[Effect and mechanism of Linggui Zhugan Decoction in regulating Sig1R on Angâ ¡-induced cardiomyocyte hypertrophy].

This study aims to explore the mechanism of Linggui Zhugan Decoction(LGZGD) in inhibiting Angiotensin Ⅱ(AngⅡ)-induced cardiomyocyte hypertrophy by regulating sigma-1 receptor(Sig1R). The model of H9c2 cardiomyocyte hypertrophy induced by AngⅡ in vitro was established by preparing LGZGD-containing serum and blank serum. H9c2 cells were divided into normal group, AngⅡ model group, 20% normal rat serum group(20% NSC), and 20% LGZGD-containing serum group. After the cells were incubated with AngⅡ(1 µmol·L~(-1)) or AngⅡ with serum for 72 h, the surface area of cardiomyocytes was detected by phalloidine staining, and the activities of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase were detected by micromethod. The mitochondrial Ca~(2+) levels were detected by flow cytometry, and the expression levels of atrial natriuretic peptide(ANP), brain natriuretic peptide(BNP), Sig1R, and inositol 1,4,5-triphosphate receptor type 2(IP_3R_2) were detected by Western blot. The expression of Sig1R was down-regulated by transfecting specific siRNA for investigating the efficacy of LGZGD-containing serum on cardiomyocyte surface area, Na~+-K~+-ATPase activity, Ca~(2+)-Mg~(2+)-ATPase activity, mitochondrial Ca~(2+), as well as ANP, BNP, and IP_3R_2 protein expressions. The results showed that compared with the normal group, AngⅡ could significantly increase the surface area of cardiomyocytes and the expression of ANP and BNP(P<0.01), and it could decrease the activities of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase, the concentration of mitochondrial Ca~(2+), and the expression of Sig1R(P<0.01). In addition, IP_3R_2 protein expression was significantly increased(P<0.01). LGZGD-containing serum could significantly decrease the surface area of cardiomyocytes and the expression of ANP and BNP(P<0.05, P<0.01), and it could increase the activities of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase, the concentration of mitochondrial Ca~(2+ )(P<0.01), and the expression of Sig1R(P<0.05). In addition, IP_3R_2 protein expression was significantly decreased(P<0.05). However, after Sig1R was down-regulated, the effects of LGZGD-containing serum were reversed(P<0.01). These results indicated that the LGZGD-containing serum could inhibit cardiomyocyte hypertrophy induced by AngⅡ, and its pharmacological effect was related to regulating Sig1R, promoting mitochondrial Ca~(2+ )inflow, restoring ATP synthesis, and protecting mitochondrial function.

Sclareol attenuates angiotensin II-induced cardiac remodeling and inflammation via inhibiting MAPK signaling.

Chronic inflammation plays an important role in hypertensive heart failure. Suppressing angiotensin II (Ang II)-induced cardiac inflammation may contribute to the treatment of hypertension-associated heart failure. Sclareol, a natural product initially isolated from the leaves and flowers of Salvia sclarea, possesses antiinflammatory and immune-regulation activity in various systems. However, its effect on Ang II-induced cardiac remodeling remains unknown. In this study, we have explored the potential effects of sclareol on Ang II-induced heart failure. In vivo experiments were conducted in mice with Ang II-pump infusion for 28 days. Sclareol administration at 5 mg·kg-1 ·d-1 significantly reduced the expression of myocardial injury markers. Sclareol also exerts protective effects against Ang II-induced cardiac dysfunction in mice which is associated with alleviated cardiac inflammation and fibrosis. Transcriptome analysis revealed that inhibition of the Ang II-activated mitogen-activated protein kinase (MAPK) pathway contributed to the protective effect of sclareol. Sclareol inhibits Ang II-activated MAPKs pathway to reduce inflammatory response in mouse hearts and cultured cardiomyocytes. Blockage of MAPKs in cardiomyocytes abolished the antiinflammatory effects of sclareol. In conclusion, we show that sclareol protects hearts against Ang II-induced injuries through inhibiting MAPK-mediated inflammation, indicating the potential use of sclareol in the prevention of hypertensive heart failure.

Qingda granule alleviate angiotensin â ±-induced hypertensive renal injury by suppressing oxidative stress and inflammation through NOX1 and NF-κB pathways.

