Aim: To compare the localization and recycling between nepmucin and CD31 molecules on transfected endothelial cells, and attempted to clarify the recycling mechanisms of nepmucin in endothelial cells.
Methods: Recycling assay and internalization assay were employed to compare the localization and recycling pathway of nepmucin and CD31. The internalized and recycling nepmucin and CD31 molecules on transfected endothelial cells were double or single stained with specific fluorchrome-labeled monoclonal antibodies against nepmucin (Alexa Fluor 488-ZAQ5) and/or CD31 (Alexa Fluor 488-anti-CD31 or Alexa Fluor 594-anti-CD31), then observed under confocal microscopy.
Results: Mouse nepmucin underwent intracellular recycling like CD31, but which recycling rate was significantly lower. The CD31 and nepmucin molecules showed largely distinct localization in endothelial cells. CD31 was found mainly on the cell surface, while nepmucin was found predominantly in the deep area of cytoplasm and partly on the cell membrane.
Conclusion: The distribution of mouse nepmucin in endothelial cells are different from CD31. Nepmucin underwent intracellular recycling like CD31 but employed different mechanisms.