Diazoxide attenuates DOX-induced cardiotoxicity in cultured rat myocytes.

Doxorubicin (DOX)-induced cardiotoxicity is a well known clinical problem, and many investigations have been made of its possible amelioration. We have investigated whether diazoxide (DIA), an agonist at mitochondrial ATP-sensitive potassium channels (mitoKATP), could reverse DOX-induced apoptotic myocardial cell loss, in cultured rat cardiomyocytes. The role of certain proteins in this pathway was also studied. The rat cardiomyocyte cell line (H9c2) was treated with DOX, and also co-treated with DOX and DIA, for 24 h. Distribution of actin filaments, mitochondrial membrane potential, superoxide dismutase (SOD) activity, total oxidant and antioxidant status (TOS and TAS, respectively), and some protein expressions, were assessed. DOX significantly decreased SOD activity, increased ERK1/2 protein levels, and depolarised the mitochondrial membrane, while DIA co-treatment inhibited such changes. DIA co-treatment ameliorated DOX-induced cytoskeletal changes via F-actin distribution and mitoKATP structure. Co-treatment also decreased ERK1/2 and cytochrome c protein levels. Cardiomyocyte loss due to oxidative stress-mediated apoptosis is a key event in DOX-induced cytotoxicity. DIA had protective effects on DOX-induced cardiotoxicity, via mitoKATP integrity, especially with elevated SUR2A levels; but also by a cascade including SOD/AMPK/ERK1/2. Therefore, DIA may be considered a candidate agent for protecting cardiomyocytes against DOX chemotherapy.

Molecularly imprinted nanoparticles with recognition properties towards diphtheria toxin for ELISA applications.

Plastic antibodies can be used for in vitro neutralization of biomacromolecules with different fragments due to their potential in separation, purification, chemical sensor, catalysis and drug production studies. These polymer nanoparticles with binding affinity and selectivity comparable to natural antibodies were prepared using functional monomer synthesis and copolymerization of acrylic monomers via miniemulsion polymerization. As a result, the in vitro cytotoxic effect from diphtheria toxin was reduced by MIPs. In vitro imaging experiments of polymer nanoparticles (plastic antibodies) were performed to examine the interaction of diphtheria toxin with actin filaments, and MIPs inhibited diphtheria toxin damage on actin filaments. The enzyme-linked immunosorbent assay (ELISA) was performed with plastic antibodies labeled with biotin, and it was determined that plastic antibodies could also be used for diagnostic purposes. We report that molecularly imprinted polymers (MIPs), which are biocompatible polymer nanoparticles, can capture and reduce the effect of diphtheria toxic and its fragment A.

Macromolecules can be imprinted by using their fragments as template molecules.MIPs gain an affinity for the template molecule by covalent binding, non-covalent interactions or ligand interactions, as well as the ability to bind, release and recognize the template molecule.The viability of cells treated with DT, NIPs and MIPs was determined by MTT assay.Immunofluorescence staining studies examined structural changes in actin filaments in HUVEC treated with DT, NIPs and MIPs.FA imprinted polymer has the ability to bind whole diphtheria toxin.FA-MIP gave significant results in terms of specificity in ELISA using diphtheria toxin.

Living with female rats exposed to restraint stress during pregnancy caused depressive-like behavior in male rats and stress-induced apoptosis.

