The role of ROS/TXNIP/NLRP3 pathway in the skin injury of trichloroethylene sensitized mice / 中华劳动卫生职业病杂志

Objective: To explore the mechanism of reactive oxygen species/thioredoxin-interacting protein/nucleotide-binding oligomerization domain-like receptor 3 (ROS/TXNIP/NLRP3) pathway in the skin injury of trichloroethylene (TCE) sensitized mice. Methods: In August 2020, 40 female BALB/c mice were randomly divided into control group (n=5) , solvent control group (n=5) , TCE treatment group (n=15) and TCE+(2-(2, 2, 6, 6-Tetrameyhylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (Mito TEMPO) treatment group (n=15) . The TCE sensitization model was established. Mice in the TCE treatment group and TCE+Mito TEMPO treatment group were divided into the sensitized positive group and the sensitized negative group according to the skin erythema and edema reactions on the back of the mice 24 h after the last stimulation. The mice were sacrificed 72 h after the last stimulation, the back skin of the mice was taken, and the skin lesions were observed. Immunohistochemistry (IHC) was used to detect the expression level of NLRP3, and the Western Blot was performed to detect the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) , cysteinyl aspartate specific proteinase 1 (Caspase 1) , Interleukin-1β (IL-1β) and TXNIP proteins in the skin of the mice, the reactive oxygen species (ROS) kit was used to detect the level of intracellular ROS in the back skin tissue. Results: The sensitization rates of TCE treatment group and TCE+Mito TEMPO treatment group were 40.0% (6/15) and 33.3% (5/15) , respectively, and there was no significant difference between the two groups (P>0.05) . The back skin of the mice in the TCE sensitized positive group was thickened and infiltrated by a large number of inflammatory cells. The number of mitochondria in the epidermis cells was significantly reduced, the mitochondrial crest disappeared and vacuolar degeneration occurred. TCE+Mito TEMPO sensitized positive group had less damage, more mitochondria and relatively normal cell structure. Compared with the solvent control group and corresponding sensitized negative groups, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE sensitized positive group and TCE+Mito TEMPO sensitized positive group were significantly increased (P<0.05) . Compared with TCE sensitized positive group, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE+Mito TEMPO sensitized positive group were significantly decreased (P<0.05) . Conclusion: ROS/TXNIP/NLRP3 pathway was activated and then encouraged the release of IL-1β, finally aggravated the TCE-induced skin injury.

Suplementação de Vitamina D Induz Remodelação Cardíaca em Ratos: Associação com a Proteína de Interação com a Tiorredoxina e a Tiorredoxina / Vitamin D Supplementation Induces Cardiac Remodeling in Rats: Association with Thioredoxin-Interacting Protein and Thioredoxin

Resumo Fundamento: A vitamina D (VD) tem um importante papel na função cardíaca. No entanto, a vitamina exerce uma curva "dose-resposta" bifásica na fisiopatologia cardiovascular e pode causar efeitos deletérios, mesmo em doses não tóxicas. A VD exerce suas funções celulares ligando-se ao seu receptor. Ainda, a expressão da proteína de interação com a tiorredoxina (TXNIP) é positivamente regulada pela VD. A TXNIP modula diferentes visa de sinalização celular que podem ser importantes para a remodelação cardíaca. Objetivos: Avaliar se a suplementação com VD leva à remodelação cardíaca, e se a TXNIP e a tiorredoxina (Trx) estão associadas com esse processo. Métodos: Duzentos e cinquenta ratos Wistar machos foram alocados em três grupos: controle (C, n=21), sem suplementação com VD; VD3 (n = 22) e VD10 (n=21), suplementados com 3,000 e 10,000 UI de VD/ kg de ração, respectivamente, por dois meses. Os grupos foram comparados por análise de variância (ANOVA) com um fator e teste post hoc de Holm-Sidak (variáveis com distribuição normal), ou pelo teste de Kruskal-Wallis e análise post-hoc de Dunn. O nível de significância para todos os testes foi de 5%. Resultados: A expressão de TXNIP foi mais alta e a atividade do Trx foi mais baixa no grupo VD10. Os animais que receberam suplementação com VD apresentaram aumento de hidroperóxido lipídico e diminuição de superóxido dismutase e glutationa peroxidase. A proteína Bcl-2 foi mais baixa no grupo VD10. Observou-se uma diminuição na β-oxidação de ácidos graxos, no ciclo do ácido tricarboxílico, na cadeia transportadora de elétrons, e um aumento na via glicolítica. Conclusão: A suplementação com VD levou à remodelação cardíaca e esse processo pode ser modulado por TXNIP e Trx, e consequentemente por estresse oxidativo.

