Mechanosensitive ion channel Piezo1 induces senescence of atrial fibroblasts by activating β-catenin / 中国药理学通报

Aim To observe whether the mechanosensitive ion channel Piezo1 was involved in the senescence of atrial fibroblasts by activating β-catenin based on our previous study which found marked increase of Piezo1 mRNA in senescent atrial fibroblasts. Methods Primary mouse atrial fibroblasts (MAFs) were isolated from male C57BL/6 mice (3-4 weeks) by enzyme digestion, and tert-butyl hydroperoxide (TBHP) was used to induce the senescence of cells. The ratio of senescent cells was detected by senescence-associated β-galactosidase (SA-β-Gal) staining. The protein levels of Piezo1, β-catenin/p-β-catenin, senescence-associated proteins p53 and p21 in the cells treated with TBHP (100 μmol · L

Prevalence and incidence of heart failure among community in China during a three-year follow-up / 老年心脏病学杂志（英文版）

BACKGROUND@#Epidemiological surveys on heart failure (HF) in Chinese community are relatively lacking. This study aimed to estimate the prevalence and incidence of HF among community residents in southern China.@*METHODS@#Baseline data of this prospective study was collected from 2015 to 2017 among 12,013 permanent residents aged ≥ 35 years in Guangzhou, China. The same survey process was carried out for individuals aged ≥ 65 years after a three-year follow-up.@*RESULTS@#The overall prevalence of HF in community residents aged ≥ 35 years was 1.06%. Male had significantly higher risk of HF prevalence [odds ratio (OR) = 1.50, P = 0.027]. The gender-adjusted risk of HF was 1.48 times higher per 10 years aging. HF prevalence was statistically associated with atrial fibrillation, valvular heart disease, hypertension and chronic obstructive pulmonary disease after adjusting for age and gender (OR = 8.30, 5.17, 1.11, 2.28, respectively; all P < 0.05). HF incidence in individuals aged ≥ 65 years were 847 per 100,000 person-years. Baseline atrial fibrillation, valvular heart disease, and diabetes mellitus were risk factors for HF incidence for individuals aged ≥ 65 years adjusting for age and gender (OR = 5.05, 3.99, 2.11, respectively; all P < 0.05). Besides, residents with new-onset atrial fibrillation and myocardial infarction were at significantly higher risk of progression to HF (OR = 14.41, 8.54, respectively; all P < 0.05).@*CONCLUSIONS@#Both pre-existing and new-onset cardiovascular diseases were associated with HF incidence in southern China. Management of related cardiovascular diseases may be helpful to reduce the incidence of HF.

Chinese consensus on the use of antiarrhythmic drugs for rhythm control in atrial fibrillation / 中华内科杂志

Rhythm control is crucial part of comprehensive management of atrial fibrillation (AF). Rhythm control can reduce the burden of AF effectively, reduce symptoms, and improve the prognosis in early AF. Antiarrhythmic drugs (AADs) are the first-line treatment for rhythm-control strategies. This consensus focuses on the principle of rhythm control in AF, the characteristics of AADs, and the medication recommendations for patients in different populations suffering from AF. Hence, this consensus aims to support clinical decision-making for AF therapy.

Piezol involved in electrical remodeling in atrial myocytes induced by high hydrostatic pressure through Src kinase / 中国药理学通报

Aim To investigate the role of mechano- sensitive ion channel Piezol in regulating electrical re-modeling of atrial myocytes induced by hypertension and to further explore the potential mechanisms.Methods Spontaneously hypertensive rats ( SHR ) aged 30 - 32 weeks treated with or without valsartan (30 mg • kg 1 • d 1 ) were used.Wistar rats were used as control.Western blot was used to detect the protein expression of Piezol , Src and Cavl.2 in atrial appendages of rats and in atrial myocytes ( HL-1 cells) exposed to different levels of high hydrostatic pressure (20 and 40 mmHg) , Piezol inhibitor (GsmTx4) and agonist ( Yodal ) in vitro.Whole-cell patch clamp technique was employed to detect L-tvpe calcium current (ICa, ) and action potential duration ( APD) of atrial myocytes.Results Compared with Wistar rats in control group, the protein expressions of Piezol and Src significantly increased and the expression of Cavl.2 decreased in SHR group (P < 0.05 ), while the a- bove changes could he reversed in SHR treated with valsartan( P < 0.05 ) .Meanwhile, higher hydrostatic pressure (40 mniHg) could increase the expressions of Piezol and Src in HL-1 cells( P <0.05) and decrease the protein expression of Cavl.2 (P <0.05 ) , accompanied by a shortened APD and a decreased ICa,.GsmTx4 could significantly reverse the above changes.In addition, Piezol agonist Yodal could simulate electrical remodeling and related signal molecule changes in atrial myocytes induced by the high hydrostatic pressure.Conclusions Mechanosensitive ion channel Piezol participates in electrical remodeling induced by hypertension via activating Src kinase signaling pathway and then leading to the decrease of ICa ,.

