Astragaloside IV alleviates LPS-induced cardiomyocyte hypertrophy and collagen expression associated with CCL2-mediated activation of NF-κB signaling pathway.

Cardiac remodeling (CR), characterized by cardiac hypertrophy and fibrosis, leads to the development and progression of heart failure (HF). Nowadays, emerging evidence implicated that inflammation plays a vital role in the pathogenesis of CR and HF. Astragaloside IV (AS-IV), an effective component of Astragalus membranaceus, exerts cardio-protective and anti-inflammatory effects, but the underlying mechanism remains not fully elucidated. This present study aimed to investigate the effects of AS-IV on cardiac hypertrophy and fibrosis in cultured H9C2 cells stimulated with LPS, as well as explore its underlying mechanisms. As a result, we found AS-IV could reduce the cell surface size, ameliorate cardiac hypertrophy and fibrosis in LPS-induced H9C2 cells. To specify which molecules or signaling pathways play key roles in the process, RNA-seq analysis was performed. After analyzing the transcriptome data, CCL2 has captured our attention, of which expression was sharply increased in model group and reversed by AS-IV treatment. The results also indicated that AS-IV could ameliorate the inflammatory response by down-regulating NF-κB signaling pathway. Additionally, a classical inhibitor of CCL2 (bindarit) were used to further explore whether the anti-inflammatory effect of AS-IV was dependent on this chemokine. Our results indicated that AS-IV could exert a potent inhibitory effect on CCL2 expression and down-regulated NF-κB signaling pathway in a CCL2-dependent manner. These findings provided a scientific basis for promoting the treatment of HF with AS-IV.

Long noncoding RNA THRIL promotes foam cell formation and inflammation in macrophages.

Tumor necrosis factor-α (TNF-α) and heterogenous nuclear ribonucleoprotein L (hnRNPL)-related immunoregulatory lincRNA (THRIL) is a long noncoding RNA (lncRNA) involved in various inflammatory diseases. However, its role in atherosclerosis is not known. In this study, we aimed to investigate the function of THRIL in mediating macrophage inflammation and foam cell formation. The expression of THRIL was quantified in THP-1 macrophages after treatment with oxidized low-density lipoprotein (oxLDL). The effect of THRIL overexpression and knockdown on oxLDL-induced inflammatory responses and lipid accumulation was determined. THRIL-associated protein partners were identified by RNA pull-down and RNA immunoprecipitation assays. We show that THRIL is upregulated in macrophages after oxLDL treatment. Knockdown of THRIL blocks oxLDL-induced expression of interleukin-1ß (IL-1ß), IL-6, and TNF-α and lipid accumulation. Conversely, ectopic expression of THRIL enhances inflammatory gene expression and lipid deposition in oxLDL-treated macrophages. Moreover, THRIL depletion increases cholesterol efflux from macrophages and the expression of ATP-binding cassette transporter (ABC) A1 and ABCG1. FOXO1 is identified as a protein partner of THRIL and promotes macrophage inflammation and lipid accumulation. Furthermore, overexpression of FOXO1 restores lipid accumulation and inflammatory cytokine production in THRIL-depleted macrophages. In conclusion, our data suggest a model where THRIL interacts with FOXO1 to promote macrophage inflammation and foam cell formation. THRIL may represent a therapeutic target for atherosclerosis.

[Silencing miRNA210 Alleviates Myocardial Cell Damage in Myocarditis by Hypoxia Inducible Factor-vascular Endothelial Growth Factor Pathway].

