Mx1-cre mediated Rgs12 conditional knockout mice exhibit increased bone mass phenotype

Area of Science:

• Molecular Biology
• Cell Biology
• Physiology

Background:

• Regulators of G-protein Signaling (Rgs) proteins are GTPase-accelerating proteins crucial for G protein-coupled receptor (GPCR) signaling.
• Rgs proteins are implicated in various diseases, including cancer, cardiovascular conditions, and inflammation.
• Rgs12, the largest Rgs protein, has known in vitro roles in cell differentiation and migration, but its in vivo function remains largely uncharacterized.

Purpose of the Study:

• To investigate the in vivo function and mechanism of Rgs12.
• To generate a conditional knockout mouse model for Rgs12 to enable time- and cell-specific deletion.

Main Methods:

• Generation of a floxed Rgs12 allele (Rgs12(flox/flox)) with loxp sites flanking exon 2.
• Inducible deletion of Rgs12 in interferon-responsive cells (monocytes, macrophages) using the Mx1-cre and Poly I:C system at postnatal day 10.
• Phenotypic analysis of Rgs12 mutant mice, including growth, bone mass, osteoclast, and osteoblast assessments.

Main Results:

• Rgs12 mutant mice exhibited growth retardation and increased bone mass.
• Deletion of Rgs12 led to a significant reduction in osteoclast numbers.
• Osteoblast formation was not significantly affected by Rgs12 deletion.

Conclusions:

• Rgs12 plays a critical role in regulating bone metabolism, specifically by influencing osteoclast formation.
• The generated Rgs12(flox/flox) conditional mice are a valuable tool for future in vivo studies of Rgs12 function.
• This research opens avenues for understanding Rgs12's role in physiological processes and disease states involving bone homeostasis.