Search

Mounting evidence demonstrates uncontrolled endoplasmic reticulum (ER) stress responses can activate the inflammasome, which generally results in endothelial dysfunction, a major pathogenetic factor of chronic inflammatory diseases such as atherosclerosis. Salvianolic acid B (SalB), produced by Radix Salviae, exerts antioxidative and anti-inflammatory activities in multiple cell types. However, SalB’s effects on ER stress-related inflammasome and endothelial dysfunction remain unknown. Here, we showed SalB substantially abrogated ER stress-induced cell death and reduction in capillary tube formation, with declined intracellular reactive oxygen species (ROS) amounts and restored mitochondrial membrane potential (MMP), as well as increased expression of HO-1 and SOD2 in bone marrow-derived endothelial progenitor cells (BM-EPCs). ER stress suppression by CHOP or caspase-4 siRNA transfection attenuated the protective effect of SalB. Additionally, SalB alleviated ER stress-mediated pyroptotic cell death via the suppression of TXNIP/NLRP3 inflammasome, as evidenced by reduced cleavage of caspase-1 and interleukin- (IL-) 1β and IL-18 secretion levels. Furthermore, this study provided a mechanistic basis that AMPK/FoxO4/KLF2 and Syndecan-4/Rac1/ATF2 signaling pathway modulation by SalB substantially prevented BM-EPCs damage associated with ER stress by decreasing intracellular ROS amounts and inducing NLRP3-dependent pyroptosis. In summary, our findings identify that ER stress triggered mitochondrial ROS release and NLRP3 generation in BM-EPCs, while SalB inhibits NLRP3 inflammasome-mediated pyroptotic cell death by regulating the AMPK/FoxO4/KLF2 and Syndecan-4/Rac1/ATF2 pathways. The current findings reveal SalB as a potential new candidate for the treatment of atherosclerotic heart disease.

Background: Obesity is major cause of cardiovascular diseases. Metabolically health obesity (MHO) may increase heart failure risk early in life, and may be reflected in impaired cardiac structure and function. Therefore, we aimed to examine the relationship between MHO in young adulthood and cardiac structure and function. Methods: A total of 3,066 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study were included, who completed echocardiography in young adulthood and middle age. The participants were grouped by obesity status (body mass index ≥30 kg/m2) and poor metabolic health (≥ 2 criteria for metabolic syndrome) into four metabolic phenotypes as follows: metabolically healthy non-obesity (MHN), MHO, metabolically unhealthy non-obesity (MUN), metabolically unhealthy obesity (MUO). The associations of the metabolic phenotypes (MHN serving as the reference) with left ventricular (LV) structure and function were evaluated using multiple linear regression models. Results: At baseline, mean age was 25 years, 56.4% were women, and 44.7% were black. After a follow-up 25 years, MUN in young adulthood was associated with worse LV diastolic function (E/é ratio, β [95% CI], 0.73 [0.18, 1.28]), worse systolic function (global longitudinal strain [GLS], 0.60 [0.08, 1.12]) in comparison with MHN. MHO and MUO were associated with LV hypertrophy (LV mass index, 7.49 g/m2 [4.63, 10.35]; 18.23 g/m2 [12.47, 23.99], respectively), worse diastolic function (E/é ratio, 0.67 [0.31, 1.02]; 1.47 [0.79, 2.14], respectively), and worse systolic function (GLS, 0.72 [0.38, 1.06]; 1.35 [0.64, 2.05], respectively) in comparison with MHN. These results were consistent in several sensitivity analyses. Conclusions: In this community-based cohort using data from the CARDIA study, obesity in young adulthood was significantly associated with LV hypertrophy, worse systolic and diastolic function regardless of metabolic status.

Objective: To assess the efficacy and safety of berberine in the treatment of prediabetes. Methods: We searched the following databases, CNKI, WanFang, VIP, CBM, PubMed, Cochrane Library, Embase, and Medline (OVID) from the databases established to December 2020 in Chinese or English language. Randomized control trials (RCTs) of berberine compared with lifestyle modification, placebo, and/or hypoglycaemics intervention on treating prediabetes were included. Data extraction and paper quality assessment were conducted according to the Cochrane Handbook. RevMan 5.4 was used for the meta-analysis. Results: Seven studies involving 859 participants were included in the study and the control groups were all lifestyle modification or metformin treatment. The clinical heterogeneity of the trials was relatively high, and the methodological quality of most trials was generally low. Meta-analysis suggested that berberine could reduce FPG (P = 0.001), 2hPG (P = 0.001) and HbA1c (P = 0.002) levels significantly as compared with lifestyle group. There was no statistical significance between berberine and metformin. No serious adverse effects from berberine were reported. Conclusions: Berberine has good efficacy and safety in the treatment of prediabetes. Due to the quality limitations of the included trials, the above conclusions need to be further verified by high-quality, large sample size and multi-center clinical trials.

