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1.
Cell Metab ; 33(10): 2059-2075.e10, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34536344

RESUMO

Myocardial ischemia-reperfusion (MIR) injury is a major cause of adverse outcomes of revascularization after myocardial infarction. To identify the fundamental regulator of reperfusion injury, we performed metabolomics profiling in plasma of individuals before and after revascularization and identified a marked accumulation of arachidonate 12-lipoxygenase (ALOX12)-dependent 12-HETE following revascularization. The potent induction of 12-HETE proceeded by reperfusion was conserved in post-MIR in mice, pigs, and monkeys. While genetic inhibition of Alox12 protected mouse hearts from reperfusion injury and remodeling, Alox12 overexpression exacerbated MIR injury. Remarkably, pharmacological inhibition of ALOX12 significantly reduced cardiac injury in mice, pigs, and monkeys. Unexpectedly, ALOX12 promotes cardiomyocyte injury beyond its enzymatic activity and production of 12-HETE but also by its suppression of AMPK activity via a direct interaction with its upstream kinase TAK1. Taken together, our study demonstrates that ALOX12 is a novel AMPK upstream regulator in the post-MIR heart and that it represents a conserved therapeutic target for the treatment of myocardial reperfusion injury.

2.
Heart Rhythm ; 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34562644

RESUMO

BACKGROUND: Obstructive sleep apnea (OSA) is associated with cardiovascular diseases and increased sympathetic tone. We previously demonstrated that OSA patients have increased skin sympathetic nerve activity (SKNA). OBJECTIVES: To test the hypothesis that continuous positive airway pressure (CPAP) treatment reduces SKNA. METHODS: The ECG, SKNA, and polysomnography were recorded simultaneously in 9 OSA patients. After baseline recording, CPAP titration was performed and the pressure was adjusted gradually for the optimal treatment, defined by reducing the apnea-hypopnea index (AHI) to ≤ 5/h. Otherwise the treatment was considered suboptimal (AHI > 5/h). Fast Fourier transform (FFT) analyses were conducted to investigate the frequency spectrum of SKNA. RESULTS: There were very low frequency (VLF), low frequency (LF) and high frequency (HF) oscillations in the SKNA. The HF oscillation matched the frequency of respiration. OSA episodes were more frequently associated with the VLF and LF than HF oscillations of the SKNA. Compared with baseline, CPAP significantly decreased the arousal index, AHI, and increased the minimal and average O2 saturation. Optimal treatment significantly increased the dominant frequency (DF), and reduced the heart rate, average SKNA (aSKNA), SKNA burst duration and total burst area. The DF negatively correlated with aSKNA. CONCLUSIONS: VLF, LF and HF oscillations are observed in human SKNA recordings. Among them, VLF and LF are associated with OSA while HF is associated with normal breathing. CPAP therapy reduces the aSKNA and shifts the frequency of SKNA oscillation from VLF or LF to HF.

