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. 2016 Jan;57(1):260-4.
doi: 10.3349/ymj.2016.57.1.260.

α-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-κB in H. pylori-Infected Gastric Epithelial AGS Cells

Affiliations

α-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-κB in H. pylori-Infected Gastric Epithelial AGS Cells

Ji Hyun Choi et al. Yonsei Med J. 2016 Jan.

Abstract

The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. α-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether α-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-κB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without α-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-κB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-κB in AGS cells, which was inhibited by α-lipoic acid. In conclusion, α-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.

Keywords: Helicobacter pylori; IL-8; Jak/Stat; MAPK; NF-κB; α-lipoic acid.

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Conflict of interest statement

The authors have no financial conflicts of interest.

Figures

Fig. 1
Fig. 1. mRNA and protein levels of IL-8 in H. pylori-infected AGS cells treated with or without α-LA. (A and B) The cells were cultured in the presence of H. pylori for indicated time points. mRNA levels of IL-8 were determined by real-time PCR. IL-8 mRNA levels were normalized to β-actin (A). IL-8 levels in the medium were assessed by ELISA (B). (C and D) The cells were pre-treated with α-LA for 2 h, and cultured in the presence of H. pylori for 3 h (IL-8 mRNA level, C) or 8 h (IL-8 level in the medium, D). All values are expressed as mean±SEM of four different experiments. *p<0.05 vs. 0 h (A and B) or control (C and D). Non (none), the cells cultured in the absence of H. pylori without treatment of α-LA; Con (control), the cells cultured in the presence of H. pylori without treatment of α-LA. H. pylori, Helicobacter pylori; α-LA, α-lipoic acid; ELISA, enzyme linked immunosorbent assay; IL, interleukin; SEM, standard error of means; AGS, gastric adenocarcinoma.
Fig. 2
Fig. 2. ROS levels, activation of NF-κB, MAPK, and Jak/Stat in H. pylori-infected AGS cells treated with or without α-LA. The cells were pretreated with α-LA for 2 h and cultured in the presence of H. pylori for 30 min (ROS levels, activation of NF-κB, MAPK, and Jak/Stat) or 1 h (NF-κB). (A) ROS levels were determined using DCF fluorescence. All values are expressed as mean±SEM of four different experiments. (B) NF-κB activation was determined using EMSA, performing western blotting for phospho- and total forms of IκBα. (C and D) The levels of phospho-specific and total forms of MAPK (ERK1/2, JNK1/2, p38, C) and Jak1, Jak2, Stat3 (D) in whole cell lysates were determined by Western blot analysis. Non (none), the cells cultured in the absence of H. pylori without treatment of α-LA; Con (control), the cells cultured in the presence of H. pylori without treatment of α-LA. *p<0.05 vs. control. H. pylori, Helicobacter pylori; ROS, reactive oxygen species; MAPK, mitogen-activated protein kinases; α-LA, α-lipoic acid; EMSA, electrophoretic mobility shift assay; ERK, extracellular signal-regulated kinase; JNK, c-Jun NH2-terminal protein kinase; Jak/Stat, janus kinase/signal transducers and activators of transcription; NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells; AGS, gastric adenocarcinoma; DCF, 2',7'-dichlorodihydrofluorescein.

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References

    1. Peek RM, Jr, Blaser MJ. Helicobacter pylori and gastrointestinal tract adenocarcinomas. Nat Rev Cancer. 2002;2:28–37. - PubMed
    1. Fan XG, Chua A, Fan XJ, Keeling PW. Increased gastric production of interleukin-8 and tumour necrosis factor in patients with Helicobacter pylori infection. J Clin Pathol. 1995;48:133–136. - PMC - PubMed
    1. Seo JH, Lim JW, Kim H, Kim KH. Helicobacter pylori in a Korean isolate activates mitogen-activated protein kinases, AP-1, and NF-kappaB and induces chemokine expression in gastric epithelial AGS cells. Lab Invest. 2004;84:49–62. - PubMed
    1. Kim H. Oxidative stress in Helicobacter pylori-induced gastric cell injury. Inflammopharmacology. 2005;13:63–74. - PubMed
    1. O'Shea JJ, Gadina M, Schreiber RD. Cytokine signaling in 2002: new surprises in the Jak/Stat pathway. Cell. 2002;109:S121–S131. - PubMed

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