This research is supported by the CounterACT Program, National Institutes of Health (NIH), Office of the Director, and the National Institute of Environmental Health Sciences (NIEHS) Grant Number U54 ES015678 (CWW). SA is also supported by Children&#39;s hospital Colorado/Colorado School of Mines Collaboration Pilot Award #G0100394 and Children&#39;s Hospital Colorado Research Institue Pilot Award #G0100471.

1. Rat Cardiomyocyte Cultures
<ol>
	<li>All experiments were performed under protocols approved by the institutional animal care and use committee, IACUC.</li>
	<li>Obtain rat cardiomyocytes from the hearts (ventricles) of male rats (240-260 g) using methods described previously4. Briefly, anesthetize animals using an intraperitoneal injection of pentobarbital (100 mg/kg; confirm anesthesia by toe pinch method) and then remove hearts into 10.0 ml, 1 mM Ca2+ containing Krebs Ringer buffer, pH 7.4.<...

<ol>
	<li>Mohan, A., 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=Acute+accidental+exposure+to+chlorine+gas:+clinical+presentation,+pulmonary+functions+and+outcomes.">Acute accidental exposure to chlorine gas: clinical presentation, pulmonary functions and outcomes.</a> Indian J Chest Dis Allied Sci. 52, 149-152 (2010).</li><li>Kose, A., 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=Myocardial+infarction,+acute+ischemic+stroke,+and+hyperglycemia+triggered+by+acute+chlorine+gas+inhalation.">Myocardial infarction, acute ischemic stroke, and hyperglycemia triggered by acute chlorine gas inhalation.</a> Am J Emerg Med. 27, 1021-1024 (2009).</li><li>Das, R., Blanc, P. 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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=Isolation+of+mouse+respiratory+epithelial+cells+and+exposure+to+experimental+cigarette+smoke+at+air+liquid+interface.">Isolation of mouse respiratory epithelial cells and exposure to experimental cigarette smoke at air liquid interface.</a> J Vis Exp. (48), (2011).</li><li>Hosokawa, T., 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=Differentiation+of+tracheal+basal+cells+to+ciliated+cells+and+tissue+reconstruction+on+the+synthesized+basement+membrane+substratum+in+vitro.">Differentiation of tracheal basal cells to ciliated cells and tissue reconstruction on the synthesized basement membrane substratum in vitro.</a> Connect Tissue Res. 48, 9-18 (2007).</li><li>Fulcher, M. 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=Well-differentiated+human+airway+epithelial+cell+cultures.">Well-differentiated human airway epithelial cell cultures.</a> Methods Mol Med. , 107-183 (2005).</li><li>Ahmad, S., 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=SERCA2+regulates+non-CF+and+CF+airway+epithelial+cell+response+to+ozone.">SERCA2 regulates non-CF and CF airway epithelial cell response to ozone.</a> PloS One. 6, e10 (2011).</li><li>Martin, J. G., 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=Chlorine-induced+injury+to+the+airways+in+mice.">Chlorine-induced injury to the airways in mice.</a> Am J Respir Crit Care Med. 168, 568-574 (2003).</li><li>Evans, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chlorine:+state+of+the+art.">Chlorine: state of the art.</a> Lung. 183, 151-167 (2005).</li><li>Vliet, A., 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=Formation+of+reactive+nitrogen+species+during+peroxidase-catalyzed+oxidation+of+nitrite.+A+potential+additional+mechanism+of+nitric+oxide-dependent+toxicity.">Formation of reactive nitrogen species during peroxidase-catalyzed oxidation of nitrite. A potential additional mechanism of nitric oxide-dependent toxicity.</a> J Biol Chem. 272, 7617-7625 (1997).</li><li>Ahmad, S., 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=Lung+epithelial+cells+release+ATP+during+ozone+exposure:+signaling+for+cell+survival.">Lung epithelial cells release ATP during ozone exposure: signaling for cell survival.</a> Free Radic Biol Med. 39, 213-226 (2005).</li><li>Allen, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+automated+system+for+exposure+of+cultured+cells+and+other+materials+to+ozone.">An automated system for exposure of cultured cells and other materials to ozone.</a> Inhal Toxicol. 15, 1039-1052 (2003).</li></ol>

The authors declare that they have no competing financial interests.

The most common type of acute toxic exposures occurs when one breathes a poisonous chemical into the lungs. These chemicals may also be quickly taken up in the bloodstream and may impact other organs such as brain and heart. Inhalation toxicity of various agents using animal models are studied and reported widely, however the mechanisms are less well understood. This is a major hurdle in developing effective therapies. Absence of in vitro exposure systems is a primary reason behind the lack of mechanistic insigh...

