Agonist-dependent internalization of the angiotensin II type one receptor (AT1): role of C-terminus phosphorylation in recruitment of beta-arrestins

β-Arrestins play a role in AT₁ endocytosis by binding the cytoplasmic, C-terminus region T332–S338, the major site of angiotensin II (Ang II)-induced phosphorylation. However, the processes responsible for recruiting β-arrestin to the activated receptor are poorly defined. In this study, we used CHO-K1 and HEK 293 cells expressing wild-type or mutant AT₁ to investigate two possibilities: activated AT₁ induces global relocation of β-arrestins to the plasma membrane or the phosphorylated C-terminus acts as bait to attract β-arrestins. Results obtained using high osmolarity and dominant-negative β-arrestin confirmed that internalization of AT₁ in both CHO-K1 and HEK 293 cells is predominately via clathrin-mediated endocytosis involving β-arrestin, and substitution of T332, S335, T336 and S338 with alanine to preclude phosphorylation markedly attenuated AT₁ internalization. Confocal microscopy revealed that wild-type AT₁ induced a time-dependent translocation of GFP-tagged β-arrestins 1 and 2 to the cell surface. In contrast, the TSTS/A mutant did not traffic β-arrestin 1 at all, and only trafficked β-arrestin 2 weakly. Results of rescue-type experiments were consistent with the idea that both β-arrestins are able to interact with the non-phosphorylated receptor, albeit with much lower affinity and β-arrestin 1 less so than β-arrestin 2. In conclusion, this study shows that the high affinity binding of β-arrestins to the phosphorylated C-terminus is the predominant mechanism of agonist-induced β-arrestin recruitment to the cell surface and AT₁ receptor.     

Angiotensin II and angiotensin-(1-7) inhibit the inner cortex Na+ -ATPase activity through AT2 receptor

In the present paper, the modulation of the basolateral membrane (BLM) Na⁺-ATPase activity of inner cortex from pig kidney by angiotensin II (Ang II) and angiotensin-(1–7) (Ang-(1–7)) was evaluated. Ang II and Ang-(1–7) inhibit the Na⁺-ATPase activity in a dose-dependent manner (from 10⁻¹¹ to 10⁻⁵ M), with maximal effect obtained at 10⁻⁷ M for both peptides. Pharmacological evidences demonstrate that the inhibitory effects of Ang II and Ang-(1–7) are mediated by AT₂ receptor: The effect of both polypeptides is completely reversed by 10⁻⁸ M PD 123319, a selective AT₂ receptor antagonist, but is not affected by either (10⁻¹²–10⁻⁵ M) losartan or (10⁻¹⁰–10⁻⁷ M) A779, selective antagonists for AT₁ and AT_(1–7) receptors, respectively. The following results suggest that a PTX-insensitive, cholera toxin (CTX)-sensitive G protein/adenosine 3′,5′-cyclic monophosphate (cAMP)/PKA pathway is involved in this process: (1) the inhibitory effect of both peptides is completely reversed by 10⁻⁹ M guanosine 5′-O-(2-thiodiphosphate) (GDPβS; an inhibitor of the G protein activity), and mimicked by 10⁻¹⁰ M guanosine 5′-O-(3-thiotriphosphate) (GTPγS; an activator of the G protein activity); (2) the effects of both peptides are mimicked by CTX but are not affected by PTX; (3) Western blot analysis reveals the presence of the G_s protein in the isolated basolateral membrane fraction; (4) (10⁻¹⁰–10⁻⁶ M) cAMP has a similar and non-additive effect to Ang II and Ang-(1–7); (5) PKA inhibitory peptide abolishes the effects of Ang II and Ang-(1–7); and (6) both angiotensins stimulate PKA activity.     

Angiotensin III and IV activation of the brain AT1 receptor subtype in cardiovascular function

The present investigation determined that native angiotensins II and III (ANG II and III) were equipotent as pressor agents when ICV infused in alert rats, whereas native angiotensin IV (ANG IV) was less potent. An analogue of each of these angiotensins was prepared with a hydroxyethylamine (HEA) amide bond replacement at the N-terminus, yielding additional resistance to degradation. These three angiotensin analogues, HEA-ANG II, HEA-ANG III, and HEA-ANG IV, were equivalent with respect to maximum elevation in pressor responses when ICV infused; and each evidenced significantly extended durations of effect compared with their respective native angiotensin. Comparing analogues, HEA-ANG II had a significantly longer effect compared with HEA-ANG III, and HEA-ANG IV, whereas the latter were equivalent. Pretreatment with the AT₁ receptor subtype antagonist, Losartan (DuP753), blocked subsequent pressor responses to each of these analogues, suggesting that these responses were mediated by the AT₁ receptor subtype. Pretreatment with the specific AT₄ receptor subtype antagonist, Divalinal (HED 1291), failed to influence pressor responses induced by the subsequent infusion of these analogues. These results suggest an important role for Ang III, and perhaps ANG IV, in brain angiotensin pressor responses mediated by the AT₁ receptor subtype.     

