Apoptotic and anti-angiogenic effects of propolis against human bladder cancer: molecular docking and in vitro screening

INTRODUCTION

Bladder cancer is still of unknown initiation and progression, it is difficult to treat the patient once bladder cancer have a distant metastasis.

MATERIALS AND METHODS

In the present study, propolis extract was evaluated against bladder cancer cells (T24). Two independent pathways were investigated, apoptosis and angiogenesis, Bax, Bcl-2, P53, and caspase-3 for apoptosis, vascular endothelial growth factor receptor and protein kinase A as angiogenesis potential targets.

OBJECTIVES

Molecular docking studies will be conducted for the major known constituents of Egyptian propolis into apoptotic and angiogenic protein targets, to give better insights to the possible binding mode and interactions and investigate the ability of propolis constituents to target both apoptotic and angiogenic pathways.

RESULTS

Propolis showed anti-proliferative activity against T24 cancer cell line, the IC₅₀ value was 6.36 µg/ml. Also significant effects of propolis on Bax, Bcl-2, P53, and caspase-3 were observed.

DISCUSSION

These obtained results proved the ability of propolis to induce cell death. Also it has revealed noticeable effects on protein kinase A and vascular endothelial growth factor receptor.

CONCLUSION

The obtained results can encourage us to say that propolis extract can induce a programmed cell death in human bladder cancer cells, and also affect angiogenesis.

2-Methoxyestradiol protects against pressure overload-induced left ventricular hypertrophy

Numerous experimental studies have supported the evidence that 2-methoxyestradiol (2 ME) is a biologically active metabolite that mediates multiple effects on the cardiovascular system, largely independent of the estrogen receptor. 2 ME is a major cytochrome P450 1B1 (CYP1B1) metabolite and has been reported to have vasoprotective and anti-inflammatory actions. However, whether 2 ME would prevent cardiac hypertrophy induced by abdominal aortic constriction (AAC) has not been investigated yet. Therefore, the overall objectives of the present study were to elucidate the potential antihypertrophic effect of 2 ME and explore the mechanism(s) involved. Our results showed that 2 ME significantly inhibited AAC-induced left ventricular hypertrophy using echocardiography. The antihypertrophic effect of 2 ME was associated with a significant inhibition of CYP1B1 and mid-chain hydroxyeicosatetraenoic acids. Based on proteomics data, the protective effect of 2 ME is linked to the induction of antioxidant and anti-inflammatory proteins in addition to the modulation of proteins involved in myocardial energy metabolism. In vitro, 2 ME has shown a direct antihypertrophic effect through mitogen-activated protein kinases- and nuclear factor-κB-dependent mechanisms. The present work shows a strong evidence that 2 ME protects against left ventricular hypertrophy. Our data suggest the potential of repurposing 2 ME as a selective CYP1B1 inhibitor for the treatment of heart failure.

Development of cellular hypertrophy by 8-hydroxyeicosatetraenoic acid in the human ventricular cardiomyocyte, RL-14 cell line, is implicated by MAPK and NF-κB

Recent studies have established the role of mid-chain hydroxyeicosatetraenoic acids (mid-chain HETEs) in the development of cardiovascular disease. Among these mid-chains, 8-HETE has been reported to have a proliferator and proinflammatory action. However, whether 8-HETE can induce cardiac hypertrophy has never been investigated before. Therefore, the overall objectives of the present study are to elucidate the potential hypertrophic effect of 8-HETE in the human ventricular cardiomyocytes, RL-14 cells, and to explore the mechanism(s) involved. Our results showed that 8-HETE induced cellular hypertrophy in RL-14 cells as evidenced by the induction of cardiac hypertrophy markers ANP, BNP, α-MHC, and β-MHC in a concentration- and time-dependent manner as well as the increase in cell surface area. Mechanistically, 8-HETE was able to induce the NF-κB activity as well as it significantly induced the phosphorylation of ERK1/2. The induction of cellular hypertrophy was associated with a proportional increase in the formation of dihydroxyeicosatrienoic acids (DHETs) parallel to the increase of soluble epoxide hydrolase (sEH) enzyme activity. Blocking the induction of NF-κB, ERK1/2, and sEH signaling pathways significantly inhibited 8-HETE-induced cellular hypertrophy. Our study provides the first evidence that 8-HETE induces cellular hypertrophy in RL-14 cells through MAPK- and NF-κB-dependent mechanism

