Abstract 1: Deletion of the Mapk-p38 From Vascular Smooth Muscle Cells and Cardiomyocytes Causes Hypotension and Dilated Cardiomyopathy in Angiotensin II Dependent Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Susanne Mende ◽  
Katharina Bottermann ◽  
Stefanie Stamer ◽  
Manuel Thieme ◽  
Axel Gödecke ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Dilated Cardiomyopathy ◽  
Vascular Smooth Muscle Cells ◽  
Vascular Injury ◽  
Muscle Cells ◽  
Ang Ii

The heart and the vasculature are key targets of angiotensin (Ang) II. In this regard, Ang II acting via Ang II type 1 (AT1)-receptors induces hypertension, cardiac hypertrophy and vascular injury. Since AT1-receptor stimulation have been shown to activate the mitogen activated protein kinase (MAPK) p38 leading to hypertrophy, migration and remodelling in cardiomocytes and vascular smooth muscle cells (VSMC)s in vitro, the MAPK p38 is considered as a major contributor in Ang II mediated cardiac and vascular injury. In order to investigate its role in Ang II dependent hypertension, we generated mice lacking p38alpha only in VSMC and cardiomyocytes (p38KO) using Cre-Loxp technology with a KISM22-cre transgene on a Bl6/C57 background. The specificity of p38alpha deletion was verified by western blot analysis. While cardiac function did not differ between both groups, blood pressures (BPs) were significantly lower under baseline conditions in p38KO mice compared to controls (106.4±5.2 vs. 123.6±5.4 mmHg; p<0.05). To test whether p38KO mice were protected from hypertensive heart failure and vascular injury, we infused Ang II (1000ng/kg/min) for 2 weeks. Ang II infusion caused a significantly attenuated increase in BPs in p38KOs than in controls (117.9±9.7 vs. 148.0±18.8mmHg; p<0.001). This effect could not be explained by an attenuated vascular response to Ang II in p38KOs, as acute pressor responses to Ang II in vivo and in the isolated perfused kidney as well as changes in renal blood flow were not attenuated in p38KO compared to controls. Surprisingly, in p38KOs, chronic Ang II infusion caused exaggerated cardiac fibrosis and severe dilated cardiomyopathy which was already apparent on day two after Ang II infusion (ejection fraction: 26.6±8.5 (p38KO) vs. 60.8±9.6% (control); p <0.001, diastolic volume: 116.9±8.6 vs. 60.2±7.6μl, p <0.001; systolic volume: 88.9±10.3 vs. 24.6±6.7μl, p <0.001). In summary, these results suggest a divergent role of p38 in regulating blood pressure and in the pathogenesis of heart failure as Ang II induces blood pressure independent dilated cardiomyopathy in p38KO mice. However, more studies are necessary to reveal the underlying mechanism.

scholarly journals Extended Cleavage Specificity of the Rat Vascular Chymase, a Potential Blood Pressure Regulating Enzyme Expressed by Rat Vascular Smooth Muscle Cells

2020 ◽  
Vol 21 (22) ◽  
pp. 8546 ◽  
Author(s):  
Petter Berglund ◽  
Srinivas Akula ◽  
Zhirong Fu ◽  
Michael Thorpe ◽  
Lars Hellman
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Phage Display ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Cleavage Site ◽  
Muscle Cells ◽  
Ang Ii ◽  
Cleavage Specificity

Serine proteases constitute the major protein content of the cytoplasmic granules of several hematopoietic cell lineages. These proteases are encoded from four different loci in mammals. One of these loci, the chymase locus, has in rats experienced a massive expansion in the number of functional genes. The human chymase locus encodes 4 proteases, whereas the corresponding locus in rats contains 28 such genes. One of these new genes has changed tissue specificity and has been found to be expressed primarily in vascular smooth muscle cells, and therefore been named rat vascular chymase (RVC). This β-chymase has been claimed to be a potent angiotensin-converting enzyme by cleaving angiotensin (Ang) I into Ang II and thereby having the potential to regulate blood pressure. To further characterize this enzyme, we have used substrate phage display and a panel of recombinant substrates to obtain a detailed quantitative view of its extended cleavage specificity. RVC was found to show a strong preference for Phe and Tyr in the P1 position, but also to accept Leu and Trp in this position. A strong preference for Ser or Arg in the P1’ position, just C-terminally of the cleavage site, and a preference for aliphatic amino acids in most other positions surrounding the cleavage site was also seen. Interesting also was a relatively strict preference for Gly in positions P3’ and P4’. RVC thereby shares similarity in its specificity to the mouse mucosal mast cell chymase mMCP-1, which efficiently converts Ang I to Ang II. This similarity adds support for the role of β-chymases as potent angiotensin converters in rodents, as their α-chymases, which have the capacity to efficiently convert Ang I into Ang II in other mammalian lineages, have become elastases. However, interestingly we found that RVC cleaved both after Arg2 and Phe8 in Ang I. Furthermore this cleavage was more than two hundred times less efficient than the consensus site obtained from the phage display analysis, indicating that RVC has a very low ability to cleave Ang I, raising serious doubts about its role in Ang I conversion.

