AUTHOR=Liao SiJing , Zhou Fei-Ran , Li Qun , Jin Tao , Xiang Gui-Fang , Wang Xin , Liu Yan , Zhu Hq , Liu Qing , Liu Yuexin , Zhang Ying TITLE=Endoglin alleviates neuropathic pain by protecting the blood–spinal cord barrier through the TGF-β/Smad2 signaling pathway JOURNAL=Frontiers in Molecular Neuroscience VOLUME=Volume 18 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2025.1603619 DOI=10.3389/fnmol.2025.1603619 ISSN=1662-5099 ABSTRACT=IntroductionCentral neuroinflammation is pivotal in neuropathic pain pathogenesis, with blood-spinal cord barrier (BSCB) dysfunction recognized as a trigger for neuroinflammation and pain, though molecular mechanisms remain poorly understood.MethodsThrough comparative clinical studies measuring serum endoglin in postherpetic neuralgia (PHN) patients versus healthy controls, and animal investigations using spared nerve injury (SNI) rat models with recombinant endoglin intervention, we assessed mechanical/thermal hyperalgesia, microglial activation, inflammatory cytokines, BSCB permeability, and TGF-βRI/Smad2/NR2B phosphorylation.ResultsPHN patients exhibited lower serum endoglin versus controls; SNI rats showed reduced spinal endoglin compared to sham controls. Recombinant endoglin alleviated hyperalgesia while reversing microglial activation, inflammation, BSCB impairment, and NR2B phosphorylation. SNI decreased spinal TGF-βRI expression and Smad2 phosphorylation.DiscussionThese findings demonstrate that endoglin reduction disrupts BSCB integrity via TGF-β/Smad2 pathway inhibition in endothelial cells, driving microglial activation, neuroinflammation, and NR2B phosphorylation, thereby elucidating a key pain mechanism and identifying endoglin as a therapeutic target.