3.
Cardiovasc Res ; 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145895

RESUMO

AIMS: The clinical use of antitumor agent doxorubicin (DOX) is hampered by its dose-dependent cardiotoxicity. Development of highly efficient and safe adjuvant intervention for preventing DOX-induced adverse cardiac events is urgently needed. We aimed to investigate whether transcutaneous vagal nerve stimulation (tVNS) plays a cardio-protective role in DOX-induced cardiotoxicity. METHODS AND RESULTS: Healthy male adult Sprague Dawley rats were used in the experiment and were randomly divided into four groups including control, DOX, tVNS and DOX+tVNS groups. A cumulative dose of 15 mg/kg DOX was intraperitoneally injected into rats to generate cardiotoxicity. Non-invasive tVNS was conducted for 6 weeks (30 min/day). After six-week intervention, the indices from the echocardiography revealed that tVNS significantly improved left ventricular function compared to the DOX group. The increased malondialdehyde (MDA) and Interleukin-1ß (IL-1ß), and decreased superoxide dismutase (SOD) were observed in the DOX group, while tVNS significantly prevented these changes. From cardiac histopathological analysis, the DOX+tVNS group showed a mild myocardial damage, and decreases in cardiac fibrosis and myocardial apoptosis compared to the DOX group. Heart rate variability (HRV) analysis showed that tVNS significantly inhibited DOX-induced sympathetic hyperactivity compared to the DOX group. Additionally, the results of RNA-sequencing analysis showed that there were 245 differentially expressed genes in the DOX group compared to the control group, among which 39 genes were downregulated by tVNS and most of these genes were involved in immune system. Moreover, tVNS significantly downregulated the relative mRNA expressions of chemokine-related genes and macrophages recruitment compared to the DOX group. CONCLUSION: These results suggest that tVNS prevented DOX-induced cardiotoxicity by rebalancing autonomic tone, ameliorating cardiac dysfunction and remodeling. Notably, crosstalk between autonomic neuromodulation and innate immune cells macrophages mediated by chemokines might be involved in the underlying mechanisms. A TRANSLATIONAL PERSPECTIVE: Non-invasive tVNS has been identified an effective neuromodulation strategy exerting beneficial effects on rebalancing autonomic tone and cardiac pathological conditions. The present study provided direct evidence for a beneficial role of tVNS in preventing DOX-induced autonomic dysfunction and cardiotoxicity in vivo. Additionally, recent studies revealed the importance of sympathetic nerve fibers involving in tumorigenesis and the benefits of higher vagal tone for tumor prognosis either in animal or human trials. Together, tVNS may not only become a novel, nonpharmacological adjuvant therapy for preventing doxorubicin-induced cardiotoxicity, but also may be beneficial for prognosis of cancer patients during chemotherapy. In our future study, we would investigate the effect of tVNS on both combined chemotherapy-induced cardiotoxicity and the antitumor efficacy of DOX in tumor models.

4.
Heart Rhythm ; 18(3): 465-472, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33246037

RESUMO

BACKGROUND: Sympathetic nerve activity, heart rate (HR), and blood pressure (BP) all have very low frequency (VLF), low frequency (LF), and high frequency (HF) oscillations. OBJECTIVE: The purpose of this study was to test the hypothesis that the frequency spectra of subcutaneous nerve activity (ScNA), stellate ganglion nerve activity (SGNA), HR, and BP are important to cardiac arrhythmogenesis. METHODS: We used radiotransmitters to record SGNA, ScNA, HR, and BP in 6 ambulatory dogs and determined the dominant frequency and paroxysmal atrial tachyarrhythmias (PATs) episodes in 3-minute windows over a 24-hour period. RESULTS: The frequency spectra determined in ScNA reflected that in SGNA. HF oscillations were present in both ScNA and SGNA at all time but could be overshadowed by the much larger LF and VLF burst activities. The dominant frequency could occur in any of the 3 frequency bands. There were circadian variations with more frequent occurrences of HF oscillations at night. HF oscillations in HR and BP matched HF oscillations in SGNA and ScNA. PATs occurred only when dominant frequencies of SGNA and ScNA were in the LF and VLF bands. CONCLUSION: HF oscillations in BP and HR correlate with HF oscillations in sympathetic nerve activity and are present at all time. HF oscillations can be overshadowed by the much larger LF and VLF burst activities. PATs occur only when LF or VLF, but not when HF, is the dominant frequency. The frequency spectra determined in ScNA reflect that in SGNA.

5.
Heart Rhythm ; 17(11): 1936-1943, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32569836

RESUMO

BACKGROUND: Obstructive sleep apnea (OSA) is associated with increased cardiac arrhythmia and sudden cardiac death. We recently developed a new method (neuECG) to noninvasively measure electrocardiogram and skin sympathetic nerve activity (SKNA). OBJECTIVE: The purpose of this study was to test the hypothesis that SKNA measured during sleep study is higher in patients with OSA than in those without OSA. METHODS: We prospectively recorded neuECG and polysomnography in 26 patients undergoing a sleep study. Sleep stages were scored into rapid eye movement (REM), and non-REM sleep stages 1 (N1), 2 (N2), and 3 (N3). Average voltage of skin sympathetic nerve activity (aSKNA) and SKNA burst area were calculated for quantification. Apnea/hypopnea index (AHI) >5 per hour was used to diagnose OSA. RESULTS: There was a positive correlation (r = 0.549; P = .018) between SKNA burst area and the arousal index in OSA but not in the control group. aSKNA during sleep was 0.61 ± 0.09 µV in OSA patients (n = 18) and 0.53 ± 0.04 µV in control patients (n = 8; P = .025). Burst area was 3.26 (1.90-4.47) µV·s/min in OSA patients and 1.31 (0.67-1.94) µV·s/min in control (P = .047). More apparent differences were found during N2, when the burst area in OSA (3.06 [1.46-5.52] µV·s/min) was much higher than that of the control (0.89 [0.79-1.65] µV·s/min; P = .03). CONCLUSION: OSA patients have higher SKNA activity than control patients, with the most pronounced differences observed during N2. Arousal at the end of apnea episodes is associated with large SKNA bursts. Overlaps of aSKNA and SKNA burst area between groups suggest that not all OSA patients have increased sympathetic tone.

