Kidney HEK293 Cells Research Articles

Identification of an Immunoglobulin M (IgM) Antibody Against Enolase 1 Protein (ENO1) Derived from HEK-293 Cells in Patients with Kidney Failure

Kidney failure is one of the most important challenges in medicine. In this study, we used HEK-293 kidney cells to evaluate and compare changes in the expression of natural antibodies in patients with kidney failure and healthy controls. We analyzed the immunoreactivity of two groups of pooled sera from patient and control groups against antigens derived from HEK-293 cell lysates. The cell lysates were immunoblotted with the pooled sera from the groups. The results showed that the patients’ sera contained IgM antibodies, which recognized enolase 1 proteins.

The conservative effects of lipopeptides from Bacillus methylotrophicus DCS1 on sunflower oil-in-water emulsion and raw beef patties quality

Lipid oxidation was considered as a problem in food conservation. The present study aims to investigate the effect of lipopeptides DCS1 on the conservation of food models against lipid oxidation by determining the primary and the secondary oxidation products. Lipopeptides DCS1 are able to preserve the nutritional properties of the emulsion during 23 days of storage, at a concentration of 0.0125% (w/w of emulsion), by slowing down the formation of hydroperoxides and malondialdehyde (MDA) compounds. The direct incorporation of lipopeptides in ground beef patties at a concentration of 0.5% (w/w of meat) was found to be more effective than gelatin film enriched with lipopeptides (2.5%, w/w of gelatin) as a coating, in inhibiting lipid oxidation. Furthermore, lipopeptides DCS1 are not toxic to human kidney cells HEK293 up to a concentration of 250 µg/ml. The results indicate that lipopeptides DCS1 are effective for the preservation of fatty foods against lipid oxidation.

Chlorogenic acid inhibits proliferation and induces apoptosis in A498 human kidney cancer cells via inactivating PI3K/Akt/mTOR signalling pathway.

Kidney cancer is a highly lethal cancer, of which the most common type is renal cell carcinoma (RCC). The targeted drugs used in treating RCC clinically have a lot of side effects. Therefore, it is urgent to find out effective agents with little toxic effects. The antiproliferation effect of chlorogenic acid (CA) was performed using the CCK-8 assay. Then, we adopted colony formation assay, Annexin V/PI staining assay and JC-1 mitochondrial membrane potential assay to explore the mechanism of anticancer effect of CA. We also conducted qPCR and Western blot to determine the pathway involved. We identified that CA selectively suppressed proliferation of human RCC cell line A498 but not the human embryonic kidney cell HEK293. Mechanistic studies showed that CA significantly induced apoptosis, as indicated by activation of caspase protein and increased ratio of pro-apoptotic protein Bax to anti-apoptotic protein Bcl-2 (P<0.05). Furthermore, we found that PI3K/Akt/mTOR signalling pathway is involved in the inhibitory effect of CA on A498 cells. Activation of this pathway increased proliferation and decreased apoptosis of A498 cells, exhibiting antagonism function against CA. Our research firstly reports the efficacy of CA against RCC cells and elucidates the underlying molecular mechanisms. These findings indicate that CA is a potential agent for treating RCC.

Helicobacter pylori virulence factor vacuolating cytotoxin A (VacA) promotes homologous recombination repair in GES-1 cells

Objective To analyze the impact of Helicobacter pylori standard strain (Hp P12) and its virulence factor vacuolating cytotoxin A (VacA) on DNA damage and homologous recombination (HR) repair in a human gastric epithelial cell line (GES-1). Methods Strains of Hp P12 and vacA gene knockout Hp P12 (Hp P12 ΔvacA) were respectively used to infect GES-1 cells at a multiplicity of infection of 100. GES-1 cells treated with etoposide (50 μmol/L) or mitomycin (0.5 μg/ml) for 2 h were used as positive control. Western blot and immunofluorescence were performed to detect the expression of DNA damage marker protein γH2AX and key HR repair proteins (Rad51, pMRE11, CtIP and pCtIP) and the recruitment of them at DNA damage sites. Human embryonic kidney HEK-293 (DR-GFP) cells were infected with Hp P12 and Hp P12 ΔvacA strains to verify the impact of VacA on HR repair efficiency. Results The expression and recruitment of γH2AX and key HR repair proteins (Rad51, pMRE11, CtIP and pCtIP) were increased in Hp P12-infected cells as compared with that in uninfected and Hp P12 ΔvacA-infected cells (all P<0.05). To evaluate the HR repair efficiency, I-SceⅠ plasmid-transfected HEK-293 (DR-GFP) cells were infected with Hp P12 and Hp P12 ΔvacA and the results showed that green fluorescent protein (GFP)-positive cells were decreased after infection, especially in Hp P12 ΔvacA-infected cells (both P<0.05). Conclusions Hp P12 infection could cause DNA damage and promote HR repair in GES-1 cells, in which the virulence factor VacA played an important role. Key words: Helicobacter pylori; Homologous recombination repair; GES-1 cell; Vacuolating cytotoxin A (VacA)

