TY - JOUR
T1 - Addition of heparin binding sites strongly increases the bone forming capabilities of BMP9 in vivo
AU - Siverino, Claudia
AU - Fahmy-Garcia, Shorouk
AU - Niklaus, Viktoria
AU - Kops, Nicole
AU - Dolcini, Laura
AU - Misciagna, Massimiliano Maraglino
AU - Ridwan, Yanto
AU - Farrell, Eric
AU - van Osch, Gerjo J.V.M.
AU - Nickel, Joachim
PY - 2023
Y1 - 2023
N2 - Bone Morphogenetic proteins (BMPs) like BMP2 and BMP7 have shown great potential in the treatment of severe bone defects. In recent in vitro studies, BMP9 revealed the highest osteogenic potential compared to other BMPs, possibly due to its unique signaling pathways that differs from other osteogenic BMPs. However, in vivo the bone forming capacity of BMP9-adsorbed scaffolds is not superior to BMP2 or BMP7. In silico analysis of the BMP9 protein sequence revealed that BMP9, in contrast to other osteogenic BMPs such as BMP2, completely lacks so-called heparin binding motifs that enable extracellular matrix (ECM) interactions which in general might be essential for the BMPs' osteogenic function. Therefore, we genetically engineered a new BMP9 variant by adding BMP2-derived heparin binding motifs to the N-terminal segment of BMP9′s mature part. The resulting protein (BMP9 HB) showed higher heparin binding affinity than BMP2, similar osteogenic activity in vitro and comparable binding affinities to BMPR-II and ALK1 compared to BMP9. However, remarkable differences were observed when BMP9 HB was adsorbed to collagen scaffolds and implanted subcutaneously in the dorsum of rats, showing a consistent and significant increase in bone volume and density compared to BMP2 and BMP9. Even at 10-fold lower BMP9 HB doses bone tissue formation was observed. This innovative approach of significantly enhancing the osteogenic properties of BMP9 simply by addition of ECM binding motifs, could constitute a valuable replacement to the commonly used BMPs. The possibility to use lower protein doses demonstrates BMP9 HB's high translational potential.
AB - Bone Morphogenetic proteins (BMPs) like BMP2 and BMP7 have shown great potential in the treatment of severe bone defects. In recent in vitro studies, BMP9 revealed the highest osteogenic potential compared to other BMPs, possibly due to its unique signaling pathways that differs from other osteogenic BMPs. However, in vivo the bone forming capacity of BMP9-adsorbed scaffolds is not superior to BMP2 or BMP7. In silico analysis of the BMP9 protein sequence revealed that BMP9, in contrast to other osteogenic BMPs such as BMP2, completely lacks so-called heparin binding motifs that enable extracellular matrix (ECM) interactions which in general might be essential for the BMPs' osteogenic function. Therefore, we genetically engineered a new BMP9 variant by adding BMP2-derived heparin binding motifs to the N-terminal segment of BMP9′s mature part. The resulting protein (BMP9 HB) showed higher heparin binding affinity than BMP2, similar osteogenic activity in vitro and comparable binding affinities to BMPR-II and ALK1 compared to BMP9. However, remarkable differences were observed when BMP9 HB was adsorbed to collagen scaffolds and implanted subcutaneously in the dorsum of rats, showing a consistent and significant increase in bone volume and density compared to BMP2 and BMP9. Even at 10-fold lower BMP9 HB doses bone tissue formation was observed. This innovative approach of significantly enhancing the osteogenic properties of BMP9 simply by addition of ECM binding motifs, could constitute a valuable replacement to the commonly used BMPs. The possibility to use lower protein doses demonstrates BMP9 HB's high translational potential.
KW - Bone morphogenetic protein 9 (BMP9)
KW - Bone regeneration
KW - Heparin binding sites
KW - Subcutaneous animal model
UR - http://www.scopus.com/inward/record.url?scp=85165094293&partnerID=8YFLogxK
U2 - 10.1016/j.bioactmat.2023.07.010
DO - 10.1016/j.bioactmat.2023.07.010
M3 - Article
AN - SCOPUS:85165094293
SN - 2452-199X
VL - 29
SP - 241
EP - 250
JO - Bioactive Materials
JF - Bioactive Materials
ER -