6.
Cardiol Res Pract ; 2020: 1358098, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32351730

RESUMO

Purpose: Recent studies have indicated that N-acetylneuraminic acid (Neu5Ac) plays a key role in severe coronary artery diseases, involving RhoA signaling pathway activation, which is critically involved in cardiac fibrosis. There is convincing evidence from many studies that left atrium fibrosis is involved in the pathophysiology of AF. Therefore, we speculated that Neu5Ac may be associated with atrial fibrillation (AF) and involved in the development of AF. This study aims to investigate the clinical relationship between Neu5Ac and AF and left atrial enlargement. Methods: Forty-five patients with AF (AF group) and forty-five patients with non-AF (control group) matched for age, sex, and hospitalization date were recruited for our study. Plasma concentrations of Neu5Ac from peripheral venous blood were analyzed using enzyme-linked immunosorbent assay (ELISA). The baseline characteristics, plasma level of Neu5Ac, and echocardiographic characteristics were evaluated. Results: The plasma level of Neu5Ac was significantly higher in the AF group than in the control group (107.66 ± 47.50 vs 77.87 ± 39.09 ng/ml; P < 0.05); the left atrial diameters were positively correlated with the plasma Neu5Ac level (R = 0.255; P < 0.05). The plasma Neu5Ac level (R = 0.368; P < 0.05) and the left atrial diameters (R = 0.402; P < 0.05) were positively correlated with AF history times. Neu5Ac (odds ratio 1.018, 95% CI 1.003-1.032; P < 0.05) and the left atrial diameter (odds ratio 1.142, 95% CI 1.020-1.280; P < 0.05) were independent risk factors for AF in multivariate regression analysis. Conclusions: Serum Neu5Ac is associated with atrial fibrillation, and the mechanism may involve left atrial enlargement.

7.
Oxid Med Cell Longev ; 2020: 7106525, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32148655

RESUMO

Objective: In renal ischemia/reperfusion injury (RIRI), nuclear factor κB (NF-κB (NF-κB (NF. Methods: Eighteen male Sprague-Dawley rats were randomly allocated into the sham group, the I/R group, and the VNS+I/R group, 6 rats per group. An RIRI model was induced by a right nephrectomy and blockade of the left renal pedicle vessels for 45 min. After 6 h of reperfusion, the blood samples and renal samples were collected. The VNS treatment was performed throughout the I/R process in the VNS+I/R group using specific parameters (20 Hz, 0.1 ms in duration, square waves) known to produce a small but reliable bradycardia. Blood was used for evaluation of renal function and inflammatory state. Renal injury was evaluated via TUNEL staining. Renal samples were harvested to evaluate renal oxidative stress, NF-κB (NF. Results: The VNS treatment reduces serum creatinine (Cr) and blood urea nitrogen (BUN) levels. Simultaneously, the levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1-beta (IL-1ß) were significantly increased in the I/R group, but VNS treatment markedly ameliorated this inflammatory response. Furthermore, the VNS ameliorated oxidant stress and renal injury, indicated by a decrease in 3-nitrotyrosine (3-NT) formation and MDA and MPO levels and an increase in the SOD level compared to that in the I/R group. Finally, the VNS also significantly decreases NF-κB (NF. Conclusion: Our findings indicate that NF-κB activation increased iNOS expression and promoted RIRI and that VNS treatment attenuated RIRI by inhibiting iNOS expression, oxidative stress, and inflammation via NF-κB inactivation.κB (NF-κB (NF.


