Different gene expression profiles in subcutaneous & visceral adipose tissues from Mexican patients with obesity.

Background & objectives: Obesity is a health problem that requires substantial efforts to understand the physiopathology of its various types and to determine therapeutic strategies for its treatment. The objective of this study was to characterize differences in the global gene expression profiles of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) between control patients (normal weight) and patients with obesity (IMC≥30) using microarrays. Methods: Employing RNA isolated from SAT and VAT samples obtained from eight control and eight class I, II and III patients with obesity, the gene expression profiles were compared between SAT and VAT using microarrays and the findings were validated via real-time quantitative polymerase chain reaction. Results: A total of 327 and 488 genes were found to be differentially expressed in SAT and VAT, respectively (P≤0.05). Upregulation of PPAP2C, CYP4A11 and CYP17A1 genes was seen in the VAT of obese individuals. Interpretation & conclusions: SAT and VAT exhibited significant differences in terms of the expression of specific genes. These genes might be related to obesity. These findings may be used to improve the clinical diagnosis of obesity and could be a tool leading to the proposal of new therapeutic strategies for the treatment of obesity.

Differential Gene Expression Profile Induced by Valproic Acid (VPA) in Pediatric Epileptic Patients.

Epilepsy is a neuronal disease that affects up to 70 million people worldwide. The development of effective therapies to combat childhood epilepsy requires early biomarkers. Here, we performed a whole-genome microarray analysis in blood cells to identify genes differentially expressed between epileptic and epileptic valproic acid (VPA)-treated children versus normal children to obtain information about the gene expression to help us to understand genetic aspects of this disease. We found that the most significant differentially expressed genes were related to the transcriptional factor cAMP-response element binding protein (CREB) that is overexpressed in children with epilepsy compared with normal children, and 6 and 12 months of VPA treatment reversed several of these changes. Interestingly, leukocyte-associated immunoglobulin-like receptor 1 (LAIR1), a type I transmembrane glycoprotein that binds collagen proteins and contains CREB binding sites, was one of the more up-regulated genes in epileptic patients, and treatment with VPA strongly reversed its up-regulation. CREB up-regulates genes related to epilepsy; here, we suggest that LAIR1 could activate CREB, and together, they trigger epilepsy. After VPA treatment, LAIR1 repressed genes by disrupting the functional LAIR1⁻CREB complex, resulting in successful treatment. A functional microarray analysis offers new information that could open novel avenues of research in biomarker discovery, which may be useful for the early identification of children with a predisposition to epilepsy.

Effects of Valproate Monotherapy on the Oxidant-Antioxidant Status in Mexican Epileptic Children: A Longitudinal Study.

Epilepsy is a neurological disorder that can produce brain injury and neuronal death. Several factors such as oxidative stress have been implicated in epileptogenesis. Valproic acid (VPA) is a widely used drug for the treatment of epilepsy, but the mechanisms underlying these benefits are complex and still not fully understood. The objective of this study was to evaluate, for the first time, the effects of VPA on the oxidant-antioxidant status in Mexican epileptic children before and after 6 or 12 months of treatment with VPA by determining the activities of several plasmatic antioxidant enzymes (glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT)) and oxidant marker (malondialdehyde (MDA), hydrogen peroxide (H2O2), 8-hydroxy-2-deoxyguanosine (8-OHdG), and 3-nitrotyrosine (3-NT) levels) profiles. The possible relationships between these markers and some clinicopathological factors were also evaluated. Plasma samples were obtained from the peripheral blood of 16 healthy children and 32 patients diagnosed with epilepsy, and antioxidant/oxidant markers were measured spectrometrically. Significant decreases in all antioxidant enzyme activities, with the exception of GPx, and increases in all oxidant markers in epileptic subjects versus healthy children were observed. Interestingly, all these effects reverted after VPA monotherapy, although the results were different depending on the treatment period (6 or 12 months). These changes were contingent upon brain imaging findings, type of epilepsy, etiology of epilepsy, and the efficacy of 6 months of VPA monotherapy. Significant and positive correlations of GPx and SOD activities and H2O2 and 8-OHdG levels with the age of children at the beginning of treatment were observed. H2O2 levels were also positively correlated with number of seizures before VPA monotherapy. VPA showed significant antioxidant effects decreasing seizure activity, possibly depending on the presence of cerebral structural alterations, treatment time, and age.

