Multifaceted therapeutic benefits of factors derived from stem cells from human exfoliated deciduous teeth for acute liver failure in rats.

In acute liver failure (ALF), a poorly controlled innate immune response causes massive hepatic destruction, which elicits a systemic inflammatory response, progressive multiple organ failure and ultimate sudden death. Although the liver has inherent tissue-repairing activities, its regeneration during ALF fails, and orthotopic liver transplantation is the only curative approach. Here we show that a single intravenous administration of stem cells derived from human exfoliated deciduous teeth (SHEDs) or of SHED-derived serum-free conditioned medium (SHED-CM) into the d-galactosamine-induced rat model of ALF markedly improved the condition of the injured liver and the animals' survival rate. The engraftment of infused SHEDs was very low, and both SHEDs and SHED-CM exerted similar levels of therapeutic effect, suggesting that the SHEDs reversed ALF by paracrine mechanisms. Importantly, SHED-CM attenuated the ALF-induced pro-inflammatory response and generated an anti-inflammatory/tissue-regenerating environment, which was accompanied by the induction of anti-inflammatory M2-like hepatic macrophages. Secretome analysis by cytokine antibody array revealed that the SHED-CM contained multiple tissue-regenerating factors with known roles in anti-apoptosis/hepatocyte protection, angiogenesis, macrophage differentiation and the proliferation/differentiation of liver progenitor cells. Taken together, our findings suggest that SHEDs produce factors that provide multifaceted therapeutic benefits for AFL.