scholarly journals PKCδ Mediates Mineralocorticoid Receptor Activation by Angiotensin II to Modulate Smooth Muscle Cell Function

Endocrinology ◽  
2019 ◽  
Vol 160 (9) ◽  
pp. 2101-2114 ◽  
Author(s):  
Qing Lu ◽  
Ana P Davel ◽  
Adam P McGraw ◽  
Sitara P Rao ◽  
Brenna G Newfell ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Mineralocorticoid Receptor ◽  
Target Gene ◽  
Cell Function ◽  
Receptor Activation ◽  
Serine Phosphorylation ◽  
Dependent Manner ◽  
Responsive Element ◽  
The Impact

Abstract Angiotensin II (AngII) and the mineralocorticoid receptor (MR) ligand aldosterone both contribute to cardiovascular disorders, including hypertension and adverse vascular remodeling. We previously demonstrated that AngII activates MR-mediated gene transcription in human vascular smooth muscle cells (SMCs), yet the mechanism and the impact on SMC function are unknown. Using an MR-responsive element-driven transcriptional reporter assay, we confirm that AngII induces MR transcriptional activity in vascular SMCs and endothelial cells, but not in Cos1 or human embryonic kidney-293 cells. AngII activation of MR was blocked by the MR antagonist spironolactone or eplerenone and the protein kinase C-δ (PKCδ) inhibitor rottlerin, implicating both in the mechanism. Similarly, small interfering RNA knockdown of PKCδ in SMCs prevented AngII-mediated MR activation, whereas knocking down of MR blocked both aldosterone- and AngII-induced MR function. Coimmunoprecipitation studies reveal that endogenous MR and PKCδ form a complex in SMCs that is enhanced by AngII treatment in association with increased serine phosphorylation of the MR N terminus. AngII increased mRNA expression of the SMC-MR target gene, FKBP51, via an MR-responsive element in intron 5 of the FKBP51 gene. The impact of AngII on FKBP51 reporter activity and gene expression in SMCs was inhibited by spironolactone and rottlerin. Finally, the AngII-induced increase in SMC number was also blocked by the MR antagonist spironolactone and the PKCδ inhibitor rottlerin. These data demonstrate that AngII activates MR transcriptional regulatory activity, target gene regulation, and SMC proliferation in a PKCδ-dependent manner. This new mechanism may contribute to synergy between MR and AngII in driving SMC dysfunction and to the cardiovascular benefits of MR and AngII receptor blockade in humans.

Abstract 1357: PGC-1 α as a Novel Regulator for Angiotensin II-induced Reactive Oxygen Species Production and Hypertrophy in Vascular Smooth Muscle Cells

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shiqin Xiong ◽  
Mushtaq Ahmad ◽  
Nikolay A Patrushev ◽  
Lula Hilenski ◽  
San Martin Almeyda Alejandra ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Phosphorylation Site ◽  
Serine Phosphorylation ◽  
H2o2 Production ◽  
Dependent Manner ◽  
Ang Ii ◽  
Akt Inhibitor

Angiotensin II (Ang II) increases H 2 O 2 production and vascular smooth muscle cell (VSMCs) hypertrophy, in part through redox-sensitive PI3K/Akt, which is inhibited by catalase overexpression. The relevant molecular mechanism remains unclear. Peroxisome proliferator-activated receptor gamma coactivator-1 α (PGC-1 α ) is reported to protect from oxidative stress by regulating expression of antioxidant enzymes such as catalase. We thus hypothesized that PGC-1 α may be important mediator for Ang II-induced H2O2 production and vascular hypertrophy. Here we show that Ang II stimulation increases serine phosphorylation of PGC-1 α (2.2 folds) with a peak at 15 min, which is inhibited by LY294002, a specific PI3 kinase inhibitor (98% decrease), and by Akt inhibitor-2/Triciribine (95% decrease). Ang II promotes PGC-1 α phosphorylation mainly at Ser 570 in an Akt-dependent manner. Ang II significantly suppresses Gal4-fused PGC-1 α transcriptional activity in a dose dependent manner, which is partially reversed by PI3K/Akt inhibition. Chromatin immunoprecipitation (ChIP) assay shows that PGC-1 α associates with the catalase promoter and this association is blocked by Ang II in a PI3K/Akt-dependent manner. Consistent with these results, Ang II stimulation time-dependently decreases endogenous catalase expression at both messenger RNA and protein levels. Ang II-induced downregulation of catalase at protein level at 24 hrs is prevented by Akt inhibitor (86%) and by overexpression of PGC-1 α S570A, an Akt phosphorylation site mutant, (75%). Moreover, overexpression of PGC-1 α S570A significantly inhibits Ang II-induced increase in H2O2 production (>80%) and leucine incorporation (>90%) as measured at 12 and 24 hrs, respectively. In summary, Akt-dependent serine phosphorylation of PGC-1 α by Ang II plays an important role for Ang II-induced downregulation of catalase, thereby increasing H2O2 production, which may contribute to ROS-dependent VSMC hypertrophy. These findings provide insight into a novel mechanisms by which Ang II promotes long-term H2O2 production to increase oxidative stress via targeting PGC-1alpha, and mediates metabolic abnormalities.

