Development of biosensors highly responsive to N-acetylneuraminic acid in Bacillus subtilis / 生物工程学报

Bacillus subtilis is recognized as a generally-regarded-as-safe strain, and has been widely used in the biosynthesis of high value-added products, including N-acetylneuraminic acid (NeuAc) which is widely used as a nutraceutical and a pharmaceutical intermediate. Biosensors responding to target products are widely used in dynamic regulation and high-throughput screening in metabolic engineering to improve the efficiency of biosynthesis. However, B. subtilis lacks biosensors that can efficiently respond to NeuAc. This study first tested and optimized the transport capacity of NeuAc transporters, and obtained a series of strains with different transport capacities for testing NeuAc-responsive biosensors. Subsequently, the binding site sequence of Bbr_NanR responding to NeuAc was inserted into different sites of the constitutive promoter of B. subtilis, and active hybrid promoters were obtained. Next, by introducing and optimizing the expression of Bbr_NanR in B. subtilis with NeuAc transport capacity, we obtained an NeuAc-responsive biosensor with wide dynamic range and higher activation fold. Among them, P535-N2 can sensitively respond to changes in intracellular NeuAc concentration, with the largest dynamic range (180-20 245) AU/OD. P566-N2 shows a 122-fold of activation, which is 2 times of the reported NeuAc-responsive biosensor in B. subtilis. The NeuAc-responsive biosensor developed in this study can be used to screen enzyme mutants and B. subtilis strains with high NeuAc production efficiency, providing an efficient and sensitive analysis and regulation tool for biosynthesis of NeuAc in B. subtilis.

Control of lupus activity during pregnancy via the engagement of IgG sialylation: novel crosstalk between IgG sialylation and pDC functions / 医学前沿

Immunoglobulin (IgG) glycosylation affects the effector functions of IgG in a myriad of biological processes and has been closely associated with numerous autoimmune diseases, including systemic lupus erythematosus (SLE), thus underlining the pathogenic role of glycosylation aberration in autoimmunity. This study aims to explore the relationship between IgG sialylation patterns and lupus pregnancy. Relative to that in serum samples from the control cohort, IgG sialylation level was aberrantly downregulated in serum samples from the SLE cohort at four stages (from preconception to the third trimester of pregnancy) and was significantly associated with lupus activity and fetal loss during lupus pregnancy. The type I interferon signature of pregnant patients with SLE was negatively correlated with the level of IgG sialylation. The lack of sialylation dampened the ability of IgG to suppress the functions of plasmacytoid dendritic cells (pDCs). RNA-seq analysis further revealed that the expression of genes associated with the spleen tyrosine kinase (SYK) signaling pathway significantly differed between IgG- and deSia-IgG-treated pDCs. This finding was confirmed by the attenuation of the ability to phosphorylate SYK and BLNK in deSia-IgG. Finally, the coculture of pDCs isolated from pregnant patients with SLE with IgG/deSia-IgG demonstrated the sialylation-dependent anti-inflammatory function of IgG. Our findings suggested that IgG influences lupus activity through regulating pDCs function via the modulation of the SYK pathway in a sialic acid-dependent manner.

Free sialic acid storage disorders with fetal hydrops in a neonate / 中国当代儿科杂志

A boy, aged 3 hours, was admitted due to a prenatal diagnosis of fetal hydrops at 3 hours after resuscitation for birth asphyxia. Prenatal examination at 5 months of gestation showed massive ascites in the fetus, and after birth, the boy had the manifestations of systemic hydroderma, massive ascites, coarse face, and hepatomegaly. Genetic testing revealed heterozygous mutations in the SLC17A5 gene, and there was a significant increase in urinary free sialic acid. Placental pathology showed extensive vacuolization in villous stromal cells, Hofbauer cells, cytotrophoblast cells, and syncytiotrophoblast cells in human placental chorionic villi. The boy was finally diagnosed with free sialic acid storage disorders (FSASDs). This is the first case of FSASDs with the initial symptom of fetal hydrops reported in China. The possibility of FSASDs should be considered for cases with non-immune hydrops fetalis, and examinations such as placental pathology and urinary free sialic acid may help with early diagnosis and clinical decision making.

