Osteopontin in Immune-mediated Diseases

A comprehensive review of research advances in the study of lactoferrin to treat viral infections

Lactoferrin (Lf) is a naturally occurring glycoprotein known for its antiviral and antibacterial properties and is present in various physiological fluids. Numerous studies have demonstrated its antiviral effectiveness against multiple viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (IFV), herpes simplex virus (HSV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV). Lf, a vital component of the mucosal defense system, plays a crucial role in inhibiting viral infection by binding to both host cells and viral particles, such as the Hepatitis C virus (HCV). This interaction enables Lf to keep viral particles away from their target cells, emphasizing its significance as a fundamental element of mucosal defense against viral infections. Additionally, Lf has the ability to modulate cytokine expression and enhance cellular immune responses. In the innate immune system, Lf serves as a unique iron transporter and helps suppress various pathogens like bacteria, fungi, and viruses. This article summarises the potential antiviral properties of Lf against various viruses, along with its other mentioned functions. The advancement of Lf-based therapies supports the homology of food and medicine, providing a promising avenue to address viral infections and other public health challenges.

The role of H3K27 acetylation in oxygen-glucose deprivation-induced spinal cord injury and potential for neuroprotective therapies

OBJECTIVE

Spinal cord injury (SCI) is a debilitating condition that often results in paralysis and lifelong medical challenges. Research has shown that epigenetic modifications, particularly histone acetylation, play a role in neuroprotection following hypoxic-ischemic events in SCI. The objective of this study was to explore the effects of histone H3K27 acetylation, along with its underlying mechanisms, on the tolerance to hypoxia and ischemia in SCI.

METHODS

This study employed an organotypic spinal cord slice culture model subjected to oxygen-glucose deprivation (OGD). We assessed cell apoptosis and changes in cellular type patterns under these conditions. Following hypoxia and ischemia, we analyzed the expression and distribution of H3K27ac across various nerve cell types. To identify key downstream genes, we integrated ChIP-seq and RNA-seq analyses, investigating molecular mechanisms driving the response to OGD in this model.

RESULTS

OGD stimulation increased cell apoptosis and induced time-dependent changes in the expression patterns of neurons, astrocytes, microglia, and oligodendrocytes in organotypic spinal cord slices, accompanied by a significant reduction in H3K27ac levels. Integrated ChIP-seq and RNA-seq analyses revealed that H3K27ac downregulation under hypoxic and ischemic conditions contributes to spinal cord damage by promoting neuroinflammation and disrupting gene regulation. Furthermore, we identified key downstream targets, including Apoc1, Spp1, Aff1, Brd4, KCNN3, and Rgma, which may represent promising therapeutic targets for SCI.

CONCLUSION

Our data underscore the pivotal role of H3K27ac in the organotypic spinal cord slice culture model following OGD exposure, offering promising avenues for neuroprotective therapies via epigenetic-immune regulation.

Glycosyltransferase B4GALNT1 promotes immunosuppression in hepatocellular carcinoma via the HES4-SPP1-TAM/Th2 axis

β-1,4-N-acetylgalactosaminyltransferase I (B4GALNT1) is a key glycosyltransferase for gangliosides. Its aberrant expression has been observed in various cancers, and its potential roles in tumor immunity were suggested recently. However, how B4GALNT1 regulate tumor progression and tumor immunity remains largely unknown. In this study, we aimed to investigate the roles of B4GALNT1 in hepatocellular carcinoma (HCC), particularly in reshaping the tumor immune microenvironment, and evaluate the potential beneficial effects of targeting B4GALNT1 in immunotherapy. Our data verified the aberrant upregulation of B4GALNT1 in HCC tumor tissues and tumor cells, which could be utilized as an independent prognostic factor and improve the predicting performance of traditional tumor node metastasis (TNM) system. We also demonstrated that B4GALNT1 increased the phosphorylation of Hes Family BHLH Transcription Factor 4 (HES4) via p38 mitogen-activated protein kinase (p38)/ c-Jun N-terminal kinase (JNK) signaling in tumor cells, thus increasing the transcriptional activity of HES4, which upregulated the synthesis and secretion of secreted phosphoprotein 1 (SPP1), modulated the composition of tumor-associated macrophages (TAMs) and T helper type 2 (Th2) cells, and eventually reshaped the immunosuppressive microenvironment. In addition, silencing B4GALNT1 was proved to enhance the tumor-killing efficiency of the programmed cell death protein 1 (PD-1)-targeting strategy in mouse model. In conclusion, this study evaluated B4GALNT1 as a prognostic predictor for HCC patients and revealed the mechanism of B4GALNT1 in microenvironmental remodeling, which extends the understanding of HCC progression and provides a novel auxiliary strategy for HCC immunotherapy.

New preclinical biomarkers for prion diseases in the cerebrospinal fluid proteome revealed by mass spectrometry

Current diagnostic methods for prion diseases only work in late stages of the disease when neurodegeneration is irreversible. Therefore, biomarkers that can detect the disease before the onset of clinical symptoms are necessary. High-throughput discovery proteomics is of great interest in the search for such molecules. Here we used mass spectrometry to analyse the cerebrospinal fluid proteome in an animal prion disease: preclinical and clinical sheep affected with natural scrapie, and healthy sheep. Interestingly, we found 46 proteins in the preclinical stage that were significantly altered (p < 0.01) compared to healthy sheep, mainly associated with biological processes such as stress and inflammatory responses. Five of them were selected for validation by enzyme-like immunosorbent assay: synaptotagmin binding, cytoplasmic RNA interacting protein (SYNCRIP), involved in nucleic acid metabolism; phospholipase D3 (PLD3) and cathepsin D (CTSD), both related to lysosomal apoptosis; complement component 4 (C4), an element of the classical immune response; and osteopontin (SPP1), a proinflammatory cytokine. These proteins significantly increased in the preclinical stage and maintained their levels in the clinical phase, except for CTSD, whose concentration returned to basal levels in the clinical group. Further research is ongoing to explore their potential as preclinical biomarkers of prion diseases.

Intracellular osteopontin potentiates the immunosuppressive activity of mesenchymal stromal cells

INTRODUCTION

Mesenchymal stromal cell (MSC)-based cell therapy is a promising approach for various inflammatory disorders based on their immunosuppressive capacity. Osteopontin (OPN) regulates several cellular functions including tissue repair, bone metabolism and immune reaction. However, the biological function of OPN in regulating the immunosuppressive capacity of MSCs remains elusive.

OBJECTIVES

This study aims to highlight the underlying mechanism of the proinflammatory cytokines affect the therapeutic ability of MSCs through OPN.

METHODS

MSCs in response to the proinflammatory cytokines were collected to determine the expression profile of OPN. In vitro T-cell proliferation assays and gene editing were performed to check the role and mechanisms of OPN in regulating the immunosuppressive capacity of MSCs. Inflammatory disease mouse models were established to evaluate the effect of OPN on improving MSC-based immunotherapy.

RESULTS

We observed that OPN, including its two isoforms iOPN and sOPN, was downregulated in MSCs upon proinflammatory cytokine stimulation. Interestingly, iOPN, but not sOPN, greatly enhanced the immunosuppressive activity of MSCs on T-cell proliferation and thus alleviated the inflammatory pathologies of hepatitis and colitis. Mechanistically, iOPN interacted with STAT1 and mediated its deubiquitination, thereby inducing the master immunosuppressive mediator inducible nitric oxide synthase (iNOS) in MSCs. In addition, iOPN expression was directly downregulated by activated STAT1, which formed a negative feedback loop to restrain MSC immunosuppressive capacity.

CONCLUSION

Our findings demonstrated that iOPN expression modulation in MSCs is a novel strategy to improve MSC-based immunotherapy.

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

BACKGROUND

Malaria remains a significant public health concern, especially for the deadliest parasite, Plasmodium falciparum. During acute malaria, various cytokines, including osteopontin (OPN), regulate the immune response. OPN has been shown to be protective against malaria in mice. Nonetheless, its precise function and potential ability to control parasites during acute malaria in humans remain poorly understood.

RESULTS

Blood samples were collected from Swedish adults with imported malaria, Ugandan children and adults with symptomatic malaria (including follow-up after 42 days), Ugandans with non-malarial fever and healthy individuals from both Uganda and Sweden. Parasitemia was determined by microscopy. Malaria-negative samples were verified by LAMP. OPN and interferon-γ (IFN- γ) levels were measured using ELISA. In children, OPN levels were significantly higher during acute infection compared to levels after 42 days, whereas Ugandan adults showed no difference. Swedish adults with imported malaria had elevated OPN levels compared to both Swedish controls and Ugandan adults with malaria. Parasitemia was significantly correlated with both OPN and IFN-γ levels across the entire cohort. While a significant correlation between OPN and IFN-γ was evident overall, it remained statistically significant only in Ugandan adults when analyzed by subgroups. This suggests that OPN is not just a general marker of inflammation but may be regulated differently during the development of malaria immunity.

