Browsing by Subject "Endothelial Cells"
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Item Open Access An active learning approach for rapid characterization of endothelial cells in human tumors.(PLoS One, 2014) Padmanabhan, Raghav K; Somasundar, Vinay H; Griffith, Sandra D; Zhu, Jianliang; Samoyedny, Drew; Tan, Kay See; Hu, Jiahao; Liao, Xuejun; Carin, Lawrence; Yoon, Sam S; Flaherty, Keith T; Dipaola, Robert S; Heitjan, Daniel F; Lal, Priti; Feldman, Michael D; Roysam, Badrinath; Lee, William MFCurrently, no available pathological or molecular measures of tumor angiogenesis predict response to antiangiogenic therapies used in clinical practice. Recognizing that tumor endothelial cells (EC) and EC activation and survival signaling are the direct targets of these therapies, we sought to develop an automated platform for quantifying activity of critical signaling pathways and other biological events in EC of patient tumors by histopathology. Computer image analysis of EC in highly heterogeneous human tumors by a statistical classifier trained using examples selected by human experts performed poorly due to subjectivity and selection bias. We hypothesized that the analysis can be optimized by a more active process to aid experts in identifying informative training examples. To test this hypothesis, we incorporated a novel active learning (AL) algorithm into FARSIGHT image analysis software that aids the expert by seeking out informative examples for the operator to label. The resulting FARSIGHT-AL system identified EC with specificity and sensitivity consistently greater than 0.9 and outperformed traditional supervised classification algorithms. The system modeled individual operator preferences and generated reproducible results. Using the results of EC classification, we also quantified proliferation (Ki67) and activity in important signal transduction pathways (MAP kinase, STAT3) in immunostained human clear cell renal cell carcinoma and other tumors. FARSIGHT-AL enables characterization of EC in conventionally preserved human tumors in a more automated process suitable for testing and validating in clinical trials. The results of our study support a unique opportunity for quantifying angiogenesis in a manner that can now be tested for its ability to identify novel predictive and response biomarkers.Item Open Access Antagonists of the system L neutral amino acid transporter (LAT) promote endothelial adhesivity of human red blood cells.(Thrombosis and haemostasis, 2017-06) Dosier, Laura Beth Mann; Premkumar, Vikram J; Zhu, Hongmei; Akosman, Izzet; Wempe, Michael F; McMahon, Timothy JThe system L neutral amino acid transporter (LAT; LAT1, LAT2, LAT3, or LAT4) has multiple functions in human biology, including the cellular import of S-nitrosothiols (SNOs), biologically active derivatives of nitric oxide (NO). SNO formation by haemoglobin within red blood cells (RBC) has been studied, but the conduit whereby a SNO leaves the RBC remains unidentified. Here we hypothesised that SNO export by RBCs may also depend on LAT activity, and investigated the role of RBC LAT in modulating SNO-sensitive RBC-endothelial cell (EC) adhesion. We used multiple pharmacologic inhibitors of LAT in vitro and in vivo to test the role of LAT in SNO export from RBCs and in thereby modulating RBC-EC adhesion. Inhibition of human RBC LAT by type-1-specific or nonspecific LAT antagonists increased RBC-endothelial adhesivity in vitro, and LAT inhibitors tended to increase post-transfusion RBC sequestration in the lung and decreased oxygenation in vivo. A LAT1-specific inhibitor attenuated SNO export from RBCs, and we demonstrated LAT1 in RBC membranes and LAT1 mRNA in reticulocytes. The proadhesive effects of inhibiting LAT1 could be overcome by supplemental L-CSNO (S-nitroso-L-cysteine), but not D-CSNO or L-Cys, and suggest a basal anti-adhesive role for stereospecific intercellular SNO transport. This study reveals for the first time a novel role of LAT1 in the export of SNOs from RBCs to prevent their adhesion to ECs. The findings have implications for the mechanisms of intercellular SNO signalling, and for thrombosis, sickle cell disease, and post-storage RBC transfusion, when RBC adhesivity is increased.Item Open Access Antagonizing the irreversible thrombomodulin-initiated proteolytic signaling alleviates age-related liver fibrosis via senescent cell killing.