Osteopontin Research Articles

Association of osteopontin and shrunken pore syndrome with hospitalization for renal failure in acute heart failure patients

Abstract Background Shrunken pore syndrome (SPS) emerges as a distinctive manifestation of glomerular filtration dysfunction mainly manifested by the impairment of moderate-sized molecular filtration, distinguished by a variance in renal filtration between cystatin C and creatinine. SPS exhibits correlations with adverse prognosis of various cardiovascular diseases. A decline in renal function correlates with a poor prognosis among individuals with heart failure (HF). Osteopontin (OPN), a protein involved to bone mineralization, has been linked to deteriorating renal function and heightened risk for adverse outcomes in patients with chronic kidney disease. Purpose To explore if OPN and SPS are associated with hospitalization for renal failure in patients with acute HF. Methods Cystatin C and creatinine were analyzed in 395 hospitalized HF patients, of which 324 also had osteopontin (OPN) analyzed using a proximity extension assay. SPS was calculated using the CKD-EPI Equations for Glomerular Filtration Rate and defined as a cystatin C-based estimated glomerular filtration rate (eGFR) <60% of the creatinine based eGFR. Hospitalization for renal failure was extracted from regional registries using ICD10 codes N17-N19. Logistic and Cox regression models were deployed to explore a) OPN’s association with SPS; b) OPN’s association with hospitalization for renal failure; and c) SPS’s association with hospitalization for renal failure, adjusting for age, sex, systolic blood pressure and use of renin-angiotensin-aldosterone system (RAAS) inhibitors. Results The study population had a mean age of 74.8 (±12.0) years, 32.4% were women and 104 (26.5%) patients presented with SPS (Table 1). During the median follow-up period of 71 (interquartile range 56-88) months, 35 (8.9%) patients were hospitalized for renal failure. OPN was associated with the prevalence of SPS (OR 1.66; 95%CI 1.08-2.27; p=0.002), as well as with higher risk of hospitalization due to renal failure (HR 2.71; 95%CI 1.61-4.56; p<0.001). Further, also prevalent SPS was associated with higher risk of hospitalization due to renal failure (HR 2.44; 95%CI 1.14-5.24; p=0.022). Conclusions Here, we demonstrate that higher OPN levels are associated with a higher prevalence of SPS and an elevated risk of hospitalization due to renal failure among patients with HF. Additionally, the presence of SPS was associated with a higher risk of renal failure-related hospitalizations. These findings highlight the potential utility of OPN and SPS as biomarkers for identifying heart failure patients at risk of renal function decline, underscoring the importance of early risk stratification and targeted interventions in this population.

Osteopontin as a biomarker for diagnosing the severity of osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis. It is characterized by the loss of cartilage and pain ultimately leading to difficulty in movement. Glycoprotein osteopontin (OPN) is an essential regulator that plays a critical role in developing osteoarthritis. The study aims to determine the level of OPN in the serum of patients with OA and its correlation with the content of calcium (Ca), phosphorus (P), and magnesium (Mg). The study was conducted on 92 male and female patients aged between 30 and 65, categorized into mild, moderate, and severe groups through clinical examination and X-rays. The control group consist of 58 healthy males and females 30-65-year old. OPN was measured using the ELISA technique, and minerals were estimated using spectrophotometry. It was shown that in OA patients, OPN level increased highly significant when compared with the control group (10.7 ± 3.4 ng/ml) and depended on OA severity. In patients with severe OA, it was higher (47.5 ± 8.1 ng/ml) than in groups with moderate (14.8 ± 4.5 ng/ml) and mild (12.1 ± 3.1 ng/ml) extent of the disease. We showed a significant positive relationship between OPN and phosphorus levels and a negative significant correlation between OPN and calcium, calcium/phosphorus ratio, and magnesium. These findings underscore the potential of OPN as a valuable biomarker for diagnosing the severity of osteoarthritis and monitoring the effectiveness of treatment. Keywords: calcium, magnesium, osteoarthritis, osteopontin, phosphorus.

Type 1 diabetes and parasite infection: An exploratory study in NOD mice.

Microorganisms have long been suspected to influence the outcome of immune-related syndromes, particularly autoimmune diseases. Type 1 diabetes (T1D) results from the autoimmune destruction of the insulin-producing beta cells of pancreatic islets, causing high glycemia levels. Genetics is part of its aetiology, but environmental factors, particularly infectious microorganisms, also play a role. Bacteria, viruses, and parasites influence the outcome of T1D in mice and humans. We used nonobese diabetic (NOD) mice, which spontaneously develop T1D, to investigate the influence of a parasitic infection, leishmaniasis. Leishmania amazonensis is an intracellular eukaryotic parasite that replicates predominantly in macrophages and is responsible for cutaneous leishmaniasis. The implication of Th1 immune responses in T1D and leishmaniasis led us to study this parasite in the NOD mouse model. We previously constructed osteopontin knockout mice with a NOD genetic background and demonstrated that this protein plays a role in the T1D phenotype. In addition, osteopontin (OPN) has been found to play a role in the immune response to various infectious microorganisms and to be implicated in other autoimmune conditions, such as multiple sclerosis in humans and experimental autoimmune encephalomyelitis (EAE) in mice. We present herein data demonstrating the role of OPN in the response to Leishmania in NOD mice and the influence of this parasitic infection on T1D. This exploratory study aimed to investigate the environmental infectious component of the autoimmune response, including Th1 immunity, which is common to both T1D and leishmaniasis.