Soluble epoxide hydrolase inhibitor, TUPS, protects against isoprenaline-induced cardiac hypertrophy

BACKGROUND AND PURPOSE

We have previously shown that isoprenaline-induced cardiac hypertrophy causes significant changes in the expression of cytochromes P450 (CYP) and soluble epoxide hydrolase (sEH) genes. Therefore, it is important to examine whether the inhibition of sEH by 1-(1-methanesulfonyl-piperidin-4-yl)-3-(4-trifluoromethoxy-phenyl)-urea (TUPS) will protect against isoprenaline-induced cardiac hypertrophy.

EXPERIMENTAL APPROACH

Male Sprague-Dawley rats were treated with TUPS (0.65 mg kg(-1) day(-1), p.o.), isoprenaline (5 mg kg(-1) day(-1), i.p.) or the combination of both. In vitro H9c2 cells were treated with isoprenaline (100 μM) in the presence and absence of either TUPS (1 μM) or 11,12 EET (1 μM). The expression of hypertrophic, fibrotic markers and different CYP genes were determined by real-time PCR.

KEY RESULTS

Isoprenaline significantly induced the hypertrophic, fibrotic markers as well as the heart to body weight ratio, which was significantly reversed by TUPS. Isoprenaline also caused an induction of CYP1A1, CYP1B1, CYP2B1, CYP2B2, CYP4A3 and CYP4F4 gene expression and TUPS significantly inhibited this isoprenaline-mediated effect. Moreover, isoprenaline significantly reduced 5,6-, 8,9-, 11,12- and 14,15-EET and increased their corresponding 8,9-, 11,12- and 14,15-dihydroxyeicosatrienoic acid (DHET) and the 20-HETE metabolites. TUPS abolished these isoprenaline-mediated changes in arachidonic acid (AA) metabolites. In H9c2 cells, isoprenaline caused a significant induction of ANP, BNP and EPHX2 mRNA levels. Both TUPS and 11,12-EET significantly decreased this isoprenaline-mediated induction of ANP, BNP and EPHX2.

CONCLUSIONS AND IMPLICATIONS

TUPS partially protects against isoprenaline-induced cardiac hypertrophy, which confirms the role of sEH and CYP enzymes in the development of cardiac hypertrophy.

Buthionine sulfoximine, an inhibitor of glutathione biosynthesis, induces expression of soluble epoxide hydrolase and markers of cellular hypertrophy in a rat cardiomyoblast cell line: roles of the NF-κB and MAPK signaling pathways

Evidence suggests that upregulation of soluble epoxide hydrolase (sEH) is associated with the development of myocardial infarction, dilated cardiomyopathy, cardiac hypertrophy, and heart failure. However, the upregulation mechanism is still unknown. In this study, we treated H9C2 cells with buthionine sulfoximine (BSO) to explore whether oxidative stress upregulates sEH gene expression and to identify the molecular and cellular mechanisms behind this upregulatory response. Real-time PCR and Western blot analyses were used to measure mRNA and protein expression, respectively. We demonstrated that BSO significantly upregulated sEH at mRNA levels in a concentration- and time-dependent manner, leading to a significant increase in the cellular hypertrophic markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Furthermore, BSO significantly increased the cytosolic phosphorylated IκB-α and translocation of NF-κB p50 subunits, as measured by Western blot analysis. This level of translocation was paralleled by an increase in the DNA-binding activity of NF-κB P50 subunits. Moreover, our results demonstrated that pretreatment with the NF-κB inhibitor PDTC significantly inhibited BSO-mediated induction of sEH and cellular hypertrophic marker gene expression in a dose-dependent manner. Additionally, mitogen-activated protein kinases (MAPKs) were transiently phosphorylated by BSO treatment. To understand further the role of MAPKs pathway in BSO-mediated induction of sEH mRNA, we examined the role of extracellular signal-regulated kinase (ERK), c-JunN-terminal kinase (JNK), and p38 MAPK. Indeed, treatment with the MEK/ERK signal transduction inhibitor, PD98059, partially blocked the activation of IκB-α and translocation of NF-κB p50 subunits induced by BSO. Moreover, pretreatment with MEK/ERK signal transduction inhibitors, PD98059 and U0126, significantly inhibited BSO-mediated induction of sEH and cellular hypertrophic marker gene expression. These results clearly demonstrated that the NF-κB signaling pathway is involved in BSO-mediated induction of sEH gene expression, and appears to be associated with the activation of the MAPK pathway. Furthermore, our findings provide a strong link between sEH-induced cardiac dysfunction and involvement of NF-κB in the development of cellular hypertrophy.

