ABSTRACT
The study aimed to explore the pathogenesis of secondary frozen shoulder and its influence on synovium tissue and angiogenesis by constructing a rat secondary frozen shoulder model along with transforming growth factor. 40 healthy male rats aged 8 weeks were divided into Sham group (n=10, no modeling treatment), Control group (n=10, modeling treatment), Low group (n=10, modeling treatment, and 10 mL/d transforming growth factor), and High group (n=10, modeling treatment, and 20 mL/d transforming growth factor). Hematoxylin and Eosin (HE) method was used for histological detection, and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and immunohistochemical staining method were adopted to detect the expression of Matrix metalloproteinase-14 (MMP-14), mitogen-activated protein kinase (p38MAPK), and Vascular endothelial growth factor (VEGF). Compared with Sham group, the range of abduction and external rotation of rat glenohumeral joint in Control group, Low group, and High group was significantly reduced, and High group had the smallest range. Compared with the Sham group, the synovium in the Control group, the Low group, and the High group had obvious hyperplasia, and the blood vessels were significantly increased. Immunohistochemical staining and RT-PCR results showed that compared with Sham group, MMP-14, p38 MAPK, and VEGF in Control group, Low group, and High group all increased significantly, among which High group increased most. The secondary frozen shoulder is mainly manifested as synovial hyperplasia and increased blood vessels, which are related to the induction of MMP-14, p38 MAPK, and VEGF by transforming growth factor, which reveals the pathogenesis of secondary frozen shoulder to a certain extent, and lays a foundation for subsequent clinical treatment of secondary frozen shoulder.
Subject(s)
Bursitis , Disease Models, Animal , Shoulder Joint , Synovial Membrane , Vascular Endothelial Growth Factor A , p38 Mitogen-Activated Protein Kinases , Animals , Male , Synovial Membrane/metabolism , Synovial Membrane/pathology , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor A/genetics , p38 Mitogen-Activated Protein Kinases/metabolism , p38 Mitogen-Activated Protein Kinases/genetics , Shoulder Joint/pathology , Bursitis/metabolism , Bursitis/pathology , Bursitis/genetics , Rats , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , Rats, Sprague-Dawley , Gene Expression Regulation , AngiogenesisABSTRACT
As a common musculoskeletal disorder, frozen shoulder is characterized by thickened joint capsule and limited range of motion, affecting 2-5% of the general population and more than 20% of patients with diabetes mellitus. Pathologically, joint capsule fibrosis resulting from fibroblast activation is the key event. The activated fibroblasts are proliferative and contractive, producing excessive collagen. Albeit high prevalence, effective anti-fibrosis modalities, especially fibroblast-targeting therapies, are still lacking. In this study, microRNA-122 was first identified from sequencing data as a potential therapeutic agent to antagonize fibroblast activation. Then, Agomir-122, an analog of microRNA-122, was loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (Agomir-122@NP), a carrier with excellent biocompatibility for the agent delivery. Moreover, relying on the homologous targeting effect, we coated Agomir-122@NP with the cell membrane derived from activated fibroblasts (Agomir-122@MNP), with an attempt to inhibit the proliferation, contraction, and collagen production of abnormally activated fibroblasts. After confirming the targeting effect of Agomir-122@MNP on activated fibroblasts in vitro, we proved that Agomir-122@MNP effectively curtailed fibroblasts activation, ameliorated joint capsule fibrosis, and restored range of motion in mouse models both prophylactically and therapeutically. Overall, an effective targeted delivery method was developed with promising translational value against frozen shoulder.
Subject(s)
Bursitis , MicroRNAs , Nanoparticles , Mice , Animals , Humans , Fibroblasts/metabolism , Bursitis/drug therapy , Bursitis/metabolism , Cell Membrane , Fibrosis , Collagen/metabolism , MicroRNAs/metabolismABSTRACT
OBJECTIVES: We evaluated mRNA expression levels of genes that encode TGF-β1; the TGF-β1 receptor; the collagen-modifying enzymes LOX, PLOD1, and PLOD2; and the extracellular matrix proteins COMP, FN1, TNC and TNXB in synovial/capsule specimens from patients with idiopathic adhesive capsulitis. Possible associations between the measured mRNA levels and clinical parameters were also investigated. METHODS: We obtained glenohumeral joint synovium/capsule specimens from 9 patients with idiopathic adhesive capsulitis who had not shown improvement in symptoms after 5 months of physiotherapy. Adhesive capsulitis was confirmed in all patients by magnetic resonance imaging. We also obtained specimens from 8 control patients who had underwent surgery for acute acromioclavicular joint dislocation and who had radiological indication of glenohumeral capsule alteration based on arthroscopic evaluation. mRNA expression in the synovium/capsule specimens was analyzed by quantitative reverse transcription PCR. The B2M and HPRT1 genes were used as references to normalize target gene expression in the shoulder tissue samples. RESULTS: The synovium/capsule samples from the patients with adhesive capsulitis had significantly higher TNC and FN1 expression than those from the controls. Additionally, symptom duration directly correlated with expression of TGFβ1 receptor I. CONCLUSION: Elevated levels of TNC and FN1 expression may be a marker of capsule injury. Upregulation of TGFβ1 receptor I seems to be dependent on symptom duration; therefore, TGFβ signaling may be involved in adhesive capsulitis. As such, TNC, FN1 and TGFβ1 receptor I may also play roles in adhesive capsulitis by contributing to capsule inflammation and fibrosis.