Crosstalk Between NK Cell Receptors and Tumor Membrane Hsp70-Derived Peptide: A Combined Computational and Experimental Study

Natural killer (NK) cells are central components of the innate immunity system against cancers. Since tumor cells have evolved a series of mechanisms to escape from NK cells, developing methods for increasing the NK cell antitumor activity is of utmost importance. It is previously shown that an ex vivo stimulation of patient-derived NK cells with interleukin (IL)-2 and Hsp70-derived peptide TKD (TKDNNLLGRFELSG, aa450-461) results in a significant upregulation of activating receptors including CD94 and CD69 which triggers exhausted NK cells to target and kill malignant solid tumors expressing membrane Hsp70 (mHsp70). Considering that TKD binding to an activating receptor is the initial step in the cytolytic signaling cascade of NK cells, herein this interaction is studied by molecular docking and molecular dynamics simulation computational modeling. The in silico results showed a crucial role of the heterodimeric receptor CD94/NKG2A and CD94/NKG2C in the TKD interaction with NK cells. Antibody blocking and CRISPR/Cas9-mediated knockout studies verified the key function of CD94 in the TKD stimulation and activation of NK cells which is characterized by an increased cytotoxic capacity against mHsp70 positive tumor cells via enhanced production and release of lytic granules and pro-inflammatory cytokines.

Investigating the Effect of Aspirin on apoAI-Induced ATP Binding Cassette Transporter 1 Protein Expression and Cholesterol Efflux in Human Astrocytes

Background

Neurons need a high amount of cholesterol to maintain the stability of their membrane-rich structures. Astrocytes synthesize and distribute cholesterol to neurons, and ABCA1 is a key mediator of cholesterol efflux to generate HDL for cholesterol transport in the brain. Several studies imply the effect of aspirin on ABCA1 expression in peripheral cells such as macrophages. Here, we compared the effect of aspirin with apoA-I on ABCA1 protein expression and cholesterol efflux in human astrocytes.

Materials and Methods

Human astrocytes were cultured, and the effects of aspirin on the expression and protein levels of ABCA1 were investigated through RT-PCR and Western blot analysis. Additionally, the effect of co-treatment with apoA-I and aspirin on ABCA1 protein level and cholesterol efflux was evaluated.

Results

Dose and time-course experiments showed that the maximum effect of aspirin on ABCA1 expression occurred at a concentration of 0.5 mM after 12 h of incubation. RT-PCR and western blot data showed that aspirin upregulates ABCA1 expression by up to 4.7-fold and its protein level by 67%. Additionally, co-treatment with aspirin and apoA-I increased cholesterol release from astrocytes, indicating an additive effect of aspirin on apoAI-mediated cholesterol efflux.

Conclusions

The results suggest a potential role of aspirin in increasing ABCA1 expression and cholesterol efflux in astrocytes, similar to the effect of apoA-I. This indicates that aspirin could potentially regulate brain cholesterol balance and can be considered in certain neurological diseases, in particular in some neurological disorders related to cholesterol accumulation such as Alzheimer's disease.

Unveiling Arformoterol as a potent LSD1 inhibitor for breast cancer treatment: A comprehensive study integrating 3D-QSAR pharmacophore modeling, molecular docking, molecular dynamics simulations and in vitro assays

Lysine Specific Demethylase 1 (LSD1) has been identified as a chromatin-modifying enzyme implicated in various cancer pathogeneses, highlighting the potential for novel epigenetic cancer treatments through the development of effective inhibitors. We employed 3D-QSAR pharmacophore modeling, molecular docking, and molecular dynamics simulations to identify a promising drug candidate for LSD1 inhibition. RMSD, RMSF, H-bond, and DSSP analysis demonstrated that ZINC02599970 (Arformoterol) and ZINC13453966 exhibited the highest LSD1 inhibitory potential. Experimental validation using MCF-7 and MDA-MB-231 cell lines revealed that Arformoterol displayed potent antiproliferative activity with IC50 values of 12.30 ± 1.48 μM and 19.69 ± 1.15 μM respectively. In contrast, the IC50 values obtained for the control (tranylcypromine) in exposure to MCF-7 and MDA-MB-231 cells were 104.6 ± 1.69 μM and 77 ± 0.67 μM, respectively. Arformoterol demonstrated greater LSD1 inhibitory potency in MCF-7 cells compared to MDA-MB-231 cells. Also, the expression of genes involved in chromatin rearrangement (LSD1), angiogenesis (VEGF1), cell migration (RORα), signal transduction (S100A8), apoptosis, and cell cycle (p53) were investigated. Arformoterol enhanced apoptosis and induced cell cycle arrest at the G2/M phase, both in MCF-7 and MDA-MB-231 cancer cells. Based on our findings, we propose that Arformoterol represents a promising candidate for breast cancer treatment, owing to its potent LSD1 inhibitory activity.

