עבודה זו נתמכה על ידי מכוני הבריאות הלאומיים מענק (R01 HL086699, HL086699-01A2S1, 1S10RR027327-01) ל-MM. מאמר שלנו נתמך בחלקו על ידי Carl Zeiss MicroImaging LLC.

<ol>
	<li>Madesh, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+role+for+superoxide+in+InsP3+receptor-mediated+mitochondrial+dysfunction+and+endothelial+apoptosis.">Selective role for superoxide in InsP3 receptor-mediated mitochondrial dysfunction and endothelial apoptosis.</a> J. Cell. Biol. 170, 1079-1090 (2005).</li><li>Droge, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Free+radicals+in+the+physiological+control+of+cell+function.">Free radicals in the physiological control of cell function.</a> Physiol. Rev. 82, 47-95 (2002).</li><li>Hamanaka, R. B., Chandel, N. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+reactive+oxygen+species+regulate+cellular+signaling+and+dictate+biological+outcomes.">Mitochondrial reactive oxygen species regulate cellular signaling and dictate biological outcomes.</a> Trends Biochem. Sci. 35, 505-513 .</li><li>Hawkins, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=S-glutathionylation+activates+STIM1+and+alters+mitochondrial+homeostasis.">S-glutathionylation activates STIM1 and alters mitochondrial homeostasis.</a> J. Cell. Biol. 190, 391-405 (2010).</li><li>Madesh, M., Hajnoczky, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=VDAC-dependent+permeabilization+of+the+outer+mitochondrial+membrane+by+superoxide+induces+rapid+and+massive+cytochrome+c+release.">VDAC-dependent permeabilization of the outer mitochondrial membrane by superoxide induces rapid and massive cytochrome c release.</a> J. Cell Biol. 155, 1003-1015 (2001).</li><li>Finkel, T., Holbrook, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidants+oxidative+stress+and+the+biology+of+ageing.">Oxidants oxidative stress and the biology of ageing.</a> Nature. 408, 239-247 (2000).</li><li>Rittirsch, D., Flierl, M. A., Ward, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Harmful+molecular+mechanisms+in+sepsis.">Harmful molecular mechanisms in sepsis.</a> Nat. Rev. Immunol. 8, 776-787 (2008).</li><li>Sanlioglu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipopolysaccharide+induces+Rac1-dependent+reactive+oxygen+species+formation+and+coordinates+tumor+necrosis+factor-alpha+secretion+through+IKK+regulation+of+NF-kappa.">Lipopolysaccharide induces Rac1-dependent reactive oxygen species formation and coordinates tumor necrosis factor-alpha secretion through IKK regulation of NF-kappa.</a> 276, 30188-30198 (2001).</li><li>Hawkins, B. J., Madesh, M., Kirkpatrick, C. J., Fisher, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Superoxide+flux+in+endothelial+cells+via+the+chloride+channel-3+mediates+intracellular+signaling.">Superoxide flux in endothelial cells via the chloride channel-3 mediates intracellular signaling.</a> Mol. Biol. Cell. 18, 2002-2012 (2007).</li><li>Vliet, A. v. a. n. d. e. r. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NADPH+oxidases+in+lung+biology+and+pathology:+host+defense+enzymes+and+more.">NADPH oxidases in lung biology and pathology: host defense enzymes and more.</a> Free Radic. Biol. Med. 44, 938-955 (2008).</li><li>Babior, B. M., Kipnes, R. S., Curnutte, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+defense+mechanisms.+The+production+by+leukocytes+of+superoxide,+a+potential+bactericidal+agent.">Biological defense mechanisms. The production by leukocytes of superoxide, a potential bactericidal agent.</a> J. Clin. Invest. 52, 741-744 (1973).</li><li>Lambeth, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NOX+enzymes+and+the+biology+of+reactive+oxygen.">NOX enzymes and the biology of reactive oxygen.</a> Nat. Rev. Immunol. 4, 181-189 (2004).</li><li>Mukhopadhyay, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+detection+of+apoptosis+and+mitochondrial+superoxide+production+in+live+cells+by+flow+cytometry+and+confocal+microscopy.">Simultaneous detection of apoptosis and mitochondrial superoxide production in live cells by flow cytometry and confocal microscopy.</a> Nat. Protoc. 2, 2295-2301 (2007).</li><li>Niethammer, P., Grabher, C., Look, A. T., Mitchison, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+tissue-scale+gradient+of+hydrogen+peroxide+mediates+rapid+wound+detection+in+zebrafish.">A tissue-scale gradient of hydrogen peroxide mediates rapid wound detection in zebrafish.</a> Nature. 459, 996-999 (2009).</li><li>Medzhitov, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toll-like+receptors+and+innate+immunity.">Toll-like receptors and innate immunity.</a> Nat. Rev. Immunol. 1, 135-145 (2001).</li></ol>

