Browse
Submit Data
Databases
API
Help

Dataset Information

8 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Scutellarin's Cardiovascular Endothelium Protective Mechanism: Important Role of PKG-Iα.

ABSTRACT: Scutellarin (SCU), a flavonoid glycoside compound, has been successfully used in clinic for treatment of ischemic diseases in China. In this report, we checked the effects of SCU on endothelium dysfunction (ED) of coronary artery (CA) against myocardial ischemia reperfusion (MIR) injury in vivo. The involvement of PKG-Iα was further studied using cultured endothelial cells subjected to hypoxia reoxygenation (HR) injury in vitro. In rat MIR model, SCU (45 and 90 mg/kg, iv) significantly reduced ischemic size and restored the endothelium-dependent vasodilation of isolated CA rings. PKG inhibitor Rp-8-Br-cGMP (50 μg/kg, iv) could ameliorate the protective effects of SCU. Increase in phosphorylation of vasodilator-stimulated phosphoprotein (VASP), a main substrate of PKG, at Ser 239 was observed in both heart tissue and serum of SCU-treated animals. In cultured human cardiac microvascular endothelial cells (HCMECs), SCU (1 and 10 μM) dose-dependently protected cell viability and increased the mRNA and protein level of PKG-Iα against HR injury. The activity of PKG was also increased by SCU treatment. The activation of PKG-1α was then studied using targeted proteomic analysis (MRM-MS) checking the phosphorylation state of the autophosphorylation domain (aa42-94). Significant decrease in phosphorylation of PKG-Iα at Ser50, Ser72, Ser89 was induced by HR injury while SCU treatment significantly increased the phosphorylation of PKG-Iα, not only at Ser50, Ser72 and Ser89, but also at Ser44 and Thr58 (two novel phosphorylation domains). Our results demonstrate PKG-Iα might play an important role in the protective effects of SCU on ED against MIR injury.

SUBMITTER: Li L

PROVIDER: S-EPMC4594915 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

An N-terminally truncated form of cyclic GMP-dependent protein kinase Iα (PKG Iα) is monomeric and autoinhibited and provides a model for activation.

Project description:The type I cGMP-dependent protein kinases (PKG I) serve essential physiological functions, including smooth muscle relaxation, cardiac remodeling, and platelet aggregation. These enzymes form homodimers through their N-terminal dimerization domains, a feature implicated in regulating their cooperative activation. Previous investigations into the activation mechanisms of PKG I isoforms have been largely influenced by structures of the cAMP-dependent protein kinase (PKA). Here, we examined PKG Iα activation by cGMP and cAMP by engineering a monomeric form that lacks N-terminal residues 1-53 (Δ53). We found that the construct exists as a monomer as assessed by whole-protein MS, size-exclusion chromatography, and small-angle X-ray scattering (SAXS). Reconstruction of the SAXS 3D envelope indicates that Δ53 has a similar shape to the heterodimeric RIα-C complex of PKA. Moreover, we found that the Δ53 construct is autoinhibited in its cGMP-free state and can bind to and be activated by cGMP in a manner similar to full-length PKG Iα as assessed by surface plasmon resonance (SPR) spectroscopy. However, we found that the Δ53 variant does not exhibit cooperative activation, and its cyclic nucleotide selectivity is diminished. These findings support a model in which, despite structural similarities, PKG Iα activation is distinct from that of PKA, and its cooperativity is driven by in trans interactions between protomers.

| S-EPMC5971464 | biostudies-literature

Structural basis for selective inhibition of human PKG Iα by the balanol-like compound N46.

