Toll-like receptors 2 and 4 mediate hyperglycemia induced macrovascular aortic endothelial cell inflammation and perturbation of the endothelial glycocalyx.
J Diabetes Complications 2016;
30:563-72. [PMID:
26908090 DOI:
10.1016/j.jdiacomp.2016.01.014]
[Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVES
Hyperglycemia-induced inflammation is central to the vascular complications in diabetes. Toll-like receptors (TLRs) are key players in regulating inflammatory responses. There are sparse data on the role of TLR2 and TLR4 in regulating human macrovascular aortic endothelial cells (HMAECs) inflammation and glycocalyx dysfunction under hyperglycemia. We examined the role of TLR2/4 in the above dysfunctions in HMAEC under high glucose (HG) conditions.
METHODS
HMAECs were treated with high or normal glucose and TLR-2, TLR-4, MyD88, IRF3, TRIF, nuclear NF-κB p65, IL-8, IL-1β, TNF-α, MCP-1, ICAM-1, sVCAM-1, monocyte adhesion to HMAECs, heparan sulfate and hyaluronic acid were measured.
RESULTS
HG upregulated TLR2 and TLR4 mRNA and protein and increased both MyD88 and non-MyD88 pathways, NF-κB p65, inflammatory biomediators, and monocyte adhesion to HMAECs. Heparan sulfate protein expression was reduced and hyaluronic acid secretion was increased on HG exposure. Inhibition of TLR2 and TLR4 signaling by inhibitory peptides and knockdown of TLR-2 and TLR-4 gene expression by siRNA attenuated HG induced inflammation, leukocyte adhesion and glycocalyx dysfunction. An increase in ROS paralleled the increase in TLR-2/4 and antioxidants treatment reduced TLR-2/4 expression and downstream inflammatory biomediators.
CONCLUSION
Thus hyperglycemia induces HMAEC inflammation and glycocalyx dysfunction through TLR-2/4 pathway activation via increased ROS.
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