(Cell research, 2023-07) Pan, Christopher C; Maeso-Díaz, Raquel; Lewis, Tylor R; Xiang, Kun; Tan, Lianmei; Liang, Yaosi; Wang, Liuyang; Yang, Fengrui; Yin, Tao; Wang, Calvin; Du, Kuo; Huang, De; Oh, Seh Hoon; Wang, Ergang; Lim, Bryan Jian Wei; Chong, Mengyang; Alexander, Peter B; Yao, Xuebiao; Arshavsky, Vadim Y; Li, Qi-Jing; Diehl, Anna Mae; Wang, Xiao-FanCellular senescence is a stress-induced, stable cell cycle arrest phenotype which generates a pro-inflammatory microenvironment, leading to chronic inflammation and age-associated diseases. Determining the fundamental molecular pathways driving senescence instead of apoptosis could enable the identification of senolytic agents to restore tissue homeostasis. Here, we identify thrombomodulin (THBD) signaling as a key molecular determinant of the senescent cell fate. Although normally restricted to endothelial cells, THBD is rapidly upregulated and maintained throughout all phases of the senescence program in aged mammalian tissues and in senescent cell models. Mechanistically, THBD activates a proteolytic feed-forward signaling pathway by stabilizing a multi-protein complex in early endosomes, thus forming a molecular basis for the irreversibility of the senescence program and ensuring senescent cell viability. Therapeutically, THBD signaling depletion or inhibition using vorapaxar, an FDA-approved drug, effectively ablates senescent cells and restores tissue homeostasis in liver fibrosis models. Collectively, these results uncover proteolytic THBD signaling as a conserved pro-survival pathway essential for senescent cell viability, thus providing a pharmacologically exploitable senolytic target for senescence-associated diseases.Item Open Access COVID-19 tissue atlases reveal SARS-CoV-2 pathology and cellular targets.(Nature, 2021-07) Delorey, Toni M; Ziegler, Carly GK; Heimberg, Graham; Normand, Rachelly; Yang, Yiming; Segerstolpe, Åsa; Abbondanza, Domenic; Fleming, Stephen J; Subramanian, Ayshwarya; Montoro, Daniel T; Jagadeesh, Karthik A; Dey, Kushal K; Sen, Pritha; Slyper, Michal; Pita-Juárez, Yered H; Phillips, Devan; Biermann, Jana; Bloom-Ackermann, Zohar; Barkas, Nikolaos; Ganna, Andrea; Gomez, James; Melms, Johannes C; Katsyv, Igor; Normandin, Erica; Naderi, Pourya; Popov, Yury V; Raju, Siddharth S; Niezen, Sebastian; Tsai, Linus T-Y; Siddle, Katherine J; Sud, Malika; Tran, Victoria M; Vellarikkal, Shamsudheen K; Wang, Yiping; Amir-Zilberstein, Liat; Atri, Deepak S; Beechem, Joseph; Brook, Olga R; Chen, Jonathan; Divakar, Prajan; Dorceus, Phylicia; Engreitz, Jesse M; Essene, Adam; Fitzgerald, Donna M; Fropf, Robin; Gazal, Steven; Gould, Joshua; Grzyb, John; Harvey, Tyler; Hecht, Jonathan; Hether, Tyler; Jané-Valbuena, Judit; Leney-Greene, Michael; Ma, Hui; McCabe, Cristin; McLoughlin, Daniel E; Miller, Eric M; Muus, Christoph; Niemi, Mari; Padera, Robert; Pan, Liuliu; Pant, Deepti; Pe'er, Carmel; Pfiffner-Borges, Jenna; Pinto, Christopher J; Plaisted, Jacob; Reeves, Jason; Ross, Marty; Rudy, Melissa; Rueckert, Erroll H; Siciliano, Michelle; Sturm, Alexander; Todres, Ellen; Waghray, Avinash; Warren, Sarah; Zhang, Shuting; Zollinger, Daniel R; Cosimi, Lisa; Gupta, Rajat M; Hacohen, Nir; Hibshoosh, Hanina; Hide, Winston; Price, Alkes L; Rajagopal, Jayaraj; Tata, Purushothama Rao; Riedel, Stefan; Szabo, Gyongyi; Tickle, Timothy L; Ellinor, Patrick T; Hung, Deborah; Sabeti, Pardis C; Novak, Richard; Rogers, Robert; Ingber, Donald E; Jiang, Z Gordon; Juric, Dejan; Babadi, Mehrtash; Farhi, Samouil L; Izar, Benjamin; Stone, James R; Vlachos, Ioannis S; Solomon, Isaac H; Ashenberg, Orr; Porter, Caroline BM; Li, Bo; Shalek, Alex K; Villani, Alexandra-Chloé; Rozenblatt-Rosen, Orit; Regev, AvivCOVID-19, which is caused by SARS-CoV-2, can result in acute respiratory distress syndrome and multiple organ failure1-4, but little is known about its pathophysiology. Here we generated single-cell atlases of 24 lung, 16 kidney, 16 liver and 19 heart autopsy tissue samples and spatial atlases of 14 lung samples from donors who died of COVID-19. Integrated computational analysis uncovered substantial remodelling in the lung epithelial, immune and stromal compartments, with evidence of multiple paths of failed tissue regeneration, including defective alveolar type 2 differentiation and expansion of fibroblasts and putative TP63+ intrapulmonary basal-like progenitor cells. Viral RNAs were enriched in mononuclear phagocytic and endothelial lung cells, which induced specific host programs. Spatial analysis in lung distinguished inflammatory host responses in lung regions with and without viral RNA. Analysis of the other tissue atlases showed transcriptional alterations in multiple cell types in heart tissue from donors with COVID-19, and mapped cell types and genes implicated with disease severity based on COVID-19 genome-wide association studies. Our foundational dataset elucidates the biological effect of severe SARS-CoV-2 infection across the body, a key step towards new treatments.Item Open Access Disrupting the vicious cycle created by NOX activation in sickle erythrocytes exposed to hypoxia/reoxygenation prevents adhesion and vasoocclusion.