Work

Conditioned media derived from HepG2 cells treated with phosphoeleganin synthetic-derived compound PE/2 improve cytokine balance and metabolic response in 3T3-L1 adipocytes

Year: 2026

Type: article

Abstract: Background The liver–adipose axis regulates insulin sensitivity and lipid metabolism, and its dysregulation contributes to metabolic disorders. PE/2, a semisynthetic derivative of the marine natural product phosphoeleganin, reduces IL-6 expression and secretion, enhancing insulin sensitivity in liver cells (HepG2). However, its role in liver–adipose communication is unclear. Methods To clarify the impact of PE/2 on liver–adipose tissue crosstalk, the conditioned media approach was used. Protein and mRNA levels were analyzed by Western blot and Real-Time RT-PCR, respectively. Lipid and glucose metabolism were evaluated by Oil Red O staining and glucose consumption assays, respectively. Results Our results indicate that in 3T3-L1 adipocytes, conditioned media derived from PE/2-treated HepG2 cells (CM PE/2 ) increased adiponectin expression by 1.85-fold and reduced interleukin-8 and interleukin-1β mRNA levels by 43% and 52%, respectively, compared with conditioned media alone (CM). The protective adipokine phenotype induced by CM PE/2 was accompanied by 1.75-fold lipid accumulation and increased expression of adipogenic markers, including PPARγ , C/EBPα , GLUT4 , and FABP4 . To examine whether this profile translates into enhanced insulin sensitivity, we evaluated the insulin pathway. Interestingly, CM from insulin-stimulated HepG2 cells (CM Ins ) did not significantly increase insulin receptor (INSR) or Akt phosphorylation compared with CM from 3T3-L1 adipocytes. However, CM derived from HepG2 co-treated with insulin and PE/2 (CM Ins+PE/2 ) increased INSR and Akt phosphorylation by 2.13- and 1.63-fold, respectively, compared to CM, and by 1.83- and 1.42-fold, respectively, compared to CM Ins . Consistently, 3T3-L1 glucose consumption significantly improved in the presence of CM Ins+PE/2 . Treatment with the PI3K/Akt inhibitor LY294002 reversed the effects of CM Ins+PE/2 . Finally, supplementing recombinant IL-6 into CM PE/2- treated cells reduced the effect of this compound on the expression of inflammatory and adipogenic genes and on glucose consumption in 3T3-L1 adipocytes, corroborating the hypothesis that IL-6 is involved in the action mediated by PE/2. Conclusion These findings suggest that PE/2 improves the metabolic–inflammatory profile in adipocytes by modulating hepatocyte–adipocyte crosstalk, highlighting its implication for metabolic dysfunctions associated with impaired liver-adipose communication.

Source: Frontiers in Pharmacology

DOI: 10.3389/fphar.2026.1909848