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

Dissecting the role of cannabinoids in vascular health and disease

Cannabis, often recognized as the most widely used illegal psychoactive substance globally, has seen a shift in its legal status in several countries and regions for both recreational and medicinal uses. This change has brought to light new evidence linking cannabis consumption to various vascular conditions. Specifically, there is an association between cannabis use and atherosclerosis, along with conditions such as arteritis, reversible vasospasm, and incidents of aortic aneurysm or dissection. Recent research has started to reveal the mechanisms connecting cannabinoid compounds to atherosclerosis development. It is well known that the primary biological roles of cannabinoids operate through the activation of cannabinoid receptor types 1 and 2. Manipulation of the endocannabinoid system, either genetically or pharmacologically, is emerging as a promising approach to address metabolic dysfunctions related to obesity. Additionally, numerous studies have demonstrated the vasorelaxant properties and potential atheroprotective benefits of cannabinoids. In preclinical trials, cannabidiol is being explored as a treatment option for monocrotaline-induced pulmonary arterial hypertension. Although existing literature suggests a direct role of cannabinoids in the pathogenesis of atherosclerosis, the correlation between cannabinoids and other vascular diseases was only reported in some case series or observational studies, and its role and precise mechanisms remain unclear. Therefore, it is necessary to summarize and update previously published studies. This review article aims to summarize the latest clinical and experimental research findings on the relationship between cannabis use and vascular diseases. It also seeks to shed light on the potential mechanisms underlying these associations, offering a comprehensive view of current knowledge in this evolving field of study.

Cardiotoxic effects of common and emerging drugs: role of cannabinoid receptors

Drug-induced cardiotoxicity has become one of the most common and detrimental health concerns, which causes significant loss to public health and drug resources. Cannabinoid receptors (CBRs) have recently achieved great attention for their vital roles in the regulation of heart health and disease, with mounting evidence linking CBRs with the pathogenesis and progression of drug-induced cardiotoxicity. This review aims to summarize fundamental characteristics of two well-documented CBRs (CB1R and CB2R) from aspects of molecular structure, signaling and their functions in cardiovascular physiology and pathophysiology. Moreover, we describe the roles of CB1R and CB2R in the occurrence of cardiotoxicity induced by common drugs such as antipsychotics, anti-cancer drugs, marijuana, and some emerging synthetic cannabinoids. We highlight the 'yin-yang' relationship between CB1R and CB2R in drug-induced cardiotoxicity and propose future perspectives for CBR-based translational medicine toward cardiotoxicity curation and clinical monitoring.

Role of Cannabinoid Signaling in Cardiovascular Function and Ischemic Injury

Cardiovascular disease represents a leading cause of death, morbidity, and societal economic burden. The prevalence of cannabis use has significantly increased due to legalization and an increased societal acceptance of cannabis. Therefore, it is critically important that we gain a greater understanding of the effects and risks of cannabinoid use on cardiovascular diseases as well as the potential for cannabinoid-directed drugs to be used as therapeutics for the treatment of cardiovascular disease. This review summarizes our current understanding of the role of cannabinoid receptors in the pathophysiology of atherosclerosis and myocardial ischemia and explores their use as therapeutic targets in the treatment of ischemic heart disease. Endocannabinoids are elevated in patients with atherosclerosis, and activation of cannabinoid type 1 receptors (CB1Rs) generally leads to an enhancement of plaque formation and atherosclerosis. In contrast, selective activation of cannabinoid type 2 receptors (CB2Rs) appears to exert protective effects against atherosclerosis. Endocannabinoid signaling is also activated by myocardial ischemia. CB2R signaling appears to protect the heart from ischemic injury, whereas the role of CB1R in ischemic injury is less clear. This narrative review serves to summarize current research on the role of cannabinoid signaling in cardiovascular function with the goal of identifying critical knowledge gaps and future studies to address those gaps in a way that facilitates the development of new treatments and better cardiovascular health. SIGNIFICANCE STATEMENT: Cardiovascular diseases, including atherosclerosis and myocardial infarction, are a leading cause of death. Cannabinoid drugs have well known acute effects on cardiovascular function, including tachycardia and orthostatic hypotension. The recent legalization of marijuana and cannabinoids for both medical and recreational use has dramatically increased their prevalence of use. This narrative review on the role of cannabinoid signaling in cardiovascular disease contributes to a better understanding of this topic by integrating current knowledge and identifying critical gaps.

H2O2/NIR-sensitive "two-step" nano theranostic system based hollow mesoporous copper sulfide/hyaluronic acid/JWH133 as an optimally designed delivery system for multidimensional treatment of RA

Cannabinoid receptors are widely distributed in many cells in Rheumatoid arthritis RA and strengthening factor to boost the development of RA diseases. Here, the hollow mesoporous copper sulfide (CuS) was used as the carrier skeleton and the cannabinoid type 2 (CB2) receptor agonist JWH133 was efficiently loaded inside of CuS through adsorption, then the outer layer was modified with hyaluronic acid (HA) to prevent the leakage of internal drugs. After the CuS-JWH133@HA nano carrier reached the target area, HA responsive cracked under RA microenvironment to realize the first step of accurate drug delivery of JWH133, and the thermally responsive CuS under near-infrared (NIR) promoted the release of internal drugs. Then, JWH133 specifically combined CB2 receptors on the surface of macrophage, synovial cells and osteoblasts to realize the second step of drug delivery. The inflammatory factors secreted by cells are significantly inhibited, and the activity of osteoblasts was significantly enhanced. Therapeutic effect by CuS-JWH133@HA of RA was well verified by decreasing levels of inflammation in vivo and improvement of inflamed and swollen joints of mice. The CuS-JWH133@HA nanocomposite showed satisfactory multidimensional therapeutic effect of RA in vitro and in vivo, which provided a novel idea for RA treatment.

How do phytocannabinoids affect cardiovascular health? An update on the most common cardiovascular diseases

Cardiovascular disease (CVD) causes millions of deaths worldwide each year. Despite the great progress in therapies available for patients with CVD, some limitations, including drug complications, still exist. Hence, the endocannabinoid system (ECS) was proposed as a new avenue for CVDs treatment. The ECS components are widely distributed through the body, including the heart and blood vessels, thus the action of its endogenous and exogenous ligands, in particular, phytocannabinoids play a key role in various pathological states. The cardiovascular action of cannabinoids is complex as they affect vasculature and myocardium directly via specific receptors and exert indirect effects through the central and peripheral nervous system. The growing interest in phytocannabinoid studies, however, has extended the knowledge about their molecular targets as well as therapeutical properties; nonetheless, some areas of their actions are not yet fully recognized. Researchers have reported various cannabinoids, especially cannabidiol, as a promising approach to CVDs; hence, the purpose of this review is to summarize and update the cardiovascular actions of the most potent phytocannabinoids and the potential therapeutic role of ECS in CVDs, including ischemic reperfusion injury, arrhythmia, heart failure as well as hypertension.

