scholarly journals Keratin5-BMP4 mechanosignaling regulates reciprocal acetylation and methylation at H3K9 to define blastema cell remodeling during zebrafish heart regeneration

2020 ◽  
Author(s):  
Xuelong Wang ◽  
Huiping Guo ◽  
Feifei Yu ◽  
Wei Zheng ◽  
Hui Zhang ◽  
...  

AbstractHeart regeneration after myocardial infarction remains challenging due to scar and ischemia-reperfusion injury. Here, we show that zebrafish blastema regeneration can effectively resalvage the wound myocardium and blood clot through cytoplasmic exocytosis and nuclear reorganization. The cell remodeling process are also visualized by spatiotemporal expression of three core blastema genes: alpha-SMA- which marks for fibrogenesis, Flk1for angiogenesis/hematopoiesis, Pax3a for remusculogensis, and by characteristic chromatin depositions of H3K9Ac/H3K9Me3. Genome-wide enhancer identification links the depositions of the two histone marks to the chromatin state and these three core blastema cell phenotypes. When the blastema subcellular fractions are introduced into the cultured zebrafish embryonic fibroblasts the altered transcription profile is comparable to the blastema transcription in terms of extracellular matrix structural constituent, vasculature development/angiogenesis, and cardiac muscle regeneration. From the subcellular fractions we identify 15 extracellular components and intermediate filaments, and show that introduction of human Krt5 and noggin peptides conversely regulate PAC2 cells F-actin reorganization, chromatin depositions of H3K9Ac/ H3K9Me3 and phosphorylation of Smad, which are accompanied by characteristic transcriptions of bmp, bmp4, three core blastema genes as well as specific histone acetylation/methylation-related genes. Collectively, this study establishes a new Krt5-BMP4 mechanosignaling cascade that links extracellular molecules to chromatin modifications and regulates blastema cell remodeling, thus providing mechanistic insights into the mesoderm-derived blastema regeneration and underlining a therapy strategy for myocardial infarction.

2021 ◽  
Vol 10 (13) ◽  
pp. 2968
Author(s):  
Alessandro Bellis ◽  
Giuseppe Di Gioia ◽  
Ciro Mauro ◽  
Costantino Mancusi ◽  
Emanuele Barbato ◽  
...  

The significant reduction in ‘ischemic time’ through capillary diffusion of primary percutaneous intervention (pPCI) has rendered myocardial-ischemia reperfusion injury (MIRI) prevention a major issue in order to improve the prognosis of ST elevation myocardial infarction (STEMI) patients. In fact, while the ischemic damage increases with the severity and the duration of blood flow reduction, reperfusion injury reaches its maximum with a moderate amount of ischemic injury. MIRI leads to the development of post-STEMI left ventricular remodeling (post-STEMI LVR), thereby increasing the risk of arrhythmias and heart failure. Single pharmacological and mechanical interventions have shown some benefits, but have not satisfactorily reduced mortality. Therefore, a multitarget therapeutic strategy is needed, but no univocal indications have come from the clinical trials performed so far. On the basis of the results of the consistent clinical studies analyzed in this review, we try to design a randomized clinical trial aimed at evaluating the effects of a reasoned multitarget therapeutic strategy on the prevention of post-STEMI LVR. In fact, we believe that the correct timing of pharmacological and mechanical intervention application, according to their specific ability to interfere with survival pathways, may significantly reduce the incidence of post-STEMI LVR and thus improve patient prognosis.


2021 ◽  
Vol 19 (4) ◽  
pp. 543-549
Author(s):  
Fanglin Luo ◽  
Shunxiang Luo ◽  
Yanqing Wu

Using a rat model, we have explored the underlying mechanism of ischemia/reperfusion (I/R)-mediated myocardial infarction and assessed the protective potential of zingerone. The results show that zingerone exhibits not only the myocardial protective effect, but also antioxidative and anti-inflammatory effects by suppression of markers of oxidation and proinflammatory cytokine release. Zingerone promotes protective effects against I/R-induced myocardial infarction by regulating Nrf2/HO-1 and NF-κB signaling pathways. These findings provide novel insights into the effects of zingerone on the cardioprotective mechanism of myocardial injury after I/R and may open new avenues for myocardial infarction treatment.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xia Yin ◽  
Yang Zheng ◽  
Xujie Zhai ◽  
Xin Zhao ◽  
Lu Cai

