Identification of microRNA-mRNA Regulatory Networks with Therapeutic Values in Alzheimer's Disease by Bioinformatics Analysis.

Background: Alzheimer's disease (AD) is the most prevalent neurological disorder worldwide, affecting approximately 24 million individuals. Despite more than a century of research on AD, its pathophysiology is still not fully understood. Objective: Recently, genetic studies of AD have focused on analyzing the general expression profile by employing high-throughput genomic techniques such as microarrays. Current research has leveraged bioinformatics advancements in genetic science to build upon previous efforts. Methods: Data from the GSE118553 dataset used in this investigation, and the analyses carried out using programs such as Limma and BioBase. Differentially expressed genes (DEGs) and differentially expressed microRNAs (DEmiRs) associated with AD identified in the studied areas of the brain. Target genes of the DEmiRs identified using the MultiMiR package. Gene ontology (GO) completed using the Enrichr website, and the protein-protein interaction (PPI) network for these genes drawn using STRING and Cytoscape software. Results: The findings introduced DEGs including CTNNB1, PAK2, MAP2K1, PNPLA6, IGF1R, FOXL2, DKK3, LAMA4, PABPN1, and GDPD5, and DEmiRs linked to AD (miR-106A, miR-1826, miR-1253, miR-10B, miR-18B, miR-101-2, miR-761, miR-199A1, miR-379 and miR-668), (miR-720, miR-218-2, miR-25, miR-602, miR-1226, miR-548K, miR-H1, miR-410, miR-548F2, miR-181A2), (miR-1470, miR-651, miR-544, miR-1826, miR-195, miR-610, miR-599, miR-323, miR-587 and miR-340), and (miR-1282, miR-1914, miR-642, miR-1323, miR-373, miR-323, miR-1322, miR-612, miR-606 and miR-758) in cerebellum, frontal cortex, temporal cortex, and entorhinal cortex, respectively. Conclusions: The majority of the genes and miRNAs identified by our findings may be employed as biomarkers for prediction, diagnosis, or therapy response monitoring.

Identification of differentially expressed genes associated with the pathogenesis of gastric cancer by bioinformatics analysis.

AIM: Gastric cancer (GC) is one of the most diagnosed cancers worldwide. GC is a heterogeneous disease whose pathogenesis has not been entirely understood. Besides, the GC prognosis for patients remains poor. Hence, finding reliable biomarkers and therapeutic targets for GC patients is urgently needed. METHODS: GSE54129 and GSE26942 datasets were downloaded from Gene Expression Omnibus (GEO) database to detect differentially expressed genes (DEGs). Then, gene set enrichment analyses and protein-protein interactions were investigated. Afterward, ten hub genes were identified from the constructed network of DEGs. Then, the expression of hub genes in GC was validated. Performing survival analysis, the prognostic value of each hub gene in GC samples was investigated. Finally, the databases were used to predict microRNAs that could regulate the hub genes. Eventually, top miRNAs with more interactions with the list of hub genes were introduced. RESULTS: In total, 203 overlapping DEGs were identified between both datasets. The main enriched KEGG pathway was "Protein digestion and absorption." The most significant identified GO terms included "primary alcohol metabolic process," "basal part of cell," and "extracellular matrix structural constituent conferring tensile strength." Identified hub modules were COL1A1, COL1A2, TIMP1, SPP1, COL5A2, THBS2, COL4A1, MUC6, CXCL8, and BGN. The overexpression of seven hub genes was associated with overall survival. Moreover, among the list of selected miRNAs, hsa-miR-27a-3, hsa-miR-941, hsa-miR-129-2-3p, and hsa-miR-1-3p, were introduced as top miRNAs targeting more than five hub genes. CONCLUSIONS: The present study identified ten genes associated with GC, which may help discover novel prognostic and diagnostic biomarkers as well as therapeutic targets for GC. Our results may advance the understanding of GC occurrence and progression.

The relationship between health-related quality of life of students at Tehran University of Medical Sciences and their knowledge, attitudes, and practices regarding COVID-19 in 2020.

