ABSTRACT
OBJECTIVE To investigate whether gas-trodin(GAS)plays a neuroprotective role by activating PI3K/Akt/BACH1 signaling axis to improve glycolytic func-tion.METHODS HT22 cells were treated with Aβ25-35 for 24 h to establish cell damage model.GAS pretreated HT22 cells for 2 h,and Akt agonist SC79,Akt inhibitor MK2206,PI3K inhibitor LY294002 were added 0.5 h before GAS treatment to detect their protective mecha-nisms.Pharmacodynamic research of GAS in this model were divided into six groups:control group,GAS group(GAS 10 μmol·L-1),model group(Aβ25-35 20 μmol·L-1),model +GAS 2.5,5 and 10 μ mol·L-1 group).Mecha-nism research of GAS in this model was divided into 6 groups:control group,Aβ25-35 20 μmol·L-1 group,Aβ25-35 20 μmol·L-1 + GAS 10 μmol·L-1 group,Aβ25-35 + SC79 group(Aβ25-35 20 μmol·L-1 +SC79 10 μmol·L-1),Aβ25-35+MK2206+GAS group(A β 25-35 20 μ mol·L-1 +MK2206 10 μmol·L-1+GAS 10 μmol·L-1),Aβ25-35+LY294002+GAS group(Aβ25-35 20 μmol·L-1+LY294002 10 μmol·L-1+GAS 10 μmol·L-1).Cell viability was detected by MTT,mor-phological changes of cells were observed by micro-scope,ATP content was detected by chemilumines-cence,and pyruvate(PA)content was detected by colo-rimetry.Western blotting was used to detect the protein levels of transcription factor BACH1,key glycolysis enzyme hexokinase(HK1)and PI3K/Akt signaling path-way related proteins PI3K,p-PI3K,Akt and p-Akt.RESULTS The results showed that compared with the control group,the cell morphology of HT22 cells damaged by Aβ25-35 was damaged,the number of cells decreased,the cell body became smaller,the number of dead cells increased,the cell survival rate,ATP and PA contents decreased significantly,and the protein expressions of p-PI3K,p-Akt,BACH1 and HK1 were significantly down-regulated.GAS treatmentcansignificantlyimprovethemor-phology of HT22 cells damaged by Aβ25-35,increase cell survival rate,ATP and PA contents,and up-regulate the expression of p-PI3K,p-Akt,BACH1 and HK1 proteins.SC79 also significantly increased cell survival rate,ATP content,protein expression of BACH1 and HK1.However,the above ameliorative effect of GAS on HT22 cell dam-age induced by Aβ25-35 was antagonized by LY294002 and MK2206.CONCLUSION GAS exerts a neuroprotec-tive effect on Aβ25-35-induced HT22 cell injury by improv-ing glycolytic function through activating PI3K/Akt/BACH1 signaling axis.
ABSTRACT
Astragaloside Ⅳ(AS-Ⅳ) has protective effects against ischemia-reperfusion injury(IRI), but its mechanism of action has not yet been determined. This study aims to investigate the protective effects and mechanism of AS-Ⅳ on H9c2 cardiomyocyte injury induced by hypoxia-reoxygenation(H/R). The H/R model of myocardial cells was established by hypoxic culture for 12 hours and then reoxygenation culture for 8 hours. After AS-Ⅳ treatment, cell viability, the reactive oxygen species(ROS) levels, as well as the content or activity of superoxide dismutase(SOD), malondialdehyde(MDA), interleukin 6(IL-6), and tumor necrosis factor alpha(TNF-α), were measured to evaluate the effect of AS-Ⅳ treatment. The effect of AS-Ⅳ on HO-1 protein expression and nuclear Nrf2 and Bach1 protein expression was determined by Western blot. Finally, siRNA was used to knock down HO-1 gene expression to observe its reversal effect on AS-Ⅳ intervention. The results showed that as compared with the H/R model group, the cell viability was significantly increased(P<0.01), ROS level in the cells, MDA, hs-CRP and TNF-α in cell supernatant and nuclear protein Bach1 expression in the cells were significantly decreased(P<0.01), while SOD content, HO-1 protein expression in cells and expression of nuclear protein Nrf2 were significantly increased(P<0.01) in H/R+AS-Ⅳ group. However, pre-transfection of HO-1 siRNA into H9c2 cells by liposome could partly reverse the above effects of AS-Ⅳ after knocking down the expression of HO-1. This study suggests that AS-Ⅳ has significant protective effect on H/R injury of H9c2 cardiomyocytes, and Nrf2/Bach1/HO-1 signaling pathway may be a key signaling pathway for the effect.
