The iron(III) and nickel(II) complexes with tetradentate thiosemicarbazones. Synthesis, experimental, theoretical characterization, and antiviral effect against SARS-CoV-2.

The discovery of new inhibitors that can be used in the treatment of viral diseases, including Covid-19, is an area open to research, and there is a need for innovative compounds with increased efficiency that provide inhibition by suppressing enzyme, and receptor mechanisms. The iron(III) and nickel(II) complexes were synthesized by template condensation of 4-methoxy-salicylaldehyde with S-methylthiosemicarbazone derivatives of 1,1,1-trifluoroacetylacetone (for Fe1) and methylacetoacetate (for Ni1). The complex structures having N2O2-chelating thiosemicarbazidato ligand were identified by analytical, spectroscopic, and X-ray crystallography results. Coordination environment of iron(III) center in complex Fe1 has a distorted square pyramidal geometry consisting of the N2O2 donor set and a chlorine atom, while that of Ni1 is square plane with the set. Inhibitory effect of Fe1 compound against SARS-CoV-2 virus specific 3C-like protease enzyme was investigated experimentally. It was determined that the highest inhibition concentration of Fe1 was 100 µM. Percent inhibition activity at this concentration was on average 30.62 ± 3.809%. Binding of both compounds to the 3C-like protease enzyme specific to the SARS-CoV-2 virus was analyzed using docking calculations. As a result of the docking calculation of Fe1, it has been observed that the compound has a binding energy of -7.4 kcal / mol to 3CL-like protease. It has been observed that the protein amino acids GLY143, THR26, and ASN142 contribute to the high binding affinity of the Fe1. The experimental and theoretical results obtained for the two complexes support each other.

Tumor necrosis factor alpha gene rs1799724 polymorphism in Alzheimer's disease.

Neurofibrillar tangles formed by the accumulation of hyperphosphorylated tau proteins in the intracellular space and the senile plaques formed by amyloid ß (Aß) accumulating in extracellular environment are shown as two main elements of Alzheimer's disease (AD). In our study, the relationship between the risk of Alzheimer's disease and TNFα rs1799724 polymorphism in the Turkish population was investigated. Our study is the first report investigating the relationship between the risk of Alzheimer's disease and TNFα rs1799724 gene polymorphism in Turkish population. No significant relation was found for rs1799724 polymorphism in AD patients. Since TNFα rs1799724 gene polymorphism was also associated with type 2 diabetes mellitus (T2DM), the polymorphism also was evaluated in T2DM within the AD patients group. According to our results rs1799724 polymorphism was found to be a significant relationship with T2DM within AD patients group. On the other hand, there was no significant difference between fasting blood glucose values of AD patients and -857C>T (rs1799724) polymorphism. According to our results, -857C>T rs1799724 polymorphism may have a relationship with T2DM as independent from AD.

Chemical and molecular characterization of metabolites from Flavobacterium sp.

In this study, a Flavobacterium sp. is isolated from natural spring, and identified using molecular techniques. Extracellular and intracellular secondary metabolites are identified using solid phase microextraction gas chromatography-mass spectrometry and ultra performance liquid chromatography. Cytotoxic activity of the extracellular compounds produced by the Flavobacterium sp. and quercetin as the standard are measured using ECV304 human endothelial cells in vitro. Our results show that Flavobacterim sp. isolate has the highest percentage of similarity with Flavobacterium cheonhonense strain ARSA-15 (99%). Quercetin is detected as the major extracellular compound produced by the Flavobacterium sp. Methanol extract of Flavobacterium sp. resulted in a higher cell viability results when compared to DMSO extracts. Computational chemistry approach was used and it has been found that polar solvent (methanol) contributed to higher antioxidant activity. In conclusion, Flavobacterium sp. can be used to produce quercetin for industrial purposes.

Apoptotic mechanisms of N1-acetylacetone, N4-4-methoxy-salicylidene-thiosemicarbazide chelating with Nickel(II) on HL60 leukemia cells.

