Herein we gathered updated knowledge regarding the alterations of gut microbiota (dysbiosis) and its correlation with human neurodegenerative and brain-related diseases, e.g., Alzheimer’s and Parkinson’s. This review underlines the importance of gut-derived metabolites and gut metabolic status as the main players in gut-brain crosstalk and their implications on the severity of neural conditions. Scientific evidence indicates that the administration of probiotic bacteria exerts beneficial and protective effects as reduced systemic inflammation, neuroinflammation, and inhibited neurodegeneration. The experimental results performed on animals, but also human clinical trials, show the importance of designing a novel microbiota-based probiotic dietary supplementation with the aim to prevent or ease the symptoms of Alzheimer’s and Parkinson’s diseases or other forms of dementia or neurodegeneration.

Immunosenescence in monocytes has been shown to be associated with several biochemical and functional changes, including development of senescence-associated secretory phenotype (SASP), which may be inhibited by klotho protein. To date, it was believed that SASP activation is associated with accumulating DNA damage. However, some literature data suggest that endoplasmic reticulum and Golgi stress pathways may be involved in SASP development. Thus, the aim of this study was to investigate the role of klotho protein in the regulation of immunosenescence-associated Golgi apparatus and ER stress response induced by bacterial antigens in monocytes. We provide evidence that initiation of immunosenescent-like phenotype in monocytes is accompanied by activation of CREB34L and TFE3 Golgi stress response and ATF6 and IRE1 endoplasmic reticulum stress response, while klotho overexpression prevents these changes. Further, these changes are followed by upregulated secretion of proinflammatory cytokines, which final modification takes place exclusively in the Golgi apparatus. In conclusion, we provide for the first time evidence of klotho involvement in the crosstalk on the line ER-Golgi, which may, in turn, affect activation of SASP. This data may be useful for a novel potential target for therapy in age-related and chronic inflammatory conditions.

Depression is a serious medical condition, typically treated by antidepressants. Conventional monotherapy can be effective only in 60–80% of patients, thus modern psychiatry deals with the challenge of new methods development. At the same moment, interactions between antidepressants and the occurrence of potential side effects raise serious concerns, which are even more exacerbated by the lack of relevant data on exact molecular mechanisms. Therefore, the aims of the study were to provide up-to-date information on the relative mechanisms of action of single antidepressants and their combinations. In this study, we evaluated the effect of single and combined antidepressants administration on mouse hippocampal neurons after 48 and 96 h in terms of cellular and biochemical features in vitro. We show for the first time that co-treatment with amitriptyline/imipramine + fluoxetine initiates in cells adaptation mechanisms which allow cells to adjust to stress and finally exerts less toxic events than in cells treated with single antidepressants. Antidepressants treatment induces in neuronal cells oxidative and nitrosative stress, which leads to micronuclei and double-strand DNA brakes formation. At this point, two different mechanistic events are initiated in cells treated with single and combined antidepressants. Single antidepressants (amitriptyline, imipramine or fluoxetine) activate cell cycle arrest resulting in proliferation inhibition. On the other hand, treatment with combined antidepressants (amitriptyline/imipramine + fluoxetine) initiates p16-dependent cell cycle arrest, overexpression of telomere maintenance proteins and finally restoration of proliferation. In conclusion, our findings may pave the way to better understanding of the stress-related effects on neurons associated with mono- and combined therapy with antidepressants.