Biology subjects

Ledue, E. L.

Publications and source records attributed to Ledue, E. L..

3 recordsLinked to original sources

bioRxiv2026

Antimicrobial cetylpyridinium chloride disrupts the mitochondrial electron transport chain as potently as cyanide, via cardiolipin interference at cytochrome C

People are widely exposed to the antimicrobial cetylpyridinium chloride (CPC) via consumer products, but CPC is a mitochondrial toxicant with potency comparable to that of canonical mitotoxicants. CPC is largely unregulated despite growing usage, bioavailability, and ability to cross the blood-brain barrier. Previously, we showed, in several cell types at non-cytotoxic and exposure-relevant doses, CPC inhibits ATP and OCR, endpoints of the electron transport chain (ETC). Mitochondrial toxicity is linked to multiple diseases (e.g., diabetes, Parkinsons, myalgic encephalomyelitis), but CPC has not been studied epidemiologically, and little mechanistic information is available. To determine why OCR and ATP are hampered by CPC, we hypothesized that CPC inhibits individual ETC components, cardiolipin, or TCA enzymes. Here, we show that, in primary human skin cells, an immune mast cell model, and isolated mitochondria, CPC apparently inhibits multiple ETC Complexes. Detailed investigation pinpointed the mechanism to the distal end of ETC: Complex III-cytochrome C-Complex IV. Using multiple approaches, we show that CPC does not directly inhibit any of the Complexes (not even Complex I as earlier reported), nor TCA enzymes, nor coenzyme Q. Yet, we found that CPC exhibits mitotoxicity as potent as cyanide. Anionic lipid cardiolipin attracts cytochrome C to the inner mitochondrial membrane so that it may shuttle electrons from Complex III to IV. Despite not altering levels of cardiolipin, CPC hinders cytochrome C by electrostatically interfering with cardiolipin. To aid epidemiology, risk analysis, and predictive toxicology, we have determined the precise biochemical mechanism of action of this ubiquitous compound.

pharmacology and toxicology↗

bioRxiv2023

Pharmaceutical agent cetylpyridinium chloride inhibits immune mast cell function by interfering with calcium mobilization

Cetylpyridinium chloride (CPC) is an antimicrobial used in numerous personal care and janitorial products and food for human consumption at millimolar concentrations. Minimal information exists on the eukaryotic toxicology of CPC. We have investigated the effects of CPC on signal transduction of the immune cell type mast cells. Here, we show that CPC inhibits the mast cell function degranulation with antigen dose-dependence and at non-cytotoxic doses [~]1000-fold lower than concentrations in consumer products. Previously we showed that CPC disrupts phosphatidylinositol 4,5-bisphosphate, a signaling lipid critical for store-operated Ca2+ entry (SOCE), which mediates degranulation. Our results indicate that CPC inhibits antigen-stimulated SOCE: CPC restricts Ca2+ efflux from endoplasmic reticulum, reduces Ca2+ uptake into mitochondria, and dampens Ca2+ flow through plasma membrane channels. While inhibition of Ca2+ channel function can be caused by alteration of plasma membrane potential (PMP) and cytosolic pH, CPC does not affect PMP or pH. Inhibition of SOCE is known to depress microtubule polymerization, and here we show that CPC indeed dose-dependently shuts down formation of microtubule tracks. In vitro data reveal that CPC inhibition of microtubules is not due to direct CPC interference with tubulin. In summary, CPC is a signaling toxicant that targets Ca2+ mobilization.

pharmacology and toxicology↗

bioRxiv2022

Mechanisms of Antimicrobial Agent Cetylpyridinium Chloride Mitochondrial Toxicity in Rodent and Primary Human Cells: Super-resolution Microscopy Reveals Nanostructural Disruption

People are exposed to high concentrations of antibacterial agent cetylpyridinium chloride (CPC) via personal care and food products, despite little information regarding CPC effects on eukaryotes. CPC is used as an antibacterial agent via a detergent mechanism when above [~]600- 900 M. While three previous studies suggested CPC mitochondrial toxicity, this phenomenon is not well-studied. Here, we show that low-micromolar CPC inhibits mitochondrial ATP production in primary human keratinocytes, mouse NIH-3T3 fibroblasts, and rat RBL-2H3 immune mast cells, in galactose media, which causes cells to produce ATP via mitochondria. ATP inhibition via CPC (EC50 1.7LJ{micro}M) is nearly as potent as that caused by canonical mitotoxicant CCCP (EC50 1.2LJ{micro}M). CPC inhibition of oxygen consumption rate (OCR) tracks with that of ATP: OCR is halved due to 1.75 M CPC in RBL-2H3 cells and 1.25 M in primary human keratinocytes. Here we demonstrate that CPC is more potent as a mitotoxicant than as an immune mast cell signaling inhibitor, an effect published previously. Mitochondrial [Ca2+] changes can cause mitochondrial dysfunction. Here we show, using a novel plate reader assay with reporter CEPIA2mt, that CPC causes mitochondrial Ca2+ efflux from mast cells via an ATP-inhibition mechanism. Using super-resolution microscopy (fluorescence photoactivation localization) in live cells, we have discovered that CPC causes mitochondrial nanostructural defects in fibroblasts, including the formation of spherical structures with donut-like cross section, as quantified by novel Fourier transform analysis. This work reveals CPC as a mitotoxicant despite widespread use, highlighting the importance of further research into its toxicological safety.

pharmacology and toxicology↗