Thiosemicarbozone complexes that have a broad spectrum of biological activity are formed as a result of condensation reaction between thiosemicarbazide [H2N(C=S)-NH-NH2] and carbonyl-containing compounds. A new Nickel(II) complexes with N1-acetylacetone, N4-4-methoxy-salicylidene-thiosemicarbazidato ligand was synthesized and characterized. We studied the antileukemic activity of the Ni(II) thiosemicarbazone compound and assessed their potential for drug development. Specifically, the effects of this Ni(II) thiosemicarbazone compound on intracellular signal nodes and apoptotic pathways were investigated. According to our results, the Ni(II) thiosemicarbazone compound has apoptotic activity against HL60 cells. Moreover, while Ni(II) thiosemicarbazone compound significantly increased levels of p53 and cleaved caspase-3 proteins, it decreased level of Phospho-Akt1 protein in HL60 cells. The Ni(II) thiosemicarbazone compound could induce HL60 cell apoptosis through inhibiting of PI3K/Akt pathway. These results showed that Ni(II) thiosemicarbozone compound might be an antileukemic agent.

High Plasma Pentraxin 3 Levels in Diabetic Polyneuropathy Patients with Nociceptive Pain.

Diabetic polyneuropathy is the most common neurologic complication of diabetes mellitus. Underlying mechanisms of diabetic polyneuropathy are related to various metabolic and inflammatory pathways. Pentraxin 3 (PTX3) is an acute phase protein that is produced locally at the inflammatory sites by several cell types. Thioredoxin binding protein 2 (TBP2) is a thioredoxin regulator involved in intracellular energy pathways and cell growth. We measured the plasma levels of PTX3 and TBP2 in type 2 diabetic patients (n = 27) with pain complaints and compared their levels with those of healthy age- and sex-matched subjects (n = 24). Moreover, the diabetic patients were divided into two groups using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale: patients with nociceptive pain that is caused by tissue damage and patients with neuropathic pain that is caused by nerve damage. Patients with LANSS scores of < 12 were considered to have nocicceptive pain (n = 15), while patients with LANSS scores of ≥ 12 were considered to have neuropathic pain (n = 12). We found that PTX3 levels were significantly higher in diabetic patients compared to controls (p = 0.03), but there was no significant difference in the TBP2 levels. Importantly, patients with nociceptive pain had significantly higher PTX3 levels compared to patients with neuropathic pain (p < 0.05). Thus, plasma PTX3 levels can be helpful for discrimination of nociceptive pain from neuropathic pain in diabetic patients. We propose that PTX3 may contribute to the onset of nociceptive pain.

Potential of GRID2 receptor gene for preventing TNF-induced neurodegeneration in autism.

Autism is one of the most common subtypes of autism spectrum disorder (ASD). Recent studies suggested a relationship between immune-dependent coding genes and ASD, indicating that long term neuroimmunological anomalies affect brain development and synaptic transmission among neural networks. Furthermore, various studies focused on biomarker potential of TNF-α in autism. Ionotropic receptors are also studied as potential marker for autism since altered gene expression levels are observed in autistic patients. GRID2 is a candidate ionotropic receptor which is involved glutamate transfer. In this study, to propose TNF-α dependent cellular processes involved in autism aetiology in relation to GRID2 we performed a bioinformatic network analysis and identified potential pathways and genes that are involved in TNF-α induced changes at GRID2 receptor levels. As a result, we ascertained the GRID2 receptor gene as a candidate gene and further studied the association between GRID2 expression levels and TNF-induced neurodegeneration. Our bioinformatic analyses and experimental results revealed that TNF-α regulates GRID2 gene expression by activating Cdc42 and GOPC genes. Moreover, increased TNF-α levels leads to increase of caspase-3 protein levels triggering neuronal apoptosis leading to neuronal deficiency, which is one of the major symptoms of autism. The study is the first to show the role of TNF-α in regulation of GRID2 gene expression and its signalling pathway. As a result, GRID2 gene can be a suppressor in TNF-induced neurodegeneration which may help to understand the main factors leading to autism.

Screening of new antileukemic agents from essential oils of algae extracts and computational modeling of their interactions with intracellular signaling nodes.