OBJECTIVE: Maternal mood disorders such as postpartum depression (PPD) can negatively affect the lives not only of mothers but also of partners. The purpose of this study investigates emotional behavior and hippocampal apoptosis alterations of the male live with a postpartum depressed female. METHODS: Pregnant rats in the stress group were exposed to restraint stress (RS). The male rats who shared the same cages were not exposed to RS. To explain the consequences of depressive-like behavior and anxiety, animals were exposed to the forced swim test (FST), open-field test (OFT), and elevated plus maze (EPM). The apoptotic cell number was detected by terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP biotin nick-end labeling (TUNEL) staining. RESULTS: According to FST, PPD caused more immobility, reduced swimming, and climbing compared to control groups in the stressed female and male (p < 0.05). For the crossing number of squares in the center area, the main effect of the group was significant (p < 0.05). Stressed groups have a higher crossing number of squares in the center area compared to control groups. In the OFT, there was a significant increase in the time spent in the center area in the stress female and male group compared to the control female and male group (p < 0.05). For the EPM, time spent in the close arms was increased in the control male and stress male compared to the stress female group (p < 0.05). Female and male rats with PPD demonstrated apoptosis in neuron and glial cells in the hippocampus. CONCLUSIONS: The present study demonstrates that RS results in PPD in females. Furthermore, it implicates RS as a potential risk factor for the development of postpartum mood disorder in males. Most of the studies on paternal PPD have been done by using self-report questionnaires. Studies on physiological and hormonal changes during the postpartum period among fathers would provide information on biological factors of depression.

Effects of Different Ammonia Levels on Tribenuron Methyl Toxicity in Daphnia magna.

The present study investigates the toxicity of the herbicide tribenuron methyl (TBM) as an anthropogenic agent and ammonia as an abiotic factor on Daphnia magna at environmentally relevant concentrations. These stressors may coexist in surface waters in agricultural regions. To achieve this objective, D. magna were exposed to TBM at a nominal concentration of 0.81 µg/L in association with a low ammonia (LA) concentration of 0.65 mg/L and a high ammonia (HA) concentration of 1.61 mg/L in acute toxicity tests of 96-h duration and chronic toxicity tests of 21-day duration. The D. magna also were exposed to TBM, HA, and LA singly. The D. magna were analysed for various biomarkers of sublethal toxicity. Glutathione peroxidase (GPx), glutathione S-transferase (GST), cholinesterase (ChE) enzyme activities, and levels of thiobarbituric acid reactive substances (TBARS) and total protein were determined spectrophotometrically. Mitochondrial membrane potential (MMP) was analysed by microscopy with fluorescence staining. Cytochrome c and 5' AMP-activated protein kinase (AMPK) were analysed by Western blotting. Morphometric properties were examined microscopically. This is the first study in which AMPK, an indicator of intracellular energy, was measured in D. magna. GST and ChE enzyme activities and TBARS and total protein levels did not change during acute exposures (i.e., 96 h) in all treatments. GPx activity increased in D. magna from the HA + TBM treatment compared with single-exposure groups. The level of cytochrome c protein was elevated in D. magna from the LA and LA + TBM treatments. AMPK protein levels increased in all treatments with daphnids, except in the LA group. MMP was depolarised in D. magna from all treatments, whereas the most notable change was observed in HA + TBM mixture group in chronic exposures. The results show that GST and ChE may not be sensitive biomarkers for evaluating the sublethal toxic effects to D. magna exposed to environmentally relevant concentrations of ammonia and TBM. Acute and chronic exposure to ammonia and TBM probably caused an energetic crisis in D. magna. Therefore, AMPK and MMP are promising biomarkers for these toxicants.

Thymoquinone improves testicular damage and sperm quality in experimentally varicocele-induced adolescent rats.

The aim of this study was to investigate the protective and therapeutic effects of thymoquinone against the negative effects of varicocele on testicular tissue and sperm morphology. Five groups were formed by random selection from a total of 40 adult male Wistar rats (n = 8). Thymoquinone (5 mg/kg/day) was administered intraperitoneally to the varicocele-dimethyl sulfoxide-olive oil-thymoquinone (VT) group and the sham-thymoquinone group. At the end of the 60th day, all groups were anaesthetised and the left testis was removed from the body quickly. One half of the testis tissue, which was divided into two, was separated for biochemical and Western blot analysis, while the other half were fixed in Bouin's fixative. As a result of biochemical, molecular and histopathological analyses, a statistically significant increase was found in the varicocele group testicular tissues in the malondialdehyde level, apoptotic index, Bax expression, cytochrome c expression and Bax/Bcl-2 ratio compared with the sham group. In addition, histopathological changes characterised by partial or complete degeneration of the germinal epithelium were observed in the seminiferous tubules in the same group. Total oxidant status level and sperm count with abnormal morphology increased in varicocele group, whereas total antioxidant status level decreased. In the VT group, all of the biochemical, molecular and histopathological changes detected in the varicocele group were statistically significantly reduced. When the findings obtained in this study are evaluated, it can be said that thymoquinone has the potential to be used as a preventive and therapeutic pharmacological agent in the medical treatment of varicocele. Although the exact mechanism of action of thymoquinone has not been fully elucidated, the findings obtained in this study support the view that thymoquinone showed a cytoprotective effect by reducing apoptosis, oxidative stress and lipid peroxidation.