Biochemical and molecular modulation of CCl4-induced peripheral and central damage by Tilia americana var. mexicanaextracts.

Around the world, species from the genus Tilia are commonly used because of their peripheral and central medicinal effects; they are prepared as teas and used as tranquilizing, anticonvulsant, and analgesic agents. In this study, we provide evidence of the protective effects of organic and aqueous extracts (100 mg/kg, i.p.) obtained from the leaves of Tilia americana var. mexicana on CCl4-induced liver and brain damage in the rat. Protection was observed in the liver and brain (cerebellum, cortex and cerebral hemispheres) by measuring the activity of antioxidant enzymes and levels of malondialdehyde (MDA) using spectrophotometric methods. Biochemical parameters were also assessed in serum samples from the CCl4-treated rats. The T. americana var. mexicana leaf extracts provided significant protection against CCl4-induced peripheral and central damage by increasing the activity of antioxidant enzymes, diminishing lipid peroxidation, and preventing alterations in biochemical serum parameters, such as the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-globulin (γ-GLOB), serum albumin (ALB), total bilirubin (BB), creatinine (CREA) and creatine kinase (CK), relative to the control group. Additionally, we correlated gene expression with antioxidant activity in the experimental groups treated with the organic and aqueous Tilia extracts and observed a non-statistically significant positive correlation. Our results provide evidence of the underlying biomedical properties of T. americana var. mexicana that confer its neuro- and hepatoprotective effects.

Status epilepticus: Using antioxidant agents as alternative therapies.

The epileptic state, or status epilepticus (SE), is the most serious situation manifested by individuals with epilepsy, and SE events can lead to neuronal damage. An understanding of the molecular, biochemical and physiopathological mechanisms involved in this type of neurological disease will enable the identification of specific central targets, through which novel agents may act and be useful as SE therapies. Currently, studies have focused on the association between oxidative stress and SE, the most severe epileptic condition. A number of these studies have suggested the use of antioxidant compounds as alternative therapies or adjuvant treatments for the epileptic state.

Asociación entre el sistema IGF y PAPP-A en ateroesclerosis coronaria / Association between IGF system and PAPP-A in coronary atherosclerosis

Resumen La aterosclerosis es una enfermedad que involucra múltiples mecanismos fisiopatológicos cuyo conocimiento no se ha dilucidado por completo. Con frecuencia, los avances científicos sobre la fisiopatología aterogénica generan que a diversas moléculas no consideradas previamente en el panorama de dicha enfermedad se les atribuyan acciones sobre el inicio o progresión de la misma. Un ejemplo representativo es el estudio de un nuevo mecanismo involucrado en el proceso aterogénico, consistente en la asociación entre el sistema de factores de crecimiento similares a la insulina (IGF) y la proteína plasmática A asociada al embarazo (PAPP-A). El sistema IGF es una familia de péptidos compuesto por 3 hormonas peptídicas, 4 receptores transmembranales y 6 proteínas transportadoras. El factor de crecimiento similar a la insulina tipo 1 (IGF-1) es el principal ligando del sistema IGF involucrado en la aterosclerosis coronaria y ejerce sus efectos mediante la activación del receptor IGF-1R en células de músculo liso vascular de las arterias coronarias o en macrófagos de placas ateroscleróticas. En células de músculo liso vascular promueve la migración y previene la apoptosis aumentando la estabilidad de la placa, y en macrófagos disminuye el transporte reverso de colesterol propiciando la formación de células espumosas. La regulación de la biodisponibilidad de IGF-1 en el endotelio se lleva a cabo por las proteasas de proteínas IGFBP, principalmente por la PAPP-A. En la presente revisión se abordan los mecanismos involucrados entre el sistema IGF y la PAPP-A en aterosclerosis coronaria con énfasis en los efectos moleculares producidos en células de músculo liso vascular y en macrófagos.

