Circulation research最新文献

{"title":"Ferroptosis Mediated Inflammation Promotes Pulmonary Hypertension.","authors":"Felipe Kazmirczak,Neal T Vogel,Sasha Z Prisco,Michael T Patterson,Jeffrey Annis,Ryan T Moon,Lynn M Hartweck,Jenna B Mendelson,Minwoo Kim,Natalia Calixto Mancipe,Todd Markowski,LeAnn Higgins,Candace Guerrero,Ben Kremer,Madelyn L Blake,Christopher J Rhodes,Jesse W Williams,Evan L Brittain,Kurt W Prins","doi":"10.1161/circresaha.123.324138","DOIUrl":"https://doi.org/10.1161/circresaha.123.324138","url":null,"abstract":"BACKGROUNDMitochondrial dysfunction, characterized by impaired lipid metabolism and heightened reactive oxygen species generation, results in lipid peroxidation and ferroptosis. Ferroptosis is an inflammatory mode of cell death that promotes complement activation and macrophage recruitment. In pulmonary arterial hypertension (PAH), pulmonary arterial endothelial cells exhibit cellular phenotypes that promote ferroptosis. Moreover, there is ectopic complement deposition and inflammatory macrophage accumulation in the pulmonary vasculature. However, the effects of ferroptosis inhibition on these pathogenic mechanisms and the cellular landscape of the pulmonary vasculature are incompletely defined.METHODSMultiomics and physiological analyses evaluated how ferroptosis inhibition-modulated preclinical PAH. The impact of adeno-associated virus 1-mediated expression of the proferroptotic protein ACSL (acyl-CoA synthetase long-chain family member) 4 on PAH was determined, and a genetic association study in humans further probed the relationship between ferroptosis and pulmonary hypertension.RESULTSFerrostatin-1, a small-molecule ferroptosis inhibitor, mitigated PAH severity in monocrotaline rats. RNA-sequencing and proteomics analyses demonstrated that ferroptosis was associated with PAH severity. RNA-sequencing, proteomics, and confocal microscopy revealed that complement activation and proinflammatory cytokines/chemokines were suppressed by ferrostatin-1. In addition, ferrostatin-1 combatted changes in endothelial, smooth muscle, and interstitial macrophage abundance and gene activation patterns as revealed by deconvolution RNA-sequencing. Ferroptotic pulmonary arterial endothelial cell damage-associated molecular patterns restructured the transcriptomic signature and mitochondrial morphology, promoted the proliferation of pulmonary artery smooth muscle cells, and created a proinflammatory phenotype in monocytes in vitro. Adeno-associated virus 1-Acsl4 induced an inflammatory PAH phenotype in rats. Finally, single-nucleotide polymorphisms in 6 ferroptosis genes identified a potential link between ferroptosis and pulmonary hypertension severity in the Vanderbilt BioVU repository.CONCLUSIONSFerroptosis promotes PAH through metabolic and inflammatory mechanisms in the pulmonary vasculature.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":20.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449312","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}

{"title":"EPHB4-RASA1 Inhibition of PIEZO1 Ras Activation Drives Lymphatic Valvulogenesis.","authors":"Di Chen,Yipei Tang,Philip E Lapinski,David Wiggins,Eva M Sevick,Michael J Davis,Philip D King","doi":"10.1161/circresaha.124.325383","DOIUrl":"https://doi.org/10.1161/circresaha.124.325383","url":null,"abstract":"BACKGROUNDEPHB4 (ephrin receptor B4) and the RASA1 (p120 Ras GTPase-activating protein) are necessary for the development of lymphatic vessel (LV) valves. However, precisely how EPHB4 and RASA1 regulate LV valve development is unknown. In this study, we examine the mechanisms by which EPHB4 and RASA1 regulate the development of LV valves.METHODSWe used LV-specific inducible EPHB4-deficient mice and EPHB4 knockin mice that express a form of EPHB4 that is unable to bind RASA1 yet retains protein tyrosine kinase activity (EPHB4 2YP) to study the role of EPHB4 and RASA1 in LV valve development in the embryo and LV valve maintenance in adults. We also used human dermal lymphatic endothelial cells in vitro to study the role of EPHB4 and RASA1 as regulators of LV valve specification induced by oscillatory shear stress, considered the trigger for LV valve specification in vivo.RESULTSLV valve specification, continued