Novel immunotherapeutic effects of topically administered ripasudil (K-115) on corneal allograft survival

Takenori Inomata,Jun Zhu,Jaemyoung Sung,Kenta Fujio,Akira Murakami,Mikiko Okano,Yuichi Okumura,Hurramhon Shokirova,Maria Miura,Toshinari Funaki,Keiichi Fujimoto,Naoko Negishi

doi:10.1038/s41598-020-76882-w

Abstract

Corneal allograft survival is mediated by the variety of immunological reactions and wound healing process. Our aim was to explore the effects of topical administration of ripasudil, a selective Rho-associated coiled-coil protein kinase inhibitor, on corneal allograft survival. Ripasudil was administered to mice thrice a day after allogeneic corneal transplantation. Corneal graft survival, opacity, neovascularization, re-epithelization, immune cell infiltration, and mRNA levels of angiogenic and pro-inflammatory factors in the grafted cornea and draining lymph nodes (dLNs) were evaluated with slit-lamp microscopy, immunohistochemistry, flow cytometry, and polymerase chain reaction. Graft survival was significantly prolonged with lower graft opacity and neovascularization scores in 0.4% and 2.0% ripasudil-treated groups, and mRNA levels of angiogenic and pro-inflammatory factors in ripasudil-treated grafted corneas were reduced. Moreover, 0.4% and 2.0% ripasudil reduced CD45+-infiltrated leukocyte frequency, Cd11b and Cd11c mRNA levels, and the frequencies of mature dendritic cells, IFNγ-, and IL-17- producing CD4+T cells in the dLNs of recipients. Re-epithelization rate of the grafted cornea was significantly higher in the 0.4% and 2.0% ripasudil groups than in the control. Topically applied ripasudil prolonged graft survival by downregulating neovascularization and inflammation factors, while promoting corneal re-epithelization, suggesting that ripasudil may be useful for suppressing immunological rejection in corneal transplantation.

Highlights

The cornea is the most commonly transplanted tissue worldwide[1], and corneal transplantation is associated with high success rates owing to its immune p rivilege[2]
We investigated the efficacy of ripasudil, a Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor, in controlling the immune reactions and wound healing responses upon corneal transplantation when applied topically on a transplanted cornea
We found that topical administration of ripasudil mediates immunological and wound healing responses owing to its ability to be rapidly deactivated downstream of neovascularization and inflammation

Summary

Introduction

The cornea is the most commonly transplanted tissue worldwide[1], and corneal transplantation is associated with high success rates owing to its immune p rivilege[2]. Host factors involved in inflammation and neovascularization lead to high rejection rates even with the use of topical steroids[3]. These effects are observed despite treatment with high doses of non-specific immunosuppressive agents, often preventing long-term graft survival combined with manifestation of severe side effects, including cataracts, glaucoma, and opportunistic infections[4,5]. The development of antiangiogenic eye drops is an unmet medical requirement, as CNV causes immune rejection in corneal transplantation and vision loss due to higher-order aberrations and edema

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