ABSTRACT
Background: Crocin is a water-soluble carotenoid compound present in saffron (Crocus sativus L.), known for its wide range of pharmacological activities, including cardioprotective, hepatoprotective, anti-tumorigenic, anti-atherosclerosis, and anti-inflammatory effects. Objectives: The instability of crocin, its low miscibility with oils, and poor bioavailability pose challenges for its pharmaceutical applications. This study aimed to design and prepare a crocin-phospholipid complex (CPC) and assess its physicochemical properties. Methods: The study investigated the formation of the complex and its binding affinity through molecular docking. Molecular dynamics (MD) simulations were conducted to find the optimal molar ratio of crocin to phospholipid for the complex's preparation. The CPC was produced using the solvent evaporation method. Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), nuclear magnetic resonance (NMR), and solubility studies were utilized to characterize and confirm the formation of CPC. Additionally, the in vitro antioxidant activity of crocin and CPC was evaluated. Results: Molecular dynamic simulations explored molar ratios of 1: 1, 1: 1.5, and 1: 2 for crocin to phospholipid. The ratio of 1: 2 was found to be the most stable, exhibiting the highest probability of hydrogen bond formation. Molecular docking, FTIR, and NMR studies indicated hydrogen bond interactions between crocin and phospholipid, confirming CPC's formation. XRD and FE-SEM analyses showed a decrease in crocin's crystallinity within the phospholipid complex. Furthermore, the solubility of crocin in n-octanol was enhanced post-complexation, indicating an increase in crocin's lipophilic nature. Conclusions: Phospholipid complexation emerges as a promising technique for enhancing the physicochemical characteristics of crocin.
ABSTRACT
The oldest human coronavirus that started pandemics is severe acute respiratory syndrome virus (SARS-CoV). While SARS-CoV was eradicated, its new version, SARS-CoV2, caused the global pandemic of COVID-19. Evidence highlights the harmful events orchestrated by these viruses are mediated by Spike (S)P protein. Experimental epitopes of the S protein which were overlapping and ancestral between SARS-CoV and SARS-CoV-2 were obtained from the immune epitopes database (IEDB). The epitopes were then assembled in combination with a 50 S ribosomal protein L7/L12 adjuvant, a Mycobacterium tuberculosis-derived element and mediator of dendritic cells (DCs) and toll-like receptor 4 (TLR4). The immunogenic sequence was modeled by the GalaxyWeb server. After the improvement and validation of the protein structure, the physico-chemical properties and immune simulation were performed. To investigate the interaction with TLR3/4, Molecular Dynamics Simulation (MDS) was used. By merging the 17 B- and T-lymphocyte (HTL/CTL) epitopes, the vaccine sequence was created. Also, the Ramachandran plot presented that most of the residues were located in the most favorable and allowed areas. Moreover, SnapGene was successful in cloning the DNA sequence linked to our vaccine in the intended plasmid. A sequence was inserted between the XhoI and SacI position of the pET-28a (+) vector, and simulating the agarose gel revealed the existence of the inserted gene in the cloned plasmid with SARS vaccine (SARSV) construct, which has a 6565 bp in length overall. In terms of cytokines/IgG response, immunological simulation revealed a strong immune response. The stabilized vaccine showed strong interactions with TLR3/4, according to Molecular Dynamics Simulation (MDS) analysis. The present ancestral vaccine targets common sequences which seem to be valuable targets even for the new variant SARS-CoV-2.
