Lilian Cataldi Rodrigues - Academia.edu (original) (raw)

Papers by Lilian Cataldi Rodrigues

Biomolecules

Patients with COVID-19 predominantly have a respiratory tract infection and acute lung failure is... more Patients with COVID-19 predominantly have a respiratory tract infection and acute lung failure is the most severe complication. While the molecular basis of SARS-CoV-2 immunopathology is still unknown, it is well established that lung infection is associated with hyper-inflammation and tissue damage. Matrix metalloproteinases (MMPs) contribute to tissue destruction in many pathological situations, and the activity of MMPs in the lung leads to the release of bioactive mediators with inflammatory properties. We sought to characterize a scenario in which MMPs could influence the lung pathogenesis of COVID-19. Although we observed high diversity of MMPs in lung tissue from COVID-19 patients by proteomics, we specified the expression and enzyme activity of MMP-2 in tracheal-aspirate fluid (TAF) samples from intubated COVID-19 and non-COVID-19 patients. Moreover, the expression of MMP-8 was positively correlated with MMP-2 levels and possible shedding of the immunosuppression mediator sHL...

Viruses, 2021

Uncontrolled inflammatory responses play a critical role in coronavirus disease (COVID-19). In th... more Uncontrolled inflammatory responses play a critical role in coronavirus disease (COVID-19). In this context, because the triggering-receptor expressed on myeloid cells-1 (TREM-1) is considered an intrinsic amplifier of inflammatory signals, this study investigated the role of soluble TREM-1 (sTREM-1) as a biomarker of the severity and mortality of COVID-19. Based on their clinical scores, we enrolled COVID-19 positive patients (n = 237) classified into mild, moderate, severe, and critical groups. Clinical data and patient characteristics were obtained from medical records, and their plasma inflammatory mediator profiles were evaluated with immunoassays. Plasma levels of sTREM-1 were significantly higher among patients with severe disease compared to all other groups. Additionally, levels of sTREM-1 showed a significant positive correlation with other inflammatory parameters, such as IL-6, IL-10, IL-8, and neutrophil counts, and a significant negative correlation was observed with ly...

BackgroundThe uncontrolled inflammatory response plays a critical role in the novel coronavirus d... more BackgroundThe uncontrolled inflammatory response plays a critical role in the novel coronavirus disease (COVID-19) and triggering receptor expressed on myeloid cells-1 (TREM-1) is thought to be intricate to inflammatory signal amplification. This study aims to investigate the association between soluble TREM-1 (sTREM-1) and COVID-19 as a prognostic biomarker to predict the disease severity, lethality and clinical management.MethodsWe enrolled 91 patients with COVID-19 in domiciliary care (44 patients) or in hospital care (47 patients), who were classified after admission into mild, moderate, severe and critical groups according to their clinical scores. As non-COVID-19 control, 30 healthy volunteers were included. Data on demographic, comorbidities and baseline clinical characteristics were obtained from their medical and nurse records. Peripheral blood samples were collected at admission and after hospitalization outcome to assess cytokine profile and sTREM-1 level by specific immu...

ABSTRACTSkeletal muscle has the intrinsic ability to self-repair through a multifactorial process... more ABSTRACTSkeletal muscle has the intrinsic ability to self-repair through a multifactorial process, but many aspects of its cellular and molecular mechanisms are not fully understood. There is increasing evidence that some members of the mammalian β-galactoside-binding protein family (galectins) are involved in the muscular repair process (MRP), including galectin-3 (Gal-3). However, there are many questions about the role of this protein on muscle self-repair. Here, we demonstrate that endogenous Gal-3 is required for: i) muscle repairin vivousing a chloride-barium myolesion mouse model, and ii) mouse primary myoblasts myogenic programming. Injured muscle from Gal-3 knockout mice (GAL3KO) showed persistent inflammation associated with compromised muscle repair and the formation of fibrotic tissue on the lesion site. InGAL3KOmice, osteopontin expression remained high even after 7 and 14 days of the myolesion, while MyoD and myogenin had decreased their expression. InGAL3KOmouse prima...

Cytokine storms and hyperinflammation, potentially controlled by glucocorticoids, occur in COVID-... more Cytokine storms and hyperinflammation, potentially controlled by glucocorticoids, occur in COVID-19; the roles of lipid mediators and acetylcholine (ACh) and how glucocorticoid therapy affects their release in Covid-19 remain unclear. Blood and bronchoalveolar lavage (BAL) samples from SARS-CoV-2- and non-SARS-CoV-2-infected subjects were collected for metabolomic/lipidomic, cytokines, soluble CD14 (sCD14), and ACh, and CD14 and CD36-expressing monocyte/macrophage subpopulation analyses. Transcriptome reanalysis of pulmonary biopsies was performed by assessing coexpression, differential expression, and biological networks. Correlations of lipid mediators, sCD14, and ACh with glucocorticoid treatment were evaluated. This study enrolled 190 participants with Covid-19 at different disease stages, 13 hospitalized non-Covid-19 patients, and 39 healthy-participants. SARS-CoV-2 infection increased blood levels of arachidonic acid (AA), 5-HETE, 11-HETE, sCD14, and ACh but decreased monocyte...

