TY - JOUR T1 - Paeonol attenuates LPS-induced endothelial dysfunction and apoptosis by inhibiting BMP4 and TLR4 signalling simultaneously but independently JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther DO - 10.1124/jpet.117.245217 SP - jpet.117.245217 AU - Ker Woon Choy AU - Yeh Siang Lau AU - Dharmani Murugan AU - Paul M. Vanhoutte AU - Mohd Rais Mustafa Y1 - 2017/01/01 UR - http://jpet.aspetjournals.org/content/early/2017/12/19/jpet.117.245217.abstract N2 - Inflammatory injury of the endothelium leads to apoptosis and endothelial dysfunction. The current study explored the effect and mechanisms of paeonol in inflammation-induced apoptosis and endothelial dysfunction induced by lipopolysaccharides (LPS). The effects of paeonol on LPS-induced inflammatory injury were assessed by Western blotting, flow cytometry and reactive oxygen species (ROS) measurement in human umbilical vein endothelial cells (HUVECs) and C57BL/6J mice. Vascular reactivity of isolated mouse aortae was examined using wire myographs. Exposure of HUVECs to LPS increased the protein presence of toll like receptor 4 (TLR4), bone morphogenic protein 4 (BMP4), BMP receptor type 1A (BMPR1A), nicotinamide adenine dinucleotide phosphate oxidase subunit 2 (NOX2), mitogen-activated protein kinases (MAPK), inducible nitric oxide synthase (iNOS) and cleaved caspase 3 as well as decreased in phosphorylated endothelial nitric oxide synthase (eNOS); these effects were prevented by treatment with paeonol. Similarly, co-treatment with paeonol reversed BMP4-induced apoptosis in HUVECs. Relaxations to the endothelium-dependent vasodilator acetylcholine were impaired in mouse aortae after exposure to LPS; this endothelial dysfunction was reversed by co-treatment with paeonol, noggin (BMP4 inhibitor), TAK242 (TLR4 antagonist), apocynin (ROS scavenger), MAPK inhibitors and aminoguanidine (iNOS inhibitor). BMP4 siRNAs abolished LPS-induced upregulation of BMP4 and cleaved caspase 3 protein but not in cells treated with TLR4 siRNA, and vice versa. Silencing of TLR4 and BMP4 abolished the inhibitory effects of paeonol on LPS-induced activation of cleaved caspase 3. The present results demonstrate that paeonol reduces LPS-induced endothelial dysfunction and apoptosis by inhibiting TLR4 and BMP4 signalling independently. ER -