ABSTRACT
Tea is a popular drink enjoyed by many people around the world. However, it is important to note that impurities and contaminants in tea can potentially threaten human health when consumed. The main objective of this research is to assess the concentration of 16 trace elements (As, Fe, Al, Co, B, Li, Cd, Ba, Pb, Cr, Zn, Hg, Ni, Mn, Sb, and Sn) present in different types brewed of tea by using the ICP-OES (the inductively coupled plasma optical emission spectrometer) device, and the human health risks related to its use were evaluated. In this study, manganese (Mn) indicated the highest mean concentration in black (917.64 µg/kg) and green tea (912.89 µg/kg), respectively. Our study showed that the highest mean concentration of element boron (B) was (44.36 µg/kg) in Stachys lavandulifolia brewed tea. Among different packaging, tea bag samples had the highest concentration of Mn (1025.65 µg/kg) and aluminum (Al) (396.63 µg/kg). However, those unpacked posed the lowest content of Mn (188.13 µg/kg) and Al (100.47 µg/kg). The lead (Pb), mercury (Hg), and cadmium (Cd) concentrations in all samples were lower than the maximum limit of the Iranian standard and the WHO. In general, the amount of tea metal in Iranian samples was higher than in imported samples. Also, increasing the brewing time (10 min) can be effective in the solubility and extraction of metals such as B, Hg, cobalt (Co), iron (Fe), and lithium (Li). Further, the correlation between the amount of metals and type in tea samples was evaluated with principal component analysis. Based on the conducted non-carcinogenic risk assessment by the Monte Carlo simulation, the hazard index (HI), due to ingestion of heavy metals via tea in the 5-min brewing of tea, was 7.39E - 03 and 2.09E - 03, and in the 10-min brewing of tea, it was 3.20E - 02 and 9.07E - 03 for children and adults, respectively. Therefore, there was no significant non-carcinogenic risk from tea consumption.
ABSTRACT
Neuropathic pain (NP) is a prevalent medical condition that lacks an effective treatment. Recently, the Sigma-2 receptor (S2R) has been proposed as a potential therapeutic target for NP. Some highly-selective S2R ligands (UKH1114, CM398, and YTD) have shown promising results in vivo, but the molecular interaction between the S2R and these ligands has been scarcely investigated. This work explores changes in the S2R upon interaction with the three mentioned ligands using in silico approaches. The results indicated that the ICL1, H1, ICL2, and ECL are the most dynamic regions of S2R in all systems. Binding interaction analysis identified amino acids with significant contribution to the binding free energy. Notably, the UKH1114-S2R simulation trajectory revealed that small alterations in the ICL1, H1, ICL2, and ECL form a new stable opening in the S2R, linking the occluded S2R binding pocket to the endoplasmic reticulum lumen, providing more evidence for the assumptions about the EBP and S2R mechanism of function. Further, the agreement between the membrane parameters in our study and experimental values confirms the validity of the MD simulations. Overall, this study provides new insights into the interaction between anti-NP ligands and the S2R.
Subject(s)
Receptors, sigma , Receptors, sigma/chemistry , Receptors, sigma/metabolism , Ligands , Computer Simulation , Molecular Dynamics SimulationABSTRACT
Background: The stratum corneum (SC) serves as the primary barrier for permeation in human skin. Penetration enhancers, such as 1,8-cineole, are utilized to enhance the permeation of drugs. Cineole increases the permeation of chemicals through different mechanisms. However, its mechanism, particularly at high concentrations, has not been well-studied and is the subject of the present investigation. Objectives: In continuation of our previous studies, the present investigation aims to elucidate the mechanism of action and concentration dependency of the effects of 1,8-cineole on the structure, diffusional properties, and partitioning behavior of the SC at high concentrations. This will be achieved through lamellar liquid crystalline models and ex-vivo skin studies. Methods: A lamellar liquid crystalline lipid matrix model in the presence (25 - 90%, w/w) and absence of cineole was prepared from SC lipids and characterized by X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and polarized light microscopy (PLM) studies. Release of the model lipophilic drug (diazepam) from cineole and cineole-treated matrices and the permeation of the drug from cineole and cineole-containing matrices (as a vehicle similar to the stratum corneum lipids) through excised rat skin were studied. Drug assay was performed by HPLC. Results: The PLM, DSC, and X-ray studies showed that the model matrix had a lamellar gel-liquid crystalline structure, and cineole fluidized the structure concentration-dependently and created other mesomorphic textures, such as myelinic figures. Release experiments showed that diffusion coefficients remained almost constant at high cineole concentrations of 40-90%, suggesting similar fluidization states. Skin permeation studies indicated that the diffusion coefficient (estimated from lag-time) increased concentration-dependently and played a role in permeability coefficient (Kp) increments alongside the increased partitioning of the model drug into the skin. Data suggest that high concentrations of cineole at the skin surface might not provide enough cineole in the skin for full fluidization, despite the similarity of the vehicle to SC lipids and even at high concentrations. Conclusions: The enhancement effect of cineole is concentration-dependent and might reach maximum fluidization at certain concentrations, but this maximum might not be easily achievable when cineole is used in formulations as pure or in a vehicle.
