LTBP2 knockdown by siRNA reverses myocardial oxidative stress injury, fibrosis and remodelling during dilated cardiomyopathy.

AIM: Dilated cardiomyopathy (DCM) is characterised by left ventricular dilation and associated with systolic dysfunction. Recent evidence has reported the high expression of latent transforming growth factor beta binding protein 2 (LTBP2) in heart diseases, which may play a role in regulating multiple biological functions of myocardial cells. Thus, this study set out to investigate the molecular mechanism and effects of LTBP2 in myocardial oxidative stress injury, fibrosis and remodelling in a rat model of DCM, with the involvement of NF-κB signalling pathway. METHODS: The rat model of DCM was treated with si-LTBP2 and/or activator of NF-κB signalling pathway to examine the haemodynamic indexes, cardiac functions, oxidative stress injury, fibrosis and remodelling. Moreover, in vitro experiments were conducted to verify the regulatory role of LTBP2 and NF-κB signalling pathway in DCM. RESULTS: LTBP2 was up-regulated in DCM rats. After LTBP2 was knocked down, haemodynamic indexes, HW/BW ratio, collagen volume fraction (CVF) level, positive expression of LTBP2, levels of reactive oxygen species (ROS), malondialdehyde (MDA), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), tumour necrosis factor beta 1 (TGF-ß1) and brain natriuretic peptide (BNP) were all decreased. Meanwhile, levels of LTBP2, Col-I, Col-III, p65 and p52 were also reduced, while HW, BW and levels of SOD and TAOC were increased. In contrast, activation of NF-κB signalling pathway reversed effects of LTBP2 gene silencing. These findings were confirmed by in vivo experiments. CONCLUSIONS: LTBP2 silencing can attenuate myocardial oxidative stress injury, myocardial fibrosis and myocardial remodelling in DCM rats by down-regulating the NF-κB signalling pathway.

Atorvastatin suppresses vascular hypersensitivity and remodeling induced by transient adventitial administration of lipopolysaccharide in rats.

BACKGROUND: The phenotypic transition of vascular smooth muscle cells (VSMCs) from a contractile to a proliferative state markedly affects the pathophysiology of cardiovascular diseases. The adventitial inflammation can promote neointimal formation and vascular remodeling. We used direct administration of lipopolysaccharide (LPS) into the periphery of the carotid artery to investigate the influence of transient adventitial inflammation on vascular remodeling and its potential mechanism. METHODS: Male 15-week-old Wistar rats were randomly assigned to four groups with six rats in each group. The rats of groups I and II were administered distilled water, and group III and IV were treated with fasudil and atorvastatin respectively. All treatments were given daily for 11 days. On day 8, the adventitia in group I was injected with 5 µL sterile saline, and the group II-IV were injected with 5 µL sterilized LPS. The carotid blood flow and femoral blood pressure were measured in vivo, and the thickness of vascular intima and middle layer was measured in vitro. Serum interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) were determined using enzyme-linked immunosorbent assay (ELISA) assay. And the Rho-associated coiled-coil-containing protein kinase 2 (ROCK2), myosin phosphatase target subunit 1 (MYPT1), myosin light chain (MLC), myocardin, SM-α actin or glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were detected by western blot. The comparisons were made by one-way analysis of variance with Bonferroni's post hoc test. A value of P<0.05 was considered to represent a statistically significant difference. RESULTS: Transient adventitial inflammation induced by LPS caused no obvious change in basal blood flow, but did lead to vascular hypersensitivity to serotonin. Morphological examinations revealed that the medial layer was the only domain affected, and showed VSMC proliferation and rearrangement. LPS increased serum IL-6 and TNFα contents, ROCK2 expression and activity, and caused changes in the expression levels of some stereotypical VSMC genes. Similar to the Rho-kinase inhibitor fasudil, atorvastatin completely restored the morphological alterations, even increased blood flow. CONCLUSIONS: Our study confirms the beneficial effect of atorvastatin on the vascular system in terms of morphology and function.

