We have reported that D,L-thiol esters, including D-cysteine ethyl ester (D-CYSee), are effective at overcoming opioid-induced respiratory depression (OIRD) in rats. Our on-going studies reveal that co-injections of D-CYSee with multi-day morphine injections markedly diminish spontaneous withdrawal that usually occurs after cessation of multiple injections of morphine in rats. Chronically administered opioids are known (1) to alter cellular redox status, thus inducing an oxidative state, and (2) for an overall decrease in DNA methylation, therefore resulting in the transcriptional activation of previously silenced long interspersed elements (LINE-1) retrotransposon genes. The first objective of the present study was to determine whether D-CYSee and the one carbon metabolism with the methyl donor, betaine, would maintain redox control and normal DNA methylation levels in human neuroblastoma cell cultures (SH-SY5Y) under overnight challenge with morphine (100 nM). The second objective was to determine whether D-CYSee and/or betaine could diminish the degree of physical dependence to morphine in male Sprague Dawley rats. Our data showed that overnight treatment with morphine reduced cellular GSH levels, induced mitochondrial damage, decreased global DNA methylation, and increased LINE-1 mRNA expression. These adverse effects by morphine, which diminished the reducing capacity and compromised the maintenance of the membrane potential of SH-SY5Y cells, was prevented by concurrent application of D-CYSee (100 µM) or betaine (300 µM). Furthermore, our data demonstrated that co-injections of D-CYSee (250 μmol/kg, IV) and to a lesser extent, betaine (250 μmol/kg, IV), markedly diminished the development of physical dependence induced by multi-day morphine injections (escalating daily doses of 10–30 mg/kg, IV), as assessed by the lesser number of withdrawal phenomena elicited by the injection of the opioid receptor antagonist, naloxone (1.5 mg/kg, IV). These findings provide evidence that D-CYSee and betaine prevent the appearance of redox alterations and epigenetic signatures commonly seen in neural cells involved in opioid physical dependence/addiction, and lessen development of physical dependence to morphine.

The ability of morphine to decrease cysteine transport into neurons by inhibition of excitatory amino acid transporter 3 (EAA3) may be a key molecular mechanism underlying the acquisition of physical and psychological dependence to morphine. This study examined whether co-administration of the cell-penetrant antioxidant D-thiol ester, D-cysteine ethyl ester (D-CYSee), with morphine, would diminish the development of physical dependence to morphine in male Sprague Dawley rats. Systemic administration of the opioid receptor antagonist, naloxone (NLX), elicited pronounced withdrawal signs (e.g., wet-dog shakes, jumps, rears, circling) in rats that received a subcutaneous depot of morphine (150 mg/kg, SC) for 36 h and continuous intravenous infusion of vehicle (20 μL/h, IV). The NLX-precipitated withdrawal signs were reduced in rats that received an infusion of D-CYSee, but not D-cysteine, (both at 20.8 μmol/kg/h, IV) for the full 36 h. NLX elicited pronounced withdrawal signs in rats treated for 48 h with morphine (150 mg/kg, SC), plus continuous infusion of vehicle (20 μL/h, IV) that began at the 36 h timepoint of morphine treatment. The NLX-precipitated withdrawal signs were reduced in rats that received a 12 h infusion of D-CYSee, but not D-cysteine, (both at 20.8 μmol/kg/h, IV) that began at the 36 h timepoint of morphine treatment. These findings suggest that D-CYSee may attenuate the development of physical dependence to morphine and reverse established dependence to the opioid in male Sprague Dawley rats. Alternatively, D-CYSee may simply suppress the processes responsible for NLX-precipitated withdrawal. Nonetheless, D-CYSee and analogues may be novel therapeutics for the treatment of opioid use disorders.

