OBJECTIVETo study the effects of deltamethrin (DM) on the mRNA expression of copper-zinc dependent SOD (CuZn-SOD), glutathione reductase (GR) and gamma glutamylcysteine synthetase (gamma-GCS) light subunit (GCSl), as well as on expression of both mRNA and protein of gamma-GCS heavy subunit (GCSh) and NFE2 related factor 2 (Nrf2) in cerebral cortex and hippocampus of rats.

METHODSEighteen Wistar male rats were randomizedly divided into three groups, six for each group. The low dosage and high dosage DM treated groups were administrated intraperitoneally with DM (the daily dosage was 3.125, 12.500 mg/kg BWT respectively) for five consecutive days while the control group was administered intraperitoneally with olive oil. The relative amount of mRNA expression of these genes was measured by the method of reverse transcription polymerase chain reaction (RT-PCR) (n = 6). The protein level was detected by the method of immunohistochemistry and image analysis system (n = 4).

RESULTSThere was no change in mRNA expression level of CuZn-SOD, GR, GCSh and Nrf2 gene in both cerebral cortex and hippocampus tissue in rats administrated with DM. However, the mRNA level of GCSl gene in cerebral cortex of high dosage group as well as in both cerebral cortex and hippocampus of the low dosage group was significantly lower than that in corresponding tissue in the control group, and was decreased to 71.1%, 63.6% and 75.2% of mRNA level of corresponding tissue in the control group (P < 0.01). There was no obvious effect on protein level of both GCSh and Nrf2 in CA1, CA2, CA3 and dentate gyrus (DG) of hippocampus as well as on that in cerebral cortex in rats treated with DM.

CONCLUSIONUnder the experimental conditions, there is no obvious effect in the mRNA expression level of CuZn-SOD, GR gene, as well as on expression of both mRNA and protein of Nrf2 gene in both cerebral cortex and hippocampus tissue in rats administered with DM. DM depresses the mRNA expression of GCSl gene, but does not affect the mRNA expression of GCSh gene.

Animals ; Cerebral Cortex ; drug effects ; metabolism ; Dose-Response Relationship, Drug ; Gene Expression ; drug effects ; Glutamate-Cysteine Ligase ; biosynthesis ; genetics ; Glutathione Reductase ; biosynthesis ; genetics ; Hippocampus ; drug effects ; metabolism ; Male ; NF-E2-Related Factor 2 ; biosynthesis ; genetics ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; RNA, Messenger ; genetics ; Random Allocation ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Superoxide Dismutase ; biosynthesis ; genetics

In vascular smooth muscle cells (VSMCs), induction of the heme oxygenase-1 (HO-1) confers vascular protection against cellular proliferation mainly via its up-regulation of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1) that is involved in negative regulation of cellular proliferation. In the present study, we investigated whether the phytochemical curcumin and its metabolite tetrahydrocurcumin could induce HO-1 expression and growth inhibition in rat VSMCs and, if so, whether their antiproliferative effect could be mediated via HO-1 expression. At non-toxic concentrations, curcumin possessing two Michael-reaction acceptors induced HO-1 expression by activating antioxidant response element (ARE) through translocation of the nuclear transcription factor E2-related factor-2 (Nrf2) into the nucleus and also inhibited VSMC growth triggered by 5% FBS in a dose-dependent manner. In contrast, tetrahydrocurcumin lacking Michael-reaction acceptor showed no effect on HO-1 expression, ARE activation and VSMC growth inhibition. The antiproliferative effect of curcumin in VSMCs was accompanied by the increased expression of p21(WAF1/CIP1). Inhibition of VSMC growth and expression of p21(WAF1/CIP1) by curcumin were partially, but not completely, abolished when the cells were co- incubated with the HO inhibitor tin protoporphyrin. In human aortic smooth muscle cells (HASMCs), curcumin also inhibited growth triggered by TNF-alpha and increased p21(WAF1/CIP1) expression via HO-1-dependent manner. Our findings suggest that curcumin has an ability to induce HO-1 expression, presumably through Nrf2-dependent ARE activation, in rat VSMCs and HASMCs, and provide evidence that the antiproliferative effect of curcumin is considerably linked to its ability to induce HO-1 expression.
Active Transport, Cell Nucleus ; Animals ; Aorta/cytology ; Cell Nucleus/metabolism ; Cell Proliferation/*drug effects ; Cells, Cultured ; Curcumin/analogs & derivatives/*pharmacology ; Cyclin-Dependent Kinase Inhibitor p21/biosynthesis/metabolism ; Gene Expression Regulation ; Heme Oxygenase (Decyclizing)/biosynthesis/genetics/*physiology ; Heme Oxygenase-1/biosynthesis/genetics/*physiology ; Humans ; Metalloporphyrins/pharmacology ; Muscle, Smooth, Vascular/drug effects/*physiology ; Myocytes, Smooth Muscle/drug effects/*physiology ; NF-E2-Related Factor 2/metabolism ; Protoporphyrins/pharmacology ; Rats ; Regulatory Sequences, Nucleic Acid ; Response Elements ; Tumor Necrosis Factor-alpha/pharmacology

