The Amyloid β peptide (Aβ) is a main component of senile plaques in Alzheimer's disease. Currently, NADPH oxidase (NOX) and mitochondria are considered as primary sources of ROS induced by Aβ. However, the contribution of NOX and mitochondria to Aβ-induced ROS generation has not been well defined. To delineate the relative involvement of NOX and mitochondria in Aβ-induced ROS generation and neuronal death in mouse cortical cultures, we examined the effect of NOX inhibitors, apocynin and AEBSF, and the mitochondria-targeted antioxidants (MTAs), mitotempol and mitoquinone, on Aβ-induced ROS generation and neuronal deaths. Cell death was assessed by measuring lactate dehydrogenase efflux in bathing media at 24 and 48 hrs after exposure to Aβ₁₋₄₂. Aβ₁₋₄₂ induced dose- and time-dependent neuronal deaths in cortical cultures. Treatment with 20 µM Aβ₁₋₄₂ markedly and continuously increased not only the DHE fluorescence (intracellular ROS signal), but also the DHR123 fluorescence (mitochondrial ROS signal) up to 8 hrs. Treatment with apocynin or AEBSF selectively suppressed the increase in DHE fluorescence, while treatment with mitotempol selectively suppressed the increase in DHR123 fluorescence. Each treatment with apocynin, AEBSF, mitotempol or mitoquinone significantly attenuated the Aβ₁₋₄₂-induced neuronal deaths. However, any combined treatment with apocynin/AEBSF and mitotempol/mitoquinone failed to show additive effects. These findings indicate that 20 µM Aβ₁₋₄₂ induces oxidative neuronal death via inducing mitochondrial ROS as well as NOX activation in mixed cortical cultures, but combined suppression of intracellular and mitochondrial ROS generation fail to show any additive neuroprotective effects against Aβ neurotoxicity.
Alzheimer Disease ; Amyloid beta-Peptides ; Amyloid* ; Animals ; Antioxidants* ; Baths ; Cell Death ; Fluorescence ; L-Lactate Dehydrogenase ; Mice* ; Mitochondria ; NADP* ; NADPH Oxidase* ; Neurons* ; Neuroprotective Agents ; Oxidative Stress ; Plaque, Amyloid

β-Amyloid peptide (Aβ) is the main component of senile plaques in patients with Alzheimer's disease, and is known to be a main pathogenic factor of the disease. Recent evidence indicates that activation of NADPH oxidase (NOX) in microglia or astrocytes may be a source of Aβ-induced reactive oxygen species (ROS). We investigated the role of neuronal NOX in Aβ-induced neuronal death in mouse mixed cortical cultures. Cell death was assessed by measuring lactate dehydrogenase efflux to bathing media 24 or 48 hr after exposure to Aβ₂₅₋₃₅, a fragment of Aβ with an equivalent neurotoxic effect. Aβ₂₅₋₃₅ induced neuronal death in concentration- and time- dependent manners with apoptotic features. Neuronal death was significantly attenuated, not only by anti-apoptotic drugs, such as z-VAD-fmk and cycloheximide, but also by antioxidants, such as trolox, ascorbic acid, and epigallocatethin gallate. We also demonstrated that treatment with 20 µM Aβ₂₅₋₃₅ increased fluorescent signals in mixed cortical cultures, but produced only weak signals in pure astrocyte cultures in the presence of 2',7'-dichlorofluorescin diacetate (DCF-DA), an indicator for intracellular ROS. Increased DCF-DA fluorescence was markedly inhibited, not only by trolox, but also by selective NOX inhibitors, such as apocynin and AEBSF. Western blot analyses revealed that Aβ₂₅₋₃₅ increased the expression of gp91phox, a main subunit of NOX in cells. The above antioxidants, apocynin, and AEBSF significantly attenuated neuronal death induced by Aβ₂₅₋₃₅. Furthermore, the gp91phox-specific siRNA-based knockdown of NOX significantly inhibited neuronal death. These results suggest that activation of neuronal NOX is involved in Aβ25-35-induced neuronal death.
Alzheimer Disease ; Amyloid beta-Peptides ; Animals ; Antioxidants ; Ascorbic Acid ; Astrocytes ; Baths ; Blotting, Western ; Cell Death ; Cycloheximide ; Fluorescence ; Humans ; L-Lactate Dehydrogenase ; Mice ; Microglia ; NADP ; NADPH Oxidase ; Neurons ; Plaque, Amyloid ; Reactive Oxygen Species

OBJECTIVEBoth of gp91(phox) (an isoform of nicotinamide adenine dinucleotide phosphate-reduced oxidases) and Src (a non-receptor protein tyrosine kinase) play a prominent role in mediating hypoxia/reoxygenation injury of neurons. The present study was designed to investigate the neuroprotective effect of equol, a predominant active metabolite of daidzein, against hypoxia/reoxygenation injury in rat pheochromocytoma cell line (PC12) and explore the underlying mechanisms.

