PROJECT SUMMARY My career goal is to lead an independent research group to investigate the pathology and resolution of pain to solve neuropathic pain problems. To achieve this goal, I propose to develop and use novel translational strategies to investigate neuron-substrate interactions in the skin layer using a combination of human and animal models of peripheral sensory neuropathy. My research focuses on a common type of peripheral sensory neuropathy induced by chemotherapy, which affects over 3 million people in the US alone. While chemotherapy- induced peripheral neuropathy (CIPN) develops in up to 80% of cancer patients treated with chemotherapeutics, there are no effective prevention or treatment strategies. Considering the dynamic extracellular environment of cutaneous sensory nerves and recent understanding that keratinocytes can also function as a nociceptor, it is vital to understand the maintenance and function of both neurons and keratinocytes to solve neuropathic pain. Hence, I propose to test the hypothesis that dysregulation of neuron and epidermal interactions underlie pathological progression of CIPN. Building from my recent work that identified protective roles of integrins in CIPN, my proposal has three aims that use cutting-edge tools and innovative multi-disciplinary approaches. In Aim 1, I will investigate neuron-substrate interactions and their regulatory mechanisms in a Drosophila in vivo CIPN model. I will use genetics and advanced microscopy approaches to label, manipulate, and detect subcellular changes in neuron to substrate contacts and link with functional changes in a CIPN model. Using integrins as a model to understand cell surface protein-mediated mechanisms underlying CIPN, I will characterize endocytic regulators that modulate surface protein expression mediating neuron-substrate contacts. In Aim 2, I will use human induced pluripotent stem cell (iPSC) technology to identify keratinocyte-nociceptive neuron interactions and cell-type-specific pathology in a co-culture CIPN model. Given species differences in sensory neurons, I expect that establishing a human model to investigate the impact of sensory neurons and extrinsic factors on pathological progression in CIPN will provide critical insights. In Aim 3, I will establish and validate a 3D human skin-nerve co-culture CIPN model to investigate neuron-substrate relationships and integrin-mediated protection. Because subtypes of nociceptive neurons target different epidermal layers and contribute to distinct pathology in peripheral neuropathy, a 3D engineered human skin will be incorporated in the model. This will allow me to investigate subtype-specific pathology and to resolve nociceptive neuron terminal degeneration and dysfunction in CIPN. This proposal will provide new insights into pathological progression and mechanisms mediated by neuron-substrate interactions and a strong foundation for my future research. As my primary expertise is in neuroscience using Drosophila models, investigating human neurons and epidermal cells requires new training in skin biology and stem cell biology. The proposed plan will significantly facilitate my career goal to solve intractable neuropathic pain problems in patients.

PROJECT NARRATIVE In the skin layer, pain-sensing neurons and keratinocytes together detect and modulate painful stimuli, yet how their interaction is disrupted in neuropathic pain conditions is poorly understood. This proposal aims to characterize their interaction, regulatory mechanisms, and functional impact in disease by developing and using novel human models and simple in vivo animal models of chemotherapy-induced peripheral neuropathy. The proposed study will provide insights into how neurons interact with their substrates in the skin layer to maintain function in health and disease and point to new therapeutic strategies in treating intractable neuropathic pain.