Orexin and cannabinoid systems modulate long-term potentiation of the hippocampus CA1 area in anesthetized rats.

Objectives: Long-term potentiation (LTP) is a kind of synaptic plasticity and has a key role in learning and memory. Endocannabinoids and orexins are the endogenous systems that can modulate synaptic plasticity. Given that new studies have shown an interaction between cannabinoid and orexin systems in the brain, we decided to examine this interaction between the two systems on LTP induction in rat's hippocampus. Materials and Methods: Twenty-eight male Wistar rats were used for evaluating the effects of co-administrating of cannabinoid-1 receptor (CB1R) antagonist (AM251) and orexin-2 receptor (OX2R) antagonist (TCS OX2 29) on the induction of LTP in the Schaffer collateral-CA1 synapses of rat hippocampus. The drugs were microinjected into the CA1 area of rat hippocampus 30 min before inducing of LTP. Results: Results showed that sole administration of the antagonists inhibited LTP, with respect to the control group. Also, co-administrating of them reduced LTP as compared to the control group, but not significantly more than that when the antagonists were solely microinjected into the CA1. Nonetheless, the inhibitory effect of concurrent administration of the antagonists on LTP lasted until the end of the recording. Conclusion: These results propose that endogenous cannabinoids and orexins play a role in the expression of LTP, at least by CA1-CB1Rs and CA1-OX2Rs, respectively. Finally, there is no interaction between CB1R and OX2R on the induction of LTP in the Schaffer collateral-CA1 synapses; therefore, these two systems possibly act through common signaling pathways in the hippocampus's CA1 region.

Neuroprotective activity of green synthesized silver nanoparticles against methamphetamine-induced cell death in human neuroblastoma SH-SY5Y cells.

The present study aimed to investigate the neuroprotective activity of the black peel pomegranate extract, and silver nanoparticles (AgNPs) biosynthesized using the extract. We pretreated the human neuroblastoma SH-SY5 cells with the extract and AgNPs and evaluated the neuroprotective activity of these agents against methamphetamine (Meth) cytotoxicity. The NPs were spherical with 19 ± 8 nm size, - 28 mV surface charge, and 0.20 PDI. Meth killed the cells by increasing proapoptotic (Bax, PTEN, AKT, PI3K, NF-κB, P53, TNF-α, Cyt C, and Cas 3) and decreasing the antiapoptotic genes (Bcl-2) expression. Exposure to Meth caused DNA fragmentation and increased the intercellular ROS and malondialdehyde (MDA) levels while reducing the mitochondrial membrane potential (MMP). A 4-h pretreatment of the cells with the extract and AgNPs could retain the viability of the cells above 80% by increasing the Bcl-2 expression up to fourfold and inhibiting the cell death pathways. ROS, MDA, and MMP levels in the pretreated cells were close to the control group. The percentage of necrosis in cells pretreated with the extract and AgNPs declined to 32% and 8%, respectively. Our promising findings indicated that AgNPs could reduce Meth-induced oxidative stress and prevent necrotic and apoptotic cell death by regulating related genes' expression.

Laser thrombolysis and in vitro release kinetics of tPA encapsulated in chitosan polysulfate-coated nanoliposome.