Chemical and biological characteristics of propolis from Apis mellifera caucasica from the Ardahan and Erzurum provinces of Turkey: a comparative study.

The aim of this study was to compare the biological activities of ethanolic propolis extracts of Apis mellifera caucasica obtained from Ardahan and Erzurum provinces of Turkey. Samples were tested for antioxidant, anticytotoxic, anticarcinogenic, antibacterial, and antifungal potentials using different techniques. Propolis samples from the two provinces had different mineral and organic compositions related to their geographical origin. The ferric reducing antioxidant power (FRAP) test showed superiority of Ardahan propolis over the Erzurum. Regardless of origin and the presence of mitomycin C in the culture medium, propolis enhanced human peripheral lymphocyte viability, which depended on the duration and propolis concentration. Antiperoxidative activity on MCF-7 breast cancer cells was concentration-dependent. Erzurum propolis showed the highest anticarcinogenic activity at the concentrations of 62.5 µg/mL and 125 µg/ mL, which dropped at higher concentrations. All propolis samples also showed antibacterial activity against the tested human pathogens similar to ampicillin and penicillin controls, except for Pseudomonas aeruginosa. However, they did not exert any antifungal activity against Candida albicans and Yarrowia lipolytica. In conclusion, propolis samples from both provinces showed promising biological activities, but further research should focus on finding the right concentrations for optimal effect and include the cell necrosis pathway to get a better idea of the anticarcinogenic effects.

Mild regular treadmill exercise ameliorated the detrimental effects of acute sleep deprivation on spatial memory.

Vulnerable areas like the hippocampus are sensitive to insults such as sleep deprivation (SD); they are also susceptible to environmental enrichment. Much evidence is accumulating that chronic sleep deprivation causes alterations in the hippocampus that responsible for spatial memory. However, there is conflicting about the differences between acute and chronic SD results. The purpose of this study was to determine the protective effects of mild treadmill exercise on acute SD rats. Four groups were created as control, exercise, sleep deprivation, exercise + sleep deprivation. Multiple platforms method was used to induce REM sleep deprivation (RD) for 48 h. The exercise was applied fivedaysperweekforfour weeks(5 × 4). For the first and second weeks, the length of the exercise was 15 min in two sessions (5 min interval) followed by 15 min in three, 15 min in four sessions. Morris water maze (MWM) was used as a spatial memory test. Gene level was determined by using the qPCR technique. Malondialdehyde (MDA) content in the hippocampus was measured as an extent of peroxidative damage to lipids by using the ELISA method. 48 h RD impaired long-term spatial memory significantly. Mild, regular treadmill exercise ameliorated the detrimental effects of acute sleep deprivation on memory. There was no significant difference in MDA between groups. Hippocampal gene expression did not show any changes in all groups. Lack of correlation between memory impairment and levels of genes in the hippocampus is likely to be related to the differences in behavioral and genetic mechanisms.

Oxidative and apoptotic effects of fluoxetine and its metabolite norfluoxetine in Daphnia magna.