Angiotensin II induces NF-kappa B activation in HUVEC via the p38MAPK pathway

Angiotensin II (Ang II) is the main active peptide of the renin–angiotensin system (RAS), producing a number of inflammatory mediators that lead to endothelial dysfunction and the progression of atherosclerosis. Ang II-induced NF-κB nuclear translocation plays a pivotal role in this response. This study examines the NF-κB activation mechanism elicited by Ang II in human umbilical vein endothelial cells (HUVEC). Electrophoretic mobility shift assays and Western blotting revealed that Ang II, signaling via AT₁, produces a time-dependent increase in NF-κB DNA binding and IκB degradation. These results also demonstrate that Ang II leads to MAPK phosphorylation and p38MAPK pathway-induced NF-κB activation. Furthermore, AT₁ is required for p38MAPK phosphorylation induced by Ang II. This study provides evidence that Ang II elicits NF-κB activation via the p38MAPK pathway in HUVEC.     

Trophic and steroidogenic effects of water deprivation on the adrenal gland of the adult female rat

The effects of a 3-day water deprivation were studied in adult female rats in order to know what are the different zones of the adrenal gland and the hormonal factors involved in the growth and the activity of the adrenal gland. Water deprivation significantly increased plasma renin activity (PRA), plasma Angiotensin II (AII), vasopressin (AVP), epinephrine, aldosterone and corticosterone concentrations but did not modify the plasma adrenocorticotropin hormone (ACTH) level. Water deprivation significantly increased the absolute weight of the adrenal capsule containing the zona glomerulosa without modification of the density of cells per area unit suggesting that the growth of the adrenal capsule was due to a cell hyperplasia of the zona glomerulosa. Water deprivation significantly increased the density of AII type 1 (AT₁) receptors in the adrenal capsule but did not modify the density of AII type 2 (AT₂) receptors in the adrenal capsule and core containing the zona fasciculata, the zona reticularis and the medulla. The treatment of dehydrated female rats with captopril, which inhibits the angiotensin converting enzyme (ACE) in order to block the production of AII, significantly decreased the absolute weight of the adrenal capsule, plasma aldosterone and the density of AT₁ receptors in the adrenal capsule. The concentration of corticosterone in the plasma, the density of AT₂ receptors and the density of cells per unit area in the zona glomerulosa of the adrenal capsule were not affected by captopril-treatment. In conclusion, these results suggest that AII seems to be the main factor involved in the stimulation of the growth and the secretion of aldosterone by the adrenal capsule containing the zona glomerulosa during water deprivation. The low level of plasma ACTH is not involved in the growth of the adrenal gland but is probably responsible for the secretion of corticosterone by the zona fasciculata.     

Mas receptor mediates cardioprotection of angiotensin‐(1‐7) against Angiotensin II‐induced cardiomyocyte autophagy and cardiac remodelling through inhibition of oxidative stress

Angiotensin II (Ang II) plays an important role in the onset and development of cardiac remodelling associated with changes of autophagy. Angiotensin1‐7 [Ang‐(1‐7)] is a newly established bioactive peptide of renin–angiotensin system, which has been shown to counteract the deleterious effects of Ang II. However, the precise impact of Ang‐(1‐7) on Ang II‐induced cardiomyocyte autophagy remained essentially elusive. The aim of the present study was to examine if Ang‐(1‐7) inhibits Ang II‐induced autophagy and the underlying mechanism involved. Cultured neonatal rat cardiomyocytes were exposed to Ang II for 48 hrs while mice were infused with Ang II for 4 weeks to induce models of cardiac hypertrophy in vitro and in vivo. LC3b‐II and p62, markers of autophagy, expression were significantly elevated in cardiomyocytes, suggesting the presence of autophagy accompanying cardiac hypertrophy in response to Ang II treatment. Besides, Ang II induced oxidative stress, manifesting as an increase in malondialdehyde production and a decrease in superoxide dismutase activity. Ang‐(1‐7) significantly retarded hypertrophy, autophagy and oxidative stress in the heart. Furthermore, a role of Mas receptor in Ang‐(1‐7)‐mediated action was assessed using A779 peptide, a selective Mas receptor antagonist. The beneficial responses of Ang‐(1‐7) on cardiac remodelling, autophagy and oxidative stress were mitigated by A779. Taken together, these result indicated that Mas receptor mediates cardioprotection of angiotensin‐(1‐7) against Ang II‐induced cardiomyocyte autophagy and cardiac remodelling through inhibition of oxidative stress.     

