Beyond basic characterization and omics: Immunomodulatory roles of platelet-derived extracellular vesicles unveiled by functional testing.

Renowned for their role in haemostasis and thrombosis, platelets are also increasingly recognized for their contribution in innate immunity, immunothrombosis and inflammatory diseases. Platelets express a wide range of receptors, which allows them to reach a variety of activation endpoints and grants them immunomodulatory functions. Activated platelets release extracellular vesicles (PEVs), whose formation and molecular cargo has been shown to depend on receptor-mediated activation and environmental cues. This study compared the immunomodulatory profiles of PEVs generated via activation of platelets by different receptors, glycoprotein VI, C-type lectin-like receptor 2 and combining all thrombin-collagen receptors. Functional assays in vivo in zebrafish and in vitro in human macrophages highlighted distinct homing and secretory responses triggered by the PEVs. In contrast, omics analyses of protein and miRNA cargo combined with physicochemical particle characterization found only subtle differences between the activated PEV types, which were insufficient to predict their different immunomodulatory functions. In contrast, constitutively released PEVs, formed in the absence of an exogenous activator, displayed a distinct immunomodulatory profile from the receptor-induced PEVs. Our findings underscore that PEVs are tunable through receptor-mediated activation. To truly comprehend their role(s) in mediating platelet functions among immune cells, conducting functional assays is imperative.

International Society for Extracellular Vesicles Workshop. QuantitatEVs: multiscale analyses, from bulk to single extracellular vesicle.

The 'QuantitatEVs: multiscale analyses, from bulk to single vesicle' workshop aimed to discuss quantitative strategies and harmonized wet and computational approaches toward the comprehensive analysis of extracellular vesicles (EVs) from bulk to single vesicle analyses with a special focus on emerging technologies. The workshop covered the key issues in the quantitative analysis of different EV-associated molecular components and EV biophysical features, which are considered the core of EV-associated biomarker discovery and validation for their clinical translation. The in-person-only workshop was held in Trento, Italy, from January 31st to February 2nd, 2023, and continued in Milan on February 3rd with "Next Generation EVs", a satellite event dedicated to early career researchers (ECR). This report summarizes the main topics and outcomes of the workshop.

Increased circulating platelet-derived extracellular vesicles in severe COVID-19 disease.

Coagulation disturbances are major contributors to COVID-19 pathogenicity, but limited data exist on the involvement of extracellular vesicles (EVs) and residual cells (RCs). Fifty hospitalized COVID-19 patients stratified by their D-dimer levels into high (>1.5 mg/L, n = 15) or low (≤1.5 mg/l, n = 35) and 10 healthy controls were assessed for medium-sized EVs (mEVs; 200-1000 nm) and large EVs/RCs (1000-4000 nm) by high sensitivity flow cytometry. EVs were analyzed for CD61, CD235a, CD45, and CD31, commonly used to detect platelets, red blood cells, leukocytes or endothelial cells, respectively, whilst phosphatidyl serine EVs/RCs were detected by lactadherin-binding implicating procoagulant catalytic surface. Small EV detection (sEVs; 50-200 nm) and CD41a (platelet integrin) colocalization with general EV markers CD9, CD63, and CD81 were performed by single particle interferometric reflectance imaging sensor. Patients with increased D-dimer exhibited the highest number of RCs and sEVs irrespective of cell origin (p < .05). Platelet activation, reflected by increased CD61+ and lactadherin+ mEV and RC levels, associated with coagulation disturbances. Patients with low D-dimer could be discriminated from controls by tetraspanin signatures of the CD41a+ sEVs, suggesting the changes in the circulating platelet sEV subpopulations may offer added prognostic value during COVID progression.

