Dronedarone Attenuates Ang II-Induced Myocardial Hypertrophy Through Regulating SIRT1/FOXO3/PKIA Axis.

BACKGROUND AND OBJECTIVES: Long-term pathological myocardial hypertrophy (MH) seriously affects the normal function of the heart. Dronedarone was reported to attenuate left ventricular hypertrophy of mice. However, the molecular regulatory mechanism of dronedarone in MH is unclear. METHODS: Angiotensin II (Ang II) was used to induce cell hypertrophy of H9C2 cells. Transverse aortic constriction (TAC) surgery was performed to establish a rat model of MH. Cell size was evaluated using crystal violet staining and rhodamine phalloidin staining. Reverse transcription quantitative polymerase chain reaction and western blot were performed to detect the mRNA and protein expressions of genes. JASPAR and luciferase activity were conducted to predict and validate interaction between forkhead box O3 (FOXO3) and protein kinase inhibitor alpha (PKIA) promoter. RESULTS: Ang II treatment induced cell hypertrophy and inhibited sirtuin 1 (SIRT1) expression, which were reversed by dronedarone. SIRT1 overexpression or PKIA overexpression enhanced dronedarone-mediated suppression of cell hypertrophy in Ang II-induced H9C2 cells. Mechanistically, SIRT1 elevated FOXO3 expression through SIRT1-mediated deacetylation of FOXO3 and FOXO3 upregulated PKIA expression through interacting with PKIA promoter. Moreover, SIRT1 silencing compromised dronedarone-mediated suppression of cell hypertrophy, while PKIA upregulation abolished the influences of SIRT1 silencing. More importantly, dronedarone improved TAC surgery-induced MH and impairment of cardiac function of rats via affecting SIRT1/FOXO3/PKIA axis. CONCLUSIONS: Dronedarone alleviated MH through mediating SIRT1/FOXO3/PKIA axis, which provide more evidences for dronedarone against MH.

TRIM65 promotes vascular smooth muscle cell phenotypic transformation by activating PI3K/Akt/mTOR signaling during atherogenesis.

BACKGROUND AND AIMS: Tripartite motif (TRIM65) is an important member of the TRIM protein family, which is a newly discovered E3 ligase that interacts with and ubiquitinates various substrates and is involved in diverse pathological processes. However, the function of TRIM65 in atherosclerosis remains unarticulated. In this study, we investigated the role of TRIM65 in the pathogenesis of atherosclerosis, specifically in vascular smooth muscle cells (VSMCs) phenotype transformation, which plays a crucial role in formation of atherosclerotic lesions. METHODS AND RESULTS: Both non-atherosclerotic and atherosclerotic lesions during autopsy were collected singly or pairwise from each individual (n = 16) to investigate the relationship between TRIM65 and the development of atherosclerosis. In vivo, Western diet-fed ApoE-/- mice overexpressing or lacking TRIM65 were used to assess the physiological function of TRIM65 on VSMCs phenotype, proliferation and atherosclerotic lesion formation. In vitro, VSMCs phenotypic transformation was induced by platelet-derived growth factor-BB (PDGF-BB). TRIM65-overexpressing or TRIM65-abrogated primary mouse aortic smooth muscle cells (MOASMCs) and human aortic smooth muscle cells (HASMCs) were used to investigate the mechanisms underlying the progression of VSMCs phenotypic transformation, proliferation and migration. Increased TRIM65 expression was detected in α-SMA-positive cells in the medial and atherosclerotic lesions of autopsy specimens. TRIM65 overexpression increased, whereas genetic knockdown of TRIM65 remarkably inhibited, atherosclerotic plaque development. Mechanistically, TRIM65 overexpression activated PI3K/Akt/mTOR signaling, resulting in the loss of the VSMCs contractile phenotype, including calponin, α-SMA, and SM22α, as well as cell proliferation and migration. However, opposite phenomena were observed when TRIM65 was deficient in vivo or in vitro. Moreover, in cultured PDGF-BB-induced TRIM65-overexpressing VSMCs, inhibition of PI3K by treatment with the inhibitor LY-294002 for 24 h markedly attenuated PI3K/Akt/mTOR activation, regained the VSMCs contractile phenotype, and blocked the progression of cell proliferation and migration. CONCLUSIONS: TRIM65 overexpression enhances atherosclerosis development by promoting phenotypic transformation of VSMCs from contractile to synthetic state through activation of the PI3K/Akt/mTOR signal pathway.

