Advanced

The effects of MEK1/2 inhibition on cigarette smoke exposure-induced ET receptor upregulation in rat cerebral arteries

Cao, Lei LU ; Ping, Na Na; Cao, Yong Xiao; Li, Wei; Cai, Yan; Warfvinge, Karin LU and Edvinsson, Lars LU (2016) In Toxicology and Applied Pharmacology 304. p.70-78
Abstract

Cigarette smoking, a major stroke risk factor, upregulates endothelin receptors in cerebral arteries. The present study examined the effects of MEK1/2 pathway inhibition on cigarette smoke exposure-induced ET receptor upregulation. Rats were exposed to the secondhand smoke (SHS) for 8 weeks followed by intraperitoneal injection of MEK1/2 inhibitor, U0126 for another 4 weeks. The urine cotinine levels were assessed with high-performance liquid chromatography. Contractile responses of isolated cerebral arteries were recorded by a sensitive wire myograph. The mRNA and protein expression levels of receptor and MEK/ERK1/2 pathway molecules were examined by real-time PCR and Western blotting, respectively. Cerebral artery receptor... (More)

Cigarette smoking, a major stroke risk factor, upregulates endothelin receptors in cerebral arteries. The present study examined the effects of MEK1/2 pathway inhibition on cigarette smoke exposure-induced ET receptor upregulation. Rats were exposed to the secondhand smoke (SHS) for 8 weeks followed by intraperitoneal injection of MEK1/2 inhibitor, U0126 for another 4 weeks. The urine cotinine levels were assessed with high-performance liquid chromatography. Contractile responses of isolated cerebral arteries were recorded by a sensitive wire myograph. The mRNA and protein expression levels of receptor and MEK/ERK1/2 pathway molecules were examined by real-time PCR and Western blotting, respectively. Cerebral artery receptor localization was determined with immunohistochemistry. The results showed the urine cotinine levels from SHS exposure group were significantly higher than those from the fresh group. In addition, the MEK1/2 inhibitor, U0126 significantly reduced SHS exposure-increased ETA receptor mRNA and protein levels as well as contractile responses mediated by ETA receptors. The immunoreactivity of increased ETA receptor expression was primarily cytoplasmic in smooth muscle cells. In contrast, ETB receptor was noted in endothelial cells. However, the SHS-induced decrease in endothelium-dependent relaxation was unchanged after U0126 treatment. Furthermore, SHS increased the phosphorylation of MEK1/2 and ERK1/2 protein in cerebral arteries. By using U0126 could inhibit the phosphorylated ERK1/2 protein but not MEK1/2. Taken together, our data show that treatment with MEK1/2 pathway inhibitor offsets SHS exposure-induced ETA receptor upregulation in rat cerebral arteries.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cerebral artery, Cigarette smoke, Endothelin receptor, MEK1/2, Rat, Receptor upregulation
in
Toxicology and Applied Pharmacology
volume
304
pages
9 pages
publisher
Academic Press
external identifiers
  • scopus:84969914906
  • wos:000379451700008
ISSN
0041-008X
DOI
10.1016/j.taap.2016.05.013
language
English
LU publication?
yes
id
8ad4fe2e-6e8b-49d7-ada7-58b32a4f0841
date added to LUP
2016-12-15 11:43:52
date last changed
2017-10-01 05:27:40
@article{8ad4fe2e-6e8b-49d7-ada7-58b32a4f0841,
  abstract     = {<p>Cigarette smoking, a major stroke risk factor, upregulates endothelin receptors in cerebral arteries. The present study examined the effects of MEK1/2 pathway inhibition on cigarette smoke exposure-induced ET receptor upregulation. Rats were exposed to the secondhand smoke (SHS) for 8 weeks followed by intraperitoneal injection of MEK1/2 inhibitor, U0126 for another 4 weeks. The urine cotinine levels were assessed with high-performance liquid chromatography. Contractile responses of isolated cerebral arteries were recorded by a sensitive wire myograph. The mRNA and protein expression levels of receptor and MEK/ERK1/2 pathway molecules were examined by real-time PCR and Western blotting, respectively. Cerebral artery receptor localization was determined with immunohistochemistry. The results showed the urine cotinine levels from SHS exposure group were significantly higher than those from the fresh group. In addition, the MEK1/2 inhibitor, U0126 significantly reduced SHS exposure-increased ET<sub>A</sub> receptor mRNA and protein levels as well as contractile responses mediated by ET<sub>A</sub> receptors. The immunoreactivity of increased ET<sub>A</sub> receptor expression was primarily cytoplasmic in smooth muscle cells. In contrast, ET<sub>B</sub> receptor was noted in endothelial cells. However, the SHS-induced decrease in endothelium-dependent relaxation was unchanged after U0126 treatment. Furthermore, SHS increased the phosphorylation of MEK1/2 and ERK1/2 protein in cerebral arteries. By using U0126 could inhibit the phosphorylated ERK1/2 protein but not MEK1/2. Taken together, our data show that treatment with MEK1/2 pathway inhibitor offsets SHS exposure-induced ET<sub>A</sub> receptor upregulation in rat cerebral arteries.</p>},
  author       = {Cao, Lei and Ping, Na Na and Cao, Yong Xiao and Li, Wei and Cai, Yan and Warfvinge, Karin and Edvinsson, Lars},
  issn         = {0041-008X},
  keyword      = {Cerebral artery,Cigarette smoke,Endothelin receptor,MEK1/2,Rat,Receptor upregulation},
  language     = {eng},
  month        = {08},
  pages        = {70--78},
  publisher    = {Academic Press},
  series       = {Toxicology and Applied Pharmacology},
  title        = {The effects of MEK1/2 inhibition on cigarette smoke exposure-induced ET receptor upregulation in rat cerebral arteries},
  url          = {http://dx.doi.org/10.1016/j.taap.2016.05.013},
  volume       = {304},
  year         = {2016},
}