Abstract Atherosclerosis is a condition that involves multiple pathophysiological mechanisms and whose knowledge has not been fully elucidated. Often, scientific advances on the atherogenic pathophysiology generate that molecules not previously considered in the scene of this disease, were attributed actions on the onset or progression of it. A representative example is the study of a new mechanism involved in the atherogenic process, consisting of the association between the insulin-like growth factor (IGF) system and pregnancy-associated plasma protein-A (PAPP-A). Insulin-like growth factor system is a family of peptides that include 3 peptide hormones, 4 transmembrane receptors and 6 binding proteins. Insulin-like growth factor-1 (IGF-1) is the main ligand of the IGF system involved in coronary atherosclerosis. IGF-1 exerts its effects via activation of the IGF-1R receptor on vascular smooth muscle cells or macrophages. In vascular smooth muscle cells promotes migration and prevents apoptosis which increases plaque stability while in macrophages reduces reverse cholesterol transport leading to the formation of foam cells. Regulation of IGF-1 endothelial bioavailability is carried out by IGFBP proteases, mainly by PAPP-A. In this review, we address the mechanisms between IGF system and PAPP-A in atherosclerosis with emphasis on molecular effects on vascular smooth muscle cells and macrophages.

Association of CYP8A1 (Prostacyclin I2 synthase) polymorphism rs5602 with breast cancer in Mexican woman.

Breast cancer (BCa) is the most common cancer in Mexican women. Certain risk factors, such as environmental and lifestyle factors have been implicated in BCa initiation and progression. Moreover, genetic factors, such as single nucleotide polymorphisms (SNPs) of the P450 system, have been reported in BCa. In this report, and for the first time in the literature, we analyzed the rs5602 (67730 T > C) polymorphism in the CYP8A1 in patients with BCa and in healthy Mexican women to identify a potential risk between this polymorphism and BCa. Leukocyte cells from 38 control patients and tissue from radical mastectomy surgeries in 64 BCa patients were used for polymorphism analysis using an allelic discrimination assay with TaqMan probes. Links with clinic-pathological characteristics were also analyzed. Statistical analysis was performed using the standard χ(2) or Fisher exact test statistic. All CYP8A1 genotypes were detected in patients with BCa and the controls. Significant differences were observed in the distribution of CYP8A1 genotypes between the patients and controls (P=0.0008) and allele C was significantly associated with BCa risk (OR 2.08, 95% CI 1.166-3.72, P=0.0178). All polymorphism frequencies were in Hardy-Weinberg Equilibrium (HWE) in the controls (P > 0.05). We found that variant 67730 T > C was significantly associated with an increased risk of BCa (P < 0.05). We not observed an association of the TT and TC + CC genotypes with the clinical stage, BIRADS, estrogen receptor (ER) status, progesterone receptor (PR) status, HER2 status, p53 status, CD34 status, metastasis or therapy use. These results indicate that the CYP8A1 rs5602 SNP is a possible risk factor for BCa in Mexican women. This study showed an association between the CYP8A1 polymorphism and BCa risk in a Mexican population.

[Association between IGF system and PAPP-A in coronary atherosclerosis]. / Asociación entre el sistema IGF y PAPP-A en ateroesclerosis coronaria.

Atherosclerosis is a condition that involves multiple pathophysiological mechanisms and whose knowledge has not been fully elucidated. Often, scientific advances on the atherogenic pathophysiology generate that molecules not previously considered in the scene of this disease, were attributed actions on the onset or progression of it. A representative example is the study of a new mechanism involved in the atherogenic process, consisting of the association between the insulin-like growth factor (IGF) system and pregnancy-associated plasma protein-A (PAPP-A). Insulin-like growth factor system is a family of peptides that include 3 peptide hormones, 4 transmembrane receptors and 6 binding proteins. Insulin-like growth factor-1 (IGF-1) is the main ligand of the IGF system involved in coronary atherosclerosis. IGF-1 exerts its effects via activation of the IGF-1R receptor on vascular smooth muscle cells or macrophages. In vascular smooth muscle cells promotes migration and prevents apoptosis which increases plaque stability while in macrophages reduces reverse cholesterol transport leading to the formation of foam cells. Regulation of IGF-1 endothelial bioavailability is carried out by IGFBP proteases, mainly by PAPP-A. In this review, we address the mechanisms between IGF system and PAPP-A in atherosclerosis with emphasis on molecular effects on vascular smooth muscle cells and macrophages.

CYP3A4 expression in breast cancer and its association with risk factors in Mexican women.

