Cardiovascular diseases are the most common cause of worldwide morbidity and mortality, highlighting the necessity for advanced therapeutic strategies. Ca2+/calmodulin-dependent protein kinase IIδ (CaMKIIδ) is a prominent inducer of various cardiac disorders, which is mediated by two oxidation-sensitive methionine residues within the regulatory domain. We previously showed that ablation of CaMKIIδ oxidation by CRISPR-Cas9 base editing enables the heart to recover function from otherwise severe damage following ischemia/reperfusion (IR) injury. Here, we extended this therapeutic concept toward potential clinical translation. We generated a humanized CAMK2D knockin mouse model, in which the genomic sequence encoding the entire regulatory domain was replaced with the human sequence. This enabled comparison and optimization of two different editing strategies for the human genome in mice. To edit CAMK2D in vivo, we packaged the optimized editing components into an engineered myotropic adeno-associated virus (MyoAAV 2A), which enabled efficient delivery at a very low AAV dose into the humanized mice at the time of IR injury. CAMK2D-edited mice recovered cardiac function, showed improved exercise performance, and were protected from myocardial fibrosis, which was otherwise observed in injured control mice post-IR. Our findings identify a potentially effective strategy for cardioprotection in response to oxidative damage.
Simon Lebek, Xurde M. Caravia, Leon G. Straub, Damir Alzhanov, Wei Tan, Hui Li, John R. McAnally, Kenian Chen, Lin Xu, Philipp E. Scherer, Ning Liu, Rhonda Bassel-Duby, Eric N. Olson
The metabolic syndrome, today affecting more than 20% of the US population, is a group of five conditions that often co-exist and that strongly predispose to cardiovascular disease. How these conditions are linked mechanistically remains unclear, especially two of these: obesity and elevated blood pressure. Here we show that high fat consumption in mice leads to the accumulation of lipid droplets in endothelial cells throughout the organism, and that lipid droplet accumulation in endothelium suppresses endothelial nitric oxide synthase (eNOS), reduces NO production, elevates blood pressure, and accelerates atherosclerosis. Mechanistically, the accumulation of lipid droplets destabilizes eNOS mRNA and activates an endothelial inflammatory signaling cascade that suppresses eNOS and NO production. Pharmacological prevention of lipid droplet formation reverses the suppression of NO production in cell culture and in vivo, and blunts blood pressure elevation in response to high fat diet. These results highlight lipid droplets as a critical and unappreciated component of endothelial cell biology, explain how lipids increase blood pressure acutely, and provide a mechanistic account for the epidemiological link between obesity and elevated blood pressure.
Boa Kim, Wencao Zhao, Soon Yew Tang, Michael G. Levin, Ayon Ibrahim, Yifan Yang, Emilia M. Roberts, Ling Lai, Jian Li, Richard K. Assoian, Garret A. FitzGerald, Zoltan Arany
Identifying branched-chain amino acid (BCAA) oxidation enzymes in the nucleus led us to predict that they are a source of propionyl-CoA that are utilized for histone propionylation and, thereby, regulate gene expression. To investigate the effects of BCAA on the development of cardiac hypertrophy and failure, we applied pressure overload on the heart in mice maintained on a diet with standard levels of BCAA (BCAA-control) versus a BCAA-free diet. The former was associated with an increase in histone H3K23-propionyl (H3K23Pr) at the promoters of upregulated genes [e.g., cell signaling and extracellular matrix genes] and a decrease at the promoters of downregulated genes [e.g., electron transfer complex (ETC I-V) and metabolic genes]. Intriguingly, the BCAA-free diet tempered the increases in promoter-H3K23Pr, thus, reducing collagen gene expression and fibrosis during cardiac hypertrophy. Conversely, the BCAA-free diet inhibited the reductions in promoter-H3K23Pr and abolished the downregulation of ETC I-V subunits, enhanced mitochondrial respiration, and curbed progression of cardiac hypertrophy. Thus, lowering the intake of BCAA reduces pressure overload-induced changes in histone propionylation-dependent gene expression in the heart, which retards the development of cardiomyopathy.