Osteopontin Promotes Cholangiocyte Secretion of Chemokines to Support Macrophage Recruitment and Fibrosis in MASH.

Osteopontin (OPN) promotes the ductular reaction and is a major driver of chronic liver disease (CLD) progression. Although CLD is characterised by the accumulation of inflammatory cells including macrophages around the peri-portal regions, the influence of OPN on recruitment is unclear. We investigated the role of OPN in cholangiocyte chemokine production and macrophage recruitment by combining invivo, invitro, and in silico approaches. The effects of OPN on cholangiocyte chemokine production and macrophage migration were assessed in culture, alongside RNA-sequencing to identify genes and pathways affected by OPN depletion. Murine liver injury models were used to assess liver chemokine expression and liver macrophage/monocyte recruitment. OPN and chemokine expression were analysed in liver tissue and plasma from biopsy-proven metabolic dysfunction-associated alcoholic steatohepatitis (MASH) patients. OPN-knockdown in cholangiocytes reduced chemokine secretion. RNA-sequencing showed OPN-related effects clustered around immunity, chemotaxis and chemokine production. Macrophage exposure to cholangiocyte-conditioned media showed OPN-supported migration via chemokines chemokine (C-C motif) ligand (CCL)2, CCL5 and chemokine (C-X-C motif) ligand (CXCL)1. These effects were related to NF-κB signalling. Murine liver fibrosis was accompanied by upregulated liver OPN, CCL2, CCL5 and CXCL1 mRNA, and accumulation of liver cluster of differentiation (CD)11b/F4/80+CC chemokine receptors (CCR2)high macrophages but treatment with OPN-specific neutralising aptamers reduced fibrosis, chemokine mRNAs and accumulation of liver CD11b/F4/80+CCR2high/lymphocyte antigen 6 complexhigh inflammatory monocytes. In human MASH, liver OPN correlated with chemokines CCL2 and IL8 in association with portal injury and fibrosis. Plasma OPN, serum CCL2 and IL8 also increased with fibrosis stage. OPN promotes cholangiocyte chemokine secretion and the accumulation of pro-inflammatory monocytes. These data support neutralisation of OPN as an anti-inflammatory and anti-fibrotic strategy.

Milk osteopontin mediates zinc uptake in intestinal cells in the presence of phytic acid

The bioavailability and the intestinal absorption of the essential mineral zinc are challenged by the food matrix and especially the content of zinc chelating antinutrients. Many milk proteins and peptides affect zinc bioavailability. Osteopontin (OPN) is an acidic and highly phosphorylated whey protein that has been shown to bind calcium, magnesium and iron. Here we report the zinc binding properties of OPN, and the effect of OPN-Zn complexes on zinc absorption in Caco-2 cells. By isothermal titration calorimetry milk OPN was shown to bind approximately 36 zinc ions (KD of ∼70 μM). The binding was mainly mediated by the phosphorylations in the protein. OPN retained zinc bound after in vitro simulated gastrointestinal transit. Interestingly the OPN-Zn complex enhanced zinc bioavailability in the presence of phytic acid, compared to inorganic zinc salts. Zinc uptake mediated by OPN significantly upregulated the gene expression of MT1G and ZnT1 which are crucial proteins involved in preserving enterocyte zinc homoeostasis. These results indicate that OPN could be incorporated into functional foods and infant formulas to increase zinc bioavailability and uptake.

Diagnostic Value of Osteopontin, Lymphocyte-to-Monocyte Ratio, and CA-125 in Ovarian Carcinoma Suspect

Osteopontin (OPN) is an important protein in cancer development and progressivity. Lymphocyte-to-Monocyte Ratio (LMR) as a systemic immunity and inflammatory indicator could be an ideal predictor biomarker because of its method’s simplicity and availability. Elevated CA-125 and OPN as well as decreased LMR were reported as signs of ovarian malignancy. Limited studies about OPN and LMR as diagnostic biomarkers, as well as various specificity and sensitivity of CA-125 intrigued the researcher to prove OPN, LMR, and CA-125 as diagnostic biomarkers for ovarian carcinoma. This study aimed to measure the diagnostic value of OPN, LMR, and CA-125 levels against histopathology results for ovarian carcinoma diagnosis. Eighty patients involved with suspected ovarian carcinoma who were referred to Dr. Kariadi Hospital, Semarang. Osteopontin and CA-125 levels were measured using ELISA, and LMR was calculated from absolute lymphocyte and monocyte counts using an automated hematology analyzer. The receiver operating characteristics curve was used to determine the cut-off and 2x2 table. The cut-off values for OPN, LMR, and CA-125 were 124 ng/mL, 3.7 and 45.4 U/mL, respectively. The sensitivity for OPN, LMR, and CA-125 was 67.24%, 62.07% and 60.34%. Specificity for OPN, LMR, and CA-125 were 68.18%, 54.55% and 59.09%. Osteopontin is the best parameter for determining the diagnosis of ovarian carcinoma but it is still not sufficient because OPN cut-off was still within the normal reference value.

