Publications

2020

Bektik, Emre, Douglas Cowan, and Da-Zhi Wang. 2020. “Long Non-Coding RNAs in Atrial Fibrillation: Pluripotent Stem Cell-Derived Cardiomyocytes As a Model System”. Int. J. Mol. Sci. 21 (15).
Atrial fibrillation (AF) is a type of sustained arrhythmia in humans often characterized by devastating alterations to the cardiac conduction system as well as the structure of the atria. AF can lead to decreased cardiac function, heart failure, and other complications. Long non-coding RNAs (lncRNAs) have been shown to play important roles in the cardiovascular system, including AF; however, a large group of lncRNAs is not conserved between mouse and human. Furthermore, AF has complex networks showing variations in mechanisms in different species, making it challenging to utilize conventional animal models to investigate the functional roles and potential therapeutic benefits of lncRNAs for AF. Fortunately, pluripotent stem cell (PSC)-derived cardiomyocytes (CMs) offer a reliable platform to study lncRNA functions in AF because of certain electrophysiological and molecular similarities with native human CMs. In this review, we first summarize the broad aspects of lncRNAs in various heart disease settings, then focus on their potential roles in AF development and pathophysiology. We also discuss current uses of PSCs in AF research and describe how these studies could be developed into novel therapeutics for AF and other cardiovascular diseases.
Salazar-Roa, María, Marianna Trakala, Mónica Álvarez-Fernández, Fátima Valdés-Mora, Cuiqing Zhong, Jaime Muñoz, Yang Yu, et al. (2024) 2020. “Transient Exposure to MiR-203 Enhances the Differentiation Capacity of Established Pluripotent Stem Cells”. EMBO J., e104324.
Full differentiation potential along with self-renewal capacity is a major property of pluripotent stem cells (PSCs). However, the differentiation capacity frequently decreases during expansion of PSCs in vitro. We show here that transient exposure to a single microRNA, expressed at early stages during normal development, improves the differentiation capacity of already-established murine and human PSCs. Short exposure to miR-203 in PSCs (miPSCs) induces a transient expression of 2C markers that later results in expanded differentiation potency to multiple lineages, as well as improved efficiency in tetraploid complementation and human-mouse interspecies chimerism assays. Mechanistically, these effects are at least partially mediated by direct repression of de novo DNA methyltransferases Dnmt3a and Dnmt3b, leading to transient and reversible erasure of DNA methylation. These data support the use of transient exposure to miR-203 as a versatile method to reset the epigenetic memory in PSCs, and improve their effectiveness in regenerative medicine.
Liu, Jianming, Zhan-Peng Huang, Mao Nie, Gang Wang, William Silva, Qiumei Yang, Paula Freire, et al. 2020. “Regulation of Myonuclear Positioning and Muscle Function by the Skeletal Muscle-Specific CIP Protein”. Proc. Natl. Acad. Sci. U. S. A.
The appropriate arrangement of myonuclei within skeletal muscle myofibers is of critical importance for normal muscle function, and improper myonuclear localization has been linked to a variety of skeletal muscle diseases, such as centronuclear myopathy and muscular dystrophies. However, the molecules that govern myonuclear positioning remain elusive. Here, we report that skeletal muscle-specific CIP (sk-CIP) is a regulator of nuclear positioning. Genetic deletion of sk-CIP in mice results in misalignment of myonuclei along the myofibers and at specialized structures such as neuromuscular junctions (NMJs) and myotendinous junctions (MTJs) in vivo, impairing myonuclear positioning after muscle regeneration, leading to severe muscle dystrophy in mdx mice, a mouse model of Duchenne muscular dystrophy. sk-CIP is localized to the centrosome in myoblasts and relocates to the outer nuclear envelope in myotubes upon differentiation. Mechanistically, we found that sk-CIP interacts with the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex and the centriole Microtubule Organizing Center (MTOC) proteins to coordinately modulate myonuclear positioning and alignment. These findings indicate that sk-CIP may function as a muscle-specific anchoring protein to regulate nuclear position in multinucleated muscle cells.
Chen, Jinmiao, Qing Ma, Justin King, Yan Sun, Bing Xu, Xiaoyu Zhang, Sylvia Zohrabian, et al. (2020) 2020. “AYAP ModRNA Reduces Cardiac Inflammation and Hypertrophy in a Murine Ischemia-Reperfusion Model”. Life Sci Alliance 3 (1). https://doi.org/10.26508/lsa.201900424.
Myocardial recovery from ischemia-reperfusion (IR) is shaped by the interaction of many signaling pathways and tissue repair processes, including the innate immune response. We and others previously showed that sustained expression of the transcriptional co-activator yes-associated protein (YAP) improves survival and myocardial outcome after myocardial infarction. Here, we asked whether transient YAP expression would improve myocardial outcome after IR injury. After IR, we transiently activated YAP in the myocardium with modified mRNA encoding a constitutively active form of YAP (aYAP modRNA). Histological studies 2 d after IR showed that aYAP modRNA reduced cardiomyocyte (CM) necrosis and neutrophil infiltration. 4 wk after IR, aYAP modRNA-treated mice had better heart function as well as reduced scar size and hypertrophic remodeling. In cultured neonatal and adult CMs, YAP attenuated HO- or LPS-induced CM necrosis. TLR signaling pathway components important for innate immune responses were suppressed by YAP/TEAD1. In summary, our findings demonstrate that aYAP modRNA treatment reduces CM necrosis, cardiac inflammation, and hypertrophic remodeling after IR stress.

