JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
G protein-coupled estrogen receptor 1 mediates relaxation of coronary arteries via cAMP/PKA-dependent activation of MLCP.
Am. J. Physiol. Endocrinol. Metab.
PUBLISHED: 07-08-2014
Show Abstract
Hide Abstract
Activation of GPER exerts a protective effect in hypertension and ischemia-reperfusion models and relaxes arteries in vitro. However, our understanding of the mechanisms of GPER-mediated vascular regulation is far from complete. In the current study, we tested the hypothesis that GPER-induced relaxation of porcine coronary arteries is mediated via cAMP/PKA signaling. Our findings revealed that vascular relaxation to the selective GPER agonist G-1 (0.3-3 ?M) was associated with increased cAMP production in a concentration-dependent manner. Furthermore, inhibition of adenylyl cyclase (AC) with SQ-22536 (100 ?M) or of PKA activity with either Rp-8-CPT-cAMPS (5 ?M) or PKI (5 ?M) attenuated G-1-induced relaxation of coronary arteries preconstricted with PGF2? (1 ?M). G-1 also increased PKA activity in cultured coronary artery smooth muscle cells (SMCs). To determine downstream signals of the cAMP/PKA cascade, we measured RhoA activity in cultured human and porcine coronary SMCs and myosin-light chain phosphatase (MLCP) activity in these artery rings by immunoblot analysis of phosphorylation of myosin-targeting subunit protein-1 (p-MYPT-1; the MLCP regulatory subunit). G-1 decreased PGF2?-induced p-MYPT-1, whereas Rp-8-CPT-cAMPS prevented this inhibitory effect of G-1. Similarly, G-1 inhibited PGF2?-induced phosphorylation of MLC in coronary SMCs, and this inhibitory effect was also reversed by Rp-8-CPT-cAMPS. RhoA activity was downregulated by G-1, whereas G36 (GPER antagonist) restored RhoA activity. Finally, FMP-API-1 (100 ?M), an inhibitor of the interaction between PKA and A-kinase anchoring proteins (AKAPs), attenuated the effect of G-1 on coronary artery relaxation and p-MYPT-1. These findings demonstrate that localized cAMP/PKA signaling is involved in GPER-mediated coronary vasodilation by activating MLCP via inhibition of RhoA pathway.
Related JoVE Video
G-protein-coupled estrogen receptor as a new therapeutic target for treating coronary artery disease.
World J Cardiol
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
Coronary heart disease (CHD) continues to be the greatest mortality risk factor in the developed world. Estrogens are recognized to have great therapeutic potential to treat CHD and other cardiovascular diseases; however, a significant array of potentially debilitating side effects continues to limit their use. Moreover, recent clinical trials have indicated that long-term postmenopausal estrogen therapy may actually be detrimental to cardiovascular health. An exciting new development is the finding that the more recently discovered G-protein-coupled estrogen receptor (GPER) is expressed in coronary arteries-both in coronary endothelium and in smooth muscle within the vascular wall. Accumulating evidence indicates that GPER activation dilates coronary arteries and can also inhibit the proliferation and migration of coronary smooth muscle cells. Thus, selective GPER activation has the potential to increase coronary blood flow and possibly limit the debilitating consequences of coronary atherosclerotic disease. This review will highlight what is currently known regarding the impact of GPER activation on coronary arteries and the potential signaling mechanisms stimulated by GPER agonists in these vessels. A thorough understanding of GPER function in coronary arteries may promote the development of new therapies that would help alleviate CHD, while limiting the potentially dangerous side effects of estrogen therapy.
Related JoVE Video
Potential roles of adenosine deaminase-2 in diabetic retinopathy.
Biochem. Biophys. Res. Commun.
