Our previous study and other related studies have shown that SPA can affect the osteogenic differentiation of BMSCs. In this study, bioinformatic analysis of transcriptome sequencing data revealed that the osteogenic differentiation of BMSCs under the effect of SPA did caused differential expression of molecular markers Cenpf, Kntc1, Nek2, Asf1b, Troap and Kif14. And these molecular biomarkers formed a network of interactions with nRNA. There were few studies on this aspect.
Kinetochore associated 1(Kntc1) encoded a protein that was one of many involved in mechanisms to ensure proper chromosome segregation during cell division. The functional enrichment analysis showed that Kntc1 was mainly related to the ‘autophagosome’ and ‘Pyrimidine metabolism’. Recent studies suggested that mitogenic proteins might be potential biomarkers and might contribute to the development of human malignancies (16). It was often associated with tumors of the digestive and genitourinary systems (17). It has been shown that Kntc1 was highly expressed in hepatocellular carcinoma (HCC) tissues and was associated with poor prognosis, suggesting a key role for Kntc1 in HCC development (18). Wnt pathway, MAPK pathway, c-Jun NH2-terminal kinase (JNK) pathway, PI3K/Akt pathway, Hedgehog signaling and other pathways are closely related to osteogenic differentiation (19–21). Kntc1 has been reported to function in a variety of diseases by participating in the PI3K/Akt signaling pathway (18), and we speculated that it may also be involved in the regulation of osteogenic differentiation in BMSCs. Centromere protein F (Cenpf) was a protein coding gene. The functional enrichment analysis showed that Cenpf was mainly enriched in the ‘regulation of autophagy’ and ‘Lysosome’. Over-expression of Cenpf was associated with tumorigenesis of many human malignant tumors (22–24). Moreover, Cenpf was a cancer stem cell (CSCs)-specific marker gene, and the latter played a key role in promoting bone destruction (25). Cenpf has a close relationship with MAPK (26, 27) and Wnt pathway (28). Antisilencing function 1b (Asf1b) had effects on cell proliferation, leading to abnormal nuclear structure and unique transcriptional features (29) and was often associated with various malignancies (30, 31). According to the functional enrichment analysis, Asf1b was mainly enriched in the ‘process utilizing autophagic mechanism’ and ‘biosynthesis of nucleotide sugars’. Furthermore, several studies have shown that Asf1b played an important role in the PI3K/Akt signaling pathway (32–34). Never in mitosis gene A-related kinase 2 (Nek2) was highly associated with drug resistance, rapid recurrence and poor outcome in a variety of cancers (35). The functional enrichment analysis showed that Nek2 was mainly related to the ‘autophagosome’ and ‘pyrimidine metabolism’. It had been shown that the over-expression of Nek2 was associated with the development of bone damage (36) and that it regulated osteoblast gene expression and affected osteoblast growth and activity (37). In addition, Nek2 induced osteoclast differentiation and bone destruction via heparanase in multiple myeloma (38). Nek2 has been reported to plays an important regulatory role in MAPK (39, 40), Wnt/β-Catenin pathway (41–43), PI3K/Akt pathway (44), and other pathways. Experimental evidence suggested that troponin-associated protein (Troap) played a key role in regulating cell proliferation in multiple tumors (45, 46). One study found that Troap accelerates glioma progression through the Wnt/β-Catenin pathway (45). Finally, Kinesin family member 14 (Kif14) was a mitotic kinesin whose abnormal function was associated with developmental defects in the brain and kidney as well as multiple cancers (47). The The functional enrichment analysis showed that Kif14 was mainly enriched in the ‘macroautophagy’ and ‘pyrimidine metabolism’. Moreover, Kif14 was also active in signaling pathways such as Wnt pathway (48, 49), Hedgehog signaling (50, 51) and PI3K/Akt pathway (52). Currently, there were no studies on the direct involvement of the above biomarkers in the osteogenic differentiation of MSCs. In conclusion, combining the current literature and the results of the present study, we suggest that Cenpf, Kntc1, Nek2, Asf1b, Troap and Kif14 might be involved in the regulation of osteogenic differentiation of BMCSs under the action of SPA.
Currently, studies on the regulation of osteogenic differentiation of BMSCs by non-coding RNAs had been reported. However, there were few studies on the regulation of osteogenic differentiation of BMSCs by non-coding RNAs in SPA mimicking inflammatory environment. From the lncRNA-miRNA-mRNA network in this study, it could be found that miR-497-5p and miR-322-5p had an action relationship with both Asf1b and Nek2. And one study showed that miR-497-5p was significantly down-regulated in bone tissue of aging and osteoporosis mouse models and up-regulated during osteogenic differentiation of MC3T3-E1 cells. The miR-497-5p over-expression promoted osteoblast differentiation and mineralization (53). In addition, one study showed that miR-322-5p was significantly down-regulated during osteogenic differentiation of rat bone marrow mesenchymal stem cells (54). Secondly, it had been shown that miR-455-3p could promote osteogenic differentiation, which might be related to fracture healing (55), while the present study found a regulatory relationship between miR-455-3p and Troap. Finally, miR-207 was significantly down-regulated during FK506-induced osteogenic differentiation of rat bone marrow mesenchymal stem cells, while the present study showed an association between miR-207 and Nek2 (56). In conclusion, the present study identified some potential molecular networks of action, and the potential significance of which was to be clarified by further studies.
Bioinformatics had been widely used for differential analysis of osteogenic differentiation at the genomic level, allowing the identification of functional pathways of differentially expressed genes (DEGs) associated with osteogenic differentiation in BMSC. In this study, bioinformatic analysis was performed to obtain some key biomarkers, which were hypothesized to be involved in the regulation of osteogenic differentiation of BMSCs in an inflammatory environment. It provides some reference to explore the key factors of SPA affecting osteogenic differentiation. There were some shortcomings in this study: first, we used SPA to simulate the inflammatory environment, which is somewhat different from the real inflammatory environment in the clinic; in addition, two of the biomarkers identified in this study were not validated successfully, which may be related to the sample quality. However, we will clarify the roles of these biomarkers through further experiments and analyze their molecular mechanisms of action in depth.