Pub Date : 2025-11-21DOI: 10.1161/circresaha.125.326647
Lu Gao,Jinhua Cao,Yue Li,Xiaoyang Ji,Qingqing Wu,Sen Guo,Xintong Cai,Ke Li,Yanna Sun,Lili Xiao,Youyou Du,Zhe Zheng,Xiaofang Wang
BACKGROUNDCardiac hypertrophy is one of the major causes of heart failure and sudden cardiac death. OTUD7a (OTU domain-containing protein 7a) is identified as a deubiquitinizing enzyme and a possible tumor suppressor. The present study is aimed at exploring the potential role and key downstream effectors of OTUD7a in cardiac hypertrophy.METHODSThe expression level of OTUD7a was detected in the cardiomyocytes with phenylephrine stimuli and the hearts subjected to transverse aortic constriction surgery. Then, the potential effects of OTUD7a on cardiac hypertrophy were evaluated in vivo by using cardiac-specific OTUD7a knockout mice and adeno-associated virus serotype 9-OTUD7a-infected mice. To further explore the direct modulation of OTUD7a on cardiomyocytes, hypertrophic parameters were detected in phenylephrine-stimulated cardiomyocytes with adenovirus system-induced OTUD7a overexpression or depletion. Furthermore, RNA-sequencing and interactome analysis, which were followed by multiple molecular biological methodologies, were combined to identify the direct target and corresponding molecular events contributing to OTUD7a function.RESULTSCardiac hypertrophy stimulates expression of OTUD7a in vitro and in vivo. Our data clearly showed that OTUD7a deficiency alleviates pathological cardiac hypertrophy in the transverse aortic constriction mouse model as well as in phenylephrine-treated cardiomyocytes, whereas overexpression of OTUD7a aggravated hypertrophic heart in vivo and enhanced cardiomyocyte enlargement in vitro. Mechanistically, TAK1 (transforming growth factor-β-activated kinase 1) was identified as a direct and essential target of OTUD7a in cardiac hypertrophy. To be more specific, OTUD7a directly interacts with TAK1 to inhibit the ubiquitination degradation of TAK1 and subsequently increase the phosphorylation levels of TAK1 and its downstream JNK (c-Jun N-terminal kinase)/P38. 5Z-7-oxozeaenol, a TAK1 inhibitor, blocked the detrimental effects of OTUD7a. Moreover, overexpression of TAK1 abolished the protection of OTUD7a depletion.CONCLUSIONSOur findings, for the first time, provide evidence supporting OTUD7a as a novel promoter of pathological cardiac hypertrophy and indicate that targeting the OTUD7a-TAK1 axis represents a promising therapeutic strategy for cardiac hypertrophy and related heart failure.
{"title":"OTUD7a Accelerates Pathological Cardiac Hypertrophy via TAK1 Activation.","authors":"Lu Gao,Jinhua Cao,Yue Li,Xiaoyang Ji,Qingqing Wu,Sen Guo,Xintong Cai,Ke Li,Yanna Sun,Lili Xiao,Youyou Du,Zhe Zheng,Xiaofang Wang","doi":"10.1161/circresaha.125.326647","DOIUrl":"https://doi.org/10.1161/circresaha.125.326647","url":null,"abstract":"BACKGROUNDCardiac hypertrophy is one of the major causes of heart failure and sudden cardiac death. OTUD7a (OTU domain-containing protein 7a) is identified as a deubiquitinizing enzyme and a possible tumor suppressor. The present study is aimed at exploring the potential role and key downstream effectors of OTUD7a in cardiac hypertrophy.METHODSThe expression level of OTUD7a was detected in the cardiomyocytes with phenylephrine stimuli and the hearts subjected to transverse aortic constriction surgery. Then, the potential effects of OTUD7a on cardiac hypertrophy were evaluated in vivo by using cardiac-specific OTUD7a knockout mice and adeno-associated virus serotype 9-OTUD7a-infected mice. To further explore the direct modulation of OTUD7a on cardiomyocytes, hypertrophic parameters were detected in phenylephrine-stimulated cardiomyocytes with adenovirus system-induced OTUD7a overexpression or depletion. Furthermore, RNA-sequencing and interactome analysis, which were followed by multiple molecular biological methodologies, were combined to identify the direct target and corresponding molecular events contributing to OTUD7a function.RESULTSCardiac hypertrophy stimulates expression of OTUD7a in vitro and in vivo. Our data clearly showed that OTUD7a deficiency alleviates pathological cardiac hypertrophy in the transverse aortic constriction mouse model as well as in phenylephrine-treated cardiomyocytes, whereas overexpression of OTUD7a aggravated hypertrophic heart in vivo and enhanced cardiomyocyte enlargement in vitro. Mechanistically, TAK1 (transforming growth factor-β-activated kinase 1) was identified as a direct and essential target of OTUD7a in cardiac hypertrophy. To be more specific, OTUD7a directly interacts with TAK1 to inhibit the ubiquitination degradation of TAK1 and subsequently increase the phosphorylation levels of TAK1 and its downstream JNK (c-Jun N-terminal kinase)/P38. 5Z-7-oxozeaenol, a TAK1 inhibitor, blocked the detrimental effects of OTUD7a. Moreover, overexpression of TAK1 abolished the protection of OTUD7a depletion.CONCLUSIONSOur findings, for the first time, provide evidence supporting OTUD7a as a novel promoter of pathological cardiac hypertrophy and indicate that targeting the OTUD7a-TAK1 axis represents a promising therapeutic strategy for cardiac hypertrophy and related heart failure.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"105 1","pages":""},"PeriodicalIF":20.1,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145559212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1161/circresaha.125.326412