Hydrogen sulfide attenuates atherosclerosis induced by low shear stress by sulfhydrylating endothelium NFIL3 to restrain MEST mediated endothelial mesenchymal transformation.

BACKGROUND: Endothelial-mesenchymal transition (EndMT) induced by low shear stress plays an important role in the development of atherosclerosis. However, little is known about the correlation between hydrogen sulfide (H2S), a protective gaseous mediator in atherosclerosis and the process of EndMT. METHODS: We constructed a stable low-shear-stress-induced(2 dyn/cm2) EndMT model, acombined with the pretreatment method of hydrogen sulfide slow release agent(GYY4137). The level of MEST was detected in the common carotid artery of ApoE-/- mice with local carotid artery ligation. The effect of MEST on atherosclerosis development in vivo was verified using ApoE-/- mice were given tail-vein injection of endothelial-specific overexpressed and knock-down MEST adeno-associated virus (AAV). RESULTS: These findings confirmed that MEST is up-regulated in low-shear-stress-induced EndMT and atherosclerosis. In vivo experiments showed that MEST gene overexpression significantly promoted EndMT and aggravated the development of atherosclerotic plaques and MEST gene knockdown significantly inhibited EndMT and delayed the process of atherosclerosis. In vitro, H2S inhibits the expression of MEST and EndMT induced by low shear stress and inhibits EndMT induced by MEST overexpression. Knockdown of NFIL3 inhibit the up regulation of MEST and EndMT induced by low shear stress in HUVECs. CHIP-qPCR assay and Luciferase Reporter assay confirmed that NFIL3 binds to MEST DNA, increases its transcription and H2S inhibits the binding of NFIL3 and MEST DNA, weakening NFIL3's transcriptional promotion of MEST. Mechanistically, H2S increased the sulfhydrylation level of NFIL3, an important upstream transcription factors of MEST. In part, transcription factor NFIL3 restrain its binding to MEST DNA by sulfhydration. CONCLUSIONS: H2S negatively regulate the expression of MEST by sulfhydrylation of NFIL3, thereby inhibiting low-shear-stress-induced EndMT and atherosclerosis.

Efficacy and Safety of Coenzyme Q10 Supplementation in the Treatment of Polycystic Ovary Syndrome: a Systematic Review and Meta-analysis.

The aim of this study is to evaluate the efficacy and safety of coenzyme Q10 supplementation in the treatment of polycystic ovary syndrome (PCOS). We first searched PubMed, Wanfang Data, CNKI, Embase, ClinicalTrial.gov, and other databases. The retrieval time from the establishment of the database to January 2021. We collected relevant randomized controlled trials (RCTs) about coenzyme Q10 in the treatment of PCOS. Risk of bias assessment and meta-analysis of RCTs were performed using RevMan 5.0 software. This systematic review and meta-analysis include a total of 9 RCTs involving 1021 patients. The results show that the addition of coenzyme Q10 may improve insulin resistance (HOMA-IR (WMD - 0.67 [- 0.87, - 0.48], P < 0.00001); fasting insulin (WMD - 1.75 [- 2.65, - 0.84], P = 0.0002); fasting plasma glucose (WMD - 5.20 [- 8.86, - 1.54], P = 0.005)), improve sex hormone levels (FSH (SMD - 0.45 [0.11, 0.78], P = 0.009); testosterone (SMD - 0.28 [- 0.49, - 0.06], P = 0.01)), and improve blood lipids (triglycerides (SMD - 0.49 [- 0.89, - 0.09], P = 0.02); total cholesterol (SMD - 0.35 [- 0.56, - 0.14], P = 0.001); LDL-C (SMD - 0.22 [- 0.43, - 0.01], P = 0.04); HDL-C (SMD 0.22 [0.01, 0.43], P = 0.04)). Only one RCT reported adverse events, and they found that patients had no adverse effects or symptoms following supplementation. Based on the current evidence, it could be considered that the addition of CoQ10 is a safe therapy to improve PCOS by improving insulin resistance (reduce HOMA-IR, FINS, FPG), increasing sex hormone levels (increase FSH, reduce testosterone), and improving blood lipids (reduce TG, TC, LDL-C, and increased HDL-C).

The Role of NLRP3 Inflammasome in Diabetic Cardiomyopathy and Its Therapeutic Implications.