valve development postspecification, and LV valve maintenance were blocked upon induced loss of EPHB4 in LV. LV specification and maintenance were also impaired in EPHB4 2YP mice. Defects in LV development were reversed by inhibition of the Ras-MAPK (mitogen-activated protein kinase) signaling pathway. In human dermal lymphatic endothelial cells, loss of expression of EPHB4 or its ephrin b2 ligand, loss of expression of RASA1, and inhibition of physical interaction between EPHB4 and RASA1 resulted in dysregulated oscillatory shear stress-induced Ras-MAPK activation and impaired expression of LV specification markers that could be rescued by Ras-MAPK pathway inhibition. The same results were observed when human dermal lymphatic endothelial cells were stimulated with the Yoda1 agonist of the PIEZO1 oscillatory shear stress sensor. Although Yoda1 increased the number of LV valves when administered to wild-type embryos, it did not increase LV valve number when administered to EPHB4 2YP embryos.CONCLUSIONSEPHB4 is necessary for LV valve specification, continued valve development postspecification, and valve maintenance. LV valve specification requires physical interaction between EPHB4 and RASA1 to limit activation of the Ras-MAPK pathway in lymphatic endothelial cells. Specifically, EPHB4-RASA1 physical interaction is necessary to dampen Ras-MAPK activation induced through the PIEZO1 oscillatory shear stress sensor. These findings reveal the mechanism by which EPHB4 and RASA1 regulate the development of LV valves.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":20.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449313","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}

{"title":"Shear-Sensing by C-Reactive Protein: Linking Aortic Stenosis and Inflammation.","authors":"Johannes Zeller,Julia Loseff-Silver,Khashayar Khoshmanesh,Sara Baratchi,Austin Lai,Tracy L Nero,Abhishek Roy,Anna Watson,Nalin Dayawansa,Prerna Sharma,Anastasia Barbaro-Wahl,Yung Chih Chen,Mitchell Moon,Mark Louis P Vidallon,Angela Huang,Julia Thome,Karen S Cheung Tung Shing,Dalton Harvie,Marie N Bongiovanni,David Braig,Craig J Morton,Nay M Htun,Dion Stub,Anthony Walton,John Horowitz,Xiaowei Wang,Geoffrey Pietersz,Michael W Parker,Steffen U Eisenhardt,James D McFadyen,Karlheinz Peter","doi":"10.1161/circresaha.124.324248","DOIUrl":"https://doi.org/10.1161/circresaha.124.324248","url":null,"abstract":"BACKGROUNDCRP (C-reactive protein) is a prototypical acute phase reactant. Upon dissociation of the pentameric isoform (pCRP [pentameric CRP]) into its monomeric subunits (mCRP [monomeric CRP]), it exhibits prothrombotic and proinflammatory activity. Pathophysiological shear rates as observed in aortic valve stenosis (AS) can influence protein conformation and function as observed with vWF (von Willebrand factor). Given the proinflammatory function of dissociated CRP and the important role of inflammation in the pathogenesis of AS, we investigated whether shear stress can modify CRP conformation and induce inflammatory effects relevant to AS.METHODSTo determine the effects of pathological shear rates on the function of human CRP, pCRP was subjected to pathophysiologically relevant shear rates and analyzed using biophysical and biochemical methods. To investigate the effect of shear on CRP conformation in vivo, we used a mouse model of arterial stenosis. Levels of mCRP and pCRP were measured in patients with severe AS pre- and post-transcatheter aortic valve implantation, and the presence of CRP was investigated on excised valves from patients undergoing aortic valve replacement surgery for severe AS. Microfluidic models of AS were then used to recapitulate the shear rates of patients with AS and to investigate this shear-dependent dissociation of pCRP and its inflammatory function.RESULTSExposed to high shear rates, pCRP dissociates into its proinflammatory monomers (mCRP) and aggregates into large particles. Our in vitro findings were further confirmed in a mouse carotid artery stenosis model, where the administration of human pCRP led to the deposition of mCRP poststenosis. Patients undergoing transcatheter aortic valve implantation demonstrated significantly higher mCRP bound to circulating microvesicles pre-transcatheter