scholarly journals Nongenomic effects of estrogen mediate the dose-related myocardial oxidative stress and dysfunction caused by acute ethanol in female rats

2014 ◽  
Vol 306 (7) ◽  
pp. E740-E747 ◽  
Author(s):  
Mahmoud M. El-Mas ◽  
Abdel A. Abdel-Rahman

Acute ethanol lowers blood pressure (BP) and cardiac output in proestrus and after chronic estrogen (E2) replacement in ovariectomized (OVX) female rats. However, whether rapid nongenomic effects of estrogen mediate these hemodynamic effects of ethanol remains unanswered. To test this hypothesis, we investigated the effect of ethanol (0.5 or 1.5 g/kg iv) on left ventricular (LV) function and oxidative markers in OVX rats pretreated 30 min earlier with 1 μg/kg E2 (OVXE2) or vehicle (OVX) and in proestrus sham-operated (SO) rats. In SO rats, ethanol caused significant and dose-related reductions in BP, rate of rise in LV pressure (LV dP/d tmax), and LV developed pressure (LVDP). These effects of ethanol disappeared in OVX rats and were restored in OVXE2 rats, suggesting rapid estrogen receptor signaling mediates the detrimental effects of ethanol on LV function. Ex vivo studies revealed that the estrogen-dependent myocardial dysfunction caused by ethanol was coupled with higher LV 1) generation of reactive oxygen species (ROS), 2) expression of malondialdehyde and 4-hydroxynonenal protein adducts, 3) phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinases (ERK1/2), and 4) catalase activity. ERK1/2 inhibition by PD-98059 (1 mg/kg iv) abrogated the myocardial dysfunction, hypotension, and the elevation in myocardial ROS generation caused by ethanol. We conclude that rapid estrogen receptor signaling is implicated in cellular events that lead to the generation of aldehyde protein adducts and Akt/ERK1/2 phosphorylation, which ultimately mediate the estrogen-dependent LV oxidative stress and dysfunction caused by ethanol in female rats.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
R Suades ◽  
S Hussain ◽  
A.W Khan ◽  
S Costantino ◽  
F Paneni ◽  
...  

Abstract Background Hyperglycemia-induced reactive oxygen species generation in diabetic heart contributes to myocardial dysfunction. JunD, a member of the activated protein 1 (AP-1) family of transcription factors, is emerging as a major gatekeeper against oxidative stress. Previous studies have shown that downregulation of AP-1 transcription factor JunD is involved in vascular aging and heart failure. However, the role of JunD in diabetes-induced myocardial dysfunction is unknown. Purpose The present study was designed to investigate whether hyperglycemia-driven epigenetic regulation of JunD contributes to oxidative stress, inflammation and myocardial dysfunction in the diabetic heart. Methods Diabetes (DB) was induced in C57BL/6 wild-type (WT) mice by streptozotocin. After four weeks of DB, left ventricular (LV) function was assessed by standard and 2D speckle-tracking echocardiography in both groups (n=10). Then, the animals were euthanized and LV specimens were collected to determine JunD mRNA and protein expression as well as superoxide anion production by ESR spectroscopy. Chromatin modifications of JunD gene promoter were assessed by chromatin immunoprecipitation. Isolated DNA was analyzed for promoter methylation following Methylminer kit. Cardiac biopsies were collected from age-matched patients with and without diabetes. Results DB mice showed LV dysfunction with reduced ejection fraction and fractional shortening. JunD mRNA and protein expression were reduced in the myocardium of DB as compared to control mice. JunD downregulation was associated with oxidative stress, increased NF-kB binding activity and expression of inflammatory mediators. Accordingly, expression of free radical scavenger superoxide dismutase 1 and aldehyde dehydrogenase 2 was reduced, whereas nicotinamide adenine dinucleotide phosphate oxidase subunits NOX2 and NOX4 were upregulated in DB. A reduction of JunD mRNA and protein expression was confirmed in LV specimens obtained from patients with diabetes. The downregulation of JunD was epigenetically regulated by promoter hypermethylation and histone modifications. Post-translational repression by tumor suppressor menin also contributed to JunD downregulation. Indeed, menin was significantly upregulated in DB hearts and co-immunoprecipitation experiments confirmed the binding of menin to JunD. Furthermore, rat ventricular myocytes exposed to high glucose (HG) showed increased menin expression. We found that miR-673 targeting menin was downregulated in hearts of DB mice. Reprogramming miR-673 in HG-treated myocytes was able to restore both menin and JunD expression to control levels. Conclusions Our findings show that downregulation of AP-1 transcription factor JunD contributes to diabetes-induced myocardial dysfunction and miR-673/menin/JunD represents a novel molecular axis involved in hyperglycemia-induced ROS-driven cardiac damage. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): European Society of Cardiology (ESC) Research Grant 2017