BACKGROUND: Present study attempts to investigate health-related quality of life (HRQoL) and its relation with knowledge, attitudes, and practices (KAP) of students of Tehran University of Medical Sciences (TUMS) during this pandemic. MATERIALS AND METHODS: In this cross-sectional study which was conducted between 23 may to 21 June 2020, 470 students in different levels of TUMS were included to the study randomly. participants completed validate, designed online questionnaire which assessed KAP towards coronavirus disease 2019 (COVID-19) and HRQoL. All statistical tests were applied, including Chi-square and Fisher's exact test, Partial correlation, analysis of variance, multiple linear regression, multiple binary and multinomial logistic regression models (P < 0.05) and were performed in SPSS 16, R 4.0.2, and GraphPad Prism 6.0 softwares. RESULTS: A total of 470 students were included in the study. The overall correct answer rate of the COVID-19 knowledge questionnaire was 74.43% and total score of the HRQoL was 72.50 (14.85). 61.7% of the students were agreed that COVID-19 will finally be successfully controlled, 44.3% had confidence that Iran can win the battle against the COVID-19, and 92.6% agreed that Quarantine will reduce the prevalence of COVID-19. Most of them adhered to health protocols and about a relation between HRQoL and knowledge we have a weak positive and unsignificant correlation between them (r = 0.05, P = 0.27). CONCLUSIONS: TUMS students showed expected levels of knowledge, proper attitudes, and preemptive practices regarding COVID-19, whereas COVID-19 outbreak substantially affected the physical and mental health but, the students were in a way better physical health rather than mental. Therefore, motivational planning and other related intervention to improve mental health can be noticeable.

Activation of L-type calcium channels and attenuation of oxidative stress are involved in the improving effect of methyl jasmonate on learning and memory and its anxiolytic property in rats.

The present study was designed to evaluate the effect of plant bioactive compound methyl jasmonate on learning and memory, anxiety-like behaviors, and brain oxidative stress in rats. It has been indicated that methyl jasmonate stimulates calcium-binding protein expression and increases intracellular calcium (Ca2+). Therefore, we investigated the potential role of L-type calcium channel on methyl jasmonate effects. The animals were intracerebroventriculary (i.c.v.) injected with different doses of methyl jasmonate (0.5, 2.5, and 5 µg/rat). L-type calcium channel blocker (nifedipine 5 µg/rat, i.c.v.) was injected 30 min before methyl jasmonate (5 µg/rat). Shuttle box apparatus was used to evaluate passive avoidance memory. Anxiety-like behaviors were assessed by open field and elevated plus maze tests. Lastly, oxidative stress-related indices were assessed in hippocampus and prefrontal cortex. The data showed that methyl jasmonate dose-dependently could improve passive avoidance learning and memory and reduce anxiogenic behaviors. The methyl jasmonate effects were significantly prevented by nifedipine. Furthermore, central microinjection of methyl jasmonate significantly decreased hydrogen peroxide concentration, and increased reactive oxygen species scavenger activity (catalase and peroxide enzymes) in rats' hippocampus as well as prefrontal cortex. Indeed, the results indicated that the beneficial effects of methyl jasmonate on learning and memory and anxiety might be partly associated with L-type calcium channel and partly on the inhibition of oxidant indices.

Hydroalcoholic Extract of Levisticum officinale Increases cGMP Signaling Pathway by Down-Regulating PDE5 Expression and Induction of Apoptosis in MCF-7 and MDA-MB-468 Breast Cancer Cell Lines

Background: This study aimed to investigate Levisticum officinale hydroalcoholic extract (LOHE) effect on both cGMP signaling pathway and phosphodiesterase 5 (PDE5) gene expression pattern and to examine the role of LOHE in apoptosis induction of MCF-7 and MDA-MB-468 cell lines. Methods: The half maximal inhibitory concentration (IC50) of LOHE was examined in both cell lines using the MTT assay. Using IC50 values of LOHE on both cells, the type of cell death was detected by flowcytometric analysis. The values of PDE5 and cGMP were evaluated by real-time PCR and ELISA methods, respectively. Results: The IC50 values were measured as 150 µg/ml for MDA-MB-468 and 200 µg/ml for MCF-7. At 12 hour of treatment, a significant decrease in the PDE5 expression and maximum increase in the amount of intracellular cGMP were observed (p < 0.05). However, these effects were more noticeable in MDA-MB-468 triple-negative cells. Conclusion: Our data suggest that LOHE extract could be a potential source for new strategies towards targeting both PDE5 and cGMP signaling pathways.

