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Zhu J, Yang L, Jia Y, Balistrieri A, Fraidenburg DR, Wang J, Tang H, Yuan JXJ. Pathogenic Mechanisms of Pulmonary Arterial Hypertension: Homeostasis Imbalance of Endothelium-Derived Relaxing and Contracting Factors. JACC. ASIA 2022; 2:787-802. [PMID: 36713766 PMCID: PMC9877237 DOI: 10.1016/j.jacasi.2022.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 08/29/2022] [Accepted: 09/14/2022] [Indexed: 12/23/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a progressive and fatal disease. Sustained pulmonary vasoconstriction and concentric pulmonary vascular remodeling contribute to the elevated pulmonary vascular resistance and pulmonary artery pressure in PAH. Endothelial cells regulate vascular tension by producing endothelium-derived relaxing factors (EDRFs) and endothelium-derived contracting factors (EDCFs). Homeostasis of EDRF and EDCF production has been identified as a marker of the endothelium integrity. Impaired synthesis or release of EDRFs induces persistent vascular contraction and pulmonary artery remodeling, which subsequently leads to the development and progression of PAH. In this review, the authors summarize how EDRFs and EDCFs affect pulmonary vascular homeostasis, with special attention to the recently published novel mechanisms related to endothelial dysfunction in PAH and drugs associated with EDRFs and EDCFs.
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Key Words
- 5-HT, 5-hydroxytryptamine
- ACE, angiotensin-converting enzyme
- EC, endothelial cell
- EDCF, endothelium-derived contracting factor
- EDRF, endothelium-derived relaxing factor
- ET, endothelin
- PAH, pulmonary arterial hypertension
- PASMC, pulmonary artery smooth muscle cell
- PG, prostaglandin
- TPH, tryptophan hydroxylase
- TXA2, thromboxane A2
- cGMP, cyclic guanosine monophosphate
- endothelial dysfunction
- endothelium-derived relaxing factor
- pulmonary arterial hypertension
- vascular homeostasis
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Affiliation(s)
- Jinsheng Zhu
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangdong Key Laboratory of Vascular Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Lei Yang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Yangfan Jia
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Angela Balistrieri
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Dustin R. Fraidenburg
- Division of Pulmonary, Critical Care, Sleep, and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Jian Wang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangdong Key Laboratory of Vascular Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China,Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Haiyang Tang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangdong Key Laboratory of Vascular Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China,Addresses for correspondence: Dr Haiyang Tang, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, 195 West Dongfeng Road, Guangzhou, Guangdong 510120, China.
| | - Jason X-J Yuan
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California, USA,Dr Jason X.-J. Yuan, Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California-San Diego, 9500 Gilman Drive, MC 0856, La Jolla, California 92093-0856, USA.
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Mulvaney EP, Renzo F, Adão R, Dupre E, Bialesova L, Salvatore V, Reid HM, Conceição G, Grynblat J, Llucià-Valldeperas A, Michel JB, Brás-Silva C, Laurent CE, Howard LS, Montani D, Humbert M, Vonk Noordegraaf A, Perros F, Mendes-Ferreira P, Kinsella BT. The thromboxane receptor antagonist NTP42 promotes beneficial adaptation and preserves cardiac function in experimental models of right heart overload. Front Cardiovasc Med 2022; 9:1063967. [PMID: 36588576 PMCID: PMC9794752 DOI: 10.3389/fcvm.2022.1063967] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Background Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary artery pressure leading to right ventricular (RV) failure. While current PAH therapies improve patient outlook, they show limited benefit in attenuating RV dysfunction. Recent investigations demonstrated that the thromboxane (TX) A2 receptor (TP) antagonist NTP42 attenuates experimental PAH across key hemodynamic parameters in the lungs and heart. This study aimed to validate the efficacy of NTP42:KVA4, a novel oral formulation of NTP42 in clinical development, in preclinical models of PAH while also, critically, investigating its direct effects on RV dysfunction. Methods The effects of NTP42:KVA4 were evaluated in the monocrotaline (MCT) and pulmonary artery banding (PAB) models of PAH and RV dysfunction, respectively, and when compared with leading standard-of-care (SOC) PAH drugs. In addition, the expression of the TP, the target for NTP42, was investigated in cardiac tissue from several other related disease models, and from subjects with PAH and dilated cardiomyopathy (DCM). Results In the MCT-PAH model, NTP42:KVA4 alleviated disease-induced changes in cardiopulmonary hemodynamics, pulmonary vascular remodeling, inflammation, and fibrosis, to a similar or greater extent than the PAH SOCs tested. In the PAB model, NTP42:KVA4 improved RV geometries and contractility, normalized RV stiffness, and significantly increased RV ejection fraction. In both models, NTP42:KVA4 promoted beneficial RV adaptation, decreasing cellular hypertrophy, and increasing vascularization. Notably, elevated expression of the TP target was observed both in RV tissue from these and related disease models, and in clinical RV specimens of PAH and DCM. Conclusion This study shows that, through antagonism of TP signaling, NTP42:KVA4 attenuates experimental PAH pathophysiology, not only alleviating pulmonary pathologies but also reducing RV remodeling, promoting beneficial hypertrophy, and improving cardiac function. The findings suggest a direct cardioprotective effect for NTP42:KVA4, and its potential to be a disease-modifying therapy in PAH and other cardiac conditions.
