title: Induced superficial chondrocyte death reduces catabolic cartilage damage in murine posttraumatic osteoarthritis.
abstract: Joints that have degenerated as a result of aging or injury contain dead chondrocytes and damaged cartilage. Some studies have suggested that chondrocyte death precedes cartilage damage, but how the loss of chondrocytes affects cartilage integrity is not clear. In this study, we examined whether chondrocyte death undermines cartilage integrity in aging and injury using a rapid 3D confocal cartilage imaging technique coupled with standard histology. We induced autonomous expression of diphtheria toxin to kill articular surface chondrocytes in mice and determined that chondrocyte death did not lead to cartilage damage. Moreover, cartilage damage after surgical destabilization of the medial meniscus of the knee was increased in mice with intact chondrocytes compared with animals whose chondrocytes had been killed, suggesting that chondrocyte death does not drive cartilage damage in response to injury. These data imply that chondrocyte catabolism, not death, contributes to articular cartilage damage following injury. Therefore, therapies targeted at reducing the catabolic phenotype may protect against degenerative joint disease.
authors.forename: Minjie
authors.initials: M
authors.lastname: Zhang
authors.forename: Sriniwasan B
authors.initials: SB
authors.lastname: Mani
authors.forename: Yao
authors.initials: Y
authors.lastname: He
authors.forename: Amber M
authors.initials: AM
authors.lastname: Hall
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.forename: Yefu
authors.initials: Y
authors.lastname: Li
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Jay
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Warman
mesh_terms: D000375:Aging; D000818:Animals; D002356:Cartilage / Q000293:injuries / Q000473:pathology*; D002358:Cartilage, Articular / Q000378:metabolism; D019902:Chondrocytes / Q000166:cytology* / Q000473:pathology; D004195:Disease Models, Animal; D021621:Imaging, Three-Dimensional; D007592:Joint Diseases / Q000473:pathology*; D007719:Knee Joint; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D010003:Osteoarthritis / Q000209:etiology* / Q000473:pathology*