J Physiol Pharmacol. 2008 Aug;59 Suppl 2:103-15.
Nitric oxide (NO)-releasing aspirin and (NO) donors in protection of gastric mucosa against stress.
S Kwiecien S, Pawlik MW, Brzozowski T, Konturek PC, Sliwowski Z, Pawlik WW, Konturek SJ. Department of Physiology Jagiellonian University Medical College, Cracow, Poland.
Acute gastric mucosal lesions represent an important clinical problem. The experimental model of acute gastritis such as water immersion restraint (WRS) stress is useful tool in examination of pathomechanism of acute gastric damage. Nitric oxide (NO) plays an important role in the maintenance of gastric barrier, however the role of reactive oxygen species (ROS) in the interaction between NO and gastric mucosa integrity has been little studied. The purpose of our present study was to explain the participation of ROS in healing of WRS-induced gastric lesions accelerated by NO. Experiments were carrying out on 120 male Wistar rats. To assess gastric blood flow (GBF) laser Doppler flowmeter was used. The number of gastric lesions was established by planimetry. The colorimetric assays were used to determine gastric tissue level of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), the products of lipid peroxidation by ROS, as well as superoxide dismutase (SOD) activity, the enzyme scavanger of ROS. We demonstrated that 3.5 h of WRS resulted in appearance of acute gastric mucosal lesions accompanied by a significant decrease of GBF. Biological effects of ROS were estimated by measuring tissue level of MDA and 4-HNE, as well as the SOD activity. It was demonstrated that 3.5 h of WRS led to significant increase of MDA and 4-HNE mucosal level, that was accompanied by a decrease of SOD activity. Pretreatment with NO-donors (SIN-1, SNAP, nitroglycerin, NO-ASA) resulted in reduction of gastric lesions number, increment of GBF, decrease of MDA and 4-HNE tissue level and increase of SOD activity. Suppression of ROS play an important role in NO-donors action in gastroprotection against gastric acute lesions induced by 3.5 h of WRS. NO-donors cause an attenuation of lipid peroxidation as documented by a decrease of MDA and 4-HNE levels and enhancement of antioxidative properties as evidenced by increase of SOD activity.
10 - 2008
Curr Alzheimer Res. 2008 Oct;5(5):422-31.
Fatty aspirin: a new perspective in the prevention of dementia of Alzheimer's type?
Pomponi M, Di Gioia A, Bria P, Pomponi MF. Catholic University of Sacred Heart (UCSC), Psychiatric Department, Rome, Italy.
Alzheimer's disease (AD) leads to a dramatic decline in cognitive abilities and memory. A more modest disruption of memory often occurs in normal aging and the same circuits that are devastated through degeneration in AD are vulnerable to sub-lethal age-related changes that alter synaptic transmission. There are numerous indications that aberrant plasticity is critically involved in Alzheimer's. Is ageing itself the major risk factor for AD? Is AD an acceleration of normal ageing? We assume that the ability of the brain is to modify its own structural organization and functioning which is liable to become impaired in ageing until it becomes dramatically impaired in Alzheimer's. Moreover, ageing can compromise the conversion of dietary alpha-linolenic acid (ALA) to docosahexaenoic acid (DHA). DHA regulates synaptogenesis and affects the synaptic structure, and synapse density is reduced in ageing. DHA and newly identified DHA-derived messenger, neuroprotecting D1 (NPD1), protect synapses and decrease the number of activated microglia in the hippocampal system. Delaying AD onset by a few years would reduce the number of the cases of dementia in the community. DHA (and NPD1?) and aspirin induce brain-derived neurotrophic factor (BDNF) protein expression and this protein has a crucial role in neuronal survival. The authors--in view of the increased neuroinflammatory reaction frequently observed during normal brain ageing--suggest the long-term use of "fatty aspirin", an association of DHA and/or NPD1 and aspirin (or nitroaspirin), to postpone, or prevent, the structural neurodegeneration of the brain.
Carcinogenesis. 2008 Sep;29(9):1794-8. Epub 2008 Jun 9.
NO-donating aspirin inhibits angiogenesis by suppressing VEGF expression in HT-29 human colon cancer mouse xenografts.
Ouyang N, Williams JL, Rigas B. Division of Cancer Prevention, Stony Brook University, Stony Brook, NY 11794, USA.
