[
International Worm Meeting,
2021]
Alzheimer's disease (AD) is the most important neurodegenerative disorder, with no effective cure. The epigenetic control of gene expression might be affected by the addition and/or removal of post-translational changes. Alterations of these modifications are linked with altered gene expression, resulting in cognitive decline. G9a is a lysine methyltransferase that forms a heterodimeric complex able to mono- and di-methylate lysine 9 of histone H3 (H3K9me1 and H3K9me2) of the N-terminal tail. Those epigenetic modifications lead to transcription repression, synaptic plasticity reduction, autophagy dysfunction, increased OS, and neuroinflammation. Hence, we hypothesize that overexpression of the G9a and its repressive mark serves as a driver of the repression of learning memory genes. Novel strategies are based on the synthesis of epigenetic drugs, regulating gene expression and translation modifications. While several small-molecules have been published to inhibit G9a, one of the most common problems of the firsts inhibitors, as BIX01294, is that the concentration values of the toxicity range and the last activity were akin one to the other, strongly limiting its uses. Moreover, these inhibitors were not or low effective in in vivo studies. In our study, several compounds were identified as a potential inhibitor through structure-based virtual screening of the Cambridge CNS MPO library of more than 4,50,000 compounds against G9a (PDB id: 5TTF) Maestro software (Schrodinger), and further in vivo screenings. Firstly, we assessed the IC50 of eleven compounds using AlphaLISA technology. To identify the best new candidates G9a inhibitors for AD, a compound screening method using transgenic Caenorhabditis elegans (C. elegans) was used to characterize and select the most promising results for further studies. Among all the compounds, four were confirmed as the best candidates through different in vivo assays, such as food clearance and motility assays, which revealed that toxicity/function ranges were safe in C. elegans. The treatment with all G9a inhibitors recovered the age-dependent paralysis presented by the CL2006 strain, like the well-established G9a inhibitor, UNC0638. Thus, this work presents 4 candidates (called "CAB1, CAB2, CAB3 and CAB4") as inhibitors of G9a with novel structures, providing both leads in G9a inhibitors design and demonstrating the participation in AD pathology.
[
International Worm Meeting,
2021]
Neurodegenerative diseases such as Alzheimer's disease (AD) are well recognized as major public health problems in the aged population. Recognized events in AD include cognitive impairment, oxidative stress (OS), AB plaques accumulation in brain tissue. The current drugs to treat AD no cure or reduce the progression of the disease. Thus, the study of different extracts can provide a wealth of bioactive compounds and their combination, which can exert a new strategy for several neurodegenerative diseases, including AD. Among the natural extracts, Ginkgo biloba is one of the most investigated herbal remedies for cognitive disorders and AD. Moreover, docosahexaenoic acid (DHA), and Pinitol and Ursolic acid (UA) are associated to a prophylactic role in certain age-related diseases with particular emphasis on some of the effects of certain degenerative diseases. This study aimed to investigate the synergistic neuroprotective effects of mixed extract composed by different concentrations of DHA (150 microM), Ginkgo (120 microM) Pinitol (105 microM), and UA (35 microM) from Biosearch Life product, including OS tolerance, Thioflavin-S staining AB plaques, and lifespan in several transgenic Caenorhabditis elegans (C. elegans) as well as cognitive performance in C. elegans and senescence-accelerated prone mice 8 (SAMP8) model. Firstly, we found a significantly higher survival percentage in C. elegans treated with Mix extract group in comparison with the single extract treated groups (DHA 150 microM group, Ginkgo 120 microM group, Pinitol 105 microM group, UA 35 microM group), reaching the Vitamin C group. Likewise, we found a significantly increased the lifespan in C. elegans Mix extract-treated group compared to the other groups, suggesting the synergistic effects. Remarkably, we determined a significant reduction in AB plaques accumulation in C. elegans strain CL2006 Mix extract group compared to other groups, including all treated groups, confirming the synergistic effect again. Finally, we demonstrated better cognitive performance in the Mix extract group in both AD models (neuronal AB C. elegans strain CL2355 and SAMP8 mice model), confirming the molecular result and demonstrating the synergist effects of this Mix extract. Taken together, our results demonstrated the potential therapeutic strategy for AD of this new Mix extract product from Biosearch Life.