Project description:Acute lung injury (ALI) is characterized by excessive inflammation and alveolar damage, arising from pathogens or systemic insults such as sepsis, and can progress to severe acute respiratory distress syndrome (ARDS). Current treatments, including mechanical ventilation, remain largely supportive, emphasizing the urgent need for the potent, cell-free therapeutic modalities. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as promising candidates for lung repair, but insufficient immunosuppressive capacity often limits their efficacy. Human adipose-derived mesenchymal stem cells (hADMSCs) were primed with IFN-γ and TNF-α to enhance the immunomodulatory properties of their secreted EVs. We characterized primed MSC-EVs (P-MEVs) and unprimed control MSC-EVs (C-MEVs) by transmission electron microscopy, nanoparticle tracking analysis, and western blotting for EV markers. Functional assays in THP-1 and A549 cells examined anti-inflammatory potency and barrier regeneration against lipopolysaccharide (LPS)-induced damage. A preclinical mouse model of LPS-induced ALI was used to evaluate inflammatory cytokine expression, immune cell infiltration, pulmonary edema, and vascular leakage. Finally, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected Vero E6 cells were tested to explore the antiviral and anti-inflammatory potential of P-MEVs. Primed hADMSCs exhibited elevated expression of immunosuppressive molecules (e.g., COX-2, IDO, TSG-6), without changing EV morphology or yield. P-MEVs mitigated LPS-induced inflammation more effectively than C-MEVs in THP-1 and A549 cells. In vivo , P-MEVs more robustly attenuated inflammatory cytokines, immune cell recruitment, and lung injury markers in mice challenged with LPS. In SARS-CoV-2-infected Vero E6 cells, P-MEVs suppressed cytopathic effects and inflammatory responses more potently than C-MEVs. Mechanistic analyses revealed that these enhancements were associated with elevated miRNA levels, involved in inhibiting inflammatory pathways.

Project description:Background: Allergic asthma is one of the chronic inflammatory diseases and is generally induced by CD4+ T helper 2 cells (Th2) in the context of persistent inhaled stimuli. Dendritic cells (DCs) are essential to mounting the Th2-mediated airway inflammation by presenting inhaled antigens to prime CD4+ T cells. Small extracellular vesicles (sEV) derived from mesenchymal stem cells (MSCs) exhibited great interest in intractable diseases. However, whether MSC-sEV play a role on DCs in airway inflammation is still unclear. Methods: We isolate MSC-sEV using anion-exchange chromatography. Mouse bone marrow-derived DCs (BMDCs) and human monocyte-derived DCs (moDCs) were used to study the effects of MSC-sEV on dendritic cell surface molecules and their cytokine release. Mice were sensitized with house dust mites (HDM) to induce airway inflammation, and treated with MSC-sEV, The effects of sEV on murine DCs were identified. Extracellular flux analysis techniques were used to study the effects of MSC-sEV on the metabolic state of dendritic cells. RNA sequencing to study altered gene expression in BMDCs after MSC-sEV treatment. Results: MSC-sEV mitigated the accumulation of Th2-associated moDCs in mouse lung in response to HDM. MSC-sEV also decreased the activation of moDCs induced in vitro including the expression of co-stimulatory molecules and cytokines secretion. Furthermore, we identified that DCs were able to take MSC-sEV in vitro and in vivo. Mechanistically, using bulk RNA-sequencing, we found that MSC-sEV played roles in the metabolic pathway of murine DCs. Using extracellular flux analysis, we found that MSC-sEV increased the requirement of oxidative phosphorylation on moDCs. Importantly, MSC-sEV displayed similar effects on human moDCs including decreased co-stimulatory molecular and cytokine production. Conclusions: MSC-sEV are able to alter the metabolic state of DCs, favoring DCs to maintain OXPHOS (oxidative phosphorylation) rather than glycolysis, thereby reducing DCs-initiated inflammatory responses and attenuating Th2 lung inflammation, suggesting MSC-sEV can be a potential clinical therapy for airway inflammation.

Project description:Background: Fibrosis is a pathological scarring process characterized by persistent myofibroblasts activation with excessive accumulation of extracellular matrix (ECM). Fibrotic disorders represent an increasing burden of disease-associated morbidity and mortality worldwide for which there are limited therapeutic options. Reversing fibrosis requires the elimination of myofibroblasts, remodeling of the ECM, and regeneration of functional tissue. Multipotent mesenchymal stromal cells (MSC) have antifibrotic properties mediated by secreted factors present in their conditioned medium (MSC-CM). However, there are no standardized in vitro assays to predict the antifibrotic effects of human MSC, and, as a consequence, we lack evidence on the effect of cytokine priming on MSC’s antifibrotic effects. We hypothesize that the MSC-CM promotes fibrosis resolution in vitro and that this effect is enhanced following MSC cytokine priming. Methods: We tested the antifibrotic effects of resting and interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) primed MSC-CM in three in vitro assays: prevention of fibroblast activation, myofibroblasts deactivation and ECM degradation. Furthermore, we performed transcriptomic analysis of myofibroblasts treated or not with resting- or primed-MSC-CM and proteomic characterization of resting- and primed-MSC-CM. Results: We report that MSC-CM treatment prevented TGF-β induced fibroblast activation and reduced fibrogenic myofibroblasts (i.e. transcriptomic upregulation of apoptosis, senescence, and inflammatory pathways). These effects were higher when primed rather than resting MSC-CM was used. Priming increased the ability of MSC-CM to remodel the extracellular matrix reducing its content of collagen I and fibronectin. Priming increased the following antifibrotic proteins in MSC-CM: DKK1, MMP-1, MMP-3, follistatin and cathepsin S. DKK1 inhibition reduced the anti-fibrotic effects of MSC-CM. Thus, cytokine priming increases antifibrotic factors in the MSC-CM which in turn amplify the anti-fibrotic effects of MSC-CM. Conclusions: In a pro-fibrotic in vitro environment MSC-CM promote fibrosis resolution, an effect enhanced following MSC cytokine priming. Specifically, MSC-CM reduces fibrogenic myofibroblasts through apoptosis, senescence, and inflammatory signals, as well as by enhancing ECM degradation. Future studies will establish the in vivo relevance of MSC priming to fibrosis resolution

Dataset Information

Inflammatory Cytokine-Primed MSC-Derived Extracellular Vesicles

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets