Conditioned media from CGRP-stimulated primary cultures of vascular smooth muscle cells induce migraine-like responses following application to the mouse dura
Editor’s note: The research described below comes from a recipient of a 2026 MSC Travel Grant supporting travel to the 68th Annual Scientific Meeting of the American Headache Society. These grants reimburse travel expenses for those who have had their abstract for a presentation or poster accepted at a meeting.
By Shiva Nematgorgani, PhD, PhD student, UT Dallas.
What is the research gap that your study addresses?
This study addresses a key research gap by investigating the unknown mechanism linking CGRP receptor activation on vascular smooth muscle cells (VSMCs) to meningeal nociceptor sensitization and migraine headache, independent of vasodilation.
It shows that CGRP-stimulated VSMCs release mediators that, when applied to the dura, induce migraine-like behavior in mice. This reveals a non-vasodilatory vascular contribution to migraine.
What is your research hypothesis?
We propose that CGRP stimulation of VSMCs triggers the secretion of distinct factors that, when released near dural afferents, induce migraine-like behavioral responses in female mice. This mechanism may, in part, explain how CGRP contributes to migraine pathophysiology through a non-vasodilatory vascular pathway.
What methodology did you use to address your research hypothesis?
To investigate the aim of our study, primary VSMCs were isolated and cultured from mouse aortas. Cells were treated with calcitonin gene-related peptide, after which conditioned media were collected to assess the effects of factors released by VSMCs following CGRP stimulation. Then, 5 µL of conditioned media was applied to the mouse dura using a non-invasive dural injection model. To evaluate migraine-like behaviors in female mice, periorbital mechanical sensitivity was assessed using von Frey filaments, and facial grimace scoring was performed at multiple time points.
What are the main results of your study?
Dural application of conditioned media from CGRP-treated VSMCs induced significant reductions in periorbital withdrawal thresholds from 3 to 24 hours after dural injection compared with the vehicle group, indicating increased facial hypersensitivity. Moreover, facial grimace scores were elevated, particularly at early post-injection time points. Conditioned media from vehicle-treated VSMCs did not show comparable behavioral changes.
What conclusions did you reach based on your results?
These findings demonstrate that CGRP stimulation of vascular smooth muscle cells may generate factors that promote migraine-like behaviors when applied to the dura. The results support the hypothesis that vascular cells contribute to migraine pathophysiology by releasing pro-nociceptive mediators, independent of vasodilation.
What are the limitations of your study?
Our study results are from mouse VSMCs and mouse migraine models, and their relevance to human migraine pathophysiology is still uncertain. Also, our study applies a mixture of all secreted factors from CGRP-stimulated VSMCs rather than identifying specific mediators. In the future, we will find the exact molecules responsible for sensitizing nociceptors.
What is the relevance of your study to migraine?
Our findings demonstrate that vascular smooth muscle cells, upon CGRP stimulation, release mediators that sensitize meningeal nociceptors and induce migraine-like pain behaviors in mice, independent of vasodilation. This reveals a novel non-vasodilatory vascular mechanism in migraine pathophysiology. By identifying a previously missing link between CGRP action on blood vessels and actual headache generation, this work provides new mechanistic insight. It also opens the door to discovering new therapeutic targets beyond direct neuronal CGRP signaling.