Evaluations of antioxidant enzyme activities, total sialic acid and trace element levels in coronary artery bypass grafting patients

Abstract Introduction: In this study, patients before and after cardiac surgery with cardiopulmonary bypass (CPB) and control subjects were evaluated for erythrocyte glutathione peroxidase, catalase and superoxide dismutase enzyme activities, in addition to glutathione, malondialdehyde, serum total sialic acid, lipid-bound sialic acid, total antioxidant status, trace elements and mineral levels. The correlation of these variables with coronary artery disease (CAD) was also assessed. Methods: A total of 30 CAD patients and 30 control subjects were included in the study. CAD patients were divided into three groups: before surgery (BS), first day after surgery (1st day AS) and seventh day after surgery (7th day AS). Results: Malondialdehyde (MDA) and total sialic acid (TSA) levels were significantly higher in CAD (BS) than in the control group (P<0.05, P<0.05). In addition, GSH and TAS levels were significantly lower in the 1st day AS group than in the control group (P<0.001, P<0.01). Moreover, Co, Cu, Mg, Se, V and Zn levels were significantly lower in CAD (BS) group than in the control group (P<0.01, P<0.01, P<0.01, P<0.01, P<0.05, P<0.001). Conclusions: It was concluded that the levels of LDL-C, total cholesterol, triglycerides and CRP significantly associated with parameters, as well as Cu, Ca and SOD activity, should be measured together to monitor CAD. It is also considered that measuring TSA and MDA might be an appropriate choice for biomarkers of CAD.

Uso do gérmen de milho desengordurado, com e sem adição de um complexo enzimático, em dietas para cães / [Use of defatted corngerm with and without the addition of an enzyme complex in dog diets]

Objetivou-se avaliar o coeficiente de digestibilidade aparente (CDA) dos nutrientes, a palatabilidade das dietas e as características fecais de cães alimentados com uma dieta controle e uma dieta contendo 20% de gérmen desengordurado (GD), com e sem adição de complexo enzimático (amilase, xilanase, betaglucanase e mananase). Para o experimento de digestibidade e das características fecais, foram utilizados 12 cães adultos, distribuídos em delineamento em blocos ao acaso, em esquema fatorial 2 x 2 (dieta x enzima). O segundo experimento avaliou a palatabilidade, por meio da primeira escolha e da razão de ingestão (RI) da dieta DC vs. 20% de GD, utilizando-se 16 cães. O teste de palatabilidade contou com três dias consecutivos, totalizando 48 repetições. A dieta com inclusão de 20% de GD teve os menores valores de CDA da MS, da EB e da EM (P<0,05). A inclusão do complexo enzimático melhorou o CDA da MS, da EB e da EM (P<0,05). Não foram observadas diferenças nas características fecais (P>0,05). Em relação à palatabilidade, os cães preferiram a dieta 20% de GD, tanto na primeira escolha como na RI (P<0,05). A inclusão de enzimas às dietas melhora a digestibilidade dos nutrientes e da EM, sendo um aditivo com potencial uso na alimentação de cães.(AU)

The objective was to evaluate the apparent digestibility coefficient (ADC) of nutrients, diet palatability and fecal characteristics of dogs fed diets containing degreased germ (DG), and a control diet (DC) - both with and without the addition of enzyme complex (amylase, xylanase, betaglucanase and mananase). For the digestibility and fecal characteristics experiment 12 adult dogs were used, distributed in a randomized block design, in a 2 x 2 factorial scheme (diet x enzyme). The second experiment evaluated palatability using the first choice and ingestion ratio (IR) of DC diet vs. 20%gD, using 16 dogs. The palatability test had three consecutive days, totaling 48 repetitions. The diet with inclusion of 20% DG had the lowest ADC values of DM, GE and ME (P <0.05). Inclusion of the enzyme complex improved ADC of DM, GE and ME (P <0.05). No differences in fecal characteristics were observed (P >0.05). Regarding palatability, dogs preferred the 20% DG diet in both first choice and IR (P <0.05). Inclusion of enzymes in diets improves nutrient digestibility and ME, being an additive with potential use in dog food.(AU)

Sialic acid-binding immunoglobulin-like lectin 9 as a potential therapeutic target for chronic obstructive pulmonary disease / 中华医学杂志(英文版)

Chronic obstructive pulmonary disease (COPD) has become the third-leading cause of death worldwide, which is a severe economic burden to the healthcare system. Chronic bronchitis is the most common condition that contributes to COPD, both locally and systemically. Neutrophilic inflammation predominates in the COPD airway wall and lumen. Logically, repression of neutrophilia is an essential fashion to COPD treatment. However, currently available anti-neutrophilic therapies provide little benefit in COPD patients and may have serious side effects. Thus, there is an urgent need to explore an effective and safe anti-neutrophilic approach that might delay progression of the disease. Sialic acid-binding immunoglobulin-like lectin (Siglec)-9 is a member of the Siglec cell surface immunoglobulin family. It is noteworthy that Siglec-9 is highly expressed on human neutrophils and monocytes. Ligation of Siglec-9 by chemical compounds or synthetic ligands induced apoptosis and autophagic-like cell death in human neutrophils. Furthermore, administration of antibody to Siglec-E, mouse functional ortholog of Siglec-9, restrained recruitment and activation of neutrophils in mouse models of airway inflammation in vivo. Given the critical role that neutrophils play in chronic bronchitis and emphysema, targeting Siglec-9 could be beneficial for the treatment of COPD, asthma, fibrosis, and related chronic inflammatory lung diseases.