(Redox biology, 2019-07) MacKinney, Anson; Woska, Emily; Spasojevic, Ivan; Batinic-Haberle, Ines; Zennadi, RahimaIn sickle cell disease (SCD), recurrent painful vasoocclusive crisis are likely caused by repeated episodes of hypoxia and reoxygenation. The sickle erythrocyte (SSRBC) adhesion plays an active role in vasoocclusion. However, the effect of prolonged reoxygenation after hypoxic stress on the molecular mechanisms in SSRBCs involved in onset of episodic vasoocclusion remain unclear. Exposure of human SSRBCs to hypoxia followed by 2 h reoxygenation, increased reactive oxygen species (ROS) production. Using specific pharmacological inhibitors, we show that excess ROS production in both reticulocytes and mature SSRBCs is regulated by NADPH oxidases (NOXs), the mitogen-activated protein kinase (ERK1/2), and G-protein coupled-receptor kinase 2 (GRK2). Consequently, SSRBC ROS create an intracellular positive feedback loop with ERK1/2 and GRK2 to mediate SSRBC adhesion to endothelium in vitro, and vasoocclusion in a mouse model of vasoocclusion in vivo. Importantly, reducing ROS levels in SSRBCs with redox-active manganese (Mn) porphyrins, commonly known as mimics of superoxide dismutase (SOD), disrupted the cycle created by ROS by affecting NOX and GRK2 activities and ERK1/2 phosphorylation, thus abrogating RBC-endothelial interactions. Inhibition adhesion assays show that LW (ICAM-4, CD242) blood group glycoprotein and CD44 are the RBC adhesion molecules mediating endothelial binding. Conversely, hypoxia/reoxygenation of normal RBCs failed to activate this feedback loop, and adhesion. These findings provide novel insights into the pathophysiological significance of the deleterious cycle created by NOX-dependent ROS, GRK2 and ERK1/2 within SSRBCs activated by hypoxia/reoxygenation, and involved in SSRBC adhesion and vasoocclusion. Thus, this loop in SSRBCs, which can be disrupted by Mn porphyrins, likely drives the profound SCD vasculopathy, and may point to new therapeutic targets to prevent chronic vasoocclusive events.Item Open Access Dose-dependent expression of claudin-5 is a modifying factor in schizophrenia.(Molecular psychiatry, 2018-11) Greene, C; Kealy, J; Humphries, MM; Gong, Y; Hou, J; Hudson, N; Cassidy, LM; Martiniano, R; Shashi, V; Hooper, SR; Grant, GA; Kenna, PF; Norris, K; Callaghan, CK; Islam, M dN; O'Mara, SM; Najda, Z; Campbell, SG; Pachter, JS; Thomas, J; Williams, NM; Humphries, P; Murphy, KC; Campbell, MSchizophrenia is a neurodevelopmental disorder that affects up to 1% of the general population. Various genes show associations with schizophrenia and a very weak nominal association with the tight junction protein, claudin-5, has previously been identified. Claudin-5 is expressed in endothelial cells forming part of the blood-brain barrier (BBB). Furthermore, schizophrenia occurs in 30% of individuals with 22q11 deletion syndrome (22q11DS), a population who are haploinsufficient for the claudin-5 gene. Here, we show that a variant in the claudin-5 gene is weakly associated with schizophrenia in 22q11DS, leading to 75% less claudin-5 being expressed in endothelial cells. We also show that targeted adeno-associated virus-mediated suppression of claudin-5 in the mouse brain results in localized BBB disruption and behavioural changes. Using an inducible 'knockdown' mouse model, we further link claudin-5 suppression with psychosis through a distinct behavioural phenotype showing impairments in learning and memory, anxiety-like behaviour and sensorimotor gating. In addition, these animals develop seizures and die after 3-4 weeks of claudin-5 suppression, reinforcing the crucial role of claudin-5 in normal neurological function. Finally, we show that anti-psychotic medications dose-dependently increase claudin-5 expression in vitro and in vivo while aberrant, discontinuous expression of claudin-5 in the brains of schizophrenic patients post mortem was observed compared to age-matched controls. Together, these data suggest that BBB disruption may be a modifying factor in the development of schizophrenia and that drugs directly targeting the BBB may offer new therapeutic opportunities for treating this disorder.Item Open Access Exosome-eluting stents for vascular healing after ischaemic injury.