The preventive effects of edible folic acid on cardiomyocyte apoptosis and survival in early onset triple-transgenic Alzheimer's disease model mice

In recent years, neuropathological and epidemiological studies have indicated an association between Alzheimer's disease (AD) and several cardiovascular risk factors. In this study, the cardio-protective effects of folic acid (FA) in early stage AD was elucidated using a triple-transgenic (3xTg) Alzheimer's mouse model. Eleven-month-old C57BL/6 mice and 3xTg mice were assigned to five groups. During the four-month treatment period, the low-FA treatment group received FA through their diet, and the high-FA treatment groups received 3 mg/dl folate in drinking water and were also gastric-fed 1.2 mg/kg folate every day. In the C57B1/6J mice, treatment with high doses of FA (HFA) did not show any considerable effect compared to the control group or the low-dose dietary FA treatment group. However, Alzheimer's mice treated with HFA showed enhanced cardio-protection. Western blot analysis revealed that FA treatment restored SIRT1 expression, which was suppressed in 3xTg mice, through enhanced AMPK expression. FA significantly enhanced the IGF1 receptor survival mechanism in the hearts of the 3xTg mice and suppressed the expression-intrinsic and extrinsic apoptosis-associated proteins. The results suggest that FA intake may significantly alleviate cellular pathological events in the heart associated with AD.

Elevated Phosphate Levels Trigger Autophagy-Mediated Cellular Apoptosis in H9c2 Cardiomyoblasts

BACKGROUND/AIM

In chronic kidney disease (CKD), kidneys fail to maintain phosphorus homeostasis in serum. Elevated phosphorus levels in serum have been associated with cardiovascular diseases in CKD patients and in normal individuals. In this study, we evaluated the level of autophagy- and apoptosis-related markers under different concentrations of hyperphosphate in myocardial cells.

METHODS

Modulation inflicted on the levels of various survival-, autophagy-, and apoptosis-related markers were determined by Western blotting analysis using total protein extract. FITC-annexin V staining was performed to quantify the apoptotic cells in all groups.

RESULTS

Hyperphosphate treatments showed to induce autophagy-related proteins beclin-1, ATG7, and LC3 II through the pAMPK-ULK1 pathway in Western blotting analysis. Further, apoptosis-associated proteins such as Bax, Bid, cytochrome c, and c-caspase-9 were also upregulated with hyperphosphate treatment. 3-Methyladenine, an autophagy inhibitor, inhibited apoptosis significantly in FITC-annexin V staining, and the inhibition of Bax, cytochrome c, and c-caspase-3 was shown by Western blotting.

CONCLUSION

The results suggest that hyperphosphate in H9c2 cardiomyoblasts would lead to cellular apoptosis via autophagy, which is mediated by the pAMPK signaling pathway. Our findings revealed the possible mechanism responsible for the heart damage under hyperphosphatemia.

E2/ER β inhibit ISO-induced cardiac cellular hypertrophy by suppressing Ca2+-calcineurin signaling

Cardiovascular incidences are markedly higher in men than in pre-menstrual women. However, this advantage in women declines with aging and therefore can be correlated with the sex hormone 17β-Estradiol (E2) which is reported to protect heart cells by acting though estrogen receptors (ERs). In this study we have determined the effect of E2/ERβ against ISO induced cellular hypertrophy in H9c2 cardiomyoblast cells. The results confirm that ISO induced cardiac-hypertrophy by elevating the levels of hypertrophy associated proteins, ANP and BNP and further by upregulating p-CaMKII, calcineurin, p-GATA4 and NFATc3 which was correlated with a significant enlargement of the H9c2 cardiomyoblast. However, overexpression of ERβ and/or administration of E2 inhibited ISO-induced hypertrophy in H9c2 cells. In addition, E2/ERβ also inhibited ISO-induced NFATc3 translocation, and reduced the protein level of downstream marker, BNP. Furthermore, by testing with the calcineurin inhibitor (CsA), it was confirmed that calcineurin acted as a key mediator for the anti-hypertrophic effect of E2/ERβ. In cells treated with calcium blocker (BATPA), the inhibitory effect of E2/ERβ on ISO-induced Ca²⁺ influx and hypertrophic effects were totally blocked suggesting that E2/ERβ inhibited calcineurin activity to activate I-1 protein and suppress PP1, then induce PLB protein phosphorylation and activation, resulting in Ca²⁺ reuptake into sarcoplasmic reticulum through SR Ca²⁺ cycling modification. In conclusion, E2/ERβ suppresses the Ca²⁺ influx and calcineurin activity induced by ISO to enhance the PLB protein activity and SR Ca²⁺ cycling.

