Abstract 3818: Notch1 Receptor Blockade Results in Dilated Cardiomyopathy in the Neonatal Mouse Heart

The objective of this study was to determine whether Notch1 receptor plays a crucial role in the commitment of c-kit-positive cardiac progenitor cells (CPCs) to the myocyte lineage. This possibility was tested in the neonatal mouse heart because of the dramatic increase in the myocyte compartment early postnatally. CPCs are located within the primitive heart and their number increases progressively with gestational age and after birth. c-kit colocalizes with transcription factors and contractile proteins specific of myocytes, pointing to a lineage relationship between CPCs and myocytes in the prenatal and postnatal heart. Notch1 intracellular domain (N1ICD) was consistently found together with Nkx2.5 suggesting that Notch1 receptor represents an early determinant of myocyte differentiation. The critical function of Notch1 in the generation of myocytes was established by interfering with this pathway through the administration of a γ-secretase inhibitor to newborn mice for 3–7 days; γ-secretase inhibition opposes the cleavage of the active fragment of Notch and initiation of transcription. Treated mice showed a dilated myopathy characterized by decreased muscle mass, wall thinning and impaired fractional shortening and ejection fraction. There was also a marked reduction in the fraction of CPCs and myocytes expressing the Notch1 active fragment N1ICD. Myocyte number decreased 28% while myocyte volume remained constant, suggesting that Notch1 blockade affects myocyte formation and conditions the development of a dilated myopathy. This hypothesis is supported further by a 57% decrease in replicating myocytes positive for Ki67. These anatomical and functional changes were accompanied by downregulation of Nkx2.5 transcripts in the pathologic heart. A perfect consensus site for the target gene of Notch, RBP-Jk, was recognized in the promoter of Nkx2.5. The formation of a functional complex between Nkx2.5 promoter and RBP-Jk protein was demonstrated by electrophoretic mobility assay, chromatin immunoprecipitation and luciferase reporter assay. In conclusion, Notch1 promotes the commitment of CPCs to the myocyte lineage and inhibition of Notch1 interferes with cardiomyogenesis leading to a dilated cardiomyopathy in the postnatal heart.

Download Full-text

Preventing permeability transition pore opening increases mitochondrial maturation, myocyte differentiation and cardiac function in the neonatal mouse heart

Pediatric Research ◽

10.1038/pr.2017.19 ◽

2017 ◽

Vol 81 (6) ◽

pp. 932-941 ◽

Cited By ~ 6

Author(s):

Jayson V. Lingan ◽

Ryan E. Alanzalon ◽

George A. Porter

Keyword(s):

Cardiac Function ◽

Permeability Transition Pore ◽

Permeability Transition ◽

Neonatal Mouse ◽

Mouse Heart ◽

Myocyte Differentiation ◽

Permeability Transition Pore Opening ◽

Pore Opening

Download Full-text

Faculty Opinions recommendation of Transient regenerative potential of the neonatal mouse heart.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.8998956.791603002 ◽

2012 ◽

Author(s):

Stephen Schwartz

Keyword(s):

Neonatal Mouse ◽

Mouse Heart

Download Full-text

Peptidomics Analysis of Transient Regeneration in the Neonatal Mouse Heart

Journal of Cellular Biochemistry ◽

10.1002/jcb.25933 ◽

2017 ◽

Vol 118 (9) ◽

pp. 2828-2840 ◽

Cited By ~ 6

Author(s):

Yi Fan ◽

Qijun Zhang ◽

Hua Li ◽

Zijie Cheng ◽

Xing Li ◽

...

Keyword(s):

Neonatal Mouse ◽

Mouse Heart

Download Full-text

Abstract 17185: Sympathetic Reinnervation is Required for Mammalian Cardiac Regeneration

Circulation ◽

10.1161/circ.132.suppl_3.17185 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Ian A White ◽

Julie Gordon ◽

Wayne Balkan ◽

Joshua M Hare

Keyword(s):

