# SATB2 promotes humeral fracture healing in rats by activating the PI3K/AKT pathway

## TL;DR

This study shows that SATB2 helps heal humeral fractures in rats by boosting the PI3K/AKT pathway, which supports bone repair.

## Contribution

The study demonstrates that SATB2 promotes fracture healing by activating the PI3K/AKT pathway in rats.

## Key findings

- SATB2 overexpression repaired humeral fractures and restored bone continuity in rats.
- SATB2 inhibits osteoclast activity and promotes osteoblast function by modulating key biomarkers.
- Activation of the PI3K/AKT pathway is essential for the bone-healing effects of SATB2.

## Abstract

The purpose of this study was to explore the potential mechanism of SATB2 and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway promoting fracture healing in vivo. An SD model of humeral fracture in rats was established and treated. Following a 6-week treatment period, the morphology of the fracture was assessed. Serum interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), osteocalcin, C-telopeptide of type I collagen (CTX-I), and bone morphogenetic protein 2 (BMP-2) were determined. Alkaline phosphatase (ALP), receptor activator of nuclear factor-kappa B ligand (RANKL), osteoprotegerin (OPG), and other relevant molecules such as PI3K and p-AKT were measured. The results showed that SATB2 overexpression repaired humeral fracture and bone continuity. SATB2 overexpression resulted in a significant reduction in RANKL, IL-6, TNF-α, and CTX-I expression, while simultaneously increasing OPG, ALP, osteocalcin, and BMP-2. This indicates that SATB2 inhibits osteoclast activity and promotes osteoblast function. Additionally, SATB2 overexpression increased PI3K and p-AKT protein expression in humerus. Furthermore, the inhibitory effect of the PI3K/AKT inhibitor on PI3K and p-AKT protein expression was counterbalanced by upregulating SATB2. In conclusion, SATB2 promotes fracture healing in humeral fracture rats by stimulating the proliferation and differentiation of osteoblasts, which is related to the activation of PI3K/AKT signaling pathway.