Acrylamide reduces plasma antioxidant vitamin levels in rats due to increased oxidative damage / Acrilamida reduz os níveis de vitamina antioxidante no plasma em ratos devido ao aumento do dano oxidativo

ABSTRACT Objective Acrylamide is a potentially neurotoxic and carcinogenic chemical and naturally creates during the heating process of carbohydrate-rich foods, such as potato chips and breakfast cereals. Acrylamide might be ingested by people via consuming food that contains it. Therefore, we investigated the effect of acrylamidegiven orally to male and female rats on plasma retinoic acid and α-tocopherol and serum sialic acid and malondialdehyde levels. Method A total of 50 Wistar rats were used (25 female and 25 male, three-four weeks old). The rats of each sex were given 2 and 5mg/kg/day acrylamide via drinking water for 90 days. At the end of the treatment, the animals were euthanized by cervical dislocation. Blood specimens were collected through cardiac puncture, and serum and plasma samples were analysed using the high-performance liquid chromatography technique with a Ultraviolet detector. Results The analysis of the plasma and serum samples revealed that serum sialic acid and malondialdehyde levels in both sexes given 5mg/kg/day acrylamide were significantly increased, and the serum sialic acid levels were higher in female rats given 2mg/kg/day acrylamide. The plasma retinoic acid and α-tocopherol levels significantly decreased in both sexes given only the highest dose. Conclusion The results show that acrylamide causes an increase in oxidative stress and leads to a decrease in the levels of retinoic acid and α-tocopherol which play a role in the defense mechanism against this stress.

RESUMO Objetivo A acrilamida é um químico potencialmente neurotóxico e carcinogênico, sendo naturalmente criada durante o processo de aquecimento de alimentos ricos em carboidratos, como batatas fritas e cereais matinais. Dado que o composto pode ser ingerido através do consumo de alimentos, o presente trabalho teve por objetivo investigar o seu efeito, quando administrado oralmente a ratos, medindo-se os níveis plasmáticos de ácido retinoico e α-tocoferol, bem como os níveis séricos de ácido siálico e malondialdeído Métodos Foram utilizados cinquenta ratos Wistar, sendo metade de cada sexo, com idade entre três e quatro semanas. Os animais foram divididos em dois grupos, os quais receberam diferentes doses diárias de acrilamida, via água potável, durante noventa dias: o primeiro ingeriu 2mg/kg/dia; e o segundo, 5mg/kg/dia. Ao final do tratamento, os animais foram eutanasiados por meio de luxação cervical. Amostras de sangue foram coletadas através de punção cardíaca, assim como amostras de soro e plasma foram medidas usando-se a técnica de cromatografia líquida de alta performance com detector de Ultravioleta. Resultados A análise das amostras de plasma e soro revelou que os níveis de ácido siálico e malondialdeído, em ratos de ambos os sexos tratados com acrilamida de 5mg/kg/dia, foram significativamente aumentados, ao passo que os níveis séricos de ácido siálico foram maiores em ratas tratadas com 2mg/kg/dia de acrilamida. Já os níveis plasmáticos de ácido retinoico e α-tocoferol diminuíram significativamente em ratos de ambos os sexos, quando tratados com a dose mais elevada.Concl Conclusão Os resultados mostram que a acrilamida causa um aumento no estresse oxidativo e leva a uma diminuição nos níveis de ácido retinoico e α-tocoferol, que desempenham um papel no mecanismo de defesa contra esse estresse.

Efecto de Trichinella spiralis y de Trichinella patagoniensis n.sp. sobre la desialización / Effect of Trichinella spiralis and Trichinella patagoniensis n.sp. on desialization

El ácido siálico tiene importantes funciones biológicas, muchas de las cuales determinan su participación en la respuesta inmune. El objetivo del trabajo fue comparar el efecto de Trichinella spiralis y Trichinella patagoniensis n.sp. sobre la desialización eritrocitaria. Se trabajó con 10 concentrados de larvas musculares de T. spiralis y 10 de T. patagoniensis de la misma concentración larval. Se realizó el tratamiento incubando el sedimento de eritrocitos frescos con igual volumen de concentrado larval (37 ºC), tomando muestra a los 30, 60 y 90 minutos. Los controles fueron incubados de la misma forma con solución salina. Se aplicó el método de Titulación de la Agregación por Polibrene y se determinó el CexpST. Los resultados mostraron que el valor medio del CexpST en los eritrocitos tratados con T. spiralis fue significativamente menor que en los glóbulos tratados con T. patagoniensis, para todos los tiempos estudiados. El aumento del tiempo de tratamiento también disminuyó significativamente el valor medio del CexpST para las dos especies. Éste fue significativamente menor a los 90 minutos de incubación que a los 60 minutos y éstos a su vez menores que a los 30 minutos. Se concluye que T. spiralis provocó mayor desialización eritrocitaria que T. patagoniensis en las condiciones experimentales estudiadas.