Project description:Activation of protein kinase G (PKG) Iα in nociceptive neurons induces long-term hyperexcitability that causes chronic pain. Recently, a derivative of the fungal metabolite balanol, N46, has been reported to inhibit PKG Iα with high potency and selectivity and attenuate thermal hyperalgesia and osteoarthritic pain. Here we determined co-crystal structures of the PKG Iα C-domain and cAMP-dependent protein kinase (PKA) Cα, each bound with N46, at 1.98 Å and 2.65 Å, respectively. N46 binds the active site with its external phenyl ring, specifically interacting with the glycine-rich loop and the αC helix. Phe-371 at the PKG Iα glycine-rich loop is oriented parallel to the phenyl ring of N46, forming a strong π-stacking interaction, whereas the analogous Phe-54 in PKA Cα rotates 30° and forms a weaker interaction. Structural comparison revealed that steric hindrance between the preceding Ser-53 and the propoxy group of the phenyl ring may explain the weaker interaction with PKA Cα. The analogous Gly-370 in PKG Iα, however, causes little steric hindrance with Phe-371. Moreover, Ile-406 on the αC helix forms a hydrophobic interaction with N46 whereas its counterpart in PKA, Thr-88, does not. Substituting these residues in PKG Iα with those in PKA Cα increases the IC50 values for N46, whereas replacing these residues in PKA Cα with those in PKG Iα reduces the IC50, consistent with our structural findings. In conclusion, our results explain the structural basis for N46-mediated selective inhibition of human PKG Iα and provide a starting point for structure-guided design of selective PKG Iα inhibitors.

| S-EPMC6052212 | biostudies-literature

Proof of Principle for a Novel Class of Antihypertensives That Target the Oxidative Activation of PKG Iα (Protein Kinase G Iα).

Project description:Arterial hypertension continues to be a major health burden. Development of new antihypertensive drugs that engage vasodilatory mechanisms not harnessed by available therapies offer therapeutic potential. Oxidants induce an interprotein disulfide in PKG Iα (protein kinase G Iα) at C42, which is associated with its targeting and activation, resulting in vasodilation and blood pressure lowering. Consequently, we developed an assay and screened for electrophilic drugs that activate PKG Iα by selectively targeting C42, as such compounds have potential as novel antihypertensives with a mechanism of action that differs from current therapies. In this way, a drug that we termed G1 was identified, which targets C42 of PKG Iα to induce vasodilation of isolated resistance blood vessels and blood pressure lowering in a mouse model of angiotensin II-induced hypertension. In contrast, these antihypertensive effects were deficient in angiotensin II-induced hypertensive C42S PKG Iα knockin mice. These transgenic mice were engineered to have the reactive cysteinyl thiol replaced with a hydroxyl so that it cannot react with endogenous vasodilatory oxidants or electrophiles such as drug G1. These studies, therefore, provide validation of PKG Iα C42 as the target of G1, as well as proof-of-principle for a new class of antihypertensive drugs that have potential for further development for clinical use in humans.

| S-EPMC5548503 | biostudies-other

MICU3 Plays an Important Role in Cardiovascular Function

Project description:Mitochondrial calcium regulates bioenergetics but also serves as a trigger for cell death.1 With a sustained increase in catecholamine or a large increase in cytosolic calcium as occurs with ischemia, mitochondrial calcium can rise to high levels, leading to activation of the mitochondrial permeability transition pore, thus initiating cell death.1 Calcium uptake into mitochondria occurs via the MCU (mitochondrial calcium uniporter), which is regulated by 3 EF (EF hand protein) hand proteins, MICU (mitochondrial calcium uptake) 1, 2, and 3.2 MICU1/MCU ratios vary in different tissues,3 and alterations in substrate flux have been shown to regulate MICU1 levels altering MCU-mediated calcium uptake.4 MICU3 has generally been thought to function primarily in neuronal tissue where it is highly expressed and thus has been largely ignored in other tissues such as the heart. We performed quantitative proteomics using Tandem mass tag labeling coupled to liquid chromatography and tandem mass spectrometry to analyze MCU and MCU regulators in cardiac and hepatic mitochondria (Figure [A]). Normalizing MICU levels to MCU in heart and liver mitochondria, we found that the MICU1/MCU ratio was 0.75 in liver and 0.25 in heart, which is consistent with previous studies3; however, the MICU3/MCU ratio in heart is >3-fold higher than that found in liver. To confirm that the MICU3 we observed in heart mitochondria was not due to contamination by mitochondria from nerve tissue in heart, we isolated cardiomyocytes and compared the ratio of MICU3 to MCU in cardiomyocytes and heart mitochondria and found similar ratios (Figure [B]). These data suggest that MICU3 might play a role in regulating MCU in heart.