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Affiliation(s)
- Eamon P. Mulvaney
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Fabiana Renzo
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Rui Adão
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal
| | | | - Lucia Bialesova
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Viviana Salvatore
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Helen M. Reid
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Glória Conceição
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Julien Grynblat
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France
| | - Aida Llucià-Valldeperas
- PHEniX Laboratory, Department of Pulmonary Medicine, Amsterdam UMC (Location VUMC), Amsterdam Cardiovascular Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands,Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Thrombosis, Amsterdam, Netherlands
| | | | - Carmen Brás-Silva
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Charles E. Laurent
- IPS Therapeutique Inc., Sherbrooke, QC, Canada,ToxiPharm Laboratories Inc., Ste-Catherine-de-Hatley, QC, Canada
| | - Luke S. Howard
- Imperial College London, National Heart and Lung Institute, London, United Kingdom
| | - David Montani
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France,AP-HP, Dept of Respiratory and Intensive Care Medicine, Pulmonary Hypertension National Referral Centre, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Marc Humbert
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France,AP-HP, Dept of Respiratory and Intensive Care Medicine, Pulmonary Hypertension National Referral Centre, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Anton Vonk Noordegraaf
- PHEniX Laboratory, Department of Pulmonary Medicine, Amsterdam UMC (Location VUMC), Amsterdam Cardiovascular Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Frédéric Perros
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France,Paris-Porto Pulmonary Hypertension Collaborative Laboratory (3PH), INSERM UMR_S 999, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM, INRAE, CarMeN Laboratory and Centre de Recherche en Nutrition Humaine Rhône-Alpes (CRNH-RA), Claude Bernard University Lyon 1, University of Lyon, Lyon, France
| | - Pedro Mendes-Ferreira
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal,Paris-Porto Pulmonary Hypertension Collaborative Laboratory (3PH), INSERM UMR_S 999, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - B. Therese Kinsella
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland,UCD School of Biomolecular and Biomedical Research, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland,*Correspondence: B. Therese Kinsella,
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Thromboxane A2 synthase inhibition ameliorates endothelial dysfunction, memory deficits, oxidative stress and neuroinflammation in rat model of streptozotocin diabetes induced dementia. Physiol Behav 2021; 241:113592. [PMID: 34534530 DOI: 10.1016/j.physbeh.2021.113592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/11/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022]
Abstract
RATIONALE Vascular dementia (VaD) is the second leading cause of dementia worldwide. It is very important to find the possible pharmacological agents which may be useful in management and therapy of VaD. OBJECTIVES The present study investigates the effect of ozagrel, a selective thromboxane A2 (TXA2) synthase inhibitor, in a rat model of VaD. METHODS Single intraperitoneal injection of streptozotocin [STZ, (50 mg/kg)] was administered to Wistar rats to induced diabetes-associated vascular endothelial dysfunction and memory impairment. Morris water maze (MWM) test was employed to assess learning and memory. Endothelial dysfunction was assessed in the isolated aorta by observing endothelial-dependent vasorelaxation and levels of serum nitrite. Various biochemical and histopathological estimations were also performed. RESULTS STZ treatment produced endothelial dysfunction, impairment of learning and memory, reduction in body weight and serum nitrite/nitrate, and increase in serum glucose, brain oxidative stress (increased brain thiobarbituric acid reactive species and decreased reduced glutathione levels), brain acetylcholinesterase activity and brain myeloperoxidase activity. Further a significant rise in brain tumor necrosis factor-α & interleukin-6 levels and brain neutrophil infiltration were also observed. Treatment of ozagrel (10 & 20 mg/kg, p. o.)/donepezil (0. 5 mg/kg, i.p., serving as standard) ameliorated STZ induced endothelial dysfunction; memory deficits; biochemical and histopathological changes. CONCLUSIONS It may be concluded that ozagrel markedly improved endothelial dysfunction; learning and memory; biochemical and histopathological alteration associated with STZ induced dementia and that TXA2 can be considered as an important therapeutic target for the management of VaD.
