1. Academic Validation
  2. N-Lactoyl Phenylalanine Disrupts Insulin Signaling, Induces Inflammation, and Impairs Mitochondrial Respiration in Cell Models

N-Lactoyl Phenylalanine Disrupts Insulin Signaling, Induces Inflammation, and Impairs Mitochondrial Respiration in Cell Models

  • Cells. 2025 Aug 20;14(16):1296. doi: 10.3390/cells14161296.
Laila Hedaya 1 Khaled Naja 1 Shamma Almuraikhy 1 Najeha Anwardeen 1 Asma A Elashi 1 Maha Al-Asmakh 2 Susu M Zughaier 3 Meritxell Espino-Guarch 4 Osama Y Aldirbashi 5 6 7 Gavin P Davey 8 Mohamed A Elrayess 1 3
Affiliations

Affiliations

  • 1 Biomedical Research Center, QU Health, Qatar University, Doha P.O. Box 2713, Qatar.
  • 2 Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha P.O. Box 2713, Qatar.
  • 3 College of Medicine, QU Health, Qatar University, Doha P.O. Box 2713, Qatar.
  • 4 Laboratory of Immunoregulation, Translational Medicine, Sidra Medicine, Doha P.O. Box 26999, Qatar.
  • 5 Department of Lab Medicine & Pathology, Hamad Medical Corporation, Doha P.O. Box 3050, Qatar.
  • 6 College of Health Sciences, QU Health, Qatar University, Doha P.O. Box 2713, Qatar.
  • 7 College of Health & Life Sciences, Hamad Bin Khalifa University, Doha P.O. Box 17666, Qatar.
  • 8 School of Biochemistry and Immunology, Trinity College Dublin, D02 PN40 Dublin, Ireland.
Abstract

N-lactoyl Amino acids (Lac-AAs) are key players that regulate appetite and body weight. The most prominent and well-studied member is N-lactoyl phenylalanine (Lac-Phe), which can be induced by food intake, exercise and metformin treatment. However, its broader metabolic impact remains insufficiently characterized. This study investigates the effects of Lac-Phe on Insulin signaling, inflammation, and mitochondrial respiration using HepG2 and differentiated C2C12 cell models, as well as isolated rat brain mitochondria and synaptosomes. Our results demonstrate that Lac-Phe significantly impairs insulin-stimulated phosphorylation of key proteins in the Insulin signaling pathway, particularly in skeletal muscle cells, indicating disrupted Insulin signaling. Additionally, Lac-Phe exposure increases the secretion of pro-inflammatory cytokines in C2C12 skeletal muscle cells and markedly impairs mitochondrial respiration in HepG2 liver cells and rat brain-derived synaptosomes, but not in isolated mitochondria. These findings highlight potential adverse metabolic effects of Lac-Phe, especially when administered at high concentrations, and underscore the necessity of conducting a comprehensive risk assessment and dose optimization before considering Lac-Phe or related Lac-AAs as therapeutic agents. Our work provides important insights into the molecular liabilities associated with Lac-Phe and calls for further studies to balance its therapeutic promise against possible metabolic risks.

Keywords

N-lactoyl phenylalanine; cytokines; insulin signaling; mitochondrial respiration.

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