Role of Microparticles in the Pathogenesis of Inflammatory Joint Diseases

Unraveling the Multifaceted Roles of Extracellular Vesicles: Insights into Biology, Pharmacology, and Pharmaceutical Applications for Drug Delivery

Extracellular vesicles (EVs) are nanoparticles released from various cell types that have emerged as powerful new therapeutic option for a variety of diseases. EVs are involved in the transmission of biological signals between cells and in the regulation of a variety of biological processes, highlighting them as potential novel targets/platforms for therapeutics intervention and/or delivery. Therefore, it is necessary to investigate new aspects of EVs' biogenesis, biodistribution, metabolism, and excretion as well as safety/compatibility of both unmodified and engineered EVs upon administration in different pharmaceutical dosage forms and delivery systems. In this review, we summarize the current knowledge of essential physiological and pathological roles of EVs in different organs and organ systems. We provide an overview regarding application of EVs as therapeutic targets, therapeutics, and drug delivery platforms. We also explore various approaches implemented over the years to improve the dosage of specific EV products for different administration routes.

Structure and function of the membrane microdomains in osteoclasts

The cell membrane structure is closely related to the occurrence and progression of many metabolic bone diseases observed in the clinic and is an important target to the development of therapeutic strategies for these diseases. Strong experimental evidence supports the existence of membrane microdomains in osteoclasts (OCs). However, the potential membrane microdomains and the crucial mechanisms underlying their roles in OCs have not been fully characterized. Membrane microdomain components, such as scaffolding proteins and the actin cytoskeleton, as well as the roles of individual membrane proteins, need to be elucidated. In this review, we discuss the compositions and critical functions of membrane microdomains that determine the biological behavior of OCs through the three main stages of the OC life cycle.

The genesis of cardiovascular risk in inflammatory arthritis: insights into glycocalyx shedding, endothelial dysfunction, and atherosclerosis initiation

This narrative review provides a comprehensive examination of the complex interplay between inflammatory arthritis (IA) and cardiovascular pathology. It particularly illuminates the roles of atherosclerosis initiation, endothelial dysfunction, and glycocalyx shedding. IA not only provokes tissue-specific inflammatory responses, but also engenders a considerable degree of non-specific systemic inflammation. This review underscores the accelerating influence of the chronic inflammatory milieu of IA on cardiovascular disease (CVD) progression. A focal point of our exploration is the critical function of the endothelial glycocalyx (EG) in this acceleration process, which possibly characterizes the earliest phases of atherosclerosis. We delve into the influence of inflammatory mediators on microtubule dynamics, EG modulation, immune cell migration and activation, and lipid dysregulation. We also illuminate the impact of microparticles and microRNA on endothelial function. Further, we elucidate the role of systemic inflammation and sheddases in EG degradation, the repercussions of complement activation, and the essential role of syndecans in preserving EG integrity. Our review provides insight into the complex and dynamic interface between systemic circulation and the endothelium.

Proteomics profiling of CD4 + T-cell-derived exosomes from patients with rheumatoid arthritis

OBJECTIVES

Our study profiled the CD4 + T-cell-derived exosomes from patients with rheumatoid arthritis (RA) using proteomics.

METHODS

Proteomic analysis of CD4 + T-cell-derived exosomes was performed by tandem mass tags (TMT) combined with LC-MS/MS. We validated the most significantly upregulated and downregulated proteins using ELISA and WB.

RESULTS

The proteomic results showed that there were 3 upregulated differentially expressed proteins and 31 downregulated differentially expressed proteins in the RA group. The results indicated that dihydropyrimidinase-related protein 3 (DPYSL3) was significantly upregulated in CD4 + T-cell-derived exosomes, whereas proteasome activator complex subunit 1 (PSME1) was significantly downregulated in the RA group. Bioinformatics analysis showed that proteins were enriched in "positive regulation of gene expression", "antigen processing and presentation", "acute-phase response" and "PI3K-AKT signaling" pathways. ELISA verified that compared to the control group, the RA group showed significant upregulation of DPYSL3, and downregulation of PSME1 in CD4 + T-cell-derived exosomes.

CONCLUSIONS

The proteomic analysis results of CD4 + T-cell-derived exosomes from patients with RA suggest that these differentially expressed proteins may be involved in RA pathogenesis. DPYSL3 and PSME1 may become useful biomarkers for RA.

