The Effects of Different Types of Sleep Disorder on Colorectal Cancer: A Nationwide Population-Based Cohort Study.

The impact of sleep disorders (SDs), particularly sleep apnea (SA), on the development of colorectal cancer (CRC) has been the subject of significant research. However, the potential contribution of other SDs to the incidence of CRC remains unexplored. The objective of this study was to examine the effects of SDs on the risk of developing CRC. This study assessed CRC risk among individuals diagnosed with SDs compared with age- and sex-matched unaffected individuals. A longitudinal, nationwide, population-based cohort study was conducted using data from the Taiwan National Health Insurance Research Database (NHIRD) encompassing 177,707 individuals diagnosed with SDs and 177,707 matched controls. Cox proportional hazard regression analysis was used to determine the relative increased risk of CRC in individuals with SDs and specific subgroups of SDs. The CRC incidences were 1.32-fold higher (95% CI 1.23-1.42) in the overall SD cohort, 1.17-fold higher (95% CI 0.82-1.68) in the SA cohort, 1.42-fold higher (95% CI 1.31-1.55) in the insomnia cohort, 1.27-fold higher (95% CI 1.17-1.38) in the sleep disturbance cohort, and 1.00-fold higher (95% CI 0.77-1.29) in the other SD cohort, after adjusting for age, sex, and comorbidities.

Protective Effects of Influenza Vaccine against Colorectal Cancer in Populations with Chronic Kidney Disease: A Nationwide Population-Based Cohort Study.

Chronic kidney disease (CKD) is associated with malignancy, including colorectal cancer, via the potential mechanism of chronic inflammation status. This study aimed to determine whether influenza vaccines can reduce the risk of colorectal cancer in patients with CKD. Our cohort study enrolled 12,985 patients older than 55 years with a diagnosis of CKD in Taiwan from the National Health Insurance Research Database at any time from 1 January 2001 to 31 December 2012. Patients enrolled in the study were divided into a vaccinated and an unvaccinated group. In this study, 7490 and 5495 patients were unvaccinated and vaccinated, respectively. A propensity score was utilized to reduce bias and adjust the results. Cox proportional hazards regression was used to estimate the correlation between the influenza vaccine and colorectal cancer in patients with CKD. The results showed that the influenza vaccine exerted a protective effect against colorectal cancer in populations with CKD. The incidence rate of colon cancer in the vaccinated group was significantly lower than in the unvaccinated group, with an adjusted hazard rate (HR) of 0.38 (95% CI: 0.30-0.48, p < 0.05). After the propensity score was adjusted for Charlson comorbidity index, age, sex, dyslipidemia, hypertension, diabetes, monthly income, and level of urbanization, the dose-dependent effect was found, and it revealed adjusted HRs of 0.74 (95% CI: 0.54-1.00, p < 0.05), 0.41 (95% CI: 0.30-0.57, p < 0.001), 0.16 (95% CI: 0.11-0.25, p < 0.001) for one, two to three, and four or more vaccinations, respectively. In summary, the influenza vaccine was found to be associated with a reduced risk of colorectal cancer in CKD patients. This study highlights the potential chemopreventive effect of influenza vaccination among patients with CKD. Future studies are required to determine whether the aforementioned relationship is a causal one.

Cafestol Inhibits High-Glucose-Induced Cardiac Fibrosis in Cardiac Fibroblasts and Type 1-Like Diabetic Rats.

Diabetes is associated with the development of myocardial fibrosis, which is related to various cardiac diseases. Cafestol, one of the active ingredients in coffee, has been reported to exert biological effects. However, whether cafestol can ameliorate diabetes-induced cardiac fibrosis remains unknown. The aim of this study was to evaluate the effects of cafestol on cardiac fibrosis in high-glucose-treated cardiac fibroblasts and streptozocin- (STZ-) induced diabetic rats. Rat cardiac fibroblasts were cultured in high-glucose (25 mM) media in the absence or presence of cafestol, and the changes in collagen synthesis, transforming growth factor-ß1 (TGF-ß1) production, and related signaling molecules were assessed on the basis of 3H-proline incorporation, enzyme-linked immunosorbent assay, and western blotting. Cardiac fibroblasts exposed to high-glucose conditions exhibited increased collagen synthesis, TGF-ß1 production, and Smad2/3 phosphorylation, and these effects were mitigated by cafestol treatment. Furthermore, cafestol increased the translocation of nuclear factor erythroid 2-related factor 2 and increased the expression of heme oxygenase-1. The results of molecular docking analysis suggested a selective interaction of cafestol with Kelch-like ECH-associated protein 1. The rats with untreated STZ-induced diabetes exhibited considerable collagen accumulation, which was ameliorated by cafestol. Moreover, activities of catalase, superoxide dismutase, general matrix metalloproteinase, and reduced glutathione concentration were upregulated, whereas malondialdehyde level was downregulated by treatment with cafestol in rats with cardiac fibrosis. These findings highlight the effects of cafestol, which may be useful in treating diabetes-related cardiac fibrosis.

