Expression and production of the long pentraxin PTX3 in rheumatoid arthritis (RA)

Clinical Phenotypes, Serological Biomarkers, and Synovial Features Defining Seropositive and Seronegative Rheumatoid Arthritis: A Literature Review

Rheumatoid arthritis (RA) is a chronic autoimmune disorder which can lead to long-term joint damage and significantly reduced quality of life if not promptly diagnosed and adequately treated. Despite significant advances in treatment, about 40% of patients with RA do not respond to individual pharmacological agents and up to 20% do not respond to any of the available medications. To address this large unmet clinical need, several recent studies have focussed on an in-depth histological and molecular characterisation of the synovial tissue to drive the application of precision medicine to RA. Currently, RA patients are clinically divided into "seropositive" or "seronegative" RA, depending on the presence of routinely checked antibodies. Recent work has suggested that over the last two decades, long-term outcomes have improved significantly in seropositive RA but not in seronegative RA. Here, we present up-to-date differences in epidemiology, clinical features, and serological biomarkers in seronegative versus seropositive RA and discuss how histological and molecular synovial signatures, revealed by recent large synovial biopsy-based clinical trials, may be exploited to refine the classification of RA patients, especially in the seronegative group.

Pentraxins in invertebrates and vertebrates: From structure, function and evolution to clinical applications

The immune system is divided into two broad categories, consisting of innate and adaptive immunity. As recognition and effector factors of innate immunity and regulators of adaptive immune responses, lectins are considered to be important defense chemicals against microbial pathogens, cell trafficking, immune regulation, and prevention of autoimmunity. Pentraxins, important members of animal lectins, play a significant role in protecting the body from pathogen infection and regulating inflammatory reactions. They can recognize and bind to a variety of ligands, including carbohydrates, lipids, proteins, nucleic acids and their complexes, and protect the host from pathogen invasion by activating the complement cascade and Fcγ receptor pathways. Based on the primary structure of the subunit, pentraxins are divided into short and long pentraxins. The short pentraxins are comprised of C-reactive protein (CRP) and serum amyloid P (SAP), and the most important member of the long pentraxins is pentraxin 3 (PTX3). The CRP and SAP exist in both vertebrates and invertebrates, while the PTX3 may be present only in vertebrates. The major ligands and functions of CRP, SAP and PTX3 and three activation pathways involved in the complement system are summarized in this review. Their different characteristics in various animals including humans, and their evolutionary trees are analyzed. The clinical applications of CRP, SAP and PTX3 in human are reviewed. Some questions that remain to be understood are also highlighted.

The pentraxin family in autoimmune disease

The pentraxins represent a family of multifunctional proteins composed of long and short pentamers. The latter includes serum amyloid P component (SAP) and C-reactive protein (CRP) whereas the former includes neuronal PTX1 and PTX2 (NPTX1 and NPTX2, respectively), PTX3 and PTX4. These serve as a bridge between adaptive immunity and innate immunity and a link between inflammation and immunity. Similarities and differences between long and short pentamers are examined and their roles in autoimmune disease are discussed. Increased CRP and PTX3 could indicate the activity of rheumatoid arthritis, systemic lupus erythematosus or other autoimmune diseases. Mechanistically, CRP and PTX3 may predict target organ injury, regulate bone metabolic immunity and maintain homeostasis as well as participate in vascular endothelial remodeling. Interestingly, PTX3 is pleiotropic, being involved in inflammation and tissue repair. Given the therapeutic potential of PTX3 and CRP, targeting these factors to exert a beneficial effect is the focus of research efforts. Unfortunately, studies on NPTX1, NPTX2, PTX4 and SAP are scarce and more research is clearly needed to elaborate their potential roles in autoimmune disease.

Vascular health in subjects with rheumatoid arthritis: assessment of endothelial function indices and serum biomarkers of vascular damage

BACKGROUND

The cardiovascular risk (CVD) in patients with rheumatoid arthritis (RA) is 1.5-2 times higher than that in individuals of the same age and sex.

AIMS

To analyse the degree of endothelial dysfunction, the atherogenic immunoinflammatory serum background and the relationships among some vascular indices, cardiovascular comorbidities, and cognitive performance in subjects with RA.

PATIENTS AND METHODS

All consecutive patients with a rheumatoid arthritis diagnosis admitted to the Rheumatology Ward of "Policlinico Paolo Giaccone" Hospital of Palermo were enrolled from July 2019 to September 2020. We evaluated our patients' cognitive functions by administering the Mini-Mental State Examination (MMSE). Reactive Hyperaemia Index (RHI) was evaluated for assessment of endothelial function. Serum levels of angiopoietin 2, osteopontin and pentraxin 3 were assessed by blood collection.

RESULTS

Fifty-eight consecutive patients with RA and 40 control subjects were analysed. RA patients showed significantly lower mean RHI values, significantly higher mean Augmentation Index (AIX) values and significantly lower mean Mini-Mental State Examination (MMSE) score values than the control group. Patients with rheumatoid arthritis also showed higher mean serum values of pentraxin 3 and angiopoietin 2 than healthy controls. Multivariate logistic regression analysis showed a significant association between pentraxin 3 and angiopoietin 2 and the presence of RA.

DISCUSSION

Angiopoietin 2 and pentraxin 3 could be considered surrogate biomarkers of endothelial activation and vascular disease, as they could play an essential role in the regulation of endothelial integrity and inflammation.

Pentraxin 3 Facilitates Shrimp-Allergic Responses in IgE-Activated Mast Cells

Background. Since food avoidance is currently the only way to prevent allergic reactions to shrimp, a better understanding of molecular events in the induction and progression of allergy, including food allergy, is needed for developing strategies to inhibit allergic responses. Pentraxin 3 (PTX3) is rapidly produced directly from inflammatory or damaged tissues and is involved in acute immunoinflammatory responses. However, the role of PTX3 in the development of immediate IgE-mediated shrimp allergy remains unknown. Methods. Wild-type BALB/c mice were immunized intraperitoneally and were challenged with shrimp extract. Serum IgE and PTX3 levels were analyzed. RBL-2H3 cells were stimulated with either dinitrophenyl (DNP) or serum of shrimp-allergic mice, and markers of degranulation, proinflammatory mediators, and phosphorylation of signal proteins were analyzed. We further examined the effect of PTX3 in shrimp extract-induced allergic responses in vitro and in vivo. Results. Mice with shrimp allergy had increased PTX3 levels in the serum and small intestine compared with healthy mice. PTX3 augmented degranulation, the production of proinflammatory mediators, and activation of the Akt and MAPK signaling pathways in mast cells upon DNP stimulation. Furthermore, the expression of transcription factor CCAAT/enhancer-binding protein delta (CEBPD) was elevated in PTX3-mediated mast cell activation. Finally, the PTX3 inhibitor RI37 could attenuate PTX3-induced degranulation, proinflammatory mediator expression, and phosphorylation of the Akt and MAPK signaling. Conclusions. The results suggested that PTX3 can facilitate allergic responses. Our data provide new insight to demonstrate that PTX3 is a cause of allergic inflammation and that RI37 can serve as a therapeutic agent in shrimp allergy.

Blockade of the pentraxin 3/CD44 interaction attenuates lung injury-induced fibrosis

BACKGROUND

Fibrosing interstitial lung diseases (fILD) are potentially fatal with limited therapeutic options and no effective strategies to reverse fibrogenesis. Myofibroblasts are chief effector cells in fibrosis that excessively deposit collagen in the pulmonary interstitium and lead to progressive impairment of gaseous exchange.

METHODS

Plasma and lung specimens from patients with fILD were applied for detecting pentraxin 3 (PTX3) abundance by ELISA and Immunohistochemistry. Masson's trichrome and Sirius red stains and hydroxyproline assay were performed for assessing collagen accumulation in the lungs of bleomycin-exposed conditional Ptx3-deficient and PTX3-neutralizing antibody (αPTX3i)-treated mice. Downstream effectors including signaling pathways and fibrotic genes were examined for assessing CD44-involved PTX3-induced fibrosis in HFL1 and primary mouse fibroblasts.

RESULTS

PTX3 was upregulated in the lungs and plasma of bleomycin-exposed mice and correlated with disease severity and adverse outcomes in fILD patients. Decreased collagen accumulation, attenuation of alveolar fibrosis and fibrotic markers, and improved lung function were observed in bleomycin-exposed conditional Ptx3-deficient mice. PTX3 activates lung fibroblasts to differentiate towards migrative and highly collagen-expressing myofibroblasts. Lung fibroblasts with CD44 inactivation attenuated the PI3K-AKT1, NF-κB, and JNK signaling pathways and fibrotic markers. αPTX3i mimic-based therapeutic studies demonstrated abrogation of the migrative fibroblast phenotype and myofibroblast activation in vitro. Notably, αPTX3i inhibited lung fibrosis, reduced collagen deposition, increased mouse survival, and improved lung function in bleomycin-induced pulmonary fibrosis.

