Plasma Osteopontin Concentrations Research Articles

Plasma and follicular fluid osteopontin levels during ovarian cycle and their correlation with follicular fluid vascular endothelial growth factor levels

Osteopontin (OPN) is a multifunctional secreted glycoprotein. We evaluated OPN concentrations in blood and follicular fluid (FF) during the ovarian cycle and their relationship with the production of vascular endothelial growth factor (VEGF), which is involved in the pathophysiology of ovarian hyperstimulation syndrome (OHSS). Twenty-two women undergoing in vitro fertilization (minimal stimulation protocol with clomiphene citrate) were enrolled. Samples were collected (a) on the third day of withdrawal bleeding, (b) 2 days before oocyte retrieval, and (c) on the day of oocyte retrieval. FF was collected during oocyte retrieval. The OPN concentration in each specimen and the VEGF concentration in FF was measured by enzyme-linked immunosorbent assays. Plasma OPN concentrations were (in ng/mL): (a) 416 ± 37.2, (b) 378 ± 35.8, and (c) 390 ± 40.0, with no significant differences between the groups. The OPN concentration in FF was 106 ± 13.4 ng/mL. A positive correlation was found between OPN concentrations in FF and plasma samples. A positive correlation was also found between plasma OPN and FF VEGF concentrations, irrespective of the blood-sampling period. Plasma OPN concentration is suggested to reflect the FF VEGF level at oocyte retrieval and maybe a novel clinical marker for predicting the risk for OHSS.

PLK2 is a novel regulator of osteopontin-driven fibrosis and diastolic dysfunction in permanent atrial fibrillation

Abstract Background and aim Atrial fibrillation (AF) is frequently accompanied by cardiac fibrosis and diastolic heart failure. Due to the heterogeneous nature and complexity of fibrosis, the knowledge of the underlying pathomechanisms is limited. Thus, effective antifibrotic pharmacotherapy is missing. The objective of this study was to decipher the role of polo-like kinase 2 (PLK2) in the pathogenesis of cardiac fibrosis and left ventricular diastolic dysfunction. We put particular emphasis on the identification of profibrotic downstream targets of PLK2, which can serve as therapeutic targets. Methods and results This study was based on human atrial tissue biopsies and peripheral blood samples, a PLK2 knockout mouse model, a canine tachy-pacing model and specific pharmacological interventions on cardiac fibroblasts. In human atrial AF tissue samples, PLK2 was 50% downregulated by hypoxia-induced promoter methylation compared to sinus rhythm (SR) control. Confirmatory analysis of a canine tachy-pacing model showed PLK2 downregulation exclusively in the atria but not in the ventricles. Specific pharmacological inhibition as well as genetic deletion of PLK2 led to a striking myofibroblast phenotype. Discovery proteomics revealed that the global knockout of PLK2 resulted in de novo secretion of the inflammatory cytokine osteopontin (OPN) in cardiac fibroblasts and concomitant ventricular fibrosis in the PLK2 knockout mouse model. An ELISA analysis of peripheral blood samples of AF patients with electrophysiologically proven fibrosis, confirmed significantly increased OPN plasma concentrations compared to SR and non-fibrosis AF controls. Consequently, echocardiography on PLK2 KO mice revealed left ventricular diastolic dysfunction, tachycardia and fibrosis-typical surface ECG anomalies (PQ and QRS prolongation). Mechanistically, we identified the ERK1/2 signaling pathway as the molecular link between reduced expression of PLK2 and elevated osteopontin transcription. In a reverse translational attempt, we successfully tested the capability of 5-amino-salicylic acid (5-ASA) to inhibit osteopontin transcription and to reverse a TGF-β-induced myofibroblast phenotype in vitro. Currently the long-term administration of 5-ASA is tested in PLK2 knockout mice to evaluate the therapeutic potential to prevent cardiac fibrosis and diastolic heart failure development. Conclusion and clinical impact We identified PLK2 as an epigenetically regulated kinase involved in the pathophysiology of fibrosis in AF. PLK2 knockout mice can serve as a model of diastolic heart failure wherein OPN is a promising therapeutic target. Our results strengthen the current hypothesis that atrial fibrillation is not only an ion channel disease but a complex systemic disorder. Restoration of physiological PLK2 expression and blockade of osteopontin release with 5-ASA may constitute valuable new drug targets for the prevention and treatment of fibrosis and diastolic heart failure in AF. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Faculty of Medicine, Carl Gustav Carus, Dresden, “MeDDrive Start” Grant

