Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), cause severe endothelial dysfunction in the lung, and vascular endothelial growth factor (VEGF) is elevated in ARDS. We found that the levels of a VEGF-regulated microRNA, microRNA-1 (miR-1), were reduced in the lung endothelium after acute injury. Pulmonary endothelial cell–specific (EC-specific) overexpression of miR-1 protected the lung against cell death and barrier dysfunction in both murine and human models and increased the survival of mice after pneumonia-induced ALI. miR-1 had an intrinsic protective effect in pulmonary and other types of ECs; it inhibited apoptosis and necroptosis pathways and decreased capillary leak by protecting adherens and tight junctions. Comparative gene expression analysis and RISC recruitment assays identified miR-1 targets in the context of injury, including phosphodiesterase 5A (PDE5A), angiopoietin-2 (ANGPT2), CNKSR family member 3 (CNKSR3), and TNF-α–induced protein 2 (TNFAIP2). We validated miR-1–mediated regulation of ANGPT2 in both mouse and human ECs and found that in a 119-patient pneumonia cohort, miR-1 correlated inversely with ANGPT2. These findings illustrate a previously unknown role of miR-1 as a cytoprotective orchestrator of endothelial responses to acute injury with prognostic and therapeutic potential.
Asawari Korde, Maria Haslip, Prachi Pednekar, Alamzeb Khan, Maurizio Chioccioli, Sameet Mehta, Francesc Lopez-Giraldez, Santos Bermejo, Mauricio Rojas, Charles Dela Cruz, Michael A. Matthay, Jordan S. Pober, Richard W. Pierce, Shervin S. Takyar
Pulmonary hypertension (PH) is a life-threatening disease characterized by a progressive narrowing of pulmonary arterioles. Although VEGF is highly expressed in lung of patients with PH and in animal PH models, the involvement of angiogenesis remains elusive. To clarify the pathophysiological function of angiogenesis in PH, we compared the angiogenic response in hypoxia (Hx) and SU5416 (a VEGFR2 inhibitor) plus Hx (SuHx) mouse PH models using 3D imaging. The 3D imaging analysis revealed an angiogenic response in the lung of the Hx-PH, but not of the severer SuHx-PH model. Selective VEGFR2 inhibition with cabozantinib plus Hx in mice also suppressed angiogenic response and exacerbated Hx-PH to the same extent as SuHx. Expression of endothelial proliferator-activated receptor γ coactivator 1α (PGC-1α) increased along with angiogenesis in lung of Hx-PH but not SuHx mice. In pulmonary endothelial cell–specific Ppargc1a-KO mice, the Hx-induced angiogenesis was suppressed, and PH was exacerbated along with increased oxidative stress, cellular senescence, and DNA damage. By contrast, treatment with baicalin, a flavonoid enhancing PGC-1α activity in endothelial cells, ameliorated Hx-PH with increased Vegfa expression and angiogenesis. Pulmonary endothelial PGC-1α–mediated angiogenesis is essential for adaptive responses to Hx and might represent a potential therapeutic target for PH.
Takayuki Fujiwara, Norifumi Takeda, Hironori Hara, Satoshi Ishii, Genri Numata, Hiroyuki Tokiwa, Manami Katoh, Sonoko Maemura, Takaaki Suzuki, Hiroshi Takiguchi, Tomonobu Yanase, Yoshiaki Kubota, Seitaro Nomura, Masaru Hatano, Kazutaka Ueda, Mutsuo Harada, Haruhiro Toko, Eiki Takimoto, Hiroshi Akazawa, Hiroyuki Morita, Satoshi Nishimura, Issei Komuro
Inadequate adaption to mechanical forces, including blood pressure, contributes to development of arterial aneurysms. Recent studies have pointed to a mechano-protective role of YAP and TAZ in vascular smooth muscle cells (SMCs). Here, we identified reduced expression of YAP1 in human aortic aneurysms. Vascular SMC-specific knockouts (KOs) of YAP/TAZ were thus generated using the novel integrin α8 (Itga8)-Cre mouse model (i8-YT-KO). i8-YT-KO mice spontaneously developed aneurysms in the abdominal aorta within two weeks of knockout induction and in smaller arteries at later times. The vascular specificity of the Itga8-Cre circumvented gastrointestinal effects. Aortic aneurysms were characterized by elastin disarray, SMC apoptosis, and accumulation of proteoglycans and immune cell populations. RNA-sequencing, proteomics, and myography demonstrated decreased contractile differentiation of SMCs and impaired vascular contractility. This associated with partial loss of myocardin expression, reduced blood pressure, and edema. Mediators in the inflammatory cGAS-STING pathway, were increased. A sizeable increase of SOX9, along with several direct target genes, including aggrecan (Acan), contributed to proteoglycan accumulation. This was the earliest detectable change, occurring three days after knockout induction and before the pro-inflammatory transition. In conclusion, Itga8-Cre deletion of YAP and TAZ represents a rapid and spontaneous aneurysm model that recapitulates features of human abdominal aortic aneurysms.
