Corilagin inhibits angiotensin II-induced atrial fibrosis and fibrillation in mice through the PI3K-Akt pathway.

Objectives: Corilagin (Cor) is reported as beiing hepatoprotective, anti-inflammatory, antibacterial, and anti-oxidant, while the effect on atrial fibrosis remains unknown. Therefore, we investigated the protective effect of Cor in angiotensin II (Ang II)-induced atrial fibrosis and atrial fibrillation (AF). Materials and Methods: C57BL/6 mice (male, 8-10 weeks, n = 40) were subcutaneously infused either with saline or Ang II (2.0 mg/kg/day) and Cor (30 mg/kg) intraperitoneally injected 2 hr before Ang II infusion for 4 weeks. Mice were grouped into the control group (n=8), Cor group (n=8), Ang II group (n=8), and Ang II + Cor group (n=8). Morphological, histological, and biochemical examinations were performed. In vivo, transesophageal burst pacing was used to generate AF. Results: Cor treatment markedly reduced Ang II-induced AF development in mice. Ang II + Cor therapy potentially decreased the atrial fibrotic area. It significantly decreased the increase in smooth muscle alpha-actin (α-SMA), CTGF, Collagen I, and Collagen III expressions brought on by Ang II treatment. Moreover, Ang II + Cor treatment remarkably decreased the malondialdehyde (MDA) content, whereas superoxide dismutase (SOD) and catalase (CAT) activities were potentially increased (all, P<0.001). In addition, Ang II + Cor significantly reduced Ang II-induced interleukin 1 beta (IL-1ß), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α) concentrations in atrial tissues. Furthermore, Cor significantly inhibited Ang II-induced p-PI3K, p-Akt, and NF-κB p-p65 protein expression in atrial tissues. Conclusion: Our data speculated that Cor could have a protective effect against Ang II-induced atrial fibrosis and AF via down-regulation of the PI3K-Akt pathway.

Interleukin-11 Is Elevated in Patients with Atrial Fibrillation, Correlates with Serum Fibrosis Markers, and Represents a Therapeutic Target for Atrial Fibrosis.

INTRODUCTION: Inflammatory cytokines are closely associated with developing cardiac fibrosis. This research aimed to explore the significant role of IL-11 in atrial fibrosis progression and potential therapeutic targets. METHODS: 207 AF patients and 160 healthy subjects were included in the case-control study. Blood samples were analyzed for the level of IL-11 by enzyme-linked immunosorbent assay (ELISA). Angiotensin II (Ang II)-treated fibrosis mouse models were generated, and expression of IL-11 mRNA and protein was detected by RT-qPCR and Western blot. IL-11 antagonist was used to evaluating atrial fibrosis-related markers. RESULTS: The persistent atrial fibrillation patients (n = 76) had significantly larger left atrial size, higher serum levels of hypertrophic protein BNP, proinflammatory cytokine high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) compared to paroxysmal atrial fibrillation patients (n = 131), and healthy subjects (all p < 0.05). Pearson correlation analysis revealed significant positive correlation between serum IL-11 and cardiac fibrosis markers BNP (r = 0.394, p < 0.001), CTX-I (r = 0.418, p < 0.001), PICP (r = 0.306, p < 0.001), PIIINP (r = 0.335, p < 0.001), and TGF-ß1 (r = 0.273, p < 0.001). In the fibrosis mouse model, Ang II infusion significantly upregulated IL-11 mRNA and protein expression in the left atrium of mice (p < 0.05), as well as staining intensity of Masson trichrome, the intensity of α-SMA, and it increased mRNA expression of collagen I and III in atrial tissue. IL-11 antagonist treatment significantly attenuated Masson trichrome, number of α-SMA-positive myofibroblasts in atrial tissue. Also, it significantly reduced the p-ERK1/2 in atrial tissue of mice infused with Ang II (p < 0.05). CONCLUSIONS: IL-11 is upregulated in the serum of AF patients, and IL-11 inhibitor significantly inhibited Ang II-induced atrial fibrosis, a key pathological feature of AF. Therefore, IL-11 could be a potential therapeutic target for AF.

