Effect of total saponins from Panax japonicus on non-alcoholic steatohepatitis by regulating autophagy / 中国中药杂志

Non-alcoholic steatohepatitis(NASH) was induced by high-sugar and high-fat diet in mice to investigate the intervention effect of total saponins from Panax japonicus(TSPJ) and explore its possible mechanism. Mice were fed with high-sugar and high-fat diet to establish NASH model, and intervened with different doses of TSPJ(15, 45 mg·kg~(-1)). The animals were fed for 26 weeks. The histomorphology and pathological changes of liver tissues were observed by HE staining. The transcriptional expression levels of miR-199 a-5 p, autophagy related gene 5(ATG5) and inflammatory cytokines interleukin-6(IL-6), interleukin-1β(IL-1β) and tumor necrosis factor α(TNF-α) in mouse liver were measured by quantitative Real-time polymerase chain reaction(qRT-PCR). Western blot was used to detect the expression of autophagy-related proteins ATG5, P62/SQSTM1(P62), and microtubule-associated protein light chain 3(LC3)-I/Ⅱ proteins in mouse liver. The expression of P62 protein was detected by immunofluorescence staining. In order to verify the targeting regulation relationship between miR-199 a-5 p and ATG5, miR mimic/inhibitor NC and miR-199 a-5 p mimic/inhibitor were transfected into Hepa 1-6 cells, and the expression of ATG5 mRNA and protein was detected. pMIR-reportor ATG5-3'UTR luciferase reporter gene plasmid was constructed and co-transfected with miR mimic/inhibitor NC and miR-199 a-5 p mimic/inhibitor into Hepa 1-6 cells to detect luciferase activity. In vivo, HE staining in the model group showed typical fatty degeneration and inflammatory infiltration, with increased expression of miR-199 a-5 p and decreased expression of ATG5 mRNA and protein. The expression of autophagy-associated protein P62 increased significantly, the ratio of LC3Ⅱ/Ⅰ decreased, and the transcriptional expression of inflammatory factors increased significantly. After the intervention by TSPJ, the pathological performance of liver tissue was significantly improved, the expression of miR-199 a-5 p decreased and the expression of ATG5 mRNA and protein increased, the expression of autophagy-associated protein P62 decreased significantly, the ratio of LC3Ⅱ/Ⅰ increased, and the transcriptional expression of inflammatory cytokines IL-6, IL-1β and TNF-α decreased significantly. In vitro, it was found that the expression of ATG5 mRNA and protein and luciferase activity decreased significantly in miR-199 a-5 p overexpression cells, while after inhibition of miR-199 a-5 p expression, the expression level of ATG5 mRNA and protein and luciferase activity increased. The results showed that TSPJ can improve NASH in mice fed with high-sugar and high-fat diet, and its mechanism may be related to the regulation of miR-199 a-5 p/ATG5 signal pathway, the regulation of autophagy activity and the improvement of inflammatory response of NASH.

Expression of autophagy related gene 5 and cyclin E in coronary heart disease and its clinical significance / 中南大学学报(医学版)

OBJECTIVES@#To explore the expression of autophagy related genes 5 (ATG5) and cyclin E in coronary heart disease (CHD) and its clinical significance.@*METHODS@#From April 2018 to August 2018, 80 patients diagnosed with CHD in the Second Xiangya Hospital, Central South University were selected as an observation group, and another 80 healthy subjects were selected as a control group. The expression of ATG5 and cyclin E mRNA in nucleate cells and the plasma protein in the 2 groups were detected and analyzed. The model of macrophage-derived foam cells induced by oxidized low density lipoprotein (ox-LDL) was used to simulate atherosclerosis. The proliferation of macrophage- derived foam cells and the protein levels of ATG5 and cyclin E induced by ox-LDL at different concentrations were examined.@*RESULTS@#Compared with the control group, the levels of ATG5 mRNA and protein in the blood in the observation group were decreased, and the cyclin E mRNA and protein levels were increased, there were statistically difference (both <0.05). Receiver operating characteristic (ROC) curve showed that the area under curve (AUC) of ATG5 mRNA, cyclin E mRNA, ATG5 protein and cyclin E protein were 0.739, 0.780, 0.671 and 0.807, respectively. Pearson analysis showed that the ATG5 mRNA was negatively correlated with the cyclin E mRNA (=-0.734, <0.05),while the plasma ATG5 protein was negatively correlated with the plasma cyclin E protein (=-0.746, <0.05). Macrophage-derived foam cell model induced by ox-LDL showed that the proliferation of foam cells and the expression levels of cyclin E protein were increased in a concentration and time-dependent manner, and the expression levels of ATG5 protein were decreased in a concentration-dependent manner.@*CONCLUSIONS@#The levels of ATG5 mRNA and protein are lowly expressed while the levels of cyclin E mRNA and protein are highly expressed in the patients with CHD.The ATG5 protein levels are lowly expressed in ox-LDL-treated macrophage-derived foam cells while the cyclin E protein levels are highly expressed in ox-LDL-treated macrophage-derived foam cells. Based on these observations, we conclude that ATG5 inhibits the degradation of the cyclin E and promotes the proliferation of macrophages, involving in the occurrence and development of CHD.

