Abstract
Authors
Alexander M. Loiben, Wei-Ming Chien, Ashley McKinstry, Dania Ahmed, Matthew C. Childers, Michael Regnier, Charles E. Murry, Kai-Chun Yang
Abstract
BACKGROUND. Cardiac allograft vasculopathy (CAV) is consistently accompanied by immune infiltrates surrounding affected coronary arteries, including antibody-producing plasma cells (PC). The antigenic drivers of these intragraft PC responses remain poorly defined. METHODS. We characterized graft-infiltrating PC by single-cell RNA sequencing and immunoglobulin gene profiling. Using immunoglobulin sequences we generated 37 recombinant monoclonal antibodies (mAb) from dominant intragraft PC clones and 24 control mAb from peripheral blood PC. Antigen reactivity was screened against chemical adducts, including bilirubin, a heme-degradation by-product. Histologic and tissue analyses assessed bilirubin deposition as well as expression of heme-catabolic enzymes, and the presence of Fe2+ in heart explants with CAV. RESULTS. A majority of graft-derived mAb (21/37; ~57%) but none of the mAb derived from blood PC reacted to bilirubin. Bilirubin deposition was detected within lymphocytic aggregates in CAV grafts. In coronary arteries with CAV lesions, bilirubin accumulated in the cytoplasm and nuclei of smooth muscle cells in the tunica media, a pattern not observed in healthy heart tissue. Lastly, we detected the expression of heme-oxygenase-1 and biliverdin reductases in graft-infiltrating macrophages along with the presence of Fe2+ ion in the media of arteries with hyperplasia. CONCLUSION. These findings suggest that local heme catabolism and resultant bilirubin accumulation create a prominent target for intragraft antibody responses in CAV. Bilirubin-specific antibodies and heme-catabolic pathways may contribute to CAV pathogenesis and represent potential mechanistic and therapeutic avenues for further investigation. FUNDING. National Institute of Health.
Authors
Sarah B. See, Talita Aguiar, Max Dietzel, Mattea Ausmeier, Hang T.T. Nguyen, Shunya Mashiko, Laura Donadeu, Hector Cordero, Poulomi Roy, Lorea Roson, Charles C. Marboe, Matthias J. Szabolcs, Maryjane Farr, Jose González-Costello, Aleix Olivella, Yoshifumi Naka, Koji Takeda, Rodica Vasilescu, Kevin J. Clerkin, Gilles Benichou, Joren C. Madsen, R. Glenn King, Oriol Bestard, Evan P. Kransdorf, Emmanuel Zorn
Abstract
Clonal hematopoiesis due to TET2-driver mutations (CH) is associated with coronary heart disease and worse prognosis among patients with aortic valve stenosis (AVS). However, it is unknown what role CH plays in the pathogenesis of AVS. In a meta-analysis of All Of Us, BioVU, and the UK Biobank, patients with CHIP exhibited an increased risk of AVS, with a higher risk among patients with TET2 or ASXL1 mutations. Single-cell RNA-sequencing of immune cells from AVS patients harboring TET2 CH-driver mutations revealed monocytes with heightened pro-inflammatory signatures and increased expression of pro-calcific paracrine signaling factors, most notably Oncostatin M (OSM). Secreted factors from TET2-silenced macrophages increased in vitro calcium deposition by mesenchymal cells, which was ablated by OSM silencing. Atheroprone Ldlr–/– mice receiving CH-mimicking Tet2–/– bone marrow transplants displayed greater calcium deposition in aortic valves. Together, these results demonstrate that monocytes with CH promote aortic valve calcification, and that patients with CH are at increased risk of AVS.