Both aldosterone and arginine vasopressin (AVP) are produced in the heart and may participate in cardiac fibrosis. However, their relationship remains unknown. This study aims to demonstrate the regulation and role of AVP in aldosterone synthesis in the heart. Rats were subjected to a sham operation or myocardial infarction (MI) by ligating the coronary artery. Cardiac function and fibrosis were assessed using echocardiography and immunohistochemical staining, respectively. In addition, the effects of AVP stimulation on cardiac microvascular endothelial cells (CMECs) were studied using ELISA, real-time PCR, and Western blotting. Compared with the rats having undergone a sham operation, the MI rats had an increased LVMI, type I collagen composition, and concentrations of aldosterone and AVP in the heart but decreased cardiac function. As the MI rats aged, the LVMI, type I collagen, aldosterone, and AVP increased, while the LVMI decreased. Furthermore, AVP time-dependently induced aldosterone secretion and CYP11B2 mRNA expression in CMECs. The p-CREB levels were significantly increased by AVP. Nevertheless, these effects were completely blocked by SR49059 or partially inhibited by KN93. This study demonstrated that AVP could induce the secretion of local cardiac aldosterone, which may involve CaMK and CREB phosphorylation and CYP11B2 upregulation through V1 receptor activation.

Background Some previous studies explored associations between vascular endothelial growth factor receptor 2 (VEGFR2) polymorphisms and atherosclerotic cardiovascular diseases (ASCVD), with conflicting findings. Hypothesis We thought that VEGFR2 polymorphisms may influence susceptibility to ASCVD. Here, we aimed to better analyze the relationship between VEGFR2 polymorphisms and ASCVD in a larger combined population by performing a meta‐analysis. Methods We searched Pubmed, Embase, and Web of Science for related articles. We calculated odds ratio (OR) and 95% confidence interval (CI) to estimate whether there are genetic associations between VEGFR2 polymorphisms and ASCVD. Results Ten studies were included for this meta‐analysis (5474 cases and 8584 controls). VEGFR2 rs1870377 (dominant comparison: 0.81 (0.73‐0.89), I 2 = 56%; recessive comparison: 1.40 (1.25‐1.57), I 2 = 34%; allele comparison: 0.81 (0.76‐0.87), I 2 = 0%), rs2071559 (dominant comparison: 0.83 (0.76‐0.91), I 2 = 0%; recessive comparison: 1.22 (1.07‐1.38), I 2 = 0%; allele comparison: 0.86 (0.81‐0.92), I 2 = 0%) and rs2305948 (dominant comparison: 0.79 (0.72‐0.87), I 2 = 25%; recessive comparison: 1.44 (1.08‐1.92), I 2 = 60%; allele comparison: 0.79 (0.68‐0.92), I 2 = 73%) polymorphisms were all found to be significantly associated with susceptibility to ASCVD in general population. Subgroup analyses by type of disease revealed similar significant findings for rs1870377, rs2071559, and rs2305948 polymorphisms in coronary artery disease (CAD) subgroup. Besides, positive results were also found for rs1870377 polymorphism in ischemic stroke (IS) subgroup. Conclusions In summary, this meta‐analysis proved that these VEGFR2 polymorphisms could be used to identify individual with elevated susceptibility to ASCVD.

Increasing evidence demonstrates that uncontrolled endoplasmic reticulum (ER) stress responses can activate the inflammasome, which often leads to endothelial dysfunction that underlies the pathogenesis of chronic inflammatory diseases such as atherosclerosis. Salvianolic acid B (SalB), a bioactive compound isolated from Radix Salviae, has been reported to exert anti-oxidative and anti-inflammatory activities in various types of cells. However, the effect of SalB on ER stress-related inflammasome and endothelial dysfunction has not been studied. In the present study, we demonstrated that SalB substantially abrogated ER stress-induced cell death and reduction in capillary tube formation that was linked to declined intracellular reactive oxygen species (ROS) levels, restored mitochondrial membrane potential (MMP), and increased expression of HO-1 and SOD2 in bone marrow-derived endothelial progenitor cells (BM-EPCs). Inhibition of ER stress by CHOP or caspase-4 siRNA transfection attenuated the protective effect of SalB. Furthermore, SalB alleviates ER stress-mediated pyroptotic cell death via suppression of TXNIP/NLRP3 inflammasome activation, as evidenced by decrease in cleavage of caspase-1 and downstream mature interleukin (IL)-1β and IL-18 secretion. Furthermore, our results provide mechanistic evidence that modulation of AMPK/FoxO4/KLF2 and Syndecan-4/Rac1/ATF2 signaling pathways by SalB significantly protected BM-EPCs against cell injury caused by ER stress via reduction of intracellular ROS levels and NLRP3-dependent pyroptosis. In summary, our findings identify that ER stress-induced mitochondrial ROS release and NLRP3 assembly in BM-EPCs, while SalB inhibit NLRP3 inflammasome-mediated pyroptotic cell death via regulating novel AMPK/FoxO4/KLF2 and Syndecan-4/Rac1/ATF2 signaling pathways. These findings suggest SalB to be a potential new agent with applications in the fields of atherosclerotic heart disease. Funding Information: The project was supported by grants from the National Natural Science Foundation of China (No. 81503281), Natural Science Foundation of Guangdong Province (No. 2021A1515011257), Science and Technology Planning Project of Guangzhou (No. 201904010109), Joint Funds of Natural Science Foundation of Guangdong Province (No. 2020B1515120094), and the Talent Grant of Sun Yat-sen University (No. 18ykpy11). Declaration of Interests: The authors declare that there is no conflict of interest to reveal. Ethics Approval Statement: Informed consent for bone marrow collection was obtained from healthy volunteers. All procedures were performed in accordance with the guidance and approval of the local institutional review board (approval no. 2016[130]).