2019

Li, Chuanwei, Zhangxue Hu, Wen Zhang, Junyi Yu, Yang Yang, Zaicheng Xu, Hao Luo, et al. (2024) 2019. “Regulation of Cholesterol Homeostasis by a Novel Long Non-Coding RNA LASER”. Scientific Reports 9 (1): 7693-93. https://doi.org/10.1038/s41598-019-44195-2.
Genome-wide association studies (GWAS) have identified many genetic variants in genes related to lipid metabolism. However, how these variations affect lipid levels remains elusive. Long non-coding RNAs (lncRNAs) have been implicated in a variety of biological processes. We hypothesize lncRNAs are likely to be located within disease or trait-associated DNA regions to regulate lipid metabolism. The aim of this study was to investigate whether and how lncRNAs in lipid- associated DNA regions regulate cholesterol homeostasis in hepatocytes. In this study, we identified a novel long non-coding RNA in Lipid Associated Single nucleotide polymorphism gEne Region (LASER) by bioinformatic analysis. We report that LASER is highly expressed in both hepatocytes and peripheral mononuclear cells (PBMCs). Clinical studies showed that LASER expression is positively related with that of cholesterol containing apolipoprotein levels. In particular, we found that LASER is positively correlated with plasma PCSK9 levels in statin free patients. siRNAs mediated knock down of LASER dramatically reduces intracellular cholesterol levels and affects the expression of genes involved in cholesterol metabolism. Transcriptome analyses show that knockdown of LASER affects the expression of genes involved in metabolism pathways. We found that HNF-1a and PCSK9 were reduced after LASER knock-down. Interestingly, the reduction of PCSK9 can be blocked by the treatment of berberine, a natural cholesterol-lowering compound which functions as a HNF-1a antagonist. Mechanistically, we found that LASER binds to LSD1 (lysine-specific demethylase 1), a member of CoREST/REST complex, in nucleus. LASER knock-down enhance LSD1 targeting to genomic loci, resulting in decreased histone H3 lysine 4 mono-methylation at the promoter regions of HNF-1a gene. Conversely, LSD1 knock-down abolished the effect of LASER on HNF-1a and PCSK9 expressions. Finally, we found that statin treatment increased LASER expression, accompanied with increased PCSK9 expression, suggesting a feedback regulation of cholesterol on LASER expression. This observation may partly explain the statin escape during anti-cholesterol treatment. These findings identified a novel lncRNA in cholesterol homeostasis. Therapeutic targeting LASER might be an effective approach to augment the effect of statins on cholesterol levels in clinics.
Q, Zhou, Yu B, Anderson C, Huang ZP, Hanus J, Zhang W, Han Y Peters DC, et al. 2019. “LncEGFL7OS Regulates Human Angiogenesis by Interacting With MAX at the EGFL7/MiR-126 Locus”. Elife. 2019 Feb 11; 8.
Publisher's Version
