Search

Background: The liver, gallbladder, and pancreas constitute a critically important system of digestive and endocrine organs in the human body, performing essential and complex physiological functions. At present, diseases of this digestive system have a high incidence in the world and is a more common disease. However, osteopontin (OPN) plays a crucial role in common liver, pancreatic, and biliary diseases, and its mechanisms of action merit further exploration and study. Methods: We performed an analysis to assess the role of osteopontin in liver, pancreatic, and biliary diseases, focusing on its significance in these conditions. Results: Osteopontin, a profoundly phosphorylated glycoprotein, can be utilized as a diagnostic marker for hepatocellular carcinoma and cholangiopathies. Additionally it assists in the treatment of non-alcoholic fatty liver disease and promotes the proliferation, migration, and invasion of pancreatic cancer cells. Furthermore, osteopontin regulates inflammatory responses in chronic pancreatitis. Conclusions: This review offers a thorough analysis of the genetic and protein architecture of OPN, and elucidates the relationship between osteopontin and liver, pancreatic, and biliary diseases. Furthermore, exclusive focus is lavished on the potential utility of OPN as a biomarker and an innovative therapeutic target in the management of these disorder. [ABSTRACT FROM AUTHOR]

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 prevent the complications related to the progression of this pathology. [ABSTRACT FROM AUTHOR]

Reconstruction of the neurovascular unit is essential for the repair of spinal cord injury (SCI). Nonetheless, detailed documentation of specific vascular changes following SCI and targeted interventions for vascular treatment remains limited. This study demonstrates that traumatic pathological vascular remodeling occurs during the chronic phase of injury, characterized by enlarged vessel diameter, disruption of blood‐spinal cord barrier, endothelial‐to‐mesenchymal transition (EndoMT), and heightened extracellular matrix deposition. After SCI, osteopontin (OPN), a critical factor secreted by immune cells, is indispensable for early vascular regeneration but also contributes to traumatic pathological vascular remodeling. This work further elucidates the mechanism by which OPN influences spinal cord microvascular endothelial cells, involving Akt‐mediated Foxo1 phosphorylation. This process facilitates the extranuclear transport of Foxo1 and decreases Smad7 expression, leading to excessive activation of the TGF‐β signaling pathway, which ultimately results in EndoMT and fibrosis. Targeted inhibition of Foxo1 phosphorylation through an endothelium‐specific aptamer‐liposome small molecule delivery system significantly mitigates vascular remodeling, thereby enhancing axon regeneration and neurological function recovery following SCI. The findings offer a novel perspective for drug therapies aimed at specifically targeting pathological vasculature after SCI. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the concentration of osteopontin in peritoneal fluid and plasma as potential biomarkers for diagnosing endometriosis. Osteopontin levels were measured using surface plasmon resonance imaging (SPRI) biosensors in patients suspected of having endometriosis. Plasma samples were collected from 120 patients, and peritoneal fluid was collected from 86 patients. Based on the detection of endometriosis lesions during laparoscopy, participants were divided into a study group (patients with endometriosis) and a control group (patients without endometriosis). The results showed no significant differences in plasma osteopontin levels between women with endometriosis and the control group (19.86 ± 6.72 ng/mL vs. 18.39 ± 4.46 ng/mL, p = 0.15). Similarly, peritoneal fluid osteopontin concentrations did not differ significantly between patients with and without endometriosis (19.04 ± 5.37 ng/mL vs. 17.87 ± 5.13 ng/mL, p = 0.29). Furthermore, osteopontin levels in both plasma and peritoneal fluid were not significantly associated with the stage of endometriosis, the presence of endometrioma, or the menstrual cycle phase. The findings of this study do not support osteopontin concentration as a reliable biomarker for endometriosis. However, further research is necessary to explore osteopontin's potential role in the disease. [ABSTRACT FROM AUTHOR]

Osteopontin (Opn) depletion can improve septic outcomes, but the underlying mechanism remains unknown. In this study, we demonstrated that nonhematopoietic but not hematopoietic Opn depletion improved septic outcomes. When compared with wild type mice, cohoused Opn −/− mice displayed enhanced production of antibacterial peptides (AMPs), decreased bacterial loads, and a distinct bacterial composition of gut microbiota. Fecal microbiota transplantation and OPN neutralization assay showed that Opn depletion could reduce bacterial loads and improve septic inflammation. By employing an intestinal organoid culture system, we proved that OPN neutralization in wild type organoids could inactivate AKT and decrease FOXO3a phosphorylation, resulting in enhanced AMP production, whereas OPN treatment in OPN-deficient organoids could activate AKT and increase FOXO3a phosphorylation, leading to reduced AMP production. Our findings identified OPN as a novel regulatory factor of AMP production to modulate bacterial loads and composition of gut microbiota, in turn affecting sepsis outcomes. [ABSTRACT FROM AUTHOR]

Endothelial cells (ECs) not only form passive blood conduits but actively contribute to nutrient transport and organ homeostasis. The role of ECs in glucose homeostasis is, however, poorly understood. Here, we show that, in skeletal muscle, endothelial glucose transporter 1 (Glut1 /Slc2a1) controls glucose uptake via vascular metabolic control of muscle-resident macrophages without affecting transendothelial glucose transport. Lowering endothelial Glut1 via genetic depletion (Glut1 ΔEC) or upon a short-term high-fat diet increased angiocrine osteopontin (OPN/ Spp1) secretion. This promoted resident muscle macrophage activation and proliferation, which impaired muscle insulin sensitivity. Consequently, co-deleting Spp1 from ECs prevented macrophage accumulation and improved insulin sensitivity in Glut1 ΔEC mice. Mechanistically, Glut1- dependent endothelial glucose metabolic rewiring increased OPN in a serine metabolism-dependent fashion. Our data illustrate how the glycolytic endothelium creates a microenvironment that controls resident muscle macrophage phenotype and function and directly links resident muscle macrophages to the maintenance of muscle glucose homeostasis. [Display omitted] • EC-specific loss of Glut1 impairs insulin sensitivity in skeletal muscle • Angiocrine OPN controls resident macrophage phenotype and function • Resident macrophage accumulation and activation impair muscle insulin sensitivity • Endothelial glucose metabolic control of OPN is serine dependent Zhang et al. found that endothelial GLUT1 regulates muscle insulin sensitivity independently of transendothelial glucose transport. Lowering endothelial GLUT1 through genetic deletion or upon a short-term high-fat diet rewires endothelial glucose metabolism, thereby increasing angiocrine OPN secretion. This promotes resident macrophage accumulation and activation, which leads to muscle insulin resistance. [ABSTRACT FROM AUTHOR]