Nicorandil prevents doxorubicin-induced human umbilical vein endothelial cell apoptosis.

Nicorandil is an adenosine triphosphate-sensitive potassium channel opener with additional antioxidant properties. Doxorubicin (DOX) is an anticancer drug that exerts oxidation-mediated adverse cardiovascular effects. This study examined the effects of nicorandil on DOX-induced cytotoxicity in human umbilical vein endothelial cells (HUVECs) and underlying intracellular signaling mechanisms. Cultured HUVECs were pretreated with nicorandil (0.1, 0.3, 1, 3, and 10 µM) for 12 h and then treated with DOX (1 µM) for 24 h. Cell viability and cytotoxicity were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays, respectively. Cell apoptosis was examined using a caspase-3 activity assay, and DNA fragmentation was detected through TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) staining. Western blot analysis was conducted to determine the related protein expression. DOX markedly increased reactive oxygen species production, p53 expression, caspase-3 activity, cleaved caspase-3 levels, and TUNEL-positive cell numbers but reduced Bcl-2 expression and intracellular antioxidant enzyme levels; these effects were effectively antagonized through nicorandil (3 µM, 12 h) pretreatment, which resulted in HUVECs being protected from DOX-induced apoptosis. Activating transcription factor 3 (ATF3), a stress-induced transcription factor, was induced by nicorandil (3 µM). Furthermore, nicorandil (3 µM) enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) translocation and heme oxygenase-1 (HO-1) expression. ATF3 short interfering RNA significantly attenuated nicorandil-mediated Nrf2 translocation, HO-1 expression, and inhibitory effects on DOX-stimulated reactive oxygen species production and cell apoptosis. In summary, nicorandil may protect HUVECs from DOX-induced apoptosis, in part through ATF3-mediated Nrf2/HO-1 signaling pathways, which potentially protect the vessels from severe DOX toxicity.

Cafestol Activates Nuclear Factor Erythroid-2 Related Factor 2 and Inhibits Urotensin II-Induced Cardiomyocyte Hypertrophy.

Through population-based studies, associations have been found between coffee drinking and numerous health benefits, including a reduced risk of cardiovascular disease. Active ingredients in coffee have therefore received considerable attention from researchers. A wide variety of effects have been attributed to cafestol, one of the major compounds in coffee beans. Because cardiac hypertrophy is an independent risk factor for cardiovascular events, this study examined whether cafestol inhibits urotensin II (U-II)-induced cardiomyocyte hypertrophy. Neonatal rat cardiomyocytes were exposed only to U-II (1 nM) or to U-II (1 nM) following 12-h pretreatment with cafestol (1-10 µ M). Cafestol (3-10 µ M) pretreatment significantly inhibited U-II-induced cardiomyocyte hypertrophy with an accompanying decrease in U-II-induced reactive oxygen species (ROS) production. Cafestol also inhibited U-II-induced phosphorylation of redox-sensitive extracellular signal-regulated kinase (ERK) and epidermal growth factor receptor transactivation. In addition, cafestol pretreatment increased Src homology region 2 domains-containing phosphatase-2 (SHP-2) activity, suggesting that cafestol prevents ROS-induced SHP-2 inactivation. Moreover, nuclear factor erythroid-2-related factor 2 (Nrf2) translocation and heme oxygenase-1 (HO-1) expression were enhanced by cafestol. Addition of brusatol (a specific inhibitor of Nrf2) or Nrf2 siRNA significantly attenuated cafestol-mediated inhibitory effects on U-II-stimulated ROS production and cardiomyocyte hypertrophy. In summary, our data indicate that cafestol prevented U-II-induced cardiomycyte hypertrophy through Nrf2/HO-1 activation and inhibition of redox signaling, resulting in cardioprotective effects. These novel findings suggest that cafestol could be applied in pharmacological therapy for cardiac diseases.

