TITLE:
Differential mRNA Expression of COX-2 and Proinflammatory Mediators in Patients with Rotator Cuff Tears and Osteoarthritis of the Hip
AUTHORS:
Tomonori Kenmoku, Kentaro Uchida, Naoshige Nagura, Hisako Fujimaki, Mitsufumi Nakawaki, Naonobu Takahira, Kensuke Fukushima, Ryo Tazawa, Kyoko Muneshige, Gen Inoue, Masashi Takaso
KEYWORDS:
Rotator Cuff Tear, Pain, Hip Osteoarthritis, Tumor Necrosis Factor-α, Interleukin (IL)-1β, COX-2, IL-6
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.9 No.11,
November
29,
2019
ABSTRACT: Purpose: Bursal
inflammation is thought to be a major cause of pain in degenerative rotator
cuff tears (RCTs). While the expression of proinflammatory mediators, such as COX-2,
TNF-α, IL-1β, and IL-6, is crucial for the pathophysiology of osteoarthritis
(OA), their role in degenerative RCTs remains unknown. The aim of this study
was to determine the expression of COX-2
and proinflammatory mediators in the development of RCT-induced pain by
comparing their levels
in patients with hip OA or RCTs. Methods: We included samples obtained
from 31 shoulders of 31 patients with RCTs and samples from 30 hips of 27 patients with hip OA. The mRNA levels of COX-2, TNF-α, IL-1β,
and IL-6 were determined using
RT-PCR, and were compared between the subacromial bursa and
hip joints. We also analyzed IL-1β-induced COX-2
expression in the subacromial bursa and synovial blast of the hip. Results: COX-2, IL-1β, and IL-6 expression levels were
significantly lower in the subacromial bursa of RCTs than in hip OA samples,
while no significant difference was observed for TNF-α. No
significant difference in the fold increase was observed between subacromial
bursa and hip OA samples, even though IL-1β-induced COX-2 expression increased in both
samples. Conclusion: Our findings suggest that the main
mechanism underlying pain development differs between patients with RCTs and
those with hip OA.