Assuntos
NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Traumatismo por Reperfusão/metabolismo , Estimulação do Nervo Vago/métodos , Animais , Masculino , Ratos , Ratos Sprague-Dawley
8.
Int J Cardiol ; 302: 59-66, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31889562

RESUMO

BACKGROUND: Previous studies indicated that inhibiting the cardiac autonomic nervous system (CANS) suppressed atrial fibrillation (AF). Clinical research revealed serum adiponectin (APN) exerted a beneficial influence on sympathetic and vagal tone in patients with type 2 diabetes. However, the effects of APN on CANS is unknown. This study aims to investigate whether APN could regulate CANS and suppress rapid atrial pacing (RAP)-induced AF. METHODS: Eighteen beagles were divided into the control group (saline plus sham RAP, N = 6), the RAP group (saline plus RAP, N = 6) and the APN + RAP group (APN plus RAP, N = 6). APN (10 µg, 0.1 µg/µL) or saline was microinjected into 4 major ganglionated plexi (GP) prior to RAP. Atrial electrophysiological parameters, anterior right GP (ARGP) function, neural activity and GP tissues were detected. RESULTS: Compared with the control treatment, RAP shortened effective refractory period (ERP) values at all sites and increased cumulative window of vulnerability (ΣWOV), ARGP function and neural activity, whereas APN injection reversed these changes. Mechanistically, APN ameliorated RAP-induced inflammatory response and down-regulated the expression of c-fos protein and nerve growth factor. Moreover, the APN receptors 1 and APN receptors 2 were detected both in neurons and in non-neuronal cells. APN pretreatment activated downstream adenosine monophosphate-activated protein kinase (AMPK) signaling, inhibited nuclear factor-kappa B signaling and promoted macrophage phenotype switching from proinflammatory to anti-inflammatory state. CONCLUSIONS: This study demonstrates that administration of APN into GP can suppress RAP-induced AF by regulating the CANS. APN signaling may provide a potential therapeutic target to AF.


Assuntos
Adiponectina/metabolismo , Fibrilação Atrial/fisiopatologia , Remodelamento Atrial , Sistema Nervoso Autônomo/metabolismo , Estimulação Cardíaca Artificial/métodos , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Animais , Fibrilação Atrial/metabolismo , Fibrilação Atrial/terapia , Sistema Nervoso Autônomo/fisiopatologia , Biomarcadores/metabolismo , Modelos Animais de Doenças , Cães , Masculino
9.
Biomed Pharmacother ; 117: 109062, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31177065

RESUMO

OBJECTIVE: Renal ischemia reperfusion (I/R) is not an isolated event; however, it results in remote organ dysfunction. Vagus nerve stimulation (VNS) has shown protective effects against renal I/R injury via an anti-inflammatory mechanism. This study aimed to investigate whether VNS could attenuate liver injury induced by renal I/R and identify the underlying mechanisms. METHODS: Eighteen healthy male Sprague-Dawley rats (200-250 g) were equally divided into three groups: sham group (sham surgery without I/R or VNS), I/R group (renal I/R) and VNS group (renal I/R plus VNS). The I/R model was established by excising the right kidney and then clamping the left renal pedicle with an occlusive nontraumatic microaneurysm clamp for 45 min followed by a 6-h reperfusion. The rats in the VNS group received spontaneous left cervical VNS with renal ischemia and reperfusion. At the end of the experiment, blood and liver tissues were collected to detect liver function, oxidative stress and inflammatory parameters. Additionally, TUNEL staining, real-time PCR, western blotting and hematoxylin and eosin staining of liver tissues were performed to assess liver injury and the underlying mechanisms. RESULTS: Kidney and liver function was severely damaged in the I/R group compared to the sham group. However, VNS significantly protected kidney and liver function. Rats treated with VNS revealed decreases in oxidative enzymes, apoptosis and levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) in serum and liver compared with rats in the I/R group. Rats in the VNS group also showed increased antioxidant stress responses compared to rats in the I/R group. CONCLUSION: VNS exerts protective effects against liver injury from renal I/R via inhibiting oxidative stress and apoptosis, downregulating inflammatory cytokines and enhancing antioxidative capability in the liver, and may become a promising adjuvant therapeutic strategy for treating liver injury induced by acute renal injury.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Rim/irrigação sanguínea , Fígado/lesões , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/tratamento farmacológico , Estimulação do Nervo Vago , Doença Aguda , Animais , Apoptose , Citocinas/sangue , Hepatócitos/metabolismo , Hepatócitos/patologia , Mediadores da Inflamação/sangue , Rim/patologia , Rim/fisiopatologia , Fígado/enzimologia , Fígado/patologia , Fígado/fisiopatologia , Masculino , Oxirredução , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Traumatismo por Reperfusão/sangue , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
10.
Oxid Med Cell Longev ; 2019: 6508328, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31214281