Genetic polymorphisms of autophagy-related gene 5 (ATG5) rs473543 predict different disease-free survivals of triple-negative breast cancer patients receiving anthracycline- and/or taxane-based adjuvant chemotherapy / 癌症

BACKGROUND@#Autophagy plays a crucial role in chemotherapy resistance of triple-negative breast cancer (TNBC). Hence, autophagy-related gene 5 (ATG5), an essential molecule involved in autophagy regulation, is presumably associated with recurrence of TNBC. This study was aimed to investigate the potential influence of single-nucleotide polymorphisms in ATG5 on the disease-free survival (DFS) of early-stage TNBC patients treated with anthracycline- and/or taxane-based chemotherapy.@*METHODS@#We genotyped ATG5 SNP rs473543 in a cohort of 316 TNBC patients treated with anthracycline- and/or taxane-based chemotherapy using the sequenom's MassARRAY system. Kaplan-Meier survival analysis and Cox proportional hazard regression analysis were used to analyze the association between ATG5 rs473543 genotypes and the clinical outcome of TNBC patients.@*RESULTS@#Three genotypes, AA, GA, and GG, were detected in the rs473543 of ATG5 gene. The distribution of ATG5 rs473543 genotypes was significantly different between patients with and without recurrence (P = 0.024). Kaplan-Meier survival analysis showed that patients carrying A allele of ATG5 rs473543 had an increased risk of recurrence and shorter DFS compared with those carrying the variant genotype GG in rs473543 (P = 0.034). In addition, after adjusting for clinical factors, multivariate Cox regression analyses revealed that the AA/GA genotype of rs473543 was an independent predictor for DFS (hazard risk [HR], 1.73; 95% confidence interval [CI], 1.04-2.87; P = 0.034). In addition, DFS was shorter in node-negative patients with the presence of A allele (AA/GA) than in those with the absence of A allele (P = 0.027).@*CONCLUSION@#ATG5 rs473543 genotypes may serve as a potential marker for predicting recurrence of early-stage TNBC patients who received anthracycline-and/or taxane-based regimens as adjuvant chemotherapy.

Antagonistic effect of vitamin E on di-2-ethylhexyl phthalate-induced reproductive toxicity in male rats / 中华男科学杂志