Association between plasma osteopontin level and mild cognitive impairment in patients with type 2 diabetes mellitus

Objective: To analyze the influencing factors of type 2 diabetes mellitus (T2DM) patients with mild cognitive impairment (MCI), and to explore the association between plasma osteopontin (OPN) levels and MCI. Methods: A retrospective analysis was conducted on the clinical data of 254 patients with T2DM admitted to Zhongda Hospital Affiliated to Southeast University from October 2021 to May 2023. The patients were divided into MCI group (n=106) and normal cognitive function control group (n=148) according to whether they had MCI. Clinical data were collected, cognitive function was assessed using neurological scales and plasma OPN levels were measured by enzyme linked immunosorbent assay. A multivariate logistic regression model was applied to analyze the influencing factors of MCI in T2DM patients. Interaction terms between gender, age, body mass index (BMI), and OPN were established to verify their significance levels. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive value of OPN for MCI in T2DM patients. The mediation model of OPN-FPG-montreal cognitive assessment(MoCA) was constructed with fasting plasma glucose (FPG) as the mediating variable to test the mediating effect, and the mediating effect percentage was calculated. Results: A total of 254 patients were included, including 162 males and 92 females, with an average age of (61.5±7.5) years old. Compared with the control group, the patients in MCI group were older[63.0(59.0, 69.0) years vs 60.0(54.2, 66.8) years], had a greater proportion of females [(43.4%(46/106) vs 31.1%(46/148)], shorter years of education[12(9, 12) years vs 12(9,15) years], longer duration of diabetes[15.0(8.0, 20.0) years vs 10.0(5.0, 15.0) years], and higher levels of FPG[7.78(6.07, 10.23) mmol/L vs 6.86(5.36, 8.59) mmol/L], insulin resistance index[2.93(2.47, 3.98) vs 2.79(2.27, 3.25)], glycated hemoglobin (HbA1c) [9.24%(7.89%, 10.96%) vs 7.97%(7.00%, 9.45%)], total cholesterol(TC)[(4.51±1.17) mmol/L vs (4.19±0.99) mmol/L], and OPN [11.30(8.68, 12.84) ng/ml vs 9.69(7.82, 11.74) ng/ml] (all P<0.05). The scores of various neuropsychological tests in MCI patients were lower than those in control group with normal cognitive function (all P<0.05). Spearman correlation analysis showed that age(r=-0.212), duration of diabetes mellitus(r=-0.156), duration of hypertension(r=-0.132), FPG(r=-0.207), insulin resistance index(r=-0.171), HbA1c(r=-0.271), OPN(r=-0.238), and total cholesterol (r=-0.125) were negatively correlated with MoCA scores, whereas years of education(r=0.285) were positively correlated with MoCA scores(all P<0.05). Multifactorial logistic regression analysis showed that age, years of education, duration of diabetes mellitus, HbA1c, TC and OPN levels were the influencing factors of T2DM patients with MCI, and the risk of MCI increased by 15% for every 1 ng/ml increase in OPN (OR=1.15, 95%CI: 1.021-1.295, P=0.021), and the relationship was not affected by age, gender and BMI(The interaction effects are all P>0.05). The area under the curve (AUC) of the working curve of subjects with OPN predicting combined MCI in patients with T2DM was 0.612 (95%CI: 0.541-0.682), and the AUC was 0.702 (95%CI: 0.638-0.767) after the combination of HbA1c and OPN. The results of the mediated effect model showed that FPG partially mediated the correlation between OPN and MoCA in T2DM patients, and the mediated effect accounted for 11.34% of the total effect. Conclusions: Plasma OPN level is associated with MCI in patients with T2DM,and the higher the OPN level, the higher the risk of T2DM patients developing MCI.

