This work was supported by NIH HL-10342

NOTA: Tutti i protocolli su animali sono stati approvati dall&#39;Università Animal Care and Use Committee Johns Hopkins. 1. Preparazione degli animali <ol><li> Preparare topi 6 C57BL / 6 di controllo per la misurazione DFCO, da loro anestetizzare con ketamina e xilazina come indicato al punto 2.3. </li><li> Preparare tutti gli altri topi con diverse patologie polmonari mostrati nella Tabella 1 usando la stessa procedura per i controlli. I dettagli specifici necessari per stabilire ciascuno di questi modelli si trovano nei riferimenti pertinenti. Topi di controllo e quelle delle altre coorti patologiche sono tutti 6-12 settimane di età. </li></ol> 2. Misura di Diffusion Factor per monossido di carbonio (DFCO) <ol><li> Impostare il modulo gascromatografo fornito con la macchina per misurare picchi di azoto, ossigeno, neon, e il monossido di carbonio. Per questo uso applicazione solo i dati al neon e CO. NOTA: Questo strumento utilizza un s molecolareIEVE colonna con l&#39;elio come gas di trasporto, con un 12,00 micron film, 320.00 ID micron e 10 m di lunghezza. La colonna cromatografo ha un volume di 0,8 ml, ma abbiamo usato 2 ml per garantire un&#39;adeguata compensazione del tubo di collegamento con il campione. </li><li> All&#39;inizio di ogni giornata sperimentale, prima di effettuare le misurazioni dei campioni dai topi, prendere un campione di 2 ml direttamente da un sacchetto di miscela di gas contenente circa lo 0,5% Ne, 0,5% di CO, e bilanciare l&#39;aria, e utilizzare questo esempio per calibrare il gascromatografo. </li><li> Anestetizzare topi con ketamina (90 mg / kg) e xilazina (15 mg / kg), e confermare l&#39;anestesia dall&#39;assenza di movimento riflesso. Applicare pomata veterinaria sugli occhi per evitare la secchezza. Tracheostomize i topi con una cannula stub ago (18 G in adulti o 20 G in molto giovani topi). NOTA: Il DFCO si completa in meno di 10 minuti dopo l&#39;anestesia e prima di ogni ventilazione meccanica o altre procedure. </li><li> Nei topi superiori a 6 settimane di età, usare una siringa da 3 ml to prelevare 0,8 ml di gas dalla sacca miscela di gas. Collegare la siringa cannula tracheale e gonfiare rapidamente il polmone. Utilizzando un metronomo, conta 9 sec, e poi rapidamente ritirare i 0,8 ml (aria espirata). </li><li> Diluire questa ritirati 0,8 ml aria espirata a 2 ml con aria ambiente, lasciarlo riposare per almeno 15 sec. Poi iniettare l&#39;intero campione nel gascromatografo per l&#39;analisi. </li><li> Analizzando questo primo campione DFCO, gonfiare il polmone mouse con una seconda 0,8 ml dal sacchetto miscela di gas, e quindi elaborare questo campione identico al primo campione. La media dei due misurazioni DFCO. NOTA: Per misure in topi giovani come 2 settimane di vita, utilizzare un volume di 0,4 ml, in quanto 0,8 ml è un volume eccessivo di fare misure in polmoni dei giovanissimi topi. E &#39;meglio usare il volume di 0,8 ml per i topi più anziani di 6 settimane, e che se è necessario il volume 0,4 ml per alcuni topi, che dovrebbe essere utilizzato in modo coerente per tutti i mouse nella coorte in fase di studio. </li><li> Calcola DFCOcome 1 - (CO 9 / CO c) / (Ne 9 / Ne c), dove C e 9 pedici riferiscono alle concentrazioni dei gas di taratura iniettati e gas rimossi dopo un tempo 9 sec apnea, rispettivamente. </li><li> Analizzare e confrontare le differenze con un one-way ANOVA e valutare il livello di significatività con correzione di Tukey per confronti multipli in tutti i topi di coorte. Considerare p &lt;0,05 valore significativo. NOTA: Tutti i topi utilizzati qui facevano parte di studi sperimentali che coinvolgono diverse misurazioni successive di ventilazione polmonare, la meccanica, lavaggio polmonare, o istologia, che non sono riportati qui. Inoltre, dato che il metodo è la stessa in tutti i modelli sperimentali come è stato fatto in precedenza nei topi di controllo, solo i risultati dei vari modelli patologiche sono presentati. Per ulteriori informazioni su questi modelli è presentato nella tabella supplementare. </li><li> Eutanasia degli animali da profondi anestheoverdose tic seguita da dislocazione cervicale o decapitazione. Dove necessario, rimuovere le cellule e / o tessuti polmonari da topi morti per ulteriori biologica o trasformazione istologica e analisi. </li></ol>

