JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Syntaxin-binding protein STXBP5 inhibits endothelial exocytosis and promotes platelet secretion.
J. Clin. Invest.
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
In humans, vWF levels predict the risk of myocardial infarction and thrombosis; however, the factors that influence vWF levels are not completely understood. Recent genome-wide association studies (GWAS) have identified syntaxin-binding protein 5 (STXBP5) as a candidate gene linked to changes in vWF plasma levels, though the functional relationship between STXBP5 and vWF is unknown. We hypothesized that STXBP5 inhibits endothelial cell exocytosis. We found that STXBP5 is expressed in human endothelial cells and colocalizes with and interacts with syntaxin 4. In human endothelial cells reduction of STXBP5 increased exocytosis of vWF and P-selectin. Mice lacking Stxbp5 had higher levels of vWF in the plasma, increased P-selectin translocation, and more platelet-endothelial interactions, which suggests that STXBP5 inhibits endothelial exocytosis. However, Stxbp5 KO mice also displayed hemostasis defects, including prolonged tail bleeding times and impaired mesenteric arteriole and carotid artery thrombosis. Furthermore, platelets from Stxbp5 KO mice had defects in platelet secretion and activation; thus, STXBP5 inhibits endothelial exocytosis but promotes platelet secretion. Our study reveals a vascular function for STXBP5, validates the functional relevance of a candidate gene identified by GWAS, and suggests that variation within STXBP5 is a genetic risk for venous thromboembolic disease.
Related JoVE Video
Genome-wide association study for circulating tissue plasminogen activator levels and functional follow-up implicates endothelial STXBP5 and STX2.
Jie Huang, Jennifer E Huffman, Munekazu Yamakuchi, Munekazu Yamkauchi, Stella Trompet, Folkert W Asselbergs, Maria Sabater-Lleal, David-Alexandre Trégouët, Wei-Min Chen, Nicholas L Smith, Marcus E Kleber, So-Youn Shin, Diane M Becker, Weihong Tang, Abbas Dehghan, Andrew D Johnson, Vinh Truong, Lasse Folkersen, Qiong Yang, Tiphaine Oudot-Mellkah, Brendan M Buckley, Jason H Moore, Frances M K Williams, Harry Campbell, Günther Silbernagel, Veronique Vitart, Igor Rudan, Geoffrey H Tofler, Gerjan J Navis, Anita DeStefano, Alan F Wright, Ming-Huei Chen, Anton J M de Craen, Bradford B Worrall, Alicja R Rudnicka, Ann Rumley, Ebony B Bookman, Bruce M Psaty, Fang Chen, Keith L Keene, Oscar H Franco, Bernhard O Böhm, André G Uitterlinden, Angela M Carter, J Wouter Jukema, Naveed Sattar, Joshua C Bis, Mohammad A Ikram, , Michèle M Sale, Barbara McKnight, Myriam Fornage, Ian Ford, Kent Taylor, P Eline Slagboom, Wendy L McArdle, Fang-Chi Hsu, Anders Franco-Cereceda, Alison H Goodall, Lisa R Yanek, Karen L Furie, Mary Cushman, Albert Hofman, Jacqueline C M Witteman, Aaron R Folsom, Saonli Basu, Nena Matijevic, Wiek H van Gilst, James F Wilson, Rudi G J Westendorp, Sekar Kathiresan, Muredach P Reilly, Russell P Tracy, Ozren Polašek, Bernhard R Winkelmann, Peter J Grant, Hans L Hillege, Francois Cambien, David J Stott, Gordon D Lowe, Timothy D Spector, James B Meigs, Winfried März, Per Eriksson, Lewis C Becker, Pierre-Emmanuel Morange, Nicole Soranzo, Scott M Williams, Caroline Hayward, Pim van der Harst, Anders Hamsten, Charles J Lowenstein, David P Strachan, Christopher J O'Donnell.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 02-27-2014
Show Abstract
Hide Abstract
Tissue plasminogen activator (tPA), a serine protease, catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for endogenous fibrinolysis. In some populations, elevated plasma levels of tPA have been associated with myocardial infarction and other cardiovascular diseases. We conducted a meta-analysis of genome-wide association studies to identify novel correlates of circulating levels of tPA.
Related JoVE Video
Enhanced assay of endothelial exocytosis using extracellular matrix components.
Anal. Biochem.