Zhi Yang, Minzhen He, Julianne Austin, Danish Sayed, Maha Abdellatif
Red blood cells (RBCs) mediate cardioprotection via nitric oxide–like bioactivity, but the signaling and the identity of any mediator released by the RBCs remains unknown. We investigated whether RBCs exposed to hypoxia release a cardioprotective mediator and explored the nature of this mediator. Perfusion of isolated hearts subjected to ischemia-reperfusion with extracellular supernatant from mouse RBCs exposed to hypoxia resulted in improved postischemic cardiac function and reduced infarct size. Hypoxia increased extracellular export of cyclic guanosine monophosphate (cGMP) from mouse RBCs, and exogenous cGMP mimicked the cardioprotection induced by the supernatant. The protection induced by hypoxic RBCs was dependent on RBC-soluble guanylate cyclase and cGMP transport and was sensitive to phosphodiesterase 5 and activated cardiomyocyte protein kinase G. Oral administration of nitrate to mice to increase nitric oxide bioactivity further enhanced the cardioprotective effect of hypoxic RBCs. In a placebo-controlled clinical trial, a clear cardioprotective, soluble guanylate cyclase–dependent effect was induced by RBCs collected from patients randomized to 5 weeks nitrate-rich diet. It is concluded that RBCs generate and export cGMP as a response to hypoxia, mediating cardioprotection via a paracrine effect. This effect can be further augmented by a simple dietary intervention, suggesting preventive and therapeutic opportunities in ischemic heart disease.
Jiangning Yang, Michaela L. Sundqvist, Xiaowei Zheng, Tong Jiao, Aida Collado, Yahor Tratsiakovich, Ali Mahdi, John Tengbom, Evanthia Mergia, Sergiu-Bogdan Catrina, Zhichao Zhou, Mattias Carlström, Takaaki Akaike, Miriam M. Cortese-Krott, Eddie Weitzberg, Jon O. Lundberg, John Pernow
Chronic kidney disease (CKD) is associated with a higher risk of atrial fibrillation (AF). The mechanistic link between CKD and AF remains elusive. Interleukin (IL)-1β, a main effector of ‘NLR-family pyrin domain-containing 3’ (NLRP3) inflammasome activation, is a key modulator of conditions associated with inflammation, such as AF and CKD. Circulating IL-1β levels were elevated in CKD-patients with AF vs CKD-patients in sinus rhythm. Moreover, NLRP3-activity was enhanced in atria of CKD-patients. To elucidate the role of NLRP3/IL-1β signaling in the pathogenesis of CKD-induced AF, wildtype (WT) and Nlrp3-/- mice were subjected to a two-stage subtotal nephrectomy protocol to induce CKD. 4-weeks post-surgery, IL-1β levels in serum and atrial tissue were increased in WT-CKD (vs WT-sham) mice. The increased susceptibility to pacing-induced AF and longer AF-duration in WT-CKD mice were associated with electrical remodeling, enlarged atria, and atrial fibrosis. Genetic inhibition of NLRP3 in Nlrp3-/- mice or neutralizing anti-IL-1β antibodies effectively reduced IL-1β-levels, normalized left atrial dimensions, reduced fibrosis and the AF-incidence. These data suggest that CKD creates a substrate for AF development by activating the NLRP3 inflammasome in atria, which is associated with structural and electrical remodeling. Neutralizing IL-1β antibodies may be beneficial for the prevention of CKD-induced AF.
Jia Song, Jose Alberto Navarro-Garcia, Jiao Wu, Arnela Saljic, Issam H. Abu-Taha, Luge Li, Satadru K. Lahiri, Joshua A. Keefe, Yuriana Aguilar-Sanchez, Oliver M. Moore, Yue Yuan, Xiaolei Wang, Markus Kamler, William E. Mitch, Gema Ruiz-Hurtado, Zhaoyong Hu, Sandhya S. Thomas, Dobromir Dobrev, Xander H.T. Wehrens, Na Li
Clonal hematopoiesis of indeterminate potential (CHIP) is associated with an increased risk of cardiovascular diseases (CVD), putatively via inflammasome activation. We pursued an inflammatory gene modifier scan for CHIP-associated CVD risk among 424,651 UK Biobank participants. CHIP was identified using whole exome sequencing data of blood DNA and modeled both as a composite and for common drivers (DNMT3A, TET2, ASXL1, and JAK2) separately. We developed predicted gene expression scores for 26 inflammasome-related genes and assessed how they modify CHIP-associated CVD risk. We identify IL1RAP as a potential key molecule for CHIP-associated CVD risk across genes and increased AIM2 gene expression leading to heightened JAK2- and ASXL1-associated CVD risks. We show that CRISPR-induced Asxl1 mutated murine macrophages have a particularly heightened inflammatory response to AIM2 agonism, associated with an increased DNA damage response, as well as increased IL-10 secretion, mirroring a CVD protective effect of IL10 expression in ASXL1 CHIP. Our study supports the role of inflammasomes in CHIP-associated CVD and provides new evidence to support gene-specific strategies to address CHIP-associated CVD risk.
