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Collagen crosslinking, mediated by lysyl oxidase, is an adaptive mechanism of the cardiac repair process initiated by cardiac fibroblasts postmyocardial injury. However, excessive crosslinking leads to cardiac wall stiffening, which impairs the contractile properties of the left ventricle and leads to heart failure. In this study, we investigated the role of periostin, a matricellular protein, in the regulation of lysyl oxidase in cardiac fibroblasts in response to angiotensin II and TGFβ1. Our results indicated that periostin silencing abolished the angiotensin II and TGFβ1-mediated upregulation of lysyl oxidase. Furthermore, the attenuation of periostin expression resulted in a notable reduction in the activity of lysyl oxidase. Downstream of periostin, ERK1/2 MAPK signaling was found to be activated, which in turn transcriptionally upregulates the serum response factor to facilitate the enhanced expression of lysyl oxidase. The periostin-lysyl oxidase association was also positively correlated in an in vivo rat model of myocardial infarction. The expression of periostin and lysyl oxidase was upregulated in the collagen-rich fibrotic scar tissue of the left ventricle. Remarkably, echocardiography data showed a reduction in the left ventricular wall movement, ejection fraction, and fractional shortening, indicative of enhanced stiffening of the cardiac wall. These findings shed light on the mechanistic role of periostin in the collagen crosslinking initiated by activated cardiac fibroblasts. Our findings signify periostin as a possible therapeutic target to reduce excessive collagen crosslinking that contributes to the structural remodeling associated with heart failure., (© 2024 John Wiley & Sons Ltd.)

As a main extraction compound from Scutellaria baicalensis Georgi, Baicalin exhibits various biological activities. However, the underlying mechanism of Baicalin on hypertension-induced heart injury remains unclear. In vivo, mice were infused with angiotensin II (Ang II; 500 ng/kg/min) or saline using osmotic pumps, followed by intragastrically administrated with Baicalin (5 mg/kg/day) for 4 weeks. In vitro, H9C2 cells were stimulated with Ang II (1 μM) and treated with Baicalin (12.5, 25 and 50 μM). Baicalin treatment significantly attenuated the decrease in left ventricular ejection fraction and left ventricular fractional shortening, increase in left ventricular mass, left ventricular systolic volume and left ventricular diastolic volume of Ang II infused mice. Moreover, Baicalin treatment reversed 314 differentially expressed transcripts in the cardiac tissues of Ang II infused mice, and enriched multiple enriched signalling pathways (including apoptosis, autophagy, AMPK/mTOR signalling pathway). Consistently, Baicalin treatment significantly alleviated Ang II-induced cell apoptosis in vivo and in vitro. Baicalin treatment reversed the up-regulation of Bax, cleaved-caspase 3, cleaved-caspase 9, and the down-regulation of Bcl-2. Meanwhile, Baicalin treatment alleviated Ang II-induced increase of autophagosomes, restored autophagic flux, and down-regulated LC3II, Beclin 1, as well as up-regulated SQSTM1/p62 expression. Furthermore, autophagy inhibitor 3-methyladenine treatment alleviated the increase of autophagosomes and the up-regulation of Beclin 1, LC3II, Bax, cleaved-caspase 3, cleaved-caspase 9, down-regulation of SQSTM1/p62 and Bcl-2 expression after Ang II treated, which similar to co-treatment with Baicalin. Baicalin treatment reduced the ratio of p-AMPK/AMPK, while increased the ratio of p-mTOR/mTOR. Baicalin alleviated Ang II-induced cardiomyocyte apoptosis and autophagy, which might be related to the inhibition of the AMPK/mTOR pathway., (© 2024 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Heart failure is a leading cause of death in the elderly. Traditional Chinese medicine, a verified alternative therapeutic regimen, has been used to treat heart failure, which is less expensive and has fewer adverse effects. In this study, a total of 15 active ingredients of Astragalus membranaceus (Huangqi, HQ) were obtained; among them, Isorhamnetin, Quercetin, Calycosin, Formononetin, and Kaempferol were found to be linked to heart failure. Ang II significantly enlarged the cell size of cardiomyocytes, which could be partially reduced by Quercetin, Isorhamnetin, Calycosin, Kaempferol, or Formononetin. Ang II significantly up-regulated ANP, BNP, β-MHC, and CTGF expressions, whereas Quercetin, Isorhamnetin, Calycosin, Kaempferol or Formononetin treatment partially downregulated ANP, BNP, β-MHC and CTGF expressions. Five active ingredients of HQ attenuated inflammation in Ang II-induced cardiomyocytes by inhibiting the levels of TNF-α, IL-1β, IL-18 and IL-6. Molecular docking shows Isorhamnetin, Quercetin, Calycosin, Formononetin and Kaempferol can bind with its target protein ESR1 in a good bond by intermolecular force. Quercetin, Calycosin, Kaempferol or Formononetin treatment promoted the expression levels of ESR1 and phosphorylated ESR1 in Ang II-stimulated cardiomyocytes; however, Isorhamnetin treatment had no effect on ESR1 and phosphorylated ESR1 expression levels. In conclusion, our results comprehensively illustrated the bioactives, potential targets, and molecular mechanism of HQ against heart failure. Isorhamnetin, Quercetin, Calycosin, Formononetin and Kaempferol might be the primary active ingredients of HQ, dominating its cardioprotective effects against heart failure through regulating ESR1 expression, which provided a basis for the clinical application of HQ to regulate cardiac hypertrophy and heart failure., (© 2024 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Aim: Protein disulfide isomerases (PDIs) are involved in platelet aggregation and intravascular thrombosis, but their role in regulating endothelial function is unclear. Here, we characterized the involvement of vascular PDIA1 in angiotensin II (Ang II)-induced endothelial dysfunction in mice., Methods: Endothelial dysfunction was induced in C57BL/6JCmd male mice via Ang II subcutaneous infusion, and PDIA1 was inhibited with bepristat. Endothelial function was assessed in vivo with magnetic resonance imaging and ex vivo with a myography, while arterial stiffness was measured as pulse wave velocity. Nitric oxide (NO) bioavailability was measured in the aorta (spin-trapping electron paramagnetic resonance) and plasma (NO 2 - and NO 3 - levels). Oxidative stress, eNOS uncoupling (DHE-based aorta staining), and thrombin activity (thrombin-antithrombin complex; calibrated automated thrombography) were evaluated., Results: The inhibition of PDIA1 by bepristat in Ang II-treated mice prevented the impairment of NO-dependent vasodilation in the aorta as evidenced by the response to acetylcholine in vivo, increased systemic NO bioavailability and the aortic NO production, and decreased vascular stiffness. Bepristat's effect on NO-dependent function was recapitulated ex vivo in Ang II-induced endothelial dysfunction in isolated aorta. Furthermore, bepristat diminished the Ang II-induced eNOS uncoupling and overproduction of ROS without affecting thrombin activity., Conclusion: In Ang II-treated mice, the inhibition of PDIA1 normalized the NO-ROS balance, prevented endothelial eNOS uncoupling, and, thereby, improved vascular function. These results indicate the importance of vascular PDIA1 in regulating endothelial function, but further studies are needed to elucidate the details of the mechanisms involved., (© 2024 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.)

