Publications by authors named "Zhuoming Li"

37 Publications

HO-1 nuclear accumulation and interaction with NPM1 protect against stress-induced endothelial senescence independent of its enzymatic activity.

Cell Death Dis 2021 Jul 26;12(8):738. Epub 2021 Jul 26.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, China.

Heme oxygenase-1 (HO-1) has attracted accumulating attention for its antioxidant enzymatic activity. However, the exact regulatory role of its non-enzymatic activity in the cardiovascular system remains unaddressed. Here, we show that HO-1 was accumulated in the nuclei of stress-induced senescent endothelial cells, and conferred protection against endothelial senescence independent of its enzymatic activity. Overexpression of ΔHO-1, a truncated HO-1 without transmembrane segment (TMS), inhibited HO-induced endothelial senescence. Overexpression of ΔHO-1, the catalytically inactive form of ΔHO-1, also exhibited anti-senescent effect. In addition, infection of recombinant adenovirus encoding ΔHO-1 with three nuclear localization sequences (NLS), alleviated endothelial senescence induced by knockdown of endogenous HO-1 by CRISPR/Cas9. Moreover, repression of HO-1 nuclear translocation by silencing of signal peptide peptidase (SPP), which is responsible for enzymatic cleavage of the TMS of HO-1, exacerbated endothelial senescence. Mechanistically, nuclear HO-1 interacted with NPM1 N-terminal portion, prevented NPM1 translocation from nucleolus to nucleoplasm, thus disrupted NPM1/p53/MDM2 interactions and inhibited p53 activation by NPM1, finally resisted endothelial senescence. This study provides a novel understanding of HO-1 as a promising therapeutic strategy for vascular senescence-related cardiovascular diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41419-021-04035-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8313700PMC
July 2021

PEX5 prevents cardiomyocyte hypertrophy via suppressing the redox-sensitive signaling pathways MAPKs and STAT3.

Eur J Pharmacol 2021 Sep 24;906:174283. Epub 2021 Jun 24.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Engineering Laboratory of Druggability and New Drug Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, China. Electronic address:

Peroxisomal biogenesis factor 5 (PEX5) is a member of peroxisome biogenesis protein family which serves as a shuttle receptor for the import of peroxisome matrix protein. The function of PEX5 on cardiomyocyte hypertrophy remained to be elucidated. Our study demonstrated that the protein expression level of PEX5 was declined in primary neonatal rat cardiomyocytes treated with phenylephrine (PE) and hearts from cardiac hypertrophic rats induced by abdominal aortic constriction (AAC). Overexpression of PEX5 alleviated cardiomyocyte hypertrophy induced by PE, while silencing of PEX5 exacerbated cardiomyocyte hypertrophy. PEX5 improved redox imbalance by decreasing cellular reactive oxygen species level and preserving peroxisomal catalase. Moreover, PEX5 knockdown aggravated PE-induced activation of redox-sensitive signaling pathways, including mitogen-activated protein kinase (MAPK) pathway and signal transducer and activator of transcription 3 (STAT3); whereas PEX5 overexpression suppressed activation of MAPK and STAT3. But PEX5 did not affect PE-induced phosphorylation of mammalian target of rapamycin (mTOR). In conclusion, the present study suggests that PEX5 protects cardiomyocyte against hypertrophy via regulating redox homeostasis and inhibiting redox-sensitive signaling pathways MAPK and STAT3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejphar.2021.174283DOI Listing
September 2021

The poly(ADP-ribosyl)ation of BRD4 mediated by PARP1 promoted pathological cardiac hypertrophy.

Acta Pharm Sin B 2021 May 14;11(5):1286-1299. Epub 2020 Dec 14.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou 510006, China.

The bromodomain and extraterminal (BET) family member BRD4 is pivotal in the pathogenesis of cardiac hypertrophy. BRD4 induces hypertrophic gene expression by binding to the acetylated chromatin, facilitating the phosphorylation of RNA polymerases II (Pol II) and leading to transcription elongation. The present study identified a novel post-translational modification of BRD4: poly(ADP-ribosyl)ation (PARylation), that was mediated by poly(ADP-ribose)polymerase-1 (PARP1) in cardiac hypertrophy. BRD4 silencing or BET inhibitors JQ1 and MS417 prevented cardiac hypertrophic responses induced by isoproterenol (ISO), whereas overexpression of BRD4 promoted cardiac hypertrophy, confirming the critical role of BRD4 in pathological cardiac hypertrophy. PARP1 was activated in ISO-induced cardiac hypertrophy and facilitated the development of cardiac hypertrophy. BRD4 was involved in the prohypertrophic effect of PARP1, as implied by the observations that BRD4 inhibition or silencing reversed PARP1-induced hypertrophic responses, and that BRD4 overexpression suppressed the anti-hypertrophic effect of PARP1 inhibitors. Interactions of BRD4 and PARP1 were observed by co-immunoprecipitation and immunofluorescence. PARylation of BRD4 induced by PARP1 was investigated by PARylation assays. In response to hypertrophic stimuli like ISO, PARylation level of BRD4 was elevated, along with enhanced interactions between BRD4 and PARP1. By investigating the PARylation of truncation mutants of BRD4, the C-terminal domain (CTD) was identified as the PARylation modification sites of BRD4. PARylation of BRD4 facilitated its binding to the transcription start sites (TSS) of hypertrophic genes, resulting in enhanced phosphorylation of RNA Pol II and transcription activation of hypertrophic genes. The present findings suggest that strategies targeting inhibition of PARP1-BRD4 might have therapeutic potential for pathological cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.apsb.2020.12.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148063PMC
May 2021

Endothelial Dysfunction in Atherosclerotic Cardiovascular Diseases and Beyond: From Mechanism to Pharmacotherapies.

Pharmacol Rev 2021 07;73(3):924-967

Department of Endocrinology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China (S.X., I.I., X.Z., S.L., J.W.); Sunshine Coast Health Institute, University of the Sunshine Coast, Birtinya, Australia (P.J.L.); School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, Queensland, Australia (P.J.L., D.K.); Department of Medical Biotechnology, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China (H.L.); The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China (H.L.); Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Laboratory of Druggability and New Drugs Evaluation, Guangzhou, China (Z.L., P.L.); College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China (J.H.); Department of Bioengineering, Northeastern University, Boston, Massachusetts (I.C.H., E.E.E.); Department of Chemical Engineering, Northeastern University, Boston, Massachusetts (E.E.E.); Department of Neuroscience, Albert Einstein College of Medicine, New York, New York (E.E.E.); Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio (S.J.C.); and ARC Centre for Personalised Therapeutics Technologies, Department of Biochemistry and Pharmacology, School of Biomedical Science, University of Melbourne, Parkville, Victoria, Australia (A.G.S.)

