Targeting BMP2 signaling pathway in osteogenesis and osteoarthritis: A path toward safer regenerative therapies.

Various signaling pathways are linked with osteogenesis and osteoarthritis progression. Bone Morphogenetic Protein 2 (BMP2), a key regulator within the TGF-β superfamily, is central to skeletal development through its ability to guide mesenchymal stem cells (MSCs) toward osteogenic and chondrogenic lineages. By activating canonical SMAD1/5/8 cascades alongside non-canonical MAPK branches (ERK, p38, JNK), BMP2 enhances transcriptional programs such as Runx2, thereby stimulating extracellular matrix synthesis, bone regeneration, and cartilage differentiation. Recombinant BMP2 (rhBMP2) has thus found clinical utility in spinal fusion and fracture repair. Yet its therapeutic translation is hindered by its paradoxical biology. Beyond regeneration, BMP2 provokes inflammatory signaling, upregulating cytokines like IL-6 and TNF-α, while driving catabolic enzymes (MMPs, ADAMTS) that degrade cartilage and intensify synovial inflammation, hallmarks of osteoarthritis (OA) progression. To address these limitations, current strategies emphasize fine-tuned regulation of BMP2 activity rather than broad stimulation. Emerging approaches include endogenous antagonists (Noggin, Gremlin), receptor decoys, selective BMPR1 blockade, spatiotemporally controlled delivery systems, and combinatorial use with stem cell or anti-inflammatory therapies. Such precision-based modulation aims to preserve BMP2's regenerative properties while suppressing its pathological consequences. Therefore, a deeper understanding of BMP2 signaling dynamics in joint biology is essential for unlocking safe therapeutic potential in OA management.