Abstract Background: Vitamin D (VD) has been shown to play an important role in cardiac function. However, this vitamin exerts a biphasic "dose response" curve in cardiovascular pathophysiology and may cause deleterious effects, even in non-toxic doses. VD exerts its cellular functions by binding to VD receptor. Additionally, it was identified that the thioredoxin-interacting protein (TXNIP) expression is positively regulated by VD. TXNIP modulate different cell signaling pathways that may be important for cardiac remodeling. Objective: To evaluate whether VD supplementation lead to cardiac remodeling and if TXNIP and thioredoxin (Trx) proteins are associated with the process. Methods: A total of 250 Male Wistar rats were allocated into three groups: control (C, n=21), with no VD supplementation; VD3 (n = 22) and VD10 (n=21), supplemented with 3,000 and 10,000 IU of VD/ kg of chow respectively, for two months. The groups were compared by one-way analysis of variance (ANOVA) and Holm-Sidak post hoc analysis, (variables with normal distribution), or by Kruskal-Wallis test and Dunn's test post hoc analysis. The significance level for all tests was 5%. Results: TXNIP protein expression was higher and Trx activity was lower in VD10. The animals supplemented with VD showed increased lipid hydroperoxide and decreased superoxide dismutase and glutathione peroxidase. The protein Bcl-2 was lower in VD10. There was a decrease in fatty acid β-oxidation, tricarboxylic acid cycle and electron transport chain with shift to increase in glycolytic pathway. Conclusion: VD supplementation led to cardiac remodeling and this process may be modulated by TXNIP and Trx proteins and consequently oxidative stress.

IInvestigation of possible oxidative damage caused by formaldehyde exposure in the rat's heart and aorta tissue / Investigación de posible daño oxidativo causado por la exposición al formaldehído en el corazón de la rata y tejido de la aorta

SUMMARY: Formaldehyde (FA) is a toxic substance used frequently in the field of medicine as well as in many industrial areas. Especially people working in the field of anatomy, histology, and pathology are in high risk group because of the use of the FA. Studies showing the effects of FA on the cardiovascular system are few in number. The purpose of the present study was to investigate the effects of FA exposure, which we believe can cause oxidative stress, on the heart and aorta with various biochemical analyses. A total of 24 Wistar Albino rats were used in our study. We divided the rats into 3 groups as the Control Group (CG), the group exposed to low-dose FA (avg. 1 ppm) (DDG) Group, and the group exposed to high-dose FA (avg. 10 ppm) (YDG). At the end of the subchronic FA exposure, the blood samples, heart and aorta tissues of the rats were taken and subjected to biochemical analyses. As a result of the analyses, statistically significant differences were detected between CG (2.96?0.85 ng/mg), and HDG (2.08?0.77 ng/mg) in aortic tissues in TXNIP analysis (p<0.05). In heart tissues, significant differences were detected between CG (0.73?0.27 ng/mg) and LDG (1.13?0.22 ng/mg) (p<0.05). Statistically significant differences were also detected between CG (1.98?0.31 mM/ml) and YDG (2.43?0.31 mM/ml) in serum MDA analyses (p<0.05). It was shown that subchronic application of FA to LDG rats through inhalation had no effects on apoptosis markers in heart tissues. More studies are required to show FA toxicity and the mechanism of action of pathology on the cardiovascular system. We believe that our study will contribute to clarifying the roles of mild and subchronic exposure of FA in heart and aortic tissues in terms of oxidative stress risk.

RESUMEN: El formaldehído es una sustancia tóxica que se utiliza con frecuencia en el campo de la medicina, así como en muchas áreas industriales. Especialmente las personas que trabajan en el area de la anatomía, y patología se encuentran en el grupo de alto riesgo debido al uso de esta sustancia. Pocos son los estudios que muestran los efectos del formaldehído en el sistema cardiovascular. El propósito del presente estudio fue investigar a través de análisis bioquímicos, los efectos de la exposición a formaldehído, que podría causar estrés oxidativo, en el corazón y la aorta. Se utilizaron un total de 24 ratas Albinas Wistar. Dividimos a las ratas en 3 grupos: grupo control (GC), grupo expuesto a dosis bajas de AG (promedio 1 ppm) (DDG) y grupo expuesto a dosis altas de AG (promedio 10 ppm) (YDG). Al término de la exposición a FA subcrónica, se tomaron muestras de sangre, tejido cardíaco y aorta de las ratas y se sometieron a análisis bioquímicos. Como resultado de los análisis, se detec- taron diferencias estadísticamente significativas entre GC (2,96 ? 0,85 ng / mg) y HDG (2,08 ? 0,77 ng / mg) en los tejidos aórticos en el análisis TXNIP (p <0,05). En los tejidos cardíacos se detectaron diferencias significativas entre GC (0,73 ? 0,27 ng / mg) y LDG (1,13 ? 0,22 ng / mg) (p <0,05). También se detectaron diferencias estadísticamente significativas entre CG (1,98 ? 0,31 mM / ml) y YDG (2,43 ? 0,31 mM / ml) en los análisis de MDA en suero (p <0,05). Se demostró que la aplicación subcrónica de formaldehído a ratas LDG a través de la inhalación no tuvo efectos sobre los marcadores de apoptosis en los tejidos del corazón. Se requieren más estudios para demostrar la toxicidad de los AG y el mecanismo de acción de la patología en el sistema cardiovascular. Creemos que nuestro estudio contribuirá a aclarar las funciones de la exposición leve y subcrónica de formaldehído en los tejidos cardíacos y aórticos en términos de riesgo al estrés oxidativo.