A thermostable alkaliphilic protein-disulfide isomerase from Bacillus subtilis DR8806: cloning, expression, biochemical characterization and molecular dynamics simulation.

Disulfide bonds are among the most important factors related to correct folding of the proteins. Protein disulfide isomerase (PDI) is the enzyme responsible for the correct formation and isomerization of these bonds. It is rarely studied so far and none of them showed industrial properties. In this study, the gene encoding for a putative PDI from Bacillus subtilis DR8806 was identified, cloned and expressed in Escherichia coli. It was encoded a 23.26kDa protein. The enzyme was purified by GST affinity chromatography with a specific activity of 1227u/mg. It was active and stable over a wide range of temperature (20-85°C) and pH (4.5-10) with an optimum at 65°C and pH 5.5. Its activity was enhanced by Mn2+ and Co2+ while Ag+ and Zn2+ decreased it. Some of the known PDI inhibitors such as Tocinoic acid and Bactiracin did not affect its activity. In-silico analysis shows the five amino acids changes in the protein sequence regarding to the consensus sequence of PDIs, have a positive impact toward the protein thermal stability. This was further confirmed by molecular dynamics simulations. By considering the overall results, the enzyme might be a potential candidate for applications in the respective industries.

The hepatoprotective effects of aquatic extract of Levisticum officinale against paraquat hepatocyte toxicity.

Paraquat is extensively used as a strong nitrogen-based herbicide for controlling weeds in agriculture. This herbicide is extremely toxic to humans and induces multiorgan failure due to accumulation in the cells. So far, many instances of fatal poisoning have been reported. Paraquat is metabolized primarily in the liver. Accordingly, the effects of aquatic Levisticum officinale extract on biochemical factors and oxidative status were evaluated in hepatocytes exposed to paraquat in this study. The results showed that paraquat-induced hepatocyte destruction is mediated by reactive oxygen species (ROS) production. The aquatic extracts of Levisticum officinale (100, 200, and 300µg/mL) could prevent lipid peroxidation and reduction in the potential of mitochondrial membranes (P<0.05). The antioxidants, ROS scavengers (mannitol, dimethyl sulfoxide, and α-tocopherol), and mitochondrial permeability transition pore-sealing agent (carnitine) inhibited the effects of paraquat. The pore-sealing compound inhibited hepatotoxicity, indicating that paraquat induces cell death via mitochondrial pathways. Hepatic cell death due to paraquat could be prevented by hepatocyte pretreatment with aquatic Levisticum officinale extracts, antioxidants, and ROS scavengers; therefore, oxidative stress might directly reduce the mitochondrial membrane potential. In conclusion, paraquat hepatotoxicity may be associated with oxidative stress and maintained by the disruption of mitochondrial membrane potential. Levisticum officinale aquatic extract, presumably due to its strong antioxidant properties, could protect against the destructive effects of paraquat on rat hepatocytes.

Inhibition of Phosphodiesterase 5 and Increasing the Level of Cyclic Guanosine 3',5' Monophosphate by Hydroalcoholic Achillea wilhelmsii C. Koch Extract in Human Breast Cancer Cell Lines MCF-7 and MDA-Mb-468.

