1.Scaffold protein MAPK8IP2 expression is a robust prognostic factor in prostate cancer associated with AR signaling activity.
Jian HUANG ; Wang LIU ; Bi-Yun LIN ; Jean C LI ; Jane LU ; Ben-Yi LI
Asian Journal of Andrology 2023;25(2):198-207
Mitogen-activated protein kinase-8-interacting protein 2 (MAPK8IP2) is a scaffold protein that modulates MAPK signal cascades. Although MAPK pathways were heavily implicated in prostate cancer progression, the regulation of MAPK8IP2 expression in prostate cancer is not yet reported. We assessed MAPK8IP2 gene expression in prostate cancer related to disease progression and patient survival outcomes. MAPK8IP2 expression was analyzed using multiple genome-wide gene expression datasets derived from The Cancer Genome Atlas (TCGA) RNA-sequence project and complementary DNA (cDNA) microarrays. Multivariable Cox regressions and log-rank tests were used to analyze the overall survival outcome and progression-free interval. MAPK8IP2 protein expression was evaluated using the immunohistochemistry approach. The quantitative PCR and Western blot methods analyzed androgen-stimulated MAPK8IP2 expression in LNCaP cells. In primary prostate cancer tissues, MAPK8IP2 mRNA expression levels were significantly higher than those in the case-matched benign prostatic tissues. Increased MAPK8IP2 expression was strongly correlated with late tumor stages, lymph node invasion, residual tumors after surgery, higher Gleason scores, and preoperational serum prostate-specific antigen (PSA) levels. MAPK8IP2 upregulation was significantly associated with worse overall survival outcomes and progression-free intervals. In castration-resistant prostate cancers, MAPK8IP2 expression strongly correlated with androgen receptor (AR) signaling activity. In cell culture-based experiments, MAPK8IP2 expression was stimulated by androgens in AR-positive prostate cancer cells. However, MAPK8IP2 expression was blocked by AR antagonists only in androgen-sensitive LNCaP but not castration-resistant C4-2B and 22RV1 cells. These results indicate that MAPK8IP2 is a robust prognostic factor and therapeutic biomarker for prostate cancer. The potential role of MAPK8IP2 in the castration-resistant progression is under further investigation.
Male
;
Humans
;
Androgens/therapeutic use*
;
Receptors, Androgen/genetics*
;
Prognosis
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Cell Line, Tumor
;
Prostatic Neoplasms/pathology*
;
Prostatic Neoplasms, Castration-Resistant/drug therapy*
;
Gene Expression Regulation, Neoplastic
2.Mechanism of Shaofu Zhuyu Decoction in treatment of endometriosis-associated dysmenorrhea with syndrome of cold coagulation and blood stasis based on MSK1/2.
Yuan-Huan CHEN ; Hai-Yan MAO ; Quan-Sheng WU ; Xiao-Hua ZHANG ; Jian SHEN ; Peng FENG ; Can-Can HUANG ; Xiu-Jia JI
China Journal of Chinese Materia Medica 2022;47(17):4674-4681
This study aims to decipher the mechanism underlying the effect of Shaofu Zhuyu Decoction on endometriosis(EMT)-associated dysmenorrhea in rats with the syndrome of cold coagulation and blood stasis based on mitogen-and stress-activated protein kinase 1/2(MSK1/2).We employed a random number table to randomly assign SPF female non-pregnant rats into the sham group, and treated the rest rats with autologous transplantation+refrigerator freezing for the modeling of the syndrome of cold coagulation and blood stasis.The modeled rats were then randomly assigned into the control group and high-, medium-and low-dose Shaofu Zhuyu Decoction groups.The rats in the low-, medium-, and high-dose decoction groups were respectively administrated with 9, 4.5, and 2.3 g·kg~(-1) decoction through gavage once a day for 2 consecutive weeks, and those in the control group were administrated with 0.24 mg·kg~(-1) gestrinone through gavage once every 3 days for 2 weeks.After that, the size of ectopic focus in each rat was measured via laparotomy.Enzyme-linked immunosorbent assay(ELISA) was adopted to determine the expression of interleukin(IL)-6, IL-10, prostaglandin E2(PGE2), tumor necrosis factor-α(TNF-α).Western blot was employed to determine the protein levels of MSK1/2 and dual-specificity phosphatase 1(DUSP1) and real-time quantitative polymerase chain reaction(RT-PCR) to