Pharmacological Blockade of the 20-HETE Receptor Lowers Blood Pressure and Alters Vascular Function in Mice with Vascular Smooth Muscle- Specific Overexpression of CYP4a12-20-HETE Synthase

20-hydroxyeicosatetraenoic acid (20-HETE) is the ω-hydroxylation product of arachidonic acid catalyzed by CYP4A and 4F enzymes. 20-HETE is a vasoactive eicosanoid of the microcirculation exhibiting effects on both vascular smooth muscle cells (VSMC) and endothelial cells (EC). In VSMCs, 20-HETE’s bioactions include the stimulation of contraction, migration, and growth. In ECs, elevated 20-HETE is associated with reduced nitric oxide (NO) bioavailability, increased angiotensin converting enzyme (ACE) expression, and the promotion of inflammation. Recently in our laboratory, we identified GPR75 as a novel target of 20-HETE that promotes changes in blood pressure and vascular function. The aim of this study is to assess the consequences of VSMC-targeted overexpression of Cyp4a12, the primary 20-HETE producing enzyme in mice, on blood pressure, vascular function, and vascular remodeling. Moreover, we looked to examine whether the administration of a 20-HETE receptor antagonist reverses the vascular phenotype associated with elevations in 20-HETE. Mice with VSMC-specific overexpression of Cyp4a12 (Myh11-4a12) and their littermate controls (WT) were generated by crossbreeding Cyp4a12-flox mice (gifted by Dr. Schunck) with Myh11-Cre mice. Myh11-4a12 were administered AAA (10 mg.kg-1.day-1), a 20-HETE receptor antagonist, in the drinking water (vehicle). At the end of the experiments (12 days), renal interlobar arteries (RIA) and mesenteric arteries (MA) were harvested for the assessment of 20-HETE levels by LC-MS/MS, and vascular contractility, vasodilation, and remodeling using wire and pressure myography. The Myh11-4a12 mice showed higher Cyp4a levels in MA compared to WT mice (6.5±0.71 vs 3.4±0.70; Cyp4a/β-actin p increased 20-HETE levels in the MA (3334±891 vs. 545±197 pg/mg protein; p HETE levels were not different (117±9 vs. 93±2 pg/mL; p=0.18) when compared to WT. Myh11-4a12 mice displayed higher SBP compared to WT mice (145±2 vs. 127±2 mmHg; Myh11-4a12 mice (124±2 mmHg vs. 147±4 mmHg, treated Myh11-4a12 mice displayed a higher media to lumen (M:L) ratio (0.277±0.025 vs 0.163 ± 0.009; (15114±1871 vs 10560±641 μm2; Moreover, RIA from Myh11-4a12 mice on AAA exhibit a lower M:L ratio compared to Myh11-4a12 mice on vehicle (0.215 ± 0.013, not different (14268 ± 1259 μm2). Higher constrictor responsiveness to phenylephrine (EC50: 1.63x10-7 ± 3.75x10-8 vs 5.00x10-7 ± 0.7.85x10-8 M, response at 10-4 M: 65 ± 1 vs 83 ± 2 % relaxation, from Myh11-4a12 mice compared to WT. Treatment of Myh11-4a12 mice with AAA diminished the constrictor responsiveness to phenylephrine (EC50 of 4.22x10-7± 4.55x10-8 M, acetylcholine (92 ± 2 % relaxation, phosphorylation of myosin light chain compared to WT mice (1.60 ± 0.23 vs 1.00 ± 0.06, Ser19 p-MLC/total MLC fold change, exhibited a decrease in myosin light chain phosphorylation compared to Myh11-4a12 mice on vehicle (0.94 ± 0.11, Ser19 p-MLC/total MLC fold change, p\u3c0.05). Upstream of myosin light chain is Rho kinase (ROCK). Expression of ROCK1 was assessed in RIA and Myh11-4a12 mice had increased ROCK1 expression compared to WT mice (1.60 ± 0.21 vs 1.00 ± 0.18, ROCK1/β-tubulin fold change, ROCK1/β-tubulin fold change). Pressure myography was performed to assess 20-HETE receptor antagonism on ROCK activity. In RIA from WT mice, 20-HETE administration promoted a greater myogenic response and both AAA and ROCK inhibitor (Y-27632) inhibited the 20-HETE response in relation to the myogenic tone. The results of this study suggest that VSMC specific overproduction of Cyp4a12 and 20-HETE promotes increase in blood pressure and changes in vascular reactivity. 20-HETE receptor antagonism was capable of reversing the vascular pathology in mice with elevated 20-HETE presumably through inhibition of ROCK activity

