of Maryland Baltimore, Baltimore, Maryland
| | - Steven A Fisher
- Department of Medicine, Cardiology, University of Maryland Baltimore, Baltimore, Maryland
| |
Collapse
|
|
7
|
Protein kinase C in enhanced vascular tone in diabetes mellitus. Int J Cardiol 2014; 174:230-42. [DOI: 10.1016/j.ijcard.2014.04.117] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/03/2014] [Accepted: 04/09/2014] [Indexed: 12/24/2022]
|
|
8
|
Wegener JW, Loga F, Stegner D, Nieswandt B, Hofmann F. Phospholipase D1 is involved in α‐adrenergic contraction of murine vascular smooth muscle. FASEB J 2014; 28:1044-8. [DOI: 10.1096/fj.13-237925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jörg W. Wegener
- For 923, Institut für Pharmakologie and Toxikologie, Technische Universität MünchenMünchenGermany
| | - Florian Loga
- For 923, Institut für Pharmakologie and Toxikologie, Technische Universität MünchenMünchenGermany
| | - David Stegner
- Lehrstuhl für Experimentelle BiomedizinUniversitätsklinikum Würzburg and Rudolf‐Virchow‐ZentrumDeutsche Forschungsgemeinschaft (DFG) Forschungszentrum für Experimentelle BiomedizinUniversität WürzburgWürzburgGermany
| | - Bernhard Nieswandt
- Lehrstuhl für Experimentelle BiomedizinUniversitätsklinikum Würzburg and Rudolf‐Virchow‐ZentrumDeutsche Forschungsgemeinschaft (DFG) Forschungszentrum für Experimentelle BiomedizinUniversität WürzburgWürzburgGermany
| | - Franz Hofmann
- For 923, Institut für Pharmakologie and Toxikologie, Technische Universität MünchenMünchenGermany
| |
Collapse
|
|
9
|
Contribution of Rho kinase to blood pressure elevation and vasoconstrictor responsiveness in type 2 diabetic Goto–Kakizaki rats. J Hypertens 2013; 31:1160-9. [DOI: 10.1097/hjh.0b013e328360383a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
|
10
|
Le Guillou V, Tamion F, Jouet I, Richard V, Mulder P, Bessou JP, Doguet F. Mesenteric endothelial dysfunction in a cardiopulmonary bypass rat model: the effect of diabetes. Diab Vasc Dis Res 2012; 9:270-9. [PMID: 22278737 DOI: 10.1177/1479164111434432] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Diabetes is a risk factor for perioperative complications after cardiac surgery. We studied its effects on mesenteric endothelial function in a cardiopulmonary bypass (CPB) model. METHODS Forty Wistar rats were divided into four groups: sham (D-CPB-), cardiopulmonary bypass (D-CPB+), diabetic (D+CPB-) and diabetic that have undergone CPB (D+CPB+). Two samples of mesenteric artery were used for nitric oxide synthase (NOS) Western blot analysis, and two others for assessing contractile response and endothelium relaxations. Nitrite products and tumour necrosis factor-alpha (TNF-α) were assessed as markers of inflammatory response. RESULTS We observed an enhanced contractile response to the α-adrenergic agonist associated with impairment of mesenteric vasorelaxation in D+CPB+ rats. Western immunoblot analysis of D+CPB+ highlighted an additive effect of hyper-expression of inducible NOS. A significantly increased inflammatory response was observed after CPB in diabetic animals. CONCLUSIONS This work confirms the potential deleterious impact of diabetes on the mesenteric endothelium during CPB in cardiac surgery.
