Soluble IL-6R-mediated IL-6 trans-signaling activation contributes to the pathological development of psoriasis

Hui Xu1, Jun Liu2, Mengyuan Niu1

  • 1Center for Translational Medicine, State Key Laboratory of Analytical Chemistry for Life Science & Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, 210093, People's Republic of China.

Journal of Molecular Medicine (Berlin, Germany)
|April 9, 2021
PubMed

IL-6 has been suggested to function as an autocrine mitogen in the psoriatic epidermis. The biological activity of IL-6 relies on interactions with its receptors, including the membrane-bound IL-6 receptor (mIL-6R) and soluble IL-6 receptor (sIL-6R). Our study presents data showing that the levels of plasma IL-6 and sIL-6R were elevated in psoriatic patients. Genotyping of two single-nucleotide polymorphisms (SNPs) in IL-6R (rs4845617 and rs2228145) demonstrated that the SNP IL-6R (rs4845617) rather than IL-6R (rs2228145) shows a significant association with psoriasis (P = 0.006). To verify the functions of sIL-6R, cultured keratinocytes and imiquimod (IMQ)-induced psoriatic model mice were treated with sIL-6R. We found that the presence of sIL-6R in the HaCaT cell culture medium enhanced the IL-6-induced Stat3 activation, which resulted in abnormal keratinocyte proliferation and aberrant differentiation. Furthermore, the application of sIL-6R in vivo accelerated the pathological development of the disease. Our results demonstrate for the first time that genetic polymorphisms in the IL-6R gene are associated with psoriasis disease phenotypes in a Chinese psoriatic patient population; sIL-6R-mediated trans-signaling pathway plays a pivotal role in keratinocyte proliferation and differentiation, suggesting potential therapeutics for psoriasis. KEY MESSAGES: Patients with psoriasis displayed higher levels of IL-6 and sIL-6R compared with healthy controls. Analysis of genotypes revealed that IL-6R rs4845617 GG genotype associated with the risk of psoriasis. Supplement of sIL-6R further enhanced IL-6-induced Stat3 activation in keratinocytes. In vivo administration of sIL-6R accelerated, whereas sgp130FC alleviated, the pathological development of psoriasis.

Related Concept Videos

T Cell Types and Functions01:24

T Cell Types and Functions

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
1.7K
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
10.0K
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors...
8.2K
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
6.8K
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a...
4.4K
NF-κB-dependent Signaling Pathway02:26

NF-κB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
8.3K