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Gαi1/3 Are Essential for BMP2-Induced Osteogenesis by Bridging BMP Receptors to the Gab1 Signaling Complex
Huajian Shan1,2, Chaowen Bai1,2, Yifei Zhu1,3
1Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
|August 10, 2026
Summary
The G protein subunit alpha i1/3 (Gαi1/3) is crucial for bone formation and repair. Its deficiency impairs bone development and healing, highlighting the Gαi1/3-Gab1 axis as a therapeutic target for osteoporosis.
Area of Science:
- Bone Biology and Skeletal Development
- Cell Signaling Pathways
- Molecular Medicine
Background:
- Bone morphogenetic protein 2 (BMP2) is vital for skeletal homeostasis and repair.
- G protein subunit alpha i1/3 (Gαi1/3) mediates G protein-coupled receptor and tyrosine kinase receptor signaling.
- The role of Gαi1/3 in BMP2 signaling and bone formation was previously unknown.
Purpose of the Study:
- To investigate the role of Gαi1/3 in BMP2 signaling and osteogenesis.
- To determine the impact of Gαi1/3 deficiency on skeletal development and bone repair.
- To elucidate the molecular mechanism of Gαi1/3 in BMP2-mediated bone formation.
Main Methods:
- Analysis of Gαi1/3 expression in osteoporotic bone tissue.
- Generation and analysis of Gαi1/3 double knockout mice and conditional knockout mice.
- Assessment of BMP2 signaling and osteogenesis in bone marrow-derived mesenchymal stem cells (BMSCs) with altered Gαi1/3 levels.
- Evaluation of fracture healing in a femoral fracture model with Gαi1/3 knockdown in BMSCs.
- Investigation of the interaction between Gαi1/3, BMP2 receptor, and Gab1.
Main Results:
- Gαi1/3 expression is downregulated in senile osteoporosis.
- Gαi1/3 deficiency in mice leads to delayed skeletal development and reduced bone mass.
- Gαi1/3 is essential for BMP2-induced osteogenesis in BMSCs; its absence impairs BMP2 downstream signaling.
- Knockdown of Gαi1/3 hinders BMP2-mediated fracture healing.
- Gαi1/3 interacts with the BMP2 receptor and Gab1 to facilitate BMP2 signaling.
Conclusions:
- The Gαi1/3-Gab1 axis is critical for BMP2 signaling and osteogenesis.
- Gαi1/3 plays a pivotal role in skeletal development, bone homeostasis, and fracture repair.
- Targeting the Gαi1/3-Gab1 pathway offers potential therapeutic strategies for osteoporosis and bone regeneration.
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