Mechanistic insights into MARK4 inhibition by galantamine toward therapeutic targeting of Alzheimer’s disease

Introduction: Hyperphosphorylation of tau is an important event in Alzheimer’s disease (AD) pathogenesis, leading to the generation of “neurofibrillary tangles,” a histopathological hallmark associated with the onset of AD and related tauopathies. Microtubule-affinity regulating kinase 4 (MARK4) is an evolutionarily conserved Ser-Thr (S/T) kinase that phosphorylates tau and microtubule-associated proteins, thus playing a critical role in AD pathology. The uncontrolled neuronal migration is attributed to overexpressed MARK4, leading to disruption in microtubule dynamics. Inhibiting MARK4 is an attractive strategy in AD therapeutics.Methods: Molecular docking was performed to see the interactions between MARK4 and galantamine (GLT). Furthermore, 250 ns molecular dynamic studies were performed to investigate the stability and conformational dynamics of the MARK4–GLT complex. We performed fluorescence binding and isothermal titration calorimetry studies to measure the binding affinity between GLT and MARK4. Finally, an enzyme inhibition assay was performed to measure the MARK4 activity in the presence and absence of GLT.Results: We showed that GLT, an acetylcholinesterase inhibitor, binds to the active site cavity of MARK4 with an appreciable binding affinity. Molecular dynamic simulation for 250 ns demonstrated the stability and conformational dynamics of the MARK4–GLT complex. Fluorescence binding and isothermal titration calorimetry studies suggested a strong binding affinity. We further show that GLT inhibits the kinase activity of MARK4 significantly (IC50 = 5.87 µM).Conclusion: These results suggest that GLT is a potential inhibitor of MARK4 and could be a promising therapeutic target for AD. GLT’s inhibition of MARK4 provides newer insights into the mechanism of GLT’s action, which is already used to improve cognition in AD patients

Cytoplasmic amino acid profiles of clinical and ATCC 29213 strains of Staphylococcus aureus harvested at different growth phases

Staphylococcus aureus strains are a great contributor to both hospital acquired infections as well as community acquired infections. The objective of the present investigation was to compare potential differences in cytoplasmic amino acid levels between clinical and ATCC 29213 strains of S. aureus. The two strains were grown under ideal conditions to mid-exponential and stationary growth phases, after which they were harvested to analyze their amino acid profiles. Initially, the amino acid patterns of both strains were compared at the mid-exponential phase when grown in controlled conditions. At the mid-exponential phase, both strains shared common features in cytoplasmic amino acid levels, with glutamic acid, aspartic acid, proline, and alanine identified as key amino acids. However, the concentration profiles of seven amino acids exhibited major variances between the strains, even though the total cytoplasmic levels of amino acids did not alter significantly. At the stationary phase, the magnitudes of the amino acids abundant in the mid-exponential phase were altered. Aspartic acid became the most abundant amino acid in both strains accounting for 44% and 59% of the total amino acids in the clinical and ATCC 29213 strains, respectively. Lysine was the second most abundant amino acid in both strains, accounting for 16% of the total cytoplasmic amino acids, followed by glutamic acid, the concentration of which was significantly higher in the clinical strain than in the ATCC 29213 strain. Interestingly, histidine was clearly present in the clinical strain but was virtually lacking in the ATCC 29213 strain. This study reveals the dynamic diversity of amino acid levels among strains, which is an essential step toward illustrating the variability in S. aureus cytoplasmic amino acid profiles and could be significant in explaining variances among strains of S. aureus

Biosurfactant derived from probiotic Lactobacillus acidophilus exhibits broad-spectrum antibiofilm activity and inhibits the quorum sensing-regulated virulence

Antimicrobial resistance by pathogenic bacteria has become a global risk to human health in recent years. The most promising approach to combating antimicrobial resistance is to target virulent traits of bacteria. In the present study, a biosurfactant derived from the probiotic strain Lactobacillus acidophilus was tested against three Gram-negative bacteria to evaluate its inhibitory potential on their biofilms, and whether it affected the virulence factors controlled by quorum sensing (QS). A reduction in the virulence factors of Chromobacterium violaceum (violacein production), Serratia marcescens (prodigiosin production) and Pseudomonas aeruginosa (pyocyanin, total protease, LasB elastase and LasA protease production) was observed at different sub-MIC concentrations in a dose-dependent manner. Biofilm development was reduced by 65.76%, 70.64% and 58.12% at the highest sub-MIC levels for C. violaceum, P. aeruginosa and S. marcescens, respectively. Biofilm formation on glass surfaces exhibited significant reduction, with less bacterial aggregation and reduced formation of extracellular polymeric materials. Additionally, swimming motility and exopolysaccharides (EPS) production were shown to be reduced in the presence of the L. acidophilus-derived biosurfactant. Furthermore, molecular docking analysis performed on compounds identified through gas chromatography–mass spectrometry (GC-MS) analysis of QS and biofilm proteins yielded further insights into the mechanism underlying the anti-QS activity. Therefore, the present study has clearly demonstrated that a biosurfactant derived from L. acidophilus can significantly inhibit virulence factors of Gram-negative pathogenic bacteria. This could provide an effective method to inhibit the formation of biofilms and QS in Gram-negative bacteria

