Cannabidiol attenuates high glucose-induced endothelial cell inflammatory response and barrier disruption

Cannabidiol, a safe and non-psychotropic ingredient of the marijuana plant Cannabis sativa, is protective in a murine model of colitis

Inflammatory bowel disease affects millions of individuals; nevertheless, pharmacological treatment is disappointingly unsatisfactory. Cannabidiol, a safe and non-psychotropic ingredient of marijuana, exerts pharmacological effects (e.g., antioxidant) and mechanisms (e.g., inhibition of endocannabinoids enzymatic degradation) potentially beneficial for the inflamed gut. Thus, we investigated the effect of cannabidiol in a murine model of colitis. Colitis was induced in mice by intracolonic administration of dinitrobenzene sulfonic acid. Inflammation was assessed both macroscopically and histologically. In the inflamed colon, cyclooxygenase-2 and inducible nitric oxide synthase (iNOS) were evaluated by Western blot, interleukin-1beta and interleukin-10 by ELISA, and endocannabinoids by isotope dilution liquid chromatography-mass spectrometry. Human colon adenocarcinoma (Caco-2) cells were used to evaluate the effect of cannabidiol on oxidative stress. Cannabidiol reduced colon injury, inducible iNOS (but not cyclooxygenase-2) expression, and interleukin-1beta, interleukin-10, and endocannabinoid changes associated with 2,4,6-dinitrobenzene sulfonic acid administration. In Caco-2 cells, cannabidiol reduced reactive oxygen species production and lipid peroxidation. In conclusion, cannabidiol, a likely safe compound, prevents experimental colitis in mice.

The emerging role of the endocannabinoid system in cardiovascular disease

Endocannabinoids are endogenous bioactive lipid mediators present both in the brain and various peripheral tissues, which exert their biological effects via interaction with specific G-protein-coupled cannabinoid receptors, the CB(1) and CB(2). Pathological overactivation of the endocannabinoid system (ECS) in various forms of shock and heart failure may contribute to the underlying pathology and cardiodepressive state by the activation of the cardiovascular CB(1) receptors. Furthermore, tonic activation of CB(1) receptors by endocannabinoids has also been implicated in the development of various cardiovascular risk factors in obesity/metabolic syndrome and diabetes, such as plasma lipid alterations, abdominal obesity, hepatic steatosis, inflammation, and insulin and leptin resistance. In contrast, activation of CB(2) receptors in immune cells exerts various immunomodulatory effects, and the CB(2) receptors in endothelial and inflammatory cells appear to limit the endothelial inflammatory response, chemotaxis, and inflammatory cell adhesion and activation in atherosclerosis and reperfusion injury. Here, we will overview the cardiovascular actions of endocannabinoids and the growing body of evidence implicating the dysregulation of the ECS in a variety of cardiovascular diseases. We will also discuss the therapeutic potential of the modulation of the ECS by selective agonists/antagonists in various cardiovascular disorders associated with inflammation and tissue injury, ranging from myocardial infarction and heart failure to atherosclerosis and cardiometabolic disorders.

Longevity is associated with increased vascular resistance to high glucose-induced oxidative stress and inflammatory gene expression in Peromyscus leucopus

Vascular aging is characterized by increased oxidative stress and proinflammatory phenotypic alterations. Metabolic stress, such as hyperglycemia in diabetes, is known to increase the production of ROS and promote inflammatory gene expression, accelerating vascular aging. The oxidative stress hypothesis of aging predicts that vascular cells of long-lived species exhibit lower steady-state production of ROS and/or superior resistance to the prooxidant effects of metabolic stress. We tested this hypothesis using two taxonomically related rodents, the white-footed mouse (Peromyscus leucopus) and the house mouse (Mus musculus), which show a more than twofold difference in maximum lifespan potential (8.2 and 3.5 yr, respectively). We compared interspecies differences in steady-state and high glucose (HG; 30 mmol/l)-induced production of O(2)(*-) and H(2)O(2), endothelial function, mitochondrial ROS generation, and inflammatory gene expression in cultured aortic segments. In P. leucopus aortas, steady-state endothelial O(2)(*-) and H(2)O(2) production and ROS generation by mitochondria were less than in M. musculus vessels. Furthermore, vessels of P. leucopus were more resistant to the prooxidant effects of HG. Primary fibroblasts from P. leucopus also exhibited less steady-state and HG-induced ROS production than M. musculus cells. In M. musculus arteries, HG elicited significant upregulation of inflammatory markers (TNF-alpha, IL-6, ICAM-1, VCAM, and monocyte chemoattractant protein-1). In contrast, the proinflammatory effects of HG were blunted in P. leucopus vessels. Thus, increased life span potential in P. leucopus is associated with decreased cellular ROS generation and increased resistance to prooxidant and proinflammatory effects of metabolic stress, which accord with predictions of the oxidative stress hypothesis of aging.