CYP enzymes, expressed within live human suspension cells, are superior to widely-used microsomal enzymes in identifying potent CYP1A1/CYP1B1 inhibitors: Identification of quinazolinones as CYP1A1/CYP1B1 inhibitors that efficiently reverse B[a]P toxicity and cisplatin resistance

Microsomal cytochrome P450 (CYP) enzymes, isolated from recombinant bacterial/insect/yeast cells, are extensively used for drug metabolism studies. However, they may not always portray how a developmental drug would behave in human cells with intact intracellular transport mechanisms. This study emphasizes the usefulness of human HEK293 kidney cells, grown in 'suspension' for expression of CYPs, in finding potent CYP1A1/CYP1B1 inhibitors, as possible anticancer agents. With live cell-based assays, quinazolinones 9i/9b were found to be selective CYP1A1/CYP1B1 inhibitors with IC50 values of 30/21 nM, and > 150-fold selectivity over CYP2/3 enzymes, whereas they were far less active using commercially-available CYP1A1/CYP1B1 microsomal enzymes (IC50, >10/1.3-1.7 μM). Compound 9i prevented CYP1A1-mediated benzo[a]pyrene-toxicity in normal fibroblasts whereas 9b completely reversed cisplatin resistance in PC-3/prostate, COR-L23/lung, MIAPaCa-2/pancreatic and LS174T/colon cancer cells, underlining the human-cell-assays' potential. Our results indicate that the most potent CYP1A1/CYP1B1 inhibitors would not have been identified if one had relied merely on microsomal enzymes.

Upregulation of endogenous erythropoietin expression by DLBS6747, a bioactive fraction of Ipomoea batatas L. leaves, via increasing HIF1α transcription factor in HEK293 kidney cells

Ipomoea batatas L., locally known as ubi jalar, is widely used in Indonesia and other countries as a folk remedy for various chronic diseases, including anemia-associated chronic kidney disease by increasing hematological parameters such as packed cell volume, white blood cells and platelet counts. The aim of this study is to evaluate the effect of DLBS6747, a bioactive fraction of I. batatas L. leaves, on increasing EPO expression through the upregulation of HIF1α. Effect of DLBS6747 on EPO expression and its transcription factor, HIFs, was evaluated in normoxia and hypoxia conditions. Effect of DLBS6747 on several genes involved in EPO expression were evaluated in a time-course manner using conventional and real-time PCR, while the protein level were revealed using western blot and ELISA. The involvement of HIF1α was also confirmed by HIF1α siRNA. Administration of DLBS6747 increased transcriptional activity of EPO through the regulation of its transcriptional factors, which include HIF1α, HIF2α and NFᴋB. The effect was found to be dependent on oxygen availability, wherein DLBS6747-increased EPO expression was found to be more significant in hypoxic condition. In normoxia and hypoxia, 40 μg/mL DLBS6747 increased HIF1α and HIF2α expressions at mRNA level, wherein the peak appeared in 12 h treatment (up to 7.9- and 8.6-folds, respectively). On the other hand, increased protein level was only found in hypoxia, where the highest HIF1α expression was observed at 6 h (7.5-folds increase) and started to decrease after the hours, while HIF2α was found to be increased time-dependently (up to 13.8-folds in 24 h). The mechanism of action of DLBS6747 as erythropoietin stimulating agent is more likely to affect the regulation of HIF1α, as confirmed by HIF1α siRNA which showed that DLBS6747 failed to increase EPO expression during co-incubation with HIF1α siRNA. DLBS6747 treatment also decreased NFᴋB time-dependently in normoxia, while no NFᴋB was detected in hypoxia, which revealed mimicking hypoxia activity of DLBS6747 to increase EPO expression. These findings showed convincing evidences that DLBS6747 increases endogenous EPO production primarily via upregulation of its transcription factors, especially HIF1α, in human embryonic kidney HEK293 cells. This is the first molecular report that reveals the mechanism of action of natural-based erythropenia drug in different oxygen availability.

