Value of a secretomic approach for distinguishing patients with COVID-19 viral pneumonia among patients with respiratory distress admitted to intensive care unit.

In intensive care units, COVID-19 viral pneumonia patients (VPP) present symptoms similar to those of other patients with Nonviral infection (NV-ICU). To better manage VPP, it is therefore interesting to better understand the molecular pathophysiology of viral pneumonia and to search for biomarkers that may clarify the diagnosis. The secretome being a set of proteins secreted by cells in response to stimuli represents an opportunity to discover new biomarkers. The objective of this study is to identify the secretomic signatures of VPP with those of NV-ICU. Plasma samples and clinical data from NV-ICU (n = 104), VPP (n = 30) or healthy donors (HD, n = 20) were collected at Nantes Hospital (France) upon admission. Samples were enriched for the low-abundant proteins and analyzed using nontarget mass spectrometry. Specifically deregulated proteins (DEP) in VPP versus NV-ICU were selected. Combinations of 2 to 4 DEPs were established. The differences in secretome profiles of the VPP and NV-ICU groups were highlighted. Forty-one DEPs were specifically identified in VPP compared to NV-ICU. We describe five of the best combinations of 3 proteins (complement component C9, Ficolin-3, Galectin-3-binding protein, Fibrinogen alpha, gamma and beta chain, Proteoglycan 4, Coagulation factor IX and Cdc42 effector protein 4) that show a characteristic receptor function curve with an area under the curve of 95.0%. This study identifies five combinations of candidate biomarkers in VPP compared to NV-ICU that may help distinguish the underlying causal molecular alterations.

Effect of Ultraviolet Radiation and Benzo[a]pyrene Co-Exposure on Skin Biology: Autophagy as a Potential Target.

The skin is the outermost protective barrier of the human body. Its role is to protect against different physical, chemical, biological and environmental stressors. The vast majority of studies have focused on investigating the effects of single environmental stressors on skin homeostasis and the induction of several skin disorders, such as cancer or ageing. On the other hand, much fewer studies have explored the consequences of the co-exposure of skin cells to two or more stressors simultaneously, which is much more realistic. In the present study, we investigated, using mass-spectrometry-based proteomic analysis, the dysregulated biological functions in skin explants after their co-exposure to ultraviolet radiation (UV) and benzo[a]pyrene (BaP). We observed that several biological processes were dysregulated, among which autophagy appeared to be significantly downregulated. Furthermore, immunohistochemistry analysis was carried out to validate the downregulation of the autophagy process further. Altogether, the output of this study provides an insight into the biological responses of skin to combined exposure to UV + BaP and highlights autophagy as a potential target that might be considered in the future as a novel candidate for pharmacological intervention under such stress conditions.

Analysis of Astroglial Secretomic Profile in the Mecp2-Deficient Male Mouse Model of Rett Syndrome.

Mutations in the X-linked MECP2 gene are responsible for Rett syndrome (RTT), a severe neurological disorder. MECP2 is a transcriptional modulator that finely regulates the expression of many genes, specifically in the central nervous system. Several studies have functionally linked the loss of MECP2 in astrocytes to the appearance and progression of the RTT phenotype in a non-cell autonomous manner and mechanisms are still unknown. Here, we used primary astroglial cells from Mecp2-deficient (KO) pups to identify deregulated secreted proteins. Using a differential quantitative proteomic analysis, twenty-nine proteins have been identified and four were confirmed by Western blotting with new samples as significantly deregulated. To further verify the functional relevance of these proteins in RTT, we tested their effects on the dendritic morphology of primary cortical neurons from Mecp2 KO mice that are known to display shorter dendritic processes. Using Sholl analysis, we found that incubation with Lcn2 or Lgals3 for 48 h was able to significantly increase the dendritic arborization of Mecp2 KO neurons. To our knowledge, this study, through secretomic analysis, is the first to identify astroglial secreted proteins involved in the neuronal RTT phenotype in vitro, which could open new therapeutic avenues for the treatment of Rett syndrome.

Quantitative Proteomic Approach Reveals Altered Metabolic Pathways in Response to the Inhibition of Lysine Deacetylases in A549 Cells under Normoxia and Hypoxia.

