Effects of different immunogenic amino acids in PD-L1 vaccine on the differentiation of T cell subsets / 中国药科大学学报

@#To compare the effects of endogenous 3-nitrotyrosine and non-natural 4-nitrophenylalanine in PD-L1 vaccine on the differentiation of T cell subsets, two immunogenic amino acids were introduced into the same site of PD-L1 vaccine. Two PD-L1 mutants with 3-nitrotyrosine and 4-nitrophenylalanine were obtained, respectively, using genetic code expansion technology. Mice were immunized with these two mutants, and their effects on the differentiation of T cell subsets in spleen were analyzed. The results of flow cytometry showed that the introduction of 4-nitrophenylalanine in PD-L1 vaccine could promote the polarization of Th1 cells while reducing the proportion of Treg cells; the introduction of 3-nitrotyrosine had no effect on the polarization of Th1 cells, while significantly increasing the proportion of Treg and Th17 cells. The introduction of both into PD-L1 vaccine could promote the response of CD8+ T cells in spleen, and the response of PD-L1 mutant containing 4-nitrophenylalanine was stronger. In summary, the non-natural 4-nitrophenylalanine is more suitable for the design of tumor vaccines as compared with endogenous 3-nitrotyrosine.

Association of serum 3-nitrotyrosine with carotid atherosclerosis in newly diagnosed type 2 diabetic patients / 中华内分泌代谢杂志

To investigate the association of serum 3-nitrotyrosine ( 3-NT ) with carotid atherosclerosis in newly diagnosed type 2 diabetic patients. 96 patients with newly diagnosed type 2 diabetes mellitus treated in the department of endocrinology of Tangshan Gongren Hospital were recruited, and were divided into two groups depending on their carotid atherosclerosis status as carotid atherosclerosis group ( CAS group, n = 54 ) and non-carotid atherosclerosis group ( NCAS group, n=42); while 51 healthy subjects without type 2 diabetes mellitus from the medical examination center were recruited as normal control group ( NC group, n=51) . Demographic and clinical data of all subjects were collected. Serum 3-NT levels were measured by Enzyme-Linked Immunosorbent Assay ( ELISA) . ( 1) The levels of 3-NT in CAS group and NCAS group were all higher than those in NC group, and the level of 3-NT in CAS group was higher than that in NCAS group (all P<0.05);(2) In type 2 diabetic patients, 3-NT was positively correlated with HbA1C and low density lipoprotein-cholesterol ( both P<0. 05); ( 3) Logistic regression analysis showed that age (OR=1.271, P=0.023), HbA1C(OR=1.812, P=0.005) , Hcy (OR=1.194, P=0.019), and 3-NT (OR=1.593, P=0.011) were risk factors of CAS in type 2 diabetic patients. Serum 3-NT was closely correlated with carotid atherosclerosis in newly diagnosed type 2 diabetic patients, suggesting that serum 3-NT may be involved in the carotid atherosclerosis of newly diagnosed type 2 diabetic patients.

Strong renal expression of heat shock protein 70, high mobility group box 1, inducible nitric oxide synthase, and nitrotyrosine in mice model of severe malaria

Abstract INTRODUCTION Renal damage is a consequence of severe malaria, and is generally caused by sequestration of Plasmodium falciparum -infected erythrocytes in the renal microcirculation, which leads to obstruction, hypoxia, and ischemia. This triggers high mobility group box 1 (HMGB1) to send a danger signal through toll-like receptors 2 and 4. This signal up-regulates inducible nitric oxide (iNOS) and nitrotyrosine to re-perfuse the tissue, and also increases heat shock protein 70 (HSP70) expression. As no study has examined the involvement of intracellular secondary molecules in this setting, the present study compared the renal expressions of HSP70, HMGB1, iNOS, and nitrotyrosine between mice suffered from severe malaria and normal mice. METHODS C57BL/6 mice were divided into an infected group (intraperitoneal injection of 10 6 P. berghei ANKA) and a non-infected group. Renal damage was evaluated using hematoxylin eosin staining, and immunohistochemistry was used to evaluate the expressions of HSP70, HMGB1, iNOS, and nitrotyrosine. RESULTS Significant inter-group differences were observed in the renal expressions of HSP70, HMGB1, and iNOS (p=0.000, Mann-Whitney test), as well as nitrotyrosine (p=0.000, independent t test). The expressions of HSP70 and HMGB1 were strongly correlated (p=0.000, R=1.000). No correlations were observed between iNOS and HMGB, HMGB1 and nitrotyrosine, HSP70 and nitrotyrosine, or iNOS and nitrotyrosine. CONCLUSIONS It appears that HMGB1, HSP70, iNOS, and nitrotyrosine play roles in the renal damage that is observed in mice with severe malaria. Only HSP70 expression is strongly correlated with the expression of HMGB1.