Investigation of crocin's protective effect on cyclophosphamide-induced hypothalamic-pituitary-gonadal axis defects in adult female rats

Cyclophosphamide is a drug used in chemotherapy. However, it has side effects, including changes in reproductive system functioning. Some herbal compounds can reduce the harmful effects of cyclophosphamide. This study aims to investigate the protective role of crocin against changes caused by Cyclophosphamide in ovarian tissue through changes in the expression of genes involved in the hypothalamic-pituitary-gonadal axis. This experimental study was performed on 24 adult female Wistar rats. Mice were divided into four groups (normal saline, 30 mg/kg cyclophosphamide, 100 mg/kg crocin and 30 mg/kg cyclophosphamide, and 200 mg/kg crocin and 30 mg/kg cyclophosphamide). At the end of the treatment period, the hypothalamus and ovaries were also removed to evaluate ob-Rb, ob-Ra, and NPY genes expression using real-time PCR and histological changes in the ovaries. Data were analyzed by SPSS statistical software. The expression of genes, number of follicles, and follicle diameter significantly decreased in the cyclophosphamide-treated groups compared with the control group. In the crocin and cyclophosphamide-treated groups, drug-induced reproductive complications were mitigated. The current findings indicate that by increasing the expression of genes ob-Rb, ob-Ra, and NPY, crocin could modulate the harmful effects of cyclophosphamide.

Paradoxical effect of Aβ on protein levels of ABCA1 in astrocytes, microglia, and neurons isolated from C57BL/6 mice: an in vitro and in silico study to elucidate the effect of Aβ on ABCA1 in the brain cells

Impaired cholesterol metabolism has been reported in Alzheimer's disease. Since ABCA1 is one of the main players in the brain's cholesterol homeostasis, here we used the in-vitro and in-silico experiments to investigate the effect of Aβ on ABCA1 protein levels in microglia, astrocytes, and neurons in mice. Microglia, astrocytes, and neurons were cultured and exposed to beta amyloid. ABCA1 in cell lysates was determined by Western blotting, and cholesterol efflux was measured in the conditioned media. Molecular docking, molecular dynamics simulations, and MM-GBSA analysis were conducted to gain a better understanding of the effects of Aβ on ABCA1. In response to Aβ, the protein levels of ABCA1 increase significantly in microglia, astrocytes, and neurons; however, its ability to enhance cholesterol efflux is diminished. Aβ inhibited the function of ABCA1 by obstructing the extracellular tunnel that transports lipids outside the cell, as determined by molecular docking. MD simulation analysis validated these findings. Our results demonstrated that Aβ could increase ABCA1 protein levels in various brain cells, regardless of cell type. Molecular docking, molecular dynamics simulation, and MM-GBSA studies indicate that Aβ has a significant effect on the structural conformation of ABCA1, possibly interfering with its function. We believe that the conformational changes of ABCA1 will inhibit its ability to subsequently release cellular cholesterol. Aβ may obstruct the extracellular tunnel of ABCA1, rendering it less accessible to proteases such as the calpain family, which may explain the increase in ABCA1 levels but decrease in its function.Communicated by Ramaswamy H. Sarma.

Cardioprotective effect of tamoxifen and raloxifene: Preventing proteoglycan synthesis by modulating non-canonical TGF-β signalling through NADPH oxidase and ERK phosphorylation

Atherosclerosis, a leading cause of cardiovascular disease, remains a significant global health concern. Tamoxifen and raloxifene, selective estrogen receptor modulators (SERMs), have demonstrated potential cardioprotective effects. However, the underlying molecular mechanisms by which these SERMs modulate Transforming Growth Factor-β (TGF-β) signaling in human vascular smooth muscle cells (VSMCs) remain largely unexplored. This study sought to investigate the impact of tamoxifen and raloxifene on TGF-β-induced CHSY1 expression and Smad2 linker region phosphorylation in VSMCs and to elucidate the role of reactive oxygen species (ROS), NADPH oxidase (NOX), and kinase pathways in mediating these effects. Employing a comprehensive experimental strategy, VSMCs were treated with TGF-β in the presence or absence of tamoxifen, raloxifene, and various pharmacological inhibitors. Subsequently, CHSY1 mRNA expression, Smad2C and Smad2L phosphorylation, ROS production, p47phox and ERK 1/2 phosphorylation were assessed. Our results revealed that tamoxifen and raloxifene significantly attenuated TGF-β-mediated CHSY1 mRNA expression and Smad2 linker region phosphorylation, without affecting the canonical TGF-β-Smad2C pathway. Furthermore, these compounds effectively inhibited ROS production, p47phox and ERK 1/2 phosphorylation, implicating the involvement of the TGF-β-NOX-ERK-Smad2L signaling cascade in their cardioprotective properties. This study provides a comprehensive understanding of the molecular mechanisms underlying the cardioprotective effects of tamoxifen and raloxifene in VSMCs, offering valuable insights for the development of targeted therapeutic strategies aimed at atherosclerosis prevention and the promotion of cardiovascular health.