A medicinal and edible formula YH0618 ameliorates the toxicity induced by Doxorubicin via regulating the expression of Bax/Bcl-2 and FOXO4

Chemotherapy is the most common and powerful cancer treatment. Although the nasty side effects seriously influence the clinical practice, no better ways can displace it. Therefore, searching for safe and effective strategies designed to ameliorate chemotherapy-induced toxicity has become an urgent issue in cancer research area. In clinical, a medicinal and edible formula YH0618 showed the effects of reducing the DOX-induced toxicity, especially improving alopecia, nail discoloration, skin hyperpigmentation and fatigue. This study was to investigate the role and mechanism of YH0618 in ameliorating DOX-induced toxicity by in vitro and in vivo experiments. YH0618 selectively attenuated DOX-induced growth inhibition and apoptosis in human normal liver L02 cells and kidney HEK-293 cells, and simultaneously potentiated the anti-cancer effect of DOX in breast cancer MCF-7 and MDA-MB-231 cells by apoptosis pathways. Western blotting results revealed that YH0618 attenuated DOX-induced apoptosis in normal liver and kidney cells through FOXO4-mediated mitochondria-dependent mechanism. Animal experiments demonstrated that, YH0618 did not interfere in DOX-induced reduction in tumor volume and significantly improved DOX-induced hair loss and the increase of alanine aminotransferase (ALT). Histological characteristics showed that YH0618 attenuated DOX-induced heart, liver and kidney damage. The study may shed light on the potential application of YH0618 as a novel medicinal food against chemotherapy-induced toxicity.

Generation of Hybridomas Producing Monoclonal Antibodies to the NS1 Protein of the Zika Virus

Hybridomas producing monoclonal antibodies (mABs) to the recombinant protein NS1 of the Zika virus synthesized in human embryonic kidney HEK293 (ZV293) cells have been obtained. The specificity of antibodies has been examined by the enzyme-linked immunosorbent assay (ELISA) using the similarly synthesized NS1 proteins of flaviviruses: the Dengue 1–4 serotype virus, Japanese encephalitis virus, yellow fever virus, tick-borne encephalitis virus, and the West Nile fever virus. Two types of hybridomas whose mABs interact with thermolabile (mABs 2F6 and 3F3) and thermostable epitopes (mABs 1B9, 6D7, and 6F2) of the NS1ZV protein have been selected. It has been shown that the 3F3 mAB, which is specific to the thermolabile determinant, can be used as both binding and detecting antibodies in the sandwich ELISA. Based on the 3F3 mAB, an experimental immunochromatographic test for the detection of the NS1ZV antigen has been developed. It has also been found that mABs 1B9, 6D7, and 6F2 against thermostable epitopes of the NS1 protein specifically recognize the NS1ZV protein after its heating for 15 min to 98°C.

Synthesis, antimalarial activities and cytotoxicities of amino-artemisinin-1,2-disubstituted ferrocene hybrids

Artemisinin-ferrocene conjugates incorporating a 1,2-disubstituted ferrocene analogous to that embedded in ferroquine but attached via a piperazine linker to C10 of the artemisinin were prepared from the piperazine artemisinin derivative, and activities were evaluated against asexual blood stages of chloroquine (CQ) sensitive NF54 and CQ resistant K1 and W2 strains of Plasmodium falciparum (Pf). The most active was the morpholino derivative 5 with IC50 of 0.86 nM against Pf K1 and 1.4 nM against Pf W2. The resistance indices were superior to those of current clinical artemisinins. Notably, the compounds were active against Pf NF54 early and late blood stage gametocytes - these exerted >86% inhibition at 1 µM against both stages; they are thus appreciably more active than methylene blue (∼57% inhibition at 1 µM) against late stage gametocytes. The data portends transmission blocking activity. Cytotoxicity was determined against human embryonic kidney cells (Hek293), while human malignant melanoma cells (A375) were used to assess their antitumor activity.

Surface-Functionalization of Zr-Fumarate MOF for Selective Cytotoxicity and Immune System Compatibility in Nanoscale Drug Delivery.