PUBLISHED: 04-30-2013
Show Abstract
Hide Abstract
The early activation of microglia that induces retinal inflammation in DR may serve as a target for therapeutic intervention of DR. Our demonstration that retinal inflammation is attenuated via adenosine receptor A(2A)AR supports the hypothesis that a mechanism to maintain extracellular concentrations of adenosine important in normal physiology is impaired in DR. Extracellular concentrations of adenosine are regulated by the interplay of equiliberative nucleoside transporter (ENT)s with enzymes of adenosine metabolism including adenosine deaminase-1 (ADA1), adenosine kinase (AK) and CD73. In the vertebrates but not rodents, a macrophage-associated ADA2 is identified. The role of ADA2 is, therefore, understudied as the sequencing probes or antibodies to mouse ADA2 are not available. We identified increased ADA2 expression and activity in human and porcine retinas with diabetes, and in Amadori glycated albumin (AGA)- or hyperglycemia-treated porcine and human microglia. In rodent as well as porcine cells, modulation of TNF-? release is mediated by A(2A)AR. Quantitative analysis of normal and diabetic porcine retinas reveals that while the expression levels of ADA2, A2AAR, ENT1, TNF-? and MMP9 are increased, the levels of AK are reduced during inflammation as an endogenous protective mechanism. To determine the role of ADA2, we found that AGA induces ADA2 expression, ADA2 activity and TNF-? release, and that TNF-? release is blocked by ADA2-neutralizing antibody or ADA2 siRNA, but not by scrambled siRNA. These results suggest that retinal inflammation in DR is mediated by ADA2, and that the anti-inflammatory activity of A(2A)AR signaling is impaired in diabetes due to increased ADA2 activity.
Related JoVE Video
GPER: a novel target for non-genomic estrogen action in the cardiovascular system.
Pharmacol. Res.
PUBLISHED: 02-19-2013
Show Abstract
Hide Abstract
A key to harnessing the enormous therapeutic potential of estrogens is understanding the diversity of estrogen receptors and their signaling mechanisms. In addition to the classic nuclear estrogen receptors (i.e., ER? and ER?), over the past decade a novel G-protein-coupled estrogen receptor (GPER) has been discovered in cancer and other cell types. More recently, this non-genomic signaling mechanism has been found in blood vessels, and mediates vasodilatory responses to estrogen and estrogen-like agents; however, downstream signaling events involved acute estrogen action remain unclear. The purpose of this review is to discuss the latest knowledge concerning GPER modulation of cardiovascular function, with a particular emphasis upon how activation of this receptor could mediate acute estrogen effects in the heart and blood vessels (i.e., vascular tone, cell growth and differentiation, apoptosis, endothelial function, myocardial protection). Understanding the role of GPER in estrogen signaling may help resolve some of the controversies associated with estrogen and cardiovascular function. Moreover, a more thorough understanding of GPER function could also open significant opportunities for the development of new pharmacological strategies that would provide the cardiovascular benefits of estrogen while limiting the potentially dangerous side effects.
Related JoVE Video
Activation of GPER Induces Differentiation and Inhibition of Coronary Artery Smooth Muscle Cell Proliferation.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Vascular pathology and dysfunction are direct life-threatening outcomes resulting from atherosclerosis or vascular injury, which are primarily attributed to contractile smooth muscle cells (SMCs) dedifferentiation and proliferation by re-entering cell cycle. Increasing evidence suggests potent protective effects of G-protein coupled estrogen receptor 1 (GPER) activation against cardiovascular diseases. However, the mechanism underlying GPER function remains poorly understood, especially if it plays a potential role in modulating coronary artery smooth muscle cells (CASMCs).
Related JoVE Video
Activation of G protein-coupled estrogen receptor induces endothelium-independent relaxation of coronary artery smooth muscle.
Am. J. Physiol. Endocrinol. Metab.
PUBLISHED: 07-26-2011
Show Abstract
Hide Abstract
Estrogens can either relax or contract arteries via rapid, nongenomic mechanisms involving classic estrogen receptors (ER). In addition to ER? and ER?, estrogen may also stimulate G protein-coupled estrogen receptor 1 (GPER) in nonvascular tissue; however, a potential role for GPER in coronary arteries is unclear. The purpose of this study was to determine how GPER activity influenced coronary artery reactivity. In vitro isometric force recordings were performed on endothelium-denuded porcine arteries. These studies were augmented by RT-PCR and single-cell patch-clamp experiments. RT-PCR and immunoblot studies confirmed expression of GPER mRNA and protein, respectively, in smooth muscle from either porcine or human coronary arteries. G-1, a selective GPER agonist, produced a concentration-dependent relaxation of endothelium-denuded porcine coronary arteries in vitro. This response was attenuated by G15, a GPER-selective antagonist, or by inhibiting large-conductance calcium-activated potassium (BK(Ca)) channels with iberiotoxin, but not by inhibiting NO signaling. Last, single-channel patch-clamp studies demonstrated that G-1 stimulates BK(Ca) channel activity in intact smooth muscle cells from either porcine or human coronary arteries but had no effect on channels isolated in excised membrane patches. In summary, GPER activation relaxes coronary artery smooth muscle by increasing potassium efflux via BK(Ca) channels and requires an intact cellular signaling mechanism. This novel action of estrogen-like compounds may help clarify some of the controversy surrounding the vascular effects of estrogens.