Collapse
Affiliation(s)
- Vincent Le Guillou
- Department of Thoracic and Cardiovascular Surgery, Rouen University Hospital, France
| | | | | | | | | | | | | |
Collapse
|
|
11
|
Potts LB, Ren Y, Lu G, Kuo E, Ngo E, Kuo L, Hein TW. Constriction of retinal arterioles to endothelin-1: requisite role of rho kinase independent of protein kinase C and L-type calcium channels. Invest Ophthalmol Vis Sci 2012; 53:2904-12. [PMID: 22427601 DOI: 10.1167/iovs.12-9542] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Although endothelin-1 (ET-1) is a potent vasoconstrictor peptide implicated in several retinal pathologies, the underlying mechanism of vasoconstriction is understood incompletely. We addressed this issue by assessing the contributions of extracellular calcium (Ca²⁺), L-type voltage-operated calcium channels (L-VOCCs), Rho kinase (ROCK), and protein kinase C (PKC) to ET-1-induced constriction of porcine retinal arterioles, all of which have been implicated commonly in vascular smooth muscle contraction. METHODS Porcine retinal arterioles (~50-100 μm) were isolated for vasomotor study and molecular assessment of ROCK isoforms. RESULTS Isolated arterioles developed stable basal tone at 55 cmH₂O luminal pressure and constricted to ET-1 (0.1 nM) with a 40 ± 6% reduction in resting diameter in 20 minutes. In the absence of extraluminal Ca²⁺, arterioles lost basal tone and failed to constrict to ET-1. Although L-VOCC inhibitor nifedipine reduced basal tone and blocked vasoconstriction to PKC activator PDBu, vasoconstriction to ET-1 was unaffected. The broad-spectrum PKC inhibitor Gö-6983 abolished vasoconstriction to PDBu, but did not alter ET-1-induced vasoconstriction or basal tone. Incubation of arterioles with ROCK inhibitor H-1152 abolished basal tone and vasoconstrictions to ET-1 and PDBu. Both ROCK1 and ROCK2 isoforms were expressed in the retinal arteriolar wall. CONCLUSIONS Extracellular Ca²⁺ entry via L-VOCCs and basal ROCK activity play important roles in the maintenance of basal tones of porcine retinal arterioles. ET-1-induced constriction is mediated by extracellular Ca²⁺ entry independent of L-VOCCs and by ROCK activation without the involvement of PKC. However, direct PKC activation can cause vasoconstriction via L-VOCC and ROCK signaling.
Collapse
Affiliation(s)
- Luke B Potts
- Department of Systems Biology and Translational Medicine, College of Medicine, Texas A&M Health Science Center, Temple, Texas, USA
| | | | | | | | | | | | | |
Collapse
|
|
12
|
Fujii K, Ogawa K, Tokinaga Y, Iranami H, Hatano Y. Sevoflurane does not alter norepinephrine-induced intracellular Ca²(+) changes in the diabetic rat aorta. Can J Anaesth 2010; 57:1095-101. [PMID: 20845014 DOI: 10.1007/s12630-010-9387-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Accepted: 09/03/2010] [Indexed: 10/19/2022] Open
Abstract
PURPOSE The effect of volatile anesthetics on the mechanism(s) of vascular contraction in diabetes mellitus (DM) has not been fully understood. The current study was designed to determine the effects of sevoflurane on the norepinephrine (NE)-induced changes in contractile state and intracellular Ca²(+) concentrations ([Ca²(+)](i)) in the spontaneously developing type 2 DM rat. METHODS The effects of sevoflurane on NE (10⁻⁶M)-induced vasoconstriction and increase in [Ca²(+)](i) in the aortas from Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a type 2 DM model, and from age-matched control Long-Evans Tokushima Otsuka (LETO) rats were investigated using an isometric force transducer and fluorometer with fura-2 as an indicator of [Ca²(+)](i). RESULTS Norepinephrine-induced increases in tension and [Ca²(+)](i) in OLETF rats were 54.8%, 95% confidence interval (CI) 36.9-72.6% and 58.8%, 95% CI 51.5-66.1%, respectively, and in LETO rats they were 46.4%, 95% CI 39.0-53.7% and 53.8%, 95% CI 46.9-60.7%, respectively, when expressed as the percentage relative to that induced by KCl 30 mM. In LETO rats, sevoflurane at a concentration of 3.4% inhibited the vascular contraction (9.4%, 95% CI 6.3-12.6%; P < 0.001) and the increase in [Ca²(+)](i) (33.3%, 95% CI 27.4-39.2%; P = 0.002). In OLETF rats, however, sevoflurane failed to affect either the NE-induced contraction (43.6%, 95% CI 28.3-58.9%; P = 0.68) or the elevation in [Ca²(+)](i) (60.5%, 95% CI 56.3-64.8%; P = 0.93). CONCLUSION Sevoflurane at clinically relevant concentrations inhibited the NE-induced increase in [Ca²(+)](i) in the aortic smooth muscle from normal rats but not in that from type 2 DM rats. Thus, a Ca²(+)- signalling pathway resistant to sevoflurane appears to exist in the type 2 DM rat aorta.