Introduction: Despite their inclination to induce tolerance, addictive states, and respiratory depression, synthetic opioids are among the most effective clinically administered drugs to treat severe acute/chronic pain and induce surgical anesthesia. Current medical interventions for opioid-induced respiratory depression (OIRD), wooden chest syndrome, and opioid use disorder (OUD) show limited efficacy and are marked by low success in the face of highly potent synthetic opioids such as fentanyl. D-Cysteine ethylester (D-CYSee) prevents OIRD and post-treatment withdrawal in male/female rats and mice with minimal effect on analgesic status. However, the potential aversive or rewarding effects of D-CYSee have yet to be fully characterized and its efficacy could be compromised by interactions with opioid-reward pathology.Methods: Using a model of fentanyl-induced conditioned place preference (CPP), this study evaluated 1) the dose and sex dependent effects of fentanyl to induce rewarding states, and 2) the extent to which D-CYSee alters affective state and the acquisition of fentanyl-induced seeking behaviors.Results: Fentanyl reward-related effects were found to be dose and sex dependent. Male rats exhibited a range-bound dose response centered at 5 µg/kg. Female rats exhibited a CPP only at 50 µg/kg. This dose was effective in 25% of females with the remaining 75% showing no significant CPP at any dose. Pretreatment with 100 mg/kg, but not 10 mg/kg, D-CYSee prevented acquisition of fentanyl seeking in males while both doses were effective at preventing acquisition in females.Discussion: These findings suggest that D-CYSee is an effective co-treatment with prescribed opioids to reduce the development of OUD.

Type 2 diabetes (T2D) affects >30 million Americans and nearly 70% of individuals with T2D will die from cardiovascular disease (CVD). Circulating levels of the inflammatory signaling lipid, prostaglandin E 2 (PGE 2 ), are elevated in the setting of obesity and T2D and are associated with decreased cardiac function. The EP3 and EP4 PGE 2 receptors have opposing actions in several tissues, including the heart: overexpression of EP3 in cardiomyocytes impairs function, while EP4 overexpression improves function. Here we performed complementary studies in vitro with isolated cardiomyocytes and in vivo using db/db mice, a model of T2D, to analyze the effects of EP3 inhibition or EP4 activation on cardiac function. Using echocardiography, we found that 2 weeks of systemic treatment of db/db mice with 20 mg/kg of EP3 antagonist, beginning at 6 weeks of age, improves ejection fraction and fractional shortening (with no effect on heart rate). We further show that either EP3 blockade or EP4 activation enhances contractility and calcium cycling in isolated mouse cardiomyocytes cultured in both normal and high glucose. Thus, peak [Ca 2+ ] I transient amplitude was increased, while time to peak [Ca 2+ ] I and [Ca 2+ ] I decay were decreased. These data suggest that modulation of EP3 and EP4 activity has beneficial effects on cardiomyocyte contractility and overall heart function.

We have reported that pretreatment with the clinically approved superoxide dismutase mimetic, Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl), blunts the cardiorespiratory depressant responses elicited by a subsequent injection of fentanyl, in halothane-anesthetized rats. The objective of the present study was to determine whether Tempol is able to reverse the effects of morphine on arterial blood-gas (ABG) chemistry in freely-moving Sprague Dawley rats. The intravenous injection of morphine (10 mg/kg) elicited substantial decreases in pH, pO2 and sO2 that were accompanied by substantial increases in pCO2 and Alveolar-arterial gradient, which results in diminished gas-exchange within the lungs. Intravenous injection of a 60 mg/kg dose of Tempol 15 min after the injection of morphine caused minor improvements in pO2 and pCO2 but not in other ABG parameters. In contrast, the 100 mg/kg dose of Tempol caused an immediate and sustained reversal of the negative effects of morphine on arterial blood pH, pCO2, pO2, sO2 and Alveolar-arterial gradient. In other rats, we used pulse oximetry to determine that the 100 mg/kg dose of Tempol, but not the 60 mg/kg dose elicited a rapid and sustained reversal of the negative effects of morphine (10 mg/kg, IV) on tissue O2 saturation (SpO2). The injection of morphine caused a relatively minor fall in mean arterial blood pressure that was somewhat exacerbated by Tempol. These findings demonstrate that Tempol can reverse the negative effects of morphine on ABG chemistry in freely-moving rats paving the way of structure-activity and mechanisms of action studies with the host of Tempol analogues that are commercially available.