אין ניגודי אינטרסים הכריז.

השיטה המתוארת כאן מאפשר מדידה כמותית מהירה של מינים חמצן תגובתי בתאים חיים או באמצעות צבעים חמצון רגיש או חיישנים פלסמיד. אגוניסטים של TLRs (קולטני Toll-כמו) הם תרכובות לגרות את התאים דרך TLRs הנוכחי על פני התא ההדק מסלולי איתות במורד 15. בפרוטוקול שלנו, אנו השתמשו בשלושה דהינו אגוניסטים שונים TLR, שאיבה, teichoic חומצה TLR2 אגוניסט, פולי (אני: C). TLR3-אגוניסט, LPS-TLR4 אגוניסט אשר דיווחו לגרום ROS כמודל למערכת כדי להדגים את המדידה ROS . מדידה של ROS באמצעות חמצון צבען רגיש הוא מהיר וניתן להשתמש בו כדי למדוד מגוון של מינים ROS. השימוש Hyper פלסמיד חיישן מבוסס סלקטיבי מזהה H 2 O 2 רמות. H 2 O 2 הוא חמצון יציב יותר גם את השימוש Hyper Cyto ו Hyper-dMito במסגרת התא יציב מוסיף יתרון על פני autooxidation-תמונה של צבעי ניאון ROS רגיש.Hyper אינו גורם artifactual דור ROS והוא יכול לשמש לצורך זיהוי של שינויים מהירים של ריכוז H 2 O 2 בתאים תאים שונים בתנאים פיזיולוגיים ופתולוגיים שונים. תאים ביציבות המבטא את Hyper חיישנים המשמשים מבחר המשובטים של האוכלוסייה, אשר מציעה מדידה אמין ומדויק יותר של H 2 O 2 רמות. חשוב לציין, ששיטה זו מתאר גם את זיהוי ומדידה כמותית של Ca 2 + גיוס בתאים חיים מופעלות על ידי ROS נגזר אוטוקריני מתאי שכנות כמו תאים חיסוניים מולדים. הליך ניסיוני בשילוב עם מיקרוסקופיה confocal עשוי להיות שימושי מאוד חשוב לחשוף במרחב ובזמן שינויים האות תא אירועים התמרה במיוחד במקרים שבהם שני סוגי תאים שונים מעורבים. אמנם, נציג את הניסויים מפורט במאמר זה הן רק דוגמה אחת לסוג של אינטראקציה למד, טכניקה זו יכולה להיות בקלותdapted ללמוד אינטראקציות הסלולר בין מספר סוגי תאים חיים.

