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.

Neutrophils constitute the largest fraction of total circulating leukocytes in humans and mediate early innate immune responses. Although they are often considered a uniform population of short-lived immune cells, emerging evidence from single-cell RNA sequencing and high-dimensional flow cytometry has revealed that neutrophils are functionally and phenotypically heterogeneous in both healthy and pathological conditions. However, a critical gap is how molecularly defined neutrophil states translate into distinct spatiotemporal behaviors in vivo. This review summarizes our current understanding of the molecular signatures underlying neutrophil heterogeneity and explores the functional in vivo behaviors in various diseases, including cancer, sepsis, and ischemic stroke. We also discuss the potential of intravital imaging to bridge the gap between static molecular profiling and dynamic cellular behavior, offering a comprehensive view of the functional heterogeneity of neutrophils.

Byeon H, et al. Immune Netw. 2026 Oct;26(5):e41. https://doi.org/10.4110/in.2026.26.e41