Glycoconjugate Journal, 2019

Mediators of Inflammation, 2016

Histoplasma capsulatumis a dimorphic fungus that develops a yeast-like morphology in host’s tissu... more Histoplasma capsulatumis a dimorphic fungus that develops a yeast-like morphology in host’s tissue, responsible for the pulmonary disease histoplasmosis. The recent increase in the incidence of histoplasmosis in immunocompromised patients highlights the need of understanding immunological controls of fungal infections. Here, we describe our discovery of the role of endogenous galectin-1 (Gal-1) in the immune pathophysiology of experimental histoplasmosis. All infected wild-type (WT) mice survived while only 1/3 of Lgals1−/−mice genetically deficient in Gal-1 survived 30 days after infection. Although infected Lgals1−/−mice had increased proinflammatory cytokines, nitric oxide (NO), and elevations in neutrophil pulmonary infiltration, they presented higher fungal load in lungs and spleen. Infected lung and infected macrophages from Lgals1−/−mice exhibited elevated levels of prostaglandin E2(PGE2, a prostanoid regulator of macrophage activation) and prostaglandin E synthase 2 (Ptgs2) ...

Galectin-1 (Gal-1) is a lectin that recognizes β-galactosides and participates in biological proc... more Galectin-1 (Gal-1) is a lectin that recognizes β-galactosides and participates in biological processes, including modulation of the inflammatory response. Literature data show the involvement of this lectin to induce exposure of phosphatidylserine (PS-a marker of apoptosis), in the generation of reactive oxygen species (ROS) and in modulation of neutrophil chemotaxis. However, there are few data related to the biological impact of exogenous and endogenous Gal-1 on the biology of these cells. This study evaluated, in vitro, some functional aspects of the interaction of Gal-1 and neutrophil. It was determined the expression level of Gal-1 (Western blotting) and its mRNA (real time PCR) on human leukocytes obtained from peripheral blood of healthy donors and human promyelocytic cell line (HL-60). Peripheral blood leukocytes and HL-60 cells do not express detectable levels of this protein as well as the Gal-1 mRNA. Through chemiluminescence testing (CL) it was possible to analyze the ability of recombinant human Gal-1 to induce and modulate the production of ROS in naïve and activated (n-Formyl-Methionyl-Leucyl-Phenylalanine-fMLP) human neutrophils. Gal-1 induces ROS production in a dose-dependent way in fMLP activated neutrophils. However, in naive neutrophils this lectin does not induce oxidative stress and can negatively modulate ROS production in response to fMLP. The effects of Gal-1 on ROS production in both non-activated cells and activated cells are partially associated with their lectin property. In the literature there are no data about the interference of Gal-1 on ROS production in activated neutrophils with repeated doses of fMLP. It is known that the subsequent treatment with fMLP reduced levels of ROS production by neutrophils; however, the presence of Gal-1 did not affect this process. Interestingly, peritoneum neutrophils from Gal-1-/mice release more ROS in response to fMLP and exogenous Gal-1 when compared to neutrophils from wild type animals. Based on the in vitro findings and considering that in polymicrobial sepsis, neutrophils play an important role, the next step was to use the M-CLP model (moderate sepsis) in mice lacking (Gal-1-/-) or not (Gal-1 +/+) Gal-1 gene. Gal-1-/animals present lower survival rate and fewer bacteria in the blood despite having higher bacterial load in infectious focus in relation to wild type mice. The rates of neutrophils influx into the peritoneum and lungs are similar for both groups. The participation of Gal-1 in the homeostasis of neutrophils was demonstrated in vitro by flow cytometry (annexin V-FITC), where induced PS by Gal-1 in the neutrophils enhanced the phagocytosis of these cells by macrophages. Therefore, this set of results suggests that Gal-1, exogenous or endogenous, can modulate immune functions of neutrophils and participate in the regulation of inflammatory/infectious disorders.

Methods in Molecular Biology, 2014

Confocal microscopy provides a unique modality to examine the expression and localization of biom... more Confocal microscopy provides a unique modality to examine the expression and localization of biomolecules in a variety of settings. Using this technique, an image is acquired from the focal plane of the objective using focused laser light making it possible to work within the resolution limit of the optical system. In addition, by acquiring multiple images from a variety of focal planes, stacked series of images can provide clear spatial localization of a probed structure or protein. We describe herein the immunofluorescence methods for galectin staining in frozen sections of tissue for galectin localization using confocal microscopy.

