Pharmacological inhibition of MDM4 alleviates pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease of unknown etiology with no cure. A better understanding of the disease processes and identification of druggable targets will benefit the development of effective therapies for IPF. We previously reported that MDM4 promoted lung fibrosis through the MDM4-p53-dependent pathway. However, it remained unclear whether targeting this pathway would have any therapeutic potential. In this study, we evaluated the efficacy of XI-011, a small molecular inhibitor of MDM4, for treating lung fibrosis. We found that XI-011 significantly reduced MDM4 expression and increased the expression of total and acetylated p53 in primary human myofibroblasts and a murine fibrotic model. XI-011 treatment resulted in the resolution of lung fibrosis in mice with no notable impact on normal fibroblast death or the morphology of healthy lungs. Based on these findings, we propose that XI-011 might be a promising therapeutic drug candidate for treating pulmonary fibrosis.

Idiopathic Pulmonary Fibrosis: An Update on Pathogenesis.

Idiopathic pulmonary fibrosis (IPF) is a progressive, lethal fibrotic lung disease that occurs primarily in middle-aged and elderly adults. It is a major cause of morbidity and mortality. With an increase in life expectancy, the economic burden of IPF is expected to continuously rise in the near future. Although the exact pathophysiological mechanisms underlying IPF remain not known. Significant progress has been made in our understanding of the pathogenesis of this devastating disease in last decade. The current paradigm assumes that IPF results from sustained or repetitive lung epithelial injury and subsequent activation of fibroblasts and myofibroblast differentiation. Persistent myofibroblast phenotype contributes to excessive deposition of the extracellular matrix (ECM) and aberrant lung repair, leading to tissue scar formation, distortion of the alveolar structure, and irreversible loss of lung function. Treatments of patients with IPF by pirfenidone and nintedanib have shown significant reduction of lung function decline and slowing of disease progression in patients with IPF. However, these drugs do not cure the disease. In this review, we discuss recent advances on the pathogenesis of IPF and highlight the development of novel therapeutic strategies against the disease.