The role of neutrophil extracellular trap in the diagnosis and treatment of complications after liver transplantation / 器官移植

Prevention and treatment of complications after liver transplantation play a significant role in maintaining liver graft function and improving clinical prognosis of the recipients. Neutrophil extracellular trap (NET) are fibrous net-like structures composed of DNA as the skeleton and histones and granular proteins released by activated neutrophils. Studies have shown that the activation of neutrophils and the release of NET in donor liver after liver transplantation are involved in the incidence of multiple liver transplantation-related complications including ischemia-reperfusion injury, acute rejection, acute liver failure and recurrence of hepatocellular carcinoma, etc. In this article, the effect of NET on the complications after liver transplantation was mainly assessed, and research progress on NET as a potential target for the prevention and treatment of complications after liver transplantation was reviewed, aiming to provide reference for the prevention and treatment of complications after liver transplantation, enhance clinical efficacy of liver transplantation and improve clinical prognosis of the recipients.

Pharmacokinetic properties and in vitro enzyme activities of TPGS-modified arginine deiminase cyclodextrin lipid nanoparticles / 中国药理学通报

Aim To investigate the pharmacokinetic properties and in vitro enzyme activities of D-a-to- copherol polyethylene glycol 1000 succinate-modified arginine deiminase cyclodextrin lipid nanoparticles (ACLN). Methods The diacetylmonooxime-thiosem- icarbazide colorimetric method was used to determine the ADI enzyme activity, and the double reciprocal plot method was used to determine the enzyme Michae- lis constants. After the rats were given intravenously free ADI and ACLN, rat plasma samples were taken at different time points to determine the activity of ADI, and the time-enzyme activity curve would be drawn and the pharmacokinetic data analyzed by DAS 2. 1. 1. Re¬sults The optimum temperature for ADI and ACLN was 37 °C and the optimum pH was 6. 5. The Km val¬ ues of free ADI and ACLN were 0. 87 and 0. 74 mmol • L"1, respectively. The Vmai values of free ADI and ACLN were 53.28, 62.50 fjimol • L"' • min"1, re-spectively. The V

Clinical relevance of autoantibodies targeting peptidylarginine deiminases 2 and 4 in rheumatoid arthritis / 中华检验医学杂志

Objective:To evaluate the clinical performance of anti-peptidylarginine deiminase 2 (PAD2) and anti-PAD4 antibodies combined testing in a Chinese rheumatoid arthritis (RA) cohort.Methods:A total of 148 RA inpatients and 35 patients with non-RA arthritis as controls (DC) were recruited from November, 2018 to November, 2019 in Peking University People′s Hospital. In addition, a total of 44 healthy controls (HC) who went to Peking University People′s Hospital for annual physical examination were collected from June 2019 to July 2019. The α-PAD2 and α-PAD4 level in clinical specimens were determined by ELISA. Statistical analysis was performed by the Mann-Whitney U test, the Kruskal-Wallis (KW) test, the χ 2 test or the Fisher′s Exact Test, as necessary. Correlation analysis were performed by logistic regression. Results:α-PAD2 and α-PAD4 were present in 26.4% (39/148) and 20.9% (31/148) patients with RA, 5.7% (2/35) and 5.7% DC (2/35) and 4.5% (2/44) and 2.3% HC (2/44), respectively. α-PAD4-positive RA patients displayed significantly longer disease duration compared to α-PAD4-negative RA patients (17.3±13.2 years vs 8.6±10.2 years, P<0.001). α-PAD4-positive RA patients showed a significantly higher incidence of interstitial lung disease (ILD) compared to those without α-PAD4 (54.8% vs 25.6%, P=0.002). No associations between α-PAD2 and ILD were found ( OR: 0.797, P=0.579). In contrast, significant associations between α-PAD4 and ILD were found ( OR: 3.521, P=0.002). In seropositive RA, α-PAD4 displayed a weak correlation with ILD ( OR: 2.324, P=0.046), but this association was greatly enhanced when combined with α-PAD2 [anti-PAD2 (-)] ( OR: 4.059, P=0.007). Conclusions:The findings delineate the clinical relevance of α-PAD2 and α-PAD4 in RA and suggest that the combined testing for α-PAD2 and α-PAD4 may provide additional diagnostic value to the current clinically available assays in RA, in particular in identifying patients at risk of RA-ILD.

