Immune checkpoint blockade (ICB) has demonstrated curative potential in several types of cancer, but only for a small number of patients. Thus, the identification of reliable and noninvasive biomarkers for predicting ICB responsiveness is an urgent unmet need. Here, we show that ICB increased tumor vessel perfusion in treatment-sensitive EO771 and MMTV-PyVT breast tumor as well as CT26 and MCA38 colon tumor models, but not in treatment-resistant MCaP0008 and 4T1 breast tumor models. In the sensitive tumor models, the ability of anti–cytotoxic T lymphocyte–associated protein 4 or anti–programmed cell death 1 therapy to increase vessel perfusion strongly correlated with its antitumor efficacy. Moreover, globally enhanced tumor vessel perfusion could be detected by Doppler ultrasonography before changes in tumor size, which predicted final therapeutic efficacy with more than 90% sensitivity and specificity. Mechanistically, CD8+ T cell depletion, IFN-γ neutralization, or implantation of tumors in IFN-γ receptor knockout mice abrogated the vessel perfusion enhancement and antitumor effects of ICB. These results demonstrated that ICB increased vessel perfusion by promoting CD8+ T cell accumulation and IFN-γ production, indicating that increased vessel perfusion reflects the successful activation of antitumor T cell immunity by ICB. Our findings suggest that vessel perfusion can be used as a novel noninvasive indicator for predicting ICB responsiveness.
Xichen Zheng, Zhaoxu Fang, Xiaomei Liu, Shengming Deng, Pei Zhou, Xuexiang Wang, Chenglin Zhang, Rongping Yin, Haitian Hu, Xiaolan Chen, Yijie Han, Yun Zhao, Steven H. Lin, Songbing Qin, Xiaohua Wang, Betty Y.S. Kim, Penghui Zhou, Wen Jiang, Qingyu Wu, Yuhui Huang
Pulmonary arterial hypertension (PAH) is characterized by a progressive accumulation of pulmonary artery smooth muscle cells (PA-SMCs) in pulmonary arterioles leading to the narrowing of the lumen, right heart failure, and death. Although most studies have supported the notion of a role for IL-6/glycoprotein 130 (gp130) signaling in PAH, it remains unclear how this signaling pathway determines the progression of the disease. Here, we identify ectopic upregulation of membrane-bound IL-6 receptor (IL6R) on PA-SMCs in PAH patients and in rodent models of pulmonary hypertension (PH) and demonstrate its key role for PA-SMC accumulation in vitro and in vivo. Using Sm22a-Cre Il6rfl/fl, which lack Il6r in SM22A-expressing cells, we found that these animals are protected against chronic hypoxia–induced PH with reduced PA-SMC accumulation, revealing the potent pro-survival potential of membrane-bound IL6R. Moreover, we determine that treatment with IL6R-specific antagonist reverses experimental PH in two rat models. This therapeutic strategy holds promise for future clinical studies in PAH.
Yuichi Tamura, Carole Phan, Ly Tu, Morane Le Hiress, Raphaël Thuillet, Etienne-Marie Jutant, Elie Fadel, Laurent Savale, Alice Huertas, Marc Humbert, Christophe Guignabert
Adult vascular smooth muscle cells (VSMCs) possess the peculiar ability to de-differentiate in response to extracellular cues, such as vascular damage and inflammation. De-differentiated VSMCs are proliferative, migratory, and have decreased contractile capacity. VSMC dedifferentiation contributes not only to vascular repair, but also to cardiovascular pathologies, such as intimal hyperplasia/restenosis in coronary artery or peripheral vascular diseases and arterial aneurysm. We here demonstrate the role of ubiquitin-like, containing PHD and RING finger domains, 1 (UHRF1) as an epigenetic master regulator of VSMC plasticity. The expression of UHRF1 correlates with the development of a wide array of vascular pathologies associated also with modulation of non-coding RNAs, such as microRNAs. Importantly, miR-145, a pivotal gene regulating VSMC plasticity, which is reduced in vascular diseases, was found to control Uhrf1 mRNA translation. In turn, UHRF1 triggers VSMC proliferation by directly repressing the promoters of cell cycle inhibitor genes, such as p21 and p27, and of key pro-differentiation genes via the methylation of DNA and histones. Local vascular viral delivery of Uhrf1 shRNAs or Uhrf1 VSMC-specific deletion prevented intimal hyperplasia in mouse carotid artery and decreased vessel damage in a mouse model of aortic aneurysm.Our study demonstrates the fundamental role of Uhrf1 in regulating VSMC phenotype by promoting proliferation and de-differentiation. UHRF1 targeting may hold therapeutic potential in vascular pathologies, modulating also the VSMC component.
