TY - JOUR
T1 - Kinase activity, heat shock protein 27 phosphorylation, and lung epithelial cell glutathione
AU - Jackson, Robert M.
AU - Garcia-Rojas, Rolando
PY - 2008/6/1
Y1 - 2008/6/1
N2 - The 27-kDa heat shock protein (Hps27) is phosphorylated in a way that appears to regulate antioxidant defenses by mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MK2), a component of the p38MAPK pathway. To investigate the role of Hsp27 in cellular resistance to oxidant stress, lung cells (A549) were incubated with MAPK inhibitors to investigate the pathway's role in antioxidant defense. Cells were harvested for measurement of reduced gluthathione and glutathione disulfide (GSH and GSSH); or, exposed to 2,3-dimethoxy-1,4-napthoquinone (DMNQ). Inhibition of MAPK with SB203580 decreased total cellular glutathione (mean ± SE): Vehicle, 150 ± 20 μM; SB203580, 57 ± 10* (*P <.01). Inhibition of MAPK tripled [GSSG]/[GSH]: Vehicle, 0.29 ± 0.09; SB203580, 1.06 ± 0.43* (*P >.05; n = 6 per group). Hsp27 protein content did not change significantly after MAPK inhibition: Vehicle 2.20 ± 0.24 ng/mg protein; SB203580, 2.03 ± 0.34 (P >.05). Transfection of epithelial cells with wild-type (pcDNA-HA-Hsp27) or phosphomimic (pcDNA-HA-Hsp27-S3D) vector increased Hsp27 protein, which significantly protected cells from oxidant stress. Inhibition of the MAPK system, including p38MAPK, results in cellular oxidant stress. Hsp27, which is phosphorylated by MK2 in the MAPK pathway, protects epithelial cells from oxidant stress.
AB - The 27-kDa heat shock protein (Hps27) is phosphorylated in a way that appears to regulate antioxidant defenses by mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MK2), a component of the p38MAPK pathway. To investigate the role of Hsp27 in cellular resistance to oxidant stress, lung cells (A549) were incubated with MAPK inhibitors to investigate the pathway's role in antioxidant defense. Cells were harvested for measurement of reduced gluthathione and glutathione disulfide (GSH and GSSH); or, exposed to 2,3-dimethoxy-1,4-napthoquinone (DMNQ). Inhibition of MAPK with SB203580 decreased total cellular glutathione (mean ± SE): Vehicle, 150 ± 20 μM; SB203580, 57 ± 10* (*P <.01). Inhibition of MAPK tripled [GSSG]/[GSH]: Vehicle, 0.29 ± 0.09; SB203580, 1.06 ± 0.43* (*P >.05; n = 6 per group). Hsp27 protein content did not change significantly after MAPK inhibition: Vehicle 2.20 ± 0.24 ng/mg protein; SB203580, 2.03 ± 0.34 (P >.05). Transfection of epithelial cells with wild-type (pcDNA-HA-Hsp27) or phosphomimic (pcDNA-HA-Hsp27-S3D) vector increased Hsp27 protein, which significantly protected cells from oxidant stress. Inhibition of the MAPK system, including p38MAPK, results in cellular oxidant stress. Hsp27, which is phosphorylated by MK2 in the MAPK pathway, protects epithelial cells from oxidant stress.
KW - Glutathione
KW - Heat shock protein
KW - Hypoxia
KW - Kinases
KW - Reactive oxygen species
UR - http://www.scopus.com/inward/record.url?scp=45849137517&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=45849137517&partnerID=8YFLogxK
U2 - 10.1080/01902140802022500
DO - 10.1080/01902140802022500
M3 - Article
C2 - 18465403
AN - SCOPUS:45849137517
VL - 34
SP - 245
EP - 262
JO - Experimental Lung Research
JF - Experimental Lung Research
SN - 0190-2148
IS - 5
ER -