2021-11-23 | MSV000088439 | MassIVE

Extracellular adenosine-induced Rac1 activation in pulmonary endothelium: Molecular mechanisms and barrier-protective role.

Project description:We have previously shown that Gs-coupled adenosine receptors (A2a) are primarily involved in adenosine-induced human pulmonary artery endothelial cell (HPAEC) barrier enhancement. However, the downstream events that mediate the strengthening of the endothelial cell (EC) barrier via adenosine signaling are largely unknown. In the current study, we tested the overall hypothesis that adenosine-induced Rac1 activation and EC barrier enhancement is mediated by Gs-dependent stimulation of cAMP-dependent Epac1-mediated signaling cascades. Adenoviral transduction of HPAEC with constitutively-active (C/A) Rac1 (V12Rac1) significantly increases transendothelial electrical resistance (TER) reflecting an enhancement of the EC barrier. Conversely, expression of an inactive Rac1 mutant (N17Rac1) decreases TER reflecting a compromised EC barrier. The adenosine-induced increase in TER was accompanied by activation of Rac1, decrease in contractility (MLC dephosphorylation), but not Rho inhibition. Conversely, inhibition of Rac1 activity attenuates adenosine-induced increase in TER. We next examined the role of cAMP-activated Epac1 and its putative downstream targets Rac1, Vav2, Rap1, and Tiam1. Depletion of Epac1 attenuated the adenosine-induced Rac1 activation and the increase in TER. Furthermore, silencing of Rac1 specific guanine nucleotide exchange factors (GEFs), Vav2 and Rap1a expression significantly attenuated adenosine-induced increases in TER and activation of Rac1. Depletion of Rap1b only modestly impacted adenosine-induced increases in TER and Tiam1 depletion had no effect on adenosine-induced Rac1 activation and TER. Together these data strongly suggest that Rac1 activity is required for adenosine-induced EC barrier enhancement and that the activation of Rac1 and ability to strengthen the EC barrier depends, at least in part, on cAMP-dependent Epac1/Vav2/Rap1-mediated signaling.

| S-EPMC6498840 | biostudies-literature

Protective Role of ?-Calcitonin Gene-Related Peptide in Cardiovascular Diseases.

Project description:?-Calcitonin gene-related peptide (?-CGRP) is a regulatory neuropeptide of 37 amino acids. It is widely distributed in the central and peripheral nervous system, predominantly in cell bodies of the dorsal root ganglion (DRG). It is the most potent vasodilator known to date and has inotropic and chronotropic effects. Using pharmacological and genetic approaches, our laboratory and other research groups established the protective role of ?-CGRP in various cardiovascular diseases such as heart failure, experimental hypertension, myocardial infarction, and myocardial ischemia/reperfusion injury (I/R injury). ?-CGRP acts as a depressor to attenuate the rise in blood pressure in three different models of experimental hypertension: (1) DOC-salt, (2) subtotal nephrectomy-salt, and (3) L-NAME-induced hypertension during pregnancy. Subcutaneous administration of ?-CGRP lowers the blood pressure in hypertensive and normotensive humans and rodents. Recent studies also demonstrated that an ?-CGRP analog, acylated ?-CGRP, with extended half-life (~7 h) reduces blood pressure in Ang-II-induced hypertensive mouse, and protects against abdominal aortic constriction (AAC)-induced heart failure. Together, these studies suggest that ?-CGRP, native or a modified form, may be a potential therapeutic agent to treat patients suffering from cardiac diseases.

| S-EPMC6614340 | biostudies-literature

Protective Role of Polyphenols against Vascular Inflammation, Aging and Cardiovascular Disease.