Methods in molecular biology (Clifton, N.J.), 2015

Glycan binding proteins (GBPs) possess the unique ability to regulate a wide variety of biologica... more Glycan binding proteins (GBPs) possess the unique ability to regulate a wide variety of biological processes through interactions with highly modifiable cell surface glycans. While many studies demonstrate the impact of glycan modification on GBP recognition and activity, the relative contribution of subtle changes in glycan structure on GBP binding can be difficult to define. To overcome limitations in the analysis of GBP-glycan interactions, recent studies utilized glycan microarray platforms containing hundreds of structurally defined glycans. These studies not only provided important information regarding GBP-glycan interactions, but have also resulted in significant insight into the binding specificity and biological activity of the galectin family. We will describe the methods used when employing glycan microarray platforms to examine galectin-glycan binding specificity and function.

Nature Medicine, 2010

The expression of ABO(H) blood group antigens causes deletion of cells that generate self antiblo... more The expression of ABO(H) blood group antigens causes deletion of cells that generate self antiblood group antibodies, but this deletion limits adaptive immunity toward pathogens bearing cognate blood group antigens. To explore potential defense mechanisms against these pathogens, given such limitations in adaptive immunity, we screened for innate proteins that could recognize human blood group antigens. Here we report that two innate immune lectins, galectins-4 and-8, which are expressed in the intestinal tract, recognize and kill human blood group antigenexpressing E. coli, while failing to alter viability of other E. coli strains or other gram-negative or gram-positive organisms both in vitro and in vivo. Killing by both galectins-4 and-8 resides within their C-terminal domains, occurs rapidly and independently of complement, and is accompanied by disruption of membrane integrity. These results demonstrate that innate defense lectins can provide immunity against pathogens that display blood group self-antigens on their surface. Recent studies suggest that blood group antigen diversity may provide a mechanism of pathogen evasion whereby distinct ABO(H) antigen structures may reduce pathogen attachment and therefore infectivity1. Because ABO(H) antigens are composed of carbohydrate structures that only differ by distinct monosaccharides on the terminal structures of glycans2, potential factors responsible for providing innate immunity toward pathogens expressing blood group antigens must recognize carbohydrates. A growing list of Users may view, print, copy, download and text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Nature Chemical Biology, 2014

Genomic approaches continue to provide unprecedented insight into the microbiome, yet host immune... more Genomic approaches continue to provide unprecedented insight into the microbiome, yet host immune interactions with diverse microbiota can be difficult to study. We therefore generated a microbial microarray containing defined antigens isolated from a broad range of microbial flora to examine adaptive and innate immunity. Serological studies with this microarray show that immunoglobulins from multiple mammalian species exhibit unique patterns of reactivity, while exposure of animals to distinct microbes induces specific serological recognition. While adaptive immunity exhibited plasticity toward microbial antigens, immunological tolerance limits reactivity toward self. We discovered that several innate immune galectins exhibit specific recognition of microbes that express self-like antigens, leading to direct killing of a broad range of gram negative and positive microbes. Thus, host protection against microbes appears to represent a balance between adaptive and innate immunity to defend against evolving antigenic determinants while protecting against molecular mimicry.

Molecular Biology of the Cell, 2009

Cells normally undergo physiological turnover through the induction of apoptosis and phagocytic r... more Cells normally undergo physiological turnover through the induction of apoptosis and phagocytic removal, partly through exposure of cell surface phosphatidylserine (PS). In contrast, neutrophils appear to possess apoptosis-independent mechanisms of removal. Here we show that Galectin-1 (Gal-1) induces PS exposure independent of alterations in mitochondrial potential, caspase activation, or cell death. Furthermore, Gal-1–induced PS exposure reverts after Gal-1 removal without altering cell viability. Gal-1–induced PS exposure is uniquely microdomain restricted, yet cells exposing PS do not display evident alterations in membrane morphology nor do they exhibit bleb formation, typically seen in apoptotic cells. Long-term exposure to Gal-1 prolongs PS exposure with no alteration in cell cycle progression or cell growth. These results demonstrate that Gal-1–induced PS exposure and subsequent phagocytic removal of living cells represents a new paradigm in cellular turnover.

Glycobiology, 2008

Muscle degenerative diseases such as Duchenne Muscular Dystrophy are incurable and treatment opti... more Muscle degenerative diseases such as Duchenne Muscular Dystrophy are incurable and treatment options are still restrained. Understanding the mechanisms and factors responsible for muscle degeneration and regeneration will facilitate the development of novel therapeutics. Several recent studies have demonstrated that Galectin-1 (Gal-1), a carbohydrate-binding protein, induces myoblast differentiation and fusion in vitro, suggesting a potential role for this mammalian lectin in muscle regenerative processes in vivo. However, the expression and localization of Gal-1 in vivo during muscle injury and repair are unclear. We report the expression and localization of Gal-1 during degenerative-regenerative processes in vivo using two models of muscular dystrophy and muscle injury. Gal-1 expression increased significantly during muscle degeneration in the murine mdx and in the canine Golden Retriever Muscular Dystrophy animal models. Compulsory exercise of mdx mouse, which intensifies degeneration, also resulted in sustained Gal-1 levels. Furthermore, muscle injury of wild-type C57BL/6 mice, induced by BaCl 2 treatment, also resulted in a marked increase in Gal-1 levels. Increased Gal-1 levels appeared to localize both inside and outside the muscle fibers with significant extracellular Gal-1 colocalized with infiltrating CD45 + leukocytes. By contrast, regenerating muscle tissue showed a marked decrease in Gal-1 to baseline levels. These results demonstrate significant regulation of Gal-1 expression in vivo and suggest a potential role for Gal-1 in muscle homeostasis and repair.