Analogous corticosteroids, 9A and EK100, derived from solid-state-cultured mycelium of Antrodia camphorata inhibit proinflammatory cytokine expression in macrophages.

Antrodia camphorata mycelium is used in traditional Chinese medicine in Taiwan. The wild-type mycelium is rare and expensive, so a solid-state-cultured mycelium of A. camphorata (SCMAC) has been developed. Previous studies have found SCMAC to have anti-inflammatory effects. However, the immunomodulatory effects of SCMAC and of its active phytosterol compounds EK100 and 9A on asthma remain unknown. In this study, BALB/c mice were repeatedly exposed to Dermatogoides pteronyssinus (Der p) at 1-week intervals and were orally administered crude SCMAC extract before the Der p challenge. The mice were sacrificed 72 h after the last challenge to examine the airway remodeling, inflammation, and expression profiles of cytokines and various genes. Then, 30-µg/mL Der p-stimulated MH-S cells with 9A or EK100 were collected for real-time PCR analysis, and the effects of 9A and EK100 on macrophages were evaluated. The crude extract reduced Der p-induced airway hyperresponsiveness, total serum immunoglobulin E levels, and recruitment of inflammatory cells to the bronchoalveolar lavage fluid through cytokine downregulation and Th1/Th2/Th17 response modulation. Additionally, 9A and EK100 inhibited IL-1ß and IL-6 expression in alveolar macrophages. These results indicate that the pharmacologically active compounds in a crude SCMAC extract exert synergistic effects on multiple targets to relieve asthma symptoms.

Nicorandil Inhibits Cyclic Strain-Induced Interleukin-8 Expression in Human Umbilical Vein Endothelial Cells.

BACKGROUND: Nicorandil, a mitochondrial adenosine triphosphate-sensitive potassium (mitoKATP) channel opener, exerts protective effects on the cardiovascular system. This study examined the effect of nicorandil on cyclic strain-induced interleukin-8 (IL-8) expression in human umbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs were exposed to cyclic strain in the presence or absence of nicorandil (1-10 µmol/l); we then analyzed IL-8 expression. We also assessed the effects of nicorandil on heme oxygenase-1 (HO-1) expression and cyclic strain-modulated IL-8 expression after HO-1 silencing in HUVECs. SUMMARY: HUVECs exposed to cyclic strain showed increased IL-8 messenger RNA expression and protein secretion. Nicorandil (1-10 µmol/l) inhibited cyclic strain-induced IL-8 expression, whereas 5-hydroxydecanoate (100 µmol/l), a selective inhibitor of the mitoKATP channel, completely reversed the inhibitory effects of nicorandil on cyclic strain-induced IL-8 expression. We demonstrated that nicorandil increased HO-1 expression in HUVECs. In addition, cobalt protoporphyrin (10 µmol/l), an inducer of HO-1 expression, mimicked the effects of nicorandil and inhibited IL-8 expression under cyclic strain, whereas zinc protoporphyrin IX (10 µmol/l), an inhibitor of HO-1 expression, antagonized the effect of nicorandil. HO-1 silencing significantly abrogated the inhibitory effects of nicorandil on cyclic strain-induced IL-8 expression, suggesting that HO-1 plays a role in the mechanism of action of nicorandil. KEY MESSAGES: This study is the first to report that nicorandil inhibits cyclic strain-induced IL-8 expression through the induction of HO-1 expression in HUVECs. This finding provides valuable new insight into the molecular pathways contributing to the vasoprotective effects of nicorandil.

Tanshinone IIA Induces Heme Oxygenase 1 Expression and Inhibits Cyclic Strain-Induced Interleukin 8 Expression in Vascular Endothelial Cells.

