Intravital Multiphoton Microscopy of the Beating Mouse Heart Reveals Altered Cardiomyocyte Contraction Dynamics and Increased Microvascular Patrolling by Leukocytes during Cardiac Hypertrophy

Background/Aims: Qiliqiangxin (QL), a traditional Chinese medicine, has long been used to treat chronic heart failure. Previous studies demonstrated that QL could prevent cardiac remodeling and hypertrophy in response to hypertensive or ischemic stress. However, little is known about whether QL could modulate cardiac hypertrophy in vitro, and (if so) whether it is through modulation of specific hypertrophy-related microRNA. Methods: The primary neonatal rat ventricular cardiomyocytes were isolated, cultured, and treated with phenylephrine (PE, 50 µmol/L, 48 h) to induce hypertrophy in vitro, in the presence or absence of pretreatment with QL (0.5 µg/ml, 48 h). The cell surface area was determined by immunofluorescent staining for α-actinin. The mRNA levels of hypertrophic markers including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and β-myosin heavy chain (MYH7) were assayed by qRT-PCRs. The protein synthesis of cardiomyocytes was determined by the protein/DNA ratio. The miR-199a-5p expression level was quantified in PE-treated cardiomyocytes and heart samples from acute myocardial infarction (AMI) mouse model. MiR-199a-5p overexpression was used to determine its role in the anti-hypertrophic effect of QL on cardiomyocytes. Results: PE induced obvious enlargement of cell surface in cardiomyocytes, paralleling with increased ANP, BNP, and MYH7 mRNA levels and elevated protein/DNA ratio. All these changes were reversed by the treatment with QL. Meanwhile, miR-199a-5p was increased in AMI mouse heart tissues. Of note, the increase of miR-199a-5p in PE-treated cardiomyocytes was reversed by the treatment with QL. Moreover, overexpression of miR-199a-5p abolished the anti-hypertrophic effect of QL on cardiomyocytes. Conclusion: QL prevents PE-induced cardiac hypertrophy. MiR-199a-5p is increased in cardiac hypertrophy, while reduced by treatment with QL. miR-199a-5p suppression is essential for the anti-hypertrophic effect of QL on cardiomyocytes.

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Abstract P189: RhoA Functions as an Antihypertrophic Switch in the Mouse Heart

Circulation Research ◽

10.1161/res.109.suppl_1.ap189 ◽

2011 ◽

Vol 109 (suppl_1) ◽

Author(s):

Davy Vanhoutte ◽

Jop Van Berlo ◽

Allen J York ◽

Yi Zheng ◽

Jeffery D Molkentin

Keyword(s):

Cardiac Hypertrophy ◽

Pressure Overload ◽

Small Gtpase ◽

Mouse Heart ◽

Activity Levels ◽

Lung Weight ◽

Pathological Cardiac Hypertrophy ◽

Rhoa Protein

Background. Small GTPase RhoA has been previously implicated as an important signaling effector within the cardiomyocyte. However, recent studies have challenged the hypothesized role of RhoA as an effector of cardiac hypertrophy. Therefore, this study examined the in vivo role of RhoA in the development of pathological cardiac hypertrophy. Methods and results . Endogenous RhoA protein expression and activity levels (GTP-bound) in wild-type hearts were significantly increased after pressure overload induced by transverse aortic constriction (TAC). To investigate the necessity of RhoA within the adult heart, RhoA-LoxP-targeted (RhoA flx/flx ) mice were crossed with transgenic mice expressing Cre recombinase under the control of the endogenous cardiomyocyte-specific β-myosin heavy chain (β-MHC) promoter to generate RhoA βMHC-cre mice. Deletion of RhoA with β-MHC-Cre produced viable adults with > 85% loss of RhoA protein in the heart, without altering the basic architecture and function of the heart compared to control hearts, at both 2 and 8 months of age. However, subjecting RhoA βMHC-cre hearts to 2 weeks of TAC resulted in marked increase in cardiac hypertrophy (HW/BW (mg/g): 9.5 ± 0.3 for RhoA βMHC-cre versus 7.7 ± 0.4 for RhoA flx/flx ; and cardiomyocyte size (mm 2 ): 407 ± 21 for RhoA βMHC-cre versus 262 ± 8 for RhoA flx/flx ; n ≥ 8 per group; p<0.01) and a significantly increased fibrotic response. Moreover, RhoA βMHC-cre hearts transitioned more quickly into heart failure whereas control mice maintained proper cardiac function (fractional shortening (%): 23.3 ± 1.2 for RhoA βMHC-cre versus 29.3 ± 1.2 for RhoA flx/flx ; n ≥ 8 per group; p<0.01; 12 weeks after TAC). The latter was further associated with a significant increase in lung weight normalized to body weight and re-expression of the cardiac fetal gene program. In addition, these mice also displayed greater cardiac hypertrophy in response to 2 weeks of angiotensinII/phenylephrine infusion. Conclusion. These data identify RhoA as an antihypertrophic molecular switch in the mouse heart.