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Du Xiang ◽  
Yang Liu ◽  
Shujun Zhou ◽  
Encheng Zhou ◽  
Yanfeng Wang

Perimenopause is an important stage of female senescence. Epidemiological investigation has shown that the incidence of cardiovascular disease in premenopausal women is lower than that in men, and the incidence of cardiovascular disease in postmenopausal women is significantly higher than that in men. This phenomenon reveals that estrogen has a definite protective effect on the cardiovascular system. In the cardiovascular system, oxidative stress is considered important in the pathogenesis of atherosclerosis, myocardial dysfunction, cardiac hypertrophy, heart failure, and myocardial ischemia. From the perspective of oxidative stress, estrogen plays a regulatory role in the cardiovascular system through the estrogen receptor, providing strategies for the treatment of menopausal women with cardiovascular diseases.


2010 ◽  
Vol 205 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Lidia I Serova ◽  
Heather A Harris ◽  
Shreekrishna Maharjan ◽  
Esther L Sabban

Previously, pretreatment with estradiol benzoate (EB) was found to modulate the response of hypothalamic–pituitary–adrenal (HPA) axis and gene expression in several catecholaminergic neuronal locations in ovariectomized (OVX) rats exposed to single immobilization stress (IMO). Here, we investigated the role of estrogen receptor (ER) subtypes, using selective agonists for ERα (propyl pyrazole triol, PPT) or ERβ (WAY-200070) in two major central noradrenergic systems and the HPA axis after exposure to single and repeated IMO. OVX female rats received 21 daily injections of either EB (25 μg/kg), PPT (10 mg/kg), WAY-200070 (10 mg/kg), or vehicle. Injections of EB and PPT, but not WAY-200070, elicited reduced body weight and increased uterine weight, showing their selectivity. Both EB and PPT increased corticosterone levels about two- to threefold, but prevented any further rise with either single or repeated IMO, indicating an ERα (ESR1)-, but not ERβ (ESR2)-, mediated mechanism. In the locus coeruleus (LC), the rise in dopamine-β-hydroxylase (Dbh) mRNA with both stress paradigms was abrogated in EB- or PPT-injected animals. However, WAY-200070 blocked the response of DBH mRNA to single IMO but not to repeated IMO. In the nucleus of the solitary tract (NTS), the rise in tyrosine hydroxylase and DBH mRNAs with both IMOs was absent, or greatly attenuated, in EB- or PPT-treated rats. In most cases, WAY-200070 inhibited the response to single IMO but not to repeated IMO. The results demonstrate that pretreatment with estradiol, or ER-selective agonists, modulates the stress-triggered induction of gene expression of norepinephrine biosynthetic enzymes in LC and NTS, with ER selectivity depending on duration of the stress.


2007 ◽  
Vol 59 (2) ◽  
pp. 105-112
Author(s):  
Zorica Zakula ◽  
Esma Isenovic ◽  
Mojca Stojiljkovic ◽  
G. Koricanac ◽  
Snezana Tepavcevic ◽  
...  