Background/Objectives: Patients with Gaucher disease have a high risk of bone disease, with osteonecrosis representing the most debilitating complication. The pathogenesis of osteonecrosis has not been fully elucidated yet, and there is an unmet need for predictive biomarkers of bone complications. We aimed to assess the utility of angiogenesis and bone turnover biomarkers as predictors of osteonecrosis in Gaucher disease. Methods: Angiogenesis and bone turnover biomarkers were measured in 146 Gaucher disease patients (70M:76F, median age 49.5 [IQR 36.7 to 61]) with/without osteonecrosis enrolled in the UK-based registry GAUCHERITE [enrolment 2015–2017]. Receiver-operating characteristic curve analysis was used to compare the osteonecrosis predictive value of angiogenesis and bone turnover biomarkers and determine the optimal cut-off values for each biomarker. Results: Sixty-two patients had osteonecrosis before study enrolment, 11 had osteonecrosis during follow-up, and 73 remained osteonecrosis-free. Patients with osteonecrosis showed increased osteopontin and matrix metalloproteinase (MMP)-2 levels and decreased MMP-9 and vascular endothelial growth factor (VEGF)-C compared with those free from osteonecrosis. MMP-9 predicted future osteonecrosis with higher sensitivity and specificity (area under the receiver operating characteristic curve [AUC] 0.84 [95% CI 0.84–0.99]; sensitivity/specificity 82%/75%; cutoff value ≤ 72,420 pg/mL) than osteopontin, MMP-2 and VEGF-C when taken alone. The combination of MMP-9 and VEGF-C further increased the discriminating accuracy. Conclusions: The osteopontin–MMPs–VEGF axis is dysregulated in Gaucher disease patients with osteonecrosis. The combination of MMP-9 and VEGF-C circulating levels may serve to identify Gaucher disease patients at risk of osteonecrosis. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's disease (AD) is the most prevalent neurodegenerative disease. Three new drugs for AD based on monoclonal antibodies against the amyloid-β peptide (Aβ) have recently been approved because they favor the reduction of the burden of senile plaque in the AD patient's brain. Nonetheless, both drugs have very limited applicability and benefits and show several side effects. These limitations invite us to find alternative strategies for treating patients with AD. Here, we explored whether tissue-nonspecific alkaline phosphatase (TNAP), an ectoenzyme upregulated in the brain of AD patients and whose inhibition has beneficial effects on tau-induced pathology, is also efficient in reducing senile plaque burden. Methods: To evaluate whether TNAP may reduce cerebral senile plaque loading and Aβ-related toxicity, we use both pharmacological and genetic approaches. We analyze postmortem samples from human AD patients, APP/PS1 mice (a mouse model that mimics amyloid pathology observed in AD patients) treated or not with TNAP inhibitors, and the newly generated transgenic mouse line, TNAP-deficient APP/PS1 mice. Results: For the first time, we describe that genetic or pharmacological blockade of TNAP effectively reduces senile plaque burden by promoting its clearance, which leads to amelioration of cognitive impairment caused by Aβ-induced toxicity. These beneficial effects of TNAP inhibition occur concomitantly with higher microglial recruitment toward the senile plaque and increased microglial phagocytic capacity of Aβ by a mechanism involving metalloprotease-depending osteopontin processing. In addition, we also found that TNAP blockade favors LRP1-mediated transport of Aβ through the BBB. Conclusions: Here, we have shown that TNAP inhibition effectively reduces brain senile plaque burden and associated behavioral defects. Furthermore, given that we had previously reported that TNAP blockade also ameliorates Tau-induced neurotoxicity and increases lifespan of P301S tauopathy mouse model, we can state that TNAP blockade may be a novel and efficient therapy for treating patients with AD. [ABSTRACT FROM AUTHOR]

Recurrent breast cancers often develop resistance to standard-of-care therapies. Identifying targetable factors contributing to cancer recurrence remains the rate-limiting step in improving long-term outcomes. In this study, we identify tumor cell-derived osteopontin as an autocrine and paracrine driver of tumor recurrence. Osteopontin promotes tumor cell proliferation, recruits macrophages, and synergizes with IL-4 to further polarize them into a pro-tumorigenic state. Macrophage depletion and osteopontin inhibition decrease recurrent tumor growth. Furthermore, targeting osteopontin in primary tumor-bearing female mice prevents metastasis, permits T cell infiltration and activation, and improves anti-PD-1 immunotherapy response. Clinically, osteopontin expression is higher in recurrent metastatic tumors versus female patient-matched primary breast tumors. Osteopontin positively correlates with macrophage infiltration, increases with higher tumor grade, and its elevated pathway activity is associated with poor prognosis and long-term recurrence. Our findings suggest clinical implications and an alternative therapeutic strategy based on osteopontin's multiaxial role in breast cancer progression and recurrence. Osteopontin promotes tumor growth in several cancer types. Here, in a preclinical model recapitulating features of human breast cancer recurrence, the authors report that osteopontin promotes the recruitment of immunosuppressive macrophages and its targeting reduces breast tumor growth and metastasis. [ABSTRACT FROM AUTHOR]

ABSTRACT Background and Aims Methods Results Conclusions 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 in vivo, in vitro, 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. [ABSTRACT FROM AUTHOR]

Simple Summary: Treatments for colorectal cancer (CRC) largely rely on chemotherapeutics. For CRC treatment, irinotecan is widely used in various combinations with other drugs. Despite being an effective drug, irinotecan treatment often leads to drug resistance and tumor relapse. Mechanistically, it inhibits topoisomerase I and induces double-strand DNA breaks, which result in p53-dependent apoptosis. In the current study, we explored irinotecan-mediated, p53-independent pro- and anti-apoptotic effects. Our data show that irinotecan induces cyclin-dependent kinase inhibitors as well as anti-apoptotic proteins [osteopontin (OPN), survivin, and ISG15], the immunomodulatory molecule PD-L1, immune modulation mediated by proliferative NF-κB signaling, and metastatic markers (CD44, Sox2, Oct4, Snail, and Slug). Inhibition of OPN and/or NF-κB signaling potentiates irinotecan efficacy. The combination of OPN and/or an NF-κB inhibitor with irinotecan may lead to increased efficacy with reduced drug resistance. Among the most popular chemotherapeutic agents, irinotecan, regarded as a prodrug belonging to the camptothecin family that inhibits topoisomerase I, is widely used to treat metastatic colorectal cancer (CRC). Although immunotherapy is promising for several cancer types, only microsatellite-instable (~7%) and not microsatellite-stable CRCs are responsive to it. Therefore, it is important to investigate the mechanism of irinotecan function to identify cellular proteins and/or pathways that could be targeted for combination therapy. Here, we have determined the effect of irinotecan treatment on the expression/activation of tumor suppressor genes (including p15Ink4b, p21Cip1, p27Kip1, and p53) and oncogenes (including OPN, IL8, PD-L1, NF-κB, ISG15, Cyclin D1, and c-Myc) using qRT-PCR, Western blotting, immunofluorescence (IF), and RNA sequencing of tumor specimens. We employed stable knockdown, neutralizing antibodies (Abs), and inhibitors of OPN, p53, and NF-κB to establish downstream signaling and sensitivity/resistance to the cytotoxic activities of irinotecan. Suppression of secretory OPN and NF-κB sensitized colon cancer cells to irinotecan. p53 inhibition or knockdown was not sufficient to block or potentiate SN38-regulated signaling, suggesting p53-independent effects. Irinotecan treatment inhibited tumor growth in syngeneic mice. Analyses of allograft tumors from irinotecan-treated mice validated the cell culture results. RNA-seq data suggested that irinotecan-mediated activation of NF-κB signaling modulated immune and inflammatory genes in mice, which may compromise drug efficacy and promote resistance. In sum, these results suggest that, for CRCs, targeting OPN, NF-κB, PD-L1, and/or ISG15 signaling may provide a potential strategy to overcome resistance to irinotecan-based chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Malaria 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. Results: Blood 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. Conclusions: In 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. [ABSTRACT FROM AUTHOR]

This study aims to demonstrate in vitro effects of osteopontin (OPN), an extracellular matrix molecule, on proliferation and migration in human umbilical vein endothelial cells (HUVEC) and Ishikawa human endometrial adenocarcinoma cells (Ishikawa) cultures. In addition, the effects of OPN on phosphatidylinositol 3 kinase (PI3K) and extracellular signal regulatory kinase 1/2 (ERK1/2), which are involved signaling pathways in cell cycle, were investigated. This research was carried out as a prospective cell culture study in Aydın Adnan Menderes University Biochemistry Laboratory. Two types of cell culture were used, HUVEC representing endothelial cells and Ishikawa representing tumour cells. The HUVEC and Ishikawa were extracted from liquid nitrogen and seeded in culture medium. With the increasing concentrations of recombinant human OPN (rhOPN) in both cell lines, proliferation and migration of cells and PI3K and ERK1/2 levels in the medium were investigated. Detection of cell proliferation in these two cell types with MTT test, and migration assay were performed. Proliferation was found to increase in both cell types with increasing levels of rhOPN (p < 0.01). In both cell cultures, rhOPN induced mesenchymal transformation, indicating migration at the highest (400 ng/mL) concentrations. Increasing levels of PI3K and ERK1/2 were measured with the increasing concentrations of rhOPN (p < 0.01 and p < 0.05, respectively). Proliferation, migration, and PI3K and ERK1/2 molecules are increased with rhOPN in both cell cultures studied. This suggests that OPN could be a candidate prognostic marker in endometrial cancer. [ABSTRACT FROM AUTHOR]