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	<li>Ogilvie, C. M., Forster, R. E., Blakemore, W. S., Morton, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+standardized+breath+holding+technique+for+the+clinical+measurement+of+the+diffusing+capacity+of+the+lung+for+carbon+monoxide.">A standardized breath holding technique for the clinical measurement of the diffusing capacity of the lung for carbon monoxide.</a> J Clin Invest. 36 (1 Pt 1), 1-17 (1957).</li><li>Miller, A., Warshaw, R., Nezamis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusing+capacity+and+forced+vital+capacity+in+5,003+asbestos-exposed+workers:+Relationships+to+interstitial+fibrosis+(ILO+profusion+score)+and+pleural+thickening.">Diffusing capacity and forced vital capacity in 5,003 asbestos-exposed workers: Relationships to interstitial fibrosis (ILO profusion score) and pleural thickening.</a> Am J Ind Med. 56 (12), 1383-1393 (2013).</li><li>Enelow, R. 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D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intercellular+adhesion+molecule-1+contributes+to+pulmonary+oxygen+toxicity+in+mice:+role+of+leukocytes+revised.">Intercellular adhesion molecule-1 contributes to pulmonary oxygen toxicity in mice: role of leukocytes revised.</a> Lung. 170 (5), 267-279 (1992).</li><li>Reinhard, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inbred+strain+variation+in+lung+function.">Inbred strain variation in lung function.</a> Mamm Genome. 13 (8), 429-437 (2002).</li><li>Sabo, J. P., Kimmel, E. C., Diamond, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+the+Clara+cell+toxin,+4-ipomeanol,+on+pulmonary+function+in+rats.">Effects of the Clara cell toxin, 4-ipomeanol, on pulmonary function in rats.</a> J Appl Physiol. 54 (2), 337-344 (1983).</li><li>Depledge, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Respiration+and+lung+function+in+the+mouse,+Mus+musculus+(with+a+note+on+mass+exponents+and+respiratory+variables).">Respiration and lung function in the mouse, Mus musculus (with a note on mass exponents and respiratory variables).</a> Respir Physiol. 60 (1), 83-94 (1985).</li><li>Depledge, M. H., Collis, C. H., Barrett, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+technique+for+measuring+carbon+monoxide+uptake+in+mice.">A technique for measuring carbon monoxide uptake in mice.</a> Int J Radiat Oncol Biol Phys. 7 (4), 485-489 (1981).</li><li>Fallica, J., Das, S., Horton, M. R., Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+Carbon+Monoxide+Diffusing+Capacity+in+the+Mouse+Lung.">Application of Carbon Monoxide Diffusing Capacity in the Mouse Lung.</a> J Appl Physiol. 110 (5), 1455-1459 (2011).</li><li>Chaudhary, N., Datta, K., Askin, F. B., Staab, J. F., Marr, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cystic+fibrosis+transmembrane+conductance+regulator+regulates+epithelial+cell+response+to+Aspergillus+and+resultant+pulmonary+inflammation.">Cystic fibrosis transmembrane conductance regulator regulates epithelial cell response to Aspergillus and resultant pulmonary inflammation.</a> Am J Respir Crit Care Med. 185 (3), 301-310 (2012).</li><li>Foster, W. M., Walters, D. M., Longphre, M., Macri, K., Miller, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methodology+for+the+measurement+of+mucociliary+function+in+the+mouse+by+scintigraphy.">Methodology for the measurement of mucociliary function in the mouse by scintigraphy.</a> J Appl Physiol. 90 (3), 1111-1117 (2001).</li><li>Yildirim, A. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Palifermin+induces+alveolar+maintenance+programs+in+emphysematous+mice.">Palifermin induces alveolar maintenance programs in emphysematous mice.</a> Am J Respir Crit Care Med. 181 (7), 705-717 (2010).</li><li>Collins, S. L., Chan-Li, Y., Hallowell, R. W., Powell, J. D., Horton, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulmonary+vaccination+as+a+novel+treatment+for+lung+fibrosis.">Pulmonary vaccination as a novel treatment for lung fibrosis.</a> PLoS One. 7 (2), e31299 (2012).</li><li>Alessio, F. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CD4+CD25+Foxp3++Tregs+resolve+experimental+lung+injury+in+mice+and+are+present+in+humans+with+acute+lung+injury.">CD4+CD25+Foxp3+ Tregs resolve experimental lung injury in mice and are present in humans with acute lung injury.</a> J Clin Invest. 119 (10), 2898-2913 (2009).</li><li>Martinez, F. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+clinical+course+of+patients+with+idiopathic+pulmonary+fibrosis.">The clinical course of patients with idiopathic pulmonary fibrosis.</a> Ann Intern Med. 142 (12 Pt 1), 963-967 (2005).</li><li>Zhou, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correction+of+lethal+intestinal+defect+in+a+mouse+model+of+cystic+fibrosis+by+human+CFTR.">Correction of lethal intestinal defect in a mouse model of cystic fibrosis by human CFTR.</a> Science. 266 (5191), 1705-1708 (1994).</li></ol>