Marycarmen Arévalo Martínez, Olivia Ritsvall, Joakim A. Bastrup, Selvi Celik, Gabriel Jakobsson, Fatima Daoud, Christopher Winqvist, Anders Aspberg, Catarina Rippe, Lars Maegdefessel, Alexandru Schiopu, Thomas A. Jepps, Johan Holmberg, Karl Swärd, Sebastian Albinsson
Specific and efficient smooth muscle cell (SMC)-targeted gene deletion is typically achieved by pairing SMMHC-CreERT2-Tg mice with mice carrying the loxP-flanked gene. However, the transgene, CreERT2, is not controlled by the endogenous Myh11 gene promoter, and the codon-modified iCreERT2 exhibits significant tamoxifen-independent leakage. Furthermore, because the Cre-bearing Bacterial Artificial Chromosome (BAC) is inserted onto the Y chromosome, the SMMHC-CreERT2-Tg mice strain can only exhibit gene deletions in male mice. Additionally, there is a lack of Myh11-driven constitutive Cre mice when tamoxifen usage is a concern. We used CRISPR/Cas9-mediated homologous recombination between a donor vector carrying the 1) CreNLSP2A or 2) CreERT2-P2A sequence and homologous arm surrounding the translation start site of the Myh11 gene to generate Cre knock-in mice. The P2A sequence enables the simultaneous translation of Cre and endogenous proteins. Using reporter mice, we assessed Cre-mediated recombination efficiency, specificity, tamoxifen-dependent controllability, and functionality in both sexes. Both constitutive (Myh11-CreNLSP2A) and inducible (Myh11-CreERT2-P2A) Cre mice demonstrated efficient, SMC-specific, sex-independent Cre recombinase activity without confounding endogenous gene expression. Combined with recently generated BAC transgenic Myh11-CreERT2-RAD mice and the Itga8-CreERT2 mouse models, our new models will help expand the research toolbox, facilitating unbiased and comprehensive research in SMCs and SMC-dependent cardiovascular diseases.
Yang Zhao, Guizhen Zhao, Ziyi Chang, Tianqing Zhu, Ying Zhao, Haocheng Lu, Chao Xue, Thomas L. Saunders, Yanhong Guo, Lin Chang, Y. Eugene Chen, Jifeng Zhang
Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Increased platelet counts and activation are observed during the course of KD, and elevated platelet counts are associated with higher risks of developing intravenous immunoglobulin (IVIG) resistance and coronary artery (CA) aneurysms. However, the role of platelets in KD pathogenesis remains unclear. Here, we analyzed transcriptomics data generated from the whole blood of KD patients and discovered changes in the expression of platelet-related genes during acute KD. In the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis, LCWE injection increased platelet counts and the formation of monocyte-platelet aggregates (MPAs), upregulated the concentration of soluble P-selectin, and increased circulating thrombopoietin (TPO) and interleukin (IL)-6. Furthermore, platelet counts correlated with the severity of cardiovascular inflammation. Genetic depletion of platelets (mpl–/– mice) or treatment with anti-CD42b antibody led to a significant reduction of LCWE-induced cardiovascular lesions. Furthermore, in the mouse model, platelets promoted vascular inflammation via the formation of MPAs, which amplify IL-1β production. Altogether, our results indicate that platelet activation exacerbates the development of cardiovascular lesions in a murine model of KD vasculitis. These findings enhance our understanding of KD vasculitis pathogenesis and highlight MPAs, which are known to enhance IL-1β production, as a potential therapeutic target for this disorder.
