Purpose:
To evaluate the effect of acupuncture on rabbit tear secretion and compare the difference in tear protein expression caused by acupuncture.
Methods:
Ten male New Zealand White rabbits were enrolled in this study. The following acupoints around the right eye, Extra 1 ( Taiyang ), BL 2 ( Zanzhu ) and SJ 23 ( Sizhukong ), were selected for acupuncture therapy. Each rabbit had received 10 acupuncture sessions of 30 minutes, three times per week. A quantity of 50 µl rabbit tear was collected at pre- and post- acupuncture stage in every subject, respectively. The total protein content analysis, one-dimensional gel electrophoresis and quantitative proteomics analysis (iTRAQ) were performed and the results were compared.
Results:
Generally, the tear protein expression after acupuncture was different from that before acupuncture though to some extent they were similar. The time spent in collecting rabbit tear after acupuncture therapy was obviously shorter than that before acupuncture. The total protein content in rabbit tear at pre- and post- acupuncture stages w 7.12 µg/µl versus 11.28 µg/µl. One-dimensional gel electrophoresis showed the tear proteins in rabbit tear which collected before acupuncture had been substantial different from those collected after acupuncture. In total, twenty-eight tear proteins were identified by quantitative proteomics analysis (iTRAQ). Associated with acupuncture were six up-regulated proteins (serum albumin, alpha-1-antiproteinase, histidine-rich glycoprotein, hemopexin, Vitamin D-binding protein, alpha-2-HS-glycoprotein) and five down-regulated proteins (Annexin A1, serum amyloid A-3 protein, Helicase-like transcription factor, 15 kDa protein A, protein S100-A9).
Conclusions:
The rabbit tear protein expression difference caused by acupuncture indicated that acupuncture could improve the quality and quantity of rabbit tear, which theologically prove the effect of acupuncture in the treatment of dry eye.
Keywords: cornea: tears/tear film/dry eye • proteomics