What is the context? Coronavirus disease 19 (COVID-19) frequently leads to blood clotting disturbances, including thromboses.Particles smaller than cells, extracellular vesicles (EVs), and residual cells (RCs) affect blood clotting, but data on their role and diagnostic utility in COVID-19 are sparse.What is new? In this study, we assessed 50 hospitalized COVID-19 patients and 10 healthy controls for their different EV subpopulations and residual cells (50­4000 nm).Blood clotting marker D-dimer, which is elevated in severe COVID-19 infection, was used to characterize disease severity and stratify the patient subgroups. Fifteen patients (30%) with high D-dimer (>1.5 mg/L) were compared to controls, and 35 patients with lower D-dimer (≤1.5 mg/mL).The most topical state-of-the-art methods for detection of EV subpopulations, that is, high sensitivity flow cytometry (hsFCM) and single particle interferometric reflectance imaging sensor (SP-IRIS), were used with markers indicative of platelet, red blood cell, leukocyte or endothelial cells. The subpopulations differentiated by platelet and tetraspanin signatures by hsFCM and SP-IRIS, respectively.The main findings are Patients with high D-dimer systematically exhibited the highest number of platelet EVs in all subpopulations (p < .05).Small EVs subpopulations (differentiated by the tetraspanin signatures) could discriminate patients with low D-dimer (p < .001) from healthy controls.Differences between the two D-dimer groups were seen in the platelet-derived (large and medium EVs and RCs), RBC-derived mEVs and l EVs and RCs, and lactadherin-positive large EVs and RCs (p < .05).What is the impact? Platelet activation, reflected by increased EVs was associated with blood clotting disturbances. Small EVs signatures revealed changes in the EV subpopulations in association with blood clotting during COVID-19. Such signatures may enable identification of severely ill patients before the increase in coagulation is evident by coagulation parameters, for example, by high D-dimer.

Tetraspanin profiles of serum extracellular vesicles reflect functional limitations and pain perception in knee osteoarthritis.

BACKGROUND: Emerging evidence suggests that extracellular vesicles (EVs) can play roles in inflammatory processes and joint degradation in primary osteoarthritis (OA), a common age-associated joint disease. EV subpopulations express tetraspanins and platelet markers that may reflect OA pathogenesis. The present study investigated the associations between these EV surface markers and articular cartilage degradation, subjectively and objectively assessed pain, and functional limitations in primary knee OA (KOA). METHODS: Serum EVs were determined by high-sensitivity flow cytometry (large CD61+ EVs) and single particle interferometric reflectance imaging sensor (small CD41+, CD63+, CD81+, and CD9+ EVs) from end-stage KOA patients and controls (n = 8 per group). Knee pain and physical functions were assessed with several health- and pain-related questionnaires, established measurements of physical medicine, and neuromuscular examination. The obtained data were analyzed using supervised and unsupervised univariate and multivariate models. RESULTS: With the combined dataset of cartilage thickness, knee function, pain, sensation, and EV molecular signatures, we identified highly correlated groups of variables and found several EV markers that were statistically significant predictors of pain, physical limitations, and other aspects of well-being for KOA patients, for instance CD41+/CD63+/CD9+ small EVs associated with the range of motion of the knee, physical performance, and pain sensitivity. CONCLUSIONS: Particular serum EV subpopulations showed clear associations with KOA pain and functional limitations, suggesting that their implications in OA pathophysiology warrant further study.

OxLDL sensitizes platelets for increased formation of extracellular vesicles capable of finetuning macrophage gene expression.

Platelet extracellular vesicles (PEVs) generated upon platelet activation may play a role in inflammatory pathologies such as atherosclerosis. Oxidized low-density lipoprotein (oxLDL), a well-known contributor to atherogenesis, activates platelets and presensitizes them for activation by other agonists. We studied the effect of oxLDL on the secretion, composition, and inflammatory functions of PEVs using contemporary EV analytics. Platelets were activated by co-stimulation with thrombin (T) and collagen (C) ± oxLDL and characterized by high-resolution flow cytometry, nanoparticle tracking analysis, proximity extension assay, western blot, and electron microscopy. The effect of PEVs on macrophage differentiation and functionality was examined by analyzing macrophage surface markers, cytokine secretion, and transcriptome. OxLDL upregulated TC-induced formation of CD61+, P-selectin+ and phosphatidylserine+ PEVs. Blocking the scavenger receptor CD36 significantly suppressed the oxLDL+TC-induced PEV formation, and HDL caused a slight but detectable suppression. The inflammatory protein cargo differed between the PEVs from stimulated and unstimulated platelets. Both oxLDL+TC- and TC-induced PEVs enhanced macrophage HLA-DR and CD86 expression and decreased CD11c expression as well as secretion of several cytokines. Pathways related to cell cycle and regulation of gene expression, and immune system signaling were overrepresented in the differentially expressed genes between TC PEV -treated vs. control macrophages and oxLDL+TC PEV -treated vs. control macrophages, respectively. In conclusion, we speculate that oxLDL and activated platelets contribute to proatherogenic processes by increasing the number of PEVs that provide an adhesive and procoagulant surface, contain inflammatory mediators, and subtly finetune the macrophage gene expression.