BACKGROUND: In Mexico, breast cancer (BCa) is the leading type of cancer in women. Cytochrome P450 (CYP450) is a superfamily of major oxidative enzymes that metabolize carcinogens and many antineoplastic drugs. In addition, these enzymes have influence on tumor development and tumor response to therapy. In this report, we analyzed the protein expression in patients with BCa and in healthy women. Links with some clinic-pathological characteristic were also assessed. MATERIALS AND METHODS: Immunohistochemical analyses were conducted on 48 sets of human breast tumors and normal breast tissues enrolled in Hospital Militar de Especialidades de la Mujer y Neonatologia and Hospital Central Militar, respectively, during the time period from 2010 to 2011. Informed consent was obtained from all participants. Statistical analysis was performed using χ2 or Fisher exact tests to estimate associations and the Mann Whitney U test for comparison of group means. RESULTS: We found a significant CYP3A4 overexpression in BCa stroma and gland regions in comparison with healthy tissue. A significant association between protein expression with smoking, alcoholism and hormonal contraceptives use was also observed. Additionally, we observed estrogen receptor (ER) and progesterone receptor (PR) positive association in BCa. CONCLUSIONS: We suggest that CYP3A4 expression promotes BCa development and can be used in the prediction of tumor response to different treatments. One therapeutic approach may thus be to block CYP3A4 function.

Contributions of microdialysis to new alternative therapeutics for hepatic encephalopathy.

Hepatic encephalopathy (HE) is a common complication of cirrhosis, of largely reversible impairment of brain function occurring in patients with acute or chronic liver failure or when the liver is bypassed by portosystemic shunts. The mechanisms causing this brain dysfunction are still largely unclear. The need to avoid complications caused by late diagnosis has attracted interest to understand the mechanisms underlying neuronal damage in order to find markers that will allow timely diagnosis and to propose new therapeutic alternatives to improve the care of patients. One of the experimental approaches to study HE is microdialysis; this technique allows evaluation of different chemical substances in several organs through the recollection of samples in specific places by semi-permeable membranes. In this review we will discuss the contributions of microdialysis in the understanding of the physiological alterations in human hepatic encephalopathy and experimental models and the studies to find novel alternative therapies for this disease.

Induction of ferroxidase enzymatic activity by copper reduces MPP+-evoked neurotoxicity in rats.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by decreased dopamine, intracellular inclusions (Lewy bodies) and brain iron deposits. PD has also been related with reduced ferroxidase activity, diminished antioxidant defenses and lipid peroxidation. Striatal injection of 1-methyl-4-phenylpyridinium (MPP(+)) into rodents reproduces the major biochemical characteristics of PD, including oxidative stress. Copper (Cu) plays an important role as prosthetic group of several proteins involved in iron metabolism and antioxidant responses, such as ceruloplasmin (Cp). In the present study, intraperitoneal CuSO4 injection (10µmol/kg) produced an insignificant increase of Cu content in striatum and midbrain (17.5% and 7%, respectively). After 10 and 11h, Cu induced 6- and 4-fold increase Cp mRNA in midbrain and striatum, respectively. Cu-supplement also produced a time-dependent increase ferroxidase activity in striatal tissue, reaching a maximum 16h after Cu treatment in midbrain; while, ferrous iron content diminished 18% in striatum and 8% in midbrain. In regard the PD model, we found that MPP(+) (10µg/8µL, intrastriatal), induced a significant (P<0.05) reduction of striatal ferroxidase activity; this effect was reverted by Cu pre-treatment 16h before MPP(+). Likewise, Cu-supplement prevented lipid fluorescent products formation in striatum, evaluated (P<0.01) 6h after MPP(+). In the long term, apomorphine-evoked circling behavior was evaluated 6 days after MPP(+) injury; Cu pre-treatment significantly reduced (P<0.05) the apomorphine-induced ipsilateral turns in MPP(+)-lesioned rats. These results suggest that Cu-induced expression of Cp could be an interesting scope against the deleterious effects of iron deposits in PD.

Modulation of antioxidant enzymatic activities by certain antiepileptic drugs (valproic acid, oxcarbazepine, and topiramate): evidence in humans and experimental models.

It is estimated that at least 100 million people worldwide will suffer from epilepsy at some point in their lives. This neurological disorder induces brain death due to the excessive liberation of glutamate, which activates the postsynaptic N-methyl-D-aspartic acid (NMDA) receptors, which in turn cause the reuptake of intracellular calcium (excitotoxicity). This excitotoxicity elicits a series of events leading to nitric oxide synthase (NOS) activation and the generation of reactive oxygen species (ROS). Several studies in experimental models and in humans have demonstrated that certain antiepileptic drugs (AEDs) exhibit antioxidant effects by modulating the activity of various enzymes associated with this type of stress. Considering the above-mentioned data, we aimed to compile evidence elucidating how AEDs such as valproic acid (VPA), oxcarbazepine (OXC), and topiramate (TPM) modulate oxidative stress.