ABSTRACT
Tamoxifen as an antiestrogen is successfully applied for the clinical treatment of breast cancer in pre- and post-menopausal women. Due to the side effects related to the oral administration of Tamoxifen (such as deep vein thrombosis, pulmonary embolism, hot flushes, ocular disturbances and some types of cancer), liposomal drug delivery is recommended for taking this drug. Drug encapsulation in a liposomal or lipid drug delivery system improves the pharmacokinetic and pharmacodynamic properties. In this regard, we carried out 200-ns molecular dynamics (MD) simulations for three systems (pure DPPC and neutral and protonated Tamoxifen-loaded DPPC). Here, DPPC is a model lipid bilayer to provide us with conditions like liposomal drug delivery systems to investigate the interactions between Tamoxifen and DPPC lipid bilayers and to estimate the preferred location and orientation of the drug molecule inside the bilayer membrane. Properties such as area per lipid, membrane thickness, lateral diffusion coefficient, order parameters and mass density, were surveyed. With insertion of neutral and protonated Tamoxifen inside the DPPC lipid bilayers, area per lipid and membrane thickness increased slightly. Also, Tamoxifen induce ordering of the hydrocarbon chains in DPPC bilayer. Analysis of MD trajectories shows that neutral Tamoxifen is predominantly found in the hydrophobic tail region, whereas protonated Tamoxifen is located at the lipid-water interface (polar region of DPPC lipid bilayers).
Subject(s)
Lipid Bilayers , Molecular Dynamics Simulation , Tamoxifen , Female , Humans , 1,2-Dipalmitoylphosphatidylcholine/chemistry , Lipid Bilayers/chemistry , Tamoxifen/chemistry , Tamoxifen/pharmacologyABSTRACT
Due to the importance of benzodiazepine drugs in clinical practice, such as the treatment of anxiety disorders, depression, and insomnia and the side effects of classical benzodiazepines, the study of new benzodiazepine agonists has received much attentions. In this work, we used in silico methods to explore the molecular mechanism of 1,2,4-triazolo [1,5-a] pyrimidinone derivatives in the modulation of α1ß2γ2 subtype of GABAA receptor. To this aim, molecular docking, molecular dynamics simulation (MD), post-MD analysis, binding free energy calculation, and prediction of ADME properties were performed. Results showed that all new compounds have a better binding affinity for the Benzodiazepine (BZD) site of the receptor than diazepam and compound 4c had the highest affinity among them. Moreover, a good agreement was observed between the calculated ΔGbinding and experimental IC50 values. Also, we noticed that residues in loop regions (particularly loop C and D-F in α1 and γ2 subunits, respectively) forming BZD binding site, take part in forming several H-bonds between the agonists and the receptor. Ser205, Thr207, Tyr160, and His102 of α1 subunit and Thr207 of γ2 subunit are mainly involved in forming H-bonds. Also, the orientation of agonists in the BZD binding site leads to π-π interactions with hydrophobic residues in loops A-F. Based on the DCCM analysis, the correlated motions in the γ2 subunit residues are greater than those of α1 subunit residues. Further, predicted ADME results indicated that all agonists meet the criteria. The triplicate MD simulation showed the reproducibility of the results and strengthened the study. Our results provide a comprehensive insight into the receptor-agonist interactions and clues for designing future BZD agonists.
