Vascular networks form, remodel and mature under the influence of both fluid shear stress (FSS) and soluble factors. Physiological FSS promotes and maintains vascular stability via synergy with Bone Morphogenic Protein 9 (BMP9) and BMP10. Conversely, mutation of the BMP receptors ALK1, Endoglin or the downstream effector SMAD4 leads to Hereditary Hemorrhagic Telangiectasia (HHT), characterized by fragile and leaky arterial-venous malformations (AVMs). But how endothelial cells (EC) integrate FSS and BMP signals in vascular development and homeostasis, and how mutations give rise to vascular malformations is not well understood. Here, we aimed to elucidate the mechanism of synergy between fluid shear stress and SMAD signaling in vascular stability and its failure in HHT. We have now found that loss of Smad4 increases ECs’ sensitivity to flow by lowering the FSS set point with resulting AVMs exhibiting features of excessive flow-mediated morphological responses. Mechanistically, loss of SMAD4 disinhibits flow-mediated KLF4-TIE2-PI3K/Akt signaling leading to cell cycle progression - mediated loss of arterial identity due to KLF4-mediated repression of cyclin dependent Kinase (CDK) inhibitors, CDKN2A and CDKN2B. Thus, AVMs caused by Smad4 deletion are characterized by chronic high flow remodeling with excessive EC proliferation and loss of arterial identity as triggering events.
Kuheli Banerjee, Yanzhu Lin, Johannes Gahn, Julio Cordero, Purnima Gupta, Islam Mohamed, Mariona Graupera, Gergana Dobreva, Martin A. Schwartz, Roxana Ola
BACKGROUND. Cellular cholesterol efflux capacity (CEC) is a better predictor of cardiovascular disease (CVD) events than High Density Lipoprotein-Cholesterol (HDL-C) but is not suitable as a routine clinical assay. METHODS. We developed an HDL-specific phospholipid efflux (HDL-SPE) assay to assess HDL functionality based on whole plasma HDL apolipoprotein-mediated solubilization of fluorescent phosphatidylethanolamine from artificial lipid donor particles. We first assessed the association of HDL-SPE with prevalent coronary artery disease (CAD); Study I: NIH severe-CAD (n=50) and non-CAD (n=50) subjects, frequency matched for gender, BMI, Type 2-diabetes mellitus and smoking; Study II: Japanese CAD (n=70) and non-CAD (n=154) subjects. We also examined the association of HDL-SPE with incident CVD events in the Prevention of Renal and Vascular End-stage Disease (PREVEND) study comparing 340 cases to 340 controls individually matched for age, sex, smoking and HDL-C levels. RESULTS. Receiver operating characteristic curves revealed stronger associations of HDL-SPE with prevalent CAD. AUC in Study I: HDL-SPE, 0.68; apoA-I, 0.62; HDL-C, 0.63; CEC, 0.52. AUC in Study II: HDL-SPE, 0.83; apoA-I, 0.64; HDL-C, 0.53. Also longitudinally, HDL-SPE was significantly associated with incident CVD events independent of traditional risk factors with odds ratios ˂ 0.2 per SD increment in the PREVEND study (p<0.001). CONCLUSION. HDL-SPE could serve as a routine clinical assay for improving CVD risk assessment and drug discovery. TRIAL REGISTRATION. ClinicalTrials.gov: NCT01621594; Jichi Medical University study protocols C17-R007, 122, 142 and 158; University Medical Center Groningen, Netherlands study approval number: MEC96/01/022. FUNDING. This work was supported by the NIH, NHLBI Intramural Research Program.