Human fetal ventricular cardiomyocyte, RL-14 cell line, is a promising model to study drug metabolizing enzymes and their associated arachidonic acid metabolites

INTRODUCTION

RL-14 cells, human fetal ventricular cardiomyocytes, are a commercially available cell line that has been established from non-proliferating primary cultures derived from human fetal heart tissue. However, the expression of different drug metabolizing enzymes (DMEs) in RL-14 cells has not been elucidated yet. Therefore, the main objectives of the current work were to investigate the capacity of RL-14 cells to express different cytochrome P450 (CYP) isoenzymes and correlate this expression to primary cardiomyocytes.

METHODS

The expression of CYP isoenzymes was determined at mRNA, protein and catalytic activity levels using real time-PCR, Western blot analysis and liquid chromatography-electron spray ionization-mass spectrometry (LC-ESI-MS), respectively.

RESULTS

Our results showed that RL-14 cells constitutively express CYP ω-hydroxylases, CYP1A, 1B, 4A and 4F; CYP epoxygenases, CYP2B, 2C and 2J; in addition to soluble epoxide hydrolayse (EPHX2) at mRNA and protein levels. The basal expression of CYP ω-hydroxylases, epoxygenases and EPHX2 was supported by the ability of RL-14 cells to convert arachidonic acid to its biologically active metabolites, 20-hydroxyeicosatetraenoic acids (20-HETEs), 14,15-epoxyeicosatrienoic acids (14,15-EET), 11,12-EET, 8,9-EET, 5,6-EET, 14,15-dihydroxyeicosatrienoic acid (14,15-DHET), 11,12-DHET, 8,9-DHET and 5,6-DHET. Furthermore, RL-14 cells express CYP epoxygenases and ω-hydroxylase at comparable levels to those expressed in adult and fetal human primary cardiomyocytes cells implying the importance of RL-14 cells as a model for studying DMEs in vitro. Lastly, different CYP families were induced in RL-14 cells using 2,3,7,8-tetrachlorodibenzo-p-dioxin and fenofibrate at mRNA and protein levels.

DISCUSSION

The current study provides the first evidence that RL-14 cells express CYP isoenzymes at comparable levels to those expressed in the primary cells and thus offers a unique in vitro model to study DMEs in the heart.

Differential modulation of cytochrome P450 1a1 by arsenite in vivo and in vitro in C57BL/6 mice

Heavy metals, typified by arsenite (As(III)), have been implicated in altering the carcinogenicity of aryl hydrocarbon receptor (AhR) ligands, typified by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), by modulating the induction of the Cyp1a1 enzyme, but the mechanism remains unresolved. In this study, the effects of As(III) on Cyp1a1 expression and activity were investigated in C57BL/6 mouse livers and isolated hepatocytes. For this purpose, C57BL/6 mice were injected intraperitoneally with As(III) (12.5 mg/kg) in the absence and presence of TCDD (15 μg/kg) for 6 and 24 h. Furthermore, isolated hepatocytes from C57BL/6 mice were treated with As(III) (1, 5, and 10 μM) in the absence and presence of TCDD (1 nM) for 3, 6, 12, and 24 h. At the in vivo level, As(III) decreased the TCDD-mediated induction of Cyp1a1 mRNA at 6h while potentiating its mRNA, protein, and catalytic activity levels at 24 h. At the in vitro level, As(III) decreased the TCDD-mediated induction of Cyp1a1 mRNA in a concentration- and time-dependent manner. Moreover, As(III) decreased the TCDD-mediated induction of Cyp1a1 protein and catalytic activity levels at 24 h. Interestingly, As(III) increased the serum hemoglobin (Hb) levels in animals treated for 24 h. Upon treatment of isolated hepatocytes with Hb alone, there was an increase in the nuclear accumulation of AhR and AhR-dependent luciferase activity. Furthermore, Hb potentiated the TCDD-induced AhR-dependent luciferase activity. Importantly, when isolated hepatocytes were treated for 5h with As(III) in the presence of TCDD and the medium was then replaced with new medium containing Hb, there was potentiation of the TCDD-mediated effect. Taken together, these results demonstrate for the first time that there is a differential modulation of the TCDD-mediated induction of Cyp1a1 by As(III) in C57BL/6 mouse livers and isolated hepatocytes. Thus, this study implicates Hb as an in vivo-specific modulator.

