Intravital two-photon imaging and quantification of hepatic steatosis and fibrosis in a live small animal model.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases closely associated with the metabolic system, including obesity and type 2 diabetes. The progression of NAFLD with advanced fibrosis is associated with an increased risk of liver cirrhosis and cancer as well as various extra-hepatic diseases. Yet, the underlying mechanism is not fully understood partly due to the absence of effective high-resolution in vivo imaging methods and the appropriate animal models recapitulating the pathology of NAFLD. To improve our understanding about complex pathophysiology of NAFLD, the need for an advanced imaging methodology to visualize and quantify subcellular-level features of NAFLD in vivo over time is ever-increasing. In this study, we established an advanced in vivo two-photon imaging technique to visualize and quantify subcellular-level pathological features of NAFLD in a live mouse animal developing hepatic steatosis, fibrosis, and disrupted microvasculature.