Hypertension has become one of the important diseases harmful to human health. In China, Qingda granule (QDG) has been used to treat hypertension for decades. Previous studies by our team have shown that oxidative stress may be one of the pathways through which QDG inhibits hypertension-induced organs injury. However, the specific molecular mechanism of its anti-hypotension and renal oxidative stress response were unclearly. This study investigated QDG's potential protective mechanism against hypertension-induced renal injury. Mice were infused with Angiotensin Ⅱ (Ang Ⅱ, 500 ng/kg/min) or equivalent saline solution (Control) and administered oral QDG (1.145 g/kg/day) or saline for four weeks. QDG treatment mitigated the elevated blood pressure and reduced renal pathological changes induced by Ang Ⅱ. As per the RNA sequencing results, QDG affects oxidative stress signaling. In agreement with these findings, QDG significantly attenuated the Ang Ⅱ-induced increase in Nitrogen oxides 1 (NOX1) and reactive oxygen species and the decrease in superoxide dismutase in renal tissue. Additionally, QDG significantly inhibited Interleukin 6 (IL-6), Tumor necrosis factor α (TNF-α), and Interleukin 1ß (IL-1ß) expression in renal tissues and blocked the phosphorylation of P65 (NF-κB subunit) and IκB. These results were confirmed in vitro. Overall, QDG reduced Ang Ⅱ-induced elevated blood pressure and renal injury by inhibiting oxidative stress and inflammation caused by NOX1 and NF-κB pathways. The results of this study provide an experimental basis for the clinical application of QDG, and to open up a new direction for the clinical treatment of hypertension.

Calcitriol Supplementation Protects Against Apoptosis and Alleviates the Severity of Abdominal Aortic Aneurysm Induced by Angiotensin II and Anti-TGFß.

The present study aims to assess the effect of vitamin D deficiency (VDD) and its supplementation on the severity of AAA in mice. AAA was induced by AngII and anti-TGF-ß administration. Animals were divided into four groups: Sham, mice with AAA, mice with AAA, and VDD, and mice with AAA supplemented with calcitriol. Blood pressure, echocardiography, abdominal aortic tissues, and plasma samples were monitored for all groups. VDD was associated with enhanced activity of cleaved MMP-9 and elastin degradation and positively correlated with the severity of AAA. Calcitriol supplementation decreased the INFγ/IL-10 ratio and enhanced the Nrf2 pathway. Moreover, Cu/Zn-superoxide dismutase expression and catalase and neutral sphingomyelinase activity were exacerbated in AAA and VDD groups. Furthermore, calcitriol supplementation showed a significantly lower protein expression of caspase-8, caspase-3, Bid, and t-Bid, and prevented the apoptosis of VSMCs treated by AngII and anti-TGF-ß. Calcitriol supplementation may alleviate AAA severity and could be of great interest in the clinical management of AAA. VDD enhances antioxidant enzymes activity and expression, whereas calcitriol supplementation alleviates AAA severity by re-activating Nrf2 and inhibiting apoptotic pathways.

An organ-on-a-chip model for pre-clinical drug evaluation in progressive non-genetic cardiomyopathy.

Angiotensin II (Ang II) presents a critical mediator in various pathological conditions such as non-genetic cardiomyopathy. Osmotic pump infusion in rodents is a commonly used approach to model cardiomyopathy associated with Ang II. However, profound differences in electrophysiology and pharmacokinetics between rodent and human cardiomyocytes may limit predictability of animal-based experiments. This study investigates the application of an Organ-on-a-chip (OOC) system in modeling Ang II-induced progressive cardiomyopathy. The disease model is constructed to recapitulate myocardial response to Ang II in a temporal manner. The long-term tissue cultivation and non-invasive functional readouts enable monitoring of both acute and chronic cardiac responses to Ang II stimulation. Along with mapping of cytokine secretion and proteomic profiles, this model presents an opportunity to quantitatively measure the dynamic pathological changes that could not be otherwise identified in animals. Further, we present this model as a testbed to evaluate compounds that target Ang II-induced cardiac remodeling. Through assessing the effects of losartan, relaxin, and saracatinib, the drug screening data implicated multifaceted cardioprotective effects of relaxin in restoring contractile function and reducing fibrotic remodeling. Overall, this study provides a controllable platform where cardiac activities can be explicitly observed and tested over the pathological process. The facile and high-content screening can facilitate the evaluation of potential drug candidates in the pre-clinical stage.

Effects of DA-9801 on the inflammation and apoptosis induced by angiotensin II in human dermal microvascular endothelial cells.

