The Expression And Correlation Analysis Of MiR21 And Autophagy Related Factors In Human Pathological Scar

Background:Pathological scar is the result of excessive tissue repair after trauma,it is a common disease in clinic.The main pathologicalfeatures were excessive fibrosis,collagen deposition and disorder in arrangement.Pathological scar includes hypertrophic scar and keloid,it is often accompanied by pruritus and pain,while scar contracture in atrophy often affects the appearance and causes joint dysfunction,causing great physical and mental burden to patients.Autophagy is a type of programmed cell death,which is critical for the reuse and homeostasis of intracellular substances.Recent studies have shown that autophagy can also be involved in fibrosis and pathological scar formation.At present,studies have pointed out that autophagy level is up-regulated in pathological scar,and studies have pointed out that autophagy level is down-regulated in pathological scar,but no unified conclusion has been reached yet.MicroRNA(miRNA)is a non-coding small molecule RNA,which is differentially expressed in a variety of fibrotic diseases.MiR21 is closely related to the occurrence and development of pathological scars.Previous studies have shown that up-regulation of miR21 can promote collagen deposition and aggravate fibrosis.At the same time,miR21 has also been observed to be a key link involved in autophagy activation,and can be involved in regulating autophagy level in a variety of diseases.However,whether miR21 can regulate autophagy level in pathological scars and its correlation have not been reported yet.Therefore,this study intends to explore the expression level and correlation between miR21 and autophagy related factors P62 and LC3 in pathological scars,aiming at a deeper understanding of the pathogenesis of pathological scarsObjective:1.To clarify the expression level of miR21 in pathological scars2.To clarify the expression level of autophagy related factor LC3 P62 in pathological scar3.To clarify the correlation between miR21 and the expressions of autophagy related factors LC3 and P62 in pathological scars4.To clarify the expression levels of miR21 and autophagy related factor LC3 P62 in pathological scar fibroblastsMethods:1.Keloid,hypertrophic scar tissue and normal skin tissue(n=10)were obtained from the Burn and Plastic Surgery Department of Affiliated of North Sichuan Medical College from November 2017 to December 2018.RNA was extracted and theexpressions of miR21 and autophagy related factor LC3,P62 were detected by real-time fluorescence quantitative PCR.Protein was extracted and the expression of autophagy related factor LC3,P62 was detected by Western Blot.2.To analyze the correlation between miR21 expression level and autophagy in pathological scar tissue.3.Keloid,hypertrophic scar tissue and normal skin tissue(n=3)were obtained from the Burn and Plastic Surgery Department of Affiliated of North Sichuan Medical College from November 2017 to December 2018.Primary tissue cells were cultured,3-5 generations of fibroblasts were taken.RNA was extracted and the expressions of miR21 and autophagy related factor LC3 P62 were detected by real-time fluorescence quantitative PCR.Protein was extracted and the expression of autophagy related factor LC3 P62 was detected by Western Blot.Results:1.Real-time fluorescence quantitative PCR results showed that the gene expression levels of miR21 and P62 in hypertrophic scar,keloid tissue and cells were higher than that in normal skin tissue,and there was no significant difference in LC3 expression.The expression level of miR21 in tissue and cell of hypertrophic scar was higher than that of keloid,and there was no significant difference in the expression of P62 and LC3.2.Western Blot results showed that the protein expression levels of P62 and LC3 II in hypertrophic scar,keloid tissue and cells were higher than that in normal skin tissue,and there was no significant difference in LC3II/LC3 I expression.3.MiR21 in hypertrophic scar tissue is positively correlated with the protein expression levels of P62 and LC3 II,but not significantly correlated with the mRNA expression levels.There was no significant correlation between miR21 and P62,LC3 protein and mRNA expression in keloid tissue.Conclusion:1.Autophagy level decreased in pathological scar,suggesting that changes in autophagy level may be involved in the formation of scar tissue.2.The increased expression of miR21 in pathological scars may be related to the formation of scar components.3.MiR21 in hypertrophic scar tissue is positively correlated with the expression levels of autophagy factors P62 and LC3 II,suggesting that miR21 is associated with the level of autophagy in hypertrophic scar tissue,which could be used as a target for further study.