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Bhatia P, Kaur G, Singh N. Ozagrel a thromboxane A2 synthase inhibitor extenuates endothelial dysfunction, oxidative stress and neuroinflammation in rat model of bilateral common carotid artery occlusion induced vascular dementia. Vascul Pharmacol 2021; 137:106827. [PMID: 33346090 DOI: 10.1016/j.vph.2020.106827] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/14/2020] [Accepted: 12/15/2020] [Indexed: 12/16/2022]
Abstract
The present study investigates the potential of ozagrel, a thromboxane A2 (TXA2) synthase inhibitor, in bilateral common carotid artery occlusion (BCCAo) induced vascular dementia (VaD). Wistar rats were subjected to BCCAo procedure under anesthesia to induce VaD. Morris water maze (MWM) test was employed on 7th day post-surgery to determine learning and memory. Endothelial dysfunction was assessed in isolated aorta by observing endothelial dependent vasorelaxation and levels of serum nitrite. A battery of biochemical and histopathological estimations was performed. Expression analysis of inflammatory cytokines TNF-α and IL-6 was carried out by RT-PCR. BCCAo produced significant impairment in endothelium dependent vasorelaxation and decrease in serum nitrite levels indicating endothelial dysfunction along with poor performance on MWM represents impairment of learning and memory. There was a significant rise in brain oxidative stress level (indicated by increase in brain thiobarbituric acid reactive species and decrease in reduced glutathione levels); increase in brain acetylcholinesterase activity; brain myeloperoxidase activity; brain TNF-α & IL-6 levels, brain TNF-α & IL-6 mRNA expression and brain neutrophil infiltration (as marker of inflammation) were also observed. Treatment of ozagrel (10 & 20 mg/kg, p. o.)/donepezil (0. 5 mg/kg, i.p., serving as standard) ameliorated BCCAo induced endothelial dysfunction; memory deficits; biochemical and histopathological changes in a significant manner. It may be concluded that ozagrel markedly improved endothelial dysfunction; learning and memory; biochemical and histopathological alteration associated with BCCAo induced VaD and that TXA2 can be considered as an important therapeutic target for the treatment of VaD.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Brain/drug effects
- Brain/enzymology
- Brain/physiopathology
- Carotid Artery, Common/surgery
- Carotid Stenosis/complications
- Dementia, Vascular/drug therapy
- Dementia, Vascular/enzymology
- Dementia, Vascular/etiology
- Dementia, Vascular/physiopathology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/physiopathology
- Enzyme Inhibitors/pharmacology
- Female
- Inflammation Mediators/metabolism
- Ligation
- Male
- Methacrylates/pharmacology
- Morris Water Maze Test/drug effects
- Oxidative Stress/drug effects
- Rats, Wistar
- Thromboxane-A Synthase/antagonists & inhibitors
- Thromboxane-A Synthase/metabolism
- Rats
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Affiliation(s)
- Pankaj Bhatia
- CNS Research lab., Pharmacology division, Department of Pharmaceutical Sciences and Drug Research, Faculty of Medicine, Punjabi University, Patiala 147002, Punjab, India
| | - Gagandeep Kaur
- CNS Research lab., Pharmacology division, Department of Pharmaceutical Sciences and Drug Research, Faculty of Medicine, Punjabi University, Patiala 147002, Punjab, India
| | - Nirmal Singh
- Pharmacology division, Department of Pharmaceutical Sciences and Drug Research, Faculty of Medicine, Punjabi University, Patiala 147002, Punjab, India.
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Bhatia P, Singh N. Ameliorative effect of ozagrel, a thromboxane A2 synthase inhibitor, in hyperhomocysteinemia-induced experimental vascular cognitive impairment and dementia. Fundam Clin Pharmacol 2020; 35:650-666. [PMID: 33020931 DOI: 10.1111/fcp.12610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/24/2020] [Accepted: 09/29/2020] [Indexed: 10/23/2022]
Abstract
The present study investigates the effect of ozagrel, a selective thromboxane A2 (TXA2) inhibitor, in rat model of hyperhomocysteinemia (HHcy)-induced vascular cognitive impairment and dementia (VCID). Wistar rats were administered L-methionine (1.7 g/kg/day; p.o. × 8 weeks) to induce VCID. Morris water maze (MWM) test was employed to assess learning and memory. Endothelial dysfunction was assessed in the isolated aorta by observing endothelial-dependent vasorelaxation and levels of serum nitrite. Various biochemical and histopathological estimations were also performed. L-methionine produced significant impairment in endothelium-dependent vasorelaxation and decreases serum nitrite levels indicating endothelial dysfunction. Further, these animals performed poorly on MWM, depicting impairment of learning and memory. Further, a significant rise in brain oxidative stress level (indicated by increase in brain thiobarbituric acid-reactive species and decrease in reduced glutathione levels), brain acetylcholinesterase activity, brain myeloperoxidase activity, brain TNF-α and IL-6 levels, and brain leukocyte (neutrophil) infiltration was also observed. Treatment of ozagrel (10 and 20 mg/kg, p. o.)/donepezil (0.5 mg/kg, i.p., serving as standard) ameliorated L-methionine-induced endothelial dysfunction, memory deficits, and biochemical and histopathological changes. It may be concluded that ozagrel markedly improved endothelial dysfunction, learning and memory, and biochemical and histopathological alteration associated with L-methionine-induced VCID and that TXA2 can be considered as an important therapeutic target for the management of VCID.
