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Tocopherol enters cell through the endocytic pathway and regulates lysosomal exocytosis

Wednesday, September 13, 2017 — Poster Session I

12:00 p.m. – 1:30 p.m.
FAES Terrace


  • M Xu
  • ZD Shi
  • S Titus
  • BY Xu
  • RE Swenson
  • W Zheng


Our previous data showed that alpha- and delta-tocopherols reduce lysosomal cholesterol accumulation in patient cells derived from Niemann-Pick disease type C (NPC). However, the molecular target and precise mechanism of action for tocopherols are still unclear. It was reported that tocopherols might enter cells by inserting its phytyl tail into the plasma membrane. We have synthesized a Cy3 dye-labeled delta-tocopherol (CY3-DT) analog that preserves the cholesterol reduction property of delta-tocopherol. We found that the Cy3-DT entered cells through a endocytic pathway and exhibited a punctuate pattern that reached a steady state in 8 hours and the fluorescence remained in cells over 24 hours. Cy3-DT distributed in the highest levels in lysosomes (29%), late endosomes (16%), and early endosomes (11%).

Category: Cell Biology