Cholinergic nerve regulation of heart regeneration

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Mahmoud
Keyword(s):  
Muscarinic Receptor ◽  
Therapeutic Potential ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Cholinergic Nerves ◽  
Cholinergic Nerve ◽  
Regenerative Response ◽  
Cholinergic Signaling ◽  
Cardiac Nerves

Abstract Background Cardiac nerves regulate many important physiological functions of the heart such as heart rate and contractility. The emerging role of cardiac nerves during tissue homeostasis and regeneration is beginning to be appreciated. We discovered that neonatal mice are capable of regenerating their hearts following injury within a brief period after birth by proliferation of the pre-existing cardiomyocytes. Furthermore, we have demonstrated that cholinergic nerves play an important role in guiding the neonatal heart regenerative response. However, the adult mammalian heart, including the human heart, is incapable of regeneration following injury. Thus, there is great excitement about understanding the evolutionarily conserved mechanisms of endogenous cardiac regeneration, so that we can explore potential avenues to reawaken this process in adult humans. Purpose Our overarching goal is to define the mechanisms by which cholinergic nerves regulate heart regeneration following ischemic injury by using the neonatal mouse heart regeneration model. These studies will uncover novel pathways by which cholinergic signaling promotes cardiomyocyte proliferation and heart regeneration, which holds significant therapeutic potential for treatment of adult heart disease. Methods In this project, we employed genetically engineered mouse models of the critical receptors for cholinergic signaling in the heart to define the mechanisms of cholinergic nerve regulation of heart regeneration. First, we generated a cardiomyocyte-specific deletion of the muscarinic receptor (M2), the most predominant muscarinic receptor subtype present in the heart. In addition, we utilized the α7 nicotinic receptor (Chrna7) knockout mice to study the role of Chrna7 in endogenous immune cells, which is the main mediator of the cholinergic anti-inflammatory pathway. These mouse models will address how cholinergic nerves regulate heart regeneration via the M2 muscarinic receptor signaling and the inflammatory response following injury. Results Our results demonstrate that inhibition of two different cholinergic receptors (muscarinic and nicotinic) results in a reduction in cardiomyocyte proliferation and inhibition of the neonatal cardiac regenerative response following injury. More importantly, we demonstrate that cholinergic signaling mediates the cardiac regenerative response mainly through suppression of pro-inflammatory cytokines via the cholinergic anti-inflammatory pathway. Conclusions Cholinergic nerve signaling plays an important role in mounting a robust cardiac regenerative response following injury. These results have significant therapeutic potential, which will forge new paradigms with respect to the role of cardiac nerves during mammalian cardiac regeneration and reveal potential mechanisms regarding the benefits of nerve stimulation following cardiac injury in humans. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): American Heart Association, Wisconsin Partnership Program

Abstract 214: TLR3 Mediates Neonatal Heart Repair and Regeneration Through Glycolysis-dependent YAP/TAZ Mediated miR-152 Expression

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Xiaohui Wang ◽  
Yuanping Hu ◽  
Tuanzhu Ha ◽  
John Kalbfleisch ◽  
Race Kao ◽  
...  
Keyword(s):  
Cardiac Metabolism ◽  
Poly I:C ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Neonatal Cardiomyocytes ◽  
Neonatal Heart ◽  
Heart Repair ◽  
Inhibition Of Glycolysis ◽  
Neonatal Cardiomyocyte

The neonatal heart possesses the capability of regenerating and repairing damaged myocardium which is lost when cardiac metabolism switches from predominate glycolysis to oxidative phosphorylation seven days after birth. We have observed that Toll-like receptor 3 (TLR3) deficient neonatal hearts exhibit impaired cardiac function and larger infarct size after myocardial infarction (MI). We also found that stimulation of neonatal cardiomyocytes with the TLR3 ligand, poly (I:C) significantly enhances glycolytic capacity. Our observation suggests that TLR3 is required for neonatal heart repair and regeneration of damaged myocardium. This study investigated the mechanisms by which TLR3 mediates neonatal heart regeneration and repair. Neonatal cardiomyocytes were isolated from one day old WT mice and treated with poly (I:C) (1μg/ml) for 12-36 hours. We observed that poly (I:C) treatment: i) significantly enhances glycolytic metabolism; ii) increases YAP/TAZ activation: iii) increases miR-152 expression; iv) suppresses expression of DNMT1 and p27kip1, and v) promotes cardiomyocyte proliferation. However, inhibition of glycolysis with 2-Deoxyglucose (2-DG) prevented poly (I:C)-induced YAP/TAZ activation and miR-152 expression in neonatal cardiomyocytes. Similarly, inhibition of YAP/TAZ activation with Verteprofin (VP) abolished poly (I:C) induced miR-152 expression and neonatal cardiomyocyte proliferation. To investigate the role of miR-152 in neonatal cardiomyocyte proliferation, we transfected neonatal cardiomyocytes with miR-152 mimics and observed that increased miR-152 levels significantly promotes neonatal cardiomyocyte proliferation. We also observed that transfection of neonatal cardiomyocytes with miR-152 mimics markedly suppresses the expression of DNMT1 and p27kip1. Inhibition of DNMT1 with 5Azcytidine significantly promotes neonatal cardiomyocyte proliferation. Finally, we observed that treatment of neonatal mice (n=6) with 2-DG abolished cardiac functional recovery 3 weeks after MI. We conclude that TLR3 is required for neonatal heart regeneration and repair after MI. The mechanisms involve glycolytic dependent activation of YAP/TAZ mediated by miR-152 which represses DNMT1/p27kip1 expression.