James B Hayes,Dharmendra Choudhary,Dylan Ritter,Abigail C Neininger-Castro,Alaina H Willet,Leah R Caplan,Yu Wang,Xiao Liu,Nilay Taneja,Zachary C Sanchez,Kyra Smart,David W J Armstrong,Cynthia A Reinhart-King,Qi Liu,Matthew J Tyska,Erdem D Tabdanov,W David Merryman,Quinn S Wells,Ela W Knapik,Dylan T Burnette
BACKGROUNDCardiac sarcomeres generate the fundamental forces of each heartbeat. Cardiac myocytes (CMs) express nonmuscle versions of muscle-specific sarcomere proteins, which have unknown relevance to sarcomere function or heart physiology.METHODSExpression levels of nonmuscle cytoskeletal proteins versus muscle-specific counterparts in CMs were directly compared. Function and subcellular localization of the nonmuscle protein ACTN4 (alpha-actinin 4) in induced pluripotent stem cell-derived CMs were determined using small interfering RNA-mediated knockdown, overexpression, and pharmacological perturbation. Impacts of ACTN4 depletion or knockout on cardiac structure function were evaluated in zebrafish embryos. Left ventricular actn4 levels were evaluated in a mouse model of chronic pressure overload. Human ACTN4 gene variants were tested for association with heart failure with preserved ejection fraction using the BioVU biobank. A meta-analysis was conducted on ventricular data sets of human cardiomyopathies.RESULTSACTN4 expression in human CMs met or exceeded some muscle-specific genes (eg, MYH6). Anti-ACTN4 antibodies colocalized with anti-ACTN2 (alpha-actinin 2) at the sarcomere Z-disc in human, mouse, and zebrafish ventricular tissue. Coimmunoprecipitation and structural modeling suggest a Z-disc ACTN4:ACTN2 complex. ACTN4 depletion from induced pluripotent stem cell-derived CMs resulted in increased sarcomere assembly, decreased sarcomere component turnover, elevated contractile force, and contractility-dependent cellular hypertrophy. Overexpression of an ACTN4 actin-binding chimera suppressed sarcomere assembly. In zebrafish embryos, ACTN4 depletion/knockout induced ventricular hypercontractility and atrial enlargement. Selective modulation of ventricular contractility was sufficient to prevent or phenocopy atrial remodeling. In mice, actn4, but not actn2, was upregulated in the left ventricular following pressure overload. One of 14 ACTN4 single-nucleotide polymorphisms was associated with reduced heart failure with preserved ejection fraction risk in humans, and prepublished studies suggest a pattern of ventricular ACTN4 upregulation in certain human cardiomyopathies.CONCLUSIONSA nonmuscle actinin (ACTN4) populates the cardiac Z-disc. ACTN4 regulates sarcomeric architecture in CMs. ACTN4 influences fractional shortening at the cell level and contractility at the tissue level. Changes in ventricular ACTN4 levels are associated with remodeling and may influence clinical outcomes related to heart failure.
{"title":"Non-Muscle α-Actinin-4 Couples Sarcomere Function to Cardiac Remodeling.","authors":"James B Hayes,Dharmendra Choudhary,Dylan Ritter,Abigail C Neininger-Castro,Alaina H Willet,Leah R Caplan,Yu Wang,Xiao Liu,Nilay Taneja,Zachary C Sanchez,Kyra Smart,David W J Armstrong,Cynthia A Reinhart-King,Qi Liu,Matthew J Tyska,Erdem D Tabdanov,W David Merryman,Quinn S Wells,Ela W Knapik,Dylan T Burnette","doi":"10.1161/circresaha.125.326412","DOIUrl":"https://doi.org/10.1161/circresaha.125.326412","url":null,"abstract":"BACKGROUNDCardiac sarcomeres generate the fundamental forces of each heartbeat. Cardiac myocytes (CMs) express nonmuscle versions of muscle-specific sarcomere proteins, which have unknown relevance to sarcomere function or heart physiology.METHODSExpression levels of nonmuscle cytoskeletal proteins versus muscle-specific counterparts in CMs were directly compared. Function and subcellular localization of the nonmuscle protein ACTN4 (alpha-actinin 4) in induced pluripotent stem cell-derived CMs were determined using small interfering RNA-mediated knockdown, overexpression, and pharmacological perturbation. Impacts of ACTN4 depletion or knockout on cardiac structure function were evaluated in zebrafish embryos. Left ventricular actn4 levels were evaluated in a mouse model of chronic pressure overload. Human ACTN4 gene variants were tested for association with heart failure with preserved ejection fraction using the BioVU biobank. A meta-analysis was conducted on ventricular data sets of human cardiomyopathies.RESULTSACTN4 expression in human CMs met or exceeded some muscle-specific genes (eg, MYH6). Anti-ACTN4 antibodies colocalized with anti-ACTN2 (alpha-actinin 