Bioactivity of CD34+ cells in patients with acute-on-chronic liver failure.

Liver failure is a life-threatened serious disease with many complications and high mortality rate. Stem cells have been applied to replacement therapy, gene therapy and tissue engineering for its capacity of self-renewal and multi-lineage differentiation. To investigate the bioactivity of the peripheral blood hematopoietic stem cells (PBHSC) in patients with acute-on-chronic liver failure, we isolated CD34+ cells from peripheral blood of patients with acute-on-chronic liver failure and healthy controls. After cultured it in serum-free medium (SFEM), we studied the bioactivity of CD34+ cells by observing the morphology, recording growth curve, detecting cell cycle and cell apoptosis. CD34+ cells and culture solution were collected at the time points of 3, 5, 7, 10, 12 and 14 days, and the levels of hepatocyte growth factor (HGF), matrix metalloproteinase-9 (MMP-9), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in culture solution were detected by ELISA. Also, the expressions of pyruvate kinase muscle isoenzyme 2 (PKM2), integrin-β1 and liver-type pyruvate kinase (LPK) were detected by RT-PCR and immunofluorescence. Our results showed the bioactivity of CD34+ cells from patients with acute-on-chronic liver failure was identified to be similar with that from healthy controls. HGF, MMP-9, TNF-α and IL-6 were found in cell culture medium. RT-PCR and immunofluorescence results indicated that PKM2, Integrin-β1 expressed on CD34+ cells from patients with acute-on-chronic liver failure. In conclusion, bioactivity of CD34+ cells of patients with acute-on-chronic liver failure was demonstrated to be normal, which could secrete HGF, MMP-9, TNF-α and IL-6, promote the growth of hepatocytes, and differentiate along a direction to hepatocyte lineage.