120 research outputs found
CD38 Exacerbates Focal Cytokine Production, Postischemic Inflammation and Brain Injury after Focal Cerebral Ischemia
BACKGROUND: Converging evidence suggests that inflammatory processes significantly influence brain injury and clinical impairment in ischemic stroke. Although early studies suggested a key role of lymphocytes, recent data has emphasized the orchestrating function of innate immunity, i.e., macrophages and microglia. The bifunctional receptor and ectoenzyme CD38 synthesizes calcium-mobilizing second messengers (e.g., cyclic ADP-ribose), which have been shown to be necessary for activation and migration of myeloid immune cells. Therefore, we investigated the dynamics of CD38 in stroke and the impact of CD38-deficiency on cytokine production, inflammation and cerebral damage in a mouse model of cerebral ischemia-reperfusion. METHODOLOGY/PRINCIPAL FINDINGS: We show that the local expression of the chemokine MCP-1 was attenuated in CD38-deficient mice compared with wildtype mice after focal cerebral ischemia and reperfusion. In contrast, no significant induction of MCP-1 expression was observed in peripheral blood after 6 hours. Flow cytometry analysis revealed less infiltrating macrophages and lymphocytes in the ischemic hemisphere of CD38-deficient mice, whereas the amount of resident microglia was unaltered. An up-regulation of CD38 expression was observed in macrophages and CD8(+) cells after focal cerebral ischemia in wildtype mice, whereas CD38 expression was unchanged in microglia. Finally, we demonstrate that CD38-deficiency decreases the cerebral ischemic injury and the persistent neurological deficit after three days of reperfusion in this murine temporary middle cerebral artery occlusion (tMCAO) model. CONCLUSION/SIGNIFICANCE: CD38 is differentially regulated following stroke and its deficiency attenuates the postischemic chemokine production, the immune cell infiltration and the cerebral injury after temporary ischemia and reperfusion. Therefore CD38 might prove a therapeutic target in ischemic stroke
CD38 promotes pristane-induced chronic inflammation and increases susceptibility to experimental lupus by an apoptosis-driven and TRPM2-dependent mechanism
In this study, we investigated the role of CD38 in a pristane-induced murine model of lupus. CD38-deficient (Cd38-/-) but not ART2-deficient (Art2-/-) mice developed less severe lupus compared to wild type (WT) mice, and their protective phenotype consisted of (i) decreased IFN-I-stimulated gene expression, (ii) decreased numbers of peritoneal CCR2hiLy6Chi inflammatory monocytes, TNF-α-producing Ly6G+ neutrophils and Ly6Clo monocytes/macrophages, (iii) decreased production of anti-single-stranded DNA and anti-nRNP autoantibodies, and (iv) ameliorated glomerulonephritis. Cd38-/- pristane-elicited peritoneal exudate cells had defective CCL2 and TNF-α secretion following TLR7 stimulation. However, Tnf-α and Cxcl12 gene expression in Cd38-/- bone marrow (BM) cells was intact, suggesting a CD38-independent TLR7/TNF-α/CXCL12 axis in the BM. Chemotactic responses of Cd38-/- Ly6Chi monocytes and Ly6G+ neutrophils were not impaired. However, Cd38-/- Ly6Chi monocytes and Ly6Clo monocytes/macrophages had defective apoptosis-mediated cell death. Importantly, mice lacking the cation channel TRPM2 (Trpm2-/-) exhibited very similar protection, with decreased numbers of PECs, and apoptotic Ly6Chi monocytes and Ly6Clo monocytes/macrophages compared to WT mice. These findings reveal a new role for CD38 in promoting aberrant inflammation and lupus-like autoimmunity via an apoptosis-driven mechanism. Furthermore, given the implications of CD38 in the activation of TRPM2, our data suggest that CD38 modulation of pristane-induced apoptosis is TRPM2-dependent.We would like to thank Dr. Yasuo Mori for providing the
Tr pm 2−/− mice, Clara Sánchez for animal husbandry
at the IPBLN-CSIC Animal Facility, and Thomas S. Simpler and Uma Mudunuru for animal husbandry at the
University of Alabama at Birmingham (UAB). We would also like to thank Laura Montosa from the Centro de
Instrumentación Cientifica (CIC) at the Universidad de Granada (UGR) for technical support with microscopy,
as well as Mohamed Tassi and Ana Santos at CIC, UGR, and Sandra García-Jiménez, Victoria Romero-del-Amo, Gemma Palencia-López, and Samuel Ruiz-Santiago at Campus Formación Granada for tissue preparations,