Growing evidence is showing that acetylation plays an essential role in cancer, but studies on the impact of KDAC inhibition (KDACi) on the metabolic profile are still in their infancy. Here, we analyzed, by using an iTRAQ-based quantitative proteomics approach, the changes in the proteome of KRAS-mutated non-small cell lung cancer (NSCLC) A549 cells in response to trichostatin-A (TSA) and nicotinamide (NAM) under normoxia and hypoxia. Part of this response was further validated by molecular and biochemical analyses and correlated with the proliferation rates, apoptotic cell death, and activation of ROS scavenging mechanisms in opposition to the ROS production. Despite the differences among the KDAC inhibitors, up-regulation of glycolysis, TCA cycle, oxidative phosphorylation and fatty acid synthesis emerged as a common metabolic response underlying KDACi. We also observed that some of the KDACi effects at metabolic levels are enhanced under hypoxia. Furthermore, we used a drug repositioning machine learning approach to list candidate metabolic therapeutic agents for KRAS mutated NSCLC. Together, these results allow us to better understand the metabolic regulations underlying KDACi in NSCLC, taking into account the microenvironment of tumors related to hypoxia, and bring new insights for the future rational design of new therapies.

Identification, Characterization and Synthesis of Walterospermin, a Sperm Motility Activator from the Egyptian Black Snake Walterinnesia aegyptia Venom.

Animal venoms are small natural mixtures highly enriched in bioactive components. They are known to target at least two important pharmacological classes of cell surface receptors: ion channels and G protein coupled receptors. Since sperm cells express a wide variety of ion channels and membrane receptors, required for the control of cell motility and acrosome reaction, two functions that are defective in infertility issues, animal venoms should contain interesting compounds capable of modulating these two essential physiological functions. Herein, we screened for bioactive compounds from the venom of the Egyptian black snake Walterinnesia aegyptia (Wa) that possess the property to activate sperm motility in vitro from male mice OF1. Using RP-HPLC and cation exchange chromatography, we identified a new toxin of 6389.89 Da (termed walterospermin) that activates sperm motility. Walterospermin was de novo sequenced using a combination of matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/TOF MS/MS) and liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF MS/MS) following reduction, alkylation, and enzymatic proteolytic digestion with trypsin, chymotrypsin or V8 protease. The peptide is 57 amino acid residues long and contains three disulfide bridges and was found to be identical to the previously cloned Wa Kunitz-type protease inhibitor II (Wa Kln-II) sequence. Moreover, it has strong homology with several other hitherto cloned Elapidae and Viperidae snake toxins suggesting that it belongs to a family of compounds able to regulate sperm function. The synthetic peptide shows promising activation of sperm motility from a variety of species, including humans. Its fluorescently-labelled analog predominantly marks the flagellum, a localization in agreement with a receptor that controls motility function.

Current trends in protein acetylation analysis.

INTRODUCTION: Acetylation is a widely occurring post-translational modification (PTM) of proteins that plays a crucial role in many cellular physiological and pathological processes. Over the last decade, acetylation analyses required the development of multiple methods to target individual acetylated proteins, as well as to cover a broader description of acetylated proteins that comprise the acetylome. Areas covered: This review discusses the different types of acetylation (N-ter/K-/O-acetylation) and then describes some major strategies that have been reported in the literature to detect, enrich, identify and quantify protein acetylation. The review highlights the advantages and limitations of these strategies, to guide researchers in designing their experimental investigations and analysis of protein acetylation. Finally, this review highlights the main applications of acetylomics (proteomics based on mass spectrometry) for understanding physiological and pathological conditions. Expert opinion: Recent advances in acetylomics have enhanced knowledge of the biological and pathological roles of protein acetylation and the acetylome. Besides, radiolabeling and western blotting remain also techniques-of-choice for targeted protein acetylation. Future challenges in acetylomics to analyze the N-ter and K-acetylome will most likely require enrichment/fractionation, MS instrumentation and bioinformatics. Challenges also remain to identify the potential biological roles of O-acetylation and cross-talk with other PTMs.

Modulation of muscle protein synthesis by amino acids: what consequences for the secretome? A preliminary in vitro study.

The modulation by amino acids of muscle secretome is largely unknown. In this study, we investigate the effect of hyperaminoacidemia or specific amino acids (citrulline or leucine) on protein synthesis and secretome in myotubes. All conditions stimulate muscle protein synthesis, and secretome is differently modulated depending of the amino acids considered. In conclusion, the activation of protein synthesis by amino acids induces different modulations of the muscle secretome, proposing a new role of amino acids in the regulation of muscle function.