Metformin suppresses high glucose-induced poly(adenosine diphosphate-ribose) polymerase overactivation in aortic endothelial cells

Overactivation of poly(adenosine diphosphate-ribose) polymerase (PARP), an enzyme involved in cellular response to DNA injury resulting from oxidative and nitrosative stress, is considered to play a key role in the pathogenesis of diabetes complications by promoting numerous vascular dysfunctions. In this study, we examined the ability of metformin, which was reported to possess intrinsic vasculoprotective properties independently of its antihyperglycemic effects, to inhibit PARP activation induced by high glucose concentrations in bovine aortic endothelial cells; and we investigated the potential mechanisms involved in this inhibition. The PARP activity was measured by cellular enzyme-linked immuno-specific assay (CELISA) method; cell poly(ribosyl)ated protein polymer accumulation was evaluated by immunofluorescence. Peroxynitrite anion productions were determined using dihydrorhodamine 123 fluoroprobe; and expression of p47phox subunit of nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase was analyzed by Western blot in the absence and presence of protein kinase C and NAD(P)H oxidase inhibitors (calphostin and diphenyleneiodonium chloride, respectively). Our data showed that a therapeutically relevant concentration of metformin (5.10(-5) mol/L) was able to abolish PARP activation, to reduce poly(ribosyl)ated protein polymer accumulation, to decrease intracellular peroxynitrite anion level, and to reverse the overexpression of p47phox in bovine aortic endothelial cells stimulated by 25 mmol/L glucose in a similar manner to that of calphostin or diphenyleneiodonium chloride. Taken together, these results suggest that metformin could inhibit glucose-induced PARP activation through blockade of a protein kinase C-dependent NAD(P)H oxidase activation pathway. We propose that some of the beneficial effects of metformin on vascular endothelial cell functions in diabetes may be related to its inhibitory effect on PARP overactivation and its deleterious consequences.

Cannabidiol attenuates cisplatin-induced nephrotoxicity by decreasing oxidative/nitrosative stress, inflammation, and cell death

The platinum compound cisplatin is one of the most potent chemotherapy agents available to treat various malignancies. Nephrotoxicity is a common complication of cisplatin chemotherapy, which involves increased oxidative and nitrosative stress, limiting its clinical use. In this study, we have investigated the effects of a nonpsychoactive cannabinoid cannabidiol, which was reported to exert antioxidant effects and has recently been approved for the treatment of inflammation, pain, and spasticity associated with multiple sclerosis in patients in a mouse model of cisplatin-induced nephropathy. Cisplatin induced increased expression of superoxide-generating enzymes RENOX (NOX4) and NOX1, enhanced reactive oxygen species generation, inducible nitric-oxide synthase expression, nitrotyrosine formation, apoptosis (caspase-3/7 activity, DNA fragmentation, and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining), poly(ADP-ribose) polymerase activity, and inflammation (tumor necrosis factor-alpha and interleukin-1beta) in the kidneys of mice, associated with marked histopathological damage and impaired renal function (elevated serum blood urea nitrogen and creatinine levels) 72 h after the administration of the drug. Treatment of mice with cannabidiol markedly attenuated the cisplatin-induced oxidative/nitrosative stress, inflammation, and cell death in the kidney, and it improved renal function. Thus, our results suggest that cannabidiol may represent a promising new protective strategy against cisplatin-induced nephrotoxicity.