Nessun conflitto di interesse, e nulla da rivelare.

Nel presente lavoro, abbiamo definito una nuova metrica di quantificare la capacità gas scambio del polmone mouse. Questo parametro è analogo alla capacità di diffusione, una misura comune clinica che misura la funzione primaria del polmone, cioè la capacità di scambiare gas. La capacità di diffusione è l&#39;unica misurazione funzionale polmonare che può essere fatto facilmente e rapidamente sia nei topi e nell&#39;uomo. Per la rilevazione di malattie polmonari nei topi, un obiettivo importante è quello di qua...

Il mouse è ora l&#39;animale principale utilizzato per modellare una varietà di malattie polmonari. Per studiare i meccanismi che sottostanno tali patologie, sono necessari metodi fenotipici in grado di quantificare il che le alterazioni patologiche. Anche se ci sono molti studi sui topi in cui sono misurati meccanici di ventilazione, queste misure sono generalmente estranei a valutazioni standard di funzionalità polmonare di solito fatto in esseri umani. Questo è un peccato, in quanto la capacità di eseguire misure equivalenti nei topi e soggetti umani possono facilitare la traduzione dei risultati in modelli murini di patologie umane. Una delle misure più comuni e facilmente realizzati in soggetti umani è la capacità di diffusione del monossido di carbonio (DLCO) 1,2, ma questa misura è stato raramente fatto solo in modelli murini. In questi studi in cui è stato segnalato 3-7, non ci sono stati studi di follow-up, in parte perché le procedure sono spesso ingombranti o possono REQuire attrezzature complesse. Un altro approccio è quello di utilizzare un metodo di CO rirespirazione in un sistema di stato stazionario, che ha il vantaggio di essere in grado di misurare CO diffusione in topi coscienti. Tuttavia questo metodo è molto ingombrante, e risultati può variare con il livello di ventilazione del topo e O 2 e CO 2 concentrazioni 8,9. Queste difficoltà sembrano essere precluso l&#39;uso di routine di capacità di individuare patologie polmonari nei topi diffusione, nonostante i suoi numerosi vantaggi. Per aggirare i problemi con la misurazione della capacità nei topi diffusione, dettagli di un semplice mezzo per misurare in topi sono stati recentemente segnalati 10. La procedura elimina il difficile problema di campionamento incontaminata gas alveolare campionando rapidamente un volume pari a tutto il gas ispirato. Questa procedura comporta una misurazione molto riproducibili, definito il fattore di diffusione per il monossido di carbonio (DFCO), che è sensibile a un host di pacambiamenti thologic del fenotipo polmonare. Il DFCO è quindi calcolato come 1 - (CO 9 / CO c) / (Ne 9 / Ne c), dove c e 9 pedici riferiscono alle concentrazioni dei gas di taratura iniettati e gas rimossi dopo un tempo 9 sec apnea, rispettivamente. DFCO è una variabile adimensionale, che varia tra 0 e 1, con 1 riflettendo completo assorbimento di tutti CO, e 0 riflettendo nessun assorbimento di CO. In questa presentazione vi mostriamo come fare questa misura la capacità di diffusione, e in che modo può essere utilizzato per documentare i cambiamenti in quasi tutti i modelli di malattia del mouse polmone esistenti, tra cui l&#39;enfisema, la fibrosi, danno polmonare acuto, e le infezioni virali e fungine.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Gas Chromatograph</td>
			<td>Inficon</td>
			<td>Micro GC Model 3000A</td>
			<td>Agilent makes a comparable model</td>
		</tr>
		<tr>
			<td>18 g Luer stub needle</td>
			<td>Becton Dickenson</td>
			<td></td>
			<td>Several other possible vendors</td>
		</tr>
		<tr>
			<td>3 mL plastic syringe</td>
			<td>Becton Dickenson</td>
			<td></td>
			<td>Several other possible vendors</td>
		</tr>
		<tr>
			<td>Polypropylene gas sample bags</td>
			<td>SKC</td>
			<td>1 or 2 liter capacity works well</td>
			<td>Other gas tight bags will work well</td>
		</tr>
		<tr>
			<td>Gas tank, 0.3% Ne,0.3% CO, balance air; (size ME)</td>
			<td>Airgas, Inc</td>
			<td>Z04 NI785ME3012</td>
			<td>This is the standard mixture used for DLCO in humans</td>
		</tr>
		<tr>
			<td>25 TCID50/mouse of influenza virus A/PR8 diluted in phosphate buffered saline.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Porcine pancreatic elastase</td>
			<td>Elastin Products, Owensville, MO</td>
			<td></td>
			<td>5.4 U</td>
		</tr>
		<tr>
			<td>Bleomycin</td>
			<td>APP Pharmaceuticals, Schaumburg, IL</td>
			<td></td>
			<td>0.25 U</td>
		</tr>
		<tr>
			<td>Escherichia coli LPS8</td>
			<td>Sigma L2880</td>
			<td></td>
			<td>3 &#956;g/g body weight; O55:B5</td>
		</tr>
		<tr>
			<td>Aspergillus fumigatus (isolate Af293) conidia were collected from mature colonies grown on potato dextrose agar.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

