Serum MicroRNA Differences Between Fracture in Postmenopausal Women with and without Diabetes.

OBJECTIVE

To screen serum microRNAs (miRNAs) which could discriminate fracture status in postmenopausal women with or without diabetes.

METHODS

The miRNA expression profile dataset GSE70318 was downloaded from Gene Expression Omnibus (GEO) database. This dataset composed of 74 samples, among these, 55 postmenopausal women was selected for bioinformatics analysis, including 19 osteoporotic fracture patients with type-2 diabetes, 19 osteoporotic fracture patients without type-2 diabetes, and 17 healthy control subjects. These samples were divided into two groups: fracture patients with diabetes vs healthy subjects (FH group) and fracture patients without diabetes vs healthy subjects (DFH group). Then, the differentially expressed miRNA (DEMs) in FH group and DFH group were respectively identified. The target genes of DEMs were predicted, followed by functional enrichment analysis. Furthermore, DEMs related to long non-coding RNAs (lncRNAs) were screened, and DEMs-lncRNA-target genes network was constructed. Subsequently, principal component analysis (PCA) of DEMs was performed to further explore the expression characteristics of the selected miRNAs in different types of fracture samples. Finally, the expression level of significant DEMs was calculated by quantitative real-time polymerase chain reaction (qPCR) to verify the accuracy of the results of bioinformatics analysis.

RESULTS

A total of 18 and 23 DEMs were identified in FH and DFH groups, respectively. Gene ontology (GO) analysis showed that genes in FH group were significantly enriched in regulation of transcription (GO: 0045449) and genes in DFH group were mainly enriched in cellular response to hormone stimulus (GO: 0032870). Meanwhile, pathway analysis indicated that genes in FH group were primarily enriched in T cell receptor signaling pathway (hsa04660) and genes in DFH group were mainly implicated in neurotrophin-signaling pathway (hsa04722). Moreover, the miRNA-lncRNA analysis revealed that miR-155-5p regulated by lncRNA MIR155HG was up-regulated in FH group; in addition, the miR-181c was significantly up-regulated and miR-375 was observably down-regulated in DFH group. Furthermore, PCA analysis suggested that the screened miRNAs were able to differentiate these two types of fractures in postmenopausal women. The miR-181c and miR-375 might be regarded as potential predictors for fracture, while miR-155-5p might be a candidate diagnostic biomarker for diabetic fracture. Finally, the results of qPCR were consistent with that of microarray data.

CONCLUSIONS

Overall, these three miRNAs might be regarded as potential diagnostic biomarkers to discriminate fracture status in postmenopausal women with and or without diabetes, and they served a putative role in the pathogenesis of these two diseases. However, these findings were only observed in serum samples and further clinical trials are urgently demanded to validate our results.