PUBLISHED: 02-07-2014
Show Abstract
Hide Abstract
Vascular inflammation plays a key role in the pathogenesis of atherosclerosis. The first step in vascular inflammation is endothelial exocytosis, in which endothelial granules fuse with the plasma membrane, releasing prothrombotic and proinflammatory messenger molecules. The development of cell culture models to study endothelial exocytosis has been challenging because the factors that modulate exocytosis in vitro are not well understood. Here we report a method for studying endothelial exocytosis that optimizes extracellular matrix components, cell density, and duration of culture. Human umbilical vein endothelial cells plated on collagen I-coated plates and cultured in the confluent state for 7-12 days in low-serum medium showed robust secretion of von Willebrand factor when stimulated with various agonists. This exocytosis assay is rapid and applicable to high-throughput screening.
Related JoVE Video
Histone deacetylase isoforms regulate innate immune responses by deacetylating mitogen-activated protein kinase phosphatase-1.
J. Leukoc. Biol.
PUBLISHED: 12-27-2013
Show Abstract
Hide Abstract
The MAPK pathway mediates TLR signaling during innate immune responses. We discovered previously that MKP-1 is acetylated, enhancing its interaction with its MAPK substrates and deactivating TLR signaling. As HDACs modulate inflammation by deacetylating histone and nonhistone proteins, we hypothesized that HDACs may regulate LPS-induced inflammation by deacetylating MKP-1. We found that mouse macrophages expressed a subset of HDAC isoforms (HDAC1, HDAC2, and HDAC3), which all interacted with MKP-1. Genetic silencing or pharmacologic inhibition of HDAC1, -2, and -3 increased MKP-1 acetylation in cells. Furthermore, knockdown or pharmacologic inhibition of HDAC1, -2, and -3 decreased LPS-induced phosphorylation of the MAPK member p38. Also, pharmacologic inhibition of HDAC did not decrease MAPK signaling in MKP-1 null cells. Finally, inhibition of HDAC1, -2, and -3 decreased LPS-induced expression of TNF-?, IL-1?, iNOS (NOS2), and nitrite synthesis. Taken together, our results show that HDAC1, -2, and -3 deacetylate MKP-1 and that this post-translational modification increases MAPK signaling and innate immune signaling. Thus, HDAC1, -2, and -3 isoforms are potential therapeutic targets in inflammatory diseases.
Related JoVE Video
Thioredoxin increases exocytosis by denitrosylating N-ethylmaleimide-sensitive factor.
J. Biol. Chem.
PUBLISHED: 02-15-2011
Show Abstract
Hide Abstract
Exocytosis involves membrane fusion between granules and the plasma membrane. Nitric oxide (NO) inhibits exocytosis by chemically modifying N-ethylmaleimide-sensitive factor (NSF), a key component of the exocytic machinery. However, cells recover the ability to release messenger molecules within hours of exposure to NO through unknown mechanisms. We now identify thioredoxin (TRX1) as a denitrosylase that reverses NO inhibition of exocytosis. Endogenously synthesized NO increases S-nitrosylated NSF levels, but S-nitrosylated NSF levels decrease within 3 h after exposure to NO. We found that NO increases the interaction between TRX1 and NSF, and endogenous TRX1 removes NO from S-nitrosylated NSF. Knockdown of TRX1 increases the level of S-nitrosylated NSF, prolongs the inhibition of exocytosis, and suppresses leukocyte adhesion. Taken together, these data show that TRX1 promotes exocytosis by denitrosylating NSF. Our findings suggest that TRX1 might regulate exocytosis in a variety of physiological settings, such as vascular inflammation, thrombosis, and insulin release.
Related JoVE Video
MicroRNA-22 regulates hypoxia signaling in colon cancer cells.
PLoS ONE
PUBLISHED: 01-18-2011
Show Abstract
Hide Abstract
MicroRNAs (MiRNAs) are short, non-coding RNA that regulate a variety of cellular functions by suppressing target protein expression. We hypothesized that a set of microRNA regulate tumor responses to hypoxia by inhibiting components of the hypoxia signaling pathway. We found that miR-22 expression in human colon cancer is lower than in normal colon tissue. We also found that miR-22 controls hypoxia inducible factor 1? (HIF-1?) expression in the HCT116 colon cancer cell line. Over-expression of miR-22 inhibits HIF-1? expression, repressing vascular endothelial growth factor (VEGF) production during hypoxia. Conversely, knockdown of endogenous miR-22 enhances hypoxia induced expression of HIF-1? and VEGF. The conditioned media from cells over-expressing miR-22 contain less VEGF protein than control cells, and also induce less endothelial cell growth and invasion, suggesting miR-22 in adjacent cells influences endothelial cell function. Taken together, our data suggest that miR-22 might have an anti-angiogenic effect in colon cancer.