The People’s Republic of China (PRC) is in the process of modernization, which it expects to achieve by 2035. This requires a national indicator to gauge the progress and level of the country’s modernization drive. This working paper provides an indicator that assesses the progress in the PRC’s modernization journey, and applies this modernization indicator—structured on thematic categories, subcategories, and intersection—to the PRC’s performance, which is then compared with countries of the Organisation for Economic Co-operation and Development and the G20. The paper also examines four major policy implications of this modernization for the PRC, which will be more durable and successful if coupled with effective division of labor and synergy with stakeholders.

It has been reported that exogenous hydrogen sulfide (H2S) protects against high glucose (HG)-induced cardiac injury and has a modulatory effect on heat shock protein (HSP) and Akt, which play a cardioprotective role. In this study, we examined whether the HSP90/Akt pathway contributes to the protective effects of exogenous H2S against HG-induced injury to H9c2 cardiac cells. Our results revealed that the exposure of H9c2 cardiac cells to 35 mM glucose (HG) for 1 to 24 h decreased the expression of HSP90 and markedly reduced the expression level of phosphorylated (p)-Akt in a time-dependent manner. Co-exposure of the cells to HG and geldanamycin (GA; an inhibitor of HSP90) aggravated the inhibition of the p-Akt expression level by HG. Of note, treatment of the cells with 400 µM NaHS (a donor of H2S) for 30 min prior to exposure to HG significantly attenuated the HG-induced decrease in the expression levels of both HSP90 and p-Akt, along with inhibition of HG-induced cell injury, as indicated by the increase in cell viability and superoxide dismutase (SOD) activity, and by a decrease in the number of apoptotic cells, reactive oxygen species (ROS) generation, as well as by the decreased dissipation of mitochondrial membrance potential (MMP). Importantly, treatment of the cells with GA or LY294002 (an inhibitor of Akt) prior to exposure to NaHS and HG considerably blocked the cardioprotective effects of NaHS against the HG-induced injury mentioned above. On the whole, the findings of this study demonstrate that the inhibition of the HSP90/Akt pathway may be an important mechanism responsible for HG-induced cardiomyocyte injury. We also provide novel evidence that exogenous H2S protects H9c2 cells against HG-induced injury by activating the HSP90/Akt pathway.

Our previous study demonstrated that angiotensin II (Ang II) upregulates the expression of Kv1.5, a promising target for atrial fibrillation (AF) therapy, by activating ROS-dependent P-Smad2/3 and P-ERK 1/2. A recent study showed that hydrogen sulfide (H2S) may modulate the effects of angiotensin II (Ang II) by inhibiting the NADPH oxidase 4 (Nox4)-ROS signaling in the heart. The present study aimed to determine whether H2S is involved in the regulation of atrial Kv1.5 via ROS-related mechanisms in AF. Cultured neonatal rat atrial myocytes and a beagle model of AF were used for this study. In the neonatal rat atrial myocytes, quantitative PCR and enzyme immunoassays revealed that the mRNA expression levels of angiotensinogen, angiotensin-converting enzyme, and Ang II type I receptor (AT1R) and the Ang II supernatant concentration were significantly increased by hydrogen peroxide (H2O2) incubation, and these H2O2-induced alterations were reversed by diphenyleneiodonium, apocynin and H2S supplementation. Flow cytometry and Western blotting revealed that blockade of H2S biosynthesis using dl-propargylglycine increased ROS production and the expression of Ang II and Kv1.5. Sodium hydrosulfide (an exogenous H2S donor) and Nox4 siRNA inhibited Ang II-induced ROS production and Ang II-induced expression of Kv1.5, P-Smad2/3, P-ERK 1/2. Sodium hydrosulfide suppressed the Ang II-induced upregulation of Nox4. In our beagle AF model, 24 h of rapid atrial pacing (RAP) increased the atrial Ang II concentration, ROS production and the protein expression of Nox4, Kv1.5, P-Smad2/3 and P-ERK 1/2. These RAP-induced changes were inhibited by H2S supplementation and losartan (an AT1R blocker) pretreatment. In conclusion, our study indicates that H2S downregulates Ang II-induced atrial Kv1.5 expression by attenuating Nox4-related ROS-triggered P-Smad2/3 and P-ERK 1/2 activation during AF. H2S supplementation would be beneficial for AF treatment via the suppression of atrial Kv1.5 expression.

Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional secreted protein that can be induced by fasting, hypoxia and glucocorticoids. ANGPTL4 has been associated with a variety of diseases; however, the role of ANGPTL4 in cardiac hypertrophy remains poorly understood. In our study, we aimed to explore the effect of ANGPTL4 on phenylephrine-induced cardiomyocyte hypertrophy. Our results showed that knockdown of ANGPTL4 expression significantly exacerbated cardiomyocyte hypertrophy, as demonstrated by increased hypertrophic marker expression, including ANP and cell surface area. Moreover, significantly reduced fatty acid oxidation, as featured by decreased CPT-1 levels, was observed in hypertrophic cardiomyocytes following ANGPTL4 down-regulation. Furthermore, knockdown of ANGPLT4 led to down-regulated expression of peroxisome proliferator-activated receptor α (PPARα), which is the key regulator of cardiac fatty acid oxidation. In addition, ANGPTL4 silencing promoted the activation of JNK1/2, and JNK1/2 signaling blockade could restore the level of PPARα and significantly ameliorate the ANGPTL4 knockdown-induced cardiomyocyte hypertrophy. Therefore, our study demonstrated that ANGPTL4 regulates PPARα through JNK1/2 signaling and is required for the inhibition of cardiomyocyte hypertrophy.

Subsequently to the publication of this article, the authors have realized that the address affiliation for the corresponding author, Chengheng Hu, and the authors Longyun Peng and Xinxue Liao appeared incorrectly. These authors' affiliation information should have appeared as follows (the corrected address affiliation is featured in bold): XIAO KE1,2*, JINGFU CHEN3*, LONGYUN PENG4, WEI ZHANG5, YIYING YANG5, XINXUE LIAO4, LIQIU MO6, RUIXIAN GUO7, JIANQIANG FENG6, CHENGHENG HU4 and RUQIONG NIE2 1Department of Cardiology, Shenzhen Sun Yat‑sen Cardiovascular Hospital, Shenzhen; 2Department of Cardiology, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong; 3Department of Cardiovascular Medicine and Dongguan Cardiovascular Institute, The Third People's Hospital of Dongguan City, Dongguan; 4Department of Cardiology and Key Laboratory on Assisted Circulation, Ministry of Health, The First Affiliated Hospital, Sun Yat‑sen University; 5Department of Cardiovasology and Cardiac Care Unit (CCU), Huangpu Division of The First Affiliated Hospital, Sun Yat‑sen University; 6Department of Anesthesiology, Huangpu Division of The First Affiliated Hospital, Sun Yat‑sen University; 7Department of Physiology, Zhongshan School of Medicine, Sun Yat‑sen University, Guangzhou, Guangdong, P.R. China *Contributed equally In addition, the address for correspondence in the correspondence box should have appeared as follows: Correspondence to: Professor Chengheng Hu, Department of Cardiology and Key Laboratory on Assisted Circulation, Ministry of Health, The First Affiliated Hospital, Sun Yat‑sen University, Guangdong, 58 Zhongshan 2rd Road, Guangzhou 510080, P.R. China E‑mail: huchengheng138@163.com The authors regret this error in the affiliations, and apologize for any inconvenience caused. [the original article was published in the International Journal of Molecular Medicine 39: 1001‑1010, 2017; DOI: 10.3892/ijmm.2017.2891].

Kv1.5 potassium channel represents a promising target for atrial fibrillation (AF) therapy. During AF, the renin-angiotensin system is markedly activated. Recent evidence indicates that angiotensin II (Ang II) can upregulate Kv1.5 channel, but the mechanism remains unknown. In this study, we report that Ang II-mediated transforming growth factor-beta1 (TGF-β1)/Smad2/3 and extracellular signal-regulated kinase (ERK) 1/2 signalings are involved in atrial Kv1.5 expression. In neonatal rat atrial myocytes, quantitative PCR and Western blotting revealed that Ang II upregulated TGF-β1, synapse-associated protein 97 (SAP97) and Kv1.5 expression in a time- and concentration-dependent manner. The Ang II-induced upregulation of Kv1.5, SAP97 and phosphorylated Smad2/3 (P-Smad2/3) were reversed by the Ang II type 1 (AT1) receptor antagonist losartan, an anti-TGF-β1 antibody and the ERK 1/2 inhibitor PD98059 but not by the AT2 receptor antagonist PD123319. mRNA knockdown of either Smad2 or Smad3 blocked Ang II-induced expression of Kv1.5 and SAP97. These data suggest that AT1 receptor/TGF-β1/P-Smad2/3 and ERK 1/2 signalings are involved in Ang II-induced Kv1.5 and SAP97 expression. Flow cytometry and Western blotting revealed that losartan and the anti-TGF-β1 antibody diminished Ang II-induced reactive oxygen species (ROS) generation and that the antioxidants diphenyleneiodonium and N-acetyl cysteine inhibited Ang II-induced expression of P-Smad2/3, phosphorylated ERK (P-ERK) 1/2, Kv1.5, SAP97, suggesting that ROS participate in Kv1.5 and SAP97 regulation by modulating Ang II-induced P-Smad2/3 and P-ERK 1/2 expression. In conclusion, we demonstrate that ROS-dependent Ang II/AT1 receptor/TGF-β1/P-Smad2/3 and Ang II/ERK 1/2 signalings are involved in atrial Kv1.5 and SAP97 expression. Antioxidants would be beneficial for AF treatment through inhibiting atrial Kv1.5 expression.

