Dataset Information

Attenuated pulmonary fibrosis in sialidase-3 knockout (Neu3^-/-) mice.

ABSTRACT: Pulmonary fibrosis involves the formation of inappropriate scar tissue in the lungs, but what drives fibrosis is unclear. Sialidases (also called neuraminidases) cleave terminal sialic acids from glycoconjugates. In humans and mice, pulmonary fibrosis is associated with desialylation of glycoconjugates and upregulation of sialidases. Of the four mammalian sialidases, we previously detected only NEU3 in the bronchoalveolar lavage fluid from mice with bleomycin-induced pulmonary fibrosis. In this report, we show that NEU3 upregulates extracellular accumulation of the profibrotic cytokines IL-6 and IL-1?, and IL-6 upregulates NEU3 in human peripheral blood mononuclear cells, suggesting that NEU3 may be part of a positive feedback loop potentiating fibrosis. To further elucidate the role of NEU3 in fibrosis, we used bleomycin to induce lung fibrosis in wild-type C57BL/6 and Neu3^-/- mice. At 21 days after bleomycin, compared with male and female C57BL/6 mice, male and female Neu3^-/- mice had significantly less inflammation, less upregulation of other sialidases and the profibrotic cytokine active transforming growth factor ?1, and less fibrosis in the lungs. Our results suggest that NEU3 participates in fibrosis and that NEU3 could be a target to develop treatments for fibrosis.

SUBMITTER: Karhadkar TR

PROVIDER: S-EPMC6985870 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Attenuated pulmonary fibrosis in sialidase-3 knockout (<i>Neu3<sup>-/-</sup></i>) mice.

Karhadkar Tejas R TR Chen Wensheng W Gomer Richard H RH

American journal of physiology. Lung cellular and molecular physiology 20191016 1

Pulmonary fibrosis involves the formation of inappropriate scar tissue in the lungs, but what drives fibrosis is unclear. Sialidases (also called neuraminidases) cleave terminal sialic acids from glycoconjugates. In humans and mice, pulmonary fibrosis is associated with desialylation of glycoconjugates and upregulation of sialidases. Of the four mammalian sialidases, we previously detected only NEU3 in the bronchoalveolar lavage fluid from mice with bleomycin-induced pulmonary fibrosis. In this ...[more]

PMID: 31617733

Similar Datasets

Project description:Neuraminidases (NAs) are critical virulence factors for several microbial pathogens. With a highly conserved catalytic domain, a microbial NA "superfamily" has been proposed. We previously reported that murine polymorphonuclear leukocyte (PMN) sialidase activity was important in leukocyte trafficking to inflamed sites and that antibodies to Clostridium perfringens NA recognized a cell surface molecule(s), presumed to be a sialidase of eukaryotic origin on interleukin-8-stimulated human and murine PMNs. These antibodies also inhibited cell sialidase activity both in vitro and, in the latter instance, in vivo We therefore hypothesized that mammalian sialidases share structural homology and epitopes with microbial NAs. We now report that antibodies to one of the isoforms of C. perfringens NA, as well as anti-influenza virus NA serum, recognize human NEU3 but not NEU1 and that antibodies to C. perfringens NA inhibit NEU3 enzymatic activity. We conclude that the previously described microbial NA superfamily extends to human sialidases. Strategies designed to therapeutically inhibit microbial NA may need to consider potential compromising effects on human sialidases, particularly those expressed in cells of the immune system.IMPORTANCE We previously reported that sialidase activity of human neutrophils plays a critical role in the host inflammatory response. Since the catalytic domains of microbial neuraminidases are highly conserved, we hypothesized that antibodies against Clostridium perfringens neuraminidase might inhibit mammalian sialidase activity. Before the recognition of four mammalian sialidase (Neu) isoforms, we demonstrated that anti-C. perfringens neuraminidase antibodies inhibited human and murine sialidase activity in vivo and in vitro We now show that the antibodies to microbial neuraminidase (C. perfringens and influenza virus) recognize human NEU3, which is important for neural development and cell signaling. Since many microbes that infect mucosal surfaces express neuraminidase, it is possible that the use of sialidase inhibitors (e.g., zanamivir), might also compromise human sialidase activity critical to the human immune response. Alternatively, sialidase inhibitors may prove useful in the treatment of hyperinflammatory conditions.