Cytochrome P450 epoxygenase metabolite, 14,15-EET, protects against isoproterenol-induced cellular hypertrophy in H9c2 rat cell line

We have previously shown that isoproterenol-induced cardiac hypertrophy causes significant changes to cytochromes P450 (CYPs) and soluble epoxide hydrolase (sEH) gene expression. Therefore, in this study, we examined the effect of isoproterenol in H9c2 cells, and the protective effects of 14,15-EET against isoproterenol-induced cellular hypertrophy. Isoproterenol was incubated with H9c2 cells for 24 and 48 h. To determine the protective effects of 14,15-EET, H9c2 cells were incubated with isoproterenol in the absence and presence of 14,15-EET. Thereafter, the expression of hypertrophic markers and different CYP genes were determined by real time-PCR. Our results demonstrated that isoproterenol significantly increased the expression of hypertrophic marker, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), parallel to a significant increase in cell surface area. Also, isoproterenol increased the mRNA expression of CYP1A1, CYP1B1, CYP2J3, CYP4F4 and CYP4F5, as well as the gene encoding sEH, EPHX2. On other hand, 14,15-EET significantly attenuated the isoproterenol-mediated induction of ANP, BNP, CYP1A1, CYP2J3, CYP4F4, CYP4F5 and EPHX2. Moreover 14,15-EET prevented the isoproterenol-mediated increase in cell surface area. Interestingly, 20-hydroxyeicosatetraenoic acid (20-HETE) treatment caused similar effects to that of isoproterenol treatment and induced cellular hypertrophy in H9c2 cells. In conclusion, isoproterenol induces cellular hypertrophy and modulates the expression of CYPs and EPHX2 in H9c2 cells. Furthermore, 14,15-EET exerts a protective effect against isoproterenol-induced cellular hypertrophy whereas, 20-HETE induced cellular hypertrophy in H9c2 cells.

Murine atrial HL-1 cell line is a reliable model to study drug metabolizing enzymes in the heart

HL-1 cells are currently the only cells that spontaneously contract while maintaining a differentiated cardiac phenotype. Thus, our objective was to examine murine HL-1 cells as a new in vitro model to study drug metabolizing enzymes. We examined the expression of cytochrome P450s (Cyps), phase II enzymes, and nuclear receptors and compared their levels to mice hearts. Our results demonstrated that except for Cyp4a12 and Cyp4a14 all Cyps, phase II enzymes: glutathione-S-transferases (Gsts), heme oxygenase-1 (HO-1), and NAD(P)H: quinone oxidoreductase (Nqo1), nuclear receptors: aryl hydrocarbon receptor (AhR), constitutive androstane receptor (CAR), pregnane X receptor (PXR), and peroxisome proliferator activated receptor (PPAR-alpha) were all constitutively expressed in HL-1 cells. Cyp2b19, Cyp2c29, Cyp2c38, Cyp2c40, and Cyp4f16 mRNA levels were higher in HL-1 cells compared to mice hearts. Cyp2b9, Cyp2c44, Cyp2j9, Cyp2j11, Cyp2j13, Cyp4f13, Cyp4f15 mRNA levels were expressed to the same extent to that of mice hearts. Cyp1a1, Cyp1a2, Cyp1b1, Cyp2b10, Cyp2d10, Cyp2d22, Cyp2e1, Cyp2j5, Cyp2j6, Cyp3a11, Cyp4a10, and Cyp4f18 mRNA levels were lower in HL-1 cells compared to mice hearts. Moreover, 3-methylcholanthrene induced Cyp1a1 while fenofibrate induced Cyp2j9 and Cyp4f13 mRNA levels in HL-1 cells. Examining the metabolism of arachidonic acid (AA) by HL-1 cells, our results demonstrated that HL-1 cells metabolize AA to epoxyeicosatrienoic acids, dihydroxyeicosatrienoic acids, and 20-hydroxyeicosatetraenoic acids. In conclusion, HL-1 cells provide a valuable in vitro model to study the role of Cyps and their associated AA metabolites in addition to phase II enzymes in cardiovascular disease states.