Hypoxia is a key inducer of neovascularization which is essential for tumor growth, invasion and metastasis. It has been proposed that the recruitment of bone-marrow-derived endothelial progenitor cells (BM-EPCs) is pivotal and requires the participation of several tumor-derived cytokines. However, it is not known whether prostate cancer (PCa) cells contribute to the recruitment and vasculogenesis of EPCs in PCa progression. In the present study, we demonstrated that all conditioned medium (CM) of PC-3 PCa cells promoted proliferation and migration, and augmented the vasculogenesis capacity of BM-EPCs, and 24-h hypoxia (24H)-CM presented stronger ability compared to 24-h normoxia (24N)-CM and 48H-CM. Human cytokine antibody array with 174 anti-cytokine antibodies revealed the changes of cytokine in CMs. Twenty-five types of cytokines significantly increased in 24H-CM compared with 24N-CM. Eleven types of cytokines (5 factors increased and 6 decreased) were significantly different between 48H-CM and 48N-CM. Twelve types of cytokines (4 factors increased and 8 decreased) were significantly different between 48H-CM and 24H-CM. Furthermore, according to the gene ontology analysis, all altered cytokines were involved in proliferation, chemotaxis, cell motility, cell migration, vasculogenesis and angiogenesis. Of note, the changed regularity of cytokines in the 24H-CM and 48H-CM of PC-3 cells was in concert with the functional changes of BM-EPCs treated by different CM of PC-3 cells in enhancing the proliferation, migration and vasculogenesis potential of BM-EPCs. These findings suggest that PCa cells may have the potential to modulate their microenvironment and facilitate BM-EPC migration and vasculogenesis by secretion of cytokines in the early stage of hypoxia.

Cardiac structures and functions change with advanced age, but the underlying mechanisms are not well understood. Autophagy and apoptosis play important roles in the process of cardiac remodeling. This study was designed to explore changes in cell autophagy and apoptosis during age-related left ventricular remodeling and to determine whether the mitogen-activated protein kinase (MAPK) pathway is an underlying mechanism. Eight 5-month-old (adult group) and eight 24-month-old male C57bl/6 mice (aged group) were studied. The heart mass index, left ventricular mass index and hydroxyproline content of both groups were compared. Western Blotting was used to quantitate the protein expression of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, caspase-3, B-cell leukemia-2 (Bcl-2) and MAPKs in the left ventricles of adult and aged mice. Our results showed that the heart mass index, left ventricular mass index and hydroxyproline content in the left ventricles of the aged mice were increased significantly compared with the adult mice, indicating that left ventricular remodeling occurs with aging. The expression of LC3 and Beclin-1 in the left ventricles of aged mice were decreased significantly compared to adult mice. Meanwhile, the level of myocardial caspase-3 in adult mice remained the same in aged mice, and the level of myocardial Bcl-2 increased significantly in aged mice. There were no differences in the expression level of myocardial extracellular signal-regulated kinase 1/2 (ERK1/2), activated/phospho-ERK1/2, c-Jun N-terminal kinase 1/2 (JNK1/2) and p38 between aged and adult mice. However, the expression of myocardial activated/phospho-JNK1/2 increased significantly in aged mice, while activated/phospho-p38 decreased significantly. These findings indicate that autophagy decreases without a concurrent change in apoptosis during age-related left ventricular remodeling in mice. The MAPK pathway may be involved in the regulation of age-related left ventricular remodeling by modulating autophagy.