Downregulation of microRNA-592 protects mice from hypoplastic heart and congenital heart disease by inhibition of the Notch signaling pathway through upregulating KCTD10.

Evidence has demonstrated that the microRNA (miR) may play a significant role in the development of congenital heart disease (CHD). Here, we explore the mechanism of microRNA-592 (miR-592) in heart development and CHD with the involvement of KCTD10 and Notch signaling pathway in a CHD mouse model. Cardiac tissues were extracted from CHD and normal mice. Immunohistochemistry staining was performed to detect positive expression rate of KCTD10. A series of inhibitor, activators, and siRNAs was introduced to verified regulatory functions for miR-592 governing KCTD10 in CHD. Furthermore, the effect of miR-592 on cell proliferation and apoptosis was also investigated. Downregulated positive rate of KCTD10 was observed in CHD mice. Downregulation of miR-592 would upregulate expression of KCTD10 and inhibit the activation of Notch signaling pathway, thus promote cell proliferation. This study demonstrates that downregulation of miR-592 prevents CHD and hypoplastic heart by inhibition of the Notch signaling pathway via negatively binding to KCTD10.

Effects of inhibitors of the renin-angiotensin system on reducing blood pressure and expression of inflammatory factors in CHD patients: A network meta-analysis.

The renin-angiotensin system (RAS) is an ever-evolving endocrine system with considerable checks and balances on the production and catabolism of angiotensin peptides most likely due to the manifold effects of angiotensins. We aimed to explore the effects of different inhibitors of RAS on blood pressure and expression of inflammatory factors in patients with coronary heart disease (CHD). We initially searched PubMed, EMBASE and Cochrane Library electronic databases with nine eligible randomized controlled trials enrolled. Direct and indirect evidence was combined to calculate the weighted mean difference value and draw surface under the cumulative ranking curves. The results demonstrated that, compared with placebo and enalapril, ramipril had a better effect on reducing systolic blood pressure after short-term usage of drugs (<12 months), while perindopril had better effects on reducing diastolic blood pressure and C-reactive protein expression. Furthermore, after long-term usage of drugs (≥12 months), there was no significant difference among olmesartan, quinapril and candesartan in the treatment of patients with CHD. Perindopril and ramipril had better effects on inhibiting blood pressure and expression of inflammatory factors among eight inhibitors after short-term usage of drugs (<12 months); while quinapril had better effects on reducing blood pressure and expression of inflammatory factor after long-term usage of drugs, and there was little difference in the effects between olmesartan and candesartan (≥12 months). Perindopril may have better short-term effects on reducing blood pressure and expression of inflammatory factor, while quinapril may have better long-term effects on reducing blood pressure and expression of inflammatory factor.

Anti-TNF therapy in patients with HBV infection--analysis of 87 patients with inflammatory arthritis.

This study aims to investigate the incidence of hepatitis B virus (HBV) reactivation in inflammatory arthritis (IA) patients with HBV infection using anti-tumor necrosis factor (TNF) agents and evaluate the efficacy of antiviral therapy in reducing the risk of viral reactivation in chronic HBV infection. IA patients using anti-TNF agents from six centers were enrolled. Their HBV infection conditions and ALT and HBV-DNA levels were monitored periodically. Among the six chronic hepatitis B patients, HBV reactivation was found in two patients without antivirus prophylaxis and no viral replication was detected in the other four patients with antivirus prophylaxis. In the 31 inactive carriers, the increase of viral load was detected in 6 of 22 (27.3 %) patients without antiviral prophylaxis, and there was no viral reactivation in the other 9 patients with antiviral prophylaxis. HBV reactivation was not found in the 50 patients with resolved HBV infection. It is suggested that anti-TNF therapy might increase the risk of HBV reactivation in patients with chronic HBV infection, and antiviral prophylaxis could effectively decrease the risk. Anti-TNF agents seem to be safe in patients with resolved HBV infection.