Virus del papiloma humano: Marcador de respuesta a radioterapia/quimiorradioterapia en cáncer cervical / Human papilloma-virus: Marker of response to radiotherapy/chemoradiotherapy in cervical cancer / Papilomavírus humano: marcador de resposta à radioterapia / quimiorradioterapia em câncer de colo uterino

El cáncer cérvico-uterino (CaCU) representa el 6% de todas las neoplasias malignas en mujeres. Evidencia epidemiológica y molecular implican al virus del papiloma humano (VPH) en la etiopatogenia del CaCU y los genotipos más frecuentemente asociados son el 16 y 18 (VPH-16 y -18). La radioterapia (RT) y la quimiorradiación (RT-QT) son las dos modalidades de tratamiento primario para el CaCU, con tasas variables de resistencia o persistencia de la enfermedad. El objetivo de este trabajo fue estudiar, por primera vez, la respuesta tumoral antes, durante y después de la RT y la RT-QT y analizar la carga viral de VPH-16 y -18 en pacientes mexicanas con CaCU. Se obtuvieron muestras de tejido tumoral en pacientes con CaCU: antes, durante y después de la RT y RT-QT, se determinó el número de copias absolutas del VPH-16 o -18 y se estudió la respuesta en relación a la carga viral por PCR en tiempo real. La disminución de la carga viral de VPH para RT-QT y RT fue de 100 y 62%, respectivamente. Se observó una mejor respuesta con la modalidad de tratamiento combinado, por lo que se sugiere que la carga viral de VPH (-16 y -18) podría ser un potencial indicador para evaluar la respuesta de ambos tratamientos en el CaCU.

Cervical cancer (CaCU) represents 6% of all malignancies in women. Molecular and epidemiological evidence relate the human papilloma virus (HPV) with the pathogenesis of the CaCU genotypes, the most frequent genotypes being 16 and 18 ( VPH-16 and -18). Radiotherapy (RT) and chemoradiotherapy (ChRT) are the two primary treatment modalities for CaCU, with variable rates of resistance or persistence of the disease. The aim of this work was to study for the first time, the tumorai response before, duríng and after RT and RT-QT and analyze HPV-16 and -18 viral load in a Mexican population with CaCU. Samples of tumor tissue were collected from patients with CaCU: before, duríng and after RT and ChRT. The absolute number of HPV-16 or -18 copies was determined, and the response related with viral load in both treatments was studíed by real-time PCR-based in fluorescence. The percentage of decrease ín HPV viral load for ChRT and RT was 100% and 62%, respectívely With ChRT, the response was better than with RTalone. HPV (-16 and -18) viral load ís suggested to be a potentíal índícator to evalúate CaCU response in both treatments.

[Molecular markers associated with prostate cancer: 3-nitrotyrosine and genetic and proteic expression of Mn-superoxide dismutasa (Mn-SOD)]. / Marcadores moleculares relacionados con cáncer de próstata: 3-nitrotirosina y expresión génica y protéica de la Mn-superóxido dismutasa (Mn-SOD).

SUMMARY OBJECTIVES: Recent reports place prostate cancer (PCa) as third cause of death in the World among males, in Mexico it is the leading cause of male death. In this study, we studied molecular markers and one genetic marker related in tissues with PCa and benign prostatic hyperplasia (BPH): The Mn-superoxide dismutase (Mn-SOD) gen and protein, prostate specific antigen (PSA) and 3-nitrotyrosine (3-NT). It was evaluated if various markers of oxidative stress show altered expression in prostate cancer and BPH. METHODS: 80 biopsies were obtained. The conditions to amplify and evaluate the immunoreactivity of the genes of interest (Mn-SOD and 3-NT) and the correlation between PSA and Mn-SOD immunoreactivity in prostate cancer and benign prostatic hyperplasia were standardized. RESULTS: Gene overexpression and Mn-SOD and 3-NT immunoreactivity were greater in prostate cancer with respect to the BPH group. Correlation between levels of PSA and the Mn-SOD immunoreactivity was not observed. CONCLUSIONS: The above results suggest that the parameters evaluated can be used as tumor markers making the determinations in biopsies of patients suspected of prostate cancer.