Subject(s)
Humans , Apoptosis , Basic-Leucine Zipper Transcription Factors , Metabolism , Cell Hypoxia , Cells, Cultured , Heme Oxygenase-1 , Metabolism , Myocytes, Cardiac , NF-E2-Related Factor 2 , Metabolism , Saponins , Pharmacology , Signal Transduction , Triterpenes , PharmacologyABSTRACT
Objective To evaluate effects of tea polyphenols on the mRNA and nucleoprotein expression of Nrf2/Bach1 in human skin fibroblasts (HSFs).Methods Some HSFs were incubated with tea polyphenols at different concentrations of 0,2.5,5,10,20 and 40 mg/L for 24 hours.Methyl thiazolyl tetrazolium (MTT) assay was conducted to evaluate the proliferative activity of HSFs to screen the optimal concentration of tea polyphenols.Then,some other HSFs were treated with tea polyphenols at this optimal concentration for 24 hours.Real-time quantitative PCR (RT-qPCR) was performed to determine mRNA expression of Nrf2 and Bach1,Western blot analysis to measure nuclear expression of Nrf2 and Bach1 proteins,and immunofluorescence assay to determine the distribution of Nrf2 and Bach1 protein in the cell nucleus.Results MTT assay showed that 5 mg/L tea polyphenols had no obvious effects on the proliferation of HSFs,so 5 mg/L was chosen as the optimal concentration of tea polyphenols for subsequent experiments.HSFs cultured without tea polyphenols served as control group.After the treatment,the 5-mg/L tea polyphenol group showed significantly decreased mRNA and nuclear protein expression of Bach 1 (mRNA:0.629 ± 0.077 vs.0.940 ± 0.033,t =6.397,P ＜ 0.05;protein:1.424 ± 0.171 vs.16.966 ± 1.702,t =15.730,P ＜ 0.05),but significantly increased mRNA and nuclear protein expression of Nrf2 (mRNA:1.467 ± 0.076 vs.0.977 ± 0.091,t =7.133,P ＜ 0.05;protein:6.929 ± 0.121 vs.3.537 ± 0.126,t =33.636,P ＜ 0.05) compared with the control group.Immunofluorescence assay showed increased accumulation of Nrf2 protein,but decreased accumulation of Bach1 protein in the nucleus.Conclusion Tea polyphenols can promote the mRNA and nuclear protein expression as well as nuclear distribution of Nrf2,but suppress the mRNA and nuclear protein expression as well as nuclear distribution of Bach 1,finally exerting antioxidative effects.
ABSTRACT
Male breast cancer (MBC) is a rare and poorly studied disease that is a growing global health problem. Interestingly, both the molecular basis of MBC and its histological profile are often quite distinct from the far more prevalent female breast cancer, emphasizing the need for increased focus on MBC. Here, we present a case report of an MBC patient from India with a strong familial history of breast cancer. This patient was normal for BRCA1/2 and many other common breast cancer-associated genes. However, upon further analysis, the individual was found to possess two mutations in the DNA helicase and tumor suppressor gene BRIP1, including a silent mutation at residue 879 as well as a P919S variant. Other family members were also screened for these mutations. To the best of our knowledge, this is the first report of BRIP1 mutation in MBC in the Indian population.
Subject(s)
Female , Humans , Male , Breast Neoplasms , Breast Neoplasms, Male , Breast , DNA , Genes, Tumor Suppressor , Global Health , India , Silent MutationABSTRACT
The Keap1-Nrf2-ARE pathway is an important antioxidant defense mechanism that protects cells from oxidative stress and the Keap1-Nrf2 protein-protein interaction (PPI) has become an important drug target to upregulate the expression of ARE-controlled cytoprotective oxidative stress response enzymes in the development of therapeutic and preventive agents for a number of diseases and conditions. However, most known Nrf2 activators/ARE inducers are indirect inhibitors of Keap1-Nrf2 PPI and they are electrophilic species that act by modifying the sulfhydryl groups of Keap1׳s cysteine residues. The electrophilicity of these indirect inhibitors may cause "off-target" side effects by reacting with cysteine residues of other important cellular proteins. Efforts have recently been focused on the development of direct inhibitors of Keap1-Nrf2 PPI. This article reviews these recent research efforts including the development of high throughput screening assays, the discovery of peptide and small molecule direct inhibitors, and the biophysical characterization of the binding of these inhibitors to the target Keap1 Kelch domain protein. These non-covalent direct inhibitors of Keap1-Nrf2 PPI could potentially be developed into effective therapeutic or preventive agents for a variety of diseases and conditions.