Background: Osteopontin (OPN) is a glycoprotein involved in various physiological and pathological processes, and its aberrant expression in cancer cells is closely linked to tumor progression. In colorectal cancer (CRC), OPN is overexpressed, but the roles of its splice variants (OPN-SVs), OPNa, OPNb, and OPNc, are not well understood. This study aimed to characterize the expression patterns of OPN-SVs and their potential diagnostic and prognostic implications in CRC using transcriptomic data deposited in TSVdb and TCGA. Methods: The expression patterns of each OPN-SV were analyzed using transcriptomic data deposited in TSVdb and TCGA, which were correlated to patient data available at cBioPortal. Results: Bioinformatic analysis revealed that OPNa, OPNb, and OPNc are overexpressed in CRC samples compared to non-tumor samples. Notably, OPNa and OPNc are overexpressed in CRC stages (II, III, and IV) compared to stage I. Higher levels of OPNa and OPNc transcripts are associated with worse overall survival (OS) and shorter progression-free survival (PFS) in CRC patients. Additionally, the expression of OPNa, OPNb, and OPNc is correlated with BRAFV600E mutations in CRC samples. Conclusions: These findings suggest that OPNa and OPNc, in particular, have potential as diagnostic and prognostic biomarkers, paving the way for their further evaluation in CRC diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

Background and Aim: 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). Subjects and Methods: In 794 drug‐naive, GADA‐negative, newly‐diagnosed T2D patients (mean ± SD age: 59 ± 9.8 years; BMI: 29.3 ± 5.3 kg/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. Results: 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). Conclusion: 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. [ABSTRACT FROM AUTHOR]

Abstract Background Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease. Three new drugs for AD based on monoclonal antibodies against the amyloid-β peptide (Aβ) have recently been approved because they favor the reduction of the burden of senile plaque in the AD patient’s brain. Nonetheless, both drugs have very limited applicability and benefits and show several side effects. These limitations invite us to find alternative strategies for treating patients with AD. Here, we explored whether tissue-nonspecific alkaline phosphatase (TNAP), an ectoenzyme upregulated in the brain of AD patients and whose inhibition has beneficial effects on tau-induced pathology, is also efficient in reducing senile plaque burden. Methods To evaluate whether TNAP may reduce cerebral senile plaque loading and Aβ-related toxicity, we use both pharmacological and genetic approaches. We analyze postmortem samples from human AD patients, APP/PS1 mice (a mouse model that mimics amyloid pathology observed in AD patients) treated or not with TNAP inhibitors, and the newly generated transgenic mouse line, TNAP-deficient APP/PS1 mice. Results For the first time, we describe that genetic or pharmacological blockade of TNAP effectively reduces senile plaque burden by promoting its clearance, which leads to amelioration of cognitive impairment caused by Aβ-induced toxicity. These beneficial effects of TNAP inhibition occur concomitantly with higher microglial recruitment toward the senile plaque and increased microglial phagocytic capacity of Aβ by a mechanism involving metalloprotease-depending osteopontin processing. In addition, we also found that TNAP blockade favors LRP1-mediated transport of Aβ through the BBB. Conclusions Here, we have shown that TNAP inhibition effectively reduces brain senile plaque burden and associated behavioral defects. Furthermore, given that we had previously reported that TNAP blockade also ameliorates Tau-induced neurotoxicity and increases lifespan of P301S tauopathy mouse model, we can state that TNAP blockade may be a novel and efficient therapy for treating patients with AD.

Abstract Background Malaria 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. Results Blood 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. Conclusions In 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.

We aim to evaluate the Osteopontin (OPN) levels in patients with Celiac disease (CD) at diagnosis and exploring its association with mucosal atrophy and osteoporosis. The study included celiac patients at diagnosis and age and sex matched healthy controls. Subjects with additional intestinal pathology, other known inflammatory and autoimmune disease accompanying CD, and patients with signs of infection were excluded. Demographics, presenting symptoms, concurrent disorders, physical examination findings, laboratory results, celiac serology and histopathological assessment were recorded. A total of 36 celiac patients (23 girls, 13 boys, mean age 9.4 ± 4.5 years) and 36 healthy controls (22 girls, 14 boys, mean age 8.7 ± 4 years) were included. The median OPN level was significantly higher in patients [10.41 (9.34–13.47) ng/ml vs. 9.42 (7.56–10.19) ng/ml, p < 0.001]. The median OPN levels of patients with osteoporosis was significantly higher than those with normal BMD values [20.7 (10.12–21.22) vs. 9.87 (9.16–10.75), respectively, p = 0.006)]. A serum OPN level of 10.74 ng/ml was found to be a cut-off value for the patient with osteoporosis with 66.7% sensitivity, 66.7% specificity, 50% positive predictive value, and 80% negative predictive value. Patients’ OPN levels were 9.53 (9.3-10.42) ng/ml in Marsh type 3a, 9.78 (8.62–15.28) ng/ml in Marsh type 3b and 11.51 (9.88–19.75) ng/ml in Marsh type 3c. Marsh-Oberhuber type 3c was found to have higher median OPN levels than type 3a and type 3b (p = 0.027). When patients were stratified based on their manifestations of either intestinal or extraintestinal symptoms, along with the presence of anemia, tissue TG IgA levels exceeding ten times the upper normal limit, and a deficiency in vitamin D, the median OPN levels exhibited no significant differences across these groups. Conclusions: In conclusion, it is suggested that serum OPN could potentially serve as an indicator of the extent of mucosal atrophy at the initial diagnosis and may have predictive value for osteoporosis. What is Known: • There is currently no routinely utilized marker that can ascertain the extent of histological involvement in celiac disease. • Bone mineral density evaluation is not routinely recommendable at diagnosis in celiac disease, as no clinical predictor is available for low bone mineral density in children. What is New: • Celiac patients have a higher level of osteopontin at diagnosis. • Osteopontin could potentially serve as an indicator of the extent of mucosal atrophy at the initial diagnosis and may have predictive value for osteoporosis. [ABSTRACT FROM AUTHOR]

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 1600 nmol), GRGDS (peptide 2; 320 and 1600 nmol), and SVAYGLK (peptide 3; 320 and 1600 nmol), were infused (n = 20–25). Restoration rates of the normal EGF profile of peptide 1 (320 and 1600 nmol) and peptide 3 (1600 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 1600 nmol; n = 50 each), peptide 3 (1600 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 1600 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. • OPN infusion into the vagina restores the normal endometrial EGF profile and fertility in repeat breeder dairy cows. • The SVAYGLK motif is the structural element of the OPN action. • The RGD motif may play a role in enhancing the effect of the SVAYGLK motif. [ABSTRACT FROM AUTHOR]

Abstract Background Circulating cytokines can represent non-invasive biomarkers to improve prediction of clinical outcomes of cancer patients. Here, plasma levels of IL-8, CCL4, osteopontin, LIF and BDNF were determined at baseline (T0), after 2 months of therapy (T2) and, when feasible, at progression (TP), in 70 melanoma patients treated with BRAF and MEK inhibitors. The association of baseline cytokine levels with clinical response, progression-free survival (PFS) and overall survival (OS) was evaluated. Methods Cytokine concentrations were measured using the xMAP technology. Their ability to discriminate between responding (Rs) and non-responding (NRs) patients was assessed by Receiver Operating Characteristics analysis. PFS and OS were estimated with the Kaplan–Meier method. The Cox proportional hazard model was used in the univariate and multivariate analyses to estimate crude and adjusted hazard ratios with 95% confidence intervals. Results CCL4 and LIF were undetectable in the majority of samples. The median osteopontin concentration at T0 and T2 was significantly higher in NRs than in Rs. The median T0 and T2 values of IL-8 were also higher in NRs than in Rs, although the statistical significance was not reached. No differences were detected for BDNF. In 39 Rs with matched T0, T2, and TP samples, osteopontin and IL-8 significantly decreased from T0 to T2 and rose again at TP, while BDNF levels remained unchanged. In NRs, none of the cytokines showed a significant decrease at T2. Only osteopontin demonstrated a good ability to discriminate between Rs and NRs. A high IL-8 T0 level was associated with significantly shorter PFS and OS and higher risk of progression and mortality, and remained an independent negative prognostic factor for OS in multivariate analysis. An elevated osteopontin T0 concentration was also significantly associated with worse OS and increased risk of death. Patients with high IL-8 and high osteopontin showed the lowest PFS and OS, and in multivariate analysis this cytokine combination remained independently associated with a three- to six-fold increased risk of mortality. Conclusion Circulating IL-8 and osteopontin appear useful biomarkers to refine prognosis evaluation of patients undergoing targeted therapy, and deserve attention as potential targets to improve its clinical efficacy.

