Combination Nanomedicine Strategy for Preventing High-Risk Corneal Transplantation Rejection.

High-risk (HR) corneal transplantation presents a formidable challenge, with over 50% of grafts experiencing rejection despite intensive postoperative care involving frequent topical eyedrop administration up to every 2 h, gradually tapering over 6-12 months, and ongoing maintenance dosing. While clinical evidence underscores the potential benefits of inhibiting postoperative angiogenesis, effective antiangiogenesis therapy remains elusive in this context. Here, we engineered controlled-release nanomedicine formulations comprising immunosuppressants (nanoparticles) and antiangiogenesis drugs (nanowafer) and demonstrated that these formulations can prevent HR corneal transplantation rejection for at least 6 months in a clinically relevant rat model.

Lack of Elevated Expression of TGFβ3 Contributes to the Delay of Epithelial Wound Healing in Diabetic Corneas.

Purpose: To investigate the mechanisms underlying the differential roles of TGFβ1 and TGFβ3 in accelerating corneal epithelial wound healing (CEWH) in diabetic (DM) corneas, with normoglycemia (NL) corneas as the control.

Methods: Two types of diabetic mice, human corneal organ cultures, mouse corneal epithelial progenitor cell lines, and bone marrow-derived macrophages (BMDMs) were employed to assess the effects of TGFβ1 and TGFβ3 on CEWH, utilizing quantitative PCR, western blotting, ELISA, and whole-mount confocal microscopy.

Results: Epithelial debridement led to an increased expression of TGFβ1 and TGFβ3 in cultured human NL corneas, but only TGFβ1 in DM corneas.

Interleukin-36 Receptor Signaling Attenuates Epithelial Wound Healing in C57BL/6 Mouse Corneas.

The IL-36 cytokines are known to play various roles in mediating the immune and inflammatory response to tissue injury in a context-dependent manner. This study investigated the role of IL-36R signaling in mediating epithelial wound healing in normal (NL) and diabetic (DM) C57BL/6 mouse corneas. The rate of epithelial wound closure was significantly accelerated in IL-36 receptor-deficient (IL-36R) compared to wild-type (WT) mice.

Diabetes Exacerbates Pseudomonas aeruginosa Keratitis in Streptozotocin-Induced and db/db Mice via Altering Programmed Cell Death Pathways.

Purpose: Patients with diabetes have a higher incidence of infections, which are often more severe. This study aimed to investigate the impact of hyperglycemia on bacterial keratitis caused by Pseudomonas aeruginosa (Pa) in two mouse models of diabetes, streptozotocin-induced type 1 diabetes mellitus (T1DM) and db/db type 2 diabetes mellitus.

Methods: The susceptibility of corneas to Pa was assessed by determining the inocula required to cause infectious keratitis.

Protective effects of resolvin D1 in Pseudomonas aeruginosa keratitis.

Purpose: Here, we explored the protective effects of resolvin D1 (RvD1) in Pseudomonas aeruginosa (PA) keratitis.

Methods: C57BL/6 (B6) mice were used as an animal model of PA keratitis. Plate counting and clinical scores were used to assess the severity of the infection and the therapeutic effects of RvD1 in the model.

Ocular nociception and neuropathic pain initiated by blue light stress in C57BL/6J mice.

To elucidate the physiological, cellular, and molecular mechanisms responsible for initiating and sustaining ocular neuropathic pain, we created a blue-light-exposure model in C57BL/6 mice. Mice were exposed to 12 h of blue or white light followed by 12 h of darkness. Before blue light exposure, baseline tear secretion, stability, and ocular hyperalgesia were assessed by measuring hyper- or hypo-osmotic solution-induced eye wiping, wind-induced eye closing, and cold-induced eye blinking.

The impact of sensory neuropathy and inflammation on epithelial wound healing in diabetic corneas.

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes, with several underlying pathophysiological mechanisms, some of which are still uncertain. The cornea is an avascular tissue and sensitive to hyperglycemia, resulting in several diabetic corneal complications including delayed epithelial wound healing, recurrent erosions, neuropathy, loss of sensitivity, and tear film changes. The manifestation of DPN in the cornea is referred to as diabetic neurotrophic keratopathy (DNK).

