We have previously reported that high glucose stimulates osteopontin (OPN) expression through protein kinase C-dependent pathways as well as hexosamine pathways in cultured rat aortic smooth muscle cells. The finding prompted us to study in vivo expression of OPN in diabetes mellitus. In the present study, we found by immunohistochemistry that medial layers of the carotid arteries of streptozot...

INTRODUCTION Osteopontin (OPN) polymorphisms are associated with muscle size and modify disease progression in Duchenne muscular dystrophy (DMD). We hypothesized that OPN may share a molecular network with myostatin (MSTN). METHODS Studies were conducted in the golden retriever (GRMD) and mdx mouse models of DMD. Follow-up in-vitro studies were employed in myogenic cells and the mdx mouse tre...

It has been shown that osteopontin (OPN) plays a pivotal role in the pathogenesis of rheumatoid arthritis (RA). However, the molecular mechanism of OPN action is yet to be elucidated. Splenic monocytes obtained from arthritic mice exhibited a significant capacity for cell migration toward thrombin-cleaved OPN but not toward full-length OPN. Migratory monocytes expressed alpha9 and alpha4 integr...

Chiba H, Ataka K, Iba K, Nagaishi K, Yamashita T, Fujimiya M. Diabetes impairs the interactions between long-term hematopoietic stem cells and osteopontin-positive cells in the endosteal niche of mouse bone marrow. Am J Physiol Cell Physiol 305: C693–C703, 2013. First published July 24, 2013; doi:10.1152/ajpcell.00400.2012.—Hematopoietic stem cells (HSCs) are maintained, and their division/prol...

We have examined the temporal changes and cellular localization of osteopontin (OPN) mRNA and protein in organotypic hippocampal slice cultures subjected to ischemia-like oxygen-glucose deprivation (OGD). The sequential induction pattern response consisted of neuronal and microglial OPN upregulation, followed by a later extended phase of expression in reactive astrocytes. OPN immunoreactivity a...

Osteopontin (OPN) is a chemotactic protein that attracts immune cells, to inflammatory sites. The sensitization phase of allergic cutaneous contact hypersensitivity (CHS) requires the migration of Langerhans cells/dendritic cells (LCs/DCs) from skin to draining lymph nodes. Characterizing OPN function for LC/DC migration we found upregulated OPN expression in hapten sensitized skin and draining...

OBJECTIVE This study aims to explore the effect of osteopontin on the inflammatory reaction of cartilage cells stimulated by LPS and its possible signal pathway. METHODS The inflammatory reaction of cartilage cells was induced by LPS, and then the cells were treated with OPN and PD98059 respectively. The expression of TNF-α, IL-1β and ERK1/2 were detected by ELISA or Western-blotting methods....

The expression of osteopontin (OPN), CD44 variants, and integrins has been correlated with tumorigenesis and metastasis. Here we show that these proteins cooperate to enhance cell motility. First, we demonstrate that several different CD44 variants bind to OPN in an arginine-glycineaspartic acid-independent manner, but that the standard form of CD44 does not. These CD44 variants bind to both th...

Osteopontin (OPN) is a multifunctional protein that has been linked to various intractable inflammatory diseases. One way by which OPN induces inflammation is the production of various functional fragments by enzyme cleavage. It has been well appreciated that OPN is cleaved by thrombin, and/or matrix metalloproteinase-3 and -7 (MMP-3/7). Although the function of thrombin-cleaved OPN is well cha...

Sarcoidosis is a systemic inflammatory disease characterised by appearance of granulomas. Precise etiology has not been elucidated. Osteopontin (Opn) is a Th1 cytokine whose levels have been found increased in granulomas and serum samples from patients with sarcoidosis. We investigated whether genetic variation in Osteopontin gene (OPN) gene contributes to susceptibility to sarcoidosis. Haploty...