[Analysis of optical coherence tomography of early and very late stent restenosis after drug-eluting stent implantation]

Objective: Using optical coherence tomography (OCT) to analyze the morphological characteristics of lesions between early in-stent restenosis (E-ISR) and very late in-stent restenosis (VL-ISR) after drug-eluting stents (DES) implantation. Methods: In 25 patients (DES) with ISR, OCT images were acquired before percutaneous coronary intervention (PCI), the morphological characteristics of E-ISR (<1 years, n=14) and VL-ISR (>3 years, n=11) were compared.The quantitative and qualitative analysis of the entire stent and the minimum lumen area (MLA) site were carried out respectively. OCT quantitative restenotic tissue analysis included the assessment of mean lumen area, mean stent area, mean neointimal area and mean neointimal burden.OCT qualitative restenotic tissue analysis included the assessment of tissue structure [homogeneous or heterogeneous intima (lipid-rich neoitima, thin-cap fibroatheroma (TCFA)-like intima)], presence of microvessels, intraluminal material (red thrombus, pale thrombus), disrupted intima with cavity and tissue prolapse and was performed at every 1-mm slice of the entire stent. Results: Compared with the E-ISR group, the proportion of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group (60.57% vs 32.93%, P=0.005), and both peristent and intraintimal microvessels were more frequently observed in the VL-ISR group (P<0.05). In addition, lipid-rich neointima (72.7% vs 21.4%, P=0.017), TCFA-like intima (54.5% vs 7.1%, P=0.021), disrupted intima with visible cavity (63.6% vs 7.1%, P=0.007) and red thrombus (63.6% vs 7.1%, P=0.007) were observed more frequently in the VL-ISR group compared with E-ISR group for the entire stent.The heterogeneous intima was observed more frequently in the VL-ISR group (90.9% vs 35.7%, P=0.012) at the MLA sites.Intraintimal microvessels and disrupted intima with visible cavity were observed only in the VL-ISR group. Conclusions: OCT imaging indicates that the morphological characteristics of restenosis lesions in VL-ISR are different from those in E-ISR.The atherosclerotic changes of neointima, such as lipid-rich neointima, disrupted intima with cavity and microvessels are more often observed in VL-ISR lesions after DES implantation compared with E-ISR.Progression of the atherosclerosis within neointima after DES implantation may be associated with VL-ISR.

High density lipoprotein (HDL) reverses palmitic acid induced energy metabolism imbalance by switching CD36 and GLUT4 signaling pathways in cardiomyocyte

In our previous study palmitic acid (PA) induced lipotoxicity and switches energy metabolism from CD36 to GLUT4 in H9c2 cells. Low level of high density lipoprotein (HDL) is an independent risk factor for cardiac hypertrophy. Therefore, we in the present study investigated whether HDL can reverse PA induced lipotoxicity in H9c2 cardiomyoblast cells. In this study, we treated H9c2 cells with PA to create a hyperlipidemia model in vitro and analyzed for CD36 and GLUT4 metabolic pathway proteins. CD36 metabolic pathway proteins (phospho-AMPK, SIRT1, PGC1α, PPARα, CPT1β, and CD36) were decreased by high PA (150 and 200 μg/μl) concentration. Interestingly, expression of GLUT4 metabolic pathway proteins (p-PI3K and pAKT) were increased at low concentration (50 μg/μl) and decreased at high PA concentration. Whereas, phospho-PKCζ, GLUT4 and PDH proteins expression was increased in a dose dependent manner. PA treated H9c2 cells were treated with HDL and analyzed for cell viability. Results showed that HDL treatment induced cell proliferation efficiency in PA treated cells. In addition, HDL reversed the metabolic effects of PA: CD36 translocation was increased and reduced GLUT4 translocation, but HDL treatment significantly increased CD36 metabolic pathway proteins and reduced GLUT4 pathway proteins. Rat neonatal cardiomyocytes showed similar results. In conclusion, HDL reversed palmatic acid-induced lipotoxicity and energy metabolism imbalance in H9c2 cardiomyoblast cells and in neonatal rat cardiomyocyte cells.