Alcohol consumption is popular worldwidely and closely associated with cardiovascular diseases. Influences of paternal preconception alcohol consumption on offspring cerebral arteries are largely unknown. Male rats were randomly given alcohol or water before being mated with alcohol-naive females to produce alcohol- and control-sired offspring. Middle cerebral artery (MCA) was tested with a Danish Myo Technology wire myograph, patch-clamp, IONOPTIX, immunofluorescence and quantitative PCR. Alcohol consumption enhanced angiotensin II (AngII)-mediated constriction in male offspring MCA mainly via AT1R. PD123,319 only augmented AngII-induced constriction in control offspring. AngII and Bay K8644 induced stronger intracellular calcium transient in vascular smooth muscle cells (VSMCs) from MCA of alcohol offspring. L-type voltage-dependent calcium channel (L-Ca 2+ ) current at baseline and after AngII-stimulation was higher in VSMCs. Influence of large-conductance calcium-activated potassium channel (BK C a ) was lower. Caffeine induced stronger constriction and intracellular calcium release in alcohol offspring. Superoxide anion was higher in alcohol MCA than control. Tempol and thenoyltrifluoroacetone alleviated AngII-mediated contractions, while inhibition was significantly higher in alcohol group. The mitochondria were swollen in alcohol MCA. Despite lower Kcnma1 and Prkce expression, many genes expressions were higher in alcohol group. Hypoxia induced reactive oxygen species production and increased AT1R expression in control MCA and rat aorta smooth muscle cell line. In conclusion, this study firstly demonstrated paternal preconception alcohol potentiated AngII-mediated vasoconstriction in offspring MCA via ROS-AT1R. Alcohol consumption increased intracellular calcium via L-Ca 2+ channel and endoplasmic reticulum and decreased BK Ca function. The present study provided new information for male reproductive health and developmental origin of cerebrovascular diseases., (© 2024 The Authors. Addiction Biology published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Pathological cardiac hypertrophy is a key contributor to heart failure, and the molecular mechanisms underlying honokiol (HNK)-mediated cardioprotection against this condition remain worth further exploring. This study aims to investigate the effect of HNK on angiotensin II (Ang II)-induced myocardial hypertrophy and elucidate the underlying mechanisms. Sprague-Dawley rats were exposed to Ang II infusion, followed by HNK or vehicle treatment for 4 weeks. Our results showed that HNK treatment protected against Ang II-induced myocardial hypertrophy, fibrosis and dysfunction in vivo and inhibited Ang II-induced hypertrophy in neonatal rat ventricular myocytes in vitro. Mechanistically, HNK suppressed the Ang II-induced Nur77 expression at the transcriptional level and promoted ubiquitination-mediated degradation of Nur77, leading to dissociation of the Nur77-LKB1 complex. This facilitated the translocation of LKB1 into the cytoplasm and activated the LKB1-AMPK pathway. Our findings suggest that HNK attenuates pathological remodelling and cardiac dysfunction induced by Ang II by promoting dissociation of the Nur77-LKB1 complex and subsequent activation of AMPK signalling. This study uncovers a novel role of HNK on the LKB1-AMPK pathway to protect against cardiac hypertrophy., (© 2023 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Angiotensin II (Ang II), a key mediator of vascular diseases, is linked to methylglyoxal (MGO) formation, a by-product of glucose metabolism implicated in vascular complications. The glyoxalase system, consisting of glyoxalase 1 (Glo1) and reduced glutathione (GSH), is responsible for detoxifying MGO. This study investigated the effect of Ang II on Glo1 activity and expression in vascular smooth muscle cells (VSMCs). Primary VSMCs were isolated from rat aortas and exposed to Ang II under standard or high glucose conditions. We examined Glo1 activity, expression, intracellular GSH, and methylglyoxal-derived hydroimidazolone 1 (MG-H1) levels. We also analyzed the expressions of nuclear factor-κB (NF-κB) p65 and nuclear factor erythroid 2-related factor 2 (Nrf2) as potential regulators of Glo1 expression. The results demonstrated that Ang II reduced Glo1 activity, expression, and GSH levels while increasing MG-H1 levels in VSMCs. Telmisartan and irbesartan, AT1R blockers, restored Glo1 activity, expression, and GSH levels and alleviated MG-H1 levels. Treatment with AT1R blockers or inhibitors targeting signaling pathways involved in Ang II-induced responses mitigated these effects. High glucose exacerbated the reduction in Glo1 activity and expression. In conclusion, this study provides evidence that Ang II reduces Glo1 activity and expression in VSMCs, which may contribute to developing vascular complications in diabetes. AT1R blockers and inhibitors targeting specific signaling pathways show potential in restoring Glo1 function and mitigating MGO-associated damage. These findings highlight the complex interactions between RAS, MGO, and vascular diseases, highlighting potential therapeutic targets for diabetic vascular complications., (© 2023 John Wiley & Sons Ltd.)

Previous studies have reported that visfatin can regulate macrophage polarisation, which has been demonstrated to participate in cardiac remodelling. The aims of this study were to investigate whether visfatin participates in transverse aortic constriction (TAC)-induced cardiac remodelling by regulating macrophage polarisation. First, TAC surgery and angiotensin II (Ang II) infusion were used to establish a mouse cardiac remodelling model, visfatin expression was measured, and the results showed that TAC surgery or Ang II infusion increased visfatin expression in the serum and heart in mice, and phenylephrine or hydrogen peroxide promoted the release of visfatin from macrophages in vitro. All these effects were dose-dependently reduced by superoxide dismutase. Second, visfatin was administered to TAC mice to observe the effects of visfatin on cardiac remodelling. We found that visfatin increased the cross-sectional area of cardiomyocytes, aggravated cardiac fibrosis, exacerbated cardiac dysfunction, further regulated macrophage polarisation and aggravated oxidative stress in TAC mice. Finally, macrophages were depleted in TAC mice to investigate whether macrophages mediate the regulatory effect of visfatin on cardiac remodelling, and the results showed that the aggravating effects of visfatin on oxidative stress and cardiac remodelling were abrogated. Our study suggests that visfatin enhances cardiac remodelling by promoting macrophage polarisation and enhancing oxidative stress. Visfatin may be a potential target for the prevention and treatment of clinical cardiac remodelling., (© 2023 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Background Prolonged activation of angiotensin II is the main mediator that contributes to the development of heart diseases, so converting angiotensin II into angiotensin 1-7 has emerged as a new strategy to attenuate detrimental effects of angiotensin II. Prolylcarboxypeptidase is a lysosomal pro-X carboxypeptidase that is able to cleave angiotensin II at a preferential acidic pH optimum. However, insufficient attention has been given to the cardioprotective functions of prolylcarboxylpeptidase. Methods and Results We established a CRISPR/CRISPR-associated protein 9-mediated global prolylcarboxylpeptidase-knockout and adeno-associated virus serotype 9-mediated cardiac prolylcarboxylpeptidase overexpression mouse models, which were challenged with the angiotensin II infusion (2 mg/kg per day) for 4 weeks, aiming to investigate the cardioprotective effect of prolylcarboxylpeptidase against hypertensive cardiac hypertrophy. Prolylcarboxylpeptidase expression was upregulated after 2 weeks of angiotensin II infusion and then became downregulated afterward in wild-type mouse myocardium, suggesting its compensatory function against angiotensin II stress. Moreover, angiotensin II-treated prolylcarboxylpeptidase-knockout mice showed aggravated cardiac remodeling and dampened cardiac contractility independent of hypertension. We also found that prolylcarboxylpeptidase localizes in cardiomyocyte lysosomes, and loss of prolylcarboxylpeptidase led to excessive angiotensin II levels in myocardial tissue. Further screening demonstrated that hypertrophic prolylcarboxylpeptidase-knockout hearts showed upregulated extracellular signal-regulated kinases 1/2 and downregulated protein kinase B activities. Importantly, adeno-associated virus serotype 9-mediated restoration of prolylcarboxylpeptidase expression in prolylcarboxylpeptidase-knockout hearts alleviated angiotensin II-induced hypertrophy, fibrosis, and cell death. Interestingly, the combination of adeno-associated virus serotype 9-mediated prolylcarboxylpeptidase overexpression and an antihypertensive drug, losartan, likely conferred more effective protection than a single treatment protocol to mitigate angiotensin II-induced cardiac dysfunction. Conclusions Our data demonstrate that prolylcarboxylpeptidase protects the heart from angiotensin II-induced hypertrophic remodeling by controlling myocardial angiotensin II levels.

Background A beneficial role for prostanoids in hypertension is suggested by clinical studies showing nonsteroidal anti-inflammatory drugs, which block the production of all prostanoids, cause sodium retention and exacerbate hypertension. Among prostanoids, prostaglandin E2 and its E-prostanoid receptor 4 receptor (EP4R) have been implicated in blood pressure control. Our previous study found that conditional deletion of EP4R from all tissues in adult mice exacerbates angiotensin II-dependent hypertension, suggesting a powerful effect of EP4R to resist blood pressure elevation. We also found that elimination of EP4R from vascular smooth muscle cells did not affect the severity of hypertension, suggesting nonvascular targets of prostaglandin E mediate this antihypertensive effect. Methods and Results Here we generated mice with cell-specific deletion of EP4R from macrophage-specific EP4 receptor knockouts or kidney epithelial cells (KEKO) to assess the contributions of EP4R in these cells to hypertension pathogenesis. Macrophage-specific EP4 receptor knockouts showed similar blood pressure responses to alterations in dietary sodium or chronic angiotensin II infusion as Controls. By contrast, angiotensin II-dependent hypertension was significantly augmented in KEKOs (mean arterial pressure: 146±3 mm Hg) compared with Controls (137±4 mm Hg; P =0.02), which was accompanied by impaired natriuresis in KEKOs. Because EP4R expression in the kidney is enriched in the collecting duct, we compared responses to amiloride in angiotensin II-infused KEKOs and Controls. Blockade of the epithelial sodium channel with amiloride caused exaggerated natriuresis in KEKOs compared with Controls (0.21±0.01 versus 0.15±0.02 mmol/24 hour per 20 g; P =0.015). Conclusions Our data suggest EP4R in kidney epithelia attenuates hypertension. This antihypertension effect of EP4R may be mediated by reducing the activity of the epithelial sodium channel, thereby promoting natriuresis.

Background Mice with cardiomyocyte-specific deletion of Bmal1, a core clock gene, had spontaneous abnormal cardiac metabolism, dilated cardiomyopathy, and shortened lifespan. However, the role of cardiomyocyte Bmal1 in pressure overload induced cardiac remodeling is unknown. Here we aimed to understand the contribution of cardiomyocyte Bmal1 to cardiac remodeling in response to pressure overload induced by transverse aortic constriction or chronic angiotensin Ⅱ (AngⅡ) infusion. Methods and Results By generating a tamoxifen-inducible cardiomyocyte-specific Bmal1 knockout mouse line (cKO) and challenging the mice with transverse aortic constriction or AngⅡ, we found that compared to littermate controls, the cKO mice displayed remarkably increased cardiac hypertrophy and augmented fibrosis both after transverse aortic constriction and AngⅡ induction, as assessed by echocardiographic, gravimetric, histologic, and molecular analyses. Mechanistically, RNA-sequencing analysis of the heart after transverse aortic constriction exposure revealed that the PI3K/AKT signaling pathway was significantly activated in the cKOs. Consistent with the in vivo findings, in vitro study showed that knockdown of Bmal1 in cardiomyocytes significantly promoted phenylephrine-induced cardiomyocyte hypertrophy and triggered fibroblast-to-myofibroblast differentiation, while inhibition of AKT remarkedly reversed the pro-hypertrophy and pro-fibrosis effects of Bmal1 knocking down. Conclusions These results suggest that postnatal deletion of Bmal1 in cardiomyocytes may promote pressure overload-induced cardiac remodeling. Moreover, we identified PI3K/AKT signaling pathway as the potential mechanistic ties between Bmal1 and cardiac remodeling.

