Osteopontin: A multifunctional protein at the crossroads of inflammation, atherosclerosis, and vascular calcification

Identifying Key Drivers in the Pathogenesis of Martorell Hypertensive Ischaemic Leg Ulcer: A Comparative Analysis with Chronic Venous Leg Ulcer

Martorell hypertensive ischaemic leg ulcer (Martorell HYTILU) is a rare but significant cause of distal leg ulcers. Although hypertension and diabetes are known factors in its development, the precise pathogenesis of Martorell HYTILU remains elusive. To reach a better understanding of Martorell HYTILU, transcriptomic analysis was conducted through RNA sequencing and immunohistochemical comparison of Martorell HYTILU (n = 17) with chronic venous ulcers (n = 4) and healthy skin (n = 4). Gene expression analysis showed a marked activation of immune-related pathways in both Martorell HYTILU and chronic venous ulcers compared with healthy skin. Notably, neutrophil activity was substantially higher in Martorell HYTILU. While pathway analysis revealed a mild downregulation of several immune pathways in Martorell HYTILU compared with chronic venous ulcers, keratinization, cornification, and epidermis development were significantly upregulated in Martorell HYTILU. Additionally, STAC2, a gene encoding for a protein promoting the expression of the calcium channel Cav1.1, was significantly upregulated in Martorell HYTILU and was detected perivascularly in situ (Martorell HYTILU n = 24; chronic venous ulcers n = 9, healthy skin n = 11). The high expression of STAC2 in Martorell HYTILU suggests that increased calcium influx plays an important role in the pathogenesis of the disease. Consequently, calcium channel antagonists could be a promising treatment avenue for Martorell HYTILU.

The interplay of collagen, macrophages, and microcalcification in atherosclerotic plaque cap rupture mechanics

The rupture of an atherosclerotic plaque cap overlying a lipid pool and/or necrotic core can lead to thrombotic cardiovascular events. In essence, the rupture of the plaque cap is a mechanical event, which occurs when the local stress exceeds the local tissue strength. However, due to inter- and intra-cap heterogeneity, the resulting ultimate cap strength varies, causing proper assessment of the plaque at risk of rupture to be lacking. Important players involved in tissue strength include the load-bearing collagenous matrix, macrophages, as major promoters of extracellular matrix degradation, and microcalcifications, deposits that can exacerbate local stress, increasing tissue propensity for rupture. This review summarizes the role of these components individually in tissue mechanics, along with the interplay between them. We argue that to be able to improve risk assessment, a better understanding of the effect of these individual components, as well as their reciprocal relationships on cap mechanics, is required. Finally, we discuss potential future steps, including a holistic multidisciplinary approach, multifactorial 3D in vitro model systems, and advancements in imaging techniques. The obtained knowledge will ultimately serve as input to help diagnose, prevent, and treat atherosclerotic cap rupture.

The Role of Osteopontin in Atherosclerosis and Its Clinical Manifestations (Atherosclerotic Cardiovascular Diseases)-A Narrative Review

Atherosclerotic cardiovascular diseases (ASCVDs) are the most common and severe public health problem nowadays. Osteopontin (OPN) is a multifunctional glycoprotein highly expressed at atherosclerotic plaque, which has emerged as a potential biomarker of ASCVDs. OPN may act as an inflammatory mediator and/or a vascular calcification (VC) mediator, contributing to atherosclerosis progression and eventual plaque destabilization. In this article, we discuss the complex role of OPN in ASCVD pathophysiology, since many in vitro and in vivo experimental data indicate that OPN contributes to macrophage activation and differentiation, monocyte infiltration, vascular smooth muscle cell (VSMC) migration and proliferation and lipid core formation within atherosclerotic plaques. Most but not all studies reported that OPN may inhibit atherosclerotic plaque calcification, making it "vulnerable". Regarding clinical evidence, serum OPN levels may become a biomarker of coronary artery disease (CAD) presence and severity. Significantly higher OPN levels have been found in patients with acute coronary syndromes than those with stable CAD. In limited studies of patients with peripheral artery disease, circulating OPN concentrations may be predictive of future major adverse cardiovascular events. Overall, the current literature search suggests the contribution of OPN to atherosclerosis development and progression, but more robust evidence is required.

Modulation of Smooth Muscle Cell Phenotype for Translation of Tissue-Engineered Vascular Grafts

Translation of small-diameter tissue-engineered vascular grafts (TEVGs) for the treatment of coronary artery disease (CAD) remains an unfulfilled promise. This is largely due to the limited integration of TEVGs into the native vascular wall-a process hampered by the insufficient smooth muscle cell (SMC) infiltration and extracellular matrix deposition, and low vasoactivity. These processes can be promoted through the judicious modulation of the SMC toward a synthetic phenotype to promote remodeling and vascular integration; however, the expression of synthetic markers is often accompanied by a decrease in the expression of contractile proteins. Therefore, techniques that can precisely modulate the SMC phenotypical behavior could have the potential to advance the translation of TEVGs. In this review, we describe the phenotypic diversity of SMCs and the different environmental cues that allow the modulation of SMC gene expression. Furthermore, we describe the emerging biomaterial approaches to modulate the SMC phenotype in TEVG design and discuss the limitations of current techniques. In addition, we found that current studies in tissue engineering limit the analysis of the SMC phenotype to a few markers, which are often the characteristic of early differentiation only. This limited scope has reduced the potential of tissue engineering to modulate the SMC toward specific behaviors and applications. Therefore, we recommend using the techniques presented in this review, in addition to modern single-cell proteomics analysis techniques to comprehensively characterize the phenotypic modulation of SMCs. Expanding the holistic potential of SMC modulation presents a great opportunity to advance the translation of living conduits for CAD therapeutics.

The route of autophagy regulation by osteopontin: a review on the linking mechanisms

Autophagy is a dynamic intracellular process of protein degradation, which is mostly triggered by nutrient deprivation. This process initiates with the formation of autophagosomes, which they capture cytosolic material that is then degraded upon fusion with the lysosome. Several factors have been found to be associated with autophagy modulation, of which extracellular matrix (ECM) components has attracted the attention of recent studies. Osteopontin (OPN) is an important extracellular matrix component that has been detected in a wide range of tumor cells, and is involved in cancer cell invasion and metastasis. Recently, a number of studies have focused on the relationship of OPN with autophagy, by delineating the intracellular signaling pathways that connect OPN to the autophagy process. We will summarize signaling pathways and cell surface receptors, through which OPN regulates the process of autophagy.

New Biomarker Combination Related to Oxidative Stress and Inflammation in Primary Open-Angle Glaucoma

Glaucoma is a multifactorial neurodegenerative disease and the second leading cause of blindness. Detection of clinically relevant biomarkers would aid better diagnoses and monitoring during treatment. In glaucoma, the protein composition of aqueous humor (AH) is relevant for the discovery of biomarkers. This study analyzes AH protein concentrations of putative biomarkers in patients with primary open-angle glaucoma (POAG) compared to a control group. Biomarkers were selected from known oxidative-stress and inflammatory pathways. Osteopontin (OPN), matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), and interleukin-10 (IL-10) were measured using the ELISA technique. Thirty-two patients were recruited to the study, including sixteen control and sixteen glaucoma patients. The glaucoma group consisted of patients diagnosed with glaucoma. In both groups, the aqueous humor sample was obtained during cataract surgery. A significant increase in OPN, MMP-9, TNF-alpha, and IL-10 was observed in the POAG aqueous humor, compared to the control group (p < 0.05). Of note, the AH of POAG patients contained 5.6 ± 1.2-fold more OPN compared to that of control patients. Different expression profiles of oxidative stress-related and inflammatory biomarkers were observed between patients with POAG and controls. This confirms the reported involvement of inflammatory and oxidative stress pathways in POAG pathophysiology. In the future, several, targeted AH proteins may be used to generate a potential biomarker expression profile of this disease, aiding diagnoses and disease progression monitoring. This approach highlights the importance of biomarkers in the future. Biomarkers provide a way to measure disease progression and response to treatment. In the future, biomarkers will play a more critical role in the toolkit of ophthalmology healthcare professionals as the field moves towards personalized medicine and precision healthcare.

Vascular cells responses to controlled surface structure and properties of bacterial nanocellulose artificial blood vessel after mercerization

Therapeutic benefits of small caliber artificial blood vessels to cure cardio and cerebrovascular diseases are mainly limited by their low patency during long-term transplantation. Bacterial nanocellulose (BNC), as a natural polysaccharide mainly synthesized by a bacterium Komagataeibatacter xylinus, has shown great potential in small-caliber vascular graft applications due to its shape controllability, and furthermore its physical surface structure can be adjusted with different treatments. However, influences of physical surface structure and properties of BNC conduits on behaviors of vascular cells have not been investigated. In this work, mercerized BNC conduits (MBNC) with different surface roughness and stiffness were constructed by controlled alkali (NaOH) treatment. The changes of surface structures and properties significantly affected the behaviors of vascular cells and gene expression; meanwhile, the cell seeding density also affected the cell responses. After mercerization with NaOH concentration > 10 %, it was observed that the increased stiffness of MBNC decreased several functional gene expressions of human vascular endothelial cells, and the pathological transformation of smooth muscle cells was inhibited. This study demonstrates physical surface structure of MBNC conduits will critically regulate functions and behaviors of vascular cells and it also provides important designing parameters to improve the long-term patency of BNC-based conduits.