Expression of cannabinoid (CB1 and CB2) and cannabinoid-related receptors (TRPV1, GPR55, and PPARα) in the synovial membrane of the horse metacarpophalangeal joint

Background

The metacarpophalangeal joint undergoes enormous loading during locomotion and can therefore often become inflamed, potentially resulting in osteoarthritis (OA). There are studies indicating that the endocannabinoid system (ECS) modulates synovium homeostasis, and could be a promising target for OA therapy. Some cannabinoid receptors, which modulate proliferative and secretory responses in joint inflammation, have been functionally identified in human and animal synovial cells.

Objective

To characterize the cellular distribution of the cannabinoid receptors 1 (CB1R) and 2 (CB2R), and the cannabinoid-related receptors transient receptor potential vanilloid type 1 (TRPV1), G protein-related receptor 55 (GPR55) and peroxisome proliferator-activated receptor alpha (PPARα) in the synovial membrane of the metacarpophalangeal joint of the horse.

Animals

The dorsal synovial membranes of 14 equine metacarpophalangeal joints were collected post-mortem from an abattoir.

Materials and methods

The dorsal synovial membranes of 14 equine metacarpophalangeal joints were collected post-mortem from an abattoir. The expression of the CB1R, CB2R, TRPV1, GPR55, and PPARα in synovial tissues was studied using qualitative and quantitative immunofluorescence, and quantitative real-time reverse transcriptase PCR (qRT-PCR). Macrophage-like (MLS) and fibroblast-like (FLS) synoviocytes were identified by means of antibodies directed against IBA1 and vimentin, respectively.

Results

Both the mRNA and protein expression of the CB2R, TRPV1, GPR55, and PPARα were found in the synoviocytes and blood vessels of the metacarpophalangeal joints. The synoviocytes expressed the mRNA and protein of the CB1R in some of the horses investigated, but not in all.

Conclusions and clinical importance

Given the expression of the CB1R, CB2R, TRPV1, GPR55, and PPARα in the synovial elements of the metacarpophalangeal joint, these findings encouraged the development of new studies supporting the use of molecules acting on these receptors to reduce the inflammation during joint inflammation in the horse.

Differential Regulation of MMPs, Apoptosis and Cell Proliferation by the Cannabinoid Receptors CB1 and CB2 in Vascular Smooth Muscle Cells and Cardiac Myocytes

Cannabinoids (CB) are implicated in cardiovascular diseases via the two main receptor subtypes CB₁R and CB₂R. This study investigated whether cannabinoids regulate the activity of matrix metalloproteases (MMP-2, MMP-9) in vascular smooth muscle cells (VSMCs) and in cells of cardiac origin (H9c2 cell line). The influence of CB₁- and CB₂ receptor stimulation or inhibition on cell proliferation, apoptosis and glucose uptake was also evaluated. We used four compounds that activate or block CB receptors: arachidonyl-2-chloroethylamide (ACEA)-CB₁R agonist, rimonabant-CB₁R antagonist, John W. Huffman (JWH133)-CB₂R agonist and CB₂R antagonist-6-Iodopravadoline (AM630). Treatment of cells with the CB₂R agonist JWH133 decreased cytokine activated secretion of proMMP-2, MMP-2 and MMP-9, reduced Fas ligand and caspase-3-mediated apoptosis, normalized the expression of TGF-beta1 and prevented cytokine-induced increase in glucose uptake into the cell. CB₁R inhibition with rimonabant showed similar protective properties as the CB₂R agonist JWH133, but to a lesser extent. In conclusion, CB₁R and CB₂R exert opposite effects on cell glucose uptake, proteolysis and apoptosis in both VSMCs and H9c2 cells. The CB₂R agonist JWH133 demonstrated the highest protective properties. These findings may pave the way to a new treatment of cardiovascular diseases, especially those associated with extracellular matrix degradation.

Myeloid But Not Endothelial Expression of the CB2 Receptor Promotes Atherogenesis in the Context of Elevated Levels of the Endocannabinoid 2-Arachidonoylglycerol

The endocannabinoid 2-arachidonoylglycerol (2-AG) is an inflammatory mediator and ligand for the cannabinoid receptors CB1 and CB2. We investigated the atherogenic mechanisms set in motion by 2-AG. Therefore, we created two atherosclerotic mouse models with distinct cell-specific knockouts of the CB2 receptor on either myeloid or endothelial cells. These mice were treated with JZL184, resulting in elevated plasma levels of 2-AG. After a high-fat high-cholesterol diet, atherosclerotic plaques were analyzed. The atherogenic effect of 2-AG was abrogated in mice lacking myeloid expression of the CB2 receptor but not in mice lacking endothelial expression of the CB2 receptor. In vitro, treatment of human monocytes with 2-AG led to the increased production of reactive oxygen species (ROS) and IL-1β. In conclusion, 2-AG shows an atherogenic effect in vivo, dependent on the presence of the CB2 receptor on myeloid cells. In addition, our in vitro data revealed 2-AG to promote inflammatory signalling in monocytes. 2-Arachidonoylglycerol shows an atherogenic effect that is abrogated in mice lacking myeloid expression of the CB2 receptor.

Pharmacological Properties, Therapeutic Potential and Molecular Mechanisms of JWH133, a CB2 Receptor-Selective Agonist

The endocannabinoid system has attracted attention as a pharmacological target for several pathological conditions. Cannabinoid (CB2)-selective agonists have been the focus of pharmacological studies because modulation of the CB2 receptor (CB2R) can be useful in the treatment of pain, inflammation, arthritis, addiction, and cancer among other possible therapeutic applications while circumventing CNS-related adverse effects. Increasing number of evidences from different independent preclinical studies have suggested new perspectives on the involvement of CB2R signaling in inflammation, infection and immunity, thus play important role in cancer, cardiovascular, renal, hepatic and metabolic diseases. JWH133 is a synthetic agonist with high CB2R selectivity and showed to exert CB2R mediated antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, and immunomodulatory activities. Cumulative evidences suggest that JWH133 protects against hepatic injury, renal injury, cardiotoxicity, fibrosis, rheumatoid arthritis, and cancer as well as against oxidative damage and inflammation, inhibits fibrosis and apoptosis, and acts as an immunosuppressant. This review provides a comprehensive overview of the polypharmacological properties and therapeutic potential of JWH133. This review also presents molecular mechanism and signaling pathways of JWH133 under various pathological conditions except neurological diseases. Based on the available data, this review proposes the possibilities of developing JWH133 as a promising therapeutic agent; however, further safety and toxicity studies in preclinical studies and clinical trials in humans are warranted.

Cannabinoids and myocardial ischemia: Novel insights, updated mechanisms, and implications for myocardial infarction

Cannabis is the most widely trafficked and abused illicit drug due to its calming psychoactive properties. It has been increasingly recognized as having potential health benefits and relatively less adverse health effects as compared to other illicit drugs; however, growing evidence clearly indicates that cannabis is associated with considerable adverse cardiovascular events. Recent studies have linked cannabis use to myocardial infarction (MI); yet, very little is known about the underlying mechanisms. A MI is a cardiovascular disease characterized by a mismatch in the oxygen supply and demand of the heart, resulting in ischemia and subsequent necrosis of the myocardium. Since cannabis is increasingly being considered a risk factor for MI, there is a growing need for better appreciating its potential health benefits and consequences. Here, we discuss the cellular mechanisms of cannabis that lead to an increased risk of MI. We provide a thorough and critical analysis of cannabinoids' actions, which include modulation of adipocyte biology, regional fat distribution, and atherosclerosis, as well as precipitation of hemodynamic stressors relevant in the setting of a MI. By critically dissecting the modulation of signaling pathways in multiple cell types, this paper highlights the mechanisms through which cannabis may trigger life-threatening cardiovascular events. This then provides a framework for future pharmacological studies which can identify targets or develop drugs that modulate cannabis' effects on the cardiovascular system as well as other organ systems. Cannabis' impact on the autonomic outflow, vascular smooth muscle cells, myocardium, cortisol levels and other hemodynamic changes are also mechanistically reviewed.

