Doxycycline-induced mitohormesis attenuates intestinal ischemia-reperfusion injury through ATF5-associated mitochondria-peroxisome remodeling.

Mild mitochondrial stress can establish an adaptive state that increases resistance to subsequent injury, but whether such mitohormetic preconditioning can protect the intestine from ischemia-reperfusion (I/R) remains unclear. Here, we investigated doxycycline as a pharmacological inducer of mild mitochondrial stress using murine intestinal I/R and Caco-2 oxygen-glucose deprivation/reoxygenation models. Doxycycline preconditioning attenuated intestinal epithelial and mitochondrial injury in vivo and increased resistance to subsequent OGD/R in vitro. Across a concentration gradient, low-dose doxycycline induced a mild mitochondrial stress response while preserving mitochondrial function, whereas higher exposure shifted the response toward mitochondrial dysfunction, consistent with a mitohormetic transition. Disruption of ATF5 or mitochondrial redox signaling destabilized this adaptive state and weakened doxycycline-mediated protection. Doxycycline also promoted ATF5-associated mitochondria-peroxisome remodeling, while catalase inhibition compromised the accompanying redox and epithelial protection, supporting a functional contribution of peroxisomal redox buffering to the adaptive response. Together, our findings show that doxycycline preconditioning induces mitohormesis that enhances mitochondrial resilience to intestinal I/R, with ATF5-associated mitochondria-peroxisome remodeling contributing to this adaptive response.