Abstract The liver carries out many essential tasks, such as synthesising cholesterol, controlling the body’s storage of glycogen, and detoxifying metabolites, in addition to performing, and regulating homeostasis. Hepatic fibrosis is a pathological state characterized by over accumulation of extracellular matrix (ECM) including collagen fibers. Sildenafil (a selective inhibitor of type 5 phosphodiesterase) has anti-inflammatory, antioxidant and anti-apoptotic properties. It is commonly used to treat erectile dysfunction in male. The purpose of the current investigation was to evaluate sildenafil’s hepatoprotective potential against liver fibrosis in rats that was caused by carbon tetrachloride (CCl4). Liver enzymes and oxidative markers as well as profibrotic genes were determined. The findings showed that sildenafil alleviates the hepatic dysfunctions caused by CCl4 by restoring normal levels of ALT, AST, and GGT as well as by restoring the antioxidant status demonstrated by increased glutathione (GSH), and catalase. In addition, a significantly down-regulated the mRNA expressions of profibrotic genes [collagen-1α, IL-1β, osteopontin (OPN), and transforming growth factor-β (TGF-β)]. Additionally, sildenafil lessens the periportal fibrosis between hepatic lobules, congestion and dilatation in the central vein, and the inflammatory cell infiltrations. As a result, it is hypothesized that sildenafil may be helpful in the management of hepatotoxicity brought on by CCl4 through suppressing OPN.

Percutaneous implants osseointegrated into the residuum of a person with limb amputation need to provide mechanical stability and protection against infections. Although significant progress has been made in the biointegration of percutaneous implants, the problem of forming a reliable natural barrier at the level of the surface of the implant and the skin and bone tissues remains unresolved. The use of a microporous implant structure incorporated into the Skin and Bone Integrated Pylon (SBIP) should address the issue by allowing soft and bone tissues to grow directly into the implant structure itself, which, in turn, should form a reliable barrier to infections and support strong osseointegration. To evaluate biological interactions between dermal fibroblasts and MC3T3-E1 osteoblasts in vitro, small titanium discs (with varying pore sizes and volume fractions to achieve deep porosity) were fabricated via 3D printing and sintering. The cell viability MTT assay demonstrated low cytotoxicity for cells co-cultured in the pores of the 3D-printed and sintered Ti samples during the 14-day follow-up period. A subsequent Quantitative Real-Time Polymerase Chain Reaction (RT-PCR) analysis of the relative gene expression of biomarkers that are associated with cell adhesion (α2, α5, αV, and β1 integrins) and extracellular matrix components (fibronectin, vitronectin, type I collagen) demonstrated that micropore sizes ranging from 200 to 500 µm of the 3D printed and sintered Ti discs were favorable for dermal fibroblast adhesion. For example, for representative 3D-printed Ti sample S6 at 72 h the values were 4.71 ± 0.08 (α2 integrin), 4.96 ± 0.08 (α5 integrin), 4.71 ± 0.08 (αV integrin), and 1.87 ± 0.12 (β1 integrin). In contrast, Ti discs with pore sizes ranging from 400 to 800 µm demonstrated the best results (in terms of marker expression related to osteogenic differentiation, including osteopontin, osteonectin, osteocalcin, TGF-β1, and SMAD4) for MC3T3-E1 cells. For example, for the representative 3D sample S4 on day 14, the marker levels were 11.19 ± 0.77 (osteopontin), 7.15 ± 0.29 (osteonectin), and 6.08 ± 0.12 (osteocalcin), while for sintered samples the levels of markers constituted 5.85 ± 0.4 (osteopontin), 4.45 ± 0.36 (osteonectin), and 4.46 ± 0.3 (osteocalcin). In conclusion, the data obtained show the high biointegrative properties of porous titanium structures, while the ability to implement several pore options in one structure using 3D printing makes it possible to create personalized implants for the best one-time integration with both skin and bone tissues. [ABSTRACT FROM AUTHOR]

Background: We investigated the expression of inflammation, placental development, and function markers, including cluster of differentiation 44 (CD44), osteopontin (OPN), and cyclooxygenase-2 (COX-2), to shed light on the controversy regarding the impact of the COVID-19 epidemic on fetal development and pregnancy outcomes. Methods: We immunohistochemically analyzed placental tissue from 170 patients (65 COVID-positive and unvaccinated women; 35 Pfeizer-vaccinated and COVID-negative women; and 70 COVID-negative and unvaccinated women, without any other associated pathology) for particularities in the expression of these three molecules. Results: CD44 expression was highest in COVID-negative and unvaccinated women, moderate in COVID-positive cases, and lowest in vaccinated and COVID-negative women. OPN expression was highest in COVID-negative and Pfeizer-vaccinated cases, moderate in COVID-negative and unvaccinated cases, and lowest in COVID-positive cases. COX-2 expression was increased in COVID-negative and unvaccinated women, modestly elevated in COVID-positive and unvaccinated cases, and lowest in vaccinated cases. Conclusions: These findings reflected an alteration in the placental structure and consequent function due to altered expression of the three studied molecules. [ABSTRACT FROM AUTHOR]

Intervertebral disc degeneration (IDD) is a major cause of discogenic pain, and is attributed to the dysfunction of nucleus pulposus, annulus fibrosus, and cartilaginous endplate (CEP). Osteopontin (OPN), a glycoprotein, is highly expressed in the CEP. However, little is known on how OPN regulates CEP homeostasis and degeneration, contributing to the pathogenesis of IDD. Here, we investigate the roles of OPN in CEP degeneration in a mouse IDD model induced by lumbar spine instability and its impact on the degeneration of endplate chondrocytes (EPCs) under pathological conditions. OPN is mainly expressed in the CEP and decreases with degeneration in mice and human patients with severe IDD. Conditional Spp1 knockout in EPCs of adult mice enhances age-related CEP degeneration and accelerates CEP remodeling during IDD. Mechanistically, OPN deficiency increases CCL2 and CCL5 production in EPCs to recruit macrophages and enhances the activation of NLRP3 inflammasome and NF-κB signaling by facilitating assembly of IRAK1-TRAF6 complex, deteriorating CEP degeneration in a spatiotemporal pattern. More importantly, pharmacological inhibition of the NF-κB/NLRP3 axis attenuates CEP degeneration in OPN-deficient IDD mice. Overall, this study highlights the importance of OPN in maintaining CEP and disc homeostasis, and proposes a promising therapeutic strategy for IDD by targeting the NF-κB/NLRP3 axis. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) is manifested by pathologic changes in the areas significantly distant from the area of primary injury. In order to find new potential therapeutic targets to restore motor function, it is particularly relevant to identify the causes and mechanisms of these shifts in the lumbar spinal cord when injury occurs in the proximal spinal cord. On the rat model of dosed SCI at the Th8 segment level the expression of Ca-binding protein parvalbumin (PARV), osteopontin (OPN), and glypican 4 (GPC4) in neurons of laminae VII, VIII and IX within segments L3-4 on 7 and 60 days of the experiment was studied. Laminas VII and IX show a decrease in the number of PARV+ neurons during the acute and chronic phase of SCI, which may indicate a decrease in calcium binding in ventral horn neurons at the level of segments L3-4. Decreased PARV expression in these neurons indicates an increased risk of their vulnerability and impaired motor function. The pattern of OPN expression in lumbar horn neurons distant from the epicenter of traumatic injury was studied for the first time. In all the studied laminae in the ventral horns of the gray matter, we did not observe shifts in the number of OPN+ neurons both in the acute and chronic phases of SCI. In lamina IX of the lumbar spinal cord, we found an increase in the number of GPC4+ neurons in the acute posttraumatic period, which can be regarded as a key positive adaptive reaction of neurons in the lumbar spinal cord remote from the epicenter of injury. The assessment of this reaction as positive is based on the data on the binding of GPC4 anchored on the neuron surface to various molecules with neuroprotective activity and stimulating neuroregeneration. [ABSTRACT FROM AUTHOR]

