Bioactivity studies of porphyrinoids against microsporidia isolated from honeybees
Bioactivity studies of porphyrinoids against microsporidia isolated from honeybees
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DOI：
10.1038/s41598-020-68420-5
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发表时间：
2020-07-14
影响因子：
4.6
通讯作者：
Tchorzewski, Marek
中科院分区：
文献类型：
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作者：
Buczek, Katarzyna;Trytek, Mariusz;Tchorzewski, Marek
由于缺乏有效的鼻塞治疗方法，微孢子虫感染对蜜蜂来说是危险的。在目前的工作中，在体外研究了几种卟啉直接灭活来自感染微孢子虫的蜜蜂的微孢子虫的能力。合成了与一个和两个氨基酸部分缀合的原卟啉 IX (PPIX) 的酰胺衍生物，并将其活性与两种阳离子卟啉 TMePyP 和 TTMePP 的活性进行了比较。最活跃的卟啉 PP[Lys-Asp](2)、PP[Lys-TFA](2)、PP[Asp(ONa)(2)](2) 和 PP[Lys-Lys](2) 在浓度低至 10-50 mu M 时对微孢子虫产生显着影响，与对照相比，孢子数量减少 67-80%。用卟啉处理的孢子的活细胞成像显示，与 50 mu M PP[Asp(ONa)(2)](2) 和 PP[Lys-Asp](2) 孵育 24 小时后，分别只有 1.6% 和 3.0% 的孢子仍然存活。 PPIX 分子中氨基酸侧链的长度及其特性影响卟啉的生物活性。重要的是，卟啉的辐射并没有增强其破坏微孢子虫孢子的效力。我们发现卟啉在活孢子内积累，但不在死孢子内积累，因此非金属化卟啉对小孢子虫的破坏不依赖于光敏作用，而是与其主动转运到孢子细胞中有关。当对蜜蜂体内给药时，PPIX[Lys-TFA](2) 和 PPIX[Lys-Lys](2) 可使受感染个体的孢子量减少 69-76%。与锌配位卟啉相比，它们对蜜蜂没有毒性作用。
Microsporidian infections are dangerous to honeybees due to the absence of an efficient treatment for nosemosis. In the present work, the abilities of several porphyrins to directly inactivate microsporidia derived from Nosema-infected honeybees were studied in vitro. Amide derivatives of protoporphyrin IX (PPIX) conjugated with one and two amino acid moieties were synthesized, and their activities were compared with those of two cationic porphyrins, TMePyP and TTMePP. The most active porphyrins, PP[Lys-Asp](2), PP[Lys-TFA](2), PP[Asp(ONa)(2)](2) and PP[Lys-Lys](2) at concentrations as low as 10-50 mu M exerted significant effects on microsporidia, reducing the number of spores by 67-80% compared to the control. Live-cell imaging of the spores treated with porphyrins showed that only 1.6% and 3.0% of spores remained alive after 24 h-incubation with 50 mu M PP[Asp(ONa)(2)](2) and PP[Lys-Asp](2), respectively. The length of the amino acid side chains and their identity in the PPIX molecules affected the bioactivity of the porphyrin. Importantly, the irradiation of the porphyrins did not enhance their potency in destroying Nosema spores. We showed that the porphyrins accumulated inside the living spores but not inside dead spores, thus the destruction of the microsporidia by non-metallated porphyrins is not dependent on photosensitization, but is associated with their active transport into the spore cell. When administered to honeybees in vivo, PPIX[Lys-TFA](2) and PPIX[Lys-Lys](2) reduced spore loads by 69-76% in infected individuals. They both had no toxic effect on honeybees, in contrast to zinc-coordinated porphyrin.