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LCZ696, an Angiotensin Receptor-Neprilysin Inhibitor, Improves Cardiac Hypertrophy and Fibrosis and Cardiac Lymphatic Remodeling in Transverse Aortic Constriction Model Mice

BioMed Research International ◽

10.1155/2020/7256862 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Qing Ge ◽

Li Zhao ◽

Chen Liu ◽

Xiaoming Ren ◽

Yi-hui Yu ◽

...

Keyword(s):

Cardiac Hypertrophy ◽

Protein Expression ◽

Lymphatic System ◽

Lymphatic Vessels ◽

Mouse Heart ◽

Transverse Aortic Constriction ◽

Aortic Constriction ◽

Expression Levels ◽

Factor C ◽

Proinflammatory Factors

Cardiac hypertrophy and ventricular remodeling following heart failure are important causes of high mortality in heart disease patients. The cardiac lymphatic system has been associated with limited research, but it plays an important role in the improvement of myocardial edema and the promotion of fluid balance. LCZ696 is a novel combination of angiotensin and neprilysin inhibitors. Here, we studied the role played by LCZ696 during transverse aortic constriction (TAC) induced cardiac hypertrophy and changes in the lymphatic system. Mice undergoing aortic coarctation were constructed to represent a cardiac hypertrophy model and then divided into random groups that either received treatment with LCZ696 (60 mg/kg/d) or no treatment. Cardiac ultrasonography was used to detect cardiac function, and hematoxylin and eosin (H&E) and Masson staining were used to detect myocardial hypertrophy and fibrosis. The proinflammatory factors interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) were detected in the blood and heart tissues of mice. The protein expression levels of lymphatic-specific markers, such as vascular endothelial growth factor C (VEGF-C), VEGF receptor 3 (VEGFR3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) were detected in mouse heart tissues. We also examined the colocalization of lymphatic vessels and macrophages by immunofluorescence. The results showed that LCZ696 significantly improved heart dysfunction, cardiac hypertrophy, and fibrosis and inhibited the expression of proinflammatory factors IL-6, IL-1β, and TNF-α in the circulating blood and heart tissues of mice. LCZ696 also decreased the protein expression levels of VEGF-C, VEGFR3, and LYVE-1 in mouse heart tissues, ameliorated the transport load of lymphatic vessels to macrophages, and improved the remodeling of the lymphatic system in the hypertrophic cardiomyopathy model induced by TAC.

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H2S Protects against Cardiac Cell Hypertrophy through Regulation of Selenoproteins

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/6494306 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Adam Greasley ◽

Yanjie Zhang ◽

Bo Wu ◽

Yanxi Pei ◽

Nelson Belzile ◽

...