The endothelium, a cellular monolayer lining the blood vessel wall, plays a critical role in maintaining multiorgan health and homeostasis. Endothelial functions in health include dynamic maintenance of vascular tone, angiogenesis, hemostasis, and the provision of an antioxidant, anti-inflammatory, and antithrombotic interface. Dysfunction of the vascular endothelium presents with impaired endothelium-dependent vasodilation, heightened oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, and endothelial cell senescence. Recent studies have implicated altered endothelial cell metabolism and endothelial-to-mesenchymal transition as new features of endothelial dysfunction. Endothelial dysfunction is regarded as a hallmark of many diverse human panvascular diseases, including atherosclerosis, hypertension, and diabetes. Endothelial dysfunction has also been implicated in severe coronavirus disease 2019. Many clinically used pharmacotherapies, ranging from traditional lipid-lowering drugs, antihypertensive drugs, and antidiabetic drugs to proprotein convertase subtilisin/kexin type 9 inhibitors and interleukin 1 monoclonal antibodies, counter endothelial dysfunction as part of their clinical benefits. The regulation of endothelial dysfunction by noncoding RNAs has provided novel insights into these newly described regulators of endothelial dysfunction, thus yielding potential new therapeutic approaches. Altogether, a better understanding of the versatile (dys)functions of endothelial cells will not only deepen our comprehension of human diseases but also accelerate effective therapeutic drug discovery. In this review, we provide a timely overview of the multiple layers of endothelial function, describe the consequences and mechanisms of endothelial dysfunction, and identify pathways to effective targeted therapies. SIGNIFICANCE STATEMENT: The endothelium was initially considered to be a semipermeable biomechanical barrier and gatekeeper of vascular health. In recent decades, a deepened understanding of the biological functions of the endothelium has led to its recognition as a ubiquitous tissue regulating vascular tone, cell behavior, innate immunity, cell-cell interactions, and cell metabolism in the vessel wall. Endothelial dysfunction is the hallmark of cardiovascular, metabolic, and emerging infectious diseases. Pharmacotherapies targeting endothelial dysfunction have potential for treatment of cardiovascular and many other diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1124/pharmrev.120.000096DOI Listing
July 2021

Sorting nexin 3 induces heart failure via promoting retromer-dependent nuclear trafficking of STAT3.

Cell Death Differ 2021 May 4. Epub 2021 May 4.

School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, P. R. China.

Sorting nexins (SNXs), the retromer-associated cargo binding proteins, have emerged as critical regulators of the trafficking of proteins involved in the pathogenesis of diverse diseases. However, studies of SNXs in the development of cardiovascular diseases, especially cardiac hypertrophy and heart failure, are lacking. Here, we ask whether SNX3, the simplest structured isoform in the SNXs family, may act as a key inducer of myocardial injury. An increased level of SNX3 was observed in failing hearts from human patients and mice. Cardiac-specific Snx3 knockout (Snx3-cKO) mice and Snx3 transgenic (Snx3-cTg) mice were generated to evaluate the role of Snx3 in myocardial hypertrophy, fibrosis, and heart function by morphology, echocardiography, histological staining, and hypertrophic biomarkers. We report that Snx3-cKO in mice significantly protected against isoproterenol (ISO)-induced cardiac hypertrophy at 12 weeks. Conversely, Snx3-cTg mice were more susceptible to ISO-induced cardiac hypertrophy at 12 weeks and showed aggravated cardiac injury even heart failure at 24 weeks. Immunoprecipitation-based mass spectrometry, immunofluorescent staining, co-immunoprecipitation, localized surface plasmon resonance, and proximity ligation assay were performed to examine the direct interaction of SNX3-retromer with signal transducer and activator of transcription 3 (STAT3). We discovered that STAT3 was a new interacting partner of SNX3-retromer, and SNX3-retromer served as an essential platform for assembling gp130/JAK2/STAT3 complexes and subsequent phosphorylation of STAT3 by direct combination at EE. SNX3-retromer and STAT3 complexes were transiently imported into the nucleus after hypertrophic stimuli. The pharmacological inhibition or knockdown of STAT3 reversed SNX3 overexpression-induced myocardial injury. STAT3 overexpression blunts the beneficial function of SNX3 knockdown on hypertrophic cardiomyocytes. We show that SNX3-retromer promoted importin α3-mediated STAT3 nuclear trafficking and ultimately leading to cardiac injury. Taken together, our study reveals that SNX3 plays a key role in cardiac function and implicates SNX3 as a potential therapeutic target for cardiac hypertrophy and heart failure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41418-021-00789-wDOI Listing
May 2021

Pterostilbene and its nicotinate derivative ameliorated vascular endothelial senescence and elicited endothelium-dependent relaxations via activation of sirtuin 1.

Can J Physiol Pharmacol 2021 Feb 2:1-10. Epub 2021 Feb 2.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Engineering Laboratory of Druggability and New Drug Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, P.R. China.

Vascular endothelial cell senescence is a leading cause of age-associated diseases and cardiovascular diseases. Interventions and therapies targeting endothelial cell senescence and dysfunction would have important clinical implications. This study evaluated the effect of 10 resveratrol analogues, including pterostilbene (Pts) and its derivatives, against endothelial senescence and dysfunction. All the tested compounds at the concentrations from 10 M to 10 M did not show cytotoxicity in endothelial cells by MTT assay. Among the 10 resveratrol analogues, Pts and Pts nicotinate attenuated the expression of senescence-associated β-galactosidase, downregulated p21 and p53, and increased the production of nitric oxide (NO) in both angiotensin II - and hydrogen peroxide - induced endothelial senescence models. In addition, Pts and Pts nicotinate elicited endothelium-dependent relaxations, which were attenuated in the presence of endothelial NO synthase (eNOS) inhibitor L-NAME or sirtuin 1 (SIRT1) inhibitor sirtinol. Pts and Pts nicotinate did not alter SIRT1 expression but enhanced its activity. Both Pts and Pts nicotinate have high binding activities with SIRT1, according to surface plasmon resonance results and the molecular docking analysis. Inhibition of SIRT1 by sirtinol reversed the anti-senescent effects of Pts and Pts nicotinate. Moreover, Pts and Pts nicotinate shared similar ADME (absorption, distribution, metabolism, excretion) profiles and physiochemical properties. This study suggests that the Pts and Pts nicotinate ameliorate vascular endothelial senescence and elicit endothelium-dependent relaxations via activation of SIRT1. These two compounds may be potential drugs for the treatment of cardiovascular diseases related to endothelial senescence and dysfunction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1139/cjpp-2020-0583DOI Listing
February 2021

PRMT5 Prevents Cardiomyocyte Hypertrophy via Symmetric Dimethylating HoxA9 and Repressing HoxA9 Expression.

Front Pharmacol 2020 10;11:600627. Epub 2020 Dec 10.

Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratoty of Druggability and New Drug Evaluation, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Higher Education Mega Center, Sun Yat-Sen University, Guangzhou, China.