β-Caryophyllene, A Natural Dietary CB2 Receptor Selective Cannabinoid can be a Candidate to Target the Trinity of Infection, Immunity, and Inflammation in COVID-19

Coronavirus disease (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing pandemic and presents a public health emergency. It has affected millions of people and continues to affect more, despite tremendous social preventive measures. Identifying candidate drugs for the prevention and treatment of COVID-19 is crucial. The pathogenesis and the complications with advanced infection mainly involve an immune-inflammatory cascade. Therefore, therapeutic strategy relies on suppressing infectivity and inflammation, along with immune modulation. One of the most promising therapeutic targets for the modulation of immune-inflammatory responses is the endocannabinoid system, particularly the activation of cannabinoid type 2 receptors (CB2R), a G-protein coupled receptor which mediates the anti-inflammatory properties by modulating numerous signaling pathways. To pharmacologically activate the CB2 receptors, a naturally occurring cannabinoid ligand, beta-caryophyllene (BCP), received attention due to its potent anti-inflammatory, antiviral, and immunomodulatory properties. BCP is recognized as a full selective functional agonist on CB2 receptors and produces therapeutic effects by activating CB2 and the nuclear receptors, peroxisome proliferator-activated receptors (PPARs). BCP is regarded as the first dietary cannabinoid with abundant presence across cannabis and non-cannabis plants, including spices and other edible plants. BCP showed tissue protective properties and favorably modulates numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Based on its pharmacological properties, molecular mechanisms, and the therapeutic potential of BCP as an immunomodulator, anti-inflammatory, organ-protective, and antiviral, we hypothesize that BCP could be a promising therapeutic and/or preventive candidate to target the triad of infection, immunity, and inflammation in COVID-19. In line with numerous studies that proposed the potential of cannabinoids in COVID-19, BCP may be a novel candidate compound for pharmaceutical and nutraceutical development due to its unique functional receptor selectivity, wide availability and accessibility, dietary bioavailability, nonpsychoactivity, and negligible toxicity along with druggable properties, including favorable pharmacokinetic and physicochemical properties. Based on reasonable pharmacological mechanisms and therapeutic properties, we speculate that BCP has potential to be investigated against COVID-19 and will inspire further preclinical and clinical studies.

LINC00472 regulates vascular smooth muscle cell migration and proliferation via regulating miR-149-3p

LncRNAs are one group of gene modulators functioning via several mechanisms in pathological and physiological conditions. We noted that LINC00472 expression level is elevated in atherosclerotic coronary tissues compared with normal coronary artery samples. LINC00472 is also upregulated in vascular smooth muscle cells (VSMCs) induced by TNF-α and PDGF-BB. Ectopic expression of LINC00472 induced VSMC migration and proliferation. The predicted binding sequence between miR-149-3p and LINC00472 was analyzed by LncBase Predicted. Overexpression of miR-149-3p decreases the luciferase activity of wild-type reporter plasmid, but not the mutant one. Ectopic expression of LINC00472 suppresses the expression of miR-149-3p in VSMCs. Furthermore, we demonstrated that miR-149-3p expression is decreased in atherosclerotic coronary tissues. MiR-149-3p was downregulated in VSMCs induced by TNF-α and PDGF-BB. Overexpression of LINC00472 induces VSMC migration and proliferation via regulating miR-149-3p. These data suggested that LINC00472 acts a critical role in the migration and proliferation of VSMCs partly via modulating miR-149-3p.

Occurrence of Morpholine in Central Nervous System Drug Discovery

Developing drugs for the central nervous system (CNS) requires fine chemical modifications, as a strict balance between size and lipophilicity is necessary to improve the permeability through the blood-brain barrier (BBB). In this context, morpholine and its analogues represent valuable heterocycles, due to their conformational and physicochemical properties. In fact, the presence of a weak basic nitrogen atom and of an oxygen atom at the opposite position provides a peculiar pK_a value and a flexible conformation to the ring, thus allowing it to take part in several lipophilic–hydrophilic interactions, and to improve blood solubility and brain permeability of the overall structure. In CNS-active compounds, morpholines are used (1) to enhance the potency through molecular interactions, (2) to act as a scaffold directing the appendages in the correct position, and (3) to modulate pharmacokinetic/pharmacodynamic (PK/PD) properties. In this perspective, selected morpholine-containing CNS drug candidates are discussed to reveal the active pharmacophores accountable for the (1) modulation of receptors involved in mood disorders and pain, (2) bioactivity toward enzymes and receptors responsible for neurodegenerative diseases, and (3) inhibition of enzymes involved in the pathology of CNS tumors. The medicinal chemistry/pharmacological activity of morpholine derivatives is discussed, in the effort to highlight the importance of morpholine ring interactions in the active site of different targets, particularly reporting binding features retrieved from PDB data, when available.

Targeting of G-protein coupled receptors in sepsis

The Third International Consensus Definitions (Sepsis-3) define sepsis as life-threatening multi-organ dysfunction caused by a dysregulated host response to infection. Sepsis can progress to septic shock-an even more lethal condition associated with profound circulatory, cellular and metabolic abnormalities. Septic shock remains a leading cause of death in intensive care units and carries a mortality of almost 25%. Despite significant advances in our understanding of the pathobiology of sepsis, therapeutic interventions have not translated into tangible differences in the overall outcome for patients. Clinical trials of antagonists of various pro-inflammatory mediators in sepsis have been largely unsuccessful in the past. Given the diverse physiologic roles played by G-protein coupled receptors (GPCR), modulation of GPCR signaling for the treatment of sepsis has also been explored. Traditional pharmacologic approaches have mainly focused on ligands targeting the extracellular domains of GPCR. However, novel techniques aimed at modulating GPCR intracellularly through aptamers, pepducins and intrabodies have opened a fresh avenue of therapeutic possibilities. In this review, we summarize the diverse roles played by various subfamilies of GPCR in the pathogenesis of sepsis and identify potential targets for pharmacotherapy through these novel approaches.