DA-9801, a plant-based drug used for the treatment of diabetic neuropathy, is known to improve angiotensin II (Ang II)-induced vascular endothelial cell dysfunction. However, the underlying mechanism is not fully understood. We aimed to determine whether the protective effect of DA-9801 against Ang II-induced endothelial cell dysfunction was mediated via inhibition of endothelial cell inflammation and apoptosis. Ang II-induced oxidative stress was attenuated by pretreatment of human dermal microvascular endothelial cells (HDMECs) with DA-9801. This prevented the Ang II-induced upregulation of NAD(P)H oxidase (the NOX4 and p22phox subunits) and reactive oxygen species. Further, pretreatment of HDMECs with DA-9801 ameliorated Ang II-mediated nuclear factor kappa B activity via prevention of the upregulation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase. It also decreased the Ang II-stimulated increase in inducible nitric oxide synthase (NOS) and decreased endothelial NOS protein expression. DA-9801 decreased Ang II-induced upregulation of intercellular adhesion molecule 1, vascular adhesion molecule, and E-selectin in HDMECs. Moreover, TUNEL and annexin V-FITC fluorescence staining for apoptosis and the activities of caspases 9, 7, and 3 decreased in HDMECs pretreated with DA-9801, indicating that the drug enhanced anti-apoptotic pathways. Thus, DA-9801 modulated Ang II-induced endothelial cell dysfunction via inflammatory and apoptotic pathways.

Group V secreted phospholipase A2 plays a protective role against aortic dissection.

Aortic dissection is a life-threatening aortopathy involving separation of the aortic wall, whose underlying mechanisms are still incompletely understood. Epidemiological evidence suggests that unsaturated fatty acids improve cardiovascular health. Here, using quantitative RT-PCR, histological analyses, magnetic cell sorting and flow cytometry assays, and MS-based lipidomics, we show that the activity of a lipid-metabolizing enzyme, secreted phospholipase A2 group V (sPLA2-V), protects against aortic dissection by endogenously mobilizing vasoprotective lipids. Global and endothelial cell-specific sPLA2-V-deficient mice frequently developed aortic dissection shortly after infusion of angiotensin II (AT-II). We observed that in the AT-II-treated aorta, endothelial sPLA2-V mobilized oleic and linoleic acids, which attenuated endoplasmic reticulum stress, increased the expression of lysyl oxidase, and thereby stabilized the extracellular matrix in the aorta. Of note, dietary supplementation with oleic or linoleic acid reversed the increased susceptibility of sPLA2-V-deficient mice to aortic dissection. These findings reveal an unexplored functional link between sPLA2-driven phospholipid metabolism and aortic stability, possibly contributing to the development of improved diagnostic and/or therapeutic strategies for preventing aortic dissection.

High content screening identifies licoisoflavone A as a bioactive compound of Tongmaiyangxin Pills to restrain cardiomyocyte hypertrophy via activating Sirt3.

BACKGROUND: Cardiac hypertrophy is a prominent feature of heart remodeling, which may eventually lead to heart failure. Tongmaiyangxin (TMYX) pills are a clinically used botanical drug for treating multiple cardiovascular diseases including chronic heart failure. The aim of the current study was to identify the bioactive compounds in Tongmaiyangxin pills that attenuate cardiomyocytes hypertrophy, and to investigate the underlying mechanism of action. METHODS AND RESULTS: The anti-hypertrophy effect of TMYX was validated in isoproterenol-induced cardiac hypertrophy model in C57BL/6 mice. After TMYX treatment for 2 weeks, the heart ejection fraction and fractional shortening of the mice model was increased by approximately 20% and 15%, respectively, (p < 0.05). Besides, TMYX dose-dependently reduced the cross section area of cardiomyocytes in the angiotensin-II induced hypertrophy H9c2 model (p < 0.01). Combining high content screening and liquid chromatography mass spectrometry, four compounds with anti-cardiac hypertrophy effects were identified from TMYX, which includes emodin, licoisoflavone A, licoricone and glyasperin A. Licoisoflavone A is one of the compounds with most significant protective effect and we continued to investigate the mechanism. Primary cultures of neonatal rat cardiomyocytes were treated with a hypertrophic agonist phenylephrine (PE) in the presence or absence of licoisoflavone A. After 48 h of treatment, cells were harvested and mitochondrial acetylation was analyzed by western blotting and Image analysis. Interestingly, the results suggested that the anti-hypertrophic effects of licoisoflavone A depend on the activation of the deacetylase Sirt3 (p < 0.01). Finally, we showed that licoisoflavone A-treatment was able to decrease relative ANF and BNP levels in the hypertrophic cardiac cells (p < 0.01), but not in cells co-treated with Sirt3 inhibitors (3-TYP) (p > 0.05). CONCLUSION: TMYX exerts its anti-hypertrophy effect possibly through upregulating Sirt3 expression. Four compounds were identified from TMYX which may be responsible for the anti-hypertrophy effect. Among these compounds, licoisoflavone A was demonstrated to block the hypertrophic response of cardiomyocytes, which required its positive regulation on the expression of Sirt3. These results suggested that licoisoflavone A is a potential Sirt3 activator with therapeutic effect on cardiac hypertrophy.

