Vascular biology
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
Abstract
Brain metastasis is a major cause of breast cancer (BC) mortality, but the cellular and molecular mechanisms have not been fully elucidated. BC cells must breach the blood-brain barrier in order to colonize the brain. Here, we determined that integrin β3 (ITGB3) expression mediated by hypoxia-inducible factor 1 (HIF-1) plays a critical role in metastasis of BC cells to the brain. Hypoxia stimulated BC cell migration and invasion ex vivo and brain colonization in vivo. Knockdown of either HIF-1α or ITGB3 expression impaired brain colonization by human or mouse BC cells injected into the cardiac left ventricle. Exposure of BC cells to hypoxia increased expression of ITGB3 and its incorporation into small extracellular vesicles (EVs). EVs harvested from the conditioned medium of hypoxic BC cells showed increased retention in the brain after intracardiac injection that was HIF-1α and ITGB3 dependent. EVs from hypoxic BC cells showed binding to brain endothelial cells (ECs), leading to increased EC–BC cell interaction, increased vascular endothelial growth factor receptor 2 signaling, increased EC permeability, and increased transendothelial migration of BC cells. Taken together, our studies implicate HIF-1–stimulated production of ITGB3+ EVs as a key mechanism by which hypoxia promotes BC brain metastasis.
Authors
Yongkang Yang, Chelsey Chen, Yajing Lyu, Olesia Gololobova, Xin Guo, Tina Yi-Ting Huang, Vijay Ramu, Varen Talwar, Elizabeth E. Wicks, Shaima Salman, Daiana Drehmer, Dominic Dordai, Qiaozhu Zuo, Kenneth W. Witwer, Kathleen L. Gabrielson, Gregg L. Semenza
Abstract
Lymphatic vessels maintain tissue fluid homeostasis and modulate inflammation, yet their spatial organisation and molecular identity in the healthy human kidney, and how these change during chronic transplant rejection, remain poorly defined. Here, we show that lymphatic capillaries initiate adjacent to cortical kidney tubules and lack smooth muscle coverage. These vessels exhibit an organ-specific molecular signature, enriched for CCL14, DNASE1L3, and MDK, with limited expression of canonical immune-trafficking markers found in other organ lymphatics, such as LYVE1 and CXCL8. In allografts with chronic mixed rejection, lymphatics become disorganised and infiltrate the medulla, with their endothelial junctions remodelling from a button-like to a continuous, zipper-like architecture. Lymphatics in rejecting kidneys localise around and interconnect tertiary lymphoid structures at different maturation stages, with altered intra- and peri-lymphatic CD4⁺ T cell distribution. The infiltrating T cells express IFNγ, which upregulates co-inhibitory ligands in lymphatic endothelial cells, including PVR and LGALS9. Simultaneously, lymphatics acquire HLA class II expression and exhibit C4d deposition, consistent with alloantibody binding and complement activation. Together, these findings define the spatial and molecular features of human kidney lymphatics, revealing tolerogenic reprogramming, accompanied by structural perturbations, during chronic transplant rejection.
Authors
Daniyal J. Jafree, Benjamin J Stewart, Karen L. Price, Maria Kolatsi-Joannou, Camille Laroche, Barian Mohidin, Benjamin Davis, Hannah Mitchell, Lauren G. Russell, Lucía Marinas del Rey, Chun Jing Wang, William J. Mason, Byung Il Lee, Lauren Heptinstall, Ayshwarya Subramanian, Gideon Pomeranz, Dale Moulding, Laura Wilson, Tahmina Wickenden, Saif N. Malik, Natalie Holroyd, Claire L. Walsh, Jennifer C. Chandler, Kevin X. Cao, Paul J.D. Winyard, Adrian S. Woolf, Marc Aurel Busche, Simon Walker-Samuel, Lucy S.K. Walker, Tessa Crompton, Peter J. Scambler, Reza Motallebzadeh, Menna R. Clatworthy, David A. Long
Abstract
Vasculopathy is a common hallmark of various fibrotic disorders including systemic sclerosis (SSc), yet its underlying etiology and contribution to fibrogenesis remain ill-defined. In SSc the vasculopathy typically precedes the onset of fibrosis and we observed that this phenomenon is recapitulated in the Snail transgenic mouse model of SSc. The vascular anomalies manifest as deformed vessels, endothelial cell dysfunction and vascular leakage. Our investigation into the underlying mechanism of this phenotype revealed that angiopoietin-like protein 2 (ANGPTL2), secreted by the Snail transgenic keratinocytes, is a principal driver of fibrotic vasculopathy. In endothelial cells, ANGPTL2 upregulates pro-fibrotic genes, downregulates various junctional proteins, and prompts the acquisition of mesenchymal characteristics. Inhibiting endothelial cell junctional instability and consequently vascular leakage with a synthetic analog of the microbial metabolite Urolithin A (UAS03) effectively mitigated the vasculopathy and inhibited fibrogenesis. Thus, ANGPTL2 emerges as a promising early biomarker of the disease and inhibiting the vasculopathy inducing effects of this protein with agents such as UAS03 presents an appealing therapeutic avenue to reduce disease severity. These insights hold the potential to revolutionize the approach to the treatment of fibrotic diseases by targeting the vascular defects.