Diabetic cardiomyopathy (DCM) is a serious complication of diabetes mellitus (DM). However, the precise molecular mechanisms remain largely unclear, and it is still a challenging disease to diagnose and treat. The nucleotide-binding oligomerization domain and leucine-rich repeat pyrin 3 domain (NLRP3) inflammasome is a critical part of the innate immune system in the host to defend against endogenous danger and pathogenic microbial infections. Dysregulated NLRP3 inflammasome activation results in the overproduction of cytokines, primarily IL-1ß and IL-18, and eventually, inflammatory cell death-pyroptosis. A series of studies have indicated that NLRP3 inflammasome activation participates in the development of DCM, and that corresponding interventions could mitigate disease progression. Accordingly, this narrative review is aimed at briefly summarizing the cell-specific role of the NLRP3 inflammasome in DCM and provides novel insights into developing DCM therapeutic strategies targeting the NLRP3 inflammasome.

PLK1 promotes cholesterol efflux and alleviates atherosclerosis by up-regulating ABCA1 and ABCG1 expression via the AMPK/PPARγ/LXRα pathway.

Polo-like kinase 1 (PLK1) is a serine/threonine kinase involving lipid metabolism and cardiovascular disease. However, its role in atherogenesis has yet to be determined. The aim of this study was to observe the impact of PLK1 on macrophage lipid accumulation and atherosclerosis development and to explore the underlying mechanisms. We found a significant reduction of PLK1 expression in lipid-loaded macrophages and atherosclerosis model mice. Lentivirus-mediated overexpression of PLK1 promoted cholesterol efflux and inhibited lipid accumulation in THP-1 macrophage-derived foam cells. Mechanistic analysis revealed that PLK1 stimulated the phosphorylation of AMP-activated protein kinase (AMPK), leading to activation of the peroxisome proliferator-activated receptor γ (PPARγ)/liver X receptor α (LXRα) pathway and up-regulation of ATP binding cassette transporter A1 (ABCA1) and ABCG1 expression. Injection of lentiviral vector expressing PLK1 increased reverse cholesterol transport, improved plasma lipid profiles and decreased atherosclerotic lesion area in apoE-deficient mice fed a Western diet. PLK1 overexpression also facilitated AMPK and HSL phosphorylation and enhanced the expression of PPARγ, LXRα, ABCA1, ABCG1 and LPL in the aorta. In summary, these data suggest that PLK1 inhibits macrophage lipid accumulation and mitigates atherosclerosis by promoting ABCA1- and ABCG1-dependent cholesterol efflux via the AMPK/PPARγ/LXRα pathway.

Hydrogen Sulfide Ameliorates Angiotensin II-Induced Atrial Fibrosis Progression to Atrial Fibrillation Through Inhibition of the Warburg Effect and Endoplasmic Reticulum Stress.

Atrial fibrosis is the basis for the occurrence and development of atrial fibrillation (AF) and is closely related to the Warburg effect, endoplasmic reticulum stress (ERS) and mitochondrion dysfunctions-induced cardiomyocyte apoptosis. Hydrogen sulfide (H2S) is a gaseous signalling molecule with cardioprotective, anti-myocardial fibrosis and improved energy metabolism effects. Nevertheless, the specific mechanism by which H2S improves the progression of atrial fibrosis to AF remains unclear. A case-control study of patients with and without AF was designed to assess changes in H2S, the Warburg effect, and ERS in AF. The results showed that AF can significantly reduce cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate thiotransferase (3-MST) expression and the H2S level, induce cystathionine-ß-synthase (CBS) expression; increase the Warburg effect, ERS and atrial fibrosis; and promote left atrial dysfunction. In addition, AngII-treated SD rats had an increased Warburg effect and ERS levels and enhanced atrial fibrosis progression to AF compared to wild-type SD rats, and these conditions were reversed by sodium hydrosulfide (NaHS), dichloroacetic acid (DCA) or 4-phenylbutyric acid (4-PBA) supplementation. Finally, low CSE levels in AngII-induced HL-1 cells were concentration- and time-dependent and associated with mitochondrial dysfunction, apoptosis, the Warburg effect and ERS, and these effects were reversed by NaHS, DCA or 4-PBA supplementation. Our research indicates that H2S can regulate the AngII-induced Warburg effect and ERS and might be a potential therapeutic drug to inhibit atrial fibrosis progression to AF.