Project description:Aging is a major risk factor in the development of chronic diseases affecting various tissues including the cardiovascular system, muscle and bones. Age-related diseases are a consequence of the accumulation of cellular damage and reduced activity of protective stress response pathways leading to low-grade systemic inflammation and oxidative stress. Both inflammation and oxidative stress are major contributors to cellular senescence, a process in which cells stop proliferating and become dysfunctional by secreting inflammatory molecules, reactive oxygen species (ROS) and extracellular matrix components that cause inflammation and senescence in the surrounding tissue. This process is known as the senescence associated secretory phenotype (SASP). Thus, accumulation of senescent cells over time promotes the development of age-related diseases, in part through the SASP. Polyphenols, rich in fruits and vegetables, possess antioxidant and anti-inflammatory activities associated with protective effects against major chronic diseases, such as cardiovascular disease (CVD). In this review, we discuss molecular mechanisms by which polyphenols improve anti-oxidant capacity, mitochondrial function and autophagy, while reducing oxidative stress, inflammation and cellular senescence in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). We also discuss the therapeutic potential of polyphenols in reducing the effects of the SASP and the incidence of CVD.

| S-EPMC6357531 | biostudies-literature

Endothelial dysfunction and its critical role in COVID-19-associated coagulopathy: Defibrotide as an endothelium-protective, targeted therapy.

Project description: Not available

| S-EPMC8426874 | biostudies-literature

Cardiovascular-renal protective effect and molecular mechanism of finerenone in type 2 diabetic mellitus.

Project description:Chronic kidney diseases (CKD) and cardiovascular diseases (CVD) are the main complications in type 2 diabetic mellitus (T2DM), increasing the risk of cardiovascular and all-cause mortality. Current therapeutic strategies that delay the progression of CKD and the development of CVD include angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), sodium-glucose co-transporter 2 inhibitors (SGLT-2i) and GLP-1 receptor agonists (GLP-1RA). In the progression of CKD and CVD, mineralocorticoid receptor (MR) overactivation leads to inflammation and fibrosis in the heart, kidney and vascular system, making mineralocorticoid receptor antagonists (MRAs) as a promising therapeutic option in T2DM with CKD and CVD. Finerenone is the third generation highly selective non-steroidal MRAs. It significantly reduces the risk of cardiovascular and renal complications. Finerenone also improves the cardiovascular-renal outcomes in T2DM patients with CKD and/or chronic heart failure (CHF). It is safer and more effective than the first- and second-generation MRAs due to its higher selectivity and specificity, resulting in a lower incidence of adverse effects including hyperkalemia, renal insufficiency and androgen-like effects. Finerenone shows potent effect on improving the outcomes of CHF, refractory hypertension, and diabetic nephropathy. Recently studies have shown that finerenone may have potential therapeutic effect on diabetic retinopathy, primary aldosteronism, atrial fibrillation, pulmonary hypertension and so on. In this review, we discuss the characteristics of finerenone, the new third-generation MRA, and compared with the first- and second-generation steroidal MRAs and other nonsteroidal MRAs. We also focus on its safety and efficacy of clinical application on CKD with T2DM patients. We hope to provide new insights for the clinical application and therapeutic prospect.

| S-EPMC9968798 | biostudies-literature

The cGMP/PKG pathway as a common mediator of cardioprotection: translatability and mechanism.

Project description:Cardiomyocyte cell death occurring during myocardial reperfusion (reperfusion injury) contributes to final infarct size after transient coronary occlusion. Different interrelated mechanisms of reperfusion injury have been identified, including alterations in cytosolic Ca(2+) handling, sarcoplasmic reticulum-mediated Ca(2+) oscillations and hypercontracture, proteolysis secondary to calpain activation and mitochondrial permeability transition. All these mechanisms occur during the initial minutes of reperfusion and are inhibited by intracellular acidosis. The cGMP/PKG pathway modulates the rate of recovery of intracellular pH, but has also direct effect on Ca(2+) oscillations and mitochondrial permeability transition. The cGMP/PKG pathway is depressed in cardiomyocytes by ischaemia/reperfusion and preserved by ischaemic postconditioning, which importantly contributes to postconditioning protection. The present article reviews the mechanisms and consequences of the effect of ischaemic postconditioning on the cGMP/PKG pathway, the different pharmacological strategies aimed to stimulate it during myocardial reperfusion and the evidence, limitations and promise of translation of these strategies to the clinical practice. Overall, the preclinical and clinical evidence suggests that modulation of the cGMP/PKG pathway may be a therapeutic target in the context of myocardial infarction.

| S-EPMC4386977 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data