The authors have declared no conflict of interest.

The overall protocol requires 2 days, including the first day of sepsis induction and isolation of BAL fluid from the animal, and the second day for exosomes isolation from the mouse BALF. All procedures have been reviewed and approved by the Institutional Animal Care and Use Committee at Atlanta VA medical center.
1. Mouse Acute Septic Lung Injury Model
<ol>
	<li>Use 6 - 8 weeks- old male wild-type C57BL/6J mice (weight 20 - 22 g) for the animal model, and perform all procedures using asept...

<ol>
	<li>Rubenfeld, G. D., Herridge, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+and+outcomes+of+acute+lung+injury.">Epidemiology and outcomes of acute lung injury.</a> Chest. 131, 554-562 (2007).</li><li>Baron, R. M., Choi, A. J., Owen, C. A., Choi, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetically+manipulated+mouse+models+of+lung+disease:+potential+and+pitfalls.">Genetically manipulated mouse models of lung disease: potential and pitfalls.</a> American journal of physiology. Lung cellular and molecular physiology. , L485-L497 (2012).</li><li>Han, S., Mallampalli, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+acute+respiratory+distress+syndrome:+from+mechanism+to+translation.">The acute respiratory distress syndrome: from mechanism to translation.</a> Journal of immunology. , 855-860 (1950).</li><li>Aeffner, F., Bolon, B., Davis, I. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+Models+of+Acute+Respiratory+Distress+Syndrome:+A+Review+of+Analytical+Approaches,+Pathologic+Features,+and+Common+Measurements.">Mouse Models of Acute Respiratory Distress Syndrome: A Review of Analytical Approaches, Pathologic Features, and Common Measurements.</a> Toxicologic pathology. 43, 1074-1092 (2015).</li><li>Matute-Bello, G., Frevert, C. W., Martin, T. 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Lung cellular and molecular physiology. , L379-L399 (2008).</li><li>Terrasini, N., Lionetti, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exosomes+in+Critical+Illness.">Exosomes in Critical Illness.</a> Critical care medicine. , (2017).</li><li>Fujita, Y., Kadota, T., Araya, J., Ochiya, T., Kuwano, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+Vesicles:+New+Players+in+Lung+Immunity.">Extracellular Vesicles: New Players in Lung Immunity.</a> American journal of respiratory cell and molecular biology. , (2017).</li><li>Kubo, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+Vesicles+in+Lung+Disease.">Extracellular Vesicles in Lung Disease.</a> Chest. 153, 210-216 (2018).</li><li>Krol, J., Loedige, I., Filipowicz, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+widespread+regulation+of+microRNA+biogenesis,+function+and+decay.">The widespread regulation of microRNA biogenesis, function and decay.</a> Nature reviews. Genetics. 11, 597-610 (2010).</li><li>Bartel, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MicroRNAs:+target+recognition+and+regulatory+functions.">MicroRNAs: target recognition and regulatory functions.</a> Cell. 136, 215-233 (2009).</li><li>Fanini, F., Fabbri, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CANCER-DERIVED+EXOSOMIC+microRNAs+SHAPE+THE+IMMUNE+SYSTEM+WITHIN+THE+TUMOR+MICROENVIRONMENT:+STATE+OF+THE+ART.">CANCER-DERIVED EXOSOMIC microRNAs SHAPE THE IMMUNE SYSTEM WITHIN THE TUMOR MICROENVIRONMENT: STATE OF THE ART.</a> Seminars in cell &amp; developmental biology. , (2016).