Efficacy and Safety of Curcumin Supplement on Improvement of Insulin Resistance in People with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Diabetes is a major public health concern. In addition, there is some evidence to support curcumin as part of a diabetes treatment program. METHODS: Data from randomized controlled trials were obtained to assess the effects of curcumin versus placebo or western medicine in patients with type 2 diabetes mellitus (T2DM). The study's registration number is CRD42018089528. The primary outcomes included homeostasis model assessment-insulin resistance (HOMA-IR), glycosylated hemoglobin (HbAlc), total cholesterol (TC), and triglyceride (TG). RESULTS: Four trials involving 453 patients were included. The HOMA-IR of curcumin group is lower in Asia (WMD: -2.41, 95% CI: -4.44 to -0.39, P=0.02) and the Middle East subgroups (WMD: -0.60, 95% CI: -0.74 to -0.46, P < 0.00001). The HbAlc in the curcumin group is lower than that in the control group (WMD: -0.69; 95% CI: -0.91, -0.48; P < 0.0001). The TC and TG levels of the curcumin group are lower in the Asia subgroup (TC: WMD: -23.45, 95% CI: -40.04 to -6.84, P=0.006; TG: WMD: -54.14, 95% CI: -95.71 to -12.57, P=0.01), while in the Middle East the difference was of not statistically significant (TC: WMD: 22.91, 95% CI: -16.94 to 62.75, P=0.26; TG: WMD: -4.56, 95% CI: -19.28 to 10.16, P=0.54). CONCLUSION: Based on the current evidence, curcumin may assist in improving the insulin resistance, glycemic control, and decreased TG and TC in patients with T2DM.

Efficacy and Safety of Resveratrol Supplements on Blood Lipid and Blood Glucose Control in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Diabetes is a major public health concern. Resveratrol has shown great beneficial effects on hyperglycemia and insulin resistance and as an antioxidant. METHODS: We searched the Chinese and English databases (such as CNKI, PubMed, and Embase) and extracted data from randomized controlled trials (RCTs). Then, RevMan 5.3 was used for bias risk assessment and meta-analysis. The primary outcome indicators include insulin-resistance-related indicators and blood-lipid-related indicators. This systematic review and meta-analysis was registered in PROSPERO (CRD42018089521). RESULTS: Fifteen RCTs involving 896 patients were included. For insulin-resistance-related indicators, the summary results showed that, compared with the control group, homeostasis model assessment for insulin resistance (HOMA-IR) in the resveratrol group is lower (WMD: -0.99; 95% CI -1.61, -0.38; P=0.002). For blood-lipid-related indicators, the total cholesterol (TC) and triglyceride (TG) in the resveratrol group is of no statistical significance (for TC, WMD: -7.11; 95% CI -16.28, 2.06; P=0.13; for TG, WMD: -2.15; 95% CI -5.52, 1.22; P=0.21). For adverse events, the summary results showed that there was no statistical difference in the incidence of adverse events between the resveratrol and control groups (WMD: 2; 95% CI 0.44, 9.03; P=0.37). CONCLUSION: Based on the current evidence, resveratrol may improve insulin resistance, lower fasting blood glucose and insulin levels, and improve oxidative stress in patients with type 2 diabetes mellitus.

H2S inhibits atrial fibrillation-induced atrial fibrosis through miR-133a/CTGF axis.

AIM: Atrial fibrillation (AF) is a common clinical arrhythmia and can cause a variety of complications. To study the therapeutic effect of H2S in atrial fibrosis and explore the important role of miR-133a, in vitro experiments in human atrial fibroblasts (HAFs) were conducted. METHODS: The fibrosis in HAFs was induced by Ang II. The expression levels of miR-133a and CTGF in HAFs were examined by qRT-PCR. The proliferation and migration of HAFs were detected by CCK-8 and cell scratch assays. The protein expressions of CTGF, collagen I, collagen III and α-SMA were detected by western blotting. The dual-luciferase reporter gene was used to detect the interaction between miR-133a and CTGF. RESULTS: The proliferation and migration of HAFs stimulated by Ang II were enhanced, the expression of miR-133a was reduced, and the levels of CTGF and fibrosis markers (collagen I, collagen III and α-SMA) were increased. Furthermore, H2S reduced fibrosis, proliferation and migration of HAFs induced by Ang II. Accordingly, overexpression of miR-133a inhibited the proliferation and migration ability on Ang II-induced HAFs, and decreased the protein expressions of related fibrosis markers and CTGF. Meanwhile, miR-133a inhibitor could reverse the inhibition effect of H2S on proliferation and migration in HAFs by Ang II-induced. By targeting CTGF, miR-133a inhibited the expression of CTGF. CONCLUSION: H2S improved myocardial cell fibrosis by significantly increasing the expression of miR-133a, and CTGF might be a potential target for miR-133a to play an important role in myocardial fibrosis.

