tretinoin and sulforaphane

The present study aimed to explore the molecular mechanisms underlying the increase of nicotinamide adenine dinucleotide phosphate:quinine oxidoreductase 1 (NQO1) and γ-glutamylcysteine synthetase (γ-GCS) in brain tissues after intracerebral hemorrhage (ICH). The microglial cells obtained from newborn rats were cultured and then randomly divided into the normal control group (NC group), model control group (MC group), rosiglitazone (RSG) intervention group (RSG group), retinoic-acid intervention group (RSG+RA group), and sulforaphane group (RSG+SF group). The expression levels of NQO1, γ-GCS, and nuclear factor E2-related factor 2 (Nrf2) were measured by real-time polymerase chain reaction (RT-PCR) and Western blotting, respectively. The results showed that the levels of NQO1, γ-GCS and Nrf2 were significantly increased in the MC group and the RSG group as compared with those in the NC group (P<0.01). They were found to be markedly decreased in the RSG+RA group and increased in the RSG+SF group when compared with those in the MC group or the RSG group (P<0.01). The RSG+SF group displayed the highest levels of NQO1, γ-GCS, and Nrf2 among the five groups. In conclusion, a medium dose of RSG increased the anti-oxidative ability of thrombin-activated microglia by increasing the expression of NQO1 and γ-GCS. The molecular mechanisms underlying the increase of NQO1 and γ-GCS in thrombin-activated microglia may be associated with the activation of Nrf2.

Topics: Animals; Animals, Newborn; Cells, Cultured; Cerebral Hemorrhage; Disease Models, Animal; Female; Glutamate-Cysteine Ligase; Isothiocyanates; Male; Microglia; NAD(P)H Dehydrogenase (Quinone); NF-E2-Related Factor 2; PPAR gamma; Primary Cell Culture; Rats; Rats, Sprague-Dawley; Rosiglitazone; Sulfoxides; Thrombin; Tretinoin

Dysfunctional Omi/HtrA2, a mitochondrial serine protease, has been implicated in various neurodegenerative disorders. Despite the wealth of evidence on the roles of Omi/HtrA2 in apoptosis, little is known about its cytosolic targets, the cleavage of which could account for the observed morphological changes such as cytoskeletal reorganizations in axons. By proteomic analysis, vimentin was identified as a substrate for Omi/HtrA2 and we have reported increased Omi/HtrA2 protease activity in Alzheimer disease (AD) brain. Here, we investigated a possible link between Omi/HtrA2 and vimentin cleavage, and consequence of this cleavage on mitochondrial distribution in neurons. In vitro protease assays showed vimentin to be cleaved by Omi/HtrA2 protease, and proximity ligation assay demonstrated an increased interaction between Omi/HtrA2 and vimentin in human primary neurons upon stress stimuli. Using differentiated neuroblastoma SH-SY5Y cells, we showed that Omi/HtrA2 under several different stress conditions induces cleavage of vimentin in wild-type as well as SH-SY5Y cells transfected with amyloid precursor protein with the Alzheimer disease-associated Swedish mutation. After stress treatment, inhibition of Omi/HtrA2 protease activity by the Omi/HtrA2 specific inhibitor, Ucf-101, reduced the cleavage of vimentin in wild-type cells. Following altered vimentin filaments integrity by stress stimuli, mitochondria was redistributed in differentiated SH-SY5Y cells and human primary neurons. In summary, the findings outlined in this paper suggest a role of Omi/HtrA2 in modulation of vimentin filamentous structure in neurons. Our results provide important findings for understanding the biological role of Omi/HtrA2 activity during stress conditions, and give knowledge of interplay between Omi/HtrA2 and vimentin which might affect mitochondrial distribution in neurons.

Topics: Amyloid beta-Protein Precursor; Axons; Cell Line, Tumor; Culture Media, Serum-Free; Cytosol; High-Temperature Requirement A Serine Peptidase 2; Humans; Interleukin-1beta; Intermediate Filaments; Isothiocyanates; Mitochondria; Mitochondrial Proteins; Mutation, Missense; Neoplasm Proteins; Nerve Tissue Proteins; Neuroblastoma; Neurogenesis; Neurons; Point Mutation; Pyrimidinones; Serine Endopeptidases; Serine Proteinase Inhibitors; Stress, Physiological; Sulfoxides; Thiones; Transfection; Tretinoin; Tunicamycin; Vimentin