Kefir peptides attenuate atherosclerotic vascular calcification and osteoporosis in atherogenic diet-fed ApoE−/− knockout mice

Aims: Vascular calcification (VC) and osteoporosis were previously considered two distinct diseases. However, current understanding indicates that they share common pathogenetic mechanisms. The available medicines for treating VC and osteoporosis are limited. We previously demonstrated that kefir peptides (KPs) alleviated atherosclerosis in high-fat diet (HFD)-induced apolipoprotein E knockout (ApoE−/−) mice. The present study further addressed the preventive effects of KPs on VC and osteoporosis in ApoE−/− mice fed a high-cholesterol atherogenic diet (AD).

Main methods: Seven-week-old ApoE−/− and wild-type C57BL/6 mice were randomly divided into five groups (n = 6). The development of VC and osteoporosis was evaluated after AD feeding for 13 weeks in KP-treated ApoE−/− mice and compared to C57BL/6 and ApoE−/− mice fed a standard chow diet (CD).

Key findings: The results indicated that KP-treated ApoE−/− mice exhibited lower serum total cholesterol, oxidized low-density lipoprotein (ox-LDL), malondialdehyde (MDA) levels, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatine kinase (CK) activities, which suggested that KPs prevented hyperlipidemia and possible damages to the liver and muscle in ApoE−/− mice. KPs reduced serum tumor necrosis factor-α (TNF-α) and the local expression of TNF-α, IL-1β, and macrophage-specific CD68 markers in aortic tissues, which suggested that KPs inhibited inflammatory responses in AD-fed ApoE−/− mice. KPs reduced the deposition of lipid, collagen, and calcium minerals in the aortic roots of AD-fed ApoE−/− mice, which suggested that KPs inhibited the calcific progression of atherosclerotic plaques. KPs exerted osteoprotective effects in AD-fed ApoE−/− mice, which was evidenced by lower levels of the bone resorption marker CTX-1 and higher levels of the bone formation marker P1NP. KPs improved cortical bone mineral density and bone volume and reduced trabecular bone loss in femurs.

Significance: The present data suggested that KPs attenuated VC and osteoporosis by reducing oxidative stress and inflammatory responses in AD-fed ApoE−/− mice. Our findings contribute to the application of KPs as preventive medicines for the treatment of hyperlipidemia-induced vascular and bone degeneration.

Lactoferrin, Osteopontin and Lactoferrin–Osteopontin Complex: A Critical Look on Their Role in Perinatal Period and Cardiometabolic Disorders

Milk-derived bioactive proteins have increasingly gained attention and consideration throughout the world due to their high-quality amino acids and multiple health-promoting attributes. Apparently, being at the forefront of functional foods, these bioactive proteins are also suggested as potential alternatives for the management of various complex diseases. In this review, we will focus on lactoferrin (LF) and osteopontin (OPN), two multifunctional dairy proteins, as well as to their naturally occurring bioactive LF–OPN complex. While describing their wide variety of physiological, biochemical, and nutritional functionalities, we will emphasize their specific roles in the perinatal period. Afterwards, we will evaluate their ability to control oxidative stress, inflammation, gut mucosal barrier, and intestinal microbiota in link with cardiometabolic disorders (CMD) (obesity, insulin resistance, dyslipidemia, and hypertension) and associated complications (diabetes and atherosclerosis). This review will not only attempt to highlight the mechanisms of action, but it will critically discuss the potential therapeutic applications of the underlined bioactive proteins in CMD.

Expression of Toll-like receptor 2, Dectin-1, and Osteopontin in murine model of pulpitis

OBJECTIVES

This in vivo animal study aimed to develop a murine model of pulpitis induced by pulp exposure with or without application of zymosan in Naval Medical Research Institute (NMRI) mice and observe expressions of Toll-like receptor (TLR)-2, TLR-4, Dectin-1, Osteopontin (OPN), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-1ß.

MATERIAL AND METHODS

A total of 168 NMRI mice were divided into two groups, i.e., group A (n = 84) (pulpitis induced by pulp exposure only) and group B (n = 84) (pulpitis induced by pulp exposure and zymosan application). Right maxillary molar pulps were exposed with ¼ round bur, and animals were sacrificed at 0, 6, 9, 12, 24, 48, and 72 h. The exposed teeth were obtained for real-time polymerase chain reaction (qRT-PCR) analysis and histological and immunohistochemistry (IHC) analysis.

RESULTS

Histological evaluation revealed a time-dependent steady increase in inflammation. Similar time-dependent increase in the expression of inflammatory cytokines was noted. Group A exhibited an increase in TLR-4, Dectin-1, and OPN at 6 h, while TLR-2 was expressed at 24 h. Group B expressed TLR-2, Dectin-1, and OPN at 9, 48, and 72 h, respectively (p ≤ 0.05). Expression of OPN and TNF-α exhibited a similar pattern in both groups. IHC also detected expression of TLR-2, Dectin-1, TLR4, and CD68 in some cells at 6 and 9 h.

CONCLUSIONS

NMRI mice provided for a stable pulp inflammation model. Zymosan may be used to develop pulp inflammation model and study inflammatory response towards fungal antigens. Dental pulp expressed Dectin-1 receptor. OPN and TNF-α exhibited a similar expression pattern.

CLINICAL RELEVANCE

Innate immunity of dental pulp is capable of detecting fungal pathogens.

Thiol-ene-based microfluidic chips for glycopeptide enrichment and online digestion of inflammation-related proteins osteopontin and immunoglobulin G

Proteins, and more specifically glycoproteins, have been widely used as biomarkers, e.g., to monitor disease states. Bottom-up approaches based on mass spectrometry (MS) are techniques commonly utilized in glycoproteomics, involving protein digestion and glycopeptide enrichment. Here, a dual function polymeric thiol-ene-based microfluidic chip (TE microchip) was applied for the analysis of the proteins osteopontin (OPN) and immunoglobulin G (IgG), which have important roles in autoimmune diseases, in inflammatory diseases, and in coronavirus disease 2019 (COVID-19). TE microchips with larger internal surface features immobilized with trypsin were successfully utilized for OPN digestion, providing rapid and efficient digestion with a residence time of a few seconds. Furthermore, TE microchips surface-modified with ascorbic acid linker (TEA microchip) have been successfully utilized for IgG glycopeptide enrichment. To illustrate the use of the chips for more complex samples, they were applied to enrich IgG glycopeptides from human serum samples with antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The dual functional TE microchips could provide high throughput for online protein digestion and glycopeptide enrichment, showing great promise for future extended applications in proteomics and the study of related diseases.

Advances in imaging and treatment of atherosclerosis based on organic nanoparticles

Atherosclerosis, a systemic chronic inflammatory disease, can lead to thrombosis and vascular occlusion, thereby inducing a series of serious vascular diseases. Currently, distinguishing unstable plaques early and achieving more effective treatment are the two main clinical concerns in atherosclerosis. Organic nanoparticles have great potential in atherosclerotic imaging and treatment, showing superior biocompatibility, drug-loading capacity, and synthesis. This article illustrates the process of atherosclerosis onset and the key targeted cells, then systematically summarizes recent progress made in organic nanoparticle-based imaging of different types of targeted cells and therapeutic methods for atherosclerosis, including optical and acoustic-induced therapy, drug delivery, gene therapy, and immunotherapy. Finally, we discuss the major impediments that need to be addressed in future clinical practice. We believe this article will help readers to develop a comprehensive and in-depth understanding of organic nanoparticle-based atherosclerotic imaging and treatment, thus advancing further development of anti-atherosclerosis therapies.

Gene expression analysis of toll like receptor 2 and 4, Dectin-1, Osteopontin and inflammatory cytokines in human dental pulp ex-vivo

BACKGROUND

Toll like receptors (TLR) 2 and 4 present on innate immune cells of the dental pulp detect cariogenic bacteria. Along with bacteria, C. albicans may also be present in dental caries. The presence of C. albicans can be detected by Dectin-1 a C type Lectin receptor. Expression of Dectin-1 in human pulpits has not been reported. Similarly, cytokines are released as a consequence of dental pulp inflammation caused by cariogenic bacteria. The T helper (Th) 1 inflammatory response leads to exacerbation of inflammation and its relationship with Osteopontin (OPN) is not known in pulp inflammation.

OBJECTIVE

The aim of this study was to observe the expression of Dectin-1, TLR-2, OPN and pro-inflammatory cytokines in irreversibly inflamed human dental pulp and to observe relationship between Dectin-1/TLR-2 and OPN/Pro-inflammatory cytokines in the presence of appropriate controls.