phenotyping mouse pulmonary function in vivo with the lung diffusing capacity

Il mouse è ora l&#39;animale principale utilizzato per modellare una varietà di malattie polmonari. Per studiare i meccanismi che sono alla base di tali patologie, sono necessari metodi fenotipici in grado di quantificare i cambiamenti patologici. Inoltre, per fornire rilevanza traslazionale ai modelli murini, tali misure devono essere prove che possono essere facilmente fatto in entrambi gli esseri umani e topi. Sfortunatamente, nella presente letteratura alcune misurazioni fenotipiche della funzione polmonare hanno applicazione diretta agli esseri umani. Un&#39;eccezione è la capacità di diffusione del monossido di carbonio, che è una misura che viene normalmente fatto in esseri umani. Nella presente relazione, descriviamo un mezzo per misurare rapidamente e semplicemente questo capacità di diffusione nei topi. La procedura implica breve gonfiaggio polmonare con gas traccianti in un mouse anestetizzato, seguito da un tempo di analisi gas 1 min. Abbiamo testato la capacità di questo metodo per individuare varie patologie polmonari, tra cui l&#39;enfisema, la fibrosi, danno polmonare acuto, e l&#39;influenza einfezioni polmonari fungine, così come il monitoraggio la maturazione polmonare in giovani cuccioli. I risultati mostrano una significativa diminuzione di tutte le patologie polmonari, nonché un aumento della capacità di diffusione con la maturazione polmonare. Questa misura di capacità di diffusione polmonare fornisce quindi un test di funzionalità polmonare, che ha una vasta applicazione con la sua capacità di rilevare i cambiamenti strutturali fenotipiche con la maggior parte dei modelli di polmone patologiche esistenti.