Collapse
Affiliation(s)
- Keisuke Fujii
- Department of Anesthesiology, Japanese Red Cross Society Wakayama Medical Centre, Japan
| | | | | | | | | |
Collapse
|
|
13
|
Kizub IV, Pavlova OO, Johnson CD, Soloviev AI, Zholos AV. Rho kinase and protein kinase C involvement in vascular smooth muscle myofilament calcium sensitization in arteries from diabetic rats. Br J Pharmacol 2010; 159:1724-31. [PMID: 20218979 DOI: 10.1111/j.1476-5381.2010.00666.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Diabetes mellitus (DM) causes multiple dysfunctions including circulatory disorders such as cardiomyopathy, angiopathy, atherosclerosis and arterial hypertension. Rho kinase (ROCK) and protein kinase C (PKC) regulate vascular smooth muscle (VSM) Ca(2+) sensitivity, thus enhancing VSM contraction, and up-regulation of both enzymes in DM is well known. We postulated that in DM, Ca(2+) sensitization occurs in diabetic arteries due to increased ROCK and/or PKC activity. EXPERIMENTAL APPROACH Rats were rendered hyperglycaemic by i.p. injection of streptozotocin. Age-matched control tissues were used for comparison. Contractile responses to phenylephrine (Phe) and different Ca(2+) concentrations were recorded, respectively, from intact and chemically permeabilized vascular rings from aorta, tail and mesenteric arteries. KEY RESULTS Diabetic tail and mesenteric arteries demonstrated markedly enhanced sensitivity to Phe while these changes were not observed in aorta. The ROCK inhibitor HA1077, but not the PKC inhibitor chelerythrine, caused significant reduction in sensitivity to agonist in diabetic vessels. Similar changes were observed for myofilament Ca(2+) sensitivity, which was again enhanced in DM in tail and mesenteric arteries, but not in aorta, and could be reduced by both the ROCK and PKC blockers. CONCLUSIONS AND IMPLICATIONS We conclude that in DM enhanced myofilament Ca(2+) sensitivity is mainly manifested in muscular-type blood vessels and thus likely to contribute to the development of hypertension. Both PKC and, in particular, ROCK are involved in this phenomenon. This highlights their potential usefulness as drug targets in the pharmacological management of DM-associated vascular dysfunction.
Collapse
Affiliation(s)
- I V Kizub
- Institute of Pharmacology and Toxicology, Academy of Medical Sciences of Ukraine, Kiev, Ukraine
| | | | | | | | | |
Collapse
|
|
14
|
Xie Z, Gong MC, Su W, Xie D, Turk J, Guo Z. Role of calcium-independent phospholipase A2beta in high glucose-induced activation of RhoA, Rho kinase, and CPI-17 in cultured vascular smooth muscle cells and vascular smooth muscle hypercontractility in diabetic animals. J Biol Chem 2010; 285:8628-38. [PMID: 20086008 DOI: 10.1074/jbc.m109.057711] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Previous studies suggest that high glucose-induced RhoA/Rho kinase/CPI-17 activation is involved in diabetes-associated vascular smooth muscle hypercontractility. However, the upstream signaling that links high glucose and RhoA/Rho kinase/CPI-17 activation is unknown. Here we report that calcium-independent phospholipase A(2)beta (iPLA(2)beta) is required for high glucose-induced RhoA/Rho kinase/CPI-17 activation and thereby contributes to diabetes-associated vascular smooth muscle hypercontractility. We demonstrate that high glucose increases iPLA(2)beta mRNA, protein, and iPLA(2) activity in a time-dependent manner. Protein kinase C is involved in high glucose-induced iPLA(2)beta protein up-regulation. Inhibiting iPLA(2)beta activity with bromoenol lactone or preventing its expression by genetic deletion abolishes high glucose-induced RhoA/Rho kinase/CPI-17 activation, and restoring expression of iPLA(2)beta in iPLA(2)beta-deficient cells also restores high glucose-induced CPI-17 phosphorylation. Pharmacological and genetic inhibition of 12/15-lipoxygenases has effects on high glucose-induced CPI-17 phosphorylation similar to iPLA(2)beta inhibition. Moreover, increases in iPLA(2) activity and iPLA(2)beta protein expression are also observed in both type 1 and type 2 diabetic vasculature. Pharmacological and genetic inhibition of iPLA(2)beta, but not iPLA(2)gamma, diminishes diabetes-associated vascular smooth muscle hypercontractility. In summary, our results reveal a novel mechanism by which high glucose-induced, protein kinase C-mediated iPLA(2)beta up-regulation activates the RhoA/Rho kinase/CPI-17 via 12/15-lipoxygenases and thereby contributes to diabetes-associated vascular smooth muscle hypercontractility.