Association of Circulating Osteopontin Levels With Lower Extremity Arterial Disease in Subjects With Type 2 Diabetes Mellitus: A Cross-Sectional Observational Study

Osteopontin (OPN) is involved in the atherosclerotic and inflammatory process. In this article, we examined the relationship between circulating OPN levels with lower extremity arterial disease (LEAD) in individuals with type 2 diabetes mellitus (T2DM). Seventy individuals with T2DM and 66 individuals without T2DM were recruited. Diagnosis of LEAD was based on the absence of triphasic waveform on the pedal arteries. Plasma OPN levels were determined by Luminex Multiplex immunoassay. LEAD was present in 34 (48.6%) patients with T2DM. In the diabetes cohort, individuals with LEAD had higher plasma OPN concentrations than those without LEAD (geometric mean [95% confidence intervals]; 43.4 [37.5-50.4] vs 26.1 [22.9-29.8] ng/mL, respectively, P < .001). Multivariable analysis showed that presence of LEAD independently associated with higher OPN levels in subjects with T2DM, with marginal statistical significance (P = .049). In both cohorts, plasma OPN concentrations were negatively associated with ankle-brachial index values (P < .05). In the total sample, there was a gradual increase of OPN levels across subgroups with triphasic, biphasic, and monophasic/blunted waveforms (P < .001). In conclusion, plasma OPN levels are associated with the presence and severity of LEAD in subjects with T2DM. Further studies are needed to investigate the role of OPN in the pathogenesis and progression of LEAD.

Potential Involvement of Osteopontin in Inflammatory and Fibrotic Processes in Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension.

Inflammation and incomplete thrombus resolution leading to obstructive fibrotic remodelling are considered critical mechanisms for the development of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE). Osteopontin (OPN) is involved in a variety of biological processes including inflammation and tissue fibrosis. OPN plasma concentrations were measured in 70 CTEPH and 119 PE patients. Tissue material from 6 CTEPH patients removed during pulmonary endarterectomy and murine venous thrombi induced by subtotal ligation of the inferior vena cava in C57BL/6 mice were analysed by (immuno)histochemistry. CTEPH patients had higher OPN plasma concentrations (median, 106.9 [interquartile range, 75.6-155.9]) compared to PE patients (90.4 [53.3-123.9] ng/mL, p = 0.001). OPN- and matrix metalloproteinase (MMP)-9-positive cells were predominantly present in myofibroblast-rich and profibrotic areas of CTEPH tissue material. Early stages of murine thrombus resolution were characterised by high numbers of OPN- and MMP-2-positive cells while OPN was almost absent in fresh thrombi of CTEPH tissue material. PE patients with OPN plasma concentrations of < 55 ng/mL had a 15.2-fold (95% confidence interval, 1.7-135.5, p = 0.015) increased risk for a diagnosis of CTEPH during follow-up. The results of the present observational translational study point to a possible involvement of OPN in the pathogenesis of CTEPH by affecting early inflammatory and late fibrotic processes.

The possibility of using osteopontin as a marker of calcification of the heart valve apparatus in patients with chronic kidney disease on replacement therapy by hemodialysis

Aim of research. To identify a possible relationship between the degree of violation of phosphorus-calcium metabolism and the intensity of the processes of calcification of heart valves in patients with chronic kidney disease on hemodialysis. Materials and methods. 51 patients with CKD stage 5 were examined. The level of calcium, serum phosphorus, calcium-phosphorus product was estimated, the level of parathyroid hormone, osteopontin was determined. Echocardiographically, the presence or absence of aortic and mitral valve calcification was assessed. Results. We revealed calcinosis of heart valves in 39.2% of patients: combined mitral-aortic calcinosis was observed in 21.5% of patients, isolated calcinosis of mitral valve – in 13.7%, isolated calcinosis of aortic valve was observed in 3.9%. Hyperphosphatemia (PЈ0.033) and an increase in the product of CaxP concentration above 5.0 (PЈ0.002) were statistically significant in the development of calcification of cardiac structures. Parathyroid hormone levels were statistically higher in the groups of patients with calcinosis and heart valve compaction (pЈ0.001) than in patients without calcinosis. Osteopontin indices were higher in the group of patients with calcinosis than in patients with compaction of heart valves (PЈ0.001) and significantly higher than in patients without calcification of heart structures (PЈ0.05). Summary. Calcification of heart valves in hemodialysis patients is associated with an increase in plasma concentrations of osteopontin, parathyroid hormone, calcium-phosphorus metabolism. Positive correlation between the level of osteopontin and the degree of heart valve damage allows to use it as a marker of cardiovascular calcification.