Heme oxygenase-1 gene transfer inhibits angiotensin II-mediated rat cardiac myocyte apoptosis but not hypertrophy

Cardiac myocyte apoptosis underlies the pathophysiology of cardiomyopathy, and plays a critical role in the transition from myocardial hypertrophy to heart failure. Angiotensin II (Ang II) induces cardiac myocyte apoptosis and hypertrophy which contribute to heart failure possibly through enhanced oxidative stress; however, the mechanisms underlying the activation of both pathways and their interactions remain unclear. In the present study, we have investigated whether overexpression of the antioxidant protein heme oxygenase-1 (HO-1) protects against apoptosis and hypertrophy in cultured rat cardiac myocytes treated with Ang II. Our findings demonstrate that Ang II (100 nM, 24 h) alone upregulates HO-1 expression and induces both myocyte hypertrophy and apoptosis, assessed by measuring terminal deoxynucleotidyltransferase dUTP nick-end labelling (TUNEL) staining, caspase-3 activity and mitochondrial membrane potential. Ang II elicited apoptosis was augmented in the presence of tin protoporphyrin, an inhibitor of HO activity, while HO-1 gene transfer to myocytes attenuated Ang II-mediated apoptosis but not hypertrophy. Adenoviral overexpression of HO-1 was accompanied by a significant increase in Ang II induced phosphorylation of Akt, however, Ang II-mediated p38 mitogen activated protein kinase (MAPK) phosphorylation was attenuated. Inhibition of phosphotidylinositol-3-kinase enhanced myocyte apoptosis elicited by Ang II, however, p38MAPK inhibition had no effect, suggesting that overexpression of HO-1 protects myocytes via augmented Akt activation and not through modulation of p38MAPK activation. Our findings identify the signalling pathways by which HO-1 gene transfer protects against apoptosis and suggest that overexpression of HO-1 in cardiomyopathies may delay the transition from myocyte hypertrophy to heart failure.     

Novel EGFR inhibitors attenuate cardiac hypertrophy induced by angiotensin II

Cardiac hypertrophy is an important risk factor for heart failure. Epidermal growth factor receptor (EGFR) has been found to play a role in the pathogenesis of various cardiovascular diseases. The aim of this current study was to examine the role of EGFR in angiotensin II (Ang II)‐induced cardiac hypertrophy and identify the underlying molecular mechanisms. In this study, we observed that both Ang II and EGF could increase the phospohorylation of EGFR and protein kinase B (AKT)/extracellular signal‐regulated kinase (ERK), and then induce cell hypertrophy in H9c2 cells. Both pharmacological inhibitors and genetic silencing significantly reduced Ang II‐induced EGFR signalling pathway activation, hypertrophic marker overexpression, and cell hypertrophy. In addition, our results showed that Ang II‐induced EGFR activation is mediated by c‐Src phosphorylation. In vivo, Ang II treatment significantly led to cardiac remodelling including cardiac hypertrophy, disorganization and fibrosis, accompanied by the activation of EGFR signalling pathway in the heart tissues, while all these molecular and pathological alterations were attenuated by the oral administration with EGFR inhibitors. In conclusion, the c‐Src‐dependent EGFR activation may play an important role in Ang II‐induced cardiac hypertrophy, and inhibition of EGFR by specific molecules may be an effective strategy for the treatment of Ang II‐associated cardiac diseases.     

