Mucins in protozoan parasites (original) (raw)

Shared expression of mucin12 in Ascaris lumbricoides and the human small intestine

Molecular and Biochemical Parasitology, 2019

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Expression of conserved mucin domains by epithelial tissues in various mammalian species

Research in Veterinary Science, 2009

Mucins are related to infectious and non-infectious diseases in Veterinary and Human Medicine. MUC1 mucin is a transmembrane glycoprotein expressed on the apical surface of human epithelia while MUC5AC is the predominant secreted mucin expressed in human gastric epithelium and goblet cells of lung and eyes. MUC5AC C-terminus cysteine rich regions and the cytoplasmic tail of MUC1 domains are conserved among several mammalian species. Objective: to compare the expression of MUC1 and MUC5AC mucins in mammalian epithelia. CT33 anti-MUC1 cytoplasmic tail (MUC1CT) polyclonal antibody and 45M1 anti-MUC5AC monoclonal antibody were employed. By immunohistochemistry, MUC1CT was expressed in most tissues while MUC5AC was restricted to gastric surface epithelium and goblet cells from trachea and lung. By western blot, MUC1CT showed a band at approximately 35 kDa in most tissues; MUC5AC revealed bands at >180 kDa in stomach and lung secretions from rat, cat, pig and cow. When rat MUC5AC was immunoprecipitated, a band at about 180 kDa was obtained.

Structure and function of epithelial mucins

Biopolymers and Cell, 1998

Mucins are the structural components of the epithelial mucose that protects the respiratory, gastrointestinal and reproductive tracts from the hostile environments, including microorganisms, toxim and abrasives. Mucins constitute a group of high molecular weight (> 200 kDa), polydisperse and highly glycosylated proteins which are present on the surface of most epithelial tissues. Our understanding of the structure and function of mucins has advanced significantly in the last decade. This progress was mainly associated with the isolation of the cDNA clones, encoding a family of epithelial mucins. To date, this family includes eight mucin genes (MUCJ-MUC8) and more await to be discovered. Based on sequence analysis and studies of subcellular localisation, epithelial mucins could be divided into two classes: membrane-associated (MUC1) and secretory (MUC2-8). This review is focused on our current knowledge of the structure of products of mucin genes and their function in normal tissues and in disease. The regulation of the expression of mucin genes, posttranslational modifications and alterations in secretion and processing will also be discussed.

Mucins in the host defence against Naegleria fowleri and mucinolytic activity as a possible means of evasion

Microbiology, 2008

Naegleria fowleri is the aetiological agent of primary amoebic meningoencephalitis (PAM). This parasite invades its host by penetrating the olfactory mucosa. During the initial stages of infection, the host response is initiated by the secretion of mucus that traps the trophozoites. Despite this response, some trophozoites are able to reach, adhere to and penetrate the epithelium. In the present work, we evaluated the effect of mucins on amoebic adherence and cytotoxicity to Madin-Darby canine kidney (MDCK) cells and the MUC5AC-inducing cell line NCI-H292. We showed that mucins inhibited the adhesion of amoebae to both cell lines; however, this inhibition was overcome in a time-dependent manner. N. fowleri re-established the capacity to adhere faster than N. gruberi. Moreover, mucins reduced the cytotoxicity to target cells and the progression of the illness in mice. In addition, we demonstrated mucinolytic activity in both Naegleria strains and identified a 37 kDa protein with mucinolytic activity. The activity of this protein was inhibited by cysteine protease inhibitors. Based on these results, we suggest that mucus, including its major mucin component, may act as an effective protective barrier that prevents most cases of PAM; however, when the number of amoebae is sufficient to overwhelm the innate immune response, the parasites may evade the mucus by degrading mucins via a proteolytic mechanism.

Mucins: a dynamic biology

Soft Matter, 2013

In this highlight, we discuss the multifaceted biology of mucins, where molecular architecture meets function, and especially the collective properties of mucin networks and gels that select adherent bacteria and restrict penetration.