(Nature biomedical engineering, 2021-10) Hu, Shiqi; Li, Zhenhua; Shen, Deliang; Zhu, Dashuai; Huang, Ke; Su, Teng; Dinh, Phuong-Uyen; Cores, Jhon; Cheng, KeDrug-eluting stents implanted after ischaemic injury reduce the proliferation of endothelial cells and vascular smooth muscle cells and thus neointimal hyperplasia. However, the eluted drug also slows down the re-endothelialization process, delays arterial healing and can increase the risk of late restenosis. Here we show that stents releasing exosomes derived from mesenchymal stem cells in the presence of reactive oxygen species enhance vascular healing in rats with renal ischaemia-reperfusion injury, promoting endothelial cell tube formation and proliferation, and impairing the migration of smooth muscle cells. Compared with drug-eluting stents and bare-metal stents, the exosome-coated stents accelerated re-endothelialization and decreased in-stent restenosis 28 days after implantation. We also show that exosome-eluting stents implanted in the abdominal aorta of rats with unilateral hindlimb ischaemia regulated macrophage polarization, reduced local vascular and systemic inflammation, and promoted muscle tissue repair.Item Open Access Genome-wide analysis identifies novel susceptibility loci for myocardial infarction.(European heart journal, 2021-03) Hartiala, Jaana A; Han, Yi; Jia, Qiong; Hilser, James R; Huang, Pin; Gukasyan, Janet; Schwartzman, William S; Cai, Zhiheng; Biswas, Subarna; Trégouët, David-Alexandre; Smith, Nicholas L; INVENT Consortium; CHARGE Consortium Hemostasis Working Group; GENIUS-CHD Consortium; Seldin, Marcus; Pan, Calvin; Mehrabian, Margarete; Lusis, Aldons J; Bazeley, Peter; Sun, Yan V; Liu, Chang; Quyyumi, Arshed A; Scholz, Markus; Thiery, Joachim; Delgado, Graciela E; Kleber, Marcus E; März, Winfried; Howe, Laurence J; Asselbergs, Folkert W; van Vugt, Marion; Vlachojannis, Georgios J; Patel, Riyaz S; Lyytikäinen, Leo-Pekka; Kähönen, Mika; Lehtimäki, Terho; Nieminen, Tuomo VM; Kuukasjärvi, Pekka; Laurikka, Jari O; Chang, Xuling; Heng, Chew-Kiat; Jiang, Rong; Kraus, William E; Hauser, Elizabeth R; Ferguson, Jane F; Reilly, Muredach P; Ito, Kaoru; Koyama, Satoshi; Kamatani, Yoichiro; Komuro, Issei; Biobank Japan; Stolze, Lindsey K; Romanoski, Casey E; Khan, Mohammad Daud; Turner, Adam W; Miller, Clint L; Aherrahrou, Redouane; Civelek, Mete; Ma, Lijiang; Björkegren, Johan LM; Kumar, S Ram; Tang, WH Wilson; Hazen, Stanley L; Allayee, HoomanAims
While most patients with myocardial infarction (MI) have underlying coronary atherosclerosis, not all patients with coronary artery disease (CAD) develop MI. We sought to address the hypothesis that some of the genetic factors which establish atherosclerosis may be distinct from those that predispose to vulnerable plaques and thrombus formation.Methods and results
We carried out a genome-wide association study for MI in the UK Biobank (n∼472 000), followed by a meta-analysis with summary statistics from the CARDIoGRAMplusC4D Consortium (n∼167 000). Multiple independent replication analyses and functional approaches were used to prioritize loci and evaluate positional candidate genes. Eight novel regions were identified for MI at the genome wide significance level, of which effect sizes at six loci were more robust for MI than for CAD without the presence of MI. Confirmatory evidence for association of a locus on chromosome 1p21.3 harbouring choline-like transporter 3 (SLC44A3) with MI in the context of CAD, but not with coronary atherosclerosis itself, was obtained in Biobank Japan (n∼165 000) and 16 independent angiography-based cohorts (n∼27 000). Follow-up analyses did not reveal association of the SLC44A3 locus with CAD risk factors, biomarkers of coagulation, other thrombotic diseases, or plasma levels of a broad array of metabolites, including choline, trimethylamine N-oxide, and betaine. However, aortic expression of SLC44A3 was increased in carriers of the MI risk allele at chromosome 1p21.3, increased in ischaemic (vs. non-diseased) coronary arteries, up-regulated in human aortic endothelial cells treated with interleukin-1β (vs. vehicle), and associated with smooth muscle cell migration in vitro.Conclusions
