Role Of NLRP3 In Estrogen Alleviating Post-Hemorrhagic Shock Mesenteric Lymph-Mediated Lung Injury

Hemorrhagic shock(HS)induces acute lung injury(ALI),which onsets early and urgently,and may lead to acute respiratory distress syndrome(ARDS).Post-hemorrhagic shock mesenteric lymph(PHSML)return is an important mechanism and key link leading to ALI.There is practical significance to explore the prevention and treatment strategies targeting PHSML for hemorrhagic shock-induce ALI.The NOD-like receptor protein3(NLRP3)inflammasome is associated with hemorrhagic shock-induce ALI.Estrogen treatment play obvious intervention effect on ALI caused by various pathogenic factors,however,whether estrogen alleviates ALI after hemorrhagic shock and PHSML-mediated ALI is related to NLRP3? It’s unclear.Basing the above analysis,we hypothesized that “estrogen alleviates PHSML-mediated ALI by inhibiting NLRP3”.To text this hypothesis,the effects of estrogen on survival time,lung structure and function,NLRP3 expression,intestinal structure and intestinal loop blood flow of hemorrhagic shock in mice were observed.In addition,the effects of PHSML venous transfusion to sham mice on above indices,and further observe the effects of E2 on PHSML venous transfusion affecting above indices.Firstly,male mice were randomly divided into hemorrhagic shock group(40±2 mm Hg,90 min,Shock group)and hemorrhagic shock plus estrogen treatment(Shock+E2 group)group to observe the survival time.The results showed that estrogen treatment significantly prolonged survival time in mice following hemorrhagic shock.Subsequently,male mice were divided into the Sham,Shock,Sham+E2,Shock+E2,Sham+PHSML,and Sham+PHSML+E2 groups,hemorrhagic shock models of male mice were established.Pulmonary function test(PFT)was measured using the small animal pulmonary function monitoring system at 3 h after resuscitation(Sham mice at the corresponding time),lung volume,pulmonary ventilation function and other indicators were recorded,and the status of living lung function of the mice was analyzed.Then,the blood flow changes in the fixed intestinal loop area of mice were observed using the laser speckle dynamic blood flow monitoring system,and the mean value of small intestinal blood perfusion volume within 1.5 min was recorded,and the changes of intestinal loop blood flow of mice in each group were analyzed.Finally,the mice were euthanized under anesthesia,and the intestinal and lung tissues were collected to observe the structure of intestinal and pulmonary tissues and the expression of NLRP3 in pulmonary tissues.The results showed that compared with the Sham group,the lung tissue structure of mice in the Shock group was more damaged,alveolar congestion,hemorrhage,edema,etc.,pulmonary function indices Lung Resistance were significantly decreased,and Maximal Mid-expiratory Flow,Forced Expiratory Volume 100 ms,Peak Expiratory Flow were significantly increased.Estrogen treatment(Shock+E2 group)significantly improved lung tissue structure and function,Lung Resistance significantly increased,Maximal Mid-expiratory Flow,Forced Expiratory Volume 100 ms,Peak Expiratory Flow significantly decreased;Intravenous PHSML induced structural injury and low function of lung tissue in Sham mice.Estrogen treatment significantly inhibited the injury effect of intravenous PHSML on Sham mice.Hemorrhagic shock significantly caused the high expression of NLRP3 mRNA and protein in the pulmonary tissue of mice.E2 treatment inhibited the expression of NLRP3 mRNA and protein in the pulmonary tissue of mice with hemorrhagic shock to a certain extent.Intravenous PHSML improved NLRP3 mRNA and protein expression in pulmonary tissue of sham mice,and E2 treatment significantly inhibited the effect of intravenous PHSML on NLRP3 mRNA and protein expression in pulmonary tissue.These results suggest that NLRP3 is involved in PHSML-mediated ALI,and E2 reduces ALI by inhibiting the NLRP3 overexpression induced by PHSML.