Magnesium promoting OVX rats' rotator cuff tear repair with relieving stem cell senescence effect

The rotator cuff tear (RCT) repairing of tendon-to-bone junction (enthese) after surgery in osteoporotic patients is mainly hindered by poor bone formation at the damaged humeral tuberosity region. We found that long-term oral supplementation of Magnesium ions (Mg²⁺) can significantly promote humeral tuberosity bone formation and enthese regeneration after RCT surgery in ovariectomized (OVX) rats, attributing to the promotive effect of Mg²⁺ on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its inhibition of new bone mineralization. Meanwhile, the in vitro replicative senescent markers of BMSCs are significantly relieved by Mg²⁺. The BMSCs' RNA-seq data analysis and cell energy metabolism results indicate that Mg²⁺ significantly increase senescent BMSCs' mitochondrial transmembrane potential and intracellular ATP content, and reduce reactive oxygen species production.