A multi-stage association study of plasma cytokines identifies osteopontin as a biomarker for acute coronary syndrome risk and severity

Cytokines play a critical role in the pathogenesis and development of cardiovascular diseases. However, data linking cytokines to risk and severity of acute coronary syndrome (ACS) are still limited. We measured plasma profile of 280 cytokines using a quantitative protein microarray in 12 ACS patients and 16 healthy controls, and identified 15 differentially expressed cytokines for ACS. Osteopontin, chemokine ligand 23, brain derived neurotrophic factor and C-reactive protein (CRP) were further validated using immunoassay in two independent case-control studies with a total of 210 ACS patients and 210 controls. We further examined their relations with incident ACS among 318 case-control pairs nested within the Dongfeng-Tongji cohort, and found plasma osteopontin and CRP concentrations were associated with incident ACS, and the multivariable-adjusted odds ratio (95% confidence interval) was 1.29 (1.06–1.57) per 1-SD increase for osteopontin and 1.30 (1.02–1.66) for CRP, respectively. Higher levels of circulating osteopontin were also correlated with higher severity of ACS, and earlier ACS onset time. Adding osteopontin alone or in combination with CRP modestly improved the predictive ability of ACS beyond the Framingham risk scores. Our findings suggested that osteopontin might be a biomarker for incident ACS, using osteopontin adds moderately to traditional cardiovascular risk factors.

Osteopontin in human milk and infant formula affects infant plasma osteopontin concentrations.

Osteopontin (OPN), a multifunctional protein, is present abundantly in human milk, but not in bovine milk and infant formulas. A recent randomized clinical trial showed that supplementing infant formula with bovine milk OPN (bOPN) resulted in better immune outcomes. Human milk OPN (hOPN) concentrations were analyzed by ELISA. Plasma samples were obtained from infants receiving one of four treatments: breast milk (BF), unsupplemented formula (F0), formula supplemented with 65 mg/L bOPN (F65), or with 130 mg/L bOPN (F130). Plasma samples were analyzed for hOPN and bOPN by ELISA. The hOPN concentration was high in early lactation (D1 to D8), decreased gradually after D9, and deceased significantly after 1 month. At 4 and 6 months, higher levels of hOPN were found in plasma samples from the BF, F65, and F130 groups than in samples from the F0 group; the plasma bOPN concentration in the F130 group was greater than that in the F65 group. Dynamic changes in the concentration of milk OPN may reflect infant needs for different amounts of milk OPN for various functions at different developmental stages. Supplemental bOPN in infant formula may exert its beneficial effects by increasing endogenous OPN in plasma.

Acute-Phase Plasma Osteopontin as an Independent Predictor for Poor Outcome After Aneurysmal Subarachnoid Hemorrhage.

Experimental studies reported that osteopontin (OPN), a matricellular protein, is induced in brain after subarachnoid hemorrhage (SAH). The aim of this study was to investigate the relationships between plasma OPN levels and outcome after aneurysmal SAH in a clinical setting. This is a prospective study consisting of 109 aneurysmal SAH patients who underwent aneurysmal obliteration within 48h of SAH. Plasma OPN concentrations were serially determined at days 1-3, 4-6, 7-9, and 10-12 after onset. Various clinical factors as well as OPN values were compared between patients with 90-day good and poor outcomes. Plasma OPN levels were significantly higher in SAH patients compared with control patients and peaked at days 4-6. Poor-outcome patients had significantly higher plasma OPN levels through all sampling points. Receiver-operating characteristic curves demonstrated that OPN levels at days 10-12 were the most useful predictor of poor outcome at cutoff values of 915.9pmol/L (sensitivity, 0.694; specificity, 0.845). Multivariate analyses using the significant variables identified by day 3 showed that plasma OPN ≥ 955.1pmol/L at days 1-3 (odds ratio, 10.336; 95% confidence interval, 2.563-56.077; p < 0.001) was an independent predictor of poor outcome, in addition to increasing age, preoperative World Federation of Neurological Surgeons grades IV-V, and modified Fisher grade 4. Post hoc analyses revealed no correlation between OPN levels and serum levels of C-reactive protein, a non-specific inflammatory parameter, at days 1-3. Acute-phase plasma OPN could be used as a useful prognostic biomarker in SAH.