Effect of Triptolide on Expression of Oxidative Carbonyl Protein in Renal Cortex of Rats with Diabetic Nephropathy / 华中科技大学学报（医学）（英德文版）

The traditional Chinese medicine (Tripterygium wilfordiiHook.f.,TWH) has been clinically used to treat primary and secondary renal diseases and proteinuria for nearly 40 years.However,there is a rare literature about the effect of triptolide (the main active ingredient of TWH) on the expression of oxidative carbonyl protein (OCP) in diabetic nephropathy (DN).This study aimed to provide experimental evidence for triptolide treatment on DN through its effect on the expression of OCP,in order to investigate the effects of triptolide on the expression of OCP in rats with DN.Sixty SD rats were randomly divided into five groups:control group,high-dose triptolide (Th) group,low-dose triptolide (T1) group,DN model group,and positive control (benazepril) group.The DN model was established using streptozotocin.Urinary protein excretion,fasting blood glucose (FBG),superoxide dismutase (SOD) in renal homogenate,malondialdehyde (MDA) in renal homogenate and renal nitrotyrosine by immunohistochemistry,and the expression of OCP by oxyblotimmune blotting were detected.In the DN model group,rat urinary protein excretion and renal MDA were significantly increased,while renal SOD significantly decreased and nitrotyrosine expression was obviously upregulated in the kidney.After triptolide treatment,24-h urinary protein excretion (61.96±19.00 vs.18.32±4.78 mg/day,P＜0.001),renal MDA (8.09±0.79 vs.5.45±0.68 nmol/L,P＜0.001),and nitrotyrosine expression were decreased.Furthermore,renal OCP significantly decreased,while renal SOD (82.50±19.10 vs.124.00±20.52 U/L,P＜0.001) was elevated.This study revealed that triptolide can down-regulate the expression of OCP in the renal cortex of DN rats.

Serum nitrotyrosine concentration in dogs with myxomatous mitral valve disease

The aim of this study was to compare serum nitrotyrosine concentrations in healthy dogs with those in dogs with myxomatous mitral valve disease (MMVD). Fifty client-owned dogs were included in this study. Based on echocardiographic results, dogs were categorized into healthy (control), mild-, moderate-, and severe-MMVD groups. Serum nitrotyrosine concentrations were determined from enzyme-linked immunosorbent assays. No significant difference between control dogs and dogs with mild MMVD was detected (p = 0.31). However, dogs with moderate MMVD had significantly higher serum concentrations of nitrotyrosine (p = 0.04) than that in controls, and dogs with severe MMVD had significantly lower serum concentrations of nitrotyrosine (p = 0.03) than that in moderate MMVD dogs. There were negative correlations in the association of serum nitrotyrosine with age (n = 30, R²= 0.067, p = 0.27), left atrial-to-aortic root diameter ratio (n = 30, R²= 0.02, p = 0.57), and platelet count (n = 30, R²= 0.39, p = 0.003); however, only the platelet correlation was significant. Among dogs with MMVD, there was no significant difference in serum nitrotyrosine concentration between males and females. The results of this study suggest that tyrosine nitration end-products might be potential biomarkers for the detection of MMVD in dogs.