Protective effect of HDL on NADPH oxidase-derived super oxide anion mediates hypoxia-induced cardiomyocyte apoptosis

Cardiovascular diseases are the leading cause of death of death in Taiwan. Atherosclerosis can lead to serious problems, including heart attack, stroke, or even death. Coronary heart disease (CHD) occurs when plaque builds up in the coronary arteries to cause the ischemic heart disease which will enhance myocardial remodeling and also induce myocardial hypoxia. High density lipoprotein (HDL) has been proposed to have cardio-protective effects. Under hypoxic conditions (1%O₂ for 24hr), in H9c2 cells, reactive oxygen species (ROS) is induced which leads to cardiomyocyte apoptosis and cardiac dysfunction. Therefore, the present study described the protective effect of HDL on hypoxia-induced cardiomyocyte damage. We investigated the NADPH oxidase-produced ROS-related signaling pathways and apoptosis in cardiomyocytes under hypoxia conditions. Results showed that the ROS mediated cardiac damage might occur via AT1 and PKC activation. Furthermore, hypoxia downregulated the survival protein (p-AKT^ser473) and anti-apoptotic protein (BCL₂), whereas pro-apoptotic protein, Bax and caspase 3 were upregulated. These detrimental effects by ROS and apoptosis were prevented by HDL pretreatment. Our findings revealed the underlying molecular mechanism by which HDL suppresses the hypoxia-induced cardiomyocyte dysfunction. Further, we elucidated the role of HDL on preventing hypoxia induced cardiomyocyte apoptosis is mediated through the inhibition of NADPH oxidase-derived ROS.

Potential phytoestrogen alternatives exert cardio-protective mechanisms via estrogen receptors

The 17 beta-estradiol (E2) is a sex hormone that is most abundant and most active estrogen in premenopausal women. The importance of E2 in providing cardioprotection and reducing the occurrence of heart disease in women of reproductive age has been well recognized. There are three subtype of estrogen receptors (ERs), including ERα, ERβ and GPR30 have been identified and accumulating evidence reveal their roles on E2-mediated genomic and nongenomic pathway in cardiomyocytes against various cardiac insults. In this review, we focus on the estrogen and ERs mediated signaling pathways in cardiomyocytes that determines cardio-protection against various stresses and further discuss the clinical implication of ERs and phytoestrogens. Further we provide some insights on phytoeostrogens which may play as alternatives in estrogen replacement therapies.

Platycodon grandiflorum (PG) reverses angiotensin II-induced apoptosis by repressing IGF-IIR expression

ETHNOPHARMACOLOGICAL RELEVANCE

Platycodon grandiflorum (PG) is a Chinese medical plant used for decades as a traditional prescription to eliminate phlegm, relieve cough, reduce inflammation and lower blood pressure. PG also has a significant effect on the cardiovascular systems.

MATERIALS AND METHODS

The aqueous extract of Platycodon grandiflorum (JACQ.) A. DC. root was screened for inhibiting Ang II-induced IGF-IIR activation and apoptosis pathway in H9c2 cardiomyocytes. The effects were also studied in spontaneously hypertensive rats (five groups, n=5) using low and high doses of PG for 50 days. The Ang II-induced IGF-IIR activation was analyzed by luciferase reporter, RT-PCR, western blot and surface IGF-IIR expression assay. Furthermore, the major active constituent of PG was carried out by high performance liquid chromatography-mass spectrometry (HPLC-MS).