A large-scale analysis comprising ∼831 000 subjects revealed novel genetic determinants of MI and implicated SLC44A3 in the pathophysiology of vulnerable plaques.Item Open Access Interstitial engraftment of adipose-derived stem cells into an acellular dermal matrix results in improved inward angiogenesis and tissue incorporation.(J Biomed Mater Res A, 2013-10) Komatsu, Issei; Yang, Jun; Zhang, Ying; Levin, L Scott; Erdmann, D; Klitzman, Bruce; Hollenbeck, Scott TAcellular dermal matrices (ADM) are commonly used in reconstructive procedures and rely on host cell invasion to become incorporated into host tissues. We investigated different approaches to adipose-derived stem cells (ASCs) engraftment into ADM to enhance this process. Lewis rat adipose-derived stem cells were isolated and grafted (3.0 × 10(5) cells) to porcine ADM disks (1.5 mm thick × 6 mm diameter) using either passive onlay or interstitial injection seeding techniques. Following incubation, seeding efficiency and seeded cell viability were measured in vitro. In addition, Eighteen Lewis rats underwent subcutaneous placement of ADM disk either as control or seeded with PKH67 labeled ASCs. ADM disks were seeded with ASCs using either onlay or injection techniques. On day 7 and or 14, ADM disks were harvested and analyzed for host cell infiltration. Onlay and injection techniques resulted in unique seeding patterns; however cell seeding efficiency and cell viability were similar. In-vivo studies showed significantly increased host cell infiltration towards the ASCs foci following injection seeding in comparison to control group (p < 0.05). Moreover, regional endothelial cell invasion was significantly greater in ASCs injected grafts in comparison to onlay seeding (p < 0.05). ADM can successfully be engrafted with ASCs. Interstitial engraftment of ASCs into ADM via injection enhances regional infiltration of host cells and angiogenesis, whereas onlay seeding showed relatively broad and superficial cell infiltration. These findings may be applied to improve the incorporation of avascular engineered constructs.Item Open Access JAK inhibitor blocks COVID-19 cytokine-induced JAK/STAT/APOL1 signaling in glomerular cells and podocytopathy in human kidney organoids.(JCI insight, 2022-06) Nystrom, Sarah E; Li, Guojie; Datta, Somenath; Soldano, Karen L; Silas, Daniel; Weins, Astrid; Hall, Gentzon; Thomas, David B; Olabisi, Opeyemi ACOVID-19 infection causes collapse of glomerular capillaries and loss of podocytes, culminating in a severe kidney disease called COVID-19-associated nephropathy (COVAN). The underlying mechanism of COVAN is unknown. We hypothesized that cytokines induced by COVID-19 trigger expression of pathogenic APOL1 via JAK/STAT signaling, resulting in podocyte loss and COVAN phenotype. Here, based on 9 biopsy-proven COVAN cases, we demonstrated for the first time, to the best of our knowledge, that APOL1 protein was abundantly expressed in podocytes and glomerular endothelial cells (GECs) of COVAN kidneys but not in controls. Moreover, a majority of patients with COVAN carried 2 APOL1 risk alleles. We show that recombinant cytokines induced by SARS-CoV-2 acted synergistically to drive APOL1 expression through the JAK/STAT pathway in primary human podocytes, GECs, and kidney micro-organoids derived from a carrier of 2 APOL1 risk alleles, but expression was blocked by a JAK1/2 inhibitor, baricitinib. We demonstrate that cytokine-induced JAK/STAT/APOL1 signaling reduced the viability of kidney organoid podocytes but was rescued by baricitinib. Together, our results support the conclusion that COVID-19-induced cytokines are sufficient to drive COVAN-associated podocytopathy via JAK/STAT/APOL1 signaling and that JAK inhibitors could block this pathogenic process. These findings suggest JAK inhibitors may have therapeutic benefits for managing cytokine-induced, APOL1-mediated podocytopathy.Item Open Access Patient-derived endothelial progenitor cells improve vascular graft patency in a rodent model.