Dynamics of osteopontin levels and correlation with parasitemia in acute malaria in Uganda and Sweden

BackgroundMalaria remains a significant public health concern, especially for the deadliest parasite, Plasmodium falciparum. During acute malaria, various cytokines, including osteopontin (OPN), regulate the immune response. OPN has been shown to be protective against malaria in mice. Nonetheless, its precise function and potential ability to control parasites during acute malaria in humans remain poorly understood.ResultsBlood samples were collected from Swedish adults with imported malaria, Ugandan children and adults with symptomatic malaria (including follow-up after 42 days), Ugandans with non-malarial fever and healthy individuals from both Uganda and Sweden. Parasitemia was determined by microscopy. Malaria-negative samples were verified by LAMP. OPN and interferon-γ (IFN- γ) levels were measured using ELISA. In children, OPN levels were significantly higher during acute infection compared to levels after 42 days, whereas Ugandan adults showed no difference. Swedish adults with imported malaria had elevated OPN levels compared to both Swedish controls and Ugandan adults with malaria. Parasitemia was significantly correlated with both OPN and IFN-γ levels across the entire cohort. While a significant correlation between OPN and IFN-γ was evident overall, it remained statistically significant only in Ugandan adults when analyzed by subgroups. This suggests that OPN is not just a general marker of inflammation but may be regulated differently during the development of malaria immunity.ConclusionsIn acute malaria, elevated OPN levels showed a stronger correlation with lack of immunity than age. These findings underscore the potential importance of OPN in malaria, particularly in non-immune individuals.

Intracellular osteopontin potentiates the immunosuppressive activity of mesenchymal stromal cells

IntroductionMesenchymal stromal cell (MSC)-based cell therapy is a promising approach for various inflammatory disorders based on their immunosuppressive capacity. Osteopontin (OPN) regulates several cellular functions including tissue repair, bone metabolism and immune reaction. However, the biological function of OPN in regulating the immunosuppressive capacity of MSCs remains elusive.ObjectivesThis study aims to highlight the underlying mechanism of the proinflammatory cytokines affect the therapeutic ability of MSCs through OPN.MethodsMSCs in response to the proinflammatory cytokines were collected to determine the expression profile of OPN. In vitro T-cell proliferation assays and gene editing were performed to check the role and mechanisms of OPN in regulating the immunosuppressive capacity of MSCs. Inflammatory disease mouse models were established to evaluate the effect of OPN on improving MSC-based immunotherapy.ResultsWe observed that OPN, including its two isoforms iOPN and sOPN, was downregulated in MSCs upon proinflammatory cytokine stimulation. Interestingly, iOPN, but not sOPN, greatly enhanced the immunosuppressive activity of MSCs on T-cell proliferation and thus alleviated the inflammatory pathologies of hepatitis and colitis. Mechanistically, iOPN interacted with STAT1 and mediated its deubiquitination, thereby inducing the master immunosuppressive mediator inducible nitric oxide synthase (iNOS) in MSCs. In addition, iOPN expression was directly downregulated by activated STAT1, which formed a negative feedback loop to restrain MSC immunosuppressive capacity.ConclusionOur findings demonstrated that iOPN expression modulation in MSCs is a novel strategy to improve MSC-based immunotherapy.

Fisetin reduces ovalbumin-triggered airway remodeling by preventing phenotypic switching of airway smooth muscle cells

BackgroundThe transformation of airway smooth muscle cells (ASMCs) from a quiescent phenotype to a hypersecretory and hypercontractile phenotype is a defining feature of asthmatic airway remodeling. Fisetin, a flavonoid compound, possesses anti-inflammatory characteristics in asthma; yet, its impact on airway remodeling and ASMCs phenotype transition has not been investigated.ObjectivesThis research seeked to assess the impact of fisetin on ovalbumin (OVA) induced asthmatic airway remodeling and ASMCs phenotype transition, and clarify the mechanisms through network pharmacology predictions as well as in vivo and in vitro validation.MethodsFirst, a fisetin-asthma-ASMCs network was constructed to identify potential targets. Subsequently, cellular and animal studies were carried out to examine the inhibitory effects of fisetin on airway remodeling in asthmatic mice, and to detemine how fisetin impacts the phenotypic transition of ASMCs.ResultsNetwork analysis indicated that fisetin might affect asthma via mediating the phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (AKT) pathway. Intraperitoneal administration of fisetin in vivo reduced airway inflammation and remodeling, as shown by reduced inflammatory cells, decreased T helper type 2 (Th2) cytokine release, diminished collagen accumulation, mitigated airway smooth muscle thickening, and decreased expression of osteopontin (OPN), collagen-I and α-smooth muscle actin (α-SMA). Moreover, fisetin suppressed the PI3K/AKT pathway in asthmatic lung tissue. According to the in vitro data, fisetin downregulated the expression of the synthetic phenotypic proteins OPN and collagen-I, contractile protein α-SMA, and inhibited cellular migration, potentially through the PI3K/AKT pathway.ConclusionThese results suggest that fisetin inhibits airway remodeling in asthma by regulating ASMCs phenotypic shift, emphasizing that fisetin is a promising candidate for the treatment of airway smooth muscle remodeling.

Determination of osteopontin in monitoring retinal damage in metabolic syndrome.

