Relative distribution and biological characterization of CXCL4L1 isoforms in platelets from healthy donors

The Role of Post-Translational Modifications of Chemokines by CD26 in Cancer

Chemokines are a large family of small chemotactic cytokines that fulfill a central function in cancer. Both tumor-promoting and -impeding roles have been ascribed to chemokines, which they exert in a direct or indirect manner. An important post-translational modification that regulates chemokine activity is the NH₂-terminal truncation by peptidases. CD26 is a dipeptidyl peptidase (DPPIV), which typically clips a NH₂-terminal dipeptide from the chemokine. With a certain degree of selectivity in terms of chemokine substrate, CD26 only recognizes chemokines with a penultimate proline or alanine. Chemokines can be protected against CD26 recognition by specific amino acid residues within the chemokine structure, by oligomerization or by binding to cellular glycosaminoglycans (GAGs). Upon truncation, the binding affinity for receptors and GAGs is altered, which influences chemokine function. The consequences of CD26-mediated clipping vary, as unchanged, enhanced, and reduced activities are reported. In tumors, CD26 most likely has the most profound effect on CXCL12 and the interferon (IFN)-inducible CXCR3 ligands, which are converted into receptor antagonists upon truncation. Depending on the tumor type, expression of CD26 is upregulated or downregulated and often results in the preferential generation of the chemokine isoform most favorable for tumor progression. Considering the tight relationship between chemokine sequence and chemokine binding specificity, molecules with the appropriate characteristics can be chemically engineered to provide innovative therapeutic strategies in a cancer setting.

Gene Expression of PSORI-CM01 and Yinxieling in the Treatment of Psoriasis Vulgaris

Background. This study aimed to explore the mechanisms of action of the PSORI-CM01 and Yinxieling formulas in the treatment of patients with psoriasis vulgaris by analyzing gene expression in peripheral blood mononuclear cells (PBMCs). Methods. PBMC samples were collected from 21 patients before and after treatment. The study included nine patients in the PSORI-CM01 treatment group, 12 patients in the Yinxieling treatment group, and nine patients in the healthy control group. Gene expression levels in PBMCs were determined using the Affymetrix gene chip technology. Results. In the PSORI-CM01 group before and after treatment, a total of 668 differentially expressed genes were found, of which 445 were upregulated and 223 were downregulated. Before and after Yinxieling treatment, 657 differentially expressed genes were found, of which 168 were upregulated and 489 were downregulated. Venn analysis showed that 78 genes were not differentially expressed in the PSORI-CM01 group and 74 were not differentially expressed in the Yinxieling group compared with those in the controls. Among these genes, 72 genes were common to both groups, which were the genes on which the two drugs acted jointly. The results of KEGG analysis and Venn analysis on the signalling pathways of drug action in treatment groups showed that haemostasis and pathways involving Rho GTPases were common signalling pathways of drug action in the two groups. Conclusions. By a comparative analysis of the treatment groups, we found that both drugs have a positive effect on patients with psoriasis vulgaris, primarily by regulating the pathways related to platelet activation, aggregation, and blood coagulation. Trial registration: ChiCTR, ChiCTR-TRC-14005185, Registered 8 August 2014, http://www.chictr.org.cn/showproj.aspx?proj=4390

The Proinflammatory and Proangiogenic Macrophage Migration Inhibitory Factor Is a Potential Regulator in Proliferative Diabetic Retinopathy

The macrophage migration inhibitory factor (MIF)/CD74 signaling pathway is strongly implicated in inflammation and angiogenesis. We investigated the expression of MIF and its receptor CD74 in proliferative diabetic retinopathy (PDR) to reveal a possible role of this pathway in the pathogenesis of PDR. Levels of MIF, soluble (s)CD74, soluble intercellular adhesion molecule-1 (sICAM-1) and vascular endothelial growth factor (VEGF) were significantly increased in the vitreous from patients with PDR compared to nondiabetic control samples. We detected significant positive correlations between the levels of MIF and the levels of sICAM-1 (r = 0.43; p = 0.001) and VEGF (r = 0.7; p < 0.001). Through immunohistochemical analysis of PDR epiretinal membranes, significant positive correlations were also found between microvessel density (CD31 expression) and the numbers of blood vessels expressing MIF (r = 0.56; p = 0.045) and stromal cells expressing MIF (r = 0.79; p = 0.001) and CD74 (r = 0.59; p = 0.045). Similar to VEGF, MIF was induced in Müller cells cultured under hypoxic conditions and MIF induced phosphorylation of ERK1/2 and VEGF production in Müller cells. Intravitreal administration of MIF in normal rats induced increased retinal vascular permeability and significant upregulation of phospho-ERK1/2, NF-κB, ICAM-1 and vascular cell adhesion molecule-1 expression in the retina. MIF induced migration and proliferation of human retinal microvascular endothelial cells. These results suggest that MIF/CD74 signaling is involved in PDR angiogenesis.