Heart failure is a major cause of morbidity and mortality worldwide. Diuretics are regarded as the first-line treatment for patients with heart failure because they provide symptomatic relief. However, the specific benefits of diuretics and their effects on heart failure survival remain unclear. This study was designed to investigate the potential of hydrochlorothiazide to improve cardiac remodeling compared with spironolactone. Heart failure was produced by ligation of the left anterior descending coronary artery in male Sprague-Dawley rats. Two weeks after coronary artery ligation, 55 rats were randomly divided into four groups: sham-operated group (n=10), control group (n=15), hydrochlorothiazide group (12.5 mg/kg/day, n=15) and spironolactone group (20 mg/kg/day, n=15). Cardiac function was assessed by echocardiography and Millar catheter after treatment with drugs for 8 weeks. Compared with the control group, ejection fraction and left ventricular end-systolic pressure were significantly improved in the hydrochlorothiazide and spironolactone treatment groups (P0.05). In addition, hydrochlorothiazide and spironolactone reduced collagen volume fraction and proinflammatory cytokine levels. Moreover, gene and protein expression of TGF-β1, Smad2, Smad3 and Smad7 (P0.05) were also reduced. Nevertheless, no significant differences were observed between the hydrochlorothiazide and spironolactone groups. These results suggest that hydrochlorothiazide improves cardiac remodeling as effectively as spironolactone by reducing proinflammatory cytokine levels and inhibiting the TGF-β signaling pathway in post-myocardial infarction congestive heart failure. Moreover, the effects of the drugs on the TGF-β signaling pathway are likely to result from inhibited TGF-β and R-Smads expression rather than increased Inhibitory-Smad7 expression.

Diastolic heart failure (DHF) is a clinical syndrome characterized by the symptoms and signs of heart failure, preserved ejection fraction (EF) and abnormal diastolic function [1]. Hypertension is the most common risk factor and the principal precursor for DHF [2]. Hypertension-induced left ventricular (LV) hypertrophy that includes myocardial hypertrophy and abnormal accumulation of fibrillar collagen causes a decreased compliance and LV diastolic dysfunction. It is estimated that 20–60% of patients with heart failure have preserved EF [3,4]. Unfortunately, in contrast to the situation of heart failure with low EF, the mortality and morbidity of DHF have not been significantly decreased in the past decades [5,6]. Magnesium is the second most abundant intracellular cation. As a cofactor formany enzymes,magnesiumplays a role in various biological functions including energy metabolism and muscle contraction [7]. It is known that activation of the rennin–angiotensin–aldosterone system and the use of diuretics in patients with essential hypertension or cardiac failure may deplete serum potassium and affect intracellular magnesium homeostasis [8,9]. We have shown the importance of maintaining magnesium homeostasis in reducing arrhythmia and myocardial hypertrophy in patients with heart failure or hypertension [10,11]. However, the role of magnesium homeostasis in diastolic heart dysfunction is not known yet. Thus, we designed this study to address this issue. Since myocardium of patients is usually not easily accessible, we measured intralymphocytic magnesium content to reflect the magnesium content in myocardial cells. This was a single center prospective study that conformed to the ethical principles outlined in the Declaration of Helsinki. The study protocol was approved by the ethics committee of the First Affiliated Hospital of the SunYat-SenUniversity (Guangzhou, China). Consecutive 206 essential hypertension patients with diastolic heart dysfunction documented by Doppler echocardiography from November 2007 to October 2009 were enrolled. Patients with diastolic heart dysfunction and clinical signs and symptoms of heart failure as described in the European Society of Cardiology Guidelines published in 2008 [12] were attributed to DHF group (group A). Those free of signs and symptoms of

Rationale: Tachycardia-induced atrial fibrosis is a hallmark of structural remodeling of atrial fibrillation (AF). The molecular mechanisms underlying the AF-induced atrial fibrosis remain unclear. Objective: To determine the role of angiotensin II (Ang II)/Ang II type 1 (AT 1 ) receptor–coupled transforming growth factor (TGF)-β 1 /Smad signaling pathway in the AF-induced atrial fibrosis. Methods and Results: Rapid atrial pacing (1000 ppm) was applied to the left atrium of rabbit heart to induce atrial fibrillation and fibrosis. Quantitative PCR and Western blot analysis revealed that rapid atrial pacing caused a marked increase in the expression of Ang II, TGF-β 1 , phosphorylated Smad2/3 (P-Smad2/3), Arkadia, and hydroxyproline synthesis. However, the expression of Smad7, a key endogenous antagonist of the TGF-β 1 /Smad-mediated fibrosis, was significantly decreased. These changes were dose-dependently reversed by AT 1 receptor antagonist losartan, implicating the involvement of AF-induced release of Ang II and activation of AT 1 receptor–specific pathway. In the adult rabbit cardiac fibroblasts, Ang II increased the expression of TGF-β 1 , P-Smad2/3, Smad4, Arkadia, and collagen I synthesis and significantly reduced Smad7 expression. These effects of Ang II were reversed by losartan but not by the AT 2 antagonist (PD123319). In addition, extracellular signal-regulated kinase inhibitor and anti–TGF-β 1 antibody also blocked the Ang II–induced downregulation of Smad7. Silencing of Smad7 gene by small interfering RNA abolished the antagonism of losartan on the fibrogenic effects of Ang II on cardiac fibroblasts, whereas overexpression of Smad7 blocked Ang II–induced increase in collagen I synthesis. Conclusions: Ang II/AT 1 receptor–specific activation of Arkadia-mediated poly-ubiquitination and degradation of Smad7 may decrease the inhibitory feedback regulation of TGF-β 1 /Smad signaling and serves as a key mechanism for AF-induced atrial fibrosis.

