Dexamethasone suppresses JMJD3 gene activation via a putative negative glucocorticoid response element and maintains integrity of tight junctions in brain microvascular endothelial cells.
The blood-brain barrier (BBB) exhibits a highly selective permeability to support the homeostasis of the central nervous system (CNS). The tight junctions in the BBB microvascular endothelial cells seal the paracellular space to prevent diffusion. Thus, disruption of tight junctions results in harmful effects in CNS diseases and injuries. It has recently been demonstrated that glucocorticoids have beneficial effects on maintaining tight junctions in both in vitro cell and in vivo animal models. In the present study, we found that dexamethasone suppresses the expression of JMJD3, a histone H3K27 demethylase, via the recruitment of glucocorticoid receptor α (GRα) and nuclear receptor co-repressor (N-CoR) to the negative glucocorticoid response element (nGRE) in the upstream region of JMJD3 gene in brain microvascular endothelial cells subjected to TNFα treatment. The decreased JMJD3 gene expression resulted in the suppression of MMP-2, MMP-3, and MMP-9 gene activation. Dexamethasone also activated the expression of the claudin 5 and occludin genes. Collectively, dexamethasone attenuated the disruption of the tight junctions in the brain microvascular endothelial cells subjected to TNFα treatment. Therefore, glucocorticoids may help to preserve the integrity of the tight junctions in the BBB via transcriptional and post-translational regulation following CNS diseases and injuries.
1 Department of Life Science, Sogang University, Seoul, Korea.
Wonho
W
Na
1 Department of Life Science, Sogang University, Seoul, Korea.
Jee Y
JY
Shin
2 Age-Related and Brain Diseases Research Center, Kyung Hee University, Seoul, Korea.
Jee Y
JY
Lee
3 Department of Molecular Biology, Chonbuk National University, Jeonju, Korea.
Sangyun
S
Jeong
1 Department of Life Science, Sogang University, Seoul, Korea.
Won-Sun
WS
Kim
2 Age-Related and Brain Diseases Research Center, Kyung Hee University, Seoul, Korea.|4 Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Korea.
Tae Y
TY
Yune
1 Department of Life Science, Sogang University, Seoul, Korea.
Bong-Gun
BG
Ju
D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000187:drug effects; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology*; D056484:Jumonji Domain-Containing Histone Demethylases / Q000235:genetics*; D051379:Mice; D055806:Microvessels / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D019108:Tight Junctions / Q000187:drug effects* / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; D014409:Tumor Necrosis Factor-alpha; C411470:glucocorticoid receptor alpha; D003907:Dexamethasone; D056484:Jumonji Domain-Containing Histone Demethylases; C523761:Kdm6b protein, mouse
Jmjd3; blood–brain barrier; dexamethasone; negative GRE; tight junction disruption