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Role of AMP-Activated Protein Kinase (AMPK) in Smoking-Induced Lung Inflammation and Emphysema.

Lee JS, Park SJ, Cho YS, Huh JW, Oh YM, Lee SD - Tuberc Respir Dis (Seoul) (2015)

Bottom Line: Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence.We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells.CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an AMPKα1-specific small interfering RNA.

View Article: PubMed Central - PubMed

Affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

ABSTRACT

Background: AMP-activated protein kinase (AMPK) not only functions as an intracellular energy sensor and regulator, but is also a general sensor of oxidative stress. Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence. Thus, it may oppose the development of chronic obstructive pulmonary disease.

Methods: To investigate the role of AMPK in cigarette smoke-induced lung inflammation and emphysema we first compared cigarette smoking and polyinosinic-polycytidylic acid [poly(I:C)]-induced lung inflammation and emphysema in AMPKα1-deficient (AMPKα1-HT) mice and wild-type mice of the same genetic background. We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells.

Results: Cigarette smoking and poly(I:C)-induced lung inflammation and emphysema were elevated in AMPKα1-HT compared to wild-type mice. CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an AMPKα1-specific small interfering RNA.

Conclusion: AMPKα1-deficient mice have increased susceptibility to lung inflammation and emphysema when exposed to cigarette smoke, and AMPK appears to reduce lung inflammation and emphysema by lowering IL-8 production.

No MeSH data available.


Related in: MedlinePlus

AMPK plays a vital role in the induction of IL-8 by CSE in A549 cells. (A, C) Cells were incubated with medium alone or exposed to 3% CSE for 3 hours after pretreatment with AICAR (1 mM) and Compound C (5 µM). (B, D) Cells were incubated with medium alone or exposed to 3% CSE for 24 hours after pretreatment with 10 nM AMPK siRNA or negative siRNA. Protein levels in cell lysates (A, B) were analyzed by Western blot, and protein levels in culture media (C, D) by enzyme-linked immunosorbent assay. The immunoblot results are representative of three independent experiments. AMPK: AMP-activated protein kinase; CSE: cigarette smoke extract; AICAR: 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside; IL-8: interleukin 8; DMSO: dimethyl sulfoxide. Data in each group are means±SEM (n=3). *p<0.05, vs. medium only. †p<0.05 vs CSE without drug or siRNA treatment.
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Figure 5: AMPK plays a vital role in the induction of IL-8 by CSE in A549 cells. (A, C) Cells were incubated with medium alone or exposed to 3% CSE for 3 hours after pretreatment with AICAR (1 mM) and Compound C (5 µM). (B, D) Cells were incubated with medium alone or exposed to 3% CSE for 24 hours after pretreatment with 10 nM AMPK siRNA or negative siRNA. Protein levels in cell lysates (A, B) were analyzed by Western blot, and protein levels in culture media (C, D) by enzyme-linked immunosorbent assay. The immunoblot results are representative of three independent experiments. AMPK: AMP-activated protein kinase; CSE: cigarette smoke extract; AICAR: 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside; IL-8: interleukin 8; DMSO: dimethyl sulfoxide. Data in each group are means±SEM (n=3). *p<0.05, vs. medium only. †p<0.05 vs CSE without drug or siRNA treatment.

Mentions: To determine whether AMPK is involved in the CSE-induced IL-8 production, A549 cells were pretreated with AICAR (1 mM) and Compound C (10 µM) for 5 hours, and then exposed to 3% CSE for 30 minutes. Cell lysates were subjected to immunoblot analysis and supernatant IL-8 was measured by ELISA. As shown in Figure 5A and C, AICAR decreased the CSE-induced IL-8 production and Compound C increased it. In addition, pretreatment with AMPK siRNA (10 nM) increased the CSE-induced IL-8 production, whereas sham pretreatment or negative (control) siRNA failed to have an effect (Figure 5B, D).