1086P - Diagnostic and prognostic impact of plasma osteopontin in nasopharyngeal carcinoma

Background: We investigated the diagnostic and prognostic impact of plasma osteopontin (pOPN) concentrations in advanced nasopharyngeal carcinoma (NPC). Methods: Pre-treatment plasma samples from 138 patients with previously untreated and biopsy-proven NPC were collected. Plasma samples from another 70 healthy volunteer were served as control. OPN concentrations were measured by the enzyme-linked immunosorbent assay (ELISA). The patient characteristics were- age range 24-83 and median 48 years, male/female=97/41, WHO pathology type I/II/III=1/105/32, stage III/IV(M0)/IVC(M1) = 57/73/8. The treatment consisted of radiotherapy alone (2), concurrent chemoradiotherapy (28), and neoadjuvant chemotherapy plus radiotherapy (100) for M0 patients, and systemic chemotherapy with or without radiotherapy for M1 patients (8). Results: NPC patients (median 97.2 ng/mL; interquartile range 72.1-130.4) had significantly higher pOPN level than normal control (median 61.6 copies/ml; interquartile range 44.9-88.1), P<0.0001. The area under ROC curve is 0.754, P=0.0001. The median concentrations of stage III, IV(M0), and IV(M1) were 85.4, 104.2, and 217.7 ng/mL respectively (P=0.0002). We divided patients into two groups by pretreatment pOPN concentration and found that patients with higher pOPN (>100 ng/mL) correlated with some clinically poor prognostic factors, such as older age, male gender, advanced T-stage, and advanced overall stage. Pretreatment pOPN affected patients’ survival as well as rates of distant failure. The 5-year overall survival (56.6% vs. 81.4%, P=0.0036) and metastasis-free survival (66.3% vs. 81.2%, P=0.0726) were significantly lower in patients with pretreatment pOPN > 100 ng/mL than in those with pOPN < 100 ng/mL. Conclusions: Pretreatment pOPN levels can serve as a useful diagnostic and prognostic marker for advanced NPC. Legal entity responsible for the study: Taichung Veteran General Hospital Funding: Taichung Veteran General Hospital Disclosure: All authors have declared no conflicts of interest.

Plasma osteopontin concentration is elevated in patients with coronary bare metal stent restenosis

Objective: Osteopontin is a component of atherosclerotic lesions, secreted by monocytes, macrophages and endothelial and vascular smooth muscle cells, which together are responsible for neointimal proliferation. We examined whether elevated plasma osteopontin concentration was associated with in-stent restenosis in patients with coronary artery disease.Subjects and methods: We enrolled 91 patients who underwent coronary artery stenting, and 60 control patients with normal findings on coronary angiography, between June 2012 and September 2013. For patients with stents, we measured plasma osteopontin concentration at the first follow-up coronary angiogram. For controls, plasma osteopontin concentration was measured at the time of angiography.Results: Of the 91 patients who had undergone coronary artery stenting, 31 (34.1%) had developed in-stent restenosis and the mean time passed to control coronary angiography was 36.7 months (±SD 35.1 months). Mean plasma osteopontin concentration in this group was 2721.4 ± 1787.8 pg/ml, significantly higher than the 60 patients (65.9%) with no in-stent restenosis (1770.4 ± 1208.2 pg/ml, p = .011) and the 60 patients with a normal coronary angiogram (1572.4 ± 904.8 pg/ml, p = .002). There was no significant difference in mean osteopontin concentration between the patients with no in-stent restenosis and the control group (p = .312).Conclusions: Elevated plasma osteopontin concentration is associated with in-stent stenosis in patients with coronary artery disease. Further studies will be needed to establish whether osteopontin can predict in-stent restenosis and guide clinical management strategies.

The relationship between tumor volume changes and serial plasma osteopontin detection during radical radiotherapy of non-small-cell lung cancer.