Schizandrin B attenuates angiotensin II induced endothelial to mesenchymal transition in vascular endothelium by suppressing NF-κB activation.

BACKGROUND: Angiotensin II (Ang II)-induced chronic inflammation and oxidative stress often leads to irreversible vascular injury, in which the endothelial to mesenchymal transition (EndMT) in the endothelial layers are involved. Schisandrin B (Sch B), a natural product isolated from traditional Schisandra chinensis, has been reported to exert vascular protective properties with unclear mechanism. HYPOTHESIS/PURPOSE: This study investigated the protective effects and mechanism of Sch B against Ang II-induced vascular injury. METHODS: C57BL/6 mice were subcutaneous injected of Ang II for 4 weeks to induce irreversible vascular injury. In vitro, Ang II-induced HUVECs injury was used to study the underlying mechanism. The markers of EndMT, inflammation and oxidative stress were studied both in vitro and in vivo. RESULTS: Pre-administration of Sch B effectively attenuated phenotypes of vascular EndMT and fibrosis in Ang II-treated animals, accompanied with decreased inflammatory cytokine and ROS. The in vitro data from HUVECs suggest that Sch B directly targets NF-κB activation to suppress Ang II-induced EndMT and vascular injury. The activation of EndMT in the presence of Ang II is regulated by the NF-κB, a common player in inflammation and oxidative stress. Ang II-induced inflammation and oxidative stress also contributed to vascular EndMT development and Sch B inhibited inflammation/ROS-mediated EndMT by suppressing NF-κB. CONCLUSION: EndMT contributes to vascular injury in Ang II-treated mice, and it can be prevented via suppressing NF-κB activation by Sch B treatment. These results also imply that NF-κB might be a promising target to attenuate vascular remodeling induced by inflammation and oxidative stress through an EndMT mechanism.

Protective effect of Fisetin against angiotensin II-induced apoptosis by activation of IGF-IR-PI3K-Akt signaling in H9c2 cells and spontaneous hypertension rats.

BACKGROUND: Fisetin, a polyphenolic compound, has drawn notable attention owing to its antioxidant, anti-inflammatory, anti-cancer and neuroprotective effects. However, the cardiac effects of fisetin are not clear yet. HYPOTHESIS: The aim of the present study is to examine the cardioprotective effect of fisetin against Ang-II induced apoptosis in H9c2 cells and in spontaneous hypertensive rats (SHR). METHODS/STUDY DESIGN: The in vitro protective effect of fisetin was evaluated after the cells were treated with fisetin (50 µM/ml/ 24  h) for 2  h prior or after Ang-II administration to induce apoptosis. For in vivo experiments, SHRs were orally administered with fisetin (10  mg/kg) twice a week for 6 weeks. Cellular apoptosis was analyzed by TUNEL staining assay and the modulation in the expression levels of proteins involved in apoptosis and cell survival were determined by western blotting. RESULTS: Our results demonstrate the potent cardioprotective efficacy of fisetin against Ang-II induced apoptosis in H9c2 cells and in SHR models. Fisetin administration reduced the apoptotic nuclei considerably And reduced the expression of apoptotic proteins such as TNF- α, Fas L, FADD, Cleaved caspase-3 and Cleaved PARP and increased the cell survival and anti-apoptotic proteins like Bcl-2, Bcl-xL, p-IGF1R, p-PI3K and p-AKT in both in vitro and in vivo models. CONCLUSION: In conclusion, the results of the present study reveal that fisetin activates the IGF-IR-dependent p-PI3K/p-Akt survival signaling pathway and suppresses the caspase dependent apoptosis.