A major challenge in managing coronary artery disease is to find an effective thrombolytic therapy with minimal side effects. Laser thrombolysis is a practical procedure to remove the thrombus from inside blocked arteries, although it can cause embolism and re-occlusion of the vessel. The present study aimed to design a liposome drug delivery system for the controlled release of tissue plasminogen activator (tPA) and delivery of drug system into the thrombus by Nd:YAG laser at a wavelength of 532 nm for the treatment of arterial occlusive diseases. In this study, tPA encapsulated into the chitosan polysulfate-coated liposome (Lip/PSCS-tPA) was fabricated by a thin-film hydration technique. The particle size of Lip/tPA and Lip/PSCS-tPA was 88 and 100 nm, respectively. The release rate of tPA from Lip/PSCS-tPA was measured to be 35 % and 66 % after 24 h and 72 h, respectively. Thrombolysis through the delivery of Lip/PSCS-tPA into the thrombus during the laser irradiation was higher compared to irradiated thrombus without the nanoliposomes. The expression of IL-10 and TNF-α genes was studied by RT-PCR. The level of TNF-α for Lip/PSCS-tPA was lower than that of tPA, which can lead to improved cardiac function. Also, in this study, the thrombus dissolution process was studied using a rat model. After 4 h, the thrombus area in the femoral vein was significantly lower for groups treated with Lip/PSCS-tPA (5 %) compared to the groups treated with tPA alone (45 %). Thus, according to our results, the combination of Lip/PSCS-tPA and laser thrombolysis can be introduced as an appropriate technique for accelerating thrombolysis.

An insight overview on COVID-19 mRNA vaccines: Advantageous, pharmacology, mechanism of action, and prospective considerations.

The worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has urged scientists to present some novel vaccine platforms during this pandemic to provide a rather prolonged immunity against this respiratory viral infection. In spite of many campaigns formed against the administration of mRNA-based vaccines, those platforms were the most novel types, which helped us meet the global demand by developing protection against COVID-19 and reducing the development of severe forms of this respiratory viral infection. Some societies are worry about the COVID-19 mRNA vaccine administration and the potential risk of genetic integration of inoculated mRNA into the human genome. Although the efficacy and long-term safety of mRNA vaccines have not yet been fully clarified, obviously their application has switched the mortality and morbidity of the COVID-19 pandemic. This study describes the structural features and technologies used in producing of COVID-19 mRNA-based vaccines as the most influential factor in controlling this pandemic and a successful pattern for planning to produce other kind of genetic vaccines against infections or cancers.

Fabrication of Fe(III)-doped mesoporous silica nanoparticles as biocompatible and biodegradable theranostic system for Remdesivir delivery and MRI contrast agent.

Coronavirus causes the majority of common colds and is spread in the same way that all viruses attack the respiratory system. Despite the trials and efforts to produce a suitable vaccine, there are solutions for the quick, effective and efficient use of existing drugs to prevent infections and improve the condition of patients. In this study, we synthesized mSiO2 NPs doped with Fe(III) (Fe(III)-mSiO2) and loaded with Rd, and then the NPs coated with PDA as gatekeeper. The several surface methods successfully approved fabrication of the nanosystem. Finally, the application of nanosystem as theranostic system was studied. The DLS measurements showed the average sizes of 115 ± 2 and 124 ± 3.6 nm for Fe-SiO2 and Fe-SiO2@PDA NPs, respectively, suitable for theranostic intentions. The drug release experiments, the in-vitro MRI measurements and MTT test were accomplished, respectively, to show applicability of the nanosystem as a biodegradable Rd delivery system, MRI contrast agent, and the biocompatibility nanocarrier. The results achieved through in-vitro tests exhibited that the Fe-SiO2 system has potential application as a contrast agent in MRI with relaxivity (r1) of 14 ± 1 mM-1 s-1. The Rd drug was released from the Fe-SiO2(Rd)load@PDA system more efficient and faster than SiO2(Rd)load@PDA at 7.4, supporting the doping of Fe in SiO2 induces a biodegradability feature in that. The in-vitro biocompatibility studies showed that the Fe-SiO2 NPs (without drug) is not toxic.

Anti-inflammatory and collagenation effects of zinc oxide-based nanocomposites biosynthesised with Mentha longifolia leaf extract.