The inhibitory effect of PNS on brain 3-NT formation in vitro / 天津医药

Objective To study the inhibitory effect of panax notoginseng saponins (PNS) on 3-nitrotyrosine (3-NT) formation in brain induced by heme/NO2 -/H2O2 or ONOO - pathways in vitro. Methods According to the two major pathways of 3-NT formation in vivo, the models of protein nitration induced by heme/NaNO2/H2O2 or ONOO-system were established, respectively, in vitro. Bovine serum albumin (BSA)/rat plasma protein or rat brain homogenate protein were utilized as reactive substrates in both systems. Samples were divided into blank-control group, 3-NT group and PNS group (including low-, medium-and high-concentration subgroups). In 3-NT group, samples were exposed to heme/NaNO2/H2O2 or ONOO-system, respectively, at 37℃for 30 min, whereas in PNS group, samples were pre-incubated with PNS (at final concentrations of 50 mg/L, 100 mg/L, and 200 mg/L) at 37℃for 5 min before the nitrating system exposure. The 3-NT level in each group was detected by Western blot assy. Results Compared with the blank-control group, both heme/NaNO2/H2O2 and ONOO-system can induce significant 3-NT generation in BSA/rat plasma protein or rat brain homogenate protein (P0.05). Medium- and high-concentrations of PNS pre-treatment markedly inhibited 3-NT accumulation, with maximum effect at the concentration of 200 mg/L (P<0.05). Conclusion Medium- and high-concentrations of PNS can inhibit 3-NT formation in brain tissue mediated by either heme/NO2-/H2O2 or ONOO-pathways, implying that potential neuroprotective action against 3-NT involves pathological conditions, like trauma, stroke, and neurodegenerative diseases.

Laminar lesions in horses with systemic oxidative stress, committed by experimentally induced or naturally occurring gastrointestinal disorders / Lesões laminares em cavalos com estresse oxidativo sistêmico, acometidos por doenças gastrintestinais experimentalmente induzidas ou de ocorrência natural

Laminitis in horses can be associated with lesions in multiple organs secondary to sepsis. Twenty-one horses suffering from gastrointestinal disorders were used in the experiment; 7 horses with experimentally induced endotoxemia and intestinal ischaemia, and 14 horses suffering from naturally occurring colic syndrome. Tissue samples of lungs, liver, heart, brain, cerebellum and hoof laminar tissue were collected for histopathological and oxidative stress evaluation using nitrotyrosine and superoxide dismutase (SOD2) immunostaining. The horses were divided into two groups: the non-oxidative lesions group (NOLG), with 7 horses showing weak immunostaining in lungs, liver and kidney, and the oxidative lesions group (OLG), with 14 horses showing immunostaining indicating systemic oxidative stress in multiple organs. The horses from OLG showed increase of laminar lesions and SOD2 immunostaining in multiple organs when compared to the horses from the NOLG. No differences were found ln regard to laminar immunostaining by nitrotyrosine and SOD2 between experimental groups. It was concluded that systemic oxidative stress can be associated with the development of laminar lesions, and that the laminar tissue does not respond to oxidative stress with increase of SOD as occurs in other organs.(AU)

A laminite em equinos pode estar associada à lesão em múltiplos órgãos secundária a sepse. Foram utilizados 21 cavalos com afecções gastrintestinais, sendo sete com endotoxemia e isquemia intestinal induzidos experimentalmente, e 14 cavalos com síndrome cólica de origem natural. Amostras teciduais de pulmão, rim, fígado, coração, cérebro e cerebelo e de tecido laminar do casco foram coletadas para avaliação de lesão histopatológica e estresse oxidativo, pela imunomarcação de nitrotirosina e superóxido dismutase (SOD2). Os animais foram divididos em dois grupos: grupo sem lesão oxidativa (NOLG), com sete cavalos com fraca imunomarcação em pulmão, fígado e rim, e grupo lesão oxidativa (OLG), contendo 14 cavalos com imunomarcação indicando estresse oxidativo em múltiplos órgãos. Os cavalos do grupo OLG apresentaram aumento de lesões laminares e imunomarcação para SOD2 em múltiplos órgãos, quando comparados ao NOLG. Não houve diferença sobre a imunomarcação laminar para nitrotirosina e SOD2 entre os grupos experimentais. Conclui-se que o estresse oxidativo sistêmico está associado ao desenvolvimento de lesões laminares, e que o tecido laminar não responde ao estresse oxidativo com aumento de SOD como ocorre nos outros órgãos.(AU)