Microalgae are very rich in bioactive compounds, minerals, polysaccharides, poly-unsaturated fatty acids and vitamins, and these rich constituents make microalgae an important resource for the discovery of new bioactive compounds with applications in biotechnology. In this study, we studied the antileukemic activity of several chosen microalgae species at the molecular level and assessed their potential for drug development. Here we identified Stichococcus bacillaris, Phaeodactylum tricornutum, Microcystis aeruginosa and Nannochloropsis oculata microalgae extracts with possible antileukemic agent potentials. Specifically we studied the effects of these extracts on intracellular signal nodes and apoptotic pathways. We characterized the composition of essential oils of these fifteen different algae extracts using gas chromatography-mass spectrometry (GC-MS). Finally, to identify potential molecular targets causing the phenotypic changes in leukemic cell lines, we docked a selected group of these essential oils to several key intracellular proteins. According to results of rank score algorithm, five of these essential oils analyzed might be considered as in silico plausible candidates to be used as antileukemic agents.

Cytotoxic effect of extract from Dunaliella salina against SH-SY5Y neuroblastoma cells.

Cytotoxic effects of essential oils extracted from Dunaliella salina on SH-SY5Y human neuroblastoma cells were investigated in this study. GC-MS analysis was used for determination of the composition of essential oils found in Dunaliella salina extract. All experimented concentrations of Dunaliella salina extract on SH-SY5Y human neuroblastoma cells were significantly more cytotoxic than the tested concentrations of the extract on ECV304 human endothelial cells used as a control. Fifthy compounds were detected in GC-MS analysis of the extract, and five major compounds were predominantly found as follows: octadecanoic acid, methyl ester (27.43%); hexadecanoic acid, methyl ester (Cas) methyl palmitate (24.82%); 9,12,15-octadecatrienoic acid, ethyl ester, (Z,Z,Z)- (7.39%); octadecanoic acid (5.03%), pentadecanoic acid (3.60%). The cytotoxic activity of Dunaliella salina extract on SH-SY5Y human neuroblastoma cells might be due to high concentrations of octadecanoic acid and hexadecanoic acid. Furthermore, results indicate that the extract demonstrates some proliferative effect on ECV304 cells in a dose-dependent manner between 0.25 and 5 µg/ml. These results suggest that Dunaliella salina may have anticancer potential against human neuroblastoma cells.

Effects of micro environmental factors on natural killer activity (NK) of beta thalassemia major patients.

The physiological mechanisms of decreased NK activity of ß-Thalassemia major (BTM) patients are unknown. To assess in vitro effects of mononuclear cells and their cytokine secretion on NK activity, we compared activator receptor levels and cytotoxic activity of purified NK cells and NK cells in mononuclear cells (MNC) pools. We collected cell supernatant from unincubated and incubated MNC with K562 cells and measured their secreted cytokines levels. CD16 was lower on the surface of NK cells in MNC pools from BTM patients compared to healthy volunteers. This inhibition does not appear when NK cells were purified. NKp30 levels in NK cells decreased both as purified cells and as part of a pool of MNC in BTM patients. After incubation of MNC pools with K562 target cells, we found that supernatant levels of IL10, TGFß1 and IL15 cytokines were also significantly higher in BTM patients compared to healthy volunteers.

CD8 lineage-specific regulation of interleukin-7 receptor expression by the transcriptional repressor Gfi1.

Interleukin-7 receptor α (IL-7Rα) is essential for T cell survival and differentiation. Glucocorticoids are potent enhancers of IL-7Rα expression with diverse roles in T cell biology. Here we identify the transcriptional repressor, growth factor independent-1 (Gfi1), as a novel intermediary in glucocorticoid-induced IL-7Rα up-regulation. We found Gfi1 to be a major inhibitory target of dexamethasone by microarray expression profiling of 3B4.15 T-hybridoma cells. Concordantly, retroviral transduction of Gfi1 significantly blunted IL-7Rα up-regulation by dexamethasone. To further assess the role of Gfi1 in vivo, we generated bacterial artificial chromosome (BAC) transgenic mice, in which a modified Il7r locus expresses GFP to report Il7r gene transcription. By introducing this BAC reporter transgene into either Gfi1-deficient or Gfi1-transgenic mice, we document in vivo that IL-7Rα transcription is up-regulated in the absence of Gfi1 and down-regulated when Gfi1 is overexpressed. Strikingly, the in vivo regulatory role of Gfi1 was specific for CD8(+), and not CD4(+) T cells or immature thymocytes. These results identify Gfi1 as a specific transcriptional repressor of the Il7r gene in CD8 T lymphocytes in vivo.