Progesterone enhances target gene transcription by receptor free of heat shock proteins hsp90, hsp56, and hsp70

1991 ◽  
Vol 11 (10) ◽  
pp. 4998-5004
Author(s):  
M K Bagchi ◽  
S Y Tsai ◽  
M J Tsai ◽  
B W O'Malley
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Transcriptional Activation ◽  
Target Gene ◽  
Steroid Hormone ◽  
Receptor Activation ◽  
Target Cells ◽  
Dependent Manner ◽  
Shock Proteins

Steroid receptors regulate transcription of target genes in vivo and in vitro in a steroid hormone-dependent manner. Unoccupied progesterone receptor exists in the low-salt homogenates of target cells as a functionally inactive 8 to 10S complex with several nonreceptor components such as two molecules of 90-kDa heat shock protein (hsp90), a 70-kDa heat shock protein (hsp70), and a 56-kDa heat shock protein (hsp56). Ligand-induced dissociation of receptor-associated proteins such as hsp90 has been proposed as the mechanism of receptor activation. Nevertheless, it has not been established whether, beyond release of heat shock proteins, the steroidal ligand plays a role in modulating receptor activity. To examine whether the release of these nonreceptor proteins from receptor complex results in a constitutively active receptor, we isolated an unliganded receptor form essentially free of hsp90, hsp70, and hsp56. Using a recently developed steroid hormone-responsive cell-free transcription system, we demonstrate for the first time that the dissociation of heat shock proteins is not sufficient to generate a functionally active receptor. This purified receptor still requires hormone for high-affinity binding to a progesterone response element and for efficient transcriptional activation of a target gene. When an antiprogestin, Ru486, is bound to the receptor, it fails to promote efficient transcription. We propose that in the cell, in addition to the release of receptor-associated inhibitory proteins, a distinct hormone-mediated activation event must precede efficient gene activation.

scholarly journals Systemic Platelet-activating Factor Receptor Activation Augments Experimental Lung Tumor Growth and Metastasis

2014 ◽  
Vol 7 ◽  
pp. CGM.S14501 ◽  
Author(s):  
Patrick C. Hackler ◽  
Sarah Reuss ◽  
Raymond L. Konger ◽  
Jeffrey B. Travers ◽  
Ravi P. Sahu
Keyword(s):  
Lung Cancer ◽  
Tumor Growth ◽  
Cancer Progression ◽  
Lung Tumor ◽  
Platelet Activating Factor ◽  
Receptor Activation ◽  
Dependent Manner ◽  
Melanoma Tumor ◽  
Tumor Growth And Metastasis ◽  
The Impact

Pro-oxidative stressors including cigarette smoke (CS) generate novel lipids with platelet-activated factor-receptor (PAF-R) agonistic activity mediate systemic immunosuppression, one of the most recognized events in promoting carcinogenesis. Our previous studies have established that these oxidized-PAF-R-agonists augment murine B16F10 melanoma tumor growth in a PAF-R-dependent manner because of its effects on host immunity. As CS generates PAF-R agonists, the current studies sought to determine the impact of PAF-R agonists on lung cancer growth and metastasis. Using the murine Lewis Lung Carcinoma (LLC1) model, we demonstrate that treatment of C57BL/6 mice with a PAF-R agonist augments tumor growth and lung metastasis in a PAF-R-dependent manner as these findings were not seen in PAF-R-deficient mice. Importantly, this effect was because of host rather than tumor cells PAF-R dependent as LLC1 cells do not express functional PAF-R. These findings indicate that experimental lung cancer progression can be modulated by the PAF system.

scholarly journals Angiotensin II type 2 receptor activation induces RhoA inhibition through Phosphorylation of its Serine 188 in Vascular Smooth Muscle Cells