Sodium nitroprusside has leishmanicidal activity independent of iNOS

Abstract: INTRODUCTION: Leishmaniasis is a zoonotic disease caused by protozoa of the genus Leishmania . Cutaneous leishmaniasis is the most common form, with millions of new cases worldwide each year. Treatments are ineffective due to the toxicity of existing drugs and the resistance acquired by certain strains of the parasite. METHODS: We evaluated the activity of sodium nitroprusside in macrophages infected with Leishmania (Leishmania) amazonensis . Phagocytic and microbicidal activity were evaluated by phagocytosis assay and promastigote recovery, respectively, while cytokine production and nitrite levels were determined by ELISA and by the Griess method. Levels of iNOS and 3-nitrotyrosine were measured by immunocytochemistry. RESULTS: Sodium nitroprusside exhibited in vitro antileishmanial activity at both concentrations tested, reducing the number of amastigotes and recovered promastigotes in macrophages infected with L. amazonensis . At 1.5µg/mL, sodium nitroprusside stimulated levels of TNF-α and nitric oxide, but not IFN-γ. The compound also increased levels of 3-nitrotyrosine, but not expression of iNOS, suggesting that the drug acts as an exogenous source of nitric oxide. CONCLUSIONS: Sodium nitroprusside enhances microbicidal activity in Leishmania -infected macrophages by boosting nitric oxide and 3-nitrotyrosine.

Simultaneous determination of 3-chlorotyrosine and 3-nitrotyrosine in human plasma by direct analysis in real time-tandem mass spectrometry

A novel method for the simultaneous determination of 3-nitrotyrosine (NT) and 3-chlorotyrosine (CT) in human plasma has been developed based on direct analysis in real time-tandem mass spectrometry (DART-MS/MS). Analysis was performed in the positive ionization mode using multiple reaction monitoring (MRM) of the ion transitions at m/z 216.2/170.1 for CT, m/z 227.2/181.1 for NT and m/z 230.2/184.2 for the internal standard, d (3)-NT. The assay was linear in the ranges 0.5-100 μg/mL for CT and 4-100 μg/mL for NT with corresponding limits of detection of 0.2 and 2 μg/mL. Intra- and inter-day precisions and accuracies were respectively <15% and ±15%. Matrix effects were also evaluated. The method is potentially useful for high throughput analysis although sensitivity needs to be improved before it can be applied in clinical research.

Effects of enos uncoupling on the endothelial dysfunction of pulmonary artery in rats with decompression sickness / 解放军医学杂志

Objective To explore the effects of unsafe decompression on the endothelial function of pulmonary artery in rat and its possible related mechanism. Methods Sixty male SD rats (260±35g) were randomly divided into two groups (30 each): control group and decompression (DCS) group. Decompression sickness (DCS) model was reproduced by placing the rats in a compression chamber with air pressure of 600kPa for 60min, followed by decompression at a rate of 100kPa/min to normal pressure. The surviving rats in both control and DCS groups were sacrificed and their pulmonary artery was harvested. The endothelium dependent vasodilatation capacity of isolated pulmonary artery was assessed. The expression and uncoupling of endothelial nitric oxide synthetase (eNOS), as well as the nitration level of each kind of protein in the pulmonary artery tissue, were analyzed by Western blotting. The concentration of reactive oxygen species (ROS) in the pulmonary artery was determined with superoxide anion probe dihematoporphyrin ether (DHE) staining. Results Ten of 30 rats in DC group died of unsafe decompression, and the endothelium dependent vasodilatation capacity of excised pulmonary artery in survived rats was found to decline obviously (P0.05), but the ratio of eNOS monomer/dimer increased significantly in DC group than in control group (P<0.05). The tyrosine nitration level of each kind of protein in the pulmonary artery tissues was higher significantly in DC group than that in control group (P<0.05). DHE showed that the generated amount of DCS in pulmonary artery tissues was obviously higher in DC group than in control group (P<0.05). Conclusions Unsafe decompression may lead to uncoupling of eNOS dimers in the endothelium of pulmonary artery. Uncoupled eNOS monomers may inhibit the synthesis of NO, thereby affect the endothelium dependent vasodilatation function. On the other hand, the eNOS monomers may facilitate the anabolism of ONOO-, leading to an increase in tyrosine nitration level of each kind of protein in the pulmonary artery tissues, thereby cause the regulation disorder of cell information system. The eNOS monomers may also increase the production of ROC, there by mediate the peroxide injuries.

