Osteoporosis is characterized by low bone mass, increased bone fragility, and elevated fracture susceptibility, affecting approximately one-third of postmenopausal women. The study notes that estrogen deficiency induces aberrant upregulation of microRNA (miRNA) expression. The 3'UTR of mRNAs can bind to and sequester target miRNAs, a process that the researchers aimed to exploit to identify target genes capable of inhibiting these miRNAs in PMOP.

The research team screened for candidate differentially expressed microRNAs by analyzing sequencing data from the whole blood and serum of PMOP patients. These candidates were subsequently validated in the serum of PMOP patients, as well as in the serum and bone tissue of ovariectomized (OVX) mice. Validation also extended to mouse osteoblasts and osteoclasts to ensure the findings were consistent across different biological contexts.

Through cross-validation, the researchers identified miR-144-5p and miR-532-5p as highly expressed in the serum of PMOP patients, the serum and bone tissue of OVX mice, and mouse osteoblasts. The common target gene for these two microRNAs was identified as CHD9. Argonaute 2 RNA immunoprecipitation (AGO2-RIP) assays were carried out to detect competing endogenous RNA (ceRNA) binding at the cellular level, supporting the interaction between the microRNAs and their target.

Luciferase reporter assays were performed to verify the specific binding sites between the candidate microRNAs and the CHD9 3'UTR. The assays confirmed that the p233-239 region within the CHD9 3'UTR is the specific binding site for miR-144-5p, while the p721-727 region is the binding site for miR-532-5p. In mouse osteoblasts, CHD9 positively regulates the expression of runt-related transcription factor 2 (RUNX2).

The study found that CHD9 achieves this by binding to the -450 to -400 region of the RUNX2 promoter. In vivo therapeutic animal experiments were implemented to test the efficacy of this mechanism. The results demonstrated that the CHD9 3'UTR ameliorates ovariectomy-induced osteoporotic phenotypes in mice.

The study highlights the role of the 3'UTR in regulating gene expression through microRNA sequestration. The findings are based on preclinical evidence from human patient samples and mouse models. While the study provides a clear mechanism for how the CHD9 3'UTR protects against osteoporosis in animal models, it does not establish clinical efficacy in humans.

Subject of Research: Molecular mechanism of CHD9 3'UTR in regulating microRNAs to protect against menopause-induced osteoporosis in preclinical models

Article Title: The 3’UTR protects bone against menopause-induced osteoporosis via regulating CHD9 expression

Article References: Zhang, Y., Huang, S., Guo, Z., Guo, X., Shen, T., & Shang, H. (2026). The 3’UTR protects bone against menopause-induced osteoporosis via regulating CHD9 expression. Scientific Reports. https://doi.org/10.1038/s41598-026-76413-z

Image Credits: AI Generated

DOI: 10.1038/s41598-026-76413-z

Keywords: osteoporosis, CHD9, 3'UTR, microRNA, miR-144-5p, miR-532-5p, RUNX2, postmenopausal, bone biology, ovariectomized mice, protects, bone