Intercellular adhesion molecule-1 (ICAM-1, CD54) is increased in adhesive capsulitis

Area of Science:

• Orthopedics
• Immunology
• Molecular Biology

Background:

• Adhesive capsulitis, or frozen shoulder, is a debilitating condition characterized by joint stiffness and pain.
• Intercellular adhesion molecule-1 (ICAM-1) is a cell surface glycoprotein involved in immune responses and inflammation.
• The role of ICAM-1 in the pathogenesis of adhesive capsulitis is not well understood.

Purpose of the Study:

• To investigate the expression levels of ICAM-1 in the glenohumeral joint capsule of patients with adhesive capsulitis.
• To determine if ICAM-1 levels are altered in the synovial fluid and peripheral blood of individuals with adhesive capsulitis.
• To explore the functional impact of ICAM-1 on cytokine gene expression in human synovial cells.

Main Methods:

• Glenohumeral capsular tissue, synovial fluid, and peripheral blood samples were collected from patients with adhesive capsulitis and healthy controls.
• ICAM-1 expression was quantified using oligonucleotide arrays, real-time RT-PCR, immunohistochemistry, Western blotting, and ELISA.
• The effect of ICAM-1 on cytokine gene expression related to inflammation and fibrosis was assessed in cultured human synovial cells.

Main Results:

• Significantly higher levels of ICAM-1 were observed in the capsular tissue, synovial fluid, and serum of patients with adhesive capsulitis compared to controls.
• ICAM-1 levels in serum were also elevated in patients with diabetes mellitus, similar to those with adhesive capsulitis.
• In vitro studies showed that ICAM-1 treatment, particularly with glucose, increased the gene expression of pro-inflammatory and pro-fibrotic cytokines in synovial cells.

Conclusions:

• ICAM-1 is upregulated in patients experiencing adhesive capsulitis.
• The elevated ICAM-1 levels in frozen shoulder mirror those found in diabetes mellitus.
• ICAM-1 may play a role in the inflammatory and fibrotic processes associated with adhesive capsulitis.