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> מגיב </td><td> חברה </td><td> מספר קטלוגי </td></tr><tr><td> Attofluor תא תא </td><td> Invitrogen </td><td> A7816 </td></tr><tr><td> Antimycin </td><td> סיגמא אולדריץ&#39; </td><td> A8674 </td></tr><tr><td> DMEM בינוני גלוקוז נמוכה </td><td> Invitrogen </td><td> 10567-014 </td></tr><tr><td> צמיחה האנדותל גורם תוספת (ECGS) </td><td> בצפון מדינת ניו יורק </td><td> 02-102 </td></tr><tr><td> סרום שור עוברית </td><td> Invitrogen </td><td> 12662011 </td></tr><tr><td> G418 </td><td> Invitrogen </td><td> 10131-027 </td></tr><tr><td> לטין </td><td> סיגמא אולדריץ&#39; </td><td> G1393 </td></tr><tr><td> H 2 DCFDA </td><td> Invitrogen </td><td> D-399 </td></tr><tr><td> LPS </td><td> סיגמא אולדריץ&#39; </td><td> L4516 </td></tr><tr><td> LTA </td><td> סיגמא אולדריץ&#39; </td><td> L2515 </td></tr><tr><td> MitoSOX האדום </td><td> Invitrogen </td><td> M36008 </td></tr><tr><td> Opti-ממ אני מופחת בינוני סרום </td><td> Invitrogen </td><td> 51985091 </td></tr><tr><td> פן / סטרפטוקוקוס (10x) </td><td> Invitrogen </td><td> 15140163 </td></tr><tr><td> pHyPer-Cyto </td><td> Evrogen </td><td> FP941 </td></tr><tr><td> pHyPer-dMito </td><td> Evrogen </td><td> FP942 </td></tr><tr><td> פולי (אני: C) </td><td> סיגמא אולדריץ&#39; </td><td> P0913 </td></tr><tr><td> פריזמה תוכנה 5.0 </td><td> GraphPad תוכנה, Inc </td><td></td></tr><tr><td> SigmaPlot 11.0 </td><td> Systat תוכנה, Inc </td><td></td></tr><tr><td> טריפסין-EDTA (10x) </td><td> Invitrogen </td><td> 15400054 </td></tr><tr><td> T-25 צלוחיות </td><td> קורנינג </td><td> 430639 </td></tr><tr><td> T-75 צלוחיות </td><td> BD פלקון </td><td> 353136 </td></tr><tr><td> גם 96-TC ומיקרו צלחת יפה </td><td> BD פלקון </td><td> 353072 </td></tr><tr><td> זן 2009 תוכנה </td><td> Carl Zeiss 510 Meta confocal מיקרוסקופיה </td><td></td></tr></tbody></table>

visualization of vascular ca2+ signaling triggered by paracrine derived ros

סטרס חמצוני היה מעורב במספר מצבים פתולוגיים כולל נזק איסכמיה / reperfusion ועל אלח דם. הרעיון של סטרס חמצוני מתייחס היווצרות חריגה של ROS (מינים חמצן תגובתי), אשר כוללים • O 2 -, H 2 O 2, רדיקלים הידרוקסיל. מינים החמצן מגיב משפיע שפע של תהליכים תאיים כולל התמרה האות, התפשטות תאים ומוות התא 1-6. ROS יש פוטנציאל נזק בכלי הדם ותאי איבר ישירות, והוא יכול ליזום תגובות כימיות משני שינויים גנטיים כי בסופו של דבר לגרום הגברה של הנזק ROS בתיווך הראשוני רקמות. רכיב מרכזי של מפל הגברה המחזקת נזק בלתי הפיך לרקמות הוא גיוס והפעלה של מחזורי תאים דלקתיים. במהלך דלקת, תאים דלקתיים לייצר ציטוקינים כגון נמק הגידול גורם-α (TNFα) ו-IL-1 כילהפעיל בתאי האנדותל (EC) ותאי אפיתל נוספת להגדיל את 7 התגובה הדלקתית. תפקוד אנדותל כלי דם הוא תכונה הוקמה דלקת חריפה. המקרופאגים לתרום תפקוד אנדותל במהלך דלקת על ידי המנגנונים אינם ברורים. הפעלה של תוצאות מקרופאגים לשחרור תאיים של O 2 • - שונות הפרו ציטוקינים דלקתיים, אשר מפעילה איתות פתולוגיים בתאים סמוכים 8. Oxidases NADPH הם המקור העיקרי והראשון במעלה של ROS ברוב סוגי התאים. לאחרונה, היא מופיעה על ידינו ואחרים 9,10 כי ROS המיוצר על ידי oxidases NADPH לעורר את הייצור המיטוכונדריאלי ROS במהלך תנאי pathophysiological רבים. מכאן מדידת הייצור המיטוכונדריאלי ROS חשוב לא פחות בנוסף למדידת cytosolic ROS. המקרופאגים מייצרים ROS על ידי האנזים מונואמין NADPH flavoprotein אשר ממלא תפקיד העיקרי לדלקת. הופעל פעם אחת,NADPH אוקסידאז phagocytic מייצרת כמויות עצומות של O 2 • - חשובים במנגנון ההגנה המארחת 11,12. למרות אוטוקריני הנגזרות O 2 • - ממלא תפקיד חשוב בפתוגנזה של מחלות כלי הדם, ויזואליזציה של ROS-Induced אוטוקריני איתות תאיים, כולל גיוס Ca 2 + עדיין השערה. פיתחנו מודל שבו מקרופאגים מופעל משמשים כמקור של O 2 • - כדי transduce איתות לתאי אנדותל סמוכים. באמצעות מודל זה אנו מראים כי macrophage הנגזרות O 2 • - להוביל סידן איתות לתאי אנדותל סמוכים.