Ischemic preconditioning (IPC) or postconditioning (Ipost) is proved to efficiently prevent ischemia/reperfusion injuries. Mortality of diabetic patients with acute myocardial infarction was found to be 2–6 folds higher than that of non-diabetic patients with same myocardial infarction, which may be in part due to diabetic inhibition of IPC- and Ipost-mediated protective mechanisms. Both IPC- and Ipost-mediated myocardial protection is predominantly mediated by stimulating PI3K/Akt and associated GSK-3β pathway while diabetes-mediated pathogenic effects are found to be mediated by inhibiting PI3K/Akt and associated GSK-3β pathway. Therefore, this review briefly introduced the general features of IPC- and Ipost-mediated myocardial protection and the general pathogenic effects of diabetes on the myocardium. We have collected experimental evidence that indicates the diabetic inhibition of IPC- and Ipost-mediated myocardial protection. Increasing evidence implies that diabetic inhibition of IPC- and Ipost-mediated myocardial protection may be mediated by inhibiting PI3K/Akt and associated GSK-3β pathway. Therefore any strategy to activate PI3K/Akt and associated GSK-3β pathway to release the diabetic inhibition of both IPC and Ipost-mediated myocardial protection may provide the protective effect against ischemia/reperfusion injuries.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Sheng-Yong Luo ◽  
Qing-Hua Xu ◽  
Gong Peng ◽  
Zhi-Wu Chen

Objectives. Total flavones from Rhododendron simsii Planch. (TFR) are the effective part extracted from the flowers of Rhododendron simsii Planch. and have obvious protective effects against cerebral ischemic or myocardial injuries in rabbits and rats. However, their mechanism of cardioprotection is still unrevealed. Therefore, the present study was designed to investigate the effect of TFR on myocardial I/R injury and the underlying mechanism. Methods. TFR groups were treated by gavage once a day for 3 days at a dose of 20, 40, and 80 mg/kg, respectively, and then the model of myocardial I/R injury was established. Myocardial infarction, ST-segment elevation, and the expression of UTR, ROCK1, ROCK2, and p-MLC protein in rat myocardium were determined at 90 min after reperfusion. UTR siRNA in vivo transfection and competition binding assay method were used to study the relationship between the protective effect of TFR and UTR. Results. The expression of UTR protein markedly decreased in myocardium of UTR siRNA transfection group rats. TFR could significantly reduce the infarct size and inhibit the increase of RhoA activity and ROCK1, ROCK2, and p-MLC protein expressions both in WT and UTR knockdown rats. The reducing rate of TFR in myocardial infarction area, RhoA activity, and ROCK1, ROCK2, and p-MLC protein expressions in UTR knockdown rats decreased markedly compared with that in WT rats. In addition, TFR had no obvious effect on the increase of ΣST in UTR knockdown rats in comparison with that in model group. In particular, TFR could significantly inhibit the combination of [I125]-hu-II and UTR, and IC50 was 0.854 mg/l. Conclusions. The results indicate that the protective effect of TFR on I/R injury may be correlated with its blocking UTR and the subsequent inhibition of RhoA/ROCK signaling pathway.


2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Ramón Rodrigo ◽  
Matías Libuy ◽  
Felipe Feliú ◽  
Daniel Hasson

Acute myocardial infarction (AMI) is the leading cause of mortality worldwide. Major advances in the treatment of acute coronary syndromes and myocardial infarction, using cardiologic interventions, such as thrombolysis or percutaneous coronary angioplasty (PCA) have improved the clinical outcome of patients. Nevertheless, as a consequence of these procedures, the ischemic zone is reperfused, giving rise to a lethal reperfusion event accompanied by increased production of reactive oxygen species (oxidative stress). These reactive species attack biomolecules such as lipids, DNA, and proteins enhancing the previously established tissue damage, as well as triggering cell death pathways. Studies on animal models of AMI suggest that lethal reperfusion accounts for up to 50% of the final size of a myocardial infarct, a part of the damage likely to be prevented. Although a number of strategies have been aimed at to ameliorate lethal reperfusion injury, up to date the beneficial effects in clinical settings have been disappointing. The use of antioxidant vitamins could be a suitable strategy with this purpose. In this review, we propose a systematic approach to the molecular basis of the cardioprotective effect of antioxidant vitamins in myocardial ischemia-reperfusion injury that could offer a novel therapeutic opportunity against this oxidative tissue damage.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
lanfang Li ◽  
Heng Zeng ◽  
Jian-Xiong Chen

