Tanshinone IIA Inhibits ß-Catenin Nuclear Translocation and IGF-2R Activation via Estrogen Receptors to Suppress Angiotensin II-Induced H9c2 Cardiomyoblast Cell Apoptosis.

Cardiomyopathy involves changes in the myocardial ultra-structure, hypertrophy, apoptosis, fibrosis and inflammation. Angiotensin II (AngII) stimulates the expression of insulin like-growth factors (IGF-2) and IGF-2 receptor (IGF-2R) in H9c2 cardiomyoblasts and subsequently leads to apoptosis. Estrogen receptors protect cardiomyocytes from apoptosis and fibrosis. Tanshinone IIA (TSN), a main active ingredient from Danshen, has been shown to protect cardiomyocytes from death caused by different stress signals. Estrogen receptor α (ER) is required for the rapid activation of the IGF-1R signaling cascade. This study aimed to investigate whether TSN protected H9c2 cardiomyocytes from AngII-induced activation of IGF-2R pathway and hypertrophy via ERs. We found that AngII caused the reduction in IGF-1R phosphorylation and the elevation of ß-catenin and IGF-2R levels. This was reversed by increasing doses of TSN and of caspase-3 and ERK1/2 phosphorylation mediated by ERs. The phytoestrogen significantly attenuated AngII-induced apoptosis and suppressed the subsequent cardiac remodeling effect. Therefore, TSN reduced the AngII-induced activation of ß-catenin and IGF-2R pathways, apoptosis and cardiac remodeling via ERs in H9c2 cardiomyoblasts.

Tanshinone-induced ERs suppresses IGFII activation to alleviate Ang II-mediated cardiac hypertrophy.

Cardiomyopathy involves changes in myocardial ultrastructure and cardiac hypertrophy. Angiotensin II (AngII) has previously been shown to stimulate the expression of IGF-2 and IGF-2R in H9c2 cardiomyoblasts and increase of blood pressure, and cardiac hypertrophy. Estrogen receptors (ERs) exert protective effects, such as anti-hypertrophy in cadiomyocytes. Tanshinone IIA (TSN), a main active ingredient from a Chinese medical herb, Salvia miltiorrhiza Bunge (Danshen), was shown to protect cardiomyocytes hypertrophy by different stress signals. We aimed to investigate whether TSN protected H9c2 cardiomyocytes from AngII-induced activation of IGF-2R pathway and hypertrophy by mediating through ERs. AngII resulted in H9c2 cardiomyoblast hypertrophy and increased inflammatory molecular markers. These were down-regulated by TSN via estrogen receptors. AngII resulted in elevation in MAPKs, IGF-2R and hypertrophic protein markers. These, again, were reduced by addition of the phytoestrogen with activation of ERs. Finally, AngII induced phosphorylation of heat shock factor-1 (HSF1) and decreased sirtuin-1 (SIRT1). In addition, AngII also caused an increase in distribution of IGF-2R molecules on cell membrane. In contrast, TSN reduced HSF1 phosphorylation and cell surface IGF-2R while elevating SIRT1 via ERs. TSN was capable of attenuating AngII-induced IGF-2R pathway and hypertrophy through ERs in H9c2 cardiomyoblast cells.

Thymoquinone induces caspase-independent, autophagic cell death in CPT-11-resistant lovo colon cancer via mitochondrial dysfunction and activation of JNK and p38.

Chemotherapy causes unwanted side effects and chemoresistance, limiting its effectiveness. Therefore, phytochemicals are now used as alternative treatments. Thymoquinone (TQ) is used to treat different cancers, including colon cancer. The irinotecan-resistant (CPT-11-R) LoVo colon cancer cell line was previously constructed by stepwise CPT-11 challenges to untreated parental LoVo cells. TQ dose-dependently increased the total cell death index and activated apoptosis at 2 µM, which then diminished at increasing doses. The possibility of autophagic cell death was then investigated. TQ caused mitochondrial outer membrane permeability (MOMP) and activated autophagic cell death. JNK and p38 inhibitors (SP600125 and SB203580, respectively) reversed TQ autophagic cell death. TQ was also found to activate apoptosis before autophagy, and the direction of cell death was switched toward autophagic cell death at initiation of autophagosome formation. Therefore, TQ resulted in caspase-independent, autophagic cell death via MOMP and activation of JNK and p38 in CPT-11-R LoVo colon cancer cells.

Dung-Shen Downregulates the Synergistic Apoptotic Effects of Angiotensin II Plus Leu 27-IGF II on Cardiomyoblasts.

BACKGROUND: Insulin growth factor II (IGFII) is expressed after ischemic stress in pig hearts and after myocardial infarction in humans. However, its receptor (IGFIIR) cannot be found in normal adult hearts. Moreover, a mouse IGFII overexpression model showed a heart and kidney hypertrophy phenomenon similar to Beckwith-Wiedemann syndrome in humans. The previous studies from our lab showed that an increase in AngII in H9c2 cells causes an elevation in IGFII and IGFIIR through MEK and JNK activation, leading to a rise in intracellular Ca(2+) ions, activation of calcineurin by PLC-ß3 via Gαq, insertion into mitochondrial membranes of BAD, and apoptosis via activation of caspases 9 and 3. Codonopsis pilosula (Dung-shen) has various uses in traditional Chinese medicine, including lowering blood pressure, and increasing red and white blood cell counts. METHODS: The purpose of our study is to investigate whether the addition of C. pilosula will attenuate the AngII plus Leu27-IGFII-induced apoptosis in H9c2 cardiomyoblast cells. RESULTS: From MTT [3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-tetrazolium bromide] results, it was revealed that AngII plus Leu(27)-IGFII significantly reduced cell viability, which was reversed by C. pilosula. Additionally, C. pilosula also reversed apoptosis (TUNEL staining) increased by AngII plus Leu27-IGFII. Up-regulation of caspase 3 by AngII plus Leu27-IGFII was attenuated by C. pilosula treatment, as shown in western blotting assay and immunofluorescence microscopy results. CONCLUSIONS: C. pilosula is able to suppress the apoptotic pathway enhanced by AngII plus Leu27-IGFII in myocardial cells. KEY WORDS: Angiotensin II; Apoptosis; Codonopsis pilosula; Leucine27-insulin like growth factor II; Mitochondrial outer membrane permeability.