Begüm Kocatürk, Youngho Lee, Nobuyuki Nosaka, Masanori Abe, Daisy Martinon, Malcolm E. Lane, Debbie Moreira, Shuang Chen, Michael C. Fishbein, Rebecca A. Porritt, Bernardo S. Franklin, Magali Noval Rivas, Moshe Arditi
Patients with peripheral artery disease (PAD) and diabetes constitute a high risk population for development of critical limb ischemia (CLI) and amputation, although the underlying mechanisms remain poorly understood. Comparison of dysregulated microRNAs from diabetic human subjects with PAD and diabetic mice with limb ischemia revealed the conserved microRNA, miR-130b-3p. In vitro angiogenic assays demonstrated miR-130b rapidly promoted proliferation, migration, and sprouting in endothelial cells (ECs), whereas miR-130b inhibition exerted anti-angiogenic effects. Local delivery of miR-130b mimics into ischemic muscles of diabetic mice (db/db) following femoral artery ligation (FAL) promoted revascularization by increasing angiogenesis and markedly improved limb necrosis and amputation. RNA-sequencing, and gene set enrichment analysis from miR-130b overexpressing ECs revealed the BMP / TGF-b signaling pathway as one of the top dysregulated pathways. Accordingly, overlapping downregulated transcripts from RNA-seq and miRNA prediction algorithms identified that miR-130b directly targeted and repressed the TGF-b superfamily member inhibin-b-A (INHBA). miR-130b overexpression or siRNA-mediated knockdown of INHBA induced IL-8 expression, a potent angiogenic chemokine. Lastly, ectopic delivery of silencer RNAs (siRNA) targeting Inhba in db/db ischemic muscles following FAL improved revascularization and limb necrosis, recapitulating the phenotype of miR-130b delivery. Taken together, a miR-130b-INHBA signaling axis may provide therapeutic targets for patients with PAD and diabetes at risk of developing CLI.
Henry S. Cheng, Daniel Pérez-Cremades, Rulin Zhuang, Anurag Jamaiyar, Winona W. Wu, Jingshu Chen, Aspasia Tzani, Lauren Stone, Jorge Plutzky, Terence E. Ryan, Philip P. Goodney, Mark A. Creager, Marc S. Sabatine, Marc P. Bonaca, Mark W. Feinberg
Abdominal aortic aneurysm (AAA) is usually asymptomatic until life-threatening complications occur, predominantly involving aortic rupture. Currently, no drug-based treatments are available, primarily due to limited understanding of AAA pathogenesis. Transcriptional regulator PR domain-containing protein 16 (PRDM16) is highly expressed in the aorta, but its functions in the aorta are largely unknown. By RNA-seq analysis, we found that VSMCs-specific Prdm16 knockout mice (Prdm16SMKO) already showed extensive changes in the expression of genes associated with extracellular matrix (ECM) remodeling and inflammation in the abdominal aorta under normal housing conditions without any pathological stimuli. Human AAA lesions displayed lower PRDM16 expression. Periadventitial elastase application to the suprarenal region of the abdominal aorta aggravated AAA formation in Prdm16SMKO. During AAA development, VSMCs undergo apoptosis because of both intrinsic and environmental changes including inflammation and ECM remodeling. Prdm16 deficiency promoted inflammation and apoptosis in VSMCs. A disintegrin and metalloproteinase 12 (ADAM12) is a gelatinase which can degrade various ECM. We found that ADAM12 is a target of transcriptional repression by PRDM16. Adam12 knockdown reversed VSMC apoptosis induced by Prdm16 deficiency. Our study demonstrated that PRDM16 deficiency in VSMCs promoted ADAM12 expression and aggravates AAA formation, which may provide potential targets for AAA treatment.
Zhenguo Wang, Xiangjie Zhao, Guizhen Zhao, Yanhong Guo, Haocheng Lu, Wenjuan Mu, Juan Zhong, Minerva Garcia-Barrio, Jifeng Zhang, Y. Eugene Chen, Lin Chang
To improve our limited understanding of the pathogenesis of thoracic aortic aneurysm (TAA) leading to acute aortic dissection, single-cell RNA sequencing (scRNA-seq) was employed to profile disease-relevant transcriptomic changes of aortic cell populations in a well-characterized mouse model of the most commonly diagnosed form of Marfan syndrome (MFS). As result, two discrete sub-populations of aortic cells (SMC3 and EC4) were identified only in the aorta of Fbn1mgR/mgR mice. SMC3 highly express genes related to extracellular matrix formation and nitric oxide signaling, whereas EC4 transcriptional profile is enriched in SMC, fibroblast, and immune cell-related genes. Trajectory analysis predicted close phenotypic modulation between SMC3 and EC4, which were therefore analyzed together as a discrete MFS-modulated (MFSmod) sub-population. In situ hybridizations of diagnostic transcripts located MFSmod cells to the intima of Fbn1mgR/mgR aortas. Reference-based dataset integration revealed transcriptomic similarity between MFSmod and an SMC-derived cell cluster modulated in human TAA. Consistent with angiotensin II type I receptor (At1r) contribution to TAA development, MFSmod cells were absent in the aorta of Fbn1mgR/mgR mice treated with the At1r antagonist losartan. Altogether, our findings indicate that a discrete dynamic alteration of aortic cell identity is associated with dissecting TAA in MFS mice and increased risk of aortic dissection in MFS patients.
