Correlation of mRNA and protein levels of Ghrelin in shoulder tissue and synovial fluid with severity of rotator cuff tear and frozen shoulder / 中华创伤骨科杂志

ABSTRACT

Objective:To investigate the correlation of mRNA and protein levels of Ghrelin in shoulder tissue and synovial fluid with severity of rotator cuff tear(RCT) and frozen shoulder(FS).Methods:Recruited for this study were 66 RCT and 66 FS patients who had been definitely diagnosed at Department of Orthopedics, The First Hospital of Huizhou from January 2018 to September 2019. Another 60 patients with rotator instability were recruited as a control group. After the severity of RCT was evaluated by ultrasonographic images, the RCT group was further divided into 3 subgroups according to the severity of RCT a massive full thickness tear (MFTT) subgroup, a non massive full thickness tear (MFTT) subgroup, and a partial thickness tear (PTT) subgroup. The FS group was conventionally divided into 31 cases of acute phase and 35 cases of adhesive phase. Samples of subacromial bursa and shoulder joint bursa tissues and shoulder joint synovial fluid were collected. The expression of Ghrelin mRNA was detected by RT-PCR and the expression of Ghrelin protein in joint synovial fluid was detected by ELISA. The symptoms and functions of shoulder joint were evaluated by visual analogue scale (VAS) and Constant-Murley functional score.Results:There were no significant differences in gender or age between the RCT, FS and control groups, showing compatibility ( P>0.05).The expression of Ghrelin mRNA in subacromial synovial capsule and shoulder joint capsule and the expression of Ghrelin protein in shoulder synovial fluid in the RCT and FS groups were significantly lower than those in the control group ( P<0.05).The expression of Ghrelin mRNA in subacromial synovial capsule and shoulder joint capsule and the expression of Ghrelin protein in shoulder synovial fluid in the PTT subgroup were the highest, followed sequentially by NMFTT and MFTT subgroups, with significant differences between subgroups ( P<0.05). For FS patients, the expression levels of Ghrelin mRNA and protein in the acute phase were significantly lower than in the adhesive phase ( P<0.05). The relative expression of Ghrelin mRNA in joint capsule and the expression of Ghrelin protein in shoulder synovial fluid were negatively correlated with VAS scores and IL-6 levels (all P<0.05), and positively correlated with the Constant-Murley scores (all P<0.05). Conclusions:The expression of Ghrelin in shoulder tissue and synovial fluid is negatively correlated with the progress of rotator cuff tear and frozen shoulder.Local supplementation of Ghrelin may be a potential therapy for rotator cuff tear and frozen shoulder.