Objective To investigate the effect of miRNA210 on primary myocardial cells in lipopolysaccharide(LPS)-induced myocarditis.Methods CCK8 method was used to detect the effect of miRNA210 on the viability of primary myocardial cells in normal or LPS-induced myocarditis rats.ELISA was performed to detect the secretion of tumor necrosis factor(TNF)-α and interleukin(IL)-1ß after miRNA210 treatment.Flow cytometry was used to detect the apoptosis of primary myocardial cells before and after the intervention.Western blotting was used to detect the expression of TNF-α and IL-1ß.The expression of apoptosis-related proteins bcl-2,bax,caspase-3,and hypoxia inducible factor 1 (HIF1)-vascular endothelial growth factor(VEGF)were detected by Western blotting.Results CCK8 detection results showed that,compared with the control group,the effect of miRNA210 mimic(t=0.000,P=1.000)and siRNA(t=0.686,P=0.500)interference had no significant difference on primary rat cardiomyocytes.The viability of rat primary cardiomyocytes significantly decreased after LPS treatment(t=8.764,P<0.001);compared with LPS group,the viability of rat primary cardiomyocytes significantly increased after inhibition of miRNA210(t=3.576, P=0.012).ELISA showed that,compared with the control group,the expressions of IL-1 ß(t=4.166,P=0.014)and TNF-α(t=6.309,P=0.003)were significantly up-regulated after LPS induction;compared with the LPS group,the expressions of IL-1 ß(t=4.096,P=0.015)and TNF-α(t=4.424,P=0.011)were significantly increased after application of miRNA210 mimic.After silencing miRNA210,IL-1 ß(t=4.287,P=0.012)and TNF-α(t=3.577,P=0.023)were significantly down-regulated.Flow cytometry showed that,compared with the control group,the apoptosis of primary cardiomyocytes induced by LPS was significantly increased(t=32.780,P<0.001);compared with LPS group,the apoptosis induced by LPS was significantly aggravated by miRNA210 mimic(t=7.412,P= 0.002),and the apoptosis rate of primary cardiomyocytes was significantly decreased after miRNA210 was silenced(t=11.720,P<0.001).Western blot analysis showed that,compared with the control group,LPS significantly down-regulated the expression of bcl-2(t=8.346,P=0.001)and increased the expressions of bax(t=12.890,P<0.001)and caspase-3(t=4.331,P=0.012).Compared with LPS group,the expression of bcl-2(t=6.074,P<0.001)was significantly decreased,and the expressions of bax(t=5.376,P=0.022)and caspase-3(t=5.859,P=0.004)were increased after miRNA210 mimic.After silencing miRNA210,the expression of bcl-2 significantly increased(t=3.873,P=0.017),the expressions of bax(t=5.205,P=0.006)and caspase-3(t=2.800,P=0.040)significantly decreased.Compared with the control group,the expressions of HIF1(t =10.380,P=0.001)and VEGF(t=4.973,P=0.008)were significantly up-regulated in LPS group.Compared with LPS group,the expressions of HIF1(t=8.952,P<0.001)and VEGF(t=11.203,P=0.001)were significantly up-regulated after miRNA210 mimic was applied,while HIF1(t=3.893,P=0.017)and VEGF expression(t=3.181,P=0.033)were decreased after miRNA210 was silenced.Compared with LPS group,the expressions of bax(t= 4.899,P=0.008),HIF1(t=2.833,P=0.047),caspase-3(t=2.877,P=0.045),and VEGF(t= 2.994, P=0.040)were significantly decreased,and the expression of bcl-2 was increased(t=3.392,P=0.017).Conclusion Silencing miRNA210 can attenuate LPS-induced cardiomyocyte injury through HIF1-VEGF-mediated apoptotic pathway.

Safety and efficacy of catheter ablation of para-Hisian accessory pathway via a direct superior vena cava approach: A multicenter study.

BACKGROUND: Radiofrequency (RF) catheter ablation of para-Hisian accessory pathways (APs) can be challenging due to proximity to the conduction system. METHODS: A total of 30 consecutive patients with para-Hisian AP were enrolled for ablation in three centers, 12 (40%) of whom had previously failed attempted ablation from the inferior vena cava (IVC) approach. Ablation was preferentially performed using a superior approach from the superior vena cava (SVC) in all patients. RESULTS: The para-Hisian AP was eliminated from the SVC approach in 28 of 30 (93.3%) patients. In the remaining two patients, additional ablation from IVC was required to successfully eliminate the AP. There were two patients experienced reversible complete atrial-ventricular block and PR prolongation during the first RF application. Long-term freedom from recurrent arrhythmia was achieved in 29 (96.7%) patients over a mean follow-up duration of 15.6 ± 4.6 months. CONCLUSION: Catheter ablation of para-Hisian AP from above using a direct SVC approach is both safe and effective, and should be considered especially in patients who have failed conventional ablation attempts from IVC approach.

Chronic intermittent hypoxia-induced BNIP3 expression mitigates contractile dysfunction and myocardial injury in animal and cell model via modulating autophagy.