The present study reveals a link between protein arginine methyltransferase 5 (PRMT5) and Homebox A9 (HoxA9) in the regulation of cardiomyocyte hypertrophy. In cardiomyocyte hypertrophy induced by β-adrenergic receptor agonist isoprenaline (ISO), PRMT5 expression was decreased while HoxA9 was upregulated. Silencing of PRMT5 or inhibition of PRMT5 by its pharmacological inhibitor EPZ augmented the expressions of cardiomyocyte hypertrophic genes brain natriuretic peptide (BNP) and β-Myosin Heavy Chain (β-MHC), whereas overexpression of PRMT5 inhibited ISO-induced cardiomyocyte hypertrophy, suggesting that PRMT5 ameliorates cardiomyocyte hypertrophy. On the contrary, HoxA9 promoted cardiomyocyte hypertrophy, as implied by the gain-of-function and loss-of-function experiments. HoxA9 was involved in the regulation of PRMT5 in cardiomyocyte hypertrophy, since HoxA9 knockdown prevented si-RPMT5-induced cardiomyocyte hypertrophy, and HoxA9 expression impaired the anti-hypertrophic effect of PRMT5. Co-immunoprecipitation experiments revealed that there were physical interactions between PRMT5 and HoxA9. The symmetric dimethylation level of HoxA9 was decreased by ISO or EPZ treatment, suggesting that HoxA9 is methylated by PRMT5. Additionally, PRMT5 repressed the expression of HoxA9. Chromatin immunoprecipitation (ChIP) assay demonstrated that HoxA9 could bind to the promoter of BNP, and that this binding affinity was further enhanced by ISO or EPZ. In conclusion, this study suggests that PRMT5 symmetric dimethylates HoxA9 and represses HoxA9 expression, thus impairing its binding to BNP promoter and ultimately protecting against cardiomyocyte hypertrophy. These findings provide a novel insight of the mechanism underlying the cardiac protective effect of PRMT5, and suggest potential therapeutic strategies of PRMT5 activation or HoxA9 inhibition in treatment of cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2020.600627DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793800PMC
December 2020

Rhamnocitrin extracted from Nervilia fordii inhibited vascular endothelial activation via miR-185/STIM-1/SOCE/NFATc3.

Phytomedicine 2020 Dec 19;79:153350. Epub 2020 Sep 19.

Mathematical Engineering Academy of Chinese Medicine; Guangdong Provincial Key Laboratory of New Drug Development and Research of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, P. R. China. Electronic address:

Background: Vascular endothelial activation is pivotal for the pathological development of various infectious and inflammatory diseases. Therapeutic interventions to prevent endothelial activation are of great clinical significance to achieve anti-inflammatory strategy. Previous studies indicate that the total flavonoids from the endemic herbal medicine Nervilia fordii (Hance) Schltr exerts potent anti-inflammatory effect and protective effect against endotoxin lipopolysaccharide (LPS)-induced acute lung injury, and shows clinical benefit in severe acute respiratory syndromes (SARS). However, the exact effective component of Nervilia fordii and its potential mechanism remain unknown.

Purpose: The aim of this study was to investigate the effect and mechanism of rhamnocitrin (RH), a flavonoid extracted from Nervilia fordii, on LPS-induced endothelial activation.

Methods: The in vitro endothelial cell activation model was induced by LPS in human umbilical vein endothelial cells (HUVECs). Cell viability was measured to determine the cytotoxicity of RH. RT-PCR, Western blot, fluorescent probe and immunofluorescence were conducted to evaluate the effect and mechanism of RH against endothelial activation.

Results: RH was extracted and isolated from Nervilia fordii. RH at the concentration from 10 M-10 M inhibited the expressions of interlukin-6 (IL-6) and -8 (IL-8), monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), vascular cell-adhesion molecule-1 (VCAM-1), and plasminogen activator inhibitor-1 (PAI-1) in response to LPS challenge. Mechanistically, RH repressed calcium store-operated Ca entry (SOCE) induced by LPS, which is due to downregulation of stromal interaction molecule-1 (STIM-1) following upregulating microRNA-185 (miR-185). Ultimately, RH abrogated LPS-induced activation of SOCE-mediated calcineurin/NFATc3 (nuclear factor of activated T cells, cytoplasmic 3) signaling pathway.

Conclusion: The present study identifies RH as a potent inhibitor of endothelial activation. Since vascular endothelial activation is a pivotal cause of excessive cytokine production, leading to cytokine storm and severe pathology in infectious diseases such as SARS and the ongoing COVID-19 pneumonia disease, RH might suggest promising therapeutic potential in the management of cytokine storm in these diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.phymed.2020.153350DOI Listing
December 2020

Prostacyclin facilitates vascular smooth muscle cell phenotypic transformation via activating TP receptors when IP receptors are deficient.

Acta Physiol (Oxf) 2021 02 20;231(2):e13555. Epub 2020 Sep 20.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangdong, PR China.

Aim: By activating prostacyclin receptors (IP receptors), prostacyclin (PGI ) exerts cardiovascular protective effects such as vasodilation and inhibition of vascular smooth muscle cell (VSMC) proliferation. However, IP receptors are dysfunctional under pathological conditions, and PGI produces detrimental effects that are opposite to its physiological protective effects via thromboxane-prostanoid (TP) receptors. This attempted to investigate whether or not IP receptor dysfunction facilitates the shift of PGI action.

Methods: The effects of PGI and its stable analog iloprost on VSMC phenotypic transformation and proliferation were examined in A10 cells silencing IP receptors, in human aortic VSMCs (HAVSMCs) knocked down IP receptor by CRISPR-Cas9, or in HAVSMCs transfected with a dysfunctional mutation of IP receptor IP .

Results: PGI /iloprost treatment stimulated cell proliferation, upregulated synthetic proteins and downregulated contractile proteins, suggesting that PGI /iloprost promotes VSMC phenotypic transformation in IP-deficient cells. The effect of PGI /iloprost was prevented by TP antagonist S18886 or TP knockdown, indicating that the VSMC detrimental effect of PGI is dependent on TP receptor. RNA sequencing and Western blotting results showed that RhoA/ROCKs, MEK1/2 and JNK signalling cascades were involved. Moreover, IP deficiency increased the distribution of TP receptors at the cell membrane.

Conclusion: PGI induces VSMC phenotypic transformation when IP receptors are impaired. This is attributed to the activation of TP receptor and its downstream signaling cascades, and to the increased membrane distribution of TP receptors. The VSMC detrimental effect of PGI medicated by IP dysfunction and TP activation might probably exacerbate vascular remodelling, accelerating cardiovascular diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/apha.13555DOI Listing
February 2021

Histone H4R3 symmetric di-methylation by Prmt5 protects against cardiac hypertrophy via regulation of Filip1L/β-catenin.

Pharmacol Res 2020 11 31;161:105104. Epub 2020 Jul 31.

Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Engineering Laboratory of Druggability and New Drug Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, No.132 East Wai-huan Road, Higher Education Mega Center, Guangzhou 510006, Guangdong, China. Electronic address:

Background And Purpose: Although histone lysine methylation has been extensively studied for their participation in pathological cardiac hypertrophy, the potential regulatory role of histone arginine methylation remains to be elucidated. The present study focused on H4R3 symmetric di-methylation (H4R3me2s) induced by protein arginine methyltransferase 5 (Prmt5), and explored its epigenetic regulation and underlying mechanisms in cardiomyocyte hypertrophy.

Methods And Results: 1. The expressions of Prmt5 and H4R3me2s were suppressed in cardiac hypertrophy models in vivo and in vitro; 2. Prmt5 silencing or its inhibitor EPZ, or knockdown of cooperator of Prmt5 (Copr5) to disrupt H4R3me2s, facilitated cardiomyocyte hypertrophy, whereas overexpression of wild type Prmt5 rather than the inactive mutant protected cardiomyocytes against hypertrophy; 3. ChIP-sequence analysis identified Filip1L as a target gene of Prmt5-induced H4R3me2s; 4. Knockdown or inhibition of Prmt5 impaired Filip1L transcription and subsequently prevented β-catenin degradation, thus augmenting cardiomyocyte hypertrophy.

Conclusions: The present study reveals that Prmt5-induced H4R3me2s ameliorates cardiomyocyte hypertrophy by transcriptional upregulation of Filip1L and subsequent enhancement of β-catenin degradation. Deficiency of Prmt5 and the resulting suppression of H4R3me2s might facilitate the development of pathological cardiac hypertrophy. Prmt5 might serve as a key epigenetic regulator in pathological cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.phrs.2020.105104DOI Listing
November 2020

Validation of Phosphodiesterase-10 as a Novel Target for Pulmonary Arterial Hypertension via Highly Selective and Subnanomolar Inhibitors.

J Med Chem 2019 04 29;62(7):3707-3721. Epub 2019 Mar 29.

School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , China.

Pulmonary arterial hypertension (PAH) causes pathological increase in pulmonary vascular resistance, leading to right-heart failure and eventual death. Previously, phosphodiesterase-10 (PDE10) was reported to be a promising target for PAH based on the studies with a nonselective PDE inhibitor papaverine, but little progress has been made to confirm the practical application of PDE10 inhibitors. To validate whether PAH is ameliorated by PDE10 inhibition rather than other PDE isoforms, here we report an integrated strategy to discover highly selective PDE10 inhibitors as chemical probes. Structural optimization resulted in a PDE10 inhibitor 2b with subnanomolar affinity and good selectivity of >45 000-fold against other PDEs. The cocrystal structure of the PDE10-2b complex revealed an important H-bond interaction between 2b and Tyr693. Finally, compound 2b significantly decreased the arterial pressure in PAH rats and thus validated the potential of PDE10 as a novel anti-PAH target. These findings suggest that PDE10 inhibition may be a viable treatment option for PAH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.9b00224DOI Listing
April 2019

SIRT6 Suppresses NFATc4 Expression and Activation in Cardiomyocyte Hypertrophy.

Front Pharmacol 2018 8;9:1519. Epub 2019 Jan 8.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.

NFATc4, a member from the Nuclear Factor of Activated T cells (NFATs) transcription factor family, plays a pivotal role in the development of cardiac hypertrophy. NFATc4 is dephosphorylated by calcineurin and translocated from the cytoplasm to the nucleus to regulate the expression of hypertrophic genes, like brain natriuretic polypeptide (BNP). The present study identified SIRT6, an important subtype of NAD dependent class III histone deacetylase, to be a negative regulator of NFATc4 in cardiomyocyte hypertrophy. In phenylephrine (PE)-induced hypertrophic cardiomyocyte model, overexpression of SIRT6 by adenovirus infection or by plasmid transfection repressed the protein and mRNA expressions of NFATc4, elevated its phosphorylation level, prevented its nuclear accumulation, subsequently suppressed its transcriptional activity and downregulated its target gene BNP. By contrast, mutant of SIRT6 without deacetylase activity (H133Y) did not demonstrate these effects, suggesting that the inhibitory effect of SIRT6 on NFATc4 was dependent on its deacetylase activity. Moreover, the effect of SIRT6 overexpression on repressing BNP expression was reversed by NFATc4 replenishment, whereas the effect of SIRT6 deficiency on upregulating BNP was recovered by NFATc4 silencing. Mechanistically, interactions between SIRT6 and NFATc4 might possibly facilitate the deacetylation of NFATc4 by SIRT6, thereby preventing the activation of NFATc4. In conclusion, the present study reveals that SIRT6 suppresses the expression and activation of NFATc4. These findings provide more evidences of the anti-hypertrophic effect of SIRT6 and suggest SIRT6 as a potential therapeutic target for cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2018.01519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6331469PMC
January 2019

Sirtuin 1 represses PKC-ζ activity through regulating interplay of acetylation and phosphorylation in cardiac hypertrophy.

Br J Pharmacol 2019 02 9;176(3):416-435. Epub 2018 Dec 9.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, Guangdong, China.

Background And Purpose: Activation of PKC-ζ is closely linked to the pathogenesis of cardiac hypertrophy. PKC-ζ can be activated by certain lipid metabolites such as phosphatidylinositol (3,4,5)-trisphosphate and ceramide. However, its endogenous negative regulators are not well defined. Here, the role of the sirtuin1-PKC-ζ signalling axis and the underlying molecular mechanisms were investigated in cardiac hypertrophy.

Experimental Approach: Cellular hypertrophy in cultures of cardiac myocytes, from neonatal Sprague-Dawley rats, was monitored by measuring cell surface area and the mRNA levels of hypertrophic biomarkers. Interaction between sirtuin1 and PKC-ζ was investigated by co-immunoprecipitation and confocal immunofluorescence microscopy. Sirtuin1 activation was enhanced by resveratrol treatment or Ad-sirtuin1 transfection. A model of cardiac hypertrophy in Sprague-Dawley rats was established by abdominal aortic constriction surgery or induced by isoprenaline in vivo.

Key Results: Overexpression of PKC-ζ led to cardiac hypertrophy and increased activity of NF-κB, ERK1/2 and ERK5, which was ameliorated by sirtuin1 overexpression. Enhancement of sirtuin1 activity suppressed acetylation of PKC-ζ, hindered its binding to phosphoinositide-dependent kinase 1 and inhibited PKC-ζ phosphorylation in cardiac hypertrophy. Consequently, the downstream pathways of PKC-ζ' were suppressed in cardiac hypertrophy. This regulation loop suggests a new role for sirtuin1 in mediation of cardiac hypertrophy.

Conclusions And Implications: Sirtuin1 is an endogenous negative regulator for PKC-ζ and mediates its activity via regulating the acetylation and phosphorylation in the pathogenesis of cardiac hypertrophy. Targeting the sirtuin1-PKC-ζ signalling axis may suggest a novel therapeutic approach against cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/bph.14538DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6329629PMC
February 2019

Heme oxygenase-1 ameliorates oxidative stress-induced endothelial senescence via regulating endothelial nitric oxide synthase activation and coupling.