Osteopontin (OPN) is a multi‐functional glycoprotein that coordinates the innate immune response, prevents nanocrystal formation in renal tubule fluid, and is a biomarker for kidney injury. OPN expression is markedly increased in cystic epithelial cells of polycystic kidney disease (PKD) kidneys; however, its role in PKD progression remains unclear. We investigated the in vitro effects of recombinant OPN on the proliferation of tubular epithelial cells from PKD and normal human kidneys and in vivo effects of OPN deletion on kidney cyst formation, fibrosis, and mineral metabolism in pcy/pcy mice, a non‐orthologous model of autosomal‐dominant PKD. In vitro studies revealed that OPN enhanced the proliferation of PKD cells but had no effect on normal kidney cells. Deletion of OPN in pcy/pcy mice significantly reduced kidney cyst burden; however, this was accompanied by increased fibrosis and no change in kidney function. The loss of OPN had no effect on kidney macrophage numbers, cyst epithelial cell proliferation, or apoptosis. Furthermore, there was no difference in kidney mineral deposition or mineral metabolism parameters between pcy/pcy mice with and without OPN expression. Global deletion of OPN reduced kidney cyst burden, while paradoxically exacerbating kidney fibrosis in mice with cystic kidney disease. [ABSTRACT FROM AUTHOR]

Cerebral malaria in young African children is associated with high mortality, and persisting neurological deficits often remain in survivors. Sequestered Plasmodium-infected red blood cells lead to cerebrovascular inflammation and subsequent neuroinflammation. Brain inflammation can play a role in the pathogenesis of neurologic sequelae. Therefore, we assessed a select set of proinflammatory analytes (IP10, IL23, MIP3α, GRO, MCP-1, and osteopontin in both the plasma and cerebrospinal fluid(CSF) of Zambian children with cerebral malaria and compared this with children with neurological symptoms that were negative for Plasmodium falciparum (non-cerebral malaria). Several similarities in plasma and CSF levels were found, as were some striking differences. We confirmed that IP10 levels were higher in the plasma of cerebral malaria patients, but this was not found in CSF. Levels of osteopontin were elevated in both the plasma and CSF of CM patients compared to the non-CM patients. These results show again a highly inflammatory environment in both groups but a different profile for CM when compared to non-cerebral malaria. Osteopontin may play an important role in neurological inflammation in CM and the resulting sequelae. Therefore, osteopontin could be a valid target for further biomarker research and potentially for therapeutic interventions in neuroinflammatory infections. [ABSTRACT FROM AUTHOR]

Simple Summary: T regulatory cells are specialized lymphocytes that prevent excessive immune responses, yet they can suppress beneficial anti-tumor immunity when infiltrating malignant tumors. Osteopontin, a versatile protein produced by various cells, including T lymphocytes, influences both inflammation-related diseases and cancer immunity. Its role in T regulatory cells, however, remains less explored. Our study examined the impact of osteopontin deficiency on T regulatory cells. We generated mice lacking osteopontin in these cells and observed impaired immune suppression capabilities, which resulted in increased tumor-fighting activity against melanoma. These findings emphasize osteopontin's crucial role in T regulatory cell stability and functionality within the tumor microenvironment, providing valuable insights for developing new immunotherapeutic strategies. Foxp3-expressing regulatory T (Treg) cells represent the most highly immunosuppressive cell in the tumor microenvironment (TME) that halts effective anti-tumor immunity. Osteopontin (Opn), an extracellular matrix (ECM) glycophosphoprotein, plays key roles in many types of immune-related diseases and is associated with cancer aggressiveness when expressed by tumor cells. However, its role in Foxp3Treg heterogeneity, function, and stability in the TME is poorly defined. We generated mice with a Foxp3-specific deletion of Opn and assessed the ability of Opn-deficient Tregs to suppress inflammation. As these mice aged, they developed a scurfy-like syndrome characterized by aberrant and excessive activation of effector T cells. We evaluated and further confirmed the reduced suppressive capacity of Opn-deficient Tregs in an in vivo suppression assay of colitis. We also found that mice with Opn-deficient Foxp3+ Tregs have enhanced anti-tumor immunity and reduced tumor burden, associated with an unstable Treg phenotype, paralleled by reduced Foxp3 expression in tumor-infiltrating lymphocytes. Finally, we observed reduced Foxp3 and Helios expression in Opn-deficient Tregs compared to wild-type controls after in vitro activation. Our findings indicate that targeting Opn in Tregs reveals vigorous and effective ways of promoting Treg instability and dysfunction in the TME, facilitating anti-tumor immunity. [ABSTRACT FROM AUTHOR]

Resting-state functional magnetic resonance imaging (rs-fMRI) has been widely utilized to investigate plasticity mechanisms and functional reorganization in multiple sclerosis (MS). Among many resting state (RS) networks, a significant role is played by the salience network (SN, ventral attention network). Previous reports have demonstrated the involvement of osteopontin (OPN) in the pathogenesis of MS, which acts as a proinflammatory cytokine ultimately leading to neurodegeneration. Concentration of serum OPN was related to MRI findings 10.22±2.84 years later in 44 patients with MS. Local and interhemispheric correlations (LCOR, IHC), ROI-to-ROI and seed-based connectivity analyses were performed using serum OPN levels as independent variable along with age and gender as nuisance variables. We found significant associations between OPN levels and local correlation in right and left clusters encompassing the central opercular- and insular cortices (p-FDR = 0.0018 and p-FDR = 0.0205, respectively). Moreover, a significant association was identified between OPN concentration and interhemispheric correlation between central opercular- and insular cortices (p-FDR = 0.00015). Significant positive associations were found between OPN concentration and functional connectivity (FC) within the SN (FC strength between the anterior insula ventral division and 3 other insular regions, F(2,13) = 7.84, p-FDR = 0.0117). Seed-based connectivity analysis using the seven nodes of the SN resulted in several positive and inverse associations with OPN level. Serum OPN level may predict FC alterations within the SN in 10 years. [ABSTRACT FROM AUTHOR]

Background: Circulating cytokines can represent non-invasive biomarkers to improve prediction of clinical outcomes of cancer patients. Here, plasma levels of IL-8, CCL4, osteopontin, LIF and BDNF were determined at baseline (T0), after 2 months of therapy (T2) and, when feasible, at progression (TP), in 70 melanoma patients treated with BRAF and MEK inhibitors. The association of baseline cytokine levels with clinical response, progression-free survival (PFS) and overall survival (OS) was evaluated. Methods: Cytokine concentrations were measured using the xMAP technology. Their ability to discriminate between responding (Rs) and non-responding (NRs) patients was assessed by Receiver Operating Characteristics analysis. PFS and OS were estimated with the Kaplan–Meier method. The Cox proportional hazard model was used in the univariate and multivariate analyses to estimate crude and adjusted hazard ratios with 95% confidence intervals. Results: CCL4 and LIF were undetectable in the majority of samples. The median osteopontin concentration at T0 and T2 was significantly higher in NRs than in Rs. The median T0 and T2 values of IL-8 were also higher in NRs than in Rs, although the statistical significance was not reached. No differences were detected for BDNF. In 39 Rs with matched T0, T2, and TP samples, osteopontin and IL-8 significantly decreased from T0 to T2 and rose again at TP, while BDNF levels remained unchanged. In NRs, none of the cytokines showed a significant decrease at T2. Only osteopontin demonstrated a good ability to discriminate between Rs and NRs. A high IL-8 T0 level was associated with significantly shorter PFS and OS and higher risk of progression and mortality, and remained an independent negative prognostic factor for OS in multivariate analysis. An elevated osteopontin T0 concentration was also significantly associated with worse OS and increased risk of death. Patients with high IL-8 and high osteopontin showed the lowest PFS and OS, and in multivariate analysis this cytokine combination remained independently associated with a three- to six-fold increased risk of mortality. Conclusion: Circulating IL-8 and osteopontin appear useful biomarkers to refine prognosis evaluation of patients undergoing targeted therapy, and deserve attention as potential targets to improve its clinical efficacy. [ABSTRACT FROM AUTHOR]