Obstructive sleep apnea syndrome is generally associated with multiple cardiovascular disorders, such as myocardial hypertrophy. Autophagy is strictly modulated to maintain cardiac homeostasis. Post-injury autophagy is closely associated with pathological cardiac hypertrophy. BCL2 interacting protein 3 (BNIP3) and BNIP3-like protein (BNIP3L) can cause cell death and are important for hypoxia-elicited autophagy. Here, we evaluated whether BNIP3 could mitigate functional remodeling and cardiac hypertrophy through regulation of autophagy. Male WT rats or rats with BNIP3 knockout were subjected to chronic intermittent hypoxia (CIH) for 8 h/day over 5 weeks. Echocardiography and morphology were employed to assess the cardioprotective effects. Autophagy was assessed via transmission electron microscopy and detection of LC3, p62, and Beclin-1. Terminal deoxynucleotidyl transferase dUTP nick end labeling and the Bax/Bcl2 ratio were used to monitor apoptosis. Biochemical evaluations were performed to assess oxidative stress. Additionally, BNIP3-knockdown H9c2 cells that were subjected to CIH were used to examine autophagy and apoptosis to confirm the findings of the animal study. The CIH group showed elevated heart weight/body weight and left ventricle weight/body weight proportions, along with left ventricular remodeling. CIH-exposed rats exhibited dramatically higher fractional shortening and ejection fractions than the controls. In addition, the levels of autophagy markers Beclin-1 and LC3-II/I were increased, whereas the level of p62 was reduced by CIH treatment. The oxidative marker levels and the apoptosis index in the CIH group were markedly increased. Knockout of BNIP3 significantly aggravated the impairment in cardiac function, apoptosis, oxidative stress, and hypertrophy of CIH rats, while significantly reducing autophagy. The autophagy-associated PI3K/Akt/mTOR pathway was also deactivated by BNIP3 knockout. At the cellular level, CIH treatment significantly upregulated autophagy and apoptosis; however, BNIP3 silencing reduced autophagy and promoted apoptosis. CIH treatment-mediated upregulation of BNIP3 expression plays a crucial role in autophagy by targeting the PI3K/Akt/mTOR pathway, alleviating cardiac hypertrophy.

Electrocardiographic predictors of validated right ventricular outflow tract septal pacing for correct localization of transthoracic echocardiography.

BACKGROUND: Electrocardiographic (ECG) characteristics of true right ventricular outflow tract (RVOT) septal pacing have not been clearly demonstrated. HYPOTHESIS: We hypothesized that ECG parameters would help operators differentiate true RVOT septum from non-septal septum. METHODS: We analyzed 151 patients who underwent pacemaker implantation with a ventricular lead in the RVOT. Transthoracic echocardiographic (TTE) determination of pacing sites was applied in all patients after implantation. A 12-lead ECG was recorded during forced ventricular pacing. RESULTS: According to TTE orientation, pacing at the RVOT septum was achieved in 94 patients (62.3%). Compared with nonseptal pacing, septal pacing had significantly shorter QRS duration (139.2 ± 18.5 ms vs 155.5 ± 14.7 ms; P < 0.001). More frequent negative or isoelectric QRS vector in lead I (76% vs 32%; P < 0.001), lead II/III R-wave amplitude ratio < 1 (52% vs 25%; P = 0.001), and aVR/aVL QS-wave amplitude ratio < 1 (59% vs 32%; P = 0.001) were observed in septal pacing. Transitional zone (TZ) score (3.8 ± 0.96 vs 4.2 ± 0.90; P = 0.004) and TZ index (0.3 ± 0.5 vs 0.6 ± 0.7; P = 0.008) were significantly lower in septal pacing than in nonseptal pacing, respectively. In multivariate analysis, paced QRS duration and negative or isoelectric QRS vector in lead I independently predicted RVOT septal pacing (P < 0.001). At ROC curve analysis, paced QRS duration ≤145 ms identified RVOT septal pacing with 85.1% sensitivity and 78.9% specificity. CONCLUSIONS: This study reveals the heterogeneity of lead placement within the RVOT. Narrower paced QRS duration and negative or isoelectric QRS vector in lead I independently predict RVOT septal pacing.