CONCLUSIONS

The present study reveals new insights into the involvement of the PTX3/CD44 axis in fibrosis and suggests PTX3 as a promising therapeutic target in fILD patients.

Pentraxin 3 regulated by miR-224-5p modulates macrophage reprogramming and exacerbates osteoarthritis associated synovitis by targeting CD32

Emerging evidence has shown an imbalance in M1/M2 macrophage polarization to play an essential role in osteoarthritis (OA) progression. However, the underlying mechanistic basis for this polarization is unknown. RNA sequencing of OA M1-polarized macrophages found highly expressed levels of pentraxin 3 (PTX3), suggesting a role for PTX3 in OA occurrence and development. Herein, PTX3 was found to be increased in the synovium and articular cartilage of OA patients and OA mice. Intra-articular injection of PTX3 aggravated, while PTX3 neutralization reversed synovitis and cartilage degeneration. No metabolic disorder or proteoglycan loss were observed in cartilage explants when treated with PTX3 alone. However, cartilage explants exhibited an OA phenotype when treated with culture supernatants of macrophages stimulated with PTX3, suggesting that PTX3 did not have a direct effect on chondrocytes. Therefore, the OA anti-chondrogenic effects of PTX3 are primarily mediated through macrophages. Mechanistically, PTX3 was upregulated by miR-224-5p deficiency, which activated the p65/NF-κB pathway to promote M1 macrophage polarization by targeting CD32. CD32 was expressed by macrophages, that when stimulated with PTX3, secreted abundant pro-inflammation cytokines that induced severe articular cartilage damage. The paracrine interaction between macrophages and chondrocytes produced a feedback loop that enhanced synovitis and cartilage damage. The findings of this study identified a functional pathway important to OA development. Blockade of this pathway and PTX3 may prevent and treat OA.

Increased Circulating Pentraxin 3 Levels in Patients with Rheumatoid Arthritis: a Meta-analysis

BACKGROUND

Pentraxin 3 (PTX3) as a soluble pattern recognition molecule not only acts as a promising indicator reflecting the disease activity of rheumatoid arthritis (RA) patients, but exerts essential pathogenic roles in the progression of RA and serves as a potential therapeutic target for RA patients. Our study intends to systematically evaluate the circulating PTX3 levels and their potential influencing factors in RA patients.

METHODS

Articles regarding the circulating PTX3 levels of RA patients were identified in Pubmed, Embase, China National Knowledge Infrastructure (CNKI), and Cochrane databases. Standardized mean difference (SMD) and corresponding 95% confidence intervals (95% CI) were calculated and further illustrated by the forest plot. Egger's regression test and sensitivity analysis were conducted to assess the publication bias and stability of the results, respectively.

RESULTS

Twenty articles with 21 individual studies were recruited in our meta-analysis. The overall results revealed that compared with healthy controls, RA patients had significantly higher circulating PTX3 levels (pooled SMD = 0.97, 95% CI: 0.48 to 1.45). Subgroup analyses further demonstrated that compared with healthy controls, RA patients of age ≤ 50 years, 2.6 < disease activity score in 28 joints (DAS28) ≤ 3.2, 3.2 < DAS28 ≤ 5.1, DAS28 > 5.1, C-reactive protein (CRP) levels > 10 mg/L, erythrocyte sedimentation rate (ESR) > 20 mm/h, and disease duration > 5 years had significantly higher circulating PTX3 levels, respectively; whereas RA patients of age > 50 years, DAS28 ≤ 2.6, CRP levels ≤ 10 mg/L, ESR ≤ 20 mm/h and disease duration ≤ 5 years had no significantly altered circulating PTX3 levels, respectively. Additionally, no matter the patients of Caucasian ethnicity or not, circulating PTX3 levels were significantly increased in RA patients.

CONCLUSION

Compared with healthy controls, circulating PTX3 levels are significantly increased in RA patients, which are influenced by the age, disease activity, CRP levels, ESR, and disease duration of the patients.

The Relationship between Plasma Pentraxin 3 and Serum Amyloid P Levels and Disease Activity in Ankylosing Spondylitis

BACKGROUND

In clinical practice, it is hard to judge the level of disease activity in some patients with ankylosing spondylitis (AS) who have low traditional acute phase reactant values such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) but have considerable pain and inflammation. The aim of this study is to investigate plasma pentraxin 3 (PTX3) and serum amyloid P (SAP) levels in patients with AS who had normal ESR and CRP but high disease activity.

METHODS

100 AS patients and 100 gender- and age-matched controls were included. Epidemiological, clinical, and treatment data and plasma levels of CRP, ESR, PTX3, and SAP were evaluated. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP were used for evaluating disease activity. Plasma levels of PTX3 and SAP were compared between AS patients and controls and also among AS patients with active and inactive disease.

RESULTS

AS patients had significantly higher plasma levels of PTX3 and SAP than controls. There were not any significant correlations between PTX3 and SAP with BASDAI, ASDAS-CRP, and ESR. There was a positive correlation between PTX3 and CRP. No significant difference in plasma levels of PTX3 and SAP was observed between patients with active disease and inactive disease, both with normal ESR and CRP levels. Disease duration and treatment did not influence plasma PTX3 levels.

CONCLUSIONS

In patients with AS, plasma levels of PTX3 and SAP were found to be elevated when compared to healthy controls. No association was observed between these biomarkers and disease activity.

The Protective Role of the Long Pentraxin PTX3 in Spontaneously Hypertensive Rats with Heart Failure

Pentraxin 3 (PTX3) is synthesized locally and released into the circulation, reflecting local inflammation in the cardiovascular system. Therefore, we conducted a study to explore the effect of PTX3 in spontaneously hypertensive heart failure (SHHF) rats. Sprague Dawley (SD) and SHHF rats were treated with recombinant PTX3 protein, and the blood pressure (BP) and echocardiographic parameters were collected. Radioimmunoassay, enzyme immunoassay and enzyme-linked immunosorbent assay (ELISA) were applied to detect plasma levels of atrial/B-type natriuretic peptide (ANP/BNP) and PTX3. The pathological changes in the myocardial tissues were observed by hematoxylin and eosin (HE) and Masson stainings. The mRNA and protein expressions were detected by quantitative real-time reverse-transcription polymerase chain reaction (qPCR) and western blotting. Cardiomyocyte apoptosis was evaluated by TUNEL staining and DNA fragmentation test. Increased plasma concentrations of PTX3 were found in SHHF rats compared with SD rats, which was further enhanced by recombinant PTX3 protein. After injection with recombinant PTX3 protein, the heart function was improved in SHHF rats with the decreased systolic and diastolic BP, and the reduced plasma levels of ANP and BNP. Moreover, PTX3 improved the myocardial damage and interstitial fibrosis in SHHF rats with reduced cardiomyocyte apoptosis and decreased mRNA expressions of pro-inflammatory factors in myocardial tissues. PTX3 could decrease the BP and plasma levels of ANP and BNP in SHHF rats, as well as improve the inflammation, cardiomyocyte apoptosis, and pathological changes of myocardial tissues, suggesting it may be a useful intervention in the treatment of SHHF.

Circulating and Synovial Pentraxin-3 (PTX3) Expression Levels Correlate With Rheumatoid Arthritis Severity and Tissue Infiltration Independently of Conventional Treatments Response

Aims

To determine the relationship between PTX3 systemic and synovial levels and the clinical features of rheumatoid arthritis (RA) in a cohort of early, treatment naïve patients and to explore the relevance of PTX3 expression in predicting response to conventional-synthetic (cs) Disease-Modifying-Anti-Rheumatic-Drugs (DMARDs) treatment.

Methods

PTX3 expression was analyzed in 119 baseline serum samples from early naïve RA patients, 95 paired samples obtained 6-months following the initiation of cs-DMARDs treatment and 43 healthy donors. RNA-sequencing analysis and immunohistochemistry for PTX3 were performed on a subpopulation of 79 and 58 synovial samples, respectively, to assess PTX3 gene and protein expression. Immunofluorescence staining was performed to characterize PTX3 expressing cells within the synovium.

Results

Circulating levels of PTX3 were significantly higher in early RA compared to healthy donors and correlated with disease activity at baseline and with the degree of structural damages at 12-months. Six-months after commencing cs-DMARDs, a high level of PTX3, proportional to the baseline value, was still detectable in the serum of patients, regardless of their response status. RNA-seq analysis confirmed that synovial transcript levels of PTX3 correlated with disease activity and the presence of mediators of inflammation, tissue remodeling and bone destruction at baseline. PTX3 expression in the synovium was strongly linked to the degree of immune cell infiltration, the presence of ectopic lymphoid structures and seropositivity for autoantibodies. Accordingly, PTX3 was found to be expressed by numerous synovial cell types such as plasma cells, fibroblasts, vascular and lymphatic endothelial cells, macrophages, and neutrophils. The percentage of PTX3-positive synovial cells, although significantly reduced at 6-months post-treatment as a result of global decreased cellularity, was similar in cs-DMARDs responders and non-responders.

