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Laaker, C.

Publications and source records attributed to Laaker, C..

3 recordsLinked to original sources

Cribriform Plate Microenvironment Assembles a Suppressive Myeloid Network during EAE-induced Neuroinflammation

During neuroinflammation, CD11c+CD11b+ myeloid cells accumulate at the cribriform plate, a key cerebrospinal fluid (CSF) and antigen outflow site in mice. At this site, podoplanin (PDPN)-expressing cells, including lymphatic vessels and meningeal layers, expand to create a distinct drainage microenvironment. In this study we sought to characterize myeloid cells which populate this region using a mouse model of neuroinflammation, experimental autoimmune encephalomyelitis (EAE). Utilizing a combination of immunohistochemistry, flow cytometry, and scRNAseq, we report that macrophages and dendritic cells (DCs) from this region display unique expressional signatures related to tolerance, cell death, and reduced inflammatory profile. Together this data supports that myeloid retention at the cribriform plate and olfactory bulb meninges promotes a local immunosuppressive environment.

immunology↗

Dual role of Vascular Endothelial Growth Factor-C (VEGF-C) in post-stroke recovery

Using a mouse model of ischemic stroke, this study characterizes stroke-induced lymphangiogenesis at the cribriform plate (CP). While blocking CP lymphangiogenesis with a VEGFR-3 inhibitor improves stroke outcome, administration of VEGF-C induced larger brain infarcts. AbstractCerebrospinal fluid (CSF), antigens, and antigen-presenting cells drain from the central nervous system (CNS) into lymphatic vessels near the cribriform plate and dural meningeal lymphatics. However, the pathological roles of these lymphatic vessels surrounding the CNS during stroke are not well understood. Using a mouse model of ischemic stroke, transient middle cerebral artery occlusion (tMCAO), we show that stroke induces lymphangiogenesis near the cribriform plate. Interestingly, lymphangiogenesis is restricted to lymphatic vessels at the cribriform plate and downstream cervical lymph nodes, without affecting the conserved network of lymphatic vessels in the dura. Cribriform plate lymphangiogenesis peaks at day 7 and regresses by day 14 following tMCAO and is regulated by VEGF-C/VEGFR-3. These newly developed lymphangiogenic vessels transport CSF and immune cells to the cervical lymph nodes. Inhibition of VEGF-C/VEGFR-3 signaling using a blocker of VEGFR-3 prevented lymphangiogenesis and led to improved stroke outcomes at earlier time points but had no effects at later time points following stroke. Administration of VEGF-C after tMCAO did not further increase post-stroke lymphangiogenesis, but instead induced larger brain infarcts. The differential roles for VEGFR-3 inhibition and VEGF-C in regulating stroke pathology call into question recent suggestions to use VEGF-C therapeutically for stroke.

immunology↗

Neuroinflammation alters the phenotype of lymphangiogenic vessels near the cribriform plate.

Meningeal lymphatic vessels residing in the dural layer surrounding the dorsal regions of the brain, basal regions, and near the cribriform plate have all been implicated in the management of neuroinflammation and edema. Interestingly, only the lymphatic vessels near the cribriform plate undergo functional lymphangiogenesis in a mouse model of Multiple Sclerosis, suggesting these particular lymphatics uniquely undergo dynamic changes in response to neuroinflammation and may have distinct access to pro-lymphangiogenic factors in the CNS. However, it is unknown if these newly formed lymphangiogenic vessels are functionally similar to steady-state or if they have any other functional changes during neuroinflammation. In this study, we generated a novel protocol to isolate lymphatic endothelial cells from the cribriform plate for single cell analysis. We demonstrate that neuroinflammation-induced lymphangiogenic vessels undergo unique changes, including the capture of CNS-derived antigens, upregulation of adhesion and immune-modulatory molecules to interact with dendritic cells, and display IFN-{gamma} dependent changes in response to the microenvironment. Single-cell trajectory analysis showed that cribriform plate lymphangiogenic vessels are post-proliferative and not generated from trans-differentiation of myeloid cells. Additionally, we show that these lymphangiogenic vessels have access to a CSF reservoir, express the water pore Aquaporin-1, and may have direct access to the CSF due to gaps in the arachnoid epithelial layer separating the dura from the subarachnoid space. These data characterize cribriform plate lymphatics and demonstrate that these vessels are dynamic structures that engage in leukocyte interactions, antigen sampling, and undergo expansion to drain excess fluid during neuroinflammation. Neuroinflammation not only induces efficient drainage of CSF but also alters the functions of lymphatic vessels near the cribriform plate.

immunology↗