Purchase this article with an account.
Vinay Kumar Aakalu, Marwan Ali, Dhara Shah, Sushma Kalmodia, Arun Balasubramaniam, Kyung-No Son; Histatins abrogate corneal epithelial toxicity. Invest. Ophthalmol. Vis. Sci. 2018;59(9):3881.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Human saliva contains myriad proteins and peptides that protect against microbial, mechanical, and chemical injuries, including histatin peptides. We have found that histatins can enhance corneal epithelial migration. Histatins have multiple potential therapeutic applications in ocular surface epithelia due to their epithelial trophic, pro-wound healing and anti-microbial properties. We sought to investigate whether histatin peptides could be useful in reduction of ocular epithelial toxicity associated with ocular surface diseases. We utilized multiple inflammatory and toxic insults [benzalkonium chloride (BAK), hyperosmolar (HoSm)] in multiple corneal epithelial cell lines and measured cellular metabolism, toxicity and cell death in response to co-treatment with histatin peptides.
Human corneal epithelial (HCE) and Human corneal limbal epithelial (HCLE) cells were exposed to toxic levels of BAK or hOSm solutions. Controls included vehicle only (“Un”), or peptide without BAK [histatin 1 or 5 (H1, H5), synthetic histatin A (SA), or synthetic histatin E (SE)] were tested using an LDH assay for cell toxicity and WST-1 assay for cell survival. Caclium levels, which are important for cell death pathways, were also assayed using a Calcium Green assay (Invitrogen, Oregon). Experiments were performed in triplicate. Values are normalized to control.
We found, using multiple cell lines, stimuli and assays that there was a statistically significant reduction in corneal epithelial cell death and toxicity when exposed to multiple toxic and inflammatory stimuli and co-treated with histatin peptide (Fig 1a-c). We also noted that there was little to no cellular toxicity from histatin peptide exposure alone. Calcium levels increased in response to BAK application and were reduced with histatin co-treatment (Fig 1d).
Histatin peptides can abrogate cellular toxicity induced by ocular surface disease relevant inflammatory conditions and future studies are underway to investigate the mechanisms by which these effects are mediated.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
Fig. 1 HCE cells were exposed to toxic levels of BAK (0.002% for 30 min) and assayed for cell toxicity (a) and viability (c). Histatin treatment reduced BAK toxicity. HCLE cells were exposed to HOsm solution. H5 reduced HOsm toxicity at both 16 and 24 hours (b). Intracellular calcium was elevated in HCE cells after BAK exposure and reduced with histatin co-treatment (d). * p<0.05; **p<0.01, Mean+/-SEM
This PDF is available to Subscribers Only