Administration of SB239063, a potent p38 MAPK inhibitor, alleviates acute lung injury induced by intestinal ischemia reperfusion in rats associated with AQP4 downregulation.

Acute lung injury (ALI), induced by intestinal ischemia reperfusion (II/R) injury, is characterized by pulmonary edema and inflammation. Aquaporin 4 (AQP4), has been pointed out recently involving in edema development. Previous studies have shown that p38 mitogen activated protein kinase (MAPK) activation resulted in lung inflammation, while p38 MAPK inhibitor can alleviate the pathology injury of lung tissue. However, the regulated mechanism of p38 MAPK in ALI induced by II/R is unclear. In this study, we established II/R rats' model by clamping the superior mesenteric artery (SMA) and coeliac artery (CA) for 40min and subsequent reperfusion for 16h, 24h, 48h. Subsequently, SB239063, a specific inhibitor of the activity of p38 MAPK, was injected (10mg/kg) intraperitoneally 60min before the operation. The severity of ALI was determined by histology analysis (HE staining and ALI scoring) and lung edema (lung wet/dry weight ratio) assessment. Western blot (WB) was applied to detect the expression level of AQP4 and phosphorylated (P)-p38 MAPK, and the localization of AQP4 was detected by immunofluorescent staining (IF). We found that AQP4 could express in the lung tissue. II/R could significantly induce lung injury, confirmed by lung injury scores and lung wet/dry weight ratios. The level of P-p38 MAPK and AQP4 were largely up-regulated in lung tissues. Moreover, inhibition of p38 MAPK activity could effectively down-regulate AQP4 expression and diminish the severity of II/R-induced ALI. These novel findings suggest that inhibition of p38 MAPK function should be a potential strategy for the prevention or treatment of ALI, by targeting AQP4 in future clinic trial.

Expressional difference, distributions of TGF-ß1 in TGF-ß1 knock down transgenic mouse, and its possible roles in injured spinal cord.

Transforming growth factor ß1 (TGF-ß1) is a multi-functional cytokine implicated in many aspects of mammalian wound healing and scar tissue formation. However, few experiments have so far addressed the potential biological effects of TGF-ß1 in the nervous system after injury, in addition to the immune system. In the present study, expressional silencing TGF-ß1 was achieved by selecting predesigning hairpins targeting mouse TGF-ß1 genes. Four homozygous transgenic offspring were generated and designed as Founder 90, Founder 12, Founder 41 and Founder 46. The down-regulated rates of TGF-ß1 in different transgenic mice were also determined. To investigate the potential roles of TGF-ß1, we observed changes in the neurological behavior of TGF-ß1-knockdown (TGF-ß1-kd) mice after spinal cord transection (SCT). Moreover, mRNA levels of inflammatory cytokines, including IL-1, IL-6, IL-10, NF-κB and TNF, were also detected in nucleate cells from blood by real-time PCR. Consequently, different TGF-ß1 expressions were detected in multiple tissues, and protein levels of TGF-ß1 decreased at different rates relative to that of wild type (WT) ones. The levels of TGF-ß1 proteins in TGF-ß1-kd mice decreased at most by 57% in Founder 90, which showed a significant recovery in Basso, Beattie, Bresnahan (BBB) scores after SCT compared with that of WT. However, expressions of immune relative genes showed no dramatic difference compared with WT ones. This study is the first to generate TGF-ß1 down regulated mice and determine the possible roles of TGF-ß1 in vivo in different conditions.