Subject(s)
Benzodiazepines , Receptors, GABA-A , Benzodiazepines/chemistry , Benzodiazepines/metabolism , Benzodiazepines/pharmacology , Binding Sites , Diazepam/pharmacology , Molecular Docking Simulation , Purines , Pyrimidinones/pharmacology , Receptors, GABA-A/metabolism , Reproducibility of ResultsABSTRACT
BACKGROUND: Immunization against the coronavirus disease 2019 (COVID-19) began in January 2021 in Iran; nonetheless, due to a lack of vaccination among children under 12, this age group is still at risk of SARS-CoV-2 infection and its complications. CASE PRESENTATION: SARS-CoV-2 infection was diagnosed in a 6-year-old girl who had previously been healthy but had developed a fever and pancytopenia. The bone marrow aspiration/biopsy demonstrated just hypocellular marrow without signs of leukemia. She was worked up for primary and secondary causes of pancytopenia. Except for a repeated reactive HIV antibody/Ag P24 assay, all test results were inconclusive. After a thorough diagnostic investigation, the cross-reactivity of the HIV antibody/Ag P24 test with SARS-CoV-2 antibodies was confirmed. The patient did not develop any COVID-19-related signs and symptoms, but she did get a severe invasive fungal infection and neutropenic enterocolitis. She died as a result of disseminated intravascular coagulopathy. CONCLUSION: It is critical to recognize children infected with SARS-CoV-2 who exhibit atypical clinical manifestations of COVID-19, such as persistent pancytopenia. SARS-CoV-2 infection can cause severe and deadly consequences in children; thus, pediatricians should be aware of COVID-19's unusual signs and symptoms mimicking other conditions such as aplastic anemia.
Subject(s)
Anemia, Aplastic , COVID-19 , Enterocolitis, Neutropenic , HIV Infections , Invasive Fungal Infections , Pancytopenia , Anemia, Aplastic/etiology , Bone Marrow/pathology , COVID-19/complications , Child , Enterocolitis, Neutropenic/complications , Female , HIV Infections/complications , Humans , Invasive Fungal Infections/complications , Pancytopenia/diagnosis , Pancytopenia/etiology , SARS-CoV-2ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the contagious coronavirus disease 2019 (COVID-19) which was first identified in Wuhan, China, in December 2019. Around the world, many researchers focused their research on identifying inhibitors against the druggable SARS-CoV-2 targets. The reported genomic mutations have a direct effect on the receptor-binding domain (RBD), which interacts with host angiotensin-converting enzyme 2 (ACE-2) for viral cell entry. These mutations, some of which are variants of concern (VOC), lead to increased morbidity and mortality rates. The newest variants including B.1.617.2 (Delta), AY.1 (Delta plus), and C.37 (Lambda) were considered in this study. Thus, an exhaustive structure-based virtual screening of a ligand library (in which FDA approved drugs are also present) using the drug-likeness screening, molecular docking, ADMET profiling was performed followed by molecular dynamics (MD) simulation, and Molecular Mechanics-Poisson Boltzmann Surface Area (MM-PBSA) calculation to identify compounds or drugs can be repurposed for inhibiting the wild type, Delta, Delta plus and Lambda variants of RBD of the spike protein. Based on the virtual screening steps, two FDA approved drugs, Atovaquone (atv) and Praziquantel (prz), were selected and repurposed as the best candidates of SARS-CoV-2 RBD inhibitors. Molecular docking results display that both atv and prz contribute in different interaction with binding site residues (Gln493, Asn501 and Gly502 in the hydrogen bond formation, Phe490 and Tyr505 in the π- π stacking and Tyr449, Ser494, and Phe497 in the vdW interactions) in the wild type, Delta, Delta plus and Lambda variants of RBD of the spike protein. MD simulations revealed that among the eight studied complexes, the wild type-atv and Delta-prz complexes have the most structural stability over the simulation time. Furthermore, MM-PBSA calculation showed that in the atv containing complexes, highest binding affinity is related to the wild type-atv complex and in the prz containing complexes, it is related to the Delta-prz complex. The validation of docking results was done by comparing with experimental data (heparin in complex with wild type and Delta variants). Also, comparison of the obtained results with the result of simulation of the k22 with the studied proteins showed that atv and prz are suitable inhibitors for these proteins, especially wild type t and Delta variant, respectively. Thus, we found that atv and prz are the best candidate for inhibition of wild type and Delta variant of the spike protein. Also, atv can be an appropriate inhibitor for the Lambda variant. Obtained in silico results may help the development of new anti-COVID-19 drugs.
