Dataset Information

Mouse aorta smooth muscle cells differentiate into lymphoid tissue organizer-like cells on combined tumor necrosis factor receptor-1/lymphotoxin beta-receptor NF-kappaB signaling.

ABSTRACT:

Objective

Mouse aorta smooth muscle cells (SMC) express tumor necrosis factor receptor superfamily member 1A (TNFR-1) and lymphotoxin beta-receptor (LTbetaR). Circumstantial evidence has linked the SMC LTbetaR to tertiary lymphoid organogenesis in hyperlipidemic mice. Here, we explored TNFR-1 and LTbetaR signaling in cultured SMC.

Methods and results

TNFR-1 signaling activated the classical RelA NF-kappaB pathway, whereas LTbetaR signaling activated the classical RelA and alternative RelB NF-kappaB pathways, and both signaling pathways synergized to enhance p100 inhibitor processing to the p52 subunit of NF-kappaB. Microarrays showed that simultaneous TNFR-1/LTbetaR activation resulted in elevated mRNA encoding leukocyte homeostatic chemokines CCL2, CCL5, CXCL1, and CX3CL1. Importantly, SMC acquired features of lymphoid tissue organizers, which control tertiary lymphoid organogenesis in autoimmune diseases through hyperinduction of CCL7, CCL9, CXCL13, CCL19, CXCL16, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. TNFR-1/LTbetaR cross-talk resulted in augmented secretion of lymphorganogenic chemokine proteins. Supernatants of TNFR-1/LTbetaR-activated SMC markedly supported migration of splenic T cells, B cells, and macrophages/dendritic cells. Experiments with ltbr(-/-) SMC indicated that LTbetaR-RelB activation was obligatory to generate the lymphoid tissue organizer phenotype.

Conclusions

SMC may participate in the formation of tertiary lymphoid tissue in atherosclerosis by upregulation of lymphorganogenic chemokines involved in T-lymphocyte, B-lymphocyte, and macrophage/dendritic cell attraction.

SUBMITTER: Lotzer K

PROVIDER: S-EPMC2874749 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Mouse aorta smooth muscle cells (SMCs) express TNF receptor superfamily member 1A (TNFR1) and lymphotoxin Ã receptor (LTÃR). Circumstantial evidence has linked the SMC LTÃR to tertiary lymphoid organogenesis in diseased aortae of hyperlipidemic mice. Here, we explored potential roles of TNFR1 and LTÃR activation in cultured SMCs. TNFR1 signaling by TNF activated the classical RelA NF-ÎºB pathway, whereas LTÃR signaling by agonistic anti LTÃR antibody activated both the classical RelA and alternative RelB NF-ÎºB pathways. Addition of both agonists synergized to enhance p100 inhibitor processing to the p52 subunit of NF-ÎºB and promoted its nuclear translocation suggesting RelA-RelB cross-talk in transcription regulation. Correspondingly, microarrays showed that simultaneous TNFR1 and LTÃR activation when compared to activation of single receptors was followed by markedly elevated levels of mRNAs encoding leukocyte homeostatic chemokines CCL2, CCL5, CXCL1, and CX3CL1. Furthermore, SMCs acquired prototypical features of mesenchymal cells known as lymphoid tissue organizers (LTOs), which control tertiary lymphoid organogenesis in autoimmune diseases, through hyperinduction of CCL7, CCL9, CXCL13, CCL19, CXCL16, VCAM-1, and ICAM-1. Experiments with ltbr-/- SMCs suggested that the LTÃR-RelB activation component of NF-ÎºB signaling was obligatory to generate the LTO phenotype. TNFR1-LTÃR crosstalk also resulted in augmented synthesis and prolonged secretion of lymphorganogenic chemokine proteins into the culture medium. Thus, combined TNFR1-LTÃR signaling triggers SMC transdifferentiation into a phenotype that strikingly resembles LTOs. LTO-like SMCs may adopt a thus far unrecognized role in diseased arteries, i.e. to coordinate tertiary lymphoid organogenesis in atherosclerosis, aortic aneurysm, and transplant vasculopathy. Experiment Overall Design: Smooth muscle cells in tissue culture were stimulated with agonists and subsequently microarray, RT-PCR, and protein assays / analyses were performed