METHODS

A total of 28 subjects diagnosed with irreversible pulpitis were included in this ex-vivo study. Fifteen samples were subjected to standard hematoxylin and Eosin (H&E) and immunohistochemistry staining. Whereas, gene expression analysis was performed on 13 samples to observe mRNA expression of pro-inflammatory cytokines; tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 beta (ß), IL-6 Dectin-1, OPN, TLR-2 and TLR-4. SPSS version 21 was used for statistical analysis. One way analysis of variance (ANOVA), Pearson correlation and Chi-square test were used at p ≤ 0.05.

RESULTS

Gene expressions of Dectin-1, TLR-2 and TLR-4 were observed in all samples. Dectin-1 and TLR-2 expressions were significantly correlated (r = 0.5587, p = 0.0002). Similarly, OPN and TNF-α expression showed a significant correlation (r = 0.5860, p = 0001). The agreement between histologic and clinical diagnosis was 69.2% in the cases of irreversible pulpitis.

CONCLUSION

Dectin-1 was expressed by inflamed human dental pulp. Dectin-1 and TLR-2 expression pattern was suggestive of a collaborative receptor response in inflamed pulp environment. OPN and TNF-α expressions showed a positive correlation indicating a possible relationship.

The Patent Ductus Arteriosus in Extremely Preterm Neonates Is More than a Hemodynamic Challenge: New Molecular Insights

Complications to preterm birth are numerous, including the presence of a patent ductus arteriosus (PDA). The biological understanding of the PDA is sparse and treatment remains controversial. Herein, we speculate whether the PDA is more than a cardiovascular imbalance, and may be a marker in response to immature core molecular and physiological processes driven by biological systems, such as inflammation. To achieve a new biological understanding of the PDA, we performed echocardiography and collected plasma samples on day 3 of life in 53 consecutively born neonates with a gestational age at birth below 28 completed weeks. The proteome of these samples was analyzed by mass spectrometry (nanoLC-MS/MS) and immunoassay of 17 cytokines and chemokines. We found differences in 21 proteins and 8 cytokines between neonates with a large PDA (>1.5 mm) compared to neonates without a PDA. Amongst others, we found increased levels of angiotensinogen, periostin, pro-inflammatory associations, including interleukin (IL)-1β and IL-8, and anti-inflammatory associations, including IL-1RA and IL-10. Levels of complement factors C8 and carboxypeptidases were decreased. Our findings associate the PDA with the renin-angiotensin-aldosterone system and immune- and complement systems, indicating that PDA goes beyond the persistence of a fetal circulatory connection of the great vessels.

Gene Expression Patterns of Osteopontin Isoforms and Integrins in Malignant Melanoma

Osteopontin (OPN) is a multifunctional glycoprotein that physiologically interacts with different types of integrins. It is considered to be a possible prognostic biomarker in certain tumor types; however, various splicing isoforms exist, which have not been investigated in melanoma. We aimed to define the relative expression pattern of five OPN isoforms and clarify the prognostic significance of the splice variants in melanoma. We also aimed to investigate the expression pattern of eight integrins in the same tumors. Gene expression analyses revealed that the relative expression of OPNa, OPNb, and OPNc is significantly higher in metastatic tumors compared to primary lesions (p < 0.01), whereas the expression of OPN4 and OPN5 was low in both. The more aggressive nodular melanomas had higher expression levels compared to the superficial spreading subtype (p ≤ 0.05). The relative expression of the eight tested integrins was low, with only the expression of ITGB3 being detectable in nodular melanoma (Median_log2 = 1.274). A positive correlation was found between Breslow thickness and the expression of OPNc variant, whereby thicker tumors (>4 mm) had significantly higher expression (p ≤ 0.05). The Breslow thickness was negatively correlated with the expression of OPN4, and similarly with ITGA2. OPNc also exhibited significant positive correlation with the presence of metastasis. Our data show that high expression of OPNa, OPNb, and especially OPNc and low expression of OPN4 and ITGA2 are associated with an advanced stage of tumor progression and poor prognosis in melanoma.

Vitamin D3 Repletion Improves Vascular Function, as Measured by Cardiorenal Biomarkers in a High-Risk African American Cohort

Background: 25-hydroxy vitamin D (Vit D)-deficiency is common among patients with chronic kidney disease (CKD) and contributes to cardiovascular disease (CVD). African Americans (AAs) suffer disproportionately from CKD and CVD, and 80% of AAs are Vit D-deficient. The impact of Vit D repletion on cardio-renal biomarkers in AAs is unknown. We examined Vit D repletion on full-length osteopontin (flOPN), c-terminal fibroblast growth factor-23 (FGF-23), and plasminogen activator inhibitor-1 (PAI-1), which are implicated in vascular and kidney pathology. Methods: We performed a randomized, placebo-controlled study of high-risk AAs with Vit D deficiency, treated with 100,000 IU Vit D3 (cholecalciferol; n = 65) or placebo (n = 65) every 4 weeks for 12 weeks. We measured kidney function (CKD-EPI eGFR), protein-to-creatinine ratio, vascular function (pulse wave velocity; PWV), augmentation index, waist circumference, sitting, and 24-h-ambulatory blood pressure (BP), intact parathyroid hormone (iPTH) and serum calcium at baseline and study end, and compared Vit D levels with laboratory variables. We quantified plasma FGF-23, PAI-1, and flOPN by enzyme-linked immunosorbent assay. Multiple regression analyzed the relationship between log flOPN, FGF-23, and PAI-1 with vascular and renal risk factors. Results: Compared to placebo, Vit D3 repletion increased Vit D3 2-fold (p < 0.0001), decreased iPTH by 12% (p < 0.01) and was significantly correlated with PWV (p < 0.009). Log flOPN decreased (p = 0.03), log FGF-23 increased (p = 0.04), but log PAI-1 did not change. Multiple regression indicated association between log flOPN and PWV (p = 0.04) and diastolic BP (p = 0.02), while log FGF-23 was associated with diastolic BP (p = 0.05), and a trend with eGFR (p = 0.06). Conclusion: Vit D3 repletion may reduce flOPN and improve vascular function in high risk AAs with Vit D deficiency.

Inhibiting vascular smooth muscle cell proliferation mediated by osteopontin via regulating gut microbial lipopolysaccharide: A novel mechanism for paeonol in atherosclerosis treatment

Background: Although the gut microbiota is involved in metabolic disease such as atherosclerosis, the underlying mechanism remains elusive. Paeonol (Pae) is a natural phenolic compound isolated from Cortex Moutan, which exhibits anti-atherosclerotic effects. Our previous research demonstrated gut microbiota as a site of Pae action. However, the mechanism by which Pae exerts its anti-atherosclerotic effect by the regulation of gut microbiota remains unclear.

Objective: To investigate a potential mechanistic link between the gut microbial lipopolysaccharide (LPS) and vascular smooth muscle cell (VSMC) proliferation in atherosclerosis progression and explore the possible role of Pae.

Methods: Experimental atherosclerosis was established in ApoE^−/− mice, and the atherosclerosis mice were treated with Pae for 4 weeks before being sacrificed for analyses while conducting fecal microbiota transplantation (FMT). The plaque area, levels of serum LPS, expressions of inflammatory factors in serum or aorta, and intestinal barrier permeability were determined. VSMCs were co-cultured with THP-1 cells. CCK-8 assay and EdU staining were performed to assess the proliferative capacity of VSMCs. Immunofluorescence staining was performed to observe the nuclear transfer of p65. Western blotting was used to detect the candidate protein expression level, and quantitative real-time PCR (qRT-PCR) was used to detect the mRNA expression level in tissues or cells of each group.

Results: During atherosclerosis progression, gut dysbiosis leads to the peripheral accumulation of gut microbial LPS, which acts as a trigger to stimulate osteopontin (OPN) production from circulating monocytes, inducing cell-to-cell crosstalk to promote VSMC proliferation in the aorta. Importantly, the elevation of LPS and OPN concentrations in the blood was also observed in patients with atherosclerosis. Pae could significantly improve atherosclerosis, suppress gut microbial LPS accumulation, and inhibit monocyte/macrophage activation and VSMC proliferation.

Conclusions: The present study provides a mechanistic scenario for how long-term stimulation of gut microbial LPS in circulating blood generates a pathological secondary response that leads to abnormal proliferation of VSMCs using high OPN expression in circulating monocytes and suggests a novel strategy for atherosclerosis therapy by remodeling the gut microbiota.

