The Role of Fibroblasts in Atherosclerosis Progression

The following chapter addresses vascular fibroblasts in a healthy, quiescent state, as well during vascular inflammation, focusing on atherosclerosis. The development of atherosclerosis, an inflammatory disease of medium- and large-sized arteries, has traditionally been viewed as an “inside-out” mechanism, with prominent roles of the innermost layer of the artery, consisting of endothelial cells. However, emerging evidence suggests a new paradigm of “outside-in” mechanism, including an earlier role for fibroblasts, constituents of the outermost adventitial layer of the artery. Phenotypic and functional changes of fibroblasts in adventitia may even occur prior to, or alongside endothelial activation. Activated adventitial fibroblasts, implicated in atherosclerosis progression, begin to transform into myofibroblasts, upregulate production of different proinflammatory cytokines, chemokines, growth factors, proteolytic enzymes, extracellular matrix proteins and reactive oxygen species, leading to extensive matrix remodeling, chemotaxis and recruitment of immune cells. Due to their suitable location for drug delivery systems, preventing fibroblast activation, modulating their activity or inducing myofibroblast dedifferentiation could represent a promising therapeutic approach for atherosclerosis regression

Colocalization of Serum Amyloid A with Microtubules in Human Coronary Artery Endothelial Cells

Serum amyloid A (SAA) acts as a major acute phase protein and represents a sensitive and accurate marker of inflammation. Besides its hepatic origin, as the main source of serum SAA, this protein is also produced extrahepatically. The mRNA levels of SAA become significantly elevated following proinflammatory stimuli, as well as, are induced through their own positive feedback in human primary coronary artery endothelial cells. However, the intracellular functions of SAA are so far unknown. Colocalization of SAA with cytoskeletal filaments has previously been proposed, so we analyzed the colocalization of SAA with all three cytoskeletal elements: actin filaments, vimentin filaments, and microtubules. Immunofluorescent double-labeling analyses confirmed by PLA method revealed a strict colocalization of SAA with microtubules and a very infrequent attachment to vimentin while the distribution of actin filaments appeared clearly separated from SAA staining. Also, no significant colocalization was found between SAA and endomembranes labeled with the fluorescent lipid stain DiO6. However, SAA appears to be located also unbound in the cytosol, as well as inside the nucleus and within nanotubes extending from the cells or bridging neighboring cells. These different locations of SAA in endothelial cells strongly indicate multiple potential functions of this protein

Extracellular Vesicles: Intercellular Communication Mediators in Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombosis, obstetric complications and the presence of antiphospholipid antibodies (aPL) that cause endothelial injury and thrombophilia. Extracellular vesicles are involved in endothelial and thrombotic pathologies and may therefore have an influence on the prothrombotic status of APS patients. Intercellular communication and connectivity are important mechanisms of interaction between healthy and pathologically altered cells. Despite well-characterized in vitro and in vivo models of APS pathology, the field of extracellular vesicles is still largely unexplored and could therefore provide an insight into the APS mechanism and possibly serve as a biomarker to identify patients at increased risk. The analysis of EVs poses a challenge due to the lack of standardized technology for their isolation and characterization. Recent findings in the field of EVs offer promising aspects that may explain their role in the pathogenesis of various diseases, including APS

Comparison and evaluation of different methodologies and tests for detection of anti-dsDNA antibodies on 889 Slovenian patients’ and blood donors’ sera

Aim To evaluate four different commercially available assays for anti-double stranded DNA (dsDNA) detection and compare them with the in-house radioimmunoassay according to Farr (FARR-RIA) in order to select the optimal primary method for use in combination with FARR-RIA. Methods Sera from 583 consecutive patients sent to our laboratory for routine diagnosis, 156 selected patients with autoimmune diseases (76 systemic lupus erythematosus [SLE] patients and 80 patients with other autoimmune diseases), and 150 blood donors were tested for anti-dsDNA antibodies with two enzyme-linked immunoassays (ELISA), two Crithidia luciliae immunoflourescence tests (CLIFT), and FARR-RIA. The specificities and sensitivities of the tests were calculated and compared. Results FARR-RIA and CLIFT 2 showed the highest specificity for SLE (100%), with CLIFT 2 showing higher sensitivity (33% vs 47%). Both ELISAs showed higher sensitivities (>53%) than FARR-RIA but lower specificities (<93%), whereas CLIFT 1 showed the lowest overall agreement with FARR-RIA. Conclusion CLIFT 2 was selected as the primary test for use in combination with FARR-RIA. The use of CLIFT 2 reduced the number of sera that needed to be tested by FARR-RIA, the time needed to report the results, and environmental toxicity, cancerogenicity, and radioactivity