Circumferential Pressure’s Inhibitory Effects on Soleus H-Reflex

Background: Circumferential pressure (CP) applied to the lower leg reduces soleus motor neuron reflex excitability (MNRE); however, the mechanism of control is unknown. Aim: To investigate the effect that CP has on disynaptic reciprocal inhibition (DSRI) and on Ia presynaptic inhibition (IaPI) of the soleus H-reflex in healthy subjects. Methods: DSRI of soleus motoneurons and presynaptic control of soleus group Ia afferents were measured before, during and after CP was applied to the calf. Pressure was set to 40–45 mmHg. DSRI was evaluated by observing changes in the H-reflex amplitude after a conditioning stimulus was applied to the common peroneal nerve. IaPI was assessed using two separate protocols involving conditioning of the soleus H-reflex: femoral nerve facilitation (FNS) (heteronymous) and D1 and D2 inhibition (homonymous). A change in DSRI and IaPI was determined by comparing the Hpressure, Hpost-pressure phases to the Hpre-pressure phase of the conditioned H-reflexes. Results: A mean 12% decrease in FNS was observed during CP (p \u3c 0.05). D1 and D2 inhibition decreased slightly. CP did not affect DSRI. Conclusion: The results show that CP applied to the calf significantly increased heteronymous soleus IaPI, but affected homonymous IaPI less. It was concluded the CP does increase IaPI of soleus motoneurons but only modestly. The change was not large enough to explain the dramatic inhibition that occurs in the (unconditioned) H-reflex amplitude when CP is applied. Therefore, IaPI is not the primary inhibitory mechanism that CP uses to lower MNRE

Effect of circumferential air-splint pressure on the soleus stretch reflex during a voluntary ramp plantar flexion

Circumferential pressure (CP) applied to the limb has been shown to decrease muscle activity in subjects without neuromuscular disorders and in individuals with a spinal cord injury and cerebrovascular accidents.Було показано, що круговий тиск (КТ), прикладений до кінцівки, зумовлює зменшення м’язової активності в осіб без нервово-м’язових розладів і у пацієнтів з пошкодженнями спинного мозку й цереброваскулярними патологіями

Metformin mitigates SASP secretion and LPS-triggered hyper-inflammation in Doxorubicin-induced senescent endothelial cells

Introduction: Doxorubicin (DOX), a chemotherapeutic drug, induces senescence and increases the secretion of senescence-associated secretory phenotype (SASP) in endothelial cells (ECs), which contributes to DOX-induced inflammaging. Metformin, an anti-diabetic drug, demonstrates senomorphic effects on different models of senescence. However, the effects of metformin on DOX-induced endothelial senescence have not been reported before. Senescent ECs exhibit a hyper-inflammatory response to lipopolysachharide (LPS). Therefore, in our current work, we identified the effects of metformin on DOX-induced endothelial senescence and LPS-induced hyper-inflammation in senescent ECs.Methods: ECs were treated with DOX ± metformin for 24 h followed by 72 h incubation without DOX to establish senescence. Effects of metformin on senescence markers expression, SA-β-gal activity, and SASP secretion were assessed. To delineate the molecular mechanisms, the effects of metformin on major signaling pathways were determined. The effect of LPS ± metformin was determined by stimulating both senescent and non-senescent ECs with LPS for an additional 24 h.Results: Metformin corrected DOX-induced upregulation of senescence markers and decreased the secretion of SASP factors and adhesion molecules. These effects were associated with a significant inhibition of the JNK and NF-κB pathway. A significant hyper-inflammatory response to LPS was observed in DOX-induced senescent ECs compared to non-senescent ECs. Metformin blunted LPS-induced upregulation of pro-inflammatory SASP factors.Conclusion: Our study demonstrates that metformin mitigates DOX-induced endothelial senescence phenotype and ameliorates the hyper-inflammatory response to LPS. These findings suggest that metformin may protect against DOX-induced vascular aging and endothelial dysfunction and ameliorate infection-induced hyper-inflammation in DOX-treated cancer survivors

EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe

AbstractIntroductionThe aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe.MethodsThis was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries.ResultsData on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge.ConclusionThe results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe.EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events

Improper body : psychomotor evaluation of subjective body after a traumatic brain injury

Introduction : Le traumatisme crânien résulte d’une atteinte cérébrale dans un contexte d’impact. Pourvoyeur de handicap, il entraîne des séquelles motrices, cognitives et psychiques qui bouleversent le rapport au corps. A travers une lecture phénoménologique inspirée des travaux de Merleau-Ponty, deux dimensions sont abordées : le corps vivant lié au schéma corporel, actif au niveau infra-conscient ; et le corps vécu accessible à la conscience, teinté de représentations. Ainsi, l’émersiologie développée par Bernard Andrieu, postule l’existence d’un processus d’émersion inconscient selon lequel certaines données de l’activité du corps vivant parviennent plus ou moins déformées à la conscience du corps vécu. L’impropriété qualifie cet écart entre la réalité objective du vivant et la perception consciente du vécu. Le traumatisme crânien altère les fonctions sensorimotrices du corps vivant et les processus cognitivo-psychiques nécessaires à l’émersion. Méthode : Les capacités motrices du corps vivant sont confrontées à leur représentation dans le vécu conscient. Ainsi, 66 personnes âgées de 20 à 60 ans sont recrutées en Ile de France : 32 sujets victimes de traumatismes crâniens modérés à sévères, en phase séquellaire, en situation de handicap modérée à sévère ; et 34 sujets sains. Le vécu est analysé via deux questionnaires sur l’image du corps et un entretien. La motricité volontaire est étudiée via quatre tests moteurs portant sur l’équilibre, les coordinations dynamiques, la motricité fine digitale et faciale. La dimension vécue est révélée via des auto-évaluations des sujets en amont et en aval d’une action. Un test de corrélation de Pearson entre les scores aux tests moteurs et les autoévaluations permet une mesure de l’impropréité ; tandis qu’un test des rangs signés de Wilcoxon appliqué aux auto-évaluations met en évidence l’émersion stimulée par l’action motrice. Résultats : La comparaison entre les résultats aux questionnaires n’est pas significative et démontre que l’image positive du corps est préservée après un traumatisme crânien. L’analyse des entretiens permet une lecture plus approfondie du phénomène et montre que même si les personnes peuvent se montrer insatisfaites par leurs capacités physiques, une certaine fierté ressort au regard des progrès faits depuis l’accident. Pour la phase motrice, l’application d’une Anova met en évidence un effet de l’action motrice sur les auto-évaluations. Les corrélations entre la représentation d’une capacité et le score au test moteur sont plus souvent significatives après l’action chez les sujets témoins ; tandis qu’elles sont significatives en amont et en aval de l’action dans la plupart des cas chez les personnes qui ont eu un traumatisme crânien. Discussion : L’émersion est stimulée par l’action motrice qui réactualise le vécu corporel conscient. La conscience corporelle préexistante avant l’action chez des personnes qui ont eu un traumatisme crânien révèle une bonne conscience des capacités motrices, probablement liée à l’expérience de la rééducation. L’analyse de l’image du corps par les questionnaires et les entretiens montre que même si des insatisfactions persistent, les capacités physiques sont assimilées aux progrès réalisés depuis la rééducation. Si bien que l’image positive du corps est préservée. En revanche nos résultats démontre qu’il est nécessaire de développer des outils d’évaluation adapté au traumatisme crânien qui tiendrait compte des différents paramètres en jeux dans la motricité.Traumatic brain injury (TBI) leads to psychic, cognitive and motor impairments. Studies have shown that the association of these disorders in patients with moderate to severe brain injury causes a lack of self-consciousness, including a default of motor skills perception. Using a phenomenological method leads to categorize two body’s dimensions: the physical body built on sensorimotricity and activated under conscious activity; the subjective body as a conscious representation modified by cognitive and psychic processes. The field of emersiology that we study, explores how the information from the physical to the subjective body is distorted. This study focuses on the emersion on motor skill information, to qualify a pathologic default of emersion on TBI patients. In our comparative study, 34 volunteers without disability and 32 patients with moderate to severe TBI where recruited (more than 2 years after their injury). We combine two methodological approaches. On one hand, a quantitative analysis involving aspect involves confrontation of objective score on motor test to an autoevaluation by the subject, before and after the action. On the other and, we qualitative exploration is based on body image scale and interviews about self-judgment. A mismatch between performance and its representation, still persistent after action, is considered as pathological. Our result suggests the positive body image is preserved after a traumatic brain injury. However the limits of this study show it is necessary to develop specific scale for TBI in the future. The psychomotor evaluation reveals the self-knowledge of is better in the TBI group which suggest patient learn about themselves since the rehabilitation started