La figura 1 mostra le misurazioni DFCO dai topi adulti in gruppi A, B, C, D, E e F. c&#39;erano diminuzioni significative con entrambe le infezioni da Aspergillus e influenza, nonché riduzioni significative del fibrotico, enfisematosa, e acuta modelli danno polmonare. La figura 2 mostra il gruppo G alterazioni dello sviluppo DFCO nel tempo come l&#39;età topi 2-6 settimane. C&#39;è stato un lieve ma significativo aumento con lo sviluppo polmonare nel corso del tempo. L&#39;effetto di...

Watch this Scientific Journal Video about Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity at JoVE.com

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

We describe a means to quickly and simply measure the lung diffusing capacity in mice and show that it is sufficiently sensitive to phenotype changes in multiple common lung pathologies. This metric thus brings direct translational relevance to the mouse models, since diffusing capacity is also easily measured in humans.

Fenotipizzazione mouse Pulmonary Function<em&gt; In Vivo</em&gt; Con la capacità polmonare Diffusione

The mouse is now the primary animal used to model a variety of lung diseases. To study the mechanisms that underlie such pathologies, phenotypic methods ...

phenotyping-mouse-pulmonary-function-vivo-with-lung-diffusing

Research

JoVE Journal

Biology

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

10.5K Views.  Johns Hopkins University Bloomberg School of Public Health. We describe a means to quickly and simply measure the lung diffusing capacity in mice and show that it is sufficiently sensitive to phenotype changes in multiple common lung pathologies. This metric thus brings direct translational relevance to the mouse models, since diffusing capacity is also easily measured in humans.

Video: Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

Imaging in vivo e trattamenti terapeutici in un modello di mouse ortotopico di cancro ovarico

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Ricerca

Biologia

Characterization of the Isolated, Ventilated, and Instrumented Mouse Lung Perfused with Pulsatile Flow

The isolated, ventilated and instrumented mouse lung preparation allows steady and pulsatile pulmonary vascular pressure-flow relationships to be measured with independent control over pulmonary arterial flow rate, flow rate waveform, airway pressure and left atrial pressure. Pulmonary vascular resistance is calculated based on multi-point, steady pressure-flow curves; pulmonary vascular impedance is calculated from pulsatile pressure-flow curves obtained at a range of frequencies. As now recognized clinically, impedance is a superior measure of right ventricular afterload than resistance because it includes the effects of vascular compliance, which are not negligible, especially in the pulmonary circulation. Three important metrics of impedance - the zero hertz impedance Z0, the characteristic impedance ZC, and the index of wave reflection RW - provide insight into distal arterial cross-sectional area available for flow, proximal arterial stiffness and the upstream-downstream impedance mismatch, respectively. All results obtained in isolated, ventilated and perfused lungs are independent of sympathetic nervous system tone, volume status and the effects of anesthesia. We have used this technique to quantify the impact of pulmonary emboli and chronic hypoxia on resistance and impedance, and to differentiate between sites of action (i.e., proximal vs. distal) of vasoactive agents and disease using the pressure dependency of ZC. Furthermore, when these techniques are used with the lungs of genetically engineered strains of mice, the effects of molecular-level defects on pulmonary vascular structure and function can be determined.

The following protocol outlines the process of isolating, ventilating and instrumenting mouse lungs to measure steady or pulsatile pulmonary vascular pressure-flow relationships in order to quantify the effects of blood flow, airflow, airway changes and vascular changes on right ventricular afterload.

Caratterizzazione del isolata, ventilata e polmone mouse Instrumented perfusi con flusso pulsatile

The isolated, ventilated and instrumented mouse lung preparation allows steady and pulsatile pulmonary vascular pressure-flow relationships to be measured ...