Metabolic syndrome (MetS) is becoming an increasing public health challenge. Many of the individual components of MetS are associated with ocular changes, but it is not yet clear what the association is. It is known that MetS can lead to diabetes and hence its consequences such as retinopathy. Osteopontin (OPN) is a phosphoglycoprotein that appears to be implicated in diabetic retinopathy. Given the involvement of OPN in retinal damage, the aim of this research was to evaluate OPN expression and its variation over time in a model of MetS induced by 30% fructose consumption for 1, 2 and 3 months. The weight of the animals and the consumption of food and fructose/water were evaluated during the experiment. The results showed a time-dependent increase in weight and liquid consumption in animals treated with fructose, while there was no significant difference in food consumption. Subsequently, the biochemical parameters confirmed that the animals treated with fructose, over time, underwent alterations like those found in patients with MetS. We then moved on to the evaluation of OPN and microglia. In both cases, we observed a time-dependent increase in OPN and Iba-1 in fructose consumption. Furthermore, the results showed a gradual loss of ZO-1 and occludin levels over time. Thus identification of OPN in patients with MetS could be used as an early marker of retinal damage, and this could help to preventthe complications related to the progression of this pathology.

Synthetic Bone Blocks Produced by Additive Manufacturing in the Repair of Critical Bone Defects.

This study evaluated the efficacy of synthetic bone blocks, composed of hydroxyapatite (HA) or β-tricalcium phosphate (B-TCP), which were produced by additive manufacturing and used for the repair of critical size bone defects (CSDs) in rat calvaria. Sixty rats were divided into five groups (n = 12): blood clot (CONTROL), 3D-printed HA (HA), 3D-printed β-TCP (B-TCP), 3D-printed HA + autologous micrograft (HA+RIG), and 3D-printed β-TCP + autologous micrograft (B-TCP+RIG). CSDs were surgically created in the parietal bone and treated with the respective biomaterials. The animals were euthanized at 30 and 60 days postsurgery for microcomputed tomography (micro-CT) histomorphometric, and immunohistochemical analysis to assess new bone formation. Micro-CT analysis showed that both biomaterials were incorporated into the animals' calvaria. The HA+RIG group, especially at 60 days, exhibited a significant increase in bone formation compared with the control. The use of 3D-printed bioceramics resulted in thinner trabeculae but a higher number of trabeculae compared with the control. Histomorphometric analysis showed bone islands in close contact with the B-TCP and HA blocks at 30 days. The HA blocks (HA and HA+RIG groups) showed statistically higher new bone formation values with further improvement when autologous micrografts were included. Immunohistochemical analysis showed the expression of bone repair proteins. At 30 days, the HA+RIG group had moderate Osteopontin (OPN) staining, indicating that the repair process had started, whereas other groups showed no staining. At 60 days, the HA+RIG group showed slight staining, similar to that of the control. Osteocalcin (OCN) staining, indicating osteoblastic activity, showed moderate expression in the HA and HA+RIG groups at 30 days, with slight expression in the B-TCP and B-TCP+RIG groups. The combination of HA blocks with autologous micrografts significantly enhanced bone repair, suggesting that the presence of progenitor cells and growth factors in the micrografts contributed to the improved outcomes. It was concluded that 3D-printed bone substitute blocks, associated with autologous micrografts, are highly effective in promoting bone repair in CSDs in rat calvaria.

Enrichment of low-abundance osteopontin in bovine milk via reciprocating free-flow isoelectric focusing.

Osteopontin (OPN) in milk plays an important role in intestinal and brain development in early infancy, and great attention has been focused on OPN isolation to add extra OPN in infant formula. However, large-scale OPN isolation is limited by the low efficiency of sample pretreatment. Herein, we utilized preparative reciprocating free-flow isoelectric focusing (RFFIEF) to showcase the enrichment of low-abundance OPN in bovine milk, which contained an extremely high concentration of unwanted proteins. The reciprocating IEF format and the design of the multi-channel collector allowed us to enrich OPN in 1 L milk within 6h. We removed 97.5% of unwanted proteins and obtained an enrichment factor of 11. Thus, our RFFIEF method can be applied to the preparative pretreatment of the large-scale milk sample and potentially improve the efficiency of downstream OPN purification.

Quercetin regulates pulmonary vascular remodeling in pulmonary hypertension by downregulating TGF-β1-Smad2/3 pathway