aortic valve implantation compared with post-transcatheter aortic valve implantation. Excised human stenotic aortic valves display mCRP deposition. pCRP dissociated in a microfluidic model of AS and induces endothelial cell activation as measured by increased ICAM-1 and P-selectin expression. mCRP also induces platelet activation and TGF-β (transforming growth factor beta) expression on platelets.CONCLUSIONSWe identify a novel mechanism of shear-induced pCRP dissociation, which results in the activation of cells central to the development of AS. This novel mechanosensing mechanism of pCRP dissociation to mCRP is likely also relevant to other pathologies involving increased shear rates, such as in atherosclerotic and injured arteries.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":20.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449310","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}

{"title":"Latrophilin-2 Deletion in Cardiomyocyte Disrupts Cell Junction, Leading to D-CMP.","authors":"Minjun Kang,Choon-Soo Lee,HyunJu Son,Jeongha Lee,Jaewon Lee,Hyun Ju Seo,Moo-Kang Kim,Murim Choi,Hyun-Jai Cho,Hyo-Soo Kim","doi":"10.1161/circresaha.124.324670","DOIUrl":"https://doi.org/10.1161/circresaha.124.324670","url":null,"abstract":"BACKGROUNDLatrophilin-2 (Lphn2), an adhesive GPCR (G protein-coupled receptor), was found to be a specific marker of cardiac progenitors during the differentiation of pluripotent stem cells into cardiomyocytes or during embryonic heart development in our previous studies. Its role in adult heart physiology, however, remains unclear.METHODSThe embryonic lethality resulting from Lphn2 deletion necessitates the establishment of cardiomyocyte-specific, tamoxifen-inducible Lphn2 knockout mice, which was achieved by crossing Lphn2flox/flox mice with mice having MerCreMer (tamoxifen-inducible Cre recombinase) under the α-myosin heavy chain promoter.RESULTSTamoxifen treatment for several days completely suppressed Lphn2 expression, specifically in the myocardium, and induced the dilated cardiomyopathy (D-CMP) phenotype with serious arrhythmia and sudden death in a short period of time. Transmission electron microscopy showed mitochondrial abnormalities, blurred Z-discs, and dehiscent myofibrils. The D-CMP phenotype, or heart failure, worsened during myocardial infarction. In a mechanistic study of D-CMP, Lphn2 knockout suppressed PGC-1α and mitochondrial dysfunction, leading to the accumulation of reactive oxygen species and the global suppression of junctional molecules, such as N-cadherin (adherens junction), DSC-2 (desmocollin-2; desmosome), and connexin-43 (gap junction), leading to the dehiscence of cardiac myofibers and serious arrhythmia. In an experimental therapeutic trial, activators of p38-MAPK, which is a downstream signaling molecule of Lphn2, remarkably rescued the D-CMP phenotype of Lphn2 knockout in the heart by restoring PGC-1α and mitochondrial function and recovering global junctional proteins.CONCLUSIONSLphn2 is a critical regulator of heart integrity by controlling mitochondrial functions and cell-to-cell junctions in cardiomyocytes. Its deficiency leads to D-CMP, which can be rescued by activators of the p38-MAPK pathway.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":20.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449311","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}

{"title":"DNA Methylation Age Mediates Effect of Metabolic Profile on Cardiovascular and General Aging.","authors":"Jiahui Si, Yu Ma, Canqing Yu, Dianjianyi Sun, Yuanjie Pang, Pei Pei, Ling Yang, Iona Y Millwood, Robin G Walters, Yiping Chen, Huaidong Du, Xiaoyan Zheng, Daniel Avery, Junshi Chen, Zhengming Chen, Liming Liang, Liming Li, Jun Lv","doi":"10.1161/CIRCRESAHA.124.325066","DOIUrl":"10.1161/CIRCRESAHA.124.325066","url":null,"abstract":"<p><strong>Background: </strong>Alterations in lipid metabolism and DNA methylation are 2 hallmarks of aging. Connecting metabolomic, epigenomic, and aging outcomes help unravel the complex mechanisms underlying aging. We aimed to assess whether DNA methylation clocks mediate the association of circulating metabolites with incident atherosclerotic cardiovascular disease (ASCVD) and frailty.