Limb remote ischemic post-conditioning reduces brain reperfusion injury by reversing eNOS uncoupling.

Limb remote ischemic postconditioning (LRIP) can reduce ischemia-reperfusion injury (IRI), but its mechanisms are still unclear. We hypothesize that LRIP reduces IRI by reversing eNOS uncoupling. Focal ischemia was induced in Sprague-Dawley rats by middle cerebral artery occlusion for 2 h followed by a 24 h reperfusion. Before this surgery, folic acid (FA) was administered to the drug treatment group by gavage for 11 days. After a 24 h reperfusion, behavioural testing, vascular function, NO concentration and superoxide dismutase activity in the serum were determined. In addition, the infarct size of the brain was also detected. The mRNA of eNOS, nNOS, GTP cyclohydrolase I (GTPCH), P22phox and xanthine oxidase (XO) in the ischemic region were detected by RT-PCR, and nitrotyrosine (Tyr-NO2) was detected using Western blot analysis. The results showed that LRIP, FA and FA+LRIP all could improve behavioural score, and increase NO–mediated endothelium-dependent vasomotor responses, reduce infarction of rats subjected to IRI. Western blot and RT-PCR analyses showed that the Tyr-NO2 levels and the mRNA expression of NADPH oxidase catalytic subunit P22phox and XO were up-regulated in the ischemic brain, which was significantly inhibited by LRIP, FA and FA+LRIP. The mRNA expression of the rate-limiting enzyme in BH4 synthesis, GTPCH, was down-regulated in the ischemic brain, which could be significantly augmented by LRIP and FA+LRIP. It can be concluded that IRI induces eNOS uncoupling in the cerebral ischemic region and LRIP partially reverses the eNOS uncoupling induced by IRI.

Malondialdehyde and 3-Nitrotyrosine in Exhaled Breath Condensate in Retired Elderly Coal Miners with Chronic Obstructive Pulmonary Disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an important cause of occupational mortality in miners exposed to coal mine dust. Although the inflammatory mediators involved in COPD have not been defined, many studies have shown that inflammatory mediators such as reactive oxygen and nitrogen species are involved in orchestrating the complex inflammatory process in COPD. METHODS: To investigate the relevance of exhaled biomarkers of oxidative and nitrosative stress in participants with COPD, we determined the levels of hydrogen peroxide, malondialdehyde (MDA), and 3-nitrotyrosine (3-NT) in exhaled breath condensate (EBC) in 90 retired elderly coal miners (53 non-COPD and 37 COPD participants). RESULTS: Mean levels of MDA (4.64 nM vs. 6.46 nM, p = 0.005) and 3-NT (3.51 nM vs. 5.50 nM, p = 0.039) in EBC were significantly higher in participants with COPD. The median level of MDA did show statistical difference among the COPD severities (p = 0.017), and the area under the receiver operating characteristic curve for MDA (0.67) for the diagnostic discrimination of COPD indicated the biomarker. The optimal cutoff values were 5.34 nM (64.9% sensitivity and 64.2% specificity) and 5.58 nM (62.2% sensitivity and 62.3% specificity) for MDA and 3-NT, respectively. The results suggest that high levels of MDA and 3-NT in EBC are associated with COPD in retired elderly miners. CONCLUSION: These results showed that the elevated levels of EBC MDA and EBC 3-NT in individuals with COPD are biomarkers of oxidative or nitrosative stress.