CONCLUSIONS

In acute malaria, elevated OPN levels showed a stronger correlation with lack of immunity than age. These findings underscore the potential importance of OPN in malaria, particularly in non-immune individuals.

Hypothalamic and hippocampal transcriptome changes in AppNL-G-F mice as a function of metabolic and inflammatory dysfunction

The progression of Alzheimer's disease (AD) has a silent phase that predates characteristic cognitive decline and eventually leads to active cognitive deficits. Metabolism, diet, and obesity have been correlated to the development of AD but is poorly understood. The hypothalamus is a brain region that exerts homeostatic control on food intake and metabolism and has been noted to be impacted during the active phase of Alzheimer's disease. This study, in using an amyloid overexpression AppNL-G-F mouse model under normal metabolic conditions, examines blood markers in young and old male AppNL-G-F mice (n = 5) that corresponds to the silent and active phases of AD, and bulk gene expression changes in the hypothalamus and the hippocampus. The results show a large panel of inflammatory mediators, leptin, and other proteins that may be involved in weakening the blood brain barrier, to be increased in the young AppNL-G-F mice but not in the old AppNL-G-F mice. There were also several differentially expressed genes in both the hypothalamus and the hippocampus in the young AppNL-G-F mice prior to amyloid plaque formation and cognitive decline that persisted in the old AppNL-G-F mice, including GABRa2 receptor, Wdfy1, and several pseudogenes with unknown function. These results suggests that a larger panel of inflammatory mediators may be used as blood markers to detect silent AD, and that a change in leptin and gene expression in the hypothalamus exist prior to cognitive effects, suggesting a coupling of metabolism with amyloid plaque induced cognitive decline.

Osteopontin predicts late-time salience network-related functional connectivity in multiple sclerosis

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

Analysis of neutrophil extracellular trap-related genes in Crohn's disease based on bioinformatics

Crohn's disease (CD) presents with diverse clinical phenotypes due to persistent inflammation of the gastrointestinal tract. Its global incidence is on the rise. Neutrophil extracellular traps (NETs) are networks released by neutrophils that capture microbicidal proteins and oxidases targeting pathogens. Research has shown that NETs are implicated in the pathogenesis of several immune-mediated diseases such as rheumatoid arthritis, systemic lupus erythematosus and inflammatory bowel disease. The goal of this study was to identify a panel of NET-related genes to construct a diagnostic and therapeutic model for CD. Through analysis of the GEO database, we identified 1950 differentially expressed genes (DEGs) associated with CD. Gene enrichment and immune cell infiltration analyses indicate that neutrophil infiltrates and chemokine-related pathways are predominantly involved in CD, with other immune cells such as CD4 and M1 macrophages also playing a role in disease progression. Utilizing weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) networks, we identified six hub genes (SPP1, SOCS3, TIMP1, IRF1, CXCL2 and CD274). To validate the accuracy of our model, we performed external validation with statistical differences(p < 0.05). Additionally, immunohistochemical experiments demonstrated higher protein expression of the hub genes in colonic tissues from CD patients compared to healthy subjects (p < 0.05). In summary, we identified six effective hub genes associated with NETs as potential diagnostic markers for CD. These markers not only offer targets for future research but also hold promise for the development of novel therapeutic interventions for CD.

Integrating multi-omics data to analyze the potential pathogenic mechanism of CTSH gene involved in type 1 diabetes in the exocrine pancreas

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of insulin-producing pancreatic islet beta cells. Despite significant advancements, the precise pathogenesis of the disease remains unknown. This work integrated data from expression quantitative trait locus (eQTL) studies with Genome wide association study (GWAS) summary data of T1D and single-cell transcriptome data to investigate the potential pathogenic mechanisms of the CTSH gene involved in T1D in exocrine pancreas. Using the summary data-based Mendelian randomization (SMR) approach, we obtained four potential causative genes associated with T1D: BTN3A2, PGAP3, SMARCE1 and CTSH. To further investigate these genes'roles in T1D development, we validated them using a scRNA-seq dataset from pancreatic tissues of both T1D patients and healthy controls. The analysis showed a significantly high expression of the CTSH gene in T1D acinar cells, whereas the other three genes showed no significant changes in the scRNA-seq data. Moreover, single-cell WGCNA analysis revealed the strongest positive correlation between the module containing CTSH and T1D. In addition, we found cellular ligand-receptor interactions between the acinar cells and different cell types, especially ductal cells. Finally, based on functional enrichment analysis, we hypothesized that the CTSH gene in the exocrine pancreas enhances the antiviral response, leading to the overexpression of pro-inflammatory cytokines and the development of an inflammatory microenvironment. This process promotes β cells injury and ultimately the development of T1D. Our findings offer insights into the underlying pathogenic mechanisms of T1D.

Single-cell transcriptomic analysis reveals transcript enrichment in oxidative phosphorylation, fluid sheer stress, and inflammatory pathways in obesity-related glomerulopathy

Obesity-related glomerulopathy (ORG) is an independent risk factor for chronic kidney disease and even progression to end-stage renal disease. Efforts have been undertaken to elucidate the mechanisms underlying the development of ORG and substantial advances have been made in the treatment of ORG, but relatively little is known about cell-specific changes in gene expression. To define the transcriptomic landscape at single-cell resolution, we analyzed kidney samples from four patients with ORG and three obese control subjects without kidney disease using single-cell RNA sequencing. We report for the first time that immune cells, including T cells and B cells, are decreased in ORG patients. Further analysis indicated that SPP1 was significantly up-regulated in T cells and B cells. This gene is related to inflammation and cell proliferation. Analysis of differential gene expression in glomerular cells (endothelial cells, mesangial cells, and podocytes) showed that these cell types were mainly enriched in genes related to oxidative phosphorylation, cell adhesion, thermogenesis, and inflammatory pathways (PI3K-Akt signaling, MAPK signaling). Furthermore, we found that the podocytes of ORG patients were enriched in genes related to the fluid shear stress pathway. Moreover, an evaluation of cell-cell communications revealed that there were interactions between glomerular parietal epithelial cells and other cells in ORG patients, with major interactions between parietal epithelial cells and podocytes. Altogether, our identification of molecular events, cell types, and differentially expressed genes may facilitate the development of new preventive or therapeutic approaches for ORG.

Ursolic acid targets secreted phosphoprotein 1 to regulate Th17 cells against metabolic dysfunction-associated steatotic liver disease

BACKGROUND/AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become an increasingly important health challenge, with a substantial rise linked to changing lifestyles and global obesity. Ursolic acid, a natural pentacyclic triterpenoid, has been explored for its potential therapeutic effects. Given its multifunctional bioactive properties, this research further revealed the pharmacological mechanisms of ursolic acid on MASLD.

METHODS

Drug target chips and bioinformatics analysis were combined in this study to explore the potential therapeutic effects of ursolic acid on MASLD. Molecular docking simulations, surface plasmon resonance analyses, pull-down experiments, and co-immunoprecipitation assays were used to verify the direct interactions. Gene knockdown mice were generated, and high-fat diets were used to validate drug efficacy. Furthermore, initial CD4+ T cells were isolated and stimulated to demonstrate our findings.

RESULTS

In this study, the multifunctional extracellular matrix phosphorylated glycoprotein secreted phosphoprotein 1 (SPP1) was investigated, highlighting its capability to induce Th17 cell differentiation, amplifying inflammatory cascades, and subsequently promoting the evolution of MASLD. In addition, this study revealed that in addition to the canonical TGF-β/IL-6 cytokine pathway, SPP1 can directly interact with ITGB1 and CD44, orchestrating Th17 cell differentiation via their joint downstream ERK signaling pathway. Remarkably, ursolic acid intervention notably suppressed the protein activity of SPP1, suggesting a promising avenue for ameliorating the immunoinflammatory trajectory in MASLD progression.

CONCLUSION

Ursolic acid could improve immune inflammation in MASLD by modulating SPP1-mediated Th17 cell differentiation via the ERK signaling pathway, which is orchestrated jointly by ITGB1 and CD44, emerging as a linchpin in this molecular cascade.

Decoding immune-related gene-signatures in colorectal neoplasia

Background

Colorectal cancer (CRC) is a significant health issue, with notable incidence rates in Norway. The immune response plays a dual role in CRC, offering both protective effects and promoting tumor growth. This research aims to provide a detailed screening of immune-related genes and identify specific genes in CRC and adenomatous polyps within the Norwegian population, potentially serving as detection biomarkers.