Aging (Albany NY) 2018 Jul;10(7):1722-1744

Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China.

Aim: Premature senescence of vascular endothelial cells is a leading cause of various cardiovascular diseases. Therapies targeting endothelial senescence would have important clinical implications. The present study was aimed to evaluate the potential of heme oxygenase-1 (HO-1) as a therapeutic target for endothelial senescence.

Methods And Results: Upregulation of HO-1 by Hemin or adenovirus infection reversed HO-induced senescence in human umbilical vein endothelial cells (HUVECs); whereas depletion of HO-1 by siRNA or HO-1 inhibitor protoporphyrin IX zinc (II) (ZnPP) triggered HUVEC senescence. Mechanistically, overexpression of HO-1 enhanced the interaction between HO-1 and endothelial nitric oxide synthase (eNOS), and promoted the interaction between eNOS and its upstream kinase Akt, thus resulting in an enhancement of eNOS phosphorylation at Ser1177 and a subsequent increase of nitric oxide (NO) production. Moreover, HO-1 induction prevented the decrease of eNOS dimer/monomer ratio stimulated by HO via its antioxidant properties. Contrarily, HO-1 silencing impaired eNOS phosphorylation and accelerated eNOS uncoupling. , Hemin treatment alleviated senescence of endothelial cells of the aorta from spontaneously hypertensive rats, through upregulating eNOS phosphorylation at Ser1177.

Conclusions: HO-1 ameliorated endothelial senescence through enhancing eNOS activation and defending eNOS uncoupling, suggesting that HO-1 is a potential target for treating endothelial senescence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/aging.101506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075439PMC
July 2018

Corrigendum to "The molecular selectivity of UNC3866 inhibitor for Polycomb CBX7 protein from molecular dynamics simulation" [Comput. Biol. Chem. 74 (2018) 339-346].

Comput Biol Chem 2018 12 13;77:455. Epub 2018 Jul 13.

Pharmacy Department, Liaocheng Third People's Hospital, Liaocheng, Shandong 252000, China.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.compbiolchem.2018.07.006DOI Listing
December 2018

The molecular selectivity of UNC3866 inhibitor for Polycomb CBX7 protein from molecular dynamics simulation.

Comput Biol Chem 2018 Jun 10;74:339-346. Epub 2018 Apr 10.

Department of medicine, Tongchuan vocational and technical college, Tongchuan, Shaanxi 727000, China.

Polycomb CBX proteins regulate gene expression by targeting Polycomb repressive complex 1 (PRC1) to sites of H3K27me3 via their chromodomains, which plays a key role in the development of numerous cancers. UNC3866, is a recently reported peptide-based inhibitor of the methyllysine (Kme) reading function of CBX chromodomains (CBX2, 4 and 6-8). The previous experiments showed that UNC3866 bound the chromodomains of CBX7 strongly, with ∼20-fold selectivity over other CBX chromodomains. However, the potential mechanism of UNC3866 preferentially binding to CBX7 is still unknown. In this study, we performed two pairs of microsecond molecular dynamic simulations (CBX2 (-UNC3866)) and (CBX7 (-UNC3866)) to study the inhibition and isoform-selective mechanism of UNC3866 to CBX7. The conformational analysis of apo- and holo- CBX2 and CBX7 indicated that the aromatic cage of CBX7 protein was more prone to be induced by UNC3866 relative to CBX2 protein. The results of predicted binding free energy suggested the binding affinity of UNC3866 with CBX7 was stronger than that with CBX2, because of the lower binding free energy of the former. Furthermore, the energetic origin of UNC3866 selective for CBX7 protein mainly came from the higher van der Waals contributions. The binding mode analysis showed that Asn47 of CBX2 formed a hydrogen bond with the OH group of C-terminal cap of UNC3866, inducing the conformational changes of diethyllysine of UNC3866 that is obviously different from that in CBX7. Additionally, His39 in CBX2 chromodomain interrupted the structured aromatic cage, partly explaining the reason for UNC3866 preferring for binding to CBX7. The proposal of this selective mechanism could be helpful for the rational design of novel selective inhibitors of the Polycomb CBX protein.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.compbiolchem.2018.04.005DOI Listing
June 2018

PARP1 interacts with STAT3 and retains active phosphorylated-STAT3 in nucleus during pathological myocardial hypertrophy.

Mol Cell Endocrinol 2018 10 1;474:137-150. Epub 2018 Mar 1.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, PR China; National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, PR China. Electronic address:

The activation of signal transducer and activator of transcription 3 (STAT3) positively regulates myocardial hypertrophy, and its transcriptional activity is finely conditioned by diverse extracellular growth factors and cytokines. Here, we introduce novel evidence that poly(ADP-ribose) polymerase 1 (PARP1) interacts with STAT3 and promotes its activation in cardiomyocytes and rat heart tissues. PARP1 activity and phosphorylated STAT3 were augmented by hypertrophic stimuli both in vitro and in vivo. Infection of PARP1 adenovirus induced cardiomyocyte hypertrophy, which could be prevented by STAT3 knockdown or inhibition. Additionally, PARP1 enhanced STAT3 phosphorylation level, nuclear accumulation and transcriptional activity. Mechanistically, PARP1 interacts with STAT3 and retains active phosphorylated-STAT3 in nucleus. In conclusion, our findings provide the first evidence that PARP1 exacerbates cardiac hypertrophy by stabilizing active phosphorylated-STAT3, which suggests that multi-target therapeutic strategies counteracting PARP1 activity and STAT3 activation would be potential for treating cardiovascular diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mce.2018.02.020DOI Listing
October 2018

Nature differences of fulvic acid fractions induced by extracted sequence as explanatory factors for binding characteristics of Cu.

Chemosphere 2018 Jan 15;191:458-466. Epub 2017 Oct 15.

College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010010, China.

The isolation of fulvic acid (FA) fractions with relatively homogeneity is a key to reveal the binding mechanisms between FA and heavy metals. In this work, nine FA fractions were obtained using sequential alkali extraction procedure and nature differences of the extracted FA fractions were considered as explanatory factors for binding characteristics of Cu. The results indicate that the contents of carboxyl and phenolic groups decrease with increasing extractions along with an opposite trend for the content of nitrogen-containing groups. The fitted results of ligand binding and bi-Langmuir models indicate that the binding sites for Cu were mainly provided by carboxyl and phenolic groups, which explained the higher sorption capacity and binding affinity of earlier extracted FAs due to its higher contents of carboxyl and phenolic groups. Furthermore, the systemic characterization of FA fractions before and after adsorption indicate the nitrogen-containing groups were gradually showing their contribution in binding Cu with increasing extractions. This work is very helpful to insight the environmental effects of natural organic matter and the behavior of heavy metals in natural environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2017.10.080DOI Listing
January 2018

SIRT3 prevents angiotensin II-induced renal tubular epithelial-mesenchymal transition by ameliorating oxidative stress and mitochondrial dysfunction.