Glycobiology, 2010

Galectin-1 (Gal-1) is important in immune function and muscle regeneration, but its expression an... more Galectin-1 (Gal-1) is important in immune function and muscle regeneration, but its expression and localization in adult tissues and primary leukocytes remain unclear. To address this, we generated a specific monoclonal antibody against Gal-1, termed αhGal-1, and defined a sequential peptide epitope that it recognizes, which is preserved in human and porcine Gal-1, but not in murine Gal-1. Using αhGal-1, we found that Gal-1 is expressed in a wide range of porcine tissues, including striated muscle, liver, lung, brain, kidney, spleen, and intestine. In most types of cells, Gal-1 exhibits diffuse cytosolic expression, but in cells within the splenic red pulp, Gal-1 showed both cytosolic and nuclear localization. Gal-1 was also expressed in arterial walls and exhibited prominent cytosolic and nuclear staining in cultured human endothelial cells. However, human peripheral leukocytes and promyelocytic HL60 cells lack detectable Gal-1 and also showed very low levels of Gal-1 mRNA. In striking contrast, Gal-1 exhibited an organized cytosolic staining pattern within striated muscle tissue of cardiac and skeletal muscle and colocalized with sarcomeric actin on I bands. These results provide insights into previously defined roles for Gal-1 in inflammation, immune regulation and muscle biology.

Methods in Molecular Biology, 2014

Cellular turnover represents a fundamental aspect of immunological homeostasis. While many factor... more Cellular turnover represents a fundamental aspect of immunological homeostasis. While many factors appear to regulate leukocyte removal during inflammatory resolution, recent studies suggest that members of the galectin family play a unique role in orchestrating this process. Unlike cellular removal through apoptotic cell death, several members of the galectin family induce surface expression of phosphatidylserine (PS), a phagocytic marker on cells undergoing apoptosis, in the absence of cell death. However, similar to PS on cells undergoing apoptosis, galectininduced PS exposure sensitizes cells to phagocytic removal. As galectins appear to prepare cells for phagocytic removal without actually inducing apoptotic cell death, this process has recently been coined preaparesis. Given the unique characteristics of galectin-induced PS exposure in the context of preaparesis, we will examine important considerations when evaluating the potential impact of different galectin family members on PS exposure and cell viability.

PLoS ONE, 2012

5-lipoxygenase-derived products have been implicated in both the inhibition and promotion of chro... more 5-lipoxygenase-derived products have been implicated in both the inhibition and promotion of chronic infection. Here, we sought to investigate the roles of endogenous 5-lipoxygenase products and exogenous leukotrienes during Histoplasma capsulatum infection in vivo and in vitro. 5-LO deficiency led to increased lung CFU, decreased nitric oxide production and a deficient primary immune response during active fungal infection. Moreover, H. capsulatum-infected 5-LO 2/2 mice showed an intense influx of neutrophils and an impaired ability to generate and recruit effector T cells to the lung. The fungal susceptibility of 5-LO 2/2 mice correlated with a lower rate of macrophage ingestion of IgG-H. capsulatum relative to WT macrophages. Conversely, exogenous LTB4 and LTC4 restored macrophage phagocytosis in 5-LO deficient mice. Our results demonstrate that leukotrienes are required to control chronic fungal infection by amplifying both the innate and adaptive immune response during histoplasmosis.

Journal of Neuroimmunology, 2009

Myofiber degeneration, inflammation, and fibrosis are remarkable features of Duchenne muscular dy... more Myofiber degeneration, inflammation, and fibrosis are remarkable features of Duchenne muscular dystrophy. We hypothesized that the administration of imatinib mesylate, an inhibitor of tyrosine kinase and TGF-beta pro-fibrogenic activity, could improve the muscular conditions in mdx mice. Four-week old mdx mice were treated and exercised for 6 weeks. Gastrocnemius and diaphragm histopathology, strength, creatine kinase, and cytokine levels were evaluated. The treated group presented increased muscular strength and decreased CK levels, injured myofibers, and inflammatory infiltrates. Pro-inflammatory cytokines and TGF-beta were also reduced, while IL-10 was increased, suggesting an immunomodulatory effect of imatinib, which can ameliorate the dystrophic phenotype in mdx mice.