Methods

The study involved 69 patients (228 biopsies) undergoing colonoscopy, divided into CRC, adenomatous polyps, and control groups. We examined the expression of 579 immune genes through nCounter analysis emphasizing differential expression in tumor versus adjacent non-tumorous tissue and performed quantitative reverse transcription polymerase chain reaction (RT-qPCR) across patient categories.

Results

Key findings include the elevated expression of CXCL1, CXCL2, IL1B, IL6, CXCL8 (IL8), PTGS2, and SPP1 in CRC tissues. Additionally, CXCL1, CXCL2, IL6, CXCL8, and PTGS2 showed significant expression changes in adenomatous polyps, suggesting their early involvement in carcinogenesis.

Conclusions

This study uncovers a distinctive immunological signature in colorectal neoplasia among Norwegians, highlighting CXCL1, CXCL2, IL1B, IL6, CXCL8, PTGS2, and SPP1 as potential CRC biomarkers. These findings warrant further research to confirm their role and explore their utility in non-invasive screening strategies.

Bidirectional pressure: a mini review of ventilator-lung-kidney interactions

Acute kidney injury and respiratory failure that requires mechanical ventilation are both common complications of critical illnesses. Failure of either of these organ systems also increases the risk of failure to the other. As a result, there is a high incidence of patients with concomitant acute kidney injury and the need for mechanical ventilation, which has a devasting impact on intensive care unit outcomes, including mortality. Despite decades of research into the mechanisms of ventilator-lung-kidney interactions, several gaps in knowledge remain and current treatment strategies are primarily supportive. In this review, we outline our current understanding of the mechanisms of acute kidney injury due to mechanical ventilation including a discussion of; 1) The impact of mechanical ventilation on renal perfusion, 2) activation of neurohormonal pathways by positive pressure ventilation, and 3) the role of inflammatory mediators released during ventilator induced lung injury. We also provide a review of the mechanisms by which acute kidney injury increases the risk of respiratory failure. Next, we outline a summary of the current therapeutic approach to preventing lung and kidney injury in the critically ill, including fluid and vasopressor management, ventilator strategies, and treatment of acute kidney injury. Finally, we conclude with a discussion outlining opportunities for novel investigations that may provide a rationale for new treatment approaches.

Osteopontin-driven partial epithelial-mesenchymal transition governs the development of middle ear cholesteatoma

Cholesteatoma is a common disease of the middle ear. Currently, surgical removal is the only treatment option and patients face a high risk of relapse. The molecular basis of cholesteatoma remains largely unknown. Here, we show that Osteopontin (OPN), a predominantly secreted protein, plays a crucial role in the development of middle ear cholesteatoma. Global transcriptome analysis revealed the loss of epithelial features and an enhanced immune response in human cholesteatoma tissues. Quantitative RT-PCR and immunohistochemical staining of middle ear cholesteatoma validated the reduced expression of epithelial markers, as well as the elevated expression of mesenchymal markers including Vimentin and Fibronectin, but not N-Cadherin, α-smooth muscle actin (α-SMA) or ferroptosis suppressor protein 1 (FSP1), indicating a partial epithelial-mesenchymal transition (EMT) state. Besides, the expression of OPN was significantly elevated in human cholesteatoma tissues. Treatment with OPN promoted cell proliferation, survival and migration and led to a partial EMT in immortalized human keratinocyte cells. Importantly, blockade of OPN signaling could remarkably improve the cholesteatoma-like symptoms in SD rats. Our mechanistic study demonstrated that the AKT-zinc finger E-box binding homeobox 2 (ZEB2) axis mediated the effects of OPN. Overall, these findings suggest that targeting the OPN signaling represents a promising strategy for the treatment of middle ear cholesteatoma.

Combined Osteopontin Blockade and Type 2 Classical Dendritic Cell Vaccination as Effective Synergetic Therapy for Conjunctival Melanoma

Angiogenesis and immune protection are essential at the onset of tumorigenesis. Angiogenesis serves to nourish the tumor, and prevention of immune defenses, for example, by dendritic cells (DCs), allows tumor growth. In this study, we investigated whether there are factors with dual functions that are both angiogenic and immunomodulatory and represent a therapeutic target. We analyzed 1) innate immune responses intratumorally and in draining lymph nodes and 2) angiogenic factors in conjunctival melanoma (CM), a potentially lethal malignant tumor at the ocular surface whose immune and vascular responses are largely unknown. For this purpose, an HGF-Cdk4R24C model in immunocompetent C57BL/6 mice was used and revealed that CD103- type 2 classical DC (cDC2s) were the most abundant DC subtype in healthy conjunctiva, whereas in CM, CD103- cDC2s, CD103+ type 1 cDCs, monocyte-derived DCs, and plasmacytoid DCs were significantly increased. In our analysis of angiogenic factors in CM, the examination of 53 angiogenesis-related factors that might interact with DCs identified osteopontin (OPN) as a major tumor-derived protein that interacts with DCs. Consistent with these findings, 3) a dual therapeutic strategy that inhibited tumor cell function by an OPN blocking Ab while enhancing the immune response by cDC2 vaccination resulted in 35% failure of tumor development. Moreover, tumor progression, monocyte-derived DC infiltration, and intratumoral angiogenesis were significantly reduced, whereas survival and CD8+ T cell infiltration were increased in treated mice compared with the control group. Therefore, we identified OPN blockade in combination with cDC2 vaccination as a potential future therapeutic intervention for early stages of CM by combining antiangiogenic and host immune stimulating effects.

OPN promotes pro-inflammatory cytokine expression via ERK/JNK pathway and M1 macrophage polarization in Rosacea

Rosacea is a chronic inflammatory dermatosis that involves dysregulation of innate and adaptive immune systems. Osteopontin (OPN) is a phosphorylated glycoprotein produced by a broad range of immune cells such as macrophages, keratinocytes, and T cells. However, the role of OPN in rosacea remains to be elucidated. In this study, it was found that OPN expression was significantly upregulated in rosacea patients and LL37-induced rosacea-like skin inflammation. Transcriptome sequencing results indicated that OPN regulated pro-inflammatory cytokines and promoted macrophage polarization towards M1 phenotype in rosacea-like skin inflammation. In vitro, it was demonstrated that intracellular OPN (iOPN) promoted LL37-induced IL1B production through ERK1/2 and JNK pathways in keratinocytes. Moreover, secreted OPN (sOPN) played an important role in keratinocyte-macrophage crosstalk. In conclusion, sOPN and iOPN were identified as key regulators of the innate immune system and played different roles in the pathogenesis of rosacea.

Emerging Role of Non-collagenous Bone Proteins as Osteokines in Extraosseous Tissues

Bone is a unique tissue, composed of various types of cells embedded in a calcified extracellular matrix (ECM), whose dynamic structure consists of organic and inorganic compounds produced by bone cells. The main inorganic component is represented by hydroxyapatite, whilst the organic ECM is primarily made up of type I collagen and non-collagenous proteins. These proteins play an important role in bone homeostasis, calcium regulation, and maintenance of the hematopoietic niche. Recent advances in bone biology have highlighted the importance of specific bone proteins, named "osteokines", possessing endocrine functions and exerting effects on nonosseous tissues. Accordingly, osteokines have been found to act as growth factors, cell receptors, and adhesion molecules, thus modifying the view of bone from a static tissue fulfilling mobility to an endocrine organ itself. Since bone is involved in a paracrine and endocrine cross-talk with other tissues, a better understanding of bone secretome and the systemic roles of osteokines is expected to provide benefits in multiple topics: such as identification of novel biomarkers and the development of new therapeutic strategies. The present review discusses in detail the known osseous and extraosseous effects of these proteins and the possible respective clinical and therapeutic significance.

Preliminary Study of the Relationship between Osteopontin and Relapsed Hodgkin's Lymphoma

The primary objective of this study was to investigate the potential role of tissue osteopontin, also known as secreted phosphoprotein 1 (SPP1), as a contributing factor to an unfavorable prognosis in classical Hodgkin's lymphoma (HL) patients who received the same treatment protocol. The study involved 44 patients aged 4-22 years, with a median follow-up period of 3 years. Patients with higher levels of SPP1 were associated with tissue necrosis and inflammation, and there was a trend toward a poorer prognosis in this group. Before therapy, we found a correlation between positron emission tomography (PET) scans and logarithmic SPP1 levels (p = 0.035). However, the addition of SPP1 levels did not significantly enhance the predictive capacity of PET scans for recurrence or progression. Elevated SPP levels were associated with tissue mRNA counts of chemotactic and inflammatory chemokines, as well as specific monocyte/dendritic cell subtypes, defined by IL-17RB, PLAUR, CXCL8, CD1A, CCL13, TREM1, and CCL24 markers. These findings contribute to a better understanding of the potential factors influencing the prognosis of HL patients and the potential role of SPP1 in the disease. While the predictive accuracy of PET scans did not substantially improve during the study, the results underscore the complexity of HL and highlight the relationships between SPP1 and other factors in the context of HL relapse.

