Taurine inhibits M2 polarization of macrophages by promoting mitophagy / 细胞与分子免疫学杂志

Objective To investigate the molecular mechanism of taurine regulating the polarization of M2 macrophages by mitophagy. Methods THP-1 cells were divided into four groups: M0 group (THP-1 cells were treated by 100 nmol/L phorbol myristate ester for 48 hours to polarize into M0), M2 group (THP-1 cells were induced to polarize into M2 macrophages by 20 ng/mL interferon-4 (IL-4) for 48 hours), M2 combined with taurine groups (added with 40 or 80 mmol/L taurine on the basis of M2 macrophages). The mRNA expression of mannose receptor C type 1(MRC-1), C-C motif chemokine ligand 22(CCL22) and dendritic cell-specific ICAM-3 grabbing non-integrin (CD209) in M2 macrophages were detected by quantitative real-time PCR. Mitochondrial and lysosome probes were used to detect the number of mitochondria and lysosomes by multifunction microplate reader and confocal laser scanning microscope. The level of mitochondrial membrane potential (MMP) was detected by JC-1 MMP assay kit. The expression of mitophagy-related proteins PTEN-induced putative kinase 1 (PINK1) and microtubule-associated protein 1 light chain 3 (LC3) were detected by Western blot analysis. Results Compared with M0 group, the expression of MRC-1, CCL22, CD209 and PINK1, the number of mitochondria and the level of MMP in M2 group were significantly increased, whereas the number of lysosomes and LC3II/LC3I ratio were decreased. Compared with M2 group, the expressions of MRC-1, CCL22 and CD209, the number of mitochondria and the level of MMP in M2 combined with taurine group dropped significantly while the number of lysosomes was found increased, and the protein expression of PINK1 and LC3II/LC3I ratio were also increased. Conclusions The polarization of M2 macrophages is regulated by taurine to prevent excessive polarization via reducing the level of MMP, improving the level of mitophagy, reducing the number of mitochondria, and inhibiting the mRNA expression of polarization markers in M2 macrophages.

Analysis of the ammonia level in air and heavy metals in drinking water in a cynomolgus monkey feedlot / 中国比较医学杂志

Objective The ammonia level in air and heavy metals in drinking water were explored in a cynomolgus monkey feedlot. Methods Air ammonia from different communities and feeding patterns of cynomolgus monkeys were collected at three time-points per day and determined by Nessler's reagent spectrophotometry. Inductively coupled plasma mass spectrometry was applied to detect the level of heavy metals in drinking water from 5 different sampling sites in the feedlot,incluing the outlet of underground water,the water tank,both monkey cages equipped with PVC or iron pipes and sewage lagoon,respectively. Results Air ammonia levels in quarantine inspection flock cages(0.59 ± 0.03 mg/m3)were significantly higher than in the cages of both reproductive flock(0.34 ± 0.03 mg/m3)and sale flock(0.27 ± 0.04 mg/m3). The ammonia level in air in different feeding patterns ranks as following:cage rearing of quarantine inspection flock(0.59 ± 0.03 mg/m3)>cage rearing of reproductive flock(0.48 ± 0.02 mg/m3)>captive bleeding of sale flock(0.30 ± 0.02 mg/m3)>cage rearing of sale flock(0.25 ± 0.01 mg/m3)> captive bleeding of reproductive flock(0.22 ± 0.02 mg/m3). The air ammonia concentrations of both former flocks were statistically higher than the latter three flocks. The highest air ammonia level among different flocks and feeding patterns occurred in the morning, before waste discharge clean-up. The iron concentration in drinking water in the cages equipped with iron pipes was higher than Chinese drinking water standard. Conclusions The air ammonia level was lower than the Chinese air quality standard. The iron concentration in drinking water in the cages equipped with iron pipes was higher than the Chinese drinking water standard.