Little is known about the pharmacological activity of Monarda fistulosa L. essential oils. To address this issue, we isolated essential oils from the flowers and leaves of M. fistulosa and analyzed their chemical composition. We also analyzed the pharmacological effects of M. fistulosa essential oils on transient receptor potential (TRP) channel activity, as these channels are known targets of various essential oil constituents. Flower (MEOFl) and leaf (MEOLv) essential oils were comprised mainly of monoterpenes (43.1% and 21.1%) and oxygenated monoterpenes (54.8% and 77.7%), respectively, with a high abundance of monoterpene hydrocarbons, including p-cymene, γ-terpinene, α-terpinene, and α-thujene. Major oxygenated monoterpenes of MEOFl and MEOLv included carvacrol and thymol. Both MEOFl and MEOLv stimulated a transient increase in intracellular free Ca2+ concentration ([Ca2+]i) in TRPA1 but not in TRPV1 or TRPV4-transfected cells, with MEOLv being much more effective than MEOFl. Furthermore, the pure monoterpenes carvacrol, thymol, and β-myrcene activated TRPA1 but not the TRPV1 or TRPV4 channels, suggesting that these compounds represented the TRPA1-activating components of M. fistulosa essential oils. The transient increase in [Ca2+]i induced by MEOFl/MEOLv, carvacrol, β-myrcene, and thymol in TRPA1-transfected cells was blocked by a selective TRPA1 antagonist, HC-030031. Although carvacrol and thymol have been reported previously to activate the TRPA1 channels, this is the first report to show that β-myrcene is also a TRPA1 channel agonist. Finally, molecular modeling studies showed a substantial similarity between the docking poses of carvacrol, thymol, and β-myrcene in the binding site of human TRPA1. Thus, our results provide a cellular and molecular basis to explain at least part of the therapeutic properties of these essential oils, laying the foundation for prospective pharmacological studies involving TRP ion channels.

The paternally imprinted neuronatin (NNAT) gene has been identified as a target of aberrant epigenetic silencing in diverse cancers, but no association with pediatric bone cancers has been reported to date. In screening childhood cancers, we identified aberrant CpG island hypermethylation in a majority of osteosarcoma (OS) samples and in 5 of 6 human OS cell lines studied but not in normal bone-derived tissue samples. CpG island hypermethylation was associated with transcriptional silencing in human OS cells, and silencing was reversible upon treatment with 5-aza-2'-deoxycytidine. Expression of NNAT was detectable in osteoblasts and chondrocytes of human bone, supporting a potential role in bone homeostasis. Enforced expression of NNAT in human OS cells lacking endogenous expression resulted in significant reduction in colony formation and in vitro migration compared to nonexpressor control cells. We next analyzed the effect of NNAT expression on intracellular calcium homeostasis and found that was associated with an attenuated decay of calcium levels to baseline following ATP-induced release of calcium from endoplasmic reticulum (ER) stores. Furthermore, NNAT expression was associated with increased cytotoxicity in OS cells from thapsigargin, an inhibitor of calcium reuptake into ER and an inducer of the ER stress response. These results suggest a possible tumor suppressor role for NNAT in human osteosarcoma. Additional study is needed ascertain sensitization to ER stress-associated apoptosis as a mechanism of NNAT-dependent cytotoxicity. In that case, epigenetic modification therapy to effect NNAT transcriptional derepression may represent a therapeutic strategy potentially of benefit to a majority of osteosarcoma patients.

