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 1

CalcrliLEC mice treated with NTG exhibit partially ameliorated chronic migraine pain.

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CalcrliLEC mice treated with NTG exhibit partially ameliorated chronic ...
(A) Experimental protocol representation. (B) Images of mouse facial expression of pain on Day 6, minute 42 following injection. Unit scores are depicted. E, ears; Y, eyes; N, nose; C, cheek. Sum of scores tallied bottom right. (C) Facial expression of pain measured 30 minutes after NTG injection and recorded for 20 minutes. Facial expression of pain is scored once per minute for the 20-minute recording duration and averaged. Mice were allowed to acclimate to the chamber 4 days before first injection (day 1) and 2 days before baseline measurement (day –1). **P < 0.01 between Calcrlfl/fl and CalcrliLEC treated with NTG. Mean grimace score on (D) day –1 (preinjection baseline) grouped by genotype. Colors indicate injection given later in experimental protocol, matching panel B. Mean Grimace Score on (E) day 3, and (F) day 9 of chronic migraine model. For C–F, n = 7–10 animals per group representing 4 independent cohorts. Significance calculated using 2-way ANOVA with Tukey’s multiple comparisons test. Graphs show mean ± SD. (G) Facial expression of pain for Ramp1–/– animals and controls. ***P < 0.001 between Ramp1–/– and WT treated with NTG. Mean grimace score on (H) day –1 (preinjection baseline) grouped by genotype. Colors indicate injection given later in experimental protocol, matching key in panel G. Not all animals were recorded for baseline. Mean grimace score on (I) day 1, and (J) day 7 of chronic migraine model. For G–J, n = 8–11 animals per group representing 3 independent cohorts. Significance calculated using 2-way ANOVA with Tukey’s multiple comparisons test. Graphs show mean ± SD.