Collapse
Affiliation(s)
- Zhongwen Xie
- Department of Physiology, University of Kentucky School of Medicine, Lexington, Kentucky 40536, USA
| | | | | | | | | | | |
Collapse
|
|
15
|
Nagareddy PR, Soliman H, Lin G, Rajput PS, Kumar U, McNeill JH, MacLeod KM. Selective inhibition of protein kinase C beta(2) attenuates inducible nitric oxide synthase-mediated cardiovascular abnormalities in streptozotocin-induced diabetic rats. Diabetes 2009; 58:2355-64. [PMID: 19587355 PMCID: PMC2750218 DOI: 10.2337/db09-0432] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Impaired cardiovascular function in diabetes is partially attributed to pathological overexpression of inducible nitric oxide synthase (iNOS) in cardiovascular tissues. We examined whether the hyperglycemia-induced increased expression of iNOS is protein kinase C-beta(2) (PKCbeta(2)) dependent and whether selective inhibition of PKCbeta reduces iNOS expression and corrects abnormal hemodynamic function in streptozotocin (STZ)-induced diabetic rats. RESEARCH DESIGN AND METHODS Cardiomyocytes and aortic vascular smooth muscle cells (VSMC) from nondiabetic rats were cultured in low (5.5 mmol/l) or high (25 mmol/l) glucose or mannitol (19.5 mmol/l mannitol + 5.5 mmol/l glucose) conditions in the presence of a selective PKCbeta inhibitor, LY333531 (20 nmol/l). Further, the in vivo effects of PKCbeta inhibition on iNOS-mediated cardiovascular abnormalities were tested in STZ-induced diabetic rats. RESULTS Exposure of cardiomyocytes to high glucose activated PKCbeta(2) and increased iNOS expression that was prevented by LY333531. Similarly, treatment of VSMC with LY333531 prevented high glucose-induced activation of nuclear factor kappaB, extracellular signal-related kinase, and iNOS overexpression. Suppression of PKCbeta(2) expression by small interference RNA decreased high-glucose-induced nuclear factor kappaB and extracellular signal-related kinase activation and iNOS expression in VSMC. Administration of LY333531 (1 mg/kg/day) decreased iNOS expression and formation of peroxynitrite in the heart and superior mesenteric arteries and corrected the cardiovascular abnormalities in STZ-induced diabetic rats, an action that was also observed with a selective iNOS inhibitor, L-NIL. CONCLUSIONS Collectively, these results suggest that inhibition of PKCbeta(2) may be a useful approach for correcting abnormal hemodynamics in diabetes by preventing iNOS mediated nitrosative stress.