Related JoVE Video
hElp3 directly modulates the expression of HSP70 gene in HeLa cells via HAT activity.
PLoS ONE
PUBLISHED: 06-30-2011
Show Abstract
Hide Abstract
Human Elongator complex, which plays a key role in transcript elongation in vitro assay, is incredibly similar in either components or function to its yeast counterpart. However, there are only a few studies focusing on its target gene characterization in vivo. We studied the effect of down-regulation of the human elongation protein 3 (hELP3) on the expression of HSP70 through antisense strategy. Transfecting antisense plasmid p1107 into HeLa cells highly suppressed hELP3 expression, and substantially reduced expression of HSP70 mRNA and protein. Furthermore, chromatin immunoprecipitation assay (ChIP Assay) revealed that hElp3 participates in the transcription elongation of HSPA1A in HeLa cells. Finally, complementation and ChIP Assay in yeast showed that hElp3 can not only complement the growth and slow activation of HSP70 (SSA3) gene transcription, but also directly regulates the transcription of SSA3. On the contrary, these functions are lost when the HAT domain is deleted from hElp3. These data suggest that hElp3 can regulate the transcription of HSP70 gene, and the HAT domain of hElp3 is essential for this function. These findings now provide novel insights and evidence of the functions of hELP3 in human cells.
Related JoVE Video
Expression of GPR30, ER? and ER? in endometrium during window of implantation in patients with polycystic ovary syndrome: a pilot study.
Gynecol. Endocrinol.
PUBLISHED: 01-27-2011
Show Abstract
Hide Abstract
Women with polycystic ovary syndrome (PCOS) exhibit a lower pregnancy rate, which may be related to decreased estrogen receptor (ER) expression or endometrial receptivity. We measured expression of ER?, ER? and the novel G protein-coupled ER (GPR30) in endometrium during window of implantation (WOI) in PCOS patients. Fifteen Chinese women with PCOS were compared to 15 normal subjects. Serial trans-vaginal ultrasonic scanner (TVUS) examinations detected follicular development, and endometrial thickness and pattern were assessed via TVUS on the day of ovulation. GPR30 expression was detected in the cytoplasm of endometrial epithelial cells, and was significantly lower in the PCOS group (p < 0.05). ER? and ER? expression was lower in the PCOS group, and was detected mainly in the nucleus of endometrial epithelial cells. There was no significant difference in endometrium thickness (p > 0.05), but there was a significant difference in the ultrasonic pattern (p < 0.05). Endometrial expression of GPR30, ER? and ER? was decreased during WOI in PCOS patients, and was accompanied by poor endometrial receptivity, low pregnancy rate and higher spontaneous abortions. We propose that restored receptor expression might improve endometrial receptivity and help lower infertility associated with PCOS.
Related JoVE Video
Estrogen and oxidative stress: A novel mechanism that may increase the risk for cardiovascular disease in women.
Steroids
PUBLISHED: 01-07-2010
Show Abstract
Hide Abstract
Although early studies demonstrated that exogenous estrogen lowered a womans risk of cardiovascular disease, recent trials indicate that HRT actually increases the risk of coronary heart disease or stroke. However, there is no clear explanation for this discrepancy. Is estrogen a helpful or a harmful hormone in terms of cardiovascular function? This review discusses some recent findings that propose a novel mechanism which may shed significant light upon this controversy. We propose that nitric oxide synthase (NOS) expressed within the vascular wall is a target of estrogen action. Under normal conditions in younger women, the primary product of estrogen action is NO, which produces a number of beneficial effects on vascular biology. As a woman ages, however, there is evidence for loss of important molecules essential for NO production (e.g., tetrahydrobiopterin, l-arginine). As these molecules are depleted, NOS becomes increasingly "uncoupled" from NO production, and instead produces superoxide, a dangerous reactive oxygen species. We propose that a similar uncoupling and reversal of estrogen response occurs in diabetes. Therefore, we propose that estrogen is neither "good" nor "bad", but simply stimulates NOS activity. It is the biochemical environment around NOS that will determine whether estrogen produces a beneficial (NO) or deleterious (superoxide) product, and can account for this dual and opposite nature of estrogen pharmacology. Further, this molecular mechanism is consistent with recent analyses revealing that HRT produces salutary effects in younger women, but mainly increases the risk of cardiovascular dysfunction in older postmenopausal women.
