In silico screening and identification of potential GSK3β inhibitors

Poly(N-acryloylglycine-acrylamide) Hydrogel Mimics the Cellular Microenvironment and Promotes Neurite Growth with Protection from Oxidative Stress

In this work, the glycine-based acryloyl monomer is polymerized to obtain a neurogenic polymeric hydrogel for regenerative applications. The synthesized poly(N-acryloylglycine-acrylamide) [poly(NAG-b-A)] nanohydrogel exhibits high swelling (∼1500%) and is mechanically very stable, biocompatible, and proliferative in nature. The poly(NAG-b-A) nanohydrogel provides a stable 3D extracellular mimetic environment and promotes healthy neurite growth for primary cortical neurons by facilitating cellular adhesion, proliferation, actin filament stabilization, and neuronal differentiation. Furthermore, the protective role of the poly(NAG-b-A) hydrogel for the neurons in oxidative stress conditions is revealed and it is found that it is a clinically relevant material for neuronal regenerative applications, such as for promoting nerve regeneration via GSK3β inhibition. This hydrogel additionally plays an important role in modulating the biological microenvironment, either as an agonist and antagonist or as an antioxidant. Furthermore, it favors the physiological responses and eases the neurite growth efficiency. Additionally, we found out that the conversion of glycine-based acryloyl monomers into their corresponding polymer modulates the mechanical performance, mimics the cellular microenvironment, and accelerates the self-healing capability due to the responsive behavior towards reactive oxygen species (ROS). Thus, the p(NAG-b-A) hydrogel could be a potential candidate to induce neuronal regeneration since it provides a physical cue and significantly boosts neurite outgrowth and also maintains the microtubule integrity in neuronal cells.

Role of GSK-3β Inhibitors: New Promises and Opportunities for Alzheimer's Disease

Glycogen synthase kinase-3 (GSK-3) was discovered to be a multifunctional enzyme involved in a wide variety of biological processes, including early embryo formation, oncogenesis, as well cell death in neurodegenerative diseases. Several critical cellular processes in the brain are regulated by the GSK-3β, serving as a central switch in the signaling pathways. Dysregulation of GSK-3β kinase has been reported in diabetes, cancer, Alzheimer's disease, schizophrenia, bipolar disorder, inflammation, and Huntington's disease. Thus, GSK-3β is widely regarded as a promising target for therapeutic use. The current review article focuses mainly on Alzheimer's disease, an age-related neurodegenerative brain disorder. GSK-3β activation increases amyloid-beta (Aβ) and the development of neurofibrillary tangles that are involved in the disruption of material transport between axons and dendrites. The drug-binding cavities of GSK-3β are explored, and different existing classes of GSK-3β inhibitors are explained in this review. Non-ATP competitive inhibitors, such as allosteric inhibitors, can reduce the side effects compared to ATP-competitive inhibitors. Whereas ATP-competitive inhibitors produce disarrangement of the cytoskeleton, neurofibrillary tangles formation, and lead to the death of neurons, etc. This could be because they are binding to a site separate from ATP. Owing to their interaction in particular and special binding sites, allosteric ligands interact with substrates more selectively, which will be beneficial in resolving drug-induced resistance and also helpful in reducing side effects. Hence, in this review, we focussed on the allosteric GSK-3β inhibitors and discussed their futuristic opportunities as anti-Alzheimer's compounds.

Screening of Azadirachta indica phytoconstituents as GSK-3β inhibitor and its implication in neuroblastoma: molecular docking, molecular dynamics, MM-PBSA binding energy, and in-vitro study

Glycogen synthase kinase-3 (GSK-3), a constitutively active serine/threonine kinase, primary regulator of various cellular activities varying from glycogen metabolism to cell proliferation and regulation. GSK-3β is associated with the pathogenesis of numerous human diseases, including cancer, metabolic disorder, and Alzheimer's disease. In this study, Azadirachta indica compounds were selected and further screened on the BOILED-Egg model. The compounds showing good GIT absorption were docked with the crystal structure of GSK-3β. The compounds with high docking score were submitted for the molecular dynamic simulation (MDS) and Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA). Based upon the MDS and MM-PBSA study, gedunin showed the highest binding energy throughout the MDS process. Gedunin was isolated from the Azadirachta indica, and its efficacy on GSK-3β inhibition was studied in the human neuroblastoma (SH-SY5Y) cells. Gedunin induced apoptosis and anti-proliferative activity by arresting G2/M phase, as evident by cell-cycle analysis. From immunoblot study, gedunin significantly enhanced the expression of an inhibitory form of GSK-3β (p-GSK-3β Ser9) in concentration-dependent manner. Our findings demonstrate that gedunin may act as an effective GSK-3β inhibitor suggesting that this compound may be used for the management of neuroblastoma. Further preclinical and clinical investigation is desirable.Communicated by Ramaswamy H. Sarma.