Subject(s)
COVID-19 Drug Treatment , COVID-19 , SARS-CoV-2 , Humans , COVID-19/genetics , Drug Repositioning/methods , Molecular Docking Simulation , Molecular Dynamics Simulation , Mutation/genetics , Peptidyl-Dipeptidase A/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistryABSTRACT
Alzheimer's disease is characterized by the presence of extraneuronal amyloid plaques composed of amyloid-beta (Aß) fibrillar aggregates in the brains of patients. In mouse models, it has previously been shown that atorvastatin (Ator), a cholesterol-lowering drug, has some reducing effect on the production of cerebral Aß. A meta-analysis on humans showed moderate effects in the short term but no improvement in the Alzheimer's Disease Assessment Scale-Cognitive Subscale behavioral test. Here, we explore a potential direct effect of Ator on Aß42 aggregation. Using NMR-based monomer consumption assays and CD spectroscopy, we observed a promoting effect of Ator in its original form (Ator-calcium) on Aß42 aggregation, as expected because of the presence of calcium ions. The effect was reversed when applying a CaCO3-based calcium ion scavenging method, which was validated by the aforementioned methods as well as thioflavin-T fluorescence assays and transmission electron microscopy. We found that the aggregation was inhibited significantly when the concentration of calcium-free Ator exceeded that of Aß by at least a factor of 2. The 1H-15N heteronuclear single quantum correlation and saturation-transfer difference NMR data suggest that calcium-free Ator exerts its effect through interaction with the 16KLVF19 binding site on the Aß peptide via its aromatic rings as well as hydroxyl and methyl groups. On the other hand, molecular dynamics simulations confirmed that the increasing concentration of Ator is necessary for the inhibition of the conformational transition of Aß from an α-helix-dominant to a ß-sheet-dominant structure.
Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Atorvastatin , Peptide Fragments , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Amyloid/metabolism , Amyloid beta-Peptides/metabolism , Animals , Atorvastatin/pharmacology , Calcium/metabolism , Humans , Mice , Peptide Fragments/metabolismABSTRACT
Background: Developing a potent and safe scaffold is challenging in anti-cancer drug discovery. Objectives: The study focused on developing novel series of compounds based on the inhibition of epidermal growth factor receptor tyrosine kinase (EGFR-TK) as one of the most promising compounds in cancer therapy. Methods: In this study, a novel series of quinazoline-2,4,6-triamine derivatives were designed and synthesized through intramolecular C-H activation reaction of para-nitro aniline, trichloroacetonitrile, and isocyanides employing a one-pot reaction. Results: The in-vitro antitumor activities of the compounds which showed acceptable inhibitory effects were investigated against breast (MCF-7), lung (A-549), and colon (HT-29) cancer cell lines by employing MTT assay. All compounds had the most negligible cytotoxicity toward normal fibroblast human cell lines. Based on structural and thermodynamics analysis results, it was found that Met 769 is a key residue in interaction with all inhibitors through the formation of hydrogen bonds with high occupancies with the amine group on the quinazoline ring of inhibitors. Also, there was a good consistency between calculated ΔG binding and experimental IC50 values of compounds 10d, 10e, and erlotinib. Conclusions: Compound 10e had an extensive range of antitumor activity on three diverse cell lines comparable with erlotinib and doxorubicin reference drugs. Also, compound 10d showed selective cytotoxicity against cancerous lung cells (A-549). On the other side, computational studies confirmed that Met 769 is a crucial residue in interaction with all inhibitors.