RESUMO

Endothelin-1 (ET-1) is synthesized primarily by endothelial cells. ET-1 administration in vivo enhances the cardiac sympathetic afferent reflex and sympathetic activity. Previous studies have shown that sympathetic hyperactivity promotes malignant ventricular arrhythmia (VA). The aim of this study was to investigate whether ET-1 could activate the left stellate ganglion (LSG) and promote malignant VA. Twelve male beagle dogs who received local microinjections of saline (control, n = 6) and ET-1 into the LSG (n = 6) were included. The ventricular effective refractory period (ERP), LSG function, and LSG activity were measured at different time points. VA was continuously recorded for 1 h after left anterior descending occlusion (LADO), and LSG tissues were then collected for molecular detection. Compared to that of the control group, local ET-1 microinjection significantly decreased the ERP and increased the occurrence of VA. In addition, local microinjection of ET-1 increased the function and activity of the LSG in the normal and ischemic hearts. The expression levels of proinflammatory cytokines and the protein expression of c-fos and nerve growth factor (NGF) in the LSG were also increased. More importantly, endothelin A receptor (ETA-R) expression was found in the LSG, and its signaling was significantly activated in the ET-1 group. LSG activation induced by local ET-1 microinjection aggravates LADO-induced VA. Activated ETA-R signaling and the upregulation of proinflammatory cytokines in the LSG may be responsible for these effects.


Assuntos
Arritmias Cardíacas/fisiopatologia , Células Endoteliais/metabolismo , Endotelina-1/metabolismo , Isquemia Miocárdica/fisiopatologia , Gânglio Estrelado/metabolismo , Animais , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Cães , Eletrocardiografia , Células Endoteliais/patologia , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Fatores de Crescimento Neural/metabolismo , Receptor de Endotelina A/metabolismo , Transdução de Sinais , Sistema Nervoso Simpático
11.
Molecules ; 24(10)2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31117232

RESUMO

The theory of persisting independent and isolated regarding microorganisms is no longer accepted. To survive and reproduce they have developed several communication platforms within the cells which facilitates them to adapt the surrounding environmental changes. This cell-to-cell communication is termed as quorum sensing; it relies upon the cell density and can stimulate several traits of microbes including biofilm formation, competence, and virulence factors secretion. Initially, this sophisticated mode of communication was discovered in bacteria; later, it was also confirmed in eukaryotes (fungi). As a consequence, many quorum-sensing molecules and inhibitors have been identified and characterized in various fungal species. In this review article, we will primarily focus on fungal quorum-sensing molecules and the production of inhibitors from fungal species with potential applications for combating fungal infections.


Assuntos
Fungos/efeitos dos fármacos , Micoses/tratamento farmacológico , Percepção de Quorum/genética , Antifúngicos/uso terapêutico , Fungos/patogenicidade , Humanos , Micoses/genética , Micoses/microbiologia , Percepção de Quorum/efeitos dos fármacos
12.
Biochem Biophys Res Commun ; 513(1): 99-104, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-30935685