2) at the sarcomere Z-disc in human, mouse, and zebrafish ventricular tissue. Coimmunoprecipitation and structural modeling suggest a Z-disc ACTN4:ACTN2 complex. ACTN4 depletion from induced pluripotent stem cell-derived CMs resulted in increased sarcomere assembly, decreased sarcomere component turnover, elevated contractile force, and contractility-dependent cellular hypertrophy. Overexpression of an ACTN4 actin-binding chimera suppressed sarcomere assembly. In zebrafish embryos, ACTN4 depletion/knockout induced ventricular hypercontractility and atrial enlargement. Selective modulation of ventricular contractility was sufficient to prevent or phenocopy atrial remodeling. In mice, actn4, but not actn2, was upregulated in the left ventricular following pressure overload. One of 14 ACTN4 single-nucleotide polymorphisms was associated with reduced heart failure with preserved ejection fraction risk in humans, and prepublished studies suggest a pattern of ventricular ACTN4 upregulation in certain human cardiomyopathies.CONCLUSIONSA nonmuscle actinin (ACTN4) populates the cardiac Z-disc. ACTN4 regulates sarcomeric architecture in CMs. ACTN4 influences fractional shortening at the cell level and contractility at the tissue level. Changes in ventricular ACTN4 levels are associated with remodeling and may influence clinical outcomes related to heart failure.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"100 1","pages":""},"PeriodicalIF":20.1,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145545085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-12DOI: 10.1161/circresaha.125.326174
Robson A S Santos,Melissa Tainan Silva Dias,Amanda de Sá Martins de Bessa,Carolina Fonseca de Barros,Matheus F Itaborahy,Filipe Alex da Silva,Sthefanie Chaves de Almeida Gonçalves,Lucas Rodrigues-Ribeiro,Kamylle Silva Ferraz,Ana Paula Davel,Natália Nóbrega,Bruno Durante da Silva,Sérgio Scalzo,Pedro Alves Soares,João Batista Rodrigues Dutra,Ivana Lula,Isadora Zhong Liang Ferreira Feng,Uri Flegler Vieira-Machado,Ana Caroline Ventris de Godoy,Adelson Héric Alves Monteiro,Marcos Eliezeck,Bruno Sanches,André Monteiro,Gabriela Magalhães,Nícia Pedreira Soares,Danilo Augusto Alves Pereira,Júlia Rezende Ribeiro,Maria Luiza Dias-Pinto,Leandro Eziquiel de Souza,Amanda de A Silva,Daisy Motta-Santos,Michael Bader,Natália Alenina,Luciano Dos Santos Aggum Capettini,Marco Antônio Peliky Fontes,Andrea Siqueira Haibara,Daniel Campos Vilella,Thiago Verano-Braga,Maria Claudia Irigoyen,Fernanda Ribeiro Marins,Carlos Henrique de Castro,Ana Cristina Simões-E-Silva,Silvia Guatimosim,M Fatima Leite,Maria José Campagnole-Santos
BACKGROUNDThe renin-angiotensin system comprises a biochemical cascade that hydrolyzes angiotensinogen into several different bioactive peptides, which can activate different receptors, promoting plenty of specific effects. This study aimed to evaluate the presence of the putative product of alamandine, the pentapeptide Ala-(1-5) (alamandine-[1-5]), in the circulation and its biological activity.METHODSTo accomplish this, we have used mass spectrometry (MALDI/TOF/TOF, LC-MS/MS) and several methodologies, including isolated blood vessels, isolated perfused hearts, isolated cardiomyocytes, blood pressure recording in freely moving normotensive and SHR, high-resolution echocardiography, central administration (ICV infusion and microinjection in the insular cortex), cell culture (endothelial cells and G-protein-coupled receptors-transfected CHO cells), and wild-type and Mas (Mas receptor proto-oncogene), MrgD (Mas-related G-protein-coupled receptor subtype D), or AT2 (angiotensin II type 2) receptor-deficient mice.RESULTSWe show that Ala-(1-5) is present in the circulation of healthy humans and rodents and promotes many biological central and peripheral actions. A major role for ACE (angiotensin-converting enzyme) activity in the formation of Ala-(1-5) from alamandine in the circulation was observed using plasma samples from angiotensinogen-KO mice. Ala-(1-5) increases baroreflex sensitivity and produces a long-lasting (≈6 hours) antihypertensive effect in SHR, associated with a significant reduction in cardiac output. Additionally, Ala-(1-5) decreases inotropism in isolated perfused hearts and reduces contractility in cardiomyocytes. In CHO-transfected cells, Ala-(1-5) can bind and stimulate NO production through all receptors from the renin-angiotensin system protective arm (Mas, MrgD, and AT2 receptors). On the other hand, the Ala-(1-5) effects on cardiomyocytes and mouse aortic rings were abolished only by MrgD genetic deletion, but not by Mas or AT2 receptor knockout.CONCLUSIONSOur data demonstrate that Ala-(1-5) is a newly identified peptide within the renin-angiotensin system, with strong blood pressure-lowering effects that vary in mechanisms of action among different tissues. Ala-(1-5) has distinct characteristics that differentiate it from the conventional renin-angiotensin system pathways responsible for reducing blood pressure.