The prognostic quality of increased osteopontin (OPN) plasma levels has been demonstrated for the chemotherapy and surgery of lung cancer. There is also evidence in the literature that tumor volume impacts prognosis in definitive radiotherapy (RT) of (lung) cancer. We previously demonstrated that elevated plasma levels of OPN before, and increasing OPN plasma levels after RT significantly correlate with survival and outcome after curative-intent RT of non-small-cell lung cancer (NSCLC). Tumor volume was also associated with prognosis. The present prospective clinical study investigated the prognostic interrelation of OPN plasma levels and tumor volume and their changes in the radical RT of NSCLC. We evaluated a subset of patients (n=27) with inoperable, non-metastasized NSCLC of the previously published patient collective. Patients were treated with radical radiochemotherapy (2 Gy ad 66 Gy). OPN plasma concentrations were determined by ELISA before (t0), at the end (t1), and 4 weeks after RT (t2). GTV was delineated PET- and CT-correlated before RT (GTV1) and after 40 Gy (GTV2). The course of OPN during and after RT and the change of GTV during RT was monitored over time and correlated with prognosis. Median GTV2 after 40 Gy (63 ml) was significantly lower than pre-RT GTV1 (90 ml, P<0.0001). Median OPN before (t0), at the end of (t1) and four weeks after RT (t2) was 846, 777 and 624 ng/ml and not significantly different. GTV significantly declined by 39 ml during RT (P<0.0001) and OPN non-significantly decreased by 56 ng/ml during (t0 to t1) and by 54 ng/ml after RT (t1 to t2). No correlations were determined between absolute OPN and GTV values or their relative changes during RT. In univariate analysis, only GTV2 significantly predicted overall survival (OS, P=0.03). In multivariate analysis, both OPN t1 (P<0.001) and GTV2 (P=0.001) remained significant predictors of OS. Relative OPN plasma level changes after (t1 to t2) and GTV changes during RT (GTV 1 to GTV 2) significantly predicted OS (P=0.02). The combination of absolute GTV values before RT (GTV1) and GTV changes during RT (GTV1 to 2) were significantly associated with OS in both uni- and multivariate analysis (P=0.03). The combination of absolute OPN plasma levels and their changes with GTV and its changes did not reach statistical significance. The lack of a significant correlation between OPN and GTV together with the finding that OPN and GTV remained independent predictors of survival outcome but were not associated with OS in combination supports the hypothesis that tumor volume (GTV) and OPN plasma levels (both their changes and absolute values) are not interrelated in terms of prognosis but do possess each parameter separately, a prognostic quality in the radical RT of NSCLC which justifies further prospective studies to validate these results.

Osteopontin: A non-invasive parameter of portal hypertension and prognostic marker of cirrhosis.

To investigate the relationship between osteopontin plasma concentrations and the severity of portal hypertension and to assess osteopontin prognostic value. A cohort of 154 patients with confirmed liver cirrhosis (112 ethylic, 108 men, age 34-72 years) were enrolled in the study. Hepatic venous pressure gradient (HVPG) measurement and laboratory and ultrasound examinations were carried out for all patients. HVPG was measured using a standard catheterization method with the balloon wedge technique. Osteopontin was measured using the enzyme-linked immunosorbent assay (ELISA) method in plasma. Patients were followed up with a specific focus on mortality. The control group consisted of 137 healthy age- and sex- matched individuals. The mean value of HVPG was 16.18 ± 5.6 mmHg. Compared to controls, the plasma levels of osteopontin in cirrhotic patients were significantly higher (P < 0.001). The plasma levels of osteopontin were positively related to HVPG (P = 0.0022, r = 0.25) and differed among the individual Child-Pugh groups of patients. The cut-off value of 80 ng/mL osteopontin distinguished patients with significant portal hypertension (HVPG above 10 mmHg) at 75% sensitivity and 63% specificity. The mean follow-up of patients was 3.7 ± 2.6 years. The probability of cumulative survival was 39% for patients with HVPG > 10 mmHg and 65% for those with HVPG ≤ 10 mmHg (P = 0.0086, odds ratio (OR), 2.92, 95% confidence interval (CI): 1.09-7.76). Osteopontin showed a similar prognostic value to HVPG. Patients with osteopontin values above 80 ng/mL had significantly lower cumulative survival compared to those with osteopontin ≤ 80 ng/mL (37% vs 56%, P = 0.00035; OR = 2.23, 95%CI: 1.06-4.68). Osteopontin is a non-invasive parameter of portal hypertension that distinguishes patients with clinically significant portal hypertension. It is a strong prognostic factor for survival.

Glucose-Dependent Insulinotropic Polypeptide Stimulates Osteopontin Expression in the Vasculature via Endothelin-1 and CREB.