The inhibitory effect of NO-donating aspirin (NO-ASA) on colon cancer has been demonstrated in vivo and in vitro but its mechanism is still obscure. We investigated the effect of NO-ASA on angiogenesis. Four groups of athymic mice (N = 12) bearing subcutaneous xenotransplants of HT-29 human colon cancer cells were injected intratumorally twice a week for 3 weeks with vehicle or m-NO-ASA or p-NO-ASA; the fourth group received no injections. The necrotic area of tumors, expressed as percentage of total area, was similar in the non-injected and vehicle-injected groups (51.8 +/- 2.8 versus 52.2 +/- 4.1, P > 0.05; mean +/- SEM for these and subsequent values). Compared with the vehicle group, the necrotic area of tumors was higher in the m-NO-ASA-treated (61.0 +/- 2.7, P < 0.02) and p-NO-ASA (65.8 +/- 2.4, P < 0.001)-treated groups. NO-ASA decreased microvessel density: vehicle = 11.7 +/- 0.8; m-NO-ASA = 7.8 +/- 0.6 (P = 0.0003 versus vehicle) and p-NO-ASA 6.2 +/- 0.7 (P = 0.0001 versus vehicle). The expression of vascular endothelial growth factor (VEGF) was significantly reduced in response to NO-ASA, with the p- isomer being more potent than the m-.NO-ASA altered the spatial distribution of VGEF expression, with 16.7% of the vehicle-treated xenografts displaying diminished VEGF in the inner region of the area between necrosis and the outer perimeter of the tumor, compared with those treated with m- (58.3%) or p-NO-ASA (75%, P < 0.01 for both versus control). Our findings indicate that NO-ASA suppresses the expression of VEGF, which leads to suppressed angiogenesis. The antiangiogenic activity of NO-ASA may be part of its antineoplastic effect.
Fatty aspirin: a new perspective in the prevention of dementia of Alzheimer's type?
Pomponi M, Di Gioia A, Bria P, Pomponi MF. Catholic University of Sacred Heart (UCSC), Psychiatric Department, Rome, Italy.
Alzheimer's disease (AD) leads to a dramatic decline in cognitive abilities and memory. A more modest disruption of memory often occurs in normal aging and the same circuits that are devastated through degeneration in AD are vulnerable to sub-lethal age-related changes that alter synaptic transmission. There are numerous indications that aberrant plasticity is critically involved in Alzheimer's. Is ageing itself the major risk factor for AD? Is AD an acceleration of normal ageing? We assume that the ability of the brain is to modify its own structural organization and functioning which is liable to become impaired in ageing until it becomes dramatically impaired in Alzheimer's. Moreover, ageing can compromise the conversion of dietary alpha-linolenic acid (ALA) to docosahexaenoic acid (DHA). DHA regulates synaptogenesis and affects the synaptic structure, and synapse density is reduced in ageing. DHA and newly identified DHA-derived messenger, neuroprotecting D1 (NPD1), protect synapses and decrease the number of activated microglia in the hippocampal system. Delaying AD onset by a few years would reduce the number of the cases of dementia in the community. DHA (and NPD1?) and aspirin induce brain-derived neurotrophic factor (BDNF) protein expression and this protein has a crucial role in neuronal survival. The authors--in view of the increased neuroinflammatory reaction frequently observed during normal brain ageing--suggest the long-term use of "fatty aspirin", an association of DHA and/or NPD1 and aspirin (or nitroaspirin), to postpone, or prevent, the structural neurodegeneration of the brain.
Carcinogenesis. 2008 Sep;29(9):1794-8. Epub 2008 Jun 9.
NO-donating aspirin inhibits angiogenesis by suppressing VEGF expression in HT-29 human colon cancer mouse xenografts.
Ouyang N, Williams JL, Rigas B. Division of Cancer Prevention, Stony Brook University, Stony Brook, NY 11794, USA.
