PROJECT SUMMARY (Overall) Chronic pain affects >25 million Americans per year, with enormous impacts on both quality of life and productivity. Despite advances in our understanding of nociception in animal models, new and effective treatments for patients with chronic pain have been lacking. The poor translation between mouse and human pain targets has highlighted limitations of animal models of pain. Recent advances in single-cell genomics and physiology directly in human tissue position pain researchers to make important new advances with improved opportunities for clinical translation. The Harvard PRECISION Human Pain Center proposes to leverage state- of-the-art single-cell technologies to characterize human nociceptor subtypes and how their gene expression patterns vary across diverse populations (Project 1) as well as in chronic pain conditions that clearly localize to these cells – chronic phantom limb pain associated with painful neuromas (Project 2). The Projects will generate a wealth of data for the scientific community by closely integrating with 5 Cores tasked with 1) procuring high- quality human pain-related tissues following strict regulatory practices, 2) offering the latest single-cell gene multi-omic technologies, 3) performing advanced single-cell spatial transcriptomic analysis, 4) managing, integrating, and distributing all of the data, and 5) administrating and connecting to Center the other PRECISION Human Pain Network Centers. The data generated by our Center will contribute to this broader PRECISION Human Pain Network and to help identify and prioritizate of novel pain therapeutic targets for future investigation.

PROJECT NARRATIVE Little is known about the molecular, structural, and physiology features of human nociceptors, the neurons responsible for detecting and transmitting pain signals to the brain. The proposed Harvard PRECISION Pain Center will provide fundamentally new insight into the molecules expressed in human nociceptors, how these molecular features correlate with nociceptor activity, and how they interact with the cells and molecules that are present in painful human neuromas that drive phantom limb pain. We envision that the intersection of these data types will have valuable implications for prioritizing new pain therapeutic targets and interpreting how human genetic variation contributes to chronic pain.