scholarly journals Stem cell conditioned medium improves acute lung injury in mice: in vivo evidence for stem cell paracrine action

2012 ◽  
Vol 303 (11) ◽  
pp. L967-L977 ◽  
Author(s):  
Lavinia Ionescu ◽  
Roisin N. Byrne ◽  
Tim van Haaften ◽  
Arul Vadivel ◽  
Rajesh S. Alphonse ◽  
...  

Mortality and morbidity of acute lung injury and acute respiratory distress syndrome remain high because of the lack of pharmacological therapies to prevent injury or promote repair. Mesenchymal stem cells (MSCs) prevent lung injury in various experimental models, despite a low proportion of donor-derived cell engraftment, suggesting that MSCs exert their beneficial effects via paracrine mechanisms. We hypothesized that soluble factors secreted by MSCs promote the resolution of lung injury in part by modulating alveolar macrophage (AM) function. We tested the therapeutic effect of MSC-derived conditioned medium (CdM) compared with whole MSCs, lung fibroblasts, and fibroblast-CdM. Intratracheal MSCs and MSC-CdM significantly attenuated lipopolysaccharide (LPS)-induced lung neutrophil influx, lung edema, and lung injury as assessed by an established lung injury score. MSC-CdM increased arginase-1 activity and Ym1 expression in LPS-exposed AMs. In vivo, AMs from LPS-MSC and LPS-MSC CdM lungs had enhanced expression of Ym1 and decreased expression of inducible nitric oxide synthase compared with untreated LPS mice. This suggests that MSC-CdM promotes alternative macrophage activation to an M2 “healer” phenotype. Comparative multiplex analysis of MSC- and fibroblast-CdM demonstrated that MSC-CdM contained several factors that may confer therapeutic benefit, including insulin-like growth factor I (IGF-I). Recombinant IGF-I partially reproduced the lung protective effect of MSC-CdM. In summary, MSCs act through a paracrine activity. MSC-CdM promotes the resolution of LPS-induced lung injury by attenuating lung inflammation and promoting a wound healing/anti-inflammatory M2 macrophage phenotype in part via IGF-I.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yu Long ◽  
Yan Xiang ◽  
Songyu Liu ◽  
Yulu Zhang ◽  
Jinyan Wan ◽  
...  

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are challenging diseases with the high mortality in a clinical setting. Baicalin (BA) is the main effective constituent isolated from the Chinese medical herb Scutellaria baicalensis Georgi, and studies have proved that it has a protective effect on ALI induced by lipopolysaccharide (LPS) due to the anti-inflammatory efficacy. However, BA has low solubility which may limit its clinical application. Hence, we prepared a novel drug delivery system—Baicalin liposome (BA-LP) in previous research—which can improve some physical properties of BA. Therefore, we aimed to explore the effect of BA-LP on ALI mice induced by LPS. In pharmacokinetics study, the values of t 1 / 2 and AUC0- t in the BA-LP group were significantly higher than that of the BA group in normal mice, indicating that BA-LP could prolong the duration time in vivo of BA. The BA-LP group also showed a higher concentration in lung tissues than the BA group. Pharmacodynamics studies showed that BA-LP had a better effect than the BA group at the same dosage on reducing the W/D ratio, alleviating the lung injury score, and decreasing the proinflammatory factors (TNF-α, IL-1β) and total proteins in bronchoalveolar lavage fluids (BALF). In addition, the therapeutic effects of BA-LP showed a dose-dependent manner. Western blot analysis indicated that the anti-inflammatory action of BA could be attributed to the inhibition of the TLR4-NFκBp65 and JNK-ERK signaling pathways. These results suggest that BA-LP could be a valuable therapeutic candidate in the treatment of ALI.


2008 ◽  
Vol 294 (2) ◽  
pp. L334-L343 ◽  
Author(s):  
Christophe Quesnel ◽  
Sylvain Marchand-Adam ◽  
Aurélie Fabre ◽  
Joëlle Marchal-Somme ◽  
Ivan Philip ◽  
...  