determine the mRNA levels of the two genes in rat eutopic endometrial tissue.Compared with the sham group, the model group showed increased levels of IL-6, PGE2, and TNF-α while decrease level of IL-10 in the serum(P<0.01).Compared with the model group, the high-and medium-dose decoction groups and the gestrinone group had declined levels of IL-6, PGE2, and TNF-α while risen level of IL-10 in the serum(P<0.01).The model group had lower protein levels and mRNA levels of MSK1/2 and DUSP1 in the eutopic endometrial tissue than the sham group(P<0.01). The high-and medium-dose decoction groups and the gestrinone group had higher protein and mRNA levels of MSK1/2 and DUSP1 in the eutopic endometrial tissue than the model group(P<0.01).The results indicated that Shaofu Zhuyu Decoction can regulate the abnormal expression of pro-inflammatory cytokines TNF-α, IL-6, and PGE2 and anti-inflammatory cytokines IL-10 and DUSP1 via MSK1/2 to alleviate EMT-associated dysmenorrhea in rats with the syndrome of cold coagulation and blood stasis.
Animals
;
Female
;
Rats
;
Anti-Inflammatory Agents/therapeutic use*
;
Cytokines
;
Dinoprostone
;
Drugs, Chinese Herbal/therapeutic use*
;
Dual-Specificity Phosphatases
;
Dysmenorrhea/genetics*
;
Endometriosis/genetics*
;
Gestrinone/therapeutic use*
;
Interleukin-10
;
Interleukin-6
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Mitogens/therapeutic use*
;
RNA, Messenger
;
Tumor Necrosis Factor-alpha/metabolism*
3.Mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination in treatment of bronchial asthma based on network pharmacology and experimental verification.
Bei-Bei ZHANG ; Meng-Nan ZENG ; Qin-Qin ZHANG ; Ru WANG ; Ju-Fang JIA ; Peng-Li GUO ; Meng LIU ; Wei-Sheng FENG ; Xiao-Ke ZHENG
China Journal of Chinese Materia Medica 2022;47(18):4996-5007
This study aims to investigate mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination(MT) in the treatment of bronchial asthma based on network pharmacology and in vivo experiment, which is expected to lay a theoretical basis for clinical application of the combination. First, the potential targets of MT in the treatment of bronchial asthma were predicted based on network pharmacology, and the "Chinese medicine-active component-target-pathway-disease" network was constructed, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the potential targets. Molecular docking was used to determine the binding activity of key candidate active components to hub genes. Ovalbumin(OVA, intraperitoneal injection for sensitization and nebulization for excitation) was used to induce bronchial asthma in rats. Rats were classified into control group(CON), model group(M), dexamethasone group(DEX, 0.075 mg·kg~(-1)), and MT(1∶1.5) group. Hematoxylin and eosin(HE), Masson, and periodic acid-Schiff(PAS) staining were performed to observe the effect of MT on pathological changes of lungs and trachea and goblet cell proliferation in asthma rats. The levels of transforming growth factor(TGF)-β1, interleukin(IL)6, and IL10 in rat serum were detected by enzyme-linked immunosorbent assay(ELISA), and the mRNA and protein levels of mitogen-activated protein kinase 8(MAPK8), cyclin D1(CCND1), IL6, epidermal growth factor receptor(EGFR), phosphatidylinositol 3-kinase(PI3 K), and protein kinase B(Akt) by qRT-PCR and Western blot. Network pharmacology predicted that MAPK8, CCND1, IL6, and EGFR were the potential targets of MT in the treatment of asthma, which may be related to PI3 K/Akt signaling pathway. Quercetin and β-sitosterol in MT acted on a lot of targets related to asthma, and molecular docking results showed that quercetin and β-sitosterol had strong binding activity to MAPK, PI3 K, and Akt. In vivo experiment showed that MT could effectively alleviate the symptoms of OVA-induced asthma rats, improve the pathological changes of lung tissue, reduce the production of goblet cells, inhibit the inflammatory response of asthma rats, suppress the expression of MAPK8, CCND1, IL6, and EGFR, and regulate the PI3 K/Akt signaling pathway. Therefore, MT may relieve the symptoms and inhibit inflammation of asthma rats by regulating the PI3 K/Akt signaling pathway, and quercetin and β-sitosterol are the candidate active components.