Exposure to toxic inhaled chemicals (TICs)/gases such as chlorine (Cl2) remains an ongoing health concern in accidental exposures as well as in their potential use as a chemical threat agent. Although the lungs are the primary target, organs such as heart and brain are also affected1-3. In vivo models are generally used for testing toxicity from TICs, but in vitro assays for toxicity assessment are simpler, faster and more cost effective. In vitro models also allow for extensive investigation of agent-cell interactions that may be difficult to evaluate in vivo. Such in vitro exposure systems are rare and moreover, in some conventional models where toxic agents are added to the culture medium in which cells are submerged, the properties of the agents can change due to interactions and binding to components in the medium. In such scenarios cell culture systems such as air-liquid&#160;interface (ALI) cultures of primary human airway epithelial cells, proposed here, that can be directly exposed to gaseous agents could be promising.
Epithelial cells lining the airway are the first lines of defense against inhaled toxic chemicals. The human airway epithelium forms a physical barrier between the lumen and the underlying cells in the lung and participates in the response of the lung. It produces a number of cytokines and other pro- and anti-inflammatory agents as well as secretes mucus/airway surface liquid (ASL) covering the epithelium. One of the limitations in conventional submerged in vitro culture systems is also that the ASL and mucus that cover the epithelial surface is removed or diluted. This does not reflect the physiological condition of lung epithelial cells that are exposed to air. Thus, an ideal in vitro system for TIC toxicity testing should replicate this architecture. There is great interest in developing rapid screening methods that predict in vivo toxicity. Epithelial cells grown at the ALI differentiate and have well-differentiated structures and functions compared to cells grown submerged and serve a superior model of the airways.
In this study, we describe the use of air-liquid-interface culture of human airway (tracheobronchial) epithelial cells for testing poisonous inhaled gas toxicity and compare it with a submerged cell culture of cardiomyocyte, hence studying another important target of toxicity.

<table border="0" cellpadding="0" cellspacing="0" width="1128">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:487px;">Name</td>
			<td style="width:329px;">Company</td>
			<td style="width:147px;">Catalog Number</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:487px;">Rats</td>
			<td style="width:329px;">Harlan Laboratories</td>
			<td>Sprague-Dawley&#160;</td>
			<td></td>
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			<td height="22" style="height:22px;width:487px;">Pentobarbital</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">P3761</td>
			<td></td>
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		<tr height="22">
			<td height="22" style="height:22px;width:487px;">Chlorine</td>
			<td style="width:329px;">AirGas, Inc</td>
			<td style="width:147px;">X02NI99CP163LS1</td>
			<td></td>
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			<td height="22" style="height:22px;width:487px;">Caspase 3/7 kit&#160;</td>
			<td style="width:329px;">Promega</td>
			<td style="width:147px;">G8091</td>
			<td></td>
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			<td height="22" style="height:22px;width:487px;">Epithelial voltohmmeter and chopstick electrode</td>
			<td style="width:329px;">World Precision Instruments</td>
			<td style="width:147px;">EVOM and STX2</td>
			<td></td>
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			<td height="22" style="height:22px;width:487px;">Snapwell inserts</td>
			<td style="width:329px;">Corning</td>
			<td style="width:147px;">07-200-708</td>
			<td></td>
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			<td height="21" style="height:21px;width:487px;">70 micron nylon cell strainer</td>
			<td style="width:329px;">Corning</td>
			<td style="width:147px;">#352360</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Polysulfone biocontainment chambers&#160;</td>
			<td style="width:329px;">BCU, Allentown Cage Equipment</td>
			<td style="width:147px;">BCU</td>
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			<td height="21" style="height:21px;">DMEM</td>
			<td style="width:329px;">Life technologies</td>
			<td style="width:147px;">12491-015</td>
			<td></td>
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			<td height="21" style="height:21px;width:487px;">Sarcomeric actin antibody</td>
			<td style="width:329px;">Abcam Cambridge, MA</td>
			<td style="width:147px;">ab28052</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SERCA2 antibody</td>
			<td style="width:329px;">&#160;Affinity Bioreagents, Golden, CO</td>
			<td style="width:147px;">MA3-9191</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ki-67 antibody</td>
			<td style="width:329px;">&#160;Dako, Carpinteria, CA</td>
			<td style="width:147px;">M7248</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Alexa-488-conjugated secondary antibody</td>
			<td style="width:329px;">&#160;Invitrogen, Grand Island, NY</td>
			<td style="width:147px;">A11029</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">BSA</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">A9418</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Carnitine</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">C0283</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Taurine</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">T8691</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Creatinine</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">C6257</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Krebs Ringer Buffer</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">K4002</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Protease</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">P5147</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Collagenase</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">C6885</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:487px;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; DNAase</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">DN-25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Lactated Ringer solution</td>
			<td style="width:329px;">Abott Laboratories</td>
			<td style="width:147px;">7953</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Donkey serum</td>
			<td style="width:329px;">Fisher Scientific</td>
			<td style="width:147px;">017-000-001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">PBS, phosphate buffered saline</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">D1408</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">4-15% SDS-PAGE gels</td>
			<td style="width:329px;">Bio-Rad</td>
			<td style="width:147px;">456-1083</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Nitrocellulose membrane</td>
			<td style="width:329px;">Bio-Rad</td>
			<td style="width:147px;">162-0115</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Dergent, Tween&#160;</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">P1379</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Peroxidase detection kit</td>
			<td style="width:329px;">Pierce</td>
			<td align="right" style="width:147px;">3402</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">DAPI</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">D9542</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Mounting media, Fluormount G</td>
			<td style="width:329px;">eBiosciences</td>
			<td style="width:147px;">00-4958-02</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Sodium citrate</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">71497</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Collagen</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">C7521</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">MEM</td>
			<td style="width:329px;">Sigma-Aldrich</td>
			<td style="width:147px;">M8028</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Laminin</td>
			<td style="width:329px;">BD biosciences</td>
			<td style="width:147px;">354259</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Penicillin/Streptomycin</td>
			<td style="width:329px;">Life Technologies</td>
			<td style="width:147px;">15070063</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">FBS</td>
			<td style="width:329px;">Gibco</td>
			<td style="width:147px;">200-6140AJ</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vitro cell culture model for toxic inhaled chemical testing