METHODSPC12 cells exposed to hypoxia/reoxygenation injury were examined for reactive oxygen species (ROS) using dihydroethidium and 2', 7'-dichlorofluorescein diacetate and analyzed for changes in lactate dehydrogenase (LDH) activity and malondialdehyde (MDA) content. The expression levels of gp91(phox) and phosphorylated Src-Tyr416 (p-Src) were measured using Western blotting.

RESULTSEquol dose-dependently restored the cell viability and decreased LDH activity and MDA content in culture medium of PC12 cells exposed to hypoxia/reoxygenation. Pretreatment of the cells with 10(-5) and 10(-6) mol/L equol inhibited hypoxia/reoxygenation-induced increase of ROS. PC12 cells treated with equol prior to hypoxia/reoxygenation injury showed significant enhancement of the protein levels of gp91(phox) and p-Src.

CONCLUSIONEquol confers neuroprotection against hypoxia/reoxygenation injury in PC12 cells by inhibiting the generation of ROS very likely as a result of down-regulation of gp91(phox) and inhibition of Src phosphorylation.

Animals ; Cell Hypoxia ; Cell Survival ; Down-Regulation ; Equol ; pharmacology ; L-Lactate Dehydrogenase ; metabolism ; Malondialdehyde ; metabolism ; Membrane Glycoproteins ; metabolism ; NADPH Oxidase 2 ; NADPH Oxidases ; metabolism ; Neurons ; drug effects ; metabolism ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; Phosphorylation ; Rats ; Reactive Oxygen Species ; metabolism ; src-Family Kinases ; metabolism

OBJECTIVETo investigate the significance of NADPH quinine oxidoreductase 1 (NQO1) protein overexpression on prognostic evaluation of head and neck squamous cell carcinoma (HNSCC).

METHODSNQO1 protein was detected in 162 of HNSCC, 45 cases of adjacent nontumor tissues and 26 samples of normal head and neck epithelia using EnVision immunohistochemical. Correlation between NQO1 overexpression and patients prognosis was also analyzed.

RESULTSThe positive rate and strongly positive rate of NQO1 protein were 84.0% (136/162) and 69.8% (113/162) in HNSCC, respectively, and both of which were significantly higher than either those in adjacent nontumor tissues and normal head and neck epithelia (both P < 0.01). NQO1 expression was significantly correlated with the clinical stage, pT and chemoradiotherapy of HNSCC (P < 0.01). Kaplan-Meier survival analysis showed that overall survival and disease-free survival rates were significantly higher in HNSCC patients with high level NQO1 expression than that those with low level of NQO1 expression (Log-rank = 6.625 , P = 0.010;Log-rank = 6.234 , P = 0.013). Additional analysis by Cox proportional hazard regression model showed that high level of NQO1 expression was an independent hazard predictor for overall survival of patients with HNSCC (Wald = 6.626, P = 0.008).

CONCLUSIONSNQO1 expression level is closely correlated with the progression and prognosis of patients with HNSCC. High level of NQO1 expression may be used as an important indicator for patients with poor prognostic HNSCC.

Breast ; enzymology ; Carcinoma, Squamous Cell ; enzymology ; mortality ; pathology ; Disease-Free Survival ; Female ; Head and Neck Neoplasms ; enzymology ; mortality ; pathology ; Humans ; Kaplan-Meier Estimate ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NADH, NADPH Oxidoreductases ; metabolism ; Prognosis ; Proportional Hazards Models

The aim of this study was to investigate the effect of platelet-rich plasma (PRP) on cavernous nerve (CN) regeneration and functional status in a nerve-crush rat model. Twenty-four Sprague-Dawley male rats were randomly divided into three equal groups: eight had a sham operation, eight underwent bilateral nerve crushing with no further intervention and eight underwent bilateral nerve crushing with an immediate application of PRP on the site of injury. Erectile function was assessed by CN electrostimulation at 3 months and nerve regeneration was assessed by toluidine blue staining of CN and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining of penile tissue. Three months after surgery, in the group that underwent bilateral nerve crushing with no further intervention, the functional evaluation showed a lower mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure (MAP) with CN stimulation than those in the sham group. In the group with an immediate application of PRP, the mean maximal ICP and maximal ICP/MAP were significantly higher than those in the injured control group. Histologically, the group with the application of PRP had more myelinated axons of CNs and more NADPH-diaphorase-positive nerve fibres than the injured control group but fewer than the sham group. These results show that the application of PRP to the site of CN-crush injury facilitates nerve regeneration and recovery of erectile function. Our research indicates that clinical application of PRP has potential repairing effect on CN and peripheral nerves.
Animals ; Disease Models, Animal ; Electric Stimulation ; Erectile Dysfunction ; pathology ; physiopathology ; therapy ; Male ; NADPH Dehydrogenase ; metabolism ; Nerve Regeneration ; physiology ; Penile Erection ; physiology ; Penis ; innervation ; Peripheral Nerve Injuries ; Peripheral Nerves ; metabolism ; pathology ; Platelet Transfusion ; Platelet-Rich Plasma ; Radiculopathy ; etiology ; pathology ; physiopathology ; Rats ; Rats, Sprague-Dawley

