The emerging and diverse roles of Src-like adaptor proteins in health and disease

Although Src-like adaptor proteins (SLAP-1 and SLAP-2) were mainly studied in lymphocytes, where they act as negative regulators and provide fine control of receptor signaling, recently, several other functions of these proteins were discovered. In addition to the well-characterized immunoregulatory functions, SLAP proteins appear to have an essential role in the pathogenesis of type I hypersensitivity, osteoporosis, and numerous malignant diseases. Both adaptor proteins are expressed in a wide variety of tissues, where they have mostly inhibitory effects on multiple intracellular signaling pathways. In this review, we summarize the diverse effects of SLAP proteins

Isolation of Exosomes from Blood Plasma: Qualitative and Quantitative Comparison of Ultracentrifugation and Size Exclusion Chromatography Methods

BACKGROUND: Exosomes are emerging targets for biomedical research. However, suitable methods for the isolation of blood plasma-derived exosomes without impurities have not yet been described. AIM: Therefore, we investigated the efficiency and purity of exosomes isolated with potentially suitable methods; differential ultracentrifugation (UC) and size exclusion chromatography (SEC). METHODS AND RESULTS: Exosomes were isolated from rat and human blood plasma by various UC and SEC conditions. Efficiency was investigated at serial UC of the supernatant, while in case of SEC by comparing the content of exosomal markers of various fractions. Purity was assessed based on the presence of albumin. We found that the diameter of the majority of isolated particles fell into the size range of exosomes, however, albumin was also present in the preparations, when 1h UC at 4 degrees C was applied. Furthermore, with this method only a minor fraction of total exosomes could be isolated from blood as deduced from the constant amount of exosomal markers CD63 and TSG101 detected after serial UC of rat blood plasma samples. By using UC for longer time or with shorter sedimentation distance at 4 degrees C, or UC performed at 37 degrees C, exosomal yield increased, but albumin impurity was still observed in the isolates, as assessed by transmission electron microscopy, dynamic light scattering and immunoblotting against CD63, TSG101 and albumin. Efficiency and purity were not different in case of using further diluted samples. By using SEC with different columns, we have found that although a minor fraction of exosomes can be isolated without significant albumin content on Sepharose CL-4B or Sephacryl S-400 columns, but not on Sepharose 2B columns, the majority of exosomes co-eluted with albumin. CONCLUSION: Here we show that it is feasible to isolate exosomes from blood plasma by SEC without significant albumin contamination albeit with low vesicle yield

Photon-counting computed tomography in the assessment of rheumatoid arthritis-associated interstitial lung disease: an initial experience

PURPOSEInterstitial lung disease (ILD) accounts for a significant proportion of mortality and morbidity in patients with rheumatoid arthritis (RA). The aim of this cross-sectional study is to evaluate the performance of novel photon-counting detector computed tomography (PCD-CT) in the detection of pulmonary parenchymal involvement.METHODSSixty-one patients with RA without a previous definitive diagnosis of ILD underwent high-resolution (HR) (0.4 mm slice thickness) and ultra-high-resolution (UHR) (0.2 mm slice thickness) PCDCT examination. The extent of interstitial abnormalities [ground-glass opacity (GGO), reticulation, bronchiectasis, and honeycombing] were scored in each lobe using a Likert-type scale. Total ILD scores were calculated as the sum of scores from all lobes.RESULTSReticulation and bronchiectasis scores were higher in the UHR measurements taken compared with the HR protocol [median (quartile 1, quartile 3): 2 (0, 3.5) vs. 0 (0, 3), P < 0.001 and 2 (0, 2) vs. 0 (0, 2), P < 0.001, respectively]; however, GGO and honeycombing scores did not differ [2 (2, 4) vs. 2 (2, 4), P = 0.944 and 0 (0, 0) vs. 0 (0, 0), P = 0.641, respectively]. Total ILD scores from both HR and UHR scans showed a mild negative correlation in diffusion capacity for carbon monoxide (HR: r = –0.297, P = 0.034; UHR: r = –0.294, P = 0.036). The pattern of lung parenchymal involvement did not differ significantly between the two protocols. The HR protocol had significantly lower volume CT dose index [0.67 (0.69, 1.06) mGy], total dose length product [29 (24.48, 33.2) mGy*cm] compared with UHR scans [8.18 (6.80, 9.23) mGy, P < 0.001 and 250 (218, 305) mGy*cm, P < 0.001].CONCLUSIONUHR PCD-CT provides more detailed information on ILD in patients with RA than low-dose HR PCDCT. HR PCD-CT image acquisition with a low effective radiation dose may serve as a valuable, low-radiation screening tool in the selection of patients for further, higher-dose UHR PCD-CT screening

Proteomic Changes of Osteoclast Differentiation in Rheumatoid and Psoriatic Arthritis Reveal Functional Differences