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Affiliation(s)
- Pankaj Bhatia
- CNS Research Lab., Pharmacology Division, Department of Pharmaceutical Sciences and Drug Research, Faculty of Medicine, Punjabi University, Patiala, Punjab, 147002, India
| | - Nirmal Singh
- Pharmacology Division, Department of Pharmaceutical Sciences and Drug Research, Faculty of Medicine, Punjabi University, Patiala, Punjab, 147002, India
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Affiliation(s)
- Roxane Paulin
- From the Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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Obata H, Sakai Y, Ohnishi S, Takeshita S, Mori H, Kodama M, Kangawa K, Aizawa Y, Nagaya N. Single Injection of a Sustained-release Prostacyclin Analog Improves Pulmonary Hypertension in Rats. Am J Respir Crit Care Med 2008; 177:195-201. [DOI: 10.1164/rccm.200703-349oc] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Abstract
Isoprostanes were first recognized as convenient markers of oxidative stress, but their powerful effects on a variety of cell functions are now also being increasingly appreciated. This is particularly true of the lung, which is comprised of a wide variety of different cell types (smooth muscle, innervation, epithelium, lymphatics, etc.), all of which have been shown to respond to exogenously applied isoprostanes. In this review, we summarize these biological responses in the lung, and also consider the roles that isoprostanes might play in a range of pulmonary clinical disorders.
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Affiliation(s)
- Luke J Janssen
- Asthma Research Group, Father Sean O'Sullivan Research Center, Firestone Institute for Respiratory Health, St. Joseph's Hospital, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
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Abstract
Isoprostanes are widely recognized as useful markers of membrane lipid peroxidation. It seems to be less well appreciated, however, that they also elicit important biological responses, even though this was first shown at the same time that they were introduced as markers of oxidative stress. The past several years have seen the list of cells/tissues which are sensitive to isoprostanes grow considerably: in fact, as we summarize here, there is now evidence that essentially every cell type in the lung responds in some pathologically relevant way to isoprostanes. In this sense, they might well be considered as not just markers of oxidative stress and inflammation, but also as a novel group of inflammatory mediators. Moreover, in addition to their pathological effects, we summarize here the evidence which has led us to hypothesize that isoprostanes could play an important role in vascular smooth muscle physiology as "endothelium-derived hyperpolarizing factors."
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Affiliation(s)
- L J Janssen
- Department of Medicine, Asthma Research Group, Father Sean O'Sullivan Research Center, Firestone Institute for Respiratory Health, St. Joseph's Hospital, McMaster University, Hamilton, Ont., Canada L8N4A6.
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Saha SL, Roche VF, Pendola K, Kearley M, Lei L, Romstedt KJ, Herdman M, Shams G, Kaisare V, Feller DR. Synthesis and in vitro platelet aggregation and TP receptor binding studies on bicyclic 5,8-ethanooctahydroisoquinolines and 5,8-ethanotetrahydroisoquinolines. Bioorg Med Chem 2002; 10:2779-93. [PMID: 12057668 DOI: 10.1016/s0968-0896(02)00101-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Eighteen novel bicyclic 1-substituted benzyl octahydro- and tetrahydroisoquinolines were synthesized and evaluated for human thromboxane A(2)/prostaglandin H(2) (TP) receptor affinity and antagonism of TP receptor-mediated platelet aggregation. In both cases, potency depended more on the presence of methoxy groups on the 1-benzyl moiety than on nitrogen substitution or extent of oxidation of the isoquinoline ring system. The most potent of the bicyclic compounds retained the 5,8-ethanooctahydroisoquinoline ring structure of the parent molecule (1) and required the 3,4,5-trimethoxybenzyl substitution pattern found in the well-characterized tetrahydroisoquinoline antiplatelet agent trimetoquinol. Differences in nitrogen substituent SAR were noted between the mono-methoxylated compounds and the 3,4,5-trimethoxybenzyl derivatives.