Tanshinone IIA is the main effective component of Salvia miltiorrhiza, known as "Danshen," which has been used in many therapeutic remedies in traditional Chinese medicine. However, the direct effects of tanshinone IIA on vascular endothelial cells have not yet been fully described. In the present study, we demonstrated that tanshinone IIA increased heme oxygenase-1 (HO-1) expression in human umbilical vein endothelial cells. Western blot analyses and experiments with specific inhibitors indicated tanshinone IIA enhanced HO-1 expression through the activation of phosphoinositide 3-kinase (PI3K)/Akt and the subsequent induction of nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation. In addition, tanshinone IIA inhibited cyclic strain induced interleukin-8 (IL-8) expression. HO-1 silencing significantly abrogated the repressive effects of tanshinone IIA on strain-induced IL-8 expression, which suggests HO-1 has a role in mediating the effects of tanshinone IIA. This study reports for the first time that tanshinone IIA inhibits cyclic strain-induced IL-8 expression via the induction of HO-1 in endothelial cells, providing valuable new insight into the molecular pathways that may contribute to the effects of tanshinone IIA.

Lycopene inhibits cyclic strain-induced endothelin-1 expression through the suppression of reactive oxygen species generation and induction of heme oxygenase-1 in human umbilical vein endothelial cells.

Lycopene is the most potent active antioxidant among the major carotenoids, and its use has been associated with a reduced risk for cardiovascular disease (CVD). Endothelin-1 (ET-1) is a powerful vasopressor synthesized by endothelial cells and plays a crucial role in the pathophysiology of CVD. However, the direct effects of lycopene on vascular endothelial cells have not been fully described. This study investigated the effects of lycopene on cyclic strain-induced ET-1 gene expression in human umbilical vein endothelial cells (HUVECs) and identified the signal transduction pathways that are involved in this process. Cultured HUVECs were exposed to cyclic strain (20% in length, 1 Hz) in the presence or absence of lycopene. Lycopene inhibited strain-induced ET-1 expression through the suppression of reactive oxygen species (ROS) generation through attenuation of p22(phox) mRNA expression and NAD(P)H oxidase activity. Furthermore, lycopene inhibited strain-induced ET-1 secretion by reducing ROS-mediated extrace-llular signal-regulated kinase (ERK) phosphorylation. Conversely, lycopene treatment enhanced heme oxygenase-1 (HO-1) gene expression through the activation of phosphoinositide 3-kinase (PI3K)/Akt pathway, followed by induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation; in addition, HO-1 silencing partially inhibited the repressive effects of lycopene on strain-induced ET-1 expression. In summary, our study showed, for the first time, that lycopene inhibits cyclic strain-induced ET-1 gene expression through the suppression of ROS generation and induction of HO-1 in HUVECs. Therefore, this study provides new valuable insight into the molecular pathways that may contribute to the proposed beneficial effects of lycopene on the cardiovascular system.

Reduction of Airway Hyperresponsiveness by KWLL in Dermatophagoides-pteronyssinus-Challenged Mice.

Urine therapy has been commonly practiced in ancient civilizations including those of India, China, and Greece. The traditional Chinese medicine KWLL, the precipitation of human urine, has been used in China to alleviate the symptoms of asthma for thousands of years. However, the mechanism of action by which KWLL exerts its immunotherapy is unclear. This study attempted to elucidate the pharmacology of KWLL in mice that had been challenged recurrently by Dermatophagoides pteronyssinus (Der p). BALB/c mice were orally administered KWLL (1 g/kg) before an intratracheal (i.t.) challenge of Der p. Allergic airway inflammation and remodeling were provoked by repetitive Der p (50 µ g/mice) challenges six times at 1 wk intervals. Airway hypersensitivity, histological lung characteristics, and the expression profiles of cytokines and various genes were assessed. KWLL reduced Der p-induced airway hyperresponsiveness and inhibited eosinophil infiltration by downregulating the protein expression of IL-5 in bronchoalveolar lavage fluid (BALF). It also inhibited neutrophil recruitment by downregulating IL-17A in BALF. KWLL effectively diminished inflammatory cells, goblet cell hyperplasia, and mRNA expression of IL-6 and IL-17A in the lung. The reduction by KWLL of airway inflammatory and hyperresponsiveness in allergic asthmatic mice was mediated via immunomodulation of IL-5, IL-6, and IL-17A.

Tanshinone IIA Attenuates H2O2 -induced injury in human umbilical vein endothelial cells.