Matrix metalloproteinase (MMP)-2, MMP-9, semen quality and sperm longevity in fractionated stallion semen.

Matrix metalloproteinase (MMP)-2 and MMP-9 are gelatinases that take part in several reproductive processes. The aim of this study was to measure levels of MMP-2 and MMP-9 in fractionated stallion ejaculates, and to evaluate the association between these components and semen quality, and sperm longevity during cooled storage. Semen quality were assessed separately for sperm-rich fractions (HIGH), sperm-poor fractions (LOW), and whole ejaculate samples (WE) from 33 stallions. After cooled storage with SP either present or removed, sperm motility and DFI were determined. The relative activity of the pro-form of MMP-2, active MMP-2 and total MMP-9 were evaluated using gelatin zymography, and all were present in all fractions of the stallion's ejaculate, with higher relative activity of the latent than active forms and the highest relative activity in the HIGH fraction. The relative activities of MMP-2 and MMP-9 were positively correlated to sperm concentration and total sperm count, but only in the HIGH fraction and not in LOW or WE. The relative activities of MMPs were not related to differences in sperm longevity during cooled storage, measured as sperm motility and DFI. There was a harmful effect of SP on DFI during storage, but this effect was not associated with differences in the relative activities of MMPs. In conclusion, the relative activities of MMPs are not useful as markers for semen quality (other than sperm concentration), or sperm survival during storage in horses.

Cancer Alters the Metabolic Fingerprint of Extracellular Vesicles.

Cancer alters cell metabolism. How these changes are manifested in the metabolite cargo of cancer-derived extracellular vesicles (EVs) remains poorly understood. To explore these changes, EVs from prostate, cutaneous T-cell lymphoma (CTCL), colon cancer cell lines, and control EVs from their noncancerous counterparts were isolated by differential ultracentrifugation and analyzed by nanoparticle tracking analysis (NTA), electron microscopy (EM), Western blotting, and liquid chromatography-mass spectrometry (LC-MS). Although minor differences between the cancerous and non-cancerous cell-derived EVs were observed by NTA and Western blotting, the largest differences were detected in their metabolite cargo. Compared to EVs from noncancerous cells, cancer EVs contained elevated levels of soluble metabolites, e.g., amino acids and B vitamins. Two metabolites, proline and succinate, were elevated in the EV samples of all three cancer types. In addition, folate and creatinine were elevated in the EVs from prostate and CTCL cancer cell lines. In conclusion, we present the first evidence in vitro that the altered metabolism of different cancer cells is reflected in common metabolite changes in their EVs. These results warrant further studies on the significance and usability of this metabolic fingerprint in cancer.

Altered Basal Autophagy Affects Extracellular Vesicle Release in Cells of Lagotto Romagnolo Dogs With a Variant ATG4D.

Lagotto Romagnolo breed dogs develop a progressive neurological disease with intracellular vacuolar storage when homozygous for a variant in the autophagy-related gene 4D (ATG4D). A lysosomal enzyme deficiency has not been proven in this disease, despite its overlapping morphology with lysosomal storage diseases. Instead, basal autophagy was altered in fibroblasts from affected dogs. The aim of this study was to clarify the origin of the limiting membrane of the accumulating vacuoles and determine whether altered basal autophagy affects the extracellular release of vesicles in cells from diseased dogs. When assessed by immunoelectron microscopy, the membrane of the cytoplasmic vacuoles in affected tissues contained ATG4D, markers for autolysosomes (microtubule-associated protein 1A/B light chain 3 and lysosome-associated membrane protein 2) and for recycling endosomes (transferrin receptor 2), indicating that the vacuoles are hybrid organelles between endocytic and autophagic pathways. Ultracentrifugation, nanoparticle tracking analysis, and mass spectrometry were used to analyze the vesicles released from cultured fibroblasts of affected and control dogs. The amount of extracellular vesicles (EVs) released from affected fibroblasts was significantly increased during basal conditions in comparison to controls. This difference disappeared during starvation. The basal EV proteome of affected cells was enriched with cytosolic, endoplasmic reticulum, and mitochondrial proteins. Heat shock proteins and chaperones, some of which are known substrates of basal autophagy, were identified among the proteins unique to EVs of affected cells. An increased release of extracellular vesicles may serve as a compensatory mechanism in disposal of intracellular proteins during dysfunctional basal autophagy in this spontaneous disease.