Eplerenone inhibits the intracrine and extracellular actions of angiotensin II on the inward calcium current in the failing heart. On the presence of an intracrine renin angiotensin aldosterone system

The influence of chronic administration of eplerenone on the intracrine as well as on the extracellular action of angiotensin II (Ang II) on L-type inward calcium current was investigated in the failing heart of cardiomyopathic hamsters (TO-2).For this, eplerenone (200 mg/kg/day) was administered orally to 2 month-old cardiomyopathic hamsters for a period of 3 months. Measurements of the peak inward calcium current (I(Ca)) was performed in single cells under voltage clamp using the whole cell configuration. The results indicated that eplerenone suppressed the intracrine action of Ang II (10(-)(8) M) on peak I(Ca) density. Moreover, the intracellular dialysis of the peptide did not change the time course of I(Ca) inactivation in animals treated chronically with eplerenone. The extracellular administration of Ang II (10(-)(8) M) incremented the peak I(Ca) density by only 20+/-8% (n=30) compared with 38+/-4% (n=35) (P<0.05) obtained in age-matched cardiomyopathic hamsters not exposed to eplerenone. Interestingly, the inhibitory of eplerenone (10(-7) M) on the intracrine action of Ang II was also found, in vitro, but required an incubation period of, at least, 24 h. The inhibitory action of eplerenone on the intracellular action of Ang II was partially reversed by exposing the eplerenone-treated cells to aldosterone (10 nM) for a period of 24 h what supports the view that: a) the mineralocorticoid receptor(MR) was involved in the modulation of the intracrine action of the peptide; b) the effect of eplerenone on the intracrine as well as on the extracellular action of Ang II was related ,in part, to a decreased expression of membrane-bound and intracellular AT1 receptors. In conclusion: a) eplerenone inhibits the intracrine action of Ang II on inward calcium current and reduces drastically the effect of extracellular Ang II on I(Ca); b) aldosterone is able to revert the effect of eplerenone; c) the mineralocorticoid receptor is an essential component of the intracrine renin angiotensin aldosterone system.     

Regulation of insulin-like growth factor-1 by the renin-angiotensin system during regression of cardiac eccentric hypertrophy through angiotensin-converting enzyme inhibitor and AT1 antagonist

Angiotensin II (Ang II) mediates its effects through its non-tyrosine-kinase G protein coupled Ang-II type 1 receptor (AT1). Growing evidence indicates that a functional insulin-like growth factor-1 (IGF-1) tyrosine kinase receptor is required for Ang-II-induced mitogenesis. Along with Ang II, we have previously shown that changes in IGF-1 receptor binding at myofibers are causative agents for cardiac eccentric hypertrophy. This study investigated the interaction of the renin-angiotensin system with the IGF-1 receptor during the development and regression of cardiac hypertrophy. Alterations in IGF-1 binding were evaluated in the CHAPS-pretreated perfused heart. Four weeks of aortocaval shunt increased relative heart mass by 76% without a major change in body mass or systolic blood pressure. Binding studies showed that IGF-1 has a higher affinity for the cardiac myofibers of shunt than sham rats. Two weeks of treatment with the angiotensin-converting enzyme (ACE) inhibitor captopril (0.5 g/L in drinking water) or the AT1-antagonist losartan (10 mg/(kg x day)) reduced cardiac hypertrophy by 54 and 42%, respectively. However, while both ACE inhibition and AT1-antagonist treatments produced equivalent regression in ventricular hypertrophy, captopril was more efficacious than losartan in the regression of atrial hypertrophy. Regression of cardiac hypertrophy in the shunt by either captopril or losartan was accompanied with a reduction or normalization of the elevated IGF-1 affinity. Thus, the induction and regression of cardiac eccentric hypertrophy seems to be largely dependent on cross talk between the renin-angiotensin system and the IGF-1 axis at the receptor level.     

Phosphoinositide hydrolysis increase by angiotensin-(1--7) in neonatal rat brain

Angiotensin (Ang)-(1–7) is an endogenous peptide hormone of the renin–angiotensin system which exerts diverse biological actions, some of them counterregulate Ang II effects. In the present study potential effect of Ang-(1–7) on phosphoinositide (PI) turnover was evaluated in neonatal rat brain. Cerebral cortex prisms of seven-day-old rats were preloaded with [³H]myoinositol, incubated with additions during 30 min and later [³H]inositol-phosphates (IPs) accumulation quantified. It was observed that PI hydrolysis enhanced 30% to 60% in the presence of 0.01 nM to 100 nM Ang-(1–7). Neither 10 nM [D-Ala⁷]Ang-(1–7), an Ang-(1–7) specific antagonist, nor 10 nM losartan, an angiotensin II type 1 (AT₁) receptor antagonist, blocked the effect of 0.1 nM Ang-(1–7) on PI metabolism. The effect of 0.1 nM Ang-(1–7) on PI hydrolysis was not reduced but it was even significantly increased in the simultaneous presence of [D-Ala⁷]Ang-(1–7) or losartan. PI turnover enhancement achieved with 0.1 nM Ang-(1–7) decreased roughly 30% in the presence of 10 nM PD 123319, an angiotensin II type 2 (AT₂) receptor antagonist. The antagonists alone also enhanced PI turnover. Present findings showing an increase in PI turnover by Ang-(1–7) represent a novel action for this peptide and suggest that it exerts a function in this signaling system in neonatal rat brain, an effect involving, at least partially, angiotensin AT₂ receptors.     