Examining BCL-2 Family Function with Large Unilamellar Vesicles

The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate apoptosis1. Following cellular stress (e.g., DNA damage), the pro-apoptotic BCL-2 family effectors BAK (BCL-2 antagonistic killer 1) and/or BAX (BCL-2 associated X protein) become activated and compromise the integrity of the outer mitochondrial membrane (OMM), though the process referred to as mitochondrial outer membrane permeabilization (MOMP)1. After MOMP occurs, pro-apoptotic proteins (e.g., cytochrome c) gain access to the cytoplasm, promote caspase activation, and apoptosis rapidly ensues2.
In order for BAK/BAX to induce MOMP, they require transient interactions with members of another pro-apoptotic subset of the BCL-2 family, the BCL-2 homology domain 3 (BH3)-only proteins, such as BID (BH3-interacting domain agonist)3-6. Anti-apoptotic BCL-2 family proteins (e.g., BCL-2 related gene, long isoform, BCL-xL; myeloid cell leukemia 1, MCL-1) regulate cellular survival by tightly controlling the interactions between BAK/BAX and the BH3-only proteins capable of directly inducing BAK/BAX activation7,8. In addition, anti-apoptotic BCL-2 protein availability is also dictated by sensitizer/de-repressor BH3-only proteins, such as BAD (BCL-2 antagonist of cell death) or PUMA (p53 upregulated modulator of apoptosis), which bind and inhibit anti-apoptotic members7,9. As most of the anti-apoptotic BCL-2 repertoire is localized to the OMM, the cellular decision to maintain survival or induce MOMP is dictated by multiple BCL-2 family interactions at this membrane.
 Large unilamellar vesicles (LUVs) are a biochemical model to explore relationships between BCL-2 family interactions and membrane permeabilization10. LUVs are comprised of defined lipids that are assembled in ratios identified in lipid composition studies from solvent extracted Xenopus mitochondria (46.5% phosphatidylcholine, 28.5% phosphatidylethanoloamine, 9% phosphatidylinositol, 9% phosphatidylserine, and 7% cardiolipin)10. This is a convenient model system to directly explore BCL-2 family function because the protein and lipid components are completely defined and tractable, which is not always the case with primary mitochondria. While cardiolipin is not usually this high throughout the OMM, this model does faithfully mimic the OMM to promote BCL-2 family function. Furthermore, a more recent modification of the above protocol allows for kinetic analyses of protein interactions and real-time measurements of membrane permeabilization, which is based on LUVs containing a polyanionic dye (ANTS: 8-aminonaphthalene-1,3,6-trisulfonic acid) and cationic quencher (DPX: p-xylene-bis-pyridinium bromide)11. As the LUVs permeabilize, ANTS and DPX diffuse apart, and a gain in fluorescence is detected. Here, commonly used recombinant BCL-2 family protein combinations and controls using the LUVs containing ANTS/DPX are described.

Biochemically-defined large unilamellar vesicles (LUVs) are a convenient model system to analyze BCL-2 family interactions with immediate implications in better understanding the mitochondrial pathway of apoptosis. A method to produce LUVs, along with standard BCL-2 family protein combinations and controls to examine LUV permeabilization, are presented.

Esaminando BCL-2 Funzione Famiglia con grandi vescicole unilamellari

The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate ...

Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface

In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. 
Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. 
In vitro models of differentiated human nasal epithelial cells will enable investigators to address novel and important research questions by using organotypic experimental models that largely mimic the nasal epithelium in vivo.

Nasal epithelial cells, obtained through superficial scrape biopsy of human volunteers, are expanded and transferred onto tissue culture inserts. Upon reaching confluency, cells are grown at air liquid interface, yielding cultures of ciliated and non-ciliated cells. Differentiated nasal epithelial cell cultures provide viable experimental models for studying the respiratory mucosa.

Coltura di cellule umane nasale epiteliali presso l&#39;Air Interface Liquid

In vitro models using human primary  epithelial cells are essential in understanding key functions of the respiratory  epithelium in the context of ...

Isolation of Mitochondria from Minimal Quantities of Mouse Skeletal Muscle for High Throughput Microplate Respiratory Measurements

Dysfunctional skeletal muscle mitochondria play a role in altered metabolism observed with aging, obesity and Type II diabetes. Mitochondrial respirometric assays from isolated mitochondrial preparations allow for the assessment of mitochondrial function, as well as determination of the mechanism(s) of action of drugs and proteins that modulate metabolism. Current isolation procedures often require large quantities of tissue to yield high quality mitochondria necessary for respirometric assays. The methods presented herein describe how high quality purified mitochondria (~ 450 &#181;g) can be isolated from minimal quantities (~75-100 mg) of mouse skeletal muscle for use in high throughput respiratory measurements. We determined that our isolation method yields 92.5&#177; 2.0% intact mitochondria by measuring citrate synthase activity spectrophotometrically. In addition, Western blot analysis in isolated mitochondria resulted in the faint expression of the cytosolic protein, GAPDH, and the robust expression of the mitochondrial protein, COXIV. The absence of a prominent GAPDH band in the isolated mitochondria is indicative of little contamination from non-mitochondrial sources during the isolation procedure. Most importantly, the measurement of O2 consumption rate with micro-plate based technology and determining the respiratory control ratio (RCR) for coupled respirometric assays shows highly coupled (RCR; &#62;6 for all assays) and functional mitochondria. In conclusion, the addition of a separate mincing step and significantly reducing motor driven homogenization speed of a previously reported method has allowed the isolation of high quality and purified mitochondria from smaller quantities of mouse skeletal muscle that results in highly coupled mitochondria that respire with high function during microplate based respirometirc assays.