Masaki Sato, Edward B. Neufeld, Martin P. Playford, Yu Lei, Alexander V. Sorokin, Angel M. Aponte, Lita A. Freeman, Scott M. Gordon, Amit K. Dey, Kianoush Jeiran, Masato Hamasaki, Maureen L. Sampson, Robert D. Shamburek, Jingrong Tang, Marcus Y. Chen, Kazuhiko Kotani, Josephine L.C. Anderson, Robin P.F. Dullaart, Nehal N. Mehta, Uwe J.F. Tietge, Alan T. Remaley
Nirmal S. Sharma, Kapil Patel, Ezgi Sari, Shruti Shankar, Maria G. Gastanadui, Diego Moncada-Giraldo, Yixel M. Soto-Vázquez, Delores A. Stacks, Louise Hecker, Kevin G. Dsouza, Mudassir Banday, Edward O'Neill, Paul Benson, Gregory A. Payne, Camilla Margaroli, Amit Gaggar
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
Senescent vascular smooth muscle cells (VSMCs) accumulate in the vasculature with age and tissue damage, and secrete factors that promote atherosclerotic plaque vulnerability and disease. Here, we report increased levels and activity of dipeptidyl peptidase 4 (DPP4), a serine protease, in senescent VSMCs. Analysis of the conditioned media from senescent VSMCs revealed a unique senescence-associated secretory phenotype (SASP) signature comprising many complement and coagulation factors; silencing or inhibiting DPP4 reduced these factors and increased cell death. Serum samples from persons with high risk for cardiovascular disease contained high levels of DPP4-regulated complement and coagulation factors. Importantly, DPP4 inhibition reduced senescent cell burden and coagulation and improved plaque stability, while single-cell resolution of senescent VSMCs reflected the senomorphic and senolytic effects of DPP4 inhibition in murine atherosclerosis. We propose that DPP4-regulated factors could be exploited therapeutically to reduce senescent cell function, reverse senohemostasis, and improve vascular disease.
Allison B. Herman, Dimitrios Tsitsipatis, Carlos Anerillas, Krystyna Mazan-Mamczarz, Angelica E. Carr, Jordan M. Gregg, Mingyi Wang, Jing Zhang, Marc Michel, Charnae' Henry-Smith, Sophia C. Harris, Rachel Munk, Jennifer L Martindale, Yulan Piao, Jinshui Fan, Julie A. Mattison, Supriyo De, Kotb Abdelmohsen, Robert W. Maul, Toshiko Tanaka, Ann Z. Moore, Megan E. DeMouth, Simone Sidoli, Luigi Ferrucci, Yie Liu, Rafael de Cabo, Edward G. Lakatta, Myriam Gorospe
Endothelial cells (ECs) are constitutively an anticoagulant surface but switch to support coagulation following pathogenic stimuli. This switch promotes thrombotic cardiovascular disease. To generate thrombin at physiologic rates, coagulation proteins assemble on a membrane containing anionic phospholipid, most notably phosphatidylserine (PS). PS can be rapidly externalized to the outer cell membrane leaflet by phospholipid “scramblases”, such as TMEM16F. TMEM16F-dependent PS externalization is well-characterized in platelets. In contrast, how ECs externalize phospholipids to support coagulation is not understood. We employed a focused genetic screen to evaluate the contribution of transmembrane phospholipid transport on EC procoagulant activity. We identified two TMEM16 family members, TMEM16F, and its closest paralog, TMEM16E, which were both required to support coagulation on ECs via PS externalization. Applying an intravital laser-injury model of thrombosis, we observed, unexpectedly, that PS externalization was concentrated at the vessel wall, not on platelets. TMEM16E-null mice demonstrated reduced vessel-wall dependent fibrin formation. The TMEM16 inhibitor benzbromarone prevented PS externalization and EC procoagulant activity and protected mice from thrombosis without increasing bleeding following tail transection. These findings indicate the activated endothelial surface is a source of procoagulant phospholipid contributing to thrombus formation. TMEM16 phospholipid scramblases may be a therapeutic target for thrombotic cardiovascular disease.
Alec A. Schmaier, Papa F. Anderson, Siyu M. Chen, Emale El-Darzi, Ivan Aivasovsky, Milan P. Kaushik, Kelsey D. Sack, H. Criss Hartzell, Samir M. Parikh, Robert Flaumenhaft, Sol Schulman
Dysfunction of vascular endothelial cells (ECs) facilitates imbalanced immune responses and tissue hyperinflammation. However, the heterogeneous functions of skin ECs and their underlying mechanism in dermatoses remain to be solved. Here, focusing on the pathogenic role of skin ECs in psoriasis, we characterized the molecular and functional heterogeneity of skin ECs from healthy individuals and psoriasis patients at the single-cell level. We found that endothelial glycocalyx destruction, a major feature of EC dysfunction in psoriasis, was a driving force during the process of T cell extravasation. Interestingly, we identified a skin EC subset, IGFBP7high ECs, in psoriasis. This subset actively responded to psoriatic-related cytokine signaling, secreted IGFBP7, damaged the endothelial glycocalyx, exposed the adhesion molecules underneath, and prepared the endothelium for immune cell adhesion and transmigration, thus aggravating skin inflammation. More importantly, we provided evidence in a psoriasis-like mouse model that anti-IGFBP7 treatment showed promising therapeutic effects for restoring the endothelial glycocalyx and alleviating skin inflammation. Taken together, our results depicted the distinct functions of EC clusters in healthy and psoriatic skin, identified IGFBP7high ECs as an active subset modulating vascular function and cutaneous inflammation, and indicated that targeting IGFBP7 is a potential therapeutic strategy in psoriasis.