Sialic acid has important biological functions, many of which determine its participation in the immune response. The objective of this paper was to compare the effect of Trichinella spiralis and Trichinella patagoniensis n.sp. on erythrocyte desialization. Work was performed on 10 larval concentrates of muscle larvae of T. spiralis and 10 of T. patagoniensis of the same larval concentration. The treatment was carried out incubating the sediment of fresh erythrocytes with an equal volume of larval concentrate (37 °C), taking samples at 30, 60 and 90 minutes. The controls were incubated in the same way treated with saline solution. Titration of aggregation by Polybrene Method was applied and the CexpST was determined. The results showed that the mean value of CexpST in erythrocytes with T. spiralis was significantly lower than in the globules treated with T. patagoniensis, for all the studied times. The increase in treatment time also significantly decreased the mean value of CexpST for the two species, being significantly lower at 90 minutes of incubation than at 60 minutes and these in turn lower than at 30 minutes. It is concluded that T. spiralis caused greater erythrocyte desialization than T. patagoniensis in the experimental conditions studied.

O ácido siálico tem importantes funções biológicas, muitas das quais determinam sua participação na resposta imune. O objetivo foi comparar o efeito de Trichinella spiralis e Trichinella patagoniensis n.sp. sobre a dessialização eritrocitária. Trabalhou-se com 10 concentrados de larvas musculares de T. spiralis e 10 de T. patagoniensis da mesma concentração larval. Realizou-se o tratamento incubando o sedimento de eritrócitos frescos com igual volume de concentrado larval (37 ºC), tomando amostra aos 30, 60 e 90 minutos. Os controles foram incubados da mesma forma com solução salina. Foi aplicado o método de Titulação da Agregação por Polibrene e se determinouo CexpST. Os resultados mostraram que o valor médio do CexpST nos eritrócitos Tratados com T. spiralis foi significativamente menor que nos glóbulos tratados com T. patagoniensis, para todos os tempos estudados. O aumento do tempo de tratamento também diminuiu significativamente o valor médio do CexpST para as duas espécies, sendo significativamente menor aos 90 minutos de incubação que aos 60 minutos e eles por sua vez menores que aos 30 minutos. Conclui-se que T. spiralis provocou maior dessialização eritrocitária que T. patagoniensis nas condições experimentais estudadas.

Neuraminidase Inhibitors from the Fruiting Body of Glaziella splendens

Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1–5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2–5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the IC₅₀ values of 30.9, 41.8, and 35.7 µM for 3 and 46.5, 50.4, and 29.9 µM for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.

Levels of Salivary Sialic Acid in Children with Autism Spectrum Disorder; Could It Be Related to Stereotypes and Hyperactivity?

OBJECTIVE: Sialic acid (Sia) is an essential nutrient for brain development, learning, memory and cognition and plays a role in neurodevelopment of infants. The aim of this study was to determine whether Sia levels are significantly associated with the autism spectrum disorder (ASD). METHODS: Forty-six ASD children and 30 typically developing children aged 3 to 10 years were included in the study. Behavioral symptoms in ASD children was assessed by the Autism Behavior Checklist (AuBC), the Childhood Autism Rating Scale, and the Aberrant Behavior Checklist (ABC). After the collection of saliva samples, the supernatant was separated. All the samples kept at −80°C until Sia analysis was done. RESULTS: Sia level was found to be significantly lower in the ASD group when compared to healthy controls (p = 0.013). There was no correlation between severity of ASD and salivary Sia levels. We found a negative correlation between AuBC scores and Sia levels and a negative correlation in both ABC Stereotypic Behavior and Hyperactivity/Noncompliance subscales with Sia levels in ASD group. CONCLUSION: The obtained data indicate that Sia levels could have an effect on autism-like behaviors, particularly on stereotypes and hyperactivity.