The injury of endothelial cell is the critical event of vascular disease. In endothelial cell, oxidative stress is regarded as critical to pathogenic factors in endothelial cell injury and apoptosis. Tanshinone IIA is the main effective component of Salvia miltiorrhiza known as "Danshen" in traditional Chinese medicine for treating cardiovascular disorders, but the mechanism by which it exerts the protective effect is not well established. The present study was designed to test the hypothesis that tanshinone IIA can inhibit hydrogen peroxide ( H(2)O(2) )-induced injury and unravel its intracellular mechanism in human umbilical vein endothelial cells (HUVECs). In this study, HUVECs were treated with tanshinone IIA in the presence/absence of H(2)O(2) . The protective effects of tanshinone IIA against H(2)O(2) were evaluated. Our results show that HUVECs incubated with 200 µM H(2)O(2) had significantly decreased the viability of endothelial cells, which was accompanied with apparent cell apoptosis, the activation of caspase-3 and the upregulation of p53 expression, which was known to play a key role in H(2)O(2) -induced cell apoptosis. However, pretreatment with tanshinone IIA (3-10 µM) resulted in a significant resistance to H(2)O(2) -induced apoptosis. In addition, pretreatment with tanshinone IIA decreased the activity of caspase-3 and p53 expression. Tanshinone IIA also induced activating transcription factor (ATF) 3 expression; while knockdown of ATF-3 with ATF-3 siRNAsignificantly reduced tanshinone IIA's protective effect. In conclusion, the present study shows that tanshinone IIA can protect endothelial cells against oxidative injury induced by H(2)O(2) , suggesting that this compound may constitute a promising intervention against cardiovascular disorders and ATF-3 may play an important role in this process.

Computational pharmaceutical analysis of anti-Alzheimer's Chinese medicine Coptidis Rhizoma alkaloids.

Alzheimer's disease (AD) is an age-related neurodegenerative disease, affecting over 20 million people worldwide. Until recently, two major hypotheses were proposed regarding the molecular mechanism of pathogenesis: the cholinergic hypothesis and the amyloid cascade hypothesis. At present, acetylcholinesterase inhibitors are the most effective therapy for AD. Most pharmacological research has focused on the ability of acetylcholinesterase to alleviate cholinergic deficit and improve neurotransmission. Coptidis rhizoma and its isolated alkaloids are reported to possess a variety of activities, including neuroprotective and antioxidant effects. However, as yet no theoretical analysis exists to support this hypothesis. To examine this theory, we applied a computational pharmaceutical analysis to reveal that Chinese medicine Coptidis rhizoma alkaloids have much higher activities than Donepezil (commercial name is Aricept) by docking and scoring.

Tanshinone IIA prevents doxorubicin-induced cardiomyocyte apoptosis through Akt-dependent pathway.

BACKGROUND: Doxorubicin, one of the original anthracyclines, remains among the most effective anticancer drugs ever developed. Clinical use of doxorubicin is, however, greatly limited by its serious adverse cardiac effects that may ultimately lead to cardiomyopathy and heart failure. Tanshinone IIA is the main effective component of Salvia miltiorrhiza known as 'Danshen' in traditional Chinese medicine for treating cardiovascular disorders. The objective of this study was set to evaluate the protective effect of tanshinone IIA on doxorubicin-induced cardiomyocyte apoptosis, and to explore its intracellular mechanism(s). METHODS: Primary cultured neonatal rat cardiomyocytes were treated with the vehicle, doxorubicin (1 µM), tanshinone IIA (0.1, 0.3, 1 and 3 µM), or tanshinone IIA plus doxorubicin. RESULTS: We found that tanshinone IIA (1 and 3 µM) inhibited doxorubicin-induced reactive oxygen species generation, reduced the quantity of cleaved caspase-3 and cytosol cytochrome c, and increased BcL-x(L) expression, resulting in protecting cardiomyocytes from doxorubicin-induced apoptosis. In addition, Akt phosphorylation was enhanced by tanshinone IIA treatment in cardiomyocytes. The wortmannin (100 nM), LY294002 (10 nM), and siRNA transfection for Akt significantly reduced tanshinone IIA-induced protective effect. CONCLUSIONS: These findings suggest that tanshinone IIA protects cardiomyocytes from doxorubicin-induced apoptosis in part through Akt-signaling pathways, which may potentially protect the heart from the severe toxicity of doxorubicin.

Tanshinone IIA attenuates cyclic strain-induced endothelin-1 expression in human umbilical vein endothelial cells.