Metal-organic frameworks (MOFs), network structures wherein metal ions or clusters link organic ligands into porous materials, are being actively researched as nanoscale drug delivery devices as they offer tunable structures with high cargo loading that can easily be further functionalized for targeting and enhanced physiological stability. The excellent biocompatibility of Zr has meant that its MOFs are among the most studied to date, in particular the archetypal Zr terephthalate UiO-66. In contrast, the isoreticular analog linked by fumarate (Zr-fum) has received little attention, despite the endogenous linker being part of the Krebs cycle. Herein, we report a comprehensive study of Zr-fum in the context of drug delivery. Reducing particle size is shown to increase uptake by cancer cells while reducing internalization by macrophages, immune system cells that remove foreign objects from the bloodstream. Zr-fum is compatible with defect loading of the drug dichloroacetate (DCA) as well as surface modification during synthesis, through coordination modulation and postsynthetically. DCA-loaded, PEGylated Zr-fum shows selective in vitro cytotoxicity toward HeLa and MCF-7 cancer cells, likely as a consequence of its enhanced caveolae-mediated endocytosis compared to uncoated precursors, and it is well tolerated by HEK293 kidney cells, J774 macrophages, and human peripheral blood lymphocytes. Compared to UiO-66, Zr-fum is more efficient at transporting the drug mimic calcein into HeLa cells, and DCA-loaded, PEGylated Zr-fum is more effective at reducing HeLa and MCF-7 cell proliferation than the analogous UiO-66 sample. In vitro examination of immune system response shows that Zr-fum samples induce less reactive oxygen species than UiO-66 analogs, possibly as a consequence of the linker being endogenous, and do not activate the C3 and C4 complement cascade pathways, suggesting that Zr-fum can avoid phagocytic activation. The results show that Zr-fum is an attractive alternative to UiO-66 for nanoscale drug delivery, and that a wide range of in vitro experiments is available to greatly inform the design of drug delivery systems prior to early stage animal studies.

The GRK2 Promoter Is Regulated by Early-Growth Response Transcription Factor EGR-1.

The G-protein-coupled receptor kinase 2 (GRK2) plays a major role in cardiovascular diseases, and its expression is increased in heart failure. However, only little is known about factors being involved in up-regulation of GRK2 expression through transcriptional regulation of its promoter. Since the transcription factor early-growth response 1 (EGR-1) is also up-regulated in patients with heart failure, we tested the hypothesis that EGR-1 regulates GRK2 transcription. Stimulation of immortalized rat cardiomyocytes (H9c2) with phorbol 12-myristate 13-acetate (PMA) resulted in up-regulation of Egr-1 and subsequently of Grk2 mRNA expression, with maximum Grk2 expression (p = 0.008) 5 hr after PMA stimulation and being abolished by actinomycin D, indicating a transcriptional mechanism. To identify naturally occurring variants affecting promoter transcriptional activity, we identified a novel G(-43)A polymorphism (rs182084609), which surrounded a putative EGR-1-binding site. While the minor A allele frequency was rare (0.02), this variant was used to explore regulation by EGR-1 and promoter construct with altered alleles at nt-43 were subjected of reporter assays in human embryonic kidney cells (Hek293). Here, EGR-1 over-expression resulted in a more than twofold increase in GRK2 promoter activity but only in the presence of the G-allele (p = 0.04). In electrophoretic mobility shift assays, EGR-1 over-expression resulted in a specific binding of transcription factors only to the G oligonucleotide. Finally, EGR-1 over-expression resulted in increased GRK2 mRNA expression (p = 0.03). We identified EGR-1 as a regulator of GRK2 transcription. Suppression of GRK2 expression by inhibition of EGR-1 binding to GRK2 might be a promising approach to mitigate adrenergic desensitization.