Poisoning by Nierembergia veitchii: Effects on vascular smooth muscle cells in the pathogenesis of enzootic calcinosis

Vascular mineralization is a hallmark of enzootic calcinosis. Histopathological, ultrastructural, and immunohistochemical investigations were performed on the external carotid arteries of seven sheep naturally poisoned by Nierembergia veitchii. Histologically, moderate to marked hyperplasia of the tunica intima was observed without mineralization. The tunica media exhibited mild to severe mineralization and osteochondroid metaplasia. Sheep with enzootic calcinosis showed arterial overexpression of osteopontin and tissue-nonspecific alkaline phosphatase and immunolabeling for osteonectin and osteocalcin in both intima and media layers of the tested arteries. The main ultrastructural finding in the tunica media was a marked phenotypic change of vascular smooth muscle cells from a contractile phenotype (VSMC-C) into a synthetic phenotype (VSMC-S). In the tunica media, VSMC-S produced matrix and extracellular vesicles, forming mineralizable granules associated with arterial mineralization. VSMC-S were also present in the tunica intima, but matrix and extracellular vesicles and mineralization were not observed. The absence of matrix and extracellular vesicles in the intimal hyperplasia, even in the presence of noncollagenous bone proteins, tissue-nonspecific alkaline phosphatase, and vitamin D receptors, reinforces the hypothesis that the presence of matrix and extracellular vesicles are crucial for the development of vascular mineralization in enzootic calcinosis. It is proposed that the two different VSMC-S phenotypes in calcinosis are due to the expression of at least two genetically different types of these cells induced by the action of 1,25(OH)₂D₃.

Aerobic Physical Exercise as a Non-medical Intervention for Brain Dysfunction: State of the Art and Beyond

Brain disorders, including stroke, Alzheimer's disease, depression, and chronic pain, are difficult to effectively treat. These major brain disorders have high incidence and mortality rates in the general population, and seriously affect not only the patient's quality of life, but also increases the burden of social medical care. Aerobic physical exercise is considered an effective adjuvant therapy for preventing and treating major brain disorders. Although the underlying regulatory mechanisms are still unknown, systemic processes may be involved. Here, this review aimed to reveal that aerobic physical exercise improved depression and several brain functions, including cognitive functions, and provided chronic pain relief. We concluded that aerobic physical exercise helps to maintain the regulatory mechanisms of brain homeostasis through anti-inflammatory mechanisms and enhanced synaptic plasticity and inhibition of hippocampal atrophy and neuronal apoptosis. In addition, we also discussed the cross-system mechanisms of aerobic exercise in regulating imbalances in brain function, such as the “bone-brain axis.” Furthermore, our findings provide a scientific basis for the clinical application of aerobic physical exercise in the fight against brain disorders.

Serum Osteopontin Level Is Positively Associated with Aortic Stiffness in Patients with Peritoneal Dialysis

Background: Osteopontin (OPN) is regarded as a proinflammatory and proatherogenic molecule related to atherosclerosis. We aimed to evaluate the relationship between serum OPN and aortic stiffness (AS) of peritoneal dialysis (PD) patients. Methods: OPN and carotid-femoral pulse wave velocity (cfPWV) were measured by a commercial enzyme-linked immunosorbent assay kit and a validated tonometry system, respectively. Patients with cfPWV > 10 m/s were designated into the AS group. Results: Twenty-two patients (31.4%) were segregated into the AS group. Multivariate linear and logistic regression analysis showed that OPN was significantly related to cfPWV and was an independent predictor of AS. The receiver operating characteristic curve analysis showed that OPN was correlated with AS with an area under the curve of 0.903 (95% CI 0.809−0.961, p < 0.001). Conclusions: For PD patients, the serum OPN level was correlated with cfPWV and could play an important role in the process of AS.

Possible causes of atherosclerosis: lncRNA COLCA1 induces oxidative stress in human coronary artery endothelial cells and impairs wound healing

Background

Atherosclerosis is the most common cause of cardiovascular disease, accompanied by high mortality and poor prognosis. Low-density lipoprotein (LDL) and its oxidized form oxidized low-density lipoprotein (oxLDL) play an important role in atherosclerosis. This article will explore the role of the lncRNA COLCA1 (colorectal cancer associated 1)/hsa-miR-371a-5p/SPP1 (secreted phosphoprotein 1) pathway in oxLDL in causing human coronary artery endothelial cells (HCAECs) inflammation and related biological function changes.

Methods

OxLDL was used to stimulate HCAECs. The inflammatory response and biological function changes of HCAECs were analyzed, total RNA-seq was performed on HCAECs before and after stimulation, and RT-Qpcr (real-time quantitative PCR) was used to verify the differential genes. Interference of the expression of COLCA1 in HCAECs was performed by siRNA interference technology to verify the role of COLCA1 in the biological function changes of HCAECs after oxLDL stimulation, and further prove that COLCA1 affects SPP1 through hsa-miR-371a-5p.

Results

OxLDL can affect the oxidative stress response of HCAECs, which in turn affects the apoptosis and wound healing ability of HCAECs. COLCA1 and SPP1 were highly expressed after oxLDL stimulation, while hsa-miR-371a-5p was the opposite. After COLCA1 interference, the oxidative stress level of HCAECs stimulated by oxLDL decreased, the apoptosis level also significantly decreased, and the wound healing ability was enhanced. After simultaneous COLCA1 interference and recovery of the expression of hsa-miR-371a-5p, these improved functions disappeared. The dual-luciferase assay confirmed that hsa-miR-371a-5p and COLCA1, hsa-miR-371a-5p and SPP1 has binding targets.

Conclusions

OxLDL can up-regulate the expression of COLCA1 in HCAECs, which in turn affects the intracellular COLCA1/hsa-miR-371a-5p/SPP1 pathway to regulate the level of oxidative stress in cells. This in turn affects the level of apoptosis and wound healing ability, which causes cells to produce a continuous inflammatory response.

The Role of Extracellular Matrix Proteins in Breast Cancer

The extracellular matrix is a structure composed of many molecules, including fibrillar (types I, II, III, V, XI, XXIV, XXVII) and non-fibrillar collagens (mainly basement membrane collagens: types IV, VIII, X), non-collagenous glycoproteins (elastin, laminin, fibronectin, thrombospondin, tenascin, osteopontin, osteonectin, entactin, periostin) embedded in a gel of negatively charged water-retaining glycosaminoglycans (GAGs) such as non-sulfated hyaluronic acid (HA) and sulfated GAGs which are linked to a core protein to form proteoglycans (PGs). This highly dynamic molecular network provides critical biochemical and biomechanical cues that mediate the cell–cell and cell–matrix interactions, influence cell growth, migration and differentiation and serve as a reservoir of cytokines and growth factors’ action. The breakdown of normal ECM and its replacement with tumor ECM modulate the tumor microenvironment (TME) composition and is an essential part of tumorigenesis and metastasis, acting as key driver for malignant progression. Abnormal ECM also deregulate behavior of stromal cells as well as facilitating tumor-associated angiogenesis and inflammation. Thus, the tumor matrix modulates each of the classically defined hallmarks of cancer promoting the growth, survival and invasion of the cancer. Moreover, various ECM-derived components modulate the immune response affecting T cells, tumor-associated macrophages (TAM), dendritic cells and cancer-associated fibroblasts (CAF). This review article considers the role that extracellular matrix play in breast cancer. Determining the detailed connections between the ECM and cellular processes has helped to identify novel disease markers and therapeutic targets.

Association of serum osteopontin with first hospitalization and all-cause mortality after kidney transplantation

Objective:

Osteopontin (OPN) is involved in vascular calcification and atherosclerosis. We evaluated the association between serum OPN levels and the first postoperative hospitalization and all-cause mortality in patients who received kidney transplantation (KT).

Materials and Methods:

Seventy KT recipients were enrolled in this study from January to April 2012. The primary end point was first postoperative hospitalization or death. All patients were monitored in the outpatient clinics until June 30, 2017. Serum OPN level was measured by enzyme-linked immunosorbent assay.

Results:

During follow-up (median length, 65 months), 47 first postoperative hospitalizations and 8 deaths occurred. In comparison with serum median OPN levels, serum OPN level was positively associated with KT duration (P = 0.048), serum blood urea nitrogen (BUN; P = 0.043), and serum creatinine levels (P = 0.045) but negatively associated with estimated glomerular filtration rate (eGFR; P = 0.049). Hospitalized KT recipients had a higher prevalence of diabetes mellitus (DM) (P = 0.032), BUN (P = 0.002), and serum OPN level (P = 0.001) but lower eGFR (P = 0.030) than did patients not hospitalized. KT recipients who died had higher serum level of creatinine (P = 0.009) and OPN (P = 0.001) but lower eGFR (P = 0.036) than did surviving patients. Multivariate Cox analysis adjusted for age, gender, DM, hypertension, eGFR, KT duration, and steroid used showed that serum OPN level was associated with both first postoperative hospitalization (P = 0.049) and all-cause mortality (P = 0.017).

Conclusions:

Serum OPN level is a potential biomarker for first postoperative hospitalization and all-cause mortality in KT recipients.