RESUMO

After myocardial infarction (MI), increased platelet number and size are inversely related to the outcomes of patients. Our previous study confirmed an excessive thrombopoiesis taking place in the bone marrow after MI. However, the mechanisms remain unknown. It has been reported that the sympathetic stimulation by noise or exercise can promote megakaryocyte (MK) producing platelets which is mediated by α2-adrenoceptor. Here, using whole-mount staining combined with western blotting and ELISA assay, we vividly showed an activation of the bone marrow sympathetic nervous system (SNS) after MI. Interestingly, we observed a direct spatial attachment between MKs and the sympathetic nerves. The administration of α-adrenoceptor antagonist, phentolamine or prazosin, could effectively attenuate post-MI MK cellularity and maturity, and alter the distribution of MK away from the bone marrow vessels. Surprisingly, the antagonists did not suppress the final stage of platelet formation. MI mice treated with phentolamine or prazosin showed elevating circulating platelets comparable as those treated with PBS as the control. Together, this study demonstrated that the activation of bone marrow SNS after MI regulates megakaryocyte expansion but not platelet production. Therefore, targeting sympathetic activation might become a novel approach for controlling post-MI bone marrow MK development, but other approaches are still needed to effectively reduce the platelet numbers.


Assuntos
Medula Óssea/inervação , Megacariócitos/patologia , Infarto do Miocárdio/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Animais , Plaquetas/patologia , Medula Óssea/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Contagem de Plaquetas
13.
Oxid Med Cell Longev ; 2019: 9208949, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30944700

RESUMO

Vagus nerve stimulation (VNS) has been shown to attenuate ischemia-reperfusion (I/R) injury in multiple organs. The present study aimed at investigating whether VNS could exert protective effects against I/R injury in the skeletal muscle. Male Sprague-Dawley rats were randomly divided into 3 groups: the control, I/R, and I/R+VNS groups. The skeletal muscle I/R (SMI/R) model was induced by occlusion of the left femoral artery for 2.5 hours followed by reperfusion for 2 hours. The vagal nerve trunk was separated, and VNS was performed during the whole I/R process. The intensity of VNS was optimized in each rat to obtain a 10% reduction in the heart rate relative to the value before stimulation. After the experiment, the blood sample and left gastrocnemius muscle tissues were collected for histological examination, biochemical analysis, and molecular biological detection. During the I/R process, VNS significantly reduced cellular apoptosis, necrosis, and inflammatory cell infiltration compared to sham VNS. The VNS treatment also decreased the inflammatory response, alleviated oxidative stress, and improved vascular endothelial function (p < 0.05 for each). In contrast, the I/R group showed an opposite effect compared to the control group. The present study indicated that VNS could protect against SMI/R injury by suppressing excessive inflammation, alleviating oxidative stress, and preserving vascular endothelial function.


Assuntos
Músculo Esquelético/lesões , Traumatismo por Reperfusão/complicações , Estimulação do Nervo Vago/métodos , Doença Aguda , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley
14.
EBioMedicine ; 44: 656-664, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30954457

RESUMO

BACKGROUND: We previously demonstrated the gut microbes-derived metabolite trimethylamine N-oxide (TMAO) could activate the atrial autonomic ganglion plexus and promote atrial arrhythmia. The cardiac sympathetic nervous system (CSNS) play important roles in modulating ventricular arrhythmia (VA). METHODS: Part 1: To test whether TMAO can directly activate the CSNS, we performed local injection of TMAO into the left stellate ganglion (LSG). Part 2: To test whether TMAO can indirectly activate the CSNS through the central nervous system, we performed intravenous injection of TMAO. Ventricular electrophysiology and LSG function and neural activity were measured before and after TMAO administration. Then, the left anterior descending coronary artery was ligated, and electrocardiograms were recorded for 1 h. At the end of the experiment, LSG and paraventricular nucleus (PVN) tissues were excised for molecular analyses. FINDINGS: Compared with the control, both intravenous and local TMAO administration significantly increased LSG function and activity, shortened effective refractory period, and aggravated ischemia-induced VA. Proinflammatory markers and c-fos in the LSG were also significantly upregulated in both TMAO-treated groups. Particularly, c-fos expression in PVN was significantly increased in the systemic TMAO administration group but not the local TMAO administration group. INTERPRETATION: The gut microbe-derived metabolite TMAO can activate the CSNS and aggravate ischemia-induced VA via the direct pathway through the LSG and the indirect pathway through central autonomic activation. FUND: This work was supported by the National Key R&D Program of China [2017YFC1307800], and the National Natural Science Foundation of China [81530011, 81770364, 81570463, 81871486, 81600395, 81600367 and 81700444].


