Stiffness of Substrate Influences the Distribution but not the Synthesis of Autophagosomes in Human Liver (LO2) Cells

Authors

  • Fang Xu Changzhou University
  • Yue Wang Changzhou University
  • Mingzhi Luo Changzhou University
  • Yan Pan Changzhou University
  • Haowen Li Capital Medical University
  • Yajie Wang Capital Medical University
  • Guohua Qiu Changzhou University
  • Linhong Deng Changzhou University

Keywords:

Hepatic cells, Substrate stiffness, Autophagy, Cirrhosis, Translocation.

Abstract

Extracellular matrix (ECM) often becomes stiffer during tumor development, which not only gives the tumor's hardness feel but also actively contributes to the tumor formation. A good example is hepatocellular carcinoma (HCC) that usually develops within chronically stiffened liver tissues due to fibrosis and cirrhosis. On the other hand, HCC cells exhibit reduced autophagy in a malignancy dependent manner, suggesting autophagy is suppressed during tumor development. However, it is not known whether ECM stiffness would influence autophagy during tumor development. To investigate this issue, We cultured the human liver (LO2) cells that stably expressed autophagosome indicator LC3 on polydimethylsiloxane (PDMS) gels with stiffness varying from 11 to 1220 kPa. and on plastic cell culture dish as controls for up to 48h. We found that the total protein level of LC3-II in LO2 cells was not affected by the substrate stiffness. However the autophagosomes in LO2 cells cultured on the soft substrate (11 kPa PDMS gel) were localized and accumulated around the nucleus, while those on the stiff substrate (1220 kPa PDMS gel or plastic dish surface) were dispersed throughout the cytoplasmic space. Therefore, our data suggest that ECM stiffness may not directly synthesize nascent autophagosomes, but instead influence the location/translocation and ultimately distribution of autophagosomes in the cells.

Author Biographies

Fang Xu, Changzhou University

Biomedical Engineering and Health Sciences

Yue Wang, Changzhou University

Nursing

Mingzhi Luo, Changzhou University

Biomedical Engineering and Health Sciences

Yan Pan, Changzhou University

Biomedical Engineering and Health Sciences

Haowen Li, Capital Medical University

Clinical Medical Research

Yajie Wang, Capital Medical University

Clinical Medical Research

Guohua Qiu, Changzhou University

Biomedical Engineering and Health Sciences

Linhong Deng, Changzhou University

Biomedical Engineering and Health Sciences

Downloads

Published

2015-04-30

Issue

Section

Articles