The Role of Autophagy as a Trigger of Post-Translational Modifications of Proteins and Extracellular Vesicles in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease, characterized by persistent joint inflammation, leading to cartilage and bone destruction. Autoantibody production is directed to post-translational modified (PTM) proteins, i.e., citrullinated or carbamylated. Autophagy may be the common feature in several types of stress (smoking, joint injury, and infections) and may be involved in post-translational modifications (PTMs) in proteins and the generation of citrullinated and carbamylated peptides recognized by the immune system in RA patients, with a consequent breakage of tolerance. Interestingly, autophagy actively provides information to neighboring cells via a process called secretory autophagy. Secretory autophagy combines the autophagy machinery with the secretion of cellular content via extracellular vesicles (EVs). A role for exosomes in RA pathogenesis has been recently demonstrated. Exosomes are involved in intercellular communications, and upregulated proteins and RNAs may contribute to the development of inflammatory arthritis and the progression of RA. In RA, most of the exosomes are produced by leukocytes and synoviocytes, which are loaded with PTM proteins, mainly citrullinated proteins, inflammatory molecules, and enzymes that are implicated in RA pathogenesis. Microvesicles derived from cell plasma membrane may also be loaded with PTM proteins, playing a role in the immunopathogenesis of RA. An analysis of changes in EV profiles, including PTM proteins, could be a useful tool for the prevention of inflammation in RA patients and help in the discovery of personalized medicine.

Extracellular vesicles: a comprehensive review of their roles as biomarkers and potential therapeutics in psoriasis and psoriatic arthritis

Psoriasis is a chronic immune-mediated condition that affects the skin and joints, with current treatments still unable to offer a cure and long-term use of treatments posing health risks. Understanding the pathogenesis of the disease has helped identify new targets that have allowed for the expansion of the therapeutic arsenal. Extracellular vesicles (EVs) have recently emerged as pathophysiological mediators of psoriasis, and there have been increasing reports of EVs as potential biomarkers and therapeutics. Given their innate role as natural vehicles for cell-to-cell communication, EVs have vast potential in their ability to determine disease status based on EV-specific cargo as well as act as therapeutics because of their anti-inflammatory properties and potential for enhancement. In this review we summarize the role of EVs in the pathogenesis of psoriasis and discuss EVs as both diagnostic and therapeutic agents.

Lipidic Profile Changes in Exosomes and Microvesicles Derived From Plasma of Monoclonal Antibody-Treated Psoriatic Patients

Psoriasis is a chronic immune-mediated inflammatory skin disorder affecting children and adults. To date no approved biomarkers for diagnosis of this disease and follow up of patients have been translated into clinical practice. Recently, extracellular vesicles (EVs) secreted by all cells and present in almost all biological fluids are playing a crucial role in diagnosis and follow up of several diseases, including psoriasis. Since many psoriatic patients show altered plasma lipid profiles and since EVs have been involved in psoriasis pathogenesis, we studied the phospholipid profile of EVs, both microvesicles (MV) or exosomes (Exo), derived from plasma of psoriatic patients undergoing systemic biological treatment (secukinumab, ustekinumab, adalimumab), in comparison with EVs of untreated patients and healthy donors (HD). EVs were evaluated by immune electronmicroscopy for their morphology and by NanoSight for their amount and dimensions. EV phospholipid profiling was performed by High Resolution Liquid Chromatography-Mass Spectrometry and statistical Partial Least Squares Discriminant Analysis. Our results demonstrated that psoriatic patients showed a higher concentration of both MV and Exo in comparison to EVs from HD. The phospholipid profile of Exo from psoriatic patients showed increased levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol and lysoPC compared to Exo from HD. Sphingomyelin (SM) and phosphatidylinositol (PI) are the only phospholipid classes whose levels changed in MV. Moreover, the therapy with ustekinumab seemed to revert the PE and PC lipid composition of circulating Exo towards that of HD and it is the only one of the three biological drugs that did not alter SM expression in MV. Therefore, the determination of lipid alterations of circulating EVs could harbor useful information for the diagnosis and drug response in psoriatic patients.