Effects of Iron Oxide Nanoparticles (γ-Fe2O3) on Liver, Lung and Brain Proteomes following Sub-Acute Intranasal Exposure: A New Toxicological Assessment in Rat Model Using iTRAQ-Based Quantitative Proteomics.

Iron Oxide Nanoparticles (IONPs) present unique properties making them one of the most used NPs in the biomedical field. Nevertheless, for many years, growing production and use of IONPs are associated with risks that can affect human and the environment. Thus, it is essential to study the effects of these nanoparticles to better understand their mechanism of action and the molecular perturbations induced in the organism. In the present study, we investigated the toxicological effects of IONPs (γ-Fe2O3) on liver, lung and brain proteomes in Wistar rats. Exposed rats received IONP solution during 7 consecutive days by intranasal instillation at a dose of 10 mg/kg body weight. An iTRAQ-based quantitative proteomics was used to study proteomic variations at the level of the three organs. Using this proteomic approach, we identified 1565; 1135 and 1161 proteins respectively in the brain, liver and lung. Amon them, we quantified 1541; 1125 and 1128 proteins respectively in the brain, liver and lung. Several proteins were dysregulated comparing treated samples to controls, particularly, proteins involved in cytoskeleton remodeling, cellular metabolism, immune system stimulation, inflammation process, response to oxidative stress, angiogenesis, and neurodegenerative diseases.

Proteomic Identification of Allergenic Proteins of Morus alba L. Pollenexacerbation.

BACKGROUND: Tree pollens are well-known aeroallergens all over the world. Little is known about the allergenicity of Morus alba (white mulberry) pollen. OBJECIVE: We aimed to explore the potential allergens of this pollen and its clinical relevance in tree pollen allergic patients living in Istanbul, Turkey. METHODS: Twenty three seasonal allergic rhinitis patients with a confirmed tree pollen allergy and 5 healthy control subjects underwent skin prick and nasal provocation tests with M.alba pollen extract. The pollen extract was then resolved by gel electrophoresis, and immunoblotted with sera from patients/control individuals to detect the potential allergenic proteins. The prevalent IgE binding proteins from 1D-gel were analyzed by MALDI-TOF/TOF. RESULTS: Eleven out of 23 patients were reactive to the extract with skin prick tests. Seven of those patients also reacted positively to the nasal provocation tests. The most common IgE-binding pollen proteins were detected between 55-100 kDa, and also at molecular weights lower than 30 kDa for some patients. Mass spectrometry analyses revealed that the principal IgE-binding protein was methionine synthase (5-methyltetrahydropteroyltriglutamate homocysteine methyltransferase), which is then proposed as a novel allergen in M.alba pollen. CONCLUSION: This study provides the first detailed information for the potential allergens of Morus alba pollen of Istanbul. Methionine synthase with an apparent molecular weight of 80 to 85 kDa has been recognized as one of the allergens in Morus alba pollen for the first time.

Isolation and characterization of an anti-leishmanial disintegrin from Cerastes cerastes venom.

Investigating new antimicrobial and antiparasitic components from Viperidae venoms represents an alternative therapeutic strategy. In this study, we report the characterization of a disintegrin isolated from Cerastes cerastes venom, exhibiting antiparasitic activity on Leishmania infantum promastigotes. Indeed, isolated disintegrin, referred to Disintegrin_Cc, induced 84.75% of parasiticidal activity and deep morphological alterations on the parasites. SDS-PAGE analysis indicated that this disintegrin was homogenous. This dimeric disintegrin of 14,193.97 Da contains an RGD domain and four intramolecular disulfide bridges. It presents a high percentage of identity with other related snake disintegrins. Predicted 3D structure indicated that this peptide shares partial homology with well-known active antimicrobial peptides. Disintegrin_Cc inhibited 80% of arachidonic acid-induced platelet aggregation. The obtained results suggest that the isolated molecule plays a dual role as a disintegrin and as an anti-leishmanial compound. This component could be useful as a drug in the treatment of leishmaniasis.

Low-molecular-weight color pI markers to monitor on-line the peptide focusing process in OFFGEL fractionation.