Conclusion

This study demonstrates that, early in the disease and prior to treatment modification, the level of circulating PTX3 is a reliable marker of RA activity and predicts a high degree of structural damages at 12-months. In the joint, PTX3 associates with immune cell infiltration and the presence of ectopic lymphoid structures. High synovial and peripheral blood levels of PTX3 are associated with chronic inflammation characteristic of RA. Additional studies to determine the mechanistic link are required.

Proteomic Analysis of Synovial Fibroblasts and Articular Chondrocytes Co-Cultures Reveals Valuable VIP-Modulated Inflammatory and Degradative Proteins in Osteoarthritis

Osteoarthritis (OA) is the most common musculoskeletal disorder causing a great disability and a reduction in the quality of life. In OA, articular chondrocytes (AC) and synovial fibroblasts (SF) release innate-derived immune mediators that initiate and perpetuate inflammation, inducing cartilage extracellular matrix (ECM) degradation. Given the lack of therapies for the treatment of OA, in this study, we explore biomarkers that enable the development of new therapeutical approaches. We analyze the set of secreted proteins in AC and SF co-cultures by stable isotope labeling with amino acids (SILAC). We describe, for the first time, 115 proteins detected in SF-AC co-cultures stimulated by fibronectin fragments (Fn-fs). We also study the role of the vasoactive intestinal peptide (VIP) in this secretome, providing new proteins involved in the main events of OA, confirmed by ELISA and multiplex analyses. VIP decreases proteins involved in the inflammatory process (CHI3L1, PTX3), complement activation (C1r, C3), and cartilage ECM degradation (DCN, CTSB and MMP2), key events in the initiation and progression of OA. Our results support the anti-inflammatory and anti-catabolic properties of VIP in rheumatic diseases and provide potential new targets for OA treatment.

New Insights on the Role of pentraxin-3 in Allergic Asthma

Pentraxins are soluble pattern recognition receptors that play a major role in regulating innate immune responses. Through their interaction with complement components, Fcγ receptors, and different microbial moieties, Pentraxins cause an amplification of the inflammatory response. Pentraxin-3 is of particular interest since it was identified as a biomarker for several immune-pathological diseases. In allergic asthma, pentraxin-3 is produced by immune and structural cells and is up-regulated by pro-asthmatic cytokines such as TNFα and IL-1β. Strikingly, some recent experimental evidence demonstrated a protective role of pentraxin-3 in chronic airway inflammatory diseases such as allergic asthma. Indeed, reduced pentraxin-3 levels have been associated with neutrophilic inflammation, Th17 immune response, insensitivity to standard therapeutics and a severe form of the disease. In this review, we will summarize the current knowledge of the role of pentraxin-3 in innate immune response and discuss the protective role of pentraxin-3 in allergic asthma.

Investigating the molecular control of deer antler extract on articular cartilage

BACKGROUND

Deer antler is considered as a precious traditional Chinese medicinal material and has been widely used to reinforce kidney's yang, nourish essence, and strengthen bone function. The most prominent bioactive components in deer antler are water-soluble proteins that play potential roles in bone formation and repair. The aim of this study was to explore the molecular control and therapeutic targets of deer antler extract (DAE) on articular cartilage.

METHODS

DAE was prepared as previously described. All rats were randomly divided into Blank group and DAE group (10 rats per group) after 7-day adaptive feeding. The rats in DAE group were orally administrated with DAE at a dose of 0.2 g/kg per day for 3 weeks, and the rats in Blank group were fed with drinking water. Total RNA was isolated from the articular cartilage of knee joints. RNA sequencing (RNA-seq) experiment combined with quantitative real-time polymerase chain reaction (qRT-PCR) verification assay was carried out to explore the molecular control and therapeutic targets of DAE on articular cartilage.

RESULTS

We demonstrated that DAE significantly increased the expression levels of functional genes involved in cartilage formation, growth, and repair and decreased the expression levels of susceptibility genes involved in the pathophysiology of osteoarthritis.

CONCLUSIONS

DAE might serve as a candidate supplement for maintaining cartilage homeostasis and preventing cartilage degeneration and inflammation. These effects were possibly achieved by accelerating the expression of functional genes involved in chondrocyte commitment, survival, proliferation, and differentiation and suppressing the expression of susceptibility genes involved in the pathophysiology of osteoarthritis. Thus, our findings will contribute towards deepening the knowledge about the molecular control and therapeutic targets of DAE on the treatment of cartilage-related diseases.

Perspectives on long pentraxin 3 and rheumatoid arthritis: several potential breakthrough points relying on study foundation of the past

Rheumatoid arthritis (RA) is a systemic chronic autoimmune inflammatory disease which is mainly characterized by synovitis and results in a severe burden for both the individual and society. To date, the underlying mechanisms of RA are still poorly understood. Pentraxin 3 (PTX3) is a typical long pentraxin protein which has been highly conserved during evolution. Meanwhile, functions as well as properties of PTX3 have been extensively studied. Several studies identified that PTX3 plays a predominate role in infection, inflammation, immunity and tumor. Interestingly, PTX3 has also been verified to be closely associated with development of RA. We therefore accomplished an elaboration of the relationships between PTX3 and RA. Herein, we mainly focus on the associated cell types and cognate cytokines involved in RA, in combination with PTX3. This review infers the insight into the interaction of PTX3 in RA and aims to provide novel clues for potential therapeutic target of RA in clinic.

K284-6111 alleviates memory impairment and neuroinflammation in Tg2576 mice by inhibition of Chitinase-3-like 1 regulating ERK-dependent PTX3 pathway

Background

Alzheimer’s disease (AD) is one of the most prevalent neurodegenerative disorders characterized by gradual memory loss and neuropsychiatric symptoms. We have previously demonstrated that the 2-({3-[2-(1-cyclohexene-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111), the inhibitor of CHI3L1, has the inhibitory effect on memory impairment in Αβ infusion mouse model and on LPS-induced neuroinflammation in the murine BV-2 microglia and primary cultured astrocyte.

Methods

In the present study, we investigated the inhibitory effect of K284-6111 on memory dysfunction and neuroinflammation in Tg2576 transgenic mice, and a more detailed correlation of CHI3L1 and AD. To investigate the effects of K284-6111 on memory dysfunction, we administered K284-6111 (3 mg/kg, p.o.) daily for 4 weeks to Tg2576 mice, followed by behavioral tests of water maze test, probe test, and passive avoidance test.

Results

Administration of K284-6111 alleviated memory impairment in Tg2576 mice and had the effect of reducing the accumulation of Aβ and neuroinflammatory responses in the mouse brain. K284-6111 treatment also selectively inactivated ERK and NF-κB pathways, which were activated when CHI3L1 was overexpressed, in the mouse brain and in BV-2 cells. Web-based gene network analysis and our results of gene expression level in BV-2 cells showed that CHI3L1 is closely correlated with PTX3. Our result revealed that knockdown of PTX3 has an inhibitory effect on the production of inflammatory proteins and cytokines, and on the phosphorylation of ERK and IκBα.

Conclusion

These results suggest that K284-6111 could improve memory dysfunction by alleviating neuroinflammation through inhibiting CHI3L1 enhancing ERK-dependent PTX3 pathway.

Pentraxin 3 inhibits fibroblast growth factor 2 induced osteoclastogenesis in rheumatoid arthritis

BACKGROUND

Synovial fibroblasts (SFs) act as key effector cells mediating synovial inflammation and joint destruction in rheumatoid arthritis (RA). Fibroblast growth factor 2 (FGF2) and its receptors (FGFRs) play important roles in RASF-mediated osteoclastogenesis. Pentraxin 3 (PTX3) is a soluble pattern recognition receptor with nonredundant roles in inflammation and innate immunity. PTX3 is produced by various cell types, including SFs and is highly expressed in RA. However, the role of PTX3 in FGF2-induced osteoclastogenesis in RA and the underlying mechanism have been poorly elucidated.

METHODS

We first determined the expression of FGF2 and RANKL in synovial tissue and synovial fluid of RA patients. We then examined the effect of PTX3 on RASF osteoclastogenesis induced by endogenous and exogenous FGF2 in isolated RASF cells treated with FGF2 and/or recombinant PTX3 (rPTX3). Thirdly, we analyzed the effect of PTX3 on FGF2 binding to FGFR-1 and HSPG receptors on RASFs. Lastly, we evaluated joint morphology after injection of rPTX3 into collagen-induced arthritis (CIA) mice.