Activation of AP-1 through reactive oxygen species by angiotensin II in rat cardiomyocytes

Cardiovascular pathogenesis induced by angiotensin II (Ang-II) is a complex process often connected to oxidative stress. In the present study we show that, 4 h after addition, Ang-II induces a four- to fivefold increase in AP-1 activity in cultured neonatal rat cardiomyocytes and that the intracellular level of reactive oxygen species (ROS) correlates with the extent of AP-1 binding activity. Ang-II stimulated ROS generation in rat cardiomyocytes in a dose- and time-dependent manner. These effects of Ang-II were suppressed by the Ang-II receptor type I (AT₁) inhibitor CV-11974 as well as by the antioxidants diphenylene iodonium (DPI) and N-acetyl-l-cysteine (NAC), but not by AT₂ antagonist PD 122319. Furthermore, Ang-II induced a two- to threefold increase in protein synthesis and cell size during 12–24 h, which could be inhibited by CV-11974 as well as by DPI and NAC. Because the rat cardiomyocytes strongly expressed gp91^phox, this suggests that ROS generated in a gp91-containing NADPH oxidase are involved in signal transduction leading to AP-1 activation. Together, these findings indicate that Ang-II elicits the activation of the redox-sensitive AP-1 via ROS through AT₁, resulting in effects on cardiomyocyte function such as hypertrophy.     

Angiotensin IV protects against angiotensin II-induced cardiac injury via AT4 receptor

Angiotensin II (Ang II) is an important regulator of cardiac function and injury in hypertension. The novel Ang IV peptide/AT4 receptor system has been implicated in several physiological functions and has some effects opposite to those of Ang II. However, little is known about the role of this system in Ang II-induced cardiac injury. Here we studied the effect of Ang IV on Ang II-induced cardiac dysfunction and injury using isolated rat hearts, neonatal cardiomyocytes and cardiac fibroblasts. We found that Ang IV significantly improved Ang II-induced cardiac dysfunction and injury in the isolated heart in response to ischemia/reperfusion (I/R). Moreover, Ang IV inhibited Ang II-induced cardiac cell apoptosis, cardiomyocyte hypertrophy, and proliferation and collagen synthesis of cardiac fibroblasts; these effects were mediated through the AT4 receptor as confirmed by siRNA knockdown. These findings suggest that Ang IV may have a protective effect on Ang II-induced cardiac injury and dysfunction and may be a novel therapeutic target for hypertensive heart disease.     

Angiotensin II induces matrix metalloproteinase-9 expression via a nuclear factor-kappaB-dependent pathway in vascular smooth muscle cells

Angiotensin II (AngII) is widely recognized as a critical regulator of the development of atherosclerosis. Matrix metalloproteinases (MMPs) are thought to participate in plaque destabilization through degradation of the extracellular matrix. In the present study, we investigated the potential mechanism of AngII-induced MMP-9 expression in vascular smooth muscle cells (VSMC). AngII upregulated the expression of MMP-9 significantly in VSMC obtained from rat aorta. RNAi-mediated knockdown of p65 and losartan, an inhibitor of AngII receptors subtype-1 (AT₁), could abolish AngII-induced MMP-9 expression. In addition, AngII induced the NF-κB binding activity via AT₁ and AT₂ receptors in VSMC, and AngII-induced activation of NF-κB is not associated with significant downregulation of IκB. In summary, this study demonstrates that AngII stimulates NF-κB nuclear translocation in VSMC via AT₁ and AT₂. AngII increases the expression of MMP-9 in VSMC, and AT₁ and NF-κB pathways have an important role in this response.     