Biomolecules

Patients with COVID-19 predominantly have a respiratory tract infection and acute lung failure is... more Patients with COVID-19 predominantly have a respiratory tract infection and acute lung failure is the most severe complication. While the molecular basis of SARS-CoV-2 immunopathology is still unknown, it is well established that lung infection is associated with hyper-inflammation and tissue damage. Matrix metalloproteinases (MMPs) contribute to tissue destruction in many pathological situations, and the activity of MMPs in the lung leads to the release of bioactive mediators with inflammatory properties. We sought to characterize a scenario in which MMPs could influence the lung pathogenesis of COVID-19. Although we observed high diversity of MMPs in lung tissue from COVID-19 patients by proteomics, we specified the expression and enzyme activity of MMP-2 in tracheal-aspirate fluid (TAF) samples from intubated COVID-19 and non-COVID-19 patients. Moreover, the expression of MMP-8 was positively correlated with MMP-2 levels and possible shedding of the immunosuppression mediator sHL...

Viruses, 2021

Uncontrolled inflammatory responses play a critical role in coronavirus disease (COVID-19). In th... more Uncontrolled inflammatory responses play a critical role in coronavirus disease (COVID-19). In this context, because the triggering-receptor expressed on myeloid cells-1 (TREM-1) is considered an intrinsic amplifier of inflammatory signals, this study investigated the role of soluble TREM-1 (sTREM-1) as a biomarker of the severity and mortality of COVID-19. Based on their clinical scores, we enrolled COVID-19 positive patients (n = 237) classified into mild, moderate, severe, and critical groups. Clinical data and patient characteristics were obtained from medical records, and their plasma inflammatory mediator profiles were evaluated with immunoassays. Plasma levels of sTREM-1 were significantly higher among patients with severe disease compared to all other groups. Additionally, levels of sTREM-1 showed a significant positive correlation with other inflammatory parameters, such as IL-6, IL-10, IL-8, and neutrophil counts, and a significant negative correlation was observed with ly...

BackgroundThe uncontrolled inflammatory response plays a critical role in the novel coronavirus d... more BackgroundThe uncontrolled inflammatory response plays a critical role in the novel coronavirus disease (COVID-19) and triggering receptor expressed on myeloid cells-1 (TREM-1) is thought to be intricate to inflammatory signal amplification. This study aims to investigate the association between soluble TREM-1 (sTREM-1) and COVID-19 as a prognostic biomarker to predict the disease severity, lethality and clinical management.MethodsWe enrolled 91 patients with COVID-19 in domiciliary care (44 patients) or in hospital care (47 patients), who were classified after admission into mild, moderate, severe and critical groups according to their clinical scores. As non-COVID-19 control, 30 healthy volunteers were included. Data on demographic, comorbidities and baseline clinical characteristics were obtained from their medical and nurse records. Peripheral blood samples were collected at admission and after hospitalization outcome to assess cytokine profile and sTREM-1 level by specific immu...

ABSTRACTSkeletal muscle has the intrinsic ability to self-repair through a multifactorial process... more ABSTRACTSkeletal muscle has the intrinsic ability to self-repair through a multifactorial process, but many aspects of its cellular and molecular mechanisms are not fully understood. There is increasing evidence that some members of the mammalian β-galactoside-binding protein family (galectins) are involved in the muscular repair process (MRP), including galectin-3 (Gal-3). However, there are many questions about the role of this protein on muscle self-repair. Here, we demonstrate that endogenous Gal-3 is required for: i) muscle repairin vivousing a chloride-barium myolesion mouse model, and ii) mouse primary myoblasts myogenic programming. Injured muscle from Gal-3 knockout mice (GAL3KO) showed persistent inflammation associated with compromised muscle repair and the formation of fibrotic tissue on the lesion site. InGAL3KOmice, osteopontin expression remained high even after 7 and 14 days of the myolesion, while MyoD and myogenin had decreased their expression. InGAL3KOmouse prima...

Cytokine storms and hyperinflammation, potentially controlled by glucocorticoids, occur in COVID-... more Cytokine storms and hyperinflammation, potentially controlled by glucocorticoids, occur in COVID-19; the roles of lipid mediators and acetylcholine (ACh) and how glucocorticoid therapy affects their release in Covid-19 remain unclear. Blood and bronchoalveolar lavage (BAL) samples from SARS-CoV-2- and non-SARS-CoV-2-infected subjects were collected for metabolomic/lipidomic, cytokines, soluble CD14 (sCD14), and ACh, and CD14 and CD36-expressing monocyte/macrophage subpopulation analyses. Transcriptome reanalysis of pulmonary biopsies was performed by assessing coexpression, differential expression, and biological networks. Correlations of lipid mediators, sCD14, and ACh with glucocorticoid treatment were evaluated. This study enrolled 190 participants with Covid-19 at different disease stages, 13 hospitalized non-Covid-19 patients, and 39 healthy-participants. SARS-CoV-2 infection increased blood levels of arachidonic acid (AA), 5-HETE, 11-HETE, sCD14, and ACh but decreased monocyte...