The aim of this study was to examine the effects of estradiol (E2) on activity of RNA polymerase I and RNA polymerase II in uterine nuclei of ovariectomized (OVX) female rats. The obtained results show that estrogen-receptor (E-R) complexes in 30 min induced an increase of polymerase II activity. A second increase of polymerase II activity was observed after 3 h-incubation of nuclei with the E-R complex formed in the cytosol fraction. However, activity of polymerase I was increased 2 h after the start of incubation, with highest activity detected at 3 h in nuclei incubated with E-R complexes. On the contrary, no stimulatory effect on either polymerase I or polymerase II activity was observed in nuclei incubated with E2 alone. These results indicate that E2 stimulates the cytosolic estrogen receptor (ER), which in turn causes uterotrophic responses in OVX rats. In addition, they suggest that in order to provoke uterotrophic responses E-R complexes formed in the cytosol need to be retained in the nucleus for a longer period of time. .


2000 ◽  
pp. 307-314 ◽  
Author(s):  
MK Mohamed ◽  
AA Abdel-Rahman

OBJECTIVE: Estrogen exerts a wide variety of actions involving many target tissues. We studied the effects of long-term ovariectomy (OVX) and OVX with 17beta-estradiol treatment (OVXE2) on the level of estrogen receptor (ER) gene expression in target tissues of female rats. DESIGN: Three groups of Sprague-Dawley female rats were utilized in this study: sham operated (SO), OVX and OVXE2. METHODS: SO and OVX were performed 2 weeks before starting the 17beta-estradiol treatment. All groups were maintained on liquid diet for 12 weeks from the time of estradiol treatment. Total RNA was prepared from the tissues of the rats and relative quantitative reverse transcription PCR was utilized to compare the ER alpha-subtype (ERalpha) mRNA level in the three groups for each target tissue. RESULTS: Following long-term OVX, the levels of ERalpha expression showed a significant increase in the uterus, kidney and cerebral cortex and no significant change in the liver, cerebellum, brainstem, heart and thoracic and abdominal aorta compared with their SO levels. On the other hand, a 12-week treatment of OVX rats with 17beta-estradiol restored the previously upregulated ERalpha mRNA to near SO levels except for the liver where the 17beta-estradiol treatment resulted in a significant increase in the ERalpha mRNA level compared with that in SO rats. CONCLUSIONS: We conclude that the regulation of ERs by its ligand is tissue specific.


Endocrinology ◽  
2015 ◽  
Vol 156 (6) ◽  
pp. 2124-2137 ◽  
Author(s):  
Long Wang ◽  
Zhi-Ping Tang ◽  
Wei Zhao ◽  
Bing-Hai Cong ◽  
Jian-Qiang Lu ◽  
...  

Abstract Hydrogen sulfide, generated in the myocardium predominantly via cystathionine-γ-lyase (CSE), is cardioprotective. Our previous study has shown that estrogens enhance CSE expression in myocardium of female rats. The present study aims to explore the mechanisms by which estrogens regulate CSE expression, in particular to clarify the role of estrogen receptor subtypes and the transcriptional factor responsible for the estrogenic effects. We found that either the CSE inhibitor or the CSE small interfering RNA attenuated the protective effect of 17β-estradiol (E2) against H2O2- and hypoxia/reoxygenation-induced injury in primary cultured neonatal cardiomyocytes. E2 stimulates CSE expression via estrogen receptor (ER)-α both in cultured cardiomyocytes in vitro and in the myocardium of female mice in vivo. A specificity protein-1 (Sp-1) consensus site was identified in the rat CSE promoter and was found to mediate the E2-induced CSE expression. E2 increases ERα and Sp-1 and inhibits microRNA (miR)-22 expression in myocardium of ovariectomized rats. In primary cardiomyocytes, E2 stimulates Sp-1 expression through the ERα-mediated down-regulation of miR-22. It was confirmed that both ERα and Sp-1 were targeted by miR-22. In the myocardium of ovariectomized rats, the level of miR-22 inversely correlated to CSE, ERα, Sp-1, and antioxidant biomarkers and positively correlated to oxidative biomarkers. In summary, this study demonstrates that estrogens stimulate Sp-1 through the ERα-mediated down-regulation of miR-22 in cardiomyocytes, leading to the up-regulation of CSE, which in turn results in an increase of antioxidative defense. Interaction of ERα, miR-22, and Sp-1 may play a critical role in the control of oxidative stress status in the myocardium of female rats.


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