*2.1. TFAM and ATP5A Expression Due to Taurine Addition yo Cultured Osteocytes in an H-D Stress Environment*

To confirm the functional preservation effect of mitochondria due to taurine, the expression of TFAM and ATP5A in osteocytes placed in an H-D stress environment was investigated. In the Dex+/hypoxia+ group, as compared with Dex−/hypoxia− group as a control, the expression of both TFAM and ATP5A decreased. In contrast, in the taurine addition group, the expression of both TFAM and ATP5A in Dex+/hypoxia+/taurine+ group as compared with Dex+/hypoxia+ group was markedly increased (Figure 1). In this way, it was confirmed that taurine preserved mitochondrial function in a stress environment.

**Figure 1.** Mitochondrial transcription factor A (TFAM) and ATP5A expression in cultured osteocytes in an H-D stress environment. (**a**) Immunocytochemical study, (**b**) Western blot. TFAM (29 kDa), ATP5A (50–55 kDa), β-actin (42 kDa). In Dex+/hypoxia+ group as compared with Dex−/hypoxia− group, expression of TFAM and ATP5A levels was decreased. In Dex+/hypoxia+/taurine+ group with addition of taurine, as compared with Dex+/hypoxia+ group, levels of both TFAM and ATP5A expression were increased. Scale bar: 20 μm.
