STAT3 is critical for skeletal development and bone homeostasis by regulating osteogenesis

Autosomal dominant hyper-immunoglobulin E syndrome (AD-HIES) is associated with mutations in STAT3, and clinical manifestations include skeletal deformities. Here, the authors show that inactivation of STAT3 in osteoblast induces AD-HIES-like skeletal defects by impairing osteogenesis, and show that pharmacological STAT3 activation rescues the phenotype. Skeletal deformities are typical AD-HIES manifestations, which are mainly caused by heterozygous and loss-of-function mutations in Signal transducer and activator of transcription 3 (STAT3). However, the mechanism is still unclear and the treatment strategy is limited. Herein, we reported that the mice with Stat3 deletion in osteoblasts, but not in osteoclasts, induced AD-HIES-like skeletal defects, including craniofacial malformation, osteoporosis, and spontaneous bone fracture. Mechanistic analyses revealed that STAT3 in cooperation with Msh homeobox 1(MSX1) drove osteoblast differentiation by promoting Distal-less homeobox 5(Dlx5) transcription. Furthermore, pharmacological activation of STAT3 partially rescued skeletal deformities in heterozygous knockout mice, while inhibition of STAT3 aggravated bone loss. Taken together, these data show that STAT3 is critical for modulating skeletal development and maintaining bone homeostasis through STAT3-indcued osteogenesis and suggest it may be a potential target for treatments.

Automated summary

The study found that inactivation of STAT3 in osteoblasts can induce AD-HIES-like skeletal defects, while pharmacological activation of STAT3 can rescue this phenotype. STAT3 cooperates with MSX1 to drive osteoblast differentiation, indicating the importance of STAT3 in modulating skeletal development and maintaining bone homeostasis.