Hydrogen sulfide improves ox­LDL­induced expression levels of Lp­PLA2 in THP­1 monocytes via the p38MAPK pathway.

Hydrogen sulfide (H2S) exerts an anti­atherosclerotic effect and decreases foam cell formation. Lipoprotein­associated phospholipase A2 (Lp­PLA2) is a key factor involved in foam cell formation. However, the association between H2S and Lp­PLA2 expression levels with respect to foam cell formation has not yet been elucidated. The present study investigated whether H2S can affect foam cell formation and potential signalling pathways via regulation of the expression and activity of Lp­PLA2. Using human monocytic THP­1 cells as a model system, it was observed that oxidized low­density lipoprotein (ox­LDL) not only upregulates the expression level and activity of Lp­PLA2, it also downregulates the expression level and activity of Cystathionine γ lyase. Exogenous supplementation of H2S decreased the expression and activity of Lp­PLA2 induced by ox­LDL. Moreover, ox­LDL induced the expression level and activity of Lp­PLA2 via activation of the p38MAPK signalling pathway. H2S blocked the expression levels and activity of Lp­PLA2 induced by ox­LDL via inhibition of the p38MAPK signalling pathway. Furthermore, H2S inhibited Lp­PLA2 activity by blocking the p38MAPK signaling pathway and significantly decreased lipid accumulation in ox­LDL­induced macrophages, as detected by Oil Red O staining. The results of the present study indicated that H2S inhibited ox­LDL­induced Lp­PLA2 expression levels and activity by blocking the p38MAPK signalling pathway, thereby improving foam cell formation. These findings may provide novel insights into the role of H2S intervention in the progression of atherosclerosis.

Roles of Perivascular Adipose Tissue in Hypertension and Atherosclerosis.

Significance: Perivascular adipose tissue (PVAT), which is present surrounding most blood vessels, from the aorta to the microvasculature of the dermis, is mainly composed of fat cells, fibroblasts, stem cells, mast cells, and nerve cells. Although the PVAT is objectively present, its physiological and pathological significance has long been ignored. Recent Advances: PVAT was considered as a supporting component of blood vessels and a protective cushion to the vessel wall from the neighboring tissues during relaxation and contraction. Nonetheless, further extensive research found that PVAT actively regulates blood vessel tone through PVAT-derived vasoactive factors, including both relaxing and contracting factors. In addition, PVAT contributes to atherosclerosis through paracrine secretion of a large number of bioactive factors such as adipokines and cytokines. Thereby, PVAT regulates the functions of blood vessels through various mechanisms operating directly on PVAT or on the underlying vessel layers, including vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). Critical Issues: PVAT is a unique adipose tissue that plays an essential role in maintaining the vascular structure and regulating vascular function and homeostasis. This review focuses on recent updates on the various PVAT roles in hypertension and atherosclerosis. Future Directions: Future studies should further investigate the actual contribution of alterations in PVAT metabolism to the overall systemic outcomes of cardiovascular disease, which remains largely unknown. In addition, the messengers and underlying mechanisms responsible for the crosstalk between PVAT and ECs and VSMCs in the vascular wall should be systematically addressed, as well as the contributions of PVAT aging to vascular dysfunction.

Regulating the Warburg effect on metabolic stress and myocardial fibrosis remodeling and atrial intracardiac waveform activity induced by atrial fibrillation.