Zhi Yu, Trevor P. Filder, Yunfeng Ruan, Caitlyn Vlasschaert, Tetsushi Nakao, Md Mesbah Uddin, Taralynn Mack, Abhishek Niroula, J. Brett Heimlich, Seyedeh M. Zekavat, Christopher J. Gibson, Gabriel K. Griffin, Yuxuan Wang, Gina M. Peloso, Nancy Heard-Costa, Daniel Levy, Ramachandran S. Vasan, François Aguet, Kristin G. Ardlie, Kent D. Taylor, Stephen S. Rich, Jerome I. Rotter, Peter Libby, Siddhartha Jaiswal, Benjamin L. Ebert, Alexander G. Bick, Alan R. Tall, Pradeep Natarajan
Hypertrophic cardiomyopathy (HCM) is the most prominent cause of sudden cardiac death in young individuals. Due to heterogeneity in the clinical manifestations, conventional HCM drugs have limitations for mitochondrial hypertrophic cardiomyopathy. Discovering more effective compounds would be of substantial benefit for further elucidating the pathogenic mechanisms of HCM and treating patients with this condition. We previously reported the MT-RNR2 variant associated with HCM that results in mitochondrial dysfunction. Here, we screened a mitochondria-associated compound library by quantifying the mitochondrial membrane potential of HCM cybrids and the survival rate of HCM induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) in galactose media. 1-Deoxynojirimycin (DNJ) was identified to rescue mitochondrial function by targeting optic atrophy protein 1 (OPA1) to promote its oligomerization, leading to reconstruction of the mitochondrial cristae. DNJ treatment further recovered the physiological properties of HCM iPSC-CMs by improving Ca2+ homeostasis and electrophysiological properties. An angiotensin II-induced cardiac hypertrophy mouse model further verified the efficacy of DNJ in promoting cardiac mitochondrial function and alleviating cardiac hypertrophy in vivo. These results demonstrated that DNJ could be a potential mitochondrial rescue agent for mitochondrial hypertrophic cardiomyopathy. Our findings will help elucidate the mechanism of HCM and provide a potential therapeutic strategy.
Qianqian Zhuang, Fengfeng Guo, Lei Fu, Yufei Dong, Shaofang Xie, Xue Ding, Shuangyi Hu, Xuanhao D. Zhou, Yangwei Jiang, Hui Zhou, Yue Qiu, Zhaoying Lei, Mengyao Li, Huajian Cai, Mingjie Fan, Lingjie Sang, Yong Fu, Dong Zhang, Aifu Lin, Xu Li, Tilo Kunath, Ruhong Zhou, Ping Liang, Zhong Liu, Qingfeng Yan
Despite the prevalence of pericytes in the microvasculature of the heart, their role during ischemia-induced remodeling remains unclear. We used multiple lineage-tracing mouse models and found that pericytes migrated to the injury site and expressed profibrotic genes, coinciding with increased vessel leakage after myocardial infarction (MI). Single-cell RNA-Seq of cardiac pericytes at various time points after MI revealed the temporally regulated induction of genes related to vascular permeability, extracellular matrix production, basement membrane degradation, and TGF-β signaling. Deleting TGF-β receptor 1 in chondroitin sulfate proteoglycan 4–expressing (Cspg4-expressing) cells reduced fibrosis following MI, leading to a transient improvement in the cardiac ejection fraction. Furthermore, genetic ablation of Cspg4-expressing cells resulted in excessive vascular permeability, a decline in cardiac function, and increased mortality in the second week after MI. These data reveal an essential role for cardiac pericytes in the control of vascular homeostasis and the fibrotic response after acute ischemic injury, information that will help guide the development of novel strategies to preserve vascular integrity and attenuate pathological cardiac remodeling.