BackgroundPulmonary arterial hypertension (PAH) is a worldwide challenging disease characterized by progressive elevation of pulmonary artery pressure. The proliferation, migration and phenotypic transformation of pulmonary smooth muscle cells are the key steps of pulmonary vascular remodeling. Quercetin (3,3', 4', 5, 6-pentahydroxyflavone, Que) is a natural flavonol compound that has antioxidant, anti-inflammatory, anti-tumor and other biological activities. Studies have shown that Que has therapeutic effects on PAH. However, the effect of quercetin on pulmonary vascular remodeling in PAH and its mechanism remain unclear.Methods and resultsIn vivo, PAH rats were constructed by intraperitoneal injection of monocrotaline (MCT) at 60 mg/kg. Human pulmonary artery smooth muscle cells (HPASMCs) were treated with platelet-derived growth factor BB (PDGF-BB) 20 ng/mL to construct PAH cell model in vitro. The results showed that in vivo studies, MCT could induce right ventricular wall hyperplasia, narrow the small and medium pulmonary artery cavity, up-regulate the expression of proliferating and migration-related proteins proliferating cell nuclear antigen (PCNA) and osteopontin (OPN), and down-regulate the expression of alpha-smooth muscle actin (α-SMA). Que reversed the MCT-induced results. This process works by down-regulating the transforming growth factor-β1 (TGF-β1)/ Smad2/3 signaling pathway. In vitro studies, Que had the same effect on PDGF-BB-induced proliferation and migration cell models.ConclusionsQue inhibits the proliferation, migration and phenotypic transformation of HPASMCs by down-regulating TGF-β1/Smad2/Smad3 pathway, thereby reducing right ventricular hyperplasia (RVH) and pulmonary vascular remodeling, providing potential pharmacological and molecular explanations for the treatment of PAH.

AEBP1 restores osteoblastic differentiation under dexamethasone treatment by activating PI3K/AKT signalling.

Adipocyte enhancer-binding protein 1 (AEBP1) is closely implicated in osteoblastic differentiation and bone fracture; this research aimed to investigate the effect of AEBP1 on restoring osteoblastic differentiation under dexamethasone (Dex) treatment, and its interaction with the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway. Pre-osteoblastic MC3T3-E1 cells were cultured in osteogenic medium and treated by Dex to mimic steroid-induced osteonecrosis cellular model. They were then further transfected with control or AEBP1-overexpressed lentiviral vectors. Finally, cells were treated with the PI3K inhibitor LY294002, with or without AEBP1-overexpressed lentiviral vectors. AEBP1 expression showed a downward trend in MC3T3-E1 cells under Dex treatment in a dose-dependent manner. AEBP1-overexpressed lentiviral vectors increased relative cell viability, alkaline phosphatase (ALP) staining, Alizarin red staining and osteoblastic differentiation markers including osteocalcin (OCN), osteopontin (OPN), collagen type I alpha 1 (COL1A1), runt-related transcription factor 2 (RUNX2) and bone morphogenetic protein 2 (BMP2), but decreased cell apoptosis rate in MC3T3-E1 cells under Dex treatment; besides, AEBP1-overexpressed lentiviral vectors positively regulated p-PI3K and p-AKT expressions. Furthermore, LY294002 treatment decreased relative cell viability, Alizarin red staining, osteoblastic differentiation markers including OCN, OPN, RUNX2 and BMP, increased cell apoptosis rate and did not affect ALP staining in MC3T3-E1 cells under Dex treatment; meanwhile, LY294002 treatment weakened the effect of AEBP1 overexpression vectors on the above cell functions. AEBP1 restores osteoblastic differentiation under Dex treatment by activating the PI3K/AKT pathway.

Identification of an osteopontin structural element for the restoration of a normal endometrial epidermal growth factor (EGF) profile determined by the EGF concentration on day 3 of estrous cycle and pregnancy outcome in repeat breeder dairy cows

The loss of a cyclic change with two peaks of increased endometrial epidermal growth factor (EGF) concentration on days 2−4 and 13−14 during the estrous cycle has been linked to low fertility in repeat breeder (RB) cows. We have shown that an intravaginal infusion of osteopontin (OPN) restored the EGF profile in RB cows. The present study aimed to determine a structural element of OPN to restore the normal EGF profile and fertility. Holstein RB cows were diagnosed the EGF profile by a single examination of the endometrial EGF concentration on day 3 of the estrous cycle. Those with an altered EGF profile were intravaginally infused with OPN and its fragments on the day of insemination (day 0); the concentration of endometrial EGF was measured on day 3, and pregnancy was diagnosed on days 30−35. In Study 1, recombinant OPN (rOPN) (16 nmol), thrombin-cleaved N- and C-terminal fragments of rOPN (N-rOPN and C-rOPN, respectively), and a combination of these fragments (Th-rOPN) were infused (n = 13−20). The restoration rate of the normal EGF profile of the N-rOPN group (25.0%) was a level in between the C-rOPN group (7.7%) and both the rOPN (55.6%) and Th-rOPN (64.3%) groups. In Study 2, PBS (n = 47), rOPN (9.5 nmol, n = 83), and peptides of integrin binding motifs, GRGDSVAYGLK (peptide 1; 32, 320, and 1,600 nmol), GRGDS (peptide 2; 320 and 1,600 nmol), and SVAYGLK (peptide 3; 320 and 1,600 nmol), were infused (n = 20−25). Restoration rates of the normal EGF profile of peptide 1 (320 and 1,600 nmol) and peptide 3 (1,600 nmol) groups (44.0−56.3%) were comparable with those of the rOPN group (63.9%) and higher than those of the PBS group (15.6%). Restoration rates of the other groups were similar to those of the PBS group. Additional cows received infusions to determine the effect on fertility. Conception rates of the peptide 1 (320 and 1,600 nmol; n = 50 each), peptide 3 (1,600 nmol; n = 55), and rOPN (n = 111) groups (41.8−50.0%) were comparable and higher than that of the PBS group (21.6%, n = 75). In Study 3, PBS (n = 24), peptide 1 (320 nmol; n = 78), and GRGESVAYGLK peptide (peptide 4; 320 and 1,600 nmol; n = 50 and 26, respectively) were infused. Restoration rates of the normal EGF profile of peptide 4 and PBS groups (16.0−19.2%) were comparable and lower than those of the peptide 1 group (44.9%). Thus, the SVAYGLK motif may be an OPN structural element to restore the normal EGF profile and fertility in RB cows, and the RGD motif may enhance its effect.