The effect of natural polyphenols Resveratrol, Gallic acid, and Kuromanin chloride on human telomerase reverse transcriptase (hTERT) expression in HepG2 hepatocellular carcinoma: role of SIRT1/Nrf2 signaling pathway and oxidative stress

BACKGROUND

There is evidence that low doses or physiological concentrations of certain natural polyphenols enhance the activity of telomerase. However, the precise mechanism by which natural polyphenols regulate telomerase activity remains unclear. Recent research indicates that NF-E2 related factor 2 (Nrf2) and silent information regulator 1 (SIRT1) are involved in human telomerase reverse transcriptase (hTERT) regulation. Thus, in order to better comprehend the mechanism by which polyphenols regulate hTERT, the present study investigated the effects of the natural polyphenols Resveratrol, Gallic acid, and Kuromanin chloride on hTERT, Nrf2, and SIRT1 expression as well as oxidative stress in HepG2 hepatocellular carcinoma.

METHODS

The trypan blue dye exclusion assay was used to assess cell viability. The level of mRNA for hTERT, Nrf2, and SIRT1 was then determined using real-time PCR. A spectrophotometric analysis was conducted to quantify oxidative stress markers.

RESULTS

The results demonstrated that Resveratrol induces the expression of hTERT and the SIRT1/Nrf2 pathway in a dose-dependent manner. Gallic acid at concentrations of 10 and 20 μM also increased the expression of the hTERT and SIRT1/Nrf2 pathway. Furthermore, dose-dependent overexpression of hTERT and Nrf2 was induced by Kuromanin chloride at 10 and 20 µM. Moreover, we found that Resveratrol and Kuromanin chloride ameliorated oxidative stress, whereas Gallic acid exacerbated it.

CONCLUSIONS

This study demonstrates that low doses of polyphenols (Resveratrol, Gallic acid, and Kuromanin chloride) upregulate the expression of the hTERT gene in the HepG2 hepatocellular carcinoma cell line, possibly via induction of the SIRT1/Nrf2 signaling pathway. Therefore, by targeting this pathway or hTERT, the anti-cancer effect of polyphenols can be enhanced.

Further evidence to support acute and chronic anti-inflammatory effects of Nasturtium officinale

Background and purpose:

Previously, we reported the anti-inflammatory properties of Nasturtium officinale (watercress) in several models of acute inflammation. This study was designed to explore the effects of topical and systemic administrations of N. officinale in the two chronic inflammatory models and to evaluate the role of TNF-α and IL-1β in these effects.

Experimental approach:

Folin-Ciocalteu and aluminum chloride methods were used to estimate the extract’s total phenol and flavonoid content, respectively. Carrageenan-induced paw edema was carried out and TNF-α and IL-1β concentrations in the carrageenan-treated paw tissue were determined. Formalin injection into rat hind paws (7 days) and the application of 12-O-tetradecanoyl phorbol-13-acetate (TPA) on mouse ears (9 days) were used to simulate chronic inflammation. Furthermore, a histological assessment of the inflamed tissues was carried out.

Findings/Results:

The extract’s flavonoid and phenolic contents were 90.26 ± 4.81 mg rutin equivalents/g and 68 ± 8.16 gallic acid equivalents/g gallic acid, respectively. N. officinale pretreatment in all doses administered considerably decreased carrageenan-induced edema. The extract also reduced IL-1β levels in carrageenan- treated paws while did not affect TNF-α levels. Oral and topical administrations of N. officinale considerably reserved the paw and ear edema. The extract also ameliorated the tissue injuries due to formalin and TPA challenges.

Conclusion and implications:

The data confirmed the topical and systemic anti-inflammatory effects of watercress against two chronic models of inflammation. They suggested that these properties are not related to TNF-α but could be attributed to inhibition of IL-1β and inhibition of leukocyte infiltration.