Icariin ameliorates angiotensin II-induced cerebrovascular remodeling by inhibiting Nox2-containing NADPH oxidase activation.

Cerebrovascular smooth muscle cells (SMCs) hyperplasia is an important contributor to cerebrovascular remodeling during hypertension. The aim of present study was to investigate the effects of Icariin on cerebrovascular SMCs proliferation and remodeling and the underlying mechanisms. The results revealed that Icariin administration attenuated the enhanced basilar artery constriction in angiotensin II (AngII)-induced hypertension rat model, as well as the inhibition of basilar artery diameter reduction in response to AngII and phenylephrine. In addition, histological analyses showed that Icariin also significantly ameliorated basilar artery remodeling in AngII hypertensive rats. In human brain vascular SMCs (HBVSMCs), AngII-induced cell proliferation, migration and invasion were markedly inhibited by Icariin treatment. Moreover, Icariin treatment largely limited AngII-induced the increase of reactive oxygen species (ROS) production in HBVSMCs, which was closely associated with cell proliferation. Analysis of the mechanisms showed that Icariin decreased ROS production via inhibiting NADPH oxidase activity but not mitochondria-derived ROS production. Further, Icariin promoted Nox2 degradation and consequently reduced its protein expression. In conclusion, these findings demonstrate that Icariin attenuates cerebrovascular SMCs hyperplasia and subsequent remodeling through inhibiting Nox2-containing NADPH oxidase activation, suggesting Icariin may be a potential therapeutic agent to prevent the onset and progression of stroke.

Scoparone attenuates angiotensin II-induced extracellular matrix remodeling in cardiac fibroblasts.

Scoparone is a biologically active constituent isolated from Artemisia capillaris and possesses a variety of pharmacological activities, such as anti-inflammatory, anti-tumor, anti-allergic and anti-cardiovascular activities. However, there are no studies focusing on the effects of scoparone against cardiac fibrosis. Therefore, the aim of this study was to investigate the effects of scoparone on Angiotensin II (Ang II)-induced extracellular matrix (ECM) remodeling and its possible mechanism in cardiac fibroblasts (CFs). Our results demonstrated that scoparone effectively attenuated CFs proliferation in Ang II-stimulated CFs. Scoparone also prevented the differentiation of CFs to myofibroblasts and ECM proteins (type I collagen and fibronectin) expression in Ang II-stimulated CFs. Furthermore, scoparone prevented Ang II-induced the activation of TGF-ß1/Smad signalling in CFs. Taken together, these studies indicated that scoparone attenuated Ang II-induced ECM remodeling in CFs, at least in part, by inhibiting TGF-ß1/Smad signalling. These findings suggest that scoparone may be used a novel therapeutic agent against cardiac fibrosis.

Acetylshikonin attenuates angiotensin II-induced proliferation and motility of human brain smooth muscle cells by inhibiting Wnt/ß-catenin signaling.

Cerebrovascular smooth muscle cell proliferation and migration contribute to hyperplasia in case of cerebrovascular remodeling and stroke. In the present study, we investigated the effects of acetylshikonin, the main ingredient of a Chinese traditional medicine Zicao, on human brain vascular smooth muscle cell (HBVSMCs) proliferation and migration induced by angiotensin II (AngII), and the underlying mechanisms. We found that acetylshikonin treatment significantly inhibited AngII-induced HBVSMCs proliferation and cell cycle transition from G1 to S phase. Wound-healing assay and Transwell assay showed that AngII-induced cell migration and invasion were markedly attenuated by acetylshikonin. In addition, AngII challenge significantly induced Wnt/ß-catenin signaling activation, as evidenced by increased ß-catenin phosphorylation and nuclear translocation and GSK-3ß phosphorylation. However, acetylshikonin treatment inhibited the activation of Wnt/ß-catenin signaling. Consequently, western blotting analysis revealed that acetylshikonin effectively reduced the expression of downstream target genes in AngII-treated cells, including c-myc, survivin and cyclin D1, which contributed to the inhibitory effect of acetylshikonin on HBVSMCs proliferation. Further, stimulation with recombinant Wnt3a dramatically reversed acetylshikonin-mediated inhibition of proliferation and cell cycle transition in HBVSMCs. Our study demonstrates that acetylshikonin prevents AngII-induced cerebrovascular smooth muscle cells proliferation and migration through inhibition of Wnt/ß-catenin pathway, indicating that acetylshikonin may present a potential option for the treatment of cerebrovascular remodeling.