(Acta Biomater, 2012-01) Stroncek, JD; Ren, LC; Klitzman, B; Reichert, WMLate outgrowth endothelial progenitor cells (EPCs) derived from the peripheral blood of patients with significant coronary artery disease were sodded into the lumens of small diameter expanded polytetrafluoroethylene (ePTFE) vascular grafts. Grafts (1mm inner diameter) were denucleated and sodded either with native EPCs or with EPCs transfected with an adenoviral vector containing the gene for human thrombomodulin (EPC+AdTM). EPC+AdTM was shown to increase the in vitro rate of graft activated protein C (APC) production 4-fold over grafts sodded with untransfected EPCs (p<0.05). Unsodded control and EPC-sodded and EPC+AdTM-sodded grafts were implanted bilaterally into the femoral arteries of athymic rats for 7 or 28 days. Unsodded control grafts, both with and without denucleation treatment, each exhibited 7 day patency rates of 25%. Unsodded grafts showed extensive thrombosis and were not tested for patency over 28 days. In contrast, grafts sodded with untransfected EPCs or EPC+AdTM both had 7 day patency rates of 88-89% and 28 day patency rates of 75-88%. Intimal hyperplasia was observed near both the proximal and distal anastomoses in all sodded graft conditions but did not appear to be the primary occlusive failure event. This in vivo study suggests autologous EPCs derived from the peripheral blood of patients with coronary artery disease may improve the performance of synthetic vascular grafts, although no differences were observed between untransfected EPCs and TM transfected EPCs.Item Open Access Peptide interfacial biomaterials improve endothelial cell adhesion and spreading on synthetic polyglycolic acid materials.(Ann Biomed Eng, 2010-06) Huang, Xin; Zauscher, Stefan; Klitzman, Bruce; Truskey, George A; Reichert, William M; Kenan, Daniel J; Grinstaff, Mark WResorbable scaffolds such as polyglycolic acid (PGA) are employed in a number of clinical and tissue engineering applications owing to their desirable property of allowing remodeling to form native tissue over time. However, native PGA does not promote endothelial cell adhesion. Here we describe a novel treatment with hetero-bifunctional peptide linkers, termed "interfacial biomaterials" (IFBMs), which are used to alter the surface of PGA to provide appropriate biological cues. IFBMs couple an affinity peptide for the material with a biologically active peptide that promotes desired cellular responses. One such PGA affinity peptide was coupled to the integrin binding domain, Arg-Gly-Asp (RGD), to build a chemically synthesized bimodular 27 amino acid peptide that mediated interactions between PGA and integrin receptors on endothelial cells. Quartz crystal microbalance with dissipation monitoring (QCMD) was used to determine the association constant (K (A) 1 x 10(7) M(-1)) and surface thickness (~3.5 nm). Cell binding studies indicated that IFBM efficiently mediated adhesion, spreading, and cytoskeletal organization of endothelial cells on PGA in an integrin-dependent manner. We show that the IFBM peptide promotes a 200% increase in endothelial cell binding to PGA as well as 70-120% increase in cell spreading from 30 to 60 minutes after plating.Item Open Access Pollutant particles produce vasoconstriction and enhance MAPK signaling via angiotensin type I receptor.(Environmental health perspectives, 2005-08) Li, Zhuowei; Carter, Jacqueline D; Dailey, Lisa A; Huang, Yuh-Chin TExposure to particulate matter (PM) is associated with acute cardiovascular mortality and morbidity, but the mechanisms are not entirely clear. In this study, we hypothesized that PM may activate the angiotensin type 1 receptor (AT1R), a G protein-coupled receptor that regulates inflammation and vascular function. We investigated the acute effects of St. Louis, Missouri, urban particles (UPs; Standard Reference Material 1648) on the constriction of isolated rat pulmonary artery rings and the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinases (MAPKs) in human pulmonary artery endothelial cells with or without losartan, an antagonist of AT1R. UPs at 1-100 microg/mL induced acute vasoconstriction in pulmonary artery. UPs also produced a time- and dose-dependent increase in phosphorylation of ERK1/2 and p38 MAPK. Losartan pretreatment inhibited both the vasoconstriction and the activation of ERK1/2 and p38. The water-soluble fraction of UPs was sufficient for inducing ERK1/2 and p38 phosphorylation, which was also losartan inhibitable. Copper and vanadium, two soluble transition metals contained in UPs, induced pulmonary vasoconstriction and phosphorylation of ERK1/2 and p38, but only the phosphorylation of p38 was inhibited by losartan. The UP-induced activation of ERK1/2 and p38 was attenuated by captopril, an angiotensin-converting enzyme inhibitor. These results indicate that activation of the local renin-angiotensin system may play an important role in cardiovascular effects induced by PM.Item Open Access Porcine endothelial cells cocultured with smooth muscle cells became procoagulant in vitro.