Basic Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Sep 26, 2023; 15(9): 908-930
Published online Sep 26, 2023. doi: 10.4252/wjsc.v15.i9.908
Multiomics reveal human umbilical cord mesenchymal stem cells improving acute lung injury via the lung-gut axis
Lu Lv, En-Hai Cui, Bin Wang, Li-Qin Li, Feng Hua, Hua-Dong Lu, Na Chen, Wen-Yan Chen
Lu Lv, En-Hai Cui, Bin Wang, Feng Hua, Hua-Dong Lu, Na Chen, Wen-Yan Chen, Department of Respiratory and Critical Care Medicine, Huzhou Central Hospital, Affiliated Huzhou Hospital, Zhejiang University School of Medicine, Huzhou 313000, Zhejiang Province, China
Li-Qin Li, Traditional Chinese Medicine Key Laboratory Cultivation Base of Zhejiang Province for the Development and Clinical Transformation of Immunomodulatory Drugs, Huzhou 313000, Zhejiang Province, China
Author contributions: Cui EH, Lv L, and Wang B conceived and designed the research; Lv L, Li LQ, and Lu HD acquired the data; Cui EH, Li LQ, and Hua F analyzed and interpreted the data; Lv L, Lu HD, Chen WY, and Chen N performed statistical analysis; Cui EH and Wang B obtained the funding; Lv L and Cui EH drafted the manuscript; Cui EH, Wang B, and Hua F revised the manuscript for important intellectual content; and all authors approved the final version of the article.
Supported by the Key Research and Development Project of Science and Technology Department of Zhejiang Province, No. 2019C03041.
Institutional review board statement: The study was reviewed and approved by the Animal Experimentation Ethics Committee of Zhejiang Eyong Pharmaceutical Research and Development Center (License No. SYXK(Zhe)2021-0033).
Institutional animal care and use committee statement: All animal experiments conformed to the internationally accepted principles for the care and use of laboratory animals (Approval No. ZJEY-20220721-02).
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: En-Hai Cui, BM BCh, Doctor, Department of Respiratory and Critical Care Medicine, Huzhou Central Hospital, Affiliated Huzhou Hospital, Zhejiang University School of Medicine, No. 1558 Third Ring North Road, Huzhou 313000, Zhejiang Province, China.
Received: May 12, 2023
Peer-review started: May 12, 2023
First decision: June 29, 2023
Revised: July 23, 2023
Accepted: September 6, 2023
Article in press: September 6, 2023
Published online: September 26, 2023

Acute lung injury (ALI) and its final severe stage, acute respiratory distress syndrome, are associated with high morbidity and mortality rates in patients due to the lack of effective specific treatments. Gut microbiota homeostasis, including that in ALI, is important for human health. Evidence suggests that the gut microbiota improves lung injury through the lung-gut axis. Human umbilical cord mesenchymal cells (HUC-MSCs) have attractive prospects for ALI treatment. This study hypothesized that HUC-MSCs improve ALI via the lung-gut microflora.


To explore the effects of HUC-MSCs on lipopolysaccharide (LPS)-induced ALI in mice and the involvement of the lung-gut axis in this process.


C57BL/6 mice were randomly divided into four groups (18 rats per group): Sham, sham + HUC-MSCs, LPS, and LPS + HUC-MSCs. ALI was induced in mice by intraperitoneal injections of LPS (10 mg/kg). After 6 h, mice were intervened with 0.5 mL phosphate buffered saline (PBS) containing 1 × 106 HUC-MSCs by intraperitoneal injections. For the negative control, 100 mL 0.9% NaCl and 0.5 mL PBS were used. Bronchoalveolar lavage fluid (BALF) was obtained from anesthetized mice, and their blood, lungs, ileum, and feces were obtained by an aseptic technique following CO2 euthanasia. Wright’s staining, enzyme-linked immunosorbent assay, hematoxylin-eosin staining, Evans blue dye leakage assay, immunohistochemistry, fluorescence in situ hybridization, western blot, 16S rDNA sequencing, and non-targeted metabolomics were used to observe the effect of HUC-MSCs on ALI mice, and the involvement of the lung-gut axis in this process was explored. One-way analysis of variance with post-hoc Tukey’s test, independent-sample Student’s t-test, Wilcoxon rank-sum test, and Pearson correlation analysis were used for statistical analyses.


HUC-MSCs were observed to improve pulmonary edema and lung and ileal injury, and decrease mononuclear cell and neutrophil counts, protein concentrations in BALF and inflammatory cytokine levels in the serum, lung, and ileum of ALI mice. Especially, HUC-MSCs decreased Evans blue concentration and Toll-like receptor 4, myeloid differentiation factor 88, p-nuclear factor kappa-B (NF-κB)/NF-κB, and p-inhibitor α of NF-κB (p-IκBα)/IκBα expression levels in the lung, and raised the pulmonary vascular endothelial-cadherin, zonula occludens-1 (ZO-1), and occludin levels and ileal ZO-1, claudin-1, and occludin expression levels. HUC-MSCs improved gut and BALF microbial homeostases. The number of pathogenic bacteria decreased in the BALF of ALI mice treated with HUC-MSCs. Concurrently, the abundances of Oscillospira and Coprococcus in the feces of HUS-MSC-treated ALI mice were significantly increased. In addition, Lactobacillus, Bacteroides, and unidentified_Rikenellaceae genera appeared in both feces and BALF. Moreover, this study performed metabolomic analysis on the lung tissue and identified five upregulated metabolites and 11 downregulated metabolites in the LPS + MSC group compared to the LPS group, which were related to the purine metabolism and the taste transduction signaling pathways. Therefore, an intrinsic link between lung metabolite levels and BALF flora homeostasis was established.


This study suggests that HUM-MSCs attenuate ALI by redefining the gut and lung microbiota.

Keywords: Acute lung injury, Human umbilical cord mesenchymal cells, Lipopolysaccharide, Microflora, Untargeted metabolomics, Toll-like receptor 4/nuclear factor kappa-B signaling pathway

Core Tip: The results of this study suggest that human umbilical cord mesenchymal cells (HUC-MSCs) inhibit the inflammatory cytokine expression levels in serum and the lung of mice with acute lung injury (ALI), which may be achieved by redefining the gut and lung microbiota. This study not only provides a scientific basis for the pathophysiological mechanisms and clinical application of HUC-MSCs, but it also provides new ideas for the development of therapeutic strategies for ALI.