Keyword(s):

Oxidative Stress ◽

Cardiac Hypertrophy ◽

Critical Role ◽

Thioredoxin Reductase ◽

Cardiac Cells ◽

Keshan Disease ◽

Mouse Heart ◽

Cardiac Cell ◽

Cell Hypertrophy ◽

Expression Of Genes

Cardiac hypertrophy is defined as the enlargement of the cardiac myocytes, leading to improper nourishment and oxygen supply due to the increased functional demand. This increased stress on the cardiac system commonly leads to myocardial infarction, contributing to 85% of all cardiac-related deaths. Cystathionine gamma-lyase- (CSE-) derived H2S is a novel gasotransmitter and plays a critical role in the preservation of cardiac functions. Selenocysteine lyase (SCLY) has been identified to produce H2Se, the selenium homologue of H2S. Deficiency of selenium is often found in Keshan disease, a congestive cardiomyopathy. The interaction of H2S and H2Se in cardiac cell hypertrophy has not been explored. In this study, cell viability was evaluated with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Oxidative stress and cell size were observed through immunostaining. The expression of genes was determined by real-time PCR and western blot. Here, we demonstrated that incubation of rat cardiac cells (H9C2) with H2O2 lead to increased oxidative stress and cell surface area, which were significantly attenuated by pretreatment of either H2S or H2Se. H2S incubation induced SCLY/H2Se signaling, which next caused higher expressions and activities of selenoproteins, including glutathione peroxidase and thioredoxin reductase. Furthermore, deficiency of CSE inhibited the expressions of SCLY and selenoprotein P in mouse heart tissues. We also found that both H2S and H2Se stimulated Nrf2-targeted downstream genes. These data suggests that H2S protects against cardiac hypertrophy through enhancement of a group of antioxidant proteins.

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Alternations of cardiac IK1 and Ito from FKBP12.6 transgenic mouse heart and potential impact of cardiac hypertrophy

International Journal of Cardiology ◽

10.1016/j.ijcard.2014.07.081 ◽

2014 ◽

Vol 176 (3) ◽

pp. 1017-1020 ◽

Cited By ~ 3

Author(s):

Bing Xu ◽

Jiu-Xin Zhu ◽

Rong Huo ◽

Zhen-Yu Yan ◽

Jian-Li He ◽

...

Keyword(s):

Cardiac Hypertrophy ◽

Transgenic Mouse ◽

Mouse Heart ◽

Potential Impact

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In vivo multiphoton microscopy of cardiomyocyte calcium dynamics in the beating mouse heart

10.1101/251561 ◽

2018 ◽

Author(s):

Jason S. Jones ◽

David M. Small ◽

Nozomi Nishimura

Keyword(s):

Action Potentials ◽

Multiphoton Microscopy ◽

Three Dimensional ◽

Heart Beat ◽

Beating Heart ◽

Mouse Heart ◽

Calcium Dynamics ◽

Intact Mouse ◽

Calcium Indicator

AbstractWe demonstrated intravital multiphoton microscopy in the beating heart in an intact mouse and optically measured action potentials with GCaMP6f, a genetically-encoded calcium indicator. Images were acquired at 30 fps with spontaneous heart beat and continuously running ventilated breathing. The data were reconstructed into three-dimensional volumes showing tissue structure, displacement, and GCaMP activity in cardiomyocytes as a function of both the cardiac and respiratory cycle.

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Knockout of Wdr1 results in cardiac hypertrophy and impaired cardiac function in adult mouse heart

Gene ◽

10.1016/j.gene.2019.02.023 ◽

2019 ◽

Vol 697 ◽

pp. 40-47

Author(s):

Xia Huang ◽

Ziyi Li ◽

Jisheng Hu ◽

Zihao Yang ◽

Zhongying Liu ◽

...

Keyword(s):

Cardiac Hypertrophy ◽

Cardiac Function ◽

Adult Mouse ◽

Mouse Heart ◽

Impaired Cardiac Function

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Myricetin Alleviates Pathological Cardiac Hypertrophy via TRAF6/TAK1/MAPK and Nrf2 Signaling Pathway

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/6304058 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 4

Author(s):

Hai-han Liao ◽

Nan Zhang ◽

Yan-yan Meng ◽

Hong Feng ◽

Jing-jing Yang ◽

...

