Abstract:OBJECTIVE: To study hepatic NF-κB level following endotoxemic liver injury, and its relationship with hepatic TNF-α and IL-6 levels in young rats. METHODS: Forty 18-day-old rats were randomly assigned to a normal control and an endotoxemia group. Endotoxemia was induced by lipopolysaccharide injection (LPS, 5 mg/kg). The endotoxemia group was subdivided into four groups sampled at 2, 6, 12 and 24 hrs after LPS injection (n=8 each). Pathological changes in liver cells were observed under a light microscope. TNF-α and IL-6 levels in liver tissue homogenates were measured using ELISA. Reitman-Frankel was used to measure serum ALT concentrations. NF-κB activation level in liver tissues was detected by immunohistochemistry. RESULTS: Liver tissue injury was the most obvious 6 hrs after LPS injection under the light microscope, and the damage rating of liver tissues was significantly higher in the endotoxemia group than that in the normal control group at all time points (P<0.05). ALT levels in the endotoxemia group were significantly higher than those in the normal control group 6, 12 and 24 hrs after LPS injection (P<0.05). NF-κB p65 protein expression in liver cells (percentage of nuclear positive cells) in the endotoxemia groups was significantly higher than that in the normal control group (P<0.05). TNF-α and IL-6 levels in liver tissue homogenates in the endotoxemia groups were significantly higher than those in the normal control group 6 and 12 hrs after LPS injection (P<0.05). CONCLUSIONS: Endotoxemia can cause liver injury, resulting in liver cell damage and changes in liver function. NF-κB activation is involved in endotoxemic liver injury which may be mediated by inflammatory cytokines TNF-α and IL-6 synthesis. [Chin J Contemp Pediatr, 2010, 12 (10):804-808]
[1]Xu FL, You HB, Li XH, Chen XF, Liu ZJ, Gong JP. Glycine attenuates endotoxin-induced liver injury by downregulating TLR4 signaling in Kupffer cells[J]. Am J Surg, 2008, 196(1): 139-148.
[2]Zhang D, Jiang J, Jiang S, Ma J, Su T, Qiu L, et al. Molecular characterization and expression analysis of a putative LPS-induced TNF-alpha factor (LITAF) from pearl oyster Pinctada fucata[J]. Fish Shellfish Immunol, 2009, 27(3): 391-396.
[4]Camargo CA, Madden JF, Gao W, Selvan RS, Clavien PA. Interleukin-6 protects liver against warm ischemia/reperfusion injury and promotes hepatocyte proliferation in the rodent[J]. Hepatology, 1997, 26(6): 1513-1520.
[5]Wang YY, Dahle MK, Steffensen KR, Reinholt FP, Collins JL, Thiemermann C, et al. Liver X receptor agonist GW3965 dose-dependently regulates lps-mediated liver injury and modulates posttranscriptional TNF-alpha production and p38 mitogen-activated protein kinase activation in liver macrophages[J]. Shock, 2009, 32(5): 548-553.
[6]Thomson RK, Arthur MJ. Mechanisms of liver cell damage and repair[J]. Eur J Gastroenterol Hepatol, 1999, 11(9): 949-955.
[7]Shibayama Y, Asaka S, Nishijima A, Nakata K. A study of endotoxin-associated hepatotoxicity on proliferating hepatocytes[J]. Exp Mol Pathol, 1992, 56(1): 70-75.
[8]Ishii K, Ito Y, Katagiri H, Matsumoto Y, Kakita A, Majima M. Neutrophil elastase inhibitor attenuates lipopolysaccharide-induced hepatic microvascular dysfunction in mice[J]. Shock, 2002, 18(2): 163-168.
[9]Qiu Z, Kwon AH, Tsuji K, Kamiyama Y, Okumura T, Hirao Y. Fibronectin prevents D-galactosamine /lipopolysaccharide-induced lethal hepatic failure in mice[J]. Shock, 2006, 25(1): 80-87.
[10]Dhainaut JF, Marin N, Mignon A, Vinsonneau C. Hepatic response to sepsis: interaction between coagulation and inflammatory[J]. Crit Care Med, 2001, 29(7 Suppl): S42-47.
[11]Amacher DE. A toxicologist′s guide to biomarkers of hepatic response[J]. Hum Exp Toxicol, 2002, 21(5): 253-262.
[12]Ozer J, Ratner M, Shaw M, Bailey W, Schomaker S. The current state of serum biomarkers of hepatotoxicity[J]. Toxicology, 2008, 245(3): 194-205.
[13]Monsalve E, Ruiz-García A, Baladrón V, Ruiz-Hidalgo MJ, Sánchez-Solana B, Rivero S, et al. Notch1 upregulates LPS-induced macrophage activation by increasing NF-kappaB activity[J]. Eur J Immunol, 2009, 39(9): 2556-2570.
[14]Maeda S, Hikiba Y, Sakamoto K, Nakagawa H, Hirata Y, Hayakawa Y, et al. Ikappa B kinasebeta/nuclear factor-kappaB activation controls the development of liver metastasis by way of interleukin-6 expression[J]. Hepatology, 2009, 50(6): 1851-1860.
[15]Blackwell TS, Christman JW. The role of nuclear factor-kappa B in cytokine gene regulation[J]. Am J Respir Cell Mol Biol, 1997, 17(1): 3-9.
[16]Sethi G, Ahn KS, Aggarwal BB. Targeting nuclear factor-kappa B activation pathway by thymoquinone: role in suppression of antiapoptotic gene products and enhancement of apoptosis[J]. Mol Cancer Res, 2008, 6(6): 1059-1070.
[17]Ciucci A, Gianferretti P, Piva R, Guyot T, Snape TJ, Roberts SM, et al. Induction of apoptosis in estrogen receptor-negative breast cancer cells by natural and synthetic cyclopentenones: role of the IkappaB kinase/nuclear factor-kappaB pathway[J]. Mol Pharmacol, 2006, 70(5): 1812-1821.
[19]Lin ST, Wang Y, Xue Y, Feng DC, Xu Y, Xu LY. Tetrandrine suppresses LPS-induced astrocyte activation via modulating IKKs-IkappaBalpha-NF-kappaB signaling pathway[J]. Mol Cell Biochem, 2008, 315(1-2): 41-94.
[20]Jeschke MG, Barrow RE, Suzuki F, Rai J, Benjamin D, Herndon DN. IGF-I/IGFBP-3 equilibrates ratios of pro-to anti-inflammatory cytokines, which are predictors for organ function in severely burned pediatric patients[J]. Mol Med, 2002, 8(5): 238-246.