Metabolic engineering study on biosynthesis of 4-hydroxybenzyl alcohol from L-tyrosine in Escherichia coli / 中国中药杂志

As an important active ingredient in the rare Chinese herb Gastrodiae Rhizoma and also the main precursor for gastrodin biosynthesis, 4-hydroxybenzyl alcohol has multiple pharmacological activities such as anti-inflammation, anti-tumor, and anti-cerebral ischemia. The pharmaceutical products with 4-hydroxybenzyl alcohol as the main component have been increasingly favored. At present, 4-hydroxybenzyl alcohol is mainly obtained by natural extraction and chemical synthesis, both of which, however, exhibit some shortcomings that limit the long-term application of 4-hydroxybenzyl alcohol. The wild and cultivated Gastrodia elata resources are limited. The chemical synthesis requires many steps, long time, and harsh reaction conditions. Besides, the resulting by-products are massive and three reaction wastes are difficult to treat. Therefore, how to artificially prepare 4-hydroxybenzyl alcohol with high yield and purity has become an urgent problem facing the medical researchers. Guided by the theory of microbial metabolic engineering, this study employed the genetic engineering technologies to introduce three genes ThiH, pchF and pchC into Escherichia coli for synthesizing 4-hydroxybenzyl alcohol with L-tyrosine. And the fermentation conditions of engineering strain for producing 4-hydroxybenzyl alcohol in shake flask were also discussed. The experimental results showed that under the conditions of 0.5 mmol·L~(-1) IPTG, 15 ℃ induction temperature, and 40 ℃ transformation temperature, M9 Y medium containing 200 mg·L~(-1) L-tyrosine could be transformed into(69±5)mg·L~(-1) 4-hydroxybenzyl alcohol, which has laid a foundation for producing 4-hydroxybenzyl alcohol economically and efficiently by further expanding the fermentation scale in the future.

CD36 gene deletion reduces muscle insulin sensitivity in mice by up-regulating PTP1B expression / 南方医科大学学报

OBJECTIVE@#To investigate the effect CD36 deficiency on muscle insulin signaling in mice fed a normal-fat diet and explore the possible mechanism.@*METHODS@#Wild-type (WT) mice and systemic CD36 knockout (CD36-/-) mice with normal feeding for 14 weeks (n=12) were subjected to insulin tolerance test (ITT) after intraperitoneal injection with insulin (1 U/kg). Real-time PCR was used to detect the mRNA expressions of insulin receptor (IR), insulin receptor substrate 1/2 (IRS1/2) and protein tyrosine phosphatase 1B (PTP1B), and Western blotting was performed to detect the protein expressions of AKT, IR, IRS1/2 and PTP1B in the muscle tissues of the mice. Tyrosine phosphorylation of IR and IRS1 and histone acetylation of PTP1B promoter in muscle tissues were detected using co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP), respectively.@*RESULTS@#CD36-/- mice showed significantly lowered insulin sensitivity with obviously decreased area under the insulin tolerance curve in comparison with the WT mice (P < 0.05