Despite their diverse physiologies and roles, the heart, skeletal muscles, and smooth muscles all derive from a common embryonic source as bones. Moreover, bone tissue, skeletal and smooth muscles, and the heart share conserved signaling pathways. The maintenance of skeletal health is precisely regulated by osteocytes, osteoblasts, and osteoclasts through coordinated secretion of bone‐derived factors known as osteokines. Increasing evidence suggests the involvement of osteokines in regulating atherosclerotic vascular disease. Therefore, this review aims to examine the evidence for the role of osteokines in atherosclerosis development and progression comprehensively. Specifically discussed are extensively studied osteokines in atherosclerosis such as osteocalcin, osteopontin, osteoprotegerin, and fibroblast growth factor 23. Additionally, we highlighted the effects of exercise on modulating these key regulators derived from bone tissue metabolism. We believe that gaining an enhanced understanding of how osteocalcin contributes to the process of atherosclerosis will enable us to develop targeted and comprehensive therapeutic strategies against diseases associated with its progression. Significance Statement: Bone is now recognized as an endocrine organ, with numerous studies demonstrating its direct effects on blood vessels and cells, as well as indirect impacts on the process of atherosclerosis. We believe that osteokines hold significant research potential in this area, and understanding their role in atherosclerosis and uncovering underlying mechanisms could lead to new therapeutic targets and improved treatment outcomes. In this review, we summarize four well‐established mechanisms through which osteokines contribute to atherosclerosis, providing valuable insights for future researchers. [ABSTRACT FROM AUTHOR]

Osteoarthritis occurs in any joints, and identification in its earlier stages helps to treat the disease and increase the recovery rate. The radiography method and imaging techniques are traditionally used to identify osteoarthritis. But these methods are expensive, and with the complicated steps. Researchers are working toward developing a highly sensitive biosensor in identifying the osteoarthritis biomarker. This research was focused on developing a C‐terminal telopeptide of type II collagen (CTX‐II) colorimetric sensor with gold nanoparticle (AuNP) for diagnosing osteoarthritis. Anti‐CTX‐II was conjugated with AuNP and then added with CTX‐II and sodium chloride for the color change. In the presence of CTX‐II, antibody releases from AuNP then binds with CTX‐II, and the color of AuNP changed to purple. Without the CTX‐II, AuNP remains its red color (dispersed). This easier colorimetric assay detected the CTX‐II as low as 2 ng/mL on linear regression [y = 0.0131x − 0.0051; R2 = 0.9205]. Furthermore, control performances with the relevant proteins osteopontin, IL‐6, and nonimmune antibody failed to change the color confirming the specific identification of CTX‐II. [ABSTRACT FROM AUTHOR]

Aquaporin-4 (AQP4) expression is associated with the development of congenital hydrocephalus due to its structural role in the ependymal membrane. Gene expression analysis of periaqueductal tissue in AQP4-knockout (KO) mice at 11 days of age (P11) showed a modification in ependymal cell adhesion and ciliary protein expression that could alter cerebrospinal fluid homeostasis. A microglial subpopulation of CD11c+ cells was overexpressed in the periaqueductal tissue of mice that did not develop hydrocephalus, suggesting a possible protective effect. Here, we verified the location of this CD11c+ expression in the corpus callosum (CC) and cerebellum of AQP4-KO mice and analysed its time course. Immunofluorescence labelling of the CD11c protein in the CC and cerebellum of WT and KO animals at P3, P5, P7 and P11 confirmed an expanded presence of these cells in both tissues of the KO animal; CD11c+ cells appeared at P3 and reached a peak at P11, whereas in the WT animal, they appeared at P5, reached their peak at P7 and were undetectable by P11. The gene expression analysis in the CC samples at P11 confirmed the presence of CD11c+ microglial cells in this tissue. Among the more than 4000 overexpressed genes, Spp1 stood out with the highest differential gene expression (≅600), with other genes, such as Gpnmb, Itgax, Cd68 and Atp6v0d2, also identified as overexpressed. Therefore, CD11c+ cells appear to be necessary for normal corpus callosum development during postnatal life, and the absence of AQP4 prolonged its expression in this tissue. [ABSTRACT FROM AUTHOR]

A relevant role of osteopontin (OPN) and gremlin 1 (Grem1) in regulating cardiac tissue remodeling and formation of heart failure (HF) are documented, with the changes of OPN and Grem1 levels in blood plasma due to acute ischemia, ischemic heart disease-induced advanced HF or dilatative cardiomyopathy being the primary focus in most of these studies. However, knowledge on the early OPN and Grem1 proteins expression changes within cardiomyocytes during remodeling due to chronic ischemia remains insufficient. The aim of this study was to determine the OPN and Grem1 proteins expression changes in human cardiomyocytes at different stages of ischemic HF. A semi-quantitative immunohistochemical analysis was performed in 105 myocardial tissue samples obtained from the left cardiac ventricles. Increased OPN immunostaining intensity was already detected in the stage A HF group, compared to the control group (p < 0.001), and continued to increase in the stage B HF (p < 0.001), achieving the peak of immunostaining in the stages C/D HF group (p < 0.001). Similar data of Grem1 immunostaining intensity changes in cardiomyocytes were documented. Significantly positive correlations were detected between OPN, Grem1 expression in cardiomyocytes and their diameter as well as the length, in addition to positive correlation between OPN and Grem1 expression changes within cardiomyocytes. These novel findings suggest that OPN and Grem1 contribute significantly to reorganization of cellular geometry from the earliest stage of cardiomyocyte remodeling, providing new insights into the ischemic HF pathogenesis. [ABSTRACT FROM AUTHOR]

The reproductive efficiency of dromedary camels is hindered by challenges such as early embryonic mortality, which may be attributed to a lack of synchronization between conceptus signalling and uterine receptivity. Understanding the intricate biological processes involved in feto‐maternal interactions during implantation is crucial to address these limitations. Osteopontin (OPN) is a protein involved in cell signalling and adhesion, playing a crucial role in embryonic implantation. Previous studies have shown the presence of OPN in the uterine endometrium of various mammalian species including dromedary camels. However, the expression pattern of OPN in dromedary conceptuses remains unexplored. Thus, the current study aimed, for the first time, to investigate the temporospatial expression of OPN in dromedary conceptuses during the peri‐implantation period at Days 8, 10, and 12 of pregnancy. Twelve conceptuses were recovered non‐surgically from pregnant females on Days 8, 10, 12 of pregnancy. Quantitative real‐time PCR (qrt‐PCR), immunohistochemistry (IHC), and immunofluorescence (IF) were employed for analysis of the expression of OPN mRNA and protein. The results revealed significant increases in both OPN mRNA and protein expression started on Day 10 and peaked at Day 12 of pregnancy. Immuno‐localization confirmed the presence of OPN protein in the trophectoderm and endoderm of dromedary conceptuses. In conclusion, the expression and localization of OPN during the peri‐implantation period in dromedary conceptuses imply its involvement as a crucial reproductive factor and its upregulation during this period, with a pronounced increase close to attachment time (Day 12 of pregnancy) further supports its role in embryo adhesion, implantation, and placentation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The liver carries out many essential tasks, such as synthesising cholesterol, controlling the body's storage of glycogen, and detoxifying metabolites, in addition to performing, and regulating homeostasis. Hepatic fibrosis is a pathological state characterized by over accumulation of extracellular matrix (ECM) including collagen fibers. Sildenafil (a selective inhibitor of type 5 phosphodiesterase) has anti-inflammatory, antioxidant and anti-apoptotic properties. It is commonly used to treat erectile dysfunction in male. The purpose of the current investigation was to evaluate sildenafil's hepatoprotective potential against liver fibrosis in rats that was caused by carbon tetrachloride (CCl4). Liver enzymes and oxidative markers as well as profibrotic genes were determined. The findings showed that sildenafil alleviates the hepatic dysfunctions caused by CCl4 by restoring normal levels of ALT, AST, and GGT as well as by restoring the antioxidant status demonstrated by increased glutathione (GSH), and catalase. In addition, a significantly down-regulated the mRNA expressions of profibrotic genes [collagen-1α, IL-1β, osteopontin (OPN), and transforming growth factor-β (TGF-β)]. Additionally, sildenafil lessens the periportal fibrosis between hepatic lobules, congestion and dilatation in the central vein, and the inflammatory cell infiltrations. As a result, it is hypothesized that sildenafil may be helpful in the management of hepatotoxicity brought on by CCl4 through suppressing OPN. [ABSTRACT FROM AUTHOR]