{"title":"Identification and Characterization of Alamandine-(1-5), a New Component of the Renin-Angiotensin System.","authors":"Robson A S Santos,Melissa Tainan Silva Dias,Amanda de Sá Martins de Bessa,Carolina Fonseca de Barros,Matheus F Itaborahy,Filipe Alex da Silva,Sthefanie Chaves de Almeida Gonçalves,Lucas Rodrigues-Ribeiro,Kamylle Silva Ferraz,Ana Paula Davel,Natália Nóbrega,Bruno Durante da Silva,Sérgio Scalzo,Pedro Alves Soares,João Batista Rodrigues Dutra,Ivana Lula,Isadora Zhong Liang Ferreira Feng,Uri Flegler Vieira-Machado,Ana Caroline Ventris de Godoy,Adelson Héric Alves Monteiro,Marcos Eliezeck,Bruno Sanches,André Monteiro,Gabriela Magalhães,Nícia Pedreira Soares,Danilo Augusto Alves Pereira,Júlia Rezende Ribeiro,Maria Luiza Dias-Pinto,Leandro Eziquiel de Souza,Amanda de A Silva,Daisy Motta-Santos,Michael Bader,Natália Alenina,Luciano Dos Santos Aggum Capettini,Marco Antônio Peliky Fontes,Andrea Siqueira Haibara,Daniel Campos Vilella,Thiago Verano-Braga,Maria Claudia Irigoyen,Fernanda Ribeiro Marins,Carlos Henrique de Castro,Ana Cristina Simões-E-Silva,Silvia Guatimosim,M Fatima Leite,Maria José Campagnole-Santos","doi":"10.1161/circresaha.125.326174","DOIUrl":"https://doi.org/10.1161/circresaha.125.326174","url":null,"abstract":"BACKGROUNDThe renin-angiotensin system comprises a biochemical cascade that hydrolyzes angiotensinogen into several different bioactive peptides, which can activate different receptors, promoting plenty of specific effects. This study aimed to evaluate the presence of the putative product of alamandine, the pentapeptide Ala-(1-5) (alamandine-[1-5]), in the circulation and its biological activity.METHODSTo accomplish this, we have used mass spectrometry (MALDI/TOF/TOF, LC-MS/MS) and several methodologies, including isolated blood vessels, isolated perfused hearts, isolated cardiomyocytes, blood pressure recording in freely moving normotensive and SHR, high-resolution echocardiography, central administration (ICV infusion and microinjection in the insular cortex), cell culture (endothelial cells and G-protein-coupled receptors-transfected CHO cells), and wild-type and Mas (Mas receptor proto-oncogene), MrgD (Mas-related G-protein-coupled receptor subtype D), or AT2 (angiotensin II type 2) receptor-deficient mice.RESULTSWe show that Ala-(1-5) is present in the circulation of healthy humans and rodents and promotes many biological central and peripheral actions. A major role for ACE (angiotensin-converting enzyme) activity in the formation of Ala-(1-5) from alamandine in the circulation was observed using plasma samples from angiotensinogen-KO mice. Ala-(1-5) increases baroreflex sensitivity and produces a long-lasting (≈6 hours) antihypertensive effect in SHR, associated with a significant reduction in cardiac output. Additionally, Ala-(1-5) decreases inotropism in isolated perfused hearts and reduces contractility in cardiomyocytes. In CHO-transfected cells, Ala-(1-5) can bind and stimulate NO production through all receptors from the renin-angiotensin system protective arm (Mas, MrgD, and AT2 receptors). On the other hand, the Ala-(1-5) effects on cardiomyocytes and mouse aortic rings were abolished only by MrgD genetic deletion, but not by Mas or AT2 receptor knockout.CONCLUSIONSOur data demonstrate that Ala-(1-5) is a newly identified peptide within the renin-angiotensin system, with strong blood pressure-lowering effects that vary in mechanisms of action among different tissues. Ala-(1-5) has distinct characteristics that differentiate it from the conventional renin-angiotensin system pathways responsible for reducing blood pressure.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"53 1","pages":""},"PeriodicalIF":20.1,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145491668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-07Epub Date: 2025-10-15DOI: 10.1161/CIRCRESAHA.125.326378
Drew M Nassal, Shivangi Mohta, Rebecca Shaheen, Haiyan Liu, Omer Cavus, Benjamin Buck, Simon Lococo, Alexander J Winkle, Jolie B Pyles, Nicholas Leahy, Xianyao Xu, Thomas J Hund
Background: Cardiac hypertrophy, defined as a stress-induced increase in heart mass/size, is a major risk factor for adverse cardiovascular events, including heart failure and arrhythmia. Within this general definition, the orientation of cell and organ growth varies considerably depending on stress type and duration, with important implications for cardiac function, yet little is known regarding the mechanisms that regulate hypertrophic orientation. Here, we evaluated the role of the cytoskeletal protein βIV-spectrin and associated prohypertrophic STAT3 (signal transducer and activator of transcription 3) to direct the orientation of hypertrophic growth.
Methods: Transgenic mouse models with altered STAT3 signaling through modified interaction with its scaffolding partner βIV-spectrin, or phospho-regulation of STAT3 directly, were evaluated at baseline, and after transaortic constriction, or aortocaval fistula. Unbiased screening of gene expression from these structurally divergent states was evaluated for pathways responsible for directing myocyte length/width. These pathways were tested in vitro using primary mouse myocytes and in vivo to tune growth patterns for therapeutic intervention.
Results: Loss of βIV-spectrin or direct STAT3 activation promoted a preferential increase in myocyte length over width, resulting in dilation of the left ventricular chamber (eccentric hypertrophy) and decreased systolic function. Conversely, preservation of βIV-spectrin favored an increase in myocyte width without left ventricular dilation (concentric hypertrophy) and preserved systolic function in response to transaortic constriction or aortocaval fistula. Differential expression of genes associated with microtubules, including the trafficking kinesin motor, KIF20A (kinesin family member 20A), were identified in concentric versus eccentric hypertrophic states. In vitro assays revealed a relationship between βIV-spectrin/STAT3 signaling, KIF20A expression, microtubule density, and spatial distribution of mRNA for the sarcomeric gene actc1. Finally, intervention with pharmacological STAT3 inhibition after chronic 6-week transaortic constriction successfully recovered concentric growth with improved systolic function.
