The role of TSG-6 in inhibiting the secretion of IL-1β by bone-marrow-derived macrophages / 中国职业医学

@#Objective To investigate the role of tumor necrosis factor alpha stimulated gene/inducible protein 6（TSG-6）on free silica（SiO2 ）-induced secretion of pro-inflammatory cytokine interleukin（IL）-1β by bone-marrow-derived macrophages （BMDMs）. Methods i）BMDMs isolated from bone marrow were divided into eight groups：the control group was untreated； lipopolysaccharide （LPS） group was stimulated by LPS with a concentration of 50 µg/L；The TSG-6 control group was stimulated by 100 µg/L of recombinant mouse TSG-6. SiO2 model group was pre-stimulated with LPS for four hours，and then stimulated with SiO2 suspension at a final concentration of 250 mg/L；Different dose of TSG-6 groups were firstly treated with above concentrations of LPS and SiO2 suspension，then 10，20，50 and 100 µg/L of recombinant mouse TSG-6 were added respectively；After 16 hours of culture，the cells were collected and the level of IL-1β in BMDMs supernatant was detected by enzyme-linked immunosorbent assay（ELISA）to screen optimal concentration of TSG-6. ii）The cells of the control group，LPS group，SiO2 model group，TSG-6 optimal concentration group and TSG-6 control group were collected. The expression of IL-1β and components of its related pathways in BMDMs was detected by Western blot，including IL-1β，pro-IL-1β，caspase-1，pro dcaspase-1，asc type amino acid transport and NOD-like receptor protein 3（NLRP3）. Results i）Compared with the control group，the expression of IL-1β in SiO2 model group was increased significantly（P<0.01）. Compared with SiO2 model group，the expression of IL-1β in 20，50，100 µg/L dose of TSG-6 groups were decreased significantly（all P<0.01），and the optimal concentration of TSG-6 was found to be 100 µg/L. ii）Compared with the control group and LPS group，the relative expression levels of IL-1β，caspase-1 and NLRP3 in SiO2 model group were increased significantly （all P<0.05）. Compared with SiO2 model group，the expression levels of IL-1β、caspase-1 and NLRP3 were decreased in 100 µg/L TSG-6 group（all P<0.05）. Conclusion TSG-6 could inhibit BMDMs to secret pro-inflammatory cytokine IL-1β by down-regulating the expression of NLRP3 and caspase-1.

[Studying the changes of the related serum complement immune indexes in patients with occupational medicamentosa-like dermatitis induced by trichloroethylene and workers occupationally exposed to trichloroethylene].

OBJECTIVE: To explore the mechanism of occupational medicamentosa-like dermatitis (OMDT) induced by trichloroethylene (TCE) and some immunity indexes in workers occupationally exposed to TCE. METHODS: The blood samples from 8 cases with medicamentosa-like dermatitis in 1st, 2nd, 3rd, 4th and 5th weeks after admitting to hospital were examined for liver function, immunoglobulin and some complement indexes. Thirty nine workers occupationally exposed to TCE were investigated for urinary TCE and some immuno-complement indexes. The TCE concentrations of air in workplaces were monitored. RESULTS: C3d-CIC and C3 of patients before admission were (92.86 ± 44.80) mg/L and 0.91 ± 0.19 mg/L, respectively. C3d-CIC and C3 of patients before discharge were (52.41 ± 17.75) mg/L and (1.14 ± 0.22) mg/L, respectively. There were significant differences between admission and discharge (P < 0.05). The average TCE concentration in 4 workplaces was (351.96 ± 36.72) mg/m(3), which was higher than the occupational exposure limits (OELs). The number of workers exposed to the TCE concentration-time weighted and TCA in urine over OELs were 28.21% and 56.41% of total subjects, respectively. The serum IgG and CIC levels of patients before discharge were (10.03 ± 1.21) mg/L and 103.50 ± 29.17 mU/L, which were significantly lower than those (17.21 ± 1.85) mg/L and (227.46 ± 111.67) mU/L of patients before admission (P < 0.01). CONCLUSION: The type II and III hypersensitivity may be associated with OMDT and the organ injure induced by TCE.

[The level of serum tumor necrosis factor-alpha and epidermal growth factor in patients with medicament-like dermatitis by trichloroethylene and its clinical significance].

OBJECTIVE: To investigate the level of tumor necrosis factor alpha (TNF-alpha) and epidermal growth factor (EGF) in patients with medicament-like dermatitis by trichloroethylene (DMLT). METHODS: Using radioimmunoassay methods, serum TNF-alpha, EGF were measured in 39 patients with DMLT and in 20 controls. RESULTS: The levels of serum TNF-alpha, EGF in patients with DMLT [(0.278 +/- 0.092) ng/L, (6.71 +/- 2.28) microg/L, respectively] were significantly higher than those of the controls [(0.128 +/- 0.029) ng/L, (4.31 +/- 1.13) microg/L respectively, P<0.05, P<0.01]. CONCLUSION: The increased levels of serum TNF-alpha, EGF in patients with DMLT may be related to the following causes: (1) Trichloroethylene and its metabolite may irritate the macrophagocyte and monocyte in human body to release TNF-alpha into blood stream; (2) Severe damage of epithelial tissue in patients with DMLT may promote more EGF synthesis to accelerate the regeneration and repair of epithelial tissue.