scholarly journals HuR regulates phospholamban expression in isoproterenol-induced cardiac remodelling

Author(s):  
Han Hu ◽  
Mingyang Jiang ◽  
Yangpo Cao ◽  
Zhuojun Zhang ◽  
Bin Jiang ◽  
...  

Abstract Aims The elevated expression of phospholamban (PLB) has been observed in heart failure and cardiac remodelling, inhibiting the affinity of Ca2+ pump to Ca2+ thereby impairing heart relaxation. However, the mechanisms underlying the regulation of PLB remains to be further studied. The present study aims to test the role of RNA-binding protein HuR in the regulation of PLB and the impact of this regulatory process in cardiac remodelling. Methods and results A mouse model specifically deleted HuR in cardiomyocytes were used for testing the role of HuR in regulating PLB during isoproterenol (ISO)-induced cardiac remodelling. HuR deficiency did not significantly influence the phenotype and function of mouse heart under static status. However, deletion of HuR in cardiomyocytes mitigated the effect of ISO in inducing PLB expression and reducing β1-AR expression, in turn aggravating ISO-induced myocardial hypertrophy and cardiac fibrosis. In H9C2 cells, association of HuR with PLB and β1-AR mRNAs stabilized PLB mRNA and destabilized β1-AR mRNA, respectively. Conclusion HuR stabilizes PLB mRNA and destabilizes β1-AR mRNA. The HuR-PLB and HuR-β1-AR regulatory processes impact on ISO-induced cardiac remodelling.

2020 ◽  
Vol 98 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Dimple Prasher ◽  
Steven C. Greenway ◽  
Raja B. Singh

Mortality and morbidity from cardiovascular diseases (CVDs) represents a huge burden to society. It is recognized that environmental factors and individual lifestyles play important roles in disease susceptibility, but the link between these external risk factors and our genetics has been unclear. However, the discovery of sequence-independent heritable DNA changes (epigenetics) have helped us to explain the link between genes and the environment. Multiple diverse epigenetic processes, including DNA methylation, histone modification, and the expression of non-coding RNA molecules affect the expression of genes that produce important changes in cellular differentiation and function, influencing the health and adaptability of the organism. CVDs such as congenital heart disease, cardiomyopathy, heart failure, cardiac fibrosis, hypertension, and atherosclerosis are now being viewed as much more complex and dynamic disorders. The role of epigenetics in these and other CVDs is currently under intense scrutiny, and we can expect important insights to emerge, including novel biomarkers and new approaches to enable precision medicine. This review summarizes the recent advances in our understanding of the role of epigenetics in CVD.


2005 ◽  
Vol 202 (11) ◽  
pp. 1549-1561 ◽  
Author(s):  
Ian P. Lewkowich ◽  
Nancy S. Herman ◽  
Kathleen W. Schleifer ◽  
Matthew P. Dance ◽  
Brian L. Chen ◽  
...  

The role of natural CD4+CD25+ regulatory T (T reg) cells in the control of allergic asthma remains poorly understood. We explore the impact of T reg cell depletion on the allergic response in mice susceptible (A/J) or comparatively resistant (C3H) to the development of allergen-induced airway hyperresponsiveness (AHR). In C3H mice, anti-CD25–mediated T reg cell depletion before house dust mite treatment increased several features of the allergic diathesis (AHR, eosinophilia, and IgE), which was concomitant with elevated T helper type 2 (Th2) cytokine production. In similarly T reg cell–depleted A/J mice, we observed a moderate increase in airway eosinophilia but no effects on AHR, IgE levels, or Th2 cytokine synthesis. As our experiments suggested that T reg cell depletion in C3H mice before sensitization was sufficient to enhance the allergic phenotype, we characterized dendritic cells (DCs) in T reg cell–depleted C3H mice. T reg cell–depleted mice had increased numbers of pulmonary myeloid DCs with elevated expression of major histocompatibility complex class II, CD80, and CD86. Moreover, DCs from T reg cell–depleted mice demonstrated an increased capacity to stimulate T cell proliferation and Th2 cytokine production, which was concomitant with reduced IL-12 expression. These data suggest that resistance to allergen-driven AHR is mediated in part by CD4+CD25+ T reg cell suppression of DC activation and that the absence of this regulatory pathway contributes to susceptibility.