Abdominal aortic aneurysm (AAA) is characterized by abdominal aorta dilatation and progressive structural impairment and is usually an asymptomatic and potentially lethal disease with a risk of rupture. To investigate the underlying mechanisms of AAA initiation and progression, seven AAA datasets related to human and mice were downloaded from the GEO database and reanalysed in the present study. After comprehensive bioinformatics analysis, we identified the enriched pathways associated with inflammation responses, vascular smooth muscle cell (VSMC) phenotype switching and cytokine secretion in AAA. Most importantly, we identified ATPase Na + /K + transporting subunit alpha 2 (ATP1A2) as a key gene that was significantly decreased in AAA samples of both human and mice; meanwhile, its reduction mainly occurred in VSMCs of the aorta; this finding was validated by immunostaining and Western blot in human and mouse AAA samples. Furthermore, we explored the potential upstream transcription factors (TFs) that regulate ATP1A2 expression. We found that the TF AT-rich interaction domain 3A (ARID3A) bound the promoter of ATP1A2 to suppress its expression. Our present study identified the ARID3A-ATP1A2 axis as a novel pathway in the pathological processes of AAA, further elucidating the molecular mechanism of AAA and providing potential therapeutic targets for AAA., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Background Elevated angiotensin II levels are thought to play an important role in atrial electrical and structural remodeling associated with atrial fibrillation. However, the mechanisms by which this remodeling occurs are still unclear. Accordingly, we explored the effects of angiotensin II on atrial remodeling using transgenic mice overexpressing angiotensin II type 1 receptor (AT1R) specifically in cardiomyocytes. Methods and Results Voltage-clamp techniques, surface ECG, programmed electrical stimulations along with quantitative polymerase chain reaction, Western blot, and Picrosirius red staining were used to compare the atrial phenotype of AT1R mice and their controls at 50 days and 6 months. Atrial cell capacitance and fibrosis were increased only in AT1R mice at 6 months, indicating the presence of structural remodeling. Ca 2+ ( I CaL ) and K + currents were not altered by AT1R overexpression (AT1R at 50 days). However, I CaL density and Ca V 1.2 messenger RNA expression were reduced by structural remodeling (AT1R at 6 months). Conversely, Na + current ( I Na ) was reduced (-65%) by AT1R overexpression (AT1R at 50 days) and the presence of structural remodeling (AT1R at 6 months) yields no further effect. The reduced I Na density was not explained by lower Na V 1.5 expression but was rather associated with an increase in sarcolemmal protein kinase C alpha expression in the atria, suggesting that chronic AT1R activation reduced I Na through protein kinase C alpha activation. Furthermore, connexin 40 expression was reduced in AT1R mice at 50 days and 6 months. These changes were associated with delayed atrial conduction time, as evidenced by prolonged P-wave duration. Conclusions Chronic AT1R activation leads to slower atrial conduction caused by reduced I Na density and connexin 40 expression.

Hypertension is associated with high circulating angiotensin II (Ang II). We have reported that autophagy regulates Ang II-induced vascular smooth muscle cell (VSMC) hypertrophy, but the mechanism mediating this effect is still unknown. Therefore, we studied how Ang II regulates LC3 levels in VSMCs and whether Bag3, a co-chaperone known to regulate LC3 total levels, may be involved in the effects elicited by Ang II. A7r5 cell line or rat aortic smooth muscle cell (RASMC) primary culture were stimulated with Ang II 100 nM for 24 h and LC3 I, LC3 II and Bag3 protein levels were determined by Western blot. MAP1LC3B mRNA levels were assessed by RT-qPCR. Ang II increased MAP1LC3B mRNA levels and protein levels of LC3 I, LC3 II and total LC3 (LC3 I + LC3 II). Cycloheximide, but not actinomycin D, abolished LC3 II and total LC3 increase elicited by Ang II in RASMCs. In A7r5 cells, cycloheximide prevented the Ang II-mediated increase of LC3 I and total LC3, but not LC3 II. Moreover, Ang II increased Bag3 levels, but this increase was not observed upon co-administration with either losartan 1 μM (AT1R antagonist) or Y-27632 10 μM (ROCK inhibitor). These results suggest that Ang II may regulate total LC3 content through transcriptional and translational mechanisms. Moreover, Bag3 is increased in response to Ang II by a AT1R/ROCK signalling pathway. These data provide preliminary evidence suggesting that Ang II may stimulate autophagy in VSMCs by increasing total LC3 content and LC3 processing., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Background Blood pressure and tissue perfusion are controlled in part by the level of intrinsic (myogenic) arterial tone. However, many of the molecular determinants of this response are unknown. We previously found that mice with targeted disruption of the gene encoding the angiotensin II type 1a receptor (AT1AR) ( Agtr1a ), the major murine angiotensin II type 1 receptor (AT1R) isoform, showed reduced myogenic tone; however, uncontrolled genetic events (in this case, gene ablation) can lead to phenotypes that are difficult or impossible to interpret. Methods and Results We tested the mechanosensitive function of AT1R using tamoxifen-inducible smooth muscle-specific AT1aR knockout (smooth muscle- Agtr1a -/- ) mice and studied downstream signaling cascades mediated by G q/11 and/or β-arrestins. FR900359, Sar1Ile4Ile8-angiotensin II (SII), TRV120027 and TRV120055 were used as selective G q/11 inhibitor and biased agonists to activate noncanonical β-arrestin and canonical G q/11 signaling of the AT1R, respectively. Myogenic and Ang II-induced constrictions were diminished in the perfused renal vasculature, mesenteric and cerebral arteries of smooth muscle- Agtr1a -/- mice. Similar effects were observed in arteries of global mutant Agtr1a -/- but not Agtr1b -/- mice. FR900359 decreased myogenic tone and angiotensin II-induced constrictions whereas selective biased targeting of AT1R-β-arrestin signaling pathways had no effects. Conclusions This study demonstrates that myogenic arterial constriction requires G q/11 -dependent signaling pathways of mechanoactivated AT1R but not G protein-independent, noncanonical pathways in smooth muscle cells.

Hypertensive cardiac remodelling is a common cause of heart failure. However, the molecular mechanisms regulating cardiac remodelling remain unclear. Pyruvate kinase isozyme type M2 (PKM2) is a key regulator of the processes of glycolysis and oxidative phosphorylation, but the roles in cardiac remodelling remain unknown. In the present study, we found that PKM2 was enhanced in angiotensin II (Ang II)-treated cardiac fibroblasts and hypertensive mouse hearts. Suppression of PKM2 by shikonin alleviated cardiomyocyte hypertrophy and fibrosis in Ang-II-induced cardiac remodelling in vivo. Furthermore, inhibition of PKM2 markedly attenuated the function of cardiac fibroblasts including proliferation, migration and collagen synthesis in vitro. Mechanistically, suppression of PKM2 inhibited cardiac remodelling by suppressing TGF-β/Smad2/3, Jak2/Stat3 signalling pathways and oxidative stress. Together, this study suggests that PKM2 is an aggravator in Ang-II-mediated cardiac remodelling. The negative modulation of PKM2 may provide a promising therapeutic approach for hypertensive cardiac remodelling., (© 2021 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Background Angiotensin II (Ang II), a critical mediator of hypertension, impairs neurovascular coupling. Since astrocytes are key regulators of neurovascular coupling, we sought to investigate whether Ang II impairs neurovascular coupling through modulation of astrocytic Ca 2+ signaling. Methods and Results Using laser Doppler flowmetry, we found that Ang II attenuates cerebral blood flow elevations induced by whisker stimulation or the metabotropic glutamate receptors agonist, 1S, 3R-1-aminocyclopentane- trans -1,3-dicarboxylic acid ( P <0.01). In acute brain slices, Ang II shifted the vascular response induced by 1S, 3R-1-aminocyclopentane- trans -1,3-dicarboxylic acid towards vasoconstriction ( P <0.05). The resting and 1S, 3R-1-aminocyclopentane- trans -1,3-dicarboxylic acid-induced Ca 2+ levels in the astrocytic endfeet were more elevated in the presence of Ang II ( P <0.01). Both effects were reversed by the AT1 receptor antagonist, candesartan ( P <0.01 for diameter and P <0.05 for calcium levels). Using photolysis of caged Ca 2+ in astrocytic endfeet or pre-incubation of 1,2-Bis(2-aminophenoxy)ethane- N,N,N',N' -tetra-acetic acid tetrakis (acetoxymethyl ester), we demonstrated the link between potentiated Ca 2+ elevation and impaired vascular response in the presence of Ang II ( P <0.001 and P <0.05, respectively). Both intracellular Ca 2+ mobilization and Ca 2+ influx through transient receptor potential vanilloid 4 mediated Ang II-induced astrocytic Ca 2+ elevation, since blockade of these pathways significantly prevented the intracellular Ca 2+ in response to 1S, 3R-1-aminocyclopentane- trans -1,3-dicarboxylic acid ( P <0.05). Conclusions These results suggest that Ang II through its AT1 receptor potentiates the astrocytic Ca 2+ responses to a level that promotes vasoconstriction over vasodilation, thus altering cerebral blood flow increases in response to neuronal activity.