Inhibition of FABP4 attenuates cardiac fibrosis through inhibition of NLRP3 inflammasome activation.

Objectives: Cardiac fibrosis is a key biological process of cardiac remodeling and heart failure. Fatty acid-binding protein 4 (FABP4) is a lipid-binding protein that can regulate glucose and lipid homeostasis, and its expression was elevated in heart failure. However, whether FABP4 is involved in cardiac fibrosis remains unknown. Materials and Methods: The cardiac fibrosis model was established in male C57BL/6 mice with subcutaneously infused angiotensin II (Ang-II) (2.8 mg/kg/day) for 4 weeks. DMSO or FABP4 inhibitor BMS309403 (50 mg/kg/day) was intraperitoneally injected for 4 weeks. Ang II-infused mice, FABP4 inhibitor (BMS309403) injected mice, and ventricular tissue were used for morphological studies, and histological and biochemical analyses (FABP4 protein composition and expression). Results: Ang II infusion increased FABP4 mRNA and protein expression in the mouse ventricular tissue. After treatment with FABP4 inhibitor BMS309403 for 4 weeks, mice showed improved cardiac structure and function as detected by echocardiography. BMS309403 suppressed cardiac and systemic inflammatory response, reduced collagen deposition, and mRNA expression of collagen type I (COL1A1) and collagen type III (COL3A1) in Ang II-infused mice. BMS309403 also reduced the number of α-smooth muscle actin (α-SMA)+cells and decreased the mRNA expression of α-SMA, matrix metalloproteinases-2 (MMP-2), MMP-9, and transforming growth factor-ß (TGFß) in ventricular tissue. Conclusion: The inhibitory effect of BMS309403 on cardiac fibrosis might be associated with inhibition of NLRP3 inflammasome activation, which Ang II activated. Thus, our data speculated that inhibition of FABP4 could significantly induce cardiac fibrosis.

Prediction model based on machine learning for short- and long-term adverse events in left atrial appendage closure.

Background: At present, the prediction of adverse events (AE) had practical significance in clinic and the accuracy of AE prediction model after left atrial appendage closure (LAAC) needed to be improved. To identify a good prediction model based on machine learning for short- and long-term AE after LAAC. Methods: In this study, 869 patients were included from the Department of Cardiovascular Medicine of Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital during 2017 and 2021. Univariate and multivariate analyses were conducted for short-term AE after LAAC to determine possible risk factors related with AE. We compared 8 machine learning algorithms for prediction short-term AE, and XGBoost was found to have the best performance. In addition, Cox-regression was used for long-term AE to find out the risk factors and establish a prediction model. Results: In univariate and multivariate analysis, body mass index (BMI) [odds ratio (OR) =0.91], congestive heart failure, hypertension, age ≥75 years, diabetes, stroke2 attack (CHADS2) score (OR =0.49) and bleeding history or predisposition, labile international normalized ratio (INR), elderly, drug/alcohol usage (BLED) score (OR =1.71) were shown to be significant risk factors for short-term AE. The XGbosst algorithm was used to predict short-term AE based on 15 possible risk factors. For long-term AE, Cox regression was used for the prediction. The CHADS2 score [hazard ratio (HR) =1.43], hypertension (HR =2.18), age more than 75 (HR =0.49), diabetes (HR =0.57), BLED score (HR=0.28), stroke (HR =19.8), hepatopathy (HR =3.97), nephropathy (HR =2.93), INR instability (HR =4.18), drinking (HR =2.67), and drugs (HR =2.36) were significant risk factors for long-term AE. The XGBoost had a good receiver operating characteristic (ROC) curve and area under the curve (AUC) was 0.85. The accuracy of the XGBoost model stayed at nearly 0.95. Conclusions: In short- and long-term AE, CHADS2 score and BLED score were the most obvious risk factors. Several other risk factors also played roles in AE of LAAC. The incidence of long-term AE is under 15% and LAAC is effective and safe. The XGBoost model had good prediction accuracy and ROC curve.