Conclusions: These data identify a novel and pivotal role for βIV-spectrin/STAT3 to modify microtubule properties and sarcomeric transcript distribution to direct myocyte geometry in response to chronic stress. These studies further illustrate the unique separation of hypertrophic growth and orientation as distinct pathways in cardiac remodeling.
背景：心脏肥厚，定义为应激引起的心脏质量/大小的增加，是不良心血管事件的主要危险因素，包括心力衰竭和心律失常。在这个一般定义中，细胞和器官的生长方向根据应激类型和持续时间的不同而有很大的变化，这对心脏功能有重要的影响，但关于肥厚取向的调节机制知之甚少。在这里，我们评估了细胞骨架蛋白βIV-spectrin和相关的促肥厚STAT3（信号换能器和转录激活因子3）在指导肥厚生长方向中的作用。方法：通过修饰其支架伙伴β iv -谱蛋白的相互作用或直接磷酸化STAT3来改变STAT3信号的转基因小鼠模型，在基线、经主动脉收缩或主动脉腔瘘后进行评估。对这些结构分化状态的基因表达进行无偏筛选，以评估负责指导肌细胞长度/宽度的途径。这些途径在体外使用原代小鼠肌细胞和体内进行了测试，以调整生长模式以进行治疗干预。结果：βIV-spectrin的缺失或STAT3的直接激活促进了心肌细胞长度比宽度优先增加，导致左心室扩张（偏心肥厚）和收缩功能下降。相反，β iv -谱蛋白的保存有利于心肌细胞宽度的增加，而不会导致左心室扩张（同心肥厚），并在经主动脉收缩或主动脉腔瘘时保留收缩功能。与微管相关的基因的差异表达，包括运输激酶运动，KIF20A（激酶家族成员20A），在同心和偏心肥大状态下被鉴定出来。体外实验揭示了βIV-spectrin/STAT3信号、KIF20A表达、微管密度和肌合成基因actc1 mRNA的空间分布之间的关系。最后，在慢性6周的经主动脉收缩后，通过药物抑制STAT3进行干预，成功地恢复了同心生长，并改善了收缩功能。结论：这些数据确定了βIV-spectrin/STAT3在改变微管特性和肌体转录分布以指导肌细胞几何形状以应对慢性应激方面的新颖和关键作用。这些研究进一步说明了肥厚生长和取向作为心脏重构的不同途径的独特分离。
{"title":"The β<sub>IV</sub>-Spectrin/STAT3 Complex Regulates the Orientation of Cardiac Hypertrophic Growth.","authors":"Drew M Nassal, Shivangi Mohta, Rebecca Shaheen, Haiyan Liu, Omer Cavus, Benjamin Buck, Simon Lococo, Alexander J Winkle, Jolie B Pyles, Nicholas Leahy, Xianyao Xu, Thomas J Hund","doi":"10.1161/CIRCRESAHA.125.326378","DOIUrl":"10.1161/CIRCRESAHA.125.326378","url":null,"abstract":"<p><strong>Background: </strong>Cardiac hypertrophy, defined as a stress-induced increase in heart mass/size, is a major risk factor for adverse cardiovascular events, including heart failure and arrhythmia. Within this general definition, the orientation of cell and organ growth varies considerably depending on stress type and duration, with important implications for cardiac function, yet little is known regarding the mechanisms that regulate hypertrophic orientation. Here, we evaluated the role of the cytoskeletal protein β<sub>IV</sub>-spectrin and associated prohypertrophic STAT3 (signal transducer and activator of transcription 3) to direct the orientation of hypertrophic growth.</p><p><strong>Methods: </strong>Transgenic mouse models with altered STAT3 signaling through modified interaction with its scaffolding partner β<sub>IV</sub>-spectrin, or phospho-regulation of STAT3 directly, were evaluated at baseline, and after transaortic constriction, or aortocaval fistula. Unbiased screening of gene expression from these structurally divergent states was evaluated for pathways responsible for directing myocyte length/width. These pathways were tested in vitro using primary mouse myocytes and in vivo to tune growth patterns for therapeutic intervention.</p><p><strong>Results: </strong>Loss of β<sub>IV</sub>-spectrin or direct STAT3 activation promoted a preferential increase in myocyte length over width, resulting in dilation of the left ventricular chamber (eccentric hypertrophy) and decreased systolic function. Conversely, preservation of β<sub>IV</sub>-spectrin favored an increase in myocyte width without left ventricular dilation (concentric hypertrophy) and preserved systolic function in response to transaortic constriction or aortocaval fistula. Differential expression of genes associated with microtubules, including the trafficking kinesin motor, KIF20A (kinesin family member 20A), were identified in concentric versus eccentric hypertrophic states. In vitro assays revealed a relationship between β<sub>IV</sub>-spectrin/STAT3 signaling, KIF20A expression, microtubule density, and spatial distribution of mRNA for the sarcomeric gene <i>actc1</i>. Finally, intervention with pharmacological STAT3 inhibition after chronic 6-week transaortic constriction successfully recovered concentric growth with improved systolic function.</p><p><strong>Conclusions: </strong>These data identify a novel and pivotal role for β<sub>IV</sub>-spectrin/STAT3 to modify microtubule properties and sarcomeric transcript distribution to direct myocyte geometry in response to chronic stress. These studies further illustrate the unique separation of hypertrophic growth and orientation as distinct pathways in cardiac remodeling.</p>","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"137 11","pages":"1316-1332"},"PeriodicalIF":16.2,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12614771/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145457715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-07Epub Date: 2025-11-06DOI: 10.1161/RES.0000000000000736