RESULTS

FGF2 was confirmed to be highly expressed in both synovial tissue and synovial fluid of RA patients. FGF2 promoted cell proliferation and increased the expressions of RANKL and ICAM-1 and RANKL/OPG to induce osteoclastogenesis in RASF, while anti-FGF2 neutralized this effect. PTX3 significantly inhibited FGF2-induced RASF cell growth and osteoclastogenesis by preventing the interaction of ¹²⁵I-FGF2 and FGFRs on the same cells. In addition, administration of rPTX3 significantly ameliorated cartilage and bone destruction in mice with CIA.

CONCLUSIONS

PTX3 exhibited an inhibitory effect on the autocrine and paracrine stimulation of FGF2 on SFs, and ameliorated bone destruction in CIA mice. PTX3 may be implicated in bone destruction in RA, which may provide theoretical evidence and potential therapeutic targets for RA treatment.

Pentraxin 3: A promising therapeutic target for autoimmune diseases

Pentraxin 3 (PTX3) is a prototypic humoral soluble pattern recognition molecule that exerts a pivotal role in innate immune response and inflammation, as well as in tissue damage and remodeling. Recently, emerging evidence has revealed that PTX3 is involved in the occurrence and development of various autoimmune diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), systemic sclerosis (SSc), inflammatory bowel disease (IBD), multiple sclerosis (MS) and psoriasis, etc. In this review, we have succinctly summarized the complex immunological functions of PTX3 and mostly focused on recent findings of the pleiotropic activities played by PTX3 in the pathogenesis of autoimmune diseases, aiming at hopefully offering possible future therapeutic alternatives.

The association of inflammatory markers and echocardiographic parameters in Behçet's disease

Background: The main objective of the current study is to find out if any association exists between specific inflammatory markers such as homocysteine (Hcy) and pentraxin-3 (PTX-3) and cardiac involvement determined by means of echocardiographic parameters in patients with Behçet disease (BD).Methods: From January 2011 to January 2012, a total of 62 Behçet's patients were enrolled in the study. Thirty-two healthy subjects constituted the control group. The diagnosis of BD was made as proposed by International Study Group of BD.Results: The mean PTX-3, Hcy, and C-reactive protein levels were significantly higher in patients with BD compared to the control group. The electromechanical delay (EMD) times were found to be prolonged in patients with BD. Also, the aortic stiffness index (SI) and elastic modulus (Ep) were significantly higher, while the aortic dispensibility was significantly lower in patients with BD. The left atrial volume, left atrial volume index, E/A ratio, E/E' septal, IRight-EMD, PA'-ML, PA'-MS, PA'-TL, SI, and Ep were correlated with PTX-3 levels. In addition, the E/A, PA'-ML, PA'-MS, SI, and Ep displayed correlation with Hcy levels in patients having BD.Conclusion: Elevated levels of PTX-3 and Hcy were found to be correlated with cardiac involvement determined by means of echocardiographic parameters in patients with BD.

Is pentraxin 3 level an effective biomarker in disease activity in patients with rheumatoid arthritis?

INTRODUCTION

The aim of the current study was to identify whether serum pentraxin 3 (PTX3) level could be a marker of increased inflammation in rheumatoid arthritis (RA) patients.

MATERIAL AND METHODS

The study included 41 patients diagnosed with RA according to the American College of Rheumatology (ACR) 1990 diagnostic criteria. We compared the serum PTX3 levels between RA patients and a healthy control group, the relationship between PTX3 level and disease activity was also examined.

RESULTS

A statistically significant difference was determined between the RA patients and controls as regards PTX3, platelets, C-reactive protein, and mean platelet volume results (p = 0.042, p = 0.007, p = 0.017, p < 0.001, respectively). There was no statistically significant difference in terms of PTX3 level between anti-CCP-positive and -negative patients (p = 0.368). No statistically significant difference was determined in respect of PTX3 levels between RA patients with different disease activity scores (p = 0.346).

CONCLUSIONS

No relationship was determined between PTX3 and disease activity in RA patients, nor with traditional clinical and biochemical measurements of disease activity. However, the PTX3 levels of the RA patients were found to be high in comparison with the control group. Because, from these results, the role of PTX3 in the pathogenesis of RA cannot be ignored, there is a need for further studies to determine the potential role of PTX3 in RA pathogenesis.

The Long Pentraxin PTX3 in Bone Homeostasis and Pathology

The innate immune system is equipped with a number of germ-line encoded soluble pattern recognition molecules (PRMs) that collectively mediate the humoral host response to infection and damage in cooperation with cells and tissues of the immune and non-immune compartments. Despite the impressive diversity in structure, source, and regulation across PRMs, these all share remarkably similar functions inasmuch as they recognize microbes and damaged tissues, activate complement, exert opsono-phagocytic activities, and regulate inflammation. The long pentraxin 3 (PTX3) is a prototypic soluble PRM. Long known as a major player in innate immunity, inflammation and matrix remodeling, only recently has PTX3 emerged as a mediator of bone homeostasis in rodents and humans. Ptx3-targeted mice exhibit reduced trabecular volume during bone development, and impaired callus mineralization following experimental fracture. The murine gene is expressed in vivo by non-hematopoietic periosteal cells in the early phases of fracture healing, and in vitro by maturing osteoblasts. Human osteoblasts do express the PTX3 protein, whose levels positively correlate with bone density in vivo and osteoblast proliferation and maturation in vitro, thus pointing to a role in bone deposition. Contrasting evidence, however, suggest osteoclastogenesis-promoting effects of PTX3, where its expression has been associated with periodontitis, arthritis, and bone metastasis, conditions hallmarked by inflammation and bone resorption. Here, we review past and recent literature on the functions exerted by this long pentraxin in bone biology, with major emphasis on physiological skeletal remodeling, fracture healing, and chronic diseases of the bone.

Plasma pentraxin 3 is associated with progression of radiographic joint damage, but not carotid atherosclerosis, in female rheumatoid arthritis patients: 3-year prospective study

Background: Pentraxin 3 (PTX3) has an important role in inflammation, immunity, and atherosclerosis. Rheumatoid arthritis (RA) is a chronic inflammatory disease featuring both joint damage and atherosclerosis. We investigated whether the plasma PTX3 level was associated with progression of joint destruction and subclinical atherosclerosis in RA patients.Methods: Plasma PTX3 levels were measured in 72 women with RA and 80 female control subjects. In RA patients, we also evaluated clinical characteristics, medications, and at one and three years, joint damage and atherosclerosis. Then we investigated whether PTX3 was associated with progression of joint destruction or an increase of carotid intima-media thickness (IMT).Results: Plasma PTX3 levels were significantly higher in the RA patients than in healthy controls (4.05 ± 2.91 ng/mL vs. 1.61 ± 1.05 ng/mL, p < .001). By multivariate linear regression analysis, the plasma pentraxin 3 level was independently associated with radiographic progression of joint damage for 3 years in the RA patients after adjustment for age, disease duration, body mass index, rheumatoid factor, MMP-3, Disease Activity Score 28-ESR, postmenopausal status, current use of corticosteroids and biologic use. On the other hands, pentraxin 3 was not associated with an increase of carotid intima-media thickness in RA patients.Conclusion: Female RA patients had elevated plasma PTX3 levels compared with control female subjects. PTX3 was independently associated with radiographic progression of joint damage in the RA patients, but not with carotid atherosclerosis.

Long Pentraxin 3 as a Broader Biomarker for Multiple Risk Factors in End-Stage Renal Disease: Association with All-Cause Mortality

Persistent inflammation in end-stage renal disease (ESRD) patients is known to underlie the progression of chronic kidney disease and to be associated with multiple risk factors including malnutrition, atherosclerosis, and cardiovascular disease (CVD). The acute-phase protein pentraxin 3 (PTX3) has a proven potential as a local inflammatory biomarker, but its clinical utility in ESRD remains unclear. Circulating levels of PTX3 and classical inflammatory mediators, including the clinical prototypical C-reactive protein (CRP), were assessed in 246 ESRD patients on dialysis and analysed in relation to the lipid profile, adipokine levels, and nutritional, cardiac, and renal fibrosis markers. Occurrence of deaths was recorded for the following year. Contrarily to the classical inflammatory markers, PTX3 levels were negatively correlated with nutritional markers and associated with a less atherogenic lipid profile. Levels of the cardiac and renal fibrosis markers and of the oxidized LDL/LDL-C ratio were found to be independent determinants of PTX3 concentration. When comparing inflammatory mediators, the increase in the PTX3 levels was the only predictor of all-cause mortality in dialysis patients in a survival model adjusted to all markers under study, other than the inflammatory ones, besides common confounding factors in dialysis. Data support the clinical applicability of PTX3 as a broader inflammatory biomarker than the classical ones, presenting a close association with inflammation, malnutrition, CVD, and renal fibrosis and a great potential to predict all-cause mortality in dialysis patients. The pleiotropic character of PTX3 may be of clinical relevance, and it could be targeted to ameliorate the high morbidity and mortality associated with ESRD.