Osteopontin in Cardiovascular Diseases

Unprecedented advances in secondary prevention have greatly improved the prognosis of cardiovascular diseases (CVDs); however, CVDs remain a leading cause of death globally. These findings suggest the need to reconsider cardiovascular risk and optimal medical therapy. Numerous studies have shown that inflammation, pro-thrombotic factors, and gene mutations are focused not only on cardiovascular residual risk but also as the next therapeutic target for CVDs. Furthermore, recent clinical trials, such as the Canakinumab Anti-inflammatory Thrombosis Outcomes Study trial, showed the possibility of anti-inflammatory therapy for patients with CVDs. Osteopontin (OPN) is a matricellular protein that mediates diverse biological functions and is involved in a number of pathological states in CVDs. OPN has a two-faced phenotype that is dependent on the pathological state. Acute increases in OPN have protective roles, including wound healing, neovascularization, and amelioration of vascular calcification. By contrast, chronic increases in OPN predict poor prognosis of a major adverse cardiovascular event independent of conventional cardiovascular risk factors. Thus, OPN can be a therapeutic target for CVDs but is not clinically available. In this review, we discuss the role of OPN in the development of CVDs and its potential as a therapeutic target.

Proliferative Vascular Smooth Muscle Cells Stimulate Extracellular Matrix Production via Osteopontin/p38 MAPK Signaling Pathway

INTRODUCTION

Extracellular matrix disorder and cellular phenotype transformation are the major histopathological features associated with ascending aortic aneurysms. Rare studies have investigated the relationship between cellular phenotype transformation and the abnormalities of the matrix constituents. In this study, we investigated whether the cellular phenotype transformation resulted in the extracellular matrix disorder.

METHODS

Aortic samples were obtained from 20 patients undergoing operations for ascending aortic aneurysms. Control aortic samples were obtained from 15 patients who underwent coronary artery bypass graft. The protein levels of osteopontin (OPN), collagen, and elastin were examined using Western blot, and quantitative reverse transcriptase-PCR was used to analyze the mRNA expression of collagen and elastin. In vitro experiment, vascular smooth muscle cells (VSMCs) were treated with recombinant human OPN (rh-OPN) or p38 MAPK inhibitor (SB203580) to investigate whether OPN and p38 MAPK regulated the expression of collagen and elastin.

RESULTS

The protein level of OPN and collagen III increased in ascending aortic aneurysm samples, compared with controls (p < 0.05). There was no difference in the protein level of elastin between aneurysm tissues and the controls. VSMCs treated with rh-OPN increased the collagen III and elastin protein level and mRNA expression (p < 0.05). Cells treated with SB203580 decreased the collagen III and elastin protein level and mRNA expression (p < 0.05). Furthermore, VSMCs incubated with SB203580 reduced the rh-OPN-induced production of collagen III and elastin (p < 0.05).

CONCLUSION

OPN, the proliferative VSMCs maker, increased the expression of extracellular matrix. OPN/p38 MAPK signaling pathways may protect against ascending aortic aneurysm progression.

Osteocalcin, Osteopontin and RUNX2 Expression in Patients' Leucocytes with Arteriosclerosis

Introduction: Calcification is a highly relevant process in terms of development of cardiovascular diseases, and its prevention may be the key to prevent disease progression in patients. In this study we investigated the expression of osteocalcin (OC), osteopontin (OPN) and RUNX2 in patients’ leukocytes and their possible role as diagnostic markers for cardiovascular diseases. Materials and Methods: Leucocytes from 38 patients were collected in the Department of Surgery of Martin-Luther-University Halle, including 8 patients without arteriosclerotic disease (PAD−) and 30 patients with symptomatic arteriosclerotic disease (PAD+). Patients’ leucocytes, in vitro calcified human umbilical vein endothelial cells (HUVEC) and vascular smooth muscle cells (VSMC) were subjected to qPCR analyses with TaqMan probes, which are specific for OC, OPN and RUNX2. Additionally, the interaction between monocytes and calcified HUVEC and VSMC was investigated in adhesion assays. Results: The leucocytes obtained from patients with symptomatic arteriosclerotic disease (PAD+) demonstrated decreased mRNA level expression of Osteocalcin, while OPN and RUNX2 were significantly upregulated in comparison to asymptomatic patients. The induction of calcification in HUVEC and VSMC cells led to an increased expression of OC, OPN and RUNX2. Immunocytochemistry of calcified HUVEC and VSMC revealed stronger expression of OC, OPN and RUNX2 in calcified cells. Conclusion: To conclude, these data demonstrate that symptomatic arteriosclerotic disease has a correlation with OC, OPN and RUNX2. The biological rationale of OC, OPN and RUNX-2 remains not yet entirely understood for atherosclerotic disease, which means it needs further investigation.

Entelon (vitis vinifera seed extract) reduces degenerative changes in bovine pericardium valve leaflet in a dog intravascular implant model

Background and aims

Inflammation and calcification are major factors responsible for degeneration of bioprosthetic valve and other substitute heart valve implantations. The objective of this study was to evaluate the anti-inflammatory and anti-calcification effects of Entelon150^® (consisting of grape-seed extract) in a beagle dog model of intravascular bovine pericardium implantation.

Methods

In total, 8 healthy male beagle dogs were implanted with a bovine pericardium bilaterally in the external jugular veins and divided into two groups. Animals in the Entelon150^® group (n = 4) were treated with 150 mg of Entelon150^® twice daily for six weeks after surgery. The negative control (NC) group (n = 4) was treated with 5 ml of saline using the same method. After six weeks, we measured the calcium content, performed histological examination, and performed molecular analysis.

Results

The calcium content of implanted tissue in the Entelon150^® group (0.56±0.14 mg/g) was significantly lower than that in the NC group (1.48±0.57 mg/g) (p < 0.05). Histopathological examination showed that infiltration of chronic inflammatory cells, such as fibroblasts and macrophages, occurred around the graft in all groups; however, the inflammation level of the implanted tissue in the Entelon150^® group was s lower than that in the NC group. Both immunohistochemical and western blot analyses revealed that bone morphogenetic protein 2 expression was significantly attenuated in the Entelon150^® group.

Conclusions

Our results indicate that Entelon150^® significantly attenuates post-implantation inflammation and degenerative calcification of the bovine pericardium in dogs. Therefore, Entelon150^® may increase the longevity of the bovine pericardium after intravascular implantation.

Osteopontin Serum Concentration and Metabolic Syndrome in Male Psoriatic Patients

Psoriasis (Ps) is an immune-mediated inflammatory skin disease that is widely associated with the clinical features of metabolic syndrome (MetS), including hypertension, abdominal obesity, insulin resistance, type 2 diabetes and dyslipidemia. Osteopontin (OPN), a multifunctional protein involved in the modulation of inflammatory processes, may contribute to the development of atherosclerosis and MetS. Therefore, the aim of the study was the assessment of the correlation between OPN concentration in the peripheral blood and the presence of MetS as well as its particular components in the Ps patients. The study comprised 107 male Ps patients (50 patients with MetS and 57 without MetS) and 38 healthy volunteers (HVs). The concentration of OPN in serum was determined using enzyme-linked immunosorbent assay (ELISA) method. Fasting blood glucose and lipid profile components: total cholesterol (total CHOL), high-density lipoprotein cholesterol (HDL-CHOL), low-density lipoprotein cholesterol (LDL-CHOL), triglycerides (TG) were examined. Ps patients with MetS had significantly higher obesity, systolic blood pressure, TG, CHOL/HDL, LDL/HDL and TG/HDL ratios than Ps patients without MetS. OPN serum concentration was significantly higher in the Ps patients than in the HVs (p = 0.022) but not significantly different between the Ps patients with and without MetS (p = 0.275). OPN serum concentration in Ps patients correlated negatively with total CHOL (p = 0.004) and TG (p = 0.009). OPN is increased in Ps patients and may serve as a biomarker of some lipid abnormalities in them.

Cerebrospinal Fluid Biomarkers of Alzheimer's Disease: Current Evidence and Future Perspectives

Alzheimer's disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ42), which diagnose Alzheimer's disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer's disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer's disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer's disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.

Osteoprotegerin and Osteopontin Serum Levels are Associated with Vascular Function and Inflammation in Coronary Artery Disease Patients

BACKGROUND

Osteoprotegerin and osteopontin have recently emerged as key factors in both vascular remodelling and atherosclerosis progression. Interleukin-6 (IL-6) is an inflammatory cytokine with a key role in atherosclerosis. The relationship of osteoprotegerin, osteopontin, and IL-6 serum levels with endothelial function and arterial stiffness was evaluated in patients with coronary artery disease (CAD).

METHODS

We enrolled 219 patients with stable CAD and 112 control subjects. Osteoprotegerin, osteopontin and IL-6 serum levels were measured using an ELISA assay. Endothelial function was evaluated by flow-mediated dilation (FMD) in the brachial artery and carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness.

RESULTS

There was no significant difference between control subjects and CAD patients according to age and sex. Compared with control subjects, CAD patients had significantly impaired FMD (p<0.001) and increased PWV (p=0.009). CAD patients also had significantly higher levels of osteoprotegerin (p<0.001), osteopontin (p<0.001) and IL-6 (p=0.03), compared with control subjects. Moreover, IL-6 levels were correlated with osteoprotegerin (r=0.17, p=0.01) and osteopontin (r=0.30, p<0.001) levels. FMD was correlated with osteoprotegerin levels independent of possible confounders [b coefficient= - 0.79, 95% CI (-1.54, -0.05), p=0.04].