Depression, anxiety, and quality of life after catheter ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: Patients with paroxysmal atrial fibrillation (AF) experience impaired quality of life (QoL) and psychological distress. Catheter ablation of AF can markedly improve QoL. However, the effect of catheter ablation of AF on psychological status is unknown. HYPOTHESIS: Depression, anxiety, and QoL improve after catheter ablation in patients with paroxysmal AF. METHODS: A total of 166 consecutive patients with symptomatic paroxysmal AF were examined. Eighty-two patients (55 men, mean age 55.9 ± 6.1 y) underwent catheter ablation and 84 patients (58 men, mean age 57.2 ± 5.4 years) received antiarrhythmic drug (AAD) therapy. The Self-Rating Depression Scale, Self-Rating Anxiety Scale, and Medical Outcomes Survey 36-item Short-Form questionnaires were completed by these patients at baseline, and at 3, 6, 9, and 12 months of follow-up. Results in the ablation group were compared with those of the AAD group. RESULTS: In the ablation group, 42.7% of patients showed symptoms of depression and 37.8% showed symptoms of anxiety, which were similar to those in the AAD group. Both groups similarly displayed reduced physical and mental QoL. Catheter ablation was effective in reducing symptoms of depression and anxiety and improving QoL, and it was superior to AAD therapy (all P < 0.001). Multiple regression analysis demonstrated that catheter ablation, no AF recurrence, avoidance of warfarin use, higher baseline depression and anxiety scores, and lower baseline QoL scores contributed to improvement of depression, anxiety, and QoL, respectively. CONCLUSIONS: Catheter ablation is more effective for improving depression, anxiety, and QoL in patients with paroxysmal AF compared with AAD therapy.

[Effect of valsartan on vasoconstriction induced by the chronic injury of the adventitia in the rat collared carotid artery].

OBJECTIVE: Vasoconstriction and vascular hypersensitivity to serotonin were previously shown in animal models of adventitia injury. We investigated the contribution of angiotensin II (AngII)/AngII receptors and oxidative stress to vascular contractility and reactivity in this model. METHODS: Wistar Kyoto rats were divided into 3 groups: normal (n = 6, no any intervention, only for measuring the serum AngII concentration), vehicle (n = 12, collared), and valsartan (n = 12, collared + valsartan 30 mg×kg(-1)×d(-1)). After one week of treatment, adventitia injury was induced by positioning a silicone collar around the right carotid artery for one week. Blood flow and vascular reactivity to serotonin were determined one week after injury, the blood from left ventricle was taken to measure the serum AngII concentration by ELISA, and carotids were harvested for morphometry and Western blot analysis. RESULTS: Adventitia injury induced lumen cross-sectional area reduction (-44% vs. -5%), media diameter increase (62% vs. 10%), blood flow reduction [(2.79 ± 0.22) vs. (4.33 ± 0.84) ml/min] were significantly attenuated by valsartan. The increased vascular reactivity sensitivity to serotonin in vehicle group was also significantly reduced in valsartan group. Serum AngII concentration was significantly increased in vehicle group [(45.21 ± 4.52) pg/ml vs. (19.83 ± 0.5) pg/ml in normal rats, P = 0.0148] and the expression of AngII type 1 (AT(1)) receptor, AngII type 2 (AT(2)) receptor, as well as p22(phox) in collared arteries were significantly upregulated. Valsartan did not affect the AT(1) receptor expression but further increased serum AngII concentration [(89.73 ± 20.44) pg/ml vs. (45.21 ± 4.52) pg/ml, P = 0.001], and AT(2) receptor expression, while downregulated p22(phox) expressions. CONCLUSIONS: Collar-induced adventitia injury resulted in chronic vasoconstriction and vascular hypersensitivity to serotonin via increased serum AngII level, upregulated AngII receptors expression in the vascular well, and activated local oxidative stress. These changes could be blocked by valsartan suggesting a crucial role of AngII/AngII receptors on vascular contractility and reactivity changes in this model.

Effect of tongxinluo on vasoconstriction induced by the chronic injury of the adventitia in the rat carotid artery.