H&E staining, and other staining procedures. Work performed in the Sancho lab was supported in part by the
European Commission in collaboration with the following Funding Agencies: (i) Junta de Andalucía (J.A.),
Consejería Innovación Ciencia y Empresa y Consejería Educación y Ciencia, Project: PC08-CTS-04046 to J.S. and M.Z., and (ii) Ministerio de Economía y Competitividad (MINECO), Projects: SAF-2011-27261 to J.S. and M.Z. and SAF2014-55088-R to R.M. Work performed in the Lund lab was supported by funds provided by UAB.S
Mice deficient in CD38 develop an attenuated form of collagen type II-induced arthritis
CD38, a type II transmembrane glycoprotein expressed in many cells of the immune system, is involved in cell signaling, migration and differentiation. Studies in CD38 deficient mice (CD38 KO mice) indicate that this molecule controls inflammatory immune responses, although its involvement in these responses depends on the disease model analyzed. Here, we explored the role of CD38 in the control of autoimmune responses using chicken collagen type II (col II) immunized C57BL/6-CD38 KO mice as a model of collagen-induced arthritis (CIA). We demonstrate that CD38 KO mice develop an attenuated CIA that is accompanied by a limited joint induction of IL-1β and IL-6 expression, by the lack of induction of IFNγ expression in the joints and by a reduction in the percentages of invariant NKT (iNKT) cells in the spleen. Immunized CD38 KO mice produce high levels of circulating IgG1 and low of IgG2a anti-col II antibodies in association with reduced percentages of Th1 cells in the draining lymph nodes. Altogether, our results show that CD38 participates in the pathogenesis of CIA controlling the number of iNKT cells and promoting Th1 inflammatory responses
Effect of controlled and uncontrolled cooling rate on motility parameters of cryopreserved ram spermatozoa
<p>Abstract</p> <p>Background</p> <p>Ram spermatozoa are sensitive to extreme changes in temperature during the freeze-thaw process. The degree of damage depends on a combined effect of various factors including freezing temperature. The aim of this study was to determine the effects of two cooling method (controlled-rate and uncontrolled-rate) on pre-freezing and post-thaw sperm motility parameters.</p> <p>Results</p> <p>Ejaculates were collected using the artificial vagina from four Chal rams and three replicates of the ejaculates were diluted with a Tris-based extender and packed in 0.25 ml straws. Then, sample processed according to the two methods. Method 1: straws cooled from 37 to 5°C, at a liner rate of -0.3°C/min in a controlled-rate cooling machine (custom-built) and equilibrated at 5°C for 80 min, then the straws were frozen at rate of -0.3°C/min from 5°C to -10°C and -25°C/min from -10°C to -150°C and plunged into liquid nitrogen for storage. Method 2: straws were transferred to refrigerator and maintained at 5°C for 3 h, then the straws were frozen in liquid nitrogen vapor, 4 cm above the liquid nitrogen for 15 min and plunged into liquid nitrogen. Computer-assisted sperm motility analysis was used to analyze sperm motion characteristics.</p> <p>Conclusions</p> <p>Controlled rate of freezing (Method 1) significantly improve the pre-freezing and post-thaw total and progressive motility compared to uncontrolled rate (Method 2). In specific kinetic parameters, Method 1 gives significantly higher value for VSL and VCL in comparison with Method 2. There are no significant differences between the two methods for VAP and LIN. In conclusion, controlled rate of cooling conferred better cryopreserving ability to ram spermatozoa compared to uncontrolled rate of cooling prior to programmable freezing.</p
Regulation of TRPM2 channels in neutrophil granulocytes by ADP-ribose: a promising pharmacological target
The FPR2-induced rise in cytosolic calcium in human neutrophils relies on an emptying of intracellular calcium stores and is inhibited by a gelsolin-derived PIP2-binding peptide
