Fluorofenidone attenuates pulmonary inflammation and fibrosis via inhibiting the activation of NALP3 inflammasome and IL‐1β/IL‐1R1/MyD88/NF‐κB pathway

Interleukin (IL)‐1β plays an important role in the pathogenesis of idiopathic pulmonary fibrosis. The production of IL‐1β is dependent upon caspase‐1‐containing multiprotein complexes called inflammasomes and IL‐1R1/MyD88/NF‐κB pathway. In this study, we explored whether a potential anti‐fibrotic agent fluorofenidone (FD) exerts its anti‐inflammatory and anti‐fibrotic effects through suppressing activation of NACHT, LRR and PYD domains‐containing protein 3 (NALP3) inflammasome and the IL‐1β/IL‐1R1/MyD88/NF‐κB pathway in vivo and in vitro. Male C57BL/6J mice were intratracheally injected with Bleomycin (BLM) or saline. Fluorofenidone was administered throughout the course of the experiment. Lung tissue sections were stained with haemotoxylin and eosin and Masson's trichrome. Cytokines were measured by ELISA, and α‐smooth muscle actin (α‐SMA), fibronectin, collagen I, caspase‐1, IL‐1R1, MyD88 were measured by Western blot and/or RT‐PCR. The human actue monocytic leukaemia cell line (THP‐1) were incubated with monosodium urate (MSU), with or without FD pre‐treatment. The expression of caspase‐1, IL‐1β, NALP3, apoptosis‐associated speck‐like protein containing (ASC) and pro‐caspase‐1 were measured by Western blot, the reactive oxygen species (ROS) generation was detected using the Flow Cytometry, and the interaction of NALP3 inflammasome‐associated molecules were measured by Co‐immunoprecipitation. RLE‐6TN (rat lung epithelial‐T‐antigen negative) cells were incubated with IL‐1β, with or without FD pre‐treatment. The expression of nuclear protein p65 was measured by Western blot. Results showed that FD markedly reduced the expressions of IL‐1β, IL‐6, monocyte chemotactic protein‐1 (MCP‐1), myeloperoxidase (MPO), α‐SMA, fibronectin, collagen I, caspase‐1, IL‐1R1 and MyD88 in mice lung tissues. And FD inhibited MSU‐induced the accumulation of ROS, blocked the interaction of NALP3 inflammasome‐associated molecules, decreased the level of caspase‐1 and IL‐1β in THP‐1 cells. Besides, FD inhibited IL‐1β‐induced the expression of nuclear protein p65. This study demonstrated that FD, attenuates BLM‐induced pulmonary inflammation and fibrosis in mice via inhibiting the activation of NALP3 inflammasome and the IL‐1β/IL‐1R1/MyD88/ NF‐κB pathway.     

EXPRESSION AND EFFECTS OF MUTANT Bombyx mori ACETYLCHOLINESTRASE1 IN BmN CELLS

The main mechanism of toxicity of organophosphate (OP) and carbamate (CB) insecticides is their irreversible binding and inhibition of acetylcholinestrase (AChE), encoded by ace1 (acetylcholinestrase gene 1), leading to eventual death of insects. Mutations in AChE may significantly reduce insects susceptibility to these pesticides. Bombyx mori is an important beneficial insect, and no OP‐ or CB‐resistant strains have been generated. In this study, wild‐type ace1 (wace1) and mutant ace1 (mace1) were introduced into BmN cells, confirmed by screening and identification. The expression of wace1 and mace1 in the cells was confirmed by Western blot and their expression levels were about 21‐fold higher than the endogenous ace1 level. The activities of AChE in wace1 and mace1 transgenic cells were 10.6 and 20.2% higher compared to control cells, respectively. mace1 transgenic cells had higher remaining activity than wace1 transgenic cells under the treatment of physostigmine (a reversible cholinesterase inhibitor) and phoxim (an OP acaricide). The results showed that ace1 transgene can significantly improve ace1 expression, and ace1 mutation at a specific site can reduce the sensitivity to AChE inhibitors. Our study provides a new direction for the exploration of the relationship between AChE mutations and drug resistance.     

Spatial patterns of soil and ecosystem respiration regulated by biological and environmental variables along a precipitation gradient in semi-arid grasslands in China

Precipitation is a key environmental factor in determining ecosystem structure and function. Knowledge of how soil and ecosystem respiration responds to climate change (e.g., precipitation) and human activities (e.g., grazing or clipping) is crucial for assessing the impacts of climate change on terrestrial ecosystems and for improving model simulations and predictions of future global carbon (C) cycling in response to human activities. In this study, we examined the spatial patterns of soil and ecosystem respiration along a precipitation gradient from 167.7 to 398.1 mm in a semi-arid grassland. Our results showed that soil and ecosystem respiration increased linearly with increasing mean annual precipitation. The trends were similar to those of shoot biomass, litter and soil total C content along the precipitation gradient. Our results indicated that precipitation was the primary controlling factor in determining the spatial pattern of soil and ecosystem respiration in semi-arid grasslands in China. The linear/nonlinear relationships in this study describing the variations of the ecosystem carbon process with precipitation can be useful for model development, parameterization and validation at the regional scale to improve predictions of how carbon processes in grasslands respond to climate change, land use and grassland management.