Collapse
Affiliation(s)
- Prabhakara Reddy Nagareddy
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Hesham Soliman
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Guorong Lin
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Padmesh S. Rajput
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Ujendra Kumar
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - John H. McNeill
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathleen M. MacLeod
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author: Kathleen M. MacLeod,
| |
Collapse
|
|
16
|
Rainbow RD, Norman RI, Everitt DE, Brignell JL, Davies NW, Standen NB. Endothelin-I and angiotensin II inhibit arterial voltage-gated K+ channels through different protein kinase C isoenzymes. Cardiovasc Res 2009; 83:493-500. [PMID: 19429666 DOI: 10.1093/cvr/cvp143] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Voltage-gated K+ (Kv) channels of arterial smooth muscle (ASM) modulate arterial tone and are inhibited by vasoconstrictors through protein kinase C (PKC). We aimed to determine whether endothelin-1 (ET-1) and angiotensin II (AngII), which cause similar inhibition of Kv, use the same signalling pathway and PKC isoenzyme to exert their effects on Kv and to compare the involvement of PKC isoenzymes in contractile responses to these agents. METHODS AND RESULTS Kv currents recorded using the patch clamp technique with freshly isolated rat mesenteric ASM cells were inhibited by ET-1 or AngII. Inclusion of a PKCepsilon inhibitor peptide in the intracellular solution substantially reduced inhibition by AngII, but did not affect that by ET-1. Kv inhibition by ET-1 was reduced by the conventional PKC inhibitor Gö 6976 but not by the PKCbeta inhibitor LY333531. Selective peptide inhibitors of PKCalpha and PKCepsilon were linked to a Tat carrier peptide to make them membrane permeable and used to show that inhibition of PKCalpha prevented ET-1 inhibition of Kv current, but did not affect that by AngII. In contrast, inhibition of PKCepsilon prevented Kv inhibition by AngII but not by ET-1. The Tat-linked inhibitor peptides were also used to investigate the involvement of PKCalpha and PKCepsilon in the contractile responses of mesenteric arterial rings, showing that ET-1 contractions were substantially reduced by inhibition of PKCalpha, but unaffected by inhibition of PKCepsilon. AngII contractions were unaffected by inhibition of PKCalpha but substantially reduced by inhibition of PKCepsilon. CONCLUSION ET-1 inhibits Kv channels of mesenteric ASM through activation of PKCalpha, while AngII does so through PKCepsilon. This implies that ET-1 and AngII target Kv channels of ASM through different pathways of PKC-interacting proteins, so each vasoconstrictor enables its distinct PKC isoenzyme to interact functionally with the Kv channel.
Collapse
Affiliation(s)
- Richard D Rainbow
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, UK.
| | | | | | | | | | | |
Collapse
|
|
17
|
Ohama T, Hori M, Fujisawa M, Kiyosue M, Hashimoto M, Ikenoue Y, Jinno Y, Miwa H, Matsumoto T, Murata T, Ozaki H. Downregulation of CPI-17 contributes to dysfunctional motility in chronic intestinal inflammation model mice and ulcerative colitis patients. J Gastroenterol 2009; 43:858-65. [PMID: 19012039 DOI: 10.1007/s00535-008-2241-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Accepted: 06/26/2008] [Indexed: 02/04/2023]
Abstract
BACKGROUND Chronic intestinal inflammation is frequently accompanied by motility disorders. We previously reported that proinflammatory cytokines, such as tumor necrosis factor alpha and interleukin (IL)-1beta downregulate CPI-17, an endogenous inhibitor of serine/threonine protein phosphatase in smooth-muscle cells, which results in the inhibition of myosin light chain phosphorylation and contractility. However, its clinical relevance has not been clarified. METHODS The present study examined the changes in CPI-17 expression in chronic intestinal inflammation using smooth-muscle tissues from IL-10 knockout mice and from patients with ulcerative colitis (UC). RESULTS The IL-10 knockout mice developed spontaneous and chronic colitis accompanied by immune cell infiltration, submucosal fibrosis, and thickening of the muscularis externa. The expression of alpha-smooth muscle actin protein in the smooth-muscle layer did not change, whereas that of CPI-17 protein was decreased by about 40% compared with healthy wild-type controls. Consistent with this observation, smooth-muscle contractile force and myosin light chain phosphorylation induced by a muscarinic agonist were reduced in the knockout mice. Moreover, we observed that CPI-17 protein expression was decreased in smooth-muscle tissues from patients with UC compared with controls. CONCLUSIONS CPI-17 downregulation might contribute to the decreased motor function in chronic inflammatory bowel diseases.