<p><b>Objective</b>To explore the antagonistic effect of vitamin E (VE) on male reproductive toxicity induced by di-2-ethylhexyl phthalate (DEHP) in pubertal SD rats and its underlying mechanisms.</p><p><b>METHODS</b>Thirty 5-week-old male SD rats were randomly divided into five groups of equal number, corn oil control, low-dose (10 mg/kg/d), medium-dose (100 mg/kg/d) and high-dose DEHP exposure (500 mg/kg/d), and VE intervention (high-dose DEHP + VE ［100 mg/kg/d］), and treated respectively for 30 successive days. At 3 days after treatment, the testes of the animals were harvested for determination of the oxidative stress index, serum reproductive hormone levels, cauda epididymal sperm parameters, and expressions of cell apoptosis-related genes and proteins.</p><p><b>RESULTS</b>Compared with the control group, the rats of the medium- and high-dose DEHP groups showed significant decreases in the levels of such serum reproductive hormones as follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T), sperm parameters as average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), straightness (STR), linearity (LIN) and wobble (WOB), and the activities of superoxide dismutase (SOD) and glutathione peroxide (GSH-Px), but significant increases were observed in the latter two groups in the content of malondialdehyde (MDA)(［3.32±0.87］ nmol/mg pro vs ［2.13±0.49］ nmol/ mg pro), mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio, and protein expressions of Cytochrome C and Caspase-3. In comparison with the high-dose DEHP group, the VE intervention group exhibited remarkably increased serum LH and T levels, sperm VAP, VSL, VCL, STR and WOB, and activities of SOD and GSH-Px, but markedly decreased mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio as well as the protein expressions of Cytochrome C and Caspase-3 in the testis tissue (P<0.05).</p><p><b>CONCLUSIONS</b>Exposure to DEHP induces androgen secretion disorders, causes oxidative damage to the testicular tissue, activates the mitochondrial apoptosis pathway in the testis, and ultimately reduces the quality of epididymal sperm, while VE can protect the rat testis from DEHP-induced reproductive toxicity.</p>

Association of autophagy related gene polymorphisms with neutrophilic airway inflammation in adult asthma

BACKGROUND/AIMS: Role of autophagy in neutrophil function and the association of autophagy and autophagy related (ATG) gene polymorphisms with asthma susceptibility were suggested. In this study, we investigated the genetic association of ATG5 and ATG7 polymorphisms with asthma risk, severity and neutrophilic airway inflammation. METHODS: We recruited 408 asthma patients and 201 healthy controls. Sputum neutrophil counts were determined by H&E staining. Serum interleukin 8 (IL-8) levels were measured by enzyme-linked immunosorbent assay (ELISA). Genetic polymorphisms of ATG5 (-769T>C, -335G>A, and 8830C>T) and ATG7 (-100A>G and 25108G>C) were genotyped. The functional activities of ATG5 -769T>C and -335G>A variants were investigated by luciferase reporter assays. RESULTS: No associations of ATG5 and ATG7 polymorphisms with asthma susceptibility and severity were found. ATG5 -769T>C and -335G>A were in complete linkage disequilibrium. In the asthma group, GA/AA genotypes at ATG5 -335G>A were associated with higher neutrophil counts in sputum (p T associated with lower FEV1% predicted value (p G and 25108G>C were significantly associated with high serum levels of IL-8 (p < 0.05 for both variants). CONCLUSIONS: Genetic polymorphisms of ATG5 and ATG7 could contribute to neutrophilic airway inflammation in the pathogenesis of adult asthma.

Autophagy induction by SIRT6 is involved in oxidative stress-induced neuronal damage

SIRT6 is a NAD(+)-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxygen/glucose deprivation (OGD) has been reported, however the role of SIRT6 in oxidative stress damage remains unclear. Here we used SH-SY5Y neuronal cells and found that overexpression of SIRT6 led to decreased cell viability and increased necrotic cell death and reactive oxygen species (ROS) production under oxidative stress. Mechanistic study revealed that SIRT6 induced autophagy via attenuation of AKT signaling and treatment with autophagy inhibitor 3-MA or knockdown of autophagy-related protein Atg5 rescued H2O2-induced neuronal injury. Conversely, SIRT6 inhibition suppressed autophagy and reduced oxidative stress-induced neuronal damage. These results suggest that SIRT6 might be a potential therapeutic target for neuroprotection.

Correlation of autophagy-associated gene Atg5 with tumorigenesis of prostate cancer / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the correlation of the autophagy-associated gene Atg5 with the pathogenesis of prostate cancer.</p><p><b>METHODS</b>Using real-time fluorescent quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry, we detected the expression of Atg5 in 50 cases of prostate intraepithelial neoplasm (PIN), 69 cases of prostate cancer (PCa), and 30 cases of benign prostatic hyperplasia (BPH).</p><p><b>RESULTS</b>The expression level of Atg5 mRNA was significantly higher in PIN (5.270 ± 0.230) and PCa (5.131 ± 0.252) than in the BPH tissue (1.723 ± 0.017) (P <0.01), and so was the positive rate of the Atg5 expression in the patients of the PIN group (94%) and PCa group (88.4%) than in those of the BPH group (6.7%) (P<0.01), but with no statistically significant differences between the PIN and PCa groups (P >0.05). No significant correlation was observed between the expression of Atg5 and the Gleason score of PCa (P >0.05).</p><p><b>CONCLUSION</b>The upregulated expression of Atg5 might play a role in the tumorigenesis of prostate cancer.</p>

