Histological and biochemical changes in a rat rotator cuff tear model with or without the subacromial bursa

• Published in: Tissue & cell Vol. 88; p. 102370
• Main Authors: Miura, Yugo, Endo, Kentaro, Sekiya, Ichiro
• Format: Journal Article
• Language: English
• Published: Scotland Elsevier Ltd 01.06.2024
• Subjects: Anti-inflammatory cytokine; Inflammatory cytokine; Rotator cuff tear; Subacromial bursa; Tendon healing; COL; IL; DAB; Subacromial bursa; H&E; Anti-inflammatory cytokine; INOS; MMP; RC; SD; SSP; Rotator cuff tear; TGF; Arg-1; Tendon healing; Inflammatory cytokine; SAB; GAPDH; RT-qPCR
• ISSN: 0040-8166; 1532-3072; 1532-3072
• DOI: 10.1016/j.tice.2024.102370

The subacromial bursa (SAB) plays an important role in the tendon healing process. Based on previous reports, co-culture of the rotator cuff (RC) and SAB have been shown to increase the tendon-related gene expressions, inflammatory cytokines, and tensile strength. However, the nature of the specific biochemical alterations during the inflammatory and repair phases of tendon healing with or without the SAB remain unknown. Using a full-thickness RC tear rat model, we determined how the presence or absence of the SAB alters the histological characteristics and gene expressions. After 3 and 6 weeks, tissues were collected for histological and real-time quantitative polymerase chain reaction (RT-qPCR) evaluations. Results showed greater cell density at 3 weeks, neovascularization and tendon thickening at 6 weeks with SAB preservation. Immunostaining revealed significant increases in type 3 collagen (COL3) expression at 6 weeks with SAB preservation. The RT-qPCR results showed that SAB preservation induced significant increases in the expression of scleraxis, matrix metalloproteinase-13 (MMP-13), interleukin-1β (IL-1β), and inducible nitric oxide synthase (iNOS) at 3 weeks and significant increases in COL3, IL-10, and arginase-1 (Arg-1) at 6 weeks. An RC tear undergoes more appropriate inflammatory and repair phases during the tendon healing process when the SAB is retained. [Display omitted] •Preservation of the SAB promotes cell growth around the injury site and the formation of new blood vessels.•Preservation of the SAB increased inflammatory cytokine expressions at 3 weeks.•Preservation of the SAB increased anti-inflammatory cytokine expressions at 6 weeks.