Transcriptome of Chronic Pain and Disease

The Functional Genomics Section (FGS) is a part of the National Institute of Dental and Craniofacial Research (NIDCR) within the National Institutes of Health (NIH). Research at the FGS focuses on understanding the mechanics involved in nociception through both clinical samples from patients with chronic pain and mouse models of pain. Pain is relayed from the periphery to the central nervous system through specialized sensory neurons known as nociceptors. The cell body of nociceptors resides in neuronal structures that branch off of the spinal cord known as dorsal root ganglia (DRG). The DRG is a heterogenous tissue containing not only sensory neurons like nociceptors, but also glial cells, capillaries, fibroblasts, and resident macrophages. The interaction between the nociceptors and these DRG cell types can have a significant role in affecting neuronal hyperexcitability and downstream pain sensitivity. To better understand the cellular factors involved in producing conditions of chronic pain, DRGs from consenting organ donors were collected from individuals experiencing pain disorders such as painful diabetic neuropathy and rheumatoid arthritis. A multi-omics approach is being used to identify molecular mechanisms that lead to pain hypersensitivity in patients with chronic pain.  ]]>
DRGs were collected from cadaveric organ donors for research purposes, including biochemical and genomic analyses. DRGs can typically be obtained only from post-mortem, often after years of chronic illness. DRGs were collected under cold ischemic conditions immediately following recovery of the transplant organs, generally within 3 hours of post cross-clamp of the aorta. Individuals in the study were ranged between 30-70 years of age. Cause of death for most subjects, including controls, was either from cerebrovascular accident/stroke or head trauma/blunt injury. For a statistical analysis, a cohort of 5 or more individuals experiencing the same single chronic pain disorder was selected for study. The examined chronic pain conditions include painful diabetic neuropathy and rheumatoid arthritis. The controls were donors without known history of chronic pains, such as osteoarthritis, back pain, chronic knee pain, etc.  ]]>