HIX003209 promotes vascular smooth muscle cell migration and proliferation through modulating miR-6089

Accumulating references have showed that long noncoding RNAs (lncRNAs) act important roles in the development of human diseases. The role and expression of HIX003209 remains unclear in the pathogenesis of atherosclerosis. We showed that HIX003209 expression was upregulated in atherosclerotic coronary tissues compared to normal coronary artery samples. HIX003209 was overexpressed in vascular smooth muscle cells (VSMCs) induced by inflammatory mediators including tumor necrosis factor-α(TNF-α), ox-LDL and latelet-derived growth factor-BB (PDGF-BB). Ectopic expression of HIX003209 enhanced cell growth and migration and induced inflammatory mediators secretion such as interleukin 6 (IL-6), TNF-α and IL-1β in VSMCs. Furthermore, we showed that miR-6089 was downregulated in atherosclerotic coronary tissues compared to normal coronary artery samples. There was a negative association between expression of HIX003209 and miR-6089 in atherosclerotic coronary tissues. MiR-6089 expression was decreased in VSMCs induced by inflammatory mediators including TNF-α, ox-LDL and PDGF-BB. Dual luciferase analysis showed that miR-6089 overexpression decreased luciferase activity of HIX003209 WT-type 3’-UTR but not the mut-type 3’-UTR. Overexpression of HIX003209 suppressed the expression of miR-6089 in VSMCs. Ectopic expression of HIX003209 induced cell growth, migration and the secretion of inflammatory mediators via regulating miR-6089 expression. These data suggested that HIX003209 promoted VSMCs proliferation, migration and the secretion of inflammatory mediators partly via regulating miR-6089.

Indole compounds with N-ethyl morpholine moieties as CB2 receptor agonists for anti-inflammatory management of pain: synthesis and biological evaluation

The CB2 receptor plays a crucial role in analgesia and anti-inflammation. To develop novel CB2 agonists with high efficacy and selectivity, a series of indole derivatives with N-ethyl morpholine moieties (compounds 1-56) were designed, synthesized and biologically evaluated. Compounds 1, 2, 3, 46 and 53 exhibited high CB2 receptor affinity at low nanomolar concentrations and good receptor selectivity (EC50(CB1)/EC50(CB2) greater than 1000). The most active compound, compound 2, was more potent than the standard drug GW405833 for in vitro agonistic action on the CB2 receptor. More importantly, in a rat model for CFA-induced inflammatory hyperalgesia, compound 2 had a potent anti-inflammatory pain effect within 12 hours after administration. At the 1 h time point, compound 2 had a dose-dependent reversal for hyperalgesia with an estimated ED50 value of 1.097 mg kg-1. Moreover, compound 2 significantly suppressed the pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) in CFA-induced lesions. These protective effects of compound 2 on inflammatory pain were superior to those of GW405833, suggesting that compound 2 may be a promising therapeutic drug that needs further validation.

Cannabinoids and Cardiovascular System

Cannabinoids influence cardiovascular variables in health and disease via multiple mechanisms. The chapter covers the impact of cannabinoids on cardiovascular function in physiology and pathology and presents a critical analysis of the proposed signalling pathways governing regulation of cardiovascular function by endogenously produced and exogenous cannabinoids. We know that endocannabinoid system is overactivated under pathological conditions and plays both a protective compensatory role, such as in some forms of hypertension, atherosclerosis and other inflammatory conditions, and a pathophysiological role, such as in disease states associated with excessive hypotension. This chapter focuses on the mechanisms affecting hemodynamics and vasomotor effects of cannabinoids in health and disease states, highlighting mismatches between some studies. The chapter will first review the effects of marijuana smoking on cardiovascular system and then describe the impact of exogenous cannabinoids on cardiovascular parameters in humans and experimental animals. This will be followed by analysis of the impact of cannabinoids on reactivity of isolated vessels. The article critically reviews current knowledge on cannabinoid induction of vascular relaxation by cannabinoid receptor-dependent and -independent mechanisms and dysregulation of vascular endocannabinoid signaling in disease states.

Anti-tumoral potential of MDA19 in human osteosarcoma via suppressing PI3K/Akt/mTOR signaling pathway

Osteosarcoma (OS) is the most common primary malignancy of skeleton with higher mortality rates amongst children and young adults worldwide, whereas effective and secure therapies have also been sought by researches with ongoing efforts. The purpose of the present study was to investigate the impact of N′-[(3Z)-1-(1-hexyl)-2-oxo-1,2-dihydro-3H-indol-3-ylidene] benzohydrazide (MDA19) on OS and explore its potential mechanism. Cell Counting Kit-8 (CCK8) and colony formation assay were employed to evaluate the potential effect of MDA19 on U2OS and MG-63 cells proliferation. Moreover, transwell migration and invasion assay were performed to assess the influence of MDA19 on U2OS and MG-63 cells migration and invasion. In addition, Annexin V-FITC/propidium iodide (Annexin V-FITC/PI) staining and flow cytometry were used to examine apoptotic ratio of the U2OS and MG-63 cells. Meanwhile, Western blot analysis was applied to explore change of relevant mechanism proteins in OS cells treated with MDA19. Our study showed that MDA19 had anti-proliferative activity of OS cells in a dose- and time-dependent manner, simultaneously, inhibition of colony formation was also observed in U2OS and MG-63 cells after incubation of MDA19. Besides, MDA19 could significantly inhibit the number of migrated and invaded OS cells and markedly increase the OS cells apoptosis rate. Mechanistically, we detected detectable reductions in apoptosis related proteins, epithelial–mesenchymal transition (EMT)-related proteins and activity of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling in U2OS and MG-63 cells exposure to MDA19. Overall, the current study indicates in vitro anti-proliferative, anti-metastatic, and pro-apoptotic potential of MDA19 in U2OS and MG-63 cells. Our findings propose a clue for further studies with this compound in preclinical and clinical treatment for OS.

The endocannabinoid system of the skin. A potential approach for the treatment of skin disorders

The skin is the largest organ of the body and has a complex and very active structure that contributes to homeostasis and provides the first line defense against injury and infection. In the past few years it has become evident that the endocannabinoid system (ECS) plays a relevant role in healthy and diseased skin. Specifically, we review how the dysregulation of ECS has been associated to dermatological disorders such as atopic dermatitis, psoriasis, scleroderma and skin cancer. Therefore, the druggability of the ECS could open new research avenues for the treatment of the pathologies mentioned. Numerous studies have reported that phytocannabinoids and their biological analogues modulate a complex network pharmacology involved in the modulation of ECS, focusing on classical cannabinoid receptors, transient receptor potential channels (TRPs), and peroxisome proliferator-activated receptors (PPARs). The combined targeting of several end-points seems critical to provide better chances of therapeutically success, in sharp contrast to the one-disease-one-target dogma that permeates current drug discovery campaigns.

Inhibition of cytokine-mediated JNK signalling by purinergic P2Y11 receptors, a novel protective mechanism in endothelial cells

Previous research from our laboratory has demonstrated a novel phenomenon whereby GPCRs play a role in inhibiting cytokine-mediated c-Jun N-terminal kinase (JNK) signalling. So far this novel phenomenon seems to have been vastly overlooked, with little research in the area. Therefore, in this study we explored this further; by assessing the potential of P2YRs to mediate inhibition of cytokine-mediated JNK signalling and related functional outcomes in human endothelial cells. We utilised primary endothelial cells, and employed the use of endogenous activators of P2YRs and well characterised pharmacological inhibitors, to assess signalling parameters mediated by P2YRs, Interleukin-1β (IL-1β), TNFα and JNK. Activation of P2YRs with adenosine tri-phosphate (ATP) resulted in a time- and concentration-dependent inhibition of IL-1β-mediated phosphorylation of JNK and associated kinase activity. The effect was specific for cytokine-mediated JNK signalling, as ATP was without effect on JNK induced by other non-specific activators (e.g. sorbitol, anisomycin), nor effective against other MAPK pathways such as p38 and the canonical NFκB cascade. Pharmacological studies demonstrated a role for the P2Y₁₁ receptor in mediating this effect, but not the P2Y₁ nor the adenosine receptors (A1, A2A, A2B & A3). The novel Gα_q/11 inhibitor YM254890 and a protein kinase A (PKA) inhibitor H89 both partially reversed ATP-mediated inhibition of IL-1β-stimulated JNK indicating involvement of both Gα_q/11 and Gα_s mediated pathways. ATP also partially reversed IL-1β-mediated induction of cyclo‑oxygenase-2 (COX-2) and E-selectin. Collectively, these studies indicate the potential for activation of purinergic receptors to protect the endothelium from inflammatory driven JNK activation and may be a new target for inflammatory disease therapy.