Effect of air-splint pressure on the soleus stretch reflex during a voluntary ramp plantar flexion

Circumferential pressure (CP) applied to the limb has been shown to decrease muscle activity in subjects without neuromuscular disorders and in individuals with spinal cord injury and cerebrovascular accidents. Thus far, studies estimating the CP efficacy with respect to reflex excitability of motoneurons mainly used the H reflex technique on a resting muscle. The purpose of our study, therefore, was to investigate the effect that CP exerts on the soleus stretch reflex (SSR) when superimposed onto a voluntary ramp plantar flexion movement in subjects without neuromuscular disorders. Forty-eight subjects volunteered for this study. SSRs were investigated before, during, and after the application of pressure to the calf. An inflated air-splint connected to a pressure transducer was used to administer and measure the pressure set to 45-50 mm Hg. The SSRs were elicited by dorsiflexing the subject\u27s ankle by 10 deg at 180 deg/sec, while the subject plantarflexed against a moving footplate at 20% of the maximum voluntary contraction through a 30 deg arc at 90 deg/sec. Twenty-five SSRs were recorded and averaged for each experimental phase; peak-to-peak amplitudes were measured and normalized, and reflex latencies were also measured. Friedman Repeated Measures Analysis of Variance on Ranks was used to analyze the differences in the SSR latency and amplitude from the baseline values. No significant general difference in the SSR amplitude was found during pressure application, although individual responses varied widely. The post-pressure values returned to the baseline, and the differences were insignificant. The reflex latencies were also unchanged with respect to the baseline levels. Thus, the CP inhibitory effect on reflex excitability of motoneurons is mild, on average, and variable when a voluntary movement is a condition. The CP technique may not be as efficacious in reducing muscle hyperactivity as was previously thought. © 2010 Springer Science+Business Media, Inc

Le corps impropre : évaluation psychomotrice du corps vécu après un traumatisme crânien