Keyword(s):

Cardiac Hypertrophy ◽

Pressure Overload ◽

Mapk Signaling ◽

Neonatal Rat ◽

Mouse Heart ◽

Pathological Cardiac Hypertrophy ◽

Pathological Hypertrophy ◽

Nrf2 Signaling Pathway

Myricetin (Myr) is a common plant-derived polyphenol and is well recognized for its multiple activities including antioxidant, anti-inflammation, anticancer, and antidiabetes. Our previous studies indicated that Myr protected mouse heart from lipopolysaccharide and streptozocin-induced injuries. However, it remained to be unclear whether Myr could prevent mouse heart from pressure overload-induced pathological hypertrophy. Wild type (WT) and cardiac Nrf2 knockdown (Nrf2-KD) mice were subjected to aortic banding (AB) surgery and then administered with Myr (200 mg/kg/d) for 6 weeks. Myr significantly alleviated AB-induced cardiac hypertrophy, fibrosis, and cardiac dysfunction in both WT and Nrf2-KD mice. Myr also inhibited phenylephrine- (PE-) induced neonatal rat cardiomyocyte (NRCM) hypertrophy and hypertrophic markers’ expression in vitro. Mechanically, Myr markedly increased Nrf2 activity, decreased NF-κB activity, and inhibited TAK1/p38/JNK1/2 MAPK signaling in WT mouse hearts. We further demonstrated that Myr could inhibit TAK1/p38/JNK1/2 signaling via inhibiting Traf6 ubiquitination and its interaction with TAK1 after Nrf2 knockdown in NRCM. These results strongly suggested that Myr could attenuate pressure overload-induced pathological hypertrophy in vivo and PE-induced NRCM hypertrophy via enhancing Nrf2 activity and inhibiting TAK1/P38/JNK1/2 phosphorylation by regulating Traf6 ubiquitination. Thus, Myr might be a potential strategy for therapy or adjuvant therapy for malignant cardiac hypertrophy.

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Abstract 17904: Deficiency of Yes-associated Protein Promotes Cardiac Dysfunction in Response to Pressure Overload in the Mouse Heart

Circulation ◽

10.1161/circ.132.suppl_3.17904 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Jaemin Byun ◽

Dominic P Del Re ◽

Peiyong Zhai ◽

Akihiro Shirakabe ◽

Junichi Sadoshima

Keyword(s):

Cardiac Hypertrophy ◽

Mammalian Cells ◽

Diastolic Pressure ◽

Systolic Function ◽

Pressure Overload ◽

Wall Stress ◽

Left Ventricular ◽

Lv Function ◽

Mouse Heart ◽

And Control

Yes-Associated Protein (YAP), a downstream effector of the Hippo pathway, plays an important role in regulating cell proliferation and survival in mammalian cells. We have shown that cardiac-specific loss of YAP leads to increased cardiomyocyte (CM) apoptosis and impaired hypertrophy during chronic myocardial infarction in the mouse heart. However, it remains unclear whether YAP mediates hypertrophy of individual CMs under stress conditions in vivo. We hypothesized that endogenous YAP plays an essential role in mediating hypertrophy and survival of CMs in response to pressure overload (PO). Three-month-old YAP+/fl;α-MHC-Cre (YAP-cKO) and YAP+/fl (control) mice were subjected to transverse aortic constriction (TAC). Two weeks later, YAP-cKO and control mice developed similar levels of cardiac hypertrophy (left ventricular (LV) weight/tibia length: 7.27±0.38, 6.93±0.29) compared to sham (5.08±0.14, 4.07±0.33). LV CM cross sectional area was similarly increased by TAC in YAP-cKO and control mice compared to their respective shams. Induction of fetal-type genes, such as Anf and Myh7, was also similar in YAP-cKO and control mice. YAP-cKO and control mice exhibited similar baseline LV systolic function (ejection fraction (EF): 75, 76%). YAP-cKO mice had significantly decreased LV function after TAC compared to Sham-control mice (EF: 51%, 76%, p<0.05) and TAC-control mice (75%, p<0.05). LV end diastolic pressure (LVEDP, mmHg) was significantly increased (19.3 ±3.2, 9.8±1.6, p<0.05), and LV +dP/dt (mmHg/s, 7250±588, 9500±453, p<0.01) and -dP/dt (mmHg/s, 6000±433, 7781± 314, p<0.05) were significantly decreased in YAP-cKO compared to in control mice after TAC. LV end diastolic diameter (mm) was significantly greater in YAP-cKO than in control mice after TAC (3.95±0.11, 3.35±0.15, p<0.05), whereas LV pressure was similar, suggesting that LV wall stress was elevated in YAP-cKO compared to in control mice. Since cardiac hypertrophy in YAP-cKO mice is similar to that in control mice despite elevated wall stress, the lack of YAP appears to limit the extent of cardiac hypertrophy in response to increased wall stress. These data suggest that endogenous YAP plays an important role in mediating adaptive hypertrophy and protecting the heart against PO.