Celastrol alleviates renal fibrosis by upregulating cannabinoid receptor 2 expression

Renal fibrosis is the final manifestation of various chronic kidney diseases, and no effective therapy is available to prevent or reverse it. Celastrol, a triterpene that derived from traditional Chinese medicine, is a known potent anti-fibrotic agent. However, the underlying mechanisms of action of celastrol on renal fibrosis remain unknown. In this study, we found that celastrol treatment remarkably attenuated unilateral ureteral obstruction (UUO)-induced mouse renal fibrosis. This was evidenced by the significant reduction in tubular injury; collagen deposition; accumulation of fibronectin, collagen I, and α-smooth muscle actin; and the expression levels of pro-fibrotic factors Vim, Cola1, and TGF-β1 mRNA, as well as inflammatory responses. Celastrol showed similar effects in a folic acid-induced mouse renal fibrosis model. Furthermore, celastrol potentiated the expression of the anti-fibrotic factor cannabinoid receptor 2 (CB2R) in established mouse fibrotic kidney tissues and transforming growth factor β1 (TGF-β1)-stimulated human kidney 2 (HK-2) cells. In addition, the CB2R antagonist (SR144528) abolished celastrol-mediated beneficial effects on renal fibrosis. Moreover, UUO- or TGF-β1-induced activation of the pro-fibrotic factor SMAD family member 3 (Smad3) was markedly inhibited by celastrol. Inhibition of Smad3 activation by an inhibitor (SIS3) markedly reduced TGF-β1-induced downregulation of CB2R expression. In conclusion, our study provides the first direct evidence that celastrol significantly alleviated renal fibrosis, by contributing to the upregulation of CB2R expression through inhibiting Smad3 signaling pathway activation. Therefore, celastrol could be a potential drug for treating patients with renal fibrosis.

Peripheral modulation of the endocannabinoid system in metabolic disease

Dysfunction of the endocannabinoid system (ECS) has been identified in metabolic disease. Cannabinoid receptor 1 (CB₁) is abundantly expressed in the brain but also expressed in the periphery. Cannabinoid receptor 2 (CB₂) is more abundant in the periphery, including the immune cells. In obesity, global antagonism of overexpressed CB₁ reduces bodyweight but leads to centrally mediated adverse psychological outcomes. Emerging research in isolated cultured cells or tissues has demonstrated that targeting the endocannabinoid system in the periphery alleviates the pathologies associated with metabolic disease. Further, peripheral specific cannabinoid ligands can reverse aspects of the metabolic phenotype. This Keynote review will focus on current research on the functionality of peripheral modulation of the ECS for the treatment of obesity.

The Endocannabinoid System and Heart Disease: The Role of Cannabinoid Receptor Type 2

Decades of research has provided evidence for the role of the endocannabinoid system in human health and disease. This versatile system, consisting of two receptors (CB1 and CB2), their endogenous ligands (endocannabinoids), and metabolic enzymes has been implicated in a wide variety of disease states, ranging from neurological disorders to cancer. CB2 has gained much interest for its beneficial immunomodulatory role that can be obtained without eliciting psychotropic effects through CB1. Recent studies have shed light on a protective role of CB2 in cardiovascular disease, an ailment which currently takes more lives each year in Western countries than any other disease or injury. By use of CB2 knockout mice and CB2-selective ligands, knowledge of how CB2 signaling affects atherosclerosis and ischemia has been acquired, providing a major stepping stone between basic science and translational clinical research. Here, we summarize the current understanding of the endocannabinoid system in human pathologies and provide a review of the results from preclinical studies examining its function in cardiovascular disease, with a particular emphasis on possible CB2-targeted therapeutic interventions to alleviate atherosclerosis.

The endocannabinoid system in cardiovascular function: novel insights and clinical implications

RATIONALE

Cardiovascular disease is now recognized as the number one cause of death in the world, and the size of the population at risk continues to increase rapidly. The dysregulation of the endocannabinoid (eCB) system plays a central role in a wide variety of conditions including cardiovascular disorders. Cannabinoid receptors, their endogenous ligands, as well as enzymes conferring their synthesis and degradation, exhibit overlapping distributions in the cardiovascular system. Furthermore, the pharmacological manipulation of the eCB system has effects on blood pressure, cardiac contractility, and endothelial vasomotor control. Growing evidence from animal studies supports the significance of the eCB system in cardiovascular disorders.

OBJECTIVE

To summarize the literature surrounding the eCB system in cardiovascular function and disease and the new compounds that may potentially extend the range of available interventions.

RESULTS

Drugs targeting CB1R, CB2R, TRPV1 and PPARs are proven effective in animal models mimicking cardiovascular disorders such as hypertension, atherosclerosis and myocardial infarction. Despite the setback of two clinical trials that exhibited unexpected harmful side-effects, preclinical studies are accelerating the development of more selective drugs with promising results devoid of adverse effects.

CONCLUSION

Over the last years, increasing evidence from basic and clinical research supports the role of the eCB system in cardiovascular function. Whereas new discoveries are paving the way for the identification of novel drugs and therapeutic targets, the close cooperation of researchers, clinicians and pharmaceutical companies is needed to achieve successful outcomes.

Diversity effect of capsaicin on different types of skeletal muscle

Capsaicin is a major pungent content in green and red peppers which are widely used as spice, and capsaicin may activate different receptors. To determine whether capsaicin has different effects on different types of skeletal muscle, we applied different concentrations (0, 0.01, and 0.02%) of capsaicin in the normal diet and conducted a four-week experiment on Sprague-Dawley rats. The fiber type composition, glucose metabolism enzyme activity, and different signaling molecules' expressions of receptors were detected. Our results suggested that capsaicin reduced the body fat deposition, while promoting the slow muscle-related gene expression and increasing the enzyme activity in the gastrocnemius and soleus muscles. However, fatty acid metabolism was significantly increased only in the soleus muscle. The study of intracellular signaling suggested that the transient receptor potential vanilloid 1 (TRPV1) and cannabinoid receptors in the soleus muscle were more sensitive to capsaicin. In conclusion, the distribution of TRPV1 and cannabinoid receptors differs in different types of muscle, and the different roles of capsaicin in different types of muscle may be related to the different degrees of activation of receptors.