Related JoVE Video
The d5 dopamine receptor mediates large-conductance, calcium- and voltage-activated potassium channel activation in human coronary artery smooth muscle cells.
J. Pharmacol. Exp. Ther.
PUBLISHED: 10-28-2009
Show Abstract
Hide Abstract
Large-conductance, calcium- and voltage-activated potassium (BK(Ca)) channels hyperpolarize coronary artery smooth muscle cells, causing vasorelaxation. Dopamine activates BK(Ca) channels by stimulating D(1)-like receptor-mediated increases in cAMP in porcine coronary artery myocytes. There are two D(1)-like receptors (R), D(1)R and D(5)R. We hypothesize that the specific D(1)-like receptor involved in BK(Ca) channel activation in human coronary artery smooth muscle cells (HCASMCs) is the D(5)R and that activation occurs via cAMP cross-activation of cGMP-dependent protein kinase (PKG), rather than cAMP-dependent protein kinase (PKA). The effects of D(1)-like receptor agonists and antagonists on BK(Ca) channel opening in HCASMCs were examined in the presence and absence of PKG/PKA inhibition by cell-attached patch clamp. In the absence of commercially available ligands specific for D(1)R or D(5)R, D(1)R or D(5)R protein was down-regulated by transfecting HCASMCs with human D(1)R or D(5)R antisense oligonucleotides, respectively: cells transfected with scrambled oligonucleotides and nontransfected HCASMCs served as controls. The predominant ion channel conducting outward currents in nontransfected HCASMCs was identified as the large-conductance, calcium- and voltage-activated potassium (BK(Ca)) channel, which was activated by D(1)-like receptor agonists despite PKA inhibition with (9R,10S,12S)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3,2,1-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid (KT 5720) (300 nM), but was abolished by inhibiting PKG with 9-methoxy-9-methoxycarbonyl-8-methyl-2,3,9,10-tetrahydro-8,11-epoxy-1H,8H,11H-2,7b-11a-triazadibenzo(a,g) cycloocta(cde)-trinden-1-one (KT 5823) (300 nM). D(1)-like receptor agonists activated BK(Ca) channels in all transfected cells except those transfected with D(5)R antisense oligonucleotides. Thus, the dopamine (D(1)-like) receptor mediates activation of BK(Ca) channels in HCASMCs by D(5)R, not D(1)R, and via PKG, not PKA. This is the first report of differential D(1)-like receptor regulation of vascular smooth muscle function in human cells.
Related JoVE Video
Essential role of the 90-kilodalton heat shock protein in mediating nongenomic estrogen signaling in coronary artery smooth muscle.
J. Pharmacol. Exp. Ther.
PUBLISHED: 03-17-2009
Show Abstract
Hide Abstract
Under normal physiological conditions, estrogen is a coronary vasodilator, and this response involves production of NO from endothelial cells. In addition, estrogen also stimulates NO production in coronary artery smooth muscle (CASM); however, the molecular basis for this nongenomic effect of estrogen is unclear. The purpose of this study was to investigate a potential role for the 90-kDa heat shock protein (Hsp90) in estrogen-stimulated neuronal nitric-oxide synthase (nNOS) activity in coronary artery smooth muscle. 17Beta-estradiol produced a concentration-dependent relaxation of endothelium-denuded porcine coronary arteries in vitro, and this response was attenuated by inhibiting Hsp90 function with 1 microM geldanamycin (GA) or 100 microg/ml radicicol (RAD). These inhibitors also prevented estrogen-stimulated NO production in human CASM cells and reversed the stimulatory effect of estrogen on calcium-activated potassium (BK(Ca)) channels. These functional studies indicated a role for Hsp90 in coupling estrogen receptor activation to NOS stimulation in CASM. Furthermore, coimmunoprecipitation studies demonstrated that estrogen stimulates bimolecular interaction of immunoprecipitated nNOS with Hsp90 and that either GA or RAD could inhibit this association. Blocking estrogen receptors with ICI182780 (fulvestrant) also prevented this association. These findings indicate an essential role for Hsp90 in nongenomic estrogen signaling in CASM and further suggest that Hsp90 might represent a prospective therapeutic target to enhance estrogen-stimulated cardiovascular protection.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.