scholarly journals Polyploidy in Cardiomyocytes

2020 ◽  
Vol 126 (4) ◽  
pp. 552-565 ◽  
Author(s):  
Wouter Derks ◽  
Olaf Bergmann
Keyword(s):  
Cardiac Injury ◽  
Physiological Role ◽  
Cell Types ◽  
Cell Number ◽  
The Body ◽  
Cardiomyocyte Hypertrophy ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Hypertrophic Growth

The hallmark of most cardiac diseases is the progressive loss of cardiomyocytes. In the perinatal period, cardiomyocytes still proliferate, and the heart shows the capacity to regenerate upon injury. In the adult heart, however, the actual rate of cardiomyocyte renewal is too low to efficiently counteract substantial cell loss caused by cardiac injury. In mammals, cardiac growth by cell number expansion changes to growth by cardiomyocyte enlargement soon after birth, coinciding with a period in which most cardiomyocytes increase their DNA content by multinucleation and nuclear polyploidization. Although cardiomyocyte hypertrophy is often associated with these processes, whether polyploidy is a prerequisite or a consequence of hypertrophic growth is unclear. Both the benefits of cardiomyocyte enlargement over proliferative growth of the heart and the physiological role of polyploidy in cardiomyocytes are enigmatic. Interestingly, hearts in animal species with substantial cardiac regenerative capacity dominantly comprise diploid cardiomyocytes, raising the hypothesis that cardiomyocyte polyploidy poses a barrier for cardiomyocyte proliferation and subsequent heart regeneration. On the contrary, there is also evidence for self-duplication of multinucleated myocytes, suggesting a more complex picture of polyploidy in heart regeneration. Polyploidy is not restricted to the heart but also occurs in other cell types in the body. In this review, we explore the biological relevance of polyploidy in different species and tissues to acquire insight into its specific role in cardiomyocytes. Furthermore, we speculate about the physiological role of polyploidy in cardiomyocytes and how this might relate to renewal and regeneration.

Role of dorsal and ventral hippocampal muscarinic receptor activity in acquisition and retention of contextual fear conditioning.

2020 ◽  
Vol 134 (5) ◽  
pp. 460-470
Author(s):  
Claudia C. Pinizzotto ◽  
Nicholas A. Heroux ◽  
Colin J. Horgan ◽  
Mark E. Stanton
Keyword(s):  
Fear Conditioning ◽  
Muscarinic Receptor ◽  
Contextual Fear Conditioning ◽  
Receptor Activity ◽  
Contextual Fear

Dysregulation of HOX as a Potential Therapeutic Target in Breast Cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Ji-Yeon Lee ◽  
Myoung Hee Kim
Keyword(s):  
Breast Cancer ◽  
Hox Genes ◽  
Therapeutic Potential ◽  
Expression Patterns ◽  
Genome Structure ◽  
Control Cell ◽  
Three Dimensional ◽  
Cellular Processes ◽  
Hox Protein

: HOX genes belong to the highly conserved homeobox superfamily, responsible for the regulation of various cellular processes that control cell homeostasis, from embryogenesis to carcinogenesis. The abnormal expression of HOX genes is observed in various cancers, including breast cancer; they act as oncogenes or as suppressors of cancer, according to context. In this review, we analyze HOX gene expression patterns in breast cancer and examine their relationship, based on the three-dimensional genome structure of the HOX locus. The presence of non-coding RNAs, embedded within the HOX cluster, and the role of these molecules in breast cancer have been reviewed. We further evaluate the characteristic activity of HOX protein in breast cancer and its therapeutic potential.