</li><li>Agarwal, U., 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=Experimental,+Systems,+and+Computational+Approaches+to+Understanding+the+MicroRNA-Mediated+Reparative+Potential+of+Cardiac+Progenitor+Cell-Derived+Exosomes+From+Pediatric+Patients.">Experimental, Systems, and Computational Approaches to Understanding the MicroRNA-Mediated Reparative Potential of Cardiac Progenitor Cell-Derived Exosomes From Pediatric Patients.</a> Circulation research. 120, 701-712 (2017).</li><li>Prattichizzo, F., 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=Extracellular+microRNAs+and+endothelial+hyperglycaemic+memory:+a+therapeutic+opportunity?.">Extracellular microRNAs and endothelial hyperglycaemic memory: a therapeutic opportunity?.</a> Diabetes, obesity &amp; metabolism. 18, 855-867 (2016).</li><li>Huang-Doran, I., Zhang, C. Y., Vidal-Puig, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+Vesicles:+Novel+Mediators+of+Cell+Communication+In+Metabolic+Disease.">Extracellular Vesicles: Novel Mediators of Cell Communication In Metabolic Disease.</a> Trends in endocrinology and metabolism: TEM. 28, 3-18 (2017).</li><li>Khalyfa, 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=Circulating+Plasma+Extracellular+Microvesicle+MicroRNA+Cargo+and+Endothelial+Dysfunction+in+Children+with+Obstructive+Sleep+Apnea.">Circulating Plasma Extracellular Microvesicle MicroRNA Cargo and Endothelial Dysfunction in Children with Obstructive Sleep Apnea.</a> American journal of respiratory and critical care medicine. 194, 1116-1126 (2016).</li><li>Thomou, 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=Adipose-derived+circulating+miRNAs+regulate+gene+expression+in+other+tissues.">Adipose-derived circulating miRNAs regulate gene expression in other tissues.</a> Nature. 542, 450-455 (2017).</li><li>Gregson, A. 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=Altered+Exosomal+RNA+Profiles+in+Bronchoalveolar+Lavage+from+Lung+Transplants+with+Acute+Rejection.">Altered Exosomal RNA Profiles in Bronchoalveolar Lavage from Lung Transplants with Acute Rejection.</a> American journal of respiratory and critical care medicine. 192, 1490-1503 (2015).</li><li>Valadi, H., 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=Exosome-mediated+transfer+of+mRNAs+and+microRNAs+is+a+novel+mechanism+of+genetic+exchange+between+cells.">Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cells.</a> Nature cell biology. 9, 654-659 (2007).</li><li>Doxaki, C., Kampranis, S. C., Eliopoulos, A. 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J., Vogel, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+activation+and+functional+specialization+of+miR-146+and+miR-155+in+innate+immune+sensing.">Differential activation and functional specialization of miR-146 and miR-155 in innate immune sensing.</a> Nucleic acids research. 41, 542-553 (2013).</li><li>Alexander, M., 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=Exosome-delivered+microRNAs+modulate+the+inflammatory+response+to+endotoxin.">Exosome-delivered microRNAs modulate the inflammatory response to endotoxin.</a> Nature communications. 6, 7321 (2015).</li><li>Yuan, Z., 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=TREM-1+is+induced+in+tumor+associated+macrophages+by+cyclo-oxygenase+pathway+in+human+non-small+cell+lung+cancer.">TREM-1 is induced in tumor associated macrophages by cyclo-oxygenase pathway in human non-small cell lung cancer.</a> PloS one. 9, e94241 (2014).</li><li>Xu, R., Richards, F. 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This work was supported by VA Merit Review 2I01BX001786-06A1 funding to RS.