Rs548234 polymorphism at PRDM1-ATG5 region susceptible to rheumatoid arthritis in Caucasians is not associated with rheumatoid arthritis in Chinese Han population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>A previous study has shown that rs548234 polymorphism at PRDM1-ATG5 region is associated with rheumatoid arthritis (RA) in Caucasian populations. The aim of this study was to investigate the effect of rs548234 polymorphism at PRDM1-ATG5 region on susceptibility to RA in Chinese Han population.</p><p><b>METHODS</b>We genotyped 848 RA patients and 1431 matched healthy controls for rs548234 single-nucleotide polymorphism (SNP) with a predesigned TaqMan SNP genotyping assay. Association analyses were performed on the whole data set and on rheumatoid factors (RF) and anti-cyclic citrullinated peptides (anti-CCP) antibody. Finally, we carried out combined analysis of rs548234 association with RA based on the published data.</p><p><b>RESULTS</b>No significant difference in the genotype distribution between RA patients and healthy controls for rs548234 (C/T) polymorphism was found in Chinese Han population, neither in whole data set nor in stratified subsets, e.g. RF and anti-CCP status. Association analysis in different ethnic groups showed that rs548234 at PRDM1-ATG5 region was associated with RA in Caucasian ancestry but not in East Asian population.</p><p><b>CONCLUSIONS</b>Our results showed no involvement of rs548234 at PRDM1-ATG5 region in the susceptibility or clinical relevance of RA in Chinese Han population.</p>

Glioblastoma stem cells resistant to temozolomide-induced autophagy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recent studies have demonstrated the existence of a small fraction of cells with features of primitive neural progenitor cells and tumor-initiating function in brain tumors. These cells might represent primary therapeutic target for complete eradication of the tumors. This study aimed to determine the resistant phenotype of glioblastoma stem cells (GSCs) to temozolomide (TMZ) and to explore the possible molecular mechanisms underlying TMZ resistance.</p><p><b>METHODS</b>Freshly resected glioblastoma specimen was collected and magnetic isolation of GSCs was carried out using the Miltenyi Biotec CD133 Cell Isolation kit. The cytotoxic effect of TMZ on CD133(+) and CD133(-) glioblastoma cells was determined by using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Autophagy-related proteins (Beclin-1, LC3 and Atg5) and cleaved caspase-3 (p17) were analyzed by Western blotting. Immunofluorescent staining was used to detect Atg5, glial fibrillary acidic protein (GFAP) and CD133 expression in glioblastoma cells. Statistical analysis was carried out using SPSS 10.0 software. For all tests, the level of statistical significance was set at P < 0.05.</p><p><b>RESULTS</b>CD133(+) glioblastoma cells exhibited neurosphere-like growth in vitro and high expression of CD133 stem cell marker. The growth-inhibiting rate in CD133(-) glioblastoma cells treated with 5 or 50 micromol/L TMZ was significantly higher than that in CD133(+) glioblastoma cells ((14.36 +/- 3.75)% vs (2.54 +/- 1.36)% or (25.95 +/- 5.25)% vs (2.72 +/- 1.84)%, respectively, P < 0.05). Atg5, LC3-II and Beclin-1 levels were significantly lower in CD133(+) glioblastoma cells than those in autologous CD133(-) cells after TMZ treatment (P < 0.05). Caspase-3 was mildly activated only in CD133(-) glioblastoma cells after exposure to TMZ (P < 0.05). Immunofluorescent staining revealed elevated expression of Atg5 in GFAP(+) cells following TMZ treatment.</p><p><b>CONCLUSIONS</b>The GSCs display strong capability of tumor's resistance to TMZ. This resistance is probably contributed by the CD133(+) cells with down-regulation of autophagy-related proteins. Future treatment should target this small population of cancer stem cells in tumors to improve survival of patients.</p>