IL-36α Enhances Host Defense against Keratitis in C57BL/6 Mouse Corneas.

The IL-36 cytokines are known to play various roles in mediating the immune response to infection in a tissue- and pathogen-dependent manner. The present study seeks to investigate the role of IL-36R signaling in C57BL/6 mouse corneas in response to infection. IL-36α, IL-36γ, and IL-36R mice had significantly more severe keratitis than wild-type mice.

Role of IL-36γ/IL-36R Signaling in Corneal Innate Defense Against Candida albicans Keratitis.

Purpose: Interleukin (IL)-36 cytokines have been shown to play either beneficial or detrimental roles in the infection of mucosal tissues in a pathogen-dependent manner, but their involvement in fungal keratitis remains elusive. We herein investigated their expression and function in mediating corneal innate immunity against Candida albicans infection.

Methods: Gene expression in mouse corneas with or without C.

Lipo-PEG nano-ocular formulation successfully encapsulates hydrophilic fluconazole and traverses corneal and non-corneal path to reach posterior eye segment.

The present study describes a special lipid-polyethylene glycol matrix solid lipid nanoparticles (SLNs; 138 nm; -2.07 mV) for ocular delivery. Success of this matrix to encapsulate (entrapment efficiency - 62.

ISG15 Acts as a Mediator of Innate Immune Response to Pseudomonas aeruginosa Infection in C57BL/6J Mouse Corneas.

Purpose: IFN-stimulated gene (ISG) 15 is a type 1 IFN-induced protein and known to modify target proteins in a manner similar to ubiquitylation (protein conjugation by ISG15 is termed ISGylation). We sought to determine the role of ISG15 and its underlying mechanisms in corneal innate immune defense against Pseudomonas aeruginosa keratitis.

Methods: ISG15 expression in cultured human corneal epithelial cells (HCECs) and mouse corneas was determined by PCR and Western blot analysis.

Role of VIP and Sonic Hedgehog Signaling Pathways in Mediating Epithelial Wound Healing, Sensory Nerve Regeneration, and Their Defects in Diabetic Corneas.

Diabetic keratopathy, a sight-threatening corneal disease, comprises several symptomatic conditions including delayed epithelial wound healing, recurrent erosions, and sensory nerve (SN) neuropathy. We investigated the role of neuropeptides in mediating corneal wound healing, including epithelial wound closure and SN regeneration. Denervation by resiniferatoxin severely impaired corneal wound healing and markedly upregulated proinflammatory gene expression.

IL-17 Promotes Keratitis in C57BL/6 Mouse Corneas.

The aim of this study was to elucidate the expression and functions of IL-17 in C57BL/6 mouse corneas in response to infection. We found that infection induced and increased signaling of IL-23/23R/17/17R in mouse corneas. Targeting IL-17A or the IL-17A-specific receptor IL-17RA/IL-17RC with neutralizing Abs resulted in a significant decrease in the severity of keratitis, including a decrease in bacterial burden and polymorphonuclear leukocyte infiltration.

Opposing Effects of Neuropilin-1 and -2 on Sensory Nerve Regeneration in Wounded Corneas: Role of Sema3C in Ameliorating Diabetic Neurotrophic Keratopathy.

The diabetic cornea exhibits pathological alterations, such as delayed epithelial wound healing and nerve regeneration. We investigated the role of semaphorin (SEMA) 3C in corneal wound healing and reinnervation in normal and diabetic B6 mice. Wounding induced the expression of SEMA3A, SEMA3C, and their receptor neuropilin-2 (NRP2), but not NRP1, in normal corneal epithelial cells; this upregulation was suppressed for SEMA3C and NRP2 in diabetic corneas.

Overlapping Roles for Interleukin-36 Cytokines in Protective Host Defense against Murine Pneumonia.

causes life-threatening pneumonia culminating in acute lung injury. Innate and adaptive cytokines play an important role in host defense against infection. Interleukin-36 (IL-36) cytokines are recently described members of the larger IL-1 cytokine family known to exert potent inflammatory effects.