RESULTS

Our results indicate that a crude extract of PG significantly suppresses the Ang II-induced IGF-IIR signaling pathway to prevent cardiomyocyte apoptosis. PG extract inhibits Ang II-mediated JNK activation and SIRT1 degradation to reduce IGF-IIR activity. Moreover, PG maintains SIRT1 stability to enhance HSF1-mediated IGF-IIR suppression, which prevents cardiomyocyte apoptosis. In animal models, the administration of PG markedly reduced this apoptotic pathway in the heart of SHRs.

CONCLUSION

Taken together, PG may be considered as an effective treatment for cardiac diseases in hypertensive patients.

Prostaglandin E2-Induced COX-2 Expressions via EP2 and EP4 Signaling Pathways in Human LoVo Colon Cancer Cells

Metastasis is the most dangerous risk faced by patients with hereditary non-polyposis colon cancer (HNPCC). The expression of matrix metalloproteinases (MMPs) has been observed in several types of human cancers and regulates the efficacy of many therapies. Here, we show that treatment with various concentrations of prostaglandin E2 (PGE2; 0, 1, 5 or 10 μM) promotes the migration ability of the human LoVo colon cancer cell line. As demonstrated by mRNA and protein expression analyses, EP2 and EP4 are the major PGE2 receptors expressed on the LoVo cell membrane. The Phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt cell survival pathway was upregulated by EP2 and EP4 activation. Following the activation of the PI3K/Akt pathway, β-catenin translocated into the nucleus and triggered COX2 transcription via LEF-1 and TCF-4 and its subsequent translation. COX2 expression correlated with the elevation in the migration ability of LoVo cells. The experimental evidence shows a possible mechanism by which PGE2 induces cancer cell migration and further suggests PGE2 to be a potential therapeutic target in colon cancer metastasis. On inhibition of PGE2, in order to determine the downstream pathway, the levels of PI3K/Akt pathway were suppressed and the β-catenin expression was also modulated. Inhibition of EP2 and EP4 shows that PGE2 induces protein expression of COX-2 through EP2 and EP4 receptors in LoVo colon cancer cells.

Treatment with 17β-Estradiol Reduced Body Weight and the Risk of Cardiovascular Disease in a High-Fat Diet-Induced Animal Model of Obesity

Estrogen receptor α (ERα) and estrogen receptor β (ERβ) play important roles in cardiovascular disease (CVD) prevention. Recently, these estrogen receptors were reconsidered as an important treatment target of obesity leading to CVD. In this study, 17β-estradiol (17β-E) replacement therapy applied to high-fat diet-induced obese C57B male mice and ovariectomized (OVX) rats were evaluated, and the protective effects against high-fat diet-induced obesity were assessed in C57B mouse hearts. The results showed that 17β-E treatment activated both ERα and ERβ, and ERβ levels increased in a dose-dependent manner in high-fat diet C57B mouse cardiomyocytes following 17β-E treatment. Notably, an almost 16% reduction in body weight was observed in the 17β-E-treated (12 μg/kg/day for 60 days) high-fat diet-induced obese C57B male mice. These results suggested that 17β-E supplements may reduce CVD risk due to obesity.

Attenuation of the LPS-induced, ERK-mediated upregulation of fibrosis-related factors FGF-2, uPA, MMP-2, and MMP-9 by Carthamus tinctorius L in cardiomyoblasts

Severe and potentially fatal hypotension and cardiac contractile dysfunction are common symptoms in patients with sepsis. LPS was previously found to dramatically upregulate expression of fibrosis-related factors FGF-2, uPA, MMP-2, and MMP-9 in primary cardiac fibroblasts. MMPs are capable of denaturing and degrading fibrillar collagens and other components of the extracellular matrix (ECM). Studies have shown that dysregulation of expression of MMPs is associated with development of myocardial extracellular matrix remodeling and cardiac fibrosis, which contribute to progression of heart failure. In this study, H9c2 cells and cardiac fibroblasts were divided into five treatment groups: control, LPS (1 μg/mL) and three concentrations of FC_EtOH (Carthami Flos ethanolic extract) (31.25, 62.5, and 125 μg/mL). Phosphorylation of ERK-1/2 was observed to be rapidly induced upon treatment with LPS. In contrast, it was significantly suppressed by the administration of FC_EtOH (125 μg/mL). Effects of FC_EtOH on LPS-induced MMP-2 and MMP-9 expression in H9c2 cells occurred directly through ERK1/2 were determined. H9c2 cells were therefore pretreated with EGF-R to activate ERK pathway. Both protein levels of MMP-2 and MMP-9 and immunefluorescent signals of MMP-9 were significantly enhanced by EGFR. In contrast, MMP-2 and MMP-9 were significantly reduced after FC_EtOH administration. Based on these findings, the authors concluded that FC_EtOH elicits a protective effect against LPS-induced cardio-fibrosis through the ERK1/2 pathway. Carthamus tinctorius L may potentially serve as a cardio-protective agent against LPS- induced cardiac fibrosis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 754-763, 2017.

