Ozone is a highly reactive environmental pollutant with well-recognized adverse effects on lung health. Bronchial hyperactivity (BHR) is one consequence of ozone exposure, particularly for individuals with underlying lung disease. Our data demonstrate ozone induces substantial ATP release from human airway epithelia in vitro and into the airways of mice in vivo, and that ATP is a potent inducer of mast cell degranulation and BHR, acting through P2X7 receptors on mast cells. Both mast cell-deficient and P2X7 receptor-deficient (P2XT-/-) mice demonstrate markedly attenuated BHR to ozone. Re-constitution of mast cell-deficient mice with WT mast cells and P2X7-/- mast cells restores ozone-induced BHR. Despite equal numbers of mast cells in reconstituted mouse lungs, mice reconstituted with P2X7-/- mast cells demonstrated significantly less robust BHR than mice reconstituted with WT mast cells. These results support a model where P2X7 on both mast cells and other cell types contribute to ozone-induce BHR.
Xiaomei Kong, William C. Bennett, Corey M. Jania, Kelly D. Chason, Zachary German, Jennifer Adouli, Samuel D. Budney, Brandon T. Oby, Catharina van Heusden, Eduardo R. Lazarowski, Ilona Jaspers, Scott H. Randell, Barry A. Hedgespeth, Glenn Cruse, Xiaoyang Hua, Stephen A. Schworer, Gregory J. Smith, Samir N. P. Kelada, Stephen L. Tilley
The epidermal growth factor receptor (EGFR) inhibitor cetuximab is the only FDA-approved oncogene-targeting therapy for head and neck squamous cell carcinoma (HNSCC). Despite variable treatment response, no biomarkers exist to stratify patients for cetuximab therapy in HNSCC. Here, we applied unbiased hierarchical clustering to reverse phase protein array (RPPA) molecular profiles from patient-derived xenograft (PDX) tumors, which revealed two PDX clusters defined by protein networks associated with EGFR inhibitor resistance. In vivo validation revealed unbiased clustering to classify PDX tumors with 88% accuracy. Next, a support vector machine (SVM) classifier algorithm identified a minimalist biomarker signature consisting of eight proteins – Caveolin-1, Sox-2, AXL, STING, Brd4, Claudin-7, Connexin-43, and Fibronectin – whose expression strongly predicted cetuximab response in PDXs using either protein (AUC=0.95) or mRNA (AUC=0.97). A combination of Caveolin-1 and Sox-2 protein levels was sufficient to maintain high predictive accuracy, which we validated in HNSCC patient tumor samples with known clinical response to cetuximab. These results support further investigation into the combined use of Caveolin-1 and Sox-2 as predictive biomarkers for cetuximab response in the clinic.
Mehdi Bouhaddou, Rex H. Lee, Hua Li, Neil E. Bhola, Rachel A. O'Keefe, Mohammad Naser, Tian Ran Zhu, Kelechi Nwachuku, Umamaheswar Duvvuri, Adam B. Olshen, Ritu Roy, Aaron Hechmer, Jennifer Bolen, Stephen B. Keysar, Antonio Jimeno, Gordon B. Mills, Scott Vandenberg, Danielle L. Swaney, Daniel E. Johnson, Nevan J. Krogan, Jennifer R. Grandis
Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disorder characterized by recurrent abscesses in the groin and flexural areas. HS is associated with a wide range of comorbidities that complicate the disease course. Although these comorbidities have been well-described, it remains unclear how these comorbidities co-associate and whether comorbidity profiles affect disease trajectory. In addition, it is unknown how comorbidity associations are modulated by race and gender. In this comprehensive analysis of 77 million patients in a large U.S. population-based cohort, we examine co-association patterns among HS comorbidities and identify clinically relevant phenotypic subtypes within HS. We demonstrate that these subtypes not only differ among races, but also influence clinical outcomes as measured by HS-related emergency department (ED) visits and cellulitis. Taken together, our findings provide key insights that elucidate the unique disease trajectories experienced by HS patients, and equip clinicians with a novel framework for risk stratification and improved targeted care in HS.
