Abstract
Human bronchial epithelium is exquisitely sensitive to high O2 levels, with tracheobronchitis usually developing after 12 h of exposure to 100% O2. To evaluate whether this vulnerability results from inability of the bronchial epithelium to provide adequate antioxidant protection, we quantified antioxidant gene expression in bronchial epithelium of normal volunteers at baseline and after exposure to 100% O2 in vivo. After 14.8 ± 0.2 h of 100% O2, 24 of 33 individuals had evidence of tracheobronchitis. Baseline gene expression of CuZn superoxide dismutase (SOD), MnSOD, and catalase in bronchial epithelium was very low (CuZnSOD 4.1 ± 0.8 transcripts/cell, MnSOD 5.1 ± 0.9, catalase 1.3 ± 0.2), with control γ- actin expression relatively abundant (50 ± 6 transcripts/cell). Importantly, despite 100% O2 exposure sufficient to cause tracheobronchitis in most individuals, antioxidant mRNA transcripts/cell in bronchial epithelium did not increase (P > 0.5). Catalase activity in bronchial epithelium did not change after exposure to hyperoxia (P > 0.05). Total SOD activity increased mildly (P < 0.01) but not sufficiently to protect the epithelium. Together, the very low levels of expression of intracellular antioxidant enzymes and the inability to upregulate expression at the mRNA level with oxidant stress likely have a role in human airway epithelium susceptibility to hyperoxia.
| Original language | English |
|---|---|
| Pages (from-to) | 1256-1262 |
| Number of pages | 7 |
| Journal | Journal of Applied Physiology |
| Volume | 75 |
| Issue number | 3 |
| Publication status | Published - 1 Jan 1993 |
| Externally published | Yes |
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Keywords
- catalase
- hyperoxia
- messenger ribonucleic acid
- quantification
- superoxide dismutase
ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
In vivo antioxidant gene expression in human airway epithelium of normal individuals exposed to 100% O2. / Erzurum, S. C.; Danel, C.; Gillissen, A.; Chu, C. S.; Trapnell, B. C.; Crystal, Ronald.
In: Journal of Applied Physiology, Vol. 75, No. 3, 01.01.1993, p. 1256-1262.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - In vivo antioxidant gene expression in human airway epithelium of normal individuals exposed to 100% O2
AU - Erzurum, S. C.
AU - Danel, C.
AU - Gillissen, A.
AU - Chu, C. S.
AU - Trapnell, B. C.
AU - Crystal, Ronald
PY - 1993/1/1
Y1 - 1993/1/1
N2 - Human bronchial epithelium is exquisitely sensitive to high O2 levels, with tracheobronchitis usually developing after 12 h of exposure to 100% O2. To evaluate whether this vulnerability results from inability of the bronchial epithelium to provide adequate antioxidant protection, we quantified antioxidant gene expression in bronchial epithelium of normal volunteers at baseline and after exposure to 100% O2 in vivo. After 14.8 ± 0.2 h of 100% O2, 24 of 33 individuals had evidence of tracheobronchitis. Baseline gene expression of CuZn superoxide dismutase (SOD), MnSOD, and catalase in bronchial epithelium was very low (CuZnSOD 4.1 ± 0.8 transcripts/cell, MnSOD 5.1 ± 0.9, catalase 1.3 ± 0.2), with control γ- actin expression relatively abundant (50 ± 6 transcripts/cell). Importantly, despite 100% O2 exposure sufficient to cause tracheobronchitis in most individuals, antioxidant mRNA transcripts/cell in bronchial epithelium did not increase (P > 0.5). Catalase activity in bronchial epithelium did not change after exposure to hyperoxia (P > 0.05). Total SOD activity increased mildly (P < 0.01) but not sufficiently to protect the epithelium. Together, the very low levels of expression of intracellular antioxidant enzymes and the inability to upregulate expression at the mRNA level with oxidant stress likely have a role in human airway epithelium susceptibility to hyperoxia.
AB - Human bronchial epithelium is exquisitely sensitive to high O2 levels, with tracheobronchitis usually developing after 12 h of exposure to 100% O2. To evaluate whether this vulnerability results from inability of the bronchial epithelium to provide adequate antioxidant protection, we quantified antioxidant gene expression in bronchial epithelium of normal volunteers at baseline and after exposure to 100% O2 in vivo. After 14.8 ± 0.2 h of 100% O2, 24 of 33 individuals had evidence of tracheobronchitis. Baseline gene expression of CuZn superoxide dismutase (SOD), MnSOD, and catalase in bronchial epithelium was very low (CuZnSOD 4.1 ± 0.8 transcripts/cell, MnSOD 5.1 ± 0.9, catalase 1.3 ± 0.2), with control γ- actin expression relatively abundant (50 ± 6 transcripts/cell). Importantly, despite 100% O2 exposure sufficient to cause tracheobronchitis in most individuals, antioxidant mRNA transcripts/cell in bronchial epithelium did not increase (P > 0.5). Catalase activity in bronchial epithelium did not change after exposure to hyperoxia (P > 0.05). Total SOD activity increased mildly (P < 0.01) but not sufficiently to protect the epithelium. Together, the very low levels of expression of intracellular antioxidant enzymes and the inability to upregulate expression at the mRNA level with oxidant stress likely have a role in human airway epithelium susceptibility to hyperoxia.
KW - catalase
KW - hyperoxia
KW - messenger ribonucleic acid
KW - quantification
KW - superoxide dismutase
UR - http://www.scopus.com/inward/record.url?scp=0027501121&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027501121&partnerID=8YFLogxK
M3 - Article
VL - 75
SP - 1256
EP - 1262
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 3
ER -