Program Director/Principal Investigator (Last, First, Middle): Nowak, Romana A. Endometriosis is an inflammatory disease that affects 10% of women but is present in up to 70% of women with pelvic pain and 30% of women with infertility. The estimated cost of endometriosis is over $22 billion in the US alone, not counting associated chronic illnesses. Thus it is safe to say that endometriosis is one of the costliest reproductive diseases in women not only in terms of treatment but also lost productivity and quality of life in affected patients. The mechanisms involved in the development and maintenance of persistent or chronic pain are not fully understood. One potential mechanism is the process of ?central sensitization?, whereby long lasting molecular changes promote neuroplasticity of nociceptive neurons within the central nervous system (CNS) resulting in amplification of pain signaling. The development of central sensitization involves changes to neuronal and glial cell populations. Neural changes have been studied in endometriosis and it has been suggested that pain attributed to endometriosis is likely to involve neuronal processes leading to central sensitization. However, a potential role for glia has yet to be investigated. Our hypothesis is that mice with endometriosis will show significant changes in the activation state and function of glial cells in the brain and spinal cord in response to persistent pro-inflammatory signaling from activated macrophages in ectopic lesions and peritoneal fluid and that this activation contributes to the development of chronic visceral pain. The goal of this exploratory research proposal is to begin testing this hypothesis using an in vivo mouse model of endometriosis to determine whether the presence of endometriotic lesions and the subsequent activation of pro-inflammatory macrophages in the peritoneum and endometriotic lesions causes substantial alterations in the proliferation, activation status and gene expression in glial cells of the spinal cord and brain. We will test this hypothesis in two specific aims: 1): To characterize changes in activation and proliferation of glial cells in the brain and spinal cord of mice that develop endometriosis and correlate these changes with development of chronic visceral pain. This will be determined by comprehensive immunohistochemical analyses of brains and spinal cords of mice with lesions as well as a panel of behavior tests that assess pain. 2): To sequence and identify genome-wide transcriptional alterations in microglia of the brain and spinal cord of mice with endometriosis. We will utilize single cell RNAseq (scRNAseq) technology to analyze changes in gene expression over time in purified populations of glial cells in spinal cords and brains of mice bearing endometriotic lesions and compare these changes with mice that have undergone sham transplantation surgery. PHS 398/2590 (Rev. 06/09) Page Continuation Format Page
The long term goal of this project is to address critical gaps in our knowledge about the molecular mechanisms and signaling pathways that lead to the development of chronic pelvic pain in endometriosis. We will use a mouse model of endometriosis to investigate the inflammatory response of glial cells in the spinal cord and brain in response to inflammatory macrophages in the peritoneum and endometriotic lesions and how this activation leads to central sensitization and chronic visceral pain. .