CONCLUSION

CAD patients have increased osteoprotegerin, osteopontin and IL-6 levels. Moreover, there is a consistent association between osteoprotegerin and osteopontin serum levels, vascular function and inflammation in CAD patients. These findings suggest another possible mechanism linking osteoprotegerin and osteopontin serum levels with CAD progression through arterial wall stiffening and inflammation.

Relationship Between Plasma Osteopontin and Arginine Pathway Metabolites in Patients With Overt Coronary Artery Disease

Introduction

Osteopontin (OPN) is involved in ectopic calcification. Its circulating form is upregulated in coronary artery disease (CAD) patients. Circulating OPN levels positively correlate with oxidative stress, one of the major triggers of endothelial dysfunction. Endothelial dysfunction is, in turn, associated with reduced nitric oxide (NO) bioavailability due to the impaired arginine pathway. The aim of this study was to better understand the correlations between OPN, oxidative stress markers, and the arginine pathway metabolites.

Methods and Results

ELISA and mass spectrometry techniques have been used to evaluate circulating OPN and arginine pathway/oxidative stress metabolites, respectively, in twenty-five control subjects and thirty-three patients with overt atherosclerosis. OPN positively correlates with 2,3-dinor-8isoPGF2a levels (p = 0.02), ornithine (p = 0.01), ADMA (p = 0.001), SDMA (p = 0.03), and citrulline (p = 0.008) levels only in CAD patients. In addition, citrulline positively correlated with ADMA (p = 0.02) levels, possibly as result of other sources of citrulline biosynthetic pathways.

Conclusion

The association between OPN and impaired arginine/NO pathway could play a role in the inhibition of endothelial NO synthase (eNOS) and/or in the arginase activation in the context of CAD patients. However, further studies are needed to verify the cause-effect relationship between OPN, oxidative stress, and arginine/NO pathway dysregulation.

The preliminary association study of osteopontin 707 C/T polymorphism with systemic lupus erythematosus in a Polish population

Introduction

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease caused by genetic, environmental, and still unknown factors which lead to deregulation of the immune system. Osteopontin (OPN) is a multifunctional glycoprotein, expressed in various cell types, and found to play key roles in immunity. OPN and variants of the OPN gene are involved in inflammatory conditions, however, their role in SLE are controversial.

Aim

To investigate the frequency of single nucleotide polymorphism (SNP) rs1126616 (707 C/T) variants in the OPN gene and its associations with SLE manifestations in Polish patients.

Material and methods

The study population consisted of 83 SLE patients and 100 gender-, age- and ethnically matched healthy controls. DNA was extracted from whole blood samples using the standard procedure. Genotyping was performed by real-time polymerase chain reaction (RT-PCR). The association between clinical features of SLE and 707 C/T genotypes was determined.

Results

The mutant (CT, TT) genotypes were observed more frequently than the wild-type (CC) genotype in SLE patients compared to controls (p = 0.037). However, no association between 707 C/T variants and SLE clinical manifestations or laboratory parameters was found.

Conclusions

The present data suggest that CT and TT genotypes of OPN 707 C/T SNP are associated with a higher SLE risk, but do not affect the clinical course of the disease in the Polish population.

Deletion of interleukin-18 attenuates abdominal aortic aneurysm formation

BACKGROUND AND AIMS

Abdominal aortic aneurysm (AAA) is a common disease; however, its exact pathogenesis remains unknown, and no specific medical therapies are available. Interleukin (IL)-18 plays a crucial role in atherosclerotic plaque destabilization and is a strong predictor of cardiovascular death. Here, we investigated the role of IL-18 in AAA pathogenesis using an experimental mouse model.

METHODS AND RESULTS

After infusion of angiotensin II (Ang II) for 4 weeks and β-aminopropionitrile (BAPN) for 2 weeks, 58% of C57/6J wild-type (WT) mice developed AAA associated with enhanced expression of IL-18; however, disease incidence was significantly lower in IL-18^-/- mice than in WT mice (p < 0.01), although no significant difference was found in systolic blood pressure between WT mice and IL-18^-/- mice in this model. Additionally, IL-18 deletion significantly attenuated Ang II/BAPN-induced macrophage infiltration, macrophage polarization into inflammatory M1 phenotype, and matrix metalloproteinase (MMP) activation in abdominal aortas, which is associated with reduced expression of osteopontin (OPN).

CONCLUSIONS

These findings indicate that IL-18 plays an important role in the development of AAA by enhancing OPN expression, macrophage recruitment, and MMP activation. Moreover, IL-18 represents a previously unrecognized therapeutic target for the prevention of AAA formation.

Increased Extracellular Osteopontin Levels in Normal Human Breast Tissue at High Risk of Developing Cancer and Its Association With Inflammatory Biomarkers in situ

Mammographic breast density is a strong independent risk factor for breast cancer (BC), but the molecular mechanisms behind this risk is yet undetermined and prevention strategies for these women are lacking. The anti-estrogen tamoxifen may reduce the risk of BC but this treatment is associated with severe side effects. Thus, other means for BC prevention, such as diet interventions, need to be developed. Osteopontin (OPN) is a major mediator of inflammation which is key in carcinogenesis. OPN may be cleaved by proteases in the tissue and cleaved OPN may in turn induce an inflammatory cascade in the extracellular microenvironment. We aimed to determine if extracellular OPN was altered in BC and in normal breast tissue with different densities and if tamoxifen or a diet of flaxseed could modify OPN levels. The study comprised 103 women; 13 diagnosed with BC, 42 healthy post-menopausal women with different breast densities at their mammography screen, and 34 post-menopausal women who added 25 g of ground flaxseed/day or were treated with tamoxifen 20 mg/day and were investigated before and after 6 weeks of exposure. Additionally, 10 premenopausal women who added flaxseed for one menstrual cycle and four who were investigated in two unexposed consecutive luteal phases of the menstrual cycle. Microdialysis was used to sample extracellular proteins in vivo in breast tissue and proteins were quantified using a multiplex proximity extension assay. We found that, similar to BC, extracellular in vivo OPN levels were significantly increased in dense breast tissue. Additionally, significant correlations were found between OPN and chemokine (C-X-C motif) ligand (CXCL)-1, −8, −9, −10, and −11, interleukin-6, vascular endothelial growth factor, matrix metalloproteinase (MMP)-1, −2, −3, 7, and −12 and urokinase-type plasminogen activator whereas no correlations were found with MMP-9, chemokine (C-C motif) ligand (CCL)-2, and −5. Estradiol did not affect OPN levels in breast tissue. None of the interventions altered OPN levels. The pro-tumorigenic protein OPN may indeed be a molecular target for BC prevention in women with increased breast density but other means than tamoxifen or flaxseed i.e., more potent anti-inflammatory approaches, need to be evaluated for this purpose.

The rs1126616 Single Nucleotide Polymorphism of the Osteopontin Gene Is Independently Associated with Cardiovascular Events in a Chronic Kidney Disease Cohort

Chronic kidney disease (CKD) is associated with a higher risk of cardiovascular events (CVE), partly due to the higher burden of atherosclerosis. Circulating Osteopontin (OPN) levels have been also shown to have a potential role in the development of atherosclerosis. Indeed, CKD patients show an increase in circulating OPN levels, but their effect of CKD-related atherosclerosis is not clear. Polymorphisms in the OPN gene (SPP1) have been studied in atheromatous disease, but reported results show conflictive findings. Thus, the main aim of the present study is to analyze the influence of SPP1 polymorphisms in CVE in CKD patients, taking into account circulating OPN levels. We followed 559 healthy controls and 2445 CKD patients without previous CVE from the National Observatory of Atherosclerosis in Nephrology study (NEFRONA study). After 48 months of follow-up 206 CVE were recorded. Genotyping for rs9138, rs1126616, rs1126772, rs11730582 and rs28357094 polymorphisms of the SPP1 gene was performed along with the measurements of plasma OPN levels. The group of patients with CVE showed higher incidence of atherosclerotic plaque (90.3% vs 64.5%; p < 0.001) and higher OPN levels (p < 0.001) at baseline. Patients with the heterozygous genotype of the rs1126616 polymorphism showed a higher hazard ratio of having a CVE, even after adjustment for multiple potential confounders. After adjustment, OPN levels were no longer associated with the incidence of CVE. We found that the rs1126616 single nucleotide polymorphism (SNP) of the SPP1 gene is independently associated with a higher incidence of CVE in a cohort of CKD patients and that it could be used to predict CVE risk.

THE EFFECT OF ANTITHYROID DRUGS ON OSTEOPONTIN AND OXIDATIVE STRESS IN GRAVES' DISEASE

OBJECTIVE

The aim of the present study is to evaluate the effects of methimazole (MTZ) and propylthiouracil (PTU) treatments on osteopontin (OPN) and oxidative stress in Graves' disease (GD).

MATERIAL AND METHODS

The study included 60 cases with GD in hyperthyroid state and taking no antithyroid treatment, and 30 healthy volunteers. GD patients were randomly separated into two groups; 30 of them took PTU, and the other 30 took MTZ treatments. Blood samples were taken from the patients with GD before the treatment, and three months after the treatment was begun, when they were in the euthyroid state; blood samples of the healthy control subjects were also taken at these times.