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ~5 fold and glucose 6-phosphate dehydrogenase activities were decreased by ~25% compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased significantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to function in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.
Animals ; Antioxidants ; Carcinoma, Hepatocellular ; Cardiovascular Diseases ; Cell Proliferation ; Chronic Disease ; Cytochrome P-450 Enzyme System ; Cytosol ; Dehydroepiandrosterone ; Diet ; DNA ; Glucose ; Glutathione Transferase ; Insulin Resistance ; Lipid Peroxidation ; Liver ; Malate Dehydrogenase ; Malates ; NADP ; NADPH-Ferrihemoprotein Reductase ; Oxidoreductases ; Peroxidase ; Rats ; Rats, Sprague-Dawley ; Vitamin E ; Vitamins

Nitric oxide (NO) is a non-adrenergic, non-cholinergic neurotransmitter found in the enteric nervous system that plays a role in a variety of enteropathies, including inflammatory bowel disease. Alteration of nitrergic neurons has been reported to be dependent on the manner by which inflammation is caused. However, this observed alteration has not been reported with acetic acid-induced colitis. Therefore, the purpose of the current study was to investigate changes in nitrergic neuromuscular transmission in experimental colitis in a rat model. Distal colitis was induced by intracolonic administration of 4% acetic acid in the rat. Animals were sacrificed at 4 h and 48 h postacetic acid treatment. Myeloperoxidase activity was significantly increased in the acetic acid-treated groups. However, the response to 60 mM KCl was not significantly different in the three groups studied. The amplitude of phasic contractions was increased by Nomega-nitro-L-arginine methyl ester (L-NAME) in the normal control group, but not in the acetic acid-treated groups. Spontaneous contractions disappeared during electrical field stimulation (EFS) in normal group. However, for the colitis groups, these contractions initially disappeared, and then reappeared during EFS. Moreover, the observed disappearance was diminished by L-NAME; this suggests that these responses were NO-mediated. In addition, the number of NADPH-diaphorase positive nerve cell bodies, in the myenteric plexus, was not altered in the distal colon; whereas the area of NADPH-diaphorase positive fibers, in the circular muscle layer, was decreased in the acetic acidtreated groups. These results suggest that NO-mediated inhibitory neural input, to the circular muscle, was decreased in the acetic acid-treated groups.
Acetic Acid/toxicity ; Animals ; Colitis/chemically induced/*pathology/*physiopathology ; Colon/drug effects/enzymology/*innervation/pathology ; Indicators and Reagents/toxicity ; Male ; Muscle Contraction/drug effects ; Muscle, Smooth/drug effects/metabolism ; Myenteric Plexus/pathology ; NADPH Dehydrogenase/metabolism ; NG-Nitroarginine Methyl Ester/pharmacology ; Neuromuscular Junction/drug effects/*metabolism ; Nitrergic Neurons/drug effects/*metabolism ; Nitric Oxide/*metabolism ; Peroxidase/metabolism ; Potassium Chloride/pharmacology ; Rats ; Rats, Sprague-Dawley