Atrial fibrillation (AF) is associated with metabolic stress and induces myocardial fibrosis reconstruction by increasing glycolysis. One goal in the treatment of paroxysmal AF (p-AF) is to improve myocardial fibrosis reconstruction and myocardial metabolic stress caused by the Warburg effect. Adopted male canine that rapid right atrial pacing (RAP) for 6 days to establish a p-AF model. The canines were pre-treated with phenylephrine (PE) or dichloroacetic acid (DCA) before exposure to p-AF or non-p-AF. P-wave duration (Pmax), minimum P-wave duration (Pmin), P wave dispersion (PWD), atrial effective refractory period (AERP) and AERP dispersion (AERPd) were measured in canine atrial cardiomyocytes. Pyruvate dehydrogenase kinase-1 (PDK-1), PDK-4, lactate dehydrogenase A (LDHA), pyruvate dehydrogenase (PDH), citrate synthase (CS), isocitrate dehydrogenase (IDH), and matrix metalloproteinase 9 (MMP-9) were evaluated by western blotting and reverse transcription polymerase chain reaction (RT-PCR), content of adenosine monophosphate (AMP), adenosine triphosphate (ATP), lactic acid and glycogen, and activity of LDHA, PDK-1 and PDK-4 were evaluated by enzyme-linked immunosorbent assay (ELISA), myocardial tissue glycogen content was evaluated by PAS, myocardial fibrosis remodeling was evaluated by hematoxylin and eosin (H&E) and Masson staining. Our findings demonstrated that p-AF increases the Warburg effect-related metabolic stress and myocardial fibrosis remodeling by increasing the expression and activity of PDK-1, PDK-4, and LDHA, content of AMP and lactic acid, and the ratio of AMP/ATP and decreasing the expression of PDH, CS, and IDH, and glycogen content. In addition, p-AF can induce cardiomyocyte fibrosis remodeling and increase MMP-9 expression, and p-AF also increases atrial intracardiac waveform activity by prolonging Pmax, Pmin, PWD, and AERPd and shortening AERP. PDK isoforms agonists (PE) produce a similar p-AF pathological effect and can produce synergistic effects with p-AF, further increasing Warburg effect-related metabolic stress, myocardial fibrosis remodeling, and atrial intracardiac waveform activity. In contrast, the use of PDK-specific inhibitors (DCA) completely reverses these pathophysiological changes induced by p-AF. We demonstrate that p-AF can induce the Warburg effect in canine atrial cardiomyocytes and significantly improve p-AF-induced metabolic stress, myocardial fibrosis remodeling, and atrial intracardiac waveform activity by inhibiting the Warburg effect.

Protective effects of hydrogen sulfide against angiotensin II-induced endoplasmic reticulum stress in HUVECs.

The inhibitory effects of hydrogen sulfide (H2S) on angiotensin II (AngII)-stimulated human umbilical vein endothelial cell (HUVEC) dysfunction remain to be elucidated. Endoplasmic reticulum (ER) stress has been detected in endothelial dysfunction (ED). The present study aimed to determine whether H2S may exert an inhibitory effect on AngII­induced ER stress. Using HUVECs as a model system, the present study used western blotting to detect protein expression, intracellular reactive oxygen species (ROS) levels were determined by oxidative conversion of cell permeable DCFH­DA to fluorescent dichlorofluorescein, CCK­8 assay was used to investigate the cell viability, methylene blue was used to investigate the CSE activity, TUNEL was used to investigate the cells apoptosis. The present study demonstrated that AngII not only upregulated the expression levels of inducible nitric oxide synthase (iNOS), stimulated ROS production and increased cell apoptosis, but also downregulated the expression levels of phosphorylated­endothelial nitric oxide synthase, decreased the expression and activity of cystathionine­c­lyase (CSE) and decreased cell viability. Furthermore, hydrogen peroxide (H2O2; an exogenous ROS) downregulated the expression and activity of CSE, and had similar effects as AngII, whereas the inhibitory effects of AngII were completely suppressed by N-acetyl-L-cysteine (a ROS scavenger). In addition, AngII induced the expression of glucose­regulated protein 78 (GRPP78) and C/EBP homologous protein (CHOP), which are markers of ER stress. Conversely, the stimulatory effects of AngII were completely inhibited by sodium hydrosulfide (NaHS; a H2S donor). Treatment with NaHS attenuated ROS production, inhibited CHOP and GRP78 expression, and decreased cell apoptosis. The present study indicated that AngII induced ED via the activation of ER stress in HUVECs. In addition, the effects of AngII on ER stress could be suppressed by H2S.

Hydrogen sulfide suppresses angiotensin II-stimulated endothelin-1 generation and subsequent cytotoxicity-induced endoplasmic reticulum stress in endothelial cells via NF-κB.