Introduction: As transcatheter aortic valve implantation (TAVI) indications expand, understanding the valve degeneration process and potential influencing biomarkers becomes increasingly important. Aim: To investigate temporal changes in biomarker levels and their potential association with 18F-fluorodeoxyglucose (18F-FDG) and 18F-sodium fluoride (18F-NaF) uptake, assessed using positron emission tomography/computed tomography (PET/CT) studies as markers for native aortic annulus calcifications and early-stage TAVI valve degeneration. Material and methods: A total of 71 TAVI patients underwent blood sampling and transthoracic echocardiography at baseline (pre-TAVI) and 6, 12, 18, and 24 months after the procedure. PET/CT using 18F-NaF and 18F-FDG was performed at 6 and 24 months. Serum levels of matrix metalloproteinase-3 (MMP-3), matrix metalloproteinase-9 (MMP-9), and osteopontin (OPN) were measured. In addition, plasma levels of osteoprotegerin (OPG), lipoprotein a (Lp(a)), and oxidized LDL (ox-LDL) were assessed. Results: Finally, 31 patients (median age: 84.0 years) completed the study. Valve function improved after TAVI and remained stable during follow-up. Over 24 months, OPN levels decreased (p = 0.010), while MMP-3 and MMP-9 levels increased (p = 0.046 and p = 0.041). MMP-3 and MMP-9 showed multiple positive correlations across time points. OPN, ox-LDL, and OPG demonstrated significant negative correlations with follow-up effective orifice area index and effective orifice area (EOA). No significant correlations were found between biomarkers and PET/CT uptake. Conclusions: Significant biomarker changes over 24 months and negative correlations with EOA suggest potential roles in aortic valve function. However, no correlations between biomarkers and PET/CT results were observed. [ABSTRACT FROM AUTHOR]

Increased choroid plexus (CP) volume has been recently implicated as a potential predictor of worse multiple sclerosis (MS) outcomes. The biomarker signature of CP changes in MS are currently unknown. To determine the blood-based biomarker characteristics of the cross-sectional and longitudinal MRI-based CP changes in a heterogeneous group of people with MS (pwMS), a total of 202 pwMS (148 pwRRMS and 54 pwPMS) underwent MRI examination at baseline and at a 5-year follow-up. The CP was automatically segmented and subsequently refined manually in order to obtain a normalized CP volume. Serum samples were collected at both timepoints, and the concentration of 21 protein measures relevant to MS pathophysiology were determined using the Olink™ platform. Age-, sex-, and BMI-adjusted linear regression models explored the cross-sectional and longitudinal relationships between MRI CP outcomes and blood-based biomarkers. At baseline, there were no significant proteomic predictors of CP volume, while at follow-up, greater CP volume was significantly associated with higher neurofilament light chain levels, NfL (standardized β = 0.373, p = 0.001), and lower osteopontin levels (standardized β = −0.23, p = 0.02). Higher baseline GFAP and lower FLRT2 levels were associated with future 5-year CP % volume expansion (standardized β = 0.277, p = 0.004 and standardized β = −0.226, p = 0.014, respectively). The CP volume in pwMS is associated with inflammatory blood-based biomarkers of neuronal injury (neurofilament light chain; NfL) and glial activation such as GFAP, osteopontin, and FLRT2. The expansion of the CP may play a central role in chronic and compartmentalized inflammation and may be driven by glial changes. [ABSTRACT FROM AUTHOR]

Background: Osteopontin (OPN) is a proinflammatory cytokine that has been recently implicated in neuroinflammation and neurodegeneration. We hypothesized that an increase in plasma OPN is a deleterious neuroinflammatory marker in people with dementia and cerebral small vessel disease (CSVD). Methods: A pilot study was conducted on participants in the Northern Manhattan Study (NOMAS). Three groups were selected based on their dementia status and evidence of subclinical CSVD and chosen to be similar in age, sex, and education attainment: No dementia/No CSVD (n = 19), Dementia/No CSVD (n = 22), and Dementia + CSVD (n = 21). Dementia (any type) was diagnosed by consensus adjudication following a series of comprehensive neuropsychological assessments and a review of the medical history. CSVD was indicated by silent brain infarcts, enlarged perivascular spaces, cerebral microbleeds, and white matter hyperintensity volumes (WMHV) on MRI. Multinomial logistic regression was used to examine the difference in OPN levels across groups, adjusting for key determinants of CSVD and neurodegeneration. Results: Plasma OPN levels were elevated in the Dementia+CSVD group (mean = 70.69 ± 39.00 ng/mL) but not in the Dementia/No CSVD group (mean = 45.46 ± 19.11 ng/mL) compared to the No Dementia/No CSVD group (mean = 36.43 ± 15.72 ng/mL). OPN was associated with Dementia+CSVD (Odds Ratio [OR] per ng/mL = 1.06, 95% CI 1.02–1.11) after adjusting for covariates, including brain volume. OPN was strongly correlated with WMHV (Spearman's rank correlation ρ = 0.46, p = 0.0001) but not with other components of CSVD. Conclusion: In this pilot, greater levels of plasma OPN were associated with dementia with evidence of CSVD. This link was predominately driven by the contribution of OPN to dementia through the burden of white matter lesions. [ABSTRACT FROM AUTHOR]

Objective: To determine the possible association between acute fetal stress during labor and maternal blood levels of osteopontin (OPN), white blood cells, sedimentation, and C-reactive protein (CRP). Methods: The study included women with a term pregnancy (37 weeks or more) who had a cesarean section during the active phase of labor. The study included 30 term pregnancies who underwent cesarean section for fetal distress and 30 pregnant women who underwent cesarean section for other indications (prior uterine surgery, head-pelvis incompatibility, large baby, non-progressing plot) as a control group. The levels of OPN and other inflammatory markers (leukocytes, sedimentation, CRP) in the maternal venous blood of 60 pregnant women were compared, and whether there was a significant association between the groups was investigated. Results: OPN levels in the fetal stress group were higher than those in the control group, and the difference was statistically significant (p=0.008). There was no statistically significant difference in white blood cell, blood sedimentation, and CRP levels between the two groups (p>0.005). Conclusion: Placental inflammation plays a role in the etiology of fetal stress, and OPN may be released because of fetal stress. The increase in OPN in maternal blood during labor may be an important marker for predicting fetal stress. [ABSTRACT FROM AUTHOR]

Osteopontin (OPN) and Bone Sialoprotein (BSP), abundantly expressed by osteoblasts and osteoclasts, appear to have important, partly overlapping functions in bone. In gene-knockout (KO, -/-) models of either protein and their double (D)KO in the same CD1/129sv genetic background, we analyzed the morphology, matrix characteristics, and biomechanical properties of femur bone in 2 and 4 month old, male and female mice. OPN−/− mice display inconsistent, perhaps localized hypermineralization, while the BSP−/− are hypomineralized throughout ages and sexes, and the low mineralization of young DKO mice recovers with age. The higher contribution of primary bone remnants in OPN−/− shafts suggests a slow turnover, while their lower percentage in BSP−/− indicates rapid remodeling, despite FTIR-based evidence in this genotype of a high maturity of the mineralized matrix. In 3-point bending assays, OPN−/− bones consistently display higher Maximal Load, Work to Max. Load and in young mice Ultimate Stress, an intrinsic characteristic of the matrix. Young male and old female BSP−/− also display high Work to Max. Load along with low Ultimate Stress. Principal Component Analysis confirms the major role of morphological traits in mechanical competence, and evidences a grouping of the WT phenotype with the OPN−/− and of BSP−/− with DKO, driven by both structural and matrix parameters, suggesting that the presence or absence of BSP has the most profound effects on skeletal properties. Single or double gene KO of OPN and BSP thus have multiple distinct effects on skeletal phenotypes, confirming their importance in bone biology and their interplay in its regulation. [ABSTRACT FROM AUTHOR]