Animals
;
Asthma/drug therapy*
;
Cyclin D1
;
Dexamethasone/adverse effects*
;
Drug Combinations
;
Drugs, Chinese Herbal/therapeutic use*
;
Eosine Yellowish-(YS)/adverse effects*
;
Ephedra
;
ErbB Receptors
;
Hematoxylin/therapeutic use*
;
Interleukin-10
;
Interleukin-6
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Molecular Docking Simulation
;
Network Pharmacology
;
Ovalbumin/adverse effects*
;
Periodic Acid/adverse effects*
;
Phosphatidylinositol 3-Kinases
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Quercetin
;
RNA, Messenger
;
Rats
4.The effect of noise exposure on insulin sensitivity in mice may be mediated by the JNK/IRS1 pathway.
Lijie LIU ; Cong FANG ; Jing YANG ; Hongyu ZHANG ; Yi HUANG ; Chuanying XUAN ; Yongfang WANG ; Shengwei LI ; Jun SHA ; Mingming ZHA ; Min GUO
Environmental Health and Preventive Medicine 2018;23(1):6-6
BACKGROUND:
Epidemiological studies have suggested that noise exposure may increase the risk of type 2 diabetes mellitus (T2DM), and experimental studies have demonstrated that noise exposure can induce insulin resistance in rodents. The aim of the present study was to explore noise-induced processes underlying impaired insulin sensitivity in mice.
METHODS:
Male ICR mice were randomly divided into four groups: a control group without noise exposure and three noise groups exposed to white noise at a 95-dB sound pressure level for 4 h/day for 1, 10, or 20 days (N1D, N10D, and N20D, respectively). Systemic insulin sensitivity was evaluated at 1 day, 1 week, and 1 month post-noise exposure (1DPN, 1WPN, and 1MPN) via insulin tolerance tests (ITTs). Several insulin-related processes, including the phosphorylation of Akt, IRS1, and JNK in the animals' skeletal muscles, were examined using standard immunoblots. Biomarkers of inflammation (circulating levels of TNF-α and IL-6) and oxidative stress (SOD and CAT activities and MDA levels in skeletal muscles) were measured via chemical analyses.
RESULTS:
The data obtained in this study showed the following: (1) The impairment of systemic insulin sensitivity was transient in the N1D group but prolonged in the N10D and N20D groups. (2) Noise exposure led to enhanced JNK phosphorylation and IRS1 serine phosphorylation as well as reduced Akt phosphorylation in skeletal muscles in response to exogenous insulin stimulation. (3) Plasma levels of TNF-α and IL-6, CAT activity, and MDA concentrations in skeletal muscles were elevated after 20 days of noise exposure.
CONCLUSIONS
Impaired insulin sensitivity in noise-exposed mice might be mediated by an enhancement of the JNK/IRS1 pathway. Inflammation and oxidative stress might contribute to insulin resistance after chronic noise exposure.
Animals
;
Biomarkers
;
metabolism
;
Inflammation
;
physiopathology
;
Insulin Receptor Substrate Proteins
;
genetics
;
metabolism
;
Insulin Resistance
;
genetics
;
immunology
;
MAP Kinase Signaling System
;
physiology
;
Male
;
Mice
;
Mice, Inbred ICR
;
Mitogen-Activated Protein Kinase 8
;
genetics
;
metabolism
;
Noise
;
adverse effects
;
Oxidative Stress
;
physiology
;
Proto-Oncogene Proteins c-akt
;
genetics
;
metabolism
;
Random Allocation
;
Time Factors
5.Inhibition of Lipopolysaccharide-stimulated Inflammatory Cytokine Production by LY303511 in Human Macrophagic THP-1 Cells.