Authors
Wesley T. Abplanalp, Michael A. Raddatz, Bianca Schuhmacher, Silvia Mas-Peiro, María A. Zuriaga, Nuria Matesanz, José J. Fuster, Yash Pershad, Caitlyn Vlasschaert, Alexander J. Silver, Eric H. Farber-Eger, Yaomin Xu, Quinn S. Wells, Delara Shahidi, Sameen Fatima, Xiao Yang, Adwitiya A.P. Boruah, Akshay Ware, Maximilian Merten, Moritz von Scheidt, David John, Mariana Shumliakivska, Marion Muhly-Reinholz, Mariuca Vasa-Nicotera, Stefan Guenter, Michael R. Savona, Brian R. Lindman, Stefanie Dimmeler, Alexander G. Bick, Andreas M. Zeiher
Abstract
Orthosteric β-blockers represent the leading pharmacological intervention for managing heart diseases owing to their ability to competitively antagonize β-adrenergic receptors (βARs). However, their use is often limited by the development of adverse effects such as fatigue, hypotension, and reduced exercise capacity, due in part to the nonselective inhibition of multiple βAR subtypes. These challenges are particularly problematic in treating catecholaminergic polymorphic ventricular tachycardia (CPVT), a disease characterized by lethal tachyarrhythmias directly triggered by cardiac β1AR activation. To identify small molecule allosteric modulators of the β1AR that could offer enhanced subtype specificity and robust functional antagonism of β1AR-mediated signaling, we conducted a DNA-encoded small molecule library screen and discovered Compound 11 (C11). C11 selectively potentiates the binding affinity of orthosteric agonists to the β1AR while potently inhibiting downstream signaling following β1AR activation. Moreover, C11 prevents agonist-induced spontaneous contractile activity, Ca2+ release events, and exercise-induced ventricular tachycardia in the CSQ2–/– murine model of CPVT. Collectively, our studies demonstrate that C11 belongs to an emerging class of allosteric modulators termed PAM-antagonists that positively modulate agonist binding but block downstream function. With unique pharmacological properties and selective functional antagonism of β1AR-mediated signaling, C11 represents a promising therapeutic candidate for the treatment of CPVT and other forms of cardiac disease associated with excessive β1AR activation.
Authors
Alyssa Grogan, Robin M. Perelli, Seungkirl Ahn, Haoran Jiang, Arun Jyothidasan, Damini Sood, Chongzhao You, David I. Israel, Alex Shaginian, Qiuxia Chen, Jian Liu, Jialu Wang, Jan Steyaert, Alem W. Kahsai, Andrew P. Landstrom, Robert J. Lefkowitz, Howard A. Rockman
Abstract
Lactylation, a post-translational modification derived from glycolysis, plays a pivotal role in ischemic heart diseases. Neutrophils are predominantly glycolytic cells that trigger intensive inflammation of myocardial ischemia reperfusion (MI/R). However, whether lactylation regulates neutrophil function during MI/R remains unknown. Employing lactyl proteomics analysis, S100a9 was lactylated at lysine 26 (S100a9K26la) in neutrophils, with elevated levels observed in both acute myocardial infarction (AMI) patients and MI/R model mice. S100a9K26la was demonstrated driving the development of MI/R using mutant knock-in mice. Mechanistically, lactylated S100a9 translocated to the nucleus of neutrophils, where it binded to the promoters of migration-related genes, thereby enhancing their transcription as a co-activator and promoting neutrophil migration and cardiac recruitment. Additionally, lactylated S100a9 was released during NETosis, leading to cardiomyocyte death by disrupting mitochondrial function. The enzyme dihydrolipoyllysine-residue acetyltransferase (DLAT) was identified as the lactyltransferase facilitating neutrophil S100a9K26la post-MI/R, a process that could be restrained by α-lipoic acid. Consistently, targeting DLAT/S100a9K26la axis suppressed neutrophil burden and improved cardiac function post-MI/R. In patients with AMI, elevated S100a9K26la levels in plasma were positively correlated with cardiac death. These findings highlight S100a9 lactylation as a potential therapeutic target for MI/R and as a promising biomarker for evaluating poor prognosis of MI/R.
