Mechanistic Pathways · 9 min read · 2027-11-11
Spirulina and SREBP-1c
A single transcription factor switches on all the lipogenesis genes simultaneously. Insulin activates it. AMPK shuts it down.
SREBP-1c Activation
SREBP-1c (sterol regulatory element binding protein 1c) is synthesized as ER-bound precursor. Insulin/mTORC1 signaling triggers proteolytic activation in Golgi, releasing the nuclear transcription factor that drives FAS, ACC1, SCD1, and other lipogenic genes. In NAFLD, sustained SREBP-1c activity drives hepatic fat accumulation.
AMPK-SIRT1 Suppression
AMPK phosphorylates SREBP-1c at Ser372, inhibiting nuclear translocation. SIRT1 deacetylates SREBP-1c at K289/K309, targeting it for ubiquitination. Spirulina's combined AMPK-SIRT1 activation produces 25-40% reduction in nuclear SREBP-1c and corresponding hepatic lipogenic gene expression.
Conclusion
Spirulina's SREBP-1c suppression drives much of its anti-NAFLD effects. Combined with ACC-malonyl-CoA suppression (covered separately), spirulina shuts down lipogenesis at both transcriptional and enzymatic levels.