Fighting against amyotrophic lateral sclerosis (ALS) with flavonoids: a computational approach to inhibit superoxide dismutase (SOD1) mutant aggregation.

Protein aggregation is a biological process that occurs when proteins misfold. Misfolding and aggregation of human superoxide dismutase (hSOD1) cause a neurodegenerative disease called amyotrophic lateral sclerosis (ALS). Among the mutations occurring, targeting the E21K mutation could be a good choice to understand the pathological mechanism of SOD1 in ALS, whereof it significantly reduces life hopefulness in patients. Naturally occurring polyphenolic flavonoids have been suggested as a way to alleviate the amyloidogenic behavior of proteins. In this study, computational tools were used to identify promising flavonoid compounds that effectively inhibit the pathogenic behavior of the E21K mutant. Initial screening identified Pelargonidin, Curcumin, and Silybin as promising leads. Molecular dynamics (MD) simulations showed that the binding of flavonoids to the mutated SOD1 caused changes in the protein stability, hydrophobicity, flexibility, and restoration of lost hydrogen bonds. Secondary structure analysis indicated that the protein destabilization and the increased propensity of ß-sheet caused by the mutation were restored to the wild-type state upon binding of flavonoids. Free energy landscape (FEL) analysis was also used to differentiate aggregation, and results showed that Silybin followed by Pelargonidin had the most therapeutic efficacy against the E21K mutant SOD1. Therefore, these flavonoids hold great potential as highly effective inhibitors in mitigating ALS's fatal and insuperable effects.Communicated by Ramaswamy H. Sarma.

Polyphenolic flavonoid compounds act as the inhibitory potential of aggregation process: Implications for the prevention and therapeutics against FALS-associated D101G SOD1 mutant.

Aggregation of proteins is a biological phenomenon caused by misfolded proteins. Human superoxide dismutase (hSOD1) misfolding and aggregation underlie the neurological illness amyotrophic lateral sclerosis (ALS). The most significant contributing factor to ALS is genetic point mutations in SOD1. particularly, D101G mutant is the most harmful because it significantly reduces the life expectancy of patients. Subsequently, the use of natural polyphenolic flavonoids is strongly recommended to reduce the amyloidogenic behavior of protopathic proteins. In this study, using computational parameters such as protein-ligand interaction and molecular dynamics (MD) simulation analyses, we are trying to identify a pharmacodynamically promising flavonoid compound that can effectively inhibit the pathogenic behavior of the D101G mutant. Epigallocatechin-gallate (EGCG), Hesperidin, Isorhamnetin, and Diosmetin were identified as potential leads in a preliminary screening of flavonoids to anti-amyloid action. The results of MD showed that the binding of flavonoids to D101G mutant caused changes in stability, hydrophobicity of protein, and flexibility, as well as significantly led to the restoration of lost hydrogen bonds. Secondary structure analysis showed that protein destabilization and the increased propensity of ß-sheet caused by the mutation were restored to the wild-type state upon binding of flavonoids. Besides, to differentiate aggregation, we elucidated alterations in the free energy landscape (FEL) and dynamic cross-correlation matrix (DCCM) of WT-SOD1 and mutant (unbound /bound) states. Among flavonoids, Epigallocatechin-gallate and Hesperidin had the most therapeutic efficacy against the D101G mutant. Therefore, Epigallocatechin-gallate and Hesperidin promise considerable therapeutic potential to develop highly effective inhibitors in reducing fatal and irreversible ALS.

The endocannabinoid system, a new gatekeeper in the pharmacology of human hepatocellular carcinoma.