Desialización eritrocitaria por larvas recién nacidas de Trichinella spiralis incubadas in vitro / Erythrocyte desialylation by Trichinella spiralis newborn larvae incubated in vitro / Dessialização eritrocitária por larvas recém-nascidas da Trichinella spiralis incubadas in vitro

Trichinella spiralis es la especie que causa la mayoría de los casos de infección humana en todo el mundo. Se comunicó que el contacto de los eritrocitos con concentrados de larvas recién nacidas (LRN) no viables provoca la disminución de ácido siálico globular. El objetivo del trabajo fue estudiar la desialización eritrocitaria producida por LRN mantenidas en cultivo. Se realizaron 2 experiencias en las que se incubaron 80 larvas con 100 μL de eritrocitos en 1 mL de medio RPMI suplementado durante 1, 2, 3, 4 y 24 horas a 37 ºC. Se aplicó el Método de Titulación de la Agregación por Polibrene y se calculó Título, Score Total y CexpCASP en los eritrocitos control e incubados con LRN. Los resultados mostraron que en la primera y segunda hora la captación de ácido siálico fue moderada. A las 3 horas el título disminuyó significativamente en relación al del control y el CexpCASP (0,14±0,014) indicó la pérdida casi total de ácido siálico globular. Ambos valores se mantuvieron a las 4 y 24 horas. Al comparar con estudios similares realizados con larvas infectantes, se sugiere que, in vivo, las LRN captarían más rápidamente el ácido siálico que las larvas musculares.

Trichinella spiralis is the species that causes most human cases of infection in the world. It was reported that contact of erythrocytes with concentrates of non-viable newborn larvae (NL) causes the decrease in erythrocyte sialic acid. The objective was to study erythrocyte desialylation produced by NL maintained in culture. Two experiments were conducted, in which 80 larvae were incubated with 100 μL of erythrocytes in 1 mL of supplemented RPMI medium for 1, 2, 3, 4 and 24 hours at 37 ºC. Titration of Aggregation by Polybrene Method was used and Title, Total Score and CexpCASP were calculated in Control erythrocytes and erythrocytes incubated with NL. The results showed that the sialic acid capture was moderated in the first and second hour. At three hours of incubation, the Title decreased significantly in relation to Control and CexpCASP (0.14±0.014) indicated almost total loss of erythrocyte sialic acid. Both values were maintained at 4 and 24 hours. When compared to similar studies conducted with infective larvae, it is suggested that, in vivo, NL would capture sialic acid faster than muscle larvae.

Trichinella spiralis é a espécie que causa a maioria dos casos de infecção humana em todo o mundo. Comunicou-se que o contato dos eritrócitos com concentrados de larvas recém-nascidas (LRN), não viáveis, provoca a diminuição de ácido siálico globular. O objetivo do trabalho foi estudar a dessialização eritrocitária produzida por LRN mantidas em cultivo. Foram realizadas duas experiências nas quais se incubaram 80 larvas com 100 μL de eritrócitos em 1 mL de meio RPMI suplementado durante 1, 2, 3, 4 e 24 horas a 37 °C. Foi aplicado o Método de Titulação da Agregação por Polibreno e se calculou Título, Pontuação Total (ST) e CexpCASP nos eritrócitos. Os resultados mostraram que na primeira e segunda hora a captação de ácido siálico foi moderada. Às 3 horas o título diminuiu significativamente em relação ao do controle e o CexpCASP (0,14±0,014) indicou a perda quase total de ácido siálico globular. Ambos os valores se mantiveram às 4 e 24 horas. Ao comparar com estudos similares realizados com larvas infetantes, sugere-se que, in vivo, as LRN captariam mais rapidamente o ácido siálico que as larvas musculares.

Salivary interleukin 6 and sialic acid in periodontitis

Aim: Periodontitis is the major multi ­factorial chronic infectious oral diseases in dentate people. Sialic acid regulates innate immunity response that release cytokines. The study aimed to evaluate interleukin-6 levels in periodontittsis and its relation to clinical features, total sialic acid and its fraction and total proteins to clarify its role. Material and Methods: The study was observational case-control study, carried out in periodontology clinic, College of Dentistry / Erbil /Iraq. A total of 60 participants were recruited in this study, They were divided into three groups: control group represent systemically and periodontally healthy subjects, clinically, diagnosed dentate periodontitis group and partial edentulous group.The data was collected through interview questionnaire, clinical periodontal examination, and biochemical tests for salivary; IL-6.total sialic acid and its fraction, and salivary total proteins Statistical analysis was done by statistical Package for Social Sciences. Results: Statistical analysis showed a significant (P≤ 0.01) highest value of total sialic acid in periodontitis. While the highest value of IL-6 was in partial edentulous group. Old ages increased salivary IL-6 significantly. In periodontitis there was significantly association of IL-6 with probe pocket depth, mobility scores of teeth, protein bonund sialic acid and significant negative association with lipid bound sialic acid in precipitate. While in partial edentulous IL-6 associated significantly with gingival index and free sialic acid in precipitate and negatively with probe pocket depth. Conclusions: Salivary sialic acid and IL-6 are periodontitis biomarkers in dentate. Pleiotropic role of IL-6 can be diagnosed by sialic acid levels. It depends on age, (which affects number of teeth and salivary flow rate), and treatment conditions