The aim of this study was to investigate the oxidative and apoptotic potential of fluoxetine, a widely used antidepressant in Turkey and the world, and of its metabolite norfluoxetine on a model non-target organism, Daphnia magna to see how exposure to this group of antidepressants (specific serotonin reuptake inhibitors) could affect the aquatic environment in which they end up. Juvenile D. magna specimens were chronically exposed to fluoxetine and norfluoxetine alone and in combination at concentrations found in the aquatic environment (0.091 and 0.011 µg/L, respectively) and to their 10-fold environmental concentrations for 21 days. Another group of 17-day-old animals were subacutely exposed to 100-fold environmental concentrations for four days. After exposure, we measured their glutathione peroxidase (GPx) and cholinesterase (ChE) activities, thiobarbituric acid-reactive substances (TBARS), and total protein content spectrophotometrically, while mitochondrial membrane potential (MMP) was analysed by fluorescence staining, and cytochrome c and ERK1/2 protein content by Western blotting. This is the first-time cytochrome c and ERK1/2 were determined at the protein level in D. magna. We also measured their carapace length, width, and caudal spine length microscopically. At environmental concentrations fluoxetine and norfluoxetine caused an increase in ChE activity and brood production. They also caused a decrease in juvenile carapace length, width, and caudal spine length and depolarised the mitochondrial membrane. At 10-fold environmental concentrations, GPx activity, lipid peroxidation levels, cytochrome c, and ERK1/2 protein levels rose. The most pronounced effect was observed in D. magna exposed to norfluoxetine. Norfluoxetine also decreased brood production. Similar effects were observed with subacute exposure to 100-fold environmental concentrations. However, total protein content decreased. All this confirms that fluoxetine and norfluoxetine have oxidative and apoptotic potential in D. magna. Daphnia spp. have a great potential to give us precious insight into the mechanisms of environmental toxicants, but there is still a long way to go before they are clarified in these organisms.

Silencing HMGB1 expression inhibits adriamycin's heart toxicity via TLR4 dependent manner through MAPK signal transduction.

PURPOSE: Adriamycin (ADR) is a commonly used anti-cancer drug. ADR has toxic effects on cardiomyocytes and leads to heart failure. However, the underlying mechanism(s) by which ADR causes heart failure is still not clarified exactly. The aim of present study is to investigate whether ADR-induced heart failure is mediated via HMGB1/TLR4 to initiate the apoptosis through MAPK/AMPK pathways. METHODS: H9c2 cell line was used to create four groups as a control, HMGB1 inhibition, ADR, ADR+HMGB1 inhibition. Silencing HMGB1 was performed with specific small interfering RNA. ADR was used at 2 µM concentration for 36 and 48 hours. Protein and genes expressions, apoptosis was measured. RESULTS: Although ADR decreased AMPK, pAMPK, ERK1/2, pERK1/2, p38, JNK protein expression, ADR+HMGB1 inhibition led to change those protein expressions. The effect of silencing of HMGB1 prevented apoptosis induced by ADR in the cells. HMGB1 caused changes a kind of posttranscriptional modification on the TLR4 receptor. This posttranscriptional modification of TLR4 receptor led to decreased AMPK protein level, but phosphorylated-AMPK. This alternation of AMPK protein caused enhancing of JNK protein, resulting from the decline of p38 and ERK protein levels. Eventually, JNK triggered apoptosis by a caspase-dependent pathway. The number of TUNEL positive and active caspase 8 cells at ADR was high, although HMGB1 silencing could decrease the cell numbers. CONCLUSIONS: Inhibition of HMGB1 might prevent the lose of the cardiac cell by inhibition of apoptotic pathway, therefore HMGB1 plays an essential role as amplifying on ADR toxicity on the heart by TLR4.

The role of toll-like receptors in the protective effect of melatonin against doxorubicin-induced pancreatic beta cell toxicity.

