Carbofuran ocular exposure affects corneal clarity and autophagy flux

Abstract

Purpose : Carbofuran (CF; a carbamate pesticide) a known pesticide, graded as Category 1 with “High Toxicity” by the Environmental Protection Agency (EPA) is a major threat pesticide used in industrial, household gardening, and agricultural purposes all over the world. More than one million people are exposed to CF and show various ocular pathologies. This study sought to explore the CF toxicological impact on ocular toxicity associated with corneal disorders that affect vision and uncover the underlying mechanism.

Methods : For in-vitro studies, the human corneal stromal fibroblast (h-CSF) cultures; and in-vivo, C57/BL6J mice were used. Live dead- and MTT- assays were used to determine the CF toxicity dose. The standard clinical imaging, histology diagnosis, and molecular level analysis were performed using immunofluorescence staining, qRT-PCR analysis, and commercially available kits to investigate the CF toxicity to the eye.

Results : The results of in-vitro studies showed that CF exposure to h-CSF showed cellular toxicity in a dose-dependent manner (p<0.01). The CF dose of 10 µm showed mild toxicity (5.2±0.2 %; p<0.01). The autophagy markers LC3, Beclin1, and SQSTM1 levels were noticeably increased in the CF indued h-CSF cells as compared to the non-treated cells (p<0.001). In-vivo (C57/BL6J) mice corneal imaging data showed mild opacity as compared to non-exposed control cornea. The molecular levels in-vivo studies showed that CF exposure to corneal tissue upregulates the LC3, Beclin1, and SQSTM1 levels as compared to the non-exposed corneal tissue (p<0.001) and may result the opacity. The in-vivo study data were aligned with the in-vitro results indicating that CF exposure to the corneal tissue impaired autophagy.

Conclusions : Pesticide (CF) exposure to the ocular tissue dysregulates the normal autophagy process which may lead to cellular toxicity and result in corneal opacity. Further, in-vivo experiments and analyses are underway to establish the correlation between the corneal opacity and autophagy flux.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.