Fig 1.
Spontaneous exploratory locomotion was not different between groups.
(A) Velocity and (B) walking distance of OA and SHAM animals during the experimental period. Data are expressed as mean ± SEM.
Fig 2.
OA increased nociception at weeks 11 and 12, and did not change body and gastrocnemius weight.
(A) Nociception and (B) body weight of OA and SHAM animals during the experimental period. Data are expressed as mean ± SEM. (C) Weight of right hind paw gastrocnemius of OA and SHAM animals at the end of the experimental period. Data are expressed as medians with interquartile range.
Fig 3.
Histopathological evaluation of the knee joints showed osteoarthritis development.
(A) OARSI grading system score and (B) OARSI cartilage degeneration score of OA and SHAM animals. Representative samples of Safranin O stained right knee joint of (C) OA and (D) SHAM animals at the end of the experimental period. Magnification: × 200. Data are expressed as medians with interquartile range. *p < 0.05 OA vs SHAM.
Fig 4.
OA animals had decreased gastrocnemius area, and increased IL-1β expression.
TNF-α and Pax7 expressions were unchanged. (A) Gastrocnemius CSA and representative samples of right hind paw gastrocnemius stained with hematoxylin-eosin of (B) OA and (C) SHAM animals at the end of the experimental period. (D) IL-1β expression estimated as IOD and representative samples of right hind paw gastrocnemius stained for IL-1β of (E) OA and (F) SHAM animals at the end of the experimental period. (G) TNF-α expression estimated as IOD and representative samples of right hind paw gastrocnemius stained for TNF-α of (H) OA and (I) SHAM animals at the end of the experimental period. (J) Pax7 expression estimated as IOD and representative samples of right hind paw gastrocnemius stained for Pax7 of (L) OA and (M) SHAM animals at the end of the experimental period. Magnification: × 200. Data are expressed as medians with interquartile range. *p < 0.05 OA vs SHAM.
Fig 5.
Myogenin expression was decreased, and myostatin expression was increased in OA animals.
Western blot analyses showing the expression of (A) myogenin, (B) MyoD, (C) myostatin and (D) MuRF-1 in gastrocnemius muscle of OA and SHAM animals at the end of the experimental period. Data are expressed as medians with interquartile range. *p < 0.05 OA vs SHAM.