Pearl Quijada, Shuin Park, Peng Zhao, Kamal S.S. Kolluri, David Wong, Kevin D. Shih, Kai Fang, Arash Pezhouman, Lingjun Wang, Ali Daraei, Matthew D. Tran, Elle M. Rathbun, Kimberly N. Burgos Villar, Maria L. Garcia-Hernandez, Thanh T.D. Pham, Charles J. Lowenstein, M. Luisa Iruela-Arispe, S. Thomas Carmichael, Eric M. Small, Reza Ardehali
Inflammation promotes adverse ventricular remodeling, a common antecedent of heart failure. Here, we set out to determine how inflammatory cells affect cardiomyocytes in the remodeling heart. Pathogenic cardiac macrophages induced an IFN response in cardiomyocytes, characterized by upregulation of the ubiquitin-like protein IFN-stimulated gene 15 (ISG15), which posttranslationally modifies its targets through a process termed ISGylation. Cardiac ISG15 is controlled by type I IFN signaling, and ISG15 or ISGylation is upregulated in mice with transverse aortic constriction or infused with angiotensin II; rats with uninephrectomy and DOCA-salt, or pulmonary artery banding; cardiomyocytes exposed to IFNs or CD4+ T cell–conditioned medium; and ventricular tissue of humans with nonischemic cardiomyopathy. By nanoscale liquid chromatography–tandem mass spectrometry, we identified the myofibrillar protein filamin-C as an ISGylation target. ISG15 deficiency preserved cardiac function in mice with transverse aortic constriction and led to improved recovery of mouse hearts ex vivo. Metabolomics revealed that ISG15 regulates cardiac amino acid metabolism, whereas ISG15 deficiency prevented misfolded filamin-C accumulation and induced cardiomyocyte autophagy. In sum, ISG15 upregulation is a feature of pathological ventricular remodeling, and protein ISGylation is an inflammation-induced posttranslational modification that may contribute to heart failure development by altering cardiomyocyte protein turnover.
Veera Ganesh Yerra, Sri Nagarjun Batchu, Harmandeep Kaur, MD Golam Kabir, Youan Liu, Suzanne L. Advani, Duc Tin Tran, Shadi Sadeghian, Phelopater Sedrak, Filio Billia, Uros Kuzmanov, Anthony O. Gramolini, Deema O. Qasrawi, Evgeniy V. Petrotchenko, Christoph H. Borchers, Kim A. Connelly, Andrew Advani
Plasma IL-6 is elevated after myocardial infarction (MI) and is associated with increased morbidity and mortality. Which cardiac cell type preferentially contributes to IL-6 and how its production is regulated is largely unknown. Here, we studied the cellular source and purinergic regulation of IL-6 formation in a murine MI model. IL-6, measured in various cell types in post MI hearts by qPCR, RNAscope and at protein level, was preferentially formed by fibroblasts (CFs). scRNAseq in infarcted mouse and human hearts confirmed this finding. Adenosine stimulated fibroblast IL-6 formation via A2bR in a Gq-dependent manner. CFs highly expressed Adora2b, rapidly degraded extracellular ATP to AMP but lacked CD73. In mice and humans Adora2B was also mainly expressed by fibroblasts (scRNAseq). Global IL-6 formation was assessed in isolated hearts in mice lacking CD73 on T-cells (CD4CD73-/-) a condition known to be associated with adverse cardiac remodeling. The ischemia-induced release of IL-6 was strongly attenuated in CD4CD73-/- mice, suggesting adenosine-mediated modulation. Together this demonstrates that post-MI IL-6 is mainly derived from activated CFs and is controlled by T-cell derived adenosine. Purinergic metabolic cooperation between CFs and T-cells is a novel mechanism with therapeutic potential which modulates IL6 formation by the heart.
Christina Alter, Anne Sophie Henseler, Christoph Owenier, Julia Hesse, Zhaoping Ding, Tobias Lautwein, Jasmin Bahr, Sikander Hayat, Rafael Kramann, Eva Kostenis, Jürgen Scheller, Jürgen Schrader