Authors
Dyuti Saha, Ravi Kiran Annadorai, Sujaya Thannimangalath, Neha P. Shroff, Sunny Kataria, Binita Dam, Abhik Dutta, Akshay Hegde, Ankita Hiwale, Venkatesh Ravula, Shagnik Saha, Lekshmi Minikumari Rahulan, Neha Nigam, Neha Singh, Vikas Agarwal, Praveen K. Vemula, Colin Jamora
Abstract
Authors
Rudy J. Castellani, Hinda Najem, Amy B. Heimberger, Pouya Jamshidi
Abstract
Myxomatous valve disease (MVD) is the most common form of cardiac valve disease in the developed world. A small fraction of MVD is syndromic and arises in association with matrix protein defects such as those in Marfan syndrome, but most MVD is acquired later in life through an undefined pathogenesis. The KLF2/4 transcription factors mediate endothelial fluid shear responses, including those required to create cardiac valves during embryonic development. Here we test the role of hemodynamic shear forces and downstream endothelial KLF2/4 in mature cardiac valves. We find that loss of hemodynamic forces in heterotopically transplanted hearts or genetic deletion of KLF2/4 in cardiac valve endothelium confers valve cell proliferation and matrix deposition associated with valve thickening, findings also observed in mice expressing the mutant fibrillin-1 protein known to cause human MVD. Transcriptomic and histologic analysis reveals increased monocyte recruitment and TGF-β signaling in both fibrillin-1–mutant valves and valves lacking hemodynamic forces or endothelial KLF2/4 function, but only loss of TGF-β/SMAD signaling rescued myxomatous changes. We observed reduced KLF2/4 expression and augmented SMAD signaling in human MVD. These studies identify hemodynamic activation of endothelial KLF2/4 as an environmental homeostatic regulator of cardiac valves and suggest that non-syndromic MVD may arise in association with disturbed blood flow across the aging valve.
Authors
Jesse A. Pace, Lauren M. Goddard, Courtney C. Hong, Liqing Wang, Jisheng Yang, Mei Chen, Yitian Xu, Martin H. Dominguez, Siqi Gao, Xiaowen Chen, Patricia Mericko-Ishizuka, Can Tan, Tsutomu Kume, Wenbao Yu, Kai Tan, Wayne W. Hancock, Giovanni Ferrari, Mark L. Kahn
Abstract
Authors
Lara Haase, Anouar Belkacemi, Laura Neises, Nicole Kiweler, Christine Wesely, Rosanna Huchzermeier, Maja Bozic, Arefeh Khakdan, Marta Sánchez, Arnaud Mary, Nadja Sachs, Hanna Winter, Enrico Glaab, Michael T. Heneka, Emiel P.C. van der Vorst, Michel Mittelbronn, Johannes Meiser, Jochen G. Schneider
Abstract
Pancreatic islet microvasculature is essential for optimal islet function and glucose homeostasis. However, islet vessel pathogenesis in obesity and its role in the manifestation of metabolic disorders remain understudied. Here, we depict the time-resolved decline of intra-islet endothelial cell responsiveness to vascular endothelial cell growth factor A (VEGF-A) and islet vessel function in a mouse model of diet-induced obesity. Longitudinal imaging of sentinel islets transplanted into mouse eyes revealed substantial vascular remodeling and diminished VEGF-A response in islet endothelial cells after 12 weeks of western diet (WD) feeding. This led to islet vessel barrier dysfunction and hemodynamic dysregulation, delaying transportation of secreted insulin into the blood. Notably, islet vessels exhibited a metabolic memory of previous WD feeding. Neither VEGF-A sensitivity nor the other vascular alterations was fully restored by control diet (CD) refeeding, resulting in modest yet significant impairment in glucose clearance despite normalized insulin sensitivity. Mechanistic analysis implicated hyperactivation of atypical protein kinase C (aPKC) under both WD and recovery conditions, which inhibited VEGF receptor 2 (VEGFR2) internalization and blunted VEGF-A triggered signal transduction in endothelial cells. In summary, prolonged WD feeding causes irreversible islet endothelial cell desensitization to VEGF-A and islet vessel dysfunction, directly undermining glucose homeostasis.