Glycoconjugate Journal, 2019

Mediators of Inflammation, 2016

Histoplasma capsulatumis a dimorphic fungus that develops a yeast-like morphology in host’s tissu... more Histoplasma capsulatumis a dimorphic fungus that develops a yeast-like morphology in host’s tissue, responsible for the pulmonary disease histoplasmosis. The recent increase in the incidence of histoplasmosis in immunocompromised patients highlights the need of understanding immunological controls of fungal infections. Here, we describe our discovery of the role of endogenous galectin-1 (Gal-1) in the immune pathophysiology of experimental histoplasmosis. All infected wild-type (WT) mice survived while only 1/3 of Lgals1−/−mice genetically deficient in Gal-1 survived 30 days after infection. Although infected Lgals1−/−mice had increased proinflammatory cytokines, nitric oxide (NO), and elevations in neutrophil pulmonary infiltration, they presented higher fungal load in lungs and spleen. Infected lung and infected macrophages from Lgals1−/−mice exhibited elevated levels of prostaglandin E2(PGE2, a prostanoid regulator of macrophage activation) and prostaglandin E synthase 2 (Ptgs2) ...

Galectin-1 (Gal-1) is a lectin that recognizes β-galactosides and participates in biological proc... more Galectin-1 (Gal-1) is a lectin that recognizes β-galactosides and participates in biological processes, including modulation of the inflammatory response. Literature data show the involvement of this lectin to induce exposure of phosphatidylserine (PS-a marker of apoptosis), in the generation of reactive oxygen species (ROS) and in modulation of neutrophil chemotaxis. However, there are few data related to the biological impact of exogenous and endogenous Gal-1 on the biology of these cells. This study evaluated, in vitro, some functional aspects of the interaction of Gal-1 and neutrophil. It was determined the expression level of Gal-1 (Western blotting) and its mRNA (real time PCR) on human leukocytes obtained from peripheral blood of healthy donors and human promyelocytic cell line (HL-60). Peripheral blood leukocytes and HL-60 cells do not express detectable levels of this protein as well as the Gal-1 mRNA. Through chemiluminescence testing (CL) it was possible to analyze the ability of recombinant human Gal-1 to induce and modulate the production of ROS in naïve and activated (n-Formyl-Methionyl-Leucyl-Phenylalanine-fMLP) human neutrophils. Gal-1 induces ROS production in a dose-dependent way in fMLP activated neutrophils. However, in naive neutrophils this lectin does not induce oxidative stress and can negatively modulate ROS production in response to fMLP. The effects of Gal-1 on ROS production in both non-activated cells and activated cells are partially associated with their lectin property. In the literature there are no data about the interference of Gal-1 on ROS production in activated neutrophils with repeated doses of fMLP. It is known that the subsequent treatment with fMLP reduced levels of ROS production by neutrophils; however, the presence of Gal-1 did not affect this process. Interestingly, peritoneum neutrophils from Gal-1-/mice release more ROS in response to fMLP and exogenous Gal-1 when compared to neutrophils from wild type animals. Based on the in vitro findings and considering that in polymicrobial sepsis, neutrophils play an important role, the next step was to use the M-CLP model (moderate sepsis) in mice lacking (Gal-1-/-) or not (Gal-1 +/+) Gal-1 gene. Gal-1-/animals present lower survival rate and fewer bacteria in the blood despite having higher bacterial load in infectious focus in relation to wild type mice. The rates of neutrophils influx into the peritoneum and lungs are similar for both groups. The participation of Gal-1 in the homeostasis of neutrophils was demonstrated in vitro by flow cytometry (annexin V-FITC), where induced PS by Gal-1 in the neutrophils enhanced the phagocytosis of these cells by macrophages. Therefore, this set of results suggests that Gal-1, exogenous or endogenous, can modulate immune functions of neutrophils and participate in the regulation of inflammatory/infectious disorders.

Methods in Molecular Biology, 2014

Confocal microscopy provides a unique modality to examine the expression and localization of biom... more Confocal microscopy provides a unique modality to examine the expression and localization of biomolecules in a variety of settings. Using this technique, an image is acquired from the focal plane of the objective using focused laser light making it possible to work within the resolution limit of the optical system. In addition, by acquiring multiple images from a variety of focal planes, stacked series of images can provide clear spatial localization of a probed structure or protein. We describe herein the immunofluorescence methods for galectin staining in frozen sections of tissue for galectin localization using confocal microscopy.