PTX3 Intercepts Vascular Inflammation in Systemic Immune-Mediated Diseases

PTX3 is a prototypic soluble pattern recognition receptor, expressed at sites of inflammation and involved in regulation of the tissue homeostasis. PTX3 systemic levels increase in many (but not all) immune-mediated inflammatory conditions. Research on PTX3 as a biomarker has so far focused on single diseases. Here, we performed a multi-group comparative study with the aim of identifying clinical and pathophysiological phenotypes associated with PTX3 release. PTX3 concentration was measured by ELISA in the plasma of 366 subjects, including 96 patients with giant cell arteritis (GCA), 42 with Takayasu's arteritis (TA), 10 with polymyalgia rheumatica (PMR), 63 with ANCA-associated systemic small vessel vasculitides (AAV), 55 with systemic lupus erythematosus (SLE), 21 with rheumatoid arthritis (RA) and 79 healthy controls (HC). Patients with SLE, AAV, TA and GCA, but not patients with RA and PMR, had higher PTX3 levels than HC. PTX3 concentration correlated with disease activity, acute phase reactants and prednisone dose. It was higher in females, in patients with recent-onset disease and in those with previous or current active vasculitis at univariate analysis. Active small- or large- vessel vasculitis were the main independent variables influencing PTX3 levels at multivariate analysis. High levels of PTX3 in the blood can contribute to identify an increased risk of vascular involvement in patients with systemic immune-mediated diseases.

Pentraxin 3 in Cardiovascular Disease

The long pentraxin PTX3 is a member of the pentraxin family produced locally by stromal and myeloid cells in response to proinflammatory signals and microbial moieties. The prototype of the pentraxin family is C reactive protein (CRP), a widely-used biomarker in human pathologies with an inflammatory or infectious origin. Data so far describe PTX3 as a multifunctional protein acting as a functional ancestor of antibodies and playing a regulatory role in inflammation. Cardiovascular disease (CVD) is a leading cause of mortality worldwide, and inflammation is crucial in promoting it. Data from animal models indicate that PTX3 can have cardioprotective and atheroprotective roles regulating inflammation. PTX3 has been investigated in several clinical settings as possible biomarker of CVD. Data collected so far indicate that PTX3 plasma levels rise rapidly in acute myocardial infarction, heart failure and cardiac arrest, reflecting the extent of tissue damage and predicting the risk of mortality.

Pentraxin 3 Modulates the Inflammatory Response in Human Dental Pulp Cells

INTRODUCTION

Pentraxin 3 (PTX3) has been suggested as a novel inflammatory biomarker in inflammation-associated diseases. The aim of this study was to examine the role of PTX3 in the inflammatory response of human dental pulp cells (HDPCs).

METHODS

HDPCs were treated with tumor necrosis factor alpha (TNF-α), and total RNA and protein were extracted. PTX3 messenger RNA and protein expression levels were analyzed using reverse transcription polymerase chain reaction and Western blotting, respectively. For PTX3 knockdown, HDPCs were transfected with a small interfering RNA against human PTX3. Macrophage chemotaxis after PTX3 silencing in HDPCs was assessed by transwell migration assays.

RESULTS

TNF-α increased PTX3 messenger RNA and protein levels in HDPCs. TNF-α-induced PTX3 expression was mediated by extracellular signal-regulated kinase 1/2 and nuclear factor kappa B. PTX3 knockdown decreased the expression levels of interleukin 6, interleukin 8, and monocyte chemoattractant protein 1 after stimulation with TNF-α in HDPCs. Moreover, PTX3 silencing in HDPCs significantly decreased the chemotactic migration of macrophages.

CONCLUSIONS

Our findings indicate PTX3 plays a critical role in the regulation of pulp inflammatory processes and reveal its underlying molecular mechanism.

Pentraxin-3 and inflammatory biomarkers related to posterolateral thoracotomy in Thoracic Surgery

Objective:

Posterolateral thoracotomy is the most frequently used operation in thoracic surgery, and may initiate an inflammatory process. We aimed to evaluate inflammatory response of the body to posterolateral thoracotomy.

Methods:

This study was conducted between January 2013 and June 2014. Blood samples were drawn from 36 patients who underwent posterolateral thoracotomy preoperatively, and on postoperative days one, three and seven The levels of PTX-3, CRP and WBC in the serums of the patients were identified. All the results were recorded and analyzed.

Results:

PTX-3 levels were found statistically significantly higher in patients with lung cancer and/or aged above 65 years. There were significant differences in WBC and CRP levels between preoperative levels and on those on postoperative days one, three and seven but not for PTX-3. The area under the curve(AUC) levels in the receiver operating characteristics(ROC) analysis, which was performed to estimate the strength of PTX-3 in the differentiation of malignant and benign patients was found statistically significant(p<0.05).

Conclusions:

The present study suggests that the novel inflammatory marker PTX-3 may be used in the diagnosis and follow-up of prognosis as a biomarker of inflammatory response in patients with lung cancer. However, it showed that PTX-3 levels are insignificant to identify the levels of inflamatuar response due to posterolateral thoracotomy in thoracic surgery.

The Long Pentraxin 3 Contributes to Joint Inflammation in Gout by Facilitating the Phagocytosis of Monosodium Urate Crystals

The purpose of this study was to investigate the role of pentraxin 3 (PTX3), a pivotal component of the innate immune system, in gout. Levels of PTX3 and IL-1β in human samples were evaluated by ELISA. Development of murine gout was evaluated through the levels of cytokines (PTX3, CXCL1, and IL-1β) and neutrophil recruitment into the joint cavity. Phagocytosis of monosodium urate (MSU) crystals and caspase-1 activation were determined by flow cytometer. Acute gout patients showed elevated concentration of PTX3 in plasma and synovial fluid as compared with healthy and osteoarthritic subjects. Moreover, there was a positive correlation between intra-articular PTX3 and IL-1β levels. PTX3 was induced in the periarticular tissue of mice postinjection of MSU crystals. Importantly, Ptx3-deficient mice showed reduced inflammation in response to MSU crystal injection compared with wild-type mice, including reduction of neutrophil recruitment into the joint cavity and IL-1β and CXCL1 production. Interestingly, addition of PTX3 in vitro enhanced MSU crystal phagocytosis by monocytes and resulted in higher production of IL-1β by macrophages. This contribution of PTX3 to the phagocytosis of MSU crystals and consequent production of IL-1β occurred through a mechanism mainly dependent on FcγRIII. Thus, our results suggest that PTX3 acts as a humoral pattern recognition molecule in gout facilitating MSU crystal phagocytosis and contributing to the pathogenesis of gouty arthritis.

Circulating levels of pentraxin-3 (PTX3) in patients with liver cirrhosis

BACKGROUND

Despite the circulating levels of PTX3 were related to the severity of various diseases, there are no studies investigating its role in patients with liver cirrhosis. We aimed to study PTX3 levels in patients with liver cirrhosis.

MATERIAL AND METHODS

A prospective cohort study included 130 patients hospitalized for acute decompensation of liver cirrhosis, 29 stable cirrhotic outpatients and 32 healthy controls evaluated in a tertiary hospital in Southern Brasil.

RESULTS

The median PTX3 level was significantly higher in stable cirrhotic patients compared to controls (2.6 vs. 1.1 ng/mL; p < 0.001), hospitalized cirrhotic patients compared to controls (3.8 vs. 1.1 ng/mL; p < 0.001), and hospitalized cirrhotic patients compared to stable cirrhotic patients (3.8 vs. 2.6 ng/mL; p = 0.001). A positive correlation was found between PTX3 and serum creatinine (r = 0.220; p = 0.012), Chronic Liver Failure - Sequential Organ Failure Assessment score (CLIF-SOFA) (r = 0.220; p = 0.010), MELD (r = 0.279; p = 0.001) and Child-Pugh score (r = 0.224; p = 0.010). Significantly higher levels of PTX3 were observed in patients on admission with ACLF (8.9 vs. 3.1 ng/mL; p < 0.001) and MELD score ≥ 20 (6.6 vs. 3.4 ng/mL; p = 0.002). Death within 90 days occurred in 30.8% of patients and was associated with higher levels of PTX3 (5.3 vs. 3.4 ng/mL; p = 0.009). The probability of Kaplan-Meier survival was 77.0% in patients with PTX-3 < 5.3 ng mL (upper tercile) and 53.5% in those with PTX3 ≥ 5.3 ng/mL (p = 0.002).

CONCLUSION

These results indicate the potential for use of PTX3 as an inflammatory biomarker for the prognosis of patients with hepatic cirrhosis.