Transcriptional co-activator p300 participates in atrial fibrosis induced by high hydrostatic pressure by regulating TGF-β/Smad3 signaling pathway / 中国药理学通报

Aim To investigate the role and potential mechanism of transcriptional co-activator p300 in atrial fibrosis caused by high hydrostatic pressure. Methods The left atrial appendage tissues of humans in three groups of sinus rhythm, atrial fibrillation (AF), hypertension and AF were collected. The expressions of p300 protein and TGF-β/Smad3 signaling pathway and fibrotic factors as type I/III collagen Alphal chain (Col-lAl/Col-3Al), matrix metalloproteinase 2/9 (MMP-2/9) were tested by Western blot. Mouse atrial appendage fibroblasts were cultured under hydrostatic pressures of 0, 20 and 40 mmHg. The fibroblasts cultured under 40 mmHg pressure were treated with curcumin and p300 interference RNA. Western blot was used to test changes in the expression of p300 and the above fibrosis indicators. CCK-8 method was used to test changes of cell proliferation. Results The expressions of p300 and TGF-β/Smad3 signaling pathway proteins and fibrotic factors in AF group and hypertension combined with AF group were significantly higher than those in sinus rhythm group (P < 0. 05). 40 mmHg high hydrostatic pressure stimulation in vitro could increase the expression of p300 and fibrotic factors in fibroblasts (P < 0. 0 5) and enhance the proliferation ability (P < 0. 05). Both curcumin and p300 interfering RNA could reverse the increased expression of p300 and fibrotic factors (P < 0. 05) and decrease cell proliferation (P < 0. 05) induced by hydrostatic pressure. Conclusions High hydrostatic pressure can induce atrial fibrosis, which involves the participation of p300 in this process by regulating the TGF-β/Smad3 signaling pathway.

Role of p300 in susceptibility of atrial Hbrillation in aged mice / 中国药理学通报

Aim To explore the role of cotranscriptional activator p300 in regulating the electrical remodeling of atrial myocytes in aging mouse, which resulted in atrial fibrillation. Methods The left atrial appendage tissues of 5 , 13 and 18monthold C57BL/6 mice were collected respectively. Western blot was used to detect the protein expression levels of p300, L type calcium channel (Cavl. 2) and aging related protein p53/p21. Acute enzymatic hydrolysis was used to isolate single atrial myocytes, and the wholecell patchclamp technique was used to detect the Ltype calcium current (I

Involvement of Src kinase in the down-regulation of ultra-rapid delayed rectifier K(+)current induced by tumor necrosis factor-α in cardiomyocytes / 中华心血管病杂志

Objective: To investigate whether inflammatory factor tumor necrosis factor-α (TNF-α) is involved in the electrical remodeling of cardiomyocytes by regulating ultra-rapid delayed rectifier K(+) current (I(kur)) and the role of Src kinase. Methods: H9c2 cells, embryonic cardiomyocytes of rat, were cultured in Dulbecco's modified Eagle's medium (DMEM) and atrium-derived HL-1 cells were cultured in Claycomb medium. Both H9c2 and HL-1 cells were cultured at 37 ℃ with 5% CO(2). Cells cultured in normal conditions without additional treatment served as control group. Experimental groups were treated with different concentration of TNF-α (25 or 50 or 100 ng/ml) for 24 hours. To study whether Src specific inhibitor PP1 could abrogate the effect of TNF-α, cells were pre-treated with 10 μmol/L PP1 for 1 hour, followed by TNF-α (100 ng/ml) for 24 hours. Western blot and the whole cell patch clamp technique were used to detect the protein expression of Kv1.5 and Src and I(kur) in each group. Results: (1) In H9c2 cells, high concentration of TNF-α treatment (100 ng/ml) significantly reduced the Kv1.5 protein expression compared with control group and TNF-α 25 ng/ml group (both P<0.05). Compared with control group, the expression of p-Src protein was higher in 25 ng/ml, 50 ng/ml, 100 ng/ml TNF-α group (all P<0.05), but there was no statistical difference in the expression of Src protein among groups (P>0.05). In addition, the current density of I(kur) was decreased in 50 ng/ml, 100 ng/ml TNF-α group (both P<0.05). Furthermore, the expression of Kv1.5 protein and the current density of I(kur) were increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (both P<0.05). There was no statistical difference in the expression of Kv1.5 protein and the current density of I(kur) between the control group and PP1+TNF-α group (both P>0.05). (2) In atrium-derived HL-1 cells, the expression of Kv1.5 protein was reduced in 100 ng/ml TNF-α group compared with control group and TNF-α 25 ng/ml group (both P<0.01). In addition, the expression of p-Src protein was increased in TNF-α 100 ng/ml group compared with control group (P<0.05), but there was no statistical difference in the protein expression of Src among groups (P>0.05). The expression of Kv1.5 protein was increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (P<0.05). Conclusion: TNF-α is involved in the pathogenesis of atrial fibrillation, probably via decreasing I(kur) current density in atrium-derived myocytes through the activation of Src kinase.

