Tenascin-C Participates The Process Of Paraquat Induced Lung Injury

Objective:Tenascin-C?TNC?is a kind of macromolecular matrix glycoprotein.It participates in tissue repair,playing a vital role in the process of inflammation,fibrosis and tumor.And the high expression of TNC in interstitial pulmonary diseases has been reported,but the expression and role in paraquat?PQ?induced lung injury has not been explored.So,this study was conducted to research the role of TNC in PQ induced lung injury.Methods:6-8week-old male C57BL/6 mice were injected with 30mg/kg PQ by intraperitoneal injection and sacrificed on 2d,7d,14d and 28d after PQ administration.In vivo,we detected the expression of TNC at all time points of lung tissues in mice by Reverse transcription-quantitative-polymerase chain reaction?RT-qPCR?,western blot,as well as immunohistochemistry?IHC?.Expression of NF-?Bp65,TGF-?₁ and?-SMA in lung tissues have also been tested.In vitro,the gene and protein expression of TNC and TGF-?₁ was detected by RT-qPCR and western blot.Then,siRNA was used to knock down TNC expression in A549 cells and TGF-?₁ expression was examined after PQ exposure.Results:TNC expression increased in lung tissues of mice model after PQ administration at both mRNA and protein levels.TNC protein expression peaked on 7d after PQ exposure,earlier than TGF-?₁.And it mostly located at the extracellular matrix of thickened alveolar septum,especially at sites of injury.TGF-?₁ showed strong expression during the whole process.NF-?Bp65 showed increasing at the 2d and 7d.?-SMA increased significantly at the late stage of lung injury of 14d and 28d.In vitro,PQ also induced high expression of TNC and TGF-?₁ in A549 cells.After knocking down TNC expression,the expression of TGF-?₁ decreased dramatically.Conclusion:The results of this study demonstrate that TNC participates in the progress of lung injury induced by PQ poisoning.And its function in lung injury is relative to TGF-?₁.