Association between nitrotyrosine and coronary heart disease in type 2 diabetes / 中国综合临床

Objective To investigate the association of nitrotyrosine with coronary heart disease (CHD) in type 2 diabetes mellitus.Methods The nitrotyrosine levels were determined in 109 patients of type 2 diabetes mellitus without CHD (T2DM).One hundred and fifty-two patients of type 2 diabetes mellitus with CHD (T2DM-CHD) and 103 healthy control subjects by ELISA.Results T2DM-CHD patients had significantly increased nitrotyrosine compared with T2DM group and the control group [ ( 78.17±10.68 )nmol/L,(70.50 ± 9.13) nmol/L vs ( 63.23 ± 11.55 ) nmol/L,Ps ＜ 0.01 ].Nitrotyrosine was correlated with total cholesterol,triglyceride,fasting glucose and Gensini Score (r=0.361,P=0.009;r =0.206,P=0.001 ;r=0.347,P=0.026; r=0.466,P ＜ 0.001 ).Multivariable logistic regression showed nitrotyrosine was independently associated with CHD combined with type 2 diabetes mellitus ( OR=1.094,95％ CI:1.053-1.137 ; P ＜ 0.01 ).Conclusion Nitrotyrosine plays an important role in the formation and development of cardiovascular disease in tvoe 2 diabetes.

Effect of tubulin tyrosine ligase like 12 and nitrotyrosine on growth of prostate cancer cells / 第二军医大学学报

Objective To study the effect of tubulin tyrosine ligase like 12 (TTLL12) and nitrotyrosine on the growth of prostate cancer cells. Methods TTLL12 and crtubulin nitrotyrosination (N-tubulin) were detected by Western blotting analysis in normal prostate epithelial cell lines PWR1E and RWPE1, and prostate cancer cell line DU145; the proliferation of cells was observed by MTT assay. Results The expression of N-tubulin was significantly lower in DU145 cells than those in PWR1E and RWPE1 cells after treatment with nitrotyrosine (P 0. 05). Conclusion TTLL12 allows an escape of prostate cancer cells from the treatment of nitrotyrosine, leading to the escape of prostate cancer cells from the body's surveillance system and acquirement of their abnormal proliferation.

Effect of sesamin on expression of inducible nitric oxide synthase and nitrotyrosine in rat liver tissue with metabolic syndromic hepatic steatosis / 中国病理生理杂志

AIM: To study the effect of sesamin on expression of inducible nitric oxide synthase(iNOS)and nitrotyrosine(NT)in rat liver tissue with metabolic syndromic hepatic steatosis. METHODS: The rat model of metabolic syndromic hepatic steatosis was induced by operation of two kidneys with one clip(2K1C)and high-fat. The rats taken from that successful model were randomly divided into model group and sesamin(120, 60, and 30 mg·kg~(-1)·d~(-1))groups. In addition, the sham-operated group was set up. The rats in treated group were given sesamin intragastrically everyday for 8 weeks. The levels of blood lipids(TC, TG and FFA)in serum were detected. The activity of SOD and MDA level in the liver homogenate were determined. The expressions of iNOS and NT proteins were detected by Western blotting analysis. The histopathological changes were observed by HE staining in the liver tissues. RESULTS: Compared to model groups, sesamin(120, 60 mg·kg~(-1))significantly inhibited the elevation of serum TC, TG, FFA, and MDA in liver homogenate(P<0.05), and increased the activity of SOD(P<0.05). It also decreased the protein expression of iNOS and NT(P<0.05), and ameliorated the degree of hepatic steatosis. CONCLUSION: Sesamin prevents and cures the metabolic syndromic hepatic steatosis. The mechanism is probably mediated through decreasing the protein expression of iNOS and NT, and alleviating the oxidative stress in addition to regulating the lipid metabolism.