Expressions of Thioredoxin Interacting Protein/Nucleotide-binding Oligomerization Domain-like Receptor Protein 3 Inflammasome in the Sciatic Nerve of Streptozotocin-induced Diabetic Rats / 中国医学科学院学报

To investigate the role of thioredoxin interacting protein(TXNIP)/ nucleotides-binding oligomerization domain-like receptor protein(NLRP)3 inflammasome in the sciatic nerve of streptozotocin(STZ)-induced diabetic rats. The diabetic rat model was established by single intraperitoneal injection of STZ.The rats with matched sex and age were taken as normal control group.The blood glucose and body weight were monitored.The mechanical withdrawal threshold was measured by von Frey filaments at 12 weeks after the model was established.At 12 weeks,the rats were sacrificed and the sciatic nerves were separated for Luxol fast blue staining,the expressions of TXNIP,NLRP3,caspase-1,and interleukin(IL)-1β were detected by immunohistochemistry and Western blot method,and the levels of IL-1β and IL-18 in serum were measured by enzyme-linked immunosorbent assay(ELISA). The expression of TXNIP protein in the sciatic nerve of diabetic rats was 3.78±0.08,which significantly increased than that in the normal control group(0.99±0.06)(=26.980,<0.0001).Compared with the normal control group(0.97±0.05),the expression of NLRP3 protein in the diabetic group(2.44±0.16)was significantly higher(=8.885,<0.0001).The expression of cleaved caspase-1 was 4.45±0.19 in the diabetic group and 1.08±0.06 in the normal control group,and the difference was significant(=16.900,<0.0001).The expression of IL-1β protein in the diabetic group(4.50±0.16)was significantly higher than that(1.19±0.08)in the normal control group(=18.630,<0.0001).Compared with the normal control group,the levels of IL-1β [(110.50±8.80)pg/ml (17.97±3.18)pg/ml,=9.892,<0.0001] and IL-18 [(591.70±8.78)pg/ml (160.70±8.33)pg/ml,=35.620,<0.0001] in the serum of diabetic rats significantly increased. The pathogenesis of diabetic peripheral neuropathy may be related to increased expression of TXNIP,activation of NLRP3 inflammasome,and downstream inflammation,which may provide a new target for diabetic peripheral neuropathy therapy.

Identification of proteins differentially expressed by glutamate treatment in cerebral cortex of neonatal rats / 한국실험동물학회지

Glutamate leads to neuronal cell damage by generating neurotoxicity during brain development. The objective of this study is to identify proteins that differently expressed by glutamate treatment in neonatal cerebral cortex. Sprague-Dawley rat pups (post-natal day 7) were intraperitoneally injected with vehicle or glutamate (10 mg/kg). Brain tissues were isolated 4 h after drug treatment and fixed for morphological study. Moreover, cerebral cortices were collected for protein study. Two-dimensional gel electrophoresis and mass spectrometry were carried out to identify specific proteins. We observed severe histopathological changes in glutamate-exposed cerebral cortex. We identified various proteins that differentially expressed by glutamate exposure. Identified proteins were thioredoxin, peroxiredoxin 5, ubiquitin carboxy-terminal hydrolase L1, proteasome subunit alpha proteins, isocitrate dehydrogenase, and heat shock protein 60. Heat shock protein 60 was increased in glutamate exposed condition. However, other proteins were decreased in glutamate-treated animals. These proteins are related to anti-oxidant, protein degradation, metabolism, signal transduction, and anti-apoptotic function. Thus, our findings can suggest that glutamate leads to neonatal cerebral cortex damage by regulation of specific proteins that mediated with various functions.

Expresión y distribución de las Tioredoxinas durante asfixia perinatal. Su rol en la regulación del equilibrio redox / EXPRESSION AND DISTRIBUTION OF THIOREDOXINS IN PERINATAL ASPHYXIA

This article deals with the expression and distribution of Thioredoxins during perinatal asphyxia, and its roll in the regulation of the redox system. Disorders in the gaseous interchange through the placenta and the fetal lungs, can lead to what is known as the perinatal asphyxia (PA). The PA can involve all the organ systems, but has more severe effects on the Central Nervous System (CNS), producing damage as much as in the short term as in the long term. The disturbance recognized as oxidative stress, is considered as a disorder in the normal process of redox regulation. Thioredoxins are a group of proteins involucrated in the regulation of the cellular redox state. The aim of this report was to analyze the changes of the expression of Thioredoxins at a long term sustained on the hypothesis that the disorder at a short term induced by the perinatal asphyxia leds to substantial changes in a large term in the CNS.

Recombinant Human Thioredoxin-1 Protects Macrophages from Oxidized Low-Density Lipoprotein-Induced Foam Cell Formation and Cell Apoptosis

Oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and apoptosis play critical roles in the pathogenesis of atherosclerosis. Thioredoxin-1 (Trx) is an antioxidant that potently protects various cells from oxidative stress-induced cell death. However, the protective effect of Trx on ox-LDL-induced macrophage foam cell formation and apoptosis has not been studied. This study aims to investigate the effect of recombinant human Trx (rhTrx) on ox-LDL-stimulated RAW264.7 macrophages and elucidate the possible mechanisms. RhTrx significantly inhibited ox-LDL-induced cholesterol accumulation and apoptosis in RAW264.7 macrophages. RhTrx also suppressed the ox-LDL-induced overproduction of lectin-like oxidized LDL receptor (LOX-1), Bax and activated caspase-3, but it increased the expression of Bcl-2. In addition, rhTrx markedly inhibited the ox-LDL-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38 mitogen-activated protein kinases (MAPK). Furthermore, anisomycin (a p38 MAPK activator) abolished the protective effect of rhTrx on ox-LDL-stimulated RAW264.7 cells, and SB203580 (a p38 MAPK inhibitor) exerted a similar effect as rhTrx. Collectively, these findings indicate that rhTrx suppresses ox-LDL-stimulated foam cell formation and macrophage apoptosis by inhibiting ROS generation, p38 MAPK activation and LOX-1 expression. Therefore, we propose that rhTrx has therapeutic potential in the prevention and treatment of atherosclerosis.

