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

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

  • Exp Cell Res. 2021 Oct 15;407(2):112784. doi: 10.1016/j.yexcr.2021.112784.
Meng Li 1 Yue Liu 2 Yang Fu 3 Ren Gong 4 Huasong Xia 5 Xiao Huang 6 Yanqing Wu 7
Affiliations

Affiliations

  • 1 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
  • 2 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
  • 3 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
  • 4 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
  • 5 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
  • 6 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
  • 7 Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China. Electronic address: [email protected].
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.

Keywords

Apoptosis; Endothelial cell activation; Inflammation; Interleukin-35; Lipopolysaccharide.

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