Zinc preconditioning protects against renal ischaemia reperfusion injury in a preclinical sheep large animal model

Ischaemia-reperfusion injury (IRI) during various surgical procedures, including partial nephrectomy for kidney cancer or renal transplantation, is a major cause of acute kidney injury and chronic kidney disease. Currently there are no drugs or methods for protecting human organs, including the kidneys, against the peril of IRI. The aim of this study was therefore to investigate the reno-protective effect of Zn2+ preconditioning in a clinically relevant large animal sheep model of IRI. Further the reno-protective effectiveness of Zn2+ preconditioning was tested on normal human kidney cell lines HK-2 and HEK293. Anaesthetised sheep were subjected to uninephrectomy and 60min of renal ischaemia followed by reperfusion. Sheep were preconditioned with intravenous injection ofzinc chloride prior to occlusion. Serum creatinine and urea were measured before ischaemia and for 7days after reperfusion. HK-2 and HEK293 cells were subjected to in vitro IRI using the oxygen- and glucose-deprivation model. Zn2+ preconditioning reduced ischaemic burden determined by creatinine and urea rise over time by ~ 70% in sheep. Zn2+ preconditioning also increased the survival of normal human kidney cells subjected to cellular stress such as hypoxia, hydrogen peroxide injury, and serum starvation. Overall, our protocol incorporating specific Zn2+ dosage, number of dosages (two), time of injection (24 and 4h prior), mode of Zn2+ delivery (IV) and testing of efficacy in a rat model, a large preclinical sheep model of IRI and cells of human origin has laid the foundation for assessment of the benefit of Zn2+ preconditioning for human applications.

Protective Effect of Selenium-Enriched Ricegrass Juice against Cadmium-Induced Toxicity and DNA Damage in HEK293 Kidney Cells.

Cadmium (Cd) contamination in food is a problem endangering human health. Cd detoxication is an interesting topic particularly using food which provides no side effects. Ricegrass juice is a squeezed juice from young rice leaves which is introduced as a functional drink rich in polyphenol components. Se-enrichment into ricegrass is initiated to provide extra advantages of their functional properties. The protective role of ricegrass juice (RG) and Se-enriched ricegrass juice (Se-RG) against Cd toxicity during pre-, co- and post-treatment on HEK293 kidney cells were investigated. Results confirmed that RG and Se-RG had very low toxicity for kidney cells. Both extracts showed a protective role during pre-treatment and co-treatment against Cd toxicity by exerting a reduction in malondialdehyde (MDA) content and the percentage of DNA damage in tail and tail length of the comets over the Cd-treated cells. However, the Se-RG indicated additional benefits in all properties over RG. High Se content in Se-RG resulted in more protective effects of the regular ricegrass juice. In summary, this study provides clear evidence that Se-enriched ricegrass juice has potential to be developed as a functional food to protect the human body from Cd contamination via the reduction of oxidative stress and DNA damage.

Tricarbonylrhenium(I) complexes with the N,6-dimethylpyridine-2-carbothioamide ligand: combined experimental and calculation studies

A new series of tricarbonyl complexes of rhenium(I) in the “2 + 1” system with the bidentate ligand N,6-dimethylpyridine-2-carbothioamide ((CH3)NC5H4-CS-NH-CH3, MeLH(Me)NS) and a monodentate ligand (halides Cl, Br, or I, and the pseudohalide NCS anion) was synthesized. The use of mixed ligands led to the formation of neutral tricarbonylrhenium(I) complexes [Re(CO)3(MeLH(Me)NS)X] (X = Cl, Br, I, NCS) (1–4). Single-crystal X-ray diffraction was used to determine the crystal structures of all four compounds and those results were compared with molecular structures obtained from DFT calculations using the PBE0/def2-TZVPD approach. The complexes were also characterized by spectroscopic (FT-IR, NMR, and UV–vis) and analytical (HPLC, TGA, EA, ESI-MS) techniques. IR and UV–vis spectra were also calculated by DFT and TD-DFT methods. The cytotoxicity of these complexes was estimated using human ovarian cancer cell lines (A2780 and A2780cis), cervical cancer cells (HeLa), and non-cancerous human embryonic kidney cells (Hek-293). The toxicity of most complexes was moderate or low toward cancer cell lines (IC50 = 46–231 μM) and similar against non-cancerous cells (IC50 = 41-121 μM). Only the complex with chlorido ligand remarkably inhibited growth of ovarian cancer cells (IC50 = 3 and 12 μM for A2780 and A2780cis, respectively). The cytotoxicity of 1 was higher than that of cisplatin.