Objective: It was our aim to study the outcome of autonomic nervous function (ANF), heart rate variability (HRV) and arrhythmias in patients with acute viral myocarditis in a 6-month follow-up period after the diagnosis. Methods: ANF was measured in patients with acute viral myocarditis 1, 3 and 6 months after the disease was diagnosed. HRV and arrhythmias were monitored by 24-hour electrocardiogram during the follow-up examination. Results: Ninety-six patients with acute viral myocarditis were enrolled in this study; 58% showed abnormal ANF tests, and the incidence was reduced to 17% after 6 months (p < 0.01). Time and frequency domain analyses of HRV were significantly reduced in the early stage of the disease and recovered after 6 months (p < 0.05). The incidence of arrhythmias in patients with abnormal ANF was significantly higher than in patients with normal ANF (p < 0.05). The incidence of arrhythmias in patients with abnormal ANF at 6 months was significantly lower than that at the first month (p < 0.05). Conclusions: There is a significant impairment of ANF and a higher incidence of arrhythmias in the early stage of acute myocarditis. ANF and HRV abnormalities are significantly improved, and the incidence of arrhythmia is significantly reduced after 6 months in patients with acute myocarditis.

We and others have shown that prior exposure to the volatile anesthetic isoflurane induces ischemic tolerance in the brain. Our results also suggest that isoflurane preconditioning reduces cell apoptosis in the penumbral region of rat brain. We designed this study to determine whether isoflurane preconditioning decreased mitochondria-dependent cell apoptosis. Adult male Sprague-Dawley rats were exposed to or not exposed to 2% isoflurane for 30 min at 24 h before the permanent middle cerebral arterial occlusion. Western blotting was used to quantify protein expression in the cytosolic and mitochondrial fractions of non-ischemic brain cortex and brain cortex in the ischemic core and penumbra. Isoflurane preconditioning significantly decreased the infarct volume of cerebral cortex and improved neurological outcome. Isoflurane increased the expression of the antiapoptotic B-cell lymphoma-2 (Bcl-2) proteins in the cerebral cortex of rats without brain ischemia. Rats preconditioned with isoflurane before brain ischemia had increased Bcl-2 expression in the penumbra. Isoflurane preconditioning reduced the release of cytochrome c from the mitochondria and the activation of caspase 3 in the penumbra. However, isoflurane preconditioning did not alter the translocation of Bid and Bax from the cytosol to the mitochondria, identified mechanisms for Bcl-2 to block the release of cytochrome c from the mitochondria. Our results suggest that isoflurane preconditioning increases Bcl-2 expression to block the release of cytochrome c from the mitochondria to decrease the cell apoptosis in the penumbra.

Background Preconditioning the brain with relatively safe drugs seems to be a viable option to reduce ischemic brain injury. The authors and others have shown that the volatile anesthetic isoflurane can precondition the brain against ischemia. Here, the authors determine whether isoflurane preconditioning improves long-term neurologic outcome after brain ischemia. Methods Six-day-old rats were exposed to 1.5% isoflurane for 30 min at 24 h before the brain hypoxia-ischemia that was induced by left common carotid arterial ligation and then exposure to 8% oxygen for 2 h. The neuropathology, motor coordination, and learning and memory functions were assayed 1 month after the brain ischemia. Western analysis was performed to quantify the expression of the heat shock protein 70, Bcl-2, and survivin 24 h after isoflurane exposure. Results The mortality was 45% after brain hypoxia-ischemia. Isoflurane preconditioning did not affect this mortality. However, isoflurane preconditioning attenuated ischemia-induced loss of neurons and brain tissues, such as cerebral cortex and hippocampus in the survivors. Isoflurane also improved the motor coordination of rats at 1 month after ischemia. The learning and memory functions as measured by performance of Y-maze and social recognition tasks in the survivors were not affected by the brain hypoxia-ischemia or isoflurane preconditioning. The expression of Bcl-2, a well-known antiapoptotic protein, in the hippocampus is increased after isoflurane exposure. This increase was reduced by the inhibitors of inducible nitric oxide synthase. Inducible nitric oxide synthase inhibition also abolished isoflurane preconditioning-induced neuroprotection. Conclusions Isoflurane preconditioning improved the long-term neurologic outcome after brain ischemia. Inducible nitric oxide synthase may be involved in this neuroprotection.