This study aimed to investigate the effect of hydroalcoholic Achillea wilhelmsii C. Koch extract (HAWE) on phosphodiesterase 5 (PDE5) gene expression and cyclic guanosine 3',5' monophosphate (cGMP) signaling in the MCF-7 and MDA-Mb-468 cell lines. The effective dose (ED50) of HAWE was examined in both cell lines using a 3-(4,5-dimethylhiazol-2-yl)-2,5-diphenyltetrazolium bromide viability test, and the type of cell death was detected by flow cytometry. The expression of PDE5 and the concentration of cGMP were measured in a time-dependent manner in the ED50 by real-time polymerase chain reaction and a colorimetric assay, respectively. Treatment with HAWE showed 25 µg/mL to be the ED50 for both cell lines, and HAWE led to a reduction in the PDE5 messenger RNA expression. The intracellular cGMP increased in a time-dependent manner. The results showed that HAWE has an antiproliferative property in MCF-7 and MDA-Mb-468 cell lines through the cGMP pathway. Therefore, HAWE is a potential source to effectively isolate inhibitory PDE5.

Anti-proliferative and apoptosis inducing potential of hydroalcoholic Achillea wilhelmsii C. Koch extract on human breast adenocarcinoma cell lines MCF-7 and MDA-Mb-468.

Achillea wilhelmsii C. Koch contains a variety of components such as flavonoid. The previous studies showed that flavonoid has anti-cancer properties. The aim of the present study was to determine the anti-proliferative and apoptosis-inducing potential of hydroalcoholic Achillea wilhelmsii C. Koch extract (HAWE) on MCF-7 and MDA-Mb-468 human breast carcinoma cell lines. The anti-proliferative activity of HAWE was evaluated using MTT, flowcytometry by annexin V/PI double staining, and caspase-3 activity. The results of MTT showed that the ED50 of MCF-7 and MDA-Mb-468 was 25µg/ml of HAWE, 48h after treatment. Flowcytometry by annexin V/PI showed that HAWE induced late apoptosis in MCF-7 and early apoptosis in MDA-Mb-468. In addition, the caspase-3 colorimetric method showed that caspase-3 increased in the MDA-Mb-468 after treatment with HAWE. This study found that the hydroalcoholic extract of Achillea wilhelmsii C. Koch induced apoptosis in both the MCF-7 and MDA-Mb-468 human breast carcinoma cell lines.

Blockade of presynaptic adenosine A1 receptor responses by nitric oxide and superoxide in rat hippocampus.

Activation of N-methyl-D-aspartate (NMDA) receptors prevents the neuronal responses to adenosine in hippocampal slices. As NMDA receptor activation leads to the generation of nitric oxide (NO) and superoxide, we have examined whether these can modify neuronal responses to adenosine and mediate the actions of NMDA. Field excitatory postsynaptic potentials were recorded in the CA1 region of rat hippocampal slices. Paired-pulse interactions were studied to localize the observed interactions to presynaptic terminals. The NO donors S-nitroso-N-acetylpenicillamine and diethylamine NONOate induced a long-lasting potentiation (NO-induced potentiation) of field excitatory postsynaptic potential slope and significantly prevented the presynaptic inhibitory effect of adenosine or the A1 receptor agonist N6-cyclopentyladenosine selectively with no effect on responses to baclofen. The superoxide-generating system of xanthine/xanthine oxidase also prevented presynaptic responses to adenosine and this effect was prevented by superoxide dismutase (SOD). The guanylate cyclase inhibitor 1H-[1,2,4]-oxadiazolo[4,3a]quinoxalin-1-one (10 microM) prevented NO-induced potentiation and the inhibitory effects of S-nitroso-N-acetylpenicillamine and xanthine/xanthine oxidase on adenosine responses. The inhibitory effect of NMDA on adenosine responses was unchanged by 1H-[1,2,4]-oxadiazolo[4,3a]quinoxalin-1-one, indicating that guanosine-3',5-cyclic monophosphate does not mediate this interaction, although it was partially reduced by SOD, suggesting that superoxide might contribute. The reduction of adenosine responses by electrically-induced long-term potentiation was prevented by NO synthase inhibition or SOD. The results indicate that the presynaptic effects of adenosine at presynaptic sites can be prevented by NO or superoxide but that neither of these individually can fully account for the prevention of adenosine responses by NMDA.