The Long Pentraxin 3 Plays a Role in Bone Turnover and Repair

Pentraxin 3 (PTX3) is an inflammatory mediator acting as a fluid-phase pattern recognition molecule and playing an essential role in innate immunity and matrix remodeling. Inflammatory mediators also contribute to skeletal homeostasis, operating at multiple levels in physiological and pathological conditions. This study was designed to investigate the role of PTX3 in physiological skeletal remodeling and bone healing. Micro-computed tomography (μCT) and bone histomorphometry of distal femur showed that PTX3 gene-targeted female and male mice (ptx3^−/−) had lower trabecular bone volume than their wild-type (ptx3^+/+) littermates (BV/TV by μCT: 3.50 ± 1.31 vs 6.09 ± 1.17 for females, p < 0.0001; BV/TV 9.06 ± 1.89 vs 10.47 ± 1.97 for males, p = 0.0435). In addition, μCT revealed lower trabecular bone volume in second lumbar vertebra of ptx3^−/− mice. PTX3 was increasingly expressed during osteoblast maturation in vitro and was able to reverse the negative effect of fibroblast growth factor 2 (FGF2) on osteoblast differentiation. This effect was specific for the N-terminal domain of PTX3 that contains the FGF2-binding site. By using the closed transversal tibial fracture model, we found that ptx3^−/− female mice formed significantly less mineralized callus during the anabolic phase following fracture injury compared to ptx3^+/+ mice (BV/TV 17.05 ± 4.59 vs 20.47 ± 3.32, p = 0.0195). Non-hematopoietic periosteal cells highly upregulated PTX3 expression during the initial phase of fracture healing, particularly CD51⁺ and αSma⁺ osteoprogenitor subsets, and callus tissue exhibited concomitant expression of PTX3 and FGF2 around the fracture site. Thus, PTX3 supports maintenance of the bone mass possibly by inhibiting FGF2 and its negative impact on bone formation. Moreover, PTX3 enables timely occurring sequence of callus mineralization after bone fracture injury. These results indicate that PTX3 plays an important role in bone homeostasis and in proper matrix mineralization during fracture repair, a reflection of the function of this molecule in tissue homeostasis and repair.

PTX3: A Potential Biomarker in Thyroid Associated Ophthalmopathy

Background

Thyroid associated ophthalmopathy (TAO) is an autoimmune disease, which involves inflammation and tissue remodeling. Pentraxin-3 (PTX3) is a component of innate immune system and recently implicated in autoimmunity. This observation may indicate that PTX3 participates in the inflammatory process of TAO.

Methods

All studies were performed on TAO patients and healthy controls (45: 28 in total). RNA-seq was used to detect differential gene expression of orbital adipose-connective tissue. Quantitative PCR was performed to verify the results. PTX3 protein in orbital adipose-connective tissues was visualized by immunohistochemistry (IHC). PTX3 concentration in serum was determined by enzyme-linked immunosorbent assay (ELISA).

Results

RNA-seq showed 1.86-log⁡2FC higher PTX3 expression in the orbital adipose-connective tissues from TAO group than controls (FDR = 0.0059). qPCR confirmed the difference (5.59-fold increase, p = 0.0012). The presence of PTX3 protein was demonstrated. Orbital adipose tissue from healthy controls showed weak staining for PTX3 while tissue from TAO group was strongly positive. Serum PTX3 concentration was significantly elevated in patients when compared to the control group (1.9-fold increase; p < 0.0001).

Conclusions

Patients with TAO showed increased presence of PTX3 in orbital tissue and serum, which may suggest a potential relationship of PTX3 and TAO.

Acute phase reactant, Pentraxin 3, as a novel marker for the diagnosis of rheumatoid arthritis

INTRODUCTION

Pentraxins are a group of highly conserved acute-phase reactant proteins and play crucial role as modulators of inflammatory processes. Pentraxin 3 (PTX3) is primarily produced and released by vascular cell wall, hence, we attempt to establish the role of PTX3 as a biomarker for Rheumatoid Arthritis (RA) compared to CRP.

METHODS

Thirty patients having active RA as cases and 30 osteoarthritis (OA) patients as controls were recruited. Paired serum and synovial fluid samples were analysed for concentrations of both PTX3 and CRP by using high sensitivity ELISA kit and ROC curve was plotted.

RESULTS

Concentrations of PTX3 and CRP were significantly higher in RA patient serum (p < 0.0001) as well as in synovial fluid (p < 0.0001) and correlated with disease severity. Upon correlation analysis, positive correlation was found between serum and synovial fluid concentrations of PTX3 and CRP. The diagnostic potential of PTX3 was observed in synovial fluid while combination of PTX3 and CRP showed better sensitivity in serum.

CONCLUSION

PTX3 found to be sensitive non-invasive indicator of clinical arthritic activity in RA patients when compared to traditional markers like CRP. Combination of PTX3 and CRP could serve as better differential diagnostic markers for RA after validation in larger patient cohort.

Pentraxin 3 plasma levels at graft-versus-host disease onset predict disease severity and response to therapy in children given haematopoietic stem cell transplantation

Acute Graft-versus-Host Disease (GvHD) remains a major complication of allogeneic haematopoietic stem cell transplantation, with a significant proportion of patients failing to respond to first-line systemic corticosteroids. Reliable biomarkers predicting disease severity and response to treatment are warranted to improve its management. Thus, we sought to determine whether pentraxin 3 (PTX3), an acute-phase protein produced locally at the site of inflammation, could represent a novel acute GvHD biomarker. Using a murine model of the disease, we found increased PTX3 plasma levels after irradiation and at GvHD onset. Similarly, plasma PTX3 was enhanced in 115 pediatric patients on day of transplantation, likely due to conditioning, and at GvHD onset in patients experiencing clinical symptoms of the disease. PTX3 was also found increased in skin and colon biopsies from patients with active disease. Furthermore, PTX3 plasma levels at GvHD onset were predictive of disease outcome since they resulted significantly higher in both severe and therapy-unresponsive patients. Multiple injections of rhPTX3 in the murine model of GvHD did not influence the disease course. Taken together, our results indicate that PTX3 constitutes a biomarker of GvHD severity and therapy response useful to tailor treatment intensity according to early risk-stratification of GvHD patients.

Pentraxin 3 and biopsy status in celiac patients

AIM

In our study we explored a possible relationship between PTX3 and CD.

BACKGROUND

Gluten sensitivity is known as a hallmark of celiac disease (CD). The diagnosis of CD requires demonstration of a typical enteropathy, and positive serology supports the diagnosis. The CD immune response involves the adaptive, as well as the innate immunity and is characterized by the presence of anti-gliadin (AGA) and anti-transglutaminase 2 antibodies (tTGA), lymphocytic infiltration in the intestinal epithelial membrane and expression of multiple cytokines. The long pentraxin 3 (PTX3), an acute-phase inflammatory molecule, plays an important role in innate immunity.

METHODS

108 CD patients were divided according to Marsh Histological grade following Marsh criteria classification in three groups: Group 1: Marsh 0, patients with a known history of CD under gluten free diet, complete remission; Group 2: Marsh1 and Marsh 2; Group 3: Marsh 3. Healthy age-matched controls without a known history of CD or gastrointestinal symptoms (n=30) served as controls. PTX3 serum levels were measured by sandwich ELISA on an automated platform.

RESULTS

PTX3 serum levels were significantly elevated in group 3 and group 2 compared with HC (mean 3.31± 1.27 ng/mL and 3.97 ± 0.54 ng/mL versus 1.06 ± 0.59 ng/mL; P < 0.005), with group 1 (0.76±0.31 ng/mL). No statistically significant differences were found between group 1 and HC group. We found a strong linear correlation between PTX3 serum levels and AGA levels in group 2 (r=0.78, P <0.0001), and group 3 (r =0.63, P < 0.005) but no correlations were detected between PTX3 serum levels and tTGA levels (group 2, r= 0.04; group 3, r=0.24). Serological data revealed that PTX3 correlated with major gastrointestinal damage patients.

CONCLUSION

PTX3 is a component of the humoral arm of the innate immune system. Our data showed that PTX3 serum levels were high in active disease patients with pathological levels of AGA. We also demonstrated that patients with normal AGA IgA levels had PTX3 serum levels compared to healthy control. We hypothesized that PTX3 is able to modulate the innate response to gliadin in CD and it could regulate the adaptive immune response.

Long pentraxin 3: A novel multifaceted player in cancer

Since its discovery in 1992, long pentraxin 3 (PTX3) has been characterized as soluble patter recognition receptor, a key player of the innate immunity arm with non-redundant functions in pathogen recognition and inflammatory responses. As a component of the extra-cellular matrix milieu, PTX3 has been implicated also in wound healing/tissue remodeling, cardiovascular diseases, fertility, and infectious diseases. Consequently, PTX3 levels in biological fluids have been proposed as a fluid-phase biomarker in different pathological conditions. In the last decade, experimental evidences have shown that PTX3 may exert a significant impact also on different aspects of cancer biology, including tumor onset, angiogenesis, metastatic dissemination and immune-modulation. However, it remains unclear whether PTX3 acts as a good cop or bad cop in cancer. In this review, we will summarize and discuss the scientific literature data focusing on the role of PTX3 in experimental and human tumors, including its putative translational implications.