Optimization, antioxidant potential, modulatory effect and anti-apoptotic action in of Euphorbia bivonae polysaccharides on hydrogen peroxide-induced toxicity in human embryonic kidney cells HEK293

For the first time, we have determined the effect of solvent, liquid-solid ratio and extraction time on polysaccharides yield was evaluated using a full factorial design (23). In this present investigation, a total of 7 molecules were determined in this species. In our analysis saccharose was the dominant monosaccharides. Arabinose, pyranose, fructose, glucose, inositol, saccharose and trehalose found in E. bivonae. The results of the in vitro antioxidant assay showed that the EBPS have higher antioxidant capacity. Accordingly, the HEK293 cells pre-treated with EBPS compounds (100 μg·mL-1) enhanced cell viability against H2O2 exposure. Our results revealed that H2O2-exposure induced a significant increase in intracellular ROS and lipid peroxidation in HEK293 cells. Additionally, the H2O2-induced alteration in HEK293 cells morphology, was ameliorated by EBPS treatment. In addition, EPBS pre-treated cells significantly enhanced the activities of HEK293 cells antioxidant status (SOD, CAT, GPx and GSH) that were decreased after hydrogen peroxide exposure.

Tricarbonylrhenium(I) complexes with the N-methylpyridine-2-carbothioamide ligand – Synthesis, characterization and cytotoxicity studies

A new series of tricarbonyl complexes of rhenium(I) in the ‘2 + 1’ system with the bidentate ligand N-methylpyridine-2-carbothioamide (NC5H4-CS-NH-CH3, LH(Me)NS) and a monodentate ligand, being either an anion (Cl, Br, I or SCN) or a neutral molecule (3,5-dimethylpyrazole (Hdmpz) or imidazole (Him)), was synthesized. The use of mixed ligands leads to the formation of neutral or cationic (in the form of PF6− salts) tricarbonylrhenium(I) complexes: [Re(CO)3(LH(Me)NS)X] (X = Cl, Br, I, NCS) (complexes 1–4) and [Re(CO)3(LH(Me)NS)Y]+ (Y = Hdmpz, Him) (5 and 6), respectively. In case of the [Re(CO)3(LH(Me)NS)NCS] complex two polymorphic forms (4a and 4b) have been distinguished. Crystal structure of all complexes was determined by single-crystal X-ray diffraction method and the results were compared with the molecular structures obtained from DFT calculations. The compounds were characterized by FT-IR, NMR, UV-Vis and HPLC techniques. IR and UV-Vis spectra were also simulated by DFT and TD-DFT methods. Cytotoxicity of the complexes was estimated using human ovarian cancer cell line (A2780), its cisplatin resistant cell line (A2780cis) and non-cancerous human embryonic kidney cells (Hek-293). The toxicity of newly synthesized complexes was comparable to cisplatin when tested against both cancerous cell lines (IC50 = 2–49 μM), but lower than cisplatin towards non-cancerous cells (IC50 = 6–63 μM). Among them, the complexes with chloride and iodide anions exhibit remarkable cytotoxicities.

Designing optimal experiments to discriminate interaction graph models.

Modern methods for the inference of cellular networks from experimental data often express nondeterminism through an ensemble of candidate models. To discriminate among these candidates new experiments need to be carried out. Theoretically, the number of possible experiments is exponential in the number of possible perturbations. In praxis, experiments are expensive and there exist several limiting constraints. Limiting factors exist on the combinations of perturbations that are technically possible, which components can be measured, and on the number of affordable experiments. Further, not all experiments are equally well suited to discriminate model candidates. The goal of optimal experiment design is to determine those experiments that discriminate most of the candidates while minimizing the costs. We present an approach for experiment planning with interaction graph models and sign consistency methods. This new approach can be used in combination with methods for network inference and consistency checking. We applied our method to study the Erythropoietin signal transduction in human kidney cells HEK293. We first used simulated experiment data from an ODE model to demonstrate in silico that our experimental design results in the inference of the gold standard model. Finally, we used the approach to plan in vivo experiments that discriminate model candidates for the Erythropoietin signal transduction in this cell line.

The influence of substituents on the reactivity and cytotoxicity of imidazothiazolotriazinones.