Role of tumor necrosis factor-alpha in the pathogenesis of atrial fibrillation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tumor necrosis factor-alpha (TNF-α) is a pleiotropic proinflammatory cytokine and contributes to many kinds of cardiovascular diseases via its receptors (TNFR1/TNFR2). We hypothesize that TNF-α plays a role in the pathogenesis of chronic atrial fibrillation (AF).</p><p><b>METHODS</b>Sixty-seven consecutive patients who were scheduled to have cardiac surgery were enrolled into the study. Thirty-one patients with rheumatic heart disease (RHD) and AF were enrolled as study group (AF group). The sinus rhythm (SR) control groups consisted of 20 patients with RHD and 16 patients with coronary artery disease (CAD). Peripheral blood sample was collected before the operation. About 5 mm(3) left atrial tissue was disserted during the operation and was separated into three parts for Western blotting, real time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) analysis.</p><p><b>RESULTS</b>Compared with the controls (RHD SR and CAD SR), the levels of TNF-α ((14.40 ± 5.45) pg/ml vs. (4.20 ± 3.19) pg/ml vs. (2.68 ± 2.20) pg/ml, P = 0.000) and its soluble receptor 1 (sTNFR1) ((1623.9 ± 558.6) pg/ml vs. (1222.3 ± 175.6) pg/ml vs. (1387.5 ± 362.2) pg/ml, P = 0.001) in plasma were higher in patients with AF. TNF-α level had positive correlation with the left atrial diameter (LAD) (r = 0.642, P = 0.000). Western blotting analysis showed that the protein levels of TNF-α (0.618 ± 0.236 vs. 0.234 ± 0.178 vs. 0.180 ± 0.103, P = 0.000) were higher in patients with AF. The RT-PCR analysis results demonstrated that the mRNA expression of TNF-α (0.103 ± 0.047 vs. 0.031 ± 0.027 vs. 0.023 ± 0.018, P = 0.000) increased in patients with AF. IHC analysis displayed that, comparing to the SR, the expression of TNF-α (0.125 ± 0.025 vs. 0.080 ± 0.027 vs. 0.070 ± 0.023, P = 0.000) increased in the AF group. The protein level and mRNA expression of TNF-α also had positive correlation with left atrium diameter (LAD) (r = 0.415, P = 0.000 and r = 0.499, P = 0.000).</p><p><b>CONCLUSIONS</b>The results revealed that TNF-α elevated in the plasma and left atrial tissue and had positive correlation with LAD in patients of chronic AF. TNF-α might involve in the pathogenesis of chronic AF.</p>

Left atrial size and function after radiofrequency catheter ablation for paroxysmal atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the impact of radiofrequency catheter ablation on left atrial (LA) size and function in patients with paroxysmal atrial fibrillation (PAF) and whether there is any difference between segmental pulmonary vein ostial isolation (SPVI) and circumferential pulmonary vein ablation (CPVA).</p><p><b>METHODS</b>Sixty-six patients with highly symptomatic atrial fibrillation were assigned to undergo either SPVI or CPVA. Transthorax echocardiography was performed before, 1 day, 1 months and 3 months after the procedure. LA dimension, LA area, late diastolic peak velocity of mitral valve inflow (A) and peak atrial systolic mitral annulus velocity (A') were recorded.</p><p><b>RESULTS</b>Of 66 consecutive patients with symptomatic PAF, 30 patients underwent SPVI and 36 underwent CPVA. After a mean follow-up of (315 +/- 153) days, 21 patients (70%) after SPVI and 28 patients (75%) after CPVA were free of atrial tachyarrhythmia. As compared with the baseline, LA area decreased at 1-month after ablation in SPVI group and at 3-month in CPVA group. LA dimension decreased also in SPVI group, but did not in CPVA group. A velocity and A' velocity declined remarkably 1 day after CPVA, and restored 3 months later. The former went back to the level of baseline, and the latter exceeded it apparently. In SPVI group, A velocity increased at 1-month, and maintained in 3-month after ablation. A' velocity increased at 3-month after ablation. No reduction of A velocity or A' velocity was found after SPVI.</p><p><b>CONCLUSIONS</b>This study demonstrated a decrease in LA area and an improvement in LA systolic function 3 months after ablation for PAF. The LA damage by CPVA was more than that by SPVI, which was characterized by the reduction of LA function 1 day after procedure and the delayed improvement of LA size and functional parameters.</p>