Background Sex is a prominent risk factor for abdominal aortic aneurysms (AAAs), and angiotensin II (Ang II) induces AAA formation to a greater degree in male than in female mice. We previously reported that cytochrome P450 1B1 contributes to the development of hypertension, as well as AAAs, in male mice. We also found that a cytochrome P450 1B1-generated metabolite of testosterone, 6β-hydroxytestosterone (6β-OHT), contributes to Ang II-induced hypertension and associated cardiovascular and renal pathogenesis in male mice. The current study was conducted to determine the contribution of 6β-OHT to Ang II-induced AAA development in Apoe -/- male mice. Methods and Results Intact or castrated Apoe -/- /Cyp1b1 +/+ and Apoe -/- /Cyp1b1 -/- male mice were infused with Ang II or its vehicle for 28 days, and administered 6β-OHT every third day for the duration of the experiment. Abdominal aortas were then evaluated for development of AAAs. We observed a significant increase in the incidence and severity of AAAs in intact Ang II-infused Apoe -/- /Cyp1b1 +/+ mice, compared with vehicle-treated mice, which were minimized in castrated Apoe -/- /Cyp1b1 +/+ and intact Apoe -/- /Cyp1b1 -/- mice infused with Ang II. Treatment with 6β-OHT significantly restored the incidence and severity of AAAs in Ang II-infused castrated Apoe -/- /Cyp1b1 +/+ and intact Apoe -/- /Cyp1b1 -/- mice. However, administration of testosterone failed to increase AAA incidence and severity in Ang II-infused intact Apoe -/- /Cyp1b1 -/- mice. Conclusions Our results indicate that the testosterone-cytochrome P450 1B1-generated metabolite 6β-OHT contributes to Ang II-induced AAA development in Apoe -/- male mice.

The activation of Wnt/β-catenin pathway plays a pivotal role in promoting renal fibrosis. The activation of Wnt/β-catenin pathway relies on the binding of Wnts to Frizzled receptors on cell membrane. However, the factor regulating Wnts production remains unclear. Here, we demonstrated that transcriptional factor FoxM1 was significantly increased in obstructed kidneys and patients' kidneys with fibrosis. The up-regulation of FoxM1 mainly distributed in tubular epithelial cells. Pharmacological inhibition of FoxM1 down-regulated multi-Wnts elevation in UUO mice and attenuated renal fibrosis. In cultured renal tubular epithelial cells, overexpression of FoxM1 promoted 8 Wnts expression, while knock-down on FoxM1-suppressed multi-Wnts including Wnt1, Wnt2b and Wnt3 expression induced by Ang II. Chromatin immunoprecipitation PCR confirmed that FoxM1 bound to Wnt1, Wnt2b, Wnt3 promoters and luciferase assay further identified that the transcriptions of Wnt1, Wnt2b and Wnt3 were regulated by FoxM1. Thus, our findings show that multi-Wnt family members were regulated by transcriptional factor FoxM1. FoxM1 might be a key switch for activating β-catenin pathway and renal fibrosis. Therefore, FoxM1 might be a potential therapeutic target in manipulating renal fibrosis., (© 2021 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Background Menopause is associated with an increase in the prevalence and severity of hypertension in women. Although premenopausal females are protected against T cell-dependent immune activation and development of angiotensin II (Ang II) hypertension, this protection is lost in postmenopausal females. Therefore, the current study hypothesized that specific CD4 + T cell pathways are regulated by sex hormones and Ang II to mediate progression from premenopausal protection to postmenopausal hypertension. Methods and Results Menopause was induced in C57BL/6 mice via repeated 4-vinylcyclohexene diepoxide injections, while premenopausal females received sesame oil vehicle. A subset of premenopausal mice and all menopausal mice were infused with Ang II for 14 days (Control, Ang II, Meno/Ang II). Proteomic and phosphoproteomic profiles of CD4 + T cells isolated from spleens were examined. Ang II markedly increased CD4 + T cell protein abundance and phosphorylation associated with DNA and histone methylation in both premenopausal and postmenopausal females. Compared with premenopausal T cells, Ang II infusion in menopausal mice increased T cell phosphorylation of MP2K2, an upstream regulator of ERK, and was associated with upregulated phosphorylation at ERK targeted sites. Additionally, Ang II infusion in menopausal mice decreased T cell phosphorylation of TLN1, a key regulator of IL-2Rα and FOXP3 expression. Conclusions These findings identify novel, distinct T cell pathways that influence T cell-mediated inflammation during postmenopausal hypertension.

Acute respiratory distress syndrome/acute lung injury (ARDS/ALI) is histologically characterized by extensive alveolar barrier disruption and excessive fibroproliferation responses. Protectin DX (PDX) displays anti-inflammatory and potent inflammation pro-resolving actions. We sought to investigate whether PDX attenuates LPS (lipopolysaccharide)-induced lung injury via modulating epithelial cell injury repair, apoptosis and fibroblasts activation. In vivo, PDX was administered intraperitoneally (IP) with 200 ng/per mouse after intratracheal injection of LPS, which remarkedly stimulated proliferation of type II alveolar epithelial cells (AT II cells), reduced the apoptosis of AT II cells, which attenuated lung injury induced by LPS. Moreover, primary type II alveolar cells were isolated and cultured to assess the effects of PDX on wound repair, apoptosis, proliferation and transdifferentiation in vitro. We also investigated the effects of PDX on primary rat lung fibroblast proliferation and myofibroblast differentiation. Our result suggests PDX promotes primary AT II cells wound closure by inducing the proliferation of AT II cells and reducing the apoptosis of AT II cells induced by LPS, and promotes AT II cells transdifferentiation. Furthermore, PDX inhibits transforming growth factor-β 1 (TGF-β 1 ) induced fibroproliferation, fibroblast collagen production and myofibroblast transformation. Furthermore, the effects of PDX on epithelial wound healing and proliferation, fibroblast proliferation and activation partly via the ALX/ PI3K signalling pathway. These data present identify a new mechanism of PDX which targets the airway epithelial cell and fibroproliferation are potential for treatment of ARDS/ALI., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Angiotensin-converting enzyme-2 (ACE2) and Mas receptor are the major components of the ACE2/Ang 1-7/Mas axis and have been shown to play a protective role in hypertension and hypertensive nephropathy individually. However, the effects of dual deficiency of ACE2 and Mas (ACE2/Mas) on Ang II-induced hypertensive nephropathy remain unexplored, which was investigated in this study in a mouse model of hypertension induced in either ACE2 knockout (KO) or Mas KO mice and in double ACE2/Mas KO mice by subcutaneously chronic infusion of Ang II. Compared with wild-type (WT) animals, mice lacking either ACE2 or Mas significantly increased blood pressure over 7-28 days following a chronic Ang II infusion (P < .001), which was further exacerbated in double ACE2/Mas KO mice (P < .001). Furthermore, compared to a single ACE2 or Mas KO mice, mice lacking ACE2/Mas developed more severe renal injury including higher levels of serum creatinine and a further reduction in creatinine clearance, and progressive renal inflammation and fibrosis. Mechanistically, worsen hypertensive nephropathy in double ACE2/Mas KO mice was associated with markedly enhanced AT1-ERK1/2-Smad3 and NF-κB signalling, thereby promoting renal fibrosis and renal inflammation in the hypertensive kidney. In conclusion, ACE2 and Mas play an additive protective role in Ang II-induced hypertension and hypertensive nephropathy. Thus, restoring the ACE2/Ang1-7/Mas axis may represent a novel therapy for hypertension and hypertensive nephropathy., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Hypertension is the key factor for the development of cardiac fibrosis and diastolic dysfunction. Our previous study showed that knockout of sirtuin 3 (SIRT3) resulted in diastolic dysfunction in mice. In the present study, we explored the role of SIRT3 in angiotensin II (Ang-II)-induced cardiac fibrosis and pericyte-myofibroblast transition. NG2 tracing reporter NG2-DsRed mouse was crossed with wild-type (WT) mice and SIRT3KO mice. Cardiac function, cardiac fibrosis and reactive oxygen species (ROS) were measured. Mice infused with Ang-II for 28 days showed a significant reduction of SIRT3 expression in the mouse hearts. Knockout of SIRT3 sensitized Ang-II-induced elevation of isovolumic relaxation time (IVRT) and reduction of ejection fraction (EF) and fractional shortening (FS). Ang-II-induced cardiac fibrosis, capillary rarefaction and hypertrophy were further enhanced by knockout of SIRT3. NG2 pericyte tracing reporter mice infused with Ang-II had a significantly increased number of NG2-DsRed pericyte in the heart. Knockout of SIRT3 further enhanced Ang-II-induced increase of pericytes. To examine pericyte-myofibroblast/fibroblast transition, DsRed pericytes were co-stained with FSP-1 and α-SMA. Ang-II infusion led to a significant increase in numbers of DsRed + /FSP-1 + and DsRed + /α-SMA + cells, while SIRT3KO further developed pericyte-myofibroblast/fibroblast transition. In addition, knockout of SIRT3 promoted Ang-II-induced NADPH oxidase-derived ROS formation together with increased expression of transforming growth factor beta 1 (TGF-β1). We concluded that Ang-II induced cardiac fibrosis partly by the mechanisms involving SIRT3-mediated pericyte-myofibroblast/fibroblast transition and ROS-TGF-β1 pathway., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