Dysregulated Expression of Arterial MicroRNAs and Their Target Gene Networks in Temporal Arteries of Treatment-Naïve Patients with Giant Cell Arteritis

In this study, we explored expression of microRNA (miR), miR-target genes and matrix remodelling molecules in temporal artery biopsies (TABs) from treatment-naïve patients with giant cell arteritis (GCA, n = 41) and integrated these analyses with clinical, laboratory, ultrasound and histological manifestations of GCA. NonGCA patients (n = 4) served as controls. GCA TABs exhibited deregulated expression of several miRs (miR-21-5p, -145-5p, -146a-5p, -146b-5p, -155-5p, 424-3p, -424-5p, -503-5p), putative miR-target genes (YAP1, PELI1, FGF2, VEGFA, KLF4) and matrix remodelling factors (MMP2, MMP9, TIMP1, TIPM2) with key roles in Toll-like receptor signaling, mechanotransduction and extracellular matrix biology. MiR-424-3p, -503-5p, KLF4, PELI1 and YAP1 were identified as new deregulated molecular factors in GCA TABs. Quantities of miR-146a-5p, YAP1, PELI1, FGF2, TIMP2 and MMP9 were particularly high in histologically positive GCA TABs with occluded temporal artery lumen. MiR-424-5p expression in TABs and the presence of facial or carotid arteritis on ultrasound were associated with vision disturbances in GCA patients. Correlative analysis of miR-mRNA quantities demonstrated a highly interrelated expression network of deregulated miRs and mRNAs in temporal arteries and identified KLF4 as a candidate target gene of deregulated miR-21-5p, -146a-5p and -155-5p network in GCA TABs. Meanwhile, arterial miR and mRNA expression did not correlate with constitutive symptoms and signs of GCA, elevated markers of systemic inflammation nor sonographic characteristics of GCA. Our study provides new insights into GCA pathophysiology and uncovers new candidate biomarkers of vision impairment in GCA

Laboratory Methodology Important in the Diagnosis and Prognosis of Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease, characterized by thrombosis and pregnancy complications with persistently elevated levels of antiphospholipid antibodies (aPL). Recently, a unique mathematical calculation has been presented to assess the risk of thrombosis in patients with APS called antiphospholipid score or global antiphospholipid syndrome score (GAPSS). This new approach in the diagnosis of APS leads to the assessment of the risk of thrombosis considering the results of different aPL (lupus anticoagulants (LA), anticardiolipin antibodies (aCL), antibodies against β2GPI (anti-β2GPI), and phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) (isotypes IgG and IgM). This chapter provides an overview of the algorithm strategy for APS diagnosis with the aims of characterizing in detail the laboratory methodology of criteria aPL (LA, aCL, and anti-β2GPI) and noncriteria aPL, such as IgA aCL and IgA anti-β2GPI, anti-domain I β2GPI, and antiprothrombin antibodies. In order to improve APS diagnosis, several new approaches in aPL detection have recently been suggested, such as multiline immunodot assay, detection of aPL by flow cytometry using beads with particular surface properties, and the newly developed automated BioPlex system technology for parallel detection of aCL and anti-β2GPI antibodies of IgG, IgA, and IgM isotypes. A completely different and promising approach in future research lies in the potential of microRNAs as biomarkers for risk of thrombosis and/or obstetric complication

Zgodnji gigantocelični arteritis

Gigantocelični arteritis (GCA) je najpogostejši primarni sistemski vaskulitis pri odraslih po 50. letu starosti v Evropi. Prizadene velike in srednje velike arterije in vnetni proces, ki zožuje ali popolnoma zapre svetlino žile, lahko dovede do hudih/trajnih ishemičnih zapletov kot so oslepitev, možganska kap ali miokardni infarkt. V zadnjem desetletju se je z vključitvijo slikovnih preiskav v diagnostični postopek pomembno skrajšal čas do prepoznave bolezni (t.i. zgodnji GCA). Pospešena obravnava bolnikov (ang. “fast track clinic”) je vodila v zmanjšanje pojavnosti najresnejših ishemičnih zapletov bolezni in znižanje stroškov zdravljenja. Vendar pa bolezen praviloma poteka kronično, s poslabšanji, kar skupaj s kroničnim glukokortikoidnem zdravljenjem vodi v kopičenje okvar organov in tkiv. Prav zato se intenzivno preučuje patogeneza bolezni, z možnostjo implementacije izsledkov kot so sodobne molekularno in celično usmerjene tarčne terapije. Glavni cilji našega preglednega članka so bili: a) analiza raziskav z navedenim časom trajanja od začetka simptomov do postavitve diagnoze, b) raziskava obetavnih molekularnih tarč za zdravljenje GCA in c) prepoznava klinično pomembnih celičnih podtipov. Najbolj obetavne tarčne molekule za tarčno zdravljenje so IL-6, IL-12/IL-23 in citototoksični z limfociti T povezan protein 4, medtem ko terapija z zaviralci TNF-α ni bila uspešna. Kliničnih raziskav z učinkovinami, usmerjenimi proti IL-17, še ni. V prispevku pa smo se dotaknili tudi drugih potencialnih terapevtskih tarč, vključno z molekulami, ki sodelujejujo v signalnih poteh