Combined proteomics and metabolomics analysis reveal the effect of a training course on the immune function of Chinese elite short-track speed skaters.

The aim of this study was to combine proteomics and metabolomics to evaluate the immune system of short-track speed skaters (STSS) before and after a training course. Our research focused on changes in urinary proteins and metabolites that have the potential to serve as indicators for training load. Urine samples were collected from 21 elite STSS (13 male and 8 female) of the China National Team before and immediately after one training course. First-beat sports sensor was used to monitor the training load. Proteomic detection was performed using a Thermo UltiMate 3000 ultra high performence chromatographynano liquid chromatograph and an Orbitrap Exploris 480 mass spectrometer. MSstats (R package) was used for the statistical evaluation of significant differences in proteins from the samples. Two filtration criteria (fold change [FC] > 2 and p < 0.05) were used to identify the differential expressed proteins. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis for differential proteins was performed to identify the pathways involved. Nontargeted metabolomic detection was performed using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS_) with an ACQUITY 2D UPLC plus Q Exactive (QE) hybrid Quadrupole-Orbitrap mass spectrometer. Differential metabolites were identified using non-parametric statistical methods (Wilcox's rank test). Two filtration criteria (FC > 1.2 and p < 0.05) were used to identify differential metabolites. Combined analysis of proteomic and metabolomics were performed on the "Wu Kong" platform. Correlation analysis was performed using Spearman's rank correlation coefficient. (1) The most upregulated proteins were immune-related proteins, including complement proteins (C9, C4-B, and C9) and immunoglobulins (IgA, IgM, and IgG). The most downregulated proteins were osteopontin (OPN) and CD44 in urine. The correlation analysis showed that the content of OPN and CD44 (the receptor for OPN) in urine were significantly negatively correlated with the upregulated immune-related proteins. The content of OPN and CD44 is sex-dependent and negatively correlated with the training load. (2) The most upregulated metabolites included lactate, cortisol, inosine, glutamine, argininosuccinate (the precursor for arginine synthesis), 3-methyl-2-oxobutyrate (the catabolite of valine), 3-methyl-2-oxovalerate (the catabolite of isoleucine), and 4-methyl-2-oxopentanoate (the catabolite of leucine), which is sex-dependent and negatively correlated with OPN and CD44. (3) The joint analysis revealed five main related pathways, including the immune and innate immune systems. The enriched immune-related proteins included complements, immunoglobulins, and protein catabolism-related proteins. The enriched immune-related metabolites included cAMP, N-acetylgalactosamine, and glutamate. (4) There is a significant negative correlation between the content of OPN and CD44 in urine and the training load. One training course can lead to the activation of the immune system and a sex-dependent decrease in the content of OPN and CD44. Training load has a significant and negative correlation with the content of OPN and CD44, suggesting that OPN and CD44 could be potential indicators for training load.

Osteopontin associated Bifidobacterium bifidum microencapsulation modulates infant fecal fermentation and gut microbiota development

Probiotic supplementation is an effective method for improving infant gut health, and probiotic encapsulation can enhance probiotic viability under adverse environmental conditions while ensuring an adequate amount of probiotic is delivered to the target site to confer a health benefit for the host. In this study, Bifidobacterium bifidum R0071 was microencapsulated using pectin or alginate, combined bovine milk osteopontin (OPN) as an excipient during the microencapsulation process. The microencapsulated probiotics were subjected to in vitro simulated infant gastrointestinal digestion and a fecal fermentation model to assess survival capacity and their impact on gas and organic acid production, as well as the development of gut microbiota. The results demonstrated that microencapsulation in the presence of osteopontin increased simulated gastrointestinal survival. During infant fecal fermentation, a significant increase in total gas production (5.5–9.1 mL) was observed for the microencapsulated probiotic with even higher level of gas production observed for osteopontin associated microencapsulated probiotic during the late stage of fermentation (8–24 h). Infant fecal fermentation of the microencapsulated probiotic also produced substantial amounts of acetate (8–17 mM) and lactate (12–35 mM), along with minor amounts of succinate (1–2 mM) and propionate (0.5–2 mM). A positive correlation was observed between metabolite production and the number of viable B. bifidum R0071 entering colon fermentation, which significantly increased with the use of OPN in the microencapsulation process. The osteopontin associated microencapsulated probiotic also significantly elevated the relative abundance of Veillonella, which, along with Bifidobacterium, influenced gas and metabolite production. Overall, our findings demonstrate that incorporating OPN as an excipient in the microencapsulation of Bifidobacterium bifidum R0071 enhances probiotic viability and positively influences the development of infant gut microbiota, highlighting its potential application in promoting infant health.