AIMS: Doxorubicin, an anticancer drug, has a toxic effect on many tissues such as heart, pancreas, liver, kidney, and testis. The aim of current study is to investigate whether melatonin would be protective in doxorubicin-induced beta (ß) cell toxicity via HMGB1/TLR2/TLR4/MAPK/NF-қB signaling pathway. MAIN METHODS: Human pancreatic ß cell (1.1B4) was used in the present study. Four experimental groups were created as control, melatonin (10 µM), doxorubicin (2 µM) and the combination of melatonin with doxorubicin. Following 24-h treatment, Mitogen-activated protein kinase (MAPKs), Toll like receptors (TLRs) including TLR2 and TLR4, pro-and anti-apoptotic protein expression levels were determined by western blotting. Total antioxidant (TAS), oxidant status (TOS) and oxidative stress index (OSI) of the cells as well as superoxide dismutase (SOD) levels were determined. Active caspase-8 activity was measured and TUNEL staining was performed to study apoptotic pathways. Mitochondrial membrane potential (MMP), some protein expressions and F-actin distribution were analyzed. KEY FINDINGS: Doxorubicin caused to depolarize MMP, resulting in enhancing apoptosis by activation of caspase-8 via MAPKs/NF-кB pathway via elevation of TOS and decreasing TAS. Also, doxorubicin destroyed F-actin distribution and elevated TLR2 and some apoptotic proteins, including Bax. However, co-treatment of melatonin with doxorubicin could reverse depolarization of MMP and inhibition of apoptosis through MAPK/NF-кB signaling by decreasing TOS and increasing TAS. The co-treatment reversed the alternations of TLR2, TLR4, MAPKs and apoptotic protein expressions induced by doxorubicin. SIGNIFICANCE: Melatonin could be a good candidate against pancreatic ß cell toxicity-induced by doxorubicin through TLR2/TLR4/MAPK/NF-кB pathways.

The effect of Diazoxide on norepinephrine-induced cardiac hypertrophy, in vitro.

Cardiac hypertrophy is associated with mitochondrial dysfunctions, which leads to heart failure if sustained. The aim of present study is to test hypothesis whether activation of mitochondrial KATP channel (mitoKATP) by diazoxide improve mitochondrial membrane potential (MMP) and oxidative stress in an in vitro model of cardiac hypertrophy. Rat cardiomyocytes cell line (H9c2) was used to create four groups as control, diazoxide, hypertrophy, hypertrophy and diazoxide. Norepinephrine was used to induce hypertrophy. Diazoxide and norepinephrine were simultaneously administered. After 24 hours treatment, total oxidant status (TOS), total antioxidant status (TAS) and superoxide dismutase (SOD) activities were measured. MMP and F-actin distribution were analyzed. Hypertrophy significantly elevated TOS level. In addition, diazoxide administration significantly increased TOS level in the normal cell line. There were no significant differences in SOD activity, TAS and oxidative stress index (OSI) between groups. Hypertrophy caused a decrease in MMP and destrupted F-actin. Diazoxide improved MMP and F-actin in mitochondria. Hypertrophy impaired the function and structure of mitochondria. The opening of mitoKATP by diazoxide failed to improve oxidative stress; however, it is effective against mitochondrial damage caused by hypertrophy.

Nicotine reduces effectiveness of doxorubicin chemotherapy and promotes CD44+CD24- cancer stem cells in MCF-7 cell populations.

Breast cancer is the most common type of cancer in females and the second most common cause of cancer mortality after lung cancer. Cancer stem cells represent a novel approach to target cancer and reduce cancer recurrence and metastasis. Many patients with breast cancer continue to smoke after receiving their diagnosis. Nicotine is a key factor in tobacco addiction and also changes some cellular functions, such as activation of mitogenic pathways, angiogenesis and cell proliferation. In the present study, the impact of nicotine was assessed in a population of MCF-7 human breast cancer cells. Cluster of differentiation (CD)44+CD24- cancer stem cell population of MCF-7 cells were evaluated using flow cytometry and scanning electron microscopy. Chemoresistance effects of nicotine were demonstrated in these cells. These findings demonstrated harmful effects of nicotine following metastasis of cancer, owing to the chemoresistance produced through uninterrupted smoking, which may impact the effectiveness of treatment.

