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

Glucose-dependent insulinotropic polypeptide (GIP)

BACKGROUND

Glucose-dependent insulinotropic polypeptide (GIP) was the first incretin identified and plays an essential role in the maintenance of glucose tolerance in healthy humans. Until recently GIP had not been developed as a therapeutic and thus has been overshadowed by the other incretin, glucagon-like peptide 1 (GLP-1), which is the basis for several successful drugs to treat diabetes and obesity. However, there has been a rekindling of interest in GIP biology in recent years, in great part due to pharmacology demonstrating that both GIPR agonism and antagonism may be beneficial in treating obesity and diabetes. This apparent paradox has reinvigorated the field, led to new lines of investigation, and deeper understanding of GIP.

SCOPE OF REVIEW

In this review, we provide a detailed overview on the multifaceted nature of GIP biology and discuss the therapeutic implications of GIPR signal modification on various diseases.

MAJOR CONCLUSIONS

Following its classification as an incretin hormone, GIP has emerged as a pleiotropic hormone with a variety of metabolic effects outside the endocrine pancreas. The numerous beneficial effects of GIPR signal modification render the peptide an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, drug-induced nausea and both bone and neurodegenerative disorders.

Targeting of AMPK/MTOR signaling in the management of atherosclerosis: Outmost leveraging

Atherosclerosis (AS) is a chronic vascular disorder that is characterized by the thickening and narrowing of arteries due to the development of atherosclerotic plaques. The traditional risk factors involved in AS are obesity, type 2 diabetes (T2D), dyslipidemia, hypertension, and smoking. Furthermore, non-traditional risk factors for AS, such as inflammation, sleep disturbances, physical inactivity, air pollution, and alterations of gut microbiota, gained attention in relation to the pathogenesis of AS. Interestingly, the pathogenesis of AS, is complex and related to different abnormalities of cellular and sub-cellular signaling pathways. It has been illustrated that AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (MTOR) pathways are involved in AS pathogenesis. Mounting evidence indicated that AMPK plays a critical role in attenuating the development of AS by activating autophagy, which is impaired during atherogenesis. AMPK has a vasculoprotective effect by reducing lipid accumulation, inflammatory cell proliferation, and the release of pro-inflammatory cytokines, as well as decreasing inflammatory cell adhesion to the vascular endothelium. AMPK activation by metformin inhibits the migration of vascular smooth muscle cells (VSMCs) and AS development. However, the MTOR pathway contributes to AS by inhibiting autophagy, highlighting autophagy as a crucial link between the AMPK and MTOR pathways in AS pathogenesis. The MTOR is a key inducer of endothelial dysfunction and is involved in the development of AS. Therefore, both the AMPK and MTOR pathways play a crucial role in the pathogenesis of AS. However, the exact role of AMPK and MTOR pathways in the pathogenesis of AS is not fully clarified. Therefore, this review aims to discuss the potential role of the AMPK/MTOR signaling pathway in AS, and how AMPK activators and MTOR inhibitors influence the development and progression of AS. In conclusion, AMPK activators and MTOR inhibitors have vasculoprotective effects against the development and progression of AS.

Neural repair function of osteopontin in stroke and stroke‑related diseases (Review)

Stroke, including hemorrhagic stroke and ischemic stroke, is a common disease of the central nervous system. It is characterized by a high mortality and disability rate and is closely associated with atherosclerosis, hypertension hyperglycemia, atrial fibrillation and unhealthy living habits. The continuous development of surgery and medications has decreased the mortality rate of patients with stroke and has greatly improved the disease prognosis. At present, the direction of clinical treatment and research has gradually shifted to the repair of nerve function after stroke. Osteopontin (OPN) is a widely distributed extracellular matrix protein. Due to its structural characteristics, OPN can be cut and modified into terminal fragments with different functions, which play different roles in various pathophysiological processes, such as formation of tumors, inflammation and autoimmune diseases. It has also become a potential diagnostic and therapeutic marker. In order to comprehensively analyze the specific role of OPN in nerve repair and its relationship with stroke and stroke-related diseases, the following key words were used: 'Osteopontin, stroke, atherosis, neuroplasticity, neural repair'. PubMed, Web of Science and Cochrane articles related to OPN were searched and summarized. The present review describes the OPN structure, isoforms, functions and its neural repair mechanism, and its association with the occurrence and development of stroke and related diseases was explored.