Mol Cell Endocrinol 2018 01 1;460:1-13. Epub 2017 Jun 1.

Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong Province, People's Republic of China; National and Local Joint Engineering Laboratory of Druggabilitiy Assessment and Evaluation, Sun Yat-sen University, Guangzhou 510006, Guangdong Province, People's Republic of China. Electronic address:

Silent mating type information regulation 2 homolog 3 (SIRT3) is a major protective mediator that ameliorates oxidative stress and mitochondrial dysfunction, which are associated with the pathogenesis of epithelial-mesenchymal transition (EMT). The present study was aimed to investigate the potential role of SIRT3 in renal tubular EMT both in vitro and in vivo. Firstly, we showed that the expression of SIRT3 was repressed in angiotensin II-induced EMT. SIRT3 deficiency triggered EMT response, while over-expression of SIRT3 attenuated EMT response. In addition, over-expression of SIRT3 repressed AngⅡ-induced excessive production of mitochondrial superoxide, as well as mitochondrial dysfunction evidenced by the maintenance of mitochondrial number and morphology, and the stabilization of mitochondrial membrane potential. In conclusion, these findings identify a protective role of SIRT3 against angiotensin II-induced EMT in the kidney, and suggest SIRT3 upregulation is a potential therapeutic strategy for the treatment of renal tubulointerstitial fibrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mce.2017.04.027DOI Listing
January 2018

The poly(ADP-ribosyl)ation of FoxO3 mediated by PARP1 participates in isoproterenol-induced cardiac hypertrophy.

Biochim Biophys Acta 2016 12;1863(12):3027-3039

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, Guangdong, PR China; National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, Guangdong, PR China; Guangdong Provincial Key Laboratory of Construction Foundation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, Guangdong, PR China. Electronic address:

The Forkhead box-containing protein, O subfamily 3 (FoxO3) transcription factor negatively regulates myocardial hypertrophy, and its transcriptional activity is finely conditioned by diverse posttranslational modifications, such as phosphorylation, acetylation, ubiquitination, methylation and glycosylation. Here, we introduce a novel modification of the FoxO3 protein in cardiomyocytes: poly(ADP-ribosyl)ation (PARylation) mediated by poly(ADP-ribose) polymerase-1 (PARP1). This process catalyzes the NAD-dependent synthesis of polymers of ADP-ribose (PAR) and their subsequent attachment to target proteins by PARPs. Primary-cultured neonatal rat cardiomyocytes were incubated with isoproterenol (ISO) to induce hypertrophy, or were infected with recombinant adenovirus vectors harboring PARP1 cDNA (Ad-PARP1). Sprague-Dawley (SD) rats were treated with ISO to induce cardiac hypertrophy, or were injected with Ad-PARP1 into the anterior and posterior left ventricular walls. Cardiomyocyte surface area, the mRNA expression of hypertrophic biomarkers, echocardiography, morphometry of the hearts were measured. The PARP1 activity was tested by cellular PAR levels. Interactions of PARP1 and FoxO3 were investigated by co-immunoprecipitation and immunofluorescence technique. PARylation of FoxO3 mediated by PARP1 facilitated its phosphorylation at the T32, S252 and S314 sites, triggered its nucleus export and suppressed its transcriptional activity and target genes expression, ultimately inducing cardiac hypertrophy. Additionally, PARP1 silencing or specific inhibition by 3-Aminobenzamide (3AB) and veliparib (ABT-888) alleviated the inhibition of FoxO3 activity by ISO, thus suppressing ISO-induced cardiac hypertrophy. Our data provide the first evidence that PARP1 exacerbates cardiac hypertrophy by PARylation of FoxO3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbamcr.2016.09.019DOI Listing
December 2016

NMNAT3 is involved in the protective effect of SIRT3 in Ang II-induced cardiac hypertrophy.

Exp Cell Res 2016 10 14;347(2):261-73. Epub 2016 Jul 14.

Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong Province, People's Republic of China; National and Local Joint Engineering Laboratory of Druggability Assessment and Evaluation, Sun Yat-sen University, Guangzhou 510006, Guangdong Province, People's Republic of China. Electronic address:

Pathological cardiac hypertrophy is a maladaptive response in a variety of organic heart disease (OHD), which is characterized by mitochondrial dysfunction that results from disturbed energy metabolism. SIRT3, a mitochondria-localized sirtuin, regulates global mitochondrial lysine acetylation and preserves mitochondrial function. However, the mechanisms by which SIRT3 regulates cardiac hypertrophy remains to be further elucidated. In this study, we firstly demonstrated that expression of SIRT3 was decreased in Angiotension II (Ang II)-treated cardiomyocytes and in hearts of Ang II-induced cardiac hypertrophic mice. In addition, SIRT3 overexpression protected myocytes from hypertrophy, whereas SIRT3 silencing exacerbated Ang II-induced cardiomyocyte hypertrophy. In particular, SIRT3-KO mice exhibited significant cardiac hypertrophy. Mechanistically, we identified NMNAT3 (nicotinamide mononucleotide adenylyltransferase 3), the rate-limiting enzyme for mitochondrial NAD biosynthesis, as a new target and binding partner of SIRT3. Specifically, SIRT3 physically interacts with and deacetylates NMNAT3, thereby enhancing the enzyme activity of NMNAT3 and contributing to SIRT3-mediated anti-hypertrophic effects. Moreover, NMNAT3 regulates the activity of SIRT3 via synthesis of mitochondria NAD. Taken together, these findings provide mechanistic insights into the negative regulatory role of SIRT3 in cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.yexcr.2016.07.006DOI Listing
October 2016

Endothelium-Dependent Contractions of Isolated Arteries to Thymoquinone Require Biased Activity of Soluble Guanylyl Cyclase with Subsequent Cyclic IMP Production.

J Pharmacol Exp Ther 2016 09 22;358(3):558-68. Epub 2016 Jun 22.

Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.).