Related JoVE Video
In the clinic. Dyslipidemia.
Ann. Intern. Med.
PUBLISHED: 08-04-2010
Show Abstract
Hide Abstract
This issue provides a clinical overview of dyslipidemia focusing on prevention, diagnosis, treatment, practice improvement, and patient information. Readers can complete the accompanying CME quiz for 1.5 credits. Only ACP members and individual subscribers can access the electronic features of In the Clinic. Non-subscribers who wish to access this issue of In the Clinic can elect "Pay for View." Subscribers can receive 1.5 category 1 CME credits by completing the CME quiz that accompanies this issue of In the Clinic. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including PIER (Physicians Information and Education Resource) and MKSAP (Medical Knowledge and Self Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACPs Medical Education and Publishing division and with assistance of science writers and physician writers. Editorial consultants from PIER and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult www.acponline.org, http://pier.acponline.org, and other resources referenced within each issue of In the Clinic.
Related JoVE Video
Ets-1 and Ets-2 regulate the expression of microRNA-126 in endothelial cells.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 07-29-2010
Show Abstract
Hide Abstract
MicroRNA plays important roles in vascular biology, but the regulation of endothelial-specific microRNA is not well characterized. MicroRNA-126 (miR-126) is highly expressed in endothelial cells, and it regulates angiogenesis and vascular inflammation. Here we show that the transcription factors Ets-1 and Ets-2 regulate miR-126 expression.
Related JoVE Video
Increased endothelial exocytosis and generation of endothelin-1 contributes to constriction of aged arteries.
Circ. Res.
PUBLISHED: 06-03-2010
Show Abstract
Hide Abstract
Circulating levels of endothelin (ET)-1 and endogenous ET(A)-mediated constriction are increased in human aging. The mechanisms responsible are not known.
Related JoVE Video
Nerve growth factor-regulated emergence of functional delta-opioid receptors.
J. Neurosci.
PUBLISHED: 04-23-2010
Show Abstract
Hide Abstract
Sorting of intracellular G-protein-coupled receptors (GPCRs) either to lysosomes for degradation or to plasma membrane for surface insertion and functional expression is a key process regulating signaling strength of GPCRs across the plasma membrane in adult mammalian cells. However, little is known about the molecular mechanisms governing the dynamic process of receptor sorting to the plasma membrane for functional expression under normal and pathological conditions. In this study, we demonstrate that delta-opioid receptor (DOPr), a GPCR constitutively targeted to intracellular compartments, is driven to the surface membrane of central synaptic terminals and becomes functional by the neurotrophin nerve growth factor (NGF) in native brainstem neurons. The NGF-triggered DOPr translocation is predominantly mediated by the signaling pathway involving the tyrosine receptor kinase A, Ca(2+)-mobilizing phospholipase C, and Ca(2+)/calmodulin-dependent protein kinase II. Importantly, it requires interactions with the cytoplasmic sorting protein NHERF-1 (Na(+)/H(+) exchange regulatory factor-1) and N-ethyl-maleimide-sensitive factor-regulated exocytosis. In addition, this NGF-mediated mechanism is likely responsible for the emergence of functional DOPr induced by chronic opioids. Thus, NGF may function as a key molecular switch that redirects the sorting of intracellularly targeted DOPr to plasma membrane, resulting in new functional DOPr on central synapses under chronic opioid conditions.
Related JoVE Video
P53-induced microRNA-107 inhibits HIF-1 and tumor angiogenesis.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-22-2010
Show Abstract
Hide Abstract
The pathway involving the tumor suppressor gene TP53 can regulate tumor angiogenesis by unclear mechanisms. Here we show that p53 regulates hypoxic signaling through the transcriptional regulation of microRNA-107 (miR-107). We found that miR-107 is a microRNA expressed by human colon cancer specimens and regulated by p53. miR-107 decreases hypoxia signaling by suppressing expression of hypoxia inducible factor-1beta (HIF-1beta). Knockdown of endogenous miR-107 enhances HIF-1beta expression and hypoxic signaling in human colon cancer cells. Conversely, overexpression of miR-107 inhibits HIF-1beta expression and hypoxic signaling. Furthermore, overexpression of miR-107 in tumor cells suppresses tumor angiogenesis, tumor growth, and tumor VEGF expression in mice. Finally, in human colon cancer specimens, expression of miR-107 is inversely associated with expression of HIF-1beta. Taken together these data suggest that miR-107 can mediate p53 regulation of hypoxic signaling and tumor angiogenesis.
Related JoVE Video
High-density lipoprotein metabolism and endothelial function.