Mitotic arrest induced in human DU145 prostate cancer cells in response to KHC-4 treatment

In this study, the antitumor activity of KHC-4 was analyzed using human prostate cancer (CaP) cells and the underlining anticancer mechanisms of KHC-4 were identified. KHC-4 inhibited cell proliferation and induced cytotoxicity in the castration-resistant CaP DU145 cell line. The most effective concentration of KHC-4 was 0.1 μM. Cell cycle analysis demonstrated that KHC-4 treatment caused G2/M arrest and a subsequent increase in the sub-G1 population. Furthermore, KHC-4 is up-regulated p21, p27, and p53 in a time- and concentration-dependent manner. The exposure of cells to KHC-4 induced Cdk1/cyclin B1 complex activity, which led to cell cycle arrest. Moreover, KHC-4 inhibited the activities of MMP-2 and MMP-9 to inhibit tumor cell metastasis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1879-1887, 2016.

[Control study of total percutaneous access with preclose technique versus open femoral artery exposure for endovascular aneurysm repair]

OBJECTIVE

To compare total percutaneous access using preclose technique with femoral artery cut-down in endovascular aneurysm repair (EVAR) and assess the safety and feasibility of preclose technique.

METHODS

In the study, 81 cases undergoing EVAR from Dec. 2011 to Nov. 2014 in Peking University People's Hospital were retrospectively reviewed. Preoperative CT angiography (CTA) showed presence of infrarenal abdominal aortic aneurysm or descending aortic aneurysm in all the cases. The maximum diameter of aneurysm >4.5 cm met the indications for surgical treatment. The conditions of bilateral femoral artery and iliac artery CTA showed were good, and there was no moderate or severe stenosis, nor was there any severe calcification in anterior wall of femoral artery. Not only were the cases fit for percutaneous endovascular aortic aneurysm repair (PEVAR), but also feasible with open endovascular aneurysm repair (OEVAR). According to the intention of the patients about the surgical incision, the cases were divided into group PEVAR and group OEVAR. The data of the general situation, operation time, blood loss, technical success rate, length of hospital stay after procedure and wound complications were analyzed statistically.

RESULTS

In the study, 44 cases (78 incisions) were enrolled in group PEVAR and 37 cases (65 incisions) in group OEVAR. There was no significant difference between the two groups in age, gender, body mass index (BMI), accompanying diseases, average number of stents and outer diameter of stent delivery system. Average operation time of group PEVAR was less than that of group OEVAR [(119.1±102.0) min vs. (163.6±61.9) min, P=0.025]. The blood loss in group PEVAR was less than that in group OEVAR [(64.7±97.0) mL vs. (98.6±88.3) mL], but there was no significant difference (P=0.106). There was no difference in the technical success rate (94.9% vs.95.4%, P=1.000). The average length of hospital stay after procedure was significantly shorter in group PEVAR [(7.8±2.8) d vs.(12.3±7.2) d, P<0.001]. There were 2 cases with subcutaneous hematoma of wound in group PEVAR and 7 cases of wound complications that occurred in group OEVAR including 3 cases with lymphatic leakage, 3 cases with lower limb ischemia and 1 case with subcutaneous hematoma. The analysis showed that PEVAR could reduce the wound complications (2.6%vs.10.8%), but there was no significant difference between the two groups (P=0.079).

CONCLUSION

Using preclose technique in EVAR is safe and effective. It can shorten the operation time and length of hospital stay after procedure.