In an effort to identify human endothelial cell (EC)-enriched lncRNAs,~500 lncRNAs were shown to be highly restricted in primary humanECs. Among them, lncEGFL7OS, located in the opposite strand of the EGFL7/miR-126 gene, is regulated by ETS factors through a bidirectional promoter in ECs. It is enriched in highly vascularized human tissues, and upregulated in the hearts of dilated cardiomyopathy patients. LncEGFL7OS silencing impairs angiogenesis as shown by EC/fibroblast co-culture, in vitro/in vivo and ex vivo human choroid sprouting angiogenesis assays, while lncEGFL7OS overexpression has the opposite function. Mechanistically, lncEGFL7OS is required for MAPK and AKT pathway activation by regulating EGFL7/miR-126 expression. MAX protein was identified as a lncEGFL7OS-interactingprotein that functions to regulate histone acetylation in the EGFL7/miR-126 promoter/enhancer. CRISPR-mediated targeting of EGLF7/miR-126/lncEGFL7OS locus inhibits angiogenesis, inciting therapeutic potential of targeting this locus. Our study establishes lncEGFL7OS as a human/primate-specific EC-restricted lncRNA critical for human angiogenesis. 
F, Gao, Kataoka M, Liu N, Liang T, Huang ZP, Gu F, Ding J, et al. 2019. “Therapeutic Role of MiR-19a/19b in Cardiac Regeneration and Protection from Myocardial Infarction”. Nat Commun, 2019 10 (1): 1802.
Publisher's Version
The primary cause of heart failure is the loss of cardiomyocytes in the diseased adult heart. Previously, we reported that the miR-17-92 cluster plays a key role in cardiomyocyte proliferation. Here, we report that expression of miR-19a/19b, members of the miR-17-92 cluster, is induced in heart failure patients. We show that intra-cardiac injection of miR-19a/19b mimics enhances cardiomyocyte proliferation and stimulates cardiac regeneration in response to myocardial infarction (MI) injury. miR-19a/19b protected the adult heart in two distinctive phases: an early phase immediately after MI and long-term protection. Genome-wide transcriptome analysis demonstrates that genes related to the immune response are repressed by miR-19a/19b. Using an adeno-associated virus approach, we validate that miR-19a/19b reduces MI-induced cardiac damage and protects cardiac function. Finally, we confirm the therapeutic potential of miR-19a/19b in protecting cardiacfunction by systemically delivering miR-19a/19b into mice post-MI. Our study establishes miR-19a/19b as potential therapeutic targets to treat heart failure.    

2018

D, Zhang, Li Y, Heims-Waldron D, Bezzerides V, Guatimosim S, Guo Y, Gu F, et al. 2018. “Mitochondrial Cardiomyopathy Caused by Elevated Reactive Oxygen Species and Impaired Cardiomyocyte Proliferation”. Circ Res. 2018 Jan 05; 122 (1): 74–87.
Publisher's Version

RATIONALE:

Although mitochondrial diseases often cause abnormal myocardial development, the mechanisms by which mitochondria influence heart growth and function are poorly understood.

OBJECTIVE:

To investigate these disease mechanisms, we studied a genetic model of mitochondrial dysfunction caused by inactivation of Tfam (transcription factor A, mitochondrial), a nuclear-encoded gene that is essential for mitochondrial gene transcription and mitochondrialDNA replication.