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone with extrapancreatic effects beyond glycemic control. Here we demonstrate unexpected effects of GIP signaling in the vasculature. GIP induces the expression of the proatherogenic cytokine osteopontin (OPN) in mouse arteries via local release of endothelin-1 and activation of CREB. Infusion of GIP increases plasma OPN concentrations in healthy individuals. Plasma endothelin-1 and OPN concentrations are positively correlated in patients with critical limb ischemia. Fasting GIP concentrations are higher in individuals with a history of cardiovascular disease (myocardial infarction, stroke) when compared with control subjects. GIP receptor (GIPR) and OPN mRNA levels are higher in carotid endarterectomies from patients with symptoms (stroke, transient ischemic attacks, amaurosis fugax) than in asymptomatic patients, and expression associates with parameters that are characteristic of unstable and inflammatory plaques (increased lipid accumulation, macrophage infiltration, and reduced smooth muscle cell content). While GIPR expression is predominantly endothelial in healthy arteries from humans, mice, rats, and pigs, remarkable upregulation is observed in endothelial and smooth muscle cells upon culture conditions, yielding a "vascular disease-like" phenotype. Moreover, the common variant rs10423928 in the GIPR gene is associated with increased risk of stroke in patients with type 2 diabetes.

Increased chemokine (C-C motif) ligand 21 expression and its correlation with osteopontin in Graves' disease.

Graves' disease (GD) is a chronic autoimmune process characterized by the production of auto-antibodies that presumably consequent to the lymphocytic infiltrates in the thyroid. Chemokine (C-C motif) ligand 21 (CCL21) is important for the circulation of CC-chemokine receptor 7 (CCR7)-expressing cells. Meanwhile, osteopontin (OPN) enhances the production of proinflammatory cytokines and chemokines through NF-κB and MAPK signaling pathways in GD. Although CCL21 has been reported to play a vital role in several autoimmune diseases, little is known about the relationship between CCL21 and GD development. This study aimed to detect the CCL21 level in GD and to examine the role of OPN in regulating CCL21 production. 40 initial GD patients, 15 euthyroid GD patients, 12 TRAb-negative GD patients, and 25 healthy control donors were recruited. CCL21 levels in plasma and culture supernatants were quantified by enzyme-linked immunosorbent assay (ELISA). CD4+ T cells were isolated from peripheral blood mononuclear cells using antibody-coated magnetic beads. Quantitative polymerase chain reaction was used to determine CCL21 expression levels in CD4+ T cells. We demonstrated for the first time that plasma CCL21 levels were overexpressed in GD patients and recovered in TRAb-negative GD patients. Moreover, CCL21 levels correlated with TRAb levels and plasma OPN concentrations. Furthermore, we demonstrated that recombinant OPN increased the expression of CCL21 in a dose- and time-dependent manner. These data indicated a clinical correlation between plasma CCL21 levels and GD. CCL21 could serve as a novel biomarker for GD as well as a potential target for TRAb-positive GD treatment.

Seminal plasma and serum fertility biomarkers in dromedary camels (Camelus dromedarius)

Eight healthy fertile (control) and 11 infertile male dromedaries were used to investigate whether specific seminal plasma and serum fertility biomarkers could be related to their in vivo fertility. Eight fertility biomarkers and testosterone were determined in both seminal plasma and serum of all studied camels during the rutting season using commercial kits. Results revealed a significant (P < 0.01) difference in semen parameters between the control and infertile camels. There was a significant (P < 0.01) difference between the control and infertile dromedaries in seminal plasma glutathione peroxidase (GPx) activity (15.04 ± 1.14 vs. 4.55 ± 0.96 nmol/min/mL, respectively) and both phospholipase A2 (sPLA2; 50.66 ± 6.28 vs. 23.56 ± 4.29 pg/mL, respectively) and testosterone concentrations (732.14 ± 57.12 vs. 396.36 ± 79.34 pg/mL, respectively). A significant (P < 0.05) difference was found between the control and infertile camels in seminal plasma concentrations of osteopontin, cysteine-rich secretory protein 3 (CRISP3), and prostaglandin D synthase (lipocalcin-type). There was a significant (P < 0.01) difference between the fertile and infertile camels in serum GPx activity 67.81 ± 12.41 vs. 21.31 ± 4.63 nmol/min/mL, respectively) and both testosterone (599.57 ± 110.90 vs. 176.09 ± 24.05 pg/mL, respectively) and clusterin concentrations (137.29 ± 14.15 vs. 253.00 ± 17.14 ng/mL, respectively). A significant (P < 0.05) difference existed between the control and infertile male dromedaries in serum concentrations of sPLA2, CRISP3, malonialdehyde, and insulinlike growth factor 1. In conclusion, CRISP3, sPLA2, GPx, and testosterone are fertility-associated biomarkers in both seminal plasma and serum of dromedary camels. Seminal plasma osteopontin is positively correlated and prostaglandin D synthase (lipocalcin-type) is negatively correlated with camels' fertility. Serum malonialdehyde, insulinlike growth factor 1, and clusterin are negatively correlated with fertility of male dromedary camels.