To investigate the prevention of cardiac remodelling and inflammatory immune response after myocardial infarction (MI) via ACEI regulating dendritic cells (DCs), we explored whether the protective effect of ACEI was repressed under hyperlipidemic environment. In vivo, the survival rate and left ventricular function of the mice were recorded on day 7 after MI. Tissue samples of the myocardium, spleen, bone marrow and peripheral blood were assessed for Ang II concentration, inflammatory cytokines and DCs expression. In vitro, DCs were treated with ox-LDL + Ang II, simulating the internal environment of MI in ApoE -/- mice to explore the mechanism involved in the DCs maturation and inflammation. Under hyperlipidemic circumstances, we found that the cardioprotective effect of ACEI was attenuated through regulating DCs maturation and inflammation after MI, affecting survival rate and left ventricular function. Effects of lisinopril on the release of spleen-derived DCs and myocardial infiltration were also reduced under hyperlipidemic conditions. In vitro, immune maturation and inflammation of DCs were further induced by ox-LDL on the basis of Ang II treatment, as indicated by the upregulation of CD83, CD86, and the expressions of cytokines and chemokines. Furthermore, ox-LDL could activate TLR4-MyD88 signalling pathway, promoting IRAK-4 and NF-κB. The present study demonstrated that ACEI reduced the recruitment of DCs to the infarct site, leading to a higher survival rate and improved function. However, this effect was inhibited under hyperlipidemic environment. TLR4-MyD88 signalling pathway may be responsible for the molecular mechanism involved in the immune maturation and inflammation of DCs induced by ox-LDL., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Visfatin is an adipocytokine with important roles in endothelial angiogenesis. Hyperbaric oxygen (HBO) has been widely used to treat various medical illness with enhanced angiogenesis. The molecular effects of HBO on visfatin under hypoxia are poorly understood. This study aimed to investigate the effect of HBO on visfatin in hypoxic human coronary arterial endothelial cells (HCAECs). HCAECs under chemical hypoxia (antimycin A, 0.01 mmol/L) were exposed to HBO (2.5 atmosphere absolute; ATA) for 2-4 hours. Western blot, real-time polymerase chain reaction, electrophoretic mobility shift assay, luciferase promoter activity, migration and tube formation assay, and in vitro glucose uptake were measured. Visfatin protein expression increased in hypoxic HCAECs with earlier angiotensin II (AngII) secretion and c-Jun N-terminal kinase (JNK) phosphorylation, which could be effectively suppressed by the JNK inhibitor (SP600125), AngII antibody or AngII receptor blocker (losartan). In hypoxic HCAECs, HBO further induced earlier expression of visfatin and AngII. Hypoxia significantly increased DNA-protein binding activity of hypoxia-inducible factor-1α (HIF-1α) and visfatin. Hypoxia, hypoxia with HBO and exogenous addition of AngII also increased promoter transcription to visfatin; SP600125 and losartan blocked this activity. In HCAECs, glucose uptake, migration and tube formation were increased in the presence of hypoxia with HBO, but were inhibited by visfatin small interfering RNA, SP600125 and losartan. In conclusion, HBO activates visfatin expression and angiogenesis in hypoxic HCAECs, an effect mediated by AngII, mainly through the JNK pathway., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

This review identifies how the classical/non-classical renin-angiotensin system (RAS) and exercise influence muscle wasting. The classical RAS axis enhances muscle loss through the interaction with NADPH oxidase (NOX), ubiquitin proteasome system (UPS), protein synthesis and fibrosis pathways. The mainstream hypothesis identifies reactive oxygen species (ROS) as the key pathway in muscle, this review recognizes alternative pathways that lead to an increase in muscle wasting through the classical RAS axis. In addition, pathways in which the non-classical RAS axis and exercise inhibit the classical RAS axis are also explored. The non-classical RAS axis and exercise have a significant negative impact on ROS production and protein synthesis. The non-classical RAS axis has been identified in this review to directly affect protein synthesis pathways not by altering the pre-existing intracellular ROS level, further supporting the idea that muscle wasting caused by the classical RAS system is not entirely due to ROS production. Exercise has been identified to modify the RAS axes making it a therapeutic option., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Transforming growth factor beta (TGFβ) plays a crucial role in tissue fibrosis. A number of studies have shown that TGFβ3 significantly attenuated tissue fibrosis. However, the mechanism involved in this effect is poorly understood. In this study we found that the expression level of TGFβ3 was higher in human myocardial infarction (MI) tissues than in normal tissues, and interestingly, it increased with the development of fibrosis post-myocardial infarction (post-MI). In vitro, human cardiac fibroblasts (CFs) were incubated with angiotensin II (Ang II) to mimic the ischaemic myocardium microenvironment and used to investigate the anti-fibrotic mechanism of TGFβ3. Then, fibrosis-related proteins were detected by Western blot. It was revealed that TGFβ3 up-regulation attenuated the proliferation, migration of human CFs and the expression of collagens, which are the main contributors to fibrosis, promoted the phenotype shift and the cross-linking of collagens. Importantly, the expression of collagens was higher in the si-smad7 groups than in the control groups, while silencing smad7 increased the phosphorylation level of the TGFβ/smad signalling pathway. Collectively, these results indicated that TGFβ3 inhibited fibrosis via the TGFβ/smad signalling pathway, possibly attributable to the regulation of smad7, and that TGFβ3 might serve as a potential therapeutic target for myocardial fibrosis post-MI., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Objectives: This study sought to determine whether salt-induced ANG II suppression contributes to impaired CBF autoregulation., Methods: Cerebral autoregulation was evaluated with LDF during graded reductions of blood pressure. Autoregulatory responses in rats fed HS (4% NaCl) diet vs LS (0.4% NaCl) diet were analyzed using linear regression analysis, model-free analysis, and a mechanistic theoretical model of blood flow through cerebral arterioles., Results: Autoregulation was intact in LS-fed animals as MAP was reduced via graded hemorrhage to approximately 50 mm Hg. Short-term (3 days) and chronic (4 weeks) HS diet impaired CBF autoregulation, as evidenced by progressive reductions of laser Doppler flux with arterial pressure reduction. Chronic low dose ANG II infusion (5 mg/kg/min, i.v.) restored CBF autoregulation between the pre-hemorrhage MAP and 50 mm Hg in rats fed short-term HS diet. Mechanistic-based model analysis showed a reduced myogenic response and reduced baseline VSM tone with short-term HS diet, which was restored by ANG II infusion., Conclusions: Short-term and chronic HS diet lead to impaired autoregulation in the cerebral circulation, with salt-induced ANG II suppression as a major factor in the initiation of impaired CBF regulation., (© 2018 John Wiley & Sons Ltd.)

Hypertensive nephropathy, clinically characterized by progressive renal fibrosis and inflammation, is a severe complication of hypertension. The objectives of this study were to investigate the roles of miR-101a in relieving angiotensin II (Ang II)-mediated hypertensive nephropathy and uncover the possible underlying mechanisms. A hypertensive mouse model was established via continuous 28-day AngII infusion. Systolic blood pressure (SBP), ratio of urine albumin to creatinine, blood urea nitrogen (BUN), serum creatinine (Scr) and glomerular filtration rate (GFR) were evaluated. Dual luciferase reporter assay was used to explore the target of miR-101a. mRNA levels of miR-101a, TGFβRI, fibrotic markers (Collagen I and α-SMA) and pro-inflammatory cytokines (IL-1β and TNF-α) were determined by real-time PCR. Protein levels of TGFβRI, Collagen I, α-SMA, IL-1β, TNF-α, t-p65, P-p65, t-Smad3, P-Smad3, t-IκBα and P-IκBα were detected by western blot. MiR-101a mimics significantly improved GFR and inhibited AngII-induced increase in the ratio of urine albumin to creatinine, BUN and Scr. MiR-101a mimics partially abolished AngII-induced increase in the mRNA and protein level of fibrotic markers by targeting TGFβRI and inhibiting TGFβ/Smad3 pathway. Moreover, TGFβRI inhibitor galunisertib inhibited AngII-mediated renal injury in mice with hypertensive nephropathy. Additionally, miR-101a overexpression blocked AngII-induced up-regulation of pro-inflammatory markers via suppressing NF-κB pathway. MiR-101a exhibited protective effects against hypertensive nephropathy via inhibiting TGFβ/Smad3 and NF-κB signalling pathways., (© 2018 John Wiley & Sons Australia, Ltd.)