The mechanisms of pulmonary repair in acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are poorly known. Hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF) are key factors involved in alveolar epithelial repair, present in the bronchoalveolar lavage fluid (BALF) from patients with ALI/ARDS. The role of BALF mediators in their production remains to be determined. We evaluated the overall effect of BALF from 52 patients (27 ventilated patients with ALI/ARDS, 10 ventilated patients without ALI, and 15 nonventilated control patients) on HGF and KGF synthesis by lung fibroblasts. Fibroblasts were cultured in the presence of BALF. HGF and KGF protein secretion was measured using ELISA, and mRNA expression was evaluated using quantitative real-time RT-PCR. Only BALF from ALI/ARDS patients upregulated both HGF and KGF mRNA expression and protein synthesis (+271 and +146% for HGF and KGF, respectively). BALF-induced HGF synthesis from ALI/ARDS patients was higher than that from ventilated patients without ALI ( P < 0.05). HGF secretion was correlated with BALF IL-1β levels (rho = 0.62, P < 0.001) and BALF IL-1β/IL-1 receptor antagonist ratio (rho = 0.54, P < 0.007) in the ALI/ARDS group. An anti-IL-1β antibody partially (>50%) inhibited the BALF-induced HGF and PGE2 secretion, whereas NS-398, a specific cyclooxygenase-2 (COX-2) inhibitor, completely inhibited it. Anti-IL-1β antibodies as well as NS-398 reversed the COX-2 upregulation induced by BALF. Therefore, IL-1β is a main BALF mediator involved in HGF secretion, which is mediated through a PGE2/COX-2-dependent mechanism. BALF mediators may participate in vivo in the production of HGF and KGF by lung fibroblasts during ALI/ARDS.


2022 ◽  
Author(s):  
Chichi Li ◽  
Min Wang ◽  
Wangjia Wang ◽  
Yuping Li ◽  
Dan Zhang

Abstract Background: Small extracellular vesicles (sEVs) have been recognized to be more effective than direct stem cell differentiation into functional target cells in preventing tissue injury and promoting tissue repair. Our previous study demonstrated the protective effect of adipose-derived stem cells (ADSCs) on lipopolysaccharide (LPS)-induced acute lung injury and the effect of autophagy on ADSC functions, but the role of ADSC-derived sEVs (ADSC-sEVs) and autophagy-mediated regulation of ADSC-sEVs in LPS-induced pulmonary microvascular barrier damage remains unclear. Methods: After treatment with sEVs from ADSCs with or without autophagy inhibition, LPS-induced human pulmonary microvascular endothelial cell (HPMVECs) barrier damage was detected. LPS-induced acute lung injury in mice was assessed in vivo after intravenous administration of sEVs from ADSCs with or without autophagy inhibition. The effects of autophagy on the bioactive miRNA components of ADSC-sEVs were assessed after prior inhibition of cell autophagy. Results: We found that ADSC-sEV effectively alleviated LPS-induced apoptosis, tight junction damage and high permeability of PMVECs. Moreover, in vivo administration of ADSC-sEV markedly inhibited LPS-triggered lung injury. However, autophagy inhibition, markedly weakened the therapeutic effect of ADSC-sEVs on LPS-induced PMVECs barrier damage and acute lung injury. In addition, autophagy inhibition, prohibited the expression of five specific miRNAs in ADSC-sEVs -under LPS-induced inflammatory conditions. Conclusions: Our results indicate that ADSC-sEVs protect against LPS-induced pulmonary microvascular barrier damage and acute lung injury. Autophagy is a positive mediator of sEVs function, at least in part through controlling the expression of bioactive miRNAs in sEVs.


2021 ◽  
pp. 175342592110133
Author(s):  
Ling-yu Wei ◽  
An-qi Jiang ◽  
Ren Jiang ◽  
Si-ying Duan ◽  
Xue Xu ◽  
...  

Trichinella spiralis represents an effective treatment for autoimmune and inflammatory diseases. The effects of recombinant T. spiralis (TS) 53-kDa protein (rTsP53) on acute lung injury (ALI) remain unclear. Here, mice were divided randomly into a control group, LPS group, and rTsP53 + LPS group. ALI was induced in BALB/c mice by LPS (10 mg/kg) injected via the tail vein. rTsP53 (200 µl; 0.4 μg/μl) was injected subcutaneously three times at an interval of 5 d before inducing ALI in the rTsP53+LPS group. Lung pathological score, the ratio and markers of classic activated macrophages (M1) and alternatively activated macrophages (M2), cytokine profiles in alveolar lavage fluid, and pyroptosis protein expression in lung tissue were investigated. RTsP53 decreased lung pathological score. Furthermore, rTsP53 suppressed inflammation by increasing IL-4, IL-10, and IL-13. There was an increase in alveolar M2 macrophage numbers, with an increase in CD206 and arginase-1-positive cells and a decrease in alveolar M1 markers such as CD197 and iNOS. In addition, the polarization of M2 macrophages induced by rTsP53 treatment could alleviate ALI by suppressing lung pyroptosis. RTsP53 was identified as a potential agent for treating LPS-induced ALI via alleviating lung pyroptosis by promoting M2 macrophage polarization.