Comparative effects of gastric bypass and sleeve gastrectomy on plasma osteopontin concentrations in humans

Bariatric surgery (BS) has proven to be an effective treatment for morbid obesity. Osteopontin (OPN) is a proinflammatory cytokine involved in the development of obesity. The aim of our study was to determine the effect of weight loss following BS on circulating levels of OPN in humans. Body composition and circulating concentrations of OPN and markers of bone metabolism were determined in obese patients who underwent Roux-en-Y gastric bypass (RYGB; n=40) or sleeve gastrectomy (SG; n=11). Patients who underwent RYGB or SG showed decreased body weight (P<0.001) and body fat percentage (P<0.001) as well as lower insulin resistance. However, plasma OPN levels were significantly increased after RYGB (P<0.001) but remained unchanged following SG (P=0.152). Patients who underwent RYGB also showed significantly increased C-terminal telopeptide of type-I collagen (ICTP) (P<0.01) and osteocalcin (P<0.001) while bone mineral density tended to decrease (P=0.086). Moreover, OPN concentrations were positively correlated with the bone resorption marker ICTP after surgery. On the other hand, patients who underwent SG showed significantly increased ICTP levels (P<0.05), and the change in OPN was positively correlated with the change in ICTP and negatively with the change in vitamin D after surgery (P<0.05). RYGB increased circulating OPN levels, while they remained unaltered after SG. The increase in OPN levels after RYGB could be related to the increased bone resorption in relation to its well-known effects on bone of this malabsorptive procedure in comparison to the merely restrictive SG.

Evaluating the efficacy of osteopontin expression as a prognostic marker in oral squamous cell carcinoma in the Indian subpopulation.

Aim:This study aimed to correlate the prognostic value of osteopontin (OPN) expression using both tissue and plasma samples from patients with clinically and histologically confirmed oral squamous cell carcinoma (OSCC).Methods and Materials:The study group comprised of sixty patients (n = 60), which were clinically and histologically diagnosed for oral squamous cell carcinoma (OSCC). The Control group comprised of ten (n = 10) healthy volunteers. Plasma OPN levels were assayed using a quantitative enzyme-linked immunosorbent assay (OPN ELISA). Expression of OPN was also identified and evaluated by immunohistochemistry in tissue sections. These OPN expressions were then correlated with different parameters like age, sex, site, clinical presentation, tumor node metastasis (TNM) staging, histopathological grading and lymph node metastasis.Statistical Analysis:One-way analysis of variance (ANOVA) was used to evaluate the difference in tissue intensity and plasma OPN levels between the OSCC and the normal control groups.Results:The distribution of the plasma OPN levels and tissue OPN intensity in OSCC cohorts were compared to histopathological grades and analyzed. When evaluated OPN expression in tissue had higher intensity observed in OSCC (95% +ve) cases. And the mean plasma OPN concentration in OSCC cohort was more in comparison to the normal cohort. The results clearly showed that the plasma OPN levels and intensity grading in tissue correlated with tumor grades.Conclusion:The study highlights OPN as a biomarker for prognosis in OSCC in both plasma and tissue samples. We would like to emphasize on the evaluation of plasma OPN as a protocol of blood examination for all cancer patient, as it may serve as an indicator for tumor progression and potential risk of metastasis.