2016 ◽  
Vol 311 (1) ◽  
pp. H96-H106 ◽  
Author(s):  
Robert A. Civitarese ◽  
Ilana Talior-Volodarsky ◽  
Jean-Francois Desjardins ◽  
Golam Kabir ◽  
Jennifer Switzer ◽  
...  

Excessive cardiac interstitial fibrosis impairs normal cardiac function. We have shown that the α11β1 (α11) integrin mediates fibrotic responses to glycated collagen in rat myocardium by a pathway involving transforming growth factor-β. Little is known of the role of the α11 integrin in the developing mammalian heart. Therefore, we examined the impact of deletion of the α11 integrin in wild-type mice and in mice treated with streptozotocin (STZ) to elucidate the role of the α11 integrin in normal cardiac homeostasis and in the pathogenesis of diabetes-related fibrosis. As anticipated, cardiac fibrosis was reduced in α11 integrin knockout mice (α11−/−; C57BL/6 background) treated with STZ compared with STZ-treated wild-type mice ( P < 0.05). Unexpectedly, diastolic function was impaired in both vehicle and STZ-treated α11−/− mice, as shown by the decreased minimum rate of pressure change and prolonged time constant of relaxation in association with increased end-diastolic pressure (all P < 0.05 compared with wild-type mice). Accordingly, we examined the phenotype of untreated α11−/− mice, which demonstrated a reduced cardiomyocyte cross-sectional cell area and myofibril thickness (all P < 0.05 compared with wild-type mice) and impaired myofibril arrangement. Immunostaining for desmin and connexin 43 showed abnormal intermediate filament organization at intercalated disks and impaired gap-junction development. Overall, deletion of the α11 integrin attenuates cardiac fibrosis in the mammalian mouse heart and reduces ECM formation as a result of diabetes. Furthermore, α11 integrin deletion impairs cardiac function and alters cardiomyocyte morphology. These findings shed further light on the poorly understood interaction between the fibroblast–cardiomyocyte and the ECM.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuechai Chen ◽  
Jianan Wang ◽  
Muhammad Tahir ◽  
Fangfang Zhang ◽  
Yuanyuan Ran ◽  
...  

AbstractAutophagy is a conserved degradation process crucial to maintaining the primary function of cellular and organismal metabolism. Impaired autophagy could develop numerous diseases, including cancer, cardiomyopathy, neurodegenerative disorders, and aging. N6-methyladenosine (m6A) is the most common RNA modification in eukaryotic cells, and the fate of m6A modified transcripts is controlled by m6A RNA binding proteins. m6A modification influences mRNA alternative splicing, stability, translation, and subcellular localization. Intriguingly, recent studies show that m6A RNA methylation could alter the expression of essential autophagy-related (ATG) genes and influence the autophagy function. Thus, both m6A modification and autophagy could play a crucial role in the onset and progression of various human diseases. In this review, we summarize the latest studies describing the impact of m6A modification in autophagy regulation and discuss the role of m6A modification-autophagy axis in different human diseases, including obesity, heart disease, azoospermatism or oligospermatism, intervertebral disc degeneration, and cancer. The comprehensive understanding of the m6A modification and autophagy interplay may help in interpreting their impact on human diseases and may aid in devising future therapeutic strategies.


Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Hongmei Peng ◽  
Oscar Carretero ◽  
Xiao-Ping Yang ◽  
Pablo Nakagawa ◽  
Jiang Xu ◽  
...  