BACKGROUND: Osteoclasts play a crucial role in the maintenance, repair, and remodeling of bones of the adult vertebral skeleton due to their bone resorption capability. Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are associated with increased activity of osteoclasts. OBJECTIVES: Our study aimed to investigate the dynamic proteomic changes during osteoclast differentiation in healthy donors, in RA, and PsA. METHODS: Blood samples of healthy donors, RA, and PsA patients were collected, and monocytes were isolated and differentiated into osteoclasts in vitro using macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κB ligand (RANK-L). Mass spectrometry-based proteomics was used to analyze proteins from cell lysates. The expression changes were analyzed with Gene Set Enrichment Analysis (GSEA). RESULTS: The analysis of the proteomic changes revealed that during the differentiation of the human osteoclasts, expression of the proteins involved in metabolic activity, secretory function, and cell polarity is increased; by contrast, signaling pathways involved in the immune functions are downregulated. Interestingly, the differences between cells of healthy donors and RA/PsA patients are most pronounced after the final steps of differentiation to osteoclasts. In addition, both in RA and PsA the differentiation is characterized by decreased metabolic activity, associated with various immune pathway activities; furthermore by accelerated cytokine production in RA. CONCLUSIONS: Our results shed light on the characteristic proteomic changes during human osteoclast differentiation and expression differences in RA and PsA, which reveal important pathophysiological insights in both diseases

A fotonszámláló detektoros CT működési alapelve, előnyei és jelentősége a klinikai gyakorlatban = Photoncounting-detector CT: Basic principles, advantages and implications in clinical practice

Az elmúlt évtizedben fizikai és preklinikai vizsgálatokkal igazolták az alapjaiban új típusú, fotonszámláló komputertomográfiás (CT) detektor kiváló képalkotási tulajdonságait, míg napjainkban a páréves klinikai felhasználás egyre szélesebb körű tapasztalatait veszik számba. A klinikai gyakorlatban elterjedt, hagyományos CT-berendezésekben energiaintegráló detektorok (EID) találhatók, melyek indirekt konverziós technológiával alakítják át a röntgenfotonok energiáját elektromos jellé. Ezzel ellentétben a fotonszámláló CT detektorai (PCD) közvetlenül és magasabb hatásfokkal képesek elektromos jellé alakítani a röntgenfotonok energiáját, megszámlálni az egyes röntgenfotonok által létrehozott töltéseket és mérni azok energiaszintjét. Az új PCD-technológia számos előnyt nyújt a hagyományos EID-technológiával összevetve: egyrészt kisebb sugárterhelés mellett jobb térbeli felbontású, kedvezőbb jel/zaj arányú, kevesebb sugárkeményedési („beam-hardening”) műterméket tartalmazó és alacsonyabb elektronikus zajjal terhelt CT-képeket hoz létre, másrészt lehetővé teszi a spektrális képalkotást, valamint csökkentett dózisú kontrasztanyag alkalmazására is lehetőséget ad. Összefoglaló közleményünk a PCD-CT műszaki és fizikai alapelveit ismerteti, valamint áttekintést nyújt annak előnyeiről és a klinikai gyakorlatban való felhasználásáról. | Over the last decade, an esentially new type of computed tomography (CT) detector, namely the photoncounting detector has demonstrated its superior capabilities over traditional CT detectors in both physical and preclinical evaluations, while is now at the stage of early clinical experiences. Conventional CT scanners available today for routine clinical practice use energy integrated detectors (EID) which rely on indirect conversion technology. In contrary, the newly-introduced photon-counting detectors (PCD) utilize a direct conversion method allowing to count the number of x-ray photons and carry detailed information about the energy level of each individual x-ray photon. Due to the fundamental changes in the physical mechanisms responsible for photon detection and signal creation, PCDs have several benefits over traditional CT detectors. In comparison to current CT technology, PCDCT can produce better spatial resolution, reduced electronic noise with a higher contrast-to-noise ratio, reduced beam-hardening and metal artifacts. Furthermore, from the spectral information, this new technology is capable to reconstruct virtual monoenergetic images and optimize iv. contrast agent dose. In our current review article, technical principles and physics of PCDs and, in addition, early clinical experiences with their applications are summarized

Extracelluláris vezikulák gyulladásos és onkológiai betegségekben

Mind jobban megismerjük az extracelluláris vezikulák jelentőségét fiziológiás és patológiás körülmények között, például gyulladásos ízületi és onkológiai betegségek patomechanizmusában. A vezikulák számának és molekuláris összetételének vizsgálata hozzájárulhat újszerű orvosi diagnosztikai eljárások fejlesztéséhez. A jövőben a vezikulák eltávolítása a daganatos betegségek adjuváns terápiájaként, valamint génterápiás és gyógyszerszállító eszközként történő alkalmazása új mérföldkövet jelenthet az orvostudományban

The emerging role of aryl hydrocarbon receptor in the activation and differentiation of Th17 cells

The aryl hydrocarbon receptor (AHR) is a cytoplasmic transcription factor, which plays an essential role in the xenobiotic metabolism in a wide variety of cells. The AHR gene is evolutionarily conserved and it has a central role not only in the differentiation and maturation of many tissues, but also in the toxicological metabolism of the cell by the activation of metabolizing enzymes. Several lines of evidence support that both AHR agonists and antagonists have profound immunological effects; and recently, the AHR has been implicated in antibacterial host defense. According to recent studies, the AHR is essential for the differentiation and activation of T helper 17 (Th17) cells. It is well known that Th17 cells have a central role in the development of inflammation, which is crucial in the defense against pathogens. In addition, Th17 cells play a major role in the pathogenesis of several autoimmune diseases such as rheumatoid arthritis. Therefore, the AHR may provide connection between the environmental chemicals, the immune regulation, and autoimmunity. In the present review, we summarize the role of the AHR in the Th17 cell functions