Extracellular vesicles from human plasma and serum are carriers of extravesicular cargo-Implications for biomarker discovery.

Extracellular vesicles (EVs) in human blood are a potential source of biomarkers. To which extent anticoagulation affects their concentration, cellular origin and protein composition is largely unexplored. To study this, blood from 23 healthy subjects was collected in acid citrate dextrose (ACD), citrate or EDTA, or without anticoagulation to obtain serum. EVs were isolated by ultracentrifugation or by size-exclusion chromatography (SEC) for fluorescence-SEC. EVs were analyzed by micro flow cytometry, NTA, TEM, Western blot, and protein mass spectrometry. The plasma EV concentration was unaffected by anticoagulants, but serum contained more platelet EVs. The protein composition of plasma EVs differed between anticoagulants, and between plasma and serum. Comparison to other studies further revealed that the shared EV protein composition resembles the "protein corona" of synthetic nanoparticles incubated in plasma or serum. In conclusion, we have validated a higher concentration of platelet EVs in serum than plasma by contemporary EV methods. Anticoagulation should be carefully described (i) to enable study comparison, (ii) to utilize available sample cohorts, and (iii) when preparing/selecting biobank samples. Further, the similarity of the EV protein corona and that of nanoparticles implicates that EVs carry both intravesicular and extravesicular cargo, which will expand their applicability for biomarker discovery.

Upregulation of CRISP-3 and kallikrein in stallion seminal plasma is associated with poor tolerance of cooled storage.

For unknown reasons, stallion fertility and sperm longevity during cooled storage of semen vary markedly between individuals. Spermatozoa from individual stallions react differently to the presence, or the removal, of seminal plasma (SP). The aim was to evaluate differences in protein content in stallion seminal plasma with either a positive or a negative effect on sperm chromatin integrity during storage. Stallion semen samples from different ejaculate fractions were stored at 5°C for 24 hr. Sperm survival was assessed after storage using a sperm chromatin structure assay. Protein expression in SP with either positive or negative effects on sperm survival during storage was studied using two-dimensional differential gel electrophoresis and liquid chromatography-mass spectrometry. Lower sperm chromatin integrity was associated with upregulation of the proteins kallikrein, CRISP-3 and HSP-1, while higher chromatin integrity was associated with upregulation of TIMP-2. In the sperm-rich fractions, kallikrein and CRISP-3 differed significantly between SP samples with differing effects on sperm chromatin integrity. In the sperm-poor fractions, TIMP-2 and HSP-1 differed significantly between the two SP groups. Differences in the seminal plasma proteome are associated with sperm longevity during cooled storage.

Fast isolation of highly specific population of platelet-derived extracellular vesicles from blood plasma by affinity monolithic column, immobilized with anti-human CD61 antibody.

A new, fast and selective immunoaffinity chromatographic method including a methacrylate-based convective interaction media (CIM®) disk monolithic column, immobilized with anti-human CD61 antibody, was developed for the isolation of CD61-containing platelet-derived extracellular vesicles (EVs) from plasma. The isolated EVs were detected and size characterized by asymmetrical flow field-flow fractionation (AsFlFFF) with multi-angle light-scattering (MALS) and dynamic light-scattering (DLS) detection, and further confirmed by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). The mean size of platelet-derived EV isolates from the anti-CD61 CIM® disk monolithic column were 174 nm (SD 60 nm) based on the NTA results. These results indicated a successful isolation of platelet-derived EVs, which was confirmed by Western blotting the isolates against the EV-specific markers CD9 and TSG101 together with transmission electron microscopy. Additional elucidation of MALS and DLS data provided detailed information of the size distribution of the isolated fractions, confirming the successful isolation of also small platelet-derived EVs ranging from 30 to 130 nm based on the hydrodynamic radii. The isolation procedure took only 19 min and the time can be even further decreased by increasing the flow rate. The same immunoaffinity chromatographic procedure, following AsFlFFF allowed also the isolation and characterization of platelet-derived EVs from plasma in under 60 min. Since it is possible to regenerate the anti-CD61 disk for multiple uses, the methodology developed in this study provides a viable substitution and addition to the conventional EV isolation procedures.

Metabolomics Applied to the Study of Extracellular Vesicles.