ABSTRACT
BACKGROUND & OBJECTIVE: Acral melanoma (AM) is a common type of cutaneous melanoma that occurs in the skin of the palms, soles, and nail beds. This malignancy, like other types of cancer, has different genetic alterations. To date, despite decades of research the roles of oncogenic BRAF mutations in the pathogenesis of AM has not been fully clarified. The present study was designed to identify V600E mutation in patients with AM from the south of Iran. METHODS: The samples were collected from the pathology lab archive of Shiraz University of Medical Sciences (2015-2020). A total of 41 patients with primary invasive AM underwent excisional biopsy or amputation were collected to evaluate BRAF V600E mutation using Polymerase Chain Reaction (PCR) and Sanger sequencing. RESULTS: Total number of 41cases (21 male and 20 female) and age range of 34-87 years were enrolled. The histological subtypes were 24 acral lentiginous melanomas (ALM), 10 cases of nodular melanoma (NM), and 7 cases of superficial spreading melanoma (SSM). In our study, only one case (a 44-year-old male with nail bed AM and the histological subtype of acral lentigenous melanoma) showed BRAF-V600E mutation. CONCLUSION: These findings suggest that the population of our interest showed a very low prevalence of this mutation providing novel insights into the pathobiology of AM and its related treatment.
ABSTRACT
Chemoinformatics appraisal and molecular docking were employed to investigate 225 complexes of 75 schizophrenia antipsychotics with the dopamine receptor subtypes D2R, D3R, and D4R. Considering the effective noncovalent interactions in the subtype-D2 receptor selectivity of antipsychotics, this study evaluated the possible physicochemical properties of ligands underlying the design of safer and more effective antipsychotics. The pan-assay interference compounds (PAINs) include about 25% of typical antipsychotics and 5% of atypicals. Popular antipsychotics like haloperidol, clozapine, risperidone, and aripiprazole are not PAINs. They have stronger interactions with D2R and D4R, but their interactions with D3R are slightly weaker, which is similar to the behavior of dopamine. In contrast to typical antipsychotics, atypical antipsychotics exhibit more noncovalent interactions with D4R than with D2R. These results suggest that selectivity to D2R and D4R comes from the synergy between hydrophobic and hydrogen-bonding interactions through their concomitant occurrence in the form of a hydrogen-bonding site adorned with hydrophobic contacts in antipsychotic-receptor complexes. All the antipsychotics had more synergic interactions with D2R and D4R in comparison with D3R. The atypical antipsychotics made a good distinction between the subtype D2 receptors with high selectivity to D4R. Among the popular antipsychotics, haloperidol, clozapine, and risperidone have hydrophobic-hydrogen-bonding synergy with D4R, while aripiprazole profits with D2R. The most important residue participating in the synergic interactions was threonine for D2R and cysteine for D4R. This work could be useful in informing and guiding future drug discovery and development studies aimed at receptor-specific antipsychotics.
Subject(s)
Antipsychotic Agents , Schizophrenia , Antipsychotic Agents/pharmacology , Humans , Molecular Docking Simulation , Receptors, Dopamine D2 , Risperidone/pharmacology , Schizophrenia/drug therapyABSTRACT
Human telomerase that activates within cancer cells has a telomeric sequence at the 3' end. Each factor that stabilizes the G-quadruplex in guanine-rich telomeric sequences can inhibit the regular telomerase activity. Therefore, the telomeric G-quadruplex is known as a promising target in cancer treatment. In this work, we studied the binding of positively charged distamycin A and its uncharged derivative to the G-quadruplex in a solution environment by Molecular Dynamics (MD) simulation. The binding mechanism and subtle conformational changes were investigated as a result of the ligand attachment. Moreover, binding free energy and clustering analysis describe the stability and flexibility of G-quadruplexes upon ligand binding. Structural analyses displayed that the favorable binding of both ligands imposes significant stability and rigidity in G-quadruplex conformation compared to free G-quadruplex, especially charged distamycin. Hydration pattern and ion distribution were different for free G-quadruplex and both of the ligand complexes. Energy decomposition reveals the electrostatic effect on the stability of G-quadruplex. The radial distribution function displayed the solvent shell and ion moving away from the groove. The hydrogen bond played an essential role in the binding of both ligands, especially for the charged derivative. van der Waals interaction is the only factor that is more important in binding uncharged distamycin into G-quadruplex than the charged one. The calculated ΔGbind showed the stability of both ligands within grooves and good agreement with the experimental binding free energy data. Finally, the results suggest that ligand modification improves the binding mode toward stabilizing G-quadruplexes.
