CREB3L2-mediated expression of Sec23A/Sec24D is involved in hepatic stellate cell activation through ER-Golgi transport

Sci Rep. 2017 Aug 11;7(1):7992. doi: 10.1038/s41598-017-08703-6.

Abstract

Hepatic fibrosis is caused by exaggerated wound healing response to chronic injury, which eventually leads to hepatic cirrhosis. Differentiation of hepatic stellate cells (HSCs) to myofibroblast-like cells by inflammatory cytokines is the critical step in fibrosis. This step is accompanied by enlargement of the endoplasmic reticulum (ER) and Golgi apparatus, suggesting that protein synthesis and secretion are augmented in the activated HSCs. However, the process of rearrangement of secretory organelles and their functions remain to be fully elucidated. Here, we revealed that differentiation alters early secretory gene expression. We observed significant isoform-specific upregulation of the inner coat protein complex II (COPII) components, Sec23A and Sec24D, via the transmembrane bZIP transcription factor, CREB3L2/BBF2H7, during HSC activation. Moreover, knockdown of these components abrogated the activation, suggesting that Sec23A/Sec24D-mediated ER to Golgi trafficking is required for HSC activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic-Leucine Zipper Transcription Factors / metabolism
  • Cells, Cultured
  • Endoplasmic Reticulum / metabolism*
  • Golgi Apparatus / metabolism*
  • Hepatic Stellate Cells / drug effects
  • Hepatic Stellate Cells / metabolism*
  • Male
  • Rats
  • Rats, Wistar
  • Secretory Pathway
  • Transforming Growth Factor beta / pharmacology
  • Up-Regulation
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*

Substances

  • Basic-Leucine Zipper Transcription Factors
  • Sec23a protein, rat
  • Transforming Growth Factor beta
  • Vesicular Transport Proteins