BackgroundCurrently suicide is the 10th leading cause of death in the United States. Despite increased awareness and availability of new drug therapies, the pathology of suicidal ideation remains elusive. Suicidal ideation is often a comorbidity associated with other neuropsychiatric and neurological disorders, including but not limited to, major depressive disorder, schizophrenia, and viral infections with neurological sequelae. In addition, interferon alpha therapy used in the treatment of chronic viral infections has a significantly increased risk of suicide and aggressive behaviors. One potential biological mechanism underlying suicidal ideation may be attributed to spatio‐temporal changes to brain transcriptome diversity. Transcriptome diversity is critical for brain development and contributes to “fine‐tuning” of signaling and other processes involved in neural plasticity. A major player in regulating transcriptome diversity is adenosine deaminase acting on RNA (ADAR), an enzyme that deaminates selected adenosine (A) residues to inosine (I), which later are interpreted by transcriptional machinery as a guanine (G). ADAR expression is in part controlled by innate immune activation, which in turn can lead to dysregulation of normal editing patterns resulting in neurological symptoms including mood instability and suicidal ideation.MethodsWe use publicly available RNA sequencing datasets of prefrontal cortex samples from brains of patients with major depressive disorder who have committed suicide to infer changes in ADAR editing landscapes. Recently developed computational pipeline AIDD (Automated Isoform Diversity Detector) is used to map and contrast ADAR expression and editing patterns across samples using random forest, hierarchal clustering, Guttman scale patterns, and principal component analysis.ResultsADAR editing sites can be found in dozens of genes, including ion channels, such as the glutamate receptor GRIA2, and in other genes with known functions in cell division and growth pathways involved in neurodevelopment and neurotransmitter processes critical for neural plasticity, memory formation, and ion homeostasis. Notably, we have confirmed differential editing patterns in the serotonin receptor subunit 2C (5HTR2C), a known player in depression, where 5 editing sites can be edited in different combinations to create variant isoforms with different binding affinities and signaling abilities. These changes to the brain excitome, including in 5HTR2C and 147 other genes with known and/or predicted ADAR editing sites, can offer insight into the molecular mechanism of action in neuropsychiatric disorders, including elucidating the potential role of infection‐triggered ADAR editing changes.ConclusionsMachine learning techniques, including random forest, and Guttman scale patterns can be used to study ADAR editing landscapes, ultimately predicting biomarkers that can be used in a clinical setting for diagnosis, prognosis, and as therapeutic drug targets to treat major depressive disorder and suicidal ideation.Support or Funding InformationFunded by Kent State University Brain Health Research Institute to H. P. and D. D.