Cleaved SPP1-rich extracellular vesicles from osteoclasts promote bone regeneration via TGFβ1/SMAD3 signaling

Bone remodeling is a tightly coupled process between bone forming osteoblasts (OBs) and bone resorbing osteoclasts (OCs) to maintain bone architecture and systemic mineral homeostasis throughout life. However, the mechanisms responsible for the coupling between OCs and OBs have not been fully elucidated. Herein, we first validate that secreted extracellular vesicles by osteoclasts (OC-EVs) promote osteogenic differentiation of mesenchymal stem cells (MSCs) and further demonstrate the efficacy of osteoclasts and their secreted EVs in treating tibial bone defects. Furthermore, we show that OC-EVs contain several osteogenesis-promoting proteins as cargo. By employing proteomic and functional analysis, we reveal that mature osteoclasts secrete thrombin cleaved phosphoprotein 1 (SPP1) through extracellular vesicles which triggers MSCs osteogenic differentiation into OBs by activating Transforming Growth Factor β1 (TGFβ1) and Smad family member 3 (SMAD3) signaling. In conclusion, our findings prove an important role of SPP1, present as cargo in OC-derived EVs, in signaling to MSCs and driving their differentiation into OBs. This biological mechanism implies a paradigm shift regarding the role of osteoclasts and their signaling toward the treatment of skeletal disorders which require bone formation.

Two different isoforms of osteopontin modulate myelination and axonal integrity

Abnormal myelination underlies the pathology of white matter diseases such as preterm white matter injury and multiple sclerosis. Osteopontin (OPN) has been suggested to play a role in myelination. Murine OPN mRNA is translated into a secreted isoform (sOPN) or an intracellular isoform (iOPN). Whether there is an isoform-specific involvement of OPN in myelination is unknown. Here we generated mouse models that either lacked both OPN isoforms in all cells (OPN-KO) or lacked sOPN systemically but expressed iOPN specifically in oligodendrocytes (OLs-iOPN-KI). Transcriptome analysis of isolated oligodendrocytes from the neonatal brain showed that genes and pathways related to increase of myelination and altered cell cycle control were enriched in the absence of the two OPN isoforms in OPN-KO mice compared to control mice. Accordingly, adult OPN-KO mice showed an increased axonal myelination, as revealed by transmission electron microscopy imaging, and increased expression of myelin-related proteins. In contrast, neonatal oligodendrocytes from OLs-iOPN-KI mice compared to control mice showed differential regulation of genes and pathways related to the increase of cell adhesion, motility, and vasculature development, and the decrease of axonal/neuronal development. OLs-iOPN-KI mice showed abnormal myelin formation in the early phase of myelination in young mice and signs of axonal degeneration in adulthood. These results suggest an OPN isoform-specific involvement, and a possible interplay between the isoforms, in myelination, and axonal integrity. Thus, the two isoforms of OPN need to be separately considered in therapeutic strategies targeting OPN in white matter injury and diseases.

Effects of Progestin on Modulation of the Expression of Biomarkers in Endometriosis

BACKGROUND

Our study aimed to examine the osteopontin (OPN) serum levels and tissue expression of CD44 and OPN in endometriosis-affected women both undergoing and not undergoing progestin treatment, and also to determine their involvement in the pathogenesis of endometriosis.

METHODS

Using an ELISA kit, we evaluated the OPN serum levels of healthy and endometriosis-affected women both undergoing and not undergoing progestin treatment. Immunohistochemical (IHC) analyses were used to assess the endometriotic tissue expressions of CD44 and OPN.

RESULTS

There were statistically significant higher OPN serum levels in the healthy control group compared to the women with endometriosis. Furthermore, there were higher OPN serum levels in the endometriosis-affected women undergoing the progestin treatment, but the difference did not reach statistical significance. In comparison to OPN, CD44 expression was significantly higher in all the endometriotic tissue glands and stroma, regardless of the patient's treatment status. Compared to the group receiving therapy, the OPN levels were higher in the endometriosis group not receiving therapy. OPN's robust cytoplasmic expression seemed to be associated with the non-treatment group.

CONCLUSION

Endometriosis, CD44, and OPN appear to be closely related. This study suggests that endometriosis that has not been treated has an immunological profile distinct to endometriosis that has received treatment.

A Dual Role of Osteopontin in Modifying B Cell Responses

The occurrence of B cell aggregates within the central nervous system (CNS) has prompted the investigation of the potential sources of pathogenic B cell and T cell responses in a subgroup of secondary progressive multiple sclerosis (MS) patients. Nevertheless, the expression profile of molecules associated with these aggregates and their role in aggregate development and persistence is poorly described. Here, we focused on the expression pattern of osteopontin (OPN), which is a well-described cytokine, in MS brain tissue. Autopsied brain sections from MS cases with and without B cell pathology were screened for the presence of CD20⁺ B cell aggregates and co-expression of OPN. To demonstrate the effect of OPN on B cells, flow cytometry, ELISA and in vitro aggregation assays were conducted using the peripheral blood of healthy volunteers. Although OPN was expressed in MS brain tissue independent of B cell pathology, it was also highly expressed within B cell aggregates. In vitro studies demonstrated that OPN downregulated the co-stimulatory molecules CD80 and CD86 on B cells. OPN-treated B cells produced significantly lower amounts of IL-6. However, OPN-treated B cells also exhibited a higher tendency to form homotypic cell aggregates in vitro. Taken together, our data indicate a conflicting role of OPN in modulating B cell responses.

OPN up-regulated proliferation and invasion of head and neck squamous cell carcinoma through the p38MAPK signaling pathway

OBJECTIVE

Osteopontin (OPN) is aberrantly expressed in various tumors. However, its role and detailed mechanisms in head and neck squamous cell carcinoma (HNSCC) have not been extensively described.

STUDY DESIGN

Expression of OPN in HNSCC was examined at the gene and protein levels. The effect of cell proliferation ability was examined by Cell Counting Kit-8, colony formation assay, cell invasiveness by Transwell assay, the effect of OPN on protein expression of Capase-3 and Bcl2 by Western blotting, and the expression of p38MAPK signaling pathway by p38MAPK inhibitor SB203580.

RESULTS

We found that OPN expression was higher in human HNSCC tissues than in adjacent tissues. Osteopontin may regulate the proliferation and invasion of HNSCC cells through the p38-MAPK signaling pathway.

DISCUSSION

Our study identifies an important role for OPN in HNSCC and further demonstrates that it may regulate the proliferation and invasion of HNSCC cells by activating the p38-MAPK signaling pathway. Osteopontin may be a promising prognostic and diagnostic indicator and a potential target for cancer therapy.

Advanced Biomarkers of Hepatotoxicity in Psychiatry: A Narrative Review and Recommendations for New Psychoactive Substances

One of the factors that increase the effectiveness of the pharmacotherapy used in patients abusing various types of new psychoactive substances (NPSs) is the proper functioning of the liver. However, the articles published to date on NPS hepatotoxicity only address non-specific hepatic parameters. The aim of this manuscript was to review three advanced markers of hepatotoxicity in psychiatry, namely, osteopontin (OPN), high-mobility group box 1 protein (HMGB1) and glutathione dehydrogenase (GDH, GLDH), and, on this basis, to identify recommendations that should be included in future studies in patients abusing NPSs. This will make it possible to determine whether NPSs do indeed have a hepatotoxic effect or whether other factors, such as additional substances taken or hepatitis C virus (HCV) infection, are responsible. NPS abusers are at particular risk of HCV infection, and for this reason, it is all the more important to determine what factors actually show a hepatotoxic effect in them.

[Methods for assessment of disease activity of polymyalgia rheumatica]

Polymyalgia rheumatica (PMR) is the second most frequent inflammatory rheumatic disease in old age. Remission and recurrence are frequently used as endpoints in clinical trials; however, there is as yet no international consensus on the definition of these states, which limits the comparability of published studies. The PMR activity score (PMR-AS) is the only composite score specifically developed for PMR, which together with remission is used to define low, middle and high disease activity. In recent studies the PMR-AS was often used and low disease activity was established as endpoint. The most important limitation of the PMR-AS is the potential influence of the individual variables by comorbidities. The value of C‑reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) are of restricted value in studies using drugs that influence the interleukin 6 (IL-6) axis. In these cases, calprotectin and osteopontin are promising alternative biomarkers, as they have already been shown to reflect disease activity independently of CRP in rheumatoid arthritis. Furthermore, imaging modalities including sonography, magnetic resonance imaging and fluorodeoxyglucose (FDG) positron emission tomography could also be helpful in monitoring disease activity; however, these techniques must first be validated in further studies. The PMR impact scale (PMR-IS) is a composite score to assess the impact of PMR on the patients; however, it has not yet been used in clinical studies. The development of additional patient reported outcomes (PRO) for PMR and the definition of standardized criteria for documentation of remission and recurrence are important questions in the future research agenda for PMR.