Curr Opin Endocrinol Diabetes Obes
PUBLISHED: 02-04-2010
Show Abstract
Hide Abstract
High-density lipoprotein (HDL) protects against atherosclerosis, transporting cholesterol from peripheral cells to the liver, where it is excreted into the bile. However, HDL also has prominent vascular protective effects.
Related JoVE Video
Glutamate excitotoxicity mediates neuronal apoptosis after hypothermic circulatory arrest.
Ann. Thorac. Surg.
PUBLISHED: 01-28-2010
Show Abstract
Hide Abstract
Prolonged hypothermic circulatory arrest results in neuronal cell death and neurologic injury. We have previously shown that hypothermic circulatory arrest causes both neuronal apoptosis and necrosis in a canine model. Inhibition of neuronal nitric oxide synthase reduced neuronal apoptosis, while glutamate receptor antagonism reduced necrosis in our model. This study was undertaken to determine whether glutamate receptor antagonism reduces nitric oxide formation and neuronal apoptosis after hypothermic circulatory arrest.
Related JoVE Video
VAMP-1, VAMP-2, and syntaxin-4 regulate ANP release from cardiac myocytes.
J. Mol. Cell. Cardiol.
PUBLISHED: 01-07-2010
Show Abstract
Hide Abstract
ANP is a peptide released by cardiac myocytes that regulates blood pressure and natriuresis. However, the molecular mechanisms controlling ANP release from cardiac myocytes are not defined. We now identify three components of the exocytic machinery that regulate ANP release from atrial myocytes. We found that cardiac myocytes express N-ethylmaleimide sensitive factor (NSF), soluble NSF attachment protein (?-SNAP), and SNAP receptors (SNAREs). Additionally we found that specific SNARE molecules, VAMP-1 and VAMP-2, both co-sediment and co-localize with ANP. Also, one SNARE molecule, syntaxin-4, partially co-sediments and partially co-localizes with ANP. Furthermore, these three SNAREs, syntaxin-4 and VAMP-1 and VAMP-2, form a SNARE complex inside cardiac myocytes. Finally, knockdown of VAMP-1, VAMP-2, or syntaxin-4 blocks regulated release of ANP. In contrast, silencing of VAMP-3 did not have an effect on ANP release. Our data suggest that three specific SNAREs regulate cardiac myocyte exocytosis of ANP. Pathways that modify the exocytic machinery may influence natriuresis and blood pressure.
Related JoVE Video
MiR-34, SIRT1 and p53: the feedback loop.
Cell Cycle
PUBLISHED: 03-02-2009
Show Abstract
Hide Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Several studies have linked dysregulation of miRNA with tumorigenesis. The TP53 is one of the most commonly mutated genes in human cancers, and its gene product p53 activates transcription of a set of miRNA including the miR-34 family of miRNA. The miR-34 family regulates cell cycle progression, cellular senescence and apoptosis, but the targets of miR-34 are not completely defined. We recently found that miR-34a inhibits SIRT1, a gene that regulates cellular senescence and limits longevity. SIRT1 also regulates p53 dependent apoptosis through deacetylating and stabilizing p53. We also discovered that SIRT1 mediates miR-34a activation of apoptosis by regulating p53 activity. Based on this observation, we propose a positive feedback loop, in which p53 induces expression of miR-34a which suppresses SIRT1, increasing p53 activity.
Related JoVE Video
Aldosterone activates endothelial exocytosis.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 02-17-2009
Show Abstract
Hide Abstract
Although elevated levels of aldosterone are associated with vascular inflammation, the proinflammatory pathways of aldosterone are not completely defined. We now show that aldosterone triggers endothelial cell exocytosis, the first step in leukocyte trafficking. Exogenous aldosterone stimulates endothelial exocytosis of Weibel-Palade bodies, externalizing P-selectin and releasing von Willebrand factor. Spironolactone, a nonselective mineralocorticoid receptor (MR) blocker, antagonizes aldosterone-induced endothelial exocytosis. Knockdown of the MR also decreases exocytosis, suggesting that the MR mediates exocytosis. Aldosterone triggers exocytosis within minutes, and this effect is not inhibited by actinomycin D, suggesting a nongenomic effect of aldosterone. Aldosterone treatment of endothelial cells increases leukocyte adherence to endothelial cells in culture. Taken together, our data suggest that aldosterone activates vascular inflammation in part through nongenomic, MR-mediated pathways. Aldosterone antagonism may decrease vascular inflammation and cardiac fibrosis in part by blocking endothelial exocytosis.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.