Klotho expression is reduced in COPD airway epithelial cells: effects on inflammation and oxidant injury

Clin Sci (Lond). 2015 Dec;129(12):1011-23. doi: 10.1042/CS20150273. Epub 2015 Jul 10.


COPD (chronic obstructive pulmonary disease) is associated with sustained inflammation, excessive injury, and accelerated lung aging. Human Klotho (KL) is an anti-aging protein that protects cells against inflammation and damage. In the present study, we quantified KL expression in the lungs of COPD patients and in an ozone-induced mouse model of COPD, and investigated the mechanisms that control KL expression and function in the airways. KL distribution and levels in human and mouse airways were measured by immunohistochemistry and Western blotting. The effect of CSE (cigarette smoke extract) on KL expression was detected in human bronchial epithelial cells. Moreover, the effect of KL on CSE-mediated inflammation and hydrogen peroxide-induced cellular injury/apoptosis was determined using siRNAs. KL expression was decreased in the lungs of smokers and further reduced in patients with COPD. Similarly, 6 weeks of exposure to ozone decreased KL levels in airway epithelial cells. CSE and TNFα (tumour necrosis factor α) decreased KL expression and release from airway epithelial cells, which was associated with enhanced pro-inflammatory cytokine expression. Moreover, KL depletion increased cell sensitivity to cigarette smoke-induced inflammation and oxidative stress-induced cell damage. These effects involved the NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase) and Nrf2 (nuclear factor erythroid 2-related factor 2) pathways. Reduced KL expression in COPD airway epithelial cells was associated with increased oxidative stress, inflammation and apoptosis. These data provide new insights into the mechanisms associated with the accelerated lung aging in COPD development.

Keywords: bronchial epithelial cells; chronic obstructive pulmonary disease (COPD); cytokines; klotho protein; oxidative stress; smoke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Case-Control Studies
  • Cell Line
  • Disease Models, Animal
  • Down-Regulation
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Glucuronidase / genetics
  • Glucuronidase / metabolism*
  • Humans
  • Inflammation Mediators / toxicity
  • Klotho Proteins
  • Lung / metabolism*
  • Lung / pathology
  • Male
  • Mice, Inbred C57BL
  • Mitogen-Activated Protein Kinases / metabolism
  • NF-E2-Related Factor 2 / metabolism
  • NF-kappa B / metabolism
  • Oxidants / toxicity
  • Oxidative Stress*
  • Ozone
  • Pneumonia / chemically induced
  • Pneumonia / genetics
  • Pneumonia / metabolism*
  • Pneumonia / pathology
  • Pulmonary Disease, Chronic Obstructive / chemically induced
  • Pulmonary Disease, Chronic Obstructive / genetics
  • Pulmonary Disease, Chronic Obstructive / metabolism*
  • Pulmonary Disease, Chronic Obstructive / pathology
  • Pulmonary Emphysema / chemically induced
  • Pulmonary Emphysema / genetics
  • Pulmonary Emphysema / metabolism*
  • Pulmonary Emphysema / pathology
  • RNA Interference
  • Signal Transduction
  • Smoke / adverse effects
  • Time Factors
  • Transfection


  • Inflammation Mediators
  • NF-E2-Related Factor 2
  • NF-kappa B
  • NFE2L2 protein, human
  • Oxidants
  • Smoke
  • Ozone
  • Mitogen-Activated Protein Kinases
  • Glucuronidase
  • Klotho Proteins