The Expression of β1 Integrin and Intercellular Adhesion Molecule-1 on Mesangial Cells and Its Modulation in Glomerulonephritis

OBJECTIVES: This study was performed to observe the effects of conditioned media (CM) of cultured mononuclear cells (MNC) on the expression of β1 integrin and intercellular adhesion molecule (ICAM)-1 on mesangial cells and the modulation by TGF-β. TNFα. or hydroxyl radical. Also these were examined in anti-Thy mesangial proliferative GN (MsPGN) or puromycin aminonucleoside nephrosis (PAN). METHODS: The expression of β1 integrin and ICAM-1 on mesangial cells was examined by ELISA and the modulation by TGF-β, TNF α, or hydroxyl radical was investigated by using neutralizing antibody and dimethylthiourea, [ · OH] scavenger. RESULTS: The CM of MNC from Control suppressed the β1 integrin expression and thymidine incorporation, and increased ICAM-1 expression on mesangial cells, compared to media alone, Especially the significant increase in ICAM-1 expression was reversed by anti-TNFα antibody. β1 integrin expression on mesangial cells was higher by the addition of CM of MNC in MsPGN than in Control, which was prevented by anti-TGF β antibody or dimethyl-thiourea. ICAM-1 expression was not different among groups. Thymidine incoporation by adding CM of MNC was lower in MsPGN and PAN, which was mitigated by anti-TGFβ and anti-TNFα. Thus the ratio of the expression of ICAM-1 to thymidine incorporation was higher in MsPGN and PAN. CONCLUSION: The expression of β1 integrin and ICAM-1, and the thymidine incorporation on mesangial cells are directly regulated by MNC, maybe through factors such as TGFβ or TNFα. In MsPGN, the overexpression of β1 integrin induced by MNC through TGFβ or hydroxyl radical on day 3 may be related to the pathogenesis.