Evaluation of peptidylarginine deiminase 4 and PADI4 polymorphisms in sepsis-induced acute kidney injury

SUMMARY BACKGROUND: The aim of this study is to evaluate the peptidylarginine deiminase 4 (PAD 4) concentration and PADI4 polymorphisms as predictors of acute kidney injury (AKI) development, the need for renal replacement therapy (RRT), and mortality in patients with septic shock. METHODS: We included all individuals aged ≥ 18 years, with a diagnosis of septic shock at ICU admission. Blood samples were taken within the first 24 hours of the patient's admission to determine serum PAD4 concentration and its PADI4 polymorphism (rs11203367) and (rs874881). Patients were monitored during their ICU stay and the development of SAKI was evaluated. Among the patients in whom SAKI developed, mortality and the need for RRT were also evaluated. RESULTS: There were 99 patients, 51.5% of whom developed SAKI and of these, 21.5% needed RRT and 80% died in the ICU. There was no difference between PAD4 concentration (p = 0.116) and its polymorphisms rs11203367 (p = 0.910) and rs874881 (p = 0.769) in patients in whom SAKI did or did not develop. However, PAD4 had a positive correlation with plasma urea concentration (r = 0.269 and p = 0.007) and creatinine (r = 0.284 and p = 0.004). The PAD4 concentration and PADI4 polymorphisms were also not associated with RRT and with mortality in patients with SAKI. CONCLUSION: PAD4 concentration and its polymorphisms were not associated with SAKI development, the need for RRT, or mortality in patients with septic shock. However, PAD4 concentrations were associated with creatinine and urea levels in these patients.

RESUMO OBJETIVO: Avaliar a concentração da peptidilarginina deiminase 4 (PAD4) e os polimorfismos de PADI4, como preditores de desenvolvimento de lesão renal aguda, necessidade de terapia renal substitutiva (TRS) e mortalidade em pacientes com choque séptico. MÉTODOS: Foram incluídos indivíduos com idade ≥18 anos, com diagnóstico de choque séptico na admissão na Unidade de Terapia Intensiva (UTI). Amostras de sangue foram coletadas nas primeiras 24 horas após a admissão do paciente para determinar a concentração sérica de PAD4 e seus polimorfismos PADI4 (rs11203367) e (rs874881). Os pacientes foram acompanhados durante a internação na UTI e tiveram avaliados desenvolvimento da lesão renal aguda séptica (Sepsis-induced acute kidney injury - Saki), necessidade TRS e mortalidade. RESULTADOS: Foram avaliados 99 pacientes; 51,5% desenvolveram Saki e, desses, 21,5% necessitaram de TRS e 80% morreram na UTI. Não houve diferença entre a concentração de PAD4 (p=0,116) e seus polimorfismos rs11203367 (p=0,910) e rs874881 (p=0,769) entre os pacientes. No entanto, o PAD4 apresentou correlação positiva com a concentração plasmática de ureia (r=0,269; p=0,007) e creatinina (r=0,284; p=0,004). A concentração de PAD4 e os polimorfismos da PADI4 também não foram associados à TRS e à mortalidade em pacientes com Saki. CONCLUSÕES: A concentração de PAD4 e seus polimorfismos não foram associados ao desenvolvimento de Saki, à necessidade de TRS ou à mortalidade em pacientes com choque séptico. No entanto, as concentrações de PAD4 foram associadas às concentrações de creatinina e ureia nesses pacientes.