Effect of ethanolic extract of Stachys pilifera Benth on subacute experimental models of inflammation and some underlying mechanisms

Background and purpose

This study was designed to evaluate the anti-inflammatory activities of S. pilifera (HESP) in two sub-acute models of inflammation and clarified some possible mechanisms.

Experimental approach

Colorimetric methods were used to determine total phenol and flavonoid contents. Carrageenan or formalin-induced rat paw edema (seven days) and multiple application TPA-induced ear edema in mice (9 days) were used. The concentration of IL-1 and TNF-α were measured in the inflamed paw, as well as MDA levels in the serum and liver. Histopathological studies and in vitro anti-inflammatory effects of the extract were also studied using heat-or hypotonicity-induced hemolysis in RBC humans.

Findings/Results

Total phenol and flavonoid contents of HESP were 101.35 ± 2.96 mg GAE/g extract and 660.79 ± 10.06 mg RE g extract, respectively. Oral (100 and 200 mg/kg) and topical application (5 mg/ear) of HESP significantly inhibited formalin-induced paw edema and multiple TPA-induced ear edema. The extract also significantly decreased the serum and liver levels of MDA in the carrageenan and formalin tests. The elevated levels of TNF-α and IL-1β in the carrageenan-injected paw were not affected by HESP. The extract (50-800 μg/mL) inhibited heat-or hypotonicity-induced hemolysis. Histopathological examination of the inflamed tissues revealed that HESP inhibited congestion and leukocyte infiltration.

Conclusion and implications

The findings confirmed the potent anti-inflammatory effects of S. pilifera in two sub-acute inflammation models and suggested that these properties were not related to IL-1 and TNF-α, but could be attributed to inhibition of lipid peroxidation, membrane stabilization, and inhibition of leukocyte penetration.

The identification of novel inhibitors of human angiotensin-converting enzyme 2 and main protease of Sars-Cov-2: A combination of in silico methods for treatment of COVID-19

The angiotensin-converting enzyme 2 (ACE2) and main protease (MPro), are the putative drug candidates for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we performed 3D-QSAR pharmacophore modeling and screened 1,264,479 ligands gathered from Pubchem and Zinc databases. Following the calculation of the ADMET properties, molecular docking was carried out. Moreover, the de novo ligand design was performed. MD simulation was then applied to survey the behavior of the ligand-protein complexes. Furthermore, MMPBSA has utilized to re-estimate the binding affinities. Then, a free energy landscape was used to find the most stable conformation of the complexes. Finally, the hybrid QM-MM method was carried out for the precise calculation of the energies.

The Hypo1 pharmacophore model was selected as the best model. Our docking results indicate that the compounds ZINC12562757 and 112,260,215 were the best potential inhibitors of the ACE2 and MPro, respectively. Furthermore, the Evo_1 compound enjoys the highest docking energy among the designed de novo ligands. Results of RMSD, RMSF, H-bond, and DSSP analyses have demonstrated that the lead compounds preserve the stability of the complexes’ conformation during the MD simulation. MMPBSA data confirmed the molecular docking results. The results of QM-MM showed that Evo_1 has a stronger potential for specific inhibition of MPro, as compared to the 112,260,215 compound.

Antioxidant and hepatoprotective effects of Artemisia dracunculus against CCl4-induced hepatotoxicity in rats

OBJECTIVE

The present study was conducted to investigate the antioxidant and hepatoprotective activity of the hydro-alcoholic extract of aerial parts of Artemisiadracunculus (HAAD) against CCl₄-induced hepatotoxicity in rats.

MATERIALS AND METHODS

The antioxidant activity was evaluated by reducing power, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 20-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Rats were pre-treated with either 50, 100, and 200 mg/kg of HAAD or silymarin (100 mg/kg; served as the positive control group) for 15 days and they received a single dose of CCl₄ on the last day. Hepatoprotective effects were investigated by assessment of serum biochemical enzymes such as alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total protein (TP), total bilirubin (TB), malondialdehyde (MDA), and antioxidant enzymes (SOD, CAT, GST and GSH), along with histopathological studies.

RESULTS

Total phenolic content was 197.22±3.73 mg gallic acid equivalent/g HAAD dry weight. HAAD indicated powerful activity in FRAP, DPPH and ABTS tests. Acute toxicity study showed that the extract had an LD₅₀ of >5000 mg/kg. Oral treatment with HAAD exhibited a significant decrease in the levels of AST, ALT, ALP and TB and an increase in the level of TP. The extract significantly diminished MDA levels. The activities of the antioxidant enzymes were significantly augmented in rats pretreated with HAAD 200 mg/kg. Histopathological examination demonstrated lower liver damage in HAAD-treated groups as compared to CCl₄ groups.

