Protection of adipose-derived mesenchymal stromal cells during acute lung injury requires autophagy maintained by mTOR

Abstract

Previous studies suggest that mesenchymal stem cells may represent a promising cellular therapy for acute lung injury (ALI); however, the underlying relevant molecular mechanisms remain unclear. Adipose-derived mesenchymal stem cells (ADSCs) were isolated and characterized by alizarin red staining, oil red staining, and flow cytometry. Lung injury and inflammatory cell infiltration were determined using the Evans blue method, wet/dry weight ratio, and H&E staining. An ELISA was used to detect the concentrations of IFN-γ, IL-2, and TNF-α. Autophagy was detected with an mRFP-GFP-LC3 dual-fluorescence autophagy indicator system, Western blotting, and electron microscopy. We first demonstrated that ADSCs did alleviate the inflammatory responses and tissue damage in lipopolysaccharide (LPS)-induced ALI. Next, we further demonstrated in vivo that autophagy plays a key role in the maintenance of ADSC therapeutic efficacy. In vitro experiments demonstrated that ADSCs co-cultured with alveolar epithelial cells depend on autophagy for significant anti-inflammatory functions. Moreover, the mammalian target of rapamycin (mTOR) is a key regulator of autophagy. Taken together, our findings demonstrate that the effect of ADSC on ALI, especially on alveolar epithelial cells, is dependent on mTOR-mediated autophagy maintenance. The significance of our study for ALI therapy is discussed with respect to a more complete understanding of the therapeutic strategy paradigm.

Injectable Decorin/Gellan Gum Hydrogel Encapsulating Adipose-Derived Stem Cells Enhances Anti-Inflammatory Effect in Cartilage Injury via Autophagy Signaling

“…Inhibiting autophagy is associated with cartilage matrix degeneration 32 . In particular, autophagy is required to maintain the anti-inflammatory potential of ADSCs 33 , 34 , whereas inhibition of autophagy mediated stress-induced apoptosis in ADSCs 35 . Despite the previous study indicating that decorin induces autophagy signaling in different cell types 36 , 37 , its precise role play in ADSC phenotype during inflammation is unclear.…”

Three‐dimensional spheroid formation of adipose‐derived stem cells improves the survival of fat transplantation by enhance their therapeutic effect

“…Studies on cancer cells and hepatocyte spheroids suggest that oxygen gradient formation is a common feature of spheroids, as they are characterized by high surface oxygen concentration and an internal hypoxic core. [ 30 ] According to previous studies, almost 90% of MSCs seeded in 3D aggregates remained viable after 3 days, while after 4 days, the number of apoptotic or necrotic cells increased. [ 31 ] When spheres of large diameters are formed, the caspase activity in MSCs is up‐regulated which induced apoptosis.…”

Effects of extracellular vesicles from adipose‐derived stem cells on human keloid fibroblasts via the SOCS1/JAK2/STAT3 pathway

“…Calcium deposition in osteoblasts was visualized by alizarin red staining to assess osteogenic ability, following the established protocol as described in a previous study 30 . Briefly, hADSCs were induced in adipogenic induction medium for 3 weeks.…”

“…Calcium deposition in osteoblasts was visualized by alizarin red staining to assess osteogenic ability, following the established protocol as described in a previous study. 30 Briefly, hADSCs were induced in adipogenic induction medium for 3 weeks. After being fixed with 95% ethanol (Sigma-Aldrich) for 10 min, the cells were cultivated with 0.1% alizarin red-tris-hcl (PH 8.3) (Sigma-Aldrich) for 30 min at 37°C.…”