自发性高血压大鼠心肌肥厚和心肌MAPK、AngⅡ的关系

放免法测定自发性高血压大鼠（ＳＨＲ）血浆及心肌血管紧张素Ⅱ（ＡｎｇⅡ）含量,凝胶内磷酸化法测定心肌丝裂素活化蛋白激酶活性（ＭＡＰＫ）,以心脏重／体重表示心肌肥厚程度。结果表明：与４个月的ＷＫＹ大鼠比较,４个月的ＳＨＲ血浆和心肌组织ＡｎｇⅡ及心肌ＭＡＰＫ活性分别增加了２１８．６％、１０１．２％和１０７．０％,心肌肥大程度严重,其中ＭＡＰＫ活性与心肌肥大程度呈明显正相关。提示４个月ＳＨＲ心肌肥厚可能是     

Chronic infusion of angiotensin-(1-7) reduces heart angiotensin II levels in rats

We tested the hypothesis that the actions of Angiotensin (Ang)-(1-7) in the heart could involve changes in tissue levels of Ang II. This possibility was addressed by determining the effect of chronic infusion of Ang-(1-7) on plasma and tissue angiotensins. Ang-(1-7) was infused subcutaneously (osmotic minipumps) in Wistar rats. Angiotensins were determined by radioimmunoassay (RIA) in plasma, heart, and kidney. Tissue and plasma angiotensin-converting enzyme (ACE) activity and plasma renin activity (PRA) were also measured. Cardiac and renal ACE2 mRNA levels and cardiac angiotensinogen mRNA levels were assessed by semi-quantitative polymerase chain reaction (PCR). AT1 receptor number was evaluated by autoradiograph. Chronic infusion of Ang-(1-7) (2 microg/h, 6 days) produced a marked decrease of Ang II levels in the heart. A less pronounced but significant decrease of Ang-(1-7) was also observed. No significant changes were observed for Ang I. Ang II was not altered in the kidney. In this tissue, a significant increase of Ang-(1-7) and Ang I concentration was observed. A significant increase of plasma Ang-(1-7) and Ang II was also observed. Ang-(1-7) infusion did not change ACE activity or PRA. A selective slight significant increase in ACE2 expression in the heart was observed. Heart angiotensinogen mRNA as well as the number of Ang II binding sites did not change. These results suggest that AT1 receptors-independent changes in heart Ang II concentration might contribute for the beneficial effects of Ang-(1-7) in the heart. Moreover, these results reinforce the hypothesis that this angiotensin plays an important site-specific role within the renin-angiotensin system.     

Long non-coding RNA Pvt1 modulates the pathological cardiac hypertrophy via miR-196b-mediated OSMR regulation

Cardiac hypertrophy is the uppermost risk factor for the development of heart failure, leading to irreversible cardiac structural remodeling and sudden death. As a major mediator of cardiac remodeling, oncostatin M (OSM) and its receptor, OSMR, attract plenty of interest. Recent studies have demonstrated key effects of noncoding RNAs on myocardial remodeling. However, whether noncoding RNAs that regulate the expression of OSMR would regulate the process of remodeling remain unclear. Herein, we observed that long noncoding RNA (lncRNA) Pvt1 expression showed to be significantly elicited by aortic banding (AB) operation in vivo and by angiotensin (Ang II) treatment in vitro. Pvt1 knockdown significantly attenuated the myocardial hypertrophy caused by pressure overload within rats and the cardiac myocyte hypertrophy caused by Ang II in vitro. Moreover, Pvt1 knockdown also decreased cellular myomesin and B-raf, which was involved in OSM function in cardiac remodeling. Based on online tools prediction, miR-196b may simultaneously target Pvt1 and OSMR 3′ untranslated region (UTR). In rat H9c2 cells and primary cardiac myocyte, Pvt1 and miR-196b exerted negative regulatory effects on each other and miR-196b negatively regulated OSMR expression. Pvt1 directly targeted miR-196b to relieve miR-196b-induced OSMR suppression via acting as a competing endogenous RNA (ceRNA). Moreover, the effect of miR-196b suppression upon the B-raf was opposite to Pvt1 knockdown, and miR-196b suppression might significantly attenuate the effect of Pvt1 knockdown. In summary, Pvt1/miR-196b axis modulating cardiomyocyte hypertrophy and remodeling via OSMR. Our findings provide a rationale for further studies on the potential therapeutic benefits of Pvt1 function and mechanism in cardiac and cardiomyocyte hypertrophy by a lncRNA-miRNA-mRNA network.