Dietary Calanus oil antagonizes angiotensin II-induced hypertension and tissue wasting in diet-induced obese mice.

BACKGROUND: We have recently shown that Calanus oil, which is extracted from the marine copepod Calanus finmarchicus, reduces fat deposition, suppresses adipose tissue inflammation and improves insulin sensitivity in high fat-fed rodents. This study expands upon our previous observations by examining whether dietary supplementation with Calanus oil could antagonize angiotensin II (Ang II)-induced hypertension and ventricular remodeling in mice given a high fat diet (HFD). METHODS: C57BL/6J mice were initially subjected to 8 weeks of HFD with or without 2% (w/w) Calanus oil. Thereafter, animals within each group were randomized for the administration of either Ang II (1µg/kg/min) or saline for another two weeks, while still on the same dietary regimen. RESULTS: Ang II caused a marked decline in body and organ weights in mice receiving non-supplemented HFD, a response which was clearly attenuated in mice receiving Calanus oil supplementation. Furthermore, Ang II-induced elevation in blood pressure was also attenuated in the Calanus oil-supplemented group. As expected, infusion of Ang II produced hypertrophy and up-regulation of marker genes (mRNA level) of both hypertrophy and fibrosis in cardiac muscle, but this response was unaffected by dietary Calanus oil. Fibrosis and inflammation were up-regulated also in the aorta following Ang II infusion. However, the inflammatory response was blocked by Calanus oil supplementation. A final, and unexpected, finding was that dietary intake of Calanus oil caused a robust increase in the level of O-GlcNAcylation in cardiac tissue. CONCLUSION: These results suggest that dietary intake of oil from the marine copepod Calanus finmarchicus could be a beneficial addition to conventional hypertension treatment. The compound attenuates inflammation and the severe metabolic stress caused by Ang II infusion. Although the present study suggests that the anti-hypertensive effect of the oil (or its n-3 PUFAs constituents) is related to its anti-inflammatory action in the vessel wall, other mechanisms such as interaction with intracellular calcium mechanisms or a direct antagonistic effect on Ang II receptors should be examined.

Alpinate Oxyphyllae Fructus Inhibits IGFII-Related Signaling Pathway to Attenuate Ang II-Induced Pathological Hypertrophy in H9c2 Cardiomyoblasts.

Angiotensin II (Ang II) is a very important cardiovascular disease inducer and may cause cardiac pathological hypertrophy and remodeling. We evaluated a Chinese traditional medicine, alpinate oxyphyllae fructus (AOF), for therapeutic efficacy for treating Ang II-induced cardiac hypertrophy. AOF has been used to treat patients with various symptoms accompanying hypertension and cerebrovascular disorders in Korea. We investigated its protective effect against Ang II-induced cytoskeletal change and hypertrophy in H9c2 cells. The results showed that treating cells with Ang II resulted in pathological hypertrophy, such as increased expression of transcription factors NFAT-3/p-NFAT-3, hypertrophic response genes (atrial natriuretic peptide [ANP] and b-type natriuretic peptide [BNP]), and Gαq down-stream effectors (PLCß3 and calcineurin). Pretreatment with AOF (60-100 µg/mL) led to significantly reduced hypertrophy. We also found that AOF pretreatment significantly suppressed the cardiac remodeling proteins, metalloproteinase (MMP9 and MMP2), and tissue plasminogen activator (tPA), induced by Ang II challenge. In conclusion, we provide evidence that AOF protects against Ang II-induced pathological hypertrophy by specifically inhibiting the insulin-like growth factor (IGF) II/IIR-related signaling pathway in H9c2 cells. AOF might be a candidate for cardiac hypertrophy and ventricular remodeling prevention in chronic cardiovascular diseases.

Attrition of Hepatic Damage Inflicted by Angiotensin II with α-Tocopherol and ß-Carotene in Experimental Apolipoprotein E Knock-out Mice.