Vivian J. Hua, James M. Kilgour, Hyunje G. Cho, Shufeng Li, Kavita Y. Sarin
We recently described a previously unknown trans-tentorial venous system (TTVS) connecting venous drainage throughout the brain in humans. Prior to this finding, it was believed that the embryologic tentorial plexus regresses, resulting in a largely avascular tentorium. Our finding contradicted this understanding and necessitated further investigation into the development of the newly described TTVS. Herein we sought to investigate mice as a model to study the development of this system. First, using vascular casting and ex vivo micro-computed tomography (micro-CT), we demonstrate that this TTVS is conserved in adult mice. Next, using high-resolution magnetic resonance imaging (MRI), we found the primitive tentorial venous plexus in murine embryo at day 14.5. We also found that, at this embryologic stage, the tentorial plexus drains the choroid plexus. Finally, using vascular casting and micro-CT, we found that the TTVS is the dominant venous drainage in the early postnatal period (P8). Herein, we demonstrate that the TTVS is conserved between mice and humans and present a longitudinal study of its development. In addition, our findings establish mice as a translational model for further study of this newly described system and its relationship to intracranial physiology.
Pashayar P. Lookian, Vikram Chandrashekhar, Anthony Cappadona, Jean-Paul Bryant, Vibhu Chandrashekhar, Jessa M. Tunacao, Danielle R. Donahue, Jeeva P. Munasinghe, James G. Smirniotopoulos, John D. Heiss, Zhengping Zhuang, Jared S. Rosenblum
Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multi-organ ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used superresolution fluorescence microscopy and electron microscopy (TEM) to localize CEP290 in the CC and in primary cilia of cultured cells with sub-diffraction resolution, and to determine effects of CEP290 deficiency in three mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout the length of the CC whereas it is confined to the very base of primary cilia in hRPE-1 cells. We found Y-shaped links, ciliary sub-structures between microtubules and membrane, throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. There were fewer cilia and no normal outer segments in the mutants, but the Y-shaped links were clearly present. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.
Valencia L. Potter, Abigail R. Moye, Michael A. Robichaux, Theodore G. Wensel
Infection is a common complication of major trauma that causes significantly increased morbidity and mortality. The mechanisms however, linking tissue injury to increased susceptibility to infection remain poorly understood. To study this relationship, we present a novel murine model where a major liver crush injury is followed by bacterial inoculation into the lung. We find that such tissue trauma both impaired bacterial clearance and was associated with significant elevations in plasma heme levels. While neutrophil (PMN) recruitment to the lung in response to Staphylococcus aureus was unchanged after trauma, PMN cleared bacteria poorly. Moreover, PMN show >50% less expression of TLR2, which is responsible, in part, for bacterial recognition. Administration of heme effectively substituted for trauma. Last, day 1 trauma patients (n=9) showed similar elevations in free heme to that seen after murine liver injury and circulating PMN showed similar TLR2 reduction compared to volunteers (n=6). These findings correlate to high infection rates.
Ghee Rye Lee, David Gallo, Rodrigo W. Alves de Souza, Shilpa Tiwari-Heckler, Eva Csizmadia, James D. Harbison, Sidharth Shankar, Valerie Banner-Goodspeed, Michael B. Yaffe, Maria Serena Longhi, Carl J. Hauser, Leo E. Otterbein
Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease associated with unremitting fibroblast activation including fibroblast-to-myofibroblast transformation (FMT), migration, resistance to apoptotic clearance, and excessive deposition of extracellular matrix (ECM) proteins in the distal lung parenchyma. Aberrant activation of lung-developmental pathways is associated with severe fibrotic lung disease; however, the mechanisms through which these pathways activate fibroblasts in IPF remain unclear. Sox9 is a member of the HMG box family of DNA-binding transcription factors that are selectively expressed by epithelial cell progenitors to modulate branching morphogenesis during lung development. We demonstrate that Sox9 is upregulated via MAPK/PI3K-dependent signaling and by the transcription factor Wilms’ tumor 1 in distal lung-resident fibroblasts in IPF. Mechanistically, using fibroblast activation assays, we demonstrate that Sox9 functions as a positive regulator of FMT, migration, survival, and ECM production. Importantly, our in vivo studies demonstrate that fibroblast-specific deletion of Sox9 is sufficient to attenuate collagen deposition and improve lung function during TGFα-induced pulmonary fibrosis. Using a mouse model of bleomycin-induced pulmonary fibrosis, we show that myofibroblast-specific Sox9 overexpression augments fibroblast activation and pulmonary fibrosis. Thus, Sox9 functions as a profibrotic transcription factor in activating fibroblasts, illustrating the potential utility of targeting Sox9 in IPF treatment.