Assuntos
Arritmias Cardíacas/etiologia , Arritmias Cardíacas/metabolismo , Sistema Nervoso Autônomo/metabolismo , Sistema Nervoso Autônomo/fisiopatologia , Microbioma Gastrointestinal , Metilaminas/metabolismo , Isquemia Miocárdica/complicações , Transdução de Sinais , Arritmias Cardíacas/fisiopatologia , Citocinas/metabolismo , Eletrocardiografia , Fenômenos Eletrofisiológicos , Humanos , Mediadores da Inflamação/metabolismo , Gânglio Estrelado/metabolismo
15.
Int J Cardiol ; 279: 64-71, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30642646

RESUMO

BACKGROUND: It is reported interleukin (IL)-17A, a classical proinflammatory cytokine, is implicated in neuroimmune-associated remodeling in neural plasticity and pathological conditions. However, the effect of IL-17A on left stellate ganglion (LSG) remodeling remains unclear. OBJECTIVE: This study was performed to determine whether exogenous IL-17A promotes LSG remodeling and destabilize ventricular electrophysiological properties (EPs) in normal canines. METHODS: 24 beagles were randomly allocated into three groups. In the first group, animals were subjected to 0.1 ml phosphate buffer saline (PBS) microinjection of into LSG (n = 8), an equivalent IL-17A was administrated in the second group (n = 8), and an equivalent anti-IL-17A mAb plus IL-17A was administrated in the third group (n = 8). The ventricular EPs, neural function and activity of the LSG were determined at baseline and 30 min after administration. In the end, LSG tissues were collected. RESULTS: Compared with the control group, the experimental group had a significantly shorter effective refractory period (ERP) and action potential duration (APD)90, an increased ERP, APD90, Smax dispersion, and APD alternans cycle length; and steepened APD restitution curves. In addition, IL-17A enhanced the neural function and activity of the LSG, upregulated the expressions of neuropeptides and proinflammatory cytokines and cells. And all these effects were attenuated by anti-IL-17A mAb. Importantly, IL-17 receptor A (IL-17R-A) was detected in sympathetic neurons in the LSG. CONCLUSION: IL-17A promoted LSG remodeling by regulating the neural inflammation response. It did so by binding to IL-17R-A, resulting in unstable ventricular electrophysiology in normal structural hearts.


Assuntos
Interleucina-17/administração & dosagem , Neuroimunomodulação/efeitos dos fármacos , Gânglio Estrelado/efeitos dos fármacos , Remodelação Vascular/efeitos dos fármacos , Animais , Cães , Interleucina-17/metabolismo , Microinjeções/métodos , Neuroimunomodulação/fisiologia , Gânglio Estrelado/imunologia , Gânglio Estrelado/metabolismo , Taquicardia Ventricular/tratamento farmacológico , Taquicardia Ventricular/imunologia , Taquicardia Ventricular/metabolismo , Remodelação Vascular/fisiologia
17.
Front Physiol ; 9: 1082, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30246788

RESUMO

Background: The NRG1/ErbB4 signaling mechanism has been widely studied in the central nervous system for many years. However, the role of this pathway in modulating the intrinsic cardiac nervous system is largely unknown. Objective: The present study investigated whether the NRG1/ErbB4 signaling system affects the activity of major atrial ganglionated plexi (GP) in a paroxysmal atrial fibrillation (AF) model by 6-h rapid atrial pacing (RAP). Methods: Twenty-four dogs were randomly divided into (1) a control group (saline microinjections into GP), (2) RAP group (saline microinjections into GP plus 6 h-RAP), (3) NRG1 group (microinjections of neuregulin-1 into GP plus 6 h-RAP) and (4) NRG1 + ERA group (microinjections of neuregulin-1 and ErbB4 receptor antagonist-ERA into GP plus 6 h-RAP). The effective refractory period (ERP), window of vulnerability (WOV), anterior right GP (ARGP) function and neural activity were measured. ARGP tissues were excised for histological study and western blotting. Results: When compared to the control group, 6 h-RAP produced a significant (1) decrease in ERP, an increase in ΣWOV, (2) an increase in ARGP neural activity and neural function, and (3) an increase in c-fos and nerve growth factor protein expression in the ARGP. However, microinjection of NRG1 into the ARGP prior to RAP prevented ERP shortening and AGRP activity enhancement and inhibited the expression of c-Fos and NGF proteins. Furthermore, these changes were significantly attenuated by pretreatment with an ErbB4 receptor antagonist. Conclusion: The NRG1/ErbB4 signaling pathway may exist in the GP, and activation of this pathway suppressed RAP-induced GP activation, atrial electrical remodeling and AF.