Mouse models of diseases are commonly used to evaluate the physiological function of specific genes and to reduce the cost of experimentation2. The acute septic lung injury described here mimics inflammatory response seen in humans with ARDS. This model is relevant to investigate the molecular pathogenesis, development of biomarkers and to test potential new therapies5.
Co-culture systems are relevant for in vivo studies in the context o...

ALI and ARDS are the life-threatening forms of respiratory failure with severe hypoxemia caused by non-cardiogenic pulmonary edema which affects approximately 1 million people worldwide annually1. The etiology of ARDS includes direct injury to the lungs from infections or aspiration and a variety of indirect insults. Over the last decade there has been an increased understanding of the molecular pathogenesis of ARDS, however, specific targeted treatments for ARDS are yet to be developed2,3.
Several animal models of acute lung injury have been developed which provide a bridge for translating experimental therapies to human studies4,5. Commonly used models include local installation of oleic acid, bacteria, LPS, and bleomycin. Other approaches include ischemia-reperfusion, cecal ligation puncture, mechanical ventilation-induced stretch injury, hyperoxia or systemic administration of bacteria and LPS5. These models provide a useful biological system to test clinical hypotheses and for the development of potential therapies. To simulate human ARDS, animal models should reproduce inflammation and acute injury to the epithelial and endothelial cells with defects in barrier function in the lungs.
Exosomes are membrane vesicles with 20 - 200 nm in diameter, whose molecular content contains proteins, DNA, RNA, and lipids, and facilitate inter-cellular communications in tissue microenvironment via molecular composition transfer. Exosomes are secreted by multiple types of cells, such as endothelial cells, epithelial cells, smooth muscle cells and tumor cells, and exist in human body fluid. Studies indicate that exosomes regulate cross-talk between immune cells and stromal cells during infectious and sterile inflammatory diseases, and their abnormal release appears to be regulated by various natural and experimental stimuli during physiological and pathological processes6. Such communication network may play an important role in the pathogenesis of lung diseases and may affect pathophysiological progression7,8. As 18 - 22 nucleotide non-coding RNAs, miRNAs exist in both tissue and body fluids, plasma, sera, and modulate mRNA expression at post-translational level9,10.
Packaged miRNAs in exosomes influence differentiation and function of multiple types of cells, and excessive levels are associated with a variety of diseases, including cancer, lung diseases, obesity, diabetes, and cardiovascular disease11,12,13,14,15,16. Entry into the recipient cells and shuttling of exosomal miRNAs facilitate intercellular communications modifying the hemostasis of microenvironment17,18. Acute lung-injury is a complex processes, involving multiple cell types with extensive intercellular communications through exosomes8. miR-155 and miR-146a share the common transcriptional regulatory mechanism and contribute to the inflammatory response and the immune tolerance19,20. Recent studies indicate that both modulate inflammatory response via exosomal miRNAs shuttling between immune cells21. However, the molecular mechanisms underlying modulatory effects of exosomal miRNAs on alveolar response to endotoxin remain unclear, undoubtedly the potential clinical relevance and translational implication merit further investigation.
Co-culture models are being employed to define the interaction of the specific cell types in the complex environment, such as inflammation and cancer22,23. These platforms provide an alternative strategy to interrogate cross talk between cell types particularly for immune and structural cells.
Intra-tracheal, aerosolized, intraperitoneal or systemic administration of LPS are widely used to induce experimental lung injury24,25,26, and have shown to induce epithelial and endothelial permeability defects. Here we use intraperitoneal LPS to induce a septic model of acute lung injury in mice. Within 24 h of intraperitoneal administration of LPS, permeability defects are induced in the lungs with recruitment of inflammatory cells. Further, we show that exosomes from BAL contain miRNA-155 and miR-146a, and exosomes from BAL fluid induce pro-inflammatory cytokines expression in recipient epithelial cells, including IL-6 and TNF-&#945;. These data are the first to show that exosomal miRNAs are secreted in BAL in this model of acute septic lung injury.

<table border="0" cellpadding="0" cellspacing="0" style="width:1276px;" width="1276">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:691px;">lipopolysaccharide</td>
			<td style="width:181px;">Sigma-Aldrich</td>
			<td style="width:224px;">Escherichia coli 055:B5</td>
			<td style="width:180px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">PBS pH7.2(1X)</td>
			<td>Life technologies</td>
			<td>20012-027</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">mirVana miRNA isolation kit</td>
			<td>Thermo Fisher</td>
			<td align="right">449774</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">TaqMan Gene Expression Master Mix</td>
			<td>Thermo Fisher</td>
			<td align="right">4369016</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">mmu-miR-155 (002571) primer</td>
			<td>Thermo Fisher</td>
			<td align="right">4427975</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">has-miR-146a (000468) primer</td>
			<td>Thermo Fisher</td>
			<td align="right">4427975</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">U6snRNA primer</td>
			<td>Thermo Fisher</td>
			<td align="right">4427975</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">TNF-&#945;(Mm00443258_m1 ) primer</td>
			<td>Thermo Fisher</td>
			<td align="right">4331182</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">IL-6 (Mm00446190_m1&#160;&#160; )primer</td>
			<td>Thermo Fisher</td>
			<td align="right">4331182</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">ZO-1 (Mm00493699_m1&#160; )primer</td>
			<td>Thermo Fisher</td>
			<td align="right">4331182</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">minimal essential medium (MEM)</td>
			<td>Thermo Fisher</td>
			<td>11095-072</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Trysin-EDTA solution(0.05%)</td>
			<td>Thermo Fisher</td>
			<td align="right">25300054</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Exosomes were labeled with PKH67 through PKH67 Green Fluorescent Cell linker Mini Kit&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>MINI67-1KT</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Exosome Spin Columns (MW3000)</td>
			<td>Thermo Fisher</td>
			<td align="right">4484449</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Beckman Coulter Optima L-100XP ultracentrifuge&#160;</td>
			<td>Beckman Coulter</td>
			<td>L-100XP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ultra-clear centrifuge tubes</td>
			<td>Beckman Coulter</td>
			<td align="right">344058</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Applied Biosystems 7500 Fast Real-Time PCR System</td>
			<td>Thermo Fisher</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">transmission electron microscopes (TEM)</td>
			<td>JEOL Ltd</td>
			<td>120 kV TEM</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Olympus BX41 microscope</td>
			<td>Olympus</td>
			<td>BX41</td>
			<td></td>
		</tr>
	</tbody>
</table>