{"title":"Meet the First Authors.","authors":"","doi":"10.1161/RES.0000000000000736","DOIUrl":"https://doi.org/10.1161/RES.0000000000000736","url":null,"abstract":"","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"137 11","pages":"1297-1298"},"PeriodicalIF":16.2,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145457746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BACKGROUNDIn high shear rate blood flow, thrombosis often starts with platelet adhesion via the interaction between VWF (von Willebrand factor) and its platelet receptor, the GPIb-IX (glycoprotein Ib-IX) complex. GPIb-IX also induces intracellular signals, mediating VWF-induced platelet activation and enhancing thrombin- and collagen-induced platelet activation. GPIb-IX signaling requires SFK (Src family kinase) Lyn. However, it remains unclear how Lyn mediates GPIb-IX signaling, whether Lyn directly binds to GPIb-IX, and if it is possible to target this signaling node for developing novel antithrombotics.METHODS AND RESULTSLyn directly binds to GPIb (glycoprotein Ib) β subunit between amino acids 144 to 161 at the transmembrane/cytoplasmic domain interface, and this binding is critical for not only the extracellular GPIb-IX ligand-induced intracellular signaling but also transmits outbound signals enhancing VWF-GPIb-IX interaction. A small peptide, mPLβ, derived from the Lyn binding site in GPIbβ, inhibited VWF-induced or α-thrombin-induced GPIbβ-Lyn interaction, Lyn/SFK activation, stable platelet adhesion and aggregation, and, notably, reduced GPIb-mediated platelet adhesion to VWF even in the presence of integrin inhibitors. Biomembrane force probe study further shows that mPLβ reduces the VWF-A1 domain-GPIb adhesion frequency and inhibits force-induced A1-mediated intraplatelet calcium elevation. Importantly, mPLβ formulated as a high-loading peptide nanoparticle inhibited platelet adhesion/aggregation induced by collagen and in vivo arterial thrombosis with a mild effect in prolonging bleeding time.CONCLUSIONSDirect binding of Lyn to GPIbβ mediates 2-way GPIb-IX signaling to activate platelets and modulate VWF-GPIb interaction. Lyn-mediated GPIb-IX signaling is critical for platelet adhesion and aggregation induced by VWF and collagen and in arterial thrombosis. Targeting the Lyn-GPIbβ interaction, thus, has the potential for treating GPIb-IX-dependent thrombosis.
{"title":"Direct Binding of Lyn to GPIbβ Transmits Two-Way GPIb-IX Signaling to Stimulate Platelet Activation and VWF Binding.","authors":"Yaping Zhang,Ying Liang,Amir Hossein Kazemipour Ashkezari,Can Wang,Claire Chang,Yanyan Bai,Xin Huang,Andrew Mack,Haotian Yang,Peiwen Cong,Ni Cheng,Cheng Zhu,Xiaoping Du","doi":"10.1161/circresaha.124.325616","DOIUrl":"https://doi.org/10.1161/circresaha.124.325616","url":null,"abstract":"BACKGROUNDIn high shear rate blood flow, thrombosis often starts with platelet adhesion via the interaction between VWF (von Willebrand factor) and its platelet receptor, the GPIb-IX (glycoprotein Ib-IX) complex. GPIb-IX also induces intracellular signals, mediating VWF-induced platelet activation and enhancing thrombin- and collagen-induced platelet activation. GPIb-IX signaling requires SFK (Src family kinase) Lyn. However, it remains unclear how Lyn mediates GPIb-IX signaling, whether Lyn directly binds to GPIb-IX, and if it is possible to target this signaling node for developing novel antithrombotics.METHODS AND RESULTSLyn directly binds to GPIb (glycoprotein Ib) β subunit between amino acids 144 to 161 at the transmembrane/cytoplasmic domain interface, and this binding is critical for not only the extracellular GPIb-IX ligand-induced intracellular signaling but also transmits outbound signals enhancing VWF-GPIb-IX interaction. A small peptide, mPLβ, derived from the Lyn binding site in GPIbβ, inhibited VWF-induced or α-thrombin-induced GPIbβ-Lyn interaction, Lyn/SFK activation, stable platelet adhesion and aggregation, and, notably, reduced GPIb-mediated platelet adhesion to VWF even in the presence of integrin inhibitors. Biomembrane force probe study further shows that mPLβ reduces the VWF-A1 domain-GPIb adhesion frequency and inhibits force-induced A1-mediated intraplatelet calcium elevation. Importantly, mPLβ formulated as a high-loading peptide nanoparticle inhibited platelet adhesion/aggregation induced by collagen and in vivo arterial thrombosis with a mild effect in prolonging bleeding time.CONCLUSIONSDirect binding of Lyn to GPIbβ mediates 2-way GPIb-IX signaling to activate platelets and modulate VWF-GPIb interaction. Lyn-mediated GPIb-IX signaling is critical for platelet adhesion and aggregation induced by VWF and collagen and in arterial thrombosis. Targeting the Lyn-GPIbβ interaction, thus, has the potential for treating GPIb-IX-dependent thrombosis.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"90 1","pages":""},"PeriodicalIF":20.1,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145440637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-04DOI: 10.1161/circresaha.125.326839
Aarushi Singhal,Stefan Russo,Umesh Kumar Dhawan,Kunzangla Bhutia,Christopher G Bell,Hedayatullah Hayat,Thomas D Nightingale,Monica de Gaetano,Orina Belton,Eoin Brennan,Patricia B Munroe,Catherine Godson,Mary Barry,Carol C Shoulders,Heather L Wilson,Guillermo Velasco,Endre Kiss-Toth,Manikandan Subramanian