The inhibitory effect of NO-donating aspirin (NO-ASA) on colon cancer has been demonstrated in vivo and in vitro but its mechanism is still obscure. We investigated the effect of NO-ASA on angiogenesis. Four groups of athymic mice (N = 12) bearing subcutaneous xenotransplants of HT-29 human colon cancer cells were injected intratumorally twice a week for 3 weeks with vehicle or m-NO-ASA or p-NO-ASA; the fourth group received no injections. The necrotic area of tumors, expressed as percentage of total area, was similar in the non-injected and vehicle-injected groups (51.8 +/- 2.8 versus 52.2 +/- 4.1, P > 0.05; mean +/- SEM for these and subsequent values). Compared with the vehicle group, the necrotic area of tumors was higher in the m-NO-ASA-treated (61.0 +/- 2.7, P < 0.02) and p-NO-ASA (65.8 +/- 2.4, P < 0.001)-treated groups. NO-ASA decreased microvessel density: vehicle = 11.7 +/- 0.8; m-NO-ASA = 7.8 +/- 0.6 (P = 0.0003 versus vehicle) and p-NO-ASA 6.2 +/- 0.7 (P = 0.0001 versus vehicle). The expression of vascular endothelial growth factor (VEGF) was significantly reduced in response to NO-ASA, with the p- isomer being more potent than the m-.NO-ASA altered the spatial distribution of VGEF expression, with 16.7% of the vehicle-treated xenografts displaying diminished VEGF in the inner region of the area between necrosis and the outer perimeter of the tumor, compared with those treated with m- (58.3%) or p-NO-ASA (75%, P < 0.01 for both versus control). Our findings indicate that NO-ASA suppresses the expression of VEGF, which leads to suppressed angiogenesis. The antiangiogenic activity of NO-ASA may be part of its antineoplastic effect.
2008 - 08
Cardiol Rev. 2008 Sep-Oct;16(5):250-9.
Investigational antiplatelet drugs for the treatment and prevention of coronary artery disease.
Zeidner JF, Frishman WH, Lerner RG. Department of Medicine, Johns Hopkins School of Medicine/Johns Hopkins Hospital, Baltimore, Maryland, USA.
Antiplatelet therapy for the prevention and treatment of coronary artery disease (CAD) has undergone dramatic changes and improvements. Aspirin remains the first-line antiplatelet drug for clinical use. Newer platelet inhibitors such as the thienopyridine agents, ticlopidine and clopidogrel, have also been shown to be effective in treating CAD. There have been ongoing efforts to evaluate newer antiplatelet drugs, with the potential to improve clinical efficacy and safety. Some of the more promising antiplatelet agents include new adenosine diphosphate receptor antagonists such as prasugrel, cangrelor, and ticagrelor (AZD6140). In addition, a new thromboxane receptor antagonist, NCX-4016, a newly discovered protease-activated receptor antagonist that targets thrombin-induced platelet aggregation, and anti-von Willebrand factor aptamers show tremendous promise in refining antiplatelet therapy by targeting different receptors and molecules.
PMID: 18708826 [PubMed - in process]
Investigational antiplatelet drugs for the treatment and prevention of coronary artery disease.
Zeidner JF, Frishman WH, Lerner RG. Department of Medicine, Johns Hopkins School of Medicine/Johns Hopkins Hospital, Baltimore, Maryland, USA.
Antiplatelet therapy for the prevention and treatment of coronary artery disease (CAD) has undergone dramatic changes and improvements. Aspirin remains the first-line antiplatelet drug for clinical use. Newer platelet inhibitors such as the thienopyridine agents, ticlopidine and clopidogrel, have also been shown to be effective in treating CAD. There have been ongoing efforts to evaluate newer antiplatelet drugs, with the potential to improve clinical efficacy and safety. Some of the more promising antiplatelet agents include new adenosine diphosphate receptor antagonists such as prasugrel, cangrelor, and ticagrelor (AZD6140). In addition, a new thromboxane receptor antagonist, NCX-4016, a newly discovered protease-activated receptor antagonist that targets thrombin-induced platelet aggregation, and anti-von Willebrand factor aptamers show tremendous promise in refining antiplatelet therapy by targeting different receptors and molecules.
PMID: 18708826 [PubMed - in process]
2008 - 05
Am J Physiol Endocrinol Metab. 2008 May 20
The nitric oxide-donating derivative of acetylsalicylic acid, NCX 4016, stimulates glucose transport and glucose transporters translocation in adipocytes.
Kaddai V, Gonzalez T, Bolla M, Lemarchand-Brustel Y, Cormont M. Unit 568, INSERM, Nice, France.