Elevated interleukin-4 (IL-4) levels are positively related to cardiac fibrosis in heart failure and hypertension. Using Balb/c exhibiting high circulating IL-4, Balb/c- Il4 tm2Nnt (IL-4 knockout with Balb/c background, IL-4 -/- ) and C57BL/6 mice, as well as cultured cardiac fibroblasts (CFs), we hypothesized that 1) high levels of IL-4 result in cardiac fibrosis, making the heart susceptible to angiotensin II (Ang II)-induced damage, and 2) IL-4 potently stimulates collagen production by CFs. Each strain (9- to 12-week old male) received vehicle or Ang II (1.4 mg/kg/day, s.c. via osmotic mini-pump) for 8 weeks. Cardiac fibrosis and function were determined by histology and echocardiography, respectively. Compared to C57BL/6, Balb/c mice had doubled interstitial collagen in the heart, enlarged left ventricle and decreased cardiac function along with elevated cardiac IL-4 protein (1.00±0.08 in C57BL/6 vs 2.61±0.46 in Balb/c, p <0.05); all those changes were significantly attenuated in IL-4 -/- (Table 1). Ang II further deteriorated cardiac fibrosis and dysfunction in Balb/c; these detrimental effects were attenuated in IL-4 -/- , although the three strains had a similar level of hypertension. In vitro study revealed that IL-4Rα was constitutively expressed in CFs (Western blot), and IL-4 potently stimulated collagen production by CFs (hydroxproline assay, from 18.89±0.85 to 38.81±3.61 μg/mg at 10 ng/ml, p <0.01). Our study demonstrates for the first time that IL-4, as a potent pro-fibrotic cytokine in the heart, contributes to cardiac fibrotic remodeling and dysfunction. Thus IL-4 may be a potential therapeutic target for cardiac fibrosis and dysfunction.


2016 ◽  
Vol 44 (5) ◽  
pp. 1321-1337 ◽  
Author(s):  
Andrew R. Clark ◽  
Jonathan L.E. Dean

Twenty years ago, the first description of a tristetraprolin (TTP) knockout mouse highlighted the fundamental role of TTP in the restraint of inflammation. Since then, work from several groups has generated a detailed picture of the expression and function of TTP. It is a sequence-specific RNA-binding protein that orchestrates the deadenylation and degradation of several mRNAs encoding inflammatory mediators. It is very extensively post-translationally modified, with more than 30 phosphorylations that are supported by at least two independent lines of evidence. The phosphorylation of two particular residues, serines 52 and 178 of mouse TTP (serines 60 and 186 of the human orthologue), has profound effects on the expression, function and localisation of TTP. Here, we discuss the control of TTP biology via its phosphorylation and dephosphorylation, with a particular focus on recent advances and on questions that remain unanswered.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 780 ◽  
Author(s):  
Robin Spiller

Despite being one of the most common conditions leading to gastroenterological referral, irritable bowel syndrome (IBS) is poorly understood. However, recent years have seen major advances. These include new understanding of the role of both inflammation and altered microbiota as well as the impact of dietary intolerances as illuminated by magnetic resonance imaging (MRI), which has thrown new light on IBS. This article will review new data on how excessive bile acid secretion mediates diarrhea and evidence from post infectious IBS which has shown how gut inflammation can alter gut microbiota and function. Studies of patients with inflammatory bowel disease (IBD) have also shown that even when inflammation is in remission, the altered enteric nerves and abnormal microbiota can generate IBS-like symptoms. The efficacy of the low FODMAP diet as a treatment for bloating, flatulence, and abdominal discomfort has been demonstrated by randomized controlled trials. MRI studies, which can quantify intestinal volumes, have provided new insights into how FODMAPs cause symptoms. This article will focus on these areas together with recent trials of new agents, which this author believes will alter clinical practice within the foreseeable future.


