Ym1, a secretory protein transiently produced by activated peritoneal macrophages elicited by parasitic infections, has been identified as a novel heparin-binding lectin. X-ray crystallography study revealed that Ym1 has a beta/alpha barrel structure with a carbohydrate-binding cleft similar to that of triose-phosphate isomerases. To further delineate the physiological significance of Ym1, we examined its expression patterns during mouse embryonic development and inflammation states elicited by agents other than parasitic infections in the peritoneal cavity and brain. This is the first report revealing prominent expression of Ym1 in early myeloid precursor cells of hematopoietic tissues-initially in the yolk sac and subsequently in fetal liver, spleen, and bone marrow. In nonhematopoietic systems, Ym1 was not detected in most of the tissues examined, with the exception of lung. Although no expression was detected up to gestation day 16.5 (E16.5), an increasing level of Ym1 expression in lung was detected from E18.5 on and persisted through adulthood. While most resident macrophages in various tissues examined are Ym1-negative, transient expression of Ym1 may be induced in their activated counterparts during inflammation in response to different stimuli in vivo, ranging from various chemical agents to brain injuries. The temporal and spatial expression in myeloid precursors and its transient induction in activated macrophages support the notion that Ym1 may be involved in hematopoiesis and inflammation. In addition, its putative functional association with heparin/heparan sulfate is discussed.
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Int Immunopharmacol
December 2024
Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi, China. Electronic address:
Biochem Biophys Res Commun
December 2024
Firestone Institute for Respiratory Health, Department of Medicine, McMaster University and the Research Institute of St. Joe's Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, L8N 4A6, Canada; McMaster Immunology Research Centre, Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L8, Canada. Electronic address:
Microb Pathog
January 2025
Facultad de Medicina, Universidad de Buenos Aires, Departamento de Microbiología, Parasitología e Inmunología, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Buenos Aires, Argentina. Electronic address:
Herein, we analyzed the in vitro effect induced by total lipid extracts from Trypanosoma cruzi amastigotes of RA and K98 strains, which were obtained after overnight incubation (RAinc and K98inc) to mimic phospholipid hydrolytic processes that occurred adjacent to degenerating amastigote nests in tissues of Chagas disease patients. We demonstrated that RAinc and K98inc might possess bioactive lipid molecules with anti-inflammatory bias since they inactivated the NF-κB pathway, in contrast to intact lipids. Moreover, different M1/M2 macrophage phenotype markers of polarization were analyzed by RT-qPCR which evidenced that RAinc and K98inc promoted an increased expression of the M2 markers Arginase-1, IL-10, FIZZ and YM-1, and a decreased expression of iNOS and proinflammatory cytokines IL-6 and TNF-α.
View Article and Find Full Text PDFFront Immunol
October 2024
Department of Ophthalmology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China.
Aim: The aim of this study was to investigate whether Dectin-1 influences the immune-inflammatory response in keratitis by modulating macrophage polarization.
Methods: 1. The models of 1-day, 3-day, and 5-day of fungal keratitis were established in SPF C57BL/6 mice after stimulation by Dectin-1 agonist (curdlan) and antagonist (laminaran) were injected separately in the mouse subconjunctivae for 1 day in the established mouse model of keratitis; PBS was used as the control.
Front Pharmacol
September 2024
Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States.
Exosomes, membrane-bound extracellular vesicles, ranging from approximately 30-200 nm in diameter, are released by almost all cell types and play critical roles in intercellular communication. In response to the prevailing stress, the exosome-bound protein signatures vary in abundance and composition. To identify the bronchoalveolar lavage fluid (BALF) exosome-bound proteins associated with mucoinflammatory lung disease and to gain insights into their functional implications, we compared BALF exosomes-derived proteins from adult transgenic (-Tg+) and wild type (WT) mice.
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