Anthocyanin Attenuates Doxorubicin-Induced Cardiomyotoxicity via Estrogen Receptor-α/β and Stabilizes HSF1 to Inhibit the IGF-IIR Apoptotic Pathway

Doxorubicin (Dox) is extensively used for chemotherapy in different types of cancer, but its use is limited to because of its cardiotoxicity. Our previous studies found that doxorubicin-induced insulin-like growth factor II receptor (IGF-IIR) accumulation causes cardiomyocytes apoptosis via down-regulation of HSF1 pathway. In these studies, we demonstrated a new mechanism through which anthocyanin protects cardiomyoblast cells against doxorubicin-induced injury. We found that anthocyanin decreased IGF-IIR expression via estrogen receptors and stabilized heat shock factor 1 (HSF1) to inhibit caspase 3 activation and apoptosis of cardiomyocytes. Therefore, the phytoestrogen from plants has been considered as another potential treatment for heart failure. It has been reported that the natural compound anthocyanin (ACN) has the ability to reduce the risk of cardiovascular disease (CVD). Here, we demonstrated that anthocyanin acts as a cardioprotective drug against doxorubicin-induced heart failure by attenuating cardiac apoptosis via estrogen receptors to stabilize HSF1 expression and down-regulated IGF-IIR-induced cardiomyocyte apoptosis.

Anti-apoptotic effect of San Huang Shel Shin Tang cyclodextrin complex (SHSSTc) on CCl4 -induced hepatotoxicity in rats

The metabolic loading is heavier in liver especially when injured or inflammation. San Huang Shel Shin Tang (SHSST) was an old traditional herbal decoction, which composed with Rheum officinale Baill, Scutellaria baicalnsis Geprgi and Coptis chinensis Franch (1:1:2 in weight), can provide a liver protection effects. We used a beta-cyclodextrin (β-CD) drug modification method in reduce of the necessary dose of the SHSST. As the results, the FAS-FADD expressions leaded apoptosis in CCl4 intraperitoneal (IP) injection induced acute liver injury in rats. Silymarin, baicalein, SHSST, and SHSST β-CD complex (SHSSTc) pretreatments protected liver through the decreasing of the expressions of FAS-FADD and downstream caspase-3 and caspase-8. Particularly, SHSSTc (30 mg/kg day) treatment enhanced cell survival pathway activation through the PI3K, Akt and Bad phosphorylation. Compared with SHSST as well as silymarin and baicalein, SHSSTc provided a magnificent liver protection effect, especially in survival pathway activation/TUNEL-apoptotic cell reduction/serum cholesterol level suppression. All these data suggested that β-CD complex modified the SHSST and promoted the bioavailability and liver protection effects. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 663-670, 2016.

San Huang Shel Shin Tang beta-cyclodextrin complex augmented the hepatoprotective effects against carbon tetrachloride-induced acute hepatotoxicity in rats

BACKGROUND

San Huang Shel Shin Tang (SHSST) is a traditional herbal decoction used as a hepato-protective agent and is composed of Rheum officinale Baill, Scutellaria baicalnsis Geprgi and Coptis chinensis Franch (2:1:1 w/w). Beta-cyclodextrin (β-CD) modification may potentially increase the solubility and spectral properties of SHSST.

METHODS

In this research, the hepato-protective effects of unmodified SHSST, β-CD modified SHSST complex (SHSSTc) and silymarin were evaluated in carbon tetrachloride (CCl4) induced acute hepatotoxicity in rats.

RESULTS

SHHSTc (40 mg/kg/day) and silymarin (100 mg/kg/day) both decreased the CCl4-induced cirrhosis pathway-related transforming growth factor beta (TGF-β) and apoptosis pathway-related caspase-8 protein expressions, but SHSST (40 mg/kg/day) did not reduce TGF-β and caspase-8 significantly . Moreover, SHHSTc (40 mg/kg/day) enhanced the activation of insulin-like growth factor 1 receptor (IGF1R) mediated survival pathway than the silymarin (100 mg/kg/day) to protect the liver from damage induced by CCl4.

CONCLUSIONS

β-CD modification promotes hepato-protective effects of SHSST and reduces the required-dosage of the SHSST.