High-throughput mass spectrometry-based proteomic analysis requires peptide fractionation to simplify complex biological samples and increase proteome coverage. OFFGEL fractionation technology became a common method to separate peptides or proteins using isoelectric focusing in an immobilized pH gradient. However, the OFFGEL focusing process may be further optimized and controlled in terms of separation time and pI resolution. Here we evaluated OFFGEL technology to separate peptides from different samples in the presence of low-molecular-weight (LMW) color pI markers to visualize the focusing process. LMW color pI markers covering a large pH range were added to the peptide mixture before OFFGEL fractionation using a 24-wells device encompassing the pH range 3-10. We also explored the impact of LMW color pI markers on peptide fractionation labeled previously for iTRAQ. Then, fractionated peptides were separated by RP_HPLC prior to MS analysis using MALDI-TOF/TOF mass spectrometry in MS and MS/MS modes. Here we report the performance of the peptide focusing process in the presence of LMW color pI markers as on-line trackers during the OFFGEL process and the possibility to use them as pI controls for peptide focusing. This method improves the workflow for peptide fractionation in a bottom-up proteomic approach with or without iTRAQ labeling.

Synergistic effects of citrulline supplementation and exercise on performance in male rats: evidence for implication of protein and energy metabolisms.

Background: Exercise and citrulline (CIT) are both regulators of muscle protein metabolism. However, the combination of both has been under-studied yet may have synergistic effects on muscle metabolism and performance. Methods: Three-month-old healthy male rats were randomly assigned to be fed ad libitum for 4 weeks with either a citrulline-enriched diet (1 g·kg-1·day-1) (CIT) or an isonitrogenous standard diet (by addition of nonessential amino acid) (Ctrl) and trained (running on treadmill 5 days·week-1) (ex) or not. Maximal endurance activity and body composition were assessed, and muscle protein metabolism (protein synthesis, proteomic approach) and energy metabolism [energy expenditure, mitochondrial metabolism] were explored. Results: Body composition was affected by exercise but not by CIT supplementation. Endurance training was associated with a higher maximal endurance capacity than sedentary groups (P<0.001), and running time was 14% higher in the CITex group than the Ctrlex group (139±4 min versus 122±6 min, P<0.05). Both endurance training and CIT supplementation alone increased muscle protein synthesis (by +27% and +33%, respectively, versus Ctrl, P<0.05) with an additive effect (+48% versus Ctrl, P<0.05). Mitochondrial metabolism was modulated by exercise but not directly by CIT supplementation. However, the proteomic approach demonstrated that CIT supplementation was able to affect energy metabolism, probably due to activation of pathways generating acetyl-CoA. Conclusion: CIT supplementation and endurance training in healthy male rats modulates both muscle protein and energy metabolisms, with synergic effects on an array of parameters, including performance and protein synthesis.

Regulation of the proteome by amino acids.

Besides their main contribution as substrates for protein synthesis, amino acids as signaling molecules could exert some regulatory functions on protein synthesis and/or proteolysis that have been emphasized in a number of recent studies. Several publications have highlighted supplemental roles of those amino acids in protein metabolism as well as in immunity, heat shock response, or apoptosis processes. In this way, via their regulatory properties, selected amino acids (such as leucine, glutamine, arginine, citrulline, or methionine) directly influence the proteome. In this review, we are proposing an overview of the regulation of the proteome by amino acids in mammals.

Fractionation and proteomic analysis of the Walterinnesia aegyptia snake venom using OFFGEL and MALDI-TOF-MS techniques.

Animal venoms are complex mixtures of more than 100 different compounds, including peptides, proteins, and nonprotein compounds such as lipids, carbohydrates, and metal ions. In addition, the existing compounds show a wide range of molecular weights and concentrations within these venoms, making separation and purification procedures quite tedious. Here, we analyzed for the first time by MS the advantages of using the OFFGEL technique in the separation of the venom components of the Egyptian Elapidae Walterinnesia aegyptia snake compared to two classical methods of separation, SEC and RP-HPLC. We demonstrate that OFFGEL separates venom components over a larger scale of fractions, preserve respectable resolution with regard to the presence of a given compound in adjacent fractions and allows the identification of a greater number of ions by MS (102 over 134 total ions). We also conclude that applying several separating techniques (SEC and RP-HPLC in addition to OFFGEL) provides complementary results in terms of ion detection (21 more for SEC and 22 more with RP-HPLC). As a result, we provide a complete list of 134 ions present in the venom of W. aegyptia by using all these techniques combined.