</p><p><strong>Methods: </strong>The China Kadoorie Biobank is a prospective cohort study with a baseline survey from 2004 to 2008 and a follow-up period until December 31, 2018. We used the Infinium Methylation EPIC BeadChip to measure the methylation levels of 988 participants' baseline blood leukocyte DNA. Metabolite profiles, including lipoprotein particles, lipid constituents, and various circulating metabolites, were measured using quantitative nuclear magnetic resonance. The pace of DNA methylation age acceleration (AA) was calculated using 5 widely used epigenetic clocks (the first generation: Horvath, Hannum, and Li; the second generation: Grim and Pheno). Incident ASCVD was ascertained through linkage with local death and disease registries and national health insurance databases, supplemented by active follow-up. The frailty index was constructed using medical conditions, symptoms, signs, and physical measurements collected at baseline.</p><p><strong>Results: </strong>A total of 508 incident cases of ASCVD were documented during a median follow-up of 9.5 years. The first generation of epigenetic clocks was associated with the risk of ASCVD (<i>P</i><0.05). For each SD increment in LiAA, HorvathAA, and HannumAA, the corresponding hazard ratios for ASCVD risk were 1.16 (1.05-1.28), 1.10 (1.00-1.22), and 1.17 (1.04-1.31), respectively. Only LiAA mediated the association of various metabolites (lipids, fatty acids, histidine, and inflammatory biomarkers) with ASCVD, with the mediating proportion reaching up to 15% for the diameter of low-density lipoprotein (<i>P</i>=1.2×10^-2). Regarding general aging, a 1-SD increase in GrimAA was associated with an average increase of 0.10 in the frailty index (<i>P</i>=2.0×10^-3), and a 33% and 63% increased risk of prefrailty and frailty at baseline (<i>P</i>=1.5×10^-2 and 5.8×10^-2), respectively; this association was not observed with other clocks. GrimAA mediated the effect of various lipids, fatty acids, glucose, lactate, and inflammatory biomarkers on the frailty index, with the mediating proportion reaching up to 22% for triglycerides in very small-sized very low-density lipoprotein (<i>P</i>=6.0×10^-3).</p><p><strong>Conclusions: </strong>These findings suggest that epigenomic mechanisms may play a role in the associations between circulating metabolites and the aging process. Different mechanisms underlie the first and second generations of DNA methylation age in cardiovascular and general aging.</p>","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":16.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142281155","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}

{"title":"Experimental TET2 Clonal Hematopoiesis Predisposes to Renal Hypertension Through an Inflammasome-Mediated Mechanism.","authors":"Ariel H Polizio, Lucila Marino, Kyung-Duk Min, Yoshimitsu Yura, Luca Rolauer, Jesse D Cochran, Megan A Evans, Eunbee Park, Heather Doviak, Emiri Miura-Yura, Miranda E Good, Abigail G Wolpe, Maria Grandoch, Brant E Isakson, Kenneth Walsh","doi":"10.1161/CIRCRESAHA.124.324492","DOIUrl":"10.1161/CIRCRESAHA.124.324492","url":null,"abstract":"<p><strong>Background: </strong>Hypertension incidence increases with age and represents one of the most prevalent risk factors for cardiovascular disease. Clonal events in the hematopoietic system resulting from somatic mutations in driver genes are prevalent in elderly individuals who lack overt hematologic disorders. This condition is referred to as age-related clonal hematopoiesis (CH), and it is a newly recognized risk factor for cardiovascular disease. It is not known whether CH and hypertension in the elderly are causally related and, if so, what are the mechanistic features.</p><p><strong>Methods: </strong>A murine model of adoptive bone marrow transplantation was employed to examine the interplay between Tet2 (ten-eleven translocation methylcytosine dioxygenase 2) clonal hematopoiesis and hypertension.