Synemin is a type IV intermediate filament (IF) protein. The two largest isoforms (α and β) are co‐expressed in a variety of cell types including muscle cells. Earlier we found that in muscle cells α‐synemin preferentially localizes to the sarcolemma and intercalated disks while β‐synemin is concentrated at the Z‐disks. Both isoforms also have an unusually long tail domain compared to most IF proteins. This domain is a site for numerous protein interactions, some unique to each isoform and some common to both. For example, in the past we found that both bind protein kinase A (PKA) and are thus also classified as A‐kinase anchoring proteins (AKAPs). AKAPs act to tether PKA to specific subcellular locations to maintain the specificity of the PKA signaling pathway. Excitingly, we have now found evidence that synemin also binds PKCɛ. Specifically, co‐immunoprecipitation studies show that PKCɛ binds to β‐synemin only upon stimulation of the β‐adrenergic pathway with isoproterenol. Additionally, western analysis using cells expressing either wild type or mutant β‐synemin indicates that, upon loss of β‐synemin anchored PKA, there is a decrease in phosphorylation of PKC substrates, including a ~22 kDa protein. Studies are ongoing to determine the identity of this protein. Based on molecular weight and known PKCɛ substrates in muscle cells we predict this protein is either troponin I (TnI) or myosin regulatory light chain 2 (RLC2). In support of RLC2, yeast‐two hybrid analysis revealed that protein‐protein interaction occurs between β‐synemin and RLC2. Thus, β‐synemin is proposed be a site of cross‐talk between PKA and PKCɛ and also may localize these kinases to the sarcomere at the substrate for PKCɛ.Support or Funding InformationNIH R01 HL65701 (DD)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Carotid body (CB) glomus (Type I) cells detect decreases in arterial oxygen (O2) tension (hypoxia) by depolarizing, opening voltage‐gated calcium channels (VGCCs) and releasing neurotransmitters. These neurotransmitters activate chemoafferent terminals within the carotid sinus nerve (CSN), which signal respiratory regions of the brainstem to increase ventilation and restore blood O2 levels. Low‐molecular mass S‐nitrosothiols (SNOs), such as S‐nitroso‐Lcysteine (LSNC), are recently being used as chemical agents for studying the biochemistry underlying the ventilatory response to hypoxia. Unpublished work from our lab shows that LSNC alters macroscopic outward potassium currents in carotid body glomus cells under both normoxic and hypoxic conditions. However, the effect of LSNC on intracellular calcium concentration ([Ca2+]i) is unknown. Our objective was to determine whether LSNC elicits changes in [Ca2+]i in CB glomus cells. We hypothesized that LSNC increases [Ca2+]i via influx through VGCCs. To test this we isolated CB glomus cells from postnatal (P) P11–P15 Sprague Dawley male rat pups, and used Ca2+ imaging to investigate for the first time the effect of LSNC on CB glomus cell [Ca2+]i. Our preliminary data reveals that 50μM LSNC causes a rise in [Ca2+]i under normoxic conditions (n=2). This data suggests that LSNC increases CB glomus cell [Ca2+]i, and this rise may trigger Ca2+‐dependent release of neurotransmitters and activation of chemoafferent fibers within the CSN.Support or Funding InformationNIH SPARC 1OT2OD023860‐02 SJLewisThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The functional expression of transient receptor potential cation channel of the ankyrin-1 subtype (TRPA1) has recently been identified in adult mouse cardiac tissue where stimulation of this ion channel leads to increases in adult mouse ventricular cardiomyocyte (CM) contractile function via a Ca2+-Calmodulin-dependent kinase (CaMKII) pathway. However, the extent to which TRPA1 induces nitric oxide (NO) production in CMs, and whether this signaling cascade mediates physiological or pathophysiological events in cardiac tissue remains elusive. Freshly isolated CMs from wild-type (WT) or TRPA1 knockout (TRPA1-/-) mouse hearts were treated with AITC (100 µM) and prepared for immunoblot, NO detection or ischemia protocols. Our findings demonstrate that TRPA1 stimulation with AITC results in phosphorylation of protein kinase B (Akt) and endothelial NOS (eNOS) concomitantly with NO production in a concentration- and time-dependent manner. Additionally, we found that TRPA1 induced increases in CM [Ca2+]i and contractility occur independently of Akt and eNOS activation mechanisms. Further analysis revealed that the presence and activation of TRPA1 promotes CM survival and viability following ischemic insult via a mechanism partially dependent upon eNOS. Therefore, activation of the TRPA1/Akt/eNOS pathway attenuates ischemia-induced CM cell death.

Objectives TRPV1 channels have been linked to the development and progression of diabetes at multiple levels, including control of appetite and weight, regulation of pancreatic function, thermogenesis, metabolism and energy homeostasis. Despite this, little information is known regarding its role in liver homeostasis and nonalcoholic fatty liver disease (NAFLD).Methods and Results To better understand the role of TRPV1 in liver metabolism, we explored the effects of a high fat/sugar diet (Western, 24-week regimen) in male and female wild type (WT) and TRPV1-null (V1KO) mice. Our data reveal that loss of the TRPV1 gene makes mice susceptible to diet-induced obesity and induces NAFLD. V1KO mice displayed gross phenotypic and gross morphological changes including insulin resistance, glucose intolerance, increased body mass and central adiposity on a western diet compared to WT counterparts. Western fed V1KO mice exhibited gross changes in liver morphology and size compared to western fed WT mice, which were supported with histological H&E and Oil Red O staining. Accompanying the liver changes, Western fed V1KO mice exhibited altered lipid profiles as demonstrated by elevated hepatic triglyceride, cholesterol and free fatty acid levels compared to western fed WT mice. Interestingly, female V1KO mice fed a western diet displayed significant protection against diet-induced obesity and the progression of NAFLD compared to their male counterparts. Taken together, these data suggest that loss of TRPV1 promotes fat accumulation, NAFLD development and changes in liver lipid profiles in male mice, the extent to which is less severe in female V1KO mice.Conclusion In conclusion, TRPV1 may be a protective therapeutic target for the prevention of NAFLD development in diet-induced obesity.Non-standard abbreviations: T2DM: Type 2 diabetes mellitusNAFLD: Nonalcoholic fatty liver diseaseTRPV1: Transient receptor potential channel vanilloid subtype 1GTT: glucose tolerance testRER: respiratory exchange ratio