Subject(s)
Antineoplastic Agents/chemistry , Distamycins/chemistry , G-Quadruplexes , Molecular Dynamics Simulation , Telomere/chemistry , HumansABSTRACT
In the recent decades, global warming has caused water shortages all over the world. This study aimed to investigate the impacts of drought caused by climate change on the chemical quality of groundwater in Saveh County, Markazi province, Iran. The physicochemical parameters of 29 wells were analyzed by the Standardized Precipitation Index (SPI) during the drought period 2004-2015. Wilcox and Schoeller diagrams were applied to evaluate the water quality of wells for irrigation and drinking purposes, respectively. Schoeller diagram was consulted to show the relative concentrations of anions and cations typically expressed in milliequivalents per liter. Also, the Wilcox diagram was consulted to determine the suitability of water for agriculture purposes. Finally, the geographic information system was applied to the zoning of the groundwater quality parameters. According to the results, almost 90% of wells were in the category of "very salty and harmful for agriculture uses" in the last year of the study period (2015). The Schoeller diagram suggests that the water quality of 72.5, 10.4, 65.5, 100, 44.9, and 69% of wells were inappropriate and exceeded the Iranian National Standard level, in terms of TDS, TH, Na+Ø Mg2+, Cl-, and SO42- in 2015, respectively. A decrease in yearly average precipitation during the studied period has not only caused overuse of groundwater as the primary water resources but also led to a significant decline in its chemical quality.
Subject(s)
Droughts , Environmental Monitoring/methods , Groundwater/chemistry , Water Pollutants, Chemical/analysis , Water Quality/standards , Water Resources/supply & distribution , Agriculture , Geographic Information Systems , Iran , Water Supply/methods , Water Supply/standards , Water WellsABSTRACT
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
ABSTRACT
During phloem unloading, multiple cell-to-cell transport events move organic substances to the root meristem. Although the primary unloading event from the sieve elements to the phloem pole pericycle has been characterized to some extent, little is known about post-sieve element unloading. Here, we report a novel gene, PHLOEM UNLOADING MODULATOR (PLM), in the absence of which plasmodesmata-mediated symplastic transport through the phloem pole pericycle-endodermis interface is specifically enhanced. Increased unloading is attributable to a defect in the formation of the endoplasmic reticulum-plasma membrane tethers during plasmodesmal morphogenesis, resulting in the majority of pores lacking a visible cytoplasmic sleeve. PLM encodes a putative enzyme required for the biosynthesis of sphingolipids with very-long-chain fatty acid. Taken together, our results indicate that post-sieve element unloading involves sphingolipid metabolism, which affects plasmodesmal ultrastructure. They also raise the question of how and why plasmodesmata with no cytoplasmic sleeve facilitate molecular trafficking.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Membrane Proteins/metabolism , Phloem/metabolism , Plasmodesmata/ultrastructure , Sphingolipids/biosynthesis , Arabidopsis/genetics , Arabidopsis/ultrastructure , Arabidopsis Proteins/genetics , Genes, Plant , Glucans/metabolism , Green Fluorescent Proteins/metabolism , Membrane Proteins/genetics , Mutation , Plant Roots/metabolism , Plasmodesmata/metabolism , Transferases (Other Substituted Phosphate Groups)/genetics , Transferases (Other Substituted Phosphate Groups)/metabolismABSTRACT
