Skeletal tissue regulation by catalase over-expression in mitochondria.

Skeletal tissue regulation by catalase over-expression in mitochondria.
Am J Physiol Cell Physiol. 2020 Aug 12;:
Authors: Schreurs AS, Torres S, Truong T, Moyer EL, Kumar A, Tahimic CGT, Alwood JS, Globus RK
Abstract
Accumulation of oxidative damage from excess reactive oxygen species (ROS) may contribute to skeletal aging and mediate adverse responses to physiological challenges. Wildtype (WT) and transgenic mice (male, 16 weeks of age) with human catalase targeted to the mitochondria (mCAT) were analyzed for skeletal responses to the remodeling stimuli of combined hindlimb unloading and exposure to ionizing radiation (137Cs, 2 Gy). Treatment for 2wk caused lipid peroxidation in WT bones but not mCAT, showing that transgene expression mitigated oxidative stress. Ex vivo osteoblast colony growth rate was 95% greater in mCAT mice than WT, and correlated with catalase activity levels (P<0.005, r=0.67), although terminal osteoblast and osteoclast differentiation were unaffected. Ambulatory control mCAT animals also displayed reduced cancellous and cortical structural properties compared to control WT. In mCAT but not WT mice, treatment caused an unexpectedly rapid radial expansion (+8% cortical area, +22% moment of inertia), reminiscent of compensatory bone growth during advancing age. In contrast, treatment caused similar structural deficits in cancellous tissue of mCAT and WT mice. In sum, mitochondrial ROS signaling via H2O2 was i...

Source: Am J Physiol Cell Ph... - August 11, 2020 Category: Cytology Authors: Schreurs AS, Torres S, Truong T, Moyer EL, Kumar A, Tahimic CGT, Alwood JS, Globus RK Tags: Am J Physiol Cell Physiol Source Type: research