Interactions of the Osteokines, Glucose/Insulin System and Vascular Risk Networks in Patients With Newly Diagnosed Type 2 Diabetes (VNDS 15).

Bone as an endocrine organ regulates metabolic processes independently of mineral metabolism through the production/release of proteins collectively named 'osteokines'. Relevant connections were reported between the insulin/glucose system, calcification of the atherosclerotic plaque, and several osteokines. We aimed to test the hypothesis that the osteokine network could be involved in beta-cell function, insulin sensitivity, and vascular damage in a cohort of people with newly diagnosed type 2 diabetes (T2D). In 794 drug-naive, GADA-negative, newly-diagnosed T2D patients (mean±SD age: 59±9.8years; BMI: 29.3±5.3kg/m2; HbA1c: 6.6±1.3%) we assessed: plasma concentration of osteocalcin (OCN), osteopontin (OPN),RANKL, and its putative decoy receptor osteoprotegerin (OPG); insulin sensitivity (SI) by hyperinsulinemic euglycemic clamp; beta cell function (BCF), estimated by OGTT minimal modelling and expressed as derivative (DC) and proportional (PC) control. Echo-doppler of carotid and lower limb arteries were also performed in 708 and 701 subjects, respectively. OCN, RANKL and OPG were significantly associated with PC (p<0.02); OCN was positively related to DC (p=0.018). OPG was associated with lower IS (p<0.001). Finally, the higher RANKL levels, the greater was the severity of atherosclerosis in common carotid artery (p<0.001). Increased OPG and OPN concentrations were related to subclinical atherosclerosis in peripheral arteries of lower limbs (p=0.023 and p=0.047, respectively). These data suggest that, in patients with newly diagnosed T2D, the osteokine network crosstalks with the glucose/insulin system and may play a role in modulating the atherosclerotic process.

Insights for possible association and impact of thyroidectomy to osteoarthritis

Background and aim of studyThyroidectomy and osteoarthritis have drawn more attention in last decades due to increase various local and systemic risk factors. This study is aimed to determine the association and impact between thyroidectomy and osteoarthritis by serological measurement of most specific related markers.ResultsMeasurement of thyroid markers showed the level of thyroid-stimulating hormone (TSH) was significantly increased, while parathyroid hormone (PTH), triiodothyronine (T3), and thyroxine (T4) levels were decreased in osteoarthritis subjected to thyroidectomy group (OTG) when compared to hyperthyroidism subjected to thyroidectomy group (TG), osteoarthritis group (OG), and healthy control group (CG). Detection the activity of bone markers showed the level of R-factor was significantly elevated concomitant with significant reduction in Dickkopf related protein 1 (DKK1), human hyaluronan-binding protein 2 (HABP2), osteocalcin (OC) in OG and OTG groups, while osteopontin (OPN) and procollagen I C-terminal propeptide (PICP) were significantly increased and decreased in TG and OTG. Furthermore, the level of S100 Calcium binding protein (S100CBP) showed significant decreased in patient’s groups, while TG with OTG groups exhibited significant reduction in sclerostin (SOST) concentration. Regarding the inflammatory markers, the levels of interleukin-1 (IL-1) was increased in the OTG, while the level of interleukin-10 (IL-10) was increased in OG and TG groups, and reduced in OTG. While, the level of transforming growth factor-beta (TGF-β) was decreased in OG and TG associated with significant increases in tumor necrosis factor-alpha level (TNF-α) in OTG. Measurement of oxidant and antioxidant activity markers showed the levels of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were significantly reduced in all patient’s groups compared to control, except the level of CAT in TG, whereas, malondialdehyde (MDA) level was increased in OG and OTG patients. Furthermore, the levels of Alkaline phosphatase (ALP), C-Reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were increased in all patient groups compared to control, while fatty acid-binding protein (FABP) level was increased in OTG only.ConclusionThis unique study in Iraq is identified the interaction effect and impact of thyroidectomy to osteoarthritis according to the results that showed various changes and degree of correlation of study biomarkers in all patient groups, however more depth of specific quantitative and qualitative studies are required to support this association and the impact claim at molecular level.