15-deoxy-Delta12,14-prostaglandin J2-induced down-regulation of endothelial nitric oxide synthase in association with HSP70 induction.
A natural ligand of peroxisome proliferator-activated receptor gamma (PPARgamma), 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), decreases endothelial nitric oxide synthase (eNOS) expression by an unknown mechanism. Here we found that 15d-PGJ(2)-induced eNOS reduction is inversely associated with heat shock protein 70 (HSP70) induction in endothelial cells. Treatment of cells with 15d-PGJ(2) decreased eNOS protein expression in a concentration- and time-dependent manner, but independently of PPARgamma with no effect on mRNA levels. Although 15d-PGJ(2) elicited endothelial apoptosis, inhibition of both pan-caspases and cathepsins failed to reverse reduction of eNOS protein. Interestingly, we observed that 15d-PGJ(2) induced HSP70 in a dose-dependent manner. Immunoprecipitation and heat shock treatment demonstrated that eNOS reduction was strongly related to HSP70 induction. Cellular fractionation revealed that treatment with 15d-PGJ(2) increased eNOS distribution 2.5-fold from soluble to insoluble fractions. These findings provide new insights into mechanisms whereby eNOS regulation by 15d-PGJ(2) is related to HSP70 induction.
Hwang
Jinah
J
Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health, Seoul, Republic of Korea.
Lee
Hyun-Il
HI
Chang
Young-Sun
YS
Lee
Soo Jae
SJ
Kim
Kwang Pyo
KP
Park
Sang Ick
SI
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D015230:Prostaglandin D2 / Q000008:administration & dosage / Q000031:analogs & derivatives*
C097240:15-deoxy-delta(12,14)-prostaglandin J2; D018840:HSP70 Heat-Shock Proteins; D052250:Nitric Oxide Synthase Type III; D015230:Prostaglandin D2