Mechanism Inducing the HL-60 Cell Differentiation by Haishengsu Tegillarca Granosa Extract via Targeting ULK1 Protein

Abstract

To investigate the proliferation, differentiation potential and autophagic mechanism HL-60 cells via ULK1 protein targeted by Haishengsu extracted from Tegillarca granosa. The HL-60 cells were divided into five groups: Haishengsu of 10,100,1000 mg/L-treated group, all-trans retinoic acid (ATRA) 5 μmol/L-treated group and control group. The cell proliferation rates were detected by MTT after culture 12,24,48 h and 72 h. The expression of differentiation and maturation markers CD11b and CD15 were detected by flow cytometry, and the expression of autophagy molecules ULK1 and LC-3 proteins were measured by Western blot. After cultured for 48 and 72 h the cell proliferation rates of HL-60 in Haishengsu 100 and 1000 mg/L groups were significantly lower than those of ATRA 5 μmol/L group and Haishengsu 10 mg/L group and control group (P<0.05). After 72 h, the levels of CD11b, CD15, ULK1 and LC-3 expression of HL-60 cell in Haishengsu 100 and 1000 mg/L groups were higher than those in ATRA 5 μmol/L group, Haishengsu 10 mg/L group and control group (P<0.05). While the HL-60 cells in Haishengsu 10, 100 and 1000 mg/L group were treated with ULK1 protein inhibitor and after cultured for 72 h, the proliferation rate of HL-60 cell increased, levels of CD11b and CD15 expression decreased at the same time, and the levels of ULK1 and LC-3 proteins in HL-60 cells also decreased (P<0.05). Haishengsu, which extracted from Tegillarca granosa, can induce HL-60 cell proliferation and differentiation by targeting ULK1 protein in a concentration and time dependent manner, its effective mochanism may be mediating autophagic activity, promoting cell differentiation and maturation.