Abrashev Radoslav, Krumova Ekaterina, Petrova Penka, Eneva Rumyana, Gocheva Yana, Engibarov Stefan, Miteva-Staleva Jeny, Dishliyska Vladislava, Stoyancheva Galina, Spasova Boryana, Kolyovska Vera, Angelova Maria
Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria.
Department of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria.
Life (Basel). 2025 Jun 8;15(6):926. doi: 10.3390/life15060926.
Sialidases/neuraminidases remove terminal sialic acid residues from glycoproteins, glycolipids, and oligosaccharides. Our previous research has revealed the distribution of sialidase in non-clinical fungal isolates from different ecological niches, including Antarctica. Fungi adapted to extremely low temperatures possess defense mechanisms necessary for their survival such as the response against oxidative stress. The relationship between oxidative stress and sialidase synthesis has been studied extremely sparsely. The aim of the present study was to investigate the involvement of sialidase in the cell response of the Antarctic strain P29 against oxidative stress induced by long- and short-term exposure to low temperatures. The changes in growth temperatures for 120 h (long-term stress) affected biomass accumulation, glucose consumption, sialidase synthesis, and the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). The short-term temperature downshift (6 h) caused oxidative stress, evidenced by changes in the levels of biomarkers, including lipid peroxidation, oxidatively damaged proteins, and the accumulation of reserve carbohydrates. Simultaneously, a sharp increase in SOD and CAT activity was found, which coincided with a significant increase in sialidase activity. This study marks the first demonstration of increased sialidase activity in filamentous fungi isolated from extreme cold environments as a response to oxidative stress.
唾液酸酶/神经氨酸酶可从糖蛋白、糖脂和寡糖中去除末端唾液酸残基。我们之前的研究揭示了唾液酸酶在包括南极洲在内的不同生态位的非临床真菌分离株中的分布情况。适应极低温度的真菌拥有生存所需的防御机制，例如对氧化应激的反应。氧化应激与唾液酸酶合成之间的关系研究极少。本研究的目的是调查唾液酸酶在南极菌株P29应对长期和短期低温诱导的氧化应激的细胞反应中的作用。120小时（长期应激）生长温度的变化影响了生物量积累、葡萄糖消耗、唾液酸酶合成以及抗氧化酶超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性。短期温度下降（6小时）导致氧化应激，这通过生物标志物水平的变化得以证明，包括脂质过氧化、氧化损伤的蛋白质以及储备碳水化合物的积累。同时，发现SOD和CAT活性急剧增加，这与唾液酸酶活性的显著增加同时发生。本研究首次证明了从极端寒冷环境中分离出的丝状真菌中唾液酸酶活性增加是对氧化应激的一种反应。
