Discovery of Potent Cyclic Sulfopeptide Chemokine Inhibitors via Reprogrammed Genetic Code mRNA Display
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Authors: Johansen-Leete, Jason; Passioura, Toby; Foster, Simon R.; Bhusal, Ram Prasad; Ford, Daniel J.; Liu, Minglong; Jongkees, Seino A. K.; Suga, Hiroaki; Stone, Martin J.; Payne, Richard J.
Abstract
Targeting chemokine signaling is an attractive avenue for the treatment of inflammatory disorders. Tyrosine sulfation is an important post-translational modification (PTM) that enhances chemokine-receptor binding and is also utilized by a number of pathogenic organisms to improve the binding affinity of immune-suppressive chemokine binding proteins (CKBPs). Here we report the display selection of tyrosine-sulfated cyclic peptides using a reprogrammed genetic code to discover high-affinity ligands for the chemokine CCL11 (eotaxin-1). The selected cyclic sulfopeptides possess high affinity for the target chemokine (as well as one or more of the related family members CCL2, CCL7 and CCL24) and inhibit CCL11 activation of CC chemokine receptor 3 (CCR3). This work demonstrates the utility of exploiting native PTMs as binding motifs for the generation of new leads for medicinal chemistry.
Upregulated C-C Motif Chemokine Ligand 2 Promotes Ischemic Stroke via Chemokine Signaling Pathway
ANNALS OF VASCULAR SURGERY
Authors: Li, Lin; Lou, Weimin; Li, Hailong; Zhu, Yuehong; Huang, Xiong'ang
Abstract
Background: This study aims to evaluate the potential effect and the underlying mechanism of C-C motif chemokine ligand 2 (CCL2) in ischemic stroke. Methods: An integrated bioinformatics analysis was performed to identify the differentially expressed (DE) genes and their related pathways in ischemic stroke. In vivo study of a rat model of middle cerebral artery occlusion (MCAO) was further established to assess the effect of CCL2 on severity of neurologic impairments. The expression levels of proinflammatory cytokines were also evaluated using the ELISA assay, and Western blot was also used to determine the expression of CCL2 and other DE proteins in the related pathways. Results: A total of 88 DE genes were identified from the microarray dataset of ischemic stroke. The bioinformatics analysis revealed that CCL2 was highly expressed in ischemic stroke tissue and promoted the ischemic stroke progression via activation of the chemokine signaling pathway and cytokine-cytokine receptor interaction pathway. The in vivo study of the ischemic stroke rat model also showed that the CCL2 expression was elevated in the MCAO/R rats, with significant neurological impairments and ischemic infarct area in the brain tissue being observed. The administration of CCL2 inhibitors significantly inhibited the inflammatory response, attenuated the neurological impairments, and decreased the ischemic infarct area in the MCAO/R rats. Furthermore, the downregulation of CCL2 also inhibited the expression of the pathway-related proteins including CCL7, CCR2, CXCL16, and TNF-alpha. Conclusions: These results indicate that the CCL2/chemokine signaling pathway is responsible for ischemic stroke progression and might represent a potential therapeutic target for ischemic stroke treatment.