Starvation-induced autophagy via calcium-dependent TFEB dephosphorylation is suppressed by Shigyakusan

PLoS One. 2020 Mar 5;15(3):e0230156. doi: 10.1371/journal.pone.0230156. eCollection 2020.

Abstract

Kampo, a system of traditional Japanese therapy utilizing mixtures of herbal medicine, is widely accepted in the Japanese medical system. Kampo originated from traditional Chinese medicine, and was gradually adopted into a Japanese style. Although its effects on a variety of diseases are appreciated, the underlying mechanisms remain mostly unclear. Using a quantitative tf-LC3 system, we conducted a high-throughput screen of 128 kinds of Kampo to evaluate the effects on autophagy. The results revealed a suppressive effect of Shigyakusan/TJ-35 on autophagic activity. TJ-35 specifically suppressed dephosphorylation of ULK1 and TFEB, among several TORC1 substrates, in response to nutrient deprivation. TFEB was dephosphorylated by calcineurin in a Ca2+ dependent manner. Cytosolic Ca2+ concentration was increased in response to nutrient starvation, and TJ-35 suppressed this increase. Thus, TJ-35 prevents the starvation-induced Ca2+ increase, thereby suppressing induction of autophagy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / drug effects*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / drug effects*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism
  • Calcineurin / metabolism
  • Calcium / metabolism
  • Drugs, Chinese Herbal / pharmacology*
  • Humans
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Phosphorylation
  • Starvation / metabolism

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Drugs, Chinese Herbal
  • TFEB protein, human
  • shigyaku-san
  • Mechanistic Target of Rapamycin Complex 1
  • Calcineurin
  • Calcium

Grants and funding

Takeshi NODA has received research grant from Tsumura CO. LTD. Tsumura CO LTD has no role in the study design; collection, analysis, and interpretation of data; writing of the paper; and decision to submit for publication.