2020 ◽  
Vol 1 (1) ◽  
pp. 38-46
Author(s):  
Mesirawati Waruwu ◽  
Yonatan Alex Arifianto ◽  
Aji Suseno

The limitless development of social media, its meaning and function have begun to shift, no longer as a means of establishing relationships, communication, but at the stage of losing the role of ethics and morals, even disputes have occurred triggered by debates from communicating in social media. The purpose of this study is to describe the role of Christian ethics education in relation to the impact of social media development in the era of disruption. Using descriptive qualitative methods with literature literature can find solutions for believers in facing moral decadence due to social media abuse by knowing the era of disruption and ethical challenges from the wrong use of social media can affect moral decadence so that Christian ethics education on a biblical basis can bring modern humans. Believers in particular have become bright in social media and their use in accordance with Christian faith in this era of disruption.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10502
Author(s):  
Huan Guo ◽  
Xinke Zhao ◽  
Haixiang Su ◽  
Chengxu Ma ◽  
Kai Liu ◽  
...  

Background Radiation exposure of the thorax is associated with a greatly increased risk of cardiac morbidity and mortality even after several decades of advancement in the field. Although many studies have demonstrated the damaging influence of ionizing radiation on cardiac fibroblast (CF) structure and function, myocardial fibrosis, the molecular mechanism behind this damage is not well understood. miR-21, a small microRNA, promotes the activation of CFs, leading to cardiac fibrosis. miR-21 is overexpressed after irradiation; however, the relationship between increased miR-21 and myocardial fibrosis after irradiation is unclear. This study was conducted to investigate gene expression after radiation-induced CF damage and the role of miR-21 in this process in rats. Methods We sequenced irradiated rat CFs and performed weighted correlation network analysis (WGCNA) combined with differentially expressed gene (DEG) analysis to observe the effect on the expression profile of CF genes after radiation. Results DEG analysis showed that the degree of gene changes increased with the radiation dose. WGCNA revealed three module eigengenes (MEs) associated with 8.5-Gy-radiation—the Yellow, Brown, Blue modules. The three module eigengenes were related to apoptosis, G2/M phase, and cell death and S phase, respectively. By blocking with the cardiac fibrosis miRNA miR-21, we found that miR-21 was associated with G2/M blockade in the cell cycle and was mainly involved in regulating extracellular matrix-related genes, including Grem1, Clu, Gdf15, Ccl7, and Cxcl1. Stem-loop quantitative real-time PCR was performed to verify the expression of these genes. Five genes showed higher expression after 8.5 Gy-radiation in CFs. The target genes of miR-21 predicted online were Gdf15 and Rsad2, which showed much higher expression after treatment with antagomir-miR-21 in 8.5-Gy-irradiated CFs. Thus, miR-21 may play the role of fibrosis and G2/M blockade in regulating Grem1, Clu, Gdf15, Ccl7, Cxcl1, and Rsad2 post-irradiation.


2020 ◽  
Vol 21 (3) ◽  
pp. 1151 ◽  
Author(s):  
Shannon E. Dougherty ◽  
Austin O. Maduka ◽  
Toshifumi Inada ◽  
Gustavo M. Silva

The eukaryotic proteome has to be precisely regulated at multiple levels of gene expression, from transcription, translation, and degradation of RNA and protein to adjust to several cellular conditions. Particularly at the translational level, regulation is controlled by a variety of RNA binding proteins, translation and associated factors, numerous enzymes, and by post-translational modifications (PTM). Ubiquitination, a prominent PTM discovered as the signal for protein degradation, has newly emerged as a modulator of protein synthesis by controlling several processes in translation. Advances in proteomics and cryo-electron microscopy have identified ubiquitin modifications of several ribosomal proteins and provided numerous insights on how this modification affects ribosome structure and function. The variety of pathways and functions of translation controlled by ubiquitin are determined by the various enzymes involved in ubiquitin conjugation and removal, by the ubiquitin chain type used, by the target sites of ubiquitination, and by the physiologic signals triggering its accumulation. Current research is now elucidating multiple ubiquitin-mediated mechanisms of translational control, including ribosome biogenesis, ribosome degradation, ribosome-associated protein quality control (RQC), and redox control of translation by ubiquitin (RTU). This review discusses the central role of ubiquitin in modulating the dynamism of the cellular proteome and explores the molecular aspects responsible for the expanding puzzle of ubiquitin signals and functions in translation.


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