Mesenchymal stem cells reverse EMT process through blocking the activation of NF-κB and Hedgehog pathways in LPS-induced acute lung injury

Abstract

Acute lung injury (ALI) is a pulmonary disorder, which can result in fibrosis of the lung tissues. Recently, mesenchymal stem cell (MSC) has become a novel therapeutic method for ALI. However, the potential mechanism by which MSC regulates the progression of ALI remains blurry. The present study focused on investigating the mechanism underneath MSC-reversed lung injury and fibrosis. At first, we determined that coculture with MSC led to the inactivation of NF-κB signaling and therefore suppressed hedgehog pathway in LPS-treated MLE-12 cells. Besides, we confirmed that MSC-exosomes were responsible for the inhibition of EMT process in LPS-treated MLE-12 cells through transmitting miRNAs. Mechanism investigation revealed that MSC-exosome transmitted miR-182-5p and miR-23a-3p into LPS-treated MLE-12 cells to, respectively, target Ikbkb and Usp5. Of note, Usp5 interacted with IKKβ to hamper IKKβ ubiquitination. Moreover, co-inhibition of miR-182-5p and miR-23a-3p offset the suppression of MSC on EMT process in LPS-treated MLE-12 cells as well as in LPS-injured lungs of mice. Besides, the retarding effect of MSC on p65 nuclear translocation was also counteracted after co-inhibiting miR-182-5p and miR-23a-3p, both in vitro and in vivo. In summary, MSC-exosome transmitted miR-23a-3p and miR-182-5p reversed the progression of LPS-induced lung injury and fibrosis through inhibiting NF-κB and hedgehog pathways via silencing Ikbkb and destabilizing IKKβ.

Extracellular Vesicles in Organ Fibrosis: Mechanisms, Therapies, and Diagnostics

“…In vitro, activation of LL29 pulmonary fibroblasts was suppressed by BM-MSC EVs and this was due to targeting of frizzled class receptor 6 ( FZD6 ) by EV miR-29b-3p, which was also shown to be required for the inhibition by BM-MSC EVs of bleomycin-induced pulmonary fibrosis in mice [ 83 ]. Exposure of LPS-treated MLE-12 type II alveolar epithelial cells to BM-MSC exosomes resulted in inactivation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, reversal of EMT due to targeting of Ikbkb by exosomal miR-182-5b, and ubiquitinylation of Ikbkb due to targeting of Usp5 by exosomal miR-23a-3p [ 84 ]. In a mouse model of silicosis, lung dysfunction and fibrosis were reduced by exosomes from human umbilical cord MSC (UMSC), which were also effective in decreasing collagen deposition in silica-exposed fibroblasts in vitro [ 85 ].…”

Mesenchymal stem cells and their derived exosomes to combat Covid–19

“…This study suggested that MSC‐Es reduce IKKβ and also increase its ubiquitination, resulting in inhibition of the NF‐κB and the Hedgehog pathways, both playing a key role in the Epithelial‐Mesenchymal Transition (EMT) process of alveolar epithelial cells (AECs) that is closely related to pulmonary fibrosis. 82 Investigation on a mouse ARDS model treated by MSC‐Es, which was differentiated to produce neurotrophic and immunomodulatory factors (MSC‐NTF) showed a substantial reduction in IFN γ, TNFα, IL‐6, and RANTES (regulated on activation, normal T cell expressed and secreted). The oxygen saturation level also was improved significantly after 72 h post‐treatment.…”

“… 86 Xiao and colleagues have demonstrated the downregulation of the Ikbkb gene results in a significant decrease in the gene expression of IKKβ, leading to downregulation of ubiquitin‐specific peptidase (Usp) 5, a deubiquitinase that blocks IKKβ ubiquitination. 82 There are a limited number of clinical trials ongoing to assess the safety and efficacy of MSC‐E for the treatment of Covid‐19, despite promising results in preclinical studies (Table 2 ).…”

Advances in mesenchymal stem cell‐mediated tissue repair of lung injury

“… 27 Further, a previous study from our group has revealed that MSC-derived exosomes transfer miR-23a-3p, and miR-182-5p reverses the progression of LPS-induced lung injury by inhibiting NF-κB and Hedgehog pathways. 28 …”