The hexosamine biosynthesis inhibitor azaserine prevents endothelial inflammation and dysfunction under hyperglycemic condition through antioxidant effects

Hexosamine biosynthetic pathway (HBP) accounts for some cardiovascular adverse effects of hyperglycemia. We investigated whether the HBP inhibitor azaserine protects against hyperglycemia-induced endothelial damage dependently of HBP. Human endothelial cells isolated from umbilical veins were exposed either to a high (30.5 mmol/l) or low concentration of glucose (5.5 mmol/l) for 4 days, followed by a stimulation with TNF-alpha (1 ng/ml, 24 h). The blockade of the rate-limiting enzyme glutamine:fructose-6-phosphate amidotransferase inhibited HBP flux and oxidative stress (generation of superoxide and peroxynitrite) under the hyperglycemic condition and prevented the synergistic stimulation of VCAM-1 and ICAM-1 expression by hyperglycemia and TNF-alpha. In the cells cultured under a low-glucose condition when no increased HBP flux occurred, azaserine enhanced the manganese-superoxide dismutase (MnSOD) protein level and also inhibited the oxidative stress and the expression of VCAM-1 and ICAM-1 in response to TNF-alpha. Moreover, the polyphenol resveratrol inhibited the oxidative stress and adhesion molecule expression and did not decrease the HBP flux under the hyperglycemia condition. In addition, in isolated rat aortas exposed to hyperglycemic buffer for 5 h when no significant HBP flux occurred, azaserine upregulated the MnSOD protein level and prevented decreased endothelium-dependent relaxations to acetylcholine. In conclusion, hyperglycemia independently increases oxidative stress and HBP flux, amplifies endothelial inflammation, and impairs endothelial function mainly through oxidative stress and not the HBP pathway. Azaserine protects against hyperglycemic endothelial damage through its antioxidant effect independently of inhibiting HBP pathway.

Long-term exposure to AZT, but not d4T, increases endothelial cell oxidative stress and mitochondrial dysfunction

Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (AZT) and stavudine (d4T), cause toxicities to numerous tissues, including the liver and vasculature. While much is known about hepatic NRTI toxicity, the mechanism of toxicity in endothelial cells is incompletely understood. Human aortic endothelial and HepG2 liver cells were exposed to 1 muM AZT or d4T for up to 5 weeks. Markers of oxidative stress, mitochondrial function, NRTI phosphorylation, mitochondrial DNA (mtDNA) levels, and cytotoxicity were monitored over time. In endothelial cells, AZT significantly oxidized glutathione redox potential, increased total cellular and mitochondrial-specific superoxide, decreased mitochondrial membrane potential, increased lactate release, and caused cell death from weeks 3 through 5. Toxicity occurred in the absence of di- and tri-phosphorylated AZT and mtDNA depletion. These data show that oxidative stress and mitochondrial dysfunction in endothelial cells occur with a physiologically relevant concentration of AZT, and require long-term exposure to develop. In contrast, d4T did not induce endothelial oxidative stress, mitochondrial dysfunction, or cytotoxicity despite the presence of d4T-triphosphate. Both drugs depleted mtDNA in HepG2 cells without causing cell death. Endothelial cells are more susceptible to AZT-induced toxicity than HepG2 cells, and AZT caused greater endothelial dysfunction than d4T because of its pro-oxidative effects.

Inducible nitric oxide synthase gene deficiency counteracts multiple manifestations of peripheral neuropathy in a streptozotocin-induced mouse model of diabetes

AIMS/HYPOTHESIS

Evidence for the importance of peroxynitrite, a product of superoxide anion radical reaction with nitric oxide, in peripheral diabetic neuropathy is emerging. The role of specific nitric oxide synthase isoforms in diabetes-associated nitrosative stress and nerve fibre dysfunction and degeneration remains unknown. This study evaluated the contribution of inducible nitric oxide synthase (iNOS) to peroxynitrite injury to peripheral nerve and dorsal root ganglia and development of peripheral diabetic neuropathy.

METHODS

Control mice and mice with iNos (also known as Nos2) gene deficiency (iNos ( -/- )) were made diabetic with streptozotocin, and maintained for 6 weeks. Peroxynitrite injury was assessed by nitrotyrosine and poly(ADP-ribose) accumulation (immunohistochemistry). Thermal algesia was evaluated by paw withdrawal, tail-flick and hot plate tests, mechanical algesia by the Randall-Selitto test, and tactile allodynia by a von Frey filament test.

RESULTS

Diabetic wild-type mice displayed peroxynitrite injury in peripheral nerve and dorsal root ganglion neurons. They also developed motor and sensory nerve conduction velocity deficits, thermal and mechanical hypoalgesia, tactile allodynia and approximately 36% loss of intraepidermal nerve fibres. Diabetic iNos ( -/- ) mice did not display nitrotyrosine and poly(ADP-ribose) accumulation in peripheral nerve, but were not protected from nitrosative stress in dorsal root ganglia. Despite this latter circumstance, diabetic iNos ( -/- ) mice preserved normal nerve conduction velocities. Small-fibre sensory neuropathy was also less severe in diabetic iNos ( -/- ) than in wild-type mice.

CONCLUSIONS/INTERPRETATION

iNOS plays a key role in peroxynitrite injury to peripheral nerve, and functional and structural changes of diabetic neuropathy. Nitrosative stress in axons and Schwann cells, rather than dorsal root ganglion neurons, underlies peripheral nerve dysfunction and degeneration.

Cannabidiol: from an inactive cannabinoid to a drug with wide spectrum of action

OBJECTIVE: The aim of this review is to describe the historical development of research on cannabidiol. METHOD: This review was carried out on reports drawn from Medline, Web of Science and SciELO. DISCUSSION: After the elucidation of the chemical structure of cannabidiol in 1963, the initial studies showed that cannabidiol was unable to mimic the effects of Cannabis. In the 1970's the number of publications on cannabidiol reached a first peak, having the research focused mainly on the interaction with delta9-THC and its antiepileptic and sedative effects. The following two decades showed lower degree of interest, and the potential therapeutic properties of cannabidiol investigated were mainly the anxiolytic, antipsychotic and on motor diseases effects. The last five years have shown a remarkable increase in publications on cannabidiol mainly stimulated by the discovery of its anti-inflammatory, anti-oxidative and neuroprotective effects. These studies have suggested a wide range of possible therapeutic effects of cannabidiol on several conditions, including Parkinson's disease, Alzheimer's disease, cerebral ischemia, diabetes, rheumatoid arthritis, other inflammatory diseases, nausea and cancer. CONCLUSION: In the last 45 years it has been possible to demonstrate that CBD has a wide range of pharmacological effects, many of which being of great therapeutic interest, but still waiting to be confirmed by clinical trials.

Cannabidiol prevents a post-ischemic injury progressively induced by cerebral ischemia via a high-mobility group box1-inhibiting mechanism

We examined the cerebroprotective mechanism of cannabidiol, the non-psychoactive component of marijuana, against infarction in a 4-h mouse middle cerebral artery (MCA) occlusion model. Cannabidiol was intraperitoneally administrated immediately before and 3h after cerebral ischemia. Infarct size and myeloperoxidase (MPO) activity, a marker of neutrophil, monocyte/macropharge, were measured at 24h after cerebral ischemia. Activated microglia and astrocytes were evaluated by immunostaining. Moreover, high-mobility group box1 (HMGB1) was also evaluated at 1 and 3 days after MCA occlusion. In addition, neurological score and motor coordination on the rota-rod test were assessed at 1 and 3 days after cerebral ischemia. Cannabidiol significantly prevented infarction and MPO activity at 20h after reperfusion. These effects of cannabidiol were not inhibited by either SR141716 or AM630. Cannabidiol inhibited the MPO-positive cells expressing HMGB1 and also decreased the expression level of HMGB1 in plasma. In addition, cannabidiol decreased the number of Iba1- and GFAP-positive cells at 3 days after cerebral ischemia. Moreover, cannabidiol improved neurological score and motor coordination on the rota-rod test. Our results suggest that cannabidiol inhibits monocyte/macropharge expressing HMGB1 followed by preventing glial activation and neurological impairment induced by cerebral ischemia. Cannabidiol will open new therapeutic possibilities for post-ischemic injury via HMGB1-inhibiting mechanism.

Role of oxidative stress in high glucose-induced decreased expression of Gialpha proteins and adenylyl cyclase signaling in vascular smooth muscle cells

We have recently shown that aorta from streptozotocin (STZ)-induced diabetic rats and A10 vascular smooth muscle cells (VSMCs) exposed to high glucose exhibited decreased levels of inhibitory guanine nucleotide regulatory protein (Gi)alpha proteins. In the present studies, we investigated the implication of oxidative stress in the hyperglycemia/diabetes-induced decreased expression of the Gialpha protein and adenylyl cyclase signaling in VSMCs by using antioxidants. The levels of Gialpha proteins were significantly decreased in A10 VSMCs exposed to high glucose and in aortic VSMCs from STZ-diabetic rats compared with control cells and were restored to control levels by antioxidants. In addition, (111)Mn-tetralis(benzoic acid porphyrin) and uric acid, scavengers of peroxynitrite, and NG-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase but not catalase, also restored the high glucose-induced decreased expression of Gialpha proteins to the control levels in A10 VSMCs. Furthermore, the enhanced production of superoxide anion (O2-) and increased activity of NADPH oxidase in these cells were also restored to control levels by diphenyleneiodonium, an inhibitor of NADPH oxidase. In addition, the diminished inhibition of adenylyl cyclase activity by inhibitory hormones and forskolin-stimulated adenylyl cyclase activity by low concentrations of GTPgammaS as well as the enhanced stimulation of adenylyl cyclase by stimulatory agonists in hyperglycemic cells were restored to control levels by antioxidant treatments. These results suggest that high glucose-induced decreased levels of Gialpha proteins and associated signaling in A10 VSMCs may be attributed to the enhanced oxidative stress due to augmented levels of peroxynitrite and not to H2O2.

Cannabinoids in health and disease

Cannabis sativa L. preparations have been used in medicine for millenia. However, concern over the dangers of abuse led to the banning of the medicinal use of marijuana in most countries in the 1930s. Only recently, marijuana and individual natural and synthetic cannabinoid receptor agonists and antagonists, as well as chemically related compounds, whose mechanism of action is still obscure, have come back to being considered of therapeutic value. However, their use is highly restricted. Despite the mild addiction to cannabis and the possible enhancement of addiction to other substances of abuse, when combined with cannabis, the therapeutic value of cannabinoids is too high to be put aside. Numerous diseases, such as anorexia, emesis, pain, inflammation, multiple sclerosis, neurodegenerative disorders (Parkinson's disease, Huntington's disease, Tourette's syndrome, Alzheimer's disease), epilepsy, glaucoma, osteoporosis, schizophrenia, cardiovascular disorders, cancer, obesity, and metabolic syndrome-related disorders, to name just a few, are being treated or have the potential to be treated by cannabinoid agonists/antagonists/cannabinoid-related compounds. In view of the very low toxicity and the generally benign side effects of this group of compounds, neglecting or denying their clinical potential is unacceptable--instead, we need to work on the development of more selective cannabinoid receptor agonists/antagonists and related compounds, as well as on novel drugs of this family with better selectivity, distribution patterns, and pharmacokinetics, and--in cases where it is impossible to separate the desired clinical action and the psychoactivity--just to monitor these side effects carefully.