Angiotensin II is one of the key regulatory peptides implicated in the pathogenesis of liver disease. The mechanisms underlying the salubrious role of α-tocopherol and ß-carotene on liver pathology have not been comprehensively assessed. Here, we investigated the mechanisms underlying the role of Angiotensin II on hepatic damage and if α-tocopherol and ß-carotene supplementation attenuates hepatic damage. Hepatic damage was induced in Apoe(-/-)mice by infusion of Angiotensin II followed by oral administration with α-tocopherol and ß-carotene-enriched diet for 60 days. Investigations showed fibrosis, kupffer cell hyperplasia, hepatocyte degeneration and hepatic cell apoptosis; sinusoidal dilatation along with haemorrhages; evidence of fluid accumulation; increased ROS level and increased AST and ALT activities. In addition, tPA and uPA were down-regulated due to 42-fold up-regulation of PAI-1. MMP-2, MMP-9, MMP-12, and M-CSF were down-regulated in Angiotensin II-treated animals. Notably, α-tocopherol and ß-carotene treatment controlled ROS, fibrosis, hepatocyte degeneration, kupffer cell hyperplasia, hepatocyte apoptosis, sinusoidal dilatation and fluid accumulation in the liver sinusoids, and liver enzyme levels. In addition, PAI-1, tPA and uPA expressions were markedly controlled by ß-carotene treatment. Thus, Angiotensin II markedly influenced hepatic damage possibly by restraining fibrinolytic system. We concluded that α-tocopherol and ß-carotene treatment has salubrious role in repairing hepatic pathology.

Beneficial effects of astragaloside IV against angiotensin II-induced mitochondrial dysfunction in rat vascular smooth muscle cells.

Angiotensin II (Ang II)-induced mitochondrial dysfunction is a prominent characteristic of the majority of cardiovascular diseases. Astragaloside IV (As-IV), the major active ingredient of Astragalus membranaceus (Fisch.) Bge. (a traditional Chinese herbal medicine), possesses antioxidant properties. The present study was carried out to examine whether As-IV can reverse Ang II-induced mitochondrial dysfunction in vascular smooth muscle cells (VSMCs) and to elucidate the underlying molecular mechanisms. Cultured rat aortic VSMCs treated with Ang II (1 µM) for 24 h exhibited mitochondrial dysfunction, including a decrease in mitochondrial oxygen consumption rates (OCRs), adenosine triphosphate (ATP) production and mitochondrial DNA (mtDNA) levels, as well as the disruption of mitochondrial structural integrity. Following treatment with Ang II, As-IV (50 µg/ml) was added to the culture medium followed by incubation for a further 24 h. The administration of As-IV significantly increased the mitochondrial OCRs, ATP production and the mtDNA levels, and reversed the mitochondrial morphological changes which occurred in the VSMCs. Treatment with As-IV also reversed the Ang II-induced increase in the production of reactive oxygen species (ROS), the increase in NADPH oxidase and xanthine oxidase activity, as well as the decrease in mitochondrial membrane potential (ΔΨm) and manganese superoxide dismutase (Mn-SOD) activity. Furthermore, treatment with As-IV led to an increase in the mRNA expression of peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) and mitochondrial transcription factor A (Tfam), and in the protein expression of PGC-1α, parkin and dynamin 1-like protein 1 (Drp1) in the VSMCs. These results indicate that As-IV exerts beneficial effects on Ang II-induced mitochondrial dysfunction in rat VSMCs and that these effects are mediated through the inhibition of ROS overproduction, as well as the promotion of mitochondrial autophagy and mitochondrial biogenesis. These data demonstrate the antioxidant properties of As-IV.

Medicinal effect and its JP2/RyR2-based mechanism of Smilax glabra flavonoids on angiotensin II-induced hypertrophy model of cardiomyocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhizome and root of Smilax glabra Roxb (Liliaceae family) is a widely used traditional Chinese medicine (TCM) named Tu-fu-ling (TFL) for cardiac disease therapy. The TFL flavonoids (TFLF) has been extracted and proven to possess the anti-cardiac hypertrophy effect in our previous reports. Such effect could be mediated by the modulation of intracellular Ca(2+) flux in myocardial cells, in which junctophilin-2 (JP2) and ryanodine receptor 2 (RyR2) play an important role. However, its mechanism of the anti-cardiac hypertrophy effect remains unclarified. MATERIALS AND METHODS: 2µmol/L Ang II was applied to induce hypertrophy model of rat primary cardiomyocytes. After treatment of TFLF at 0.25, 0.5 and 1.0mg/ml, the cell size was microscopic measured, and the protein and mRNA expressions of JP2 and RyR2 in cardiomyocytes were estimated by immunofluorescence imaging, ELISA and real-time PCR assay. RESULTS: Obvious hypertrophy of cardiomyocytes was induced by Ang II but reversed by TFLF from 0.5 to 1.0mg/ml. The protein and mRNA expressions of JP2 and RyR2 in cardiomyocytes were also inhibited by Ang II but restored by TFLF at its dose range. Such effect of TFLF was exerted at a dose dependent manner, which was even better than that of verapamil. CONCLUSIONS: Our findings may evidence the correlation between JP2/RyR2 and myocardiac hypertrophy, and indicate the JP2/RyR2-mediated anti-hypertrophy mechanism of TFLF for the first time. It deserves to be developed as a promising TCM candidate of new drug for myocardial hypertrophy treatment.

