Hypothesis

Berberine can impart a germline‑like epigenetic and proteostatic state to somatic hepatocytes by simultaneously degrading UHRF1, activating AMPK‑AXIN1 signaling, and reshaping the gut‑derived bile acid pool, thereby resetting age‑associated DNA methylation and mitochondrial damage.

Mechanistic Rationale

• UHRF1 loss reduces DNMT1 recruitment, causing passive demethylation at loci that accumulate age‑related hypermethylation (e.g., promoters of PCSK9 and SREBP‑1c) [2] [3]
• AMPK‑AXIN1 activation boosts mitochondrial autophagy (mitophagy) and NAD+ biosynthesis, mirroring germline mitochondrial quality control [1]
• Gut microbiome shift induced by berberine increases secondary bile acids (e.g., deoxycholic acid) that activate TGR5 and FXR, further stimulating AMPK and promoting histone deacetylase activity, akin to germline chromatin remodeling.

Testable Predictions

1. In primary mouse hepatocytes, berberine treatment will reduce UHRF1 protein levels by >50 % within 6 h and decrease methylation at the PCSK9 promoter by ≥20 % after 48 h, an effect blocked by proteasome inhibitor MG‑132.
2. Berberine‑treated hepatocytes will show increased LC3‑II/I ratio and mitochondrial membrane potential (JC‑1 red/green) comparable to germline‑like PGC‑1α overexpression.
3. Germ‑free mice or mice receiving antibiotics will lose the berberine‑driven methylation changes, indicating microbiome dependence.
4. Combining berberine with a FXR antagonist will attenuate the increase in histone H3K9 acetylation normally seen after treatment.

Experimental Design

• In vitro: Isolate hepatocytes from wild‑type C57BL/6 mice, treat with berberine (10 µM) ± MG‑132 (5 µM) or FXR antagonist (glycine‑β‑muricholic acid, 10 µM). Measure UHRF1 (Western), PCSK9 methylation (bisulfite seq), mitophagy (mt‑Keima), and acetylation (Western).
• In vivo: Feed mice high‑fat diet with or without berberine (0.2 % w/w) for 8 weeks. Groups: conventional, antibiotic‑treated, germ‑free. Liver tissue analysed for UHRF1, methylation array, bile acid profiling (LC‑MS), and histology.

Potential Confounds

Off‑target effects of berberine on other E3 ligases could influence UHRF1 independently of proteasome activity; use CRISPR‑knockout of UHRF1 to isolate methylation effects.