</p><p><strong>Results: </strong>In this model, a subpressor dose of Ang II (angiotensin II) resulted in elevated systolic and diastolic blood pressure as early as 1 day after challenge. These conditions led to the expansion of Tet2-deficient proinflammatory monocytes and bone marrow progenitor populations. Tet2 deficiency promoted renal CCL5 (C-C motif ligand 5) chemokine expression and macrophage infiltration into the kidney. Consistent with macrophage involvement, Tet2 deficiency in myeloid cells promoted hypertension when mice were treated with a subpressor dose of Ang II. The hematopoietic Tet2^-/- condition led to sodium retention, renal inflammasome activation, and elevated levels of IL (interleukin)-1β and IL-18. Analysis of the sodium transporters indicated NCC (sodium-chloride symporter) and NKCC2 (Na⁺-K⁺-Cl^- cotransporter 2) activation at residues Thr53 and Ser105, respectively. Administration of the NLRP3 (NLR family pyrin domain containing 3) inflammasome inhibitor MCC950 reversed the hypertensive state, sodium retention, and renal transporter activation.</p><p><strong>Conclusions: </strong>Tet2-mediated CH sensitizes mice to a hypertensive stimulus. Mechanistically, the expansion of hematopoietic Tet2-deficient cells promotes hypertension due to elevated renal immune cell infiltration and activation of the NLRP3 inflammasome, with consequences on sodium retention. These data indicate that carriers of TET2 CH could be at elevated risk for the development of hypertension and that immune modulators could be useful in treating hypertension in this patient population.</p>","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":16.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11519839/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132008","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}

{"title":"Meet the First Authors.","authors":"","doi":"10.1161/RES.0000000000000696","DOIUrl":"https://doi.org/10.1161/RES.0000000000000696","url":null,"abstract":"","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":16.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399565","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}

{"title":"Salt and CHIP: <i>Tet2</i>-CH Aggravates Salt-Sensitive Hypertension in Mice.","authors":"Caitlyn Vlasschaert, Steven D Crowley, Alexander G Bick","doi":"10.1161/CIRCRESAHA.124.325364","DOIUrl":"10.1161/CIRCRESAHA.124.325364","url":null,"abstract":"","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":16.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11512599/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399566","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}

{"title":"Chronic Activation of Tubulin Tyrosination Improves Heart Function.","authors":"Niels Pietsch, Christina Y Chen, Svenja Kupsch, Lucas Bacmeister, Birgit Geertz, Marisol Herrera-Rivero, Bente Siebels, Hannah Voß, Elisabeth Krämer, Ingke Braren, Dirk Westermann, Hartmut Schlüter, Giulia Mearini, Saskia Schlossarek, Jolanda van der Velden, Matthew A Caporizzo, Diana Lindner, Benjamin L Prosser, Lucie Carrier","doi":"10.1161/CIRCRESAHA.124.324387","DOIUrl":"10.1161/CIRCRESAHA.124.324387","url":null,"abstract":"<p><strong>Background: </strong>Hypertrophic cardiomyopathy (HCM) is the most common cardiac genetic disorder caused by sarcomeric gene variants and associated with left ventricular hypertrophy and diastolic dysfunction. The role of the microtubule network has recently gained interest with the findings that microtubule detyrosination (dTyr-MT) is markedly elevated in heart failure. Acute reduction of dTyr-MT by inhibition of the detyrosinase (VASH [vasohibin]/SVBP [small VASH-binding protein] complex) or activation of the tyrosinase (TTL [tubulin tyrosine ligase]) markedly improved contractility and reduced stiffness in human failing cardiomyocytes and thus posed a new perspective for HCM treatment. In this study, we tested the impact of chronic tubulin tyrosination in an HCM mouse model (<i>Mybpc3</i> knock-in), in human HCM cardiomyocytes, and in SVBP-deficient human engineered heart tissues (EHTs).</p><p><strong>Methods: </strong>Adeno-associated virus serotype 9-mediated TTL transfer was applied in neonatal wild-type rodents, in 3-week-old knock-in mice, and in HCM human induced pluripotent stem cell-derived cardiomyocytes.