Watch this Scientific Journal Video about Visualization of Vascular Ca2+ Signaling Triggered by Paracrine Derived ROS at JoVE.com

Visualization of Vascular Ca2+ Signaling Triggered by Paracrine Derived ROS

שיטה יעילה כדי להשיג תובנות לדמיין את האינדוקציה אוטוקריני הנגזרות ROS של האנדותל Ca2 + איתות מתואר. שיטה זו מנצלת את מדידת ROS נגזר אוטוקריני מופעלות Ca2 + לגיוס בתאי האנדותל בכלי הדם במודל שיתוף תרבות.

ויזואליזציה של כלי דם Ca 2 + איתות מופעלות על ידי ROS נגזר אוטוקריני

Oxidative stress has been implicated in a number of pathologic conditions including ischemia/reperfusion damage and sepsis. The concept of oxidative ...

visualization-vascular-ca2-signaling-triggered-paracrine-derived

Google

Research

JoVE Journal

Biology

Visualization of Vascular Ca2+ Signaling Triggered by Paracrine Derived ROS

15.4K Views.  Temple University. שיטה יעילה כדי להשיג תובנות לדמיין את האינדוקציה אוטוקריני הנגזרות ROS של האנדותל Ca2 + איתות מתואר. שיטה זו מנצלת את מדידת ROS נגזר אוטוקריני מופעלות Ca2 + לגיוס בתאי האנדותל בכלי הדם במודל שיתוף תרבות.

Video: Visualization of Vascular Ca2+ Signaling Triggered by Paracrine Derived ROS

Techniques for Imaging Ca2+ Signaling in Human Sperm

Fluorescence microscopy of cells loaded with fluorescent, Ca2+-sensitive dyes is used for measurement of spatial and temporal aspects of Ca2+ signaling in live cells. Here we describe the method used in our laboratories for loading suspensions of human sperm with Ca2+-reporting dyes and measuring the fluorescence signal during physiological stimulation. Motile cells are isolated by direct swim-up and incubated under capacitating conditions for 0-24 h, depending upon the experiment. The cell-permeant AM (acetoxy methyl ester) ester form of the Ca2+-reporting dye is then added to a cell aliquot and a period of 1 h is allowed for loading of the dye into the cytoplasm. We use visible wavelength dyes to minimize photo-damage to the cells, but this means that ratiometric recording is not possible. Advantages and disadvantages of this approach are discussed. During the loading period cells are introduced into an imaging chamber and allowed to adhere to a poly-D-lysine coated coverslip. At the end of the loading period excess dye and loose cells are removed by connection of the chamber to the perfusion apparatus. The chamber is perfused continuously, stimuli and modified salines are then added to the perfusion header. Experiments are recorded by time-lapse acquisition of fluorescence images and analyzed in detail offline, by manually drawing regions of interest. Data are normalized to pre-stimulus levels such that, for each cell (or part of a cell), a graph showing the Ca2+ response as % change in fluorescence is obtained.