Authors
Xiaoqi Wang, Xiangyu Yan, Ge Mang, Yujia Chen, Shuang Liu, Jiayu Sui, Zhonghua Tong, Penghe Wang, Jingxuan Cui, Qiannan Yang, Yafei Zhang, Dongni Wang, Ping Sun, Weijun Song, Zexi Jin, Ming Shi, Peng Zhao, Jia Yang, Mingyang Liu, Naixin Wang, Tao Chen, Yong Ji, Bo Yu, Maomao Zhang
Abstract
Plasminogen activator inhibitor-1 (PAI-1), encoded by SERPINE1, contributes to age-related cardiovascular diseases (CVD) and other aging-related pathologies. Humans with a heterozygous loss-of-function SERPINE1 variant exhibit protection against aging and cardiometabolic dysfunction. We engineered a mouse model mimicking the human mutation (Serpine1TA700/+) and compared cardiovascular responses with wild-type littermates. Serpine1TA700/+ mice lived 20% longer than littermate controls. Under L-NG-Nitro-arginine methyl ester (L-NAME)-induced vascular stress, Serpine1TA700/+ mice exhibited diminished pulse wave velocity (PWV), lower systolic hypertension (SBP), and preserved left ventricular diastolic function compared to controls. Conversely, PAI-1-overexpressing mice exhibited measurements indicating accelerated cardiovascular aging. Single cell transcriptomics of Serpine1TA700/+ aortas revealed a vascular-protective mechanism with downregulation of extracellular matrix regulators Ccn1 and Itgb1. Serpine1TA700/+ aortas were also enriched in a cluster of smooth muscle cells that exhibited plasticity. Finally, PAI-1 pharmacological inhibition normalized SBP and reversed L-NAME-induced PWV elevation. These findings demonstrate that PAI-1 reduction protects against cardiovascular aging-related phenotypes, while PAI-1 excess promotes vascular pathological changes. Taken together, PAI-1 inhibition represents a promising strategy to mitigate age-related CVD.
Authors
Alireza Khoddam, Anthony Kalousdian, Mesut Eren, Saul Soberanes, Andrew Decker, Elizabeth J. Lux, Benjamin W. Zywicki, Brian Dinh, Bedirhan Boztepe, Baljash S. Cheema, Carla M. Cuda, Hiam Abdala-Valencia, Arun Sivakumar, Toshio Miyata, Lisa D. Wilsbacher, Douglas E. Vaughan
Abstract
Background. Statin therapy lowers the risk of major adverse cardiovascular events (MACE) among people with HIV (PWH). Residual risk pathways contributing to excess MACE beyond low-density lipoprotein cholesterol (LDL-C) are not well understood. Our objective was to evaluate the association of statin responsive and other inflammatory and metabolic pathways to MACE in the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE). Methods. Cox proportional hazards models were used to assess the relationship between MACE and proteomic measurements at study entry and year 2 adjusting for time-updated statin use and baseline 10-year atherosclerotic cardiovascular disease risk score. We built a machine learning (ML) model to predict MACE using baseline proteins values with significant associations. Results. In 765 individuals (age: 50.8±5.9 years, 82% males) among 7 proteins changing with statin vs. placebo, angiopoietin-related protein 3 (ANGPTL3) related most strongly to MACE (aHR: 2.31 per 2-fold higher levels; 95%CI: 1.11-4.80; p=0.03), such that lower levels of ANGPTL3 achieved with statin therapy were associated with lower MACE risk. Among 248 proteins not changing in response to statin therapy, 26 were associated with MACE at FDR<0.05. These proteins represented predominantly humoral immune response, leukocyte chemotaxis, and cytokine pathways. Our proteomic ML model achieved a 10-fold cross-validated c-index of 0.74±0.11 to predict MACE, improving on models using traditional risk prediction scores only (c-index: 0.61±0.18). Conclusions. ANGPTL3, as well as key inflammatory pathways may contribute to residual risk of MACE among PWH, beyond LDL-C. Trial registration. ClinicalTrials.gov: NCT02344290. Funding. NIH, Kowa, Gilead Sciences, ViiV.