BACKGROUNDDefective macrophage efferocytosis is a key driver of chronic nonresolving inflammation in dyslipidemia-associated diseases, such as obesity and atherosclerosis. However, the mechanism by which intracellular lipid accumulation impairs macrophage efferocytosis remains unclear. We hypothesized that lipid-induced endoplasmic reticulum (ER) stress mediates defective macrophage efferocytosis.METHODSBone marrow-derived macrophages were exposed to 7-ketocholesterol or palmitate to induce ER stress, and efferocytosis was quantified by measuring uptake of fluorescently labeled apoptotic cells with microscopy and flow cytometry. Key pathways were interrogated with pharmacological inhibitors, siRNA, and in vivo models, including obese mice and in Ldlr-/- mice with hematopoietic-specific deletion of TRIB3 (Tribbles pseudokinase-3). Human relevance was assessed by testing efferocytosis in macrophages from individuals carrying the TRIB3 Q84R coronary artery disease risk variant (rs2295490) and by examining carotid endarterectomy samples.RESULTSActivation of the ATF4 (activating transcription factor 4) branch of the ER stress pathway in lipid-loaded foamy macrophages led to upregulation of TRIB3, which triggered the downregulation of Rab27a, resulting in impaired focal exocytosis of intracellular membrane pools towards nascent, apoptotic cell-containing phagosomes. The resultant delay in phagosome closure stalled efferocytosis. In obese mice, this impairment was reversed using an ER stress-relieving chemical chaperone and via macrophage-specific knockdown of ATF4 or TRIB3. In atherosclerotic mice, hematopoietic cell-specific deletion of TRIB3 led to increased lesional efferocytosis, decreased plaque necrosis, and increased collagen, which are characteristic of stable plaques. In humans, TRIB3 expression was higher in vulnerable regions of carotid plaques, and macrophages from individuals carrying the gain-of-function TRIB3 Q84R risk variant expressed more TRIB3 and displayed decreased efferocytosis.CONCLUSIONSLipid-induced ER stress impairs macrophage efferocytosis via activation of the ATF4-TRIB3-Rab27a signaling axis, leading to exacerbated plaque necrosis. Targeted disruption of TRIB3 signaling in macrophages represents a novel therapeutic approach to promote efferocytosis and stabilize atherosclerotic plaques.
{"title":"TRIB3 Links Endoplasmic Reticulum Stress to Impaired Efferocytosis in Atherosclerosis.","authors":"Aarushi Singhal,Stefan Russo,Umesh Kumar Dhawan,Kunzangla Bhutia,Christopher G Bell,Hedayatullah Hayat,Thomas D Nightingale,Monica de Gaetano,Orina Belton,Eoin Brennan,Patricia B Munroe,Catherine Godson,Mary Barry,Carol C Shoulders,Heather L Wilson,Guillermo Velasco,Endre Kiss-Toth,Manikandan Subramanian","doi":"10.1161/circresaha.125.326839","DOIUrl":"https://doi.org/10.1161/circresaha.125.326839","url":null,"abstract":"BACKGROUNDDefective macrophage efferocytosis is a key driver of chronic nonresolving inflammation in dyslipidemia-associated diseases, such as obesity and atherosclerosis. However, the mechanism by which intracellular lipid accumulation impairs macrophage efferocytosis remains unclear. We hypothesized that lipid-induced endoplasmic reticulum (ER) stress mediates defective macrophage efferocytosis.METHODSBone marrow-derived macrophages were exposed to 7-ketocholesterol or palmitate to induce ER stress, and efferocytosis was quantified by measuring uptake of fluorescently labeled apoptotic cells with microscopy and flow cytometry. Key pathways were interrogated with pharmacological inhibitors, siRNA, and in vivo models, including obese mice and in Ldlr-/- mice with hematopoietic-specific deletion of TRIB3 (Tribbles pseudokinase-3). Human relevance was assessed by testing efferocytosis in macrophages from individuals carrying the TRIB3 Q84R coronary artery disease risk variant (rs2295490) and by examining carotid endarterectomy samples.RESULTSActivation of the ATF4 (activating transcription factor 4) branch of the ER stress pathway in lipid-loaded foamy macrophages led to upregulation of TRIB3, which triggered the downregulation of Rab27a, resulting in impaired focal exocytosis of intracellular membrane pools towards nascent, apoptotic cell-containing phagosomes. The resultant delay in phagosome closure stalled efferocytosis. In obese mice, this impairment was reversed using an ER stress-relieving chemical chaperone and via macrophage-specific knockdown of ATF4 or TRIB3. In atherosclerotic mice, hematopoietic cell-specific deletion of TRIB3 led to increased lesional efferocytosis, decreased plaque necrosis, and increased collagen, which are characteristic of stable plaques. In humans, TRIB3 expression was higher in vulnerable regions of carotid plaques, and macrophages from individuals carrying the gain-of-function TRIB3 Q84R risk variant expressed more TRIB3 and displayed decreased efferocytosis.CONCLUSIONSLipid-induced ER stress impairs macrophage efferocytosis via activation of the ATF4-TRIB3-Rab27a signaling axis, leading to exacerbated plaque necrosis. Targeted disruption of TRIB3 signaling in macrophages represents a novel therapeutic approach to promote efferocytosis and stabilize atherosclerotic plaques.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"128 1","pages":""},"PeriodicalIF":20.1,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145433893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-27DOI: 10.1161/circresaha.125.326701
