Shimolina Liubov E, Khlynova Aleksandra E, Elagin Vadim V, Bureev Pavel A, Sherin Petr S, Kuimova Marina K, Shirmanova Marina V
Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky Square, 10/1, 603005 Nizhny Novgorod, Russia.
Department of Chemistry, Imperial College London, White City Campus, London W12 0BZ, UK.
Biomedicines. 2024 Nov 8;12(11):2550. doi: 10.3390/biomedicines12112550.
Despite the fundamental importance of cell membrane microviscosity, changes in this biophysical parameter of membranes during photodynamic therapy (PDT) have not been fully understood.
In this work, changes in the microviscosity of membranes of live HeLa Kyoto tumor cells were studied during PDT with KillerRed, a genetically encoded photosensitizer, in different cellular localizations. Membrane microviscosity was visualized using fluorescence lifetime imaging microscopy (FLIM) with a viscosity-sensitive BODIPY2 rotor.
Depending on the localization of the phototoxic protein, different effects on membrane microviscosity were observed. With nuclear localization of KillerRed, a gradual decrease in microviscosity was detected throughout the entire observation period, while for membrane localization of KillerRed, a dramatic increase in microviscosity was observed in the first minutes after PDT, and then a significant decrease at later stages of monitoring. The obtained data on cell monolayers are in good agreement with the data obtained for 3D tumor spheroids.
These results indicate the involvement of membrane microviscosity in the response of tumor cells to PDT, which strongly depends on the localization of reactive oxygen species attack via targeting of a genetically encoded photosensitizer.
尽管细胞膜微粘度具有根本重要性，但在光动力疗法（PDT）期间膜的这一生物物理参数的变化尚未完全了解。
在这项工作中，研究了在不同细胞定位下，使用基因编码的光敏剂KillerRed对活的HeLa Kyoto肿瘤细胞进行光动力疗法期间细胞膜微粘度的变化。使用带有粘度敏感的BODIPY2转子的荧光寿命成像显微镜（FLIM）对膜微粘度进行可视化。
根据光毒性蛋白的定位，观察到对膜微粘度有不同影响。当KillerRed定位于细胞核时，在整个观察期内检测到微粘度逐渐降低，而当KillerRed定位于细胞膜时，在光动力疗法后的最初几分钟内观察到微粘度急剧增加，然后在监测后期显著降低。在细胞单层上获得的数据与在三维肿瘤球体上获得的数据高度一致。
这些结果表明膜微粘度参与肿瘤细胞对光动力疗法的反应，这在很大程度上取决于通过基因编码光敏剂的靶向作用而产生的活性氧攻击的定位。
