Cellular and molecular characterization and origin of leukocytes accumulated in the dorsal root meninges after peripheral and nerve injuries

• Grant number: 23/07031-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2023
• End date: August 31, 2025
• Field of knowledge: Biological Sciences - Pharmacology - General Pharmacology
• Principal Investigator: Thiago Mattar Cunha
• Grantee: Glauce Regina Pigatto
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 13/08216-2 - CRID - Center for Research in Inflammatory Diseases, AP.CEPID

Abstract

Injuries and diseases affecting the somatosensory system lead to the development of neuropathic pain. The genesis and maintenance of this condition are determined by alterations in the nociceptive sensory apparatus that increase pain sensitivity. Many of these changes are mediated by the activity of immune cells present in central and peripheral sites of pain modulation, such as the spinal cord or the dorsal root ganglia (DRG). Recently, our research group demonstrated that following peripheral nerve injury, immune cells, specifically dendritic cells (DCs), accumulate in the meninges of the dorsal roots and spinal cord near the ipsilateral DRGs to the injury, mediating the development of neuropathic pain. However, the cellular and molecular profile of the various types of immune cells that accumulate in this tissue and the pathways through which they are recruited have not yet been elucidated. Therefore, the objective of this project is to identify the recruited cells in the leptomeninges of neuropathic animals, as well as to characterize their transcriptional profile and the pathway through which these cells reach the mentioned structure. To do so, we intend to use the state-of-the-art technique of single-cell RNA sequencing (scRNAseq). The use of this approach will allow us to accurately determine the profile of the cellular populations present in the meninges after peripheral nerve injury. The scRNAseq results will be validated by multiparametric flow cytometry analyses. In addition, we will investigate the structures that serve as a passage for the recruited cells to this tissue. Unpublished preliminary data from our group indicate two possibilities: a) some of these cells migrate from the periphery (blood); b) bone marrow (BM) cells from the vertebral bones gain direct access to the dorsal meninges through ossified channels in these bones (see preliminary data). We will delve into understanding which subtypes of leukocytes use a particular pathway. Given the above, our project aims to contribute to the understanding of a newly described biological process by our group, as well as the description of new mechanisms involved in the development of neuropathic pain associated with the recruitment of these cells to the meninges after peripheral nerve injury. (AU)