Leonardo Elia, Paolo Kunderfranco, Pierluigi Carullo, Marco Vacchiano, Floriana Maria Farina, Ignacio Fernando Hall, Stefano Mantero, Cristina Panico, Roberto Papait, Gianluigi Condorelli, Manuela Quintavalle
BACKGROUND. Sporadic vascular malformations (VMs) are complex congenital anomalies of blood vessels that lead to stroke, life-threatening bleeds, disfigurement, overgrowth, and/or pain. Therapeutic options are severely limited and multi-disciplinary management remains challenging, particularly for high-flow arteriovenous malformations (AVM). METHODS. To investigate the pathogenesis of sporadic intracranial and extracranial VMs in 160 children in which known genetic causes had been excluded, we sequenced DNA from affected tissue and optimised analysis for detection of low mutant allele frequency. RESULTS. We discovered multiple mosaic activating variants in four genes of the RAS-MAPK pathway, KRAS, NRAS, BRAF, and MAP2K1, a pathway commonly activated in cancer and responsible for the germ-line RAS-opathies. These variants were more frequent in high-flow than low-flow VMs. In vitro characterisation and two transgenic zebrafish AVM models which recapitulated the human phenotype validated the pathogenesis of the mutant alleles. Importantly, treatment of AVM-BRAF mutant zebrafish with the BRAF inihibitor, Vemurafinib, restored blood flow in AVM. CONCLUSIONS. Our findings uncover a major cause of sporadic vascular malformations of different clinical types, and thereby offer the potential of personalised medical treatment by repurposing existing licensed cancer therapies. FUNDING. This work was funded or supported by grants from AVM Butterfly Charity, the Wellcome Trust (UK), the Medical Research Council (UK), the UK National Institute for Health Research, L’Oreal-Melanoma Research Alliance, the European Research Council, and the National Human Genome Research (US).
Lara Al-Olabi, Satyamaanasa Polubothu, Katherine Dowsett, Katrina A. Andrews, Paulina Stadnik, Agnel P. Joseph, Rachel Knox, Alan Pittman, Graeme Clark, William Baird, Neil Bulstrode, Mary Glover, Kristiana Gordon, Darren Hargrave, Susan M. Huson, Thomas S. Jacques, Gregory James, Hannah Kondolf, Loshan Kangesu, Kim M. Keppler-Noreuil, Amjad Khan, Marjorie J. Lindhurst, Mark Lipson, Sahar Mansour, Justine O'Hara, Caroline Mahon, Anda Mosica, Celia Moss, Aditi Murthy, Juling Ong, Victoria E. Parker, Jean-Baptiste Rivière, Julie C. Sapp, Neil J. Sebire, Rahul Shah, Branavan Sivakumar, Anna Thomas, Alex Virasami, Regula Waelchli, Zhiqiang Zeng, Leslie G. Biesecker, Alex Barnacle, Maya Topf, Robert K. Semple, E. Elizabeth Patton, Veronica A. Kinsler
Intake of hemoglobin by the hemoglobin-haptoglobin receptor CD163 leads to a distinct alternative non–foam cell antiinflammatory macrophage phenotype that was previously considered atheroprotective. Here, we reveal an unexpected but important pathogenic role for these macrophages in atherosclerosis. Using human atherosclerotic samples, cultured cells, and a mouse model of advanced atherosclerosis, we investigated the role of intraplaque hemorrhage on macrophage function with respect to angiogenesis, vascular permeability, inflammation, and plaque progression. In human atherosclerotic lesions, CD163+ macrophages were associated with plaque progression, microvascularity, and a high level of HIF1α and VEGF-A expression. We observed irregular vascular endothelial cadherin in intraplaque microvessels surrounded by CD163+ macrophages. Within these cells, activation of HIF1α via inhibition of prolyl hydroxylases promoted VEGF-mediated increases in intraplaque angiogenesis, vascular permeability, and inflammatory cell recruitment. CD163+ macrophages increased intraplaque endothelial VCAM expression and plaque inflammation. Subjects with homozygous minor alleles of the SNP rs7136716 had elevated microvessel density, increased expression of CD163 in ruptured coronary plaques, and a higher risk of myocardial infarction and coronary heart disease in population cohorts. Thus, our findings highlight a nonlipid-driven mechanism by which alternative macrophages promote plaque angiogenesis, leakiness, inflammation, and progression via the CD163/HIF1α/VEGF-A pathway.