OBJECTIVE: Tongxinluo (TXL) is a traditional Chinese medicine that is developed on the meridian theory of traditional Chinese medicine, with the function of alleviating the angina. The present study was undertaken to explore the molecular mechanism of TXL in treating the pectoris angina through observing the effectiveness of TXL superfine powder on the vasoconstriction and the activation of RhoA/Rho-kinase pathway induced by the injury of the adventitia. METHODS: 36 male Wistar Kyoto rats were assigned to 3 treatments (n=12): vehicle, TXL (400 mg kg(-1) day(-1)) and fasudil (15 mg kg(-1) day(-1)). After 1 week of treatment, adventitia injury was induced by positioning a silicone collar around the right carotid artery for 1 week. Blood flow and vascular reactivity to serotonin were determined 1 week after injurying, the both sides of carotids were harvested for morphometry, Western blotting analysis and RT-PCR analysis. RESULTS: Adventitia injury leaded to histological changes of vasoconstriction with the lumen cross-sectional area of 44.7% (p<0.001) decreasing and the media diameter of 62.31% (p<0.001) increasing, accompanying by the reduction of the blood flow and the increase of vascular reactivity sensitivity to serotonin. Treatment with both TXL superfine powder and fasudil can prevent the development of vasoconstriction, improve the carotid blood flow and normalize the vascular hypersensitivity to serotonin. Adventitia injuring of the rat carotid increased the expression of Rho-kinase mRNA and p-MYPT1(Thr696) protein by 1.78-fold (p<0.05) and >2-fold respectively (p<0.05). TXL reduced the expression of Rho-kinase mRNA and p-MYPT1(Thr696) protein by 54.2% (p<0.05) and 57.1% (p<0.05) respectively in collared arteries. Fasudil restrained the p-MYPT1(Thr696) protein expression by 63.8% (p<0.05) in collared arteries, did not affect the collar-induced the increase of Rho-kinase mRNA expression (p>0.05). CONCLUSIONS: Treatment with TXL, similar to that with fasudil, can effectively prevent collar-induced vasoconstriction and vascular hyperreactivity to serotonin through inhibiting the RhoA/Rho-kinase pathway.

[Effects of different catheter ablation strategies in treatment of typical atrial flutter complicated with paroxysmal atrial fibrillation].

OBJECTIVE: To evaluate the clinical effects of different catheter ablation strategies in the treatment of typical atrial flutter complicated with paroxysmal atrial fibrillation (PAF). [CTIA, pulmonary vein segmental isolation (PVSI), CTIA + PVI] to the patients coexisted with typical atrial flutter and PAF. METHODS: 66 patients with typical atrial flutter complicated with PAF were divided into 3 groups: Group A (n = 30), undergoing cavotricuspid isthmus ablation, (CTIA), Group B (n = 17), undergoing pulmonary vein segmental isolation, (PVSI), and Group C (n = 19), undergoing CTIA + PVSI. Follow-up was conducted for 30.5 weeks +/- 10.4 weeks. The clinical curative effects, operation safety, and complication were evaluated. RESULTS: The recurrence rate of typical atrial flutter within 12 weeks after operation of Groups A and C were 13.3% and 10.5% respectively, both significantly lower than that of Group B (52.9%, both P < 0.05) without no significant difference between Group A and Group C (P > 0.05). The recurrence rate of typical atrial flutter within 36 weeks after operation of the Groups A, B, and C were 10%, 11.8%, and 10.5% respectively, without significant differences among these 3 groups (all P > 0.05). The recurrence rates of PAF within 12 weeks and 30 weeks after operation of Groups B and C were 29.4% and 31.6%, and 23.5% and 26.3% respectively, all significantly lower than those of Group A (46.7% and 73.3% respectively, all P < 0.05) without significant o differences between Groups B and C. CONCLUSION: In patients with both typical atrial flutter and PAF, pure CTIA has a good effect on typical atrial flutter, whereas the PAF recurrence rate is higher; Pure PVSI has a good control of typical atrial flutter while curing PAF; PVSI + CTIA only reduces the early recurrence of typical atrial flutter, however, has no advantage in long-term follow up.