Despite numerous prevention methodologies and treatment options, hepatocellular carcinoma (HCC) still remains as the third leading life-threatening cancer. It is thus pertinent to develop new treatment modality to fight this devastating carcinoma. Ample recent studies have shown the anti-inflammatory and antitumor roles of the endocannabinoid system in various forms of cancers. Preclinical studies have also confirmed that cannabinoid therapy can be an optimal regimen for cancer treatments. The endocannabinoid system is involved in many cancer-related processes, including induction of endoplasmic reticulum (ER) stress-dependent apoptosis, autophagy, PITRK and ERK signaling pathways, cell invasion, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) phenotypes. Moreover, changes in signaling transduction of the endocannabinoid system can be a potential diagnostic and prognostic biomarker for HCC. Due to its pivotal role in lipid metabolism, the endocannabinoid system affects metabolic reprogramming as well as lipid content of exosomes. In addition, due to the importance of non-coding RNAs (ncRNAs), several studies have examined the relationship between microRNAs and the endocannabinoid system in HCC. However, HCC is a pathological condition with high heterogeneity, and therefore using the endocannabinoid system for treatment has faced many controversies. While some studies favored a role of the endocannabinoid system in carcinogenesis and tumor induction, others exhibited the anticancer potential of endocannabinoids in HCC. In this review, specific studies delineating the relationship between endocannabinoids and HCC are examined. Based on collected findings, detailed studies of the molecular mechanism of endocannabinoids as well as preclinical studies for investigating therapeutic or carcinogenic impacts in HCC cancer are strongly suggested.

Diabetes as one of the long-term COVID-19 complications: from the potential reason of more diabetic patients' susceptibility to COVID-19 to the possible caution of future global diabetes tsunami.

According to recent researches, people with diabetes mellitus (type 1 and 2) have a higher incidence of coronavirus disease 2019 (COVID-19), which is caused by a SARS-CoV-2 infection. In this regard, COVID-19 may make diabetic patients more sensitive to hyperglycemia by modifying the immunological and inflammatory responses and increasing reactive oxygen species (ROS) predisposing the patients to severe COVID-19 and potentially lethal results. Actually, in addition to COVID-19, diabetic patients have been demonstrated to have abnormally high levels of inflammatory cytokines, increased virus entrance, and decreased immune response. On the other hand, during the severe stage of COVID-19, the SARS-CoV-2-infected patients have lymphopenia and inflammatory cytokine storms that cause damage to several body organs such as ß cells of the pancreas which may make them as future diabetic candidates. In this line, the nuclear factor kappa B (NF-κB) pathway, which is activated by a number of mediators, plays a substantial part in cytokine storms through various pathways. In this pathway, some polymorphisms also make the individuals more competent to diabetes via infection with SARS-CoV-2. On the other hand, during hospitalization of SARS-CoV-2-infected patients, the use of some drugs may unintentionally lead to diabetes in the future via increasing inflammation and stress oxidative. Thus, in this review, we will first explain why diabetic patients are more susceptible to COVID-19. Second, we will warn about a future global diabetes tsunami via the SARS-CoV-2 as one of its long-term complications.

Receptor tyrosine kinase inhibitors in cancer.

Targeted therapy is a new cancer treatment approach, involving drugs that particularly target specific proteins in cancer cells, such as receptor tyrosine kinases (RTKs) which are involved in promoting growth and proliferation, Therefore inhibiting these proteins could impede cancer progression. An understanding of RTKs and the relevant signaling cascades, has enabled the development of many targeted drug therapies employing RTK inhibitors (RTKIs) some of which have entered clinical application. Here we discuss RTK structures, activation mechanisms and functions. Moreover, we cover the potential effects of combination drug therapy (including chemotherapy or immunotherapy agents with one RTKI or multiple RTKIs) especially for drug resistant cancers.

Computational insight into in silico analysis and molecular dynamics simulation of the dimer interface residues of ALS-linked hSOD1 forms in apo/holo states: a combined experimental and bioinformatic perspective.