Liang Guo, Hirokuni Akahori, Emanuel Harari, Samantha L. Smith, Rohini Polavarapu, Vinit Karmali, Fumiyuki Otsuka, Rachel L. Gannon, Ryan E. Braumann, Megan H. Dickinson, Anuj Gupta, Audrey L. Jenkins, Michael J. Lipinski, Johoon Kim, Peter Chhour, Paul S. de Vries, Hiroyuki Jinnouchi, Robert Kutys, Hiroyoshi Mori, Matthew D. Kutyna, Sho Torii, Atsushi Sakamoto, Cheol Ung Choi, Qi Cheng, Megan L. Grove, Mariem A. Sawan, Yin Zhang, Yihai Cao, Frank D. Kolodgie, David P. Cormode, Dan E. Arking, Eric Boerwinkle, Alanna C. Morrison, Jeanette Erdmann, Nona Sotoodehnia, Renu Virmani, Aloke V. Finn
Disordered coagulation contributes to death in sepsis and lacks effective treatments. Existing markers of disseminated intravascular coagulation (DIC) reflect its sequelae rather than its causes, delaying diagnosis and treatment. Here we show that disruption of the endothelial Tie2 axis is a sentinel event in septic DIC. Proteomics in septic DIC patients revealed a network involving inflammation and coagulation with the Tie2 antagonist, Angiopoietin-2 (Angpt-2), occupying a central node. Angpt-2 was strongly associated with traditional DIC markers including platelet counts, yet more accurately predicted mortality in two large independent cohorts (combined N = 1077). In endotoxemic mice, reduced Tie2 signaling preceded signs of overt DIC. During this early phase, intravital imaging of microvascular injury revealed excessive fibrin accumulation, a pattern remarkably mimicked by Tie2 deficiency even without inflammation. Conversely, Tie2 activation normalized pro-thrombotic responses by inhibiting endothelial tissue factor and phosphatidylserine exposure. Critically, Tie2 activation had no adverse effects on bleeding. These results mechanistically implicate Tie2 signaling as a central regulator of microvascular thrombus formation in septic DIC and indicate that circulating markers of the Tie2 axis could facilitate earlier diagnosis. Finally, interventions targeting Tie2 may normalize coagulation in inflammatory states while averting the bleeding risks of current DIC therapies.
Sarah J. Higgins, Karen De Ceunynck, John Kellum, Xiuying Chen, Xuesong Gu, Sharjeel A. Chaudhry, Sol Schulman, Towia A. Libermann, Shulin Lu, Nathan I. Shapiro, David C. Christiani, Robert Flaumenhaft, Samir M. Parikh
Before insulin can stimulate myocytes to take up glucose, it must first move from the circulation to the interstitial space. The continuous endothelium of skeletal muscle (SkM) capillaries restricts insulin’s access to myocytes. The mechanism by which insulin crosses this continuous endothelium is critical to understand insulin action and insulin resistance; however, methodological obstacles have limited understanding of endothelial insulin transport in vivo. Here, we present an intravital microscopy technique to measure the rate of insulin efflux across the endothelium of SkM capillaries. This method involves development of a fully bioactive, fluorescent insulin probe, a gastrocnemius preparation for intravital microscopy, an automated vascular segmentation algorithm, and the use of mathematical models to estimate endothelial transport parameters. We combined direct visualization of insulin efflux from SkM capillaries with modeling of insulin efflux kinetics to identify fluid-phase transport as the major mode of transendothelial insulin efflux in mice. Model-independent experiments demonstrating that insulin movement is neither saturable nor affected by insulin receptor antagonism supported this result. Our finding that insulin enters the SkM interstitium by fluid-phase transport may have implications in the pathophysiology of SkM insulin resistance as well as in the treatment of diabetes with various insulin analogs.
Ian M. Williams, Francisco A. Valenzuela, Steven D. Kahl, Doraiswami Ramkrishna, Adam R. Mezo, Jamey D. Young, K. Sam Wells, David H. Wasserman
Type 2 diabetes mellitus (T2DM) is a common complication of obesity. Here, we have shown that activation of the IgG receptor FcγRIIB in endothelium by hyposialylated IgG plays an important role in obesity-induced insulin resistance. Despite becoming obese on a high-fat diet (HFD), mice lacking FcγRIIB globally or selectively in endothelium were protected from insulin resistance as a result of the preservation of insulin delivery to skeletal muscle and resulting maintenance of muscle glucose disposal. IgG transfer in IgG-deficient mice implicated IgG as the pathogenetic ligand for endothelial FcγRIIB in obesity-induced insulin resistance. Moreover, IgG transferred from patients with T2DM but not from metabolically healthy subjects caused insulin resistance in IgG-deficient mice via FcγRIIB, indicating that similar processes may be operative in T2DM in humans. Mechanistically, the activation of FcγRIIB by IgG from obese mice impaired endothelial cell insulin transcytosis in culture and in vivo. These effects were attributed to hyposialylation of the Fc glycan, and IgG from T2DM patients was also hyposialylated. In HFD-fed mice, supplementation with the sialic acid precursor N-acetyl-D-mannosamine restored IgG sialylation and preserved insulin sensitivity without affecting weight gain. Thus, IgG sialylation and endothelial FcγRIIB may represent promising therapeutic targets to sever the link between obesity and T2DM.