Population Genetics of European Anchovy (<i>Engraulis encrasicolus</i> L.) in the Seas of Turkey Based on Microsatellite DNA

The European anchovy Engraulis encrasicolus (Linnaeus, 1758) is a small pelagic fish included Actinopterygii has considerable economical importance in fisheries. Distribution area of European anchovy is shallow waters (0-400m) of Black and Azov seas, Mediterranean and Atlantic coastline of Europe. In this study we examined 13 microsatellite loci in total 541 individual genotype data to determine population genetic structuring and genetic stocks of European anchovy in the Turkish territorial waters. Material and Methods: Localities where anchovy samples collected were as follows: (1) the eastern Mediterranean Sea (İskenderun and Mersin Bay), (2) the western Mediterranean Sea (Antalya) (3) the Aegean Sea (Kuşadası), (4) the Marmara Sea (İstanbul and Bandırma), (5) the western Black Sea (Zonguldak), (6) mid-Black Sea (Terme, Perşembe and Fatsa) and (7) the eastern Black Sea (Trabzon, Ardeşen and Batumi). Microsatellite genotypes of anchovy samples were scored using GeneMarker software v 2.2.0 (SoftGeneticsLLC). Allele numbers in each locus and each population, observed-expected heterozygosity (Ho, He), pairwise FST values were calculated and deviations from Hardy-Weinberg (HW) equilibrium tested with Fisher exact test Markov Chain algorithm (Guo and Thomson, 1992) using Arlequin ver. 3.5.1.3 (Excoffier, 2010). Hierarchical analysis of molecular variance (AMOVA) was carried out for determination of population structuring and genetic differentiation between population and groups were tested with both infinite allele mutational (IAM) model and step-wise mutation model (SMM) using Arlequin software. Allelic richness and FIS (Weir and Cockerham, 1984) values between populations were calculated by FSTAT v 2.9.3.2 (Goudet, 2001). The computer GenAlEx v 6.5 (Peakall and Smouse, 2012) was used to calculate private alleles of populations. Genetic variation between populations was determined based on Nei’s genetic distance (Nei, 1978) using Unweigted Pair Group Method with Arithmetic Mean (UPGMA). For this aim Tools for Population Genetic Analyses (TFPGA) v 1.3 (Miller, 1997) was used to create UPGMA three has 10000-permutation bootstrap value per branch. In multidimensional space to see genetic differentiation of individuals Fractional Correspondence Analyses (FCA) (Lebart, et al,.1984) test was executed using Genetix 4.05.2 (Belkhir et al., 2004) software. To infer how many genetic group was structured in anchovies of Turkish territories we performed Bayesian approach implemented by STRUCTURE ver 2.3 (Pritchard et al., 2000) computer program. Results: In this study, 13 microsatellite loci in 541 samples were analysed for determination of genetic structure of anchovy along Turkish coasts. The genetic variability was high among population, the average alleles numbers per locus per population ranged from 11.0 to 22.8. Observed heterozygosity per population was ranged from 0.612 (Mersin) to 0.733 (İstanbul) while expected heterozygosity was ranged from 0.774 (Mersin) to 0.823 (Perşembe). The highest genetic distance was found between Antalya and Trabzon populations (FST=0.06949), the lowest between Antalya and İskenderun populations (0,00010). Analyses of 13 microsatellite loci were showed that there was low population structuring among all anchovy population (Fst: 0,024; SE 0,005). Although high genetic diversities was detected, for most loci with most populations were showed Hardy-Weinberg disequilibrium. Genetic distance analyses showed up Mediterranean specimens were highly distinct from Aegean and Black sea populations. Aegean populations were closer to Black sea populations because of higher gene flow between them rather than Mediterranean. A STRUCTURE computer program was indicated the presence of four possible genetic groups in Turkish territorial waters. Conclusions: Data to obtained from this study has found useful for the identification of genetic structuring of European anchovy distributed along the coasts of Turkish Seas. Results are also useful for planning of fishery management of anchovies in Turkey

Distribution of N-acetyltransferase Type 1 (NAT1) genotypes and alleles in a Turkish population

