Interleukin-35 inhibits lipopolysaccharide-induced endothelial cell activation by downregulating inflammation and apoptosis.

Abstract

Inflammation is an essential factor contributing to sepsis-induced endothelial cell (EC) activation. Interleukin-35 (IL-35) is an anti-inflammatory/immunosuppressive cytokine that exerts protective effects on many inflammatory diseases. In this study, we investigated the effects of IL-35 on lipopolysaccharide (LPS)-induced EC activation and the potential underlying mechanism. Human umbilical vein endothelial cells (HUVECs) were incubated with LPS (1 μg/ml) for 24 h and then cocultured with different concentrations (0, 1, 10, or 100 ng/ml) of recombinant human IL-35 (rhIL-35) for 12 h. Flow cytometry analysis revealed that IL-35 inhibited LPS-induced HUVEC apoptosis in a dose-dependent manner. RT-qPCR and Western blot analyses showed significantly higher mRNA and protein levels of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the inflammatory factors IL-6 and IL-8 in the LPS group than in the control group. These changes were alleviated by IL-35 treatment, suggesting that IL-35 protects ECs by downregulating inflammation. Furthermore, IL-35 induced signal transducer and activator of transcription 1 (STAT1) and STAT4 activation and promoted their interaction. Blocking STAT1 or STAT4 expression by fludarabine (STAT1 inhibitor) treatment or siRNA-STAT4-interfering fragment transfection inhibited the protective effect of IL-35 on ECs. Moreover, we observed a similar protective effect of IL-35 treatment on ECs in a mouse sepsis model induced by intraperitoneal LPS injection. This study indicated that IL-35 exerts anti-inflammatory and antiapoptotic effects on LPS-induced EC activation by activating the STAT1 and STAT4 signaling pathways.

• Authors: Meng Li, Yue Liu, Yang Fu, Ren Gong, Huasong Xia, Xiao Huang, Yanqing Wu
• Journal: Experimental cell research (Exp Cell Res) Vol. 407 Issue 2 Pg. 112784 (10 15 2021) ISSN: 1090-2422 [Electronic] United States
• PMID: 34508746 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2021 Elsevier Inc. All rights reserved.

Chemical References

• Anti-Inflammatory Agents
• Interleukins
• Lipopolysaccharides
• NF-kappa B
• STAT1 Transcription Factor
• STAT4 Transcription Factor
• interleukin-35, human

Topics

• Animals
• Anti-Inflammatory Agents (pharmacology)
• Apoptosis
• Endothelium, Vascular (drug effects, metabolism, pathology)
• Gene Expression Regulation
• Humans
• Inflammation (chemically induced, metabolism, pathology, prevention & control)
• Interleukins (administration & dosage, genetics, metabolism)
• Lipopolysaccharides (toxicity)
• Male
• Mice
• Mice, Inbred C57BL
• NF-kappa B (genetics, metabolism)
• STAT1 Transcription Factor (genetics, metabolism)
• STAT4 Transcription Factor (genetics, metabolism)
• Sepsis (chemically induced, metabolism, pathology, prevention & control)
• Signal Transduction