Inhibition of macrophage signaling pathway by bone marrow mesenchymal stem cells (BMSC) and alleviation of pulmonary alveolitis in mice exposed to silica dust / 上海预防医学

Objective To study the mechanism of bone marrow mesenchymal stem cell (BMSC)-mediated alleviation of pulmonary alveolitis in mice exposed to silica dust. Methods Thirty mice were randomly divided into 3 groups:control group, and two silica groups with or without BMSCs transplantation.Through the tracheal tube clearance, mice in control group received a single injection 20.0 μL of 0.90% sodium chloride solution by one time.Mice from in silica group and silica/BMSCs transplantation group first received a single injection of 20.0 μL silica dust suspension (mass concentration 250 g/L); followed by either 500.0 μL of 0.90% sodium chloride solution or by 500.0 μL of BMSCs suspension (cell density 1×109/L) through tail vein infusion 6 hours later.Mice were euthanized on the 3th day of the experiments.The levels of NALP3 inflammasome in lungs was determined by Western blot.Transwell system was used for co-culture of BMDM (in upper-chamber) and BMSC (in lower-chamber) co-culture.The level of cytokines IL-1β in BMDM cultural supernatant was detected by enzyme linked immunosorbent assay after stimulated by SiO2 stimulation.The levels of NALP3 inflammasome of in BMDM was determined by Western blot. Results The levels of pro-IL-1β, IL-1β, pro-caspase-1, caspase-1 in lungs of silica/BMSCs transplantation group were lower than that in silica group (P < 0.01).In the experiment in vitro, the concentrations of IL-1β in SiO2 exposed BMSC/BMDM co-culture group were lower than the SiO2 exposure only groups (P < 0.05).Meanwhile, the levels of pro-IL-1β, IL-1β, pro-caspase-1, caspase-1 in BMDM was lower than that in silica group (P < 0.01).The level of these proteins didn′t change while when the cell-free supernatant of BMSC culture was directly added. Conclusion The BMSC could inhibit NALP3 inflammasome of macrophages stimulated by SiO2.

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 / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the mechanism of occupational medicamentosa-like dermatitis (OMDT) induced by trichloroethylene (TCE) and some immunity indexes in workers occupationally exposed to TCE.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>The type II and III hypersensitivity may be associated with OMDT and the organ injure induced by TCE.</p>

The level of serum tumor necrosis factor-alpha and epidermal growth factor in patients with medicament-like dermatitis by trichloroethylene and its clinical significance / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>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).</p><p><b>METHODS</b>Using radioimmunoassay methods, serum TNF-alpha, EGF were measured in 39 patients with DMLT and in 20 controls.</p><p><b>RESULTS</b>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].</p><p><b>CONCLUSION</b>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.</p>