Study on the expression of epidermal growth factor receptor protein during benzo(a)pyrene induced carcinogenesis / 中华预防医学杂志

Objective@#To explore the expression of epidermal growth factor receptor(EGFR) protein during benzo(a)pyrene (BaP) induced carcinogenesis.@*Methods@#This study, we firstly utilized immunofluorescence assay and Western-blot to examine EGFR expression of the BaP which was constructed previously by project team induced malignant transformation human bronchial epithelial cell (BTC) and the control (16HBE cell). Then, we selected 36 healthy SD rats, divided into two groups according to simple random method, 18 rats each group. The constructed rat lung neoplasm model induced by pulmonary injection of BaP (10 mg/ml of BaP solution in 0.2 ml corn oil), contrast group use 0.2 ml corn oil, lung tissue was collected and the EGFR expression of lung tissue was detected by immunofluorescence assay and Western blot. T analysis was used to test the different of EGFR between two groups.@*Results@#Immunofluorescence analysis showed that the EGFR expression in BTC was significantly higher than 16HBE cell. Meanwhile, Western blot also was used to confirmed this result, the relative expression of EGFR protein in the rats of the model group the control group were 1.04±0.13 and 2.32±0.12, respectively, and the difference was statistically significance (t=12.39, P<0.001). In vivo, well-defined tumor was found in the rat with pulmonary injection of BaP, and the lung showed diffuse alveolar septal thickening, alveolar wall destruction and pulmonary alveoli fusion, which suggested that the rat lung neoplasm model was constructive successfully. Furthermore, we found the EGFR expression of lung was increased dramatically in the rat lung neoplasm model by immunofluorescence detection and Western blot. The relative expression of EGFR protein in the rats of the model group the control group were 0.21±0.03 and 1.30±0.07, respectively, and the difference was statistically significance (t=12.84, P<0.001).@*Conclusion@#Expression of EGFR protein was increased during BaP carcinogenesis, and EGFR may play an important role in the carcinogenesis of BaP.

Investigation of the action mechanisms of poly-ADP-ribosylation in hexavalent chromium induced cell damage / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of poly-ADP-ribosylation in hexavalent chromium Cr(VI) induced cell damage.</p><p><b>METHODS</b>The study object, poly (ADP-ribose) glycohydrolase (PARG) deficient human bronchial epithelial cells (16HBE cells), was constructed previously by our research group. Normal 16HBE cells and PARG-deficient cells were treated with different doses of Cr (VI) for 24 h to compare the differences to Cr (VI) toxicity, meanwhile set up the solvent control group. On this basis, 5.0 µmol/L of Cr (VI) was selected as the exposure dose, after the exposure treatment, total proteins of both cells were extracted for two dimension fluorescence difference gel electrophoresis (2D-DIGE) separation, statistically significant differential protein spots were screened and identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS/MS), and further validated by Western blot.</p><p><b>RESULTS</b>After Cr (VI) treatment, the survival rate of PARG-deficient cells was higher than normal 16HBE cells. When the doses reached up to 5.0 µmol/L, the survival rate of 16HBE cells and PARG-deficient cells were respectively (59.67 ± 6.43)% and (82.00 ± 6.25)%, the difference between which was significant (t = -4.32, P < 0.05). 18 protein spots were selected and successfully identified after 2D-DIGE comparison of differential proteins between normal 16HBE cells and PARG-deficient cells before and after exposure. The function of those proteins was involved in the maintenance of cell shape, energy metabolism, DNA damage repair and regulation of gene expression. The differential expression of cofilin-1 was successfully validated by Western blot. The expression level of cofilin-1 in the 16HBE cells increased after Cr (VI) exposure with the relative expression quantity of 1.41 ± 0.04 in treated group and 1.00 ± 0.01 in control group, the difference of which was statistically significant (t = -18.00, P < 0.05), while the expression level in PARG-deficient cells had no statistically significant difference (t = -8.61, P > 0.05).</p><p><b>CONCLUSION</b>Most of the identified differential proteins are closely related to tumorigenesis, suggesting that poly-ADP-ribosylation reaction may resist the cytotoxicity of Cr(VI) by inhibiting Cr (VI) induced tumorigenesis, which provides important reference data to clarify the mechanisms of poly-ADP-ribosylation in Cr (VI) induced cell damage.</p>