Abstract：Objective To investigate the effects of Toll-like receptor blockers TLR2-Ab and TLR4-Ab on the tight junction protein ZO-1 in intestinal epithelial cells in mice, as well as their effects on nuclear factor-kappa B (NF-κB) and tumor necrosis factor-α (TNF-α).Methods A total of 32 BALB/C mice were divided into control group, model group, TLR4 treatment group, and TLR2 treatment group, with 8 mice in each group. A mouse model of endotoxemia was established by intraperitoneal injection of lipopolysaccharide. The mice in the TLR4 treatment group and the TLR2 treatment group were given intraperitoneal injection of TLR4 antibody and TLR2 antibody (10 μg each mouse), respectively, and those in the control group were given normal saline. The distal small intestinal tissue was collected, and RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α.Results Compared with the control group, the model group had significantly lower mRNA and protein expression of ZO-1 and significantly higher mRNA expression of NF-κBp65 and TNF-α (P < 0.05). Compared with the model group, the TLR4 treatment group and the TLR2 treatment group had significantly higher mRNA and protein expression of ZO-1 and significantly lower mRNA and protein expression of NF-κBp65 and TNF-α (P < 0.05). There were no significant differences in the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α between the TLR4 treatment group and the TLR2 treatment group (P > 0.05).Conclusions Anti-TLR2 and anti-TLR4 monoclonal antibodies can reduce the activation of nuclear transcription factors, inhibit the secretion of inflammatory factors, and protect tight junction protein, which is expected to provide new ideas for the treatment of enterogenous infectious diseases.
Shindou H, Ishii S, Yamamoto M, et al. Priming effect of lipopolysaccharide on acetyl-coenzyme A:lyso-platelet-activating factor acetyltransferase is MyD88 and TRIF independent[J]. Immunol, 2005, 175(2):1177-1183.
Zareie M, Riff J, Donato K, et al. Novel effects of the prototype translocating Escherichia coli, strain C25 on intestinal epithelial structure and barrier function[J]. Cell Microbiol, 2005, 7(12):1782-1797.
[8]
Lendemans S, Kreuzfelder E, Rani M, et al. Toll-like recepor 2 and 4 expression after severe injury is not involved in he dysregulation of the innate immune system[J]. J Trauma, 2007, 63(4):740-746.
Yuki T, Yoshida H, Akazawa Y, et al. Activation of TLR2 enhances tight junction barrier in epidermal keratinocytes[J]. J Immunol, 2011, 187(6):3230-3237.
[11]
Boulard O, Asquith MJ, Powrie F, et al. TLR2-independent induction and regulation of chronic intestinal inflammation[J]. Eur J Immunol, 2010, 40(2):516-524.
[12]
González-Mariscal L, Betanzos A, Nava P, et al. Tight junction proteins[J]. Prog Biophys Mol Biol, 2003, 81(1):1-44.
[13]
Huang B, Zhao J, Unkeless JC, et al. TLR signaling by tumor and immune cells:a double-edged sword[J]. Oncogene, 2008, 27(2):218-224.
[14]
Lu YC, Yeh WC, Ohashi PS. LPS/TLR4 signal transduction pathway[J]. Cytokine, 2008, 42(2):145-151.
[15]
Kim TW, Staschke K, Bulek K, et al. A critical role for IRAK 4 kinase activity in Toll-like receptor-mediated innate immunity[J]. J Exp Med, 2007, 204(5):1025-1036.
[16]
Akira S, Uematsu S, Takeuchi O. Pathogen recognition and innate immunity[J]. Cell, 2006, 124(4):783-801.
[17]
Mazzon E, Sturniolo GC, Puzzolo D, et al. Effect of stress on the paracellular barrier in the rat ileum[J]. Gut, 2002, 51(4):507-513.
[18]
Fukata M, Michelsen KS, Eri R, et al. Toll-like receptor-4 is required for intestinal response to epithelial injury and limiting bacterial translocation in a murine model of acute colitis[J]. Am J Physiol Gastrointest Liver Physiol, 2005, 288(5):G1055-G1065.
[19]
Rakoff-Nahoum S, Paglino J, Eslami-Varzaneh F, et al. Recognition of commensal microflora by toll-like receptors is required for intestinal homeostasis[J]. Cell, 2004, 118(2):229-241.
[20]
Cario E, Gerken G, Podolsky DK. Toll-like receptor 2 controls mucosal inflammation by regulating epithelial barrier function[J]. Gastroenterology, 2007, 132(4):1359-1374.
[21]
Ye D, Ma I, Ma TY. Molecular mechanism of tumor necrosis factor-alpha modulation of intestinal epithelial tight junction barrier[J]. Am J Physiol Gastrointest Liver Physiol, 2006, 290(3):G496-G504.
Andonegui G, Goyert SM, Kubes P. Lipopolysaccharide-induced leukocyte-endothelial cell interactions:a role for CD14 versus toll-like receptor 4 within microvessels[J]. J Immunol, 2002, 169(4):2111-2119.
Han X, Fink MP, Delude RL. Proinflammatory cytokines cause NO*-dependent and -independent changes in expression and localization of tight junction proteins in intestinal epithelial cells[J]. Shock, 2003, 19(3):229-237.
Kuo IH, Carpenter-Mendini A, Yoshida T, et al. Activation of epidermal toll-like receptor 2 enhances tight junction function:implications for atopic dermatitis and skin barrier repair[J]. J Invest Dermatol, 2013, 133(4):988-998.
[28]
Ragupathy S, Esmaeili F, Paschoud S, et al. Toll-like receptor 2 regulates the barrier function of human bronchial epithelial monolayers through atypical protein kinase C zeta, and an increase in expression of claudin-1[J]. Tissue Barriers, 2014, 2:e29166.