Qingyang Li, Shuai Shao, Zhenlai Zhu, Jiaoling Chen, Junfeng Hao, Yaxing Bai, Bing Li, Erle Dang, Gang Wang
Christian Lacks Lino Cardenas, Lauren C. Briere, David A. Sweetser, Mark E. Lindsay, Patricia L. Musolino
Impaired angiogenesis in diabetes is a key process contributing to ischemic diseases such as peripheral arterial disease. Epigenetic mechanisms, including those mediated by long non-coding RNAs are crucial links connecting diabetes and the related chronic tissue ischemia. Here we identify the LncRNA that Enhances Endothelial Nitric oxide synthase Expression (LEENE) as a regulator of angiogenesis and ischemic response. LEENE expression is decreased in diabetic conditions in cultured endothelial cells (EC), mouse hindlimb muscles, and human arteries. Inhibition of LEENE in human microvascular ECs reduces their angiogenic capacity with a dysregulated angiogenic gene program. Diabetic mice deficient in leene demonstrate impaired angiogenesis and perfusion following hindlimb ischemia. Importantly, overexpression of human LEENE rescues the impaired ischemic response in leene knockout mice at tissue functional and single-cell transcriptomic levels. Mechanistically, LEENE RNA promotes transcription of pro-angiogenic genes in ECs, such as KDR and eNOS, potentially by interacting with LEO1, a key component of RNA Polymerase II-associated factor complex and MYC, a crucial transcription factor for angiogenesis. Taken together, our findings demonstrate an essential role for LEENE in the regulation of angiogenesis and tissue perfusion. Functional enhancement of LEENE to restore angiogenesis for tissue repair and regeneration may represent a potential strategy to tackle ischemic vascular diseases.
Xiaofang Tang, Yingjun Luo, Dongqiang Yuan, Riccardo Calandrelli, Naseeb Kaur Malhi, Kiran Sriram, Yifei Miao, Chih Hong Lou, Walter Tsark, Alonso Tapia, Aleysha T. Chen, Guangyu Zhang, Daniel Roeth, Markus Kalkum, Zhao V. Wang, Shu Chien, Rama Natarajan, John P. Cooke, Sheng Zhong, Zhen Bouman Chen
Pain signals are relayed to the brain via a nociceptive system, and in rare situations, this nociceptive system contains genetic variants that can limit pain response. Here we questioned whether a human transient receptor potential vanilloid 1 (TRPV1) missense variant causes a resistance to noxious stimuli and further if we can target this region by a cell-permeable peptide as a pain therapeutic. Initially using a computational approach, we identified a human K710N TRPV1 missense variant in an otherwise highly conserved region of mammalian TRPV1. After generating a TRPV1K710N knock-in mouse using CRISPR/Cas9, we discovered the K710N variant reduced capsaicin-induced calcium influx in dorsal root ganglion neurons. The TRPV1K710N rodents also had less acute behavioral response to chemical noxious stimuli and less hypersensitivity to nerve injury-induced pain, while leaving the response to noxious heat intact. Furthermore, blocking this K710 region in wild-type rodents by a cell-penetrating peptide limited acute behavioral responses to noxious stimuli and rescued pain hypersensitivity induced by nerve injury back to baseline. These findings identify K710 TRPV1 as a discrete site crucial for the control of nociception and provides new insights into how to leverage rare genetic variants in humans to uncover fresh strategies for developing pain therapeutics.
Shufang He, Vanessa O. Zambelli, Pritam Sinharoy, Laura Brabenec, Yang Bian, Freeborn Rwere, Rafaela C.R. Hell, Beatriz Stein Neto, Barbara Hung, Xuan Yu, Meng Zhao, Zhaofei Luo, Chao Wu, Lijun Xu, Katrin J. Svensson, Stacy L. McAllister, Creed M. Stary, Nana-Maria Wagner, Ye Zhang, Eric R. Gross