1. Tanshinone IIA, one of the active components of the Radix of Salvia miltiorrhiza, is used in traditional Chinese medicine to treat cardiovascular diseases. However, the intracellular mechanism of action of tanshinone IIA remain to be determined. The aims of the present study were to test the hypothesis that tanshinone IIA alters strain-induced endothelin (ET)-1 expression and nitric oxide (NO) production, as well as to identify the putative signalling pathways involved, in human umbilical vein endothelial cells (HUVEC). 2. Cultured HUVEC were exposed to cyclic strain in the presence of 1-10 µmol/L tanshinone IIA. Expression of ET-1 was examined by reverse transcription-polymerase chain reaction and ELISA. Phosphorylation of endothelial NO synthase (eNOS) and activating transcription factor (ATF) 3 was assessed by western blot analysis. 3. Tanshinone IIA (3 and 10 µmol/L) inhibited strain-induced ET-1 expression. In contrast, NO production, eNOS phosphorylation and ATF3 expression were enhanced by tanshinone IIA. The eNOS inhibitor N(G) -nitro-L-arginine methyl ester (l-NAME; 100 µmol/L), the phosphatidylinositol 3-kinase inhibitor LY294002 (5 µmol/L) and the soluble guanylyl cyclase inhibitor 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ; 10 µmol/L) inhibited tanshinone IIA-induced increases in ATF3 expression. Moreover, treatment of HUVEC with either an NO donor (3,3-bis [aminoethyl]-1-hydroxy-2-oxo-1-triazene; 500 µmol/L) or an ATF3 activator (carbobenzoxy-L-leucyl-L-leucyl-L-leucinal; 5 µmol/L) resulted in the repression of strain-induced ET-1 expression. The inhibitory effect of tanshinone IIA on strain-induced ET-1 expression was significantly attenuated by l-NAME, ODQ and the transfection of small interfering RNA for ATF3. 4. In conclusion, tanshinone IIA inhibits strain-induced ET-1 expression by increasing NO and upregulating ATF3 in HUVEC. The present study provides important new insights into the molecular pathways that may contribute to the beneficial effects of tanshinone IIA in the cardiovascular system.

Nicorandil attenuates cyclic strain-induced endothelin-1 expression via the induction of activating transcription factor 3 in human umbilical vein endothelial cells.

Nicorandil is an adenosine triphosphate-sensitive potassium channel opener that combines an organic nitrate and a nicotinamide group which respectively confer to nicorandil the additional properties of being a nitric oxide (NO) donor and antioxidant; it also induces vasodilation, decreases the blood pressure, and protects the heart. However, the intracellular mechanism of nicorandil remains to be delineated. The aims of this study were to test the hypothesis that nicorandil alters strain-induced endothelin-1 secretion and NO production, and to identify the putative underlying signaling pathways in human umbilical vein endothelial cells (HUVECs). Cultured HUVECs were exposed to cyclic strain in the presence of nicorandil; endothelin-1 expression was examined by reverse-transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. Activation of extracellular signal-regulated protein kinase (ERK), endothelial NO synthase (eNOS), and activating transcription factor (ATF)-3 was assessed by Western blot analysis. We show that nicorandil inhibited strain-induced endothelin-1 expression. Nicorandil also inhibited strain-increased reactive oxygen species formation and ERK phosphorylation. On the contrary, NO production, eNOS phosphorylation, and ATF3 expression were enhanced by nicorandil; however, L-NAME (an inhibitor of eNOS) and LY294002 (an inhibitor of phosphatidylinositol 3-kinase) inhibited nicorandil-increased ATF3 expression. Moreover, treatment of HUVECs with either an NO donor (NOC18; 3,3-bis[aminoethyl]-1-hydroxy-2-oxo-1-triazene) or an ATF3 activator (MG-132; carbobenzoxy-L-leucyl-L-leucyl-L-leucinal) resulted in repression of strain-induced endothelin-1 expression. Furthermore, L-NAME, and small interfering RNA transfection of eNOS also partially attenuated the inhibitory effect of nicorandil on strain-induced endothelin-1 expression. We demonstrate for the first time that nicorandil inhibits strain-induced endothelin-1 secretion via an increase in NO and upregulation of ATF3 in HUVECs. This study provides important new insights into the molecular pathways that may contribute to the beneficial effects of nicorandil in the cardiovascular system.

Tanshinone IIA inhibits angiotensin II-induced cell proliferation in rat cardiac fibroblasts.