Organic osmolytes, as major cellular compounds, cause protein stabilization in the native form. In the present study, the possible chaperone effects of the three naturally occurring osmolytes on the two-chain form of tenecteplase (tc-TNK), a recombinant, genetically engineered mutant tissue plasminogen activator, have been explored by using circular dichroism, steady-state fluorescence, UV-Visible spectroscopy, and in silico experiments. The tc-TNK is derived from the one-chain protein upon disruption of one peptide bond. Thermal denaturation experiments showed a slightly more stabilizing effect of the three co-solvents on the single-chain TNK (sc-TNK) in comparison to that on tc-TNK. Unlike single-chain tenecteplase, the two-chain form undergoes reversible denaturation which is somehow perturbed in some cases as the result of the presence of osmolytes. Very minor changes in the secondary structure and the tertiary structure were observed. The molecular dynamics simulations and comparative structural analysis of catalytic domain of the protein in the single-chain and two-chain forms in pure water, mannitol/water, trehalose/water, and sucrose/water showed that while the stabilizing effect of the three osmolytes on tc-TNK might be induced by preferential accumulation of these molecules around the nonpolar and aromatic residues, that is to say, fewer water-hydrophobic residues' interactions in tc-TNK, sc-TNK is stabilized by preferential exclusion effect.
Subject(s)
Molecular Dynamics Simulation , Protein Conformation , Tenecteplase/chemistry , Animals , Enzyme Activation , Peptides/chemistry , Protein Conformation/drug effects , Protein Stability , Spectrum Analysis , ThermodynamicsABSTRACT
BACKGROUND: Methamphetamine is a neuro-stimulant with neurodegenerative effects, and ambiguous mechanism of action. Metformin is an antidiabetic agent with neuroprotective properties but not fully understood mechanisms. The present study investigated the molecular basis of metformin neuroprotection against methamphetamine-induced neurodegeneration. BRIEF METHOD: Sixty adult male rats were randomly divided into six groups: group 1 (received normal saline), group 2 (received 10 mg/kg of methamphetamine) and groups 3, 4, 5 and 6 [received methamphetamine (10 mg/kg) plus metformin (50, 75, 100 and 150 mg/kg) respectively]. Elevated Plus Maze (EPM), Open Field Test (OFT), Forced Swim Test (FST), Tail Suspension Test (TST) and Morris Water Maze (MWM) were used to assess the level of anxiety, depression and cognition in experimental animals. Also animals' hippocampus were isolated and oxidative stress and inflammatory parameters and expression of total and phosphorylated forms of cAMP response element binding (CREB), brain-derived neurotrophic factor (BDNF), protein kinase B (Akt) and glycogen synthase kinase 3 (GSK3) proteins were evaluated by ELISA method. RESULTS: According to the data obtained, methamphetamine caused significant depression, anxiety, motor activity disturbances and cognition impairment in experimental animals. Metformin, in all used doses, decreased methamphetamine induced behavioral disturbances. Also chronic administration of methamphetamine could increase malondialdehyde (MDA), tumor necrosis factor-Alpha (TNF-α) and interleukine-1 beta (IL-1ß) in rats, while caused reduction of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) activities. Metformin, especially in high doses, could prevent these malicious effects of methamphetamine. Also Metformin could activate CREB (both forms), BDNF and Akt (both forms) proteins' expression and inhibited GSK3 (both forms) protein expression in methamphetamine treated rats. SIGNIFICANCE: According to obtained data, metformin could protect the brain against methamphetamine-induced neurodegeneration probably by mediation of CREB/BDNF or Akt/GSK3 signaling pathways. These data suggested that CREB/BDNF or Akt/GSK3 signaling pathways may have a critical role in methamphetamine induced neurotoxicity and/or neuroprotective effects of metformin.