Hypoxia Augments Increased HIF-1α and Reduced Survival Protein p-Akt in Gelsolin (GSN)-Dependent Cardiomyoblast Cell Apoptosis

Cytoskeleton filaments play an important role in cellular functions such as maintaining cell shape, cell motility, intracellular transport, and cell division. Actin-binding proteins (ABPs) have numerous functions including regulation of actin filament nucleation, elongation, severing, capping, cross linking, and actin monomer sequestration. Gelsolin (GSN) is one of the actin-binding proteins. Gelsolin (GSN) is one of the actin-binding proteins that regulate cell morphology, differentiation, movement, and apoptosis. GSN also regulates cell morphology, differentiation, movement, and apoptosis. In this study, we have used H9c2 cardiomyoblast cell and H9c2-GSN stable clones to understand the roles and mechanisms of GSN overexpression in hypoxia-induced cardiomyoblast cell death. The data show that hypoxia or GSN overexpression induces HIF-1α expression and reduces the expression of survival markers p-Akt and Bcl-2 in H9c2 cardiomyoblast cells. Under hypoxic conditions, GSN overexpression further reduces p-Akt expression and elevates total as well as cleaved GSN levels and HIF-1α levels. In addition, GSN overexpression enhances apoptosis in cardiomyoblasts under hypoxia. Hypoxic challenge further induced activated caspase-3 and cell death that was attenuated after GSN knock down, which implies that GSN is a critical therapeutic target against hypoxia-induced cardiomyoblast cell death.

Angiotensin-(1-7) attenuated long-term hypoxia-stimulated cardiomyocyte apoptosis by inhibiting HIF-1α nuclear translocation via Mas receptor regulation

Extreme hypoxia often leads to myocardial apoptosis and causes heart failure. Angiotensin-(1-7)Ang-(1-7) is well known for its cardio-protective effects. However, the effects of Ang-(1-7) on long-term hypoxia (LTH)-induced apoptosis remain unknown. In this study, we found that Ang-(1-7) reduced myocardial apoptosis caused by hypoxia through the Mas receptor. Activation of the Ang-(1-7)/Mas axis down-regulated the hypoxia pro-apoptotic signaling cascade by decreasing the protein levels of hypoxia-inducible factor 1α (HIF-1α) and insulin-like growth factor binding protein-3 (IGFBP3). Moreover, the Ang-(1-7)/Mas axis further inhibited HIF-1α nuclear translocation. On the other hand, Ang-(1-7) activated the IGF1R/PI3K/Akt signaling pathways, which mediate cell survival. However, the above effects were abolished by A779 treatment or silencing of Mas expression. Taken together, our findings indicate that the Ang-(1-7)/Mas axis protects cardiomyocytes from LTH-stimulated apoptosis. The protective effect of Ang-(1-7) is associated with the inhibition of HIF-1α nuclear translocation and the induction of IGF1R and Akt phosphorylation.

Effects of garlic oil on interleukin-6 mediated cardiac hypertrophy in hypercholesterol-fed hamsters

Hypercholesterol diets are the major causes of cardiac hypertrophy and various cardiac disorders. The purpose of this study is to evaluate the effects of garlic oil on cardiac hypertrophy induced by hypercholesterol diets. Golden Syrian hamsters were fed with 2% cholesterol or 2% cholesterol plus 1% garlic oil for 2 months. Heart architecture changes were measured by hematoxylin-eosin staining and the molecular mechanism was determined by western blotting. Garlic oil reduced whole-heart weight to bone weight ratio, and left ventricle weight to bone weight ratio in the cholesterol-fed group. Moreover, the garlic oil group showed significantly reduced interleukin-6, phosphorylated (p)-extracellular signal-regulated kinase-5, p-mitogen-activated protein kinase-5, calcineurin, nuclear transcription factor of nuclear factor of activated T-cells-3 and p-GATA binding protein 4 when compared with the cholesterol group. However, no changes were observed in gp-130, signal transducer and activator of transcription-3, p-P38 and p-Jun N-terminal kinases protein levels in all groups. The results show that garlic oil may be useful in the treatment of hypertrophy-associated cardiovascular diseases.