The Bone-Vascular Axis: A Key Player in Chronic Kidney Disease Associated Vascular Calcification

Background

The bone-vascular axis plays a key role in the pathogenesis of vascular calcification (VC) in patients with chronic kidney disease (CKD). Understanding and managing the role of the bone-vascular axis in CKD-mineral and bone disorder (CKD-MBD) is critical for preventing and treating associated complications, including osteoporosis, arterial calcification, and cardiovascular diseases. This study aimed to comprehensively summarize the role of bone metabolism markers in uremic VC.

Summary

The skeleton, as an endocrine organ, can regulate systemic metabolic processes by secreting various bioactive substances. These molecules can induce the transdifferentiation of vascular smooth muscle cells, promoting their transition to other functional states, thereby affecting vascular growth and remodeling.

Key Messages

The prevalence of VC in individuals with CKD is notably high. CKD-associated VC is characterized by the widespread accumulation of hydroxyapatite within the arterial media, which occurs as a result of the transformation of smooth muscle cells into osteoblastic smooth muscle cells under the influence of uremic toxins. Osteoblasts and osteoclasts in bone tissue secrete mineral metabolic proteins, which can influence neighboring cells, primarily vascular smooth muscle cells, through paracrine signaling. Both circulating and osteocytic sclerostin can exert a protective effect by inhibiting wingless/integrated (WNT)-induced calcification. The therapeutic goal for CKD-MBD is to reduce production of sclerostin by decreasing the osteogenic transdifferentiation of vascular smooth muscle cells. Calciprotein particles act as a physiological agent for delivering calcium-phosphate the bone and inducing fibroblast growth factor-23 expression in osteoblasts.

Osteopontin and Clinical Outcomes in Hemodialysis Patients

BACKGROUND/OBJECTIVES

Chronic kidney disease (CKD) and end-stage kidney disease (ESKD) are significant public health issues, with cardiovascular morbidity and mortality being the leading causes of death in hemodialysis patients. Osteopontin (OPN), a multifunctional glycoprotein, has emerged as a potential biomarker for vascular disease in CKD due to its role in inflammation, tissue remodeling, and calcification.

METHODS

This cohort study included 1124 hemodialysis patients from the PROGREDIRE study, a registry involving 35 dialysis units in Southern Italy. Serum osteopontin levels were measured using enzyme-linked immunosorbent assay (ELISA). The primary endpoints were all-cause and cardiovascular mortality. Multivariate Cox regression analyses were performed to assess the association between osteopontin levels and mortality, adjusting for traditional risk factors, biomarkers of inflammation, nutritional status, and ESKD-related factors.

RESULTS

During a mean follow-up of 2.8 years, 478 patients died, 271 from cardiovascular causes. Independent correlates of osteopontin included alkaline phosphatase and parathyroid hormone. Elevated osteopontin levels were significantly associated with increased all-cause mortality (HR 1.19, 95% CI 1.09-1.31, p < 0.001) and cardiovascular mortality (HR 1.22, 95% CI 1.08-1.38, p = 0.001) after adjusting for confounders.

CONCLUSIONS

Elevated osteopontin levels are associated with increased all-cause and cardiovascular mortality in hemodialysis patients. These findings implicate osteopontin in the high risk for death and cardiovascular disease in the hemodialysis population. Intervention studies are needed to definitively test this hypothesis.

From Cells to Plaques: The Molecular Pathways of Coronary Artery Calcification and Disease

Coronary artery calcification (CAC) is a hallmark of atherosclerosis and a critical factor in the development and progression of coronary artery disease (CAD). This review aims to address the complex pathophysiological mechanisms underlying CAC and its relationship with CAD. We examine the cellular and molecular processes that drive the formation of calcified plaques, highlighting the roles of inflammation, lipid accumulation, and smooth muscle cell proliferation. Additionally, we explore the genetic and environmental factors that contribute to the heterogeneity in CAC and CAD presentation among individuals. Understanding these intricate mechanisms is essential for developing targeted therapeutic strategies and improving diagnostic accuracy. By integrating current research findings, this review provides a comprehensive overview of the pathways linking CAC to CAD, offering insights into potential interventions to mitigate the burden of these interrelated conditions.