scholarly journals RGS5 Attenuates Baseline Activity of ERK1/2 and Promotes Growth Arrest of Vascular Smooth Muscle Cells

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1748
Author(s):  
Eda Demirel ◽  
Caroline Arnold ◽  
Jaspal Garg ◽  
Marius Andreas Jäger ◽  
Carsten Sticht ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Genetic Ablation ◽  
Variable Expression ◽  
Arterial Blood

The regulator of G-protein signaling 5 (RGS5) acts as an inhibitor of Gαq/11 and Gαi/o activity in vascular smooth muscle cells (VSMCs), which regulate arterial tone and blood pressure. While RGS5 has been described as a crucial determinant regulating the VSMC responses during various vascular remodeling processes, its regulatory features in resting VSMCs and its impact on their phenotype are still under debate and were subject of this study. While Rgs5 shows a variable expression in mouse arteries, neither global nor SMC-specific genetic ablation of Rgs5 affected the baseline blood pressure yet elevated the phosphorylation level of the MAP kinase ERK1/2. Comparable results were obtained with 3D cultured resting VSMCs. In contrast, overexpression of RGS5 in 2D-cultured proliferating VSMCs promoted their resting state as evidenced by microarray-based expression profiling and attenuated the activity of Akt- and MAP kinase-related signaling cascades. Moreover, RGS5 overexpression attenuated ERK1/2 phosphorylation, VSMC proliferation, and migration, which was mimicked by selectively inhibiting Gαi/o but not Gαq/11 activity. Collectively, the heterogeneous expression of Rgs5 suggests arterial blood vessel type-specific functions in mouse VSMCs. This comprises inhibition of acute agonist-induced Gαq/11/calcium release as well as the support of a resting VSMC phenotype with low ERK1/2 activity by suppressing the activity of Gαi/o.

scholarly journals Apolipoprotein J/Clusterin Is Induced in Vascular Smooth Muscle Cells After Vascular Injury

Circulation ◽  
2001 ◽  
Vol 104 (12) ◽  
pp. 1407-1412 ◽  
Author(s):  
Masaaki Miyata ◽  
Sadatoshi Biro ◽  
Hiroshi Kaieda ◽  
Hideyuki Eto ◽  
Koji Orihara ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Vascular Injury ◽  
Muscle Cells ◽  
Apolipoprotein J

Angiotensin II modulates frizzled-2 receptor expression in rat vascular smooth muscle cells

2005 ◽  
Vol 108 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Giovanna CASTOLDI ◽  
Serena REDAELLI ◽  
Willy M. M. van de GREEF ◽  
Cira R. T. di GIOIA ◽  
Giuseppe BUSCA ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Ang Ii ◽  
Aortic Smooth Muscle

Ang II (angiotensin II) has multiple effects on vascular smooth muscle cells through the modulation of different classes of genes. Using the mRNA differential-display method to investigate gene expression in rat aortic smooth muscle cells in culture in response to 3 h of Ang II stimulation, we observed that Ang II down-regulated the expression of a member of the family of transmembrane receptors for Wnt proteins that was identified as Fzd2 [Fzd (frizzled)-2 receptor]. Fzds are a class of highly conserved genes playing a fundamental role in the developmental processes. In vitro, time course experiments demonstrated that Ang II induced a significant increase (P<0.05) in Fzd2 expression after 30 min, whereas it caused a significant decrease (P<0.05) in Fzd2 expression at 3 h. A similar rapid up-regulation after Ang II stimulation for 30 min was evident for TGFβ1 (transforming growth factor β1; P<0.05). To investigate whether Ang II also modulated Fzd2 expression in vivo, exogenous Ang II was administered to Sprague–Dawley rats (200 ng·kg−1 of body weight·min−1; subcutaneously) for 1 and 4 weeks. Control rats received normal saline. After treatment, systolic blood pressure was significantly higher (P<0.01), whereas plasma renin activity was suppressed (P<0.01) in Ang II- compared with the saline-treated rats. Ang II administration for 1 week did not modify Fzd2 expression in aorta of Ang II-treated rats, whereas Ang II administration for 4 weeks increased Fzd2 mRNA expression (P<0.05) in the tunica media of the aorta, resulting in a positive immunostaining for fibronectin at this time point. In conclusion, our data demonstrate that Ang II modulates Fzd2 expression in aortic smooth muscle cells both in vitro and in vivo.

