A New Perspective on Osteogenesis Imperfecta: From Cellular Mechanisms to the Systemic Impact of Collagen Dysfunction.

Osteogenesis imperfecta (OI) is a rare genetic disease caused by mutations in collagen type I, leading to defective protein folding and an impaired extracellular matrix structure and remodelling. Beyond skeletal fragility, these molecular defects trigger a network of intracellular stress responses with multiorgan implications: the accumulation of misfolded collagen can induce persistent endoplasmic reticulum stress, which can in turn compromise mitochondrial function and autophagy or lead to cell death activation, and it can even promote widespread redox imbalance and inflammation. The interplay between intracellular stress, widespread oxidative damage and inflammation not only underlies cellular dysfunction but also the multisystemic manifestations of osteogenesis imperfecta. Targeting these interconnected pathways may result in new insights for a better understanding of OI and possibly offer novel therapeutic strategies designed to restore proteostasis and improve cell homeostasis and overall patient outcomes, highlighting the need for an integrated understanding of the cellular and molecular mechanisms involved in the pathogenesis of this disease and their translation into patient-centred therapeutic interventions.