Diagnostic Value of Plasma Pentraxin-3 in Acute Appendicitis

PURPOSE

To measure serum PTX3 levels in patients admitted with right lower quadrant pain to emergency department and to investigate whether this parameter will be helpful for the diagnosis of acute appendicitis.

MATERIALS AND METHODS

This study was conducted with a group of 89 patients over 17 years of age who were admitted with the complaint of right lower quadrant pain to ED and had a preliminary diagnosis of acute appendicitis clinically and the control group of 31 healthy volunteers in a tertiary university hospital for 3 months.

RESULTS

Median PTX3 levels were 3.28 (1.08-30.24) ng/mL in the acute appendicitis groups and 0.97 (0.34-2.62) ng/mL in the control group. A significant difference was observed between acute appendicitis groups and the control group (p < 0.05).

CONCLUSION

PTX3 was found to be significantly higher in patient with acute appendicitis compared to the control group and the patients with non-specific abdominal pain. PTX3 can be used as an aid in the diagnosis of acute appendicitis.

The Relationship Between Serum Pentraxine 3 Levels and Hematological Markers in Patients With Rheumatoid Arthritis

Objectives

This study aims to investigate the association of pentraxin 3 (PTX3) with neutrophil/lymphocyte ratio (NLR) rather than the disease activity score 28 using C-reactive protein in rheumatoid arthritis (RA).

Patients and methods

The study included 59 RA patients (11 males, 48 females; mean age 53.79±13.55 years; range 40 to 66 years) and 20 healthy controls (5 males, 15 females; mean age 50.41±6.11 years; range 43 to 56 years). Complete blood count tests were recorded and NLR and platelet/ lymphocyte ratio were calculated. PTX3 and interleukin-6 levels were examined in serum samples. Disease activity of RA patients was assessed by disease activity score 28.

Results

Demographic characteristics were similar between the two groups, with no statistically significant difference in terms of sex, age, and body mass index (p>0.05). NLR, PTX3 and interleukin-6 levels were higher in patients with RA than the control group (p<0.05). While erythrocyte sedimentation rate had a positive correlation with mean platelet volume, we found no correlation between NLR and other parameters of disease activity, PTX3, and interleukin-6.

Conclusion

We found no correlation between PTX3 and disease activity score 28 or NLR, although PTX3 levels were higher in RA patients than the controls. As a result, we were unable to establish a relationship between PTX3 and disease activity, directly or indirectly. To our knowledge, our study was the first to investigate the relationship between PTX3 and NLR.

Anti-rheumatic treatment is not associated with reduction of pentraxin 3 in rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis

Background

Pentraxin 3 is proposed to be a marker of inflammation and cardiovascular risk, but its role in inflammatory rheumatic diseases (IRDs) is still uncertain. Therefore, we wanted to examine if anti-rheumatic treatment reduced serum PTX3 (s-PTX3) levels in IRDs, and if s-PTX3 levels were related to other markers of inflammation and to endothelial function (EF).

Methods

We examined s-PTX3, EF and established inflammatory biomarkers in 114 IRD patients from the PSARA study before and after 6 weeks and 6 months of treatment with methotrexate (MTX) or anti-tumor necrosis factor alpha (anti-TNF) therapy with or without MTX co-medication.

Results

s-PTX3 levels in all IRD diagnoses were above the upper limit of the reference range. In contrast to established inflammatory markers, in particular CRP and ESR, s-PTX3 levels did not change significantly after 6 weeks and 6 months of anti-rheumatic therapy. There was no difference in change in s-PTX3 levels from baseline to 6 weeks and 6 months between MTX monotherapy and anti-TNF regimens. CRP, ESR and EF were not related to changes in s-PTX3 neither in crude nor adjusted analyses.

Conclusion

IRD patients have increased s-PTX3 levels, which, in contrast to other inflammatory markers, do not seem to improve within 6 months of therapy with MTX and/or anti-TNF. Thus, s-PTX3 might reflect a persisting immune process, even a causal factor of inflammation, not inhibited by the standard anti-rheumatic treatment. Furthermore, even though s-PTX3 is thought to be a strong predictor of cardiovascular prognosis, it was not related to EF.

Pentraxin 3 in serum and synovial fluid of patients with rheumatoid arthritis with and without autoantibodies

OBJECTIVES

Pentraxin 3 (PTX3) is a locally produced multifunctional protein involved in inflammation, matrix deposition, and immunity. As patients with seropositive rheumatoid arthritis (RA) have a more severe disease course and higher risk of joint destruction than seronegative patients, the aim of the present study was to examine differences in PTX3 in synovial fluid (SF) (and serum) in seropositive compared to seronegative RA, and other local markers of inflammation and destruction.

METHOD

Ninety-seven RA patients with knee effusion were included. Serum and SF levels of PTX3, as well as serum levels of anti-citrullinated protein antibody and rheumatoid factor of immunoglobulin A and M subclasses, and markers of inflammation and potential destruction in SF: white blood cell counts, tumour necrosis factor, interleukin-6, vascular endothelial growth factor, metalloproteinase 3, and cartilage oligomeric matrix protein, were analysed. In addition, a radiographic knee examination was performed.

RESULTS

Seropositive patients had significantly higher PTX3 levels in SF than seronegative patients, whereas there was no difference for serum levels. SF-PTX3 levels correlated with disease activity and with local inflammatory markers, especially polymorphonuclear cells, and with autoantibody levels. There was no correlation between PTX3 levels in serum and SF.

CONCLUSION

The correlation of disease activity and autoantibody levels with SF-PTX3 levels in antibody-positive patients suggests a role for PTX3 in the inflammatory process specifically in seropositive RA joints, and supports the hypothesis that seropositive and seronegative RA are different disease entities. Polymorphonuclear granulocytes may be an important source of PTX3 in RA SF.

Can Pentraxin-3 be a Candidate Marker in the Follow-Up of the Patients With Behçet's Disease?

Objectives

This study aims to assess the level of pentraxin-3 (PTX-3) as an inflammatory marker and compare it with C-reactive protein (CRP) levels in patients with Behçet's disease (BD).

Patients and methods

Forty-two patients with BD (15 males, 27 females; mean age 39.7±8.6 years; range 20 to 64 years) and 42 age- and sex- matched healthy controls (14 males, 28 females; mean age 40.8±8.2 year; range 25 to 60 years) were included in the study. Serum CRP and plasma PTX-3 levels were measured. Subgroup analyses were performed according to clinical manifestations of patients with BD.

Results

Both PTX-3 and CRP levels were significantly higher in patients with BD than controls (1.33±0.29 vs 0.85±0.12, p<0.05 for PTX-3 and 0.71±0.13 vs 0.27±0.03, p<0.001 for CRP, respectively). Area under the curve was 0.633±0.062 vs 0.729±0.05, respectively. Mean PTX-3 and CRP levels were 1.1 vs 1.5, p=0.5; 0.5 vs 0.9, p=0.5; respectively, in patients with mucocutaneous involvement alone and with other involvements, whereas they were 0.9 vs 1.6, p=0.1; 0.5 vs 0.8, p=0.3; respectively, in patients with and without peripheral arthritis, and were 1.7 vs 0.9, p=0.06; 1.0 vs 0.5, p=0.07; respectively, in patients with and without uveitis.

Conclusion

Although PTX-3 levels were higher in patients with BD than healthy controls, sensitivity and specificity of PTX-3 was not different than CRP in patients with BD.

Tunicamycin-induced Endoplasmic Reticulum Stress Upregulates the Expression of Pentraxin 3 in Human Retinal Pigment Epithelial Cells

PURPOSE

To investigate the production of long pentraxin 3 (PTX3) in response to tunicamycin-induced endoplasmic reticulum (ER) stress and its role in ER stress-associated cell death, PTX3 expression was evaluated in the human retinal pigment epithelial cell line, ARPE-19.

METHODS

PTX3 production in ARPE-19 cells was analyzed in the absence or presence of tunicamycin treatment by enzyme-linked immunosorbent assay. PTX3 protein and mRNA levels were estimated using western blot analysis and real-time reverse transcription-polymerase chain reaction, respectively. Protein and mRNA levels of CCAAT-enhancer-binding protein homologous protein (CHOP) and ARPE-19 cell viability were measured in the presence of tunicamycin-induced ER stress in control or PTX3 small hairpin RNA (shRNA)-transfected ARPE-19 cells.