Tanshinone IIA extracted from danshen, a popular medicinal herb used in traditional Chinese medicine, exhibits cardio-protective effects. However, the mechanism of its cardioprotective effect is not well established. The aims of this study were to examine whether tanshinone IIA may alter angiotensin II (Ang II)-induced cell proliferation and to identify the putative underlying signaling pathways in rat cardiac fibroblasts. Cultured rat cardiac fibroblasts were pre-treated with tanshinone IIA and stimulated with Ang II, cell proliferation and endothelin-1 (ET-1) expression were examined. The effect of tanshinone IIA on Ang II-induced reactive oxygen species (ROS) formation, and extracellular signal-regulated kinase (ERK) phosphorylation were also examined. In addition, the effect of tanshinone IIA on nitric oxide (NO) production, and endothelial nitric oxide synthase (eNOS) phosphorylation were tested to elucidate the intracellular mechanism. The increased cell proliferation and ET-1 expression by Ang II (100 nM) were partially inhibited by tanshinone IIA. Tanshinone IIA also inhibited Ang II-increased ROS formation, and ERK phosphorylation. In addition, tanshinone IIA was found to increase the NO generation, and eNOS phosphorylation. N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NOS, and the short interfering RNA transfection for eNOS markedly attenuated the inhibitory effect of tanshinone IIA on Ang II-induced cell proliferation. The results suggest that tanshinone IIA prevents cardiac fibroblast proliferation by interfering with the generation of ROS and involves the activation of the eNOS-NO pathway.

Nicorandil inhibits angiotensin-II-induced proliferation of cultured rat cardiac fibroblasts.

BACKGROUND/AIMS: Nicorandil, an ATP-sensitive potassium (K(ATP)) channel opener, nitric oxide (NO) donor and antioxidant, was shown to exert a variety of pharmacological effects including cardioprotective properties. However, its mechanisms of action are not completely understood. The aims of this study were to examine whether nicorandil may alter angiotensin-II (Ang II)-induced cell proliferation and to identify the putative underlying signaling pathways in rat cardiac fibroblasts. METHODS: Cultured rat cardiac fibroblasts were pretreated with nicorandil, then stimulated with Ang II, and cell proliferation and endothelin-1 (ET-1) expression were examined. The effects of nicorandil on Ang-II-induced reactive oxygen species (ROS) formation and extracellular signal-regulated kinase (ERK) phosphorylation were also examined. In addition, the effects of nicorandil on NO production and endothelial nitric oxide synthase (eNOS) phosphorylation were tested to elucidate the intracellular mechanism. RESULTS: Nicorandil (0.1-10 µmol/l) caused a concentration-dependent inhibition of Ang-II-increased cell proliferation and ET-1 expression which were prevented by the K(ATP) channel blocker glibenclamide (1 µmol/l). Nicorandil also inhibited Ang-II-increased ROS and ERK phosphorylation. In addition, nicorandil was found to increase the NO and eNOS phosphorylation. N-nitro-L-arginine methyl ester, an inhibitor of NOS, and the short interfering RNA transfection for eNOS markedly attenuated the inhibitory effect of nicorandil on Ang-II-induced cell proliferation. CONCLUSION: Our results suggest that nicorandil prevents cardiac fibroblast proliferation, and the inhibitory effect might be associated with the opening K(ATP) channels, by interfering with the generation of ROS, and the activation of the eNOS-NO pathway.

L-carnitine reduces doxorubicin-induced apoptosis through a prostacyclin-mediated pathway in neonatal rat cardiomyocytes.

