Bone Development and Gene Regulation in Transgenic Models

Bone formation and maintenance depend on the coordinated activity of osteoblasts, osteoclasts and osteocytes, whose differentiation and function are governed by tightly regulated gene networks. Transgenic models, chiefly in mice, have revolutionised our understanding of these processes by enabling tissue-specific gene manipulation, lineage tracing and temporal control of gene expression. Conditional knockouts and knock-ins, often implemented via Cre-loxP or CRISPR/Cas systems, dissect the roles of transcription factors, signalling pathways and extracellular factors in osteogenesis, mineralisation and remodelling. Key regulators include Runx2 and Osterix in osteoblast commitment, RANKL in osteoclastogenesis, and mechanosensitive molecules in osteocyte maturation. Insights from transgenic studies have elucidated how imbalances in gene regulation contribute to osteoporosis, fracture healing deficits and inflammatory bone loss, and have highlighted potential therapeutic targets to restore skeletal health.

Research from Nature Portfolio

Recent studies have demonstrated that osteocytes play a direct role in inflammatory bone destruction. Using transgenic mice with osteocyte-specific deletion and restoration of the MYD88 adaptor protein, researchers have shown that bacterial pathogen-associated molecular patterns trigger osteocyte MYD88 signalling to up-regulate RANKL via enhanced CREB and STAT3 activity. Mice lacking MYD88 in osteocytes are protected from calvarial and jawbone resorption, whereas selective MYD88 restoration reinstates osteolysis and inflammatory infiltration. Systemic inhibition of MYD88 in these models prevents bone loss in periodontitis, revealing osteocyte-centric gene regulation as a promising therapeutic avenue.

Bone Development and Gene Regulation in Transgenic Models publication trend

The graph below shows the total number of articles in bone development and gene regulation in transgenic models across all publications each year (not limited to Nature Index journals).

Technical terms

Cre-loxP system: A genetic tool that uses Cre recombinase to excise or invert DNA between loxP sites, enabling tissue-specific gene alteration.

Conditional knockout: Targeted gene deletion in a defined cell type or developmental stage, often using Cre drivers under cell-specific promoters.

Osteoblast: A bone-forming cell responsible for synthesising and mineralising extracellular matrix.

Osteocyte: A mature bone cell embedded within mineralised matrix that senses mechanical forces and regulates remodelling.

RANKL: Receptor activator of nuclear factor κB ligand, a cytokine secreted by osteoblasts and osteocytes that drives osteoclast differentiation and activation.

References

1. Osteocytes directly regulate osteolysis via MYD88 signaling in bacterial bone infection. Nature Communications (2022).
2. The Past, Present, and Future of Genetically Engineered Mouse Models for Skeletal Biology. Biomolecules (2023).
3. Cell Transitions Contribute to Glucocorticoid-Induced Bone Loss. Cells (2023).
4. The role of Clec11a in bone construction and remodeling. Frontiers in Endocrinology (2024).