Quantitative proteomic approach to understand metabolic adaptation in non-small cell lung cancer.

KRAS mutations in non-small cell lung cancer (NSCLC) are a predictor of resistance to EGFR-targeted therapies. Because approaches to target RAS signaling have been unsuccessful, targeting lung cancer metabolism might help to develop a new strategy that could overcome drug resistance in such cancer. In this study, we applied a large screening quantitative proteomic analysis to evidence key enzymes involved in metabolic adaptations in lung cancer. We carried out the proteomic analysis of two KRAS-mutated NSCLC cell lines (A549 and NCI-H460) and a non tumoral bronchial cell line (BEAS-2B) using an iTRAQ (isobaric tags for relative and absolute quantitation) approach combined with two-dimensional fractionation (OFFGEL/RP nanoLC) and MALDI-TOF/TOF mass spectrometry analysis. Protein targets identified by our iTRAQ approach were validated by Western blotting analysis. Among 1038 proteins identified and 834 proteins quantified, 49 and 82 proteins were respectively found differently expressed in A549 and NCI-H460 cells compared to the BEAS-2B non tumoral cell line. Regarding the metabolic pathways, enzymes involved in glycolysis (GAPDH/PKM2/LDH-A/LDH-B) and pentose phosphate pathway (PPP) (G6PD/TKT/6PGD) were up-regulated. The up-regulation of enzyme expression in PPP is correlated to their enzyme activity and will be further investigated to confirm those enzymes as promising metabolic targets for the development of new therapeutic treatments or biomarker assay for NSCLC.

Proteomic Methods to Study Autophagy in Skin Exposed to Pollutants.

Autophagy refers to the natural cellular process by which cells degrade and recycle their own damaged or dysfunctional cellular components. It is an essential mechanism for maintaining cellular homeostasis removing toxic substances and providing energy during times of stress or nutrient deprivation. When autophagy is dysregulated or impaired, it can have detrimental effects on cell function and overall health. Studying autophagy in skin exposed to pollutants can provide valuable insights into the cellular mechanisms underlying pollutant-induced skin damage. Proteomic methods, which involve the large-scale analysis of proteins, can be employed to investigate the changes in protein expression associated with biological processes including autophagy. Here, we thus describe a method where LC-MS/MS was applied to identify the deregulated proteins in pollutant exposed-skin. Using bioinformatics and statistical analysis, we extracted the qualitative and quantitative information for proteins involved in autophagy. These deregulated proteins were then validated by immunohistochemistry (IHC). These methods help to understand how the pollutants affect the autophagy process.

Kampo herbal ointments for skin wound healing.

The management of skin wound healing problems is a public health issue in which traditional herbal medicines could play a determining role. Kampo medicine, with three traditionally used ointments, provides interesting solutions for these dermatological issues. These ointments named Shiunko, Chuoko, and Shinsen taitsuko all have in common a lipophilic base of sesame oil and beeswax from which herbal crude drugs are extracted according to several possible manufacturing protocols. This review article brings together existing data on metabolites involved in the complex wound healing process. Among them are representatives of the botanical genera Angelica, Lithospermum, Curcuma, Phellodendron, Paeonia, Rheum, Rehmannia, Scrophularia, or Cinnamomum. Kampo provides numerous metabolites of interest, whose content in crude drugs is very sensitive to different biotic and abiotic factors and to the different extraction protocols used for these ointments. If Kampo medicine is known for its singular standardization, ointments are not well known, and research on these lipophilic formulas has not been developed due to the analytical difficulties encountered in biological and metabolomic analysis. Further research considering the complexities of these unique herbal ointments could contribute to a rationalization of Kampo's therapeutic uses for wound healing.

TOX4 and its binding partners recognize DNA adducts generated by platinum anticancer drugs.