OBJECTIVE: The integration of nanomaterials and herbal medicine has led to the design of new nanocomposites, which are therapeutically more effective. The purpose of this study was to prepare different zinc oxide (ZnO)-based nanoparticles (NPs) via Mentha longifolia extract based on gauze linen fibre and study its effects on wound healing. METHODS: The textural properties, morphology, thermal stability, purity, spectroscopic and phase structure of nanoparticles were investigated. Subsequently, male Wistar rats were subjected to wounds in six different treatment groups: Group I: control; group II: ZnO/W prepared in water (W); group III: ZnO/M synthesised with Mentha longifolia (M) extract; group IV: ZnO/copper(II) oxide (CuO)/M nanocomposite synthesised with M extract; group IV: treated with ZnO/silver (Ag)/M nanocomposite; group V: treated with ZnO/Ag/M nanocomposite; and finally, group VI: treated with ZnO/CuO/Ag/M nanocomposite. In all groups, the wounds were treated for 21 days with prepared samples. Every seven days, after measuring the decreasing rate of the wound size, tissue samples from each group were taken for histopathological analysis. The prepared tissue sections were assessed by haematoxylin and eosin staining for the formation of the epidermis, dermis and muscular tissue, and Masson's Trichrome staining for the formation of collagen fibres. RESULTS: The results showed that the ZnO/CuO/Ag/M nanocomposite was a significantly more effective wound healing material in comparison with other samples (p<0.05). CONCLUSION: In this study, the integration of ZnO/CuO/Ag nanocomposites with secondary metabolites of Mentha longifolia gave rise to a superior combination, which could support different phases of wound healing via the regulation of cytokines and growth factors in the course of healing.

Fabrication and evaluation of optical nanobiosensor based on localized surface plasmon resonance (LSPR) of gold nanorod for detection of CRP.

C-reactive protein (CRP) is a plasma protein that is one of the most expressed proteins in acute phase inflammation cases. It is a well-known biomarker for inflammatory disorders. There is a significant correlation between increasing CRP concentration and the risk of being exposed to cardiovascular diseases (CVD) and sepsis; thus, monitoring and quantifying CRP levels in a simple, inexpensive, and quick manner can improve clinical diagnostics and help prevent major inflammatory conditions. Here a nanobiosensor was developed, benefiting from the LSPR property of gold-nanorod (GNR) to measure CRP concentration. Nanorods were fabricated using One-pot synthesis by trimethyl ammonium bromide (CTAB) as a surfactant. This method provides the advantage of both step and time reduction in synthesis and decreases the contamination probability of nanorods as the products. The nanorods were characterized using TEM with an average size of (24 ± 1 nm) × (5 ± 1 nm) and a typical aspect ratio of ∼4.9. The surface of the rods was modified with a specific aptamer for the target protein, and the LSPR shifts due to the gold nanorod's refractive index change as the result of protein interaction with the biosensor investigated using a 100-900 nm UV absorption device. The results indicated that the nanobiosensor could respond to different CRP concentrations within 30 min. The selectivity test has shown nonresponsive results of nanobiosensor to BSA and TNF-α proteins which are used to evaluate the biosensor behavior in non-target proteins. The detection limit was evaluated at 2 nM, and the sensor's linear response ranged between 2 - 20 nM.

High-performance strategy for the construction of electrochemical biosensor for simultaneous detection of miRNA-141 and miRNA-21 as lung cancer biomarkers.

In this study, the dual signal-labeled hairpin-structured DNA (dhDNA)-based probes have been developed to construct a novel nano-biosensor. This one hairpin-structured probe consists of a thiolated methylene blue-labeled hairpin capture probe (MB-HCP) as an inner reference probe and a ferrocene-modified anti-miRNA-21 DNA probe (Fc-AP-21). This novel integrated structure of MB-HCP and Fc-AP-21 was designed on one sensing interface for sensitive and simultaneous detection of the miRNA-141 and miRNA-21 in one single assay. The proposed strategy has a good ability to reduce the interference of environmental factors and it was designed to control the initial responses of Fc-AP to MB-HCP ((IFc/IMB)0) at a 1:1 ratio, which is desirable for further increase in the sensitivity and signal-to-noise ratio of the biosensor operation. Besides, the biosensor was first prepared by immobilizing the dhDNA (Fc-AP-21/MB-HCP) onto the modified glassy carbon electrode. After hybridization with the anti-miRNA-141 complementary sequence (ACP-141), the dhDNA structure was compelled to open and form the final structure of the biosensor. Also, the miRNA-141 and miRNA-21 dissociate duplex structures due to the highly matched sequences between the miRNA-141 and ACP-141 and the miRNA-21 and Fc-AP-21. A linear relationship was found between the logarithm of miRNA-141 and miRNA-21 concentrations and the signal changes. This feature was used to detect the two miRNAs. This sensitive biosensor provided low detection limits of 0.89 and 1.24 fM for the miRNA-141 and miRNA-21, respectively. Also, it has wide linear ranges of 2.0 to 105 fM, with highly selective and accurate results for its application in plasma samples. Therefore, this strategy can be promising as a suitable platform for simultaneous and early detection of various cancer biomarkers.

