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    Photostimulation of extravasation of beta-amyloid through the model of blood-brain barrier
    (Basel : MDPI AG, 2020) Zinchenko, Ekaterina; Klimova, Maria; Mamedova, Aysel; Agranovich, Ilana; Blokhina, Inna; Antonova, Tatiana; Terskov, Andrey; Shirokov, Alexander; Navolokin, Nikita; Morgun, Andrey; Osipova, Elena; Boytsova, Elizaveta; Yu, Tingting; Zhu, Dan; Kurths, Juergen; Semyachkina-Glushkovskaya, Oxana
    Alzheimer’s disease (AD) is an incurable pathology associated with progressive decline in memory and cognition. Phototherapy might be a new promising and alternative strategy for the effective treatment of AD, and has been actively discussed over two decades. However, the mechanisms of therapeutic photostimulation (PS) effects on subjects with AD remain poorly understood. The goal of this study was to determine the mechanisms of therapeutic PS effects in beta-amyloid (Aβ)-injected mice. The neurological severity score and the new object recognition tests demonstrate that PS 9 J/cm2 attenuates the memory and neurological deficit in mice with AD. The immunohistochemical assay revealed a decrease in the level of Aβ in the brain and an increase of Aβ in the deep cervical lymph nodes obtained from mice with AD after PS. Using the in vitro model of the blood-brain barrier (BBB), we show a PS-mediated decrease in transendothelial resistance and in the expression of tight junction proteins as well an increase in the BBB permeability to Aβ. These findings suggest that a PS-mediated BBB opening and the activation of the lymphatic clearance of Aβ from the brain might be a crucial mechanism underlying therapeutic effects of PS in mice with AD. These pioneering data open new strategies in the development of non-pharmacological methods for therapy of AD and contribute to a better understanding of the PS effects on the central nervous system. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
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    Photodynamic opening of the blood-brain barrier using different photosensitizers in mice
    (Basel : MDPI, 2019) Semyachkina-Glushkovskaya, Oxana; Borisova, Ekaterina; Mantareva, Vanya; Angelov, Ivan; Eneva, Ivelina; Terskov, Andrey; Mamedova, Aysel; Shirokov, Alexander; Khorovodov, Alexander; Klimova, Maria; Agranovich, Ilana; Blokhina, Inna; Lezhnev, Nikita; Kurths, Jurgen
    In a series of previous studies, we demonstrated that the photodynamic therapy (PDT), as a widely used tool for treatment of glioblastoma multiforme (GBM), also site-specifically opens the blood-brain barrier (BBB) in PDT-dose and age-related manner via reversible disorganization of the tight junction machinery. To develop the effective protocol of PDT-opening of the BBB, here we answer the question of what kind of photosensitizer (PS) is the most effective for the BBB opening. We studied the PDT-opening of the BBB in healthy mice using commercial photosensitizers (PSs) such as 5-aminolevulenic acid (5-ALA), aluminum phthalocyanine disulfonate (AlPcS), zinc phthalocyanine (ZnPc) and new synthetized PSs such as galactose functionalized ZnPc (GalZnPc). The spectrofluorimetric assay of Evans Blue albumin complex (EBAC) leakage and 3-D confocal imaging of FITC-dextran 70 kDa (FITCD) extravasation clearly shows a revisable and dose depended PDT-opening of the BBB toEBACand FITCD associated with a decrease in presence of tight junction (TJ) in the vascular endothelium. The PDT effects on the BBB permeability, TJ expression and the fluorescent signal from the brain tissues are more pronounced in PDT-GalZnPc vs. PDT-5-ALA/AlPcS/ZnPc. These pre-clinical data are the first important informative platform for an optimization of the PDT protocol in the light of new knowledge about PDT-opening of the BBB for drug brain delivery and for the therapy of brain diseases. © 2019 by the authors.