Platinating agents are commonly prescribed anticancer drugs damaging DNA. Induced lesions are recognized by a wide range of proteins. These are involved in cellular mechanisms such as DNA repair, mediation of cytotoxicity or chromatin remodeling. They therefore constitute crucial actors to understand pharmacology of these drugs. To expand our knowledge about this subproteome, we developed a ligand fishing trap coupled to high throughput proteomic tools. This trap is made of damaged plasmids attached to magnetic beads, and was exposed to cell nuclear extracts. Retained proteins were identified by nanoHPLC coupled to tandem mass spectrometry. This approach allowed us to establish a list of 38 proteins interacting with DNA adducts generated by cisplatin, oxaliplatin and satraplatin. Some of them were already known interactome members like high mobility group protein 1 (HMGB1) or the human upstream binding factor (hUBF), but we also succeeded in identifying unexpected proteins such as TOX HMG box family member 4 (TOX4), phosphatase 1 nuclear targeting subunit (PNUTS), and WD repeat-containing protein 82 (WDR82), members of a recently discovered complex. Interaction between TOX4 and platinated DNA was subsequently validated by surface plasmon resonance imaging (SPRi). These interactions highlight new cellular responses to DNA damage induced by chemotherapeutic agents.

Untargeted metabolomics approach to discriminate mistletoe commercial products.

Mistletoe (Viscum album L.) is used in German-speaking European countries in the field of integrative oncology linking conventional and complementary medicine therapies to improve quality of life. Various companies sell extracts, fermented or not, for injection by subcutaneous or intra-tumoral route with a regulatory status of anthroposophic medicinal products (European Medicinal Agency (EMA) assessment status). These companies as well as anthroposophical physicians argue that complex matrices composed of many molecules in mixture are necessary for activity and that the host tree of the mistletoe parasitic plant is the main determining factor for this matrix composition. The critical point is that parenteral devices of European mistletoe extracts do not have a standard chemical composition regulated by EMA quality guidelines, because they are not drugs, regulatory speaking. However, the mechanism of mistletoe's anticancer activity and its effectiveness in treating and supporting cancer patients are not fully understood. Because of this lack of transparency and knowledge regarding the matrix chemical composition, we undertook an untargeted metabolomics study of several mistletoe extracts to explore and compare their fingerprints by LC-(HR)MS(/MS) and 1H-NMR. Unexpectedly, we showed that the composition was primarily driven by the manufacturer/preparation method rather than the different host trees. This differential composition may cause differences in immunostimulating and anti-cancer activities of the different commercially available mistletoe extracts as illustrated by structure-activity relationships based on LC-MS/MS and 1H-NMR identifications completed by docking experiments. In conclusion, in order to move towards an evidence-based medicine use of mistletoe, it is a priority to bring rigor and quality, chemically speaking.

Synovial fluid proteomic fingerprint: S100A8, S100A9 and S100A12 proteins discriminate rheumatoid arthritis from other inflammatory joint diseases.

OBJECTIVE: We investigated SF and serum proteomic fingerprints of patients suffering from RA, OA and other miscellaneous inflammatory arthritides (MIAs) in order to identify RA-specific biomarkers. METHODS: SF profiles of 65 patients and serum profiles of 31 patients were studied by surface-enhanced laser desorption and ionization-time-of-flight-mass spectrometry technology. The most discriminating RA biomarkers were identified by matrix-assisted laser desorption ionization-time of flight and their overexpression was confirmed by western blotting and ELISA. RESULTS: Three biomarkers of 10 839, 10 445 and 13 338 Da, characterized as S100A8, S100A12 and S100A9 proteins, were the most up-regulated proteins in RA SF. Their expression was about 10-fold higher in RA SF vs OA SF. S100A8 exhibited a sensitivity of 82% and a specificity of 69% in discriminating RA from other MIAs, whereas S100A12 displayed a sensitivity of 79% and a specificity of 64%. Three peptides of 3351, 3423 and 3465 Da, corresponding to the alpha-defensins-1, -2 and -3, were also shown to differentiate RA from other MIAs with weaker sensitivity and specificity. Levels of S100A12, S100A8 and S100A9 were statistically correlated with the neutrophil count in MIA SF but not in the SF of RA patients. S100A8, S100A9, S100A12 and alpha-defensin expression in serum was not different in the three populations. CONCLUSION: The most enhanced proteins in RA SF, the S100A8, S100A9 and S00A12 proteins, distinguished RA from MIA with high accuracy. Possible implication of resident cells in this increase may play a role in RA physiopathology.