So Hee KIM ; Yun Woong PAEK ; In Chol KANG
International Journal of Oral Biology 2017;42(3):117-121
We have previously shown that the specific phosphatidylinositol 3-kinase inhibitor LY294002 (LY29), and its inactive analog LY303511 (LY30), inhibit a monocyte chemoattractant protein-1 (MCP-1) expression in human umbilical vein endothelial cells; these results suggest the potential of LY30 as an anti-inflammatory drug. In this study, we determined the effects of LY30 on the production of various inflammatory cytokines in human macrophagic THP-1 cells which were stimulated with lipopolysaccharide (LPS). LY30 selectively suppressed the mRNA expression of IL-12 p40, TNF-α, and MCP-1 without affecting the expression of IL-1α, IL-6, and IL-8. Inhibition of the production of IL-12 and TNF-α by LY30 was also demonstrated using ELISA assays. In order to elucidate the mechanisms of the action of LY30, we examined the role played by the mitogen-activated protein kinases and the key transcription factors, AP-1 and NF-κB in LPS-stimulated THP-1 cells. The results revealed that LY30 inhibited LPS-induced activation of ERK, but not p38 or JNK. Furthermore, the AP-1 DNA binding activity was suppressed by LY30 based upon the dosage, whereas NF-κB DNA binding was not affected. These results suggest that LY30 selectively inhibits cytokine production in the LPS-stimulated macrophagic THP-1 cells by downregulating the activation of ERK and AP-1.
Chemokine CCL2
;
Cytokines
;
DNA
;
Enzyme-Linked Immunosorbent Assay
;
Human Umbilical Vein Endothelial Cells
;
Humans*
;
Interleukin-12
;
Interleukin-6
;
Interleukin-8
;
Mitogen-Activated Protein Kinases
;
Phosphatidylinositol 3-Kinase
;
RNA, Messenger
;
Transcription Factor AP-1
;
Transcription Factors
6.Proteomic analysis of novel targets associated with the enhancement of TrkA-induced SK-N-MC cancer cell death caused by NGF.
Eun Joo JUNG ; Ky Hyun CHUNG ; Dong Won BAE ; Choong Won KIM
Experimental & Molecular Medicine 2016;48(5):e235-
Nerve growth factor (NGF) is known to regulate both cancer cell survival and death signaling, depending on the cellular circumstances, in various cell types. In this study, we showed that NGF strongly upregulated the protein level of tropomyosin-related kinase A (TrkA) in TrkA-inducible SK-N-MC cancer cells, resulting in increases in various TrkA-dependent cellular processes, including the phosphorylation of c-Jun N-terminal kinase (JNK) and caspase-8 cleavage. In addition, NGF enhanced TrkA-induced morphological changes and cell death, and this effect was significantly suppressed by the JNK inhibitor SP600125, but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. To investigate novel targets associated with the enhancement of TrkA-induced SK-N-MC cell death caused by NGF, we performed Coomassie Brilliant Blue staining and two-dimensional (2D) proteomic analysis in TrkA-inducible SK-N-MC cells. We identified 31 protein spots that were either greatly upregulated or downregulated by TrkA during NGF treatment using matrix-associated laser desorption/ionization time of flight/time of flight mass spectrometry, and we analyzed the effects of SP600125 and wortmannin on the spots. Interestingly, 11 protein spots, including heterogeneous nuclear ribonucleoprotein K (hnRNP K), lamin B1 and TAR DNA-binding protein (TDP43), were significantly influenced by SP600125, but not by wortmannin. Moreover, the NGF/TrkA-dependent inhibition of cell viability was significantly enhanced by knockdown of hnRNP K using small interfering RNA, demonstrating that hnRNP K is a novel target associated with the regulation of TrkA-dependent SK-N-MC cancer cell death enhanced by NGF.
Caspase 8
;
Cell Death*
;
Cell Survival
;
Heterogeneous-Nuclear Ribonucleoprotein K
;
JNK Mitogen-Activated Protein Kinases
;
Mass Spectrometry
;
Nerve Growth Factor*
;
Phosphatidylinositol 3-Kinase
;
Phosphorylation
;
Phosphotransferases
;
RNA, Small Interfering
7.alpha-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-Infected Gastric Epithelial AGS Cells.