ABSTRACT
[ ABSTRACT] AIM:To determine the role of transcription factor Bach1 in the functions of human microvascular en-dothelial cells ( HMVECs ) .METHODS: Bach1 siRNA was transfected into HMVECs to knock down the expression of Bach1.In vitro endothelial cell tube formation assay in Matrigel culture was used as a surrogate assay for angiogenic poten-tial.Migration of HMVECs was determined by using Transwell chambers.Cell proliferation was measured by CCK-8 assay. Real-time PCR, Western blotting, and ELISA were employed to determine mRNA expression and protein level.Reporter as-say was performed to determine vascular endothelial growth factor ( VEGF) transcriptional activity.RESULTS:Knockdown of Bach1 expression in HMVECs led to an increase in the tube formation and increased endothelial cell migration ability, whereas it has little effect on cell proliferation.Bach1 silencing increased the mRNA and protein expression of heme oxygen-ase-1 (HO-1), and enhanced VEGF transcriptional activation, and mRNA and protein expression.CONCLUSION:Bach1 silencing increases HO-1 and VEGF expression, thus promoting the cell migration and tube formation of HMVECs, indicating that Bach1 is a repressor for angiogenesis.
ABSTRACT
In 1998, a amovie entitled "A Civil Action" was released. The movie described the Woburn case, begun in 1982 and concluded in 1990, one of the most famous cases of trichloroethylene pollution. In a small town near Boston, twelve children died of leukemia, which seemed attributable to trichloroethylene contamination of the drinking water. The victims, however, could not win the case, since evidence that the identified chemicals could cause leukemia and other human illnesses was rather sketchy. There have been many cases of trichloroethylene pollution in industrial nations including Japan, therefore, we reconsidered the missing link. Our conclusion is that the disease occurred not by a direct effect of the chemical hazard on biological macromolecules but by an indirect effect through the physiological system such as signal transduction and transcriptional regulation. In 1984, we reported a marked reduction in the regulatory heme pool by trichloroethylene exposure, however, the biological significance was not well understood. Recently, we found that the DNA binding activity of Bach1, a negative regulator of genes, is controlled by heme, the regulation of which seems to explain how leukemia develops. The heterodimer of Bach1 with MafK recognizes Maf recognition elements (MAREs) competing with the erythroid type positive regulator, a complex of NF-E2 with MafK. Bach1/MafK occupies MAREs under lower heme conditions, whereas MAREs are open to NF-E2/MafK along with increasing heme concentration. Since the NF-E2/MafK function is closely related to normal erythroid differentiation, of which disorders such as sideroblastic anemia are often related to neoplasia; i.e., a clonal disorder that can progress to leukemia. Thus, a marked decline in regulatory heme by trichloroethylene intoxication could be one of the pathways to leukemia.
ABSTRACT
In 1998, a movie entitled “A Civil Action” was released. The movie described the Woburn case, begun in 1982 and concluded in 1990, one of the most famous cases of trichloroethylene pollution. In a small town near Boston, twelve children died of leukemia, which seemed attributable to trichloroethylene contamination of the drinking water. The victims, however, could not win the case, since evidence that the identified chemicals could cause leukemia and other human illnesses was rather sketchy. There have been many cases of trichloroethylene pollution in industrial nations including Japan, therefore, we reconsidered the missing link. Our conclusion is that the disease occurred not by a direct effect of the chemical hazard on biological macromolecules but by an indirect effect through the physiological system such as signal transduction and transcriptional regulation. In 1984, we reported a marked reduction in the regulatory heme pool by trichloroethylene exposure, however, the biological significance was not well understood. Recently, we found that the DNA binding activity of Bach1, a negative regulator of genes, is controlled by heme, the regulation of which seems to explain how leukemia develops. The heterodimer of Bach1 with MafK recognizes Maf recognition elements (MAREs) competing with the erythroid type positive regulator, a complex of NF-E2 with MafK. Bach1/MafK occupies MAREs under lower heme conditions, whereas MAREs are open to NF-E2/MafK along with increasing heme concentration. Since the NF-E2/MafK function is closely related to normal erythroid differentiation, of which disorders such as sideroblastic anemia are often related to neoplasia; i.e., a clonal disorder that can progress to leukemia. Thus, a marked decline in regulatory heme by trichloroethylene intoxication could be one of the pathways to leukemia.