Circulating extracellular vesicles and rheumatoid arthritis: a proteomic analysis

Circulating extracellular vesicles (EVs) are membrane-bound nanoparticles secreted by most cells for intracellular communication and transportation of biomolecules. EVs carry proteins, lipids, nucleic acids, and receptors that are involved in human physiology and pathology. EV cargo is variable and highly related to the type and state of the cellular origin. Three subtypes of EVs have been identified: exosomes, microvesicles, and apoptotic bodies. Exosomes are the smallest and the most well-studied class of EVs that regulate different biological processes and participate in several diseases, such as cancers and autoimmune diseases. Proteomic analysis of exosomes succeeded in profiling numerous types of proteins involved in disease development and prognosis. In rheumatoid arthritis (RA), exosomes revealed a potential function in joint inflammation. These EVs possess a unique function, as they can transfer specific autoantigens and mediators between distant cells. Current proteomic data demonstrated that exosomes could provide beneficial effects against autoimmunity and exert an immunosuppressive action, particularly in RA. Based on these observations, effective therapeutic strategies have been developed for arthritis and other inflammatory disorders.

Role of Circulating Microparticles in Type 2 Diabetes Mellitus: Implications for Pathological Clotting

Type 2 diabetes mellitus (T2DM) is a multifactorial chronic metabolic disease characterized by chronic hyperglycemia due to insulin resistance and a deficiency in insulin secretion. The global diabetes pandemic relates primarily to T2DM, which is the most prevalent form of diabetes, accounting for over 90% of all cases. Chronic low-grade inflammation, triggered by numerous risk factors, and the chronic activation of the immune system are prominent features of T2DM. Here we highlight the role of blood cells (platelets, and red and white blood cells) and vascular endothelial cells as drivers of systemic inflammation in T2DM. In addition, we discuss the role of microparticles (MPs) in systemic inflammation and hypercoagulation. Although once seen as inert by-products of cell activation or destruction, MPs are now considered to be a disseminated storage pool of bioactive effectors of thrombosis, inflammation, and vascular function. They have been identified to circulate at elevated levels in the bloodstream of individuals with increased risk of atherothrombosis or cardiovascular disease, two significant hallmark conditions of T2DM. There is also general evidence that MPs activate blood cells, express proinflammatory and coagulant effects, interact directly with cell receptors, and transfer biological material. MPs are considered major players in the pathogenesis of many systemic inflammatory diseases and may be potentially useful biomarkers of disease activity and may not only be of prognostic value but may act as novel therapeutic targets.

The role of extracellular vesicles in rheumatoid arthritis: a systematic review

Rheumatoid arthritis (RA) is a chronic inflammatory disease that carries high social and economic costs and can lead to permanent disability. RA pathogenesis has not been completely elucidated yet. Extracellular vesicles (EVs) are membrane-contained vesicles released by cells playing a role in cell-to-cell communication and they could be involved in different diseases. Evidence on the involvement of EVs in RA is currently inconclusive. Therefore, a systematic review on the role of EVs in RA was performed in order to explore this relationship. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The research was conducted on PubMed, Scopus, and Embase up to March 5, 2020: 41 studies were analyzed out of 674 screened. The total plasmatic and synovial fluid (SF) EV number seems increased in RA as compared with healthy controls. Both RA plasma and SF contained EVs subpopulations of heterogenous origin, especially derived from platelets and immune system cells. No univocal evidence emerged on miRNA expression and EV content profile within RA patients. EVs showed to enhance pro-inflammatory pathways, such as cytokines and chemokine release and TNF blockade seemed to revert this effect. Our work highlights the requirement to standardize study methodologies in order to make results comparable and draw conclusions that remain, at present, unclear.

Pulmonary Thromboembolism in Immune Thrombocytopenia: A Report of Five Cases and a Review of the Literature

Objective

To provide a reference for the diagnosis and treatment of patients with immune thrombocytopenia (ITP) complicated with pulmonary thromboembolism (PTE) by analyzing the clinical characteristics of five such patients.

Methods

This paper summarizes the clinical manifestations and hematological indexes of five patients with ITP complicated with pulmonary embolism.

Results

In this study, the incidence of ITP complicated with PTE was 2.75%. All five cases were elderly patients with nonspecific clinical manifestations. Platelet counts were different when PTE occurred. The time from the diagnosis of ITP to the occurrence of PTE was from 5 to 24 months, with an average of 12.8 months. There was no significant change in hemoglobin, white blood cell levels, prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen levels, or the international normalized ratio. Four patients had significantly increased D-dimer levels, while D-dimer was only slightly increased in one patient. Antithrombin (AT) was significantly decreased in four cases (less than 70%), and C-reactive protein (CRP) was increased in all five cases.