Effect of mercury on aryl hydrocarbon receptor-regulated genes in the extrahepatic tissues of C57BL/6 mice

The individual toxic effects of aryl hydrocarbon receptors (AhR) ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or heavy metals typified by mercury (Hg(2+)) has been previously demonstrated. However, little is known about the combined toxic effects of TCDD and Hg(2+)in vivo. Therefore, we examined the effect of exposure to Hg(2+) (2.5mg/kg) in the absence and presence of TCDD (15 μg/kg) on the AhR-regulated genes using C57Bl/6 mice. Hg(2+) alone did not affect kidney, lung, or heart Cyp1a1/1a2/1b1 mRNA levels. On the contrary, Hg(2+) alone significantly induced kidney Cyp1a1/1a2/1b1 and lung Cyp1b1 protein and catalytic activities. Hg(2+) also induced Nqo1, Gsta1, and HO-1 at the mRNA, protein, and activity levels in the kidney and heart but not in the lung. Upon co-exposure to Hg(2+) and TCDD, Hg(2+) significantly potentiated the TCDD-mediated induction of kidney and lung Cyp1a1/1a2/1b1 mRNA levels, while it decreased their kidney protein and catalytic activity and it increased their lung protein. In addition, Hg(2+) potentiated the TCDD-mediated induction of Nqo1, Gsta1, and HO-1 at mRNA, protein and activity levels in all tissues. The present study demonstrates that Hg(2+) modulates the constitutive and TCDD-induced AhR-regulated genes in a time-, tissue- and, AhR-regulated enzyme genes manner.

Modulation of NAD(P)H:quinone oxidoreductase by vanadium in human hepatoma HepG2 cells

Recent studies demonstrated the carcinogenicity and the mutagenicity of vanadium compounds. In addition, vanadium (V(5+)) was found to enhance the effects of other genotoxic agents. However, the mechanism by which V(5+) induce toxicity remain unknown. In the current study we examined the effect of V(5+) (as ammonium metavanadate, NH(4)VO(3)) on the expression of NAD(P)H: quinone oxidoreductase 1 (NQO1) in human hepatoma HepG2 cells. Therefore, HepG2 cells were treated with increasing concentrations of V(5+) in the presence of two NQO1 inducers, the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and isothiocyanate sulforaphane (SUL). Our results showed that V(5+) inhibited the TCDD- and SUL-mediated induction of NQO1 at mRNA, protein and activity levels. Investigating the effect of V(5+) at transcriptional levels revealed that V(5+) significantly inhibited the TCDD- and SUL-mediated induction of antioxidant responsive element (ARE)-dependent luciferase reporter gene expression. In addition, V(5+) was able to decrease the TCDD- and SUL-induced nuclear accumulation of nuclear factor erythroid 2-related factor-2 (Nrf2) without affecting Nrf2 mRNA or protein levels. Looking at the post-transcriptional level, V(5+) did not affect NQO1 mRNA stability, thus eliminating the possible role of V(5+) in decreasing NQO1 mRNA levels through this mechanism. In contrast, at post-translational level, V(5+) was able to significantly decrease NQO1 protein half-life. The present study demonstrates for the first time that V(5+) down-regulates NQO1 at the transcriptional and post-translational levels in the human hepatoma HepG2 cells via AhR- and Nrf2-dependent mechanisms.