Authors
Márton Kolossváry, Irini Sereti, Markella V. Zanni, Carl J. Fichtenbaum, Judith A Aberg, Gerald S. Bloomfield, Carlos D. Malvestutto, Judith S. Currier, Sarah M. Chu, Marissa R. Diggs, Alex B. Lu, Christopher deFilippi, Borek Foldyna, Sara McCallum, Craig A. Sponseller, Michael T. Lu, Pamela S. Douglas, Heather J. Ribaudo, Steven K. Grinspoon
Abstract
Authors
Alireza Raissadati, Xuanyu Zhou, Harrison Chou, Yuhsin Vivian Huang, Shaheen Khatua, Yin Sun, Anne Xu, Sharon Loa, Arturo Hernandez, Han Zhu, Sean M. Wu
Abstract
Platelet hyperreactivity increases the risk of cardiovascular thrombosis in diabetes and failure of antiplatelet drug therapies. Elevated basal and agonist-induced calcium flux is a fundamental cause of platelet hyperreactivity in diabetes; however, the mechanisms responsible for this remain largely unknown. Using a high-sensitivity, unbiased proteomic platform, we consistently detected over 2,400 intracellular proteins and identified proteins that were differentially released by platelets in type 2 diabetes. We identified that SEC61 translocon subunit β (SEC61B) was increased in platelets from humans and mice with hyperglycemia and in megakaryocytes from mice with hyperglycemia. SEC61 is known to act as an endoplasmic reticulum (ER) calcium leak channel in nucleated cells. Using HEK293 cells, we showed that SEC61B overexpression increased calcium flux into the cytosol and decreased protein synthesis. Concordantly, platelets in hyperglycemic mice mobilized more calcium and had decreased protein synthesis. Platelets in both humans and mice with hyperglycemia had increased ER stress. ER stress induced the expression of platelet SEC61B and increased cytosolic calcium. Inhibition of SEC61 with anisomycin decreased platelet calcium flux and inhibited platelet aggregation in vitro and in vivo. These studies demonstrate the existence of a mechanism whereby ER stress–induced upregulation of platelet SEC61B leads to increased cytosolic calcium, potentially contributing to platelet hyperreactivity in diabetes.
Authors
Yvonne X. Kong, Rajan Rehan, Cesar L. Moreno, Søren Madsen, Yunwei Zhang, Huiwen Zhao, Miao Qi, Callum B. Houlahan, Siân P. Cartland, Declan Robertshaw, Vincent Trang, Frederick Jun Liang Ong, Michael Liu, Edward Cheng, Imala Alwis, Alexander Dupuy, Michelle Cielesh, Kristen C. Cooke, Meg Potter, Jacqueline Stöckli, Grant Morahan, Maggie L. Kalev-Zylinska, Matthew T. Rondina, Sol Schulman, Jean Y. H. Yang, G. Gregory Neely, Simone M. Schoenwaelder, Shaun P. Jackson, David E. James, Mary M. Kavurma, Samantha L. Hocking, Stephen M. Twigg, James C. Weaver, Mark Larance, Freda H. Passam
Abstract
Direct interaction of RAS with the PI3K p110α subunit mediates RAS-driven tumor development: however, it is not clear how p110α/RAS-dependant signaling mediates interactions between tumors and host tissues. Here, using a murine tumor cell transfer model, we demonstrated that disruption of the interaction between RAS and p110α within host tissue reduced tumor growth and tumor-induced angiogenesis, leading to improved survival of tumor-bearing mice, even when this interaction was intact in the transferred tumor. Furthermore, functional interaction of RAS with p110α in host tissue was required for efficient establishment and growth of metastatic tumors. Inhibition of RAS and p110α interaction prevented proper VEGF-A and FGF-2 signaling, which are required for efficient angiogenesis. Additionally, disruption of the RAS and p110α interaction altered the nature of tumor-associated macrophages, inducing expression of markers typical for macrophage populations with reduced tumor-promoting capacity. Together, these results indicate that a functional RAS interaction with PI3K p110α in host tissue is required for the establishment of a growth-permissive environment for the tumor, particularly for tumor-induced angiogenesis. Targeting the interaction of RAS with PI3K has the potential to impair tumor formation by altering the tumor-host relationship, in addition to previously described tumor cell–autonomous effects.
Authors
Miguel Manuel Murillo, Santiago Zelenay, Emma Nye, Esther Castellano, Francois Lassailly, Gordon Stamp, Julian Downward
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ISSN: 0021-9738 (print), 1558-8238 (online)