PM2.5 exposure induces alveolar epithelial cell apoptosis and causes emphysema through p53/Siva-1.

OBJECTIVE: This study aims to investigate whether PM2.5 exposure is involved in the induction of alveolar epithelial cell apoptosis and the progression of emphysema in mice, and to further explore its specific molecular mechanism. MATERIALS AND METHODS: A certain number of PM2.5 exposed mice and normal control mice were selected, and a lung resection operation was performed to collect the pulmonary tissue samples, which were then analyzed by hematoxylin and eosin (H&E) staining assay. Subsequently, the total protein in the pulmonary tissues of mice in PM2.5 exposure group and control group was extracted, and the p53 protein level was detected by Western blot. Meanwhile, in A549 cells, after treatment of different doses of PM2.5, the protein levels of p53, caspase3, and clv-caspase3 were examined by Western blot while the mRNA levels of p53, Siva-1, and clv-caspase3 were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), respectively. In addition, flow cytometry was carried out to measure the incidence of cell apoptosis, while chromatin immunoprecipitation (ChIP) assay was performed to verify whether p53 binds to the Siva-1 promoter region and thus regulates its transcription process. RESULTS: H&E staining revealed that PM2.5 exposure caused pathological damage in the pulmonary tissues and the expansion of the spatial structure of alveoli, which led to emphysema in mice. Moreover, p53 protein expression in pulmonary tissue of mice in PM2.5 exposure group was remarkably higher than that in the control group. Subsequently, A549 cells were treated with 0, 25, 50, 100 µg/ml PM2.5 for 48 h, and it was found that, with the increase of PM2.5 exposure dose, the p53 protein level, Siva-1 mRNA level and cell apoptosis rate were all found increased in a dose-dependent manner, which could be partially reversed by transfection of si-p53 in A549 cells. In addition, CHIP experiments confirmed that p53 can bind to the Siva-1 promoter region and directly regulate Siva-1 transcription. In A549 cells, PM2.5 exposure increased the expression of the clv-caspase3 protein, which was reversed by the knockdown of p53; however, simultaneous overexpression of Siva-1 could further increase the clv-caspase3 protein level. Additionally, flow cytometry also revealed that PM2.5 exposure induced apoptosis of alveolar epithelial cells, while the knockdown of p53 reduced that, which could be promoted by the overexpression of Siva-1. CONCLUSIONS: PM2.5 exposure can promote the transcription of Siva-1 to induce apoptosis of alveolar epithelial cells and accelerate the progression of emphysema in mice by enhancing p53 protein expression.

[Recombinant human tumor necrosis factor receptor type â ¡-IgG Fc fusion protein for treatment of occupational medicamentosa-like dermatitis induced by trichloroethylene].

Objective: To investigate the efficacy and safety of the recombinant human tumor necrosis factor receptor Ⅱ-IgG Fc fusion protein (rhTNFR: Fc, etanercept) for the treatment of occupational medicamentosa-like dermatitis induced by trichloroethylene (OMLDT) . Methods: In September 2011 to February 2016, 12 patients with OMLDT were treated with etanercept 25 mg, subcutaneous injection, twice per week, doubling of first dose. The course of treatment was 6 weeks. The drug eruption area and severity index (DASI) score, the proportion of patients achieving a 50%, 75% and 90% reduction in DASI (DASI50, DASI75, DASI90) and the serum level of TNF-α were used to assess the efficacy at different times. Adverse reactions were also recorded and evaluated. The results were statistically analyzed by nonparametric Friedman test and repetitive measurement ANOVA using the software SPSS19.0. Results: After 4 weeks treatment, the DASI score decreased form 56.33±7.02 to 0.50±0.91 (P<0.01) . The DASI50, DASI75 and DASI90 were all increased to 12 (100%) . The serum level of TNF-α decreased form (43.74±41.62) pg/ml to (3.03±0.47) pg/ml (P<0.01) . Statistically significant difference was observed from the above indexes. There were no adverse reactions in clinical application. Conclusion: Recombinant human tumor necrosis factor receptor Ⅱ-IgG Fc fusion protein may be a safe and effective drug in the treatment of OMLDT.

Oridonin inhibits tumor growth in glioma by inducing cell cycle arrest and apoptosis.

Glioma is the most common malignant intracranial tumors. Despite newly developed therapies, these treatments mainly target oncogenic signals, and unfortunately, fail to provide enough survival benefit in both human patients and mouse xenograft models, especially the first-generation therapies. Oridonin is purified from the Chinese herb Rabdosia rubescens and considered to exert extensive anti-cancer effects on human tumorigenesis. In this study, we systemically investigated the role of Oridonin in tumor growth and the underlying mechanisms in human glioma. We found that Oridonin inhibited cell proliferations in a dose- and time-dependent manner in both glioma U87 and U251 cells. Moreover, these anti-cancer effects were also confirmed in a mouse model bearing glioma. Furthermore, cell cycle arrest in S phase was observed in Oridonin-mediated growth inhibition by flow cytometry. Cell cycle arrest in S phase led to eventual cell apoptosis, as revealed by Hoechst 33342 staining and annexin V/PI double-staining. The cell apoptosis might be accomplished through a mitochondrial manner. In all, we were the first to our knowledge to report that Oridonin could exert anti-cancer effects on tumor growth in human glioma by inducing cell cycle arrest and eventual cell apoptosis. The identification of Oridonin as a critical mediator of glioma growth may potentiate Oridonin as a novel therapeutic strategies in glioma treatments.

Fusion Expression and Purification of OSBP PH Domain and Preliminary Analysis of Its Second Structure.

Oxysterol binding protein (OSBP) is a regulator of oxysteroid metabolism. To investigate the function and the structure-function relationship of OSBP, the recombinant vector OSBP PH-pRSET-A was transformed into E.coli JM109(DE3), and the strain highly expressing soluble 6His-OSBP PH domain in minimal medium were obtained. The fusion protein was purified by Ni(2 )-NTA agarose beads. The secondary structure of the purified 6His-OSBP PH domain fusion protein was analysed by circular dichronism. The results indicated the PH domain was composed of alpha-helix 7.2%, beta-pleated sheets 71.1% and radom coil 21.7%.

Modulation of O6-methylguanine-DNA methyltransferase-mediated 1-(4-amino-2-methyl-5-Pyrimidinyl)- methyl-3-(2-Chloroethyl)-3-nitrosourea resistance by antisense RNA.

Mer+ HeLa S3 tumor cells with high levels of O6-methylguanine-DNA methyltransferase (MGMT) gene expression were transduced by retroviral-mediated MGMT antisense RNA. The MGMT mRNA, MGMT protein, and MGMT activity in transduced cells were only 28.7%, 32.7%, and 39. 1% of that in HeLa S3 cells, respectively. The transduced cells showed more sensitive to ACNU than HeLa S3 cells both in cell survival and in nude mice experiments. Pathologic examination confirmed that transduced grafts were killed by ACNU. Our results suggested that MGMT gene expression could be modulated by retroviral-mediated antisense RNA and that Mer+ tumor drug resistance to ACNU could be reversed by modulation of MGMT gene expression.

[The first isolation of Vibrio alginolyticus from samples which caused food poisoning].

We report an event of food poisoning traced to eating salted shrimps. Vibrio alginolyticus was shown to be the causative agent through epidemiological investigations and etiological tests. Vibro alginolyticus can bring about human septicaemia and wound infection and it was found in the feces of patients with diarrhea, but no determination on its pathogenicity was done. From the samples of food which led to food poisoning. Vibrio alginolyticus was isolated, and for the first time it was determined as a pathogen of food poisoning.