ABSTRACT: Apelin is an endogenous ligand for the angiotensin-like 1 receptor (APJ) and has beneficial effects against hypertension and myocardial ischemia/reperfusion injury. Little is known about the role of apelin in the homing of vascular progenitor cells (PCs) and cardiac remodeling post-myocardial infarction (MI). The present study investigates whether apelin affects PCs homing to the infarcted myocardium thereby mediating cardiac remodeling post-MI. Mice were infarcted by coronary artery ligation and apelin-13 (1 mg/kg.d) was injected for three days prior to MI and for either 24 hours or 14 days post MI. Homing of vascular progenitor cell (CD133 + /c-kit + /Sca1 + , CD133 + /SDF-1α + and CD133 + /CXCR4 + ) into the ischemic area were examined at 24 hours and 14 days post-MI. Myocardial Akt, eNOS, VEGF, Jagged1, Notch3, SDF-1α and CXCR4 expression were assessed. Functional analyses were performed at day 14 after MI. Mice receiving apelin-13 treatment demonstrated upregulation of SDF-1α/CXCR4 expression and dramatically increased the number of CD133 + /c-kit + /Sca1 + , CD133 + /SDF-1α + and c-kit + /CXCR4 + cells in the infarcted hearts. Apelin-13 also significantly increased Akt and eNOS phosphorylation and upregulated VEGF, Jagged1, Notch3 expression in the ischemic hearts. This was accompanied by a significant reduction of myocardial apoptosis. Further, treatment with apelin-13 promoted myocardial angiogenesis, attenuated cardiac fibrosis and hypertrophy together with a significant improvement of cardiac function at 14 days post-MI mice. Apelin-13 increases angiogenesis and improves cardiac remodeling by a mechanism involving upregulation of SDF-1α/CXCR4 and homing of vascular progenitor cells.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Miao Cui ◽  
Atmanli Ayhan ◽  
Ning Liu ◽  
Rhonda S Bassel-duby ◽  
Eric N Olson

Cardiomyocyte loss is the underlying basis for a majority of heart diseases. Preventing cardiomyocytes from death (cardioprotection) and replenishing the lost myocardium (regeneration) are the central goals for heart repair. Although cardioprotection and heart regeneration have been traditionally thought to involve separate mechanisms, protection of cardiomyocytes from injury or disease stimuli is a prerequisite to any meaningful regenerative response. In our study, we sought to understand how neonatal cardiomyocytes cope with injury-induced stress to regenerate damaged myocardium and whether the underlying mechanisms could be leveraged to promote heart regeneration and repair in adults. Using spatial transcriptomic profiling, we visualized regenerative cardiomyocytes reconstituting damaged myocardium after ischemia, and found that they are marked by expression of Nrf1, an ER-bound stress responsive transcription factor. Single-nucleus RNA sequencing revealed that genetic deletion of Nrf1 prevented neonatal cardiomyocytes from activating a transcriptional program required for heart regeneration. Conversely, overexpression of Nrf1 protected the adult mouse heart from ischemia/reperfusion injury. Nrf1 also protected human induced pluripotent stem cell-derived cardiomyocytes from cardiotoxicity induced by the chemotherapeutic drug doxorubicin. The cardioprotective function of Nrf1 is mediated by a dual stress response mechanism involving activation of the proteasome and maintenance of redox balance. Taken together, our study uncovers a unique adaptive mechanism activated in response to injury that maintains the tissue homeostatic balance required for heart regeneration. Reactivating these mechanisms in the adult heart represents a potential therapeutic approach for cardiac repair.


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