Topical Senolytics for Chronic Wound Healing

点击翻译按钮获取中文摘要

ABSTRACT Chronic non-healing ulcers affect over 6.5 million people, predominantly elderly, in the United States. Aging is a major risk factor for most chronic diseases that account for morbidity, mortality, and health care costs. It may be feasible to delay age-related diseases as a group by targeting aging mechanisms, such as cellular senescence. Indeed, senescence in wound healing exhibits a context-dependent role whereby persistent senescence expression as in a chronic wound bed is detrimental. We found that senescence-associated genes and protein-protein interaction networks are upregulated in human diabetic foot ulcers, which can manifest for months to years despite standard-of-care. This is contrary to the dogma that cellular senescence plays a beneficial role in acute wound healing. To recapitulate the chronic wound bed, we established an oxidative stress-induced chronic wound model in mice that expresses higher senescence burden in dermal tissues, contributing to wound healing delay. Our hypothesis is that topical pharmacological targeting of survival pathways in senescent cells can improve chronic wound healing. It is crucial to develop compounds that selectively target senescent cells –senolytic agents. We curated prototype clinical-grade topical senolytic agents that selectively eliminate senescent cells in vitro and in vivo. Aim 1 is to define specific senescent cell types in chronic wound bed. We will dissect senescent cell surival and accural mechanisms affiliated with wound chronicity. We found that human diabetic ulcers harbor higher levels of cellular senescence in areas of dermal fibrosis. Thus, we suspect there are sensecent cell subtypes, specifically senescent fibroblasts, that contribute to adverse phenotypes. We will leverage our finding that senescent cells arising from different cell types vary in susceptibility to different senolytic agents to discover cell type-specific senolytic pathways. Aim 2 is to test effectiveness of oral senolytic agents versus topical senolytic agents in clearing chronic wound senescent cells in vivo. We will evaluate senescent cell clearance in a oxidative stress-induced chronic wound bed in INKATTAC mice. Effects of senolytic agents and combinations will be tested on aging phenotypes and in models revelant to chronic wound. Targeting new strategies for elimination of senescent cells could lead to a transformation in treating chronic non-healing ulcers in the elderly population.