Interaction of the Blood Components with Ascending Thoracic Aortic Aneurysm Wall: Biomechanical and Fluid Analyses.

BACKGROUND: Ascending thoracic aortic aneurysm (ATAA) is an asymptomatic localized dilation of the aorta that is prone to rupture with a high rate of mortality. While diameter is the main risk factor for rupture assessment, it has been shown that the peak wall stress from finite element (FE) simulations may contribute to refinement of clinical decisions. In FE simulations, the intraluminal boundary condition is a single-phase blood flow that interacts with the thoracic aorta (TA). However, the blood is consisted of red blood cells (RBCs), white blood cells (WBCs), and plasma that interacts with the TA wall, so it may affect the resultant stresses and strains in the TA, as well as hemodynamics of the blood. METHODS: In this study, discrete elements were distributed in the TA lumen to represent the blood components and mechanically coupled using fluid-structure interaction (FSI). Healthy and aneurysmal human TA tissues were subjected to axial and circumferential tensile loadings, and the hyperelastic mechanical properties were assigned to the TA and ATAA FE models. RESULTS: The ATAA showed larger tensile and shear stresses but smaller fluid velocity compared to the ATA. The blood components experienced smaller shear stress in interaction with the ATAA wall compared to TA. The computational fluid dynamics showed smaller blood velocity and wall shear stress compared to the FSI. CONCLUSIONS: This study is a first proof of concept, and future investigations will aim at validating the novel methodology to derive a more reliable ATAA rupture risk assessment considering the interaction of the blood components with the TA wall.

Utilization of SUMO Tag and Freeze-thawing Method for a High-level Expression and Solubilization of Recombinant Human Angiotensinconverting Enzyme 2 (rhACE2) Protein in E. coli.

BACKGROUND: SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) as a receptor for entering the host cells. Production of the ACE2 molecule is important because of its potency to use as a blocker and therapeutic agent against SARS-CoV-2 for the prophylaxis and treatment of COVID-19. OBJECTIVE: The recombinant human ACE2 (rhACE2) is prone to form an inclusion body when expressed in the bacterial cells. METHODS: We used the SUMO tag fused to the rhACE2 molecule to increase the expression level and solubility of the fusion protein. Afterward, the freeze-thawing method plus 2 M urea solubilized aggregated proteins. Subsequently, the affinity of solubilized rhACE2 to the receptor binding domain (RBD) of the SARS-CoV-2 spike was assayed by ELISA and SPR methods. RESULTS: SUMO protein succeeded in increasing the expression level but not solubilization of the fusion protein. The freeze-thawing method could solubilize and recover the aggregated fusion proteins significantly. Also, ELISA and SPR assays confirmed the interaction between solubilized rhACE2 and RBD with high affinity. CONCLUSION: The SUMO tag and freeze- Conclusion: The SUMO tag and freeze-thawing method would be utilized for high-level expression and solubilization of recombinant rhACE2 protein.

A ratiometric electrochemical DNA-biosensor for detection of miR-141.