Effect of fluoride on salivary immunoglobulins and sialic acid

Summary Objective: The aim of our study was to evaluate the effect of fluoride on salivary immunoglobulin and sialic acid levels in children with dental fluorosis and healthy teeth who live in places with high fluoride concentration in drinking water. Method: Fifty-one (51) healthy children between 6 and 12 years old with no caries were randomly selected from primary schools enrolled in the dental-care program operated by the Department of Pediatric Dentistry. The children were divided into two groups: group I comprised 26 children with dental fluorosis [Thylstrup-Fejerskov Dental Fluorosis Index (TFI) = 4] who lived in Isparta (2.7-2.8 ppm), and group II consisted of 25 children without dental fluorosis who were born in low-fluoride areas and had lived in Isparta for only the previous two years. Stimulated and unstimulated saliva were collected and analyzed for fluoride, salivary immunoglobulins and sialic acid levels. Results: Sialic acid level was correlated negatively with age. Levels of secretory immunoglobulin A (sIgA) and secretory immunoglobulin G (sIgG) were higher in children with dental fluorosis compared with those in group II, although these differences were not significant. Conclusion: Increased sIgA and sIgG levels may arrest the progression of caries in subjects with dental fluorosis. Given the risks of dental fluorosis, further studies of the effects of different fluoride levels in drinking water on salivary composition of children with mixed dentition are needed to confirm the results of our study and to provide data for comparison.

Anti-bacterial effects of enzymatically-isolated sialic acid from glycomacropeptide in a Helicobacter pylori-infected murine model

BACKGROUND/OBJECTIVES: Helicobacter pylori (H. pylori) colonization of the stomach mucosa and duodenum is the major cause of acute and chronic gastroduodenal pathology in humans. Efforts to find effective anti-bacterial strategies against H. pylori for the non-antibiotic control of H. pylori infection are urgently required. In this study, we used whey to prepare glycomacropeptide (GMP), from which sialic acid (G-SA) was enzymatically isolated. We investigated the anti-bacterial effects of G-SA against H. pylori in vitro and in an H. pylori-infected murine model. MATERIALS/METHODS: The anti-bacterial activity of G-SA was measured in vitro using the macrodilution method, and interleukin-8 (IL-8) production was measured in H. pylori and AGS cell co-cultures by ELISA. For in vivo study, G-SA 5 g/kg body weight (bw)/day and H. pylori were administered to mice three times over one week. After one week, G-SA 5 g/kg bw/day alone was administered every day for one week. Tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and IL-10 levels were measured by ELISA to determine the anti-inflammatory effects of G-SA. In addition, real-time PCR was performed to measure the genetic expression of cytotoxin-associated gene A (cagA). RESULTS: G-SA inhibited the growth of H. pylori and suppressed IL-8 production in H. pylori and in AGS cell co-cultures in vitro. In the in vivo assay, administration of G-SA reduced levels of IL-1β and IL-6 pro-inflammatory cytokines whereas IL-10 level increased. Also, G-SA suppressed the expression of cagA in the stomach of H. pylori-infected mice. CONCLUSION: G-SA possesses anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect in an experimental H. pylori-infected murine model. G-SA has potential as an alternative to antibiotics for the prevention of H. pylori infection and H. pylori-induced gastric disease prevention.

Captación de ácido siálico por larvas musculares de Trichinella spiralis durante incubación in vitro / Sialic acid capture by Trichinella spiralis muscle larvae during incubation in vitro / Captação de ácido siálico por larvas musculares de Trichinella spiralis durante a incubação in vitro

Se ha comunicado que los eritrocitos (GR) incubados in vitro con larvas infectantes (LM) de T. spiralis presentan mayor agregación que los GR Controles incubados con solución salina, lo que indica que el parásito capta el ácido siálico globular. El objetivo del trabajo fue estudiar la captación de ácido siálico por LM durante incubación in vitro. Se incubaron 30, 60, 90 y 180 larvas con 30 mL del sedimento de GR en 1 mL de solución salina durante 24 y 48 h (37 °C). Se aplicó el Método de Agregación por Polibrene y se calculó Tïtulo, Score Total y CexpCASP. Los resultados mostraron una disminución significativa de estos 3 valores en relación al Control, excepto en el cultivo con 30 LM donde solo se observó un descenso moderado del Score Total y CexpCASP. La captación fue máxima a las 24 h, sin diferencias con los valores obtenidos a las 48 h. Posteriormente se incubaron 60 LM durante 1, 2 y 3 h. Se observó que no hubo captación de ácido siálico en la primera hora de incubación y que fue moderada a las 3 h. La experiencia demostró la captación de ácido siálico globular por las LM in vitro, lo que sugiere que podrían secuestrarlo del miocito con el objeto de evadir y/o interferir la respuesta inmune a los fines de asegurar su permanencia en el hospedador.