Conclusion

PTE may be related to AT and CRP in patients with ITP, which is of great clinical significance to the diagnosis and treatment of ITP complicated with PTE.

Circulating microparticles in patients with chronic hepatitis C and changes during direct-acting antiviral therapy

BACKGROUND

Microparticles (MPs) are heterogeneous vesicles derived from membranes of different cells. Between 70 to 90% of MPs detected in blood originate from platelets. The release of MPs is associated with proinflammatory and procoagulant states. Elevated levels of MPs have been found in different diseases. We investigated MPs levels in patients with chronic hepatitis C (CHC) and changes in level during treatment using direct-acting antivirotics (DAA).

PATIENTS AND METHODS

Thirty-six patients with CHC and forty healthy volunteers were included in the study. Concentrations of MPs were determined indirectly by measuring their procoagulant activity in plasma at baseline, end of therapy (EOT), and 12 weeks after EOT when the sustained virological response was assessed (SVR12).

RESULTS

All patients achieved SVR12, which was associated with rapid improvement of markers of liver damage and function as well as liver stiffness (P=0.002). MPs levels were significantly higher in CHC patients than in healthy volunteers (P<0.001). No statistically significant decrease was found observed between baseline and SVR12 (P=0,330). Analysis of subpopulations with minimal fibrosis F0-1 (P=0.647), advanced fibrosis F2-4 (P=0.370), women(P=0.847), men (P=0.164) and genotype 1 (P=0.077) showed no significant changes during the follow-up period.

CONCLUSIONS

MPs levels are higher in CHC patients and remain elevated shortly after achieving SVR. Higher concentrations of MPs in plasma are probably caused by a chronic uncontrolled exaggerated inflammatory response caused by CHC. Longer observation would probably confirm the significance of MPs levels decrease because normalization of liver function, inflammation, and structure after SVR requires more than 12 weeks.

Serum Biomarkers of Inflammation and Turnover of Joint Cartilage Can Help Differentiate Psoriatic Arthritis (PsA) Patients from Osteoarthritis (OA) Patients

The aim of this study was to find characteristic biomarkers in the serum of patients with osteoarthritis (OA) and psoriatic arthritis (PsA) responsible for inflammation and destruction of joint cartilage, which could differentiate these two diseases. The study included 67 people: 22 patients with knee OA, 22 patients with PsA, and 23 individuals who were the control group of healthy individuals (HC). The concentration of IL-18, IL-20, IL-6, MMP-1, MMP-3, COMP, PG-AG, and YKL-40 in serum were determined. Among the OA and PsA patients group, the radiological assessment and clinical assessment were also performed. The concentration of 7 out of 8 of examined biomarkers (except MMP-1) was statistically significantly higher in the serum of patients with OA and PsA than in the control group. Compering OA and PsA groups only, the serum PG-AG level in OA patients was statistically significantly higher than in PsA patients (p < 0.001). The results of univariate and multivariate logistic regression analysis comparing OA and PsA biomarker serum levels identified PG-AG and COMP as markers that are significantly different between patients with OA and PsA (odds ratio 0.995 and 1.003, respectively). The ROC curve constructed using the model with age showed PG-AG and COMP had an AUC of 0.907. The results of this study show that COMP and PG-AG may be sensitive markers differentiating patients with osteoarthiritis from psoriatic arthritis.

Induction of NF-κB inflammatory pathway in monocytes by microparticles from patients with systemic lupus erythematosus

Background

Elevated levels of circulating microparticles (MPs) and molecules of the complement system have been reported in patients with systemic lupus erythematosus (SLE). Moreover, microparticles isolated from patients with SLE (SLE-MPs) contain higher levels of damage-associated molecular patterns (DAMPs) than MPs from healthy controls (CMPs). We hypothesize that the uptake of MPs by monocytes could contribute to the chronic inflammatory processes observed in patients with SLE. Therefore, the aim of this study was to evaluate the expression of activation markers, production of proinflammatory mediators, and activation of the NF-κB signaling pathway in monocytes treated with CMPs and SLE-MPs.