Traumatic brain injury (TBI) leads to psychic, cognitive and motor impairments. Studies have shown that the association of these disorders in patients with moderate to severe brain injury causes a lack of self-consciousness, including a default of motor skills perception. Using a phenomenological method leads to categorize two body’s dimensions: the physical body built on sensorimotricity and activated under conscious activity; the subjective body as a conscious representation modified by cognitive and psychic processes. The field of emersiology that we study, explores how the information from the physical to the subjective body is distorted. This study focuses on the emersion on motor skill information, to qualify a pathologic default of emersion on TBI patients. In our comparative study, 34 volunteers without disability and 32 patients with moderate to severe TBI where recruited (more than 2 years after their injury). We combine two methodological approaches. On one hand, a quantitative analysis involving aspect involves confrontation of objective score on motor test to an autoevaluation by the subject, before and after the action. On the other and, we qualitative exploration is based on body image scale and interviews about self-judgment. A mismatch between performance and its representation, still persistent after action, is considered as pathological. Our result suggests the positive body image is preserved after a traumatic brain injury. However the limits of this study show it is necessary to develop specific scale for TBI in the future. The psychomotor evaluation reveals the self-knowledge of is better in the TBI group which suggest patient learn about themselves since the rehabilitation started.Introduction : Le traumatisme crânien résulte d’une atteinte cérébrale dans un contexte d’impact. Pourvoyeur de handicap, il entraîne des séquelles motrices, cognitives et psychiques qui bouleversent le rapport au corps. A travers une lecture phénoménologique inspirée des travaux de Merleau-Ponty, deux dimensions sont abordées : le corps vivant lié au schéma corporel, actif au niveau infra-conscient ; et le corps vécu accessible à la conscience, teinté de représentations. Ainsi, l’émersiologie développée par Bernard Andrieu, postule l’existence d’un processus d’émersion inconscient selon lequel certaines données de l’activité du corps vivant parviennent plus ou moins déformées à la conscience du corps vécu. L’impropriété qualifie cet écart entre la réalité objective du vivant et la perception consciente du vécu. Le traumatisme crânien altère les fonctions sensorimotrices du corps vivant et les processus cognitivo-psychiques nécessaires à l’émersion. Méthode : Les capacités motrices du corps vivant sont confrontées à leur représentation dans le vécu conscient. Ainsi, 66 personnes âgées de 20 à 60 ans sont recrutées en Ile de France : 32 sujets victimes de traumatismes crâniens modérés à sévères, en phase séquellaire, en situation de handicap modérée à sévère ; et 34 sujets sains. Le vécu est analysé via deux questionnaires sur l’image du corps et un entretien. La motricité volontaire est étudiée via quatre tests moteurs portant sur l’équilibre, les coordinations dynamiques, la motricité fine digitale et faciale. La dimension vécue est révélée via des auto-évaluations des sujets en amont et en aval d’une action. Un test de corrélation de Pearson entre les scores aux tests moteurs et les autoévaluations permet une mesure de l’impropréité ; tandis qu’un test des rangs signés de Wilcoxon appliqué aux auto-évaluations met en évidence l’émersion stimulée par l’action motrice. Résultats : La comparaison entre les résultats aux questionnaires n’est pas significative et démontre que l’image positive du corps est préservée après un traumatisme crânien. L’analyse des entretiens permet une lecture plus approfondie du phénomène et montre que même si les personnes peuvent se montrer insatisfaites par leurs capacités physiques, une certaine fierté ressort au regard des progrès faits depuis l’accident. Pour la phase motrice, l’application d’une Anova met en évidence un effet de l’action motrice sur les auto-évaluations. Les corrélations entre la représentation d’une capacité et le score au test moteur sont plus souvent significatives après l’action chez les sujets témoins ; tandis qu’elles sont significatives en amont et en aval de l’action dans la plupart des cas chez les personnes qui ont eu un traumatisme crânien. Discussion : L’émersion est stimulée par l’action motrice qui réactualise le vécu corporel conscient. La conscience corporelle préexistante avant l’action chez des personnes qui ont eu un traumatisme crânien révèle une bonne conscience des capacités motrices, probablement liée à l’expérience de la rééducation. L’analyse de l’image du corps par les questionnaires et les entretiens montre que même si des insatisfactions persistent, les capacités physiques sont assimilées aux progrès réalisés depuis la rééducation. Si bien que l’image positive du corps est préservée. En revanche nos résultats démontre qu’il est nécessaire de développer des outils d’évaluation adapté au traumatisme crânien qui tiendrait compte des différents paramètres en jeux dans la motricité