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.
Animals ; Antioxidants/*metabolism/*pharmacology ; Apoptosis/drug effects ; Caspase 3/metabolism ; Caspase 8/metabolism ; Cell Line ; Cisplatin/*toxicity ; Cysteine/*analogs & derivatives/pharmacology ; Gene Expression Regulation/*drug effects ; Gene Knockdown Techniques ; Glutathione/*metabolism ; Heme Oxygenase-1/genetics ; Intracellular Space/metabolism ; Male ; Metabolic Detoxication, Phase II/genetics ; Mice ; NF-E2-Related Factor 2/genetics ; Nitric Oxide/biosynthesis ; Organ of Corti/*drug effects/*metabolism ; RNA Interference ; Rats ; Reactive Oxygen Species/metabolism ; Superoxide Dismutase/genetics

Sulforaphane (SFN) is a naturally occurring compound which is known to induce the phase II antioxidant genes via Nrf2 activation, although the underlying mechanism has not been fully elucidated. In this study, we investigated Nrf2 induction in response to SFN in human bronchial epithelial BEAS-2B cells and determined the signaling pathways involved in this process. SFN treatment reduced cell viability. Prior to cell death, intracellular reactive oxygen species (ROS) were generated at a high rate within a minute of commencing SFN treatment. Pretreatment with antioxidant N-acetylcysteine (NAC) blocked SFN-induced decrease in cell growth. Erk1/2 was activated within 30 min of SFN addition, whereas Akt phosphorylation did not significantly change until the first 8 hr after SFN treatment but then became substantially low until 48 hr. Inhibition of Erk1/2 phosphorylation attenuated SFN-induced loss of cell viability. Nrf2 protein levels in both nuclear and whole cell lysates were increased by SFN treatment, which was dependent on ROS production. Knockdown of Nrf2 with siRNA attenuated SFN-induced heme oxygenase-1 (HO-1) up-regulation. Induction of the Nrf2/HO-1 after SFN treatment was potently suppressed by pretreatment with NAC. Overall, our results indicate that SFN mediates antioxidative and antiproliferative responses by generating ROS in BEAS-2B cells.
Acetylcysteine/pharmacology ; Anticarcinogenic Agents/pharmacology ; Antioxidants/*pharmacology ; Bronchi/cytology/*drug effects/metabolism ; Cell Line ; Cell Proliferation/*drug effects ; Epithelial Cells/drug effects/metabolism ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Free Radical Scavengers/pharmacology ; Heme Oxygenase-1/biosynthesis ; Humans ; NF-E2-Related Factor 2/biosynthesis/genetics ; Oxidative Stress/drug effects ; Proto-Oncogene Proteins c-akt/metabolism ; RNA Interference ; RNA, Small Interfering ; Reactive Oxygen Species/*metabolism ; Respiratory Mucosa/cytology/*drug effects/metabolism ; Signal Transduction/drug effects ; Thiocyanates/*pharmacology