18.
Int J Cardiol ; 269: 259-264, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30072157

RESUMO

BACKGROUND: Leptin is an adipocytokine predominantly secreted by adipose tissue that participates in immune modulation. Mast cells are important immune cells that are related to altered sympathetic activity. Previous study has shown that leptin promotes activation of the left stellate ganglion (LSG) directly via the leptin receptor. This study aims to investigate whether mast cells play a key role in indirect activation. METHODS: Twenty-eight canines were randomly divided into 3 groups: the control group (saline, n = 8), leptin group (leptin, n = 9), and DSCG group (disodium cromoglycate plus leptin, n = 11). Drugs were locally microinjected into the LSG. The function and neural activity of the LSG were evaluated to investigate LSG activation. Tryptase was adopted to identify activated mast cells in the LSG. RESULTS: Compared with the control group, leptin injection (18 µg) markedly increased the function and neural activity of the LSG. Leptin also upregulated c-fos, nerve growth factor (NGF), and tryptase expression in the LSG. However, these effects of leptin were attenuated by pre-injection of DSCG (25 mg). Additionally, the immunofluorescence analysis revealed that many mast cells were present in the LSG and that those cells were located close to sympathetic neurons. The presence of leptin receptors on the mast cells was verified. CONCLUSIONS: Immune mast cells play an important supplementary role in the pathogenesis of leptin-induced LSG activation.


Assuntos
Leptina/administração & dosagem , Mastócitos/imunologia , Mastócitos/metabolismo , Gânglio Estrelado/imunologia , Gânglio Estrelado/metabolismo , Animais , Cães , Masculino , Mastócitos/efeitos dos fármacos , Microinjeções , Distribuição Aleatória , Gânglio Estrelado/efeitos dos fármacos
19.
J Hypertens ; 36(6): 1342-1350, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29621066

RESUMO

OBJECTIVE: Blood pressure elevation in response to transient renal nerve stimulation (RNS) has been used to determine the ablation target and endpoint of renal denervation. This study aimed to evaluate the safety of transient RNS in canines with normal or ischaemic hearts. METHODS: In ten normal (Group 1) and six healed myocardial infarction (HMI) (Group 2) canines, a large-tip catheter was inserted into the left or right renal artery to perform transient RNS. The left stellate ganglion neural activity (LSGNA) and ventricular electrophysiological parameters were measured at baseline and during transient RNS. In another 20 acute myocardial infarction (AMI) canines, RNS (Group 3, n = 10) or sham RNS (Group 4, n = 10) was intermittently (1 min ON and 4 min OFF) performed for 1 h following AMI induction. The LSGNA and AMI-induced ventricular arrhythmias were analysed. RESULTS: In normal and HMI canines, although transient RNS significantly increased the LSGNA and facilitated the action potential duration (APD) alternans, it did not induce any ventricular arrhythmias and did not change the ventricular effective refractory period, APD or maximum slope of the APD restitution curve. In AMI canines, transient RNS significantly exacerbated LSG activation and promoted the incidence of ventricular arrhythmias. CONCLUSION: Transient RNS did not increase the risk of ventricular arrhythmias in normal or HMI hearts, but it significantly promoted the occurrence of ventricular arrhythmias in AMI hearts. Therefore, electrical stimulation-based renal nerve mapping may be unsafe in AMI patients and in patients with a high risk for malignant ventricular arrhythmias.


Assuntos
Arritmias Cardíacas/fisiopatologia , Estimulação Elétrica/efeitos adversos , Rim/inervação , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Potenciais de Ação/fisiologia , Animais , Cães , Ventrículos do Coração/fisiopatologia , Gânglio Estrelado/fisiopatologia
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