A series of tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7(1H,6H)-diones were synthesized via the reaction of imidazotriazinethiones and bromoacetic acid followed by condensation with isatins. Amidine skeletal rearrangement of 3,3a,9,9a-tetrahydroimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7 (1H,6H)-diones into 1,3a,4,9a-tetrahydroimidazo[4,5-e]thiazolo[2,3-c]-1,2,4-triazine-2,8 (3H,7H)-diones under KOH treatment has been studied. The influence of substituents at positions 1,3,3a,6,9a of imidazothiazolotriazine on the ability to undergo rearrangement was analyzed based on experimental data and theoretical calculations. Both imidazothiazolo[3,2-b]triazines and their rearrangement products were evaluated for their cytotoxic activity against rhabdomyosarcoma, A549, HCT116 and MCF7 human cancer cell lines by MTT assay. Among the derivatives, 1,3-diethyl-6-[1-(2-propyl)-2-oxoindolin-3-ylidene]-3,3a,9,9a-tetrahydroimidazo [4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7(1H,6H)-dione 4i was found to have the highest antiproliferative activity toward the tested cell lines (4i: [Formula: see text], 2.29, 0.47 and [Formula: see text], respectively). The [Formula: see text] value of compound 4i against normal human embryonic kidney cells HEK293 was [Formula: see text], which appeared to be 6-41-fold higher than [Formula: see text] values of 4i against human cancer cells.

The activity of organic anion transporter-3: Role of dexamethasone

Human organic anion transporter-3 (hOAT3) is richly expressed in the kidney, where it plays critical roles in the secretion, from the blood to urine, of clinically important drugs, such as anti-viral therapeutics, anti-cancer drugs, antibiotics, antihypertensives, and anti-inflammatories. In the current study, we examined the role of dexamethasone in hOAT3 transport activity in the kidney HEK293cells. Cis-inhibition study showed that dexamethasone exhibited a concentration-dependent inhibition of hOAT3-mediated uptake of estrone sulfate, a prototypical substrate for the transporter, with IC50 value of 49.91μM. Dixon plot analysis revealed that inhibition by dexamethasone was competitive with a Ki=47.08μM. In contrast to the cis-inhibition effect of dexamethasone, prolonged incubation (6h) of hOAT3-expressing cells with dexamethasone resulted in an upregulation of hOAT3 expression and transport activity, kinetically revealed as an increase in the maximum transport velocity Vmax without meaningful alteration in substrate-binding affinity Km. Such upregulation was abrogated by GSK650394, a specific inhibitor for serum- and glucocorticoid-inducible kinases (sgk). Dexamethasone also enhanced sgk1 phosphorylation. Our study demonstrated that dexamethasone exhibits dual effects on hOAT3: it is a competitive inhibitor for hOAT3-mediated transport, and interestingly, when entering the cells, it stimulates hOAT3 expression and transport activity through sgk1.

Comparative anticancer and antimicrobial activity of aerial parts of Acacia salicina, Acacia laeta, Acacia hamulosa and Acacia tortilis grown in Saudi Arabia

The standardized ethanol extract (EE) of aerial parts of four Acacia species [A. salicina (ASEE), A. laeta (ALEE), A. hamulosa (AHEE), and A. tortilis (ATEE)] were examined in order to compare their cytotoxic and antimicrobial activities. All the extracts were standardized by UPLC- PDA method using rutin as standard compound. The extracts ALEE, AHEE and ATEE were found to contain rutin along with several other phytoconstituents while rutin was absent in ASEE. All the extracts showed varying level of antimicrobial activity with zone of inhibition ranged from 11 to 21 mm against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The ALEE and ATEE showed relatively high antimicrobial potency (MIC = 0.2 to 1.6 mg mL−1) in comparison to other extracts. All the extracts were found to reduce the biofilm of P. aeruginosa PAO1 strain significantly in comparison to the untreated control. The cytotoxic property of ASEE, ALEE, AHEE, ATEE were evaluated against HepG2 (Liver), HEK-293 (Kidney), MCF-7 (Breast) and MDA-MB 231 (Breast) cancer cells. Of these, ALEE, AHEE and ATEE exhibited moderate cytotoxic property against human liver carcinoma cells (HepG2; IC50 = 46.2, 39.2 and 42.3 μg mL−1, respectively) and breast cancer cell lines (MCF-7; IC50 = 57.2, 55.3 and 65.7 μg mL−1, respectively). The ATEE and ALEE showed moderate cytotoxicity against HEK-293 (kidney) cells with IC50 = 49.1 and 53.5 μg mL−1, respectively. Since, Acacia species (A. laeta and A. hamulosa) contains numerous polyphenols which might prove to be highly cytotoxic and antimicrobial agents, we suggest that these species can be further subjected to the isolation of more cytotoxic and antimicrobial compounds.