(Tissue Eng Part A, 2010-06) Pang, Zhengyu; Niklason, Laura E; Truskey, George AEndothelial cell (EC) seeding represents a promising approach to provide a nonthrombogenic surface on vascular grafts. In this study, we used a porcine EC/smooth muscle cell (SMC) coculture model that was previously developed to examine the efficacy of EC seeding. Expression of tissue factor (TF), a primary initiator in the coagulation cascade, and TF activity were used as indicators of thrombogenicity. Using immunostaining, primary cultures of porcine EC showed a low level of TF expression, but a highly heterogeneous distribution pattern with 14% of ECs expressing TF. Quiescent primary cultures of porcine SMCs displayed a high level of TF expression and a uniform pattern of staining. When we used a two-stage amidolytic assay, TF activity of ECs cultured alone was very low, whereas that of SMCs was high. ECs cocultured with SMCs initially showed low TF activity, but TF activity of cocultures increased significantly 7-8 days after EC seeding. The increased TF activity was not due to the activation of nuclear factor kappa-B on ECs and SMCs, as immunostaining for p65 indicated that nuclear factor kappa-B was localized in the cytoplasm in an inactive form in both ECs and SMCs. Rather, increased TF activity appeared to be due to the elevated reactive oxygen species levels and contraction of the coculture, thereby compromising the integrity of EC monolayer and exposing TF on SMCs. The incubation of cocultures with N-acetyl-cysteine (2 mM), an antioxidant, inhibited contraction, suggesting involvement of reactive oxygen species in regulating the contraction. The results obtained from this study provide useful information for understanding thrombosis in tissue-engineered vascular grafts.Item Open Access Recent advances in lung organoid development and applications in disease modeling.(The Journal of clinical investigation, 2023-11) Vazquez-Armendariz, Ana I; Tata, Purushothama RaoOver the last decade, several organoid models have evolved to acquire increasing cellular, structural, and functional complexity. Advanced lung organoid platforms derived from various sources, including adult, fetal, and induced pluripotent stem cells, have now been generated, which more closely mimic the cellular architecture found within the airways and alveoli. In this regard, the establishment of novel protocols with optimized stem cell isolation and culture conditions has given rise to an array of models able to study key cellular and molecular players involved in lung injury and repair. In addition, introduction of other nonepithelial cellular components, such as immune, mesenchymal, and endothelial cells, and employment of novel precision gene editing tools have further broadened the range of applications for these systems by providing a microenvironment and/or phenotype closer to the desired in vivo scenario. Thus, these developments in organoid technology have enhanced our ability to model various aspects of lung biology, including pathogenesis of diseases such as chronic obstructive pulmonary disease, pulmonary fibrosis, cystic fibrosis, and infectious disease and host-microbe interactions, in ways that are often difficult to undertake using only in vivo models. In this Review, we summarize the latest developments in lung organoid technology and their applicability for disease modeling and outline their strengths, drawbacks, and potential avenues for future development.Item Open Access Sensitization of Vascular Endothelial Cells to Ionizing Radiation Promotes the Development of Delayed Intestinal Injury in Mice.