Production of L-citrulline by a recombinant Corynebacterium crenatum SYPA 5-5 whole-cell biocatalyst / 生物工程学报

Arginine deiminase (ADI) was first high-efficient expressed in Corynebacterium crenatum SYPA 5-5. The ADI was purified by Ni-NTA affinity chromatography and SDS-PAGE analysis showed the molecular weight (MW) was 46.8 kDa. The optimal temperature and pH of ADI were 37 ℃ and 6.5 respectively. The Michaelis constant was 12.18 mmol/L and the maximum velocity was 0.36 μmol/(min·mL). Under optimal conditions, 300 g/L of arginine was transformed and the productivity reach 8 g/(L·h). The recombinant strain was cultivated in a 5-L fermentor and used for whole-cell transformation of 300 g/L arginine, under repeated-batch bioconversion, the cumulative production reached 1 900 g/L.

Posible papel de Porphyromonas gingivalis en el desarrollo de la artritis reumatoide / Possible role of Porphyromonas gingivalis in the develpment of rheumatoid arthritis

Varios estudios han sugerido una asociación entre la periodontitissevera, la prevalencia de la bacteria Porphyromonas gingivalis y el desarrollo de artritis reumatoide. Como fundamento de esta relación, se ha observado que esta bacteria secreta una enzima, peptidil-arginina deiminasa, que es capaz de citrulinar proteínas del hospedero y así favorecer una respuesta autoinmune. Sin embargo, debido a la heterogeneidad de diseños experimentales, selección de pacientes y valoración de los desenlaces, los resultados no han mostrado la reproducibilidad deseada. Asimismo, observaciones recientes apuntan a que la actividad enzimática podría ser generada por otras especies bacterianas, lo que hace más compleja su relación. Sin embargo, por otro lado, algunos estudios sugieren que el tratamiento periodontal puede limitar el desarrollo de la artritis reumatoide.

Various studies have suggested a link between severe periodontitis,the prevalence of Porphyromonas gingivalis, and the development ofrheumatoid arthritis. As evidence of this relationship, P. gingivalis hasbeen found to secrete an enzyme, peptidyl arginine deiminase, which isable to citrullinate host proteins and thus help activate an autoimmuneresponse. However, due to the heterogeneity of experimental designs,patient selection, and assessment of clinical outcomes, the results havenot shown the desired reproducibility. Furthermore, recent fi ndingsindicate that the enzymatic activity may be produced by other species ofbacteria, which suggests the relationship is more complex. However, anumber of studies have shown that periodontal treatment could inhibitthe development of rheumatoid arthritis.

Selective Isolation and Identification of Arginine Degrading Bacteria; the Optimized Arginine Deaminase Production by Enterobacter sp. sgn1 as a New Source of This Potentially Anti-Tumor Enzyme.

Since certain tumor cells are auxotrophic for arginine, depletion of the extracellular arginine by means of arginine degrading enzymes might be exploited to target such tumors. Among the arginine degrading enzymes, arginine deaminase has attracted more attention as a potential anti-cancer agent for arginine–auxotrophic tumors. In order to find some new sources for arginine degrading enzymes, this study was designed to screen bacterial species, applying a simple and convenient procedure, using a selective medium and Nessler’s reagent test. The characterization of the isolated samples was carried out using 16S ribosomal DNA gene sequence analysis, which were further identified as Enterobacter sp., Bacillus sp., Erwinia sp., Oceanomonas sp., Acinetobacter sp., Cronobacter sp. Enterobacter sp. sgn1 was further studied as the arginine deiminase producing bacteria, by investigating the effect of some factors on enzyme production (using Minitab software and measuring the amount of citrulline as the product of ADI enzyme). According to our results; the arginine deiminase production and activity of Enterobacter sp. sgn1 were affected by: temperature, the concentration of glucose and Mg+ ion. Moreover, the phylogenetic tree was constructed using Mega 6 software and it was observed that among the isolated species, Bacillus species are very close to Mycoplasma arginini.