Techniques for Imaging Ca2+ Signaling in Human Sperm

Stimulus-evoked [Ca2+]i signals of individual human sperm are assessed. Motile cells are loaded with Ca2+-sensitive fluorescent dye (AM-ester method) and immobilised in a perfusable chamber. Cells are imaged by time-lapse fluorescence microscopy and stimulated via the perfusing medium. Responses of single cells (or regions) are analysed offline using Excel.

טכניקות הדמיה Ca 2 + איתות זרע אנושי

Fluorescence microscopy of cells loaded with fluorescent, Ca2+-sensitive dyes is used for measurement of spatial and temporal aspects of Ca2+ signaling in ...

Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography

Electron cryo-tomography is a powerful tool in structural biology, capable of visualizing the three-dimensional structure of biological samples, such as cells, organelles, membrane vesicles, or viruses at molecular detail. To achieve this, the aqueous sample is rapidly vitrified in liquid ethane, which preserves it in a close-to-native, frozen-hydrated state. In the electron microscope, tilt series are recorded at liquid nitrogen temperature, from which 3D tomograms are reconstructed. The signal-to-noise ratio of the tomographic volume is inherently low. Recognizable, recurring features are enhanced by subtomogram averaging, by which individual subvolumes are cut out, aligned and averaged to reduce noise. In this way, 3D maps with a resolution of 2 nm or better can be obtained. A fit of available high-resolution structures to the 3D volume then produces atomic models of protein complexes in their native environment. Here we show how we use electron cryo-tomography to study the in situ organization of large membrane protein complexes in mitochondria. We find that ATP synthases are organized in rows of dimers along highly curved apices of the inner membrane cristae, whereas complex I is randomly distributed in the membrane regions on either side of the rows. By subtomogram averaging we obtained a structure of the mitochondrial ATP synthase dimer within the cristae membrane.

We present a protocol of how to collect and process electron cryo-tomograms of whole mitochondria. The technique provides detailed insights into the structure, function, and organization of large membrane protein complexes in native biological membranes.

ויזואליזציה של הדימרים synthase ATP במיטוכונדריה על ידי אלקטרונים קריו טומוגרפיה

Electron cryo-tomography is a powerful tool in structural biology, capable of visualizing the three-dimensional structure of biological samples, such as ...

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone metabolites can be detected in the feces of horses and assessment offers a non-invasive option to evaluate long term patterns of adrenal activity. Fecal assessment offers advantages over other techniques that monitor adrenal activity including blood plasma and saliva analysis. The non-invasive nature of the method avoids sampling stress which can confound results. It also allows the opportunity for repeated sampling over time and is ideal for studies in free ranging horses. This protocol describes the enzyme linked immunoassay (EIA) used to assess feces for corticosterone, in addition to the associated biochemical validation.

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. The method offers a non-invasive option to assess long term patterns in both domestic and free ranging horses. This protocol describes the enzyme linked immunoassay involved and the associated biochemical validation.

ניתוח Glucocorticoid צואה: לא פולשני ניטור הכליה ב Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, ...

DiI Perfusion as a Method for Vascular Visualization in Ambystoma mexicanum

Perfusion techniques have been used for centuries to visualize the circulation of tissues. Axolotl (Ambystoma mexicanum) is a species of salamander that has emerged as an essential model for regeneration studies. Little is known about how revascularization occurs in the context of regeneration in these animals. Here we report a simple method for visualization of the vasculature in axolotl via perfusion of 1,1&#8217;-Dioctadecy-3,3,3&#8217;,3&#8217;-tetramethylindocarbocyanine perchlorate (DiI). DiI is a lipophilic carbocyanine dye that inserts into the plasma membrane of endothelial cells instantaneously. Perfusion is done using a peristaltic pump such that DiI enters the circulation through the aorta. During perfusion, dye flows through the axolotl&#8217;s blood vessels and incorporates into the lipid bilayer of vascular endothelial cells upon contact. The perfusion procedure takes approximately one hour for an eight-inch axolotl. Immediately after perfusion with DiI, the axolotl can be visualized with a confocal fluorescent microscope. The DiI emits light in the red-orange range when excited with a green fluorescent filter. This DiI perfusion procedure can be used to visualize the vascular structure of axolotls or to demonstrate patterns of revascularization in regenerating tissues.