<p>Abstract</p> <p>Background</p> <p>The molecular basis for neutrophil recognition of chemotactic peptides is their binding to specific G-protein-coupled cell surface receptors (GPCRs). Human neutrophils express two pattern recognition GPCRs, FPR1 and FPR2, which belong to the family of formyl peptide receptors. The high degree of homology between these two receptors suggests that they share many functional and signal transduction properties, although they exhibit some differences with respect to signaling. The aims of this study were to determine whether FPR2 triggers a unique signal that allows direct influx of extracellular calcium without the emptying of intracellular calcium stores, and whether the gelsolin-derived PIP<sub>2</sub>-binding peptide, PBP10, selectively inhibits FPR2-mediated transient rise in intracellular Ca<sup>2+</sup>.</p> <p>Results</p> <p>The transient rise in intracellular Ca<sup>2+ </sup>induced by agonists for FPR1 or FPR2 in human neutrophils occurred also in the presence of a chelator of Ca<sup>2+ </sup>(EGTA). PBP10 inhibited not only FPR2-induced oxidase activity, but also the transient rise in intracellular Ca<sup>2+</sup>.</p> <p>Conclusions</p> <p>Ca<sup>2+ </sup>signaling mediated <it>via </it>FPR2 follows the same route as FPR1, which involves initial emptying of the intracellular stores. PBP10 inhibits selectively the signals generated by FPR2, both with respect to NADPH-oxidase activity and the transient rise in intracellular Ca<sup>2+ </sup>induced by agonist exposure.</p
The Cyclophilin-Binding Agent Sanglifehrin A Is a Dendritic Cell Chemokine and Migration Inhibitor
Sanglifehrin A (SFA) is a cyclophilin-binding immunosuppressant but the immunobiology of action is poorly understood. We and others have reported that SFA inhibits IL-12 production and antigen uptake in dendritic cells (DC) and exhibits lower activity against lymphocytes. Here we show that SFA suppresses DC chemokine production and migration. Gene expression analysis and subsequent protein level confirmation revealed that SFA suppressed CCL5, CCL17, CCL19, CXCL9 and CXCL10 expression in human monocyte-derived DC (moDC). A systems biology analysis, Onto Express, confirmed that SFA interferes with chemokine-chemokine receptor gene expression with the highest impact. Direct comparison with the related agent cyclosporine A (CsA) and dexamethasone indicated that SFA uniquely suppresses moDC chemokine expression. Competitive experiments with a 100-fold molar excess of CsA and with N-Methyl-Val-4-cyclosporin, representing a nonimmunosuppressive derivative of CsA indicated chemokine suppression through a cyclophilin-A independent pathway. Functional assays confirmed reduced migration of CD4+ Tcells and moDCs to supernatant of SFA-exposed moDCs. Vice versa, SFA-exposed moDC exhibited reduced migration against CCL19. Moreover, SFA suppressed expression of the ectoenzyme CD38 that was reported to regulate DC migration and cytokine production. These results identify SFA as a DC chemokine and migration inhibitor and provide novel insight into the immunobiology of SFA
Bronchoscopist's perception of the quality of the single-use bronchoscope (Ambu aScope4™) in selected bronchoscopies: a multicenter study in 21 Spanish pulmonology services
Background: The disposable bronchoscope is an excellent alternative to face the problem of SARS-CoV-2 and other cross infections, but the bronchoscopist's perception of its quality has not been evaluated.
Methods: To evaluate the quality of the Ambu-aScope4 disposable bronchoscope, we carried out a cross-sectional study in 21 Spanish pulmonology services. We use a standardized questionnaire completed by the bronchoscopists at the end of each bronchoscopy. The variables were described with absolute and relative frequencies, measures of central tendency and dispersion depending on their nature. The existence of learning curves was evaluated by CUSUM analysis.
Results: The most frequent indications in 300 included bronchoscopies was bronchial aspiration in 69.3% and the median duration of these was 9.1 min. The route of entry was nasal in 47.2% and oral in 34.1%. The average score for ease of use, image, and aspiration quality was 80/100. All the planned techniques were performed in 94.9% and the bronchoscopist was satisfied in 96.6% of the bronchoscopies. They highlighted the portability and immediacy of the aScope4TM to start the procedure in 99.3%, the possibility of taking and storing images in 99.3%. The CUSUM analysis showed average scores > 70/100 from the first procedure and from the 9th procedure more than 80% of the scores exceeded the 80/100 score.
Conclusions: The aScope4™ scored well for ease of use, imaging, and aspiration. We found a learning curve with excellent scores from the 9th procedure. Bronchoscopists highlighted its portability, immediacy of use and the possibility of taking and storing images
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