2021 ◽  
Author(s):  
Mingzhu Xia ◽  
Zhi Huang ◽  
Mingyu Xu ◽  
Chao Hai ◽  
Wenbo Diao ◽  
...  

Abstract Our previous studies have shown that Dexmedetomidine (Dex), α2 adrenergic receptor (α2AR) agonist, reduces pulmonary edema in LPS-induced acute lung injury (ALI), but the mechanism is not clear. The purpose of this study is to explore whether Dex promotes AFC by upregulating the expression of Na,K-ATPase in LPS-induced ALI and possible molecular mechanisms. Histology of the lungs was assayed with H-E staining, and the lung injury score was calculated. PaO2, PaO2/FiO2 , the lung index, wet/dry (W/D) ratio of the lung tissues and alveolar fluid clearance(AFC) was measured; The concentrations of TNF-α, IL-1β, IL-6 in bronchoalveolar lavage fluid (BALF) and serum were measured. Myeloperoxidase (MPO) activity in lung tissues were determined. The apoptosis rate of A549 cells and the expression of Bcl-2 and Bax were evaluated. The expression of Na,K-ATPase , p-PI3K and p-Akt in vivo and in vitro were evaluated. Dex significantly alleviated lung tissue injury induced by LPS. Dex treatment reduced the W/D, lung index and MPO activity, increased PaO2, PaO2/FiO2 and AFC in LPS-induced ALI. In addition, Dex reduced the concentrations of TNF-α, IL-β and IL-6 in BALF and serum. Dex reduced the apoptosis rate, up-regulated the expression of Bcl-2 and down-regulated the expression of Bax in LPS-stimulated A549 cells. Furthermore, Dex increased the expression of α1Na,K-ATPase, β1 Na,K-ATPase and p-PI3K , p-Akt in vivo and vitro. However, these effects of Dex were partially reversed by the α2AR inhibitor yohim-bine or PI3K inhibitor LY294002. Collectively, these results suggest that Dex attenuates pulmonary edema by stimulating AFC via upregulating the Na,K-ATPase expressi-on in LPS-induced acute lung injury by modulating the α2AR/PI3K/Akt signaling pathway.


2019 ◽  
Vol 20 (9) ◽  
pp. 2208 ◽  
Author(s):  
Vincent Yi-Fong Su ◽  
Chi-Shiuan Lin ◽  
Shih-Chieh Hung ◽  
Kuang-Yao Yang

The immunomodulatory effects of mesenchymal stem cells (MSCs) are established. However, the effects of MSCs on neutrophil survival in acute lung injury (ALI) remain unclear. The goal of this study was to investigate the effect of an MSC-conditioned medium (MSC-CM) on neutrophil apoptosis in endotoxin-induced ALI. In this study, an MSC-CM was delivered via tail vein injection to wild-type male C57BL/6 mice 4 h after an intratracheal injection of lipopolysaccharide (LPS). Twenty-four hours later, bronchoalveolar lavage fluid (BALF) and lung tissue were collected to perform histology, immunohistochemistry, apoptosis assay of neutrophil, enzyme-linked immunosorbent assays, and an electrophoretic mobility shift assay. Human neutrophils were also collected from patients with sepsis-induced acute respiratory distress syndrome (ARDS). Human neutrophils were treated in vitro with LPS, with or without subsequent MSC-CM co-treatment, and were then analyzed. Administration of the MSC-CM resulted in a significant attenuation of histopathological changes, the levels of interleukin-6 and macrophage inflammatory protein 2, and neutrophil accumulation in mouse lung tissues of LPS-induced ALI. Additionally, MSC-CM therapy enhanced the apoptosis of BALF neutrophils and reduced the expression of the anti-apoptotic molecules, Bcl-xL and Mcl-1, both in vivo and in vitro experiments. Furthermore, phosphorylated and total levels of nuclear factor (NF)-κB p65 were reduced in lung tissues from LPS + MSC-CM mice. Human MSC-CM also reduced the activity levels of NF-κB and matrix metalloproteinase-9 in the human neutrophils from ARDS patients. Thus, the results of this study suggest that the MSC-CM attenuated LPS-induced ALI by inducing neutrophil apoptosis, associated with inhibition of the NF-κB pathway.


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