Secreted Ectodomain of SIGLEC-9 and MCP-1 Synergistically Improve Acute Liver Failure in Rats by Altering Macrophage Polarity

Takanori Ito,Marina Hirata,Tetsuya Ishikawa,Minoru Ueda,Yoshiki Hirooka,Akihito Yamamoto,Kohki Matsubara,Hidemi Goto,Masatoshi Ishigami,Yoshihiro Matsushita,Hideharu Hibi

doi:10.1038/srep44043

Takanori Ito, Marina Hirata + Show 9 more

Open Access

https://doi.org/10.1038/srep44043

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Journal: Scientific Reports	Publication Date: Mar 8, 2017
Citations: 30	License type: open-access

Affiliation: Nagoya University, Tokushima University

Abstract

Effective treatments for acute liver failure (ALF) are still lacking. We recently reported that a single intravenous administration of serum-free conditioned medium from stem cells derived from human exfoliated deciduous teeth (SHED-CM) into the D-galactosamine (D-Gal)-induced rat ALF model improves the liver injury. However, the specific factors in SHED-CM that are responsible for resolving ALF remain unclear. Here we found that depleting SHED-CM of two anti-inflammatory M2 macrophage inducers—monocyte chemoattractant protein-1 (MCP-1) and the secreted ectodomain of sialic acid-binding Ig-like lectin-9 (sSiglec-9)—abolished its ability to resolve rat ALF. Furthermore, treatment with MCP-1/sSiglec-9 alone dramatically improved the survival of ALF rats. This treatment induced anti-inflammatory M2, suppressed hepatocyte apoptosis, and promoted hepatocyte proliferation. Treatment with an M2-depletion reagent (mannosylated clodronate liposomes) suppressed the recovery. In addition, MCP-1 and sSiglec-9 synergistically promoted the M2 differentiation of bone marrow-derived macrophages via CCR2, accompanied by the production of multiple liver-regenerating factors. The conditioned medium from MCP-1/sSiglec-9-activated M2 macrophages, but not from interleukin-4-induced ones, suppressed the D-Gal- and LPS-induced apoptosis of primary hepatocytes and promoted their proliferation in vitro. The unique combination of MCP-1/sSiglec-9 ameliorates rat ALF by inhibiting hepatocellular apoptosis and promoting liver regeneration through the induction of anti-inflammatory/tissue-repairing M2 macrophages.

Highlights

In acute liver failure (ALF), a poorly controlled inflammatory response causes extensive hepatic destruction, which leads to systemic inflammation, multiple organ failure, and sudden death[1,2]
monocyte chemoattractant protein-1 (MCP-1) and sSiglec-9 were immunodepleted from the SHED-conditioned medium (CM), and their loss was confirmed by Enzyme-Linked ImmunoSorbent Assay (ELISA) (Supplementary Table S1)
We previously reported that SHEDs, a type of mesenchymal stromal cells (MSCs), secrete a broad repertoire of trophic and immunomodulatory factors, and that a single administration of either SHEDs or SHED-CM protects rats from D-Gal-induced ALF; the factors that mediate this protection have been unclear

Summary

Introduction

In acute liver failure (ALF), a poorly controlled inflammatory response causes extensive hepatic destruction, which leads to systemic inflammation, multiple organ failure, and sudden death[1,2]. Activated M1 cells initiate inflammation and accelerate tissue destruction by releasing high levels of pro-inflammatory cytokines, reactive oxygen species, and nitric oxide, whereas M2 cells counteract pro-inflammatory M1 conditions by secreting anti-inflammatory cytokines, scavenging cellular debris, and suppressing fibrosis. The balance of these polarized macrophages is thought to be important for tissue repair and regeneration[7,10]. We analyzed the secretome of SHED-CM and identified a novel set of anti-inflammatory M2 macrophage inducers: monocyte chemoattractant protein-1/CC chemokine ligand 2 (MCP-1/CCL2) and the secreted ectodomain of sialic acid-binding Ig-like lectin-9 (sSiglec-9)[14]. We investigated the roles of MCP-1/sSiglec-9 in the SHED-CM-mediated recovery from rodent ALF and their therapeutic potential for ALF

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