Relation Analysis of Synovial Anti-Citrullinated Epitope Peptide Expression and Peptidyl Arginine Deiminase 4 Gene in the Rheumatoid Arthritis Patient / 现代检验医学杂志

Objective To investigate the relation of synovial anti-citrullinated epitope peptide(CCP)expression and peptidyl arginine deiminase 4 (PADI4)gene in the rheumatoid arthritis patient.Methods From February 2013 to 2015 in Dongfeng General Hospital Affiliated to Hubei University,selected 110 patients with rheumatoid arthritis as the observation group, and selected 110 healthy people at the same period in this hospital for medical examination as the control group,both groups were given the synovial CCP expression positive rate and PADI4 gene expression detecting and correlation analysis.Results The synovial anti-CCP expression positive rates in the observation group and the control group were 70.9% and 9.1% re-spectively,and the observation group were significantly higher than the control group (P<0.05).The PADI4-104 genotype expression frequency compared between the observation group and control group,the difference were statistically significant (P<0.05).The G/G expression was more in the observation group,while the control group was more wit the C/G expres-sion.Pearson correlation analysis showed that in the observation group,synovial CCP positive expression were significant correlated to the expression of genotype PADI4-104 (r=0.344,P<0.05).Logistic regression analysis showed PADI4-104 genotype frequency were the main factors for the synovial CCP epitope expression (P<0.05).Conclusion The rheumatoid arthritis was more with synovial anti-CCP positive expression.There were also PADI4 polymorphism disorder expression, and clear correlation between the two.Thus impact the incidence of rheumatoid arthritis.

Peptidyl arginine deiminase 4 participates in the pathogenesis of rheumatoid arthritis by influencing histone methylation / 中华内科杂志

Objective To explore the probable function of peptidyl arginine deiminase 4 (PAD4) in rheumatoid arthritis(RA).Methods Real-time quantitative polymerase chain reaction (PCR) was used to determine the expression of PAD4 mRNA in peripheral blood mononucleated cells (PBMCs) from 60 RA patients and 40 healthy individuals.Asymmetric di-methylation of histone H3R17,symmetric di-methylation and mono-methylation of H4R3 were semi-quantified by Western blotting in 12 patients with osteoarthritis (OA),26 patients with RA and 10 healthy controls.Results PAD4 mRNA in RA was significantly higher than that in healthy controls [34.6 (16.7,70.8) vs 20.6 (11.1,51.8),P ＜ 0.05].The level of histone H3R17 asymmetric di-methylation in RA was significantly higher than that of OA or control groups(71.34 ±25.65 vs 37.18 ± 18.62 vs 50.67 ± 13.99,P ＜0.01),which was positively related to Tender joint count and Swollen joint count in 28 joints (r =0.418,P =0.034 ; r =0.402,P =0.042).The level of histone H4R3 symmetric di-methylation was similar in RA,OA and control groups (75.02 ± 20.35 vs 57.92 ± 22.77 vs 68.37 ± 17.57,P ＞ 0.05).The level of histone H4R3 mono-methylation in RA patients was significantly lower than that of OA patients and healthy individuals (11.24 ±7.81 vs 32.77 ±30.77 vs 51.20 ±47.14,P ＜ 0.05).The level of histone H4R3 mono-methylation in RA patients was negatively correlated to PAD4 (r =-0.643,P ＜ 0.01).The level of histone H3R17 asymmetric di-methylation and H4R3 symmetric di-methylation was not associated with PAD4 level in RA group (r =-0.185,P =0.377; r =0.198,P =0.344).Conclusions The level of histone H3R17 asymmetric di-methylation is significantly higher and the level of histone H4R3 mono-methylation is significantly lower in RA patients comparing with OA and control groups.Abnormality of histone methylation may be one of the mechanisms for the development of RA.PAD4 probably plays an important role in rheumatoid arthritis by influencing histone methylation.

Actividad y efectos de ureasa y arginina deiminasa en saliva y biopelícula oral humana / Activity and effects of urease and arginine deiminase in saliva and oral human biofilm

El objetivo de esta revisión es mostrar los hallazgos emergentes de las potenciales propiedades anticariogénicas de biomoléculas del metabolismo oral relacionados con la producción de amonio. El análisis de la literatura soporta una nueva dimensiónpreventiva en el conocimiento de la enfermedad caries dental al estudiar la evidencia in vitro publicada, en la que el amonio producido desde la urea y la arginina del ambiente oral presentan importantes factores endógenos inhibitorios del desarrollo de lesiones de caries dental. Este hecho apoyaría la hipótesis que la producción de amonio por urealisis y por el sistema de arginina deiminasa, podrían inhibirpotencialmente el desarrollo de la caries dental por la neutralización de ácidos y la estabilización de la microbiota oral, favoreciendo las condiciones para el mantenimiento de la salud oral. Esta revisión presenta estudios de la actividad enzimática oral, que puedeconstituir un prometedor campo para establecer nuevas líneas de investigación en cariología, particularmente in vivo e in situ, destinados a establecer la efectividad y aplicación clínica de estos compuestos en la prevención de caries dental.

