Research Paper Volume 11, Issue 23 pp 11391—11415

Melatonin protects blood-brain barrier integrity and permeability by inhibiting matrix metalloproteinase-9 via the NOTCH3/NF-κB pathway

Weiwei Qin 1, *, , Jing Li 2, *, , Rongjia Zhu 2, , Suhua Gao 3, , Junfen Fan 2, , Mingrong Xia 1, , Robert Chunhua Zhao 2, , Jiewen Zhang 1, ,

  • 1 Department of Neurology, State Key Clinical Specialty of the Ministry of Health for Neurology, Henan Provincial People’s Hospital, School of Clinical Medicine, Henan University, Zhengzhou, Henan, China
  • 2 Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Center of Excellence in Tissue Engineering Chinese Academy of Medical Sciences, Beijing Key Laboratory (No. BZO381), Beijing 100005, China
  • 3 Department of Scientific Research and Discipline Construction, Henan Provincial People’s Hospital, Zhengzhou, Henan, China
* Equal contribution

received: September 7, 2019 ; accepted: November 19, 2019 ; published: December 7, 2019 ;
How to Cite

Copyright © 2019 Qin et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


The pathophysiological mechanism of white matter hyperintensities of cerebral small vessel disease (CSVD) includes an impaired blood-brain barrier (BBB) with increased permeability. Neuroinflammation likely contributes to the disruption of the BBB in CSVD. Therefore, understanding the molecular mechanism of how neuroinflammation causes BBB damage is essential to preventing BBB disruption in CSVD. Matrix metalloproteinase 9 (MMP-9) contributes to BBB damage in neuroinflammatory diseases. In this study, we observed that interleukin-1β (IL-1β)-induced MMP-9 secretion in pericytes increased BBB permeability to sodium fluorescein (Na-F) by damaging the disruption of VE-cadherin, occludin, claudin-5, and zonula occludin-1 (ZO-1). Melatonin reduced BBB permeability to Na-F and inhibited the disruption of the adherens and tight junction proteins. Melatonin also downregulated MMP-9 and upregulated tissue inhibitor of metalloproteinases 1 (TIMP-1) gene expression, which decreased the MMP-9/TIMP-1 ratio. In addition, nuclear translocation of NF-κB/p65 induced by IL-1β in pericytes upregulated MMP-9 expression, which was inhibited by the NF-κB inhibitor PDTC. However, the NOTCH3 inhibitor DAPT significantly inhibited NF-κB/p65 translocation to the nucleus, while melatonin in combination with DAPT significantly prevented NF-κB/p65 translocation than DAPT alone. Our results suggest that melatonin reduced MMP-9-induced permeability of the BBB. Melatonin reduced MMP-9 expression and activity, which was induced by IL-1β through the regulation of the NOTCH3/NF-κB signaling pathway in pericytes, suggesting that pericytes regulate BBB integrity and function.


CSVD: cerebral small vessel disease; CNS: central nervous system; BBB: blood-brain barrier; IL-1β: interleukin-1β; Na-F: sodium fluorescein; ZO-1: zonula occludin-1; MMP-9: matrix metalloproteinase 9; MMP-2: matrix metalloproteinase 2; TIMP-1: tissue inhibitor of metalloproteinases 1; TIMP-2: tissue inhibitor of metalloproteinases 2; NF-κB: nuclear factor κB; WMH: white matter hyperintensities; MRI: magic resonance imaging; AD: Alzheimer’s disease; PD: Parkinson’s disease; MS: multiple sclerosis; CADASIL: cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy; α-SMA: α-smooth muscle actin; NG2: neuron-glial antigen 2; vWF: von Willebrand factor; GFAP: glial fibrillary acidic protein; DAPT: N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butyl ester; PDTC: pyrrolidinedithiocarbamate ammonium; MEL: melatonin; HUVEC: human umbilical vein endothelial cells; hPSC: human pluripotent stem cells; TNF-α: tumor necrosis factor alpha; DAPI: 4′,6-diamidino-2-phenylindole.