Transplantation of Mesenchymal Stem Cells Attenuates Acute Liver Failure in Mice via an Interleukin-4-dependent Switch to the M2 Macrophage Anti-inflammatory Phenotype

Jinglin Wang; Haoran Ding; Jingchao Zhou; Senzhe Xia; Xiaolei Shi; Haozhen Ren

doi:10.14218/JCTH.2021.00127

Transplantation of Mesenchymal Stem Cells Attenuates Acute Liver Failure in Mice via an Interleukin-4-dependent Switch to the M2 Macrophage Anti-inflammatory Phenotype

J Clin Transl Hepatol. 2022 Aug 28;10(4):669-679. doi: 10.14218/JCTH.2021.00127. Epub 2022 Jan 4.

Authors

Jinglin Wang^{1

2

3}, Haoran Ding^{1

2

3}, Jingchao Zhou^{1

2

3}, Senzhe Xia⁴, Xiaolei Shi^{1

2

3}, Haozhen Ren^{1

2

3}

Affiliations

¹ Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China.
² Department of Hepatobiliary Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
³ Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Jiangsu, China.
⁴ Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Jiangsu University, Nanjing, Jiangsu, China.

Abstract

Background and aims: Transplantation of mesenchymal stem cells (MSCs) derived from bone marrow (BM) is an alternative treatment of acute liver failure (ALF) mainly because of the resulting anti-inflammatory activity. It is not known how MSCs regulate local immune responses and liver regeneration. This study explored the effects of MSCs on hepatic macrophages and the Wnt signaling pathway in ALF.

Methods: MSCs were isolated from BM aspirates of C57BL/6J mice, and transplanted in mice with ALF induced by D-galactosamine (D-Gal). The proliferation of hepatocytes was assayed by immunohistochemical (IHC) staining of Ki-67 and proliferating cell nuclear antigen (PCNA). The levels of key proteins in the Wnt signaling pathway were assayed by western blotting and cytokines were determined enzyme-linked immunosorbent assays (ELISAs). A macrophage polarization assay characterized the M1/M2 ratio. The potential role of interleukin-4 (IL-4) in the biological activity of MSCs was determined by silencing of IL-4.

Results: Transplantation of allogeneic MSCs significantly attenuated D-Gal-induced hepatic inflammation and promoted liver regeneration. MSC transplantation significantly promoted a phenotypic switch from proinflamatory M1 macrophages to anti-inflammatory M2 macrophages, leading to significant Wnt-3a induction and activation of the Wnt signaling pathway in mice with D-Gal-induced ALF. Of the paracrine factors secreted by MSCs (G-CSF, IL-6, IL-1 beta, IL-4, and IL-17A), IL-4 was specifically induced following transplantation in the ALF model mice. The silencing of IL-4 significantly abrogated the phenotypic switch to M2 macrophages and the protective effects of MSCs in both the ALF model mice and a co-culture model in an IL-4 dependent manner.

Conclusions: In vivo and in vitro studies showed that MSCs ameliorated ALF through an IL-4-dependent macrophage switch toward the M2 anti-inflammatory phenotype. The findings may have clinical implications in that overexpression of IL-4 may enhance the therapeutic effects of allogeneic MSC transplantation in the treatment of ALF.

Keywords: Acute liver failure; Interleukin 4; Macrophage; Mesenchymal stem cells; Wnt signaling pathway.