NCX 4016 is a nitric oxide (NO)-donating derivative of acetylsalicylic acid. NO and salicylate, in vivo metabolites of NCX 4016, were shown to be potential actors in controlling glucose homeostasis. In this study, we evaluated the action of NCX 4016 on the capacity of 3T3-L1 adipocytes to transport glucose in basal and insulin-stimulated conditions. NCX 4016 induced a two fold increase in glucose uptake and the translocation of the glucose transporters GLUT1 and GLUT4 to the plasma membrane, leaving unaffected their expression. Importantly, NCX 4016 further increased glucose transport induced by a physiological concentration of insulin. This stimulatory effect of NCX 4016 appears to be mediated by its NO moiety. Indeed, it is inhibited by a NO scavenger and treatment with acetylsalicylic or salicylic acid had no effect. Although NO is involved in the action of NCX 4016, it did not mainly depend on the soluble cGMP-cyclase/protein kinase G pathway. Furthermore, NCX 4016-stimulated glucose transport did not involve the insulin signaling cascade required to stimulate glucose transport. NCX 4016 induces a small activation of the MAP kinases p38 and JNK, and no activation of other stress-activated signaling molecules including ERK, IkappaB, or AMP-activated kinases. Interestingly, NCX 4016 modified the content of S-nitrosylated proteins in adipocytes. Taken together, our results indicate that NCX 4016 induced glucose transport in adipocyte through a novel mechanism possibly involving S-nitrosylation. NCX 4016 thus possesses interesting characteristics to be considered as a candidate molecule for treatment of patients suffering from metabolic syndrome and type 2 diabetes.
Nitric Oxide. 2008 Apr 23
Nitrates and NO-NSAIDs in cancer chemoprevention and therapy: In vitro evidence querying the NO donor functionality.
Dunlap T, Abdul-Hay S, Chandrasena RE, Hagos GK, Sinha V, Wang Z, Wang H, Thatcher GR.
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612, USA.
Properties of the NO-ASA family of NO-donating NSAIDs (NO-NSAIDs), notably NCX 4016 (mNO-ASA) and NCX 4040 (pNO-ASA), reported in more than hundred publications, have included positive preclinical data in cancer chemoprevention and therapy. Evidence is presented that the antiproliferative, the chemopreventive (antioxidant/electrophile response element (ARE) activation), and the anti-inflammatory activity of NO-ASA in cell cultures is replicated by X-ASA derivatives that are incapable of acting as NO donors. pBr-ASA and mBr-ASA are conisogenic with NO-ASA, but are not NO donors. The biological activity of pNO-ASA is replicated by pBr-ASA; and both pNO-ASA and pBr-ASA are bioactivated to the same quinone methide electrophile. The biological activity of mNO-ASA is replicated by mBr-ASA; mNO-ASA and mBr-ASA are bioactivated to different benzyl electrophiles. The observed activity is likely initiated by trapping of thiol biomolecules by the quinone and benzyl electrophiles, leading to depletion of GSH and modification of Cys-containing sensor proteins. Whereas all NO-NSAIDs containing the same structural "linker" as NCX 4040 and NCX 4016 are anticipated to possess activity resulting from bioactivation to electrophilic metabolites, this expectation does not extend to other linker structures. Nitrates require metabolic bioactivation to liberate NO bioactivity, which is often poorly replicated in vitro, and NO bioactivity provided by NO-NSAIDs in vivo provides proven therapeutic benefits in mitigation of NSAID gastrotoxicity. The in vivo properties of X-ASA drugs await discovery.
2008 - 04
J Transl Med. 2008 Feb 26;6:9.
NCX-4040, a nitric oxide-releasing aspirin, sensitizes drug-resistant human ovarian xenograft tumors to cisplatin by depletion of cellular thiols.
Bratasz A, Selvendiran K, Wasowicz T, Bobko A, Khramtsov VV, Ignarro LJ, Kuppusamy P. Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA. kuppusamy.1@osu.edu
BACKGROUND: Ovarian carcinoma is the leading cause of mortality among gynecological cancers in the world. The high mortality rate is associated with lack of early diagnosis and development of drug resistance. The antitumor efficacy and mechanism of NCX-4040, a nitric oxide-releasing aspirin derivative, against ovarian cancer is studied. METHODS: NCX-4040, alone or in combination with cisplatin (cis-diamminedichloroplatinum, cDDP), was studied in cisplatin-sensitive (A2780 WT) and cisplatin-resistant (A2780 cDDP) cell lines as well as xenograft tumors grown in nude mice. Electron paramagnetic resonance (EPR) was used for measurements of nitric oxide and redox state. Immunoblotting analysis of A2780 cDDP tumor xenografts from mice was used for mechanistic studies. RESULTS: Cells treated with NCX-4040 (25 microM) showed a significant reduction of cell viability (A2780 WT, 34.9 +/- 8.7%; A2780 cDDP, 41.7 +/- 7.6%; p <>
NCX-4040, a nitric oxide-releasing aspirin, sensitizes drug-resistant human ovarian xenograft tumors to cisplatin by depletion of cellular thiols.