Cardiac hypertrophy is a common pathological change frequently accompanied by chronic hypertension and myocardial infarction. Nevertheless, the pathophysiological mechanisms of cardiac hypertrophy have never been elucidated. Recent studies indicated that miR-103 expression was significantly decreased in heart failure patients. However, less is known about the role of miR-103 in cardiac hypertrophy. The present study was designed to investigate the relationship between miR-103 and the mechanism of pressure overload-induced cardiac hypertrophy. TRPV3 protein, cardiac hypertrophy marker proteins (BNP and β-MHC) and autophagy associated proteins (Beclin-1 and LC3-II) were up-regulated, as well as, miR-103 expression and autophagy associated proteins (p62) were down-regulated in cardiac hypertrophy models in vivo and in vitro respectively. Further results indicated that silencing TRPV3 or forcing overexpression of miR-103 could dramatically inhibit cell surface area, relative fluorescence intensity of Ca 2+ signal and the expressions of BNP, β-MHC, Beclin-1 and LC3-II, but promote p62 expression. Moreover, TRPV3 protein was decreased in neonatal rat ventricular myocyte transfected with miR-103, but increased by AMO-103. Co-transfection of the miR-103 with the luciferase reporter vector into HEK293 cells caused a sharp decrease in luciferase activity compared with transfection of the luciferase vector alone. The miR-103-induced depression of luciferase activity was rescued by an AMO-103. These findings suggested that TRPV3 was a direct target of miR-103. In conclusion, miR-103 could attenuate cardiomyocyte hypertrophy partly by reducing cardiac autophagy activity through the targeted inhibition of TRPV3 signalling in the pressure-overloaded rat hearts., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

MURC (muscle-restricted coiled-coil protein) is a hypertrophy-related gene. Hypertrophy can be induced by mechanical stress. The purpose of this research was to investigate the hypothesis that MURC mediates hypertrophy in cardiomyocytes under mechanical stress. We used the in vivo model of an aortocaval shunt (AV shunt) in adult Wistar rats to induce myocardial hypertrophy. We also used the in vitro model of cyclic stretch in rat neonatal cardiomyocytes to clarify MURC expression and the molecular regulation mechanism. The flexible membrane culture plate seeding with cardiomyocytes Cardiomyocytes seeded on a flexible membrane culture plate were stretched by vacuum pressure to 20% of maximum elongation at 60 cycles/min. AV shunt induction enhanced MURC protein expression in the left ventricular myocardium. Treatment with atorvastatin inhibited the hypertrophy induced by the AV shunt. Cyclic stretch markedly enhanced MURC protein and mRNA expression in cardiomyocytes. Addition of extracellular-signal-regulated kinase (ERK) inhibitor PD98059, ERK small interfering RNA (siRNA), angiotensin II (Ang II) antibody and atorvastatin before stretch, abolished the induction of MURC protein. An electrophoretic mobility shift assay showed that stretch enhanced the DNA binding activity of serum response factor. Stretch increased but MURC mutant plasmid, ERK siRNA, Ang II antibody and atorvastatin reversed the transcriptional activity of MURC induced by stretch. Adding Ang II to the cardiomyocytes also induced MURC protein expression. MURC siRNA and atorvastatin inhibited the hypertrophic marker and protein synthesis induced by stretch. Treatment with atorvastatin reversed MURC expression and hypertrophy under volume overload and cyclic stretch., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Aim: The histone demethylase Jarid1b limits gene expression by removing the active methyl mark from histone3 lysine4 at gene promoter regions. A vascular function of Jarid1b is unknown, but a vasoprotective function to inflammatory and hypertrophic stimuli, like angiotensin II (AngII) could be inferred. This hypothesis was tested using Jarid1b knockout mice and the inhibitor PBIT., Methods: Mice or aortic segments were treated with AngII to induce endothelial dysfunction. Aortae from WT and Jarid1b knockout were studied in organ chambers and endothelium-dependent dilator responses to acetylcholine and endothelium-independent responses to DetaNONOate were recorded after pre-constriction with phenylephrine in the presence or absence of the NO-synthase inhibitor nitro-L-arginine. Molecular mechanisms were investigated with chromatin immunoprecipitation, RNA-Seq, RNA-3'-adaptor-ligation, actinomycin D and RNA-immunoprecipitation., Results: Knockout or inhibition of Jarid1b prevented the development of endothelial dysfunction in response to AngII. This effect was not a consequence of altered nitrite oxide availability but accompanied by a loss of the inflammatory response to AngII. As Jarid1b mainly inhibits gene expression, an indirect effect should account for this observation. AngII induced the soluble epoxide hydrolase (sEH), which degrades anti-inflammatory lipids, and thus promotes inflammation. Knockout or inhibition of Jarid1b prevented the AngII-mediated sEH induction. Mechanistically, Jarid1b maintained the length of the 3'untranslated region of the sEH mRNA, thereby increasing its stability and thus sEH protein expression. Loss of Jarid1b activity therefore resulted in sEH mRNA destabilization., Conclusion: Jarid1b contributes to the pro-inflammatory effects of AngII by stabilizing sEH expression. Jarid1b inhibition might be an option for future therapeutics against cardiovascular dysfunction., (© 2018 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.)

Apoptosis is associated with various myocardial diseases. Angiotensin II (Ang II) plays a central role in the pathogenesis of RAAS-triggered cardiac apoptosis. Our previous studies showed that mammalian Ste20-like kinase 1 (Mst1) aggravates cardiac dysfunction in cardiomyocyte under pathological conditions, but its role in Ang II-mediated cardiomyocyte apoptosis is not known. We addressed this in the present study by investigating whether cardiac-specific Mst1 knockout can alleviate Ang II-induced cardiomyocyte apoptosis along with the underlying mechanisms. In vitro and in vivo experiments showed that Ang II increased intracellular reactive oxygen species (ROS) production and cardiomyocyte apoptosis; these were reversed by administration of the ROS scavenger N-acetylcysteine and by Mst1 deficiency, which suppressed c-Jun N-terminal kinase (JNK) phosphorylation and downstream signaling. Interestingly, Mst1 knockout failed to alleviate Ang II-induced phosphorylation of extracellular signal-regulated kinase 1/2, and inactivated apoptosis signal-regulating kinase1 (ASK1) by promoting its association with thioredoxin (Trx), which reversed the Ang II-induced activation of the ASK1-JNK pathway and suppressed Ang II-induced cardiomyocyte apoptosis. Thus, cardiac-specific Mst1 knockout inhibits ROS-mediated JNK signalling to block Ang II-induced cardiomyocyte apoptosis, suggesting Mst1 as a potential therapeutic target for treatment of RAAS-activated heart failure., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

New Findings: What is the central question of this study? Can chymase inhibition prevent angiotensin I-induced hypertension through inhibiting the conversion of angiotensin I to angiotensin II in the kidney? What is the main finding and its importance? Treatment with TEI-F00806 decreased angiotensin II content of the kidney, renal cortical angiotensinogen protein levels and chymase mRNA expression, and attenuated the development of hypertension., Abstract: The effects of the selective chymase inhibitor TEI-F00806 were examined on angiotensin I (Ang I)-induced hypertension and intrarenal angiotensin II (Ang II) production in salt-treated mice. Twelve-week-old C57BL male mice were given a high-salt diet (4% NaCl + saline (0.9% NaCl)), and divided into three groups: (1) sham + vehicle (5% acetic acid in saline), (2) Ang I (1 μg kg -1  min -1 , s.c.) + vehicle, and (3) Ang I + TEI-F00806 (100 mg kg -1  day -1 , p.o.) (n = 8-10 per group). Systolic blood pressure was measured weekly using a tail-cuff method. Kidney Ang II content was measured by radioimmunoassay. Chronic infusion of Ang I resulted in the development of hypertension (P < 0.001), and augmented intrarenal chymase gene expression (P < 0.05), angiotensinogen protein level (P < 0.001) and Ang II content (P < 0.01) in salt-treated mice. Treatment with TEI-F00806 attenuated the development of hypertension (P < 0.001) and decreased Ang II content of the kidney (P < 0.05), which was associated with reductions in renal cortical angiotensinogen protein levels (P < 0.001) and chymase mRNA expression (P < 0.05). These data suggest that a chymase inhibitor decreases intrarenal renin-angiotensin activity, thereby reducing salt-dependent hypertension., (© 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.)

Purpose: This study aimed to explore the effects of microRNA-133b (miR-133b) on diabetic retinopathy (DR) by targeting angiotensinogen (AGT) through the angiotensin-II (AngII) extracellular signal-regulated kinase 1/2 (ERK1/2) signalling pathway in rats., Methods: The DR rat model was established using retinal tissues of DR rats and normal rats. Immunohistochemistry was performed to detect the protein expressions of AGT and CD34 in retinal tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were applied to detect miR-133b expression, AGT, AngII, ERK1/2 mRNA, and protein expressions in tissues and cells after transfection. Retinal vascular endothelial cells were cultured and divided into normal, blank, miR-133b mimics, miR-133b mimics negative control (NC), miR-133b inhibitors, miR-133b inhibitors NC, siRNA NC, siRNA-AGT, and miR-133b inhibitors + siRNA-AGT groups. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to detect cell proliferation. Cell cycle and apoptosis were evaluated using flow cytometry., Results: Compared with normal rats, AGT and CD34 were expressed more frequently in DR rats. MicroRNA (miR)-133b expression was downregulated but AGT, AngII, ERK1 and ERK2 mRNA expressions were upregulated in retinal tissues of DR rats. When compared to the normal group, all other groups displayed decreased cell proliferation, increased cell number in G0/G1, decreased cell number in S stage, increased cell apoptosis rate and declined miR-133b expression. As well, significant increased expressions of AGT and the AngII-ERK1/2 pathway-related proteins were observed in retinal vascular endothelial cells in all groups except the normal group. The miR-133b mimics and siRNA-AGT groups had increased cell proliferation, decreased cell number in the G0/G1 phase, increased cell number in S stage, decreased cell apoptosis rate and decreased expressions of AGT and AngII-ERK1/2 pathway-related proteins than the miR-133b inhibitors + siRNA-AGT group. The miR-133b inhibitors group exhibited opposite trends compared with the miR-133b mimics and siRNA-AGT groups., Conclusion: The study provides data to suggest that miR-133b induces proliferation and inhibits apoptosis of retinal vascular endothelial cells by targeting AGT through the AngII-ERK1/2 signalling pathway in DR rats., (© 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

