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)
- author
- Cao, Lei
LU
; Ping, Na Na
; Cao, Yong Xiao
; Li, Wei
; Cai, Yan
; Warfvinge, Karin
LU
and Edvinsson, Lars
LU
- organization
- publishing date
- 2016-08-01
- 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
-
- pmid:27212444
- wos:000379451700008
- scopus:84969914906
- 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
- 2025-01-12 17:47:40
@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}},
keywords = {{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}},
doi = {{10.1016/j.taap.2016.05.013}},
volume = {{304}},
year = {{2016}},
}