p21 Mice Exhibit Spontaneous Articular Cartilage Regeneration Post-Injury.

Objective: Recent studies have implicated the cyclin dependent kinase inhibitor, p21, in enhanced tissue regeneration observed in MRL/MpJ "super-healer" mice. Specifically, p21 is downregulated in MRL cells and similar ear hole closure to MRL mice has been observed in p21 mice. However, the direct implications of p21 deletion in endogenous articular cartilage regeneration remain unknown.

CCL2 But Not CCR2 Is Required for Spontaneous Articular Cartilage Regeneration Post-Injury.

The role of the inflammatory response in articular cartilage degeneration and/or repair is often debated. Chemokine networks play a critical role in directing the recruitment of immune cells to sites of injury and have been shown to regulate cell behavior. In this study, we investigated the role of the CCL2/CCR2 signaling axis in cartilage regeneration and degeneration.

Integrin α1β1 participates in chondrocyte transduction of osmotic stress.

Background/purpose: The goal of this study was to determine the role of the collagen binding receptor integrin α1β1 in regulating osmotically induced [Ca(2+)]i transients in chondrocytes.

Method: The [Ca(2+)]i transient response of chondrocytes to osmotic stress was measured using real-time confocal microscopy. Chondrocytes from wildtype and integrin α1-null mice were imaged ex vivo (in the cartilage of intact murine femora) and in vitro (isolated from the matrix, attached to glass coverslips).