Plasma osteopontin concentrations in patients with cutaneous melanoma

An effective circulating tumour marker is needed for melanoma especially with the advent of targeted therapies. Gene expression studies examining primary melanomas have shown that increased expression of osteopontin (SPP1) is associated with poor prognosis. Studies subsequently reported higher blood levels in melanoma patients with metastatic disease than those without. This study was designed to determine whether osteopontin plasma concentrations in disease-free patients after initial treatment predict survival. An enzyme-linked immunosorbent assay (ELISA) was used to measure osteopontin levels in stored plasma samples (N=215) from participants in the Leeds Melanoma Cohort. AJCC stage at sampling was statistically significant associated with osteopontin levels (P=0.03). Participants with untreated stage IV disease at sampling (n=10) had higher median osteopontin levels compared to those with treated stage I–III disease (n=158) (P<0.001) confirming previous findings. There was a trend for increased risk of death with increasing osteopontin levels but this was not statistically significant. If a level of 103.14 ng/ml (95th centile of healthy controls) was taken as the upper end of the normal range then 2.5% of patients with treated stage I–III (4/110), 17.6% of patients with untreated stage III (3/17) and 30% of patients with untreated stage IV disease (3/10) had higher levels. These findings suggest that plasma osteopontin levels warrant investigation as a tumour marker in a larger study in which the significance of change in levels over time should be studied in relation to detectable disease recurrence.

Osteopontin: Participation in Inflammation or Mucosal Protection in Inflammatory Bowel Diseases?

Osteopontin (OPN) is associated with the Th1 immune response in inflammatory bowel diseases (IBD). While OPN has been shown to play an important role in maintaining the epithelial barrier, its role in IBD remains unclear. The aim of this study was to assess OPN function in patients with IBD and in the mouse colitis model. Osteopontin expression in colonic samples from IBD patients was determined by a semi-quantitative immunohistochemical staining method. Colitis in BALB/c mice was induced by 5 % dextran sodium sulfate (DSS), followed by treatment with salazosulfapyridine (SASP) and infliximab, respectively. The plasma OPN concentration was measured by an enzyme-linked immunosorbent assay. The expression of OPN in colonic tissues was detected by reverse transcriptase PCR, real-time PCR and Western blot, and the localization of OPN was determined by a semi-quantitative immunohistochemical staining method. The immune function of OPN was investigated by measuring the production of cytokines, and the amount of cytokines produced was then used to determine OPN immune functions. Osteopontin expression in intestinal epithelial cells was significantly lower in IBD patients than in controls, while its expression in lamina propria exudative cells was significantly higher in IBD patients than in controls. In DSS-induced mice, OPN expression in plasma and colonic tissues increased significantly, and this increase was significantly reduced after the mice were treated with SASP and infliximab. OPN promoted the Th1 immune response and strengthened inflammation in the mouse colitis model. Our results indicate that OPN plays an important role in the immune response and is also involved in the mucosal protective mechanism in IBD.

CTX (Crosslaps) Rather than Osteopontin Is Associated with Disturbed Glucose Metabolism in Gestational Diabetes

ObjectiveReciprocal interaction between bone and glucose metabolism might play a pivotal role in the development of type 2 diabetes. We recently demonstrated that osteocalcin is increased in women with gestational diabetes (GDM) compared to healthy pregnant women and related to enhanced insulin secretion. Here, we aimed to investigate the role of the bone resorption marker CTX and osteopontin (OPN), a key molecule in subclinical inflammation underlying insulin resistance, in gestational diabetes.MethodsInsulin sensitivity and secretion (derived from OGTT) as well as CTX and osteopontin were investigated in 26 GDM and 52 women with normal glucose tolerance during pregnancy [CON] between 24th and 28th gestational weeks; 24 women also underwent postpartum examination.ResultsCTX was significantly higher in GDM compared to CON (0.44±0.20 vs.0.28±0.12 ng/ml, p<.0001) and positively correlated with osteocalcin (R = 0.64, p<.0001) and parameters of insulin secretion. Osteopontin plasma concentrations were decreased in GDM compared to CON (28.81±22.12 vs.37.68±19.63 ng/ml, p = 0.04), and did not show any relation to insulin secretion or sensitivity, but were significantly correlated with CRP (R = 0.3, p<0.007) and liver enzymes. Twelve weeks after delivery CTX and OPN were increased compared to pregnancy (both p<.0001) and did not differ between GDM and CON.ConclusionOur findings support the idea of a tight regulation between bone and glucose metabolism, and suggest, that less curbed CTX during pregnancy might be involved in osteocalcin-mediated amelioration of insulin secretion in GDM. On the other hand, osteopontin was unrelated to insulin resistance in GDM, but associated with inflammatory markers and liver enzymes in all women.