Cell-secreted extracellular vesicles (EVs) have rapidly gained prominence as sources of biomarkers for non-invasive biopsies, owing to their ubiquity across human biofluids and physiological stability. There are many characterisation studies directed towards their protein, nucleic acid, lipid and glycan content, but more recently the metabolomic analysis of EV content has also gained traction. Several EV metabolite biomarker candidates have been identified across a range of diseases, including liver disease and cancers of the prostate and pancreas. Beyond clinical applications, metabolomics has also elucidated possible mechanisms of action underlying EV function, such as the arginase-mediated relaxation of pulmonary arteries or the delivery of nutrients to tumours by vesicles. However, whilst the value of EV metabolomics is clear, there are challenges inherent to working with these entities-particularly in relation to sample production and preparation. The biomolecular composition of EVs is known to change drastically depending on the isolation method used, and recent evidence has demonstrated that changes in cell culture systems impact upon the metabolome of the resulting EVs. This review aims to collect recent advances in the EV metabolomics field whilst also introducing researchers interested in this area to practical pitfalls in applying metabolomics to EV studies.

Metabolic signature of extracellular vesicles depends on the cell culture conditions.

One of the greatest bottlenecks in extracellular vesicle (EV) research is the production of sufficient material in a consistent and effective way using in vitro cell models. Although the production of EVs in bioreactors maximizes EV yield in comparison to conventional cell cultures, the impact of their cell growth conditions on EVs has not yet been established. In this study, we grew two prostate cancer cell lines, PC-3 and VCaP, in conventional cell culture dishes and in two-chamber bioreactors to elucidate how the growth environment affects the EV characteristics. Specifically, we wanted to investigate the growth condition-dependent differences by non-targeted metabolite profiling using liquid chromatography-mass spectrometry (LC-MS) analysis. EVs were also characterized by their morphology, size distribution, and EV protein marker expression, and the EV yields were quantified by NTA. The use of bioreactor increased the EV yield >100 times compared to the conventional cell culture system. Regarding morphology, size distribution and surface markers, only minor differences were observed between the bioreactor-derived EVs (BR-EVs) and the EVs obtained from cells grown in conventional cell cultures (C-EVs). In contrast, metabolomic analysis revealed statistically significant differences in both polar and non-polar metabolites when the BR-EVs were compared to the C-EVs. The results show that the growth conditions markedly affected the EV metabolite profiles and that metabolomics was a sensitive tool to study molecular differences of EVs. We conclude that the cell culture conditions of EV production should be standardized and carefully detailed in publications and care should be taken when EVs from different production platforms are compared with each other for systemic effects.

Extracellular Vesicles Derived from Hypoxic Colorectal Cancer Cells Confer Metastatic Phenotype to Non-metastatic Cancer Cells.

BACKGROUND/AIM: Tumor-secreted extracellular vesicles (EVs) play an important role as mediators of intercellular communication. Hypoxia is a common feature of solid tumors frequently associated with an aggressive clinical behavior. This study aimed to gain a deeper understanding into the functions of EVs in intercellular communication between primary and metastatic cancer cells under hypoxic conditions. MATERIALS AND METHODS: EVs were isolated from two isogenic colorectal cancer (CRC) cell lines SW480 and SW620 cultured under normoxic and hypoxic conditions. Their uptake and effects in SW480 and SW620 cells were studied using EV uptake, proliferation, spheroid-formation, wound healing and invasion assays. RESULTS: Our data showed that hypoxia enhanced the release of EVs from CRC cells in a Hypoxia Induced Factor (HIF)-1-dependent manner. Hypoxic EVs were taken up by CRC cells more efficiently than normoxic EVs. Hypoxic EVs stimulated motility, invasiveness and stemness of primary tumour-derived SW480 cells, whereas they had a little effect on metastasis-derived SW620 cells. CONCLUSION: Hypoxic colorectal cancer-derived EVs confer aggressiveness and invasiveness to hypoxia-naïve cancer cells.

Changes in energy metabolism, and levels of stress-related hormones and electrolytes in horses after intravenous administration of romifidine and the peripheral α-2 adrenoceptor antagonist vatinoxan.