A combination of Chinese herbs,Astragalus membranaceus var.mongholicus and Angelica sinensis,suppresses oxidative stress in obstructed rat kidney / 中华肾脏病杂志

Objective To investigate the influence of a combination of Chinese herbs,Astragalus membranaceus var.mongholicus and A ngelica sinensis (A&A)on the production and elimination of reactive oxygen species (ROS)and the underlying mechanism during the process of renal interstitial fibrosis in the obstructive kidneys of rats with unilateral ureteral obstruction(uuo).Method Male Wistar rats were randomly divided into control,sham,UUO and UAA (UUO+A&A)groups.The rats in UAA group were administered with A&A(14 g/kg)by oral gavage once daily:the ones in sham and UUO group were given with equal volumes of water.Three days after setting up models,pathological injury of renal tissue was evaluated.Level of total antioxidant capacity(T-AOC)and activity of CuZn superoxide dismutase(CuZn-SOD)in renal homogenates were measured bv spectrophotometry.Expression of NADPH oxidase subunits p47-phox,p22-phox and nintrotyrosine was analyzed by Western blot. Results Severe interstitial inflammatory cells infiltration, mild tubular atrophy and interstitial fibrosis were found in UUO group, which were alleviated by A&A administration. Compared to sham group, T-AOC of UUO group was not significantly changed, but the expression of the nitrotyrosine, NADPH oxidase subunits p47-phox and p22-phox was increased significantly (P<0.05). After A&A administration, T-AOC level was increased (2.5±1.1 vs 1.5±0.5, P<0.05) and the expression of nitrotyrosine was decreased (P< 0.05) in UAA group compared with UUO group. Additionally, the expression of p47-phox was reduced at day 3 (P<0.05), accompanied with a reduced expression of p22-phox (P< 0.05). CuZn-SOD activity was not significantly changed among the groups. Conclusion The inhibition of A&A in NADPH oxidase subunits p47-phox and p22-phox, which is responsible for reduction of oxidative stress, is associated with the alleviation of renal fibrosis in obstructive rat kidney.

Tyrosine nitration site specificity identified by LC/MS in nitrite-modified collagen type IV

Non-enzymatic nitrite induced collagen cross-linking results in changes reminiscent of age-related damage and parallels the well-known model system, non-enzymatic glycation. We have recently observed that nitrite modification of basement membrane proteins can induce deleterious effects on overlying retinal pigment epithelial cells in studies relevant to age-related macular degeneration. The present work was undertaken in order to confirm 3-nitro-tyrosine (3-NT) as a product of the reaction and to identify the site specificity of nitration in collagen IV, a major component of basement membranes. Human collagen type IV was modified via incubation with 200 mM NaNO2 (pH=7.38) for one week at 37degrees C. The modified protein was prepared in 2 different ways, including acid hydrolysis and trypsin digestion for site specificity determination. The samples were analyzed by LC/MS using a C12 RP column. Site specificity was determined from tandem MS/MS data utilizing TurboSEQUEST software and the Swiss-Prot sequence database. 3-NT was detected in protein digests and acid hydrolysates of nitrite modified collagen IV. Positive identification with standard 3-NT was confirmed by identical Rt, lambda(max)=279 nm and 355 nm, and m/z=227. Analyses of tryptic digests identified four sites of tyrosine nitration, alpha1(IV)Y348, alpha1(IV)Y534, alpha2(IV)Y327, and alpha2(IV)Y1081. These sites are located in the triple-helical region of the protein and provide clues regarding potential sites for nitrite modification in collagen type IV.