A sensitive biosensor for the detection of miR-141 has been constructed. The DNA-biosensor is prepared by first immobilizing the thiolated methylene blue-labeled hairpin capture probe (MB-HCP) on two-layer nanocomposite film graphene oxide-chitosan@ polyvinylpyrrolidone-gold nanourchin modified glassy carbon electrode. We used the hematoxylin as an electrochemical auxiliary indicator in the second stage to recognize DNA hybridization via the square wave voltammetry (SWV) responses that record the accumulated hematoxylin on electrode surfaces. The morphology and chemical composition of nanocomposite was characterized using TEM, FE-SEM, and FT-IR techniques. The preparation stages of the DNA-biosensor were screened by electrochemical impedance spectroscopy and cyclic voltammetry. The proposed DNA-biosensor can distinguish miR-141 from a non-complementary and mismatch sequence. A detection limit of 0.94 fM and a linear range of 2.0 -5.0 × 105 fM were obtained using SWV for miR-141 detection. The working potential for methylene blue and hematoxylin was -0.28 and + 0.15 V vs. Ag/AgCl, respectively. The developed biosensor can be successfully used in the early detection of non-small cell lung cancer (NSCLC) by directly measuring miR-141 in human plasma samples. This novel DNA-biosensor is of promise in early sensitive clinical diagnosis of cancers with miR-141 as its biomarker.

Potential diagnostic and prognostic of efferocytosis-related unwanted soluble receptors/ligands as new non-invasive biomarkers in disorders: a review.

Efferocytosis is the process by which apoptotic cells are removed without inflammation to maintain tissue homeostasis, prevent unwanted inflammatory responses, and inhibit autoimmune responses. Coordination of efferocytosis occurs via many surfaces and chemotactic molecules and adaptors. Recently, soluble positive or negative mediators of efferocytosis, have been more noticeable as non-invasive valuable biomarkers in prognosis and targeted therapy. These soluble factors can be detected in different bodily fluids, such as serum, plasma, and urine as a non-invasive method. There are lots of studies that have tried to show the importance of receptors and ligands in disorders; while a few studies tried to indicate the importance of soluble forms of receptors/ligands and their clinical aspects as a systemic compound and shedding of targets related to efferocytosis. Some of these soluble forms also can be as sensitive as specific biomarkers for certain diseases compared with routine biomarkers, such as soluble circulatory Lectin-like oxidized low-density lipoprotein receptor-1 vs. troponin T in the acute coronary syndrome. Thus, this review tried to gain more understanding about efferocytosis-related unwanted soluble receptors/ligands, their roles, the clinical significance, and potential for diagnosis, and prognosis related to different diseases.

Designing new nanoliposomal formulations and evaluating their effects on myeloid-derived suppressor cells and regulatory T cells in a colon cancer model aiming to develop an efficient delivery system for cancer treatment; an in vitro and in vivo study.

Regulfatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) are common immunosuppressive cells in the tumor microenvironment. These cells, through various mechanisms, inhibit antitumor immune responses and impede effective therapies. Therefore, designing an efficient protocol for inducing immune surveillance in tumors is highly recommended. Recently, nanoliposomes have provided broad-spectrum and state-of-the-art vehicles to deliver antigens or immune system compartments in immunotherapies. It has been shown that different lipids in the structure of liposomes and various liposomal formulations can affect immune responses in the tumor microenvironment. This study was aimed to evaluate the effects of four different liposomal formulations on MDSCs and Tregs in C26 tumor-bearing mice. To this end, after preparing liposomes, they were injected into tumor-inoculated mice and analyzed MDSC and Treg population and functions in spleen and tumor tissues. Results showed that 1,2-dioleoyl-3-trimethylammonium propane (DOTAP)-containing liposomes reduced MDSC population and activity in the spleen, but not tumor, compared with other groups significantly (p < 0.05 and p < 0.01, respectively). Moreover, DOTAP-containing liposomes reduced the expression of S100A8 and arginase-1 genes in splenic MDSCs (p < 0.05). In conclusion, we provided evidence that DOTAP-containing liposomes contributed to stimulating immune responses and provided a situation to inhibit immunosuppression in the tumor microenvironment.