BACKGROUND: Romifidine, an α-2 adrenoceptor agonist, is a widely-used sedative in equine medicine. Besides the desired sedative and analgesic actions, α-2 adrenoceptor agonists have side effects like alterations of plasma concentrations of glucose and certain stress-related hormones and metabolites in various species. Vatinoxan (previously known as MK-467), in turn, is an antagonist of α-2 adrenoceptors. Because vatinoxan does not cross the blood brain barrier in significant amounts, it has only minor effect on sedation induced by α-2 adrenoceptor agonists. Previously, vatinoxan is shown to prevent the hyperglycaemia, increase of plasma lactate concentration and the decrease of insulin and non-esterified free fatty acids (FFAs) caused by α-2 adrenoceptor agonists in different species. The aim of our study was to investigate the effects of intravenous romifidine and vatinoxan, alone and combined, on plasma concentrations of glucose and some stress-related hormones and metabolites in horses. RESULTS: Plasma glucose concentration differed between all intravenous treatments: romifidine (80 µg/kg; ROM), vatinoxan (200 µg/kg; V) and the combination of these (ROM + V). Glucose concentration was the highest after ROM and the lowest after V. Serum FFA concentration was higher after V than after ROM or ROM + V. The baseline serum concentration of insulin varied widely between the individual horses. No differences were detected in serum insulin, cortisol or plasma adrenocorticotropic hormone (ACTH) concentrations between the treatments. Plasma lactate, serum triglyceride or blood sodium and chloride concentrations did not differ from baseline or between the treatments. Compared with baseline, plasma glucose concentration increased after ROM and ROM + V, serum cortisol, FFA and base excess increased after all treatments and plasma ACTH concentration increased after V. Serum insulin concentration decreased after V and blood potassium decreased after all treatments. CONCLUSIONS: Romifidine induced hyperglycaemia, which vatinoxan partially prevented despite of the variations in baseline levels of serum insulin. The effects of romifidine and vatinoxan on the insulin concentration in horses need further investigation.

The role of active transport in the transcellular movement of the peripheral α2-adrenoceptor antagonist, MK-467: An in vitro pilot study.

MK-467 is a peripherally acting α2-adrenoceptor antagonist due to its low lipid solubility and poor penetration of the blood-brain barrier (BBB). The aim of this study was to assess whether MK-467 could be a substrate of an active efflux transport mechanism. Using Madin-Darby Canine Kidney cells (MDCKII) and MDCKII cells transfected with the human multidrug resistance gene 1, drug transport was assessed in apical-basolateral and basolateral-apical directions. MK-467 was studied at 2 concentrations: 200 and 1000 ng/mL. Samples for analysis were taken at 15, 30, 45, 60, and 90 min after drug application. Drug concentrations were measured using liquid chromatography and mass spectrometry. MK-467 showed no apparent permeability in the apical-basolateral direction, transport in the basolateral-apical direction occurred in both cell lines. Efflux ratios were not calculated. However, MK-467 appeared to undergo active cellular transport. The identity of the transporter requires further investigation.

L'objectif de la présente étude était d'évaluer si le MK-467 pourrait être un substrat pour un mécanisme de transport par efflux actif. En utilisant des cellules rénales canines (Madin-Darby Canine Kidney cells, MDCKII) et des cellules MDCKII transfectées par le gène humain 1 multi-résistant aux médicaments, le transport des médicaments a été évalué dans les 2 directions : apicale-basolatérale et basolatéraleapicale. Deux concentrations de MK-467 ont été évaluées : 200 et 1000 ng/mL. Les échantillons pour l'analyse ont été prélevés 15, 30, 45, 60 et 90 min après l'application du médicament. Les concentrations du MK-467 ont étés mesurées par la chromatographie en phase liquide et la spectrométrie de masse. MK-467 n'a pas démontré une perméabilité visible dans la direction apicale-basolatérale; le transport dans la direction basolatérale-apicale a été vérifié dans les 2 lignes cellulaires. Les ratios d'efflux n'ont pas été calculés. Cependant, le MK-467 semble subir un transport cellulaire actif. Pour clarifier le véhicule de la substance, des recherches plus approfondies (ultérieures) sont nécessaires.(Traduit par Docteur Serge Messier).

Activation of complement system in kidney after ketoprofen-induced kidney injury in sheep.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat inflammatory pain in humans and animals. An overdose of an NSAID is nephrotoxic and can lead to acute kidney injury (AKI). Complement activation occurs in several types of renal disorders with proteinuria. The aim of this study was to investigate whether complement system becomes activated in kidneys after a high dose of NSAID. Kidney tissue and urine samples were collected from six sheep with ketoprofen-induced AKI and from six healthy control sheep. The localization of complement proteins in kidney tissue was carried out using immunohistochemical stainings, and excretion of C3 was tested by immunoblotting. RESULTS: The complement system was found to become activated in the kidney tissue as demonstrated by positive immunostaining for C1q, C3c, C4c, C5, C9 and factor H and by Western blotting analysis of C3 activation products in urine samples in sheep with AKI. CONCLUSIONS: Our results thus suggest that the alternative complement pathway is activated, and it may contribute to the acute tubular injury seen in the kidneys of NSAID-induced AKI sheep. Inhibition of complement activation may serve as potential therapeutic target for intervention in drug-induced AKI.

