Mucins goblet cells

Ishikawa, N., Horii, Y. and Nawa, Y. (1993) Immune mediated alteration of the terminal sugars of goblet cell mucins in the small intestine of Nippostrongylus brasiliensis infected rats. Immunology 78, 303-307. 

Nimmerfall, F., and J. Rosenthaler. 1980. Significance of the goblet-cell mucin layer, the outermost luminal barrier to passage through the gut wall. Biochem Biophys Res Commun 94 960. 

Increased numbers of goblet cells (GCs) and qualitative changes in mucus secretions are coincident with infection with a number of nematode parasites and it has been proposed that mucin proteins mediate this response by enveloping the parasites and/or interrupting attachment (Nawa et al., 1994). However, the role of GCs and mucus in the generation of a protective response versus its role in resolving intestinal inflammation following infection with GI nematode parasites remains unresolved. 

Muc2 and Muc3, and mucin mRNA are coordinately upregulated in response to T. spiralis infection and may form the basis of an innate mucosal response independent of specific IFN-y, TNF and IL-4 cytokines. Importandy, this study also demonstrated that goblet cell hyperplasia and upregulated mucin secretion are not essential components of the protective immune response to GI helminths. 

A number of ocular surface disorders collectively termed as Dry Eye Syndromes have also been associated with the conjunctiva. For example, a deficiency and/or imbalance in compositions of the tear film is often found on the ocular surface during keratoconjunctivitis sicca. Since the conjunctiva plays a direct role in the maintenance of the tear fluid stability via secretion of mucin [1] by its resident goblet cells [4] and basal fluid secretion driven by electro-osmotic gradients across the tissue [3], the conjunctiva is a well deserved, but not intensively studied, target of interest in research efforts aimed against combating Dry Eye Syndromes. 

The construction of the eye is completely different. The outer layer of this mucosa consists of a tiny tear layer of lipids and water which covers a superficial epithelium closed by double layer lipid membranes of 30-70 nm size interconnected by tight jnnctions. Three to seven layers of epithelial cells cover the stromal structures of conjunctiva or cornea. The conjnnctival surface has interposed cells secreting small amonnts of mucin, the so-called goblet cells, which are typically missing within the corneal epithelinm. The regeneration of epithelial structnres is dne to the limbal stem cells located deep in the Vogt s crypts, for the cornea. 

First, we will describe briefly the biology of secretory cells in general and goblet cells in particular. Next, we will outline our earlier studies on the conformation of mudn networks using dynamic laser scattering. Short discussions on the Donnan swelling properties of the mucin network will bring us to the application of the theory of polymer gel phase transition to explain condensation and decondensation in secretion. 

Results obtained in mucin-secreting goblet cells, which will be reviewed here, and in histamine-secreting mast cells, which have been presented elsewhere [2], are prompting us to abandon some long-established ideas about packing and release in secretion and to sketch a new hypothesis based on current polymer-gel theory. 

Members of the trefoil factor family of small proteins are solid candidates to be mucin interchain cross-linkers (Otto and Thim 2005). For example, TFF1 is mainly expressed in the goblet cells of gastric mucosa, where it co-localizes with and binds to MUC5AC (Ruchaud-Sparagano et al. 2004). Yeast two-hybrid... 

Perez-Vilar J., Randell S.H. and Boucher R.C. (2004). C-Mannosylation of MUC5AC and MUC5B Cys subdomains. Glycobiology 4, 325-337 Perez-Vilar J., Olsen J.C., Chua M. and Boucher R.C. (2005a). pH-dependent intraluminal organization of mucin granules in live human mucous/goblet cells. J. Biol. Chem. 280, 16868-16881... 

Perez-Vilar J., Mabolo R. McVaugh C.T., Bertozzi C.R. and Boucher R.C. (2006). Mucin granule intraluminal organization in living mucous/goblet cells. Roles of protein post-translational modifications and secretion. J Biol Chem. 281, 4844-4855 Perez-Vilar J. (2007). Mucin granule intraluminal organization. Am J Respir Cell Mol Biol,... 

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