Efeito pró-oxidante do hidroperóxido de urato sobre proteínas sensíveis às alterações redox: implicações na resposta inflamatória / Pro-oxidant effect of urate hydroperoxide on redoxsensitive proteins: implications on inflammatory reponse

O hidroperóxido de urato (HOOU) é o produto da oxidação do ácido úrico por peroxidases. Sua produção é favorecida durante a inflamação e hiperuricemia, uma vez que há grande quantidade de ácido úrico, peroxidases inflamatórias e superóxido. Neste sentido, o objetivo deste estudo foi avaliar o efeito do hidroperóxido de urato sobre proteínas sensíveis à modulação redox em um ambiente inflamatório asséptico e outro que imita infecção. Assim, nesta tese comparou-se a estrutura química do HOOU obtido fotoquimicamente daquele obtido através da catálise enzimática pela mieloperoxidase. A obtenção do HOOU por foto-oxidação permitiu o melhor isolamento do composto. Este oxidante foi capaz de reagir especificamente com os aminoácidos contendo enxofre (metionina e cisteína). Neste sentido, foi investigada sua reatividade com tiol-peroxidases detoxificadoras de peróxido, a peroxiredoxina 1 e 2 (Prx1 e Prx2). O HOOU apresentou cinética rápida de reação com a Prx1, k = 4,9 × 105 M-1s-1 e Prx2, k = 2,3 × 106 M-1s-1, o que as torna um provável alvo celular, além disso, foi capaz de oxidar a Prx2 de eritrócitos humanos, mostrando ser capaz de atravessar a membrana plasmática. Além das Prxs, a albumina do soro também desempenha papel importante na homeostase redox. O HOOU foi capaz de oxidar a albumina com constante de velocidade de 0,2 × 102 M-1s- 1. Outra tiol-proteína com importante função na homeostase e sinalização redox é a tioredoxina (Trx). A Trx foi oxidada pelo HOOU com constante de reação de 2,8 × 102 M-1s-1 e foi liberada juntamente com a Prx1 e Prx2 das células de macrófagos humanos (linhagem THP-1) quando estas células foram incubadas com HOOU. A liberação dessas proteínas é reconhecidamente um sinal de estresse celular. Assim o HOOU pode estar envolvido na exacerbação do estresse oxidativo em ambiente inflamatório. Quando neutrófilos (linhagem HL- 60) e macrófagos humanos (linhagem THP-1) foram incubados na presença de ácido úrico e Pseudomonas aeruginosa houve uma diminuição na produção de ácido hipocloroso (HOCl). Isto se deveu à competição entre ácido úrico e cloreto pela mieloperoxidase e resultou em menor atividade microbicida pelas células, demonstrando que a formação do HOOU não contribui e, ao contrário, prejudica a atividade microbicida das células inflamatórias. Dessa forma, a oxidação do ácido úrico e formação do hidroperóxido de urato tanto altera a atividade microbicida das células inflamtárias, quanto leva à oxidação de tiósproteínas importantes para manutenção da homeostase redox. Assim, o HOOU pode ser o responsável pelos efeitos pró-oxidantes e pró-inflamatórios do ácido úrico solúvel, e isso indica que o papel antioxidante do ácido úrico deve ser revisto em situações de inflamação.

Urate hydroperoxide (HOOU) is the product of the oxidation of uric acid by peroxidases. The formation of HOOU is favored during inflammation and in hyperuricemia, where there is plenty amount of uric acid, inflammatory peroxidases and superoxide. Therefore, the aim of the present study was to evaluate the effect of urate hydroperoxide on redox sensitive proteins in an inflammatory environment and another that mimics infection. In this thesis the chemical structure of the HOOU produced by photo-oxidation was compared to that obtained by myeloperoxidase catalysis. The chemical production of HOOU allowed a better purification of the compound. This oxidant was able to specifically react with sulfur containing amino acids (methionine and cysteine). In this sense, its reactivity with peroxiredoxins (Prx1 and Prx2) was investigated. HOOU reacted fast with Prx1 k = 4.9 × 105 M-1s-1 and Prx2 k = 2.3 × 106 M-1s-1. In addition, HOOU was able to oxidize Prx2 from intact erythrocytes at the same extend as does hydrogen peroxide. Albumin is an important thiol-containing protein to redox homeostasis in plasma. HOOU was able to oxidize albumin with a rate constant of 0.2 × 102 M-1s-1. Another protein with important function in redox homeostasis is thioredoxin (Trx). Trx was oxidized by HOOU with a rate constant of 2.8 × 102 M-1s-1 and was released together with Prx1 and Prx2 from human macrophages cells (THP-1 cell line) that were incubated with HOOU. The release of these proteins is a signal of cellular stress. Thus, HOOU may be involved in the exacerbation of oxidative stress in inflammatory environments. When neutrophil (HL-60 cell line) and macrophages (THP-1 cell line) were incubated with uric acid and Pseudomonas aeruginosa there was a decrease in hypochlorous acid (HOCl) production because of the competition between chloride and uric acid by myeloperoxidase. It decreased HOCl and impaired the microbicidal activity of the cells, showing that HOOU does not contribute in bacteria clearance. Therefore, the oxidation of uric acid to urate hydroperoxide impairs microbicidal activity and oxidizes thiol-proteins in inflammatory cells contributing to a pro-oxidant status. In this context, the antioxidant role of uric acid in inflammatory response should be reviwed.