Evaluation of renal impairment in dogs after envenomation by the common European adder (Vipera berus berus).

Envenomation by the common European adder (Vipera berus berus) causes clinical renal injury in dogs. In this study, serum concentrations of albumin, creatinine, total protein and urea were measured in 32 dogs bitten by adders. Urinary creatinine, protein, and retinol binding protein 4 concentrations, and the activities of γ-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP), were measured in 32 affected dogs and 23 healthy controls. Clinical assessment was conducted with a grading scale and a renal function score was applied to classify dogs based on laboratory findings. Urinary protein:creatinine, GGT:creatinine and ALP:creatinine ratios appear to be useful in evaluating renal impairment in dogs with adder envenomation. Increasing kidney function score was correlated with increased urinary ALP:creatinine and GGT:creatinine ratios.

Proteomic analysis of bronchoalveolar lavage fluid samples obtained from West Highland White Terriers with idiopathic pulmonary fibrosis, dogs with chronic bronchitis, and healthy dogs.

OBJECTIVE: To evaluate protein expression in bronchoalveolar lavage fluid (BALF) obtained from West Highland White Terriers with idiopathic pulmonary fibrosis (IPF), dogs with chronic bronchitis, and healthy control dogs to identify potential biomarkers for IPF. SAMPLES: BALF samples obtained from 6 West Highland White Terriers with histologically confirmed IPF, 5 dogs with chronic bronchitis, and 4 healthy Beagles. PROCEDURES: Equal amounts of proteins in concentrated BALF samples were separated via 2-D differential gel electrophoresis. Proteins that were differentially expressed relative to results for healthy control dogs were identified with mass spectrometry and further verified via western blotting. RESULTS: Expression of 6 proteins was upregulated and that of 1 protein was downregulated in dogs with IPF or chronic bronchitis, compared with results for healthy dogs. Expression of proteins ß-actin, complement C3, α-1-antitrypsin, apolipoprotein A-1, haptoglobin, and transketolase was upregulated, whereas expression of lysozyme C was downregulated. CONCLUSIONS AND CLINICAL RELEVANCE: Proteomics can be used to search for biomarkers and to reveal disease-specific mechanisms. The quantitative comparison of proteomes for BALF obtained from dogs with IPF and chronic bronchitis and healthy dogs revealed similar changes for the dogs with IPF and chronic bronchitis, which suggested a common response to disease processes in otherwise different lung diseases. Specific biomarkers for IPF were not identified.

Proteomic profiling of dog urine after European adder (Vipera berus berus) envenomation by two-dimensional difference gel electrophoresis.

Between April and September every year, many dogs in Finland are bitten by Vipera berus berus, also known as the European adder, the only venomous snake in the area. Exposure to snake bite venom causes local and systemic symptoms and in severe cases can lead to death. Urine samples were collected from four dogs bitten by V. berus berus and treated in the intensive care unit of the Veterinary Teaching Hospital at the University of Helsinki. The inclusion criteria were a strong suspicion of an adder bite no more than two days before admission and clinical signs of an adder bite. Exclusion criteria were defined as ongoing treatment with glucocorticoids or a known history of liver or kidney diseases. Six privately owned, healthy dogs were obtained as controls. Samples were subjected to 2D-DIGE analysis. Image analysis was performed with DeCyder 7.0 2D software, and protein spots demonstrating a minimum 1.5-fold difference in average spot volume ratios between envenomed and control dogs with a Student's t-test p-value of less than 0.05 were picked and identified using LC-MS/MS. In 2D-DIGE analysis, seven proteins were significantly (p < 0.05) over-expressed in the urine of dogs bitten by V. berus berus compared to the control group. From these, five proteins were identified: beta-2-microglobulin (b2MG), alpha-1-antitrypsin (AAT), albumin, fetuin-B and superoxide dismutase (SOD1). Results indicate that envenomation by V. berus berus alter the urinary protein profile in dogs.