The effects of hydrogen sulfide (H2S) and the nuclear factor κB (NF-κB) signaling pathway in angiotensin II (AngII)-induced endothelin-1 (ET-1) expression and subsequent cytotoxicity remain unclear. The present study aimed to investigate the hypothesis that H2S protects human umbilical vein endothelial cells (HUVECs) against AngII­stimulated ET­1 generation and subsequent cytotoxicity­induced endoplasmic reticulum stress via the NF­κB signaling pathway. The results of the present study demonstrated that AngII significantly upregulated the expression levels of ET­1, glucose­regulated protein 78, CCAAT­enhancer­binding protein homologous protein, phosphorylated (p)­p65 and inducible nitric oxide synthase; stimulated nitric oxide production; suppressed the expression and activity of cystathionine-γ-lyase (CSE), a H2S synthetase; and decreased cell viability. Conversely, BQ788 (an ET­1 receptor antagonist) exhibited an inhibitory effect on the AngII­mediated suppression of CSE expression and activity in HUVECs. The effects of AngII were abrogated by sodium hydrosulfide (NaHS, an H2S donor), BQ788 or pyrrolidinedithiocarbamic acid (PDTC, an inhibitor of NF­κB). Furthermore, pretreatment with NaHS or PDTC attenuated AngII­induced apoptosis and cleaved caspase-12 generation. The pretreatment of HUVECs with BQ788 prior to AngII exposure mimicked the inhibitory effect of NaHS on the expression of p­p65 induced by AngII. In conclusion, the present study provides evidence that exogenous H-2S attenuates AngII­induced inflammation and cytotoxicity via inhibition of the ET­1/NF­κB signaling pathway in HUVECs.

PI3K/Akt/FoxO3a signaling mediates cardioprotection of FGF-2 against hydrogen peroxide-induced apoptosis in H9c2 cells.

Cardiovascular disease is a growing major global public health problem. Oxidative stress is regarded as one of the key regulators of pathological physiology, which eventually leads to cardiovascular disease. However, mechanisms by which FGF-2 rescues cells from oxidative stress damage in cardiovascular disease is not fully elucidated. Herein this study was designed to investigate the protective effects of FGF-2 in H2O2-induced apoptosis of H9c2 cardiomyocytes, as well as the possible signaling pathway involved. Apoptosis of H9c2 cardiomyocytes was induced by H2O2 and assessed using methyl thiazolyl tetrazolium assay, Hoechst, and TUNEL staining. Cells were pretreated with PI3K/Akt inhibitor LY294002 to investigate the possible PI3K/Akt pathways involved in the protection of FGF-2. The levels of p-Akt, p-FoxO3a, and Bim were detected by immunoblotting. Stimulation with H2O2 decreased the phosphorylation of Akt and FoxO3a, and induced nuclear localization of FoxO3a and apoptosis of H9c2 cells. These effects of H2O2 were abrogated by pretreatment with FGF-2. Furthermore, the protective effects of FGF-2 were abolished by PI3K/Akt inhibitor LY294002. In conclusion, our data suggest that FGF-2 protects against H2O2-induced apoptosis of H9c2 cardiomyocytes via activation of the PI3K/Akt/FoxO3a pathway.

Upregulation of peroxiredoxin III in doxorubicin-induced cytotoxicity and the FoxO3a-dependent expression in H9c2 cardiac cells.

Doxorubicin (DOX) is an efficient drug used in cancer therapy; however, it produces reactive oxygen species (ROS) that induce severe cytotoxicity, limiting its clinical application. The aim of the present study was to investigate the role of peroxiredoxin III (Prx III) in DOX-induced H9c2 cell injuries. Following DOX treatment, the expression of phosphorylated-FoxO3a (p-FoxO3a) was decreased and Prx III expression was increased in H9c2 cells. In order to detect whether oxidative stress was involved in the induction of Prx III expression by FoxO3a, exogenous H2O2 was used to induce oxidative stress in the H9c2 cells. Apoptosis of H9c2 cardiomyocytes was assessed using methyl thiazolyl tetrazolium assay and Hoechst staining. The levels of Prx III and p-FoxO3a were evaluated using western blot analysis. As expected, H2O2 was found to mimic the effect of DOX, decreasing the expression of p-FoxO3a and increasing the expression of Prx III. In addition, the study evaluated whether the transcription factor FoxO3a was essential for the expression of Prx III. Pretreatment of H9c2 cells with N-acetyl-L-cysteine (NAC), a scavenger of ROS, prior to exposure to DOX dramatically increased the phosphorylation of FoxO3a and led to a marked reduction in Prx III expression in the H9c2 cells. In conclusion, the results of the current study suggest that FoxO3a mediates the expression of Prx III in DOX-induced injuries.