Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Production and localization of Muc4/sialomucin complex and its receptor tyrosine kinase ErbB2 in the rat lacrimal gland
Autore:
Arango, ME; Li, P; Komatsu, M; Montes, C; Carraway, CAC; Carraway, KL;
Indirizzi:
Univ Miami, Sch Med, Dept Cell Biol & Anat, Miami, FL 33101 USA Univ Miami Miami FL USA 33101 Dept Cell Biol & Anat, Miami, FL 33101 USA
Titolo Testata:
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
fascicolo: 12, volume: 42, anno: 2001,
pagine: 2749 - 2756
SICI:
0146-0404(200111)42:12<2749:PALOMC>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
MAMMARY ADENOCARCINOMA CELLS; SIALOMUCIN COMPLEX; OCULAR SURFACE; CONJUNCTIVAL EPITHELIA; GLYCOPROTEIN COMPLEX; MOLECULAR-CLONING; TEAR FLUID; MUCIN; EXPRESSION; OVEREXPRESSION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Carraway, KL Univ Miami, Sch Med, Dept Cell Biol & Anat R124, POB 016960, Miami, FL 33101 USA Univ Miami POB 016960 Miami FL USA 33101 Miami, FL 33101 USA
Citazione:
M.E. Arango et al., "Production and localization of Muc4/sialomucin complex and its receptor tyrosine kinase ErbB2 in the rat lacrimal gland", INV OPHTH V, 42(12), 2001, pp. 2749-2756

Abstract

PURPOSE. To show the presence and forms of sialomucin complex (rat Muc4) and receptor tyrosine kinase ErbBs in the rat lacrimal gland and analyze forcomplexes of ErbB2 and its ligand Muc4. METHODS. Northern blot analyses were used to identify sialomucin complex/Muc4 (SMC/Muc4) mRNA in rat lacrimal gland. Immunoblot analyses were performed to detect SMC/Muc4 and ErbBs. Sequential immunoprecipitation and immunoblot analyses were used to differentiate membrane and soluble forms of the SMC/Muc4 transmembrane subunit ASGP-2. Methacarn-fixed. paraffin-embedded sections of lacrimal glands from female adult rats were immunocytochemically stained using antisera to SMC/Muc4 and ErbBs to determine their relative locations in the gland. Colocalization of SMC/Muc4 and ErbB2 was confirmed byconfocal immunofluorescence. Sequential immunoprecipitation and immunoblotwere performed to analyze complexes of the SMC/Muc4 and ErbB2 in the lacrimal tissue. RESULTS. Northern blot analyses of rat lacrimal glands, with a probe for SMC/Muc4, demonstrated the presence of a similar to9-kb transcript, consistent with observations in other tissues. Similarly, immunoblot analyses with antibodies against both the transmembrane (ASGP-2) and mucin (ASGP-1) subunits showed the presence of the two SMC/Muc4 subunits in lysates from rat lacrimal gland. Significantly, two different forms of ASGP-2 were observed, ahigh-molecular-weight (similar to 200-kDa) form and the more common 120- to 140-kDa form. Sequential immunoprecipitation and immunoblot analyses to differentiate membrane and soluble forms of SMC/Muc4 indicated that the high-molecular-weight form of ASGP-2 was predominantly associated with membranes, whereas the 120- to 140-kDa form was both membrane-associated and soluble. The lacrimal gland consists of acini connected by intercalated and interlobular ducts. Both acini and some intercalated ducts were stained by anti-ASGP-2 monoclonal antisera. Two patterns of acinar staining were observed membrane staining at the borders of the epithelial cells and a granular staining within the cells. Staining of ductal surfaces with antibody to the cytoplasmic domain of ASGP-2 suggests that membrane SMC/Muc4 is being producedby the ductal cells and is not simply an adsorbed soluble product from theacinar cells. Immunoblot and immunocytochemical analyses demonstrated the presence of all four ErbBs. with ErbB2 showing the most widespread distribution, similar to that of SMC/Muc4. Immunofluorescence colocalization of membrane SMC/Muc4 and ErbB2 and coimmunoprecipitation of a complex of the two provided evidence of their association in membranes of lacrimal gland acinar cells. CONCLUSIONS. SMC/Muc4 is produced by the rat lacrimal gland as both membrane and soluble forms, specifically associated with both acinar and ductal cells. Because sialomucin complex is also present in the ocular tear film, the rat lacrimal gland represents a second source of this mucin for the tearfilm, in addition to the corneal and conjunctival epithelia. Moreover, thepresence of a complex of SMC/Muc4 and the receptor tyrosine kinase ErbB2 in lacrimal tissue suggests that SMC/Muc4 acts as a ligand for the receptor and has functions in the lacrimal gland other than that of a mucin.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 19:17:38