Effect of bilirubin on expression of toll-like receptor 4 in cord blood monocytes
LIU Hui-Ling, CHEN Chang-Hui, CHEN Min, WU Qing, LI Mao-Jun
Department of Pediatrics, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China. Email: chen966888@yahoo.com.cn
Abstract OBJECTIVE: To study the effect of different concentrations of bilirubin on expression of toll-like receptor 4 (TLR4) in cord blood monocytes (CBMC). METHODS: Under the sterile condition, umbilical vein blood samples were obtained from normal full-term newborns, and the monocytes were in vitro separated by the method of gelatin/plasma coated flasks. The monocytes were preincubated with various concentrations (0-307.8 μmol/L) of bilirubin dissolved in bovine albumin solution for 1 hr. Bilirubin-treated CBMC were further cultured with LPS (1 μg/mL) to induce cellular activation for 24 hrs, and then the CBMC were collected. The expression of TLR4 in monocytes was measured by indirect immunofluorescence method. RESULTS: Bilirubin at the concentrations of 102.6, 153.9, 220.6 and 307.8 μmol/L inhibited the expression of TLR4 of CBMC. The inhibition effect increased with the increasing concentration of bilirubin. CONCLUSIONS: Bilirubin can inhibit the TLR4 expression of CBNC in a dose-dependent manner.
LIU Hui-Ling,CHEN Chang-Hui,CHEN Min et al. Effect of bilirubin on expression of toll-like receptor 4 in cord blood monocytes[J]. 中国当代儿科杂志, 2011, 13(2): 153-156.
LIU Hui-Ling,CHEN Chang-Hui,CHEN Min et al. Effect of bilirubin on expression of toll-like receptor 4 in cord blood monocytes[J]. CJCP, 2011, 13(2): 153-156.
［1］ Liu Y, Li P, Lu J, Xiong W, Oger J, Tetzlaff W, et al. Bilirubin possesses powerful immuno-modulatory activity and suppresses experimental auto-immune encephalomyelitis［J］. J Immunol, 2008, 181(3): 1887-1897.
［7］Freundlich B, Avdalovic N. Use of gelatin/plasma coated flasks for isolating human peripheral blood monocytes［J］. Immunol Methods, 1983, 62（1）：31-37.
［10］Daly KA, Lefevre C, Nicholas K, Deane E, Williamson P. CD14 and TLR4 are expressed early in tammar (Macropus eugenii) neonate development［J］. J Exp Biol, 2008, 211（8）: 1344-1351.
［11］Forster Waldl E, Sadeghi K, Tamandl D, Gerhold B, Hallwirth U, Rohrmeister K, et al. Monocyte toll-like receptor 4 expression and LPS-induced cytokine production increase during gestational aging［J］.Pediatr Res, 2005, 58(1): 121-124.
［12］Yan SR, Qing G, Byers DM, Stadnyk AW, Alhertani W, Bortolussi R, et al. Role of MyD88 in diminished tumor necrosis factor alpha production by newborn mononuclear cells in response to lipopolysaccharide［J］. Infect Immun, 2004, 72(3): 1223-1229.
［14］Marodi L. Neonatal innate immunity to infectious agents［J］. Infect Immun, 2006, 74(4): 1999-2006.
［15］Wynn JL, Scumpia PO, Winfield RD, Delano MJ, Kelly-Scumpia K, Barker T, et al. Defective innate immunity predisposes murine neonates to poor sepsis outcome but is reversed by TLR agonists［J］.Blood, 2008, 112（5）: 1750-1758.
［16］LeBouder E, Rey-Nores JE, Raby AC, Affolter M, Vidal K, Thornton CA, et al. Modulation of neonatal microbial recognition: TLR-mediated innate immune responses are specifically and differentially modulated by human milk［J］. J Immunol, 2006, 176(6): 3742-3752.
［17］Watchko JF. Hyperbilirubinemia and bilirubin toxicity in the late preterm infant［J］. Clin Perinatol, 2006, 33(4): 839-852.
［18］Stocker R, Yamamoto Y, McDonagh AF, Glazer AN, Ames BN. Bilirubin is an antioxidant of possible physiological importance［J］. Science, 1987, 235(4792): 1043-1046.
［19］Miler I, Sima P, Vetvicka V, Indrova M, Slavikova M. The potential immunosuppressive effect of bilirubin［J］. Allerg Immunol (Leipz), 1988, 34(3): 177-184.
［20］Brito MA, Silva RF, Brites D. Bilirubin toxicity to human erythrocytes: a review［J］.Clin Chim Acta, 2006, 374(1-2): 4656.
［21］Ostrow JD, Tiribelli C. Bilirubin, a curse and a boon［J］. Gut, 2003, 52(12): 1668-1670.
［22］Falcao AS, Silva RF, Pancadas S, Fernandes A, Brito MA, Brites D. Apoptosis and impairment of neurite network by short exposure of immature rat cortical neurons to unconjugated bilirubin increase with cell differentiation and are additionally enhanced by an inflammatory stimulus［J］. J Neurosci Res, 2007, 85(6): 1229-1239.