NOX4 as a critical effector mediating neuroinflammatory cytokines, myeloperoxidase and osteopontin, specifically in astrocytes in the hippocampus in Parkinson's disease

Oxidative stress and mitochondrial dysfunction have been believed to play an important role in the pathogenesis of aging and neurodegenerative diseases, including Parkinson's disease (PD). The excess of reactive oxygen species (ROS) increases with age and causes a redox imbalance, which contributes to the neurotoxicity of PD. Accumulating evidence suggests that NADPH oxidase (NOX)-derived ROS, especially NOX4, belong to the NOX family and is one of the major isoforms expressed in the central nervous system (CNS), associated with the progression of PD. We have previously shown that NOX4 activation regulates ferroptosis via astrocytic mitochondrial dysfunction. We have previously shown that activation of NOX4 regulates ferroptosis through mitochondrial dysfunction in astrocytes. However, it remains unclear why an increase in NOX4 in neurodegenerative diseases leads to astrocyte cell death by certain mediators. Therefore, this study was designed to evaluate how NOX4 in the hippocampus is involved in PD by comparing an MPTP-induced PD mouse model compared to human PD patients. We could detect that the hippocampus was dominantly associated with elevated levels of NOX4 and α-synuclein during PD and the neuroinflammatory cytokines, myeloperoxidase (MPO) and osteopontin (OPN), were upregulated particularly in astrocytes. Intriguingly, NOX4 suggested a direct intercorrelation with MPO and OPN in the hippocampus. Upregulation of MPO and OPN induces mitochondrial dysfunction by suppressing five protein complexes in the mitochondrial electron transport system (ETC) and increases the level of 4-HNE leading to ferroptosis in human astrocytes. Overall, our findings indicate that the elevation of NOX4 cooperated with the MPO and OPN inflammatory cytokines through mitochondrial aberration in hippocampal astrocytes during PD.

Protein biomarkers in multiple sclerosis

This review aimed to elucidate protein biomarkers in body fluids, such as blood and cerebrospinal fluid (CSF), to identify those that may be used for early diagnosis of multiple sclerosis (MS), prediction of disease activity, and monitoring of treatment response among MS patients. The potential biomarkers elucidated in this review include neurofilament proteins (NFs), glial fibrillary acidic protein (GFAP), leptin, brain-derived neurotrophic factor (BDNF), chitinase-3-like protein 1 (CHI3L1), C-X-C motif chemokine 13 (CXCL13), and osteopontin (OPN), with each biomarker playing a different role in MS. GFAP, leptin, and CHI3L1 levels were increased in MS patient groups compared to the control group. NFs are the most studied proteins in the MS field, and significant correlations with disease activity, future progression, and treatment outcomes are evident. GFAP CSF level shows a different pattern by MS subtype. Increased concentration of CHI3L1 in the blood/CSF of clinically isolated syndrome (CIS) is an independent predictive factor of conversion to definite MS. BDNF may be affected by chronic progression of MS. CHI3L1 has potential as a biomarker for early diagnosis of MS and prediction of disability progression, while CXCL13 has potential as a biomarker of prognosis of CIS and reflects MS disease activity. OPN was an indicator of disease severity. A periodic detailed patient evaluation should be performed for MS patients, and broadly and easily accessible biomarkers with higher sensitivity and specificity in clinical settings should be identified.

The Role and Clinical Relevance of Osteopontin in Allergic Airway Diseases

The airway epithelium is exposed to numerous external irritants including infectious agents, environmental allergens, and atmospheric pollutants, releasing epithelial cytokines including thymic stromal lymphopoietin (TSLP), IL-33, and IL-25 and initiating downstream type 2 (IL-4, IL-13, and IL-5) and IgE-driven pathways. These pathways trigger the initiation and progression of allergic airway diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP), allergic rhinitis (AR), and allergic asthma. However, the use of biological agents that target downstream cytokines, such as IL-5, IL-4, and IL-13 receptors and IgE, might not be sufficient to manage some patients successfully. Instead of blocking downstream cytokines, targeting upstream epithelial cytokines has been proposed to address the complex immunologic networks associated with allergic airway diseases. Osteopontin (OPN), an extracellular matrix glyco-phosphoprotein, is a key mediator involved in Th1-related diseases, including systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Emerging evidence, including ours, indicates that epithelial-cell-derived OPN also plays an essential role in Th2-skewed airway diseases, including CRSwNP, AR, and allergic asthma involving the Th17 response. Therefore, we reviewed the current knowledge of epithelial-cell-derived OPN in the pathogenesis of three type-2-biased airway diseases and provided a direction for its future investigation and clinical relevance.

Blocking osteopontin expression attenuates neuroinflammation and mitigates LPS-induced depressive-like behavior in mice

INTRODUCTION

Neuroinflammation plays an important role in the development of major depressive disorder (MDD). Osteopontin (OPN) is one of the key molecules involved in neuroinflammation. We demonstrate here for the first time a key role of OPN in lipopolysaccharide (LPS)-induced depressive-like behavioral syndrome.

METHODS

Systemic administration of LPS (5 mg/kg) mimics distinct depressive-like behavior, which could significantly upregulate OPN expression in microglia/macrophage in the hippocampus. The neurobehavioral assessments, quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), Western blot, immunofluorescent staining, flow cytometry cell staining and Golgi staining were performed.

RESULTS

Similar to fluoxetine treatment (the positive control), OPN knockdown with shRNA lentivirus markedly reversed LPS-induced depressive-like behavior. Moreover, knockdown of OPN suppressed LPS-induced proinflammatory cytokine expression, microglial activation, dendritic spines loss, as well as unregulated PSD-95 and BDNF in the hippocampus.

CONCLUSION

We demonstrated that targeting OPN expression in microglia/macrophage might help to rescue LPS-induced depressive-like behavior. The underlying mechanism may relate to the modulation of neuroinflammation, BDNF signaling and synaptic structural complexity.

Identification of anti-citrullinated osteopontin antibodies and increased inflammatory response by enhancement of osteopontin binding to fibroblast-like synoviocytes in rheumatoid arthritis

BACKGROUND

Anti-citrullinated protein/peptide antibodies (ACPAs) are present in patients at onset and have important pathogenic roles during the course of rheumatoid arthritis (RA). The characteristics of several molecules recognized by ACPA have been studied in RA, but the positivity rate of autoantibodies against each antigen is not high, and the pathogenic mechanism of each antibody is not fully understood. We investigated the role of anti-citrullinated osteopontin (anti-cit-OPN) antibodies in RA pathogenesis.

METHODS

Enzyme-linked immunosorbent assays on RA patients' sera were used to detect autoantibodies against OPN. Fibroblast-like synoviocytes (FLS) isolated from RA patients were used to test the binding activity and inflammatory response of OPN mediated by anti-cit-OPN antibodies, and their effect was tested using an inflammatory arthritis mouse model immunized with cit-OPN. Anti-cit-OPN antibody positivity and clinical characteristics were investigated in the patients as well.

RESULTS

Using sera from 224 RA patients, anti-cit-OPN antibodies were positive in approximately 44% of RA patients, while approximately 78% of patients were positive for the cyclic citrullinated peptide (CCP2) assay. IgG from patients with anti-cit-OPN antibody increased the binding activity of OPN to FLSs, which further increased matrix metalloproteinase and interleukin-6 production in TNF-stimulated FLSs. Mice immunized with cit-OPN antibodies experienced severe arthritis. Anti-cit-OPN antibodies in RA patients decreased the drug survival rate of tumor necrosis factor (TNF) inhibitors, while it did not decrease that of CTLA4-Ig.

CONCLUSIONS

Anti-cit-OPN antibodies were detected in patients with RA. IgG from patients with anti-cit-OPN antibodies aggravated RA, and anti-cit-OPN antibody was a marker of reduced the survival rate of TNF inhibitors in RA patients.

