Project description:Fibrotic scar tissue formation is conserved throughout the central nervous system in humans and mice, and impairs tissue regeneration and functional recovery. However, the origin of scar-forming stromal fibroblasts is controversial. Here, we show that stromal fibroblasts found after spinal cord injury derive from two populations of perivascular cells that are anatomically and transcriptionally defined as pericytes and perivascular fibroblasts. We identify two distinct perivascular cell populations, which activate and transcriptionally converge on the generation of stromal myofibroblasts after injury. Our results suggest potential targets to improve tissue regeneration and functional recovery after central nervous system injuries.
Project description:Fibrotic scar tissue formation is conserved throughout the central nervous system in humans and mice, and impairs tissue regeneration and functional recovery. However, the origin of scar-forming stromal fibroblasts is controversial. Here, we show that stromal fibroblasts found after spinal cord injury derive from two populations of perivascular cells that are anatomically and transcriptionally defined as pericytes and perivascular fibroblasts. We identify two distinct perivascular cell populations, which activate and transcriptionally converge on the generation of stromal myofibroblasts after injury. Our results suggest potential targets to improve tissue regeneration and functional recovery after central nervous system injuries.
Project description:Fibrotic scar tissue formation is conserved throughout the central nervous system in humans and mice, and impairs tissue regeneration and functional recovery. However, the origin of scar-forming stromal fibroblasts is controversial. Here, we show that stromal fibroblasts found after spinal cord injury derive from two populations of perivascular cells that are anatomically and transcriptionally defined as pericytes and perivascular fibroblasts. We identify two distinct perivascular cell populations, which activate and transcriptionally converge on the generation of stromal myofibroblasts after injury. Our results suggest potential targets to improve tissue regeneration and functional recovery after central nervous system injuries.
Project description:Scar formation is a major hindrance to central nervous system regeneration upon traumatic injury. Glial cells are key players during the wound healing process, and their reaction to injury determines the extent of tissue restoration. Here, we used the regenerative potential of the zebrafish telencephalon to identify specific molecular and cellular mechanisms regulating glial scar formation. We demonstrated that contact of the cerebrospinal fluid with the brain parenchyma after injury activates toll-like receptor 2 (Tlr2) and the chemokine receptor 3 (Cxcr3) innate immunity pathways leading to initiation of a glial scar. These pathways were critical for scarring even after ablation of microglia and infiltrating monocytes. Our data support a specific role for the injury-induced Tlr1/2 and Cxcr3 signaling pathways in controlling proliferation of the oligodendrocyte progenitors and therefore exacerbated glial reactivity, contributing to scar formation. Interference with the Tlr1/2 and Cxcr3 pathways after injury alleviated glial scar formation and improved tissue restoration.
Project description:Deficiency in hematopoietic phosphatase Ptpn6/Shp1 hyperactivates the innate immune system and impairs control of bacterial infections in zebrafish embryos
Project description:In mammals, retinal damage is followed by Müller glia cell activation and proliferation. While retinal gliosis persists in adult mammals after an insult or disease, some vertebrates, including zebrafish, have the capacity to regenerate. We believe we are the first group to show that gliosis is a fibrotic-like process in mammals’ eyes caused by differential activation of canonical and non-canonical TGFβ signaling pathways.
