Cholesterol Depletion in Cell Membranes of Human Airway Epithelial Cells Suppresses MUC5AC Gene Expression

다국어 초록 (Multilingual Abstract)

Purpose: If cholesterol in the cell membrane is depleted by treating cells with methyl-β-cyclodextrin (MβCD), the activities of transmembrane receptors are altered in a cell-specific and/or receptor-specific manner. The proinflammatory cytokines,IL-1β is potent inducers of MUC5AC mRNA and protein synthesis in human airway epithelial cells. Cells activated by IL-1β showed increased phosphorylation of extracellular signal regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). Thus, we investigated the effects of cholesterol depletion on the expression of MUC5AC in human airway epithelial cells and whether these alterations to MUC5AC expression were related to MAPK activity. Materials and Methods: After NCI-H292 cells were pretreated with 1% MβCD before adding IL-1β for 24 hours, MUC5AC mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and real time-PCR. Cholesterol depletion by MβCD was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK and p38 MAPK, was analyzed by western blot. Results: Cholesterol in the cell membrane was significantly depleted by treatment with MβCD on cells. IL-1β-induced MUC5AC mRNA expression was decreased by MβCD and this decrease occurred IL-1-receptor-specifically. Moreover, we have shown that MβCD suppressed the activation of ERK1/2 and p38 MAPK in cells activated with IL-1β. This result suggests that MβCD-mediated suppression of IL-1β-induced MUC5AC mRNA operated via the ERK- and p38 MAPK-dependent pathway. Conclusion: Cholesterol depletion in NCI-H292 cell membrane may be considered an anti-hypersecretory method since it effectively inhibits mucus secretion of respiratory epithelial cells.

참고문헌 (Reference)

1 Kim JH, "[6]-Gingerol suppresses interleukin-1 beta-induced MUC5AC gene expression in human airway epithelial cells" 23 : 385-391, 2009

2 Lee JH, "Type I IL-1 receptor (IL-1RI) as potential new therapeutic target for bronchial asthma" 2010 : 567351-, 2010

3 Edidin M, "The state of lipid rafts: from model membranes to cells" 32 : 257-283, 2003

4 Zuo W, "Specific activation of mitogen-activated protein kinase by transforming growth factor-beta receptors in lipid rafts is required for epithelial cell plasticity" 20 : 1020-1029, 2009

5 Maxfield FR, "Role of cholesterol and lipid organization in disease" 438 : 612-621, 2005

6 Burger K, "Regulation of receptor function by cholesterol" 57 : 1577-1592, 2000

7 Wickström C, "MUC5B is a major gel-forming, oligomeric mucin from human salivary gland, respiratory tract and endocervix: identification of glycoforms and C-terminal cleavage" 334 : 685-693, 1998

8 Hovenberg HW, "MUC5AC, but not MUC2, is a prominent mucin in respiratory secretions" 13 : 839-847, 1996

9 Calleros L, "Low cell cholesterol levels increase NFkappaB activity through a p38 MAPK-dependent mechanism" 18 : 2292-2301, 2006

10 Pike LJ, "Lipid rafts: bringing order to chaos" 44 : 655-667, 2003

11 Simons K, "Lipid rafts and signal transduction" 1 : 31-39, 2000

12 Muppidi JR, "Ligand-independent redistribution of Fas (CD95) into lipid rafts mediates clonotypic T cell death" 5 : 182-189, 2004

13 Lambert S, "Ligand-independent activation of the EGFR by lipid raft disruption" 126 : 954-962, 2006

14 Lambert S, "Internalization of EGF receptor following lipid rafts disruption in keratinocytes is delayed and dependent on p38 MAPK activation" 217 : 834-845, 2008

15 Song KS, "Interleukin-1 beta and tumor necrosis factor-alpha induce MUC5AC overexpression through a mechanism involving ERK/p38 mitogen-activated protein kinases-MSK1-CREB activation in human airway epithelial cells" AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC 278 (278): 23243-23250, 2003

16 Cuschieri J, "Implications of lipid raft disintegration: enhanced anti-inflammatory macrophage phenotype" 136 : 169-175, 2004

17 Thornton DJ, "Identification of two glycoforms of the MUC5B mucin in human respiratory mucus. Evidence for a cysteine-rich sequence repeated within the molecule" 272 : 9561-9566, 1997

18 Brown DA, "Functions of lipid rafts in biological membranes" 14 : 111-136, 1998

19 Simons K, "Functional rafts in cell membranes" 387 : 569-572, 1997

20 Bang B, "Disruption of lipid rafts causes apoptotic cell death in HaCaT keratinocytes" 14 : 266-272, 2005

21 Gniadecki R, "Depletion of membrane cholesterol causes ligand-independent activation of Fas and apoptosis" 320 : 165-169, 2004

22 김상민, "Cholesterol, a Major Component of Caveolae, Down-regulates Matrix Metalloproteinase-1 Expression through ERK/JNK Pathway in Cultured Human Dermal Fibroblasts" 대한피부과학회 22 (22): 379-388, 2010

23 Jans R, "Cholesterol depletion upregulates involucrin expression in epidermal keratinocytes through activation of p38" 123 : 564-573, 2004

24 Chen X, "Cholesterol depletion from the plasma membrane triggers ligand-independent activation of the epidermal growth factor receptor" 277 : 49631-49637, 2002

25 Garofalo T, "Association of the death-inducing signaling complex with microdomains after triggering through CD95/Fas. Evidence for caspase-8-ganglioside interaction in T cells" 278 : 8309-8315, 2003