Bratasz A, Selvendiran K, Wasowicz T, Bobko A, Khramtsov VV, Ignarro LJ, Kuppusamy P. Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA. kuppusamy.1@osu.edu
BACKGROUND: Ovarian carcinoma is the leading cause of mortality among gynecological cancers in the world. The high mortality rate is associated with lack of early diagnosis and development of drug resistance. The antitumor efficacy and mechanism of NCX-4040, a nitric oxide-releasing aspirin derivative, against ovarian cancer is studied. METHODS: NCX-4040, alone or in combination with cisplatin (cis-diamminedichloroplatinum, cDDP), was studied in cisplatin-sensitive (A2780 WT) and cisplatin-resistant (A2780 cDDP) cell lines as well as xenograft tumors grown in nude mice. Electron paramagnetic resonance (EPR) was used for measurements of nitric oxide and redox state. Immunoblotting analysis of A2780 cDDP tumor xenografts from mice was used for mechanistic studies. RESULTS: Cells treated with NCX-4040 (25 microM) showed a significant reduction of cell viability (A2780 WT, 34.9 +/- 8.7%; A2780 cDDP, 41.7 +/- 7.6%; p <>
2008 - 01
Cell Cycle. 2007 Sep 28;7(1) [Epub ahead of print]
NCX-4016, a nitro-derivative of aspirin, inhibits EGFR and STAT3 signaling and modulates Bcl-2 proteins in cisplatin-resistant human ovarian cancer cells and xenografts.
Selvendiran K, Bratasz A, Tong L, Ignarro LJ, Kuppusamy P.
Davis Heart and Lung Research Institute and Comprehensive Cancer Center, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA.
We have previously reported the inhibitory effect of NCX-4016, a nitro derivative of aspirin, on the proliferation of cisplatin-resistant human ovarian cancer cells, in vitro (Bratasz et al., Proc Natl Acad Sci USA 2006; 103:3914-9). In this report we present the results of our study on the mechanistic aspects of drug action including the molecular and signaling pathways involved in an in vitro cell line, as well as in a murine tumor xenograft. We report, for the first time, that NCX-4016 significantly inhibited the growth of cisplatin-resistant human ovarian cancer xenografts in mice. We observed that the inhibitory effect of NCX-4016 on cell proliferation was associated with G(1) phase cell cycle arrest with increased activity of p53, p21 and p27 proteins. NCX-4016 modulated the Bcl-2 family of proteins, and induced apoptosis by activating Bax and cytochrome c release in a time-dependent manner. In addition, NCX-4016 selectively down-regulated the phosphorylated forms of EGFR (Tyr845, Tyr992), pAkt (Ser473, Thr305), and STAT3 (Tyr705, Ser727), in vitro and in vivo. Taken together, the results clearly suggested that NCX-4016 causes significant induction of cell cycle arrest and apoptosis in cisplatin-resistant human ovarian cancer cells via down-regulation of EGFR/PI3K/STAT3 signaling and modulation of Bcl-2 family proteins. Thus, NCX-4016 appears to be a potential therapeutic agent for treating recurrent human ovarian carcinoma.
Am J Physiol Heart Circ Physiol. 2007 Dec;293(6):H3636-42. Epub 2007 Oct 12.
Roles of platelet and endothelial cell COX-1 in hypercholesterolemia-induced microvascular dysfunction.
Tailor A, Wood KC, Wallace JL, Specian RD, Granger DN.
Department of Molecular and Cellular Physiology, Health Sciences Center, Louisiana State University, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.
Aspirin is a common preventative therapy in patients at risk for cardiovascular diseases, yet little is known about how aspirin protects the vasculature in hypercholesterolemia. The present study determines whether aspirin, nitric oxide-releasing aspirin (NCX-4016), a selective cyclooxygenase (COX)-1 inhibitor (SC560), or genetic deficiency of COX-1 prevents the inflammatory and prothrombogenic phenotype assumed by hypercholesterolemic (HC) venules. Aspirin or NCX-4016 (60 mg/kg) was administered orally for the last week of a 2-wk HC diet. COX-1-deficient (COX-1(-/-)) and wild-type (WT) mice were transplanted with WT (WT/COX-1(-/-)) or COX-1(-/-) (COX-1(-/-)/WT) bone marrow, respectively. HC-induced adhesion of platelets and leukocytes in murine intestinal venules, observed with intravital fluorescence microscopy, was greatly attenuated in aspirin-treated mice. Adhesion of aspirin-treated platelets in HC venules was comparable to untreated platelets, whereas adhesion of SC560-treated platelets was significantly attenuated. HC-induced leukocyte and platelet adhesion in COX-1(-/-)/WT chimeras was comparable to that in SC560-treated mice, whereas the largest reductions in blood cell adhesion were in WT/COX-1(-/-) chimeras. NCX-4016 treatment of platelet recipients or donors attenuated leukocyte and platelet adhesion independent of platelet COX-1 inhibition. Platelet- and endothelial cell-associated COX-1 promote microvascular inflammation and thrombogenesis during hypercholesterolemia, yet nitric oxide-releasing aspirin directly inhibits platelets independent of COX-1.
