Novel Molecular Targets and Mechanisms for Neuroprotective Modulation in Neurodegenerative Disorders.

BACKGROUND: Neuronal death underlies the symptoms of several human neurological disorders, including Alzheimer's, Parkinson's and Huntington's diseases, and amyotrophic lateral sclerosis and their precise pathophysiology have not yet been elucidated. According to various studies, the prohibition is the best therapy with neuroprotective approaches, which are advanced and safe methods. METHODS: This review summarizes some of the already-known and newly emerged neuroprotective targets and strategies and their experimental effects have also been reported. Accordingly, literature was studied from 2000 to 2021, and appropriate articles were searched in Google Scholar and Scopus with the keywords given in the keywords section of the current review. RESULTS: Lewy bodies are the histopathologic characteristics of neurodegenerative disorders and are protein-rich intracellular deposits in which Alpha-synuclein is its major protein. Alphasynuclein's toxic potential provides a compelling rationale for therapeutic strategies aimed at decreasing its burden in neuronal cells through numerous pathways, including ubiquitin-proteasome system and autophagy-lysosome pathway, proteolytic breakdown via cathepsin D, kallikrein-6 (neurosin), calpain-1 or MMP9, heat shock proteins, and proteolysis targeting chimera which consists of a target protein-ligand and an E3 ubiquitin ligase (E3) followed by target protein ubiquitination (PROTACs). Other targets that have been noticed recently are the mutant huntingtin, tau proteins and glycogen synthase kinase 3ß; their accumulation proceeds extensive neuronal damage and up to the minute approach such as proteolysis targeting chimera promotes its degradation in cells. Various studies demonstrated that Mendelian gene mutations can result in neurodegenerative diseases. An additional target that has gained much interest is epigenetics, such as mutation, phosphodiesterase, RNA binding proteins and Nuclear respiratory factor 1. CONCLUSION: The novel molecular targets and new strategies compiled and introduced here can be used by scientists to design and discover more efficient small molecule drugs against neurodegenerative diseases. And also, the genes in which their mutations can lead to the α-synuclein aggregation or accumulation have been discussed and considered a valuable information on epigenetics in dementia.

A crystallographic and theoretical study of an (E)-2-Hydroxyiminoethanone derivative: prediction of cyclooxygenase inhibition selectivity of stilbenoids by MM-PBSA and the role of atomic charge.

We recently reported that the hydroxyiminoethanone derivative, (E)-OXM, behaves as a highly selective COX-1 inhibitor (COX-1 SI = 833), and also an interesting scaffold with unique characteristics. In the current study, a comprehensive crystallographic and computational study was performed to elucidate its conformational stability and pharmacological activity. Its conformational energy was studied at the B3LYP/6-311G** level of theory and compared to the single-crystal X-ray diffraction data. In addition, computational studies of three structurally different stilbenoid derivatives used as selective COX-1 or COX-2 inhibitors were undertaken to predict their COX selectivity potentials. Flexible docking was performed for all compounds at the active site of both COX-1 and COX-2 enzymes by considering some of the key residues as flexible during the docking operation. In the next step, molecular dynamic simulation and binding free energy calculations were performed by MM-PBSA. Final results were found to be highly dependent on the atomic charges of the inhibitors and the choice of force field used to calculate the atomic charges. The binding conformation of the hydroxyiminoethanone derivative is highly correlated with the type of COX isoform inhibited. Our predictive approach can truly predict the cyclooxygenase inhibition selectivity of stilbenoid inhibitors.

In vitro and in silico evaluation of P-glycoprotein inhibition through 99m Tc-methoxyisobutylisonitrile uptake.

P-glycoprotein (P-gp) is a multidrug resistance (MDR) transporter with unknown structural details. This macromolecule is normally responsible for extruding xenobiotics from normal cells. Overexpression of P-gp in tumor cells is a major obstacle in cancer chemotherapy. In this study, human 3D model of P-gp was built by homology modeling based on mouse P-gp crystallographic structure and stabilized through 1 ns molecular dynamics (MD) simulation. Stabilized human P-gp structure was used for flexible docking of 80 drugs into the putative active site of P-gp. Accordingly, digoxin, itraconazole, risperidone, ketoconazole, prazosin, verapamil, cyclosporine A, and ranitidine were selected for further in vitro assay. Subsequently, cell-based P-gp inhibition assay was performed on Caco-2 cells while 99m Tc-methoxyisobutylisonitrile (MIBI) was used as a P-gp efflux substrate for calculating IC50 values. Results of the 99m Tc-MIBI uptake in drug-treated Caco-2 cells were in agreement with the previously reported activities. This study for the first time described the relation between molecular dynamics and flexible docking with cellular experiments using 99m Tc-MIBI radiotracer for evaluation of potencies of P-gp inhibitors. Finally, results showed that our radiotracer-cell-based assay is an accurate and fast screening tool for detecting P-gp inhibitors and non-inhibitors in drug development process.