DiI Perfusion as a Method for Vascular Visualization in Ambystoma mexicanum

Using a lipophilic 1,1&#39;-Dioctadecy-3,3,3&#39;,3&#39;-tetramethylindocarbocyanine perchlorate (DiI) staining technique, Ambystoma mexicanum can undergo vascular perfusion to allow for easy visualization of the vasculature.

DiI זלוף כשיטת ויזואליזציה של כלי הדם<em&gt; Ambystoma מקסיקניום</em

Perfusion techniques have been used for centuries to visualize the circulation of tissues. Axolotl (Ambystoma mexicanum) is a species of salamander that ...

Visualization of DNA Compaction in Cyanobacteria by High-voltage Cryo-electron Tomography

This protocol describes how to visualize the transient DNA compaction in cyanobacteria. DNA compaction is a dramatic cytoplasmic event recently found to occur in some cyanobacteria before cell division. However, due to the large cell size and the transient character, it is difficult to investigate the structure in detail. To overcome the difficulties, first, DNA compaction is reproducibly produced in the cyanobacterium Synechococcus elongatus PCC 7942 by synchronous culture using 12 h each light/dark cycle. Second, DNA compaction is monitored by fluorescence microscopy and captured by rapid freezing. Third, the detailed structure of DNA compacted cells is visualized in three dimensions (3D) by high voltage cryo-electron tomography. This set of methods is widely applicable to investigate transient structures in bacteria, e.g. cell division, chromosome segregation, phage infection etc., which are monitored by fluorescence microscopy and directly visualized by cryo-electron tomography at appropriate time points.

This protocol describes how to visualize the transient DNA compaction in cyanobacteria. Synchronous cultivation, monitoring by fluorescence microscopy, rapid freezing, and high voltage cryo-electron tomography are used. A protocol for these methodologies is presented, and future applications and developments are discussed.

ויזואליזציה של דחיסת DNA ב כחוליות על ידי מתח גבוה הקפאה-אלקטרון טומוגרפיה

This protocol describes how to visualize the transient DNA compaction in cyanobacteria. DNA compaction is a dramatic cytoplasmic event recently found to ...

Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-&#946; Signaling

Phenotypic plasticity of endothelial cells underlies cardiovascular system development, cardiovascular diseases, and various conditions associated with organ fibrosis. In these conditions, differentiated endothelial cells acquire mesenchymal-like phenotypes. This process is called endothelial-mesenchymal transition (EndMT) and is characterized by downregulation of endothelial markers, upregulation of mesenchymal markers, and morphological changes. EndMT is induced by several signaling pathways, including transforming growth factor (TGF)-&#946;, Wnt, and Notch, and regulated by molecular mechanisms similar to those of epithelial-mesenchymal transition (EMT) important for gastrulation, tissue fibrosis, and cancer metastasis. Understanding the mechanisms of EndMT is important to develop diagnostic and therapeutic approaches targeting EndMT. Robust induction of EndMT in vitro is useful to characterize common gene expression signatures, identify druggable molecular mechanisms, and screen for modulators of EndMT. Here, we describe an in vitro method for induction of EndMT. MS-1 mouse pancreatic microvascular endothelial cells undergo EndMT after prolonged exposure to TGF-&#946; and show upregulation of mesenchymal markers and morphological changes as well as induction of multiple inflammatory chemokines and cytokines. Methods for the analysis of microRNA (miRNA) modulation are also included. These methods provide a platform to investigate mechanisms underlying EndMT and the contribution of miRNAs to EndMT.

Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-&amp;#946; Signaling

A protocol for in vitro induction of endothelial-mesenchymal transition (EndMT), which is useful for investigating cellular signaling pathways involved in EndMT, is described. In this experimental model, EndMT is induced by treatment with TGF-&#946; in MS-1 endothelial cells.