Evidence that Extreme Dilutions of Paclitaxel and Docetaxel Alter Gene Expression of In Vitro Breast Cancer Cells.

BACKGROUND: Gene expression analysis of cells treated with extreme dilutions or micro amounts of drugs has been used to provide useful suggestions about biological responses. However, most of the previous studies were performed on medicines being prepared from a variety of herbal and metal sources. This study investigated the effects of ultramolecular dilution of the taxane anti-cancer drugs, which are not commonly used in homeopathic medicines, on mRNA expression profiles of five key genes (p53, p21, COX-2, TUBB2A and TUBB3) in the breast cancer cell line MCF-7. METHOD: MCF-7 cells were exposed to paclitaxel (Taxol) or docetaxel (Taxotere) preparations (6X, 5C and 15C dilutions prepared from pharmacological concentration of 25 nmol/L) for 72 hours. The cell culture groups were evaluated with the trypan blue dye exclusion method for the proliferation/cytotoxicity rates, immuno-staining ß-tubulin for microtubule organization, and reverse transcription polymerase chain reaction for gene expression levels.Fold-change in gene expression was determined by the ΔΔCt method. RESULTS: The administration of diluted preparations had little or no cytotoxic effect on MCF-7 cells, but altered the expression of genes analyzed with a complex effect. According to the ΔΔCt method with a five-fold expression difference (p < 0.05) as a cut-off level, ultra-high dilutions of paclitaxel and docetaxel showed differential effects on the studied genes with a concentration-independent activity. Furthermore, the dilutions disrupted the microtubule structure of MCF-7 cells, suggesting that they retain their biological activity. CONCLUSION: Despite some limitations, our findings demonstrate that gene expression alterations also occur with ultra-high dilutions of taxane drugs.

Comparative developmental toxicity evaluation of di- n-hexyl phthalate and dicyclohexyl phthalate in rats.

To investigate the effects of di- n-hexyl phthalate (DHP) and dicyclohexyl phthalate (DCHP) on the development of fetus and placenta in utero, pregnant rats were exposed to DHP or DCHP at dosages of 0, 20, 100, and 500 mg/kg bw/day, by gavage, on gestational days 6-19. Anogenital distance (AGD) and AGD-body weight1/3 ratio of female fetuses decreased in all treatment groups in a non-dose-response way. The ossification centers of bones and the intensity of Alizarin red stain of the fetuses decreased in all treatment groups. The white blood cell levels of fetuses in DHP and DCHP exposed groups increased at all dosages. Mean cell hemoglobin, hemoglobin concentrations, and hemoglobin levels of all DHP and DCHP treated male and female fetuses were reduced. Histopathologic changes (hemorrhage in labyrinth, degeneration of spongiotrophoblast, hemorrhage, decreased and irregular vessel formation, and edema in the basal zone) were observed in placentas at high dosages of DHP and DCHP. In contrast, there was no change in weight gain of dams in DHP and DCHP exposed groups compared to control, but resorption rate, reduced fetal weight, delayed ossification, placental disruption, and hematologic parameters clearly indicated that in utero DHP and DCHP exposure resulted in intrauterine growth retardation in rats.

Inhibition of Angiotensin-II Production Increases Susceptibility to Acute Ischemia/Reperfusion Arrhythmia.