Nicotinamide Reduces the Infarct Volume in a Rat Model of Transient Middle Cerebral Artery Occlusion

BACKGROUND: Cerebral ischemia depletes ATP and causes irreversible tissue injury. Nicotinamide is a precursor of NAD+ and it is also a poly (ADP-ribose) polymerase (PARP) inhibitor that increases the neuronal ATP concentration and so protects against stroke. Therefore we examined whether nicotinamide could protect against cerebral ischemia by using a model of transient middle cerebral artery occlusion (MCAO) (reperfusion 2 h post ischemia) in Sprague-Dawley rats. METHODS: Nicotinamide (500 mg/kg) or normal saline was administered intraperitoneally 24 and 0 h before and after MCAO, respectively. The infarction volumes were determined with triphenyltetrazolium chloride staining 24 h after reperfusion. The nitrotyrosine, PAR polymer and PARP-1 expressions were examined by immunohistochemistry with using brain slices obtained from the rats that were sacrificed at 0, 15, 30, 60 and 120 min after reperfusion. RESULTS: The infarction volumes were significantly attenuated (21.8%, p<0.05). The nitrotyrosine expressions were increased at 0, 15 and 30 min, and those expressions for PARP polymer and PARP-1 were increased at 60 and 120 min, respectively. Nicotinamide partly reduced the expressions for nitrotyrosine and PAR polymer except for PARP-1. CONCLUSIONS: These results suggest that nicotinamide may attenuate ischemic brain injury through its antioxidant activity and the inhibition of PARP-1.

Effects of Tempol on Blood Pressure and Tissue Oxidative Stress in DOCA-alt and L-AME-nduced Hypertension / 대한신장학회잡지

BACKGROUND: Effects of oxidative stress on the development of deoxycorticosterone acetate (DOCA)-salt or N(G)-nitro-L-arginine (L-NAME) hypertension were examined. METHODS: Male Sprague-awley rats were treated with DOCA (200 mg/kg, subcutaneous)-salt or L-NAME (40 mg/L in daily drinking water) for 4 weeks. To reduce the oxidative stress, 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol, 3 mM/L) was cotreated in drinking water. The expression of endothelial nitric oxide synthase (eNOS) and nitrotyrosine proteins was determined in the renal cortex and thoracic aorta. RESULTS: Tempol prevented the development of DOCA-salt hypertension, whereas it was without effect on L-NAME hypertension. In DOCA-salt hypertension, the eNOS expression in the renal cortex was increased, the degree of which was attenuated by Tempol. The renal expression of nitrotyrosine was decreased, which was further decreased by Tempol. In the aorta, the expression of both eNOS and nitrotyrosine was decreased, which was not further affected by Tempol. In L-NAME hypertension, the renal expression of eNOS was significantly increased, which was blocked by Tempol. The expression of eNOS in the aorta was slightly decreased, and was not further affected by Tempol. The renal expression of nitrotyrosine was not significantly altered. However, its expression was significantly decreased in the aorta, and was further reduced by Tempol. CONCLUSION: The blockade of oxidative stress may attenuate the development of hypertension and provide tissue protection in DOCA-salt hypertension. The blockade of oxidative stress may also contribute to a tissue protection in L-NAME hypertension.

Effects of Simulated Microgravity on the Morphology and Growth of PC12 Cells / 航天医学与医学工程

Objective To observe whether the increase of oxidative stress in PC12 cells could influence the levels of protein carbonyls and nitrotyrosine and alter the cytoskeleton and cell morphology under clinostat condition,and whether the increase of content of nitrate/nitrite in cell culture medium could influence the cell proliferation and differentiation.Method Cell morphology,carbonylated actin and nitrotyrosinated tubulin,and mRNA and protein express of nNOS and iNOS were observed and determined with immunofluorescence and RT-PCR technology in clinostat rotated and control static groups.At the same time,cell density was measured and cell cycles were detected with flow cytometry.The relationship between all these changes and NOS were also analyzed.Result The levels of carbonylated and nitrotyrosinated cytoskeleton protein were altered,no obvious changes in cell morphology but neurite outgrowth after on a clinostat rotation.Cell density also increased significantly,DNA synthesis in cell cycles was shortened.Conclusion All of these results indicate that simulated weightlessness do not alter cell morphology and is beneficial to the growth of PC12 cells.The mechanism involved may be associated with the increase of NOS activity.