Temporal changes in biomarker levels and their association with the early degeneration stage of transcatheter aortic valves in 18F-fluorodeoxyglucose and 18F-sodium fluoride positron emission tomography studies

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.

Biomarkers That Seem to Have the Greatest Impact on Promoting the Formation of Atherosclerotic Plaque in Current Scientific Research

Atherosclerosis is a chronic inflammatory disease that causes degenerative and productive changes in the arteries. The resulting atherosclerotic plaques restrict the vessel lumen, causing blood flow disturbances. Plaques are formed mainly in large- and medium-sized arteries, usually at bends and forks where there is turbulence in blood flow. Depending on their location, they can lead to various disease states such as myocardial infarction, stroke, renal failure, peripheral vascular diseases, or sudden cardiac death. In this work, we reviewed the literature on the early detection of atherosclerosis markers in the application of photodynamic therapy to atherosclerosis-related diseases. Herein, we described the roles of C-reactive protein, insulin, osteopontin, osteoprotegerin, copeptin, the TGF-β cytokine family, and the amino acid homocysteine. Also, we discuss the role of microelements such as iron, copper, zinc, and Vitamin D in promoting the formation of atherosclerotic plaque. Dysregulation of the administered compounds is associated with an increased risk of atherosclerosis. Additionally, taking into account the pathophysiology of atherosclerotic plaque formation, we believe that maintaining homeostasis in the range of biomarkers mentioned in this article is crucial for slowing down the process of atherosclerotic plaque development and the stability of plaque that is already formed.

A Multi-Biomarker Approach to Increase the Accuracy of Diagnosis and Management of Coronary Artery Disease

Non-invasive possibilities of predicting cardiovascular risk and monitoring the treatment and progression of coronary artery disease (CAD) are important subjects of cardiovascular research. Various inflammatory markers have been identified as potential biomarkers of CAD, including interleukin-6 (IL-6), lipocalin-2 (LCN-2), growth differentiation factor 15 (GDF-15), and T cell immunoglobulin and mucin domain-3 (TIM-3). This research aims to identify their utility in the investigation of CAD severity and progression. The basic anthropometric parameters, as well as the levels of urea, creatinine, CRP, leukocytes, fibrinogen, and biomarkers of inflammation, were measured in 130 patients who underwent coronary angiography. In male patients, divided according to findings on coronary angiography, we observed an increasing expression of GDF-15 with increasing stenosis (with worsening findings). In females, we observed increasing fibrinogen expression with increasing stenosis, i.e., findings on coronary angiography. Correlation analysis did not confirm the relationship between TIM-3, LCN and 2, IL-6 and the severity of findings obtained by coronary angiography; however, the correlation of TIM-3 and LCN-2 expression was positive with the finding, and the correlation of IL-6 with the finding was surprisingly negative. Understanding the role of these inflammatory markers in CAD can be helpful in risk stratification, guiding therapeutic strategies, and monitoring treatment responses in patients with CAD.

Mechanisms of damage and therapies for cardiac amyloidosis: a role for inflammation?

The term cardiac amyloidosis (CA) refers to the accumulation of extracellular amyloid deposits in the heart because of different conditions often affecting multiple organs including brain, kidney and liver. Notably, cardiac involvement significantly impacts prognosis of amyloidosis, with cardiac biomarkers playing a pivotal role in prognostic stratification. Therapeutic management poses a challenge due to limited response to conventional heart failure therapies, necessitating targeted approaches aimed at preventing, halting or reversing amyloid deposition. Mechanisms underlying organ damage in CA are multifactorial, involving proteotoxicity, oxidative stress, and mechanical interference. While the role of inflammation in CA remains incompletely understood, emerging evidence suggests its potential contribution to disease progression as well as its utility as a therapeutic target. This review reports on the cardiac involvement in systemic amyloidosis, its prognostic role and how to assess it. Current and emerging therapies will be critically discussed underscoring the need for further efforts aiming at elucidating CA pathophysiology. The emerging evidence suggesting the contribution of inflammation to disease progression and its prognostic role will also be reviewed possibly offering insights into novel therapeutic avenues for CA.