Advancement in therapeutic strategies for immune-mediated oral diseases

BACKGROUND

Immune-mediated diseases are a diverse group of conditions characterized by alteration of cellular homeostasis and inflammation triggered by dysregulation of the normal immune response. Several immune-mediated diseases exhibit oral signs and symptoms. Traditionally, these conditions are treated with corticosteroids or immunosuppressive agents, including azathioprine, cyclophosphamide, and thalidomide. Recent research into the developmental pathways of these diseases has led to the exploration of novel approaches in treatment. This review examines newer treatment modalities for the management of immune-mediated diseases with oral presentations. Topical calcineurin inhibitors (TCIs) such as tacrolimus and pimecrolimus have been employed successfully in managing oral lichen planus and pemphigus vulgaris. Biologic agents, comprising monoclonal antibodies, fusion proteins, and recombinant cytokines, can provide targeted therapy with fewer adverse effects. Neutraceutical agents comprising aloe vera, curcumin, and honey are commonly used in traditional medicine and offer a holistic approach. They may have a place as adjuvants to current standard therapeutic protocols. Photodynamic therapy (PDT) and low-level laser therapy (LLLT) utilize a specific wavelength of light to achieve desired cellular change. While the use of PDT in immune-mediated diseases is contentious, LLLT has shown positive results. Newer therapeutic modalities involve kinase inhibitors, S1P₁ receptor modulators, MSCs, and iRNA providing targeted treatment of specific diseases.

The Role of Single-Nucleotide Polymorphisms in Cholangiocarcinoma: A Systematic Review

Single-nucleotide polymorphisms (SNPs) play an essential role in various malignancies, but their role in cholangiocarcinoma (CCA) remains to be elucidated. Therefore, the purpose of this systematic review was to evaluate the association between SNPs and CCA, focusing on tumorigenesis and prognosis. A systematic literature search was carried out using PubMed, Embase, Web of Science and the Cochrane database for the association between SNPs and CCA, including literature published between January 2000 and April 2022. This systematic review compiles 43 SNPs in 32 genes associated with CCA risk, metastatic progression and overall prognosis based on 34 studies. Susceptibility to CCA was associated with SNPs in genes related to inflammation (PTGS2/COX2, IL6, IFNG/IFN-γ, TNF/TNF-α), DNA repair (ERCC1, MTHFR, MUTYH, XRCC1, OGG1), detoxification (NAT1, NAT2 and ABCC2), enzymes (SERPINA1, GSTO1, APOBEC3A, APOBEC3B), RNA (HOTAIR) and membrane-based proteins (EGFR, GAB1, KLRK1/NKG2D). Overall oncological prognosis was also related to SNPs in eight genes (GNB3, NFE2L2/NRF2, GALNT14, EGFR, XRCC1, EZH2, GNAS, CXCR1). Our findings indicate that multiple SNPs play different roles at various stages of CCA and might serve as biomarkers guiding treatment and allowing oncological risk assessment. Considering the differences in SNP detection methods, patient ethnicity and corresponding environmental factors, more large-scale multicentric investigations are needed to fully determine the potential of SNP analysis for CCA susceptibility prediction and prognostication.

Promotion effect of the blend containing 2'-FL, OPN and DHA on oligodendrocyte progenitor cells myelination in vitro

During early neurodevelopment of infant, myelination plays an essential role in brain connectivity and emergence of behavioral and cognitive function. Early life nutrition is an important factor to shape myelination and consequently cognitive appearance. To analyze the effects of additive nutrients, including 2'-fucosyllactose (2'-FL), osteopontin (OPN), docosahexaenoic acid (DHA), on neurocognitive function and brain structure, the current study evaluated the effects of different composition of breast milk nutrients on oligodendrocyte progenitor cells (OPCs) myelination with a neural primary cell model in vitro. The study showed that the three nutrients promoted the proliferation, maturation and differentiation of OPCs into mature oligodendrocytes (OLs) in each phage of the cell growth, and the effect of the nutrients blend is obviously stronger than that of the nutrient treatment alone, showing a synergistic effect in promotion of OPCs. The results of this experiment clarified the effects of 2′-FL OPN and DHA to promote myelination development of neural cells, and laid an experimental basis for further optimization of infant formula.

Osteopontin/secreted phosphoprotein-1 harnesses glial-, immune-, and neuronal cell ligand-receptor interactions to sense and regulate acute and chronic neuroinflammation

Osteopontin (OPN) also known by its official gene designation secreted phosphoprotein-1 (SPP1) is a fascinating, multifunctional protein expressed in a number of cell types that functions not only in intercellular communication, but also in the extracellular matrix (ECM). OPN/SPP1 possesses cytokine, chemokine, and signal transduction functions by virtue of modular structural motifs that provide interaction surfaces for integrins and CD44-variant receptors. In humans, there are three experimentally verified splice variants of OPN/SPP1 and CD44's ten exons are also alternatively spiced in a cell/tissue-specific manner, although very little is known about how this is regulated in the central nervous system (CNS). Post-translational modifications of phosphorylation, glycosylation, and localized cleavage by specific proteases in the cells and tissues where OPN/SPP1 functions, provides additional layers of specificity. However, the former make elucidating the exact molecular mechanisms of OPN/SPP1 function more complex. Flexibility in OPN/SPP1 structure and its engagement with integrins having the ability to transmit signals in inside-out and outside-in direction, is likely why OPN/SPP1 can serve as an early detector of inflammation and ongoing tissue damage in response to cancer, stroke, traumatic brain injury, pathogenic infection, and neurodegeneration, processes that impair tissue homeostasis. This review will focus on what is currently known about OPN/SPP1 function in the brain.

Dysregulated Expression of Three Genes in Colorectal Cancer Stratifies Patients into Three Risk Groups

Despite advances in recent years in the study of the molecular profile of sporadic colorectal cancer (sCRC), the specific genetic events that lead to increased aggressiveness or the development of the metastatic process of tumours are not yet clear. In previous studies of the gene expression profile (GEP) using a high-density array (50,000 genes and 6000 miRNAs in a single assay) in sCRC tumours, we identified a 28-gene signature that was found to be associated with an adverse prognostic value for predicting patient survival. Here, we analyse the differential expression of these 28 genes for their possible association with tumour local aggressiveness and metastatic processes in 66 consecutive sCRC patients, followed for >5 years, using the NanoString nCounter platform. The global transcription profile (expression levels of the 28 genes studied simultaneously) allowed us to discriminate between sCRC tumours and nontumoral colonic tissues. Analysis of the biological and functional significance of the dysregulated GEPs observed in our sCRC tumours revealed 31 significantly altered canonical pathways. Among the most commonly altered pathways, we observed the increased expression of genes involved in signalling pathways and cellular processes, such as the PI3K-Akt pathway, the interaction with the extracellular matrix (ECM), and other functions related to cell signalling processes (SRPX2). From a prognostic viewpoint, the altered expression of BST2 and SRPX2 genes were the only independent variables predicting for disease-free survival (DFS). In addition to the pT stage at diagnosis, dysregulated transcripts of ADH1B, BST2, and FER1L4 genes showed a prognostic impact on OS in the multivariate analysis. Based on the altered expression of these three genes, a scoring system was built to stratify patients into low-, intermediate-, and high-risk groups with significantly different 5-year OS rates: 91%, 83%, and 52%, respectively. The prognostic impact was validated in two independent series of sCRC patients from the public GEO database (n = 562 patients). In summary, we show a strong association between the altered expression of three genes and the clinical outcome of sCRC patients, making them potential markers of suitability for adjuvant therapy after complete tumour resection. Additional prospective studies in larger series of patients are required to confirm the clinical utility of the newly identified biomarkers because the number of patients analysed remains small.

Longitudinal changes of lactopontin (milk osteopontin) in term and preterm human milk

Background

Lactopontin (LPN) in breast milk, also known as milk osteopontin is thought to play a myriad of important roles in infants when they are immature. The purpose of the present study was to examine the longitudinal changes in LPN concentrations in term and preterm milk, and elucidate the links between maternal characteristics, LPN levels, and child growth in a birth cohort.

Methods

131 mothers who delivered term, moderate-late preterm (MPT), very preterm (VPT), and extremely preterm (EPT) infants were included, milk samples were collected at 7, 14, 28, and 120 days postpartum. LPN concentration was determined by multiple reaction monitoring (MRM) using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Results

Our results indicated that LPN change over time of VPT (P = 0.024) and EPT (P = 0.003) were significantly different from term milk, although they all gradually decreased with lactation. In terms of LPN-related factors, maternal age was a significant contributor in late mature milk and pre-pregnancy BMI a significant contributor to colostrum and transitional milk. We further investigated relationships between LPN levels and infant weight and our results suggested that high levels of LPN in breast milk might be useful for the catch-up growth of infants.

Conclusion

LPN levels in breast milk are related to maternal factors, and differences in LPN levels may affect the growth of infants. As milk is a critical part in the mother-breastmilk-infant "triad," the association between maternal-infant factors and milk LPN levels warrants further study.