NAT1 is an intronless gene on chromosome 8p21.3 encoding a 290-amino-acid-long protein showing acetyltransferase activity. Some 26 alleles of NAT1 gene have been identified in human populations. In the present study we determined the distributions of NAT1 genotypes and alleles in a sample of 201 individuals from the Turkish population in Central Anatolia. The most frequent genotypes were NAT1*4/NAT1*4 (51.74%), NAT1*10/NAT1*4 (22.39%), NAT1*11/NAT1*4 (7.46), NAT1*10/NAT1*10 (3.98%). Frequencies of NAT1*3, *4 (wild-type), *10 and *11 alleles were 3.73%, 69.6%, 17.66% and 7.2%, respectively. The frequency of NAT1*11 was the highest amongst the populations studied so far, the other allele frequencies being close to those described in Caucasian populations

Chloroquine and Hydroxychloroquine Interact Differently with ACE2 Domains Reported to Bind with the Coronavirus Spike Protein: Mediation by ACE2 Polymorphism

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection inducing coronavirus disease 2019 (COVID-19) is still an ongoing challenge. To date, more than 95.4 million have been infected and more than two million deaths have been officially reported by the WHO. Angiotensin-converting enzyme (ACE) plays a key role in the disease pathogenesis. In this computational study, seventeen coding variants were found to be important for ACE2 binding with the coronavirus spike protein. The frequencies of these allele variants range from 3.88 × 10−3 to 5.47 × 10−6 for rs4646116 (K26R) and rs1238146879 (P426A), respectively. Chloroquine (CQ) and its metabolite hydroxychloroquine (HCQ) are mainly used to prevent and treat malaria and rheumatic diseases. They are also used in several countries to treat SARS-CoV-2 infection inducing COVID-19. Both CQ and HCQ were found to interact differently with the various ACE2 domains reported to bind with coronavirus spike protein. A molecular docking approach revealed that intermolecular interactions of both CQ and HCQ exhibited mediation by ACE2 polymorphism. Further explorations of the relationship and the interactions between ACE2 polymorphism and CQ/HCQ would certainly help to better understand the COVID-19 management strategies, particularly their use in the absence of specific vaccines or drugs

Chloroquine and Hydroxychloroquine Interact Differently with ACE2 Domains Reported to Bind with the Coronavirus Spike Protein: Mediation by ACE2 Polymorphism

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection inducing coronavirus disease 2019 (COVID-19) is still an ongoing challenge. To date, more than 95.4 million have been infected and more than two million deaths have been officially reported by the WHO. Angiotensin-converting enzyme (ACE) plays a key role in the disease pathogenesis. In this computational study, seventeen coding variants were found to be important for ACE2 binding with the coronavirus spike protein. The frequencies of these allele variants range from 3.88 &times; 10&minus;3 to 5.47 &times; 10&minus;6 for rs4646116 (K26R) and rs1238146879 (P426A), respectively. Chloroquine (CQ) and its metabolite hydroxychloroquine (HCQ) are mainly used to prevent and treat malaria and rheumatic diseases. They are also used in several countries to treat SARS-CoV-2 infection inducing COVID-19. Both CQ and HCQ were found to interact differently with the various ACE2 domains reported to bind with coronavirus spike protein. A molecular docking approach revealed that intermolecular interactions of both CQ and HCQ exhibited mediation by ACE2 polymorphism. Further explorations of the relationship and the interactions between ACE2 polymorphism and CQ/HCQ would certainly help to better understand the COVID-19 management strategies, particularly their use in the absence of specific vaccines or drugs

Genetic Structure of Anchovy Engraulis encrasicolus in the Adriatic Sea using Microsatellite DNA Analysis

Stock structure analysis of anchovy from the Rovinj, Maslenica and Island of Korčulain in the Adriatic Sea was carried out by using 13 microsatellite loci. Overall, 259 alleles were detected in 13 loci, the number of alleles per locus and population ranged from 4 to 28. The allelic richness of overall loci was found to be highest in the Rovinj population and lowest in the Island of Korčula population. The highest and lowest value of population specific alleles was found in the Rovinj population and Island of Korčula population, respectively. Observed heterozygosity per population was ranged from 0.714 (Rovinj) to 0.678 (Maslenica). Pairwise FST values revealed that there is no significant genetic differences between populations (P>0.05). However, the highest and lowest genetic distance were found between the Rovinj and Maslenica populations (FST=0.00626) and between the Island of Korčula and Maslenica populations, respectively. The UPGMA dendrogram clustered the Maslenica and Island of Korčula populations together, and the Rovinj population was a distinct cluster from these two