(Radiation research, 2019-09) Lee, Chang-Lung; Daniel, Andrea R; Holbrook, Matt; Brownstein, Jeremy; Silva Campos, Lorraine Da; Hasapis, Stephanie; Ma, Yan; Borst, Luke B; Badea, Cristian T; Kirsch, David GExposure of the gastrointestinal (GI) tract to ionizing radiation can cause acute and delayed injury. However, critical cellular targets that regulate the development of radiation-induced GI injury remain incompletely understood. Here, we investigated the role of vascular endothelial cells in controlling acute and delayed GI injury after total-abdominal irradiation (TAI). To address this, we used genetically engineered mice in which endothelial cells are sensitized to radiation due to the deletion of the tumor suppressor p53. Remarkably, we found that VE-cadherin-Cre; p53FL/FL mice, in which both alleles of p53 are deleted in endothelial cells, were not sensitized to the acute GI radiation syndrome, but these mice were highly susceptible to delayed radiation enteropathy. Histological examination indicated that VE-cadherin-Cre; p53FL/FL mice that developed delayed radiation enteropathy had severe vascular injury in the small intestine, which was manifested by hemorrhage, loss of microvessels and tissue hypoxia. In addition, using dual-energy CT imaging, we showed that VE-cadherin-Cre; p53FL/FL mice had a significant increase in vascular permeability of the small intestine in vivo 28 days after TAI. Together, these findings demonstrate that while sensitization of endothelial cells to radiation does not exacerbate the acute GI radiation syndrome, it is sufficient to promote the development of late radiation enteropathy.Item Open Access Tissue engraftment of hypoxic-preconditioned adipose-derived stem cells improves flap viability.(Wound Repair Regen, 2012-11) Hollenbeck, Scott T; Senghaas, Annika; Komatsu, Issei; Zhang, Ying; Erdmann, Detlev; Klitzman, BruceAdipose-derived stem cells (ASCs) have the ability to release multiple growth factors in response to hypoxia. In this study, we investigated the potential of ASCs to prevent tissue ischemia. We found conditioned media from hypoxic ASCs had increased levels of vascular endothelial growth factor (VEGF) and enhanced endothelial cell tubule formation. To investigate the effect of injecting rat ASCs into ischemic flaps, 21 Lewis rats were divided into three groups: control, normal oxygen ASCs (10(6) cells), and hypoxic preconditioned ASCs (10(6) cells). At the time of flap elevation, the distal third of the flap was injected with the treatment group. At 7 days post flap elevation, flap viability was significantly improved with injection of hypoxic preconditioned ASCs. Cluster of differentiation-31-positive cells were more abundant along the margins of flaps injected with ASCs. Fluorescent labeled ASCs localized aside blood vessels or throughout the tissue, dependent on oxygen preconditioning status. Next, we evaluated the effect of hypoxic preconditioning on ASC migration and chemotaxis. Hypoxia did not affect ASC migration on scratch assay or chemotaxis to collagen and laminin. Thus, hypoxic preconditioning of injected ASCs improves flap viability likely through the effects of VEGF release. These effects are modest and represent the limitations of cellular and growth factor-induced angiogenesis in the acute setting of ischemia.Item Open Access Up-regulation of tissue factor in human pulmonary artery endothelial cells after ultrafine particle exposure.(Environmental health perspectives, 2007-04) Karoly, ED; Li, Z; Dailey, LA; Hyseni, X; Huang, YCBACKGROUND: Epidemiology studies have linked exposure to pollutant particles to increased cardiovascular mortality and morbidity, but the mechanisms remain unknown. OBJECTIVES: We tested the hypothesis that the ultrafine fraction of ambient pollutant particles would cause endothelial cell dysfunction. METHODS: We profiled gene expression of human pulmonary artery endothelial cells (HPAEC) exposed to ultrafine particles (UFPs; 100 microg/mL) from Chapel Hill, North Carolina, or vehicle for 4 hr with Affymetrix HG U133 Plus 2.0 chips (n = 4 each). RESULTS: We found 320 up-regulated genes and 106 down-regulated genes (p < 0.01, 5% false discovery rate). We noted up-regulation of genes related to coagulation [tissue factor (F3) and coagulation factor II receptor-like 2 (F2RL2)] and differential regulation of genes related to F3 signaling (FOS, JUN, and NFKBIA). Results of quantitative polymerase chain reaction show a significant up-regulation of F3 after 10 and 100 microg/mLUFP exposures. Additionally, the water-soluble fractions of UFPs were sufficient to induce the expression of F3, F2RL2, and heme oxygenase 1 (HMOX1). Treatment of HPAEC with UFPs for 16 hr increased the release of interleukin (IL)-6 and IL-8. Pretreatment of HPAEC with a blocking antibody against F3 attenuated IL-6 and IL-8 release by 30 and 70%, respectively. CONCLUSIONS: Using gene profiling, we discovered that UFPs may induce vascular endothelial cells to express genes related to clotting. These results indicate that PM may cause adverse cardiovascular health effects by activating coagulation-inflammation circuitry.