Preliminary experiments on isolated rat arteries demonstrated that thymoquinone, a compound widely used for its antioxidant properties and believed to facilitate endothelium-dependent relaxations, as a matter of fact caused endothelium-dependent contractions. The present experiments were designed to determine the mechanisms underlying this unexpected response. Isometric tension was measured in rings (with and without endothelium) of rat mesenteric arteries and aortae and of porcine coronary arteries. Precontracted preparations were exposed to increasing concentrations of thymoquinone, which caused concentration-dependent, sustained further increases in tension (augmentations) that were prevented by endothelium removal, Nω-nitro-L-arginine methyl ester [L-NAME; nitric oxide (NO) synthase inhibitor], and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; soluble guanylyl cyclase [sGC] inhibitor). In L-NAME-treated rings, the NO-donor diethylenetriamine NONOate restored the thymoquinone-induced augmentations; 5-[1-(phenylmethyl)-1H-indazol-3-yl]-2-furanmethanol (sGC activator) and cyclic IMP (cIMP) caused similar restorations. By contrast, in ODQ-treated preparations, the cell-permeable cGMP analog did not restore the augmentation by thymoquinone. The compound augmented the content (measured with ultra-high performance liquid chromatography-tandem mass spectrometry) of cIMP, but not that of cGMP; these increases in cIMP content were prevented by endothelium removal, L-NAME, and ODQ. The augmentation of contractions caused by thymoquinone was prevented in porcine arteries, but not in rat arteries, by 1-(5-isoquinolinylsulfonyl)homopiperazine dihydrochloride and trans-4-[(1R)-1-aminoethyl]-N-4-pyridinylcyclohexanecarboxamide dihydrochloride (Rho-kinase inhibitors); in the latter, but not in the former, it was reduced by 3,5-dichloro-N-[[(1α,5α,6-exo,6α)-3-(3,3-dimethylbutyl)-3-azabicyclo[3.1.0]hex-6-yl]methyl]-benzamide hydrochloride (T-type calcium channel inhibitor), demonstrating species/vascular bed differences in the impact of cIMP on calcium handling. Thymoquinone is the first pharmacological agent that causes endothelium-dependent augmentation of contractions of isolated arteries, which requires endothelium-derived NO and biased sGC activation, resulting in the augmented production of cIMP favoring the contractile process.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1124/jpet.116.234153DOI Listing
September 2016

STAT3 Suppression Is Involved in the Protective Effect of SIRT6 Against Cardiomyocyte Hypertrophy.

J Cardiovasc Pharmacol 2016 Sep;68(3):204-14

*Department of Pharmacology and Toxicology, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China; †Department of Pharmacology, School of Medicine, Xizang Minzu University, Shaanxi, China; and ‡Department of Anesthesiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.

The activation of signal transducer and activator of transcription 3 (STAT3) is critical for the development of cardiac hypertrophy and heart failure. Sirtuin 6 (SIRT6) protects cardiomyocytes from hypertrophy. This study focused on the association between SIRT6 and STAT3 in the regulation of cardiomyocyte hypertrophy. In the phenylephrine (PE)-induced hypertrophic cardiomyocyte model and in the hearts of isoprenaline-induced cardiac hypertrophic rat model, the mRNA and protein expressions of STAT3 and its phosphorylated level at tyrosine 705 (P-STAT3) were significantly increased. By contrast, the deacetylation activity of SIRT6 was weakened without altering its protein expression. In addition, the nuclear localization of STAT3 and P-STAT3 was enhanced by PE, suggesting that STAT3 was activated in cardiomyocyte hypertrophy. Adenovirus infection-induced SIRT6 overexpression repressed the activation of STAT3 by decreasing its mRNA and protein levels, by suppressing its transcriptional activity, and by hindering the expressions of its target genes. Moreover, the effect of SIRT6 overexpression on eliminating PE-induced expressions of hypertrophic biomarkers, such as atrial natriuretic factor and brain natriuretic peptide, was reversed by STAT3 overexpression. Likewise, SIRT6 knockdown-induced upregulation of atrial natriuretic factor and brain natriuretic peptide was reversed by STAT3 silencing. These observations suggest that the antihypertrophic effect of SIRT6 involves STAT3 suppression. In conclusion, SIRT6 prevents PE-induced activation of STAT3 in cardiomyocyte hypertrophy; the inhibitory effect of SIRT6 on STAT3 contributes to cardiac protection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/FJC.0000000000000404DOI Listing
September 2016

PKCζ interacts with STAT3 and promotes its activation in cardiomyocyte hypertrophy.

J Pharmacol Sci 2016 Sep 29;132(1):15-23. Epub 2016 Mar 29.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou 510006, PR China. Electronic address:

This study was aimed to investigate the crosstalk between protein kinase C ζ (PKCζ) and signal transducer and activator of transcription 3 (STAT3) in cardiomyocyte hypertrophy. In neonatal rat cardiomyocyte hypertrophic model induced by phenylephrine (PE), the levels of phosphorylated PKCζ and phosphorylated STAT3 were significantly increased, suggesting the activation of both PKCζ and STAT3 in cardiomyocyte hypertrophy. Overexpression of PKCζ by adenovirus infection elevated the expressions of hypertrophic markers atrial natriuretic factor (ANF) and brains natriuretic polypeptide (BNP), as well as the cell surface area; while genetic silencing of PKCζ inhibited PE-induced cardiomyocyte hypertrophy. An interaction between PKCζ and STAT3 in cardiomyocytes was shown by co-immunoprecipitation experiments. Overexpression of PKCζ increased the phosphorylated level of STAT3 at both Ser727 and Tyr705, promoted the nuclear translocation of STAT3, and enhanced the expression of STAT3 downstream target genes c-fos and angiotensinogen (aGT); whereas PKCζ knockdown prevented PE-induced STAT3 activation, nuclear shuttling and transcriptional activation. In conclusion, PKCζ interacts with STAT3 and promotes its activation in cardiomyocyte hypertrophy. Strategies targeting inhibition of PKCζ-STAT3 signaling pathway suggest a therapeutic potential for cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jphs.2016.03.010DOI Listing
September 2016

SIRT6 suppresses phenylephrine-induced cardiomyocyte hypertrophy though inhibiting p300.

J Pharmacol Sci 2016 Sep 1;132(1):31-40. Epub 2016 Apr 1.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, Guangdong, PR China; National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong, PR China; Guangdong Provincial Key Laboratory of Construction Foundation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong, PR China. Electronic address:

SIRT6 is a member of the sirtuin family of class III histone deacetylases. It plays important roles in regulating genomic stability, metabolism, stress response and aging. Our previous study has revealed that SIRT6 attenuates myocardial hypertrophy by inhibiting NF-κB activation, but the related molecular mechanisms remain to be clarified. In the present study, we showed that the p300 acetylase was involved in the protective effect of SIRT6 against phenylephrine (PE)-induced cardiomyocyte hypertrophy. In cultured neonatal rat cardiomyocytes, the expression and activity of SIRT6 declined following PE treatment, while the protein level of p300 was upregulated. PE triggered significant hypertrophic responses as manifested by increase in cellular surface area and expression of hypertrophy marker genes, which could be blocked by SIRT6 overexpression. Mechanistically, SIRT6 reduced p300 protein expression via promoting its degradation, which could be attributed to the suppression of PI3K/Akt signaling. The downregulation of p300 protein level by SIRT6 subsequently decreased the acetylation and transcriptional activity of NF-κB p65 subunit. These findings help to further understand mechanisms underlying the anti-hypertrophic role of SIRT6 and suggest the potential of SIRT6 as a therapeutic target for cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jphs.2016.03.013DOI Listing
September 2016

SIRT6 suppresses isoproterenol-induced cardiac hypertrophy through activation of autophagy.