Ji Hyun CHOI ; Soon Ok CHO ; Hyeyoung KIM
Yonsei Medical Journal 2016;57(1):260-264
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-kappaB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. alpha-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 alpha-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without alpha-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-kappaB-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-kappaB in AGS cells, which was inhibited by alpha-lipoic acid. In conclusion, alpha-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.
Enzyme-Linked Immunosorbent Assay
;
Epithelial Cells/metabolism
;
Gastric Mucosa/*drug effects/metabolism/microbiology
;
Gene Expression Regulation, Bacterial
;
Helicobacter Infections/immunology/*metabolism
;
Helicobacter pylori/drug effects/*pathogenicity
;
Humans
;
Interleukin-8/genetics/*metabolism
;
JNK Mitogen-Activated Protein Kinases
;
Janus Kinase 1
;
Mitogen-Activated Protein Kinases/*biosynthesis
;
NF-kappa B/*metabolism
;
RNA, Messenger/isolation & purification/metabolism
;
Reactive Oxygen Species/metabolism
;
STAT3 Transcription Factor
;
Stomach/metabolism/*microbiology
;
Thioctic Acid/*pharmacology
8.27-O-(E)-p-coumaric acyl ursolic acid via JNK/SAPK signal pathway regulates apoptosis of human breast cancer MDA-MB-231 cell line.
China Journal of Chinese Materia Medica 2015;40(4):722-726
27-O-(E)-p-coumaric acyl ursolic acid( DY-17) from Ilex latifolia is a compound of the monomer. To investigate the DY-17 inducing apoptosis in the human breast cancer cell line, the MDA-MB-231 cells were used as research object in this experiment. The proliferation activity of the MDA-MB-231 cells stimulated with the different concentrations of DY-17 (20, 40 µmol · L(-1)) was detected at different time( 12, 24, 36, 48, 60,72 h) . We surveyed the DY-17 inducing apoptosis of the MDA-MB-231 cells with the fluorescent staining technology. The rate of MDA-MB-231 cells apoptosis and necrosis was determined by flow cell cytometry (FCC). Moreover, expression of JNK, phosphorylated JNK, Bax, PARP shear and caspase-3 shear related to JNK/SAPK pathways were investigated in every group ( control group, EGF group, EGF + DY-17 40 µmol · L(1) group and EGF + SP600125 group) with Western blot. The MTT results showed that, in the presence of DY-17, the proliferation activity of MDA-MB-231 cells decreased in a dose-dependent and time-dependent manner. The apoptosis and necrosis rates of MDA-MB-231 cells with DY-17(20, 40 µmol · L(-1)) groups was respectively 31.86%, 49.91% by flow cytometry and significantly increased compared with control group under Fluores- cence microscopy. Up-regulation of the JNK phosphorylation protein expression was observed in EGF group compared with control group. In addition, markedly decreased the expression of JNK phosphorylation protein were also surveyed in EGF + DY-17 40 µmol · L(-1) group compared with EGF group. The expression of Bax, shear PARP and shear caspase-3 protein in EGF + DY-17 40 µmol · L(-1) group were significantly increased in comparison with EGF group. The results showed DY-17 induced apoptosis of human breast cancer MDA-MB-231 cell line related to down-regulating JNK/SAPK signal pathways.
Apoptosis
;
drug effects
;
Breast Neoplasms
;
drug therapy
;
enzymology
;
genetics
;
Cell Line, Tumor
;
Cell Proliferation
;
drug effects
;
Drugs, Chinese Herbal
;
pharmacology
;
Female
;
Humans
;
MAP Kinase Kinase 4
;
genetics
;
metabolism
;
Mitogen-Activated Protein Kinase 8
;
genetics
;
metabolism
;
Signal Transduction
;
drug effects
;
Triterpenes
;
chemistry
;
pharmacology
9.Effects of hydrogen sulfide on myocardial fibrosis and MAPK1/3 and MMP-8 expression in diabetic rats.
