Identify differential gene expressions in fatty infiltration process in rotator cuff

Pengfei Hu,Lidong Wu,Lifeng Jiang

doi:10.1186/s13018-019-1182-1

Abstract

BackgroundRotator cuff tears are one of the most frequent upper extremity injuries and lead to pain and disability. Recent studies have implicated fatty infiltration in rotator cuff is a key failure element with the higher re-tear rates and poorer functional prognosis. Therefore, we investigated the differential expression of key genes in each stage of rotator cuff tear.MethodsA published expression profile was downloaded from the Gene Expression Omnibus database and analyzed using the Linear Models for Microarray Data (LIMMA) package in R language to identify differentially expressed genes (DEGs) in different stages of injured rotator cuff muscles. Gene ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to annotate the function of the DEGs. Finally, PPI network and module analysis were used to identify hub genes.ResultsA total of 1089 fatty infiltration-related DEGs were identified, including 733 upregulated and 356 downregulated genes, and GO analyses confirmed that fatty infiltration was strongly associated with inflammatory response, aging, response to lipopolysaccharide, and immune response. Significantly enriched KEGG pathways associated with these DEGs included the phagosome, cell adhesion molecules, tuberculosis, and osteoclast differentiation. Further analyses via a PPI network and module analysis identified a total of 259 hub genes. Among these, Tmprss11d, Ptprc, Itgam, Mmp9, Tlr2, Il1b, Il18, Ccl5, Cxcl10, and Ccr7 were the top ten hub genes.ConclusionsOur findings indicated the potential key genes and pathways involved in fatty degeneration in the development of fatty infiltration and supplied underlying therapeutic targets in the future.

Highlights

Rotator cuff tears are one of the most frequent upper extremity injuries and lead to pain and disability
According to a survey performed by Hiroshi in 2012, the prevalence of Rotator cuff tear (RCT) was 22.1% was in the general population, and the prevalence was significantly increased with advanced age [2]
Data distribution analyses and differentially expressed genes (DEGs) screening In GSE103266, a total of 17147 genes were detected in 16 samples

Summary

Introduction

Rotator cuff tears are one of the most frequent upper extremity injuries and lead to pain and disability. Recent studies have implicated fatty infiltration in rotator cuff is a key failure element with the higher retear rates and poorer functional prognosis. Rotator cuff tear (RCT) is one of the most common musculoskeletal disorder in orthopedics department. Common risk factors for RCT include advancing age, overuse of shoulder, trauma, and shoulder arthritis [3]. The size of the defect, tendon retraction, muscular atrophy, and degree of fatty degeneration were regarded as failure elements and resulted in higher rate of no-heal and re-tear [8, 9]. Fatty infiltration was introduced and staged by Goutallier et al in 1994 and was viewed as a key factor responsible for the higher re-tear rates and poorer functional prognosis [10, 11].

Methods

Results

Conclusion