BMPR1A is necessary for chondrogenesis and osteogenesis, whereas BMPR1B prevents hypertrophic differentiation.

BMP2 stimulates bone formation and signals preferably through BMP receptor (BMPR) 1A, whereas GDF5 is a cartilage inducer and signals preferably through BMPR1B. Consequently, BMPR1A and BMPR1B are believed to be involved in bone and cartilage formation, respectively. However, their function is not yet fully clarified.

The GDF-5 mutant M1673 exerts robust anabolic and anti-catabolic effects in chondrocytes.

The growth and differentiation factor 5 (GDF-5) is known to play a key role in cartilage morphogenesis and homeostasis, and a single-nucleotide polymorphism in its promoter sequence was found to be associated with osteoarthritis (OA). In addition, GDF-5 was shown to promote extracellular matrix (ECM) production in healthy chondrocytes, to stimulate chondrogenesis of mesenchymal stem cells (MSCs) and to protect against OA progression in vivo. Therefore, GDF-5 appears to be a promising treatment for osteoarthritis.

Short-time pre-washing of brushite-forming calcium phosphate cement improves its in vitro cytocompatibility.

A pre-washing protocol was developed for resorbable, brushite-forming calcium phosphate cements (CPCs) to avoid harmful in vitro effects on cells. CPC discs (JectOS+, Kasios; self-developed CPC) were pre-washed with repeated changes of phosphate-buffered saline (PBS; 24h total). Unwashed or PBS-pre-washed discs were incubated in culture medium (5% fetal calf serum; up to 10days) and then tested for their influence on pH/calcium/phosphate levels in HO extracts.

Enhanced reconstruction of long bone architecture by a growth factor mutant combining positive features of GDF-5 and BMP-2.

Non healing bone defects remain a worldwide health problem and still only few osteoinductive growth factors are available for clinical use in bone regeneration. By introducing BMP-2 residues into growth and differentiation factor (GDF)-5 we recently produced a mutant GDF-5 protein BB-1 which enhanced heterotopic bone formation in mice. Designed to combine positive features of GDF-5 and BMP-2, we suspected that this new growth factor variant may improve long bone healing compared to the parent molecules and intended to unravel functional mechanisms behind its action.

New insights into the molecular mechanism of multiple synostoses syndrome (SYNS): mutation within the GDF5 knuckle epitope causes noggin-resistance.

Growth and differentiation factor 5 (GDF5), a member of the bone morphogenetic protein (BMP) family, is essential for cartilage, bone, and joint formation. Antagonists such as noggin counteract BMP signaling by covering the ligand's BMP type I (BMPRI) and type II (BMPRII, ActRII, ActRIIB) interaction sites. The mutation GDF5-S94N is located within the BMPRII interaction site, the so-called knuckle epitope, and was identified in patients suffering from multiple synostoses syndrome (SYNS).