BACKGROUND: Clinical use of doxorubicin is greatly limited by its severe cardiotoxic side effects. L-carnitine is a vitamin-like substance which has been successfully used in many cardiomyopathies, however, the intracellular mechanism(s) remain unclear. The objective of this study was set to evaluate the protective effect of L-carnitine on doxorubicin-induced cardiomyocyte apoptosis, and to explore its intracellular mechanism(s). METHODS: Primary cultured neonatal rat cardiomyocytes were treated with doxorubicin (1 µM) with or without pretreatment with L-carnitine (1-30 mM). Lactate dehydrogenase assay, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining, and flow cytometry measurement were used to assess cytotoxicity and apoptosis. Fluorescent probes 2',7'-dichlorofluorescein diacetate and chemiluminescence assay of superoxide production were used to detect the production of reactive oxygen species. Western blotting was used to evaluate the quantity of cleaved caspase-3, cytosol cytochrome c, and Bcl-x(L) expression. RESULTS: L-carnitine inhibited doxorubicin-induced reactive oxygen species generation and NADPH oxidase activation, reduced the quantity of cleaved caspase-3 and cytosol cytochrome c, and increased Bcl-x(L) expression, resulting in protecting cardiomyocytes from doxorubicin-induced apoptosis. In addition, L-carnitine was found to increase the prostacyclin (PGI(2)) generation in cardiomyocytes. The siRNA transfection for PGI(2) synthase significantly reduced L-carnitine-induced PGI(2) and L-carnitine's protective effect. Furthermore, blockade the potential PGI(2) receptors, including PGI(2) receptors (IP receptors), and peroxisome proliferator-activated receptors alpha and delta (PPARα and PPARδ), revealed that the siRNA-mediated blockage of PPARα considerably reduced the anti-apoptotic effect of L-carnitine. CONCLUSIONS: These findings suggest that L-carnitine protects cardiomyocytes from doxorubicin-induced apoptosis in part through PGI(2) and PPARα-signaling pathways, which may potentially protect the heart from the severe toxicity of doxorubicin.

Tanshinone IIA attenuates angiotensin II-induced apoptosis via Akt pathway in neonatal rat cardiomyocytes.

AIM: to examine the effects of tanshinone IIA, the main effective component of Salvia miltiorrhiza (known as 'Danshen' in traditional Chinese medicine) on angiotensin II (Ang II)-mediated cardiomyocyte apoptosis. METHODS: rat neonatal cardiomyocytes were primarily cultured with Ang II or Ang II plus tanshinone IIA. Myocyte apoptosis was evaluated by caspase-3 activity and DNA strand break level with TdT-mediated dUTP nick-end labeling (TUNEL) staining. Western blot analysis was employed to determine the related protein expression and flow cytometry assay was used to determine the TUNEL positive cells and the intracellular reactive oxygen species (ROS) production. SiRNA targeted to Akt was used. RESULTS: ang II (0.1 micromol/L) remarkably increased caspase-3 activity, TUNEL positive cells, and cleaved caspase-3 and cytochrome c expression, but reduced Bcl-X(L) expression. These effects were effectively antagonized by pretreatment with tanshione IIA (1-3 micromol/L). Tanshinone IIA had no effect on basal ROS level, while attenuated the ROS production by Ang II. Interestingly, tanshione IIA significantly increased the phosphorylated Akt level, which was countered by the PI3K antagonist wortmannin or LY294002. Knockdown of Akt with Akt siRNA significantly reduced Akt protein levels and tanshinone IIA protective effect. CONCLUSION: tanshinone IIA prevents Ang II-induced apoptosis, thereby suggesting that tanshinone IIA may be used for the prevention of the cardiac remodeling process.

Leptin stimulates endothelin-1 expression via extracellular signal-regulated kinase by epidermal growth factor receptor transactivation in rat aortic smooth muscle cells.

Obesity is a major risk factor for the development of hypertension. Recent studies have suggested that leptin, a 167-amino acid peptide hormone produced by white adipose tissue, is related to the pathogenesis of obesity-related hypertension. However, the signaling mechanisms underlying the effects of leptin remain to be extensively examined. In this study, we found that leptin induced extracellular signal-regulated kinase phosphorylation and endothelin-1 expression in rat aortic smooth muscle cells. Both PD98059 and U0126, inhibitors of the upstream activator of mitogen-activated protein kinase kinase, inhibited augmentation of endothelin-1 expression stimulated with leptin. Leptin induced significant tyrosine phosphorylation of epidermal growth factor receptor, which was significantly attenuated by two inhibitors, an epidermal growth factor receptor tyrosine kinase inhibitor, AG1478, and a broad-spectrum matrix metalloproteinase inhibitor, GM6001. This indicates that the pathway of epidermal growth factor receptor transactivation induced by leptin is dependent on proteolytically released epidermal growth factor receptor ligands. Pretreatment of cells with AG1478 significantly reduced the degree of phosphorylation of extracellular signal-regulated kinase and endothelin-1 expression. Our results reveal that epidermal growth factor receptor transactivation is involved in the leptin signaling pathway in vascular smooth muscle cells, which may be related to the increased risk of hypertension and other cardiovascular diseases in obese subjects.