Collapse
Affiliation(s)
- Takashi Ohama
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
|
18
|
Nelson CP, Willets JM, Davies NW, Challiss RAJ, Standen NB. Visualizing the temporal effects of vasoconstrictors on PKC translocation and Ca2+ signaling in single resistance arterial smooth muscle cells. Am J Physiol Cell Physiol 2008; 295:C1590-601. [PMID: 18829899 DOI: 10.1152/ajpcell.00365.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Arterial smooth muscle (ASM) contraction plays a critical role in regulating blood distribution and blood pressure. Vasoconstrictors activate cell surface receptors to initiate signaling cascades involving increased intracellular Ca(2+) concentration ([Ca(2+)](i)) and recruitment of protein kinase C (PKC), leading to ASM contraction, though the PKC isoenzymes involved vary between different vasoconstrictors and their actions. Here, we have used confocal microscopy of enhanced green fluorescence protein (eGFP)-labeled PKC isoenzymes to visualize PKC translocation in primary rat mesenteric ASM cells in response to physiological vasoconstrictors, with simultaneous imaging of Ca(2+) signaling. Endothelin-1, angiotensin II, and uridine triphosphate all caused translocation of each of the PKC isoenzymes alpha, delta, and epsilon; however, the kinetics of translocation varied between agonists and PKC isoenzymes. Translocation of eGFP-PKCalpha mirrored the rise in [Ca(2+)](i), while that of eGFP-PKCdelta or -epsilon occurred more slowly. Endothelin-induced translocation of eGFP-PKCepsilon was often sustained for several minutes, while responses to angiotensin II were always transient. In addition, preventing [Ca(2+)](i) increases using 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra-(acetoxymethyl) ester prevented eGFP-PKCalpha translocation, while eGFP-PKCdelta translocated more rapidly. Our results suggest that PKC isoenzyme specificity of vasoconstrictor actions occurs downstream of PKC recruitment and demonstrate the varied kinetics and complex interplay between Ca(2+) and PKC responses to different vasoconstrictors in ASM.
Collapse
Affiliation(s)
- Carl P Nelson
- Department of Cell Physiology & Pharmacology, Univ. of Leicester, LE1 9HN, UK.
| | | | | | | | | |
Collapse
|
|
19
|
Abstract
The vascular effects of glucose-intolerance were investigated using the neonatal streptozotocin-treated (nSTZ) rat model. Glucose-intolerance was initiated by administration of STZ (90 mg/kg, IP) into 2-day-old male rats. Aortic reactivity was assessed in vitro at 3 and 6 months of age. Both the 3- and 6-month-old nSTZ rats displayed higher blood glucose levels in response to a glucose challenge. At 3 months of age, aortic responsiveness to both norepinephrine and acetylcholine was not altered. However, at 6 months of age, the responses of endothelium-denuded aortas from nSTZ rats to norepinephrine and serotonin were enhanced compared to controls. Endothelium-mediated relaxation of aortas from these animals to acetylcholine was also augmented, and this effect was linked to NO release. Although norepinephrine did not elicit enhancement of aortic contraction in calcium-free medium in 6-month-old nSTZ rats, the responses to both maximum and submaximum concentrations of the agonist after readdition of calcium were greater in these tissues than in control preparations. Pretreatment of aortas with calphostin C eliminated the difference in NE-induced contraction between the control and experimental groups. Although the concentration-response curves for phorbol 12,13-dibutyrate were not different between the 2 groups, the responses of the aortas from 6-month-old nSTZ rats to a submaximum concentration of the phorbol ester were enhanced relative to controls, and this enhancement was normalized with calphostin C. Overall, the data suggest that glucose-intolerance of sufficient duration causes increases in vascular reactivity to agonists. While these findings warrant further investigations, such vascular alterations during the prediabetes stage of glucose intolerance can be a predisposing factor for the eventual development of cardiovascular complications.