We previously observed that disruption of FK506-binding protein 12.6 (FKBP12.6) gene resulted in cardiac hypertrophy in male mice. Studies showed that overexpression of FKBP12.6 attenuated thoracic aortic constriction (TAC)-induced cardiac hypertrophy in mice, whereas the adenovirus-mediated overexpression of FKBP12.6 induced hypertrophy and apoptosis in cultured neonatal cardiomyocytes, indicating that the role of FKBP12.6 in cardiac hypertrophy is still controversial. In this study, we aimed to investigate the roles and mechanisms of FKBP12.6 in angiotensin II (AngII)-induced cardiac hypertrophy using various transgenic mouse models in vivo and in vitro. FKBP12.6 knockout (FKBP12.6 -/- ) mice and cardiac-specific FKBP12.6 overexpressing (FKBP12.6 TG) mice were infused with AngII (1500 ng/kg/min) for 14 days subcutaneously by implantation of an osmotic mini-pump. The results showed that FKBP12.6 deficiency aggravated AngII-induced cardiac hypertrophy, while cardiac-specific overexpression of FKBP12.6 prevented hearts from the hypertrophic response to AngII stimulation in mice. Consistent with the results in vivo, overexpression of FKBP12.6 in H9c2 cells significantly repressed the AngII-induced cardiomyocyte hypertrophy, seen as reductions in the cell sizes and the expressions of hypertrophic genes. Furthermore, we demonstrated that the protection of FKBP12.6 on AngII-induced cardiac hypertrophy was involved in reducing the concentration of intracellular Ca 2+ ([Ca 2+ ]i), in which the protein significantly inhibited the key Ca 2+ /calmodulin-dependent signalling pathways such as calcineurin/cardiac form of nuclear factor of activated T cells 4 (NFATc4), calmodulin kinaseII (CaMKII)/MEF-2, AKT/Glycogen synthase kinase 3β (GSK3β)/NFATc4 and AKT/mTOR signalling pathways. Our study demonstrated that FKBP12.6 protects heart from AngII-induced cardiac hypertrophy through inhibiting Ca 2+ /calmodulin-mediated signalling pathways., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Background: DNA methylation is believed to be maintained in adult somatic cells. Recent findings, however, suggest that all methylation patterns are not stable. We demonstrate that stimulatory signals can change the DNA methylation status around transcription factor binding sites and a transcription start site and activate expression of the aldosterone synthase gene ( CYP11B2 )., Methods and Results: DNA methylation of CYP11B2 was analyzed in aldosterone-producing adenomas, nonfunctioning adrenal adenomas, and adrenal glands and compared with the gene expression levels. CpG dinucleotides in the CYP11B2 promoter were found to be hypormethylated in tissues with high expression, but not in those with low expression, of CYP11B2 . Methylation of the CYP11B2 promoter fused to a reporter gene decreased transcriptional activity. Methylation of recognition sequences of transcription factors, including CREB1, NGFIB (NR4A1), and NURR1 (NR4A2) diminished their DNA-binding activity. A methylated-CpG-binding protein MECP2 interacted directly with the methylated CYP11B2 promoter. In rats, low salt intake led to upregulation of CYP11B2 expression and DNA hypomethylation in the adrenal gland. Treatment with angiotensin II type 1 receptor antagonist decreased CYP11B2 expression and led to DNA hypermethylation., Conclusions: DNA demethylation may switch the phenotype of CYP11B2 expression from an inactive to an active state and regulate aldosterone biosynthesis., (© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

New Findings: What is the topic of this review? We describe roles of crucial signalling molecules in the paraventricular nucleus of the hypothalamus and highlight recent data suggesting sex-specific changes in the expression of crucial signalling molecules and their receptors, which may underlie sex differences in both cardiovascular and metabolic function. What advances does it highlight? This review highlights the integrative capacity of the paraventricular nucleus in mediating cardiovascular and metabolic effects by integrating information from multiple signalling molecules. It also proposes that these signalling molecules have sex-specific differential gene expression, indicating the importance of considering these differences in our ongoing search to understand the female-male differences in the regulation of crucial autonomic systems. Many traditional cardiovascular hormones have been implicated in metabolic function. Conversely, many hormones traditionally involved in metabolic regulation have an effect on cardiovascular function. Many of these signalling molecules exert such effects through specific actions in the paraventricular nucleus, an integrative autonomic control centre located in the hypothalamus. Here, we focus on four cardiovascular/metabolic peptide hormones that signal within the paraventricular nucleus, namely angiotensin II, orexin, adiponectin and nesfatin-1. Each of these hormones has specific electrophysiological effects on paraventricular nucleus neurons that can be related to its physiological actions. In addition, we introduce preliminary transcriptomic data indicating that the genes for some of these hormones and their receptors have sex-specific differential expression., (© 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.)

New Findings: What is the topic of this review? This report describes sex differences in the responses to angiotensin II, with a focus on fluid intake. What advances does it highlight? There are conflicting reports on the direction of the sex difference in fluid intake in response to angiotensin II. This review highlights how accounting for differences in body weight contributes to the discrepancies in the literature. In certain conditions, body weight influences fluid intake in a sex-specific manner. This review also highlights the divergent effects of oestrogen receptor activation on fluid intake, which are likely to underlie the discussed sex differences. Sex has a clear effect on the renin-angiotensin-aldosterone system. Although sex differences in the pressor response to angiotensin II (Ang II) are well established, understanding of the sex differences in the fluid intake response to Ang II is clouded by conflicting reports. Here, I suggest that accounting for differences in body weight contributes to the discrepancies in the literature. Our recent findings demonstrate that body weight influences Ang II-stimulated water intake in certain conditions in male, but not in female rats. When differences in body weight are corrected for in the appropriate circumstances, we found that males consume more water in response to Ang II compared with females. Males and females also show differences in drinking microstructure, i.e. bottle spout lick patterns, which provide clues into the mechanism(s) underlying this sex difference. Oestrogens, which inhibit Ang II-stimulated fluid intake and circulate at higher concentrations in females, are likely to contribute to this sex difference. This review also discusses the diversity in oestrogen signalling via multiple oestrogen receptor subtypes, which selectively inhibit Ang II-stimulated fluid intake., (© 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.)

New Findings: What is the central question of this study? What are the effects of exercise training on the hepatic renin-angiotensin system and their contribution to damage resulting from fructose overload in rats? What is the main finding and its importance? Exercise training attenuated the deleterious actions of the angiotensin-converting enzyme/angiotensin II/angiotensin II type 1 receptor axis and increased expression of the counter-regulatory (angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor) axis in the liver. Therefore, our study provides evidence that exercise training modulates the hepatic renin-angiotensin system, which contributes to reducing the progression of metabolic dysfunction and non-alcoholic fatty liver disease in fructose-fed rats. The renin-angiotensin system (RAS) has been implicated in the development of metabolic syndrome. We investigated whether the hepatic RAS is modulated by exercise training and whether this modulation improves the deleterious effects of fructose overload in rats. Male Wistar rats were divided into (n = 8 each) control (CT), exercise control (CT-Ex), high-fructose (HFr) and exercise high-fructose (HFr-Ex) groups. Fructose-drinking rats received d-fructose (100 g l -1 ). After 2 weeks, CT-Ex and HFr-Ex rats were assigned to a treadmill training protocol at moderate intensity for 8 weeks (60 min day -1 , 4 days per week). We assessed body mass, glucose and lipid metabolism, hepatic histopathology, angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity, the angiotensin concentration and the expression profile of proteins affecting the hepatic RAS, gluconeogenesis and inflammation. Neither fructose overload nor exercise training influenced body mass gain and serum ACE and ACE2 activity. The HFr group showed hyperinsulinaemia, but exercise training normalized this parameter. Exercise training was effective in preventing hepatic steatosis and in preventing triacylglycerol and glycogen accumulation. Furthermore, exercise improved the response to the deleterious effects of HFr overload by normalizing the gluconeogenesis pathway and the protein levels of interleukin-6 and tumour necrosis factor-α. The HFr rats displayed increased hepatic ACE activity and protein expression and angiotensin II concentration, which were attenuated by exercise training. Exercise training restored the ACE2/angiotensin-(1-7)/Mas receptor axis. Exercise training may favour the counter-regulatory ACE2/angiotensin-(1-7)/Mas receptor axis over the classical RAS (ACE/angiotensin II/angiotensin II type 1 receptor axis), which could be responsible for the reduction of metabolic dysfunction and the prevention of non-alcoholic fatty liver disease., (© 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.)

Angiotensin II (Ang II) is the product of the proteolytic action of angiotensin-converting enzyme (ACE) on the precursor peptide, angiotensin I (Ang I). In addition to its vasoactive properties, Ang II is able to stimulate angiogenesis and act as a mitogen, promoting cellular proliferation. Recently, evidence has emerged that Ang II is also able to promote tumour invasion, a key step in the metastatic cascade, although the mechanisms by which it does so remain largely obscure. Here we show that Ang II is able to promote the invasion and migration of head and neck squamous cell carcinoma (HNSCC) cells both in an autocrine manner and by triggering stromal tumour-paracrine interactions. The effects of Ang II on autocrine and paracrine signalling pathways are mediated by angiotensin receptor 1 (AT 1 R) and inhibited by angiotensin 1-7 (Ang 1-7), a peptide produced from Ang II by the action of angiotensin-converting enzyme 2 (ACE2). These data are the first to demonstrate a role for the renin-angiotensin system in oral carcinogenesis and raise the possibility of utilizing AT 1 R receptor antagonists and/or Ang 1-7 as novel therapeutic agents for HNSCC., (© 2017 Eur J Oral Sci.)

