Effects Of Kallistatin On Serum Inflammatory Mediators And Lung Tissue Apoptosis In Rat Model Of Sepsis

Objective: To investigate the effect of Ad-KS on serum inflammatory mediators and lung tissue apoptosis in rat model of sepsis.Methods:1. Thirty two clean male SD rats,280±20g weight, were randomly divided into four groups, Sham group(SC group), sepsis group(SEP group), Ad-KS treatment group(KS group), and Ad-Null control group(AC group). Rat sepsis models are performed with cecal ligation and puncture(CLP).2. KS group and AC group were treated with Ad-KS and Ad-Null through rat tail vein injection at 48 h before CLP surgery so that KS can be expressed in rats.3. Blood and lung tissue were collected at 24 h after surgery of all surviving rats. Blood picking from abdominal aortic for blood gas analysis, from heart for blood routine and blood biochemistry, serum for ELISA tests. Rats were sacrificed by bloodletting, and lung tissue was collected as soon as possible.4. Lung tissue morphology was observed by HE staining. Levels of inflammatory mediators TNF-α, IL-6, and IL- 10 were detected by ELISA assay. Caspase-3, Bax and Bcl-2 expression in Lung tissue were detected by Western Blot. Apoptosis in rat lungs was detected by TUNEL assay.Results:1. Each group underwent biopsy of lung tissue and HE staining. SC group showed intact alveolar structure, without interstitial thickening and edema, and without infiltration of neutrophils and erythrocyte. Alveolar collapse, pulmonary interstitial thickening and edema, infiltration of neutrophils and erythrocyte, and partially tissue consolidation were visible in both SEP group and AC group. Alveolar collapse, interstitial edema and infiltration were reduced in KS group compared with SEP group and AC group.2. Serum inflammatory mediators were detected by ELISA. TNF-α and IL-6 levels of SEP group and AC group increased compared with the SC group(P <0.05), but the anti-inflammatory cytokine IL-10 showed no significant increase. IL-6 and TNF-α levels of KS group decreased and IL-10 increased compared with SEP group and AC group.(P <0.05)3. Expression of apoptosis related proteins were detected by Western blot. Caspase-3 expression of SEP group and AC group were significantly increased compared with the SC group(P <0.05). Caspase-3 expression of KS group decreased compared with SEP group and AC group. All results are statistically significant(P <0.05). But expression of Bax and Bcl-2 between Sham group、SEP group and AC group showed no significant deference. The expression of Bax decreased and Bcl-2 increased in KS group compared to the other three groups.4. Lung tissue apoptosis was detected by TUNEL. Lung apoptosis in SEP group and AC group increased compared with the SC group. Apoptosis in KS group reduced compared with SEP group and AC group. There is no difference between SEP group and AC group.Conclusion:1. Ad-KS decrease serum levels of TNF-α and IL-6 and increase IL-10 of rat model of sepsis, play a role of anti-inflammatory.2. Ad-KS inhibit cell apoptosis and Caspase-3 expression in lung tissue, reduced lung injury in rat model of sepsis.