The aggregation of misfolded SOD1 proteins in neurodegenerative illnesses is a key pathological hallmark in amyotrophic lateral sclerosis (ALS). SOD1 is stabilized and enzymatically activated after binding to Cu/Zn and forming intramolecular disulfide. SOD1 aggregation/oligomerization is triggered by the dissociation of Cu and/or Zn ions. Therefore, we compared the possible effects of ALS-associated point mutations of the holo/apo forms of WT/I149T/V148G SOD1 variants located at the dimer interface to determine structural characterization using spectroscopic methods, computational approaches as well as molecular dynamics (MD) simulations. Predictive results of computational analysis of single-nucleotide polymorphisms (SNPs) suggested that mutant SOD1 has a deleterious effect on activity and structure destabilization. MD data analysis indicated that changes in flexibility, stability, hydrophobicity of the protein as well as increased intramolecular interactions of apo-SOD1 were more than holo-SOD1. Furthermore, a decrease in enzymatic activity in apo-SOD1 was observed compared to holo-SOD1. Comparative intrinsic and ANS fluorescence results of holo/apo-WT-hSOD1 and mutants indicated structural alterations in the local environment of tryptophan residue and hydrophobic patches, respectively. Experimental and MD data supported that substitution effect and metal deficiency of mutants (apo forms) in the dimer interface may promote the tendency to protein mis-folding and aggregation, consequently disrupting the dimer-monomer equilibrium and increased propensity to dissociation dimer into SOD-monomer ultimately leading to loss of stability and function. Overall, data analysis of apo/holo SOD1 forms on protein structure and function using computational and experimental studies will contribute to a better understanding of ALS pathogenicity.

Evaluation of Expression of Cytochrome P450 Aromatase and Inflammatory, Oxidative, and Apoptotic Markers in Testicular Tissue of Obese Rats (Pre)Treated with Garlic Powder.

Today, adolescent obesity is recognized as an epidemic and a cause of reproductive disorders. Decreased testosterone levels occur due to functional defects in the hypothalamus-pituitary axis, excessive activity of cytochrome P450 aromatase enzyme, and testicular dysfunction in these people. Oxidative damage, inflammation, and apoptosis are also the main mechanisms of testicular damage during obesity. The use of herbal products such as garlic can improve this disorder due to its anti-inflammatory and antioxidant properties. Therefore, the aim of this study is to investigate the effect of pretreatment and treatment of garlic powder on the expression of cytochrome P450 aromatase enzyme and the expression of genes involved in testosterone synthesis, inflammation, oxidative damage, apoptosis in testicular tissue, and metabolic function of liver tissue in young male obese rats. Eighty male Wistar rats were divided into the controlled and treated groups. Serum levels of lipid, glucose, and insulin as metabolic factors were measured along with the testicular antioxidant and inflammation markers. The expression of Bcl2, Bax, and caspase-3 along with NF-κB, SREBP-1c, CPT-1beta, Nrf-2, CD36, FAS, CYP19A1, P450scc, StAR, 17ßHSD, PPARα, and aromatase (CYP19, P450arom) was also measured. Testicular histological evaluation and spermatogenic process was also performed. The results showed that oxidative, inflammatory, and metabolic factors significantly increased in obese rats. The testicular expression of aromatase, NF-κB, Bax, and caspase 3 increased and Nrf2 expression decreased in obese rats, while (pre) treatment with garlic powder significantly decreased the expression of these genes in obese rats. These results were also confirmed by the findings of the histological evaluation and sperm analysis. It can be concluded that garlic powder could improve reproductive dysfunction in obese rats.

Zinc binding loop mutations of hSOD1 promote amyloid fibrils under physiological conditions: Implications for initiation of amyotrophic lateral sclerosis.

Neurotoxic species of misfolded hSOD1 are involved in the process of causing amyotrophic lateral sclerosis (ALS), which is a devastating neurodegenerative disease. Considerable evidence exists on that hSOD1 mutants-mediated toxicity is resulted from gain-of-function, while the mechanism of this toxicity is unknown yet. In the present study, we focused on the possible mechanism of two point-mutations (namely L67P and D76Y) on metal-binding sites and their possible consequent effects on ALS progress. For this purpose, the exposed hydrophobic patches were detected using ANS fluorescence and the formation of hSOD1 aggregates was monitored using the ThT fluorescence and absorption spectra of Congo red (CR). Moreover, to assess aggregate's morphology, transmission electron microscopy (TEM) was used. The specific activity of wild-type, as well as L67P and D76Y mutants was obtained as 12345, 8625, and 7066 U/mg, respectively. The existence of ß-sheet-dominated structures was observed under amyloidogenic conditions using far UV CD and FTIR spectroscopy. As well, comparative study of wild-type and mutants by intrinsic and extrinsic fluorescence revealed structural alterations and the increased hydrophobic surface pockets, respectively. The formation of the amyloid fibrils was monitored under destabilizing. The results of ThT and CR showed the process formation of amyloid aggregates and moreover, the presence of morphological forms was confirmed by the TEM image. Overall, our findings supported that mutation in the zinc-binding loop could significantly increase the tendency to mediate amyloid aggregation and it may possibly trigger misfolding and fibrillar aggregation, which are pathological changes in familial forms of ALS.

