The regulation of sclerostin by cathepsin K in periodontal ligament cells.

Sclerostin is a clinically important protein with key functions in the musculoskeletal system playing a key role in bone formation and remodelling. Whilst a wide range of mechanisms have been identified which regulate sclerostin expression, little is known about the degradation of the protein. The aim of this study was to identify enzymes capable of degrading sclerostin in peridontal ligament (PDL) fibroblasts cells in vitro and to investigate the functionality of these enzymes.

Ionic solutes impact collagen scaffold bioactivity.

The structure of ice-templated collagen scaffolds is sensitive to many factors. By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen.

The effects of scaffold architecture and fibrin gel addition on tendon cell phenotype.

Development of tissue engineering scaffolds relies on careful selection of pore architecture and chemistry of the cellular environment. Repair of skeletal soft tissue, such as tendon, is particularly challenging, since these tissues have a relatively poor healing response. When removed from their native environment, tendon cells (tenocytes) lose their characteristic morphology and the expression of phenotypic markers.

Type II collagen deposition in cruciate ligament precedes osteoarthritis in the guinea pig knee.

Objective: To examine the collagens in cruciate ligaments of young Dunkin-Hartley guinea pigs, to determine whether a change in specific collagen types is an early feature of the spontaneous osteoarthritis (OA), which consistently develops in the medial compartment of the knee in this strain.

Design: Collagen types I, II, III, IX, and XI were detected by immunofluorescence microscopy in the anterior and posterior cruciate ligaments of animals at 3, 4-5 and 12 weeks of age. Type II collagen in PCL was further analysed by confocal microscopy or biochemical assay after cyanogen bromide digestion, SDS-PAGE and immunoblotting.

Up-regulation of matrix metalloproteinase expression and activation following cyclical compressive loading of articular cartilage in vitro.

Osteoarthritis (OA) results in articular cartilage degeneration and subchondral bone remodeling. Excessive or abnormal loading of the joint may contribute to matrix destruction by creating an imbalance between proteinases and their inhibitors. This study investigates whether cyclical loading regulates expression and/or activation of metalloproteinases 2 and 9 (MMPs) in articular cartilage explants.