The expression levels of MicroRNA-146a, RANKL and OPG after non-surgical periodontal treatment.

OBJECTIVE: MicroRNA-146a (miR-146a) is a regulator of inflammatory response. Periodontitis is a disease with immune pathophysiology of the periodontium in which the inflammation results in the destruction of the soft tissues and alveolar bone. Therefore, the aim of this study was to investigate the expressions of miR-146a, OPG, and RANKL in diseased and healthy periodontal tissues to understand whether miR-146a expression level may associate with OPG and RANKL mRNA levels and OPG/RANKL ratio after non-surgical periodontal treatment. METHODS: The levels of miR-146a, RANKL, and OPG in gingival tissues from patients with generalized periodontitis stages II and III and grades A and B (n = 15, group A), patients with generalized periodontitis stages III and IV and grade C (n = 15, group B), and healthy individuals (n = 10) were determined by real-time PCR. The associations of miR-146a expression with OPG and RANKL levels were evaluated. RESULTS: The levels of miR-146a in two subgroups within periodontitis patients were significantly higher than healthy subjects (P < 0.0001). MiR-146a showed the increased level in group A of patients compared with group B (P < 0.05). Clinical parameters such as probing depth (PD) and clinical attachment loss (CAL) were significantly higher in patients than control group (P < 0.05). The levels of OPG and RANKL were increased in patients compared with healthy subjects, although the elevated levels were not statistically significant. MiR-146a was not associated with OPG and RANKL levels and OPG/RANKL ratio. CONCLUSIONS: The results of this study failed to show the associations of miR-146a level with OPG and RANKL levels and OPG/RANKL ratio in periodontitis after non-surgical periodontal treatment.

Targeted nanostructured lipid carrier containing galangin as a promising adjuvant for improving cytotoxic effects of chemotherapeutic agents.

Resistance to chemotherapeutic drugs is the main limitation of cancer therapy. The combination use of chemotherapeutic agents and galangin (a naturally active flavonoid) amplifies the effectiveness of cancer treatment. This study aimed to prepare arginyl-glycyl-aspartic acid (RGD) containing nanostructured lipid carrier (NLC-RGD) to improve the bioavailability of galangin and explore its ability in improving the cytotoxic effects of doxorubicin (DOX). Galangin-loaded NLC-RGD was prepared by hot homogenization method and characterized by diverse techniques. Then, cytotoxicity, uptake, and apoptosis induction potential of prepared nanoparticles beside the DOX were evaluated on A549 lung cancer cells. Finally, the expression level of some ABC transporter genes was evaluated in galangin-loaded NLC-RGD-treated cells. Nanoparticles with appropriate characteristics of the delivery system (size: 120 nm, polydispersity index: 0.23, spherical morphology, and loading capacity: 59.3 mg/g) were prepared. Uptake experiments revealed that NLC-RGD promotes the accumulation of galangin into cancerous cells by integrin-mediated endocytosis. Results also showed higher cytotoxicity and apoptotic effects of DOX + galangin-loaded NLC-RGD in comparison to DOX + galangin. Gene expression analysis demonstrated that galangin-loaded NLC-RGD downregulates ABCB1, ABCC1, and ABCC2 more efficiently than galangin. These findings indicated that delivery of galangin by NLC-RGD makes it an effective adjuvant to increase the efficacy of chemotherapeutic agents in cancer treatment.

Preparation, characterization and release behavior of chitosan-coated nanoliposomes (chitosomes) containing olive leaf extract optimized by response surface methodology.

