The polyene amphotericin B (AMB) exerts a powerful and broad antifungal activity. AMB acts by (i) binding to ergosterol, leading to pore formation at the fungal plasma membrane with subsequent ion leakage, and (ii) inducing the intracellular accumulation of reactive oxygen species (ROS). Herein, we have deciphered the AMB resistance mechanisms in clinical isolates of complex (, , var. ) in comparison to other clinically relevant non- species. Membrane gas chromatography-mass spectrometry analysis revealed that the vast majority of sterols were composed of ergosterol pathway intermediates, evidencing the absence of AMB target. Supporting this data, species complex demonstrated poor membrane permeability after AMB treatment. Regarding the oxidative burst, AMB induced the formation of ROS in all species tested; however, this phenomenon was slightly seen in complex isolates. Our results indicated that these isolates displayed altered respiratory status, as revealed by their poor growth in nonfermented carbon sources, low consumption of oxygen, and derisive mitochondrial membrane potential. The use of specific inhibitors of mitochondrial respiratory chain (complex I-IV) revealed no effects on the yeast growth, highlighting the metabolic shift to fermentative pathway in strains. Also, complex proved to be highly resistant to oxidative burst agents, which can be correlated with a high activity of antioxidant enzymes. Our data demonstrated primary evidence suggesting that ergosterol content, mitochondrial function, and fungal redox homeostasis are involved in AMB fungicidal effects and might explain the resistance presented in this multidrug-resistant, emergent, and opportunistic fungal complex.
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http://dx.doi.org/10.1021/acsinfecdis.0c00117 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Institut Langevin, École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Université Paris Sciences & Lettres, CNRS, Paris 7587, France.
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State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
The abrupt drop of resistance to zero at a critical temperature is a key signature of the current paradigm of the metal-superconductor transition. However, the emergence of an intermediate bosonic insulating state characterized by a resistance peak preceding the onset of the superconducting transition has challenged this traditional understanding. Notably, this phenomenon has been predominantly observed in disordered or chemically doped low-dimensional systems, raising intriguing questions about the generality of the effect and its underlying fundamental physics.
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Cancer Biology & Genetics Program, Sloan Kettering Institute, New York, NY 10065.
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January 2025
Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China.
Host plants and various fungicides inhibit plant pathogens by inducing the release of excessive reactive oxygen species (ROS) and causing DNA damage, either directly or indirectly leading to cell death. The mechanisms by which the oomycete manages ROS stress resulting from plant immune responses and fungicides remains unclear. This study elucidates the role of histone acetylation in ROS-induced DNA damage responses (DDR) to adapt to stress.
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Laboratory of Precision Medicine and Biopharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
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