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Protein kinase C delta mice exhibit structural alterations in articular surface, intra-articular and subchondral compartments.

Yang X, Teguh D, Wu JP, He B, Kirk TB, Qin S, Li S, Chen H, Xue W, Ng B, Chim SM, Tickner J, Xu J - Arthritis Res. Ther. (2015)

Bottom Line: Structural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population.The morphology and organization of chondrocytes were studied using confocal microscopy.Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement.

View Article: PubMed Central - PubMed

Affiliation: Guangzhou Institute of Traumatic Surgery, the Fourth Affiliated Hospital of Medical College, Jinan University, Guangzhou, 510220, China. dr.yang1192@yahoo.com.

ABSTRACT

Introduction: Structural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.

Methods: Histological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone-cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.

Results: We uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone-cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.

Conclusions: Our data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.

No MeSH data available.


Related in: MedlinePlus

Histological examination of safranin O staining and polarized light microscopy analysis of cartilage from protein kinase C delta (PKC-δ)+/+ and PKC-δ−/− mice. a, d Representative images of articular cartilage stained with safranin O (50×). b, e Higher magnification images of dashed square area of images a and d respectively (200×). c, f Polarized images of direct red stained articular cartilage of the approximate location of b and e, respectively
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Fig1: Histological examination of safranin O staining and polarized light microscopy analysis of cartilage from protein kinase C delta (PKC-δ)+/+ and PKC-δ−/− mice. a, d Representative images of articular cartilage stained with safranin O (50×). b, e Higher magnification images of dashed square area of images a and d respectively (200×). c, f Polarized images of direct red stained articular cartilage of the approximate location of b and e, respectively

Mentions: Using histology with safranin O staining, we first observed a decreased safranin O staining in the articular cartilage surface in PKC-δ KO mice (Fig. 1d,e) as compared to WT mice (Fig. 1a,b). Interestingly, we also observed a thickening of articular cartilage and calcified bone–cartilage interface in the PKC-δ KO mice (Fig. 1d,e) as compared to those from WT mice (Fig. 1a,b). The thickening of articular cartilage and calcified bone–cartilage interface was further confirmed using polarized imaging in the PKC-δ KO mice (Fig. 1f) as compared to WT mice (Fig. 1c). In addition, the polarized image stained with direct red revealed an irregular articular cartilage surface in PKC-δ KO mice, with all layers of chondrocytes exhibiting disorganization, uneven size and lack of normal hierarchy (Fig. 1f), as compared to the articular cartilage surface in WT mice (Fig. 1c).Fig. 1


Protein kinase C delta mice exhibit structural alterations in articular surface, intra-articular and subchondral compartments.

Yang X, Teguh D, Wu JP, He B, Kirk TB, Qin S, Li S, Chen H, Xue W, Ng B, Chim SM, Tickner J, Xu J - Arthritis Res. Ther. (2015)

Histological examination of safranin O staining and polarized light microscopy analysis of cartilage from protein kinase C delta (PKC-δ)+/+ and PKC-δ−/− mice. a, d Representative images of articular cartilage stained with safranin O (50×). b, e Higher magnification images of dashed square area of images a and d respectively (200×). c, f Polarized images of direct red stained articular cartilage of the approximate location of b and e, respectively
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4538913&req=5

Fig1: Histological examination of safranin O staining and polarized light microscopy analysis of cartilage from protein kinase C delta (PKC-δ)+/+ and PKC-δ−/− mice. a, d Representative images of articular cartilage stained with safranin O (50×). b, e Higher magnification images of dashed square area of images a and d respectively (200×). c, f Polarized images of direct red stained articular cartilage of the approximate location of b and e, respectively
Mentions: Using histology with safranin O staining, we first observed a decreased safranin O staining in the articular cartilage surface in PKC-δ KO mice (Fig. 1d,e) as compared to WT mice (Fig. 1a,b). Interestingly, we also observed a thickening of articular cartilage and calcified bone–cartilage interface in the PKC-δ KO mice (Fig. 1d,e) as compared to those from WT mice (Fig. 1a,b). The thickening of articular cartilage and calcified bone–cartilage interface was further confirmed using polarized imaging in the PKC-δ KO mice (Fig. 1f) as compared to WT mice (Fig. 1c). In addition, the polarized image stained with direct red revealed an irregular articular cartilage surface in PKC-δ KO mice, with all layers of chondrocytes exhibiting disorganization, uneven size and lack of normal hierarchy (Fig. 1f), as compared to the articular cartilage surface in WT mice (Fig. 1c).Fig. 1

Bottom Line: Structural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population.The morphology and organization of chondrocytes were studied using confocal microscopy.Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement.

View Article: PubMed Central - PubMed

Affiliation: Guangzhou Institute of Traumatic Surgery, the Fourth Affiliated Hospital of Medical College, Jinan University, Guangzhou, 510220, China. dr.yang1192@yahoo.com.

ABSTRACT

Introduction: Structural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.

Methods: Histological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone-cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.

Results: We uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone-cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.

Conclusions: Our data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.

No MeSH data available.


Related in: MedlinePlus