Sympathetic Innervation ◽

Cardiac Regeneration ◽

Ventricular Myocardium ◽

Left Ventricular ◽

Neonatal Mouse ◽

Left Ventricular Myocardium ◽

Autonomic Nerves ◽

Mouse Heart ◽

Minimal Scarring ◽

Age Related

Rationale: Established animal models of tissue and limb regeneration demonstrate a critical dependence on concurrent reinnervation by the peripheral nervous system. The abundance of autonomic nerves in the mammalian heart suggests they play a similar role in the response to cardiac injury. Objective: To test the hypothesis that reinnervation is required for innate neonatal cardiac regeneration. Methods and Results: Crossing Wnt1:cre transgenic mice with a double-tandem (td) tomato reporter strain identified all neural crest-derived cell lineages including the peripheral autonomic nerves in the heart. Whole mount epi-fluorescence microscopy facilitated the clear resolution of subepicardial autonomic nerves in the mouse ventricles providing unprecedented detail of the subepicardial neuroanatomy of the mouse heart. We confirmed that sympathetic nerve structures envelop the entire heart, and importantly, exhibit robust re-growth into the regenerating myocardium following resection of the left ventricular apex in neonatal mice. While innervated hearts regenerate with minimal scarring to the left ventricular myocardium, we report that innate cardiac regeneration was inhibited following sympathectomy, as determined by cross-sectional percentage of viable LV myocardium (n=9, 0.87±1.4% vs. n=6, 14.05±4.4% ; p<0.01). Conclusions: Ablation of post-ganglionic sympathetic nerves blocks the innate regenerative capacity of neonatal mouse hearts. Therefore, the innate ability of the neonatal mouse heart to undergo regeneration in response to injury is dependent on sympathetic innervation of the ventricular myocardium. This finding has significant implications for adult regeneration following myocardial infarction where nerve growth is hindered by age related influences and scar tissue.

Download Full-text

Acute inflammation stimulates a regenerative response in the neonatal mouse heart

Cell Research ◽

10.1038/cr.2015.110 ◽

2015 ◽

Vol 25 (10) ◽

pp. 1137-1151 ◽

Cited By ~ 68

Author(s):

Chunyong Han ◽

Yu Nie ◽

Hong Lian ◽

Rui Liu ◽

Feng He ◽

...

Keyword(s):

Acute Inflammation ◽

Neonatal Mouse ◽

Mouse Heart ◽

Regenerative Response

Download Full-text

Clonal Analysis of the Neonatal Mouse Heart using Nearest Neighbor Modeling

Journal of Visualized Experiments ◽

10.3791/61656 ◽

2020 ◽

Author(s):

Melanie Bakovic ◽

Devang Thakkar ◽

Paige DeBenedittis ◽

Diana C. Chong ◽

Michael C. Thomas ◽

...

Keyword(s):

Nearest Neighbor ◽

Clonal Analysis ◽

Neonatal Mouse ◽

Mouse Heart

Download Full-text

Propofol Ameliorates Microglia Activation by Targeting MicroRNA-221/222-IRF2 Axis

Journal of Immunology Research ◽

10.1155/2021/3101146 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Xi Xiao ◽

Yuanyuan Hou ◽

Wei Yu ◽

Sihua Qi

Keyword(s):

Molecular Mechanism ◽

Neuroprotective Effect ◽

Ectopic Expression ◽

Microglia Activation ◽

Luciferase Reporter ◽

Enzyme Linked Immunosorbent Assay ◽

Loss Of Function ◽

Critical Function ◽

Bv2 Cells ◽

Primary Mouse

Background. Propofol is a widely used intravenous anesthetic drug with potential neuroprotective effect in diverse diseases of neuronal injuries such as traumatic brain injury and ischemic stroke. However, the underlying molecular mechanism remains largely unknown. Methods. Real-time qPCR, enzyme-linked immunosorbent assay, and Western blotting were used to identify the expression pattern of miR-221/222, inflammatory genes, cytokines, and IRF2. The biological roles and mechanisms of propofol in microglia activation were determined in BV2 cells and primary microglia. Bioinformatic analysis and luciferase reporter assay were used to confirm the regulatory role of miR-221/222 in Irf2 expression. Results. We found that miR-221 and miR-222 were downstream targets of propofol and were consistently upregulated in lipopolysaccharide- (LPS-) primed BV2 cells. Gain- and loss-of-function studies revealed that miR-221 and miR-222 were profoundly implicated in microglia activation. Then, interferon regulatory factor 2 (Irf2) was identified as a direct target gene of miR-221/222. IRF2 protein levels were reduced by miR-221/222 and increased by propofol treatment. Ectopic expression of IRF2 attenuated the proinflammatory roles induced by LPS in BV2 cells. More importantly, the suppressive effects of propofol on LPS-primed activation of BV2 cells or primary mouse microglia involved the inhibition of miR-221/222-IRF2 axis. Conclusions. Our study highlights the critical function of miR-221/222, which inhibited Irf2 translation, in the anti-inflammatory effects of propofol, and provides a new perspective for the molecular mechanism of propofol-mediated neuroprotective effect.