Transient receptor potential cation channel, subfamily A, member 1 (TRPA1), is activated by a broad range of noxious stimuli. Cdk5, a member of the Cdk family, has recently been identified as a modulator of pain signaling pathways. In the current study, we investigated the extent to which Cdk5 modulates TRPA1 activity. Cdk5 inhibition was found to attenuate TRPA1 response to agonist in mouse DRG sensory neurons. Additionally, the presence of active Cdk5 was associated with increased TRPA1 phosphorylation in transfected HEK293 cells that was roscovitine-sensitive and absent in the mouse mutant S449A full-length channel. Immunopurified Cdk5 was observed to phosphorylate human TRPA1 peptide substrate at S448A in vitro. Our results point to a role for Cdk5 in modulating TRPA1 activity.

Background Transient receptor potential (TRP) ion channels have emerged as key components contributing to vasoreactivity. Propofol, an anesthetic is associated with adverse side effects including hypotension and acute pain upon infusion. Our objective was to determine the extent to which TRPA1 and/or TRPV1 ion channels are involved in mediating propofol-induced vasorelaxation of mouse coronary arterioles in vitro and elucidate the potential cellular signal transduction pathway by which this occurs. Methods Hearts were excised from anesthetized mice and coronary arterioles were dissected from control C57Bl/6J, TRPA1-/-, TRPV1-/- and double-knockout mice (TRPAV-/-). Isolated microvessels were cannulated and secured in a temperature-controlled chamber and allowed to equilibrate for 1 hr. Vasoreactivity studies were performed in microvessels pre-constricted with U46619 to assess the dose-dependent relaxation effects of propofol on coronary microvascular tone. Results Propofol-induced relaxation was unaffected in vessels obtained from TRPV1-/- mice, markedly attenuated in pre-constricted vessels obtained from TRPA1-/- mice and abolished in vessels obtained from TRPAV-/- mice. Furthermore, NOS inhibition with L-NAME or endothelium denuding abolished the proporfol-induced depressor response in pre-constricted vessels obtained from all mice. In the absence of L-NAME, BKCa inhibition with penitrem A markedly attenuated propofol-mediated relaxation in vessels obtained from wild-type mice and to a lesser extent in vessels obtained from TRPV1-/-, mice with no effect in vessels obtained from TRPA1-/- or TRPAV-/- mice. Conclusions TRPA1 and TRPV1 appear to contribute to the propofol-mediated antagonism of U46619-induced constriction in murine coronary microvessels that involves activation of NOS and BKCa.

ABSTRACT Rationale: Transient receptor potential channels of the ankyrin subtype-1 (TRPA1) are non-selective cation channels that show high permeability to calcium. Previous studies from our laboratory have demonstrated that TRPA1 ion channels are expressed in adult mouse ventricular cardiomyocytes (CMs) and are localized at the z-disk, costamere and intercalated disk. The functional significance of TRPA1 ion channels in the modulation of CM contractile function have not been explored. Objective: To identify the extent to which TRPA1 ion channels are involved in modulating CM contractile function and elucidate the cellular mechanism of action. Methods and Results: Freshly isolated CMs were obtained from murine heart and loaded with Fura-2 AM. Simultaneous measurement of intracellular free Ca2+ concentration ([Ca2+]i) and contractility was performed in individual CMs paced at 0.3 Hz. Our findings demonstrate that TRPA1 stimulation with AITC results in a dose-dependent increase in peak [Ca2+]i and a concomitant increase in CM fractional shortening. Further analysis revealed a dose-dependent acceleration in time to peak [Ca2+]i and velocity of shortening as well as an acceleration in [Ca2+]i decay and velocity of relengthening. These effects of TRPA1 stimulation were not observed in CMs pre-treated with the TRPA1 antagonist, HC-030031 (10 µmol/L) nor in CMs obtained from TRPA1−/− mice. Moreover, we observed no significant increase in cAMP levels or PKA activity in response to TRPA1 stimulation and the PKA inhibitor peptide (PKI 14–22; 100 nmol/L) failed to have any effect on the TRPA1-mediated increase in CM contractile function. However, TRPA1 stimulation resulted in a rapid phosphorylation of Ca2+/calmodulin-dependent kinase II (CaMKII) (1–5 min) that correlated with increases in CM [Ca2+]i and contractile function. Finally, all aspects of TRPA1-dependent increases in CM [Ca2+]i, contractile function and CaMKII phosphorylation were virtually abolished by the CaMKII inhibitors, KN-93 (10 µmol/L) and autocamtide-2-related peptide (AIP; 20 µmol/L). Conclusions: These novel findings demonstrate that stimulation of TRPA1 ion channels in CMs results in activation of a CaMKII-dependent signaling pathway resulting in modulation of intracellular Ca2+ availability and handling leading to increases in CM contractile function. Cardiac TRPA1 ion channels may represent a novel therapeutic target for increasing the inotropic and lusitropic state of the heart.

