Fig 1.
Effect of genetic deletion of Tyro3/Axl/Mertk on synovial cellularity in ankle joints.
(A) Ankle joints of naive wild-type (WT) and Tyro3/Axl/Mertk triple knock-out (TAM TKO) mice of 14, 34 and 52 weeks old were processed for histology. Sections were stained with hematoxylin and eosin. Shown are representative pictures in 50x magnification. Staining is representative for 6 mice (14 and 34 weeks old mice) or 12 mice (52 weeks old mice). (B) Synovial cellularity was quantified in all joints in a random and blinded manner using Leica Application Suite software. Data are presented as dot-plots with mean. Data were statistically analyzed with a Mann Whitney test. n = 6 at 14 and 34 weeks old, n = 12 at 52 weeks old. BM = bone marrow, ON = os naviculare, OT = os talus, S = synovium, T = tibia. Black scale bars represent 100 μm.
Fig 2.
Effect of genetic deletion of Tyro3/Axl/Mertk on cartilage destruction in ankle joints.
(A) Ankle joints of naive wild-type (WT) and Tyro3/Axl/Mertk triple knock-out (TAM TKO) mice of 14, 34 and 52 weeks old were processed for histology. Sections were stained with safranin O and fast green. Shown are representative pictures of the tibia–os talus region and os talus–os naviculare region in 50x magnification. Staining is representative for 6 mice (14 and 34 weeks old mice) or 12 mice (52 weeks old mice). (B) Cartilage proteoglycan depletion was quantified in both regions in all joints in a random and blinded manner using Leica Application Suite software. Data are presented as dot-plots with mean. Data were statistically analyzed with a Mann Whitney test. n = 6 at 14 and 34 weeks old, n = 12 at 52 weeks old. ON = os naviculare, OT = os talus, T = tibia. Black scale bars represent 100 μm.
Fig 3.
Effect of genetic deletion of Tyro3/Axl/Mertk on bone marrow edema.
Ankle joints of naive wild-type (WT) and Tyro3/Axl/Mertk triple knock-out (TAM TKO) mice of 14, 34 and 52 weeks old were processed for histology. (A) Sections were stained with hematoxylin and eosin. Shown are representative pictures in 100x magnification of the os naviculare, os talus and tibia of 52 weeks old mice. Staining is representative for 12 mice. (B) Bone marrow edema was quantified in all joints in a random and blinded manner using Leica Application Suite software. Data are presented as dot-plots with mean. Data were statistically analyzed with a Mann Whitney test. * = p<0.05, ** = p<0.01. n = 6 at 14 and 34 weeks old, n = 12 at 52 weeks old. Black scale bars represent 100 μm. See S1 Fig for comparison of bone marrow edema quantification in WT mice among different ages.
Fig 4.
Characterization of bone marrow cells in mice lacking Tyro3/Axl/Mertk.
Ankle joints of naive wild-type (WT) and Tyro3/Axl/Mertk triple knock-out (TAM TKO) mice of 52 weeks old were processed for histology. Sections were immunohistochemically stained for the cell surface marker of interest, or IgG negative control, and counterstained with hematoxylin. Shown are representative pictures in 200x magnification of the os naviculare, os talus and tibia. Staining is representative for 12 mice. (A) F4/80, (B) CD3, (C) CD19. Black scale bars represent 100 μm.