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Malvyne Rolli‐Derkinderen ◽  
Christophe Guilluy ◽  
Laurent Loufrani ◽  
Daniel Henrion ◽  
Gervaise Loirand ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Receptor Activation

scholarly journals Mineralocorticoid receptor antagonism improves parenchymal arteriole dilation via a TRPV4-dependent mechanism and prevents cognitive dysfunction in hypertension

2018 ◽  
Vol 315 (5) ◽  
pp. H1304-H1315 ◽  
Author(s):  
Janice M. Diaz-Otero ◽  
Ting-Chieh Yen ◽  
Courtney Fisher ◽  
Daniel Bota ◽  
William F. Jackson ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Angiotensin Ii ◽  
Mineralocorticoid Receptor ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Receptor Activation ◽  
Myogenic Tone ◽  
Transient Receptor Potential Vanilloid ◽  
Cerebrovascular Function ◽  
Transient Receptor

Hypertension and mineralocorticoid receptor activation cause cerebral parenchymal arteriole remodeling; this can limit cerebral perfusion and contribute to cognitive dysfunction. We used a mouse model of angiotensin II-induced hypertension to test the hypothesis that mineralocorticoid receptor activation impairs both transient receptor potential vanilloid (TRPV)4-mediated dilation of cerebral parenchymal arterioles and cognitive function. Mice (16−18 wk old, male, C57Bl/6) were treated with angiotensin II (800 ng·kg−1·min−1) with or without the mineralocorticoid receptor antagonist eplerenone (100 mg·kg−1·day−1) for 4 wk; sham mice served as controls. Data are presented as means ± SE; n = 5–14 mice/group. Eplerenone prevented the increased parenchymal arteriole myogenic tone and impaired carbachol-induced (10−9–10−5 mol/l) dilation observed during hypertension. The carbachol-induced dilation was endothelium-derived hyperpolarization mediated because it could not be blocked by N-nitro-l-arginine methyl ester (10−5 mol/l) and indomethacin (10−4 mol/l). We used GSK2193874 (10−7 mol/l) to confirm that in all groups this dilation was dependent on TRPV4 activation. Dilation in response to the TRPV4 agonist GSK1016790A (10−9–10−5 mol/l) was also reduced in hypertensive mice, and this defect was corrected by eplerenone. In hypertensive and eplerenone-treated animals, TRPV4 inhibition reduced myogenic tone, an effect that was not observed in arterioles from control animals. Eplerenone treatment also improved cognitive function and reduced microglia density in hypertensive mice. These data suggest that the mineralocorticoid receptor is a potential therapeutic target to improve cerebrovascular function and cognition during hypertension. NEW & NOTEWORTHY Vascular dementia is a growing public health issue that lacks effective treatments. Transient receptor potential vanilloid (TRPV)4 channels are important regulators of parenchymal arteriole dilation, and they modulate myogenic tone. The data presented here suggest that TRPV4 channel expression is regulated by the mineralocorticoid receptor (MR). MR blockade also improves cognitive function during hypertension. MR blockade might be a potential therapeutic approach to improve cerebrovascular function and cognition in patients with hypertension.

scholarly journals Interleukin-9 Deletion Relieves Vascular Dysfunction and Decreases Blood Pressure via the STAT3 Pathway in Angiotensin II-Treated Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yunzhao Yang ◽  
Shaoqun Tang ◽  
Chunchun Zhai ◽  
Xin Zeng ◽  
Qingjian Liu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Inflammatory Response ◽  
Vascular Dysfunction ◽  
Control Group ◽  
Dependent Manner ◽  
Ang Ii ◽  
Stat3 Pathway

Background. Multiple interleukin (IL) family members were reported to be closely related to hypertension. We aimed to investigate whether IL-9 affects angiotensin II- (Ang II-) induced hypertension in mice. Methods. Mice were treated with Ang II, and IL-9 expression was determined. In addition, effects of IL-9 knockout (KO) on blood pressure were observed in Ang II-infused mice. To determine whether the effects of IL-9 on blood pressure was mediated by the signal transducer and activator of the transcription 3 (STAT3) pathway, Ang II-treated mice were given S31-201. Furthermore, circulating IL-9 levels in patients with hypertension were measured. Results. Ang II treatment increased serum and aortic IL-9 expression in a dose-dependent manner; IL-9 levels were the highest in the second week and continued to remain high into the fourth week after the treatment. IL-9 KO downregulated proinflammatory cytokine expression, whereas it upregulated anti-inflammatory cytokine levels, relieved vascular dysfunction, and decreased blood pressure in Ang II-infused mice. IL-9 also reduced smooth muscle 22α (SM22α) expression and increased osteopontin (OPN) levels both in mice and in vitro. The effects of IL-9 KO on blood pressure and inflammatory response were significantly reduced by S31-201 treatment. Circulating IL-9 levels were significantly increased in patients with the hypertension group than in the control group, and elevated IL-9 levels positively correlated with both systolic blood pressure and diastolic blood pressure in patients with hypertension. Conclusions. IL-9 KO alleviates inflammatory response, prevents phenotypic transformation of smooth muscle, reduces vascular dysfunction, and lowers blood pressure via the STAT3 pathway in Ang II-infused mice. IL-9 might be a novel target for the treatment and prevention of clinical hypertension.