Advances in Potential Cerebrospinal Fluid Biomarkers for Autoimmune Encephalitis: A Review

Autoimmune encephalitis (AE) is a severe inflammatory disease of the brain. Patients with AE demonstrate amnesia, seizures, and psychosis. Recent studies have identified numerous associated autoantibodies (e.g., against NMDA receptors (NMDARs), LGI1, etc.) involved in the pathogenesis of AE, and the levels of diagnosis and treatment are thus improved dramatically. However, there are drawbacks of clinical diagnosis and treatment based solely on antibody levels, and thus the application of additional biomarkers is urgently needed. Considering the important role of immune mechanisms in AE development, we summarize the relevant research progress in identifying cerebrospinal fluid (CSF) biomarkers with a focus on cytokines/chemokines, demyelination, and nerve damage.

L-Cysteine attenuates osteopontin-mediated neuroinflammation following hypoxia-ischemia insult in neonatal mice by inducing S-sulfhydration of Stat3

We previously show that L-Cysteine administration significantly suppresses hypoxia-ischemia (HI)-induced neuroinflammation in neonatal mice through releasing H₂S. In this study we conducted proteomics analysis to explore the potential biomarkers or molecular therapeutic targets associated with anti-inflammatory effect of L-Cysteine in neonatal mice following HI insult. HI brain injury was induced in postnatal day 7 (P7) neonatal mice. The pups were administered L-Cysteine (5 mg/kg) at 24, 48, and 72 h post-HI. By conducting TMT-based proteomics analysis, we confirmed that osteopontin (OPN) was the most upregulated protein in ipsilateral cortex 72 h following HI insult. Moreover, OPN was expressed in CD11b⁺/CD45^low cells and infiltrating CD11b⁺/CD45^high cells after HI exposure. Intracerebroventricular injection of OPN antibody blocked OPN expression, significantly attenuated brain damage, reduced pro-inflammatory cytokine levels and suppressed cerebral recruitment of CD11b⁺/CD45^high immune cells following HI insult. L-Cysteine administration reduced OPN expression in CD11b⁺/CD45^high immune cells, concomitant with improving the behavior in Y-maze test and suppressing cerebral recruitment of CD11b⁺/CD45^high immune cells post-HI insult. Moreover, L-Cysteine administration suppressed the Stat3 activation by inducing S-sulfhydration of Stat3. Intracerebroventricular injection of Stat3 siRNA not only decreased OPN expression, but also reversed HI brain damage. Our data demonstrate that L-Cysteine administration effectively attenuates the OPN-mediated neuroinflammation by inducing S-sulfhydration of Stat3, which contributes to its anti-inflammatory effect following HI insult in neonatal mice. Blocking OPN expression may serve as a new target for therapeutic intervention for perinatal HI brain injury.

Combined Efficacy of CXCL5, STC2, and CHI3L1 in the Diagnosis of Colorectal Cancer

Objective

To improve the diagnostic capacity of serum biomarkers for colorectal cancer (CRC), we introduced three novel indicators, namely, the C-X-C motif chemokine ligand 5 (CXCL5), stanniocalcin 2 (STC2), and chitinase 3 like 1 (CHI3L1) and assessed their performances in the detection of CRC.

Methods

A total of 887 serum samples (153 health, 342 polyps, and 392 CRCs) were collected. Concentrations of CXCL5, STC2, and CHI3L1 were measured by the ELISA. CEA and CA199 were determined by electrochemiluminescence. Binary logistic regression was used to build the combination model. ROC analysis was used to evaluate the performance of biomarkers alone or in combination.

Results

Model_2 that based on CXCL5, STC2, and CHI3L1 was the best approach in discriminating CRC from non-CRC controls (AUC, 0.943 (0.922–0.960); sensitivity, 0.848; specificity, 0.917; and accuracy, 0.887 in the training cohort and 0.959 (95% CI 0.927–0.980), 0.878, 0.917, and 0.900 in the testing cohort, respectively). In the detection of early CRC, Model_2 revealed AUC, sensitivity, specificity, and accuracy of 0.925 (0.897–0.947), 0.793, 0.917, and 0.886 in the training cohort and those of 0.926 (0.979–0.959), 0.786, 0.931, and 0.898 in the testing cohort. Furthermore, Model_2 exhibited an excellent diagnostic performance in CEA-negative cases (0.938 (0.913–0.957), 0.826, 0.917, and 0.888 in the training cohort and 0.961 (0.925–0.983), 0.887, 0.931, and 0.918 in the testing cohort). As used alone, STC2 achieved the capacities that is second only to that of Model_2 (0.866 (0.837–0.892), 0.859, 0.842, and 0.853 in the training cohort and 0.887 (0.842–0.923), 0.922, 0.799, and 0.853 in the testing cohort). STC2 alone also yielded acceptable results for early CRC detection (0.815 (0.776–0.849), 0.767, 0.849, and 0.829 in the training cohort and 0.870 (0.812–0.914), 0.952, 0.799, and 0.833 in the testing cohort). Moreover, STC2 maintained diagnostic accuracy for CRC patients with negative CEA (0.874 (0.842–0.901), 0.862, 0.849, and 0.853 in the training cohort and 0.898 (0.848–0.936), 0.930, 0.801, and 0.842 in the testing cohort). In comparison, the performances of the CEA and CA199 based Model_1 were far from satisfactory, especially in early cases (0.767 (0.726–0.805), 0.491, 0.863, and 0.771 in the training cohort and 0.817 (0.754–0.870), 0.476, 0.889, and 0.796 in the testing cohort).

Conclusions

STC2 was a promising serum biomarker for CRC diagnosis either used alone or in combination with CXCL5 and CHI3L1.

Brain Peri-Hematomal Area, a Strategic Interface for Blood Clearance: A Human Neuropathological and Transcriptomic Study

Background:

Enhancing the blood clearance process is a promising therapeutic strategy for intracerebral hemorrhage (ICH). We aimed to investigate the kinetic of this process after ICH in human brain tissue through the monocyte-macrophage scavenger receptor (CD163)/HO-1 (hemoxygenase-1) pathway.

Methods:

We led a cross-sectional post-mortem study including 22 consecutive ICH cases (2005–2019) from the Lille Neurobank. Cases were grouped according to the time of death: ≤72 hours, 4 to 7 days, 8 to 15 days, 16 to 90 days, and >90 days after ICH onset. Paraffin-embedded tissue was extracted from 4 strategic areas, including hematoma core and peri-hematomal area to perform histological investigations. Additionally, we extracted RNA from the peri-hematomal area of 6 cases to perform transcriptomic analysis.

Results:

We included 19 ICH cases (median age: 79 [71–89] years; median delay ICH-death: 13 [5–41] days). The peri-hematomal area concentrated most of reactive microglia, CD163/HO-1 and iron deposits as compared with other brain areas. We found a surge in the blood clearance process from day 8 to day 15 after ICH onset. Transcriptomic analysis showed that HO-1 was the most upregulated gene (2.81±0.39, adjusted P =1.11×10 –10 ) and CD163 the sixth (1.49±0.29, adjusted P =1.68×10 – 5 ). We also identified several upregulated genes that exert a beneficial role in terminating inflammation and enhancing tissue repair.

Conclusions:

We provide histological and transcriptomic-based evidence in humans for the key role of peri-hematomal area in endogenous blood clearance process through the CD163/HO-1 pathway, especially from day 8 after ICH and favored by an anti-inflammatory environment. Our findings contribute to identify innovative therapeutic strategies for ICH.

OPN N-glycosylation Promoted Bone Destruction

OBJECTIVES

Exploring the role of OPN N-glycosylation in osteoblasts and osteoclasts.

METHODS

Immunohistochemistry was used to detect the expression of OPN in mice with apical periodontitis. The asparagine at position 79 of the OPN protein was mutated to glutamine, and the above plasmids were transfected into osteoblasts and osteoclasts. The effect of OPN N-glycosylation on proliferation of osteoblasts and osteoclasts was detected by CCK8 assays. Western blotting was used to detect the expression of OPN N-glycosylation on osteoclasts and osteoblasts. Detection of N-glycosylation of OPN activated the NF-κB signaling pathway to regulate osteoblasts and osteoclasts.

RESULTS

OPN increased expression in a mice model of apical periodontitis. The expression curve of OPN resembled a reverse V shape. The OPN N-glycosylation site was identified as 79 by MS. N-glycosylation of OPN promoted the proliferation of osteoclasts. But the N79 glycosylation site of mutant OPN couldn't increase the proliferation of osteoblasts. OPN N-glycosylation modulated the expression of osteoclast- and osteoblast-associated factors through the NF-κB signaling pathway. N-glycosylation of OPN promoted nuclear translocation of NF-κB in osteoclasts and osteoblasts.

CONCLUSIONS

The N-glycosylation site of OPN is 79. N-glycosylation of OPN played an important role in the biological function of OPN protein.