The purpose of this review is to present the emerging findings on the potential anti-cariogenic properties of the bioactive molecules of oral metabolism related with ammonia production. The literature analysis supports a new preventive dimension in the knowledge of dental caries disease by studying the published evidence provided by in vitro and clinical studies, in which the ammonia produced from urea and arginine in the oral environment represents an important endogenous inhibitory factor in the development of dental caries lesions. This fact would support the hypothesis that ammonia production by urease and the arginine deiminase system could potentially inhibit the development of dental caries by neutralizing acids and stabilizing the oral microbiota, thus enhancing the conditions for oral healthmaintenance. This review presents studies on the oral enzyme activity which may constitute a promising field in the definition of new lines of research in cariology, particularly in vivo and in situ, aimed at establishing the effectiveness and clinical application of these compounds in the prevention of dental caries.

Study on the Expression, Purification and Activity of Arginine Deiminase / 中国生物工程杂志

Objective: To develop a high efficient expression, purification system of recombinant arginine deiminase(ADI).Methods: cDNA fragment encoding for mycoplasma ADI was obtained by artificial synthesis and was cloned into prokaryotic expression vector(pBV220). The recombinant ADI was generated by the transformation of the recombinant vector into the host strain DH5?. Anion exchange and gel filtration chromatography was carried out for purification of the recombinant ADI. The biological activity of final product was detected by the assay of agrinine degradation in vitro. Results: A prokaryotic expression plasmid pBV220-ADI was generated successfully, and was identified by DNA sequencing; the recombinant protein was highly expressed in DH5?, the proportion of the recombinant protein is exceeded 35% of the whole protein. The inclusion bodies were solubilized with 6mol/L guanidine hydrochloride under reducing conditions in order to avoid incorrect disulfide-bond formation of the recombinant ADI molecules. Dilution and dialysis at lower degrees temperature were the optimum renaturation methods. After gel filtration, the purity and specific activity of rADI reached 95% and 80 IU/mg respectively. Conclusions: A set of protocols for high efficient rADI expression and purification has been established, which is simple, efficient and applicable.

The Research of Enzymology Characterization about Arginine Deiminase from Enterococcus faecalis / 微生物学通报

Arginine Deiminase(ADI) was purified to homogeneity using ammonium sulfate precipitation,Q-Sepharose Fast Flow anion exchange chromatography and SephadexG-75 gel filtration chromatography. This purification protocol resulted in a 34.5-fold purification of ADI with 31.4% final yield. A molecular weight of about 190 kD determined by native gradient polyacrylamide gel electrophoresis. The enzyme has only one kind of 46 kD subunit determined by SDS-PAGE. Combining the results from the two kinds of electrophoresis,the authors deduce that the enzyme may be a tetramer. The optimum pH and temperature for lipolytic activity of ADI was pH 6.5 and 50℃,respectively. It was extremely stable at 45℃ and retained 97.9% of its original activity for 30 min. The stability declined rapidly as soon as the temperature rose over 50℃. ADI was highly stable in the pH range from pH 5-8. ADI acted on L-arginine but not on D-arginine. ADI catabolism was dependent on metal ions. At their adequate concentration,Mn2+,Mg2+ and Co2+ were the effective promoter,while superfluous Zn2+and Co2+ inhibited ADI activity. L-citrulline did not act on ADI,but L-ornithine inhibited ADI activity. The degradation of L-arginine with ADI catalysis was according to simple Michaelis-Menten equation. The Michaelis constant was 3.2686 mmol/L and the maxi-mum velocity was 2.44 ?mol/min.