Mechanism of angiotensin II-induced arachidonic acid metabolite release in aortic smooth muscle cells: involvement of phospholipase D

1997 ◽  
Vol 136 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Junji Shinoda ◽  
Osamu Kozawa ◽  
Atsushi Suzuki ◽  
Yasuko Watanabe-Tomita ◽  
Yutaka Oiso ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Smooth Muscle Cells ◽  
Phospholipase D ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Ang Ii ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle

Abstract In a previous study, we have shown that angiotensin II (Ang II) activates phosphatidylcholinehydrolyzing phospholipase D due to Ang II-induced Ca2+ influx from extracellular space in subcultured rat aortic smooth muscle cells. In the present study, we have investigated the role of phospholipase D in Ang II-induced arachidonic acid (AA) metabolite release and prostacyclin synthesis in subcultured rat aortic smooth muscle cells. Ang II significantly stimulated AA metabolite release in a concentration-dependent manner in the range between 1 nmol/l and 0·1 μmol/l. d,l-Propranolol hydrochloride (propranolol), an inhibitor of phosphatidic acid phosphohydrolase, significantly inhibited the Ang II-induced release of AA metabolites. The Ang II-induced AA metabolite release was reduced by chelating extracellular Ca2+ with EGTA. Genistein, an inhibitor of protein tyrosine kinases, significantly suppressed the Ang II-induced AA metabolite release. 1,6-Bis-(cyclohexyloximinocarbonylamino)-hexane (RHC-80267), a potent and selective inhibitor of diacylglycerol lipase, significantly inhibited the Ang II-induced AA metabolite release. Both propranolol and RHC-80267 inhibited the Ang II-induced synthesis of 6-keto-prostaglandin F1α, a stable metabolite of prostacyclin. The synthesis was suppressed by genistein. These results strongly suggest that the AA metabolite release induced by Ang II is mediated, at least in part, through phosphatidylcholine hydrolysis by phospholipase D activation in aortic smooth muscle cells. European Journal of Endocrinology 136 207–212

scholarly journals The G0/G1 switch gene 2 is a novel PPAR target gene

2005 ◽  
Vol 392 (2) ◽  
pp. 313-324 ◽  
Author(s):  
Fokko Zandbergen ◽  
Stéphane Mandard ◽  
Pascal Escher ◽  
Nguan Soon Tan ◽  
David Patsouris ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Target Gene ◽  
Mrna Level ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Wild Type ◽  
Hepatic Expression ◽  
Peroxisome Proliferator Activated Receptors ◽  
Novel Target ◽  
Responsive Element

PPARs (peroxisome-proliferator-activated receptors) α, β/δ and γ are a group of transcription factors that are involved in numerous processes, including lipid metabolism and adipogenesis. By comparing liver mRNAs of wild-type and PPARα-null mice using microarrays, a novel putative target gene of PPARα, G0S2 (G0/G1 switch gene 2), was identified. Hepatic expression of G0S2 was up-regulated by fasting and by the PPARα agonist Wy14643 in a PPARα-dependent manner. Surprisingly, the G0S2 mRNA level was highest in brown and white adipose tissue and was greatly up-regulated during mouse 3T3-L1 and human SGBS (Simpson–Golabi–Behmel syndrome) adipogenesis. Transactivation, gel shift and chromatin immunoprecipitation assays indicated that G0S2 is a direct PPARγ and probable PPARα target gene with a functional PPRE (PPAR-responsive element) in its promoter. Up-regulation of G0S2 mRNA seemed to be specific for adipogenesis, and was not observed during osteogenesis or myogenesis. In 3T3-L1 fibroblasts, expression of G0S2 was associated with growth arrest, which is required for 3T3-L1 adipogenesis. Together, these data indicate that G0S2 is a novel target gene of PPARs that may be involved in adipocyte differentiation.

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