This study was dedicated to the optimization and preparation of chitosan-coated liposomes (chitosomes) as promising nanocarriers for retention of olive leaf extract optimized by Response surface methodology (RSM) based on central composite design. Accordingly, the best sample was chosen for further tests with the encapsulation efficiency, stability and electrical conductivity of 94%, 98% and 9.545 mS respectively. The average size of the optimal chitosome and nanoliposome were lower than 100 nm and the zeta potential was altered from a negative charge to positive after addition coating process with chitosan. Moreover, the differential scanning calorimetry of blank and loaded chitosome revealed the increase of fluidity and lower temperature of phase transition in loaded chitosome compared to blank one. FTIR spectra demonstrated that electrostatic interactions and hydrogen bonds occur between phospholipid polar groups, chitosan amine moieties and major olive leaf extract polyphenols including oleuropein and hydroxy tyrosol. Furthermore, the optimal loaded chitosome had the highest stability during 25 days at the temperature of 4 °C. Finally, the in vitro release tests were best fitted with Peppas-Sahlin and Kopcha models in food simulants and gastrointestinal simulated juice respectively revealing erosion-based release model. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at (10.1007/s13197-021-04972-2).

A cross-linked anti-TNF-α aptamer for neutralization of TNF-α-induced cutaneous Shwartzman phenomenon: A simple and novel approach for improving aptamers' affinity and efficiency.

To increase the efficiency of aptamers to their targets, a simple and novel method has been developed based on aptamer oligomerization. To this purpose, previously anti-human TNF-α aptamer named T1-T4 was trimerized through a trimethyl aconitate core for neutralization of in vitro and in vivo of TNF-α. At first, 54 mer T1-T4 aptamers with 5'-NH2 groups were covalently coupled to three ester residues in the trimethyl aconitate. In vitro activity of novel anti-TNF-α aptamer and its dissociation constant (Kd ) was done using the L929 cell cytotoxicity assay. In vivo anti-TNF-α activity of new oligomerized aptamer was assessed in a mouse model of cutaneous Shwartzman. Anchoring of three T1-T4 aptamers to trimethyl aconitate substituent results in formation of the 162 mer fragment, which was well revealed by gel electrophoresis. In vitro study indicated that the trimerization of T1-T4 aptamer significantly improved its anti-TNF-α activity compared to non-modified aptamers (P < 0.0001) from 40% to 60%. The determination of Kd showed that trimerization could effectively enhance Kd of aptamer from 67 nM to 36 nM. In vivo study showed that trimer aptamer markedly reduced mean scar size from 15.2 ± 1.2 mm to 1.6 ± 0.1 mm (P < 0.0001), which prevent the formation of skin lesions. In vitro and in vivo studies indicate that trimerization of anti-TNF-α aptamer with a novel approach could improve the anti-TNF-α activity and therapeutic efficacy. According to our findings, a new anti-TNF-α aptamer described here could be considered an appropriate therapeutic agent in treating several inflammatory diseases.

Rapamycin attenuates gene expression of programmed cell death protein-ligand 1 and Foxp3 in the brain; a novel mechanism proposed for immunotherapy in the brain.

BACKGROUND AND PURPOSE: Programmed cell death protein-1 (PD1) expresses on the cell surface of the activated lymphocytes and at least a subset of Foxp3+ regulatory T cells. The binding of PD1 to its ligands including PD-L1 and PD-L2 leads to deliver an inhibitory signal to the activated cells. Although PD1/PD-L signal deficiency can lead to failure in the self-tolerance and development of autoimmunity disorders, PD1 blockade with monoclonal antibodies is considered an effective strategy in cancer immunotherapy. Determining effective environmental factors such as stress conditions on the expression of PD1 and PD-L1 genes can provide an immunotherapeutic strategy to control PD1 signaling in the patients Mammalian target of rapamycin signaling is a stress-responsive pathway in the cells that can be blocked by rapamycin. In this study, the effects of rapamycin on the expression of immunoregulatory genes were investigated in the stress condition. EXPERIMENTAL APPROACH: Daily administration of rapamycin (1.5 mg/kg per day) was used in the mouse model of restraint stress and the relative expression of PD1, PD-L1, and Foxp3 genes in the brain and spleen were evaluated using quantitative real-time polymerase chain reaction method. FINDINGS/RESULTS: With our observation, daily restraint stress ceased rapamycin to decrease the expression of Foxp3 in the brain significantly. These findings would be beneficial in developing tolerance to autoimmune diseases and finding immunopathology of stress in the CNS. In another observation, daily administration of rapamycin decreased the expression of PD-L1 in the brain cells of mice. In the spleen samples, significant alteration in genes of interest expression was not detected for all groups of the study. CONCLUSION AND IMPLICATIONS: Downregulation of the PD-L1 gene in the brain induced by rapamycin can be followed in future experiences for preventing immunosuppressive effects of PD/PD-L1 signal in the brain.

