Ocular side effects of systemic medications: utilization of the 3D human corneal epithelial tissue model

Many systemic medications administered at high doses have the potential to induce unwanted ocular effects, including light sensitivity, pain, or corneal edema that are due to inflammation and/or cytotoxicity. Current drug screening experiments utilize animal models which are not suitable for rapid drug screening, as they have poor species extrapolation, and lack standardization. There is a need for physiologically relevant, human primary corneal epithelial tissue models to evaluate ocular safety of new drug formulations.

We have utilized the 3D human corneal epithelial tissue model, EpiCorneal, to analyze the effect of common drugs with known adverse ocular side effects. EpiCorneal tissues are comprised of normal human corneal epithelial cells, express site-specific mucins and tight junctions, and attain morphology, barrier properties (TEER > 900±200 Ω·cm2 ), and gene expression similar to the in vivo human cornea. The effect of physiologically relevant concentrations of Chlorpromazine hydrochloride (CPZ), a common psychotropic agent; Hydroxychloroquine sulfate (HCQ), an anti-inflammatory and anti-malaria drug; Alfuzosin Hydrochloride (ALF), an antihypertensive drug; and Fosamax (Alendronate Sodium, FOS), a common anti-osteoporosis agent, were investigated. Effects on tissue viability (MTT assay), barrier function (Transepithelial electrical resistance, TEER), histology, and LDH and cytokine release were studied.

EpiCorneal tissues were exposed to culture medium containing CPZ at 6.25 – 100 µM, HCQ at 6.17 – 500 µg/ml, or FOS at 0.1 – 100 µg/ml for 24h and 48h. For CPZ-treated tissues, a significant decrease in barrier function (67.4% of NC) was observed in tissues treated with 12.5 µM for 24h, and a dose of 25 µM decreased tissue viability (60.5% of NC) at 48h. For HCQtreated tissues, a decline in TEER was observed in tissues treated with 18.5 µg/ml HCQ at 24h (67.4% of NC), and tissues treated with 55.6 µg/mL HCQ for 48h (53.6% of NC). For FOS-treated tissues, a significant TEER decrease was observed in tissues treated with 0.1 µg/mL FOS (57.8% of NC) and 10 µg/mL (85.7% of NC) both at 48h. Treatment-specific changes in tissue morphology and dose dependent changes in LDH and cytokine release were also observed.

The EpiCorneal tissue model has been very useful for evaluating formulations with negligible irritation potential. It will model systemic drug exposure for extended time, will generate rapid response, avoid species extrapolation, be more cost effective and more reproducible than animal methods, and will facilitate drug discovery by allowing screening and optimization of pharmaceuticals prior to clinical studies.

 EpiCorneal (COR-100) , systemic exposure, Chlorpromazine hydrochloride, psychotropic agent,  Hydroxychloroquine sulfate, anti-inflammatory, anti-malaria, Alfuzosin Hydrochloride, antihypertensive, Fosamax (Alendronate Sodium, anti-osteoporosis agent, histology, LDH, TEER, MTT, ZO-1, occludin, mucin 1, keratin 3/12, tight junctions

Chlorpromazine hydrochloride, Hydroxychloroquine sulfate, Alfuzosin Hydrochloride, Fosamax, Alendronate Sodium