Abstract
Purpose: :
Mucins maintain health and stability of fluid film lining the epithelia. On the ocular surface mucins are believed to attract and hold water thanks to their hydrophilic properties, thus preventing desiccation of the surface. Moreover, they play a role in lubrication during blinking, ocular defence against pathogen penetration, and preservation of a smooth refractive surface.MUC1 is a mucinous glycoprotein which is normally expressed on the surfaces of a variety of epithelial cells, including those of the corneal layer, and aberrantly overexpressed in some human tumors.Arabinogalactan (AG) is a natural polysaccharide with a pronounced restorative action of the corneal epithelium abrasions due to its positive influence on the growth of corneal epithelial cells.The study was aimed at investigating the effect of AG on proliferation of human corneal epithelial cells and regulation of MUC1 gene transcription.
Methods: :
Cell viability test was based on the ready-to-use cell proliferation reagent WST-1, while the levels of MUC1 mRNA expression were evaluated by RT-PCR. RNA from cells was extracted by using the RNeasy Mini kit and reverse-transcribed by the QuantiTect Reverse Transcription kit and PCR was performed by the Hot StartTaq Master Mix kit.Primers used were: 5’-AGACGTCAGCGTGAGTGATG-3’(F) and 5’-AGTGTCCGAGAAATTGGTGG-3’(R) for MUC1; 5’-GTGAAGGTCGGAGTCAACG-3’(F) and 5’-GGTGAAGACGGCCAGTGGACTC-3’(R) for GAPDH and the expected amplification products were 522 and 299 bp long, respectively. Relative densitometry of bands was measured using NIH ImageJ gel analysis.
Results: :
AG was able to stimulate corneal cell growth up to 180% of untreated control, after 48 and 72 hours of exposure. After 24-exposure to AG at 2.5%, MUC1 mRNA expression levels in treated cells were similar to those in control cells.
Conclusions: :
These findings suggest that AG may enhance epithelial protection by stimulating cell proliferation and preserving the physiological regulation of MUC1 gene expression.
Keywords: cornea: surface mucins • protective mechanisms • wound healing