Emetine dihydrochloride alleviated radiation-induced lung injury through inhibiting EMT.

Radiation-induced lung injury (RILI), divided into early radiation pneumonia (RP) and late radiation-induced pulmonary fibrosis (RIPF), is a common serious disease after clinical chest radiotherapy or nuclear accident, which seriously threatens the life safety of patients. There has been no effective prevention or treatment strategy till now. Epithelial-mesenchymal transition (EMT) is a key step in the occurrence and development of RILI. In this study, we demonstrated that emetine dihydrochloride (EDD) alleviated RILI through inhibiting EMT. We found that EDD significantly attenuated EMT-related markers, reduced Smad3 phosphorylation expression after radiation. Then, for the first time, we observed EDD alleviated lung hyperaemia and reduced collagen deposit induced by irradiation, providing protection against RILI. Finally, it was found that EDD inhibited radiation-induced EMT in lung tissues. Our study suggested that EDD alleviated RILI through inhibiting EMT by blocking Smad3 signalling pathways. In summary, our results indicated that EDD is a novel potential radioprotector for RILI.

Microplastic (1 and 5 µm) exposure disturbs lifespan and intestine function in the nematode Caenorhabditis elegans.

As an emerging environmental pollutant, microplastics (MPs) are increasingly viewed as a serious health concern to terrestrial and aquatic ecosystems. However, previous toxicological studies examining MPs on freshwater and terrestrial organisms provide contradictory results, possibly due to few investigations at environmentally relevant concentrations. Here, the nematode Caenorhabditis elegans (C. elegans), a model organisms with both aquatic and terrestrial free-living forms, was employed to investigate the effects of 1 and 5 µm MPs (107-1010 particles/m2) on the intake, lifespan, defecation rhythm, defecation-related neurons and transcriptional expression of related genes (skn-1, mkk-4, pmk-1, cpr-1 and itr-1). We demonstrated that the percentage of MP-contaminated nematodes increased with increasing exposure concentrations and duration. The lifespan of nematodes in the lower concentration exposure groups (2.4 × 107 and 2.4 × 108 particles/m2) decreased more prominently than that of higher concentration groups (2.4 × 109 and 2.4 × 1010 particles/m2) after a 72-h exposure period. Concomitantly, expression of the skn-1 gene, involved in detoxification and lifespan regulation, was significantly altered at lower MP concentrations. Physiologically, the defecation rhythm after a 72-h exposure period was most strongly affected by 1 µm MPs at 2.4 × 108 particles/m2. The significant up-regulation of related genes by 1 µm MPs appears responsible for the shortened defecation interval. Results of this study identified a potential toxicity threat to C. elegans from exposure to MPs at environmentally relevant concentrations and provide novel evidence for MP risks to freshwater and terrestrial organisms. Capsule. After exposure to 1 and 5 µm MPs (107-1010 particles/m2), the lifespan of C. elegans decreased more rapidly at lower concentrations.