Objective quantitative evaluation of anti-fibrotic agents in animal models
Fibrosis is becoming a leading cause of death in organ injuries, particularly among aging population, without effective and safe therapies to date. One of the major hurdles in fibrosis-related drug discovery is the dependence on manual scoring for therapeutic effects of lead compounds in animal models. Here we introduce a service of animal models coupled to a digital imaging and quantitation method. The method incorporated nonlinear microscopy by second harmonic generation to produce collagen-specific images, and by two-photon excitation fluorescence to delineate tissue morphology. The imaging and subsequent analysis were validated with fibrotic diseases in liver, kidney, lung, bone marrow, and other organs, using reference compounds including Imatinib, Nintedanib, and Pirfenidone. The therapeutic effects of the compounds observed in our models were definitive and reproducible. The results correlated well with those of parallel biomarker analysis. The method is straightforward and stain-free. It provides further histological detail of disease status. We present this method as revolution in histological evaluation of anti-fibrosis drugs in pre-clinical settings.