bronchoalveolar lavage exosomes in lipopolysaccharide-induced septic lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a heterogeneous group of lung diseases which continues to have a high morbidity and mortality. The molecular pathogenesis of ALI is being better defined; however, because of the complex nature of the disease molecular therapies have yet to be developed. Here we use a lipopolysaccharide (LPS) induced mouse model of acute septic lung injury to delineate the role of exosomes in the inflammatory response. Using this model, we were able to show that mice that are exposed to intraperitoneal LPS secrete exosomes in Broncho-alveolar lavage (BAL) fluid from the lungs that are packaged with miRNA and cytokines which regulate inflammatory response. Further using a co-culture model system, we show that exosomes released from macrophages disrupt expression of tight junction proteins in bronchial epithelial cells. These results suggest that 1) cross talk between innate immune and structural cells through the exosomal shuttling contribute to the inflammatory response and disruption of the structural barrier and 2) targeting these miRNAs may provide a novel platform to treat ALI and ARDS.

To induce septic lung injury, mice were treated with intraperitoneal LPS (15 mg/kg). Within 24 h of LPS administration, neutrophilic influx was seen in the lungs, as shown in Figure 1A. Mouse BAL fluid was drawn, followed by isolation and purification of exosomes. Morphology of BALF exosomes was confirmed by electron transmission microscopy (Figure 1B).
Expression of se...

Watch this Scientific Journal Video about Bronchoalveolar Lavage Exosomes in Lipopolysaccharide-induced Septic Lung Injury at JoVE.com

Bronchoalveolar Lavage Exosomes in Lipopolysaccharide-induced Septic Lung Injury

Mice exposed to intraperitoneal LPS secrete exosomes in Broncho-alveolar lavage (BAL) fluid that are packaged with miRNAs. Using a co-culture system, we show that exosomes released in the BAL fluid disrupt expression of tight junction proteins in bronchial epithelial cells and increase expression of pro-inflammatory cytokines that accentuate lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a heterogeneous group of lung diseases which continues to have a high ...