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Abstract 18122: Mir-206 Plays an Important Role in Mediating Pressure Overload-induced Cardiac Hypertrophy

Circulation ◽

10.1161/circ.132.suppl_3.18122 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Sebstiano Sciarretta ◽

Yanfei Yang ◽

Dominic P Del Re ◽

Junichi Sadoshima

Keyword(s):

Cardiac Hypertrophy ◽

Sequence Similarity ◽

Pressure Overload ◽

Left Ventricular ◽

Pcr Analysis ◽

Mouse Heart ◽

Sham Operation ◽

Hippo Signaling ◽

Qrt Pcr

Introduction: Expression of miR-206 is upregulated by YAP, a key transcription co-factor controlled by the Hippo signaling pathway, and mediates YAP-induced hypertrophy and survival of cardiomyocytes. Although miR-206 is known to promote hypertrophy of skeletal muscle, the role of miR-206 in the heart under clinically relevant conditions in vivo remains unknown. We investigated the role of miR-206 in mediating cardiac hypertrophy in response to pressure overload (PO). Results: The level of miR-206 in the mouse heart, as evaluated by qRT-PCR, was upregulated 2.9 fold (p<0.05) 7 days after transverse aortic constriction (TAC) compared to sham operation. In order to evaluate the involvement of miR-206 in cardiac hypertrophy, wild-type C57B/6J mice were administered LNA inhibitor designed to selectively inhibit miR-206, or control scrambled LNA, by tail vein injection. Specificity of the LNA inhibitor was confirmed by qRT-PCR analysis of miRNA expression 48 hours after treatment. Notably, the LNA inhibitor did not affect the level of miR-1, which has a sequence similarity with miR-206. After 48 hours, mice from both treatment groups were subjected to sham operation or TAC. After 7 days of TAC, echocardiography was performed and mice were sacrificed. Upregulation of myocardial miR-206 expression levels after 7 days TAC observed in LNA control-treated mice was completely abolished in LNA-anti-206 -treated mice. A significant increase in left ventricular weight/tibial length (mg/mm) in LNA control-treated mice following TAC was observed (sham vs TAC: 3.7, 4.8, p<0.05); however, no increase was observed in LNA-anti-206 -treated mice (3.8, 3.8). We also noted significant differences in chamber wall thickness (mm) between the LNA-control and LNA-anti-206-treated TAC groups (diastolic posterior wall 0.91, 0.61, p<0.05). Additionally, cardiomyocyte cross sectional area (1.23, 0.9, p<0.05) and ANF expression (2.5, 1.3, P<0.05) were significantly increased in the LNA control-treated TAC group, and these responses were attenuated in the LNA-anti-206-treated mice. Conclusions: These data demonstrate that inhibition of miR-206 impairs PO-induced hypertrophy and indicates that miR-206 is an important endogenous mediator of heart growth in response to PO.

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