| 초록 |
Recent advances in genomic technology have allowed a creation of animal model for human disease with genetically encoded biomarkers such as green fluorescent protein (GFP), which has opened up a new avenue to investigate complex pathophysiology of human disease in much greater details at cellular and molecular level. Over the recent years, intravital laser-scanning microscopy has demonstrated dynamic 3D visualization of various biological processes in the living subject, which provides unprecedented insights those were impossible to obtain by traditional static 2D snapshots (e.g. histopathology and cytometry). It has been utilized to monitor gene expression, protein activity, drug delivery, cell trafficking, cell interaction, physiological response under external stimuli in live animal in vivo, which provides new insights unobtainable by conventional ex vivo and in vitro observation. In this talk, recent in vivo cellular imaging studies utilizing custom-design ultrafast laser-scanning intravital microscopy system will be introduced. First, in vivo visualization of T and B lymphocyte trafficking at the high endothelial venule (HEV) of lymph node will be demonstrated. Individual endothelial cell of HEV can be clearly identified with its distinctive cuboidal morphology. Dynamic flowing behaviors of T and B lymphocytes and their dynamic migrations across endothelial cells and fibroblastic reticular cells were analyzed in vivo. Second, in vivo monitoring of small lipid and drug molecules in intestinal villi will be described. By utilizing lacteal-reporter (Prox-1-GFP) mouse, we successfully visualized transepithelial absorption of molecules across villus enterocyte, diffusion through lamina propria and subsequent transport via lacteal. Interestingly, we observed active contractile movement of lacteal in concert with villi motion, which suggests lacteal may act as an active pump during lipid absorption, not merely as a passive conduit. Moreover, we identified highly diverse pattern in absorption dynamics of various exogenous molecules as well as intrinsically fluorescent drugs through enterocytes and lacteal in vivo. |