CONCLUSION

Our findings indicated hepatoprotective effects of the hydro-alcoholic extract of A. dracunculus on CCl₄-induced hepatic damage in rats and suggested that these effects may be produced by reducing oxidative stress.

Pramipexole reduces inflammation in the experimental animal models of inflammation

Pramipexole is a dopamine (DA) agonist (D2 subfamily receptors) that widely use in the treatment of Parkinson's diseases. Some epidemiological and genetic studies propose a role of inflammation in the pathophysiology of Parkinson's disease. To our knowledge, there is no study regarding the anti-inflammatory activity of pramipexol. Therefore, the aim of the study was to investigate anti-inflammatory effect of pramipexol. Anti-inflammatory effects of pramipexole were studied in three well-characterized animal models of inflammation, including carrageenan- or formalin-induced paw inflammation in rats, and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema in mice. The animals received pramipexol (0.25, 0.5 and 1 mg/kg, I.P.) 30 min before subplantar injection of carrageenan or formalin. Pramipexol (0.5 and 1 mg/kg) was also injected 30 min before topical application of TPA on the ear mice. Serum malondialdehyde (MDA) levels were evaluated in the carrageenan test. Finally, pathological examination of the inflamed tissues was carried out. Pramipexole significantly inhibited paw inflammation 1, 2, 3 and 4 h after carrageenan challenge compared with the control group (p < .001). Pramipexol also showed considerable anti-inflammatory activity against formalin-evoked paw edema over a period of 24 h (p < .001). TPA-induced ear edema was markedly decreased by pramipexol (p < .001). The pathological evaluation of the paws and ears revealed that pramipexole reduced tissue injury, neutrophil infiltration, and subcutaneous edema. Pramipexole did not alter the increased serum levels of MDA due to carrageenan injection. These data clearly indicate that pramipexol possesses significant anti-inflammatory activity. It seems that its antioxidants do not play an important role in these effects.

Application of an optimized modified stir bar with ZnS nanoparticles loaded on activated carbon for preconcentration of carbofuran and propoxur insecticides in water samples and their HPLC determination

In this study, the stir bar was coated with the ZnS-NPs loaded on activated carbon (ZnS-AC) as well as [EMIM][PF₆] ionic liquid using sol gel technique was used for stir bar sorptive extraction (SBSE) of carbofuran and propoxur.

A new magnetic tailor made polymer for separation and trace determination of cadmium ions by flame atomic absorption spectrophotometry

Magnetic ion imprinted polymers have been prepared and applied for the selective extraction and trace monitoring of cadmium ions in food samples.

Anti-inflammatory Activity of Stachys Pilifera Benth

Background:

Stachys piliferaBenth has long been used to treat infectious diseases as well as respiratory and rheumatoid disorders in Iranian folk medicine. Antioxidants, antitumor, and antimicrobial properties of the plant have been reported.

Objectives:

This experimental study was designed to evaluate systemic and topical anti-inflammatory effects of the hydro-alcoholic extract from aerial parts of Stachys pilifera (HESP).

Materials and Methods:

Anti-inflammatory effects of HESP was studied in four well-known animal models of inflammation, including carrageenan- or formalin-induced paw edema in rat (thirteen groups, 6 rats per each group), and 12-O-tetradecanoylphorbol-13-acetate (TPA)- or xylene-induced ear edema in mouse (ten groups, 6 mice per each group). The rats received HESP (50-400 mg/ kg) orally 45 minutes before the subplantar injection of carrageenan or formalin. In TPA or xylene tests, HESP (1, 2.5, and 5 mg/ear) was applied topically simultaneous with these phlogistic agents on the ear mice. Finally, pathological examination of the inflamed tissues (paw and ear) was carried out.

Results:

Acute toxicity study of the extract showed that no rats were killed at 5000 mg/kg (LD50 > 5000 mg/kg). The extract (100 and 200 mg/ kg) significantly suppressed carrageenan-induced paw edema 1, 2, 3, and 4 hours after carrageenan challenge in comparison with the control group (P < 0.001). The HESP (100 and 200 mg/kg) also produced a considerable antiedematogenic effect in the formalin test over a period of 24 hours (P < 0.01). Furthermore, topical administration of the HESP (1, 2.5, and 5 mg/ear) inhibited TPA- and xylene-induced ear edema in comparison with the control group (P < 0.001). The pathological analysis of the paws and ears revealed that HESP was capable of reducing tissue destruction, cellular infiltration, and subcutaneous edema induced by the indicated phlogistic agents.

Conclusions:

The present data confirmed systemic and topical anti-inflammatory effects of Stachys pilifera which is comparable to indomethacin.