Emerging Biomarkers of Multiple Sclerosis in the Blood and the CSF: A Focus on Neurofilaments and Therapeutic Considerations

INTRODUCTION

Multiple Sclerosis (MS) is the most common immune-mediated chronic neurodegenerative disease of the central nervous system (CNS) affecting young people. This is due to the permanent disability, cognitive impairment, and the enormous detrimental impact MS can exert on a patient's health-related quality of life. It is of great importance to recognise it in time and commence adequate treatment at an early stage. The currently used disease-modifying therapies (DMT) aim to reduce disease activity and thus halt disability development, which in current clinical practice are monitored by clinical and imaging parameters but not by biomarkers found in blood and/or the cerebrospinal fluid (CSF). Both clinical and radiological measures routinely used to monitor disease activity lack information on the fundamental pathophysiological features and mechanisms of MS. Furthermore, they lag behind the disease process itself. By the time a clinical relapse becomes evident or a new lesion appears on the MRI scan, potentially irreversible damage has already occurred in the CNS. In recent years, several biomarkers that previously have been linked to other neurological and immunological diseases have received increased attention in MS. Additionally, other novel, potential biomarkers with prognostic and diagnostic properties have been detected in the CSF and blood of MS patients.

AREAS COVERED

In this review, we summarise the most up-to-date knowledge and research conducted on the already known and most promising new biomarker candidates found in the CSF and blood of MS patients.

DISCUSSION

the current diagnostic criteria of MS relies on three pillars: MRI imaging, clinical events, and the presence of oligoclonal bands in the CSF (which was reinstated into the diagnostic criteria by the most recent revision). Even though the most recent McDonald criteria made the diagnosis of MS faster than the prior iteration, it is still not an infallible diagnostic toolset, especially at the very early stage of the clinically isolated syndrome. Together with the gold standard MRI and clinical measures, ancillary blood and CSF biomarkers may not just improve diagnostic accuracy and speed but very well may become agents to monitor therapeutic efficacy and make even more personalised treatment in MS a reality in the near future. The major disadvantage of these biomarkers in the past has been the need to obtain CSF to measure them. However, the recent advances in extremely sensitive immunoassays made their measurement possible from peripheral blood even when present only in minuscule concentrations. This should mark the beginning of a new biomarker research and utilisation era in MS.

Osteopontin in autoimmune disorders: current knowledge and future perspective

Osteopontin (OPN) is a multifunctional cytokine and adhesion molecule, as well as an unusual regulator for both innate and adaptive immune responses. Several immune cells can produce OPN, including dendritic cells (DCs), macrophages, and T lymphocytes. OPN expression is reported to be increased in a wide range of disorders, including autoimmunity, cancer, and allergy. The overexpression of OPN in several autoimmune disorders, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), Type 1 diabetes (T1D), inflammatory bowel disease (IBD), Sjögren's, and myasthenia gravis, have been shown to be correlated with disease severity. Regarding the important regulatory roles of OPN in the immune system, this study aimed to review the role of this molecule in autoimmune disorders and to provide a complete view of the current knowledge in this field.

Pathogenic insights from genetic causes of autoinflammatory inflammasomopathies and interferonopathies

A number of systemic autoinflammatory diseases arise from gain-of-function mutations in genes encoding IL-1-activating inflammasomes or cytoplasmic nucleic acid sensors including the receptor and sensor STING and result in increased IL-1 and type I interferon production, respectively. Blocking these pathways in human diseases has provided proof-of-concept, confirming the prominent roles of these cytokines in disease pathogenesis. Recent insights into the multilayered regulation of these sensor pathways and insights into their role in amplifying the disease pathogenesis of monogenic and complex genetic diseases spurred new drug development targeting the sensors. This review provides insights into the pathogenesis and genetic causes of these "prototypic" diseases caused by gain-of function mutations in IL-1-activating inflammasomes (inflammasomopathies) and in interferon-activating pathways (interferonopathies) including STING-associated vasculopathy with onset in infancy, Aicardi-Goutieres syndrome, and proteasome-associated autoinflammatory syndromes that link activation of the viral sensors STING, "self" nucleic acid metabolism, and the ubiquitin-proteasome system to "type I interferon production" and human diseases. Clinical responses and biomarker changes to Janus kinase inhibitors confirm a role of interferons, and a growing number of diseases with "interferon signatures" unveil extensive cross-talk between major inflammatory pathways. Understanding these interactions promises new tools in tackling the significant clinical challenges in treating patients with these conditions.

Colon Expression of Chemokines and Their Receptors Depending on the Stage of Colitis and Oat Beta-Glucan Dietary Intervention-Crohn's Disease Model Study

Crohn’s disease (CD), a condition characterized by chronic inflammation of the gastrointestinal tract with alternating periods of exacerbation and remission, is becoming common around the world. This study aimed to analyze the molecular mechanisms underlying the anti-inflammatory properties of oat beta-glucans of varying molar masses by modulating the expression of chemokines and their receptors as well as other proteins related to both stages of TNBS (2,4,6-trinitrobenzosulfonic acid)-induced colitis, which is an animal model of CD. The experiment involved 96 Sprague–Dawley rats, which were divided into two main groups: control and TNBS-induced colitis. Both groups of rats were further divided into three dietary subgroups, which were fed with standard feed or feed supplemented with low- or high-molar-mass oat beta-glucans for 3 (reflecting acute inflammation) or 7 days (reflecting pre-remission). The gene expression of chemokines and their receptors in the colon wall was determined by RT-PCR, and the expression of selected proteins in the mucosa was determined by immunohistochemical analysis. The results showed that acute and pre-remission stages of colitis were characterized by the increased gene expression of seven chemokines and four chemokine receptors in the colon wall as well as disrupted protein expression of CXCL1, CCL5, CXCR2, CCR5, and OPN in the mucosa. The consumption of oat beta-glucans resulted in decreased expression of most of these genes and modulated the expression of all proteins, with a stronger effect observed with the use of high-molar-mass beta-glucan. To summarize, dietary oat beta-glucans, particularly those of high molar mass, can reduce colitis by modulating the expression of chemokines and their receptors and certain proteins associated with CD.

Targeting Mechano-Transcription Process as Therapeutic Intervention in Gastrointestinal Disorders

Mechano-transcription is a process whereby mechanical stress alters gene expression. The gastrointestinal (GI) tract is composed of a series of hollow organs, often encountered by transient or persistent mechanical stress. Recent studies have revealed that persistent mechanical stress is present in obstructive, functional, and inflammatory disorders and alters gene transcription in these conditions. Mechano-transcription of inflammatory molecules, pain mediators, pro-fibrotic and growth factors has been shown to play a key role in the development of motility dysfunction, visceral hypersensitivity, inflammation, and fibrosis in the gut. In particular, mechanical stress-induced cyclooxygenase-2 (COX-2) and certain pro-inflammatory mediators in gut smooth muscle cells are responsible for motility dysfunction and inflammatory process. Mechano-transcription of pain mediators such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) may lead to visceral hypersensitivity. Emerging evidence suggests that mechanical stress in the gut also leads to up-regulation of certain proliferative and pro-fibrotic mediators such as connective tissue growth factor (CTGF) and osteopontin (OPN), which may contribute to fibrostenotic Crohn's disease. In this review, we will discuss the pathophysiological significance of mechanical stress-induced expression of pro-inflammatory molecules, pain mediators, pro-fibrotic and growth factors in obstructive, inflammatory, and functional bowel disorders. We will also evaluate potential therapeutic targets of mechano-transcription process for the management of these disorders.

Osteopontin levels are associated with late-time lower regional brain volumes in multiple sclerosis

Osteopontin (OPN) is a proinflammatory marker produced by systemic immune and central nervous system (CNS) resident cells. We examined, if the level of OPN in the cerebrospinal fluid (CSF) and blood is associated with late-time regional brain volumes and white matter (WM) lesion load in MS. Concentrations of OPN in blood and CSF were related to MRI findings 10.1 ± 2.0 years later in 46 patients with MS. OPN concentration was measured by ELISA, while regional brain volumes and lesion load was assessed by magnetic resonance imaging (MRI) using 3D MPRAGE sequence and automated MR volumetry. OPN measured in the CSF was associated with several regional brain volumes and WM lesion load measured 10.1 ± 2.0 years later. CSF OPN concentration correlated with long-term enlargement of lateral- and inferior lateral ventricles and the elevation of gross CSF volume, in conjunction with the reduction of several cortical/subcortical gray matter and WM volumes. Serum OPN showed no long-term association with regional brain volumes. OPN measured from the CSF but not from the serum was associated with lower regional brain volumes measured a decade later, indicating the primary role of inflammation within the CNS in developing long-term brain related alterations.