Electrochemical aptasensor for Escherichia coli O157:H7 bacteria detection using a nanocomposite of reduced graphene oxide, gold nanoparticles and polyvinyl alcohol.

In recent years, public attention has drawn to food safety due to the constant outbreaks of foodborne diseases; subsequently, to control and prevent this group of diseases, early screening of foodborne pathogens has become significant. In this study, a new aptamer-based electrochemical sensor was proposed to detect Escherichia coli O157:H7 (E. coli), one of the most threatening bacterial pathogens, using nanoparticles-modified glassy carbon electrode. Firstly, the electrode was coated with a reduced graphene oxide-poly(vinyl alcohol) and gold nanoparticles nanocomposite (AuNPs/rGO-PVA/GCE) to increase the electrode surface area and consequently raise the sensor sensitivity. Afterwards, to enhance the selectivity of the modified electrode, aptamers were attached to the surface of the prepared electrode. The prepared electrode was characterized using energy-dispersive spectroscopy, field-emission scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, and electrochemical impedance spectroscopy. The relationship of the E. coli concentration and the peak current in the range from 9.2 CFU mL-1 to 9.2 × 108 CFU mL-1 was linear, and the limit of detection was calculated as 9.34 CFU mL-1. The suitability of the proposed sensor for real sample measurements was investigated by recovery studies in tap water, milk, and meat samples. The results showed that the biosensor and traditional culture counting methods are equally sensitive for detecting E. coli.

Group A Streptococcus Antibiotic Resistance in Iranian Children: A Meta-analysis.

OBJECTIVES: Streptococcus pyogenes is associated with mild to severe infections, particularly in children and young adults. Proper antimicrobial treatment of S. pyogenes infections is important to prevent post-streptococcal complications. Therefore, the purpose of this meta-analysis was to evaluate the prevalence of S. pyogenes antibiotic resistance among Iranian children. METHODS: We identified all published studies up to 20 March 2019 related to S. pyogenes antibiotic resistance by searching Persian and English electronic databases. Search terms included S. pyogenes, children, and Iran. Out of 1022 publications, 12 articles were eligible and included based on the inclusion and exclusion criteria. RESULTS: Our analysis indicated the following prevalence pattern for S. pyogenes antimicrobial resistance in Iran: 4.2% to penicillin, 38.3% to amoxicillin, 5.4% to erythromycin, 12.0% to azithromycin, 12.6% to clarithromycin, 12.4% to clindamycin, 15.3% to rifampicin, 8.1% to ceftriaxone, 17.6% to cefixime, 36.9% to ampicillin, 14.1% to vancomycin, 8.4% to chloramphenicol, 30.4% to tetracycline, 8.8% to cefotaxime, 82.8% to trimethoprim/sulfamethoxazole, 39.6% to gentamicin, 11.9% to ofloxacin, 28.3% to carbenicillin, 3.1% to ciprofloxacin, 6.1% to imipenem, 18.2% to cephalothin, 57.6% to tobramycin, 49.3% to kanamycin, 79.0% to cloxacillin, 12.9% to cephalexin, 10.7% to cefazolin, and 89.5% to amoxicillin-clavulanic acid. CONCLUSIONS: Our findings suggest penicillin (in non-allergic children) and macrolides, lincosamides, and narrow-spectrum cephalosporins (in penicillin-allergic children) as the treatments of choice in Iran.