RESULTS

TAS and OSI levels before treatment were significantly higher in the GD group, when compared to the control group (p<0.001, for each). GD subjects taking PTU treatment had significantly higher TAS levels (p=0.001), and significantly lower TOS and OSI levels (p=0.008 and p=0.001, respectively). TAS levels significantly decreased in the patients taking MTZ treatment (p=0.029), but TOS and OSI levels did not change significantly (p>0.05). Pretreatment OPN levels were significantly higher in GD patients, when compared to the control group (p=0.014). OPN level significantly decreased in the GD group taking PTU treatment; however OPN levels in the group taking MTZ treatment did not change significantly when compared to the pretreatment value.

CONCLUSION

PTU treatment is more effective in decreasing OPN and oxidative stress in GD patients, when compared to the MTZ treatment.

In Search of the Ideal Valve: Optimizing Genetic Modifications to Prevent Bioprosthetic Degeneration

BACKGROUND

Bioprosthetic heart valves undergo structural degeneration and calcification. Similarities exist in the histopathologic features of explanted bioprosthetic valves and rejected pig tissues and organs after xenotransplantation into nonhuman primates. The development of more durable bioprosthetic valves, namely from genetically modified pigs, could negate the need for the insertion of mechanical prostheses in children and young adults with the requirement for life-long anticoagulation and might avoid the need for reoperation in elderly patients.

METHODS

We reviewed the literature (MedlinePlus, PubMed, Google Scholar) through September 1, 2018, under four key terms: (1) bioprosthetic heart valves, (2) xenograft antigens, (3) immunologic responses to bioprosthetic valves, and (4) genetic modification of xenografts.

RESULTS

Advances in tissue and organ xenotransplantation have elucidated important immunologic barriers that provide innovative approaches to prevent structural degeneration of bioprosthetic heart valves. The current evidence suggests that bioprosthetic valves derived from genetically modified pigs lacking xenogeneic antigens (namely Gal, Neu5Gc, and Sda), termed triple-knockout pigs, would function considerably longer than current wild-type (genetically unmodified) porcine valves in human recipients.

CONCLUSIONS

Preclinical and clinical studies to determine the safety and efficacy of triple-knockout porcine bioprosthetic valves will likely establish that they are more resistant to human immune responses and thus less susceptible to structural degeneration.

Stiffness of Aligned Fibers Regulates the Phenotypic Expression of Vascular Smooth Muscle Cells

Electrospun uniaxially aligned ultrafine fibers show great promise in constructing vascular grafts mimicking the anisotropic architecture of native blood vessels. However, understanding how the stiffness of aligned fibers would impose influences on the functionality of vascular cells has yet to be explored. The present study aimed to explore the stiffness effects of electrospun aligned fibrous substrates (AFSs) on phenotypic modulation in vascular smooth muscle cells (SMCs). A stable jet coaxial electrospinning (SJCES) method was employed to generate highly aligned ultrafine fibers of poly(l-lactide- co-caprolactone)/poly(l-lactic acid) (PLCL/PLLA) in shell-core configuration with a remarkably varying stiffness region from 0.09 to 13.18 N/mm. We found that increasing AFS stiffness had no significant influence on the cellular shape and orientation along the fiber direction with the cultured human umbilical artery SMCs (huaSMCs) but inhibited the cell adhesion rate, promoted cell proliferation and migration, and especially enhanced the F-actin fiber assembly in the huaSMCs. Notably, higher fiber stiffness resulted in significant downregulation of contractile markers like alpha-smooth muscle actin (α-SMA), smooth muscle myosin heavy chain, calponin, and desmin, whereas upregulated the gene expression of pathosis-associated osteopontin ( OPN) in the huaSMCs. These results allude to the phenotype of huaSMCs on stiffer AFSs being miserably modulated into a proliferative and pathological state. Consequently, it adversely affected the proliferation and migration behavior of human umbilical vein endothelial cells as well. Moreover, stiffer AFSs also revealed to incur significant upregulation of inflammatory gene expression, such as interleukin-6 ( IL-6), monocyte chemoattractant protein-1 ( MCP-1), and intercellular adhesion molecule-1 ( ICAM-1), in the huaSMCs. This study stresses that although electrospun aligned fibers are capable of modulating native-like oriented cell morphology and even desired phenotype realization or transition, they might not always direct cells into correct functionality. The integrated fiber stiffness underlying is thereby a critical parameter to consider in engineering structurally anisotropic tissue-engineered vascular grafts to ultimately achieve long-term patency.

Osteogenic capacity of diluted platelet-rich plasma in ectopic bone-forming model: Benefits for bone regeneration

Platelet-rich plasma (PRP) with normal and below-normal physiological concentrations of platelets is designated as diluted PRP (dPRP). The aims of this study are to evaluate whether bone mineral matrix in combination with dPRP possesses osteogenic capacity; and whether the differences in dynamics and osteogenic process pattern depend on different platelet concentrations, to what extent, and also what could be benefits for bone regeneration in clinical practice. Three types of implants were made: BMM-bone mineral matrix alone; dPRP/10-bone mineral matrix mixed with dPRP (concentration of platelets 10 times lower than physiological level) and dPRP/3-bone mineral matrix mixed with dPRP (concentration of platelets 3 times lower than physiological level). A subcutaneous implantation model in Balb/c mice was used. The implants were analyzed using expression analysis of bone-related genes, histochemical, immunohistochemical and histomorphometrical analysis. All types of implants induced creation of necessary preconditions for supporting osteogenic processes, but did not induce visible young bone growth. Implant types dPRP/10 and dPRP/3 showed very similar and significantly better stimulatory effects on osteogenic processes than bone matrix alone. In this study, significant ectopic osteogenic potential of concentration of platelets in PRP that are lower than physiological level in blood plasma in combination with bone mineral matrix was demonstrated. Diluted platelet-rich plasma could be a promising and useful adjuvant therapeutic agent in bone regeneration.

Vascular Stem/Progenitor Cell Migration and Differentiation in Atherosclerosis

SIGNIFICANCE

Atherosclerosis is a major cause for the death of human beings, and it takes place in large- and middle-sized arteries. The pathogenesis of the disease has been widely investigated, and new findings on vascular stem/progenitor cells could have an impact on vascular regeneration. Recent Advances: Recent studies have shown that abundant stem/progenitor cells present in the vessel wall are mainly responsible for cell accumulation in the intima during vascular remodeling. It has been demonstrated that the mobilization and recruitment of tissue-resident stem/progenitor cells give rise to endothelial and smooth muscle cells (SMCs) that participate in vascular repair and remodeling such as neointimal hyperplasia and arteriosclerosis. Interestingly, cell lineage tracing studies indicate that a large proportion of SMCs in neointimal lesions is derived from adventitial stem/progenitor cells.

CRITICAL ISSUES

The influence of stem/progenitor cell behavior on the development of atherosclerosis is crucial. An understanding of the regulatory mechanisms that control stem/progenitor cell migration and differentiation is essential for stem/progenitor cell therapy for vascular diseases and regenerative medicine.

FUTURE DIRECTIONS

Identification of the detailed process driving the migration and differentiation of vascular stem/progenitor cells during the development of atherosclerosis, discovery of the environmental cues, and signaling pathways that control cell fate within the vasculature will facilitate the development of new preventive and therapeutic strategies to combat atherosclerosis. Antioxid. Redox Signal. 00, 000-000.

Precise theranostic nanomedicines for inhibiting vulnerable atherosclerotic plaque progression through regulation of vascular smooth muscle cell phenotype switching

Coronary heart disease is a prevalent and fatal killer caused by vulnerable atherosclerotic plaques (VASPs). However, the precise detection and treatment of VASPs remains a difficult challenge. Here, we present the development of noninvasive human serum albumin (HSA)-based theranostic nanomedicines (NMs) for the specific diagnosis and effective therapy of VASPs.

Methods: The ICG/SRT@HSA-pept NMs were formulated to contain payloads of the near-infrared (NIR) fluorescent dye indocyanine green (ICG) and the sirtuin 1 (Sirt1) activator SRT1720, and modified with a peptide moiety targeting osteopontin (OPN). The in vivo atherosclerotic mouse model was established with the high-fat diet (HFD). The in vitro vascular smooth muscle cells (VSMCs) phenotypic switching was induced using the ox-LDL stimulation.

Results: Due to the overexpression of OPN in activated VSMCs and VASPs, the targeted NMs specifically accumulated within the VASPs region after intravenous injection into the atherosclerotic mice, achieving the precise detection of VASPs. In addition, in the presence of SRT1720, the NMs could activate intracellular Sirt1 and activate an antiatherogenesis effect by inhibiting the phenotypic switching of VSMCs, which is an essential contributor to the vulnerability and progression of atherosclerotic plaques. After therapeutic administration of the ICG/SRT@HSA-pept NMs for two weeks, the physiological sizes and plaque compositions of VASPs were markedly improved. Furthermore, ICG/SRT@HSA-pept NMs-treated mice presented a more favorable plaque phenotype than that was observed in free SRT1720-treated mice, suggesting the enhanced delivery of pharmaceutical agents to the atherosclerotic lesions and improved therapeutic efficacy of NMs compared with free SRT1720.

