Objective      To determine the expression profile of ZCWCC1 (Zinc-finger CW-type coiled-coil protein 1) protein in the process of steatosis of immortalized hepatocyte cell line L02 (hereinafter referred to as L02 cells).       Methods      L02 cells were cultured in the medium containing 500 μmol/L oleic acid to induce steatosis

then confirmed by oil red O staining. Immunofluorescence assay and fluorescent confocal microscopy were employed to observe the protein levels of ZCWCC1 during induction of steatosis

and Western blotting was used to semi-quantify the results. Lysine protease inhibitor

N-Ethylmaleimide (NEM)

and proteasome inhibitor

MG132 were used to enhance or block the ubiquitin-proteasome pathway which is important for protein degradation.       Results      Oil red O staining and cellular triglyceride measurement confirmed the establishment of L02 steatosis model. Immunofluorescence assay and Western blot analysis indicated that ZCWCC1 was mainly located in the nucleus

and its expression level was descending during the induction of steatosis (56 283±303

56 753±539

55 561±996

56 257±326

48 339±712

and 43 022±2 198 respectively in 0

3

6

12

24 and 48 h after induction

P0.01). NEM treatment resulted in enhanced degradation of ZCWCC1 in the L02 cells

while MG132 inversed the descending tendency of ZCWCC1 during L02 steatosis.       Conclusion      Protein level of ZCWCC1 was descending in the process of steatosis of hepatocyte L02 cells

which might be relative to the ubiquitin-proteasome pathway.