Shear stress inhibits smooth muscle cell-induced inflammatory gene expression in endothelial cells: role of NF-kappaB.
OBJECTIVE
Vascular endothelial cells (ECs) are influenced by shear stress and neighboring smooth muscle cells (SMCs). We investigated the inflammation-relevant gene expression in EC/SMC cocultures under static condition and in response to shear stress.


METHODS
Under static condition, DNA microarrays and reverse-transcription polymerase chain reaction identified 23 inflammation-relevant genes in ECs whose expression was significantly affected by coculture with SMCs, with 18 upregulated and 5 downregulated. Application of shear stress (12 dynes/cm2) to the EC side of the coculture for 6 hours inhibited most of the proinflammatory gene expressions in ECs induced by coculture with SMCs. Inhibition of nuclear factor-kappaB (NF-kappaB) activation by the p65-antisense, lactacystin, and N-acetyl-cysteine blocked the coculture-induced EC expression of proinflammatory genes, indicating that the NF-kappaB binding sites in the promoters of these genes play a significant role in their expression as a result of coculture with SMCs. Chromatin immunoprecipitation assays demonstrated the in vivo regulation of NF-kappaB recruitment to selected target promoters. Shear stress inhibited the SMC coculture-induced NF-kappaB activation in ECs and monocytic THP-1 cell adhesion to ECs.


CONCLUSIONS
Our findings suggest that shear stress plays an inhibitory role in the proinflammatory gene expression in ECs located in close proximity to SMCs.
Chiu
Jeng-Jiann
JJ
Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan, Republic of China. jjchiu@nhri.org.tw
Chen
Li-Jing
LJ
Chang
Shun-Fu
SF
Lee
Pei-Ling
PL
Lee
Chih-I
CI
Tsai
Min-Chien
MC
Lee
Ding-Yu
DY
Hsieh
Hsing-Pang
HP
Usami
Shunichi
S
Chien
Shu
S
D002448:Cell Adhesion / Q000276:immunology; D002450:Cell Communication / Q000502:physiology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics; D002843:Chromatin / Q000502:physiology; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D047468:Immunoprecipitation; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D009000:Monocytes / Q000166:cytology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000502:physiology*; D052002:NF-kappa B p50 Subunit / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D013314:Stress, Mechanical; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism*; D014657:Vasculitis / Q000235:genetics / Q000276:immunology / Q000503:physiopathology*
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D002843:Chromatin; D052002:NF-kappa B p50 Subunit; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D018799:Intercellular Adhesion Molecule-1