Importance: Endochondral ossification plays an important role in skeletal development. Recent studies have suggested a link between increased intracellular reactive oxygen species (ROS) and skeletal disorders. Moreover, previous studies have revealed that increasing the levels of myeloperoxidase (MPO) and osteopontin (OPN) while inhibiting NADPH oxidase 4 (NOX4) can enhance bone growth. This investigation provides further evidence by showing a direct link between NOX4 and MPO, OPN in bone function. Objective: This study investigates NOX4, an enzyme producing hydrogen peroxide, in endochondral ossification and bone remodeling. NOX4's role in osteoblast formation and osteogenic signaling pathways is explored. Methods: Using NOX4-deficient (NOX4+) and ovariectomized (OVX) mice, we identify NOX4's potential mediators in bone maturation. Results: NOX4+ mice displayed significant differences in bone mass and structure. Compared to the normal Control and OVX groups. Hematoxylin and eosin staining showed NOX4+ mice had the highest trabecular bone volume, while OVX had the lowest. Proteomic analysis revealed significantly elevated MPO and OPN levels in bone marrow-derived cells in NOX4+ mice. Immunohistochemistry confirmed increased MPO, OPN, and collagen II (COLII) near the epiphyseal plate. Collagen and chondrogenesis analysis supported enhanced bone development in NOX4+ mice. Conclusions and Relevance: Our results emphasize NOX4's significance in bone morphology, mesenchymal stem cell proteomics, immunohistochemistry, collagen levels, and chondrogenesis. NOX4 deficiency enhances bone development and endochondral ossification, potentially through increased MPO, OPN, and COLII expression. These findings suggest therapeutic implications for skeletal disorders. [ABSTRACT FROM AUTHOR]

Osteopontin (OPN), a bioactive milk protein in breast milk, has diverse applications in food and medicine. OPN is predominantly extracted from fresh bovine milk; however, the concentration of OPN in bovine milk is exceedingly low. To address these issues, in the present study, we used Komagataella phaffii for the recombinant expression of human OPN (hOPN). The results of host cell screening revealed that X33 cells were more suitable than other K. phaffii hosts for hOPN expression, yielding a titer of 340.5 μg/L. Subsequently, it was observed that the extracellular production of hOPN significantly increased to 8.02 mg/L from strain XPSA01 using the PAOX1 promoter and the hybrid signal peptide PROSCW10-α. Meanwhile, the co-expression of transcription factors, translation factors, and molecular chaperones resulted in a 2.94-fold enhancement in extracellular hOPN production compared with that in XPSA01, resulting in a titer of 23.6 mg/L. Finally, the above strategies were combined to obtain the recombinant strain XPSA01-CP, which achieved titers of 35.6 and 128.5 mg/L hOPN in shake-flask fermentation and 3-L bioreactor, respectively. To the best of our knowledge, this is the highest extracellular yield of hOPN ever reported.

Abstract Reconstruction of the neurovascular unit is essential for the repair of spinal cord injury (SCI). Nonetheless, detailed documentation of specific vascular changes following SCI and targeted interventions for vascular treatment remains limited. This study demonstrates that traumatic pathological vascular remodeling occurs during the chronic phase of injury, characterized by enlarged vessel diameter, disruption of blood‐spinal cord barrier, endothelial‐to‐mesenchymal transition (EndoMT), and heightened extracellular matrix deposition. After SCI, osteopontin (OPN), a critical factor secreted by immune cells, is indispensable for early vascular regeneration but also contributes to traumatic pathological vascular remodeling. This work further elucidates the mechanism by which OPN influences spinal cord microvascular endothelial cells, involving Akt‐mediated Foxo1 phosphorylation. This process facilitates the extranuclear transport of Foxo1 and decreases Smad7 expression, leading to excessive activation of the TGF‐β signaling pathway, which ultimately results in EndoMT and fibrosis. Targeted inhibition of Foxo1 phosphorylation through an endothelium‐specific aptamer‐liposome small molecule delivery system significantly mitigates vascular remodeling, thereby enhancing axon regeneration and neurological function recovery following SCI. The findings offer a novel perspective for drug therapies aimed at specifically targeting pathological vasculature after SCI.

Osteopontin (OPN) is a pro-inflammatory protein that influences bone remodelling, wound healing, angiogenesis, allergic inflammation, and skin diseases such as psoriasis, contact dermatitis and skin cancer. However, the role of OPN in the skin remains unclear. Therefore, this study aimed to investigate the role of OPN in the skin, particularly in the context of ultraviolet (UV) irradiation-induced inflammation. OPN expression and its effects on inflammatory modulators were assessed in human skin, in a mouse model and in vitro, using a UV source emitting both UVB and UVA radiation, which collectively contribute to UV-induced skin inflammation. OPN expression increased in human and mouse skin after UV irradiation. Compared with wild-type mice, UV irradiation-induced skin phenotypes, such as erythema and skin thickening, were alleviated in OPN−/− mice. In addition, the number of immune cells recruited to the skin after UV irradiation and the expression of inflammatory cytokines and matrix metalloproteinases (MMPs) were observed to be decreased in the skin of OPN−/− mice compared with that of wild-type mice. By contrast, the degree of skin inflammation was higher in the hOPN KI mice than in wild-type mice. Treatment with recombinant OPN increased the expression of MMP-1 and inflammatory cytokines in human dermal fibroblasts and epidermal keratinocytes in vitro. Our results suggest that OPN may play a regulatory role in UV-induced skin inflammation.

Summary: Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a spectrum of disease states ranging from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH), which can eventually lead to the development of cirrhosis and hepatocellular carcinoma. Macrophages have long been implicated in driving the progression from steatosis to end-stage disease, yet we still know relatively little about the precise involvement of these cells in MASLD progression and/or regression. Rather, there are a considerable number of conflicting reports regarding the precise roles of these cells. This confusion stems from the fact that, until recently, macrophages in the liver were considered a homogenous population. However, thanks to recent technological advances including multi-parameter flow cytometry, single-cell RNA sequencing and spatial proteogenomics, we now know that this is not the case. Rather hepatic macrophages, even in the healthy liver, are heterogenous, existing in multiple subsets with distinct transcriptional profiles and hence likely functions. This heterogeneity is even more prominent in MASLD, where the macrophage pool consists of multiple different subsets of resident and recruited cells. To probe the unique functions of these cells and determine if targeting macrophages may be a viable therapeutic strategy in MASLD, we first need to unravel this complexity and decipher which populations and/or activation states are present and what functions each of these may play in driving MASLD progression. In this review, we summarise recent advances in the field, highlighting what is currently known about the hepatic macrophage landscape in MASLD and the questions that remain to be tackled.

Introduction: Psoriasis is a chronic inflammatory disease affecting 2%-3% of the global population via immune-mediated mechanisms. Osteopontin plays a crucial role in T-helper 1 and T-helper 17-mediated illnesses, including psoriasis. Ocular complications in psoriasis have been reported and their assessment is of importance. Osteopontin is normally expressed constitutively in ocular structures and is linked to ocular homeostasis. Objective: This study aimed to clarify the role of osteopontin (OPN) in psoriasis (PS) and its correlation with disease severity and ocular manifestations. Methods: A case-control study involving 40 psoriatic patients and an equal number of age and sex-matched healthy subjects was conducted. We used the psoriasis area severity index (PASI) to assess disease severity and performed a comprehensive ophthalmological examination. Additionally, we measured serum osteopontin levels using Enzyme-Linked Immunosorbent Assay (ELISA) in both groups. Results: A significant elevation in serum OPN levels in psoriatic patients compared to controls was found (P=0.00). Furthermore, there was a highly significant positive correlation between serum OPN levels and patient age, disease duration, and PASI scores. Notably, a higher prevalence of ocular complications, including blepharitis, corneal affection, conjunctivitis, keratoconjunctivitis sicca, and cataract, in psoriatic patients compared to controls was observed. Importantly, significant associations between serum OPN levels and the presence of cataracts and intraocular pressure (IOP) were identified. Additionally, significant correlations between serum OPN levels and measures of visual acuity and ocular surface health were found. Conclusions: Osteopontin is considered a marker of psoriasis severity and is associated with ocular comorbidities in psoriasis.