ANGPTL4 Attenuates Ang II-Induced Atrial Fibrillation and Fibrosis in Mice via PPAR Pathway.

Atrial fibrillation (AF) is the more significant portion of arrhythmia in clinical practice, with inflammation and fibrosis as its central pathological mechanisms. This study aimed to investigate angiopoietin-like 4 (ANGPTL4) effects on angiotensin II- (Ang II-) induced AF and its related pathophysiological mechanisms. C57BL/6J mice were randomized and divided into three groups: the control group, the Ang II group, and the ANGPTL4 group (Ang II with ANGPTL4 treatment). Mice were infused with Ang II (2000 ng/kg/min) and were administrated with recombinant human ANGPTL4 (rhANGPTL4, 20 µg/kg/day) for 3 weeks. The fibrosis was evaluated with Masson's trichrome staining in the atrial myocardium. mRNA levels of IL-1ß, IL-6, collagen I, and collagen III were measured using real-time qRT-PCR. Protein levels of PPARα, PPARγ, CPT-1, and SIRT3 were measured using Western blotting. Compared to the control group, the mice infused with Ang II showed electrocardiogram characteristics of AF, and this effect was markedly attenuated in ANGPTL4-treated mice. ANGPTL4 also reversed the increase in cardiomyocyte apoptosis, inflammation, interstitial collagen fraction, and collagen gene expression in mice with Ang II. Mechanistically, ANGPTL4 inhibited the activation of several fatty acid metabolism-related proteins, including PPARα, PPARγ, and CPT-1, and the expression of SIRT3 protein in atrial tissues. In conclusion, ANGPTL4 attenuates Ang II-induced AF and atrial fibrosis by modulation in the SIRT3, PPARα, and PPARγ signaling pathways.

[Stromal interaction molecule 1 silencing attenuates the proliferation and migration capacities of endothelial progenitor cells].

OBJECTIVE: The purpose of this study is to explore the impact of stromal interaction molecule 1 (STIM1) knockdown on the proliferation and migration capacities of endothelial progenitor cells (EPCs). METHODS: The rat bone marrow derived EPCs were obtained and divided into three groups: adenovirus negative control (NSC) group, rat STIM1 adenovirus vector transfection (si/rSTIM1) group and rat and human recombinant STIM1 adenovirus transfection (si/rSTIM1+hSTIM1) group. The STIM1 expressions in each group were detected by reverse transcription PCR after transfection. The cell proliferation was tested by [(3)H] thymidine incorporation assay ((3)H-TdR). Cell cycle was analyzed by flow cytometry. The cells migration activity was detected by Boyden assay. Calcium ion concentration was detected by confocal laser scanning microscopy. RESULTS: 48 h after transfection, the expression level of STIM1 in si/rSTIM1 group was significantly lower than that in NSC group (0.21 ± 0.12 vs. 1.01 ± 0.01, P < 0.05), and number of EPCs at G1 phase in si/rSTIM1 group ((93.31 ± 0.24)%) was significantly higher than that in NSC group ((78.03 ± 0.34)%, P < 0.05), and EPCs' migration activity in si/rSTIM1 group (10.03 ± 0.33) was significantly lower than that in NSC group (32.11 ± 0.54, P < 0.05), and EPCs calcium ion concentration in EPCs in si/rSTIM1 group (38.03 ± 0.13) was significantly lower than that in NSC group (98.11 ± 0.34, P < 0.05), while there was no significant difference between si/rSTIM1+hSTIM1 group and NSC group on the above four indexes. CONCLUSION: Silencing STIM1 could attenuate EPCs proliferation and migration capacities by modulating the calcium ion concentration in EPCs.

Silence of STIM1 attenuates the proliferation and migration of EPCs after vascular injury and its mechanism.

