Expression And Target Regulation Of MiR-590-3p And TFAM In Radon-induced Lung Injury

Objective:To investigate the changes in expression and targeted regulation of miR-590-3p and mitochondrial transcription factor A(TFAM)in radon-induced lung injury of mice.Methods:(1)Balb/c mice were exposed to radon and its progeny in a multifunction ecological radon room at a constant radiation level of 100,000Bq/m~3,with accumulative doses of 30,60 and 120 working level month(WLM)respectively.Histopathological changes of lung tissue were observed by HE staining.Immunohistochemistry was used to detect the expression of TFAM.The expression of miR-590-3p and TFAM in lung tissue was detected by Western-blotting.Real-time PCR was used to detect the expression of genes of miR-590-3p,TFAM and mitochondrial DNA copy number.The ATP level was determined by illuminometer.(2)The expression of miR-590-3p and TFAM protein was detected by Western blotting.The expression of miR-590-3p,TFAM gene and mitochondria DNA copy number were detected by Real-time PCR.The ATP level was determined by illuminometer.The colony formation,cell migration rate and invasion ability were measured during the process.(3)The Targets can online prediction and dual luciferase reporter assay were used to detect the targeted relationship between miR-590-3p and TFAM.The miR-590-3p overexpression plasmids and interfering RNAs were transfected into Rn5 and Rn10cells.Western-blotting and Real-time PCR was used to determine the expression of TFAM protein mtDNA copy number.The ATP level was determined by luminometer.The TFAM overexpression plasmids were transfected into Rn5 and Rn10 cells,and the mtDNA copy number,ATP content,cell clonal formation,cell invasion and migration potential were again examined.Results:(1)Pathological observation revealed the thickening of alveolar walls and inflammatory cell infiltration in lung tissue,with airway smooth muscle hyperplasia and thickening.The expression of miR-590-3p and TFAM significantly increased in lung tissues of mice exposed to radon.(2)Morphological changes were found in cells with radon exposure.Cell clonal formation,migration and invasion were enhanced,with increased mitochondrial copy number and ATP content.(3)The expression of TFAM decreased with miR-590-3p overexpression,and increased with miR-590-3p inhibition.After overexpression of TFAM,Also,mitochondrial DNA copy number,ATP content,cell clonal formation,migration and invasion increased with miR-590-3p overexpression,but decreased with miR-590-3p inhibition.Conclusions:Taken together,these results indicate that radon induced lung damage may be a combined effects of alteration in mtDNA,energy metabolism disorder and mitochondria genes expression,and the target regulation of miR-590-3p to TFAM may play an important role in mediation of radon induced lung damage.