Peroxiredoxin-3 Is Involved in Bactericidal Activity through the Regulation of Mitochondrial Reactive Oxygen Species

Peroxiredoxin-3 (Prdx3) is a mitochondrial protein of the thioredoxin family of antioxidant peroxidases and is the principal peroxidase responsible for metabolizing mitochondrial hydrogen peroxide. Recent reports have shown that mitochondrial reactive oxygen species (mROS) contribute to macrophage-mediated bactericidal activity in response to Toll-like receptors. Herein, we investigated the functional effect of Prdx3 in bactericidal activity. The mitochondrial localization of Prdx3 in HEK293T cells was confirmed by cell fractionation and confocal microscopy analyses. To investigate the functional role of Prdx3 in bactericidal activity, Prdx3-knockdown (Prdx3(KD)) THP-1 cells were generated. The mROS levels in Prdx3(KD) THP-1 cells were significantly higher than those in control THP-1 cells. Moreover, the mROS levels were markedly increased in response to lipopolysaccharide. Notably, the Salmonella enterica serovar Typhimurium infection assay revealed that the Prdx3(KD) THP-1 cells were significantly resistant to S. Typhimurium infection, as compared with control THP-1 cells. Taken together, these results indicate that Prdx3 is functionally important in bactericidal activity through the regulation of mROS.

Downregulation of Reactive Oxygen Species in Apoptosis

Generation of reactive oxygen species (ROS) by diverse anti-cancer drugs or phytochemicals has been closely related with the induction of apoptosis in cancers. Also, the downregulation of ROS by these chemicals has been found to block initiation of carcinogenesis. Therefore, modulation of ROS by phytochemicals emerges as a crucial mechanism to regulate apoptosis in cancer prevention or therapy. This review summarizes the current understanding of the selected chemical compounds and related cellular components that modulate ROS during apoptotic process. Metformin, quercetin, curcumin, vitamin C, and other compounds have been shown to downregulate ROS in the cellular apoptotic process, and some of them even induce apoptosis in cancer cells. The cellular components mediating the downregulation of ROS include nuclear factor erythroid 2-related factor 2 antioxidant signaling pathway, thioredoxin, catalase, glutathione, heme oxygenase-1, and uncoupling proteins. The present review provides information on the relationship between these compounds and the cellular components in modulating ROS in apoptotic cancer cells.

A expressão dos genes codificantes da proteína de interação com tiorredoxina, da beta 2 microglobulina e do transportador de tiamina 1, correlaciona-se com marcadores clínicos da doença renal em pacientes com diabetes tipo 1 / The expression of the genes encoding thioredoxin interacting protein, beta 2 microglobulin and thiamine transporter 1, correlates with clinical markers of renal disease in type 1 diabetes patients

A nefropatia diabética (ND) é uma das principais causas de doença renal terminal. Além da lesão glomerular, o compartimento tubulointersticial é afetado no desenvolvimento da ND, não somente pela proteinúria como pelos efeitos pró-inflamatórios, profibróticos, pró-oxidantes e angiogênicos da hiperglicemia e dos produtos finais de glicação avançada (AGEs). Sabese que as concentrações de marcadores do estresse oxidativo estão aumentadas em pacientes com diabetes mellitus (DM). O sistema tiorredoxina (TXN) é um dos principais sistemas antioxidantes endógenos. A TXN é capaz de interagir com um grande número de fatores de transcrição e proteínas, tal como a Thioredoxin interacting protein (TXNIP) que tem sido reconhecida na patogênese do DM e de suas complicações. Além da TXNIP, a deficiência de tiamina, ou vitamina B1, já foi relatada em modelos experimentais de DM, concomitantemente a um aumento de seu clearance renal. Os transportadores de tiamina 1 (THTR1) e 2 (THTR2) (codificados pelos genes SLC19A2 e SLC19A3, respectivamente) são os responsáveis pela reabsorção de tiamina no túbulo proximal após sua filtração pelo glomérulo. Estudos já demonstraram que a excreção aumentada de tiamina pode ser um fator de risco para o declínio precoce da função renal em pacientes DM. Uma outra proteína de interesse é a beta 2 microglobulina (B2M), expressa em situações que cursam com inflamação, um fenômeno bem caracterizado na tubulopatia diabética. O estudo da ativação intrarenal de vias potencialmente associadas à evolução da ND em humanos é dificultada pela necessidade de biópsia renal. Recentemente o sedimento urinário tem sido utilizado na avaliação das doenças renais, tanto na tentativa de identificar biomarcadores que possam predizer o declínio da função renal, como para o melhor entendimento da patogênese dessa complicação. O objetivo deste trabalho foi estudar a participação dos genesalvo TXNIP, TXN, SLC19A2, SLC19A3 e B2M na patogênese da ND...