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Affiliation(s)
- Shankar L Saha
- School of Pharmacy & Allied Health Professions, Creighton University, 2500 California Plaza, Omaha, NE 68005, USA
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Janssen LJ. Isoprostanes: an overview and putative roles in pulmonary pathophysiology. Am J Physiol Lung Cell Mol Physiol 2001; 280:L1067-82. [PMID: 11350785 DOI: 10.1152/ajplung.2001.280.6.l1067] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Isoprostanes are produced during peroxidation of membrane lipids by free radicals and reactive oxygen species. Initially, they were recognized as being valuable markers of oxidative stress, and in the past 10 years, dozens of disease states and experimental conditions with diverse etiologies have been shown to be associated with marked increases in urinary, plasma, and tissue levels of isoprostanes. However, they are not just mere markers; they evoke important biological responses on virtually every cell type found within the lung, and these responses exhibit compound-, tissue-, and species-related variations. In fact, the isoprostanes may mediate many of the features of the disease states for which they are used as indicators. In this review, I describe the chemistry, metabolism, and pharmacology of isoprostanes, with a particular emphasis on pulmonary cell types, and the possible roles of isoprostanes in pulmonary pathophysiology.
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Affiliation(s)
- L J Janssen
- Asthma Research Group, Father Sean O'Sullivan Research Center, St. Joseph's Hospital, McMaster University, 50 Charlton Ave. East, Hamilton, Ontario L8N 4A6, Canada.
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Abstract
Primary pulmonary hypertension (PPH) is a syndrome of dyspnea, chest pain, and syncope defined by increased pulmonary vascular resistance and the absence of a known cause. It also occurs in a familial form, which is linked to unidentified genes on chromosome 2. This syndrome is characterized by abnormalities of pulmonary vascular biology in each compartment of the blood vessel. The lumen has a prothrombotic diathesis, the endothelium displays an excessive production of vasoconstrictors relative to vasodilators, and the smooth muscle cells are depolarized and calcium-overloaded, which is due in part to reduced expression of voltage-gated potassium channels (Kv). This causes vasoconstriction and may promote cell proliferation. The adventitia displays excessive remodeling, which is associated with exaggerated metalloproteinase and elastase activity. Conceptually, PPH seems to require a permissive genotype, a susceptible phenotype (eg, endothelial dysfunction) and, in many cases, an exogenous trigger (eg, an anorexigen). Although there is not a generally accepted, unifying hypothesis regarding its cause, impaired function and the expression of vascular and platelet Kv channels suggest PPH may be a disease of the ion channels. Abnormal matrix metalloproteinase and elastase activity could also explain the abnormal vascular tone, platelet activation, and remodeling in PPH. Although calcium-channel blockers and prostacyclin, particularly when coadministered with warfarin, improve survival, PPH has a 5-year mortality rate of approximately 50%. Pharmacological and gene therapies aimed at enhancing the activity of prostacyclin, nitric oxide synthases, and Kv channels or at inhibiting endothelin and matrix metalloproteinases are promising areas for future development.
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Affiliation(s)
- S Archer
- Division of Cardiolgy, Department of Medicine, University of Alberta, WMC 2C2.36,8440, Edmonton, Alberta, Canada.
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Janssen LJ. Isoprostanes: generation, pharmacology, and roles in free-radical-mediated effects in the lung. Pulm Pharmacol Ther 2000; 13:149-55. [PMID: 10930353 DOI: 10.1006/pupt.2000.0244] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Isoprostanes are produced during peroxidation of membrane lipids by free radicals and reactive oxygen species, and are currently used as markers of many disease states and experimental conditions in which oxidative stress is a prominent feature. A small number of reports have described the ability of some isoprostanes to evoke important biological effects in smooth muscle and other cell types. However, most of these studies were done using rat tissues, and only two specific isoprostanes - 8-iso-PGE(2)and 8-iso-PGF(2alpha)- were tested. In this review, we describe the generation of isoprostanes during oxidative stress, and their effects on smooth muscle, including our novel findings of their effects on human airway, pulmonary artery and pulmonary vein smooth muscles. Collectively, the data suggest that isoprostanes may not only be markers, but may in fact mediate the effects of free radicals and reactive oxygen species.
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Affiliation(s)
- L J Janssen
- Asthma Research Group, Father Sean O'Sullivan Research Center, Hamilton, Ontario, Canada.
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