Green synthesis of silver nanoparticles (AgNPs) by Pistacia terebinthus extract: Comprehensive evaluation of antimicrobial, antioxidant and anticancer effects.

In recent years, because of the various functions associated with silver nanoparticles (AgNPs) in manufacturing, different ways for their synthesis have been established. The antioxidant and antibacterial effects of terebinth (Pistacia terebinthus) have been proven. In this study, for the first time, using the extract of terebinth, we have synthesized AgNPs using a green method. Ultraviolet-visible spectrophotometry, X-ray diffraction (XRD), Infrared spectroscopy (FTIR), and the field emission scanning electron microscopy (FE-SEM) spectroscopy analyses were applied to evaluate and verify the formation of NPs, and the antioxidant, antibacterial and anticancer activity of synthesized AgNPs was also studied. The highest absorption was obtained 24 h following the synthesis at 420 nm because of the Ag + to Ag0 reduction. The functional groups stabilizing activity was obtained by FTIR. Moreover, size and surface morphology were assessed by FE-SEM. The present research showed the AgNPs had spherical shape and had a 32 nm diameter. The face-centered cubic construction of AgNPs was evaluated through XRD method with peaks at 2θ = 37°, 49°, 63°, and 76° (related to the planes of silver 111, 200, 220, 311), respectively. Antimicrobial assessment revealed that the biosynthesized AgNPs had a great antimicrobial activity in response to Gram-positive and Gram-negative strains. Suppression of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was determined to be associated with dosage. In addition, a high anticancer activity, against MCF-7 cell line, was observed for the 25 µg/mL concentration of the AgNPs. Altogether, these results show that biogenic AgNPs can be functioned as beneficial medicinal compounds.

Development of In Silico Analysis and Molecular Dynamics Simulation on L67P and D76Y Mutants of the Human Superoxide Dismutase 1(hSOD1) Related to Amyotrophic Lateral Sclerosis.

Background: One neurodegenerative disorder that is caused by a mutation in the hSOD1 gene is Amyotrophic lateral sclerosis (ALS). Objectives: The current study was developed in order to evaluate the effect exerted by two ALS-associated point mutations, L67P and D76Y are located in the metal-binding loop, on structural characterization of hSOD1 protein using molecular dynamics (MD) simulations and computational predictions. Materials and Methods: In this study, GROMACS was utilized to perform molecular dynamics simulations along with 9 different algorithms such as Predict SNP, PhD-SNP, MAPP, PolyPhen-1, Polyphen-2, SNP, SIFT, SNP&GO, and PMUT for predicting and also evaluating the mutational effect on the structural and conformational characterization of hSOD1. Results: Our study was done by several programs predicting the destabilizing and harmful effect exerted by mutant hSOD1. The deleterious effect of L67P mutation was predicted by MAPP and PhD-SNP algorithms, and D76Y mutation was predicted by 9 algorithms. Comparative studies that were conducted on mutants and wild-type indicated the altar in flexibility and protein conformational stability influenced the metal-binding loop's conformation. The outcomes of the MD exhibited an increase and decrease of flexibility for D76Y and L67P mutants compared to the wild type, respectively. On the other hand, analysis of the gyration radius indicated lower and higher compactness for D76Y and L67P, respectively, suggesting that replacing amino acid at the metal-binding loop can alter the protein compactness compared with the protein the wild type. Conclusions: Overall, these findings provided insight into the effect of mutations on the hSOD1, which leads to neurodegeneration disorders in humans. The results show that the mutations of L67P and D76Y influence the stability of protein conformational and flexibility associated with ALS disease. Thus, results of such mutations are can be a prerequisite to achieve a thorough understanding of ALS pathogenicity.