OBJECTIVE: To investigate the effect of stromal interaction molecule 1(STIM1) knockdown on the proliferation and migration of endothelial progenitor cells (EPCs) after vascular injury and its mechanism. METHODS: The rat bone marrow derived EPCs were divided into three groups: adenovirus negative control (group NSC), rat STIM1 adenovirus vector transfection group (group si/rSTIM1) and rat &human recombinant STIM1 adenovirus transfection group (group si/rSTIM1+hSTIM1). The STIM1 expressions in each group were detected by reverse transcription PCR after transfection; the cell proliferation was tested by [(3)H] thymidine incorporation assay ((3)H-TdR); Cell cycle was analyzed by flow cytometry; the cells' migration activity was detected by Boyden assay; Calcium ion concentration was detected by using laser confocal method. RESULTS: 48 h later after transfection, the expression level of STIM1 in si/rSTIM1 cells was significantly lower than that in NSC group (0.21 ± 0.12 vs 1.01 ± 0.01, P<0.05); EPCs that stayed in G1 phase in si/rSTIM1 group [(93.31 ± 0.24)%] were significantly more than that in NSC group [(78.03 ± 0.34)%, P<0.05]; EPCs' migration activity in si/rSTIM1 group (10.03±0.33) was significantly lower than that in NSC group: (32.11 ± 0.54, P<0.05); EPCs calcium ion concentration changes in EPCs in si/rSTIM1 group (38.03 ± 0.13) was significantly lower than that in NSC group (98.11 ± 0.34, P<0.05). While there was no significant difference between si/rSTIM1+hSTIM1 group and NSC group on the four indexes above. CONCLUSIONS: Silence of STIM1 attenuates EPCs proliferation and migration after vascular injury, by mediating the calcium ion concentration in EPCs.

[Biochemical regulatory mechanism of asiaticoside in preventing and treating stent restenosis].

OBJECTIVE: To discuss whether asiaticosides could effectively reduce the endothelial cell damage as a biochemical modulator, so as to further inhibit the post-stenting intima-media membrane hyperplasia. METHOD: Human aortic smooth muscle cells and aortic fibroblasts were selected and divided into the blank group, the rapamycin group and the asiaticoside group and the rapamycin and asiaticoside group. The expressions of muscle cells and fibroblasts TGF-beta1, Smad7 and I-collagen gene were determined by RT-PCR. The expression quantity of I-collagen protein was assayed by ELISA. The coefficient of drug interaction (CDI) between rapamycin and asiaticoside was calculated. Additionally, 16 Chinese mini-swines were randomly divided into group A and group B. One sirolimus drug-eluting stent of the same type was implanted after the high-pressure pre-expansion of anterior descending artery balloon. After the operation, the group A was intravenously injected with normal saline 30 mL x d(-1). Whereas the group B was intravenously injected with asiaticoside 30 mg x kg(-1) x d(-1)(diluted to 30 mL). The expressions of plasma vWF of the two groups were measured at the 7th and 14th days after the operation. At the 28th day after the operation, tissues of the stented vessel segments were sliced and stained to calculate the vessel area, inner stent area, lumen area and neointima area RESULT: Compared with the control group, the combination group showed significant up-regulation in smooth muscle cells and fibroblast Smad7 gene, down-regulation in TGF-beta, and obvious inhibition of I-collagen gene expression (P < 0.01). As for smooth muscle cells, there was no difference in the expression of I-collagen between the combination group and the rapamycin group, with CDI at 0. 83. As for fibroblasts, there was a significant difference in the expression of I-collagen between the combination group and the rapamycin group (P < 0.05), with CDI at 0.77. Plasma vWF of the group B was significantly lower than that of the group A (P < 0.05) at the 7th and 14th days after the operation. At the 28th day after the operation, no difference was observed in vessel area and stent area between the two groups. However, the lumen area in the group B was significantly larger than that of the group A(P < 0.05), and the neointima area of the group B was significantly smaller than that of the group A (P < 0.05). CONCLUSION: As an effective biochemical modulator for rapamycin, asiaticosides could inhibit TGF-beta expression, significantly decrease the synthesis and secretion of extracellular matrix, further inhibit the post-stenting intima-media membrane hyperplasia and reduce the endothelial cell damage by effectively up-regulate the expression of Smad7 protein.