The overall goal of this experiment is to delineate the role of exosomes in the inflammatory responses in an LPS induced, acute septic lung injury mouse model. So this method can help answer key questions related to cell cross talk in acute lung injury and acute respiratory distress syndrome. Especially intercellular communication within the alveolar-micro environment via exosome shuttling.The main advantage of this technique is that it allows the isolation and characterization of highly purified bronchoalveolar lavage exosomes derived from endotoxin treated septic mice with acute lung injury. Demonstrating the procedure is Dr.Zhihong Yuan and Dr.Chetna Bedi. To begin, load a one milliliter syringe equipped with a 27 gauge needle with 0.1 milliliters of LPS and PBS per mouse and manually restrain the first six to eight week old male C57 black 6J mouse.Deliver the LPS intra-peritoneally and return the animal to its cage. 24 hours later, make a five millimeter incision in the center of the neck of the first animal and use blunt forceps to gently separate the muscles to expose the trachea. Next, gently insert a 27 gauge needle attached to a sterile 10 milliliter syringe into the trachea and inject one milliliter of sterile PBS.Then immediately replace the 10 milliliter syringe with a three milliliter syringe equipped with a new 27 gauge needle. Aspirate the bronchoalveolar lavage fluid or BOLF and add the BOLF to an appropriately labeled 15 milliliter conical tube on ice. To isolate the exosomes, centrifuge the BOLF samples and transfer the supernatants to new 15 milliliter tubes.Centrifuge the samples again and transfer the supernatants to ultra-centrifuge tubes to remove the larger, cellular particles. Transfer the supernatants to new conical tubes and load the samples into 0.2 micron syringe filters to remove any remaining larger particles. Add the filtered samples to new ultra-centrifuge tubes to pellet the exosomes.Carefully discard the supernatants and re-suspend the pellets in 100 microliters of PBS per tube. Then transfer the exosome samples into individual 1.5 milliliter tubes for their minus 80 degree Celsius storage. To purify the exosomes, add 0.4 microliters of the appropriate exosome dye to one tube containing 100 microliters of suspension solution per sample and quickly add one thawed exosome sample to each tube of dye.Thoroughly mix the exosomes with the dye and incubate the samples at room temperature for five minutes, protected from light. At the end of the incubation, place one exosome spin column per sample into a 1.5 milliliter illusion tube and transfer the exosome solutions to the center of each spin column. Then centrifuge the samples, discard the columns, and store the alluded samples at minus 20 degrees Celsius.To measure exosome uptake by recipient cells, first seed one times 10 to the fourth mouse lung epithelial 12 cells in 0.5 milliliters of medium into each well of an eight well chamber slide for a 16 hour culture at 37 degrees Celsius in 5%carbon dioxide. After thawing, add 10 microliters of the purified fluorescent labeled exosomes to each well and return the cell cultures to the incubator for one hour. At the end of the incubation, wash the cells with PBS and fix each co-culture with 1%paraformaldehyde for 10 minutes at room temperature.Remove the medium and then mount the slide with medium supplemented with DAPI and image the samples by fluorescence microscopy at a 40 times magnification. To verify exosome interaction with recipient cells, seed two times 10 to the fifth mouse lung epithelial 12 cells in two milliliters of medium per well in a 12 well culture plate containing the appropriate culture medium for a two hour incubation at 37 degrees Celsius and 5%carbon dioxide. At the end of the incubation, add 20 micrograms of exosomes to three wells of epithelial cells per experimental group and return the cells to the incubator.After 24 hours, remove the medium, wash the cells with PBS, and add 600 microliters of lysis buffer to each well with gentle shaking. Then transfer the entire contents of each well into individual 1.5 milliliter tubes and analyze the samples according to the standard real time PCR protocols. Within 24 hours of LPS administration, neutrophilic influx is observed in the lungs of LPS treated animals.After their isolation and purification as just demonstrated, the presence of exosomes in the BOLF from septic lung injury animals can be confirmed by transmission electron microscopy. The expression of select pro-inflammatory micro RNA is significantly increased in bronchoalveolar fluid exosomes from LPS treated animals compared to controlled PBS treated mice. LPS treated exosomes are taken up by mouse bronchiole epithelial cells as evidenced by the co-localization of fluorescent dye labeled exosomes with DAPI labeled cells after one hour of co-culture.Pro-inflammatory mediator expression is significantly increased in epithelial cells co-cultured with exosomes from LPS treated animals compared to co-culture with exosomes from control PBS treated mice. Further, cells treated with exosomes from LPS treated mice demonstrate a significantly attenuated expression of zonula occludens one compared to controls indicating a less intact cell integrity after LPS treated exosome co-culture. The intra-peritoneal injection of LPS, the bronchoalveolar lavage extraction, and exosome delegation from the bronchoalveolar lavage all the steps can be completed in a relatively short amount of time.Following this procedure, other methods like exosome and epithelial cell co-culture can be performed to answer additional questions about the cross talk between innate and structural cells in the lung alveolar micro-environment. Cross talk between innate immune and structural cells via exosome shuttling contributes to the inflammatory response and to structural barrier disruption suggesting exosomal micro-RNA targeting may provide a normal platform for treating acute lung injury and acute respiratory distress syndrome. After watching this video you should have a good understanding of how to induce septic lung injury in mice, isolate bronchoalveolar lavage fluid from mice, isolate exosomes from the lavage fluid, and use a co-culture model for interrogating intracellular cross talk.Don't forget that working with LPS can be hazardous and that precautions such as wearing the appropriate personal protective equipment should always be taken while performing this procedure.

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10.8K visualizações.  Atlanta VAMC. The overall goal of this experiment is to delineate the role of exosomes in the inflammatory responses in an LPS induced, acute septic lung injury mouse model. So this method can help answer key questions related to cell cross talk in acute lung injury and acute respiratory distress syndrome. Especially intercellular communication within the alveolar-micro environment via exosome shuttling.The main advantage of this technique is that it allows the isolation and characterization of high...