Here, we present a modification of a previously reported method that allows for the isolation of high quality and purified mitochondria from smaller quantities of mouse skeletal muscle. This procedure results in highly coupled mitochondria that respire with high function during microplate based respirometirc assays.

L&#39;isolamento di mitocondri da minime quantità di muscolo scheletrico del mouse per misurazioni High Throughput micropiastre respiratorie

Dysfunctional skeletal muscle mitochondria play a role in altered metabolism observed with aging, obesity and Type II diabetes. Mitochondrial ...

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, is expressed in neurons in response to various stimuli. The protein product can be readily detected with immunohistochemical techniques leading to the use of c-FOS detection to map groups of neurons that display changes in their activity. In this article, we focused on the identification of brainstem neuronal populations involved in the ventilatory adaptation to hypoxia or hypercapnia. Two approaches were described to identify involved neuronal populations in vivo in animals and ex vivo in deafferented brainstem preparations. In vivo, animals were exposed to hypercapnic or hypoxic gas mixtures. Ex vivo, deafferented preparations were superfused with hypoxic or hypercapnic artificial cerebrospinal fluid. In both cases, either control in vivo animals or ex vivo preparations were maintained under normoxic and normocapnic conditions. The comparison of these two approaches allows the determination of the origin of the neuronal activation i.e., peripheral and/or central. In vivo and ex vivo, brainstems were collected, fixed, and sliced into sections. Once sections were prepared, immunohistochemical detection of the c-FOS protein was made in order to identify the brainstem groups of cells activated by hypoxic or hypercapnic stimulations. Labeled cells were counted in brainstem respiratory structures. In comparison to the control condition, hypoxia or hypercapnia increased the number of c-FOS labeled cells in several specific brainstem sites that are thus constitutive of the neuronal pathways involved in the adaptation of the central respiratory drive.

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo.

La proteina C-FOS immunoistologiche Detection: uno strumento utile come indicatore di percorsi centrali coinvolti nelle risposte fisiologiche specifiche<em&gt; In Vivo</em&gt; e<em&gt; Ex Vivo</em

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, ...

In Vivo Study of Human Endothelial-Pericyte Interaction Using the Matrix Gel Plug Assay in Mouse

Angiogenesis is the process by which new blood vessels are formed from existing vessels. New vessel growth requires coordinated endothelial cell proliferation, migration, and alignment to form tubular structures followed by recruitment of pericytes to provide mural support and facilitate vessel maturation. Current in vitro cell culture approaches cannot fully reproduce the complex biological environment where endothelial cells and pericytes interact to produce functional vessels. We present a novel application of the in vivo matrix gel plug assay to study endothelial-pericyte interactions and formation of functional blood vessels using severe combined immune deficiency mutation (SCID) mice. Briefly, matrix gel is mixed with a solution containing endothelial cells with or without pericytes followed by injection into the back of anesthetized SCID mice. After 14 days, the matrix gel plugs are removed, fixed and sectioned for histological analysis. The length, number, size and extent of pericyte coverage of mature vessels (defined by the presence of red blood cells in the lumen) can be quantified and compared between experimental groups using commercial statistical platforms. Beyond its use as an angiogenesis assay, this matrix gel plug assay can be used to conduct genetic studies and as a platform for drug discovery. In conclusion, this protocol will allow researchers to complement available in vitro assays for the study of endothelial-pericyte interactions and their relevance to either systemic or pulmonary angiogenesis.

In Vivo Study of Human Endothelial-Pericyte Interaction Using the Matrix Gel Plug Assay in Mouse

We present a protocol to study human endothelial-pericyte interactions in mouse using a variation of the matrix gel plug angiogenesis assay.

