Osteopontin (Opn), a multifunctional extracellular matrix protein, is implicated in the pathogenesis of various inflammatory disorders. Under physiologic conditions, its expression is restricted to certain tissues including bone and kidney tubule. However, cellular activation during disease development induces Opn expression in various immune cells. In this study, using Opn-EGFP knock-in (KI) m...

Glioblastoma (GBM) represents the most aggressive and common solid human brain tumor. We have recently demonstrated the importance of osteopontin (OPN) in the acquisition/maintenance of stemness characters and tumorigenicity of glioma initiating cells. Consultation of publicly available TCGA database indicated that high OPN expression correlated with poor survival in GBM patients. In this study...

BACKGROUND The effect of segment-specific proximal tubular injury on spatio-temporal osteopontin (OPN) distribution was determined in two different nephrotoxic rat models to evaluate its conceivability with a possible role for OPN in acute renal failure (ARF). OPN gene expression was further determined in proximal and distal tubular cells to investigate the origin of increased renal OPN. METH...

Osteopontin (OPN) is a multifunctional cytokine that is strongly expressed in healing wounds and fibrotic lesions, both of which are characterized by the formation of myofibroblasts. We examined the role of OPN in myofibroblast differentiation induced by the profibrotic cytokine transforming growth factor-beta1. In cultured cardiac or dermal fibroblasts treated with transforming growth factor-b...

CONTEXT Osteopontin (OPN) is a multifunctional protein involved in bone metabolism, cardiovascular disease, diabetes, and obesity. OPN levels are elevated in the plasma and adipose tissue of obese subjects, and are decreased with diet-induced weight loss. OBJECTIVE We investigated the effect of bariatric surgery on plasma OPN concentrations in morbidly obese patients. SETTING The study was ...

Osteopontin (OPN), which is highly expressed in malignant glioblastoma (GBM), possesses inflammatory activity modulated by proteolytic cleavage by thrombin and plasma carboxypeptidase B2 (CPB2) at a highly conserved cleavage site. Full-length OPN (OPN-FL) was elevated in cerebrospinal fluid (CSF) samples from all cancer patients compared with noncancer patients. However, thrombin-cleaved OPN (O...

We found that absence of osteopontin (OPN) in immunocompromised Rag2(-/-) mice, which lack T and B cells, made the mice extremely susceptible to an opportunistic fungus Pneumocystis, although immunocompetent OPN-deficient mice could clear Pneumocystis as well as wild-type mice. OPN has been studied as an extracellular protein, and the role of an intracellular isoform of OPN (iOPN) is still larg...

Transected axons can regenerate beyond the site of injury in the peripheral but not in the central nervous system (CNS). Increasing evidence implicates inflammatory processes as modulators of axon regeneration after injury. In this study, we addressed a possible role of the matricellular glycoprotein osteopontin (OPN) using crush lesions of the optic and sciatic nerve as models of central and p...

The expression of osteopontin (OPN) has been correlated with tumor growth and metastasis. However, the mechanisms by which OPN promotes tumor metastasis remain unclear. In this study, we aimed to investigate the anti-tumor effects of OPN by silencing OPN expression in the gastric cancer cell line SGC7901, using lentiviral-OPN small interfering RNA (siRNA) technology. Plasmid vectors containing ...

Idiopathic pulmonary fibrosis (IPF) is the most common and deadly form of interstitial lung disease. Osteopontin (OPN), a matricellular protein with proinflammatory profibrotic properties, plays major role in several fibrotic diseases, including IPF; OPN highly upregulated patients’ samples. In this study, we knocked down bleomycin (BLM)-induced (PF) mouse model using small interfering RNA (siR...