Methods in molecular biology (Clifton, N.J.), 2015

Glycan binding proteins (GBPs) possess the unique ability to regulate a wide variety of biologica... more Glycan binding proteins (GBPs) possess the unique ability to regulate a wide variety of biological processes through interactions with highly modifiable cell surface glycans. While many studies demonstrate the impact of glycan modification on GBP recognition and activity, the relative contribution of subtle changes in glycan structure on GBP binding can be difficult to define. To overcome limitations in the analysis of GBP-glycan interactions, recent studies utilized glycan microarray platforms containing hundreds of structurally defined glycans. These studies not only provided important information regarding GBP-glycan interactions, but have also resulted in significant insight into the binding specificity and biological activity of the galectin family. We will describe the methods used when employing glycan microarray platforms to examine galectin-glycan binding specificity and function.

Nature Medicine, 2010

The expression of ABO(H) blood group antigens causes deletion of cells that generate self antiblo... more The expression of ABO(H) blood group antigens causes deletion of cells that generate self antiblood group antibodies, but this deletion limits adaptive immunity toward pathogens bearing cognate blood group antigens. To explore potential defense mechanisms against these pathogens, given such limitations in adaptive immunity, we screened for innate proteins that could recognize human blood group antigens. Here we report that two innate immune lectins, galectins-4 and-8, which are expressed in the intestinal tract, recognize and kill human blood group antigenexpressing E. coli, while failing to alter viability of other E. coli strains or other gram-negative or gram-positive organisms both in vitro and in vivo. Killing by both galectins-4 and-8 resides within their C-terminal domains, occurs rapidly and independently of complement, and is accompanied by disruption of membrane integrity. These results demonstrate that innate defense lectins can provide immunity against pathogens that display blood group self-antigens on their surface. Recent studies suggest that blood group antigen diversity may provide a mechanism of pathogen evasion whereby distinct ABO(H) antigen structures may reduce pathogen attachment and therefore infectivity1. Because ABO(H) antigens are composed of carbohydrate structures that only differ by distinct monosaccharides on the terminal structures of glycans2, potential factors responsible for providing innate immunity toward pathogens expressing blood group antigens must recognize carbohydrates. A growing list of Users may view, print, copy, download and text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Nature Chemical Biology, 2014

Genomic approaches continue to provide unprecedented insight into the microbiome, yet host immune... more Genomic approaches continue to provide unprecedented insight into the microbiome, yet host immune interactions with diverse microbiota can be difficult to study. We therefore generated a microbial microarray containing defined antigens isolated from a broad range of microbial flora to examine adaptive and innate immunity. Serological studies with this microarray show that immunoglobulins from multiple mammalian species exhibit unique patterns of reactivity, while exposure of animals to distinct microbes induces specific serological recognition. While adaptive immunity exhibited plasticity toward microbial antigens, immunological tolerance limits reactivity toward self. We discovered that several innate immune galectins exhibit specific recognition of microbes that express self-like antigens, leading to direct killing of a broad range of gram negative and positive microbes. Thus, host protection against microbes appears to represent a balance between adaptive and innate immunity to defend against evolving antigenic determinants while protecting against molecular mimicry.

Molecular Biology of the Cell, 2009

Cells normally undergo physiological turnover through the induction of apoptosis and phagocytic r... more Cells normally undergo physiological turnover through the induction of apoptosis and phagocytic removal, partly through exposure of cell surface phosphatidylserine (PS). In contrast, neutrophils appear to possess apoptosis-independent mechanisms of removal. Here we show that Galectin-1 (Gal-1) induces PS exposure independent of alterations in mitochondrial potential, caspase activation, or cell death. Furthermore, Gal-1–induced PS exposure reverts after Gal-1 removal without altering cell viability. Gal-1–induced PS exposure is uniquely microdomain restricted, yet cells exposing PS do not display evident alterations in membrane morphology nor do they exhibit bleb formation, typically seen in apoptotic cells. Long-term exposure to Gal-1 prolongs PS exposure with no alteration in cell cycle progression or cell growth. These results demonstrate that Gal-1–induced PS exposure and subsequent phagocytic removal of living cells represents a new paradigm in cellular turnover.

Glycobiology, 2008

Muscle degenerative diseases such as Duchenne Muscular Dystrophy are incurable and treatment opti... more Muscle degenerative diseases such as Duchenne Muscular Dystrophy are incurable and treatment options are still restrained. Understanding the mechanisms and factors responsible for muscle degeneration and regeneration will facilitate the development of novel therapeutics. Several recent studies have demonstrated that Galectin-1 (Gal-1), a carbohydrate-binding protein, induces myoblast differentiation and fusion in vitro, suggesting a potential role for this mammalian lectin in muscle regenerative processes in vivo. However, the expression and localization of Gal-1 in vivo during muscle injury and repair are unclear. We report the expression and localization of Gal-1 during degenerative-regenerative processes in vivo using two models of muscular dystrophy and muscle injury. Gal-1 expression increased significantly during muscle degeneration in the murine mdx and in the canine Golden Retriever Muscular Dystrophy animal models. Compulsory exercise of mdx mouse, which intensifies degeneration, also resulted in sustained Gal-1 levels. Furthermore, muscle injury of wild-type C57BL/6 mice, induced by BaCl 2 treatment, also resulted in a marked increase in Gal-1 levels. Increased Gal-1 levels appeared to localize both inside and outside the muscle fibers with significant extracellular Gal-1 colocalized with infiltrating CD45 + leukocytes. By contrast, regenerating muscle tissue showed a marked decrease in Gal-1 to baseline levels. These results demonstrate significant regulation of Gal-1 expression in vivo and suggest a potential role for Gal-1 in muscle homeostasis and repair.