Project description:Pulmonary fibrosis is a devastating disease with no effective treatments to cure, stop or reverse the unremitting, fatal fibrosis. A critical barrier to treating this disease is the lack of understanding of the pathways leading to fibrosis as well as those regulating the resolution of fibrosis. Fibrosis is the pathologic side of normal tissue repair that results when the normal wound healing programs go awry. Successful resolution of tissue injury requires several highly coordinated pathways, and this research focuses on the interplay between these overlapping pathways: immune effectors, inflammatory mediators and fibroproliferation in the resolution of fibrosis. Previously we have successfully prevented, mitigated, and even reversed established fibrosis using vaccinia vaccination immunotherapy in two models of murine lung fibrosis. The mechanism by which vaccinia reverses fibrosis is by vaccine induced lung specific Th1 skewed tissue resident memory (TRMs) in the lung. In this study, we isolated a population of vaccine induced TRMs - CD49a+ CD4+ T cells - that are both necessary and sufficient to reverse established pulmonary fibrosis. Using adoptive cellular therapy, we demonstrate that intratracheal administration of CD49a+ CD4+ TRMs into established fibrosis, reverses the fibrosis histologically, by promoting a decrease in collagen, and functionally, by improving lung function, without the need for vaccination. Furthermore, co-culture of in vitro derived CD49+ CD4+ human TRMs with human fibroblasts from individuals with idiopathic pulmonary fibrosis (IPF) results in the down regulation of IPF fibroblast collagen production. Lastly, we demonstrate in human IPF lung histologic samples that CD49a+ CD4+ TRMs, which can down regulate human IPF fibroblast function, fail to increase in the IPF lungs, thus potentially failing to promote resolution. Thus, we define a novel unappreciated role for tissue resident memory T cells in regulating established lung fibrosis to promote resolution of fibrosis and re-establish lung homeostasis. We demonstrate that immunotherapy, in the form of adoptive transfer of CD49a+ CD4+ TRMs into the lungs of mice with established fibrosis, not only stops progression of the fibrosis but more importantly reverses the fibrosis. These studies provide the insight and preclinical rationale for a novel paradigm shifting approach of using cellular immunotherapy to treat lung fibrosis.

Project description:BACKGROUND: Large surface loops contained within compact protein structures and not involved in catalytic process have been proposed as preferred regions for protein family evolution. These loops are subjected to lower sequence constraints and can evolve rapidly in novel structural variants. A good model to study this hypothesis is represented by sialidase enzymes. Indeed, the structure of sialidases is a ?-propeller composed by anti-parallel ?-sheets connected by loops that suit well with the rapid evolving loop hypothesis. These features prompted us to extend our studies on this protein family in birds, to get insights on the evolution of this class of glycohydrolases. RESULTS: Gallus gallus (Gg) genome contains one NEU3 gene encoding a protein with a unique 188 amino acid sequence mainly constituted by a peptide motif repeated six times in tandem with no homology with any other known protein sequence. The repeat region is located at the same position as the roughly 80 amino acid loop characteristic of mammalian NEU4. Based on molecular modeling, all these sequences represent a connecting loop between the first two highly conserved ?-strands of the fifth blade of the sialidase ?-propeller. Moreover this loop is highly variable in sequence and size in NEU3 sialidases from other vertebrates. Finally, we found that the general enzymatic properties and subcellular localization of Gg NEU3 are not influenced by the deletion of the repeat sequence. CONCLUSION: In this study we demonstrated that sialidase protein structure contains a surface loop, highly variable both in sequence and size, connecting two conserved ?-sheets and emerging on the opposite site of the catalytic crevice. These data confirm that sialidase family can serve as suitable model for the study of the evolutionary process based on rapid evolving loops, which may had occurred in sialidases. Giving the peculiar organization of the loop region identified in Gg NEU3, this protein can be considered of particular interest in such evolutionary studies and to get deeper insights in sialidase evolution.

Dataset Information

Attenuated pulmonary fibrosis in sialidase-3 knockout (Neu3^-/-) mice.

Publications

Attenuated pulmonary fibrosis in sialidase-3 knockout (<i>Neu3<sup>-/-</sup></i>) mice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Attenuated pulmonary fibrosis in sialidase-3 knockout (Neu3-/-) mice.

Publications

Attenuated pulmonary fibrosis in sialidase-3 knockout (<i>Neu3<sup>-/-</sup></i>) mice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Attenuated pulmonary fibrosis in sialidase-3 knockout (Neu3^-/-) mice.