</p><p><strong>Results: </strong>We show (1) TTL for 6 weeks dose dependently reduced dTyr-MT and improved contractility without affecting cytosolic calcium transients in wild-type cardiomyocytes; (2) TTL for 12 weeks reduced the abundance of dTyr-MT in the myocardium, improved diastolic filling, compliance, cardiac output, and stroke volume in knock-in mice; (3) TTL for 10 days normalized cell area in HCM human induced pluripotent stem cell-derived cardiomyocytes; (4) TTL overexpression activated transcription of tubulins and other cytoskeleton components but did not significantly impact the proteome in knock-in mice; (5) SVBP-deficient EHTs exhibited reduced dTyr-MT levels, higher force, and faster relaxation than TTL-deficient and wild-type EHTs. RNA sequencing and mass spectrometry analysis revealed distinct enrichment of cardiomyocyte components and pathways in SVBP-deficient versus TTL-deficient EHTs.</p><p><strong>Conclusions: </strong>This study provides the first proof of concept that chronic activation of tubulin tyrosination in HCM mice and in human EHTs improves heart function and holds promise for targeting the nonsarcomeric cytoskeleton in heart disease.</p>","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":16.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11465905/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142281154","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}

{"title":"Arg92Leu-cTnT Alters the cTnC-cTnI Interface Disrupting PKA-Mediated Relaxation.","authors":"Melissa L Lynn,Jesus Jimenez,Romi L Castillo,Catherine Vasquez,Matthew M Klass,Anthony Baldo,Andrew Kim,Cyonna Gibson,Anne M Murphy,Jil C Tardiff","doi":"10.1161/circresaha.124.325223","DOIUrl":"https://doi.org/10.1161/circresaha.124.325223","url":null,"abstract":"BACKGROUNDImpaired left ventricular relaxation, high filling pressures, and dysregulation of Ca2+ homeostasis are common findings contributing to diastolic dysfunction in hypertrophic cardiomyopathy (HCM). Studies have shown that impaired relaxation is an early observation in the sarcomere-gene-positive preclinical HCM cohort, which suggests the potential involvement of myofilament regulators in relaxation. A molecular-level understanding of mechanism(s) at the level of the myofilament is lacking. We hypothesized that mutation-specific, allosterically mediated, changes to the cTnC (cardiac troponin C)-cTnI (cardiac troponin I) interface can account for the development of early-onset diastolic dysfunction via decreased PKA accessibility to cTnI.METHODSHCM mutations R92L-cTnT (cardiac troponin T; Arg92Leu) and Δ160E-cTnT (Glu160 deletion) were studied in vivo, in vitro, and in silico via 2-dimensional echocardiography, Western blotting, ex vivo hemodynamics, stopped-flow kinetics, time-resolved fluorescence resonance energy transfer, and molecular dynamics simulations.RESULTSThe HCM-causative mutations R92L-cTnT and Δ160E-cTnT result in different time-of-onset diastolic dysfunction. R92L-cTnT demonstrated early-onset diastolic dysfunction accompanied by a localized decrease in phosphorylation of cTnI. Constitutive phosphorylation of cTnI (cTnI-D23D24) was sufficient to recover diastolic function to non-Tg levels only for R92L-cTnT. Mutation-specific changes in Ca2+ dissociation rates associated with R92L-cTnT reconstituted with cTnI-D23D24 led us to investigate potential involvement of structural changes in the cTnC-cTnI interface as an explanation for these observations. We probed the interface via time-resolved fluorescence resonance energy transfer revealing a repositioning of the N-terminus of cTnI, closer to cTnC, and concomitant decreases in distance distributions at sites flanking the PKA consensus sequence. Implementing time-resolved fluorescence resonance energy transfer distances as constraints into our atomistic model identified additional electrostatic interactions at the consensus sequence.CONCLUSIONSThese data show that the early diastolic dysfunction observed in a subset of HCM is attributable to allosterically mediated structural changes at the cTnC-cTnI interface that impair accessibility of PKA, thereby blunting β-adrenergic responsiveness and identifying a potential molecular target for therapeutic intervention.","PeriodicalId":10147,"journal":{"name":"Circulation research","volume":null,"pages":null},"PeriodicalIF":20.1,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328759","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}