Diabetic nephropathy (DN) is a major cause of end stage renal disease. Glomerular and tubulointerstitial compartments are affected not only by proteinuria but also by the pro-inflammatory, profibrotic, pro-oxidants and pro-angiogenic effects exerted by hyperglycemia and advanced glycation end products (AGEs) in the development of DN. It is well known that concentrations of oxidative stress markers are increased in patients with diabetes mellitus (DM). The thioredoxin system (TXN) is one of the majors endogenous antioxidant systems; TXN molecule is able to interact with a large number of transcription factors and proteins such as Thioredoxin interacting protein (TXNIP), which has been recognized in the pathogenesis of DM and its complications. Deficiency of thiamine, or B1 vitamin, has been reported in experimental models of DM concomitantly with an increase in its renal clearance. Thiamine transporter 1 (THTR1), encoded by the SLC19A2 gene and Thiamine transporter 2 (THTR2), encoded by the SLC19A3 gene are responsible for thiamine reabsorption in the proximal tubule after glomerular filtration. Studies have shown that increased urinary excretion of thiamine may be a risk predictor for an early decline in kidney function in diabetic patients. Another protein of interest is beta-2-microglobulin (B2M), expressed in situations of inflammation, a well-characterized phenomenon in diabetic tubulopathy. The study of activation or inactivation of intrarenal pathways potentially associated with progression of DN in humans is complicated by the need for renal biopsy. Recently urinary sediment has been used in the evaluation of kidney diseases in an attempt to identify biomarkers that can predict kidney function decline and as a tool for a better understanding of the pathogenesis of this complication. The objective of this work was to study the participation of the target genes TXNIP, TXN, SLC19A2, SLC19A3 and B2M in the pathogenesis of DN in type 1 DM (T1D)...

Construction of novel thioredoxin fusion protein expression system and the production of recombinant Lf-CATH2 / 生物工程学报

The objective of this study was to construct an improved thioredoxin fusion protein expression system, and express the cathelicidin-derived peptide, Lf-CATH2. The improved fusion vector Lf-CATH2-pET32α(-TS) was successfully constructed by firstly deleting the thrombin site and S tag from the pET-32α vector, then inserting the Lf-CATH2 plus a thrombin site instead. Afterwards, Lf-CATH2 was expressed in Escherichia coli as fusion protein. After the cleavage by thrombin, Lf-CATH2 was released and subsequently separated using affinity chromatography. The antimicrobial activity of purified Lf-CATH2 was also examined. The improved expression vector significantly increased enzyme cleavage efficiency by 37%, and Lf-CATH2 could be expressed in high yield and maintain the biological activity. This novel thioredoxin fusion protein expression system enables a quick production of high-yield bioactive cationic peptides like cathelicidins.

Astragalus polysaccharides improved the cardiac function in Sjögren's syndrome model rats based on keap 1-Nrf2/ARE signaling pathway: a mechanism exploration / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the mechanism of Astragalus polysaccharides (APS) for improving the cardiac function of Sjogren's syndrome (SS) model rats based on Keapl-Nrf2/ARE signaling pathway.</p><p><b>METHODS</b>Totally 48 male Wistar rats were randomly divided into four groups by random digit table, i.e., the blank control group,the model control group,the APS group, and the hydroxychloroquine group, 12 in each group. Except those in the blank control group, 0. 1 mL mixed antigen protein of sufficiently emulsified Freund's complete adjuvant and submandibular gland protein was injected from two feet plantar to induce SS model. The intervention was started from 19th day after inflammation induction. Equal volume of normal saline was given to rats in the blank control group (1 mL/100 g), APS was administered to those in the APS group (1 mg/100 g), and hydroxychloroquine (0.03 125 g/kg) was administered to those in the hydroxychloroquine group. All rats were intervened once per day for 30 consecutive days. Changes of rats' body mass and drinking water quantity, submandibular gland index, spleen index, histological changes of glands were observed. Changes of the heart function were monitored using invasive hemodynamics. Serum reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAC), tumor necrosis factor alpha (TNF-alpha), and interleukin-35 (IL-35)were detected using ELISA method. The pathological changes were observed using HE staining. The protein expression of ROS, reactive nitrogen species (RNS), glutathione (GSH), and thioredoxin (TRX) were observed by immunohistochemical staining. The mRNA expression of Keap1, Nrf2, and ARE was detected using real time fluorescent quantitative PCR. The protein expression levels of gamma-glutamic acid and a half long glycine synthetase (gamma-GCS) and heme oxygenase 1 (HO-1) in the myocardial tissue were determined by Western blot method. Results Compared with the blank control group, the quantity of drinking water, submandibular gland index, spleen index, heart rate (HR), cardiac index (HI), left ventricular systolic pressure (LVSP), left ventricular diastolic pressure (LVEDP), MDA, ROS, TNF-alpha, ROS protein expression, RNS protein expression, Keap 1 mRNA expression, Maf mRNA expression, Nfr2 mRNA expression, and HO-1 protein expression, and gamma-GCS protein expression significantly increased (P <0.01); body mass, +/-dp/dtmax, SOD, TAC, IL-35, GSH, and TRX significantly decreased (P <0.01) in the model group. Compared with the model group, the quantity of drinking water, submandibular gland index, spleen index, LVEDP, MDA, ROS, TNF-alpha, ROS protein expression, RNS protein expression, Keap1 mRNA expression, Maf mRNA expression, Nfr2 mRNA expression, and HO-1 protein expression, and gamma-GCS protein expression significantly decreased (P<0.05); body mass, +/-dp/dtmax, SOD, TAC, IL-35, GSH protein expression, and TRX protein expression significantly increased (P < 0.05, P <0.01) in the AR group and the hydroxychloroquine group. In the hydroxychloroquine group HR increased (P <0.05). In the AR group HR and LVSP decreased (P <0. 05, P <0. 01). Compared with the hydroxychloroquine group, HR, LVEDP, - dp/dtmax, y-GCS protein expression significantly decreased (P <0. 05, P <0. 01); SOD, TAC, GSH, TRX, HO-1 protein expression increased (P <0.01 )in the AR group. HI was positively correlated with ROS (P <0. 05). LVSP and LVEDP were positively correlated with Keap1 -Nrf2/ARE signaling pathways (P <0. 01) , and negatively correlated with TAC (P <0. 05, P <0. 01 ). +/-dp/dtmax was negatively correlated with Keap1-Nrf2/ARE signaling pathways(P <0.05), and positively correlated with TNF alpha (P <0. 05).</p><p><b>CONCLUSIONS</b>Declined heart function exists in SS rats. The mechamechanism of APS for improving the heart function might be closely correlated with activating Keap1-Nrf2/ARE signaling pathway.</p>