Transl Res 2016 06 10;172:96-112.e6. Epub 2016 Mar 10.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, P.R. China. Electronic address:

Reduction in autophagy has been reported to contribute to the pathogenesis of cardiac hypertrophy. However, the molecular pathways leading to impaired autophagy at the presence of hypertrophic stimuli remain to be elucidated. The present study aimed to investigate the role of sirtuin 6 (SIRT6), a sirtuin family member, in regulating cardiomyocyte autophagy, and its implication in prevention of cardiac hypertrophy. Primary neonatal rat cardiomyocytes (NRCMs) or Sprague-Dawley (SD) rats were submitted to isoproterenol (ISO) treatment, and then the hypertrophic responses and changes in autophagy activity were measured. The influence of SIRT6 on autophagy was observed in cultured NRCMs with gain- and loss-of-function approaches to regulate SIRT6 expression, and further confirmed in vivo by intramyocardial delivery of an adenovirus vector encoding SIRT6 cDNA. In addition, the involvement of SIRT6-mediated autophagy in attenuation of cardiomyocyte hypertrophy induced by ISO was determined basing on genetic or pharmaceutical disruption of autophagy, and the underlying mechanism was preliminarily explored. ISO-caused cardiac hypertrophy accompanying with a significant decrease in autophagy activity. SIRT6 overexpression enhanced autophagy in NRCMs and in rat hearts, whereas knockdown of SIRT6 by RNA interference led to suppression of cardiomyocyte autophagy. Furthermore, the protective effect of SIRT6 against ISO-stimulated hypertrophy was associated with induction of autophagy. SIRT6 promoted nuclear retention of forkhead box O3 transcription factor possibly via attenuating Akt signaling, which was responsible for autophagy activation. Our findings revealed that SIRT6 positively regulates autophagy in cardiomyocytes, which may help to ameliorate ISO-induced cardiac hypertrophy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.trsl.2016.03.002DOI Listing
June 2016

Deletion of sirtuin 6 accelerates endothelial dysfunction and atherosclerosis in apolipoprotein E-deficient mice.

Transl Res 2016 06 11;172:18-29.e2. Epub 2016 Feb 11.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China; National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China; Guangdong Provincial Key Laboratory of Construction Foundation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China. Electronic address:

Sirtuin 6 (SIRT6) is a chromatin-associated deacetylase that plays a leading role in genomic stability and aging. However, the precise role of SIRT6 in atherosclerosis, an aging-associated cardiovascular disease, remains elusive. This study aims at defining the role of SIRT6 in atherosclerotic lesion development. SIRT6 messenger RNA and protein expression are markedly decreased in atherosclerotic aortas of apolipoprotein E-deficient (ApoE(-/-)) mice fed a high-cholesterol diet. SIRT6 was knocked down in ApoE(-/-) mice using small hairpin RNAs (shRNAs) lentivirus injection. SIRT6-shRNA-treated ApoE(-/-) mice showed impaired endothelium-dependent vasodilation, increased plaque size (in aortic sinus, aortic root and en face aorta), and augmented plaque vulnerability (evidenced by increased necrotic core areas and macrophage accumulation and reduced collagen content). At the cellular level, SIRT6 depletion by RNA interference in human umbilical vein endothelial cells significantly increased monocyte adhesion to endothelial cells by inducing the expression of intracellular adhesion molecule-1. Consistently, intracellular adhesion molecule-1 expression was significantly upregulated in aortic endothelium of SIRT6-shRNA-treated ApoE(-/-) mice compared with controls. In sum, the aforementioned findings suggest that SIRT6 is a primary negative regulation factor in endothelial dysfunction and atherosclerosis development. As a result, SIRT6 is a promising therapeutic target for treating atherosclerosis and its cardiovascular complications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.trsl.2016.02.005DOI Listing
June 2016

The orphan receptor NOR1 participates in isoprenaline-induced cardiac hypertrophy by regulating PARP-1.

Br J Pharmacol 2015 Jun 26;172(11):2852-63. Epub 2015 Mar 26.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China.

Background And Purpose: The orphan nuclear receptor NOR1 belongs to the NR4A subfamily of the nuclear hormone receptor superfamily, and is involved in glucose and fat metabolism. However, its potential contribution to cardiovascular diseases remains to be assessed. Here, the roles of NOR1 in cardiac hypertrophy induced by isoprenaline and the underlying molecular mechanisms were investigated.

Experimental Approach: NOR1 was expressed in cardiomyocytes treated with isoprenaline. After NOR1 overexpression or knockdown in neonatal rat cardiomyocytes, cellular hypertrophy was monitored by measuring cell surface area and the mRNA of hypertrophic biomarkers. Interactions between NOR1 and PARP-1 were investigated by co-immunoprecipitation. NOR1 expression and PARP-1 activity were measured in rats with cardiac hypertrophy induced by isoprenaline.

Key Results: Treatment with isoprenaline significantly up-regulated NOR1 expression and PARP-1 activity both in vivo and in vitro. Specific gene silencing of NOR1 attenuated isoprenaline-induced cardiomyocyte hypertrophy, whereas NOR1 overexpression exacerbated cardiac hypertrophy. We identified a physical interaction between NOR1 and PARP-1, which was enhanced by NOR1 transfection and thereby led to PARP-1 activation. Overexpression of NOR1, but not C293Y, a NOR1 mutant lacking the PARP-1 binding activity, increased cellular surface area and the mRNA levels of atrial natriuretic factor and brain natriuretic polypeptide, effects blocked by the PARP-1 inhibitor 3-aminobenzamide or siRNA for PARP-1.

Conclusions And Implications: This is the first evidence that NOR1 was involved in isoprenaline-induced cardiac hypertrophy. The pro-hypertrophic effect of NOR1 can be partly attributed to its regulation of PARP-1 enzymic activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/bph.13091DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4439880PMC
June 2015

RIP140 triggers foam-cell formation by repressing ABCA1/G1 expression and cholesterol efflux via liver X receptor.

FEBS Lett 2015 Feb 20;589(4):455-60. Epub 2015 Jan 20.

Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, PR China; National and Local United Engineering Laboratory of Druggability and New Drugs Evaluation, Guangzhou 510006, PR China. Electronic address:

Receptor-interacting protein 140 (RIP140) is a multifunctional coregulator of lipid metabolism and inflammation. However, the potential role of RIP140 in atherosclerosis remains unknown. The present study investigated the impact of RIP140 on foam cell formation, a critical step in pathogenesis of atherosclerosis. The expression of RIP140 was increased in foam cells. RIP140 overexpression resulted in decreased cholesterol efflux in macrophages and their concomitant differentiation into foam cells. Moreover, RIP140 negatively regulated the macrophage expression of ATP-binding cassette transporters A1 and G1 (ABCA1/G1), by suppressing the expression and activity of liver X receptor (LXR). These findings shed light onto the contribution of RIP140 to the development and progression of atherosclerosis, and suggest a novel therapeutic target for the treatment of atherosclerosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.febslet.2015.01.001DOI Listing
February 2015
-->