Hydrogen sulfide (H2S) has been recently found to be an endogenous signaling gasotransmitter. Cardiac hypertrophy often develops in the course of heart failure. It is unknown whether or not endogenous H2S protects cardiac hypertrophy. This study was conducted to examine the effects of H2S on cardiac hypertrophy and fibrosis induced by abdominal aortic coarctation and to explore its mechanisms. Male Sprague-Dawley rats were randomly divided into five groups: normal, sham, abdominal aortic coarctation (AAC), AAC treated with enalapril and AAC treated with H2S. One week after surgery, enalapril and sodium hydrosulfide (NaHS)-treated rats were fed for 28 consecutive days and sacrificed. After that, the left ventricle mass index (LVMI), cardiomyocyte size and areas, collagen volume fraction (CVF) of the rats were measured. In the AAC rats, the LVMI, the cardiomyocyte size and areas, and the CVF were all markedly increased while in the H2S groups they were significantly reduced. H2S decreased the levels of Ang-II in the heart, but not in plasma. In addition, H2S also improved the expression of connexin 43 (Cx43). Our results suggest that H2S can significantly suppress cardiac hypertrophy and fibrosis induced by overloaded pressure, possibly by inhibiting the activity of intracardiac Ang-II and by modifying expression of Cx43.
Prolonged benzodiazepine treatment of rats results in anticonvulsant tolerance in vivo. Studies of in vitro hippocampal slices following 1 wk flurazepam administration show reduced GABA-mediated inhibition in the CA1 region, and a decrease in GABAA agonist and benzodiazepine potency to inhibit CA1 pyramidal cell-evoked responses. To investigate the molecular basis of benzodiazepine tolerance in the hippocampus, in situ hybridization techniques were used to evaluate the expression of the mRNAs for the alpha 1, alpha 5, and gamma 2 subunits of the GABAA receptor in the hippocampal formation and frontal cortex of chronic flurazepam-treated rats. A discretely localized decrease in alpha 1, but not alpha 5 or gamma 2 mRNA expression was found in the CA1 region (35-40%) and in layers II-III and IV of cortex (50-60%) 2 d after cessation of flurazepam treatment. The decrease in the expression of alpha 1 subunit mRNA in cortex is similar to that reported following other chronic benzodiazepine treatment regimens. This is the first report of a reduction in alpha 1 subunit mRNA expression in the hippocampal formation.
Background and purpose: Combining statin and fibrate in clinical practice provides a greater reduction of triglycerides than either drug given alone, but the mechanism for this effect is poorly understood. Apolipoprotein AV (apoAV) has been implicated in triglyceride metabolism. This study was designed to investigate the effect of the combination of statin and fibrate on apoAV and the underlying mechanism(s). Experimental approach: Hypertriglyceridaemia was induced in rats by giving them 10% fructose in drinking water for 2 weeks. They were then treated with atorvastatin, fenofibrate or the two agents combined for 4 weeks, and plasma triglyceride and apoAV measured. We also tested the effects of these two agents on triglycerides and apoAV in HepG2 cells in culture. Western blot and reverse transcription polymerase chain reaction was used to measure apoAV and peroxisome proliferatoractivated receptor-a (PPARa) expression. Key results: The combination of atorvastatin and fenofibrate resulted in a greater decrease in plasma triglycerides and a greater increase in plasma and hepatic apoAV than either agent given alone. Hepatic expression of the PPARa was also more extensively up-regulated in rats treated with the combination. A similar, greater increase in apoAV and a greater decrease in triglycerides were observed following treatment of HepG2 cells pre-exposed to fructose), with the combination. Adding an inhibitor of PPARa (MK886) abolished the effects of atorvastatin on HepG2 cells.
Conclusions and implications:A combination of atorvastatin and fenofibrate increased apoAV and decreased triglycerides through up-regulation of PPARa.
Context: Berberine is used in traditional Chinese medicine for thousands of years with recent reports of its anticancer activity.Objective: To test antiangiogenic effects of berberine on human glioblastoma and clarify involvement of the VEGFR2/ERK pathway.Materials and methods: Cell viability, proliferation and migration assays were performed to determine in vitro antiangiogenic effects of berberine (6.25–200 μmol/L, 6–48 h). Ectopic and orthotopic xenograft models in BALB/c nude mice were induced to determine antitumour and antiangiogenic effects of berberine (50 mg/kg by oral gavage for 28 days) or vehicle control (carboxymethylcellulose sodium).Results: Berberine inhibited cell viability (IC50 of 42 and 32 μmol/L, respectively) and proliferation of U87 and U251 human glioblastoma cell lines. Berberine (50 μmol/L) inhibited cell migration of HUVEC by 67.50 ± 8.14% in the Transwell assay and tube formation of HUVEC by 73.00 ± 11.12% in the Matrigel assay. In the ectopic xenograft model, tumour weight was significantly decreased by 50 mg/kg of berberine (401.2 ± 71.5 mg vs. 860.7 ± 117.1 mg in vehicle group, p ˂ 0.001). Berberine significantly decreased haemoglobin content (28.81 ± 3.64 μg/mg vs. 40.84 ± 5.15 μg/mg in vehicle group, p ˂ 0.001) and CD31 mRNA expression in tumour tissue. In the orthotopic xenograft model, berberine (50 mg/kg) significantly improved the survival rate of mice (p = 0.0078). Berberine inhibited (p ˂ 0.001) the phosphorylation of VEGFR2 and ERK.Discussion and conclusions: Berberine inhibited angiogenesis in glioblastoma xenografts by targeting the VEGFR2/ERK pathway. Our work sheds new light on complementary and alternative therapy for glioblastoma.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.