PURPOSE: This study examined the changes in intracavernous pressure, expression of nitric oxide synthase(NOS), and content of penile smooth muscle in castrated rats and testosterone-supplied castrated rats. MATERIALS AND METHODS: Sprague Dawley rats were used for this study and divided into control, castrated, and testosterone-supplied castrated groups. Castration was performed by bilateral orchietomy under general anesthesia, and testosterone propionate 3 mg/kg was injected subcutaneously daily for a week beginning 4 weeks after orchiectomy. Intracavernous pressure was measured by stimulating the cavernous nerve at 10 volts, 2.4 mA. Expression of NOS was measured by immunohistochemical staining for NADPH diaphorase, and content of penile smooth muscle was measured by H&E staining of the corpus cavernosum. The stained area-to-tissue ratio was calculated by computer scanning for each case. RESULTS: Compared with the control group(3.45+/-0.25 ng/ml), the serum testosterone level of the castrated group (0.78+/-0.34 ng/ml) was lower. Serum testosterone level was restored in the testosterone-supplied castrated group. Compared with the(67.2+/-14.3 cmH2O) was decreased (p <0.05). There was no significant difference between the testosterone-supplied group(94.7+/-11.4 cmH2O) and control group, so intracavernosal pressure was restored by testosterone treatment. Immunohistochemical staining for NOS showed that NADPH diaphorase was stained as brown nerve fiber. Compared with the control group(37.5+/-2.8%), the NOS activity of the castrated group(7.5+/-2.1%) was significantly decreased(p <0.05). NOS activity was slightly increased in the testosterone-supplied group(47.5+/-2.4%) compared with the control group, but the difference was not statistically significant. Thus, testosterone treatment restored NOS activity after castration. By H&E staining, the content of penile smooth muscle was 76.5+/-2.8% in the control group, but significantly lower in the castrated group(46.2+/-3.4% p <0.05). Smooth muscle content was slightly decreased in the testosterone-supplied group(63.8+/-4.7%) compared with control group, but the difference was not statistically significant. Thus, smooth muscle content was restored by testosterone treatment after castration. CONCLUSIONS: Decline of factors involved in erectile function can be restored by testosterone replacement after castration.
Anesthesia, General ; Animals ; Castration ; Male ; Muscle, Smooth ; NADPH Dehydrogenase ; Nerve Fibers ; Nitric Oxide ; Orchiectomy ; Penile Erection* ; Rats* ; Rats, Sprague-Dawley ; Testosterone Propionate ; Testosterone*

PURPOSE: The purpose of this study was to investigate the changes of serum testosterone, intracavernous pressure, expression of nitric-oxide synthase (NOS) and content of penile smooth muscle in aged rat. MATERIALS AND METHODS: Sprague Dawley rats were used for this study and divided into control and aging groups. Intracavernous pressure was measured by stimulating the cavernous nerve with 10volt, 2.4mA. Expression of NOS was measured by immunohistochemical staining for NADPH (nicotinamide adenine dinucleotide phosphate) diaphorase and the content of penile smooth muscle was measured by Masson's trichrome staining for corpus cavernosum. In each case the stained area-tissue ratio was calculated by computer scanning. RESULTS: Compared with the control group (3.34-0.25ng/ml), the serum testosterone level of the aged group (1.41-0.37ng/ml) was decreased significantly. Compared with the control group (106.7-13.2cmH2O), the intracavernosal pressure of the aged group (71.2-12.3cmH2O) was decreased significantly. Immunohistochemical staining for NOS showed that NADPH diaphorase was stained as brown nerve fiber. Compared with the control group (40.5-3.1%), NOS activity of the aged group (9.5-2.5%) was decreased significantly. On Masson's trichrome staining, the content of penile smooth muscle was 62.8 3.9% in the control group. Compared with the control group, the smooth muscle content of the aged group (35.2-2.4%) was decreased significantly. CONCLUSIONS: In conclusion, the factors involved in erectile function were decreased in aged rats.
Adenine ; Aging* ; Animals ; Muscle, Smooth ; NADP ; NADPH Dehydrogenase ; Nerve Fibers ; Nitric Oxide Synthase* ; Rats* ; Rats, Sprague-Dawley ; Testosterone

This study was conducted to define the molecular mechanism of fasting-induced down-regulation of neuronal nitric oxide synthase (nNOS) expression in the hypothalamic paraventricular nucleus (PVN). Rats were adrenalectomized (ADX), and then either underwent food deprivation or received varying doses of dexamethasone for 48 h. The brain tissues were processed for NADPH-diaphorase (NADPH-d) staining, a histochemical marker of nNOS enzyme activity. Both the ADX and the sham operated rats showed a significant weight loss after 48 h of food deprivation. Food deprivation decreased the number of NADPH-d containing cells in the PVN of sham rats, however, not in the ADX rats. Dexamethasone dose- dependently decreased NADPH-d cells in the PVN of ADX rats. The effect of ADX or dexamethasone was limited to the parvocellular subdivision of PVN. These results suggest that the adrenal glucocorticoids may down-regulate nNOS expression in the PVN during food deprivation.
*Adrenalectomy ; Animals ; Biological Markers ; Dexamethasone/blood/pharmacology ; Down-Regulation/physiology ; Fasting/*physiology ; Food Deprivation/physiology ; Glucocorticoids/blood/pharmacology ; Male ; NADPH Dehydrogenase/*metabolism ; Nitric-Oxide Synthase/*metabolism ; Paraventricular Hypothalamic Nucleus/*enzymology ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't