Osteopontin is critically involved in rheumatoid arthritis; however, the molecular cross-talk between osteopontin and joint cell components that leads to the inflammatory joint destruction is largely unknown. We found that not only osteopontin but also tenascin-C and their common receptor, alpha(9) integrin, are expressed at arthritic joints. The local production of osteopontin and tenascin-C is mainly due to synovial fibroblasts and, to a lesser extent, synovial macrophages. Synovial fibroblasts and macrophages express alpha(9) integrin, and autocrine and paracrine interactions of alpha(9) integrin on synovial fibroblasts and macrophages and its ligands contribute differently to the production of proinflammatory cytokines and chemokines. alpha(9) integrin is also involved in the recruitment and accumulation of inflammatory cells. Inhibition of alpha(9) integrin function with an anti-alpha(9) integrin Ab significantly reduces the production of arthrogenic cytokines and chemokines and ameliorates ongoing arthritis. Thus, we identified alpha(9) integrin as a critical intrinsic regulator that controls the development of autoimmune arthritis.

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.0900725DOI Listing

Publication Analysis

Top Keywords

alpha9 integrin
28
synovial fibroblasts
12
development autoimmune
8
autoimmune arthritis
8
osteopontin tenascin-c
8
fibroblasts macrophages
8
cytokines chemokines
8
alpha9
7
integrin
7
integrin ligands
4

Similar Publications

Carnosic acid inhibits integrin expression and prevents pulmonary metastasis of melanoma.

Biosci Biotechnol Biochem

November 2024

Department of Molecular Immunology, Faculty of Pharmaceutical Sciences, Fukuyama University, Gakuen-cho 1, Fukuyama, Hiroshima 729-0292, Japan.

Carnosic acid is a naturally occurring, plant-derived polyphenolic abietane diterpene with anti-tumor properties. However, its underlying mechanisms are still unclear. Therefore, we investigated the effects of carnosic acid on lung metastasis in a murine melanoma model.

View Article and Find Full Text PDF

C286, an orally available retinoic acid receptor β agonist drug, regulates multiple pathways to achieve spinal cord injury repair.

Front Mol Neurosci

August 2024

Neuroscience Drug Discovery Unit, Wolfson Sensory, Pain and Regeneration Centre, King's College London, Guy's Campus, London, United Kingdom.

Retinoic acid receptor β2 (RARβ2) is an emerging therapeutic target for spinal cord injuries (SCIs) with a unique multimodal regenerative effect. We have developed a first-in-class RARβ agonist drug, C286, that modulates neuron-glial pathways to induce functional recovery in a rodent model of sensory root avulsion. Here, using genome-wide and pathway enrichment analysis of avulsed rats' spinal cords, we show that C286 also influences the extracellular milieu (ECM).

View Article and Find Full Text PDF

Genetic ablation of myeloid integrin α9 attenuates early atherosclerosis.

J Leukoc Biol

November 2024

Division of Hematology/Oncology, Department of Internal Medicine, University of Iowa, 3160 Medical Labs, Iowa City, IA 52242, United States.

Article Synopsis
  • Integrin α9β1 plays a crucial role in helping leukocytes stick to blood vessel linings, which is significant in the context of atherosclerosis.
  • In experiments with mice lacking myeloid cell-specific α9β1, researchers found that these mice had fewer early signs of atherosclerosis compared to their counterparts, indicating a protective effect.
  • This reduction in atherosclerosis was linked to lower levels of neutrophils and their associated inflammatory traps in the blood vessels, suggesting that disabling α9β1 helps to limit excessive immune responses.
View Article and Find Full Text PDF

Integrin-α9 overexpression underlies the niche-independent maintenance of leukemia stem cells in acute myeloid leukemia.

Gene

November 2024

Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan; Department of General Internal Medicine, Kumamoto Kenhoku Hospital, Kumamoto, Japan. Electronic address:

Leukemia stem cells (LSCs) are widely believed to reside in well-characterized bone marrow (BM) niches; however, the capacity of the BM niches to accommodate LSCs is insufficient, and a significant proportion of LSCs are instead maintained in regions outside the BM. The molecular basis for this niche-independent behavior of LSCs remains elusive. Here, we show that integrin-α9 overexpression (ITGA9 OE) plays a pivotal role in the extramedullary maintenance of LSCs by molecularly mimicking the niche-interacting status, through the binding with its soluble ligand, osteopontin (OPN).

View Article and Find Full Text PDF

Venous thromboembolic events are significant contributors to morbidity and mortality in patients with stroke. Neutrophils are among the first cells in the blood to respond to stroke and are known to promote deep vein thrombosis (DVT). Integrin α9 is a transmembrane glycoprotein highly expressed on neutrophils and stabilizes neutrophil adhesion to activated endothelium via vascular cell adhesion molecule 1 (VCAM-1).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!