Fang LI ; Ou ZENG ; Jian LUO ; Zhi-Xiong WU ; Ting XIAO ; Jing-Jing ZHANG ; Jun YANG
Journal of Southern Medical University 2015;35(4):549-552
OBJECTIVETo explore the effects of hydrogen sulfide (H(2)S) on myocardial fibrosis and expressions of MAPK1/3 and MMP-8 in diabetic rats.
METHODSForty adult male SD rats were randomized into 4 groups, namely the control group, diabetes mellitus group (STZ group), diabetes mellitus with H(2)S treatment group (STZ+H(2)S group), and normal rats with H(2)S treatment group (H(2)S group). Diabetes was induced by intraperitoneal injections of 40 mg/kg streptozotocin (STZ). The rats in the control group received daily intraperitoneal injections of saline, and those in STZ+H(2)S group and H(2)S group were given NaHS (100 µmol/kg) injections. After 8 weeks, the pathologies of cardiac fibrosis were examined with HE staining, and the expressions of collagen I, MAPK1/3 and MMP-8 were analyzed with Western blotting.
RESULTSCompared with the control group, the diabetic rats showed increased collagen content and obvious interstitial fibrosis in the myocardial tissue with significantly increased expression levels of collagen I, MAPK1/3 and MMP-8 (P<0.05); all these changes were obviously reversed by treatment with H(2)S (P<0.05). Collagen I, MAPK1/3 and MMP-8 expression levels and the degree of myocardial fibrosis were comparable between H(2)S group and control group (P>0.05).
CONCLUSIONHydrogen sulfide can attenuate cardiac fibrosis in diabetic rats, and the mechanism may involve the inhibition of MAPK1/3/MMP-8 signal pathway.
Animals ; Collagen Type I ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Fibrosis ; Hydrogen Sulfide ; pharmacology ; Injections, Intraperitoneal ; Male ; Matrix Metalloproteinase 8 ; metabolism ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocardium ; pathology ; Rats ; Rats, Sprague-Dawley
10.Effect of Cholesterol Depletion on Interleukin-8 Production in Human Respiratory Epithelial Cells.
Min Jung KIM ; Jung Yeon HONG ; Kyung Eun LEE ; Kyung Won KIM ; Myung Hyun SOHN ; Kyu Earn KIM
Allergy, Asthma & Immunology Research 2013;5(6):402-408
PURPOSE: The lipid entities of cell membranes are components of the immune system and important mediators of inflammation. Despite increasing interest in the function of epithelial cells in inflammation, the role of cholesterol in this process has not been described. Here, we investigated the effect of cholesterol depletion on the inflammatory process in airway epithelial cells via the expression of interleukin (IL)-8 as a marker of inflammation. METHODS: A 549 cells were treated with 0.5% methyl-beta-cyclodextrin as a selective cholesterol extractor. The IL-8 level was assessed by enzyme-linked immunosorbent assay and reassessed after cholesterol repletion. Mitogen-activated protein kinase (MAPK) inhibitors were used to determine the upstream signaling pathway for IL-8 production in cholesterol-depleted cells. RESULTS: We found a relationship between the amount of cholesterol in A 549 cells and inflammation of the airway. IL-8 production was increased in cholesterol-depleted A 549 cells and restored by cholesterol repletion. IL-8 production was decreased by pretreatment with the extracellular signal-regulated kinase (ERK) inhibitor U0126 but not with JNK inhibitor II or the p38 MAPK inhibitor SB202190. CONCLUSIONS: Our findings suggest that inflammatory responses are increased in cholesterol-depleted epithelial cells via the MAPK signaling system, predominantly by the ERK pathway. We conclude that the lipid components of airwayepithelial cells may play a role in the inflammatory process.
beta-Cyclodextrins
;
Butadienes
;
Cell Membrane
;
Cholesterol
;
Enzyme-Linked Immunosorbent Assay
;
Epithelial Cells
;
Humans
;
Immune System
;
Inflammation
;
Inflammation Mediators
;
Interleukin-8
;
Interleukins
;
MAP Kinase Signaling System
;
Nitriles
;
p38 Mitogen-Activated Protein Kinases
;
Phosphotransferases
;
Protein Kinases

Result Analysis
Print
Save
E-mail