The mechanism of inhibition by xanthine of adenosine A1-receptor responses in rat hippocampus.

We have recently observed that the free radical-generating mixture of xanthine and xanthine oxidase (X/XO) can suppress the inhibitory effects of adenosine on synaptic transmission in the hippocampus, but that this action can be mimicked by xanthine alone. We have now clarified the mechanism of these interactions by using the new, potent and highly selective inhibitor of xanthine oxidase, 1-(3-cyano-4-neopentyloxyphenyl)pyrazole-4-carboxylic acid (Y-700). Field excitatory postsynaptic potentials (fEPSPs) were recorded in the CA1 region of rat hippocampal slices. X/XO induced a long-lasting increase of fEPSP slope and significantly reduced the presynaptic inhibitory effect of adenosine. Both these actions were prevented by Y-700 at a concentration of only 200nM. Similarly the superfusion of xanthine alone increased fEPSP slope and reduced sensitivity to adenosine but these effects were also prevented by Y-700. The results indicate that the antagonism of adenosine responses by X/XO or by xanthine alone are entirely attributable to the activity of the added or endogenous XO activity, probably generating free radicals, and are not likely to be caused by a direct antagonistic action at the xanthine-sensitive site on the adenosine receptor.

Interactions between adenosine and metabotropic glutamate receptors in the rat hippocampal slice.

1. We have examined excitatory postsynaptic potentials and paired-pulse interactions in rat hippocampal slices to obtain more information about the site and mechanism of interactions between metabotropic glutamate receptors and adenosine receptors. 2. The results show that the suppression of adenosine sensitivity is explained by a selectively reduced responsiveness to A(1) receptor stimulation, and does not involve any facilitation of A(2A) adenosine receptors, since it can be obtained in the absence of endogenous adenosine and is not prevented by the A(2A) receptor blocker ZM241385. 3. The glutamate receptors involved are of the group I class since the suppression of adenosine sensitivity is produced by ACPD and the group I selective compound DHPG. Furthermore, the effects of DHPG could be prevented by LY367385, a selective antagonist at the mGlu(1a) subtype of group I receptors. The selective antagonist at mGlu(5) receptors, SIB1893, did not prevent the suppression of adenosine sensitivity by DHPG. Blockade of the DHPG/adenosine interaction was also obtained by superfusion with the protein kinasae C inhibitor chelerythrine. 4. Since the suppression of adenosine responses by metabotropic receptor agonists was seen in the paired-pulse paradigm, we conclude that the observed interactions occur at the level of the presynaptic terminals. 5. The interaction with adenosine receptors is not specific, but applies also to a suppression of responses mediated by the GABA(B) receptor agonist baclofen. 6. We conclude that activation of the mGlu1a subtype of receptor can suppress responses mediated via adenosine A1 receptors, probably by activating protein kinase C. Since the changes induced by metabotropic glutamate receptor agonists last for at least 60 min, the data also imply that these interactions could play an important role in changes of synaptic function long after even transient increases of glutamate release in the CNS.

Long-term potentiation and adenosine sensitivity are unchanged in the AS/AGU protein kinase Cgamma-deficient rat.

The AS/AGU rat is a spontaneously occurring mutation which exhibits locomotor abnormalities, reduced tyrosine hydroxylase levels in substantia nigra and lower extracellular levels of dopamine, making it a valuable model for some human locomotor disorders, and spontaneous chronic degeneration. The molecular defect is an absence of protein kinase Cgamma (PKCgamma), an enzyme suggested to play a role in synaptic plasticity. We have therefore examined long-term potentiation (LTP) in hippocampal slices from the mutant animals compared with the normal control strain of Albino Swiss rat. In the CA1 region, LTP was of the same magnitude in mutant and control animals, and the presynaptic inhibitory effects of adenosine were unchanged in naïve slices or following LTP. Paired-pulse inhibition and facilitation were normal. It is concluded that the absence of PKCgamma in this strain does not modify synaptic plasticity or presynaptic sensitivity to adenosine.