אנליזה מולקולרית של אנדותל-mesenchymal מעבר המושרה על ידי הפיכת גורם גידול-β איתות

Phenotypic plasticity of endothelial cells underlies cardiovascular system development, cardiovascular diseases, and various conditions associated with ...

Retinal Cryo-sections, Whole-Mounts, and Hypotonic Isolated Vasculature Preparations for Immunohistochemical Visualization of Microvascular Pericytes

Retinal pericytes play an important role in many diseases of the eye. Immunohistochemical staining techniques of retinal vessels and microvascular pericytes are central to ophthalmological research. It is vital to choose an appropriate method of visualizing the microvascular pericytes. We describe retinal microvascular pericyte immunohistochemical staining in cryo-sections, whole-mounts, and hypotonic isolated vasculature using antibodies for platelet-derived growth factor receptor &#946; (PDGFR&#946;) and nerve/glial antigen 2 (NG2). This allows us to highlight advantages and shortcomings of each of the three tissue preparations for the visualization of the retinal microvascular pericytes. Cryo-sections provide transsectional visualization of all retinal layers but contain only a few occasional transverse cuts of the microvasculature. Whole-mount provides an overview of the entire retinal vasculature, but visualization of the microvasculature can be troublesome. Hypotonic isolation provides a method to visualize the entire retinal vasculature by the removal of neuronal cells, but this makes the tissue very fragile.

We demonstrate three different tissue preparation techniques for immunohistochemical visualization of rat retinal microvascular pericytes, i.e., cryo-sections, whole-mounts, and hypotonic isolation of the vascular network.

הקפאה-מקטעי רשתית, שלם-טעינות, וההכנות להערכת מבודד היפוטוניק להמחשת Immunohistochemical של Microvascular Pericytes

Retinal pericytes play an important role in many diseases of the eye. Immunohistochemical staining techniques of retinal vessels and microvascular ...

A Proximal Culture Method to Study Paracrine Signaling Between Cells

Intercellular interactions play an important role in many biological processes, including tumor progression, immune responses, angiogenesis, and development. Paracrine or juxtacrine signaling mediates such interactions. The use of a conditioned medium and coculture studies are the most common methods to discriminate between these two types of interactions. However, the effect of localized high concentrations of secreted factors in the microenvironment during the paracrine interactions is not accurately recapitulated by conditioned medium and, thus, may lead to imprecise conclusions. To overcome this problem, we have devised a proximal culture method to study paracrine signaling. The two cell types are grown on either surface of a 10 &#181;m-thick polycarbonate membrane with 0.4 &#181;m pores. The pores allow the exchange of secreted factors and, at the same time, inhibit juxtacrine signaling. The cells can be collected and lysed at the endpoint to determine the effects of the paracrine signaling. In addition to allowing for localized concentration gradients of secreted factors, this method is amenable to experiments involving prolonged periods of culture, as well as the use of inhibitors. While we use this method to study the interactions between ovarian cancer cells and the mesothelial cells they encounter at the site of metastasis, it can be adapted to any two adherent cell types for researchers to study paracrine signaling in various fields, including tumor microenvironment, immunology, and development.

Paracrine and juxtacrine cellular interactions play an important role in many biological processes, including tumor progression, immune responses, angiogenesis, and development. Here, a proximal culture method is used to study paracrine signaling where the localized concentrations of the secreted factors are maintained while preventing direct cellular contact.

שיטה תרבות Proximal ללמוד Paracrine איתות בין תאים

Intercellular interactions play an important role in many biological processes, including tumor progression, immune responses, angiogenesis, and ...