BACKGROUND Myocardial ischemia and reperfusion lead to impairment of electrolyte balance and, eventually, lethal arrhythmias. The aim of this study was to investigate the effects of pharmacological inhibition of angiotensin-II (Ang-II) production on heart tissue with ischemia-reperfusion damage, arrhythmia, and oxidative stress. MATERIAL AND METHODS Rats were divided into 4 groups: only ischemia/reperfusion (MI/R), captopril (CAP), aliskiren (AL), and CAP+AL. The drugs were given by gavage 30 min before anesthesia. Blood pressure and electrocardiography (ECG) were recorded during MI/R procedures. The heart tissue and plasma was kept so as to evaluate the total oxidant (TOS), antioxidant status (TAS), and creatine kinase-MB (CK-MB). RESULTS Creatine kinase-MB was not different among the groups. Although TAS was not affected by inhibition of Ang-II production, TOS was significantly lower in the CAP and/or AL groups than in the MI/R group. Furthermore, oxidative stress index was significantly attenuated in the CAP and/or AL groups. Captopril significantly increased the duration of VT during ischemia; however, it did not have any effect on the incidence of arrhythmias. During reperfusion periods, aliskiren and its combinations with captopril significantly reduced the incidence of other types of arrhythmias. Captopril alone had no effect on the incidence of arrhythmias, but significantly increased arrhythmias score and durations of arrhythmias during reperfusion. MAP and heart rate did not show changes in any groups during ischemic and reperfusion periods. CONCLUSIONS Angiotensin-II production appears to be associated with elevated levels of reactive oxygen species, but Ang-II inhibitions increases arrhythmia, mainly by initiating ventricular ectopic beats.

Low dose monoethyl phthalate (MEP) exposure triggers proliferation by activating PDX-1 at 1.1B4 human pancreatic beta cells.

Phthalate plasticizers used in a wide range of common plastic products are released into the environment and may pose a risk of increased incidence of type 2 diabetes. In this work, we studied the effects of monoethyl phthalate (MEP), the metabolite of diethyl phthalate, exposure on 1.1B4 human pancreatic beta cells at low doses (1-1000 nM). We showed that MEP treatment induced proliferation in 1.1B4 cells. Also PCNA protein expression levels were increased related to proliferation induction. It has been noted that phthalates can exert estrogen mediated response by interacting with ER. In our study 24 h MEP treatment decreased ERα protein expression level conversely it increased the same protein expression level after 72 h treatment. Also MEP treatment decreased ERß expression after 72 h at 1.1B4 cells. Our results further show that insulin content of 1.1B4 cells were increased with low dose MEP treatment. Along with our insulin content results, PDX- 1 expression levels were also increased at 1.1B4 cells with MEP treatment. These findings suggest that MEP acts as an estrogenic compound and PPARγ agonist at lower concentrations. Also it should be noted that PDX-1 may be a critical regulator of 1.1B4 cells treated with MEP.

The Cooperative Effect of Local Angiotensin-II in Liver with Adriamycin Hepatotoxicity on Mitochondria.

BACKGROUND: Adriamycin (ADR) is a drug used clinically for anticancer treatment; however, it causes adverse effects in the liver. The mechanism by which these adverse effects occur remains unclear, impeding efforts to enhance the therapeutic effects of ADR. Its hepatotoxicity might be related to increasing reactive oxygen species (ROS) and mitochondrial dysfunction. The interaction between ADR and the local renin-angiotensin system (RAS) in the liver is unclear. ADR might activate the RAS. Angiotensin-II (Ang-II) leads to ROS production and mitochondrial dysfunction. In the present study we investigated whether ADR's hepatotoxicity interacts with local RAS in causing oxidative stress resulting from mitochondrial dysfunction in the rat liver. MATERIAL/METHODS: Rats were divided into 5 groups: control, ADR, co-treated ADR with captopril, co-treated ADR with Aliskiren, and co-treated ADR with both captopril and Aliskiren. Mitochondria and cytosol were separated from the liver, then biochemical measurements were made from them. Mitochondrial membrane potential (MMP) and ATP levels were evaluated. RESULTS: ADR remarkably decreased MMP and ATP in liver mitochondria (p<0.05). Co-administration with ADR and Aliskiren and captopril improved the dissipation of MMP (p<0.05). The decreased ATP level was restored by treatment with inhibitors of ACE and renin. CONCLUSIONS: Angiotensin-II may contribute to hepatotoxicity of in the ADR via mitochondrial oxidative production, resulting in the attenuation of MMP and ATP production.

Melatonin Prevents Mitochondrial Damage Induced by Doxorubicin in Mouse Fibroblasts Through Ampk-Ppar Gamma-Dependent Mechanisms.