Marcadores moleculares relacionados con cáncer de próstata: 3-Nitrotirosina y expresión génica y protéica de la Mn-superóxido dismutasa (Mn-SOD) / Molecular markers associated with prostate cáncer: 3-nitrotyrosine and genetic and proteic expression of Mn-Superoxide dismutasa (Mn-SOD)

OBJETIVO: Recientes reportes ubican al cáncer de próstata en el tercer lugar mundial, en México es la principal causa de muerte masculina. En este estudio se evaluaron: marcadores moleculares y un marcador génico en tejidos con cáncer de próstata e hiperplasia prostática benigna (HPB): el gen de la Mn-superóxido dismutasa (Mn-SOD) y su proteína, el antígeno prostático específico (APE) y 3-nitrotirosina (3-NT).Se evaluó si existe alguna alteración en la expresión de diversos marcadores de estrés oxidativo en cáncer de próstata e hiperplasia prostática benigna.MÉTODOS: Se obtuvieron 80 biopsias. Se estandarizaron las condiciones para amplificar y evaluar la inmunorreactividad del gen de interés (Mn-SOD y 3-NT) y la correlación entre el antígeno prostático específico (APE) y la inmunorreactividad de Mn-SOD en cáncer de próstata e hiperplasia prostática benigna.RESULTADOS: La sobreexpresión del gen y la inmunorreactividad de Mn-SOD, así como la inmunorreactividad de 3-NT en cáncer de próstata fue mayor con respecto al grupo con hiperplasis prostática benigna. No se observó una correlación entre los niveles de APE y la inmunorreactividad de Mn-SOD.CONCLUSIONES: Los resultados anteriores sugieren que la determinación de los parámetros evaluados pueden ser utilizados como marcadores tumorales realizando las determinaciones en biopsias de pacientes sospechosos de cáncer de próstata(AU)

OBJECTIVES: Recent reports place prostate cancer (PCa) as third cause of death in the World among males, in Mexico it is the leading cause of male death. In this study, we studied molecular markers and one genetic marker related in tissues with PCa and benign prostatic hyperplasia(BPH) : The Mn-superoxide dismutase (Mn-SOD) gen and protein , prostate specific antigen (PSA) and 3-nitrotyrosine (3-NT). It was evaluated if various markers of oxidative stress show altered expression in prostate cancer and BPH. METHODS. 80 biopsies were obtained. The conditions to amplify and evaluate the immunoreactivity of the genes of interest (Mn-SOD and 3-NT) and the correlation between PSA and Mn-SOD immunoreactivity in prostate cancer and benign prostatic hyperplasia were standardized.RESULTS. Gene overexpression and Mn-SOD and 3-NT immunoreactivity were greater in prostate cancer with respect to the BPH group. Correlation between levels of PSA and the Mn-SOD immunoreactivity was not observed.CONCLUSIONS. The above results suggest that the parameters evaluated can be used as tumor markers making the determinations in biopsies of patients suspected of prostate cancer(AU)

Time-related changes in constitutive and inducible nitric oxide synthases in the rat striatum in a model of Huntington's disease.

Excitotoxicity and oxidative stress are mechanisms involved in the neuronal cell death induced by the intrastriatal injection of quinolinic acid (QUIN) as a model of Huntington's disease. Production of nitric oxide by nitric oxide synthase (NOS) has been proposed to participate in QUIN-induced neurotoxicity; however, the precise role of NOS in QUIN-induced toxicity still remains controversial. In order to provide further information on the role of NOS isoforms in QUIN toxicity, we performed real time RT-PCR and immunohistochemistry of inducible NOS (iNOS), endothelial NOS (eNOS) and neuronal NOS (nNOS) and determined Ca(2+)-dependent and Ca(2+)-independent NOS activity in a temporal course (3-48h), after an intrastriatal injection of QUIN to rats. NOS isoforms exhibited a transitory expression of mRNA and protein after QUIN infusion: eNOS increased between 3 and 24h, iNOS between 12 and 24h, while nNOS at 35 and 48h. Ca(2+)-independent activity (iNOS) did not show any change, while Ca(2+)-dependent activity (constitutive NOS: eNOS/nNOS) exhibited increased levels at 3h. Our results support the participation of Ca(2+)-dependent NOS isoforms during the toxic events produced at early times after QUIN injection.