TSLP Protects Corneas From Pseudomonas aeruginosa Infection by Regulating Dendritic Cells and IL-23-IL-17 Pathway.

Purpose: We sought to determine the role of epithelium-produced thymic stromal lymphopoietin (TSLP) and its underlying mechanisms in corneal innate immune defense against Pseudomonas (P.) aeruginosa keratitis.

Methods: The expression of TSLP and TSLPR in cultured human corneal epithelial cells (HCECs) and mouse corneas was determined by PCR, Western, and/or ELISA.

Opposing Effects of IL-1Ra and IL-36Ra on Innate Immune Response to Infection in C57BL/6 Mouse Corneas.

keratitis is characterized by severe corneal ulceration and may lead to blindness if not treated properly in a timely manner. Although the roles of the IL-1 subfamily of cytokines are well established, as a newly discovered subfamily, IL-36 cytokine regulation, immunological relevance, and relation with IL-1 cytokines in host defense remain largely unknown. In this study, we showed that infection induces the expression of IL-36α and IL-36γ, as well as IL-1β and secreted IL-1Ra (sIL-1Ra), but not IL-36Ra.

Inhibition of Soluble Epoxide Hydrolase 2 Ameliorates Diabetic Keratopathy and Impaired Wound Healing in Mouse Corneas.

EPHX2 (encoding soluble epoxide hydrolase [sEH]) converts biologically active epoxyeicosatrienoic acids (EETs), anti-inflammatory and profibrinolytic effectors, into the less biologically active metabolites, dihydroxyeicostrienoic acids. We sought to characterize the expression and the function of EPHX2 in diabetic corneas and during wound healing. The expression of EPHX2 at both mRNA and protein levels, as well as sEH enzymatic activity, was markedly upregulated in the tissues/cells, including corneal epithelial cells as well as the retina of human type 2 and mouse type 1 (streptozotocin [STZ] induced) and/or type 2 diabetes.

Metformin suppresses retinal angiogenesis and inflammation in vitro and in vivo.

The oral anti-diabetic drug metformin has been found to reduce cardiovascular complications independent of glycemic control in diabetic patients. However, its role in diabetic retinal microvascular complications is not clear. This study is to investigate the effects of metformin on retinal vascular endothelium and its possible mechanisms, regarding two major pathogenic features of diabetic retinopathy: angiogenesis and inflammation.

CXCL10 suppression of hem- and lymph-angiogenesis in inflamed corneas through MMP13.

Though not present in the normal adult cornea, both hem- and lymph-angiogenesis can be induced in this tissue after an inflammatory, infectious, or traumatic insult. We previously showed that the chemokine CXCL10 plays a key role in eradicating invading Candida (C.) albicans in C57BL6 mouse corneas.

ISG15 in Host Defense Against Candida albicans Infection in a Mouse Model of Fungal Keratitis.

Purpose: ISG15, a di-ubiquitin-like protein, is critical for controlling certain viral and bacterial infections. We sought to determine if ISG15 plays a role in corneal innate immunity against Candida albicans (C. albicans) using a C57BL/6 (B6) mouse model of human fungal keratitis.

IL-24 Promotes Keratitis in C57BL/6 Mouse Corneas.

The aim of this study was to elucidate the expression and functions of IL-24 in C57BL/6 mouse corneas in response to infection. Among IL-20R cytokines, only IL-24 was induced at both mRNA and protein levels by infection at early time points. The upregulation of IL-24 was dampened by flagellin pretreatment, which protects the corneas from microbial infection.

Zika virus infects cells lining the blood-retinal barrier and causes chorioretinal atrophy in mouse eyes.

Zika virus (ZIKV) is an important pathogen that causes not only neurologic, but also ocular, abnormalities. Thus, it is imperative that models to study ZIKV pathogenesis in the eye are developed to identify potential targets for interventions. Here, we studied ZIKV interactions with human retinal cells and evaluated ZIKV's pathobiology in mouse eyes.