Preventive effect of gomisin J from Schisandra chinensis on angiotensin II-induced hypertension via an increased nitric oxide bioavailability.

Gomisin J (GJ) is a small molecular weight lignan found in Schisandra chinensis and has been demonstrated to have vasodilatory activity. In this study, the authors investigated the effect of GJ on blood pressure (BP) in angiotensin II (Ang II)-induced hypertensive mice. In addition, we determined the relative potencies of gomisin A (GA) and GJ with respect to vasodilatory activity and antihypertensive effects. C57/BL6 mice infused s.c. with Ang II (2 µg kg(-1) min(-1) for 2 weeks) showed an increase in BP and a decrease in plasma nitric oxide (NO) metabolites. In the thoracic aortas of Ang II-induced hypertensive mice, a decrease in vascular NO was accompanied by an increase in reactive oxygen species (ROS) production. Furthermore, these alterations in BP, plasma concentrations of NO metabolites and in the vascular productions of NO and ROS in Ang II-treated mice were reversed by the co-administration of GJ (1 and 3 µg kg(-1) min(-1)). In in vitro studies, Ang II decreased the cellular concentration of NO, which was accompanied by a reduction in phosphorylated endothelial nitric oxide synthase (eNOS) and an increase in ROS production. These eNOS phosphorylation and ROS production changes in Ang II-treated cells were also reversed by GJ pretreatment (0-3 µg ml(-1)). Interestingly, the vasodilatory and antihypertensive effects of GJ were more prominent than those of GA. Collectively, an increase in BP in mice treated with Ang II was markedly attenuated by GJ, which was attributed to the preservations of vascular NO bioavailability and eNOS function, and to the inhibition of ROS production in Ang II-induced hypertensive mice.

Inhibiting the Th17/IL-17A-related inflammatory responses with digoxin confers protection against experimental abdominal aortic aneurysm.

OBJECTIVE: T helper 17 cells and interleukin-17A have been implicated in the progression of abdominal aortic aneurysm (AAA). Retinoic acid-related orphan receptor gamma thymus, the master transcription factor of T helper 17 cell differentiation, is selectively antagonized by digoxin. However, the effect of antagonizing retinoic acid-related orphan receptor gamma thymus on AAA has not been investigated. APPROACH AND RESULTS: We used human aortic sample analysis and 2 different experimental AAA models: (a) Angiotensin II (Ang II)-induced ApoE(-/-) male mice (Ang II/APOE model) and (b) porcine pancreatic elastase perfusion C57BL/6 mice (porcine pancreatic elastase/C57 model). In the Ang II/APOE model, all mice (n=80) were divided into 4 groups: sham group (saline+0.5% dimethyl sulfoxide treatment), control group (Ang II+0.5% dimethyl sulfoxide treatment), low-dose group (Ang II+low-dose digoxin, 20 µg/d per mouse), and high-dose group (Ang II+high-dose digoxin, 40 µg/d per mouse). All treatments began on day 0 after surgery. Efficacy was determined via aortic diameter and systolic blood pressure measurements, histopathology and protein expression, and flow cytometry analysis when euthenized. Human aortic tissue analysis showed that both interleukin-17A and retinoic acid-related orphan receptor gamma thymus increased in AAA tissues. The low-dose and high-dose groups had AAA incidences of 60% and 35%, respectively, compared with 70% in the control group. The T helper 17- and interleukin-17A-related inflammatory responses were dose-dependently attenuated by digoxin treatment. Digoxin was also highly effective in the porcine pancreatic elastase/C57 model. CONCLUSIONS: Digoxin attenuates experimental AAA progression in a model-independent manner. Antagonizing retinoic acid-related orphan receptor gamma thymus activity by digoxin may become a novel strategy for nonsurgical AAA treatment.