NCX-4016, a nitro-derivative of aspirin, inhibits EGFR and STAT3 signaling and modulates Bcl-2 proteins in cisplatin-resistant human ovarian cancer cells and xenografts.
Selvendiran K, Bratasz A, Tong L, Ignarro LJ, Kuppusamy P.
Davis Heart and Lung Research Institute and Comprehensive Cancer Center, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA.
We have previously reported the inhibitory effect of NCX-4016, a nitro derivative of aspirin, on the proliferation of cisplatin-resistant human ovarian cancer cells, in vitro (Bratasz et al., Proc Natl Acad Sci USA 2006; 103:3914-9). In this report we present the results of our study on the mechanistic aspects of drug action including the molecular and signaling pathways involved in an in vitro cell line, as well as in a murine tumor xenograft. We report, for the first time, that NCX-4016 significantly inhibited the growth of cisplatin-resistant human ovarian cancer xenografts in mice. We observed that the inhibitory effect of NCX-4016 on cell proliferation was associated with G(1) phase cell cycle arrest with increased activity of p53, p21 and p27 proteins. NCX-4016 modulated the Bcl-2 family of proteins, and induced apoptosis by activating Bax and cytochrome c release in a time-dependent manner. In addition, NCX-4016 selectively down-regulated the phosphorylated forms of EGFR (Tyr845, Tyr992), pAkt (Ser473, Thr305), and STAT3 (Tyr705, Ser727), in vitro and in vivo. Taken together, the results clearly suggested that NCX-4016 causes significant induction of cell cycle arrest and apoptosis in cisplatin-resistant human ovarian cancer cells via down-regulation of EGFR/PI3K/STAT3 signaling and modulation of Bcl-2 family proteins. Thus, NCX-4016 appears to be a potential therapeutic agent for treating recurrent human ovarian carcinoma.
Am J Physiol Heart Circ Physiol. 2007 Dec;293(6):H3636-42. Epub 2007 Oct 12.
Roles of platelet and endothelial cell COX-1 in hypercholesterolemia-induced microvascular dysfunction.
Tailor A, Wood KC, Wallace JL, Specian RD, Granger DN.
Department of Molecular and Cellular Physiology, Health Sciences Center, Louisiana State University, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.
Aspirin is a common preventative therapy in patients at risk for cardiovascular diseases, yet little is known about how aspirin protects the vasculature in hypercholesterolemia. The present study determines whether aspirin, nitric oxide-releasing aspirin (NCX-4016), a selective cyclooxygenase (COX)-1 inhibitor (SC560), or genetic deficiency of COX-1 prevents the inflammatory and prothrombogenic phenotype assumed by hypercholesterolemic (HC) venules. Aspirin or NCX-4016 (60 mg/kg) was administered orally for the last week of a 2-wk HC diet. COX-1-deficient (COX-1(-/-)) and wild-type (WT) mice were transplanted with WT (WT/COX-1(-/-)) or COX-1(-/-) (COX-1(-/-)/WT) bone marrow, respectively. HC-induced adhesion of platelets and leukocytes in murine intestinal venules, observed with intravital fluorescence microscopy, was greatly attenuated in aspirin-treated mice. Adhesion of aspirin-treated platelets in HC venules was comparable to untreated platelets, whereas adhesion of SC560-treated platelets was significantly attenuated. HC-induced leukocyte and platelet adhesion in COX-1(-/-)/WT chimeras was comparable to that in SC560-treated mice, whereas the largest reductions in blood cell adhesion were in WT/COX-1(-/-) chimeras. NCX-4016 treatment of platelet recipients or donors attenuated leukocyte and platelet adhesion independent of platelet COX-1 inhibition. Platelet- and endothelial cell-associated COX-1 promote microvascular inflammation and thrombogenesis during hypercholesterolemia, yet nitric oxide-releasing aspirin directly inhibits platelets independent of COX-1.
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