BACKGROUND Doxorubicin (brand name: Adriamycin®) is used to treat solid tissue cancer but it also affects noncancerous tissues. Its mechanism of cytotoxicity is probably related to increased oxidation, mitochondrial dysfunction, and apoptosis. Melatonin is reported to have antiapoptotic and antioxidative effects. The aim of this study was to determine whether melatonin would counteract in vitro cytotoxicity of doxorubicin in mouse fibroblasts and determine the pathway of its action against doxorubicin-induced apoptosis. MATERIAL AND METHODS We measured markers of apoptosis (cytochrome-c, mitochondrial membrane potential, and apoptotic cell number) and oxidative stress (total oxidant and antioxidant status) and calculated oxidant stress index in 4 groups of fibroblasts: controls, melatonin-treated, doxorubicin-treated, and fibroblasts concomittantly treated with a combination of melatonin and doxorubicin. RESULTS Melatonin given with doxorubicin succesfully countered apoptosis generated by doxorubicin alone, which points to its potential as a protective agent against cell death in doxorubicin chemotherapy. This also implies that patients should be receiving doxorubicin treatment when their physiological level of melatonin is at its highest, which is early in the morning. CONCLUSIONS This physiological level may not be high enough to overcome doxorubicin-induced oxidative stress, but adjuvant melatonin treatment may improve quality of life. Further research is needed to verify our findings.

Association between non-coding polymorphisms of HOPX gene and syncope in hypertrophic cardiomyopathy.

OBJECTIVE: Homeodomain Only Protein X (HOPX) is an unusual homeodomain protein which regulates Serum Response Factor (SRF) dependent gene expression. Due to the regulatory role of HOPX on SRF activity and the regulatory role of SRF on cardiac hypertrophy, we aimed to investigate the relationship between HOPX gene variations and hypertrophic cardiomyopathy (HCM). METHODS: In this study, designed as a case-control study, we analyzed coding and flanking non-coding regions of the HOPX gene through 67 patients with HCM and 31 healty subjects. Certain regions of the gene were investigated by Single Stranded Conformation Polymorphism (SSCP) and Restriction Fragment Length Polymorphism (RFLP). Statistical analyses of genotypes and their relationship with clinical parameters were performed by chi-square, Kruskal-Wallis and the Fisher's exact test. RESULTS: In 5' Untranslated Region (UTR) and intronic region of the HOPX gene, we found a C>T substitution and an 8-bp insertion/deletion (In/Del) polymorphism, respectively. These two polymorphisms seemed to constitute an haplotype. While the frequency of homozygous genotypes of In/Del and C/T polymorphisms were found significantly lower in the patients with syncope (p=0.014 and p=0.017, respectively), frequency of their heterozygous genotypes were found significantly higher in the patients with syncope (p=0.048 and p=0.030, respectively). CONCLUSION: Though there was not found any mutation in coding sequence of HOPX gene, two non-coding polymorphisms were found related to syncope in HCM patients. While homozygous status of these polymorphisms was found to be protective against the syncope, their heterozygous status seemed to be a risk factor for syncope in HCM patients. Our results suggest that HOPX may contribute to pathogenesis or manifestation of HCM as a modifier gene.

Actin--an inhibitor of eukaryotic elongation factor activities.

An inhibitor of diphtheria toxin- and endogenous transferase-dependent ADP-ribosylation of eukaryotic elongation factor 2 (eEF2) has been found in the cytoplasmic fraction from rat liver. We provide evidence that this cytoplasmic inhibitor corresponds to actin, which gives rise also to inhibition of polyphenylalanine (polyPhe) synthesis. Both globular monomeric (G-actin) and filamentous (F-actin) forms of actin appear to be inhibitory on the action of elongation factors 1 and 2 (eEF1 and eEF2) in polyPhe synthesis with the inhibitory effect of G-actin proving to be stronger. Some component(s) in the postribosomal supernatant (S-130) fraction and also DNase I prevent actin-promoted inhibition of polyPhe synthesis.