Collapse
|
|
20
|
Abebe W. Effects of taurine on the reactivity of aortas from diabetic rats. Life Sci 2008; 82:279-89. [DOI: 10.1016/j.lfs.2007.11.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 11/13/2007] [Accepted: 11/18/2007] [Indexed: 10/22/2022]
|
|
21
|
Cheng ZJ, Jiang YF, Ding H, Severson D, Triggle CR. Vascular dysfunction in type 2 diabetic TallyHo mice: role for an increase in the contribution of PGH2/TxA2 receptor activation and cytochrome p450 products. Can J Physiol Pharmacol 2007; 85:404-12. [PMID: 17612649 DOI: 10.1139/y07-010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In this study, we tested the hypothesis that spontaneously diabetic TallyHo (TH) mice, a novel polygenic model for type 2 diabetes, will exhibit endothelial dysfunction associated with an increased contribution from endothelium-derived contractile factors (EDCF). The cellular mechanisms underlying the increased contribution of EDCF were explored in 16 and 30-week-old male TH and age-matched male C57BL/6J mice (n=4-9). Blood glucose and serum lipid profiles were markedly increased in the TH mice. Superoxide generation, assessed with a lucigenin chemiluminescence assay, was markedly increased in the aortae of TH mice. Endothelium-dependent vascular relaxations and contractions to acetylcholine (ACh), but not endothelium-independent relaxations to sodium nitroprusside, were impaired and vascular contractions to phenylephrine were significantly enhanced in aortae from TH mice. Nomega-nitro-L-arginine methyl ester markedly increased the ACh-induced contractions in TH mice, whereas SQ29548, a thromboxane receptor antagonist, and cytochrome P450 (CYP) inhibitors 17-octadecynoic acid and sulfaphenazole, the latter being specific for CYP2C6 and 2C9, decreased and (or) normalized the contractile response to ACh in TH mice. The present study indicates that enhanced contribution of prostaglandin H2/thromboxane A2 receptor and CYP, likely CYP2C6 and 2C9, play a critical role in the pathogenesis of increased EDCF in the aortae of type 2 diabetic TH mice.
Collapse
MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiopathology
- Blood Glucose/analysis
- Bridged Bicyclo Compounds, Heterocyclic
- Cytochrome P-450 Enzyme Inhibitors
- Cytochrome P-450 Enzyme System/metabolism
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Fatty Acids, Unsaturated/pharmacology
- Hydrazines/pharmacology
- Lipids/blood
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Potassium Chloride/pharmacology
- Prostaglandin H2/metabolism
- Receptors, Thromboxane A2, Prostaglandin H2/antagonists & inhibitors
- Receptors, Thromboxane A2, Prostaglandin H2/metabolism
- Sulfaphenazole/pharmacology
- Superoxides/metabolism
- Vasoconstriction/drug effects
- Vasodilation
Collapse
Affiliation(s)
- Zhong Jian Cheng
- Smooth Muscle Research Group, Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, AB T2N 4N1, Canada
| | | | | | | | | |
Collapse
|
|
22
|
Gradin KA, Zhu H, Jeansson M, Simonsen U. Enhanced neuropeptide Y immunoreactivity and vasoconstriction in mesenteric small arteries from the early non-obese diabetic mouse. Eur J Pharmacol 2006; 539:184-91. [PMID: 16707122 DOI: 10.1016/j.ejphar.2006.03.080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 03/27/2006] [Accepted: 03/31/2006] [Indexed: 11/29/2022]
Abstract
The present study investigated whether sympathetic neurotransmission is altered at an early stage of diabetes in mesenteric small arteries isolated from female non-obese diabetic (NOD) and control animals without diabetes from the same mouse strain. The NOD diabetic mice had increased plasma glucose and hypertension. Confocal microscopy showed distribution of nerve terminals was similar, but immunoreaction intensity for neuropeptide Y (NPY) and tyrosine hydroxylase was higher in small arteries from NOD diabetic compared with NOD control mice. In the presence of prazosin and activated with vasopressin, electrical field stimulation evoked contractions which were more pronounced in mesenteric arteries from NOD diabetic versus NOD control mice and inhibited by the NPY Y(1) receptor antagonist, BIBP 3226. NPY concentration-response curves were leftward shifted in arteries from NOD diabetic versus NOD control both in arteries with and without endothelium, but not in the presence of the BIBP 3226. The present findings suggest that enhanced NPY content and vasoconstriction to NPY by activation of NPY Y(1) receptors in arteries from diabetic mice may contribute to the enhanced sympathetic nerve activity and vascular resistance in female non-obese early diabetic animals.
Collapse
Affiliation(s)
- Kathryn A Gradin
- Institute for Neuroscience and Physiology, Department of Pharmacology, University of Göteborg, Medicinaregatan 11, 413 90 Göteborg, Sweden.
| | | | | | | |
Collapse
|