Background: The kidney is easily affected by aging-associated changes, including glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Particularly, renal tubulointerstitial fibrosis is a final common pathway in most forms of progressive renal disease. Angiotensin II type 1 receptor (AT1R)-associated protein (ATRAP), which was originally identified as a molecule that binds to AT1R, is highly expressed in the kidney. Previously, we have shown that ATRAP suppresses hyperactivation of AT1R signaling, but does not affect physiological AT1R signaling., Methods and Results: We hypothesized that ATRAP has a novel functional role in the physiological age-degenerative process, independent of modulation of AT1R signaling. ATRAP-knockout mice were used to study the functional involvement of ATRAP in the aging. ATRAP-knockout mice exhibit a normal age-associated appearance without any evident alterations in physiological parameters, including blood pressure and cardiovascular and metabolic phenotypes. However, in ATRAP-knockout mice compared with wild-type mice, the following takes place: (1) age-associated renal function decline and tubulointerstitial fibrosis are more enhanced; (2) renal tubular mitochondrial abnormalities and subsequent increases in the production of reactive oxygen species are more advanced; and (3) life span is 18.4% shorter (median life span, 100.4 versus 123.1 weeks). As a key mechanism, age-related pathological changes in the kidney of ATRAP-knockout mice correlated with decreased expression of the prosurvival gene, Sirtuin1 . On the other hand, chronic angiotensin II infusion did not affect renal sirtuin1 expression in wild-type mice., Conclusions: These results indicate that ATRAP plays an important role in inhibiting kidney aging, possibly through sirtuin1-mediated mechanism independent of blocking AT1R signaling, and further protecting normal life span., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Vascular ageing in conditions such as atherosclerosis, diabetes and chronic kidney disease, is associated with the activation of the renin angiotensin system (RAS) and diminished expression of antioxidant defences mediated by the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). The anti-ageing hormone klotho promotes longevity and protects against cardiovascular and renal diseases. Klotho has been shown to activate Nrf2 and attenuate oxidative damage in neuronal cells, however, the mechanisms by which it protects against vascular smooth muscle cell VSMC dysfunction elicited by Angiotensin II (AngII) remain to be elucidated. AngII contributes to vascular ageing and atherogenesis by enhancing VSMC oxidative stress, senescence and apoptosis. This study demonstrates that soluble klotho (1 nM, 24 hrs) significantly induces expression of Nrf2 and the antioxidant enzymes haeme oxygenase (HO-1) and peroxiredoxin-1 (Prx-1) and enhances glutathione levels in human aortic smooth muscle cells (HASMC). Silencing of Nrf2 attenuated the induction of HO-1 and Prx-1 expression by soluble klotho. Furthermore, soluble klotho protected against AngII-mediated HASMC apoptosis and senescence via activation of Nrf2. Thus, our findings highlight a novel Nrf2-mediated mechanism underlying the protective actions of soluble klotho in HAMSC. Targeting klotho may thus represent a therapeutic strategy against VSMC dysfunction and cardiovascular ageing., (© 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Aims: Among patients with type 2 diabetes and albuminuria, cardiorenal morbidity and mortality are high despite multifactorial treatment. Short-term reduction in albuminuria is considered suggestive of long-term renoprotective effects. We evaluated the renal effects of the glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide on top of multifactorial care, including renin-angiotensin-system (RAS)-inhibition., Materials and Methods: Randomized, double-blind, placebo-controlled, cross-over trial including patients with type 2 diabetes and persistent albuminuria (urinary albumin-to-creatinine ratio >30 mg/g) and estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m 2 . Patients received liraglutide (1.8 mg/d) and matched placebo for 12 weeks in a random order. The primary endpoint was change in 24-h urinary albumin excretion rate (UAER)., Results: A total of 32 patients were randomized and 27 completed the study. After placebo treatment, geometric mean (IQR) UAER was 199 (81-531) mg/24-h, mean (SD) measured GFR (mGFR) 75 (36) mL/min/1.73 m 2 , 24-h blood pressure 145/80 (15/8) mm Hg and HbA1c 61 (11) mmol/mol. Liraglutide reduced HbA1c by 8 (95% CI: 5; 11) mmol/mol (P < .001) and weight by 1.8 (95% CI: 0.2; 3.4) kg (P = .032) compared to placebo. Furthermore, liraglutide reduced UAER by 32 (95% CI: 7; 50)% ( P = .017) compared with placebo. The change in mGFR was -5 (95% CI: -11; 2) mL/min/1.73 m 2 ( P = .15), and change in 24-h systolic blood pressure was -5 (95% CI: -10; 0) mm Hg ( P = .07). In multivariate regression models, change in UAER was associated with change in 24-h systolic blood pressure ( P = .025) but not with change in HbA1c, weight or mGFR ( P ≥ .14), overall model R 2 = .39., Conclusions: Our placebo-controlled randomized trial suggests that liraglutide has renoprotective effects on top of multifactorial treatment, including RAS-inhibition, in patients with type 2 diabetes and albuminuria., (© 2016 John Wiley & Sons Ltd.)

Angiotensin II (AngII) is the final active product of the renin enzymatic cascade, which is responsible for sustaining blood pressure. To investigate the effect of N-terminal cyclization on AT 1 activation and tachyphylaxis, we designed conformationally constrained analogues with an i-(i + 1) lactam bridge. All analogues presented the same binding coefficient and tachyphylactic index, but some of them such as Cyclo (0-1a) [Glu 0 , endo-(Lys 1a )]-AngII and Cyclo (0-1a) [Asp 0 , endo-(Orn 1a )]-AngII showed higher potency. The same tachyphylactic index presented by AngII and cyclic analogues was surprising. We expected a variation after the modification of AngII N-terminal region., (© 2016 John Wiley & Sons A/S.)

Background: This study aimed to investigate the possible synergistic effects of lipid disorder with renin-angiotensin system (RAS) activation in non-alcoholic fatty liver disease (NAFLD)., Methods: Apolipoprotein E gene-knockout mice, angiotensin II (Ang II) type 1 receptor (AT1) gene-knockout mice and human hepatoblastoma cell line (HepG2) were used for experiments. Lipid accumulation was examined by Filipin staining and intracellular cholesterol quantitative assay. The gene and protein expression of molecules involved in RAS and low-density lipoprotein receptor (LDLr) pathway was examined by real-time PCR, immunofluorescent staining and Western blot., Results: There was significantly increased expression of RAS components and extracellular matrix (ECM) in livers of high-fat-diet-fed apolipoprotein E gene-knockout mice compared with controls. Upregulation of RAS components was positively associated with increased plasma levels of lipid profile. The in vitro study further confirmed that cholesterol loading increased supernatant renin activity and Ang II level of HepG2 cells, accompanied by increased ECM production that was positively associated with increased expression of intracellular RAS components. Interestingly, Ang II treatment increased lipid accumulation in livers of C57BL/6 mice and HepG2 cells. Furthermore, Ang II treatment increased gene and protein expression of sterol regulatory element-binding protein (SREBP) cleavage activating protein (SCAP), SREBP-2 and LDLr, which were mediated by enhanced SCAP/SREBP-2 complex translocation from endoplasmic reticulum to Golgi. However, LDLr pathway was accordingly downregulated in livers of AT1 gene-knockout C57BL/6 mice or in HepG2 cells treated by telmisartan., Conclusion: These findings demonstrate that lipid disorder and intrahepatic RAS activation synergistically accelerate NAFLD progression., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

New Findings: What is the central question of this study? We examined, in hypertensive rats, whether the angiotensin-converting enzyme-independent enzymes generating angiotensin II in the tissues modulate blood pressure, peripheral circulation and renal function. What is the main finding and its importance? The results suggest that chymostatin-sensitive enzymes diminish vascular tone in renal and extrarenal vascular beds. Chymase or similar chymostatin-sensitive enzymes have a significant role in the synthesis of angiotensin II in different tissues but do not control blood pressure in the short term, similarly in salt-dependent or Goldblatt-type rat hypertension. In salt-dependent hypertension, chymase blockade protected renal outer medullary perfusion, probably by reducing the angiotensin II content in the kidney. Chymase is presumed to be a crucial enzyme of the non-angiotensin-converting enzyme pathway of angiotensin II (Ang II) generation in tissues, a process involved in vascular remodelling and development of hypertension. We examined the role of chymase in hypertension induced by exposure of uninephrectomized rats to high dietary salt intake (UNX HS) and in the Goldblatt renal artery stenosis (two-kidney, one-clip) model. In acute experiments with anaesthetized rats of either model, chymostatin at 2 mg kg(-1) h(-1) or 0.05% DMSO solvent was infused i.v. Mean arterial blood pressure, heart rate, iliac blood flow (a measure of hindlimb perfusion), total renal blood flow and intrarenal regional perfusion (laser-Doppler technique) were measured continuously, along with the glomerular filtration rate and renal excretion. In both models, chymase blockade distinctly decreased plasma and tissue Ang II without lowering mean blood pressure or consistently altering the other functional parameters measured. Unexpectedly, in Goldblatt hypertensive rats the blockade increased the renal and hindlimb vascular resistances by 51 and 33%, respectively (P < 0.05). In UNX HS hypertensive rats, chymase blockade abolished the solvent-induced decrease in outer medullary blood flow. We conclude that chymase or similar chymostatin-sensitive enzyme(s) has a significant role in the synthesis of Ang II in different tissues but does not participate in short-term control of blood pressure in salt-dependent or Goldblatt-type rat hypertension. In the Goldblatt model, chymase appeared to reduce the renal and hindlimb vascular resistances by an unknown mechanism. In salt-dependent hypertension, chymase blockade protected renal outer medullary perfusion, probably by reducing Ang II content in the kidney., (© 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.)