Aims Our previous study indicates that hydrochlorothiazide inhibits transforming growth factor (TGF)-β/Smad signaling pathway, improves cardiac function and reduces fibrosis. We determined whether these effects were common among the diuretics and whether angiotensin II receptor type 1 (AT1) signaling pathway played a role in these effects. Methods Heart failure was produced by ligating the left anterior descending coronary artery in adult male Sprague-Dawley rats. Two weeks after the ligation, 70 rats were randomly divided into five groups: sham-operated group, control group, valsartan group (80 mg/kg/day), hydrochlorothiazide group (12.5 mg/kg/day) and furosemide group (20 mg/kg/day). In addition, neonatal rat ventricular fibroblasts were treated with angiotensin II. Results After eight-week drug treatment, hydrochlorothiazide group and valsartan group but not furosemide group had improved cardiac function (ejection fraction was 49.4 ± 2.1%, 49.5 ± 1.8% and 39.9 ± 1.9%, respectively, compared with 40.1 ± 2.2% in control group), reduced cardiac interstitial fibrosis and collagen volume fraction (9.7 ± 1.2%, 10.0 ± 1.3% and 14.1 ± 0.8%, respectively, compared with 15.9 ± 1.1% in control group), and decreased expression of AT1, TGF-β and Smad2 in the cardiac tissues. In addition, hydrochlorothiazide reduced plasma angiotensin II and aldosterone levels. Furthermore, hydrochlorothiazide inhibited angiotensin II-induced TGF-β1 and Smad2 protein expression in the neonatal rat ventricular fibroblasts. Conclusions Our study indicates that the cardiac function and remodeling improvement after ischemic heart failure may not be common among the diuretics. Hydrochlorothiazide may reduce the left ventricular wall stress and angiotensin II signaling pathway to provide these beneficial effects. This article is protected by copyright. All rights reserved.

Angiotensin II is a powerful mediator to induce cardiac remodeling and fibrosis. Transforming growth factor-beta1 (TGF-beta1) and extracellular signal-regulated kinase (ERK) have been implicated in the angiotensin II-induced cardiac fibrosis. However, the signaling pathways for this angiotensin II effect and the interaction between ERK and the TGF-beta1 signaling in this effect have not been well-illustrated. Cardiac fibroblasts were prepared from the ventricles of adult male Sprague-Dawley rats. They were treated with 1 microM angiotensin II in the presence or absence of losartan (angiotensin II AT(1) receptor antagonist), PD123319 (angiotensin II AT(2) receptor antagonist), an anti-TGF-beta1 antibody or PD98059 (ERK inhibitor). The cells were collected for Western blotting and reverse transcription-polymerase chain reaction. Angiotensin II caused a significant increase of the expression of TGF-beta(1), ERK1, phosphorylated-Smad2/3, Smad4 and collagen I. This increase was attenuated by losartan but was not affected by PD123319. An anti-TGF-beta(1) antibody and PD98059 diminished angiotensin II-induced Smad2/3 phosphorylation and the expression of Smad7 and collagen I. Our results suggest that angiotensin II induces collagen I expression through angiotensin II AT(1) receptor-TGF-beta(1)-Smads signaling pathway in cardiac fibroblasts. ERK, by regulating Smads signaling, also participated in the angiotensin II-induced collagen I expression.

Statins ameliorate myocardial fibrosis after myocardial infarction. We designed this study to determine whether fluvastatin reduced hypertension-induced myocardial hypertrophy and fibrosis and whether these fluvastatin effects involved transforming growth factor beta1 (TGF-beta1) and Smad 7, factors known to play a role in the myocardial hypertrophy and fibrosis. We randomized 14 week old spontaneously hypertensive rats (SHRs) to receiving vehicle or 5-20 mg/kg/day fluvastatin for 8 weeks. Wistar Kyoto (WKY) rats receiving vehicle or 10 mg/kg/day fluvastatin were also studied. SHRs had an increased blood pressure, left ventricular hypertrophy and fibrosis compared with WKY rats. SHRs also had an elevated TGF-beta1 expression and a decreased Smad 7 expression. These changes in SHRs were dose-dependently attenuated by fluvastatin. For example, the hydroxyproline content was 3.2+/-0.1, 4.0+/-0.1 and 3.5+/-0.1 microg/mg heart and the Smad 7 protein expression was 5.1+/-0.6, 1.0+/-0.1 and 4.1+/-0.7 arbitrary units for WKY rats, SHRs and SHRs receiving 20 mg/kg/day fluvastatin, respectively. The hydroxyproline content in the SHRs treated with or without fluvastatin was positively correlated with the left ventricular mass index, systolic blood pressure and the amount of TGF-beta1 proteins and negatively correlated with the Smad 7 expression level. The left ventricular mass index was positively correlated with the systolic blood pressure. Fluvastatin did not alter the blood pressure, left ventricular mass index and collagen content of WKY rats. These results suggest that fluvastatin reduces hypertension-induced myocardial hypertrophy and fibrosis. These effects may involve an increased expression of Smad 7 and a decreased expression of TFG-beta1. Our results call for clinical studies to evaluate these fluvastatin effects in hypertensive patients.