Suppression of NLRP3/Caspase-1/GSDMD Mediated Corneal Epithelium Pyroptosis Using Melatonin-Loaded Liposomes to Inhibit Benzalkonium Chloride-Induced Dry Eye Disease

Abstract

Introduction Benzalkonium chloride (BAC) is widely employed as a preservative in eye drops, which will cause the death of corneal epithelial cells due to ROS production, DNA strand breakage, and mitochondrial dysfunction, resulting in dry eye disease (DED)-like changes in ocular surface tissues. In this study, Melatonin (MT) liposomes (TAT-MT-LIPs) designed by loading MT into TAT-modified liposomes have been developed, characterized, and used for inhibiting BAC-induced DED (BAC-DED). Methods The TAT was chemically grafted onto the Mal-PEG 2000 -DSPE by Michael’s addition between the sulfhydryl group in TAT and the maleimide group in Mal-PEG 2000 -DSPE. TAT-MT-LIPs were prepared using film dispersion followed by the extrusion method and topically treated in rats once a day. BAC-DED was induced in rats by topical administration with 0.2% BAC twice daily. Defects, edema, and inflammation of the corneas, as well as IOP, were examined. Histologic analyses of corneas were performed to assess the change of mitochondrial DNA oxidation and NLRP3/Caspase-1/GSDMD signaling transduction. Results After topical administration, TAT-MT-LIPs significantly alleviated DED-clinical symptoms of experimental animals by inhibiting tissue inflammation and preventing the loss of the corneal epithelium and conjunctival goblet cells. Our data suggested continuous ocular surface exposure of BAC-induced NLRP3/Caspase-1/GSDMD mediated corneal epithelium pyroptosis, which was not reported before. BAC caused substantial mt-DNA oxidation, which promoted the transduction of NLRP3/Caspase-1/GSDMD and consequent corneal epithelium pyroptosis. TAT-MT-LIPs could efficiently suppress the BAC-induced corneal epithelium pyroptosis and inflammation by inhibiting mt-DNA oxidation and the subsequent signal transmission. Conclusion NLRP3/Caspase-1/GSDMD mediated corneal epithelium pyroptosis is involved in the development of BAC-DED. The present study provided new insights into the adverse effects of BAC, which can serve as a new target for protecting corneal epithelium when applying BAC as a preservative in eye drops. The developed TAT-MT-LIPs can efficiently inhibit BAC-DED and give great potential to be developed as a new DED treatment.

The Therapeutic Trip of Melatonin Eye Drops: From the Ocular Surface to the Retina

“…Lipid nanoparticles (LNPs) are spherical vesicles with an average size ranging between 40 and 100 nm, composed of a dispersed phase consisting of a solid lipid stabilized with a biocompatible surfactant used as an emulsifier. These lipid nanoparticles are conventionally classified into SLNs (Solid Lipid Nanoparticles) and NLCs (Nanostructured Lipid Carriers) [ 38 ]. SLNs are systems comprising a solid lipid matrix, while NLCs are modified SLNs in which a mixture of solid and liquid lipids is present to enhance their drug-loading capacity and stability.…”

“…The findings suggest Mel-Mic as a potentially effective treatment for DED. A different model system addressed the efficacy of topical administration of TAT-modified melatonin liposomes (TAT-MT-LIPs) (obtained by chemical grafting of Trans-Activator of Transcription (TAT) onto liposomes) on the ocular surface of rats with Benzalkonium-Chloride (BAC)-induced DED [ 38 ]. TAT-MT-LIPs significantly alleviated clinical symptoms by inhibiting tissue inflammation and preventing corneal epithelium and conjunctival goblet cell loss.…”

The Therapeutic Trip of Melatonin Eye Drops: From the Ocular Surface to the Retina

“…Lipid nanoparticles (LNPs) are spherical vesicles with an average size ranging between a biocompatible surfactant used as an emulsifier. These lipid nanoparticles are conventionally classified into SLNs (Solid Lipid Nanoparticles) and NLCs (Nanostructured Lipid Carriers) [38]. SLNs are systems comprising a solid lipid matrix, while NLCs are modified SLNs in which a mixture of solid and liquid lipids is present to enhance their drug-loading capacity and stability.…”

Utilization of Nitrogen-Doped Graphene Quantum Dots to Neutralize ROS and Modulate Intracellular Antioxidant Pathways to Improve Dry Eye Disease Therapy

“… 4 Although the exact pathophysiology of the varied forms of DED remains unclear, it is evident that an accumulation of reactive oxygen species (ROS), including superoxide anion ( ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radicals (·OH), on the ocular surface is pivotal. 5 This heightened ROS concentration denotes oxidative stress. Exacerbated oxidative stress in both the conjunctiva and tear fluid can instigate an inflammatory cascade, potentially initiating DED.…”