The effects of Gemcitabine and Vinorelbine on inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) distribution of MCF-7 breast cancer cells

Gemcitabine, which induces S-phase arrest, and Vinorelbine, which arrests microtubule organization, are two agents that have demonstrate preferred anti-tumor activity. Nitric oxide acts in diverse functions including anti-tumor and anti-pathogenic activities. In this study, we aimed to examine the distribution of immunoreactivities of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in cells of the MCF-7 breast cancer cell line in response to treatment with Gemcitabine (G), Vinorelbine (V) and combination of Gemcitabine and Vinorelbine (G+V). The distributions of iNOS and eNOS were determined by using indirect immunoperoxidase or immunofluorescence methods and ELISA. Cells incubated with G, V and G+V for 24, 48 and 72 h were immunolabelled with anti-eNOS and anti-iNOS primary antibodies. Apoptosis was determined by TUNEL assay. A significant increase of eNOS immunolabelling on MCF-7 cells treated with G and G+V was observed. Apoptotic cells were also detected in G, V and G+V treated MCF-7 cells. The immunolabelling of iNOS was detected in all groups but this immunoreactivity was not different among the groups. In conclusion, while G treatment, induced S-phase arrest, triggered the NOS pathway after treatment of MCF-7 cells, V treatment, arrested microtubule organization and did not change the NOS pathway. Detection of increased eNOS immunolabelling and apoptosis after G treatment of MCF-7 cells could be important to the treatment of human breast cancer.     

Stimulation of Sigma-1 receptor signaling by dehydroepiandrosterone ameliorates pressure overload-induced hypertrophy and dysfunctions in ovariectomized rats

Objective: Decreased dehydroepiandrosterone (DHEA) levels are associated with endothelial dysfunction and increased cardiovascular mortality in postmenopausal women. We investigated the role of DHEA, also known as sigma-1 receptor (Sig-1R) agonist, in myocardial hypertrophy, cardiac functional recovery and defined mechanisms of cardioprotective action. Methods: Wistar rats subjected to bilateral ovariectomy (OVX) were further treated with abdominal aortic stenosis. DHEA (15 and 30 mg/kg) was administered orally once a day for 14 days starting from 2 weeks after aortic banding. Results: Time course study indicated that left ventricle (LV) weight:body weight (BW) ratio increased time-dependently from 1 to 4 weeks after pressure-overload (PO) with significant inversed regulation of Sig-1R expression. Treatment with the Sig-1R agonist, DHEA, significantly attenuated PO-induced myocardial hypertrophy with increased expression of Sig-1R in the LV. DHEA also attenuated hypertrophy-induced impaired LV end diastolic pressure, LV developed pressure and LV contractility (± dp/dt_max). DHEA treatment significantly restored PO-induced impaired eNOS and Akt activity in the LV. Conclusion: We report, for the first time to our knowledge, the potential role of Sig-1R expression in the heart to attenuate PO-induced hypertrophy in ovariectomized rats. DHEA treatment protects against PO-induced cardiac injury via upregulation of Sig-1R and stimulation of Sig-1R-mediated Akt-eNOS signaling.     

eNOS gene influences platelet phenotype in acute coronary syndrome patients on dual antiplatelet treatment

Nitric Oxide (NO) plays a relevant role in regulating platelet recruitment and eNOS is the major isoform known to be expressed in platelets. Polymorphisms in the eNOS gene with a reduced NO availability might affect platelet phenotype. The aim of our study was to evaluate the role of eNOS–786T > C, 894G > T and 4a/4b polymorphisms in modulating platelet phenotype in 1442 acute coronary syndrome (ACS) patients on dual antiplatelet therapy, previously investigated in relation to platelet function. Platelet aggregation on platelet-rich plasma after collagen (2 µg/mL), ADP (10 µM) and arachidonic acid (AA) (1 mM) stimuli and the genetic analysis of eNOS polymorphisms were assessed. In subjects carrying the eNOS 4a and -786C alleles a significantly higher maximal platelet aggregation value after AA was found (p = 0.02 and p = 0.047, respectively). eNOS 4a but not -786C allele weakly influenced platelet aggregation after collagen stimulus (p = 0.05). eNOS 4a allele significantly and independently influenced AA-induced platelet aggregation (p = 0.01). A significantly higher percentage of patients with AA-induced high residual platelet reactivity (RPR) was found in subjects carrying both eNOS 4a and -786C allele (p = 0.03 and p = 0.04, respectively). At logistic multivariate analysis, the eNOS 4a allele significantly influenced the AA-induced high residual platelet reactivity (p = 0.02). This study evidences a role for eNOS gene in moderately, but significantly, modulating platelet phenotype in a high-risk population on dual antiplatelet treatment.     

柚皮苷调控PI3K/Akt/eNOS通路控制2型糖尿病大鼠脑血管内皮氧化损伤的作用探讨

目的 探讨柚皮苷对2型糖尿病大鼠脑血管内皮氧化损伤的治疗效果,以及柚皮苷对3-磷酸肌醇激酶(PI3K)/蛋白激酶B(AKT)/内皮型一氧化氮(eNOS)信号通路的调控作用.方法 2019年3月15日至2020年5月20日,将SD大鼠(南京医科大学实验动物中心)按随机字母表法分为4组,对照组大鼠给予标准饲料,其他组给予高...