Caveolin‐1 (Cav‐1), a scaffolding protein responsible for the formation of caveolae, is ubiquitously expressed and prominently in endothelial cells. Moreover, Cav‐1 is known to associate with several ion channels including various Kv and TRP subtypes. It is well established that when Cav‐1 and endothelial nitric oxide synthase (eNOS) are bound, Cav‐1 exerts an inhibitory effect on eNOS activity and thus decreases NO production until a Ca2+ dependent signal untethers the proteins. Our lab and others have shown that TRPV1 regulates eNOS activity and NO production; specifically, via a calcium‐mediated AKT‐CaMKII‐AMPK signaling cascade. Therefore, we hypothesize that TRPV1, Cav‐1, and eNOS form a regulatory protein complex in endothelial cells responsible for the modulation of NO production. Examination of the TRPV1 amino acid sequence revealed 4 potential Cav‐1 binding motifs (where Ø represents any aromatic amino acid and X represents any amino acid): ØXXØXXXXØØ, ØXXØXXXØ, ØXXXØXXØ, and ØXXXØXØ. Computational modeling predicted an interaction between TRPV1 and Cav‐1. Confirmation of a direct TRPV1/Cav‐1 association was illustrated using Proximity Ligation Assay (PLA) in mouse coronary endothelial cells, which was increased following treatment with the TRPV1 agonist capsaicin. Furthermore, capsaicin treatment decreased the interaction between Cav‐1 and eNOS visualized with PLA, further defining the nature of this NO mediated cellular response. Similarly, NO production increased following capsaicin treatment. In conclusion, this is the first evidence of a direct interaction between TRPV1 and Cav‐1 and its implications in the regulation of NO production and vascular function.

Essential oil extracts from Ferula iliensis have been used traditionally in Kazakhstan for treatment of inflammation and other illnesses. Because little is known about the biologic activity of these essential oils that contributes to their therapeutic properties, we analyzed their chemical composition and evaluated their phagocyte immunomodulatory activity. The main components of the extracted essential oils were (E)-propenyl sec-butyl disulfide (15.7-39.4%) and (Z)-propenyl sec-butyl disulfide (23.4-45.0%). Ferula essential oils stimulated [Ca2+]i mobilization in human neutrophils and activated ROS production in human neutrophils and murine bone marrow phagocytes. Activation of human neutrophil [Ca2+]i flux by Ferula essential oils was dose-dependently inhibited by capsazepine, a TRPV1 channel antagonist, indicating that TRPV1 channels mediate this response. Furthermore, Ferula essential oils stimulated Ca2+ influx in TRPV1 channel-transfected HEK293 cells and desensitized the capsaicin-induced response in these cells. Additional molecular modeling with known TRPV1 channel agonists suggested that the active component is likely to be (Z)-propenyl sec-butyl disulfide. Our results provide a cellular and molecular basis to explain at least part of the beneficial therapeutic properties of FEOs.