Cannabinoids in the Cardiovascular System

Cannabinoids are known to modulate cardiovascular functions including heart rate, vascular tone, and blood pressure in humans and animal models. Essential components of the endocannabinoid system, namely, the production, degradation, and signaling pathways of endocannabinoids have been described not only in the central and peripheral nervous system but also in myocardium, vasculature, platelets, and immune cells. The mechanisms of cardiovascular responses to endocannabinoids are often complex and may involve cannabinoid CB₁ and CB₂ receptors or non-CB_1/2 receptor targets. Preclinical and some clinical studies have suggested that targeting the endocannabinoid system can improve cardiovascular functions in a number of pathophysiological conditions, including hypertension, metabolic syndrome, sepsis, and atherosclerosis. In this chapter, we summarize the local and systemic cardiovascular effects of cannabinoids and highlight our current knowledge regarding the therapeutic potential of endocannabinoid signaling and modulation.

ACPA and JWH-133 modulate the vascular tone of superior mesenteric arteries through cannabinoid receptors, BKCa channels, and nitric oxide dependent mechanisms

BACKGROUND

Some cannabinoids, a family of compounds derived from Cannabis sativa (marijuana), have previously shown vasodilator effects in several studies, a feature that makes them suitable for the generation of a potential treatment for hypertension. The mechanism underlying this vasodilator effect in arteries is still controversial. In this report, we explored how the synthetic cannabinoids ACPA (CB₁-selective agonist) and JWH-133 (CB₂-selective agonist) regulate the vascular tone of rat superior mesenteric arteries.

METHODS

To screen the expression of CB₁ (Cannabinoid receptor 1) and CB₂ (Cannabinoid receptor 2) receptors in arterial rings or isolated smooth muscle cells obtained from the artery, immunocytochemistry, immunohistochemistry, and confocal microscopy were performed. In addition, the effects on vascular tone induced by the two cannabinoids were tested in isometric tension experiments in rings obtained from superior mesenteric arteries. The participation of voltage and calcium-activated potassium channel of big conductance (BK_Ca) and the role of nitric oxide (NO) release on the vascular effects induced by ACPA and JWH-133 were tested.

RESULTS

CB₁ and CB₂ receptors were highly expressed in the rat superior mesenteric artery, in both smooth muscle and endothelium. The vasodilation effect shown by ACPA was endothelium-dependent through a mechanism involving CB₁ receptors, BK_Ca channel activation, and NO release; meanwhile, the vasodilator effect of JWH-133 was induced by the activation of CB₂ receptors located in smooth muscle and by a CB₂ receptor-independent mechanism inducing NO release.

CONCLUSIONS

CB₁ and CB₂ receptor activation in superior mesenteric artery causes vasorelaxation by mechanisms involving BK_Ca channels and NO release.

Maternal alcohol exposure during mid-pregnancy dilates fetal cerebral arteries via endocannabinoid receptors

Prenatal alcohol exposure often results in fetal alcohol syndrome and fetal alcohol spectrum disorders. Mechanisms of fetal brain damage by alcohol remain unclear. We used baboons (Papio spp.) to study alcohol-driven changes in the fetal cerebral artery endocannabinoid system. Pregnant baboons were subjected to binge alcohol exposure via gastric infusion three times during a period equivalent to the second trimester of human pregnancy. A control group was infused with orange-flavored drink that was isocaloric to the alcohol-containing solution. Cesarean sections were performed at a time equivalent to the end of the second trimester of human pregnancy. Fetal cerebral arteries were harvested and subjected to in vitro pressurization followed by pharmacological profiling. During each alcohol-infusion episode, maternal blood alcohol concentrations (BAC) reached 80 mg/dL, that is, equivalent to the BAC considered legal intoxication in humans. Circulating anandamide (AEA) and 2-arachidonoylglycerol (2-AG) remained unchanged. Ultrasound studies on pregnant mothers revealed that fetal alcohol exposure decreased peak systolic blood velocity in middle cerebral arteries when compared to pre-alcohol levels. Moreover, ethanol-induced dilation was observed in fetal cerebral arteries pressurized in vitro. This dilation was abolished by the mixture of AM251 and AM630, which block cannabinoid receptors 1 and 2, respectively. In the presence of AM251, the cannabinoid receptor agonist AEA evoked a higher, concentration-dependent dilation of cerebral arteries from alcohol-exposed fetuses. The difference in AEA-induced cerebral artery dilation vanished in the presence of AM630. CB1 and CB2 receptor mRNA and protein levels were similar in cerebral arteries from alcohol-exposed and control-exposed fetuses. In summary, alcohol exposure dilates fetal cerebral arteries via endocannabinoid receptors and results in an increased function of CB2.

Activation of cannabinoid receptor type II by AM1241 protects adipose-derived mesenchymal stem cells from oxidative damage and enhances their therapeutic efficacy in myocardial infarction mice via Stat3 activation

The poor survival of cells in ischemic sites diminishes the therapeutic efficacy of stem cell therapy. Previously we and others have reported that Cannabinoid receptor type II (CB2) is protective during heart ischemic injury for its anti-oxidative activity. However, whether CB2 activation could improve the survival and therapeutic efficacy of stem cells in ischemic myocardium and the underlying mechanisms remain elusive. Here, we showed evidence that CB2 agonist AM1241 treatment could improve the functional survival of adipose-derived mesenchymal stem cells (AD-MSCs) in vitro as well as in vivo. Moreover, AD-MSCs adjuvant with AM1241 improved cardiac function, and inhibited cardiac oxidative stress, apoptosis and fibrosis. To unveil possible mechanisms, AD-MSCs were exposed to hydrogen peroxide/serum deprivation to simulate the ischemic environment in myocardium. Results delineated that AM1241 blocked the apoptosis, oxidative damage and promoted the paracrine effects of AD-MSCs. Mechanistically, AM1241 activated signal transducers and activators of transcription 3 (Stat3) through the phosphorylation of Akt and ERK1/2. Moreover, the administration of AM630, LY294002, U0126 and AG490 (inhibitors for CB2, Akt, ERK1/2 and Stat3, respectively) could abolish the beneficial actions of AM1241. Our result support the promise of CB2 activation as an effective strategy to optimize stem cell-based therapy possibly through Stat3 activation.

Cannabinoid signaling in health and disease

Cannabis sativa has long been used for medicinal purposes. To improve safety and efficacy, compounds from C. sativa were purified or synthesized and named under an umbrella group as cannabinoids. Currently, several cannabinoids may be prescribed in Canada for a variety of indications such as nausea and pain. More recently, an increasing number of reports suggest other salutary effects associated with endogenous cannabinoid signaling including cardioprotection. The therapeutic potential of cannabinoids is therefore extended; however, evidence is limited and mechanisms remain unclear. In addition, the use of cannabinoids clinically has been hindered due to pronounced psychoactive side effects. This review provides an overview on the endocannabinoid system, including known physiological roles, and conditions in which cannabinoid receptor signaling has been implicated.

β-Caryophyllene protects against alcoholic steatohepatitis by attenuating inflammation and metabolic dysregulation in mice

BACKGROUND AND AIMS

β-Caryophyllene (BCP) is a plant-derived FDA approved food additive with anti-inflammatory properties. Some of its beneficial effects in vivo are reported to involve activation of cannabinoid CB₂ receptors that are predominantly expressed in immune cells. Here, we evaluated the translational potential of BCP using a well-established model of chronic and binge alcohol-induced liver injury.

