Meningeal lymphatic CGRP signaling governs pain via cerebrospinal fluid efflux and neuroinflammation in migraine models
Nathan P. Nelson-Maney, László Bálint, Anna L.S. Beeson, D. Stephen Serafin, Bryan M. Kistner, Elizabeth S. Douglas, Aisha H. Siddiqui, Alyssa M. Tauro, Kathleen M. Caron
Nathan P. Nelson-Maney, László Bálint, Anna L.S. Beeson, D. Stephen Serafin, Bryan M. Kistner, Elizabeth S. Douglas, Aisha H. Siddiqui, Alyssa M. Tauro, Kathleen M. Caron
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Research Article Cell biology Vascular biology

Meningeal lymphatic CGRP signaling governs pain via cerebrospinal fluid efflux and neuroinflammation in migraine models

Abstract

Recently developed antimigraine therapeutics targeting calcitonin gene–related peptide (CGRP) signaling are effective, though their sites of activity remain elusive. Notably, the lymphatic vasculature is responsive to CGRP signaling, but whether meningeal lymphatic vessels (MLVs) contribute to migraine pathophysiology is unknown. Mice with lymphatic vasculature deficient in the CGRP receptor (CalcrliLEC mice) treated with nitroglycerin-mediated (NTG-mediated) chronic migraine exhibit reduced pain and light avoidance compared with NTG-treated littermate controls. Gene expression profiles of lymphatic endothelial cells (LECs) isolated from the meninges of Rpl22HA/+;Lyve1Cre RiboTag mice treated with NTG revealed increased MLV-immune interactions compared with cells from untreated mice. Interestingly, the relative abundance of mucosal vascular addressin cell adhesion molecule 1–interacting (MAdCAM1-interacting) CD4+ T cells was increased in the deep cervical lymph nodes of NTG-treated control mice but not in NTG-treated CalcrliLEC mice. Treatment of cultured hLECs with CGRP peptide in vitro induced vascular endothelial–cadherin (VE-cadherin) rearrangement and reduced functional permeability. Likewise, intra cisterna magna injection of CGRP caused rearrangement of VE-cadherin, decreased MLV uptake of cerebrospinal fluid (CSF), and impaired CSF drainage in control mice but not in CalcrliLEC mice. Collectively, these findings reveal a previously unrecognized role for lymphatics in chronic migraine, whereby CGRP signaling primes MLV-immune interactions and reduces CSF efflux.

Authors

Nathan P. Nelson-Maney, László Bálint, Anna L.S. Beeson, D. Stephen Serafin, Bryan M. Kistner, Elizabeth S. Douglas, Aisha H. Siddiqui, Alyssa M. Tauro, Kathleen M. Caron

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Figure 8

CGRP reduces CSF uptake into MLVs.

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CGRP reduces CSF uptake into MLVs. (A) Schematic of MLV anatomy. Blue da...
(A) Schematic of MLV anatomy. Blue dashed square indicates location assessed, while the white dashed square indicates the location for dye measurement, as visualized in B. The asterisk (*) indicates the space outside the sinus. Scale bar: 200 μm. (B) Left, representative image of LYVE1+ (Green) MLVs outlined with white dashed line. Right, EB fluorescence in black. Black dashed line, MLV border. Scale bar: 50 μm. (C) Representative integrated fluorescence intensity across MLV measured using plot profile feature in ImageJ. An average background fluorescence intensity for each field was measured and subtracted from raw EB fluorescence intensity values. Green line, LYVE1 MFI, Blue line, EB MFI, Blue box, margins of MLV. (D) Quantification of background adjusted integral of EB intensity across MLV. n = 3 animals 1 drainage site assessed per animal from 3 independent cohorts. Graph shows mean ± SD. Significance calculated using 2-way ANOVA with Tukey’s multiple comparisons test. P value shown if less than 0.05.