Conclusions: The theranostic ICG/SRT@HSA-pept NMs showed great potential for the precise identification and targeted treatment of atherosclerotic diseases.

Reducing immunoreactivity of porcine bioprosthetic heart valves by genetically-deleting three major glycan antigens, GGTA1/β4GalNT2/CMAH

Bioprosthetic heart valves (BHVs) originating from pigs are extensively used for heart valve replacement in clinics. However, recipient immune responses associated with chronic calcification lead to structural valve deterioration (SVD) of BHVs. Two well-characterized epitopes on porcine BHVs have been implicated in SVD, including galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc) whose synthesis are catalyzed by α(1,3) galactosyltransferase (encoded by the GGTA1 gene) and CMP-Neu5Ac hydroxylase (encoded by the CMAH gene), respectively. It has been reported that BHV from αGal-knockout pigs are associated with a significantly reduced immune response by human serum. Moreover, valves from αGal/Neu5Gc-deficient pigs could further reduce human IgM/IgG binding when compared to BHV from αGal-knockout pigs. Recently, another swine xenoantigen, Sd(a), produced by β-1,4-N-acetyl-galactosaminyl transferase 2 (β4GalNT2), has been identified. To explore whether tissue from GGTA1, CMAH, and β4GalNT2 triple gene-knockout (TKO) pigs would further minimize human antibody binding to porcine pericardium, TKO pigs were successfully produced by CRISPR/Cas9 mediated gene targeting. Our results showed that the expression of αGal, Neu5G and Sd(a) on TKO pigs was negative, and that human IgG/IgM binding to pericardium was minimal. Moreover, the analysis of collagen composition and physical characteristics of porcine pericardium from the TKO pigs indicated that elimination of the three xenoantigens had no significant impact on the physical proprieties of porcine pericardium. Our results demonstrated that TKO pigs would be an ideal source of BHVs.

STATEMENT OF SIGNIFICANCE

Surgical heart valve replacement is an established lifesaving treatment for diseased heart valve. Bioprosthetic heart valves (BHVs) made from glutaraldehyde-fixed porcine or bovine tissues are widely used in clinics but exhibit age-dependent structural valve degeneration (SVD) which is associated with the immune response against BHVs. Three major xenoantigens present on commercial BHVs, Galactosea α1,3 galactose (αGal), N-glycolylneuraminic acid (Neu5Gc) and glycan products of β-1,4-N-acetyl-galactosaminyl transferase 2 (β4GalNT2) are eliminated through CRISPR/Cas9 mediated gene targeting in the present study. The genetically modified porcine pericardium showed reduced immunogenicity but comparable collagen composition and physical characteristics of the pericardium from wild-type pigs. Our data suggested that BHVs from TKO pigs is a promising alternative for currently available BHVs from wild-type pigs.

Characterization of voiding function and structural bladder changes in a rat model of neurogenic underactive bladder disease

OBJECTIVES

To create an animal model for neurogenic underactive bladder disease (UAB) and identify markers to describe secondary myogenic changes in the bladder wall.

MATERIALS AND METHODS

Male rats underwent either bilateral pelvic nerve injury or sham surgery. Four weeks after surgery functional evaluation was performed and tissue was harvested. Functional evaluation consisted of analysis of voiding pattern, 24-h urine collection in a metabolic cage, in vivo cystometry and in-vitro contractile function assessment. PCR and immunohistochemical localization of different smooth muscle cell and extracellular matrix markers was performed on bladder strips.

RESULTS

After pelvic nerve injury, dry bladder weight increased and voiding contractions were absent, resulting in overflow incontinence. In-vitro contractile response to carbachol was decreased. This was paired with an upregulation of synthetic smooth muscle cell (SMC) markers mRNA expression such as retinol binding protein 1 (RBP1), myosin 10 (MYH10) and osteopontin (OPN), and a downregulation of contractile SMC marker smoothelin (SMTL). The SMTL/OPN mRNA ratio was 50 times higher in sham bladders compared to PNI bladders.

CONCLUSIONS

The loss of in-vivo and in-vitro contractile function following pelvic nerve transection is characterized by a switch from a contractile to synthetic SMC phenotype, which is best characterized by the ratio SMTL/OPN mRNA expression. Modulating this phenotypical switch is a potential target for the development of UAB therapy. We suggest for the first time a set of markers that may be useful to evaluate therapeutic strategies on improvements in bladder wall structure.

Sodium-DNA for Bone Tissue Regeneration: An Experimental Study in Rat Calvaria

Surgical techniques in dental and maxillofacial surgery request fast bone tissue regeneration, so there is a significant need to improve therapy for bone regeneration. Several studies have recently underlined the importance of nucleotides and nucleosides to increase cell proliferation and activity; in particular, the ability of polydeoxyribonucleotide (PDRN) to induce growth and activity of human osteoblasts was demonstrated. Sodium-DNA is the deoxyribonucleic acid (DNA) extracted from the gonadic tissue of male sturgeon and then purified, depolymerized, and neutralized with sodium hydroxide. To date, there are no evidences about the use of Sodium-DNA for bone tissue regeneration. Consequently, our question is about the efficacy of Sodium-DNA in bone healing. For testing the role of Sodium-DNA in bone healing we used a rat calvarial defect model. Sodium-DNA at different concentrations used alone or in association with Fibrin and/or Bio-Oss was used for healing treatments and the bone healing process was evaluated by histomorphometric and immunohistochemical analyses. Our results suggested a positive effect of Sodium-DNA in bone regeneration, providing a useful protocol and a model for the future clinical evaluation of its osteogenic properties.

Effect of Phosphorylation on a Human-like Osteopontin Peptide

The last decade established that the dynamic properties of the phosphoproteome are central to function and its modulation. The temporal dimension of phosphorylation effects remains nonetheless poorly understood, particularly for intrinsically disordered proteins. Osteopontin, selected for this study due to its key role in biomineralization, is expressed in many species and tissues to play a range of distinct roles. A notable property of highly phosphorylated isoforms of osteopontin is their ability to sequester nanoclusters of calcium phosphate to form a core-shell structure, in a fluid that is supersaturated but stable. In Biology, this process enables soft and hard tissues to coexist in the same organism with relative ease. Here, we extend our understanding of the effect of phosphorylation on a disordered protein, the recombinant human-like osteopontin rOPN. The solution structures of the phosphorylated and unphosphorylated rOPN were investigated by small-angle x-ray scattering and no significant changes were detected on the radius of gyration or maximum interatomic distance. The picosecond-to-nanosecond dynamics of the hydrated powders of the two rOPN forms were further compared by elastic and quasi-elastic incoherent neutron scattering. Phosphorylation was found to block some nanosecond side-chain motions while increasing the flexibility of other side chains on the faster timescale. Phosphorylation can thus selectively change the dynamic behavior of even a highly disordered protein such as osteopontin. Through such an effect on rOPN, phosphorylation can direct allosteric mechanisms, interactions with substrates, cofactors and, in this case, amorphous or crystalline biominerals.

The embryonic type of SPP1 transcriptional regulation is re-activated in glioblastoma

Osteopontin (SPP1, a secreted phosphoprotein 1) is primarily involved in immune responses, tissue remodelling and biomineralization. However, it is also overexpressed in many cancers and regulates tumour progression by increasing migration, invasion and cancer stem cell self-renewal. Mechanisms of SPP1 overexpression in gliomas are poorly understood. We demonstrate overexpression of two out of five SPP1 isoforms in glioblastoma (GBM) and differential isoform expression in glioma cell lines. Up-regulated SPP1 expression is associated with binding of the GLI1 transcription factor to the promoter and OCT4 (octamer-binding transcription factor 4) to the first SPP1 intron of the SPP1 gene in human glioma cells but not in non-transformed astrocytes. GLI1 knockdown reduced SPP1 mRNA and protein levels in glioma cells. GLI1 and OCT4 are known regulators of stem cell pluripotency. GBMs contain rare cells that express stem cell markers and display ability to self-renew. We reveal that SPP1 is overexpressed in glioma initiating cells defined by high rhodamine 123 efflux, sphere forming capacity and stemness marker expression. Forced differentiation of human glioma spheres reduced SPP1 expression. Knockdown of SPP1, GLI1 or CD44 with siRNAs diminished sphere formation. C6 glioma cells stably depleted of Spp1 displayed reduced sphere forming capacity and downregulated stemness marker expression. Overexpression of the wild type Spp1, but not Spp1 lacking a Cd44 binding domain, rescued cell ability to form spheres. Our findings show re-activation of the embryonic-type transcriptional regulation of SPP1 in malignant gliomas and point to the importance of SPP1-CD44 interactions in self-renewal and pluripotency glioma initiating cells.