Differential effects of cigarette smoke on oxidative stress and proinflammatory cytokine release in primary human airway epithelial cells and in a variety of transformed alveolar epithelial cells

Table 2 Cigarette smoke extract dose-dependently caused induction of proinflammatory cytokine (IL-8 and IL-6) release from primary human small airway epithelial cells

Proinflammatory cytokine (pg/ml)	Treatment
	Control	CSE (0.2%)	CSE (0.5%)	CSE (1.0%)	TNF-α (10 ng/ml)
Interleukin-8 (IL-8)	56.2 ± 7.1	126 ± 40.6***	171 ± 21.8***	418 ± 52.3***	591 ± 76.2***
Interleukin-6 (IL-6)	87. 3 ± 7.2	187 ± 43.5***	275 ± 31.6***	476 ± 54.8***	623 ± 51.7***

Primary human small airway epithelial cells (SAEC) were treated for 24 hr with cigarette smoke extract (0.2–1.0%) prepared from 1R3F research grade cigarettes and TNF-α was used as a positive control (10 ng/ml). Cells were harvested, and supernatants were collected for the measurement of IL-8 and IL-6 levels by sandwich ELISA. CSE treatment dose-dependently induced the release of both IL-8 and IL-6 from human SAEC. Data represent mean ± SEM of 3 individual experiments. ***p < 0.001 compared to control values. CSE: cigarette smoke extract.