title: The role of TNF-alpha and its receptors in the production of beta-1,4-galactosyltransferase I mRNA by rat primary type-2 astrocytes.
abstract: beta-1,4-galactosyltransferase I (beta-1,4-GalT I) plays an important role in the synthesis of the backbone structure of adhesion molecules involved in leukocyte-endothelial cell interaction. The expression of beta-1,4-GalT I mRNA increased in primary human endothelial cells after exposure to tumor necrosis factor-alpha (TNF-alpha). In the central nervous system (CNS), astrocytes play a pivotal role in immunity as immunocompetent cells by secreting cytokines and inflammatory mediators, there are two types of astrocytes. Type-1 astrocytes can secrete TNF-alpha when stimulated with Lipopolysaccharide (LPS), while the responses of type-2 astrocytes during inflammation are unknown. So we examined the expression change of beta-1,4-GalT I mRNA in type-2 astrocytes after exposure to TNF-alpha and LPS. Real-time PCR showed that TNF-alpha or LPS affected beta-1,4-GalT I mRNA expression in a time- and dose-dependent manner. RT-PCR analysis revealed that TNFR1 and TNFR2 were present in normal untreated type-2 astrocytes, and that TNF-alpha, TNFR1 and TNFR2 increased in type-2 astrocytes after exposure to TNF-alpha or LPS. Immunocytochemistry showed that TNFR1 was expressed in the cytoplasm, nucleus and processes of normal untreated type-2 astrocytes, and distributed mainly in the cytoplasm and processes after exposure to LPS. TNFR2 was mainly expressed in the nucleus of normal untreated type-2 astrocytes, and distributed mainly in the processes of type-2 astrocytes after exposure to LPS. Both anti-TNFR1 and anti-TNFR2 antibodies suppressed beta-1,4-GalT I mRNA expression induced by TNF-alpha or LPS. From these results, we conclude that TNF-alpha signaling via both TNFR1 and TNFR2 translocated from nucleus to cytoplasm or processes is sufficient to induce beta-1,4-GalT I mRNA. In addition, we observed that not only exogenous TNF-alpha but also TNF-alpha produced by type-2 astrocytes affected beta-1,4-GalT I mRNA production in type-2 astrocytes. These results suggest that an autocrine loop involving TNF-alpha contributes to the production of beta-1,4-GalT I mRNA in response to inflammation.
authors: Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qi-Xiu Road, Nantong, Jiangsu Province, 226001, P.R. China.
authors: Meijuan
authors: M
authors: Yan
authors: Chunlin
authors: C
authors: Xia
authors: Shuqiong
authors: S
authors: Niu
authors: Chun
authors: C
authors: Cheng
authors: Xiaoyi
authors: X
authors: Shao
authors: Aiguo
authors: A
authors: Shen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000494:pharmacology; D001253:Astrocytes / Q000166:cytology / Q000201:enzymology* / Q000276:immunology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004660:Encephalitis / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D005700:Galactosyltransferases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000276:immunology / Q000378:metabolism*; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000276:immunology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D000906:Antibodies; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; C506237:Tnfrsf1a protein, rat; D014409:Tumor Necrosis Factor-alpha; D005700:Galactosyltransferases; C119701:beta-1,4-galactosyltransferase I
references: Development. 2001 Mar;128(5):645-54
references: 11171390
references: Proc Natl Acad Sci U S A. 1986 Mar;83(6):1573-7
references: 2419911
references: Brain Res. 2006 Oct 20;1116(1):12-8
references: 16956589
references: Nature. 1983 Jun 2-8;303(5916):390-6
references: 6304520
references: J Biol Chem. 2005 Apr 1;280(13):12676-82
references: 15668241
references: FASEB J. 1995 Jul;9(10):899-909
references: 7542214
references: Neurol Res. 1995 Aug;17(4):242-8
references: 7477737
references: J Exp Med. 1997 Nov 3;186(9):1585-90
references: 9348316
references: Glycoconj J. 1998 Jun;15(6):537-48
references: 9881758
references: Blood. 2003 Sep 1;102(5):1678-85
references: 12714507
references: Brain Pathol. 2002 Oct;12(4):475-81
references: 12408234
references: Life Sci. 2001 Mar 23;68(18):2081-91
references: 11324713
references: Brain Res. 1989 Jul 10;491(2):394-7
references: 2765895
references: FEBS Lett. 2002 Mar 27;515(1-3):119-26
references: 11943206
references: Dev Biol. 1984 Nov;106(1):53-60
references: 6489611
references: J Cell Sci. 1995 Feb;108 ( Pt 2):839-47
references: 7539442
references: Proc Natl Acad Sci U S A. 1979 Oct;76(10):4913-7
references: 388422
references: Annu Rev Immunol. 1995;13:437-57
references: 7542010
references: Glycobiology. 1991 Dec;1(6):563-75
references: 1822236
references: Neurotoxicology. 1998 Apr;19(2):269-81
references: 9553964
references: J Neurosci. 1983 Jun;3(6):1289-1300
references: 6343560
references: J Neuroimmunol. 2005 May;162(1-2):89-96
references: 15833363
references: Glycobiology. 1993 Apr;3(2):97-130
references: 8490246
references: J Neurosci Res. 2005 Dec 1;82(5):701-16
references: 16267827
references: Development. 1997 Oct;124(20):4121-31
references: 9374408