Yifei Sun, Keiichi Asano, Lauriane Sedes, Anna Cantalupo, Jens Hansen, Ravi Iyengar, Martin J. Walsh, Francesco Ramirez
Lipid regulation of ion channels is largely explored using in silico modeling with minimal experimentation in intact tissue; thus, the functional consequences of these predicted lipid-channel interactions within native cellular environments remain elusive. The goal of this study is to investigate how lipid regulation of endothelial Kir2.1, an inwardly rectifying potassium channel that regulates membrane hyperpolarization, contributes to vasodilation in resistance arteries. First, we show phosphatidylserine (PS) localizes to a specific subpopulation of myoendothelial junctions (MEJs), crucial signaling microdomains that regulate vasodilation in resistance arteries, and in silico data has implied PS may compete with PIP2 binding on Kir2.1. We found 83.33% of Kir2.1-MEJs also contained PS, possibly indicating an interaction where PS regulates Kir2.1. Electrophysiology experiments on HEK cells demonstrate PS blocks PIP2 activation of Kir2.1, and addition of exogenous PS blocks PIP2-mediated Kir2.1 vasodilation in resistance arteries. Using a mouse model lacking canonical MEJs in resistance arteries (Elnfl/fl/Cdh5-Cre), PS localization in endothelium was disrupted and PIP2 activation of Kir2.1 was significantly increased. Taken together, our data suggests PS enrichment to MEJs inhibits PIP2-mediated activation of Kir2.1 to tightly regulate changes in arterial diameter, and demonstrates the intracellular lipid localization within endothelium is an important determinant of vascular function.
Claire A. Ruddiman, Richard G. Peckham, Melissa A. Luse, Yen-Lin Chen, Maniselvan Kuppusamy, Bruce A. Corliss, Jordan Hall, Chien-Jung Lin, Shayn M. Peirce, Swapnil K. Sonkusare, Robert P. Mecham, Jessica E. Wagenseil, Brant E. Isakson
Vascular smooth muscle-derived Sca1+ adventitial progenitor (AdvSca1-SM) cells are tissue resident, multipotent stem cells that contribute to progression of vascular remodeling and fibrosis. Upon acute vascular injury, AdvSca1-SM cells differentiate into myofibroblasts and are embedded in perivascular collagen and extracellular matrix. While the phenotypic properties of AdvSca1-SM-derived myofibroblasts have been defined, the underlying epigenetic regulators driving the AdvSca1-SM-to-myofibroblast transition are unclear. We show that the chromatin remodeler, Smarca4/Brg1, facilitates AdvSca1-SM myofibroblast differentiation. Brg1 mRNA and protein was upregulated in AdvSca1-SM cells after acute vascular injury and pharmacological inhibition of Brg1 by the small molecule PFI-3 attenuated perivascular fibrosis and adventitial expansion. TGF-β1 stimulation of AdvSca1-SM cells in vitro reduced expression of stemness genes while inducing expression of myofibroblast genes that was associated with enhanced contractility; PFI blocked TGF-β1-induced phenotypic transition. Similarly, genetic knockdown of Brg1 in vivo reduced adventitial remodeling and fibrosis and reversed AdvSca1-SM-to-myofibroblast transition in vitro. Mechanistically, TGF-β1 promoted redistribution of Brg1 from distal intergenic sites of stemness genes and recruitment to promoter regions of myofibroblast-related genes, which was blocked by PFI-3. These data shed insight into epigenetic regulation of resident vascular progenitor cell differentiation and support that manipulating the AdvSca1-SM phenotype will provide important anti-fibrotic clinical benefit.
Austin J. Jolly, Sizhao Lu, Allison M. Dubner, Keith A. Strand, Marie F. Mutryn, Aaron Pilotti-Riley, Etienne P. Danis, Raphael A. Nemenoff, Karen S. Moulton, Mark W. Majesky, Mary C.M. Weiser-Evans
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