Characterization of Bone Tissue and Bone Morphology in Taurine Transporter Knockout Mice

Taurine, a sulfur-containing amino acid, has been shown to protect against tissue damage. It is highly accumulated in bone cells, including osteoblasts, where it enhances bone tissue formation. The quality of bone is defined by its microarchitecture, accumulated microscopic damage, collagen quality, mineral crystal size, and turnover rate. In this study, the effects of taurine depletion on bone metabolism and bone quality were investigated in taurine transporter knockout (TauT-/-) mice. The bone volume and trabecular number of 20-month-old male TauT-/- and TauT+/+ mice were measured by micro-computed tomography, and bone tissues were observed using hematoxylin and eosin and immunohistochemical staining methods. In the TauT-/- mice, the bone area of the proximal region of the femur was significantly smaller than that in the TauT+/+ mice, and the bone volume and trabecular number of the femur neck were significantly lower. Although the bone mineral densities in the mid-diaphysis and proximal regions were lower in the TauT-/- mice, the difference was significant for the proximal region only. Moreover, taurine depletion decreased the mineral density and strength parameters in the cancellous bone. The results of this study suggest that taurine plays an important role in maintaining bone quality.