Evaluation of oxidative stress in D-serine induced nephrotoxicity.

It has been suggested that oxidative stress is involved in d-serine-induced nephrotoxicity. The purpose of this study was to assess if oxidative stress is involved in this experimental model using several approaches including (a) the determination of several markers of oxidative stress and the activity of some antioxidant enzymes in kidney and (b) the use of compounds with antioxidant or prooxidant effects. Rats were sacrificed at several periods of time (from 3 to 24h) after a single i.p. injection of d-serine (400mg/kg). Control rats were injected with l-serine (400mg/kg) and sacrificed 24h after. The following markers were used to assess the temporal aspects of renal damage: (a) urea nitrogen (BUN) and creatinine in blood serum, (b) kidney injury molecule (KIM-1) mRNA levels, and (c) tubular necrotic damage. In addition, creatinine clearance, proteinuria, and urinary excretion of N-acetyl-beta-d-glucosaminidase (NAG) were measured 24h after d-serine injection. Protein carbonyl content, malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), fluorescent products of lipid peroxidation, reactive oxygen species (ROS), glutathione (GSH) content, and heme oxygenase-1 (HO-1) expression were measured as markers of oxidative stress in the kidney. Additional experiments were performed using the following compounds with antioxidant or pro-oxidant effects before d-serine injection: (a) alpha-phenyl-tert-butyl-nitrone (PBN), a spin trapping agent; (b) 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron(III) (FeTPPS), a soluble complex able to metabolize peroxynitrite; (c) aminotriazole (ATZ), a catalase (CAT) inhibitor; (d) stannous chloride (SnCl(2)), an HO-1 inductor; (e) tin mesoporphyrin (SnMP), an HO inhibitor. In the time-course study, serum creatinine and BUN increased significantly on 15-24 and 20-24h, respectively, and KIM-1 mRNA levels increased significantly on 6-24h. Histological analyses revealed tubular necrosis at 12h. The activity of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase remained unchanged at all times studied. Protein carbonyl content, MDA, 4-HNE, and ROS remained unchanged at all time-points studied. GSH content decreased transiently on 9 and 12h. Interestingly, fluorescent products of lipid peroxidation decreased significantly on 3-24h. HO-1 expression was undetectable by Western blot and the immunohistochemistry studies revealed that the intensity of HO-1 staining was weak. The administration of PBN, FeTPPS, ATZ, SnCl(2), and SnMP did not prevent or enhance renal damage induced by d-serine. Our data taken as a whole suggest that oxidative stress is not involved in the early phase of the nephrotoxicity induced by d-serine.

Nordihydroguaiaretic acid is a potent in vitro scavenger of peroxynitrite, singlet oxygen, hydroxyl radical, superoxide anion and hypochlorous acid and prevents in vivo ozone-induced tyrosine nitration in lungs.

The antioxidant nordihydroguaiaretic acid (NDGA) has recently become well known as a putative anticancer drug. In this paper, it was evaluated the in vitro peroxynitrite (ONOO(-)), singlet oxygen ((1)O(2)), hydroxyl radical (OH(v)), hydrogen peroxide (H(2)O(2)), superoxide anion and hypochlorous acid (HOCl) scavenging capacity of NDGA. It was found that NDGA scavenges: (a) ONOO(-) (IC(50) = 4 +/- 0.94 microM) as efficiently as uric acid; (b) (1)O(2) (IC(50) = 151 +/- 20 microM) more efficiently than dimethyl thiourea, lipoic acid, N-acetyl-cysteine and glutathione; (c) OH(v) (IC(50) = 0.15 +/- 0.02 microM) more efficiently than dimethyl thiourea, uric acid, trolox, dimethyl sulfoxide and mannitol, (d) (IC(50) = 15 +/- 1 microM) more efficiently than N-acetyl-cysteine, glutathione, tempol and deferoxamine and (e) HOCl (IC(50) = 622 +/- 42 microM) as efficiently as lipoic acid and N-acetyl-cysteine. NDGA was unable to scavenge H(2)O(2). In an in vivo study in rats, NDGA was able to prevent ozone-induced tyrosine nitration in lungs. It is concluded that NDGA is a potent in vitro scavenger of ONOO(-), (1)O(2), OH(v), and HOCl and is able to prevent lung tyrosine nitration in vivo.