In-silico design and ADMET predictions of some new imidazo[1,2-a]pyridine-3-carboxamides (IPAs) as anti-tubercular agents

Tuberculosis (TB) is one of the leading infectious diseases worldwide even with the ravaging COVID-19 pandemic in recent times. This mandated further search and exploration of more possible anti-TB drug candidates against M. tuberculosis strains. As an extension of our previous work on the homology modeled cytochrome b subunit of the bc1 complex (QcrB) of Mycobacterium tuberculosis, an in-silico design was carried out in order to further explore more newly potential anti-TB compounds. Ligand 26 was selected as the lead template (scaffold A) based on our previous docking results and its less bulky structure. Successively, eight (8) new ligands (A1–A8) were designed with better binding affinities in comparison to the scaffold template (−6.8 kcal/mol) and isoniazid standard drug (−6.00 kcal/mol) respectively. In addition, three (3) designed ligands namely, A6, A2, and A7 with higher binding affinities were validated via ADME and toxicity prediction analysis, and the results showed zero violations of Lipinski rules with similar bioavailability, and high rate in gastrointestinal absorption, while toxicity parameters such as carcinogenicity and cytotoxicity were all predicted as non-toxic (inactiveness). The designed IPA compounds in the present study could serve as a promising gateway that could help the medicinal and synthetic chemist in the exploration of a new set of derivatives as anti-TB agents. Therefore, this research strongly recommends further experimental consideration of the newly designed IPA compounds through synthesis, in-vitro and in-vivo studies to validate the theoretical findings.

Current trends in computer aided drug design and a highlight of drugs discovered via computational techniques: A review

Computer-aided drug design (CADD) is one of the pivotal approaches to contemporary pre-clinical drug discovery, and various computational techniques and software programs are typically used in combination, in a bid to achieve the desired outcome. Several approved drugs have been developed with the aid of CADD. On SciFinder®, we evaluated more than 600 publications through systematic searching and refining, using the terms, virtual screening; software methods; computational studies and publication year, in order to obtain data concerning particular aspects of CADD. The primary focus of this review was on the databases screened, virtual screening and/or molecular docking software program used. Furthermore, we evaluated the studies that subsequently performed molecular dynamics (MD) simulations and we reviewed the software programs applied, the application of density functional theory (DFT) calculations and experimental assays. To represent the latest trends, the most recent data obtained was between 2015 and 2020, consequently the most frequently employed techniques and software programs were recorded. Among these, the ZINC database was the most widely preferred with an average use of 31.2%. Structure-based virtual screening (SBVS) was the most prominently used type of virtual screening and it accounted for an average of 57.6%, with AutoDock being the preferred virtual screening/molecular docking program with 41.8% usage. Following the screening process, 38.5% of the studies performed MD simulations to complement the virtual screening and GROMACS with 39.3% usage, was the popular MD software program. Among the computational techniques, DFT was the least applied whereby it only accounts for 0.02% average use. An average of 36.5% of the studies included reports on experimental evaluations following virtual screening. Ultimately, since the inception and application of CADD in pre-clinical drug discovery, more than 70 approved drugs have been discovered, and this number is steadily increasing over time.

High-throughput screening of natural compounds and inhibition of a major therapeutic target HsGSK-3β for Alzheimer's disease using computational approaches

BACKGROUND

Alzheimer's disease is a leading neurodegenerative disease worldwide and is the 6th leading cause of death in the USA. AD is a very complex disease and the drugs available in the market cannot fully cure it. The glycogen synthase kinase 3 beta plays a major role in the hyperphosphorylation of tau protein which forms the neurofibrillary tangles which is a major hallmark of AD. In this study, we have used a series of computational approaches to find novel inhibitors against GSK-3β to reduce the TAU hyperphosphorylation.

RESULTS

We have retrieved a set of compounds (n=167,741) and screened against GSK-3β in four sequential steps. The resulting analysis of virtual screening suggested that 404 compounds show good binding affinity and can be employed for pharmacokinetic analysis. From here, we have selected 20 compounds those were good in terms of pharmacokinetic parameters. All these compounds were re-docked by using Autodock Vina followed by Autodock. Four best compounds were employed for MDS and here predicted RMSD, RMSF, Rg, hydrogen bonds, SASA, PCA, and binding-free energy. From all these analyses, we have concluded that out of 167,741 compounds, the ZINC15968620, ZINC15968622, and ZINC70707119 can act as lead compounds against HsGSK-3β to reduce the hyperphosphorylation.

CONCLUSION

The study suggested three compounds (ZINC15968620, ZINC15968622, and ZINC70707119) have great potential to be a drug candidate and can be tested using in vitro and in vivo experiments for further characterization and applications.

SRV2 promotes mitochondrial fission and Mst1-Drp1 signaling in LPS-induced septic cardiomyopathy

Mitochondrial fission is associated with cardiomyocyte death and myocardial depression, and suppressor of ras val-2 (SRV2) is a newly discovered pro-fission protein. In this study, we examined the mechanisms of SRV2-mediated mitochondrial fission in septic cardiomyopathy. Western blotting, ELISA, and immunofluorescence were used to evaluate mitochondrial function, oxidative balance, energy metabolism and caspase-related death, and siRNA and adenoviruses were used to perform loss- and gain-of-function assays. Our results demonstrated that increased SRV2 expression promotes, while SRV2 knockdown attenuates, cardiomyocyte death in LPS-induced septic cardiomyopathy. Mechanistically, SRV2 activation promoted mitochondrial fission and physiological abnormalities by upregulating oxidative injury, ATP depletion, and caspase-9-related apoptosis. Our results also demonstrated that SRV2 promotes mitochondrial fission via a Mst1-Drp1 axis. SRV2 knockdown decreased Mst1 and Drp1 levels, while Mst1 overexpression abolished the mitochondrial protection and cardiomyocyte survival-promoting effects of SRV2 knockdown. SRV2 is thus a key novel promotor of mitochondrial fission and Mst1-Drp1 axis activity in septic cardiomyopathy.