Keiji Tanigaki, Anastasia Sacharidou, Jun Peng, Ken L. Chambliss, Ivan S. Yuhanna, Debabrata Ghosh, Mohamed Ahmed, Alexander J. Szalai, Wanpen Vongpatanasin, Robert F. Mattrey, Qiushi Chen, Parastoo Azadi, Ildiko Lingvay, Marina Botto, William L. Holland, Jennifer J. Kohler, Shashank R. Sirsi, Kenneth Hoyt, Philip W. Shaul, Chieko Mineo
Abnormal activity of the renin-angiotensin-aldosterone system plays a causal role in the development of hypertension, atherosclerosis, and associated cardiovascular events such as myocardial infarction, stroke, and heart failure. As both a vasoconstrictor and a proinflammatory mediator, angiotensin II (Ang II) is considered a potential link between hypertension and atherosclerosis. However, a role for Ang II–induced inflammation in atherosclerosis has not been clearly established, and the molecular mechanisms and intracellular signaling pathways involved are not known. Here, we demonstrated that the RhoA GEF Arhgef1 is essential for Ang II–induced inflammation. Specifically, we showed that deletion of Arhgef1 in a murine model prevents Ang II–induced integrin activation in leukocytes, thereby preventing Ang II–induced recruitment of leukocytes to the endothelium. Mice lacking both LDL receptor (LDLR) and Arhgef1 were protected from high-fat diet–induced atherosclerosis. Moreover, reconstitution of Ldlr–/– mice with Arhgef1-deficient BM prevented high-fat diet–induced atherosclerosis, while reconstitution of Ldlr–/– Arhgef1–/– with WT BM exacerbated atherosclerotic lesion formation, supporting Arhgef1 activation in leukocytes as causal in the development of atherosclerosis. Thus, our data highlight the importance of Arhgef1 in cardiovascular disease and suggest targeting Arhgef1 as a potential therapeutic strategy against atherosclerosis.
Maria Luigia Carbone, Gilliane Chadeuf, Sandrine Heurtebise-Chrétien, Xavier Prieur, Thibault Quillard, Yann Goueffic, Nathalie Vaillant, Marc Rio, Laure Castan, Maxim Durand, Céline Baron-Menguy, Julien Aureille, Juliette Desfrançois, Angela Tesse, Raul M. Torres, Gervaise Loirand
Primary congenital glaucoma (PCG) is a leading cause of blindness in children worldwide and is caused by developmental defects in 2 aqueous humor outflow structures, Schlemm’s canal (SC) and the trabecular meshwork. We previously identified loss-of-function mutations in the angiopoietin (ANGPT) receptor TEK in families with PCG and showed that ANGPT/TEK signaling is essential for SC development. Here, we describe roles for the major ANGPT ligands in the development of the aqueous outflow pathway. We determined that ANGPT1 is essential for SC development, and that Angpt1-knockout mice form a severely hypomorphic canal with elevated intraocular pressure. By contrast, ANGPT2 was dispensable, although mice deficient in both Angpt1 and Angpt2 completely lacked SC, indicating that ANGPT2 compensates for the loss of ANGPT1. In addition, we identified 3 human subjects with rare ANGPT1 variants within an international cohort of 284 PCG patients. Loss of function in 2 of the 3 patient alleles was observed by functional analysis of ANGPT1 variants in a combined in silico, in vitro, and in vivo approach, supporting a causative role for ANGPT1 in disease. By linking ANGPT1 with PCG, these results highlight the importance of ANGPT/TEK signaling in glaucoma pathogenesis and identify a candidate target for therapeutic development.
Benjamin R. Thomson, Tomokazu Souma, Stuart W. Tompson, Tuncer Onay, Krishnakumar Kizhatil, Owen M. Siggs, Liang Feng, Kristina N. Whisenhunt, Tammy L. Yanovitch, Luba Kalaydjieva, Dimitar N. Azmanov, Simone Finzi, Christine E. Tanna, Alex W. Hewitt, David A. Mackey, Yasmin S. Bradfield, Emmanuelle Souzeau, Shari Javadiyan, Janey L. Wiggs, Francesca Pasutto, Xiaorong Liu, Simon W.M. John, Jamie E. Craig, Jing Jin, Terri L. Young, Susan E. Quaggin