METHODS AND RESULTS:

Tfam inactivation by Nkx2.5Cre caused mitochondrial dysfunction and embryonic lethal myocardial hypoplasia. Tfam inactivation was accompanied by elevated production of reactive oxygen species (ROS) and reduced cardiomyocyte proliferation. Mosaic embryonic Tfam inactivation confirmed that the block to cardiomyocyte proliferation was cell autonomous. Transcriptional profiling by RNA-seq demonstrated the activation of the DNA damage pathway. Pharmacological inhibition of ROS or the DNA damage response pathway restored cardiomyocyte proliferation in cultured fetal cardiomyocytes. Neonatal Tfam inactivation by AAV9-cTnT-Cre causedprogressive, lethal dilated cardiomyopathy. Remarkably, postnatal Tfam inactivation and disruption of mitochondrial function did not impair cardiomyocyte maturation. Rather, it elevated ROS production, activated the DNA damage response pathway, and decreased cardiomyocyteproliferation. We identified a transient window during the first postnatal week when inhibition of ROS or the DNA damage response pathway ameliorated the detrimental effect of Tfam inactivation.

CONCLUSIONS:

Mitochondrial dysfunction caused by Tfam inactivation induced ROS production, activated the DNA damage response, and caused cardiomyocyte cell cycle arrest, ultimately resulting in lethal cardiomyopathy. Normal mitochondrial function was not required for cardiomyocyte maturation. Pharmacological inhibition of ROS or DNA damage response pathways is a potential strategy to prevent cardiac dysfunction caused by some forms of mitochondrial dysfunction.

 

ZP, Huang, and Wang DZ. 2018. “MiR-22 in Smooth Muscle Cells: A Potential Therapy for Cardiovascular Disease”. Circulation. 2018 137 (17): 1842–1845.
Publisher's Version
Cardiovascular disease (CVD) continues to be the leading cause of death and disability in the United States. Furthermore, over 40% of the US adult population is projected to have some form of CVD by 2030. Vascular smooth muscle cells (VSMCs) participate importantly in atherosclerosis, the major cause of myocardial infarction and stroke. MicroRNAs (miRNAs) are a class of small non-coding RNAs containing ~22 nucleotides. Studies using mouse models have shown that miRNAs are essential for cardiovascular development and function. Furthermore, miRNAs are required for proliferation and differentiation of VSMCs during embryonic development and for maintaining vascular contractile function, SMC contractile differentiation, and vascular remodeling in the postnatal stage. Numerous studies have linked altered miRNA expression to various diseases, indicating that miRNAs may play important roles in the pathogenesis of CVD.
YW, Lu, and Wang DZ. 2018. “Non-Coding RNA in Ischemic and Non-Ischemic Cardiomyopathy”. Curr Cardiol Rep. 2018 Sep 26; 20 (11): 115.
Publisher's Version

PURPOSE OF REVIEW:

This review aims to summarize and discuss the function and molecular mechanism of miRNA and lncRNA in the heart, focusing on ischemic and non-ischemic cardiomyopathy.

RECENT FINDINGS:

Extensive studies in the past decades have identified numerous protein-coding genes that are highly expressed in the heart, playing essential roles in the regulation of cardiac gene expression, heart development, and function. Furthermore, mutations in many of these genes have been identified and are linked to cardiovascular disease. Intriguingly, it is now recognized that majority of our genome is "non-coding," which produces a large amount of non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Emerging evidence has indicated that these classes of non-coding RNAs participate in most (if not all) aspects of cardiac gene expression, cardiomyocyte proliferation, differentiation, and cardiac remodeling in response to stress. Recent findings have demonstrated important functions for non-coding RNA in ischemic and non-ischemic cardiomyopathy. It is expected that non-coding RNAs will become promising therapeutic targets for cardiovascular diseases.

KEYWORDS:

Heart failure; Ischemic cardiomyopathy; Non-ischemic cardiomyopathy; lncRNA; miRNA