Efficacy of the Neuropeptide Alpha-Melanocyte Stimulating Hormone (α-MSH) in Promoting Survival of Corneal Endothelial Cells in Eye Banking and Transplantation

神经肽α-黑素细胞刺激激素（α-MSH）在眼库和移植中促进角膜内皮细胞存活的功效

• 批准号: 9762115
• 负责人: Reza Dana
• 金额: $ 29.55万
• 依托单位: SCHEPENS EYE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9762115
• 关键词: Acute; Aging; Allogenic; Allografting; Antioxidants; Apoptosis; Apoptotic; Applications Grants; Area; Biology; Cell Count; Cell Death; Cell Density; Cell Survival; Cell Transplantation; Cell Transplants; Cells; Cessation of life; Clinical; Clinical Data; Collaborations; Cornea; Corneal Endothelium; Cytoprotection; Data; Diabetes Mellitus; Edema; Endothelial Cells; Endothelium; Eye; Eye Banks; Eye diseases; Graft Rejection; Graft Survival; Grant; Herpetic Keratitis; Human; Hydrogen Peroxide; Immune; Immunity; Inflammation; Inflammatory; Interferons; Investigation; Keratitis; Keratoplasty; Knock-out; Lead; Measurable; Mediating; Mediator of activation protein; Methodology; Monitor; Mus; Nerve; Nerve Tissue; Neuropeptide Receptor; Neuropeptides; Optisol; Outcome; Oxidants; Oxidative Stress; Penetrating Keratoplasty; Play; Postoperative Period; Supplementation; TNF gene; TdT-Mediated dUTP Nick End Labeling Assay; Testing; Thick; Tissue Donors; Tissue Grafts; Tissue Preservation; Tissues; Translating; Transplantation; Work; alpha-Melanocyte stimulating hormone; base; cell injury; cellular targeting; corneal epithelium; cytochrome c; cytokine; density; eye dryness; graft failure; immunoregulation; improved; melanocortin receptor; monolayer; nerve injury; nerve supply; oxidant stress; oxidative DNA damage; oxidative damage; premature; prospective; receptor expression; response; synergism; transplant model

Corneal endothelial cells (CEnC) are critical for maintaining corneal transparency. Many factors, including aging, oxidative stress, and inflammation have been implicated in CEnC damage. CEnC loss also complicates eye banking where prolonged storage can lead to progressive decline in CEnC density, which can lead to graft edema. CEnC damage is also the chief proximate cause of graft failure, whether immune-driven or not. Thus, cytoprotective strategies that enhance CEnC viability could have a major impact on (i) the quality and number of donor corneas available for transplantation, and (ii) graft outcomes. Clinical data have suggested a correlation between nerve density and CEnC numbers; numerous conditions, including diabetes, dry eye, and herpetic keratitis, which induce nerve damage, are also associated with measurable CEnC loss. Procurement of donor corneas for eye banking also requires severing donor tissue from nerves, and is associated with significant CEnC loss. Our preliminary data show (1) high constitutive expression of melanocortin receptor (MCR) for the neuropeptide alpha-melanocyte stimulating hormone (α-MSH) in both human and murine CEnC; (2) significant suppression of CEnC death induced by inflammatory cytokines or the oxidant hydrogen peroxide by α-MSH; and 3) decrease in eye banked CEnC loss when donor tissues are kept in medium supplemented with α-MSH. Based on these preliminary data, we hypothesize that α-MSH provides cytoprotection to CEnC from both oxidative stress and inflammatory cytokines, and thus predict that α-MSH promotes survival of CEnC (i) in cornea storage and (ii) after transplantation. To test this hypothesis, we will pursue two specific aims. In Aim 1, we evaluate the effect of α-MSH on CEnC loss in eye bank-stored corneas in collaboration with the Eversight Eye Bank. We will keep human donor corneas in either standard Optisol-GS medium (Aim 1A) or in medium supplemented with hydrogen peroxide to induce oxidant stress (Aim 1B) before adding α-MSH or control PBS. Tissues will be monitored and assessed prospectively using standard eye bank methodologies, and tests for CEnC viability (TUNEL assay and cytochrome c release) and oxidative DNA damage. In Aim 2, we will assess the effect of α-MSH on the function and survival of grafted CEnC in murine corneal grafting. To discriminate the potential immunomodulatory effect of α-MSH from its cytoprotective effect, α-MSH (or control treatment) will be used in syngeneic grafts in Aim 2A. Then, we will use a variety of MCR knockout combinations in hosts (Aim 2B) or donors (Aim 2C) to discriminate the cellular targets of α-MSH. This grant, which represents a new area of investigation for our lab, brings together synergy between our lab with core expertise in transplantation, with an investigative group that includes experts on CEnC (Dr. Jurkunas) and neuropeptide biology (Dr. Taylor). We aim to employ data generated in this exploratory grant to generate a more mechanistically focused R01 application whose results can then be employed by eye banks for optimized tissue preservation.

角膜内皮细胞（CEnC）对维持角膜透明度至关重要。很多因素，包括