Blockade of chronic high glucose-induced endothelial apoptosis by Sasa borealis bamboo extract

Hyperglycemia is a causal factor in the development of diabetic vascular complications including impaired vascular smooth muscle contractility and increased cell proliferation. The present study was designed to investigate the effects of Sasa borealis water-extract (SBwE) on chronic hyperglycemia-induced oxidative stress and apoptosis in human umbilical endothelial cells (HUVEC). HUVEC were cultured in 5.5 mM low glucose, 5.5 mM glucose plus 27.5 mM mannitol as an osmotic control, or 33 mM high glucose for 5 days in the absence and presence of 1-30 microg/ ml SBwE. Caspase-3 activation and Annexin V staining revealed chronic high glucose-induced endothelial apoptotic toxicity with a generation of oxidants detected by DCF-fluorescence, and these effects were reversed by SBwE at > or =1 microg/ml in a dose-dependent manner. Cytoprotective SBwE substantially reduced the sustained high glucose-induced expression of endothelial nitric oxide synthase and attenuated the formation of peroxynitrite radicals. The suppressive effects of SBwE were most likely mediated through blunting activation of PKC beta 2 and NADPH oxidase promoted by high glucose. In addition, this bamboo extract modulated the high glucose-triggered mitogen-activated protein kinase-dependent upregulation of heat-shock proteins. Our results suggest that SBwE suppressed these detrimental effects caused by PKC-dependent peroxynitrite formation via activation of NADPH oxidase and induction of nitric oxide synthase and heat-shock protein family that may be essential mechanisms responsible for increased apoptotic oxidative stress in diabetic vascular complications. Moreover, the blockade of high glucose-elicited heat-shock protein induction appeared to be responsible for SBwE-alleviated endothelial apoptosis. Therefore, SBwE may be a therapeutic agent for the prevention and treatment of diabetic endothelial dysfunction and related complications.

CB2 cannabinoid receptor agonists attenuate TNF-alpha-induced human vascular smooth muscle cell proliferation and migration

BACKGROUND AND PURPOSE

Vascular smooth muscle proliferation and migration triggered by inflammatory stimuli are involved in the development and progression of atherosclerosis and restenosis. Cannabinoids may modulate cell proliferation in various cell types through cannabinoid 2 (CB2) receptors. Here, we investigated the effects of CB2 receptor agonists on TNF-alpha-induced proliferation, migration and signal transduction in human coronary artery smooth muscle cells (HCASMCs).

EXPERIMENTAL APPROACH

HCASMCs were stimulated with TNF-alpha. Smooth muscle proliferation was determined by the extent of BrdU incorporation and the migration was assayed by modified Boyden chamber. CB2 and/or CB1 receptor expressions were determined by immunofluorescence staining, western blotting, RT-PCR, real-time PCR and flow cytometry.

KEY RESULTS

Low levels of CB2 and CB1 receptors were detectable in HCASMCs compared to the high levels of CB2 receptors expressed in THP-1 monocytes. TNF-alpha triggered up to approximately 80% increase (depending on the method used) in CB2 receptor mRNA and/or protein expression in HCASMCs, and induced Ras, p38 MAPK, ERK 1/2, SAPK/JNK and Akt activation, while increasing proliferation and migration. The CB2 agonists, JWH-133 and HU-308, dose-dependently attenuated these effects of TNF-alpha.

CONCLUSIONS AND IMPLICATIONS

Since the above-mentioned TNF-alpha-induced phenotypic changes are critical in the initiation and progression of atherosclerosis and restenosis, our findings suggest that CB2 agonists may offer a novel approach in the treatment of these pathologies by decreasing vascular smooth muscle proliferation and migration.

Cannabinoid receptors in acute and chronic complications of atherosclerosis

Atherosclerosis is a chronic inflammatory disease that is the primary cause of myocardial infarction and stroke, which occur after sudden thrombotic occlusion of an artery. A growing body of evidence suggests that cannabinoid signalling plays a fundamental role in atherosclerosis development and its clinical manifestations. Thus, CB2 receptors are protective in myocardial ischaemia/reperfusion and implicated in the modulation of chemotaxis, which is crucial for the recruitment of leukocytes during inflammation. Delta-9-Tetrahydrocannabinol (THC)-mediated activation has been shown to inhibit atherosclerotic plaque progression in a CB2 dependent manner. Although CB1 and CB2 expression has been reported on platelets, their involvement in thrombus formation is still controversial. While several reports suggest that CB1 receptors may have a relevant role in neuroprotection after ischaemic stroke, recent studies show the protective effects in various forms of neuroprotection are not related to CB1 stimulation, and a protective role of CB1 blockade has also been reported. In addition, vascular and myocardial CB1 receptors contribute to the modulation of blood pressure and heart rate. It is tempting to suggest that pharmacological modulation of the endocannabinoid system is a potential novel therapeutic strategy in the treatment of atherosclerosis. For these purposes, it is important to better understand the complex mechanisms of endocannabinoid signalling and potential consequences of its pharmacological modulation, as it may have both pro- and anti-atherosclerotic effects.

Decreased age-related cardiac dysfunction, myocardial nitrative stress, inflammatory gene expression, and apoptosis in mice lacking fatty acid amide hydrolase

Recent studies have uncovered important cross talk between inflammation, generation of reactive oxygen and nitrogen species, and lipid metabolism in the pathogenesis of cardiovascular aging. Inhibition of the endocannabinoid anandamide metabolizing enzyme, the fatty acid amide hydrolase (FAAH), is emerging as a promising novel approach for the treatment of various inflammatory disorders. In this study, we have investigated the age-associated decline of cardiac function and changes in inflammatory gene expression, nitrative stress, and apoptosis in FAAH knockout (FAAH(-/-)) mice and their wild-type (FAAH(+/+)) littermates. Additionally, we have explored the effects of anandamide on TNF-alpha-induced ICAM-1 and VCAM-1 expression and monocyte-endothelial adhesion in human coronary artery endothelial cells (HCAECs). There was no difference in the cardiac function (measured by the pressure-volume conductance catheter system) between 2- to 3-mo-old (young) FAAH(-/-) and FAAH(+/+) mice. In contrast, the aging-associated decline in cardiac function and increased myocardial gene expression of TNF-alpha, gp91phox, matrix metalloproteinase (MMP)-2, MMP-9, caspase-3 and caspase-9, myocardial inducible nitric oxide synthase protein expression, nitrotyrosine formation, poly (ADP-ribose)polymerase cleavage and caspase-3/9 activity, observed in 28- to 31-mo-old (aging) FAAH(+/+) mice, were largely attenuated in knockouts. There was no difference in the myocardial cannabinoid CB(1) and CB(2) receptor gene expression between young and aging FAAH(-/-) and FAAH(+/+) mice. Anandamide dose dependently attenuated the TNF-alpha-induced ICAM-1 and VCAM-1 expression, NF-kappaB activation in HCAECs, and the adhesion of monocytes to HCAECs in a CB(1)- and CB(2)-dependent manner. These findings suggest that pharmacological inhibition of FAAH may represent a novel protective strategy against chronic inflammation, oxidative/nitrative stress, and apoptosis associated with cardiovascular aging and atherosclerosis.

Simultaneous detection of apoptosis and mitochondrial superoxide production in live cells by flow cytometry and confocal microscopy

Annexin V and Sytox Green are widely used markers to evaluate apoptosis in various cell types using flow cytometry and fluorescent microscopy. Recently, a novel fluoroprobe MitoSOX Red was introduced for selective detection of superoxide in the mitochondria of live cells and was validated for confocal microscopy and flow cytometry. This protocol describes simultaneous measurements of mitochondrial superoxide generation with apoptotic markers (Annexin V and Sytox Green) by both flow cytometry and confocal microscopy in endothelial cell lines. The advantages of the described flow cytometry method over other cell-based techniques are the tremendous speed (1-2 h), exquisite precision and the possibility of simultaneous quantitative measurements of mitochondrial superoxide generation and apoptotic (and other) markers, with maximal preservation of cellular functions. This method combined with fluorescent microscopy may be very useful to reveal important spatial-temporal changes in mitochondrial superoxide production and execution of programmed cell death in virtually any cell type.