Exogenous rhTRX reduces lipid accumulation under LPS-induced inflammation

Redox-regulating molecule, recombinant human thioredoxin (rhTRX) which shows anti-inflammatory, and anti-oxidative effects against lipopolysaccharide (LPS)-stimulated inflammation and regulate protein expression levels. LPS-induced reactive oxygen intermediates (ROI) and NO production were inhibited by exogenous rhTRX. We identified up/downregulated intracellular proteins under the LPS-treated condition in exogenous rhTRX-treated A375 cells compared with non-LPS-treated cells via 2-DE proteomic analysis. Also, we quantitatively measured cytokines of in vivo mouse inflammation models using cytometry bead array. Exogenous rhTRX inhibited LPS-stimulated production of ROI and NO levels. TIP47 and ATP synthase may influence the inflammation-related lipid accumulation by affecting lipid metabolism. The modulation of skin redox environments during inflammation is most likely to prevent alterations in lipid metabolism through upregulation of TIP47 and ATP synthase and downregulation of inflammatory cytokines. Our results demonstrate that exogenous rhTRX has anti-inflammatory properties and intracellular regulatory activity in vivo and in vitro. Monitoring of LPS-stimulated pro-inflammatory conditions treated with rhTRX in A375 cells could be useful for diagnosis and follow-up of inflammation reduction related with candidate proteins. These results have a therapeutic role in skin inflammation therapy.

Expression of thioredoxin-2 for monitoring minimal residual disease in acute leukemia / 中南大学学报(医学版)

OBJECTIVE@#To investigate the significance of human thioredoxin-2 (TRX-2) in monitoring minimal residual disease (MRD) in acute leukemia (AL).@*METHODS@#We used real-time quantitative PCR to serially quantitize TRX-2 expression levels in the bone marrow of AL patients at diagnosis (n=68), at complete hematologic remission (CHR, n=57) and at relapse (n=25). Another 25 normal donors served as normal controls. The upper limit of the bone marrow at 91 was regarded as the reference. TRX-2 expression level at CHR with 91). TRX-2 level was correlated to the expression level of MRD.@*CONCLUSION@#TRX-2 may be the marker for AL and used in MRD monitoring.

Effect of adenovirus-mediated TXNIP overexpression on apoptosis and injury of H9C2 cardiomyocytes / 生理学报

Adenovirus transfection technique was used in the current study to show if thioredoxin-interacting protein (TXNIP) overexpression can induce cell apoptosis and injury in H9C2 cardiomyocytes cultured in normal glucose condition. And the mechanisms were then investigated. Briefly, H9C2 cardiomyocytes in logarithmic growth phase were randomly divided into three groups: normal cultured group, empty adenovirus vector group (Ad-eGFP) and TXNIP overexpression group (Ad-TXNIP-eGFP). All cells were cultured in DMEM containing normal concentration of glucose (5 mmol/L) and lipid. 72 h after adenovirus transfection, cells and culture mediums were collected for further assay. The results showed that Ad-eGFP and Ad-TXNIP-eGFP adenovirus transfected H9C2 cells successfully, and the transfection efficiency reached the peak at 72 h. Compared with Ad-eGFP group, Ad-TXNIP-eGFP transfection significantly increased TXNIP mRNA (P < 0.05) and protein expression level (P < 0.01). TXNIP overexpression induced remarkable cell apoptosis and injury as evidenced by increased caspase-3 activity (P < 0.05), apoptotic rate (P < 0.01) and LDH activity (P < 0.01). To further analysis the mechanisms of TXNIP-induced cell apoptosis, we also determined Trx activity, Trx related free radical injury and p38 kinase activation, which are involved in free radical induced apoptosis. The results showed that, compared with those in Ad-eGFP group, Trx activity was significantly decreased (P < 0.01), while malondialdehyde (MDA), 3-nitrotyrosine contents and p38 kinase activity were significantly increased (P < 0.01) in TXNIP overexpression group. These results suggest that TXNIP overexpression alone can induce severe apoptosis and injury in H9C2 cardiomyocytes even they are cultured in normal glucose and lipid concentration conditions. The mechanism involved is that overexpressed TXNIP can bind and inhibit Trx, impairs its antioxidative and antiapoptotic function, and then increases free radical induced injury and p38 kinase dependent apoptosis.

