The Penn Human Precision Pain Center (HPPC): Discovery and Functional Evaluation of Human Primary Somatosensory Neuron Types at Normal and Chronic Pain Conditions

Abstract Text

Migraine, one of the most common primary headache disorders, affects 1 in 4 US households. This complex neurologic disorder is mediated in part by alterations in trigeminal somatosensation, which manifests as head/fa- cial pain and/or trigeminal allodynia. Effective treatments for migraine are still limited, and our knowledge about human trigeminal system at baseline and migraine conditions are sparse. In response to RFA-NS-22-018, HEAL Initiative: Discovery and Functional Evaluation of Human Pain-associated Genes & Cells, we propose to form the Penn Human Precision Pain Center (Penn HPPC) to elucidate molecular, cellular, epigenetic, and physiological profiles of human trigeminal ganglion (TG) sensory neurons at baseline and migraine conditions. The Penn HPPC will be composed of Penn and international investigators with multidisciplinary expertise. The PI, two MPIs, and two co-Is are currently collaborating on a single-soma deep RNA-seq of human dorsal root ganglion (DRG) neuron project, which form a strong foundation for this application. Specifically, the Penn HPPC will contain three cores and perform three projects. The administrative core will serve as a sole organizational and administrative entity for the Penn HPPC. The human tissue core will function as the sole entity for procuring and storing human tissues and distributing human tissues among research projects. The data core will be the sole entity for storage, processing, and distribution of all data from the HPPC projects. In project 1, we will employ three complementary approaches, a laser capture microdissection based single-neuron-soma deep RNA-seq (a novel method developed by the PI’s lab, which has been successfully used with human DRG neu- rons), 10 x Visium (a commercially available spatial transcriptomics platform), and MERSCOPE (another com- mercially available spatial transcriptomics platform) to conduct single-soma RNA-seq of neurons and non-neu- ronal cells of TGs from control donors and those with migraine. In project 2, we will perform two types of single- nucleus multi-omics sequencing with TGs from control donors and those with migraine: chromatin accessibility (ATAC plus RNA, 10x Genomics multiome assay) and DNA methylation (methylation plus RNA, snmCAT-seq). In project 3, we will recruit migraine patients and control human subjects to conduct pain questionnaires, soma- tosensory tests, blink reflex, and in vivo microneurography recordings of trigeminal and spinal sensory afferents. Together, our proposed Penn HPPC will produce comprehensive and multi-dimensional datasets of human TGs at baseline and migraine conditions, which will generate unprecedent molecular, cellular, and functional atlas to understand normal trigeminal sensations and abnormal sensations associated with migraine. Our results may also lead to discovery of new biomarkers for migraine diagnosis and/or identification of novel potential drug targets for migraine treatment.