RESULTS

The protein and mRNA levels of PTX3 were found to be significantly increased by tunicamycin treatment. PTX3 production was significantly decreased in inositol-requiring enzyme 1α shRNA-transfected ARPE-19 cells compared to control shRNA-transfected cells. Furthermore, pretreatment with the NF-κB inhibitor abolished tunicamycin-induced PTX3 production. Decreased cell viability and prolonged protein and mRNA expression of CHOP were observed under tunicamycin-induced ER stress in PTX3 shRNA transfected ARPE-19 cells.

CONCLUSIONS

These results suggest that PTX3 production increased in the presence of tunicamycin-induced ER stress. Therefore, PTX3 could be an important protector of ER stress-induced cell death in human retinal pigment epithelial cells. Inositol-requiring enzyme 1α and the NF-κB signaling pathway may serve as potential targets for regulation of PTX3 expression in the retina. Therefore, their role in PTX3 expression needs to be further investigated.

Sputum pentraxin 3 as a candidate to assess airway inflammation and remodeling in childhood asthma

Pentraxin 3 (PTX3) is a soluble pattern recognition receptor and an acute-phase protein. It has gained attention as a new biomarker reflecting tissue inflammation and damage in a variety of diseases. Aim of this study is to investigate the role of PTX3 in childhood asthma.In total, 260 children (140 patients with asthma and 120 controls) were enrolled. PTX3 levels were measured in sputum supernatants using enzyme-linked immunosorbent assay test. We performed spirometry and methacholine challenge tests and measured the total eosinophil count and the serum levels of total IgE and eosinophil cationic protein (ECP) in all subjects.Sputum PTX3 concentration was significantly higher in children with asthma than in control subjects (P < 0.001). Furthermore, sputum PTX3 levels correlated with atopic status and disease severity among patients with asthma. A positive significant correlation was found between sputum PTX3 and the bronchodilator response (r = 0.25, P = 0.013). Sputum PTX3 levels were negatively correlated with forced expiratory volume in 1 second (FEV1) (r = -0.30, P = 0.001), FEV1/forced vital capacity (FVC) (r = -0.27, P = 0.002), and FEF25-75 (r = -0.392, P < 0.001), which are indicators of airway obstruction and inflammation. In addition, the PTX3 concentration in sputum showed negative correlations with post-bronchodilator (BD) FEV1 (r = -0.25, P < 0.001) and post-BD FEV1/FVC (r = -0.25, P < 0.001), which are parameters of persistent airflow limitation reflecting airway remodeling.Sputum PTX3 levels increased in children with asthma, suggesting that PTX3 in sputum could be a candidate molecule to evaluate airway inflammation and remodeling in childhood asthma.

Low serum fibroblast growth factor 2 levels not accompanied by increased serum pentraxin 3 levels in patients with systemic sclerosis

There are scarce clinical data regarding serum pentraxin 3 (PTX3) and fibroblast growth factor 2 (FGF2) in patients with systemic sclerosis (SSc). Study was conducted to evaluate serum levels in our SSc cohort. Serum PTX3 and FGF2 concentrations were compared among SSc, disease control (systemic lupus erythematosus (SLE)), and healthy control groups. We also examined the association of serum levels of PTX3 and FGF2 with disease manifestations. Serum PTX3 levels were similarly distributed among SSc (n = 93) and healthy groups (n = 66) (p = 1.00) while PTX3 levels were higher in SLE controls (n = 86) compared to both SSc and healthy groups. PTX3 levels were higher in limited SSc cases compared to diffuse cases (p = 0.016). Median PTX3 levels in SSc cases with lung involvement were lower compared to cases with no lung involvement (p = 0.006). Patients with SSc had significantly lower serum levels of FGF2 compared to SLE and healthy groups. Serum FGF2 concentration was undetectable in 61.3% of cases with SSc while 30.2% of SLE and only 4.5% of healthy cases had undetectable FGF2 levels (p < 0.01). Diffuse and limited SSc cases, as well as cases with and without lung involvement, had similar rates of undetectable serum FGF2 levels (p = 0.15 and p = 0.59, respectively). FGF2 levels were mostly undetectably low in patients with SSc, and serum PTX3 was lower in diffuse SSc and in cases with lung involvement compared to limited SSc and cases with no lung involvement, respectively, in our cohort.

Association of Genetic Variants in Pentraxin 3 Gene with Ankylosing Spondylitis

Background

Pentraxin 3 is considered to play an important role in immune and inflammatory reaction. This study aimed to detect the effect of pentraxin3 gene (PTX3) polymorphisms on ankylosing spondylitis (AS) risk.

Material/Methods

The genotyping of PTX3 polymorphisms in 101 AS patients and 93 controls was conducted by allelic discrimination assay and the genotype distribution was assessed for Hardy-Weinberg equilibrium (HWE). The differences of genotype, allele, haplotype, and some basic indexes were compared by χ² test. Odds ratio (OR) and 95% confidence interval (95%CI) were also calculated by χ² test and were used to evaluate the association intensity between gene polymorphisms and disease. Haploview software was used to analyze the linkage disequilibrium (LD) and haplotypes of PTX3 polymorphisms.

Results

CC genotype of rs3816527 had an obviously higher frequency in cases than in controls and had a positive effect on AS occurrence (OR=3.14, 95%CI=1.04–9.52), and the same was true of the C allele in rs3816527. For rs3845978, CT genotype showed a significant frequency difference between the case and control groups (P=0.03) and people with genotypes carrying the T allele developed AS earlier (OR=1.94, 95%CI=1.09–3.47), and the same was found in the analysis of the T allele. G-C-T haplotype dramatically increased the risk of AS, as may A-C-C haplotype.

Conclusions

In PTX3 polymorphisms rs3816527 and rs3845978 were found to be associated with AS, but rs2305619 was not.

Innate immunity and atherogenesis

Atherosclerosis is recognized as the pathological basis of cardiovascular disease (CVD) and recent advances in basic science have shown that it should be considered as a chronic inflammatory process. Both elements of the innate and the adaptive immunity appear to be actively involved in atherogenesis. In fact, the potential role played by pattern-recognition receptors (Toll-like receptors and scavenger receptors), cytokines (such as IL-1, IL-6, TNFa), chemokines and pentraxines (such as CRP and PTX3) represents an emerging field of investigation in atherogenesis. In the near future we expect a better definition of the real biological and clinical impact on CVD of these mediators. On one side, they could become useful to complement traditional risk factors, in order to identify new categories of subjects prone to CVD development. On the other, they could become an additional potential target for therapeutic strategies.

Pentraxin 3 Is Closely Associated With Tubulointerstitial Injury in Lupus Nephritis: A Large Multicenter Cross-Sectional Study

Lupus nephritis always elicits immune inflammatory tissue damages in kidney. Pentraxin 3 (PTX3), mainly produced at inflammatory sites, is known to be involved in the regulation of the innate immunity system. The aim of this study was to investigate the serum and urine levels of PTX3, and the expression of PTX3 in renal tissues in lupus nephritis patients from a large Chinese cohort.The study used cross-sectional survey and 288 active lupus nephritis patients, including discovery cohort and validation cohort, 115 systemic lupus erythematosus (SLE) patients without clinical renal involvement and 46 healthy controls were enrolled. Serum and urine PTX3 were screened by enzyme-linked immunosorbent assay (ELISA). The renal deposition of PTX3 was detected by immunohistochemistry and immunofluorescence.The average level of serum PTX3 in the discovery cohort of lupus nephritis was significantly higher than that in nonrenal involvement SLE group and normal controls (P < 0.001, P < 0.001, respectively), which was confirmed by the validation cohort. Serum PTX3 levels of 15 lupus nephritis patients in remission decreased significantly compared with that in active phase. Serum PTX3 levels were significantly higher in patients with hematuria (P = 0.014), leucocyturia (P = 0.002), acute renal failure (P = 0.001), and nephrotic syndrome (P = 0.036). There were significant correlations between serum PTX3 levels and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, serum creatinine value, renal pathological activity indices, and serum complement 3 (C3) in active lupus nephritis patients. The urinary PTX3 levels were significantly higher in active lupus nephritis patients compared with patients in remission and normal controls (P = 0.011, P = 0.008, respectively). There were significant associations between urinary PTX3 levels and multiple indices of tubulointerstitial lesions, including urinary KIM-1 (r = 0.368, P = 0.016), neutrophil gelatinase-associated lipocalin (NGAL) (r = 0.320, P = 0.039), microalbumin (r = 0.621, P = 0.003), transferring (r = 0.451, P = 0.040) levels and renal pathological indices scores, especially interstitial inflammation (r = 0.349, P = 0.025) in active lupus nephritis patients. A significant correlation was found between serum and urine PTX3 levels (r = 0.431, P = 0.006). PTX3 staining was mainly observed in tubulointerstitial areas of patients with lupus nephritis, and immunofluorescence study showed that PTX3 could colocalize with fibroblast in interstitium.Circulating and local PTX3 levels were significantly increased in patients with active lupus nephritis and might be a biomarker for the disease progression, especially of tubulointerstitial injury.