Role of AMP-Activated Protein Kinase (AMPK) in Smoking-Induced Lung Inflammation and Emphysema.

Lee JS, Park SJ, Cho YS, Huh JW, Oh YM, Lee SD - Tuberc Respir Dis (Seoul) (2015)

AMPK plays a vital role in the induction of IL-8 by CSE in A549 cells. (A, C) Cells were incubated with medium alone or exposed to 3% CSE for 3 hours after pretreatment with AICAR (1 mM) and Compound C (5 µM). (B, D) Cells were incubated with medium alone or exposed to 3% CSE for 24 hours after pretreatment with 10 nM AMPK siRNA or negative siRNA. Protein levels in cell lysates (A, B) were analyzed by Western blot, and protein levels in culture media (C, D) by enzyme-linked immunosorbent assay. The immunoblot results are representative of three independent experiments. AMPK: AMP-activated protein kinase; CSE: cigarette smoke extract; AICAR: 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside; IL-8: interleukin 8; DMSO: dimethyl sulfoxide. Data in each group are means±SEM (n=3). *p<0.05, vs. medium only. †p<0.05 vs CSE without drug or siRNA treatment.
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Related In: Results  -  Collection

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Figure 5: AMPK plays a vital role in the induction of IL-8 by CSE in A549 cells. (A, C) Cells were incubated with medium alone or exposed to 3% CSE for 3 hours after pretreatment with AICAR (1 mM) and Compound C (5 µM). (B, D) Cells were incubated with medium alone or exposed to 3% CSE for 24 hours after pretreatment with 10 nM AMPK siRNA or negative siRNA. Protein levels in cell lysates (A, B) were analyzed by Western blot, and protein levels in culture media (C, D) by enzyme-linked immunosorbent assay. The immunoblot results are representative of three independent experiments. AMPK: AMP-activated protein kinase; CSE: cigarette smoke extract; AICAR: 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside; IL-8: interleukin 8; DMSO: dimethyl sulfoxide. Data in each group are means±SEM (n=3). *p<0.05, vs. medium only. †p<0.05 vs CSE without drug or siRNA treatment.
Mentions: To determine whether AMPK is involved in the CSE-induced IL-8 production, A549 cells were pretreated with AICAR (1 mM) and Compound C (10 µM) for 5 hours, and then exposed to 3% CSE for 30 minutes. Cell lysates were subjected to immunoblot analysis and supernatant IL-8 was measured by ELISA. As shown in Figure 5A and C, AICAR decreased the CSE-induced IL-8 production and Compound C increased it. In addition, pretreatment with AMPK siRNA (10 nM) increased the CSE-induced IL-8 production, whereas sham pretreatment or negative (control) siRNA failed to have an effect (Figure 5B, D).

Bottom Line: Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence.We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells.CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an AMPKα1-specific small interfering RNA.

View Article: PubMed Central - PubMed

Affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

ABSTRACT

Background: AMP-activated protein kinase (AMPK) not only functions as an intracellular energy sensor and regulator, but is also a general sensor of oxidative stress. Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence. Thus, it may oppose the development of chronic obstructive pulmonary disease.

Methods: To investigate the role of AMPK in cigarette smoke-induced lung inflammation and emphysema we first compared cigarette smoking and polyinosinic-polycytidylic acid [poly(I:C)]-induced lung inflammation and emphysema in AMPKα1-deficient (AMPKα1-HT) mice and wild-type mice of the same genetic background. We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells.

Results: Cigarette smoking and poly(I:C)-induced lung inflammation and emphysema were elevated in AMPKα1-HT compared to wild-type mice. CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an AMPKα1-specific small interfering RNA.

Conclusion: AMPKα1-deficient mice have increased susceptibility to lung inflammation and emphysema when exposed to cigarette smoke, and AMPK appears to reduce lung inflammation and emphysema by lowering IL-8 production.

No MeSH data available.


Related in: MedlinePlus