It has been reported that erythrocytes (RBC) incubated with infective larvae of T. spiralis (ML) exhibit higher aggregation than Control RBC incubated with saline solution, indicating that the parasite captures erythrocyte sialic acid. The objective of this work was to study sialic acid capture by ML during in vitro incubation. A total of 30, 60, 90 and 180 larvae were incubated with 30 mL of GR sediment in 1 mL of saline solution for 24 to 48 hours (37 °C). Aggregation by Polybrene Method was used, and Titre, Total Score and CexpCASP were calculated. The results showed a significant decrease of these three values compared to Control except in the culture with 30 ML where only a moderate decrease of Total Score and CexpCASP were observed. The capture was maximal at 24 hours, with no difference with the values obtained at 48 hours. Then, 60 ML were incubated for 1, 2 and 3 hours. It was noted that ML did no capture sialic acid in the first hour of incubation and the capture was moderate at 3 hours. The experience showed globular sialic acid capture by ML in vitro, suggesting that they could sequester it from the myocyte in order to evade and/or interfere with the immune response for the purposes of assuring their permanence in the host.

Foi informado que os eritrócitos (GV) incubados in vitro com larvas infetantes (LM) da T. spiralis apresentam maior agregação que os GV Controles incubados com solução salina, indicando que o parasita capta o ácido siálico globular. O objetivo do trabalho foi estudar a captação de ácido siálico por LM durante a incubação in vitro. Foram incubadas 30 , 60 , 90 e 180 larvas com 30 μL do sedimento de GV em 1 mL de solução salina durante 24 a 48 horas (37 °C). Foi aplicado o Método de Agregação por Polibrene e se calculou o Título, Pontuação Total e CexpCASP. Os resultados mostraram uma diminuição significativa desses três valores em relação ao Controle, exceto na cultura com 30 LM, onde foi observada apenas uma redução moderada da Pontuação Total e CexpCASP. A captação foi máxima às 24 horas, sem diferença com os valores obtidos às 48 horas. Posteriormente 60 LM foram incubadas durante 1, 2 e 3 horas. Observou-se que não houve captação alguma de ácido siálico na primeira hora de incubação e que foi moderada às 3 horas. A experiência mostrou captação de ácido siálico globular pelas LM in vitro, sugerindo que poderiam sequestrá-lo do miócito visando a evadir e/ou interferir a resposta imune, para garantir sua permanência no hospedeiro.

Liraglutide in diabetes mellitus: more facts and findings

Liraglutide exert favorable effects on most of the diabetes associated cardiovascular [CV] risk factors and this study was designed to further explore the benefits of liraglutide by observing its effect on plasma sialic acid [PSA] in diabetic rats. A total of 30 streptozotocin induced [50mg/Kg; i. p] diabetic rats were randomized into vehicle treated [1 ml/Kg s.c, twice daily] group I, liraglutide treated groups II and III [30 micro g/Kg and 150 micro g/Kg, twice daily respectively] and studied for 6 weeks. Liraglutide treated groups showed significant reductions in fructosamine levels [p

Anti-Helicobacter pylori activity of crude N-acetylneuraminic acid isolated from glycomacropeptide of whey / 한국실험동물학회지

Helicobacter pylori colonizes the gastric mucosa of about half of the world's population, causing chronic gastritis and gastric cancer. An increasing emergence of antibiotic-resistant H. pylori arouses demand on alternative non-antibiotic-based therapies. In this study, we freshly prepared crude N-acetylneuraminic acid obtained from glycomacropeptide (G-NANA) of whey through a neuraminidase-mediated reaction and evaluated its antibacterial ability against H. pylori and H. felis. Overnight cultures of the H. pylori were diluted with fresh media and different concentrations (1-150 mg/mL) of crude G-NANA were added directly to the culture tube. Bacterial growth was evaluated by measuring the optical density of the culture medium and the number of viable bacteria was determined by a direct count of the colony forming units (CFU) on agar plates. For the in vivo study, mice were orally infected with 100 µL (5×108 cfu/mL) of H. felis four times at a day's interval, accompanied by a daily administration of crude G-NANA or vehicle. A day after the last infection, the mice were daily administered the crude G-NANA (0, 75, and 300 mg/mL) for 10 days and euthanized. Their stomachs were collected and bacterial colonization was determined by quantitative real-time PCR. Crude G-NANA inhibited H. pylori's growth and reduced the number of viable bacteria in a dose-dependent manner. Furthermore, crude G-NANA inhibited bacterial colonization in the mice. These results showed that crude G-NANA has antibacterial activity against Helicobacter and demonstrated its therapeutic potential for the prevention of chronic gastritis and gastric carcinogenesis induced by Helicobacter infection in humans.

