TY - JOUR
T1 - Functional interdependence and colocalization of endothelial nitric oxide synthase and heat shock protein 90 in cerebral arteries
AU - Khurana, Vini G.
AU - Feterik, Kristian
AU - Springett, Margaret J.
AU - Eguchi, Daihiko
AU - Shah, Vijay
AU - Katusic, Zvonimir S.
PY - 2000
Y1 - 2000
N2 - Heat shock protein 90 (HSP90), an essential component of several signal transduction systems, participates in the activation of endothelial nitric oxide synthase (eNOS) in cells. The objective of the current study was to determine if HSP90 and eNOS were functionally interdependent and colocalized in the cerebral circulation. The authors used isometric force recording, cyclic 3'5'-guanosine monophosphate (cGMP) radioimmunoassay (RIA), and immunogold electron microscopy (EM) to study canine basilar artery. They found that geldanamycin (0.1 to 10 μg/mL), a selective HSP90 inhibitor, caused concentration-dependent contractions in arterial rings (n = 6 dogs). Contractions to geldanamycin were unaffected by a cyclooxygenase inhibitor, indomethacin (10 μmol/L; P < 0.05, n = 6). Functional evidence for interaction between HSP90 and nitric oxide (NO)-mediated signaling included observations that the contractile effect of geldanamycin was the following: (1) endothelium-dependent, (2) abolished by N(g)-nitro-L-arginine methylester (L-NAME; 0.3 mmol/L), and (3) nonadditive with the contractile effect of this NOS inhibitor (P <0.01, n = 6 for each). Furthermore, RIA showed significant reduction in cGMP levels in arteries treated with geldanamycin (3 μg/mL; P < 0.02, n = 8), whereas immunogold EM demonstrated areas of colocalization of HSP90 and eNOS selectively in the cytoplasm of endothelial cells. The current findings suggest that in cerebral arteries, endothelial HSP90 plays an important role in modulation of basal NO-mediated signaling. This interaction may be particularly important in stress-induced up-regulation of HSP90 with subsequent alteration of vasomotor function.
AB - Heat shock protein 90 (HSP90), an essential component of several signal transduction systems, participates in the activation of endothelial nitric oxide synthase (eNOS) in cells. The objective of the current study was to determine if HSP90 and eNOS were functionally interdependent and colocalized in the cerebral circulation. The authors used isometric force recording, cyclic 3'5'-guanosine monophosphate (cGMP) radioimmunoassay (RIA), and immunogold electron microscopy (EM) to study canine basilar artery. They found that geldanamycin (0.1 to 10 μg/mL), a selective HSP90 inhibitor, caused concentration-dependent contractions in arterial rings (n = 6 dogs). Contractions to geldanamycin were unaffected by a cyclooxygenase inhibitor, indomethacin (10 μmol/L; P < 0.05, n = 6). Functional evidence for interaction between HSP90 and nitric oxide (NO)-mediated signaling included observations that the contractile effect of geldanamycin was the following: (1) endothelium-dependent, (2) abolished by N(g)-nitro-L-arginine methylester (L-NAME; 0.3 mmol/L), and (3) nonadditive with the contractile effect of this NOS inhibitor (P <0.01, n = 6 for each). Furthermore, RIA showed significant reduction in cGMP levels in arteries treated with geldanamycin (3 μg/mL; P < 0.02, n = 8), whereas immunogold EM demonstrated areas of colocalization of HSP90 and eNOS selectively in the cytoplasm of endothelial cells. The current findings suggest that in cerebral arteries, endothelial HSP90 plays an important role in modulation of basal NO-mediated signaling. This interaction may be particularly important in stress-induced up-regulation of HSP90 with subsequent alteration of vasomotor function.
KW - Endothelium
KW - HSP90
KW - Heat shock protein
KW - Nitric oxide synthase
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U2 - 10.1097/00004647-200011000-00006
DO - 10.1097/00004647-200011000-00006
M3 - Article
C2 - 11083231
AN - SCOPUS:0033762055
SN - 0271-678X
VL - 20
SP - 1563
EP - 1570
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 11
ER -