Kim Jürgen Krott,Tobias Feige,Agnes Bosbach,Alicia Noeme Beele,Irena Krüger,Friedrich Reusswig,Elena Schickentanz-Dey,Susanne Pfeiler,Alexandra Chadt,Malte Kelm,Norbert Gerdes,Kerstin Jurk,Klytaimnistra Kiouptsi,Christoph Reinhardt,Hadi Al-Hasani,Beate E Kehrel,Saoussen Karray,Madhumita Chatterjee,Hubert Schelzig,Markus Udo Wagenhäuser,Margitta Elvers
BACKGROUNDRed blood cells (RBCs) contribute to hemostasis and thrombosis by interacting with platelets via the FasL-FasR pathway to induce procoagulant activity and thrombin formation. Here, we identified a novel mechanism of platelet-RBC interaction via the CD36-TSP-1 (thrombospondin-1) signaling pathway that plays a prominent role in arterial thrombosis and abdominal aortic aneurysm (AAA) formation and progression. AAA is a life-threatening atherosclerotic-related disease, characterized by the progressive dilation of the abdominal aorta, due to chronic inflammation and extracellular matrix remodeling/degradation within the vessel wall. The objective of the present study was to elucidate a new mechanism of platelet-RBC interaction via the TSP1-CD36 axis and its significance for arterial thrombosis and the pathology of AAA.METHODSTSP-1-deficient and CD36 cell-type-specific (RBCs and platelets) knock-out mice were analyzed in experimental mouse models of arterial thrombosis and AAA. Blood samples from patients with AAA from peripheral sites (laminar flow) and from inside the aneurysm segment (turbulent flow) were analyzed by flow cytometry and compared with age-matched controls.RESULTSAfter platelet activation, platelet-released TSP-1 binds to CD36 at the RBC and platelet membrane to enhance procoagulant activity of both cells, leading to platelet aggregation and thrombosis. Patients with AAA exhibit enhanced procoagulant activity, elevated TSP-1 and CD36 plasma levels, as well as increased exposure of TSP-1 and CD36 at the RBC and platelet surface. In addition, biomechanically stress in the aneurysmal segment reinforces CD36 externalization on RBCs and platelets as well as the formation of platelet-RBC aggregates. In line, genetic deletion of either CD36 (RBC restricted) or TSP-1 protected mice against experimentally induced AAA formation.CONCLUSIONSOur findings imply that CD36 on RBCs and platelets, as well as platelet-released TSP-1, contribute to procoagulant activity, playing a crucial role in arterial thrombosis and AAA progression.
{"title":"Interplay Between Thrombospondin-1 and CD36 Modulates Platelet-RBC Interaction in Thrombosis and Abdominal Aneurysm Formation.","authors":"Kim Jürgen Krott,Tobias Feige,Agnes Bosbach,Alicia Noeme Beele,Irena Krüger,Friedrich Reusswig,Elena Schickentanz-Dey,Susanne Pfeiler,Alexandra Chadt,Malte Kelm,Norbert Gerdes,Kerstin Jurk,Klytaimnistra Kiouptsi,Christoph Reinhardt,Hadi Al-Hasani,Beate E Kehrel,Saoussen Karray,Madhumita Chatterjee,Hubert Schelzig,Markus Udo Wagenhäuser,Margitta Elvers","doi":"10.1161/circresaha.125.326701","DOIUrl":"https://doi.org/10.1161/circresaha.125.326701","url":null,"abstract":"BACKGROUNDRed blood cells (RBCs) contribute to hemostasis and thrombosis by interacting with platelets via the FasL-FasR pathway to induce procoagulant activity and thrombin formation. Here, we identified a novel mechanism of platelet-RBC interaction via the CD36-TSP-1 (thrombospondin-1) signaling pathway that plays a prominent role in arterial thrombosis and abdominal aortic aneurysm (AAA) formation and progression. AAA is a life-threatening atherosclerotic-related disease, characterized by the progressive dilation of the abdominal aorta, due to chronic inflammation and extracellular matrix remodeling/degradation within the vessel wall. The objective of the present study was to elucidate a new mechanism of platelet-RBC interaction via the TSP1-CD36 axis and its significance for arterial thrombosis and the pathology of AAA.METHODSTSP-1-deficient and CD36 cell-type-specific (RBCs and platelets) knock-out mice were analyzed in experimental mouse models of arterial thrombosis and AAA. Blood samples from patients with AAA from peripheral sites (laminar flow) and from inside the aneurysm segment (turbulent flow) were analyzed by flow cytometry and compared with age-matched controls.RESULTSAfter platelet activation, platelet-released TSP-1 binds to CD36 at the RBC and platelet membrane to enhance procoagulant activity of both cells, leading to platelet aggregation and thrombosis. Patients with AAA exhibit enhanced procoagulant activity, elevated TSP-1 and CD36 plasma levels, as well as increased exposure of TSP-1 and CD36 at the RBC and platelet surface. In addition, biomechanically stress in the aneurysmal segment reinforces CD36 externalization on RBCs and platelets as well as the formation of platelet-RBC aggregates. In line, genetic deletion of either CD36 (RBC restricted) or TSP-1 protected mice against experimentally induced AAA formation.CONCLUSIONSOur findings imply that CD36 on RBCs and platelets, as well as platelet-released TSP-1, contribute to procoagulant activity, playing a crucial role in arterial thrombosis and AAA progression.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":"59 1","pages":""},"PeriodicalIF":20.1,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145370623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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