Studies on In Vivo Function of Peroxiredoxins in Knockout Mice / 한양의대학술지

Peroxiredoxins (Prxs) are a family of antioxidant proteins that reduce peroxide levels by using reducing agents such as thioredoxin. These proteins were characterized to have a number of cellular functions, including cell proliferation and differentiation and protection of specific proteins from oxidative damage. Thus, it is important to clarify the physiological role of Prxs by generating mouse models deficient in each Prx to better understand the in vivo function of Prxs. We have generated and characterized mice deficient in Prx I and II that are abundantly expressed in almost all types of cells. The Prx II-/- mice were healthy in appearance and fertile, however showed several pathophysiological disorders. Using the mice, we found that Prx II is an essential antioxidant enzyme that prevents oxidative stress in erythropoiesis, protects against endotoxin-induced lethal shock, regulates platelet-derived growth factor signaling and angiogenesis, inhibits cellular senescence, preserves cognitive function against age-linked hippocampal oxidative damage and exacerbates tumorigenesis in a liver cancer mouse model. The Prx I-/- mice were also healthy in appearance and fertile like Prx II-/- mice. With the mice, we found that Prx I suppresses K-ras-driven lung tumorigenesis by opposing the redox-sensitive extracellular-signal-regulated kinase/cyclin D1 pathway and plays concerted action with sulfiredoxin in preventing against alcohol-induced oxidative injury in the mouse liver. The results obtained suggest that Prx I and II are essential antioxidant enzymes for maintaining redox homeostasis in mice.

Diagnosis and Management of Grain-Induced Asthma

Grain-induced asthma is a frequent occupational allergic disease mainly caused by inhalation of cereal flour or powder. The main professions affected are bakers, confectioners, pastry factory workers, millers, farmers, and cereal handlers. This disorder is usually due to an IgE-mediated allergic response to inhalation of cereal flour proteins. The major causative allergens of grain-related asthma are proteins derived from wheat, rye and barley flour, although baking additives, such as fungal alpha-amylase are also important. This review deals with the current diagnosis and treatment of grain-induced asthma, emphasizing the role of cereal allergens as molecular tools to enhance diagnosis and management of this disorder. Asthma-like symptoms caused by endotoxin exposure among grain workers are beyond the scope of this review. Progress is being made in the characterization of grain and bakery allergens, particularly cereal-derived allergens, as well as in the standardization of allergy tests. Salt-soluble proteins (albumins plus globulins), particularly members of the alpha-amylase/trypsin inhibitor family, thioredoxins, peroxidase, lipid transfer protein and other soluble enzymes show the strongest IgE reactivities in wheat flour. In addition, prolamins (not extractable by salt solutions) have also been claimed as potential allergens. However, the large variability of IgE-binding patterns of cereal proteins among patients with grain-induced asthma, together with the great differences in the concentrations of potential allergens observed in commercial cereal extracts used for diagnosis, highlight the necessity to standardize and improve the diagnostic tools. Removal from exposure to the offending agents is the cornerstone of the management of grain-induced asthma. The availability of purified allergens should be very helpful for a more refined diagnosis, and new immunomodulatory treatments, including allergen immunotherapy and biological drugs, should aid in the management of patients with this disorder.

Diagnosis and Management of Grain-Induced Asthma

Grain-induced asthma is a frequent occupational allergic disease mainly caused by inhalation of cereal flour or powder. The main professions affected are bakers, confectioners, pastry factory workers, millers, farmers, and cereal handlers. This disorder is usually due to an IgE-mediated allergic response to inhalation of cereal flour proteins. The major causative allergens of grain-related asthma are proteins derived from wheat, rye and barley flour, although baking additives, such as fungal alpha-amylase are also important. This review deals with the current diagnosis and treatment of grain-induced asthma, emphasizing the role of cereal allergens as molecular tools to enhance diagnosis and management of this disorder. Asthma-like symptoms caused by endotoxin exposure among grain workers are beyond the scope of this review. Progress is being made in the characterization of grain and bakery allergens, particularly cereal-derived allergens, as well as in the standardization of allergy tests. Salt-soluble proteins (albumins plus globulins), particularly members of the alpha-amylase/trypsin inhibitor family, thioredoxins, peroxidase, lipid transfer protein and other soluble enzymes show the strongest IgE reactivities in wheat flour. In addition, prolamins (not extractable by salt solutions) have also been claimed as potential allergens. However, the large variability of IgE-binding patterns of cereal proteins among patients with grain-induced asthma, together with the great differences in the concentrations of potential allergens observed in commercial cereal extracts used for diagnosis, highlight the necessity to standardize and improve the diagnostic tools. Removal from exposure to the offending agents is the cornerstone of the management of grain-induced asthma. The availability of purified allergens should be very helpful for a more refined diagnosis, and new immunomodulatory treatments, including allergen immunotherapy and biological drugs, should aid in the management of patients with this disorder.