Cell cultures are indispensable to develop and study efficacy of therapeutic agents, prior to their use in animal models. We have the unique ability to model well differentiated human airway epithelium and heart muscle cells. This could be an invaluable tool to study the deleterious effects of toxic inhaled chemicals, such as chlorine, that can normally interact with the cell surfaces, and form various byproducts upon reacting with water, and limiting their effects in submerged cultures. Our model using well differentiated human airway epithelial cell cultures at air-liqiuid interface circumvents this limitation as well as provides an opportunity to evaluate critical mechanisms of toxicity of potential poisonous inhaled chemicals. We describe enhanced loss of membrane integrity, caspase release and death upon toxic inhaled chemical such as chlorine exposure. In this article, we propose methods to model chlorine exposure in mammalian heart and airway epithelial cells in culture and simple tests to evaluate its effect on these cell types.

Primary rod shaped cardiomyocytes attach on laminin matrices and spread and differentiate into confluent cultures (Figure 1A and its inset). These cells were further characterized on the basis of sarcomeric actin and SERCA2 expression (Figures 1B and 1C). Rat cardiomyocytes are highly susceptible to chlorine toxicity as 15 min exposure to 100 ppm chlorine caused extensive cell rounding and death in submerged cultures and disruption of confluent layers on cells grown on l...

Watch this Scientific Journal Video about In vitro Cell Culture Model for Toxic Inhaled Chemical Testing at JoVE.com

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing

This protocol is designed to demonstrate exposure method of cell cultures to inhaled toxic chemicals. Exposure of differentiated air-liquid&#160;interface (ALI) cultures of airway epithelial cells provides a unique model of airway exposure to toxic gases such as chlorine. In this manuscript we describe effect of chlorine exposure on air-liquid&#160;interface cultures of epithelial cells and submerged culture of cardiomyocytes. In vitro exposure systems allow important mechanistic studies to evaluate pathways that could then be utilized to develop novel therapeutic agents.

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing

Cell cultures are indispensable to develop and study efficacy of therapeutic agents, prior to their use in animal models. We have the unique ability to ...

in-vitro-cell-culture-model-for-toxic-inhaled-chemical-testing

Research

JoVE Journal

Bioengineering

10.6K visualizações.  University of Colorado.  Este protocolo destina-se a demonstrar o método de exposição de culturas de células a produtos químicos tóxicos inalados. Exposição de diferenciado interface ar-líquido (LPA) culturas de células epiteliais das vias aéreas oferece um modelo único de exposição das vias aéreas de gases tóxicos como o cloro. Nesse artigo, descrevem efeito de exposição ao cloro em culturas de interface ar-líquido de células epiteliais e de cultura submersa de cardiomiócit...