scholarly journals Nox5 in Vascular Smooth Muscle Cells Mediates Ang II‐Induced Renal Fibrosis and Inflammation

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Augusto Montezano ◽  
Francisco Rios ◽  
Livia Camargo ◽  
Roberto Palacios‐Ramirez ◽  
Antoine Tarjus ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Renal Fibrosis ◽  
Muscle Cells ◽  
Ang Ii

Abstract MP19: Smooth Muscle Cell Cytochrome B5 Reductase 3 Causes Heart Failure With Reduced Ejection Fraction Under Hypoxic Stress

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Brittany G Durgin ◽  
Adam C Straub ◽  
Katherine C Wood ◽  
Scott A Hahn
Keyword(s):  
Heart Failure ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Ejection Fraction ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Cytochrome B5 ◽  
Muscle Cells ◽  
Right Heart

Pulmonary hypertension causes increased pulmonary vascular resistance and right heart failure. Nitric oxide (NO) binds to its receptor soluble guanylyl cyclase (sGC) within vascular smooth muscle cells in its reduced heme (Fe 2+ ) form to increase intracellular cGMP production, activate protein kinase G signaling, and induce vessel relaxation. In pulmonary hypertension, endothelial damage leading to decreased NO bioavailability combined with oxidation of the sGC heme (Fe 3+ ) in vascular smooth muscle cells rendering it NO-insensitive results in vasonstriction. Notably, we have previously shown that cytochrome b5 reductase 3 (CYB5R3) in vascular smooth muscle cells is an sGC reductase (Fe 3+ to Fe 2+ ) that maintains NO-dependent vasodilation in vascular disease. We therefore hypothesized that CYB5R3 confers protection in pulmonary hypertension. To test this, we subjected smooth muscle cell-specific CYB5R3 knockout mice (SMC CYB5R3 KO) to 21 days of continuous hypoxia (10% O 2 ) and assessed vascular and cardiac function. We found that SMC CYB5R3 KO led to enhanced cardiac hypertrophy when compared to wild-type (WT) controls (n=8/ group). Specifically, SMC CYB5R3 KO mice had a larger right ventricle per tibia size, left ventricle mass, and Fulton index compared to WT (n=8/ group). Moreover, SMC CYB5R3 KO mice had a significantly impaired ejection fraction and fractional shortening, and increased left ventricular posterior wall pressure (n=3-5/group). No differences in right heart function or overall cardiac fibrosis were observed between groups (n=3-5/group). With respect to vascular function, hypoxic pulmonary arteries from SMC CYB5R3 KO mice also had a blunted response to sodium nitroprusside induced NO-dependent vasodilation though no difference in sGC activator BAY 58-2667 induced NO-independent vasodilation was observed as compared to WT (n=8-11/ group). No differences in pulmonary arterial sGC levels or medial area were observed between groups (n=6-7). Combined, these data implicate that loss of SMC CYB5R3 exacerbates cardiomyocyte hypertrophy and reduces cardiac function independent of pulmonary pressure differences.

K depletion alters angiotensin II receptor expression in vascular smooth muscle cells

1990 ◽  
Vol 258 (5) ◽  
pp. C849-C854 ◽  
Author(s):  
S. L. Linas ◽  
R. Marzec-Calvert ◽  
M. E. Ullian
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Receptor Expression ◽  
Ang Ii ◽  
Surface Receptors ◽  
K Depletion

Dietary K depletion (KD) results in increases in the number of angiotensin II (ANG II) receptors and prevents ANG II-induced downregulation of ANG II receptors in membrane preparations of vessels from KD animals. Because dietary KD results in changes in factors other than K, we K depleted vascular smooth muscle cells (VSMC) in culture to determine the specific effects of KD on ANG II receptor expression and processing. Scatchard analysis of ANG II uptake at 4 degrees C revealed that the number of surface receptors was increased by 37% in cells in which K had been reduced by 45%. This increase also occurred in the presence of cycloheximide. To determine the effect of KD on receptor processing, we measured the number of surface receptors after exposure to ANG II in concentrations sufficient to cause down-regulation. After 30-min exposure to ANG II, the number of surface receptors was reduced by 63% in control cells but only 33% in KD cells. Thirty minutes after withdrawing ANG II, surface binding returned to basal levels in control cells but was still reduced by 20% in KD cells. To determine the functional significance of impaired receptor processing, we measured ANG II uptake at 21 degrees C. Uptake at 21 degrees C depends on the functional number of receptors, i.e., the absolute number of surface receptors and the rate at which receptors are recycled to the surface after ANG II binding. ANG II uptake at 21 degrees C was reduced by 50% in KD cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document