Myeloid Innate Signaling Pathway Regulation by MALT1 Paracaspase Activity

Besides its function in lymphoid cells, which has been addressed by numerous studies, the paracaspase MALT1 also plays an important role in innate cells downstream of pattern recognition receptors. Best studied are the Dectin-1 and Dectin-2 members of the C-type lectin-like receptor family that induce a SYK- and CARD9-dependent signaling cascade leading to NF-&#954;B activation, in a MALT1-dependent manner. By contrast, Toll-like receptors (TLR), such as TLR-4, propagate NF-&#954;B activation but signal via an MYD88/IRAK-dependent cascade. Nonetheless, whether MALT1 might contribute to TLR-4 signaling has remained unclear. Recent evidence with MLT-827, a potent and selective inhibitor of MALT1 paracaspase activity, indicates that TNF- production downstream of TLR-4 in human myeloid cells is independent of MALT1, as opposed to TNF- production downstream of Dectin-1, which is MALT1 dependent. Here, we addressed the selective involvement of MALT1 in pattern recognition sensing further, using a variety of human and mouse cellular preparations, and stimulation of Dectin-1, MINCLE or TLR-4 pathways. We also provided additional insights by exploring cytokines beyond TNF-, and by comparing MLT-827 to a SYK inhibitor (Cpd11) and to an IKK inhibitor (AFN700). Collectively, the data provided further evidence for the MALT1-dependency of C-type lectin-like receptor &#8212;signaling by contrast to TLR-signaling.

MALT1 regulates innate immunity but how this occurs remains ill-defined. We used the selective MALT1 paracaspase inhibitor MLT-827 to unravel the contribution of MALT1 to innate signaling downstream of Toll-like or C-type lectin-like receptors, demonstrating that MALT1 regulates the production of myeloid cytokines, and downstream of C-type lectin-like receptors, selectively.

תאים מיאלואידים מולדת איתות לשביל רגולציה על-ידי פעילות Paracaspase MALT1

Besides its function in lymphoid cells, which has been addressed by numerous studies, the paracaspase MALT1 also plays an important role in innate cells ...

Applications of Spatio-temporal Mapping and Particle Analysis Techniques to Quantify Intracellular Ca2+ Signaling In Situ

Ca2+ imaging of isolated cells or specific types of cells within intact tissues often reveals complex patterns of Ca2+ signaling. This activity requires careful and in-depth analyses and quantification to capture as much information about the underlying events as possible. Spatial, temporal and intensity parameters intrinsic to Ca2+ signals such as frequency, duration, propagation, velocity and amplitude may provide some biological information required for intracellular signalling. High-resolution Ca2+ imaging typically results in the acquisition of large data files that are time consuming to process in terms of translating the imaging information into quantifiable data, and this process can be susceptible to human error and bias. Analysis of Ca2+ signals from cells in situ typically relies on simple intensity measurements from arbitrarily selected regions of interest (ROI) within a field of view (FOV). This approach ignores much of the important signaling information contained in the FOV. Thus, in order to maximize recovery of information from such high-resolution recordings obtained with Ca2+dyes or optogenetic Ca2+ imaging, appropriate spatial and temporal analysis of the Ca2+ signals is required. The protocols outlined in this paper will describe how a high volume of data can be obtained from Ca2+ imaging recordings to facilitate more complete analysis and quantification of Ca2+ signals recorded from cells using a combination of spatiotemporal map (STM)-based analysis and particle-based analysis. The protocols also describe how different patterns of Ca2+ signaling observed in different cell populations in situ can be analyzed appropriately. For illustration, the method will examine Ca2+ signaling in a specialized population of cells in the small intestine, interstitial cells of Cajal (ICC), using GECIs.

Applications of Spatio-temporal Mapping and Particle Analysis Techniques to Quantify Intracellular Ca2+ Signaling In Situ

Genetically encoded Ca2+ indicators (GECIs) have radically changed how in situ Ca2+ imaging is performed. To maximize data recovery from such recordings, appropriate analysis of Ca2+ signals is required. The protocols in this paper facilitate the quantification of Ca2+ signals recorded in situ using spatiotemporal mapping and particle-based analysis.

יישומים של מיפוי-עתיים, טכניקות ניתוח חלקיקים לכמת Ca תאיים2 + איתות בחיי עיר

Ca2+ imaging of isolated cells or specific types of cells within intact tissues often reveals complex patterns of Ca2+ signaling. This activity requires ...