Authors
Yan Xiong, Andrea Dicker, Montse Visa, Erwin Ilegems, Per-Olof Berggren
PIEZO1 mediates mechanical reprogramming of neutrophils for proangiogenic specialization in the lung
Abstract
Neutrophils are the most abundant immune cells that constantly patrol or marginate inside vascular beds to support immune homeostasis. The extent to which neutrophils undergo reprogramming in response to the changes in vascular architecture and the resultant biological implications of such adaptations remain unclear. Here, we performed intravital imaging and transcriptional profiling to investigate neutrophil behavior across different tissues. Our findings revealed that neutrophils had significant deformability and spontaneous calcium signaling while navigating through the narrow pulmonary vessels. Pulmonary neutrophils exhibited unique transcriptional profiles and were specialized for proangiogenic functions. We found that the mechanosensitive ion channel Piezo-type mechanosensitive ion channel component 1 (PIEZO1) was essential for neutrophil reprogramming. Deletion of Piezo1 in neutrophils ablated the lung-specific proangiogenic transcriptional signature and impaired capillary angiogenesis in both physiological and pathological conditions. Collectively, these data show that mechanical adaptation of neutrophils within the pulmonary vasculature drives their reprogramming in the lungs and promotes pulmonary vascular homeostasis.
Authors
Jin Wang, Wenying Zhao, Wenjuan Bai, Dong Dong, Hui Wang, Xin Qi, Ajitha Thanabalasuriar, Youqiong Ye, Tian-le Xu, Hecheng Li, Paul Kubes, Bin Li, Jing Wang
Abstract
Atherosclerosis is a slowly progressing inflammatory disease characterized with cholesterol disorder and intimal plaques. Asparagine endopeptidase (AEP) is an endolysosomal protease that is activated under acidic conditions and is elevated substantially in both plasma and plaques of patients with atherosclerosis. However, how AEP accelerates atherosclerosis development remains incompletely understood, especially from the view of cholesterol metabolism. This project aims to reveal the crucial substrate of AEP during atherosclerosis plaque formation and to lay the foundation for developing novel therapeutic agents for Atherosclerosis. Here, we show that AEP is augmented in the atherosclerosis plaques obtained from patients and proteolytically cuts apolipoprotein A1 (APOA1) and impairs cholesterol efflux and high-density lipoprotein (HDL) formation, facilitating atherosclerosis pathologies. AEP is activated in the liver and aorta of apolipoprotein E–null (APOE-null) mice, and deletion of AEP from APOE–/– mice attenuates atherosclerosis. APOA1, an essential lipoprotein in HDL for cholesterol efflux, is cleaved by AEP at N208 residue in the liver and atherosclerotic macrophages of APOE–/– mice. Blockade of APOA1 cleavage by AEP via N208A mutation or its specific inhibitor, #11a, substantially diminishes atherosclerosis in both APOE–/– and LDLR–/– mice. Hence, our findings support that AEP disrupts cholesterol metabolism and accelerates the development of atherosclerosis.
Authors
Mengmeng Wang, Bowei Li, Shuke Nie, Xin Meng, Guangxing Wang, Menghan Yang, Wenxin Dang, Kangning He, Tucheng Sun, Ping Xu, Xifei Yang, Keqiang Ye
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)