It has been found that nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2-ARE) signaling pathway plays a role in antioxidative response, anti-inflammatory response, and neuron-protection in intracerebral hemorrhage (ICH). The aim of this study is to explore mechanisms underlying the perifocal neuroprotective effect of the Nrf2-ARE signaling pathway after ICH.. There were a total of 90 rats with basal ganglia hemorrhage, which were randomly divided into the following four groups: ICH (Sprague-Dawley rats with autologous femoral arterial blood injection into the basal ganglia), sulforaphane (SFN) (SFN was intraperitoneally administered into rats), retinoic acid (RA) (RA was intraperitoneally administered into rats), and dimethyl sulfoxide (the rats were treated with dimethyl sulfoxide). We observed the neurological score of the rats in the different groups, and collected brain tissues for immunofluorescence, Western blot, and reverse transcription polymerase chain reaction to detect expression of Nrf2, heme oxygenase (HO-1), nuclear factor-κB (NF-κB), and tumor necrosis factor-α (TNF-α).. The results indicated that neurological dysfunction of rats was significantly improved in the SFN group, and the expressions of Nrf2 and HO-1 in tissues surrounding the hemorrhage were increased. Also, the level of NF-κB and TNF-α were reduced compared to the ICH group. The RA group exhibited more severe neurological dysfunction and lower levels of Nrf2 and HO-1 than the SFN and ICH groups. Compared to the ICH group, the NF-κB and TNF-α expression in the RA groups was increased. In conclusion, RA inhibits Nrf2 dissociation and translocation into nucleus, thereby suppressing the anti-inflammatory effect of Nrf2-ARE signaling pathway. The activation of Nrf2-ARE signaling pathway by SFN can elevate expression of antioxidant enzyme HO-1, reduce perifocal inflammatory response after ICH, and thus may play a neuroprotective role.. The results suggest that Nrf2-ARE signaling pathway may serve as a new target for treatment of perifocal inflammatory injury caused by ICH.

Topics: Animals; Antioxidant Response Elements; Blotting, Western; Cerebral Hemorrhage; Dimethyl Sulfoxide; Disease Models, Animal; Heme Oxygenase-1; Isothiocyanates; Male; Neuroprotection; NF-E2-Related Factor 2; NF-kappa B; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Sulfoxides; Tretinoin; Tumor Necrosis Factor-alpha

The ability to adapt to acute oxidative stress (e.g. H(2)O(2), peroxynitrite, menadione, and paraquat) through transient alterations in gene expression is an important component of cellular defense mechanisms. We show that such adaptation includes Nrf2-dependent increases in cellular capacity to degrade oxidized proteins that are attributable to increased expression of the 20 S proteasome and the Pa28αβ (11 S) proteasome regulator. Increased cellular levels of Nrf2, translocation of Nrf2 from the cytoplasm to the nucleus, and increased binding of Nrf2 to antioxidant response elements (AREs) or electrophile response elements (EpREs) in the 5'-untranslated region of the proteasome β5 subunit gene (demonstrated by chromatin immunoprecipitation (or ChIP) assay) are shown to be necessary requirements for increased proteasome/Pa28αβ levels, and for maximal increases in proteolytic capacity and stress resistance; Nrf2 siRNA and the Nrf2 inhibitor retinoic acid both block these adaptive changes and the Nrf2 inducers DL-sulforaphane, lipoic acid, and curcumin all replicate them without oxidant exposure. The immunoproteasome is also induced during oxidative stress adaptation, contributing to overall capacity to degrade oxidized proteins and stress resistance. Two of the three immunoproteasome subunit genes, however, contain no ARE/EpRE elements, and Nrf2 inducers, inhibitors, and siRNA all have minimal effects on immunoproteasome expression during adaptation to oxidative stress. Thus, immunoproteasome appears to be (at most) minimally regulated by the Nrf2 signal transduction pathway.

Topics: Active Transport, Cell Nucleus; Adaptation, Physiological; Animals; Anticarcinogenic Agents; Antineoplastic Agents; Antioxidants; Cell Nucleus; Cells, Cultured; Curcumin; Cytoplasm; Enzyme Induction; Isothiocyanates; Mice; NF-E2-Related Factor 2; Oxidative Stress; Proteasome Endopeptidase Complex; Response Elements; Sulfoxides; Thioctic Acid; Thiocyanates; Tretinoin