# The Yeast‐Fermented Garlic and a Balance of Spermine/Spermidine Activates Autophagy via EGR1 Transcriptional Factor

## TL;DR

Yeast-fermented garlic boosts cell cleanup (autophagy) through a specific balance of polyamines and a key gene called EGR1.

## Contribution

The study reveals a novel mechanism where a specific spermine/spermidine ratio activates autophagy via EGR1, independent of mTORC1.

## Key findings

- Yeast-fermented garlic increases autophagic flux in cells without involving mTORC1 signaling.
- The specific spermine/spermidine ratio in yeast-fermented garlic is essential for autophagy activation.
- EGR1 is critical for the autophagy-enhancing and proteostress-reducing effects of yeast-fermented garlic.

## Abstract

Spermine (SPM) and spermidine (SPD) are polyamines found in all organisms, and their concentrations can be regulated by ingestion. We demonstrated that yeast‐fermented garlic (YF) extract significantly increased autophag flux in OUMS‐36T‐1 and HeLa cells expressing the fluorescent probe (GFP‐LC3‐RFP‐LC3ΔG). YF‐induced increase of autophagy occurred independently of mTORC1 signaling, and RNA‐sequencing analysis revealed that EGR1 was the most significantly altered gene in YF‐treated OUMS‐36T‐1 cells. YF‐treated EGR1‐deficient HAP1 cells displayed reduced autophagic flux (p < 0.05). YF‐induced increasing of autophagic flux occurred via a specific SPM/SPD ratio. HAP1 cells treated with equivalent amounts of SPD or SPM as that found in YF did not increase autophagic flux (p > 0.05); however, treatment with SPD and SPM in the same ratio as that found in YF increased autophagic flux (p < 0.05). This specific SPM/SPD ratio reduced MG132‐induced proteostress via EGR1‐dependent pathways (p < 0.05). Thus, the SPM/SPD balance may regulate autophagy via EGR1‐dependent pathways, and controlling this balance may provide a strategy to maintain cellular homeostasis.

Spermine (SPM) and spermidine (SPD) are polyamines crucial for cellular functions, and their balance can be influenced by dietary intake. Yeast‐fermented garlic (YF) extract was shown to significantly enhance autophagic flux in vitro, independently of mTORC1 signaling. RNA sequencing revealed that EGR1 plays a critical role in mediating YF‐induced autophagy. The specific SPM/SPD ratio present in YF was identified as essential for this effect, as neither SPM nor SPD alone replicated the autophagy‐enhancing activity. This ratio also alleviated proteostress through EGR1‐dependent pathways, highlighting the importance of SPM/SPD balance in regulating autophagy and maintaining cellular homeostasis.