Prathibha R. Gajjala, Rajesh K. Kasam, Divyalakshmi Soundararajan, Debora Sinner, Steven K. Huang, Anil G. Jegga, Satish K. Madala
Endothelial dysfunction accompanies the microvascular thrombosis commonly observed in severe COVID-19. Constitutively, the endothelial surface is anticoagulant, a property maintained at least in part via signaling through the Tie2 receptor. During inflammation, the Tie2 antagonist angiopoietin-2 (Angpt-2) is released from endothelial cells and inhibits Tie2, promoting a prothrombotic phenotypic shift. We sought to assess whether severe COVID-19 is associated with procoagulant endothelial dysfunction and alterations in the Tie2-angiopoietin axis. Primary human endothelial cells treated with plasma from patients with severe COVID-19 upregulated expression of thromboinflammatory genes, inhibited expression of antithrombotic genes, and promoted coagulation on the endothelial surface. Pharmacologic activation of Tie2 with the small molecule AKB-9778 reversed the prothrombotic state induced by COVID-19 plasma in primary endothelial cells. Lung autopsies from COVID-19 patients demonstrated a prothrombotic endothelial signature. Assessment of circulating endothelial markers in a cohort of 98 patients with mild, moderate, or severe COVID-19 revealed endothelial dysfunction indicative of a prothrombotic state. Angpt-2 concentrations rose with increasing disease severity and highest levels were associated with worse survival. These data highlight the disruption of Tie2-angiopoietin signaling and procoagulant changes in endothelial cells in severe COVID-19. Our findings provide rationale for current trials of Tie2-activating therapy with AKB-9778 in COVID-19.
Alec A. Schmaier, Gabriel M. Pajares Hurtado, Zachary J. Manickas-Hill, Kelsey D. Sack, Siyu M. Chen, Victoria Bhambhani, Juweria Quadir, Anjali K. Nath, Ai-ris Y. Collier, Debby Ngo, Dan H. Barouch, Nathan I. Shapiro, Robert E. Gerszten, Xu Yu, Kevin G. Peters, Robert Flaumenhaft, Samir M. Parikh
Proline rich 11 (PRR11), a novel tumor-related gene, has been identified in different tumors. However, the relevant biological functions of PRR11 in human clear cell renal cell carcinoma (ccRCC) have not been studied. In this study, we first identified PRR11 as a biomarker of ccRCC and predictor of poor prognosis by bioinformatics. Then, we confirmed that PRR11 silencing significantly reduced ccRCC cell proliferation and migration in vitro and in vivo. Importantly, we found that PRR11 could induce the degradation of the E2F1 protein through its interaction with E2F1, and PRR11 reduced the stability of the E2F1 protein in ccRCC cells, thereby affecting cell cycle progression. Further results indicated that the downregulation of E2F1 expression could partially reverse the changes in ccRCC cell biology caused by PRR11 deletion. In addition, we proved for the first time that PRR11 is a target gene of c-Myc. The transcription factor c-Myc may promote the expression of PRR11 in ccRCC cells by binding to the PRR11 promoter region, thereby accelerating the progression of ccRCC. In summary, we found that PRR11 could serve as a novel oncogene in ccRCC, and PRR11 could reduce the protein stability of E2F1 and could be activated by c-Myc.
Siming Chen, Zhiwen He, Tiancheng Peng, Fenfang Zhou, Gang Wang, Kaiyu Qian, Lingao Ju, Yu Xiao, Xinghuan Wang
Autophagy has long been associated with longevity and it is well established that autophagy reverts and prevents vascular deterioration associated with aging and cardiovascular diseases. Currently, our understanding of how autophagy benefits the vasculature is centered on the premise that reduced autophagy leads to the accumulation of cellular debris resulting in inflammation and oxidative stress, which are then reversed by reconstitution or upregulation of autophagic activity. Evolutionarily, autophagy also functions to mobilize endogenous nutrients in response to starvation. Therefore, we hypothesized that the biosynthesis of the most physiologically abundant ketone body, β-hydroxybutyrate (βHB), would be autophagy dependent, and exert vasodilatory effects via its canonical receptor, Gpr109a. We have revealed for the first time that the biosynthesis of βHB can be impaired by preventing autophagy. Subsequently, βHB caused potent vasodilation via potassium-channels, but not Gpr109a. Finally, we observed that chronic consumption of a high salt diet negatively regulates both βHB biosynthesis and hepatic autophagy, and that reconstitution of βHB bioavailability prevents high salt diet-induced endothelial dysfunction. In summary, this work offers an alternative mechanism to the anti-inflammatory and anti-oxidative stress hypothesis of autophagy-dependent vasculoprotection. Furthermore, it reveals a direct mechanism, by which ketogenic interventions (e.g., intermittent fasting) improve vascular health.
Cameron G. McCarthy, Saroj Chakraborty, Gagandeep Singh, Beng San Yeoh, Zachary J. Schreckenberger, Avinash Singh, Blair Mell, Nicole R. Bearss, Tao Yang, Xi Cheng, Matam Vijay-Kumar, Camilla F. Wenceslau, Bina Joe
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