Methodology

Monocytes isolated from healthy individuals were pretreated or not with pyrrolidine dithiocarbamate (PDTC) and cultured with CMPs and SLE-MPs. The cell surface expression of CD69 and HLA-DR were evaluated by flow cytometry; cytokine and eicosanoid levels were quantified in culture supernatants by Cytokine Bead Array and ELISA, respectively; and the NF-κB activation was evaluated by Western blot and epifluorescence microscopy.

Results

The cell surface expression of HLA-DR and CD69, and the supernatant levels of IL-6, IL-1β, PGE2, and LTB4 were higher in cultures of monocytes treated with SLE-MPs than CMPs. These responses were blocked in the presence of PDTC, a pharmacological inhibitor of the NF-κB pathway, with concomitant reduction of IκBα and cytoplasmic p65, and increased nuclear translocation of p65.

Conclusions

The present findings indicate that significant uptake of SLE-MPs by monocytes results in activation, production of inflammatory mediators, and triggering of the NF-κB signaling pathway.

A Novel Pool of Microparticle Cholesterol Is Elevated in Rheumatoid Arthritis but Not in Systemic Lupus Erythematosus Patients

Microparticles are sub-micron, membrane-bound particles released from virtually all cells and which are present in the circulation. In several autoimmune disorders their amount and composition in the circulation is altered. Microparticle surface protein expression has been explored as a differentiating tool in autoimmune disorders where the clinical pictures can overlap. Here, we examine the utility of a novel lipid-based marker-microparticle cholesterol, present in all microparticles regardless of cellular origin-to distinguish between rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We first isolated a series of microparticle containing lipoprotein deficient fractions from patient and control plasma. There were no significant differences in the size, structure or protein content of microparticles isolated from each group. Compared to controls, both patient groups contained significantly greater amounts of platelet and endothelial cell-derived microparticles. The cholesterol content of microparticle fractions isolated from RA patients was significantly greater than those from either SLE patients or healthy controls. Our data indicate that circulating non-lipoprotein microparticle cholesterol, which may account for 1-2% of measured cholesterol in patient samples, may represent a novel differentiator of disease, which is independent of cellular origin.

Research of Pathogenesis and Novel Therapeutics in Arthritis 2.0

Arthritis has a high prevalence globally and includes over 100 types, the most common of which are rheumatoid arthritis, osteoarthritis, psoriatic arthritis, and inflammatory arthritis. All types of arthritis share common features of disease, including monocyte infiltration, inflammation, synovial swelling, pannus formation, stiffness in the joints and articular cartilage destruction. The exact etiology of arthritis remains unclear, and no cure exists as of yet. Anti-inflammatory drugs (NSAIDs and corticosteroids) are commonly used in the treatment of arthritis. However, these drugs are associated with significant side effects, such as gastric bleeding and an increased risk for heart attack and other cardiovascular problems. It is therefore crucial that we continue to research the pathogenesis of arthritis and seek to discover novel modes of therapy. This editorial summarizes and discusses the themes of the 27 articles published in our Special Issue “Research of Pathogenesis and Novel Therapeutics in Arthritis 2.0”, a continuation of our 2019 Special Issue “Research of Pathogenesis and Novel Therapeutics in Arthritis”. These Special Issues detail important novel research discoveries that contribute to our current understanding of arthritis.

Platelet activation and prothrombotic mediators at the nexus of inflammation and atherosclerosis: Potential role of antiplatelet agents

Platelets are central to inflammation-related manifestations of cardiovascular diseases (CVD) such as atherosclerosis. Platelet-activating factor (PAF), thrombin, thromboxane A₂ (TxA₂), and adenosine diphosphate (ADP) are some of the key agonists of platelet activation that are at the intersection between a plethora of inflammatory pathways that modulate pro-inflammatory and coagulation processes. The aim of this article is to review the role of platelets and the relationship between their structure, function, and the interactions of their constituents in systemic inflammation and atherosclerosis. Antiplatelet therapies are discussed with a view to primary prevention of CVD by the clinical reduction of platelet reactivity and inflammation. Current antiplatelet therapies are effective in reducing cardiovascular risk but increase bleeding risk. Novel therapeutic antiplatelet approaches beyond current pharmacological modalities that do not increase the risk of bleeding require further investigation. There is potential for specifically designed nutraceuticals that may become safer alternatives to pharmacological antiplatelet agents for the primary prevention of CVD but there is serious concern over their efficacy and regulation, which requires considerably more research.