METHODS

In this study, we investigated the effects of BCP on liver injury induced by chronic plus binge alcohol feeding in mice in vivo by using biochemical assays, real-time PCR and histology analyses. Serum and hepatic BCP levels were also determined by GC/MS.

RESULTS

Chronic treatment with BCP alleviated the chronic and binge alcohol-induced liver injury and inflammation by attenuating the pro-inflammatory phenotypic `M1` switch of Kupffer cells and by decreasing the expression of vascular adhesion molecules intercellular adhesion molecule 1, E-Selectin and P-Selectin, as well as the neutrophil infiltration. It also beneficially influenced hepatic metabolic dysregulation (steatosis, protein hyperacetylation and PPAR-α signalling). These protective effects of BCP against alcohol-induced liver injury were attenuated in CB₂ receptor knockout mice, indicating that the beneficial effects of this natural product in liver injury involve activation of these receptors. Following acute or chronic administration, BCP was detectable both in the serum and liver tissue homogenates but not in the brain.

CONCLUSIONS

Given the safety of BCP in humans, this food additive has a high translational potential in treating or preventing hepatic injury associated with oxidative stress, inflammation and steatosis.

LINKED ARTICLES

This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.

Endocannabinoids in the gastrointestinal tract

The endocannabinoid system mainly consists of endogenously produced cannabinoids (endocannabinoids) and two G protein-coupled receptors (GPCRs), cannabinoid receptors 1 and 2 (CB₁ and CB₂). This system also includes enzymes responsible for the synthesis and degradation of endocannabinoids and molecules required for the uptake and transport of endocannabinoids. In addition, endocannabinoid-related lipid mediators and other putative endocannabinoid receptors, such as transient receptor potential channels and other GPCRs, have been identified. Accumulating evidence indicates that the endocannabinoid system is a key modulator of gastrointestinal physiology, influencing satiety, emesis, immune function, mucosal integrity, motility, secretion, and visceral sensation. In light of therapeutic benefits of herbal and synthetic cannabinoids, the vast potential of the endocannabinoid system for the treatment of gastrointestinal diseases has been demonstrated. This review focuses on the role of the endocannabinoid system in gut homeostasis and in the pathogenesis of intestinal disorders associated with intestinal motility, inflammation, and cancer. Finally, links between gut microorganisms and the endocannabinoid system are briefly discussed.

From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology

Apart from having been used and misused for at least four millennia for, among others, recreational and medicinal purposes, the cannabis plant and its most peculiar chemical components, the plant cannabinoids (phytocannabinoids), have the merit to have led humanity to discover one of the most intriguing and pleiotropic endogenous signaling systems, the endocannabinoid system (ECS). This review article aims to describe and critically discuss, in the most comprehensive possible manner, the multifaceted aspects of 1) the pharmacology and potential impact on mammalian physiology of all major phytocannabinoids, and not only of the most famous one Δ9-tetrahydrocannabinol, and 2) the adaptive pro-homeostatic physiological, or maladaptive pathological, roles of the ECS in mammalian cells, tissues, and organs. In doing so, we have respected the chronological order of the milestones of the millennial route from medicinal/recreational cannabis to the ECS and beyond, as it is now clear that some of the early steps in this long path, which were originally neglected, are becoming important again. The emerging picture is rather complex, but still supports the belief that more important discoveries on human physiology, and new therapies, might come in the future from new knowledge in this field.

Synthesis, molecular modeling and SAR study of novel pyrazolo[5,1-f][1,6]naphthyridines as CB2 receptor antagonists/inverse agonists

Pyrazolo[5,1-f][1,6]naphthyridine-carboxamide derivatives were synthesized and evaluated for the affinity at CB₁ and CB₂ receptors. Based on the AgOTf and proline-cocatalyzed multicomponent methodology, the ethyl 5-(p-tolyl)pyrazolo[5,1-f][1,6]naphthyridine-2-carboxylate (12) and ethyl 5-(2,4-dichlorophenyl)pyrazolo[5,1-f][1,6]naphthyridine-2-carboxylate (13) intermediates were synthesized from the appropriate o-alkynylaldehydes, p-toluenesulfonyl hydrazide and ethyl pyruvate. Most of the novel compounds feature a p-tolyl (8a-i) or a 2,4-dichlorophenyl (8j) motif at the C₅-position of the tricyclic pyrazolo[5,1-f][1,6]naphthyridine scaffold. Structural variation on the carboxamide moiety at the C₂-position includes basic monocyclic, terpenoid and adamantine-based amines. Among these derivatives, compound 8h (N-adamant-1-yl-5-(p-tolyl)pyrazolo[5,1-f][1,6]naphthyridine-2-carboxamide) exhibited the highest CB₂ receptor affinity (K_i=33nM) and a high degree of selectivity (K_iCB₁/K_iCB₂=173:1), whereas a similar trend in the near nM range was seen for the bornyl analogue (compound 8f, K_i=53nM) and the myrtanyl derivative 8j (K_i=67nM). Effects of 8h, 8f and 8j on forskolin-stimulated cAMP levels were determined, showing antagonist/inverse agonist properties for such compounds. Docking studies conducted for these derivatives and the reference antagonist/inverse agonist compound 4 (SR144528) disclosed the specific pattern of interactions probably related to the pyrazolo[5,1-f][1,6]naphthyridine scaffold as CB₂ inverse agonists.

Toxicological Evaluation of β-Caryophyllene Oil: Subchronic Toxicity in Rats

In a subchronic toxicity study, administration of β-caryophyllene (BCP) oil by oral gavage to Wistar rats at dosages of 0, 150, 450, or 700 mg/kg/d for 90 days, including a 21-day recovery period, did not produce any significant toxicologic manifestations. The study design also included a 28-day interim sacrifice in the control and high-dose groups. The BCP oil test article was well tolerated as evidenced by the absence of major treatment-related changes in the general condition and appearance of the rats, neurobehavioral end points, growth, feed and water intake, ophthalmoscopic examinations, routine hematology and clinical chemistry parameters, urinalysis, and necropsy findings. The no observed adverse effect level was the highest dosage level administered of 700 mg/kg body weight/d for both male and female rats. The study was conducted as part of an investigation to examine the safety of BCP oil for its proposed use in medical food products.

Expression of the endocannabinoid receptors in human fascial tissue

Cannabinoid receptors have been localized in the central and peripheral nervous system as well as on cells of the immune system, but recent studies on animal tissue gave evidence for the presence of cannabinoid receptors in different types of tissues. Their presence was supposed also in myofascial tissue, suggesting that the endocannabinoid system may help resolve myofascial trigger points and relieve symptoms of fibromyalgia. However, until now the expression of CB1 (cannabinoid receptor 1) and CB2 (cannabinoid receptor 2) in fasciae has not yet been established. Small samples of fascia were collected from volunteers patients during orthopedic surgery. For each sample were done a cell isolation, immunohistochemical investigation (CB1 and CB2 antibodies) and real time RT-PCR to detect the expression of CB1 and CB2. Both cannabinoid receptors are expressed in human fascia and in human fascial fibroblasts culture cells, although to a lesser extent than the control gene. We can assume that the expression of mRNA and protein of CB1 and CB2 receptors in fascial tissue are concentrated into the fibroblasts. This is the first demonstration that the fibroblasts of the muscular fasciae express CB1 and CB2. The presence of these receptors could help to provide a description of cannabinoid receptors distribution and to better explain the role of fasciae as pain generator and the efficacy of some fascial treatments. Indeed the endocannabinoid receptors of fascial fibroblasts can contribute to modulate the fascial fibrosis and inflammation.

