Chest response assessment of post-mortem swine under blast loadings

Study on chest injury and bulletproof vest protection under the combined action of blast wave and fragments

Using a simulation based method, this paper analysis the damage effect of blast wave and fragments on human body and the protective effect of bulletproof vest. The results show that compared with the single blast shock wave, the chest injury is more serious under the combined action of blast shock wave and fragments. The peak stress of sternum, costal cartilage and rib increases by 334.34%, 170.23% and 39.72%, respectively. The peak stress on the side of the lung decreases by 3.95%, with little change. The peak stress on the front and back of the lung increases by 83.58% and 409.09% respectively. Overall, the lung injury is aggravated. With the addition of the bulletproof vest, the damage caused by fragments is reduced, and the peak stress of the sternum and the costal cartilage decreases by 48.77% and 69.78%, respectively. Due to the interaction of the blast wave with the vest and the chest, the damage caused by blast wave is aggravated. The peak stress of rib increases by 13.55%, and the peak stress of lung front, side and back increases by 1.22%, 6.51% and 3.57%, respectively.

Tensile Overload Injures Human Alveolar Epithelial Cells through YAP/F-Actin/MAPK Signaling

BACKGROUND

Explosion shockwaves can generate overloaded mechanical forces and induce lung injuries. However, the mechanism of lung injuries caused by tensile overload is still unclear.

METHODS

Flow cytometry was used to detect the apoptosis of human alveolar epithelial cells (BEAS-2B) induced by tensile overload, and cell proliferation was detected using 5-ethynyl-2'-deoxyuridine (EdU). Immunofluorescence and Western blot analysis were used to identify the tensile overload on the actin cytoskeleton, proteins related to the mitogen-activated protein kinase (MAPK) signal pathway, and the Yes-associated protein (YAP).

RESULTS

Tensile overload reduced BEAS-2B cell proliferation and increased apoptosis. In terms of the mechanism, we found that tensile overload led to the depolymerization of the actin cytoskeleton, the activation of c-Jun N-terminal kinase (JNK) and extracellular-signal-regulated kinase 1/2 (ERK1/2), and the upregulation of YAP expression. Jasplakinolide (Jasp) treatment promoted the polymerization of the actin cytoskeleton and reduced the phosphorylation of tension-overload-activated JNK and ERK1/2 and the apoptosis of BEAS-2B cells. Moreover, the inhibition of the JNK and ERK1/2 signaling pathways, as well as the expression of YAP, also reduced apoptosis caused by tensile overload.

CONCLUSION

Our study establishes the role of the YAP/F-actin/MAPK axis in tensile-induced BEAS-2B cell injury and proposes new strategies for the treatment and repair of future lung injuries.

Tanshinone IIA alleviates blast-induced inflammation, oxidative stress and apoptosis in mice partly by inhibiting the PI3K/Akt/FoxO1 signaling pathway

Although Tanshinone IIA (Tan IIA) has been associated with inflammation, oxidative stress and apoptosis, the effects of Tan IIA on lung blast injury remain uncertain. In this study, we explored the effects of Tan IIA on lung blast injury, studied its possible molecular mechanisms. Fifty C57BL/6 mice were randomly divided into the control, blast, blast + Tan IIA, blast + LY294002 (a PI3K inhibitor), or blast + Tan IIA + LY294002 groups. Serum and lung samples were collected 48 h after blast injury. The data showed that Tan IIA significantly inhibited blast-induced increases in the lung weight/body weight and wet/dry (W/D) weight ratios, decreased the CD44^-and CD163-positive inflammatory cell infiltration in the lungs, reduced the IL-1β, TNF-α and IL-6 expression, and enhanced IL-10 expression. Tan IIA also significantly alleviated the increases in MDA5 and IRE-a and the decrease in SOD-1 and reversed the low Bcl-2 expression and the high Bax and Caspase-3 expressions. Additionally, Tan IIA significantly decreased p-PI3K and p-Akt expression and increased p-FoxO1 expression. More importantly, both LY294002 and Tan IIA pretreatment markedly protected against blast-induced inflammation, oxidative stress and apoptosis in lung blast injury. These results suggest that Tan IIA protects against lung blast injury, which may be partly mediated by inhibiting the PI3K/Akt/FoxO1 signaling pathway.