Identification of Suitable Natural Inhibitor against Influenza A (H1N1) Neuraminidase Protein by Molecular Docking

The influenza A (H1N1) virus, also known as swine flu is a leading cause of morbidity and mortality since 2009. There is a need to explore novel anti-viral drugs for overcoming the epidemics. Traditionally, different plant extracts of garlic, ginger, kalmegh, ajwain, green tea, turmeric, menthe, tulsi, etc. have been used as hopeful source of prevention and treatment of human influenza. The H1N1 virus contains an important glycoprotein, known as neuraminidase (NA) that is mainly responsible for initiation of viral infection and is essential for the life cycle of H1N1. It is responsible for sialic acid cleavage from glycans of the infected cell. We employed amino acid sequence of H1N1 NA to predict the tertiary structure using Phyre2 server and validated using ProCheck, ProSA, ProQ, and ERRAT server. Further, the modelled structure was docked with thirteen natural compounds of plant origin using AutoDock4.2. Most of the natural compounds showed effective inhibitory activity against H1N1 NA in binding condition. This study also highlights interaction of these natural inhibitors with amino residues of NA protein. Furthermore, among 13 natural compounds, theaflavin, found in green tea, was observed to inhibit H1N1 NA proteins strongly supported by lowest docking energy. Hence, it may be of interest to consider theaflavin for further in vitro and in vivo evaluation.

Estudio de la cinética de captación de ácido siálico por larvas musculares de Trichinella spiralis / Study of kinetics of sialic acid capture by muscle larvae of Trichinella spiralis / Estudo da cinética de captaçao de ácido siálico por larvas musculares da Trichinella spiralis

Se ha comunicado que los eritrocitos (GR) incubados con larvas infectantes de Trichinella spiralis presentan mayor agregación que los GR Controles incubados con solución salina, lo cual indica que el parásito capta el ácido siálico globular. El objetivo fue estudiar la cinética de captación de ácido siálico por larvas musculares de T. spiralis aplicando Análisis Digital de Imágenes. Se trabajó con concentrados larvales de T. spiralis incubados en partes iguales con GR Grupo O, en medio salino y enzimático (GR Tratados), durante 120 minutos a intervalos de 15 minutos. Los Controles fueron incubados con igual volumen de solución salina. Se aplicó Análisis Digital de Imágenes y se calculó el valor del Coeficiente de células aisladas (CCA). Para analizar el efecto del tiempo de incubación en los valores de CCA, se utilizó un análisis de la variancia para un diseño en bloques completos aleatorizados. Los resultados mostraron que el valor promedio de CCA, en ambos medios, varió significativamente con el tiempo de incubación, lo que evidencia que el aumento del contacto de las larvas con los GR produce una disminución del ácido siálico que se refleja en mayores valores de CCA. La experiencia realizada sugeriría que durante su permanencia y viabilidad en el quiste, las larvas de T. spiralis podrían ir captando ácido siálico de la célula muscular con el objeto de interferiry /o evadir la respuesta inmune del hospedador...

Study of Serum Sialic Acid and Copper as Inflammatory Markers in Type 2 Diabetes Mellitus.

The study aims to understand the relationship between increased serum levels of acute- phase reactants like Sialic Acid (SA) and transitional metals like Copper (Cu) which are indicated to be associated with the etiology and pathogenesis of type 2 diabetes mellitus (DM) and its various chronic complications. Serum SA and Cu levels, measured colorimetrically using Ehrilch’s reagent and Atomic Absorption Spectrophotometer (AAS) respectively among 30 cases each of type 2 DM with and without long-term complications, were significantly higher in all the cases compared to controls. The values are even higher in cases with complications, compared to diabetics without complications. Serum lipid profile was significantly altered in both the experimental groups. Serum SA and Cu levels are positively correlated to duration and degree of impaired glycemic status and altered lipid profile in type 2 DM. Measurement of these new serum markers can explain the inflammatory process, implicated towards the development of diabetic complications like cardiovascular diseases and microangiopathies thereby helping in early medical intervention.