Sulforaphane activates heat shock response and enhances proteasome activity through up-regulation of Hsp27.
Level 5 - mechanism / opinion, no new human data
In vitro bench study in cultured mammalian cells without human data
PubMed 20833711 · doi:10.1074/jbc.M110.152686
What was done
Researchers investigated the mechanism by which sulforaphane stimulates proteasome activity in mammalian cells. They evaluated the involvement of heat shock transcription factor 1 and heat shock protein 27 (Hsp27) using Hsp27-overexpressing and Hsp27-silenced cells, tested isogenic REG cells stably expressing Hsp27 versus Hsp27-free parental cells, and assessed whether Hsp27 phosphorylation is required for proteasome activation.
What was found
Sulforaphane activated heat shock transcription factor 1-mediated response and induced Hsp27 expression. Sulforaphane-induced proteasome activity was significantly enhanced in Hsp27-overexpressing cells, absent in Hsp27-silenced cells, and present only in Hsp27-expressing isogenic REG cells versus parental controls. Phosphorylation of Hsp27 was found to be irrelevant to proteasome activation. The abstract does not report specific numerical values, concentrations, or effect sizes.
Why it matters
This study identifies an Hsp27-dependent heat shock response pathway by which sulforaphane stimulates proteasomal clearance of damaged proteins, revealing a cytoprotective mechanism distinct from the established Keap1-Nrf2 antioxidant pathway.
Limits
The findings are strictly from in vitro cell culture models, lacking in vivo mammalian or human validation. Numerical values, dose ranges, and sample replicate numbers are not provided in the abstract.
Cited by
- supports Sulforaphane induces the expression of heat shock proteins.