Osteopontin: A Versatile Biomarker-Insights and Innovations from Three Decades of Research

This second Biomedicines Special Issue-"30 Years of osteopontin (OPN) Milestones and Future Avenues 2 [...].

SPP1 promotes tumor progression in esophageal carcinoma by activating focal adhesion pathway

Background

Recurrence and metastasis are the major obstacles affecting the therapeutic efficacy and clinical outcomes for patients with esophageal carcinoma (ESCA). Secreted phosphoprotein 1 (SPP1) is considered as a hub gene in ESCA and is negatively associated with disease-free survival (DFS) in ESCA. However, the exact roles and underlying mechanisms remain elusive. This study aims to examine the roles of SPP1 on ESCA, and elucidate the potential mechanisms.

Methods

Bioinformatics were used to analyze the expression of SPP1 in ESCA tissues, and its relations with clinicopathological characteristics and clinical prognosis in patients with ESCA based on The Cancer Genome Atlas (TCGA) dataset. Loss-of-function was conducted to examine the roles of SPP1 on malignant behaviors of ESCA cells by cell counting kit-8 (CCK8), plate clone, wound healing, and transwell assays. Gene set enrichment analysis (GSEA) was conducted to screen the pathways associated with SPP1 in ESCA. Then, the enriched pathway and the underlying mechanism were elucidated by western blotting, cell adhesion, and cell spreading assays. Lastly, Y15 [a specific inhibitor of focal adhesion kinase (FAK)] was used to examine its potential to inhibit tumor growth in ESCA cells.

Results

SPP1 was upregulated in ESCA tissues compared to the adjacent nontumorous tissues, which was closely associated with clinical stage, lymph node metastasis, histological subtype, and p53 mutation. A high expression of SPP1 indicated a poor clinical prognosis in patients with ESCA. The knockdown of SPP1 inhibited cell proliferative, migratory, and invasive capacities in ESCA cells. GSEA indicated that the focal adhesion pathway was closely related with SPP1 in ESCA. Further studies confirmed that the knockdown of SPP1 suppressed cell adhesion ability and reduced the expression of p-FAK and p-Erk in ESCA cells. In addition, Y15 inhibited FAK autophosphorylation and dramatically inhibited cell proliferation, migration, and invasion in ESCA cells.

Conclusions

SPP1 promotes tumor progression in ESCA by activating FAK/Erk pathway, and FAK is a potential therapeutic target to overcome tumor recurrence and metastasis of ESCA.

Niobium carbide MXenzyme-Driven comprehensive cholesterol regulation for photoacoustic image-guided and anti-inflammatory photothermal ablation in atherosclerosis

Foam cells play a pivotal role in the progression of atherosclerosis progression by triggering inflammation within arterial walls. They release inflammatory molecules that attract additional immune cells, leading to further macrophage recruitment and plaque development. In this study, we develop an osteopontin (OPN) antibody-conjugated niobium carbide (Nb2C-aOPN) MXenzyme designed to selectively target and mildly ablate foam cells while reducing inflammation in the plaque microenvironment. This approach utilizes photonic hyperthermia to decrease plaque size by enhancing cholesterol regulation through both passive cholesterol outflow and positive cholesterol efflux. Nb2C-aOPN MXenzyme exhibits multiple enzyme-mimicking properties, including catalase, superoxide dismutase, peroxidase and glutathione peroxidase, and acts as a scavenger for reactive oxygen and nitrogen species. The inhibition of reactive oxygen and nitrogen species synergizes with photothermal ablation to promote positive cholesterol efflux, leading to reduced macrophage recruitment and a shift in macrophage phenotype from M1 to M2. This integrative strategy on cholesterol regulation and anti-inflammation highlights the potential of multifunctional 2D MXenzyme-based nanomedicine in advancing atherosclerotic regression.

Beyond the Biomarker: Unveiling the Multifaceted Role of Osteopontin in Both Physiological and Pathological Processes

Osteopontin (OPN), a multifunctional protein, has emerged as a fascinating subject of study due to its diverse roles in various physiological and pathological processes [...].