Single cell RNA sequencing in autoimmune inflammatory rheumatic diseases

Single cell RNA sequencing (scRNA-seq) represents a new large scale and high throughput technique allowing analysis of the whole transcriptome at the resolution of an individual cell. It has emerged as an imperative method in life science research, uncovering complex cellular networks and providing indices that will eventually lead to the development of more targeted and personalized therapies. The importance of scRNA-seq has been particularly highlighted through the analysis of complex biological systems, in which cellular heterogeneity is a key aspect, such as the immune system. Autoimmune inflammatory rheumatic diseases represent a group of disorders, associated with a dysregulated immune system and high patient heterogeneity in both pathophysiological and clinical aspects. This complicates the complete understanding of underlying pathological mechanisms, associated with limited therapeutic options available and their long-term inefficiency and even toxicity. There is an unmet need to investigate, in depth, the cellular and molecular mechanisms driving the pathogenesis of rheumatic diseases and drug resistance, identify novel therapeutic targets, as well as make a step forward in using stratified and informed therapeutic decisions, which could now be achieved with the use of single cell approaches. This review summarizes the current use of scRNA-seq in studying different rheumatic diseases, based on recent findings from published in vitro, in vivo, and clinical studies, as well as discusses the potential implementation of scRNA-seq in the development of precision medicine in rheumatology

Bio-performance of hydrothermally and plasma-treated titanium

The research presented herein follows an urgent global need for the development of novel surface engineering techniques that would allow the fabrication of next-generation cardiovascular stents, which would drastically reduce cardiovascular diseases (CVD). The combination of hydrothermal treatment (HT) and treatment with highly reactive oxygen plasma (P) allowed for the formation of an oxygen-rich nanostructured surface. The morphology, surface roughness, chemical composition and wettability of the newly prepared oxide layer on the Ti substrate were characterized by scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) analysis. The alteration of surface characteristics influenced the material’s bio-performanceplatelet aggregation and activation was reduced on surfaces treated by hydrothermal treatment, as well as after plasma treatment. Moreover, it was shown that surfaces treated by both treatment procedures (HT and P) promoted the adhesion and proliferation of vascular endothelial cells, while at the same time inhibiting the adhesion and proliferation of vascular smooth muscle cells. The combination of both techniques presents a novel approach for the fabrication of vascular implants, with superior characteristics

Antiphospholipid Antibody Syndrome-Associated Increased Surface Expression of VLA4 Integrin on Human Monocytes

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombosis and/or obstetric complications in the presence of antiphospholipid antibodies (aPL). Catastrophic APS (CAPS) is the most severe form of the disease, in which microvascular thromboses develop rapidly, leading to multiorgan failure. Monocytes, along with endothelial cells, are critical players in the pathogenesis of APS. Recruitment of these cells to the site of injury/inflammation involves a series of events, including capture, rolling, adhesion enhancement, and transmigration, which are controlled by surface adhesion molecules. The aim of our study was to investigate the surface adhesion profile of monocytes from APS patients and monocytes stimulated in vitro with aPL from a CAPS patient. The surface expression of the adhesion molecules LFA1, L-selectin, MAC1, PSGL1, and VLA4 was analyzed by flow cytometry. To our knowledge, this preliminary study was the first to show that VLA4 was significantly increased on the surface of monocytes from APS patients. Moreover, in vitro stimulations mimicking CAPS showed an even greater increase in VLA4. Our data suggest that the surface adhesion profile on monocytes is altered in APS and CAPS and may be involved in the thrombotic pathophysiology of the disease by enhancing monocyte adhesion