Involvement of Heme Oxygenase-1 in Neuropsychiatric and Neurodegenerative Diseases

2018 ◽  
Vol 24 (20) ◽  
pp. 2283-2302 ◽  
Author(s):  
Vivian B. Neis ◽  
Priscila B. Rosa ◽  
Morgana Moretti ◽  
Ana Lucia S. Rodrigues
Keyword(s):  
Neurodegenerative Diseases ◽  
Heme Oxygenase ◽  
Therapeutic Potential ◽  
Redox Homeostasis ◽  
Antioxidant Defenses ◽  
Heme Oxygenase 1 ◽  
Physiological Conditions ◽  
And Oxidative Stress ◽  
Defensive Mechanism

Heme oxygenase (HO) family catalyzes the conversion of heme into free iron, carbon monoxide and biliverdin. It possesses two well-characterized isoforms: HO-1 and HO-2. Under brain physiological conditions, the expression of HO-2 is constitutive, abundant and ubiquitous, whereas HO-1 mRNA and protein are restricted to small populations of neurons and neuroglia. HO-1 is an inducible enzyme that has been shown to participate as an essential defensive mechanism for neurons exposed to oxidant challenges, being related to antioxidant defenses in certain neuropathological conditions. Considering that neurodegenerative diseases (Alzheimer’s Disease (AD), Parkinson’s Disease (PD) and Multiple Sclerosis (MS)) and neuropsychiatric disorders (depression, anxiety, Bipolar Disorder (BD) and schizophrenia) are associated with increased inflammatory markers, impaired redox homeostasis and oxidative stress, conditions that may be associated with alterations in HO-levels/activity, the purpose of this review is to present evidence on the possible role of HO-1 in these Central Nervous System (CNS) diseases. In addition, the possible therapeutic potential of targeting brain HO-1 is explored in this review.

High Mobility Group Box-1 (HMGB1): A Potential Target in Therapeutics

2019 ◽  
Vol 20 (14) ◽  
pp. 1474-1485 ◽  
Author(s):  
Eyaldeva C. Vijayakumar ◽  
Lokesh Kumar Bhatt ◽  
Kedar S. Prabhavalkar
Keyword(s):  
Myocardial Infarction ◽  
Vagus Nerve Stimulation ◽  
Nuclear Protein ◽  
Therapeutic Potential ◽  
High Mobility ◽  
Dna Binding Protein ◽  
High Mobility Group ◽  
Eukaryotic Cells ◽  
Hmgb1 Protein

High mobility group box-1 (HMGB1) mainly belongs to the non-histone DNA-binding protein. It has been studied as a nuclear protein that is present in eukaryotic cells. From the HMG family, HMGB1 protein has been focused particularly for its pivotal role in several pathologies. HMGB-1 is considered as an essential facilitator in diseases such as sepsis, collagen disease, atherosclerosis, cancers, arthritis, acute lung injury, epilepsy, myocardial infarction, and local and systemic inflammation. Modulation of HMGB1 levels in the human body provides a way in the management of these diseases. Various strategies, such as HMGB1-receptor antagonists, inhibitors of its signalling pathway, antibodies, RNA inhibitors, vagus nerve stimulation etc. have been used to inhibit expression, release or activity of HMGB1. This review encompasses the role of HMGB1 in various pathologies and discusses its therapeutic potential in these pathologies.

Isoform-Selective PI3K Inhibitors for Various Diseases

2020 ◽  
Vol 20 (12) ◽  
pp. 1074-1092 ◽  
Author(s):  
Rammohan R.Y. Bheemanaboina
Keyword(s):  
Intracellular Signaling ◽  
Kinase Inhibitors ◽  
Therapeutic Potential ◽  
Type I ◽  
Selective Inhibitors ◽  
Pi3k Inhibitors ◽  
Wide Range ◽  
Lipid Kinases ◽  
Isoform Selectivity

Phosphoinositide 3-kinases (PI3Ks) are a family of ubiquitously distributed lipid kinases that control a wide variety of intracellular signaling pathways. Over the years, PI3K has emerged as an attractive target for the development of novel pharmaceuticals to treat cancer and various other diseases. In the last five years, four of the PI3K inhibitors viz. Idelalisib, Copanlisib, Duvelisib, and Alpelisib were approved by the FDA for the treatment of different types of cancer and several other PI3K inhibitors are currently under active clinical development. So far clinical candidates are non-selective kinase inhibitors with various off-target liabilities due to cross-reactivities. Hence, there is a need for the discovery of isoform-selective inhibitors with improved efficacy and fewer side-effects. The development of isoform-selective inhibitors is essential to reveal the unique functions of each isoform and its corresponding therapeutic potential. Although the clinical effect and relative benefit of pan and isoformselective inhibition will ultimately be determined, with the development of drug resistance and the demand for next-generation inhibitors, it will continue to be of great significance to understand the potential mechanism of isoform-selectivity. Because of the important role of type I PI3K family members in various pathophysiological processes, isoform-selective PI3K inhibitors may ultimately have considerable efficacy in a wide range of human diseases. This review summarizes the progress of isoformselective PI3K inhibitors in preclinical and early clinical studies for anticancer and other various diseases.

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