Glycobiology, 2010

Galectin-1 (Gal-1) is important in immune function and muscle regeneration, but its expression an... more Galectin-1 (Gal-1) is important in immune function and muscle regeneration, but its expression and localization in adult tissues and primary leukocytes remain unclear. To address this, we generated a specific monoclonal antibody against Gal-1, termed αhGal-1, and defined a sequential peptide epitope that it recognizes, which is preserved in human and porcine Gal-1, but not in murine Gal-1. Using αhGal-1, we found that Gal-1 is expressed in a wide range of porcine tissues, including striated muscle, liver, lung, brain, kidney, spleen, and intestine. In most types of cells, Gal-1 exhibits diffuse cytosolic expression, but in cells within the splenic red pulp, Gal-1 showed both cytosolic and nuclear localization. Gal-1 was also expressed in arterial walls and exhibited prominent cytosolic and nuclear staining in cultured human endothelial cells. However, human peripheral leukocytes and promyelocytic HL60 cells lack detectable Gal-1 and also showed very low levels of Gal-1 mRNA. In striking contrast, Gal-1 exhibited an organized cytosolic staining pattern within striated muscle tissue of cardiac and skeletal muscle and colocalized with sarcomeric actin on I bands. These results provide insights into previously defined roles for Gal-1 in inflammation, immune regulation and muscle biology.

Methods in Molecular Biology, 2014

Cellular turnover represents a fundamental aspect of immunological homeostasis. While many factor... more Cellular turnover represents a fundamental aspect of immunological homeostasis. While many factors appear to regulate leukocyte removal during inflammatory resolution, recent studies suggest that members of the galectin family play a unique role in orchestrating this process. Unlike cellular removal through apoptotic cell death, several members of the galectin family induce surface expression of phosphatidylserine (PS), a phagocytic marker on cells undergoing apoptosis, in the absence of cell death. However, similar to PS on cells undergoing apoptosis, galectininduced PS exposure sensitizes cells to phagocytic removal. As galectins appear to prepare cells for phagocytic removal without actually inducing apoptotic cell death, this process has recently been coined preaparesis. Given the unique characteristics of galectin-induced PS exposure in the context of preaparesis, we will examine important considerations when evaluating the potential impact of different galectin family members on PS exposure and cell viability.

PLoS ONE, 2012

5-lipoxygenase-derived products have been implicated in both the inhibition and promotion of chro... more 5-lipoxygenase-derived products have been implicated in both the inhibition and promotion of chronic infection. Here, we sought to investigate the roles of endogenous 5-lipoxygenase products and exogenous leukotrienes during Histoplasma capsulatum infection in vivo and in vitro. 5-LO deficiency led to increased lung CFU, decreased nitric oxide production and a deficient primary immune response during active fungal infection. Moreover, H. capsulatum-infected 5-LO 2/2 mice showed an intense influx of neutrophils and an impaired ability to generate and recruit effector T cells to the lung. The fungal susceptibility of 5-LO 2/2 mice correlated with a lower rate of macrophage ingestion of IgG-H. capsulatum relative to WT macrophages. Conversely, exogenous LTB4 and LTC4 restored macrophage phagocytosis in 5-LO deficient mice. Our results demonstrate that leukotrienes are required to control chronic fungal infection by amplifying both the innate and adaptive immune response during histoplasmosis.

Journal of Neuroimmunology, 2009

Myofiber degeneration, inflammation, and fibrosis are remarkable features of Duchenne muscular dy... more Myofiber degeneration, inflammation, and fibrosis are remarkable features of Duchenne muscular dystrophy. We hypothesized that the administration of imatinib mesylate, an inhibitor of tyrosine kinase and TGF-beta pro-fibrogenic activity, could improve the muscular conditions in mdx mice. Four-week old mdx mice were treated and exercised for 6 weeks. Gastrocnemius and diaphragm histopathology, strength, creatine kinase, and cytokine levels were evaluated. The treated group presented increased muscular strength and decreased CK levels, injured myofibers, and inflammatory infiltrates. Pro-inflammatory cytokines and TGF-beta were also reduced, while IL-10 was increased, suggesting an immunomodulatory effect of imatinib, which can ameliorate the dystrophic phenotype in mdx mice.