Download Full-text

Characterizing the Key Metabolic Pathways of the Neonatal Mouse Heart Using a Quantitative Combinatorial Omics Approach

Frontiers in Physiology ◽

10.3389/fphys.2018.00365 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 16

Author(s):

Maciej M. Lalowski ◽

Susann Björk ◽

Piet Finckenberg ◽

Rabah Soliymani ◽

Miikka Tarkia ◽

...

Keyword(s):

Metabolic Pathways ◽

Neonatal Mouse ◽

Mouse Heart

Download Full-text

LncRNA ADAMTS9-AS2 in osteosarcoma inhibits cell proliferation and enhances paclitaxel sensitivity by suppressing microRNA-130a-5p

European Journal of Inflammation ◽

10.1177/2058739220934560 ◽

2020 ◽

Vol 18 ◽

pp. 205873922093456 ◽

Cited By ~ 1

Author(s):

Xiaoqiang Ren ◽

Jingwei Cai ◽

Yongheng Wang ◽

Xingren Zhu ◽

Jun Qian ◽

...

Keyword(s):

Cell Proliferation ◽

Noncoding Rna ◽

Target Gene ◽

Luciferase Reporter ◽

Critical Function ◽

Downstream Target ◽

Downstream Target Gene ◽

Proliferation Ability ◽

Polymerase Chain ◽

Qpcr Experiment

Introduction: Long noncoding RNA ADAMTS9-AS2 (lncRNA ADAMTS9-AS2) has critical function in tumor growth and drug resistance of various cancers. However, the role and mechanism of lncRNA ADAMTS9-AS2 in osteosarcoma (OS) is still unclear. Methods: The expression of lncRNA ADAMTS9-AS2 and MicroRNAs-130a-5p (miR-130a-5p) was detected by real-time polymerase chain reaction (RT-qPCR) experiment. In addition, we used the plasmids transfection to construct the lncRNA ADAMTS9-AS2 overexpressed OS cell lines. Subsequently, the cell proliferation ability and the sensitivity to paclitaxel (PTX) in OS cells upon up-regulating lncRNA ADAMTS9-AS2 expression were analyzed via CCK-8 assay, while Western blotting experiment was performed to detect the regulatory mechanism. Results: We found that lncRNA ADAMTS9-AS2 was down-regulated in OS tissues, and the OS patients with lncRNA ADAMTS9-AS2 downexprssion were usually accompanied with a poor prognosis. Subsequently, we discovered that up-regulation of lncRNA ADAMTS9-AS2 inhibited cell proliferation and increased the sensitivity to PTX in OS cells. Interestingly, the Western blot results showed that overexpression of lncRNA ADAMTS9-AS2 could lead to PTEN expression increased, with PI3K and p-AKT expression decreased, indicating that lncRNA ADAMTS9-AS2 could increase the OS cell sensitivity to PTX via regulating PTEN-PI3K/AKT pathway. Furthermore, we identified MicroRNAs-130a-5p (miR-130a-5p) as the downstream target gene of lncRNA ADAMTS9-AS2, which was further confirmed by the luciferase reporter assay. More importantly, our data revealed that miR-130a-5p mimics could partly reverse the influence on cell proliferation and drug sensitivity induced by lncRNA ADAMTS9-AS2 overexpression. Conclusion: LncRNA ADAMTS9-AS2 exerts its anti-carcinogenesis function by sponging miR-130a-5p, which might be a new therapeutic target for OS treatment.

Download Full-text