American journal of physiology. Lung cellular and molecular physiology
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Am. J. Physiol. Lung Cell Mol. Physiol. · Apr 2020
Single-step RT-qPCR for detection of extracellular vesicle microRNAs in vivo: a time- and cost-effective method.
Emerging evidence suggests that extracellular vesicle (EV)-associated microRNAs (miRNAs) are a potential diagnostic tool for liquid biopsy in various human diseases. However, the experimental procedure for the detection of EV-associated miRNAs (EV-miRNAs) from body fluids is relatively complex and not cost-effective. Due to the limited amount of EVs and EV-RNAs, a column-based RNA purification, which is an expensive approach, is often used to detect EV-miRNAs via reverse transcription-quantitative real-time PCR (RT-qPCR). ⋯ Moreover, repeated freeze-thaw cycling significantly interferes the EV-miRNA quantification. Collectively, the single-step RT-qPCR for the detection of EV-miRNAs in vivo will potentially provide a fast, accurate, and convenient way to quantify circulating and/or body fluid-derived EV-miRNAs. This method may potentially be applied to the diagnostic blood testing used in the medical centers or research laboratories.
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Am. J. Physiol. Lung Cell Mol. Physiol. · Apr 2020
Adipose-derived exosomes protect the pulmonary endothelial barrier in ventilator-induced lung injury by inhibiting the TRPV4/Ca2+ signaling pathway.
Mechanical ventilation (MV) is the main supportive treatment of acute respiratory distress syndrome (ARDS), but it may lead to ventilator-induced lung injury (VILI). Large epidemiological studies have found that obesity was associated with lower mortality in mechanically ventilated patients with acute lung injury, which is known as "obesity paradox." However, the effects of obesity on VILI are unknown. In the present study, wild-type mice were fed a high-fat diet (HFD) and ventilated with high tidal volume to investigate the effects of obesity on VILI in vivo, and pulmonary microvascular endothelial cells (PMVECs) were subjected to 18% cyclic stretching (CS) to further investigate its underlying mechanism in vitro. ⋯ We extracted three adipose-derived exosomes, including HFD mouse serum exosome (S-Exo), adipose tissue exosome (AT-Exo), and adipose-derived stem cell exosome (ADSC-Exo), and further explored their effects on MV or 18% CS-induced VILI in vivo and in vitro. Administration of three exosomes protected against VILI by suppressing pulmonary endothelial barrier hyperpermeability, repairing the expression of adherens junctions, and alleviating inflammatory response in vivo and in vitro, accompanied by transient receptor potential vanilloid 4 (TRPV4)/Ca2+ pathway inhibition. Collectively, these data indicated that HFD-induced obesity plays a protective role in VILI by alleviating the pulmonary endothelial barrier injury and inflammatory response via adipose-derived exosomes, at least partially, through inhibiting the TRPV4/Ca2+ pathway.