Studio in vivo di Human Interaction endoteliale-pericyte Utilizzando la matrice di gel Plug Assay nel topo

Angiogenesis is the process by which new blood vessels are formed from existing vessels. New vessel growth requires coordinated endothelial cell ...

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a versatile analytical tool for characterizing viscoelastic mechanical properties for a variety of materials ranging from hard (plastic, glass, metal, etc.) surfaces to cells on any substrate. It has been widely used to measure the stiffness of cells, but less frequently used to measure the stiffness of aortas. In this paper, we will describe the procedures for using AFM in contact mode to measure the ex vivo elastic modulus of unloaded mouse arteries. We describe our procedure for isolation of mouse aortas, and then provide detailed information for the AFM analysis. This includes step-by-step instructions for alignment of the laser beam, calibration of the spring constant and deflection sensitivity of the AFM probe, and acquisition of force curves. We also provide a detailed protocol for data analysis of the force curves.

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

We present detailed protocols for isolation of aortas from mouse and measurement of their elastic modulus using atomic force microscopy.

Misurare la rigidità<em&gt; Ex Vivo</em&gt; Mouse aorte Utilizzando microscopia a forza atomica

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a ...

Induction of Right Ventricular Failure by Pulmonary Artery Constriction and Evaluation of Right Ventricular Function in Mice

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of RVF. Previous rat models imitating RVF progression have been described. Compared with rats, mice are more accessible, economical, and widely used in animal experiments. We developed a pulmonary artery constriction (PAC) approach which is comprised of banding the pulmonary trunk in mice to induce right ventricular (RV) hypertrophy. A special surgical latch needle was designed that allows for easier separation of the aorta and the pulmonary trunk. In our experiments, the use of this fabricated latch needle reduced the risk of arteriorrhexis and improved the surgical success rate to 90%. We used different padding needle diameters to precisely create quantitative constriction, which can induce different degrees of RV hypertrophy. We quantified the degree of constriction by evaluating the blood flow velocity of the PA, which was measured by noninvasive transthoracic echocardiography. RV function was precisely evaluated by right heart catheterization at 8 weeks after surgery. The surgical instruments made inhouse were composed of common materials using a simple process that is easy to master. Therefore, the PAC approach described here is easy to imitate using instruments made in the lab and can be widely used in other labs. This study presents a modified PAC approach that has a higher success rate than other models and an 8-week postsurgery survival rate of 97.8%. This PAC approach provides a useful technique for studying the mechanism of RVF and will enable an increased understanding of RVF.

Here, we provide a useful approach for studying the mechanism of right ventricular failure. A more convenient and efficient approach to pulmonary artery constriction is established using surgical instruments made inhouse. In addition, methods to evaluate the quality of this approach by echocardiography and catheterization are provided.

Induzione del fallimento ventricolare destro da parte della costrizione dell'arteria polmonare e valutazione della funzione ventricolare destra nei topi

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of ...

In vivo Measurement of Knee Extensor Muscle Function in Mice

Skeletal muscle plasticity in response to countless conditions and stimuli mediates concurrent functional adaptation, both negative and positive. In the clinic and the research laboratory, maximal muscular strength is widely measured longitudinally in humans, with knee extensor musculature the most reported functional outcome. Pathology of the knee extensor muscle complex is well documented in aging, orthopedic injury, disease, and disuse; knee extensor strength is closely related to functional capacity and injury risk, underscoring the importance of reliable measurement of knee extensor strength. Repeatable, in vivo assessment of knee extensor strength in pre-clinical rodent studies offers valuable functional endpoints for studies exploring osteoarthritis or knee injury. We report an in vivo and non-invasive protocol to repeatedly measure isometric peak tetanic torque of the knee extensors in mice across time. We demonstrate consistency using this novel method to measure knee extensor strength with repeated assessment in multiple mice producing similar results.

Quantification of knee extensor maximal strength is imperative to understand functional adaptations to aging, disease, injury, and rehabilitation. We present a novel method to repeatedly measure in vivo knee extension isometric peak tetanic torque.

Misurazione in vivo della funzione muscolare estensore del ginocchio nei topi

Skeletal muscle plasticity in response to countless conditions and stimuli mediates concurrent functional adaptation, both negative and positive. In the ...