Matrine inhibits the expression of adhesion molecules in activated vascular smooth muscle cells

Atherosclerosis is a chronic inflammatory disease associated with increased expression of adhesion molecules in vascular smooth muscle cells (VSMCs). Matrine is a main active ingredient of Sophora flavescens roots, which are used to treat inflammatory diseases. However, the effects of matrine on the expression of adhesion molecules in VSMCs have largely remained elusive. Therefore, the present study investigated the effects of matrine on the expression of adhesion molecules in tumor necrosis factor (TNF)‑α‑stimulated human aortic smooth muscle cells (HASMCs). The results showed that matrine inhibited the expression of vascular cell adhesion molecule‑1 (VCAM‑1) and intercellular adhesion molecule‑1 (ICAM‑1) in TNF‑α‑stimulated HASMCs. Matrine markedly inhibited the TNF‑α‑induced expression of nuclear factor (NF)‑κB p65 and prevented the TNF‑α‑caused degradation of inhibitor of NF‑κB; it also inhibited TNF‑α‑induced activation of mitogen‑activated protein kinases (MAPKs). Furthermore, matrine inhibited the production of intracellular reactive oxygen species (ROS) in TNF‑α‑stimulated HASMCs. In conclusion, the results of the present study demonstrated that matrine inhibited the expression of VCAM‑1 and ICAM‑1 in TNF‑α‑stimulated HASMCs via the suppression of ROS production as well as NF‑κB and MAPK pathway activation. Therefore, matrine may have a potential therapeutic use for preventing the advancement of atherosclerotic lesions.

Endocannabinoids and the Cardiovascular System in Health and Disease

The endocannabinoid system is widely distributed throughout the cardiovascular system. Endocannabinoids play a minimal role in the regulation of cardiovascular function in normal conditions, but are altered in most cardiovascular disorders. In shock, endocannabinoids released within blood mediate the associated hypotension through CB(1) activation. In hypertension, there is evidence for changes in the expression of CB(1), and CB(1) antagonism reduces blood pressure in obese hypertensive and diabetic patients. The endocannabinoid system is also upregulated in cardiac pathologies. This is likely to be cardioprotective, via CB(2) and CB(1) (lesser extent). In the vasculature, endocannabinoids cause vasorelaxation through activation of multiple target sites, inhibition of calcium channels, activation of potassium channels, NO production and the release of vasoactive substances. Changes in the expression or function of any of these pathways alter the vascular effect of endocannabinoids. Endocannabinoids have positive (CB(2)) and negative effects (CB(1)) on the progression of atherosclerosis. However, any negative effects of CB(1) may not be consequential, as chronic CB(1) antagonism in large scale human trials was not associated with significant reductions in atheroma. In neurovascular disorders such as stroke, endocannabinoids are upregulated and protective, involving activation of CB(1), CB(2), TRPV1 and PPARα. Although most of this evidence is from preclinical studies, it seems likely that cannabinoid-based therapies could be beneficial in a range of cardiovascular disorders.

Cannabinoid Receptor Type 2 (CB2) Dependent and Independent Effects of WIN55,212-2 on Atherosclerosis in Ldlr-null Mice

PURPOSE

WIN55,212-2, a potent synthetic agonist of cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2), reduces atherosclerosis in apolipoprotein E (ApoE) null mice. Although pharmacologic evidence suggests the anti-atherosclerotic effects of WIN55,212-2 are mediated via CB2, this remains to be confirmed by genetic studies. Therefore, in this study, we investigated the effects of WIN55,212-2 on development of atherosclerosis in low-density lipoprotein receptor (Ldlr) null mice with and without homozygous deletion of the CB2 gene.

METHODS

After 6 weeks on an atherogenic diet, groups of CB2^+/+ and CB2^-/- Ldlr-null mice received a daily intraperitoneal injection of WIN55,212-2 or vehicle. After two weeks, plasma lipid levels and atherosclerosis in the aortic root were quantified.

RESULTS

Plasma cholesterol and triglyceride levels did not differ between CB2^+/+ and CB2^-/- mice and WIN55,212-2 had no effect on total cholesterol levels in either genotype. However, triglyceride levels in both CB2^+/+ and CB2^-/- mice were significantly lowered by WIN55,212-2. The size of aortic root lesions did not differ significantly between CB2^+/+ and CB2^-/- mice with or without WIN55,212-2 treatment. However, WIN55,212-2 treatment significantly lowered lesional macrophage accumulation in CB2^+/+ mice, and lesional smooth muscle content in both CB2^+/+ and CB2^-/- mice. Lesional apoptosis was also greater in CB2^+/+ mice compared to CB2^-/-mice, and only reduced by WIN55,212-2 in CB2^+/+ mice. Collagen content and elastin fiber fragmentation were unaffected by genotype or WIN55,212-2.

CONCLUSIONS

WIN55,212-2 treatment does not alter lesion size in Ldlr null-mice, but does modify lesion cellularity via CB2-dependent and CB2-independent mechanisms.

Cannabidiol causes endothelium-dependent vasorelaxation of human mesenteric arteries via CB1 activation

Aims

The protective effects of cannabidiol (CBD) have been widely shown in preclinical models and have translated into medicines for the treatment of multiple sclerosis and epilepsy. However, the direct vascular effects of CBD in humans are unknown.

Methods and results

Using wire myography, the vascular effects of CBD were assessed in human mesenteric arteries, and the mechanisms of action probed pharmacologically. CBD-induced intracellular signalling was characterized using human aortic endothelial cells (HAECs). CBD caused acute, non-recoverable vasorelaxation of human mesenteric arteries with an R_max of ∼40%. This was inhibited by cannabinoid receptor 1 (CB₁) receptor antagonists, desensitization of transient receptor potential channels using capsaicin, removal of the endothelium, and inhibition of potassium efflux. There was no role for cannabinoid receptor-2 (CB₂) receptor, peroxisome proliferator activated receptor (PPAR)γ, the novel endothelial cannabinoid receptor (CB_e), or cyclooxygenase. CBD-induced vasorelaxation was blunted in males, and in patients with type 2 diabetes or hypercholesterolemia. In HAECs, CBD significantly reduced phosphorylated JNK, NFκB, p70s6 K and STAT5, and significantly increased phosphorylated CREB, ERK1/2, and Akt levels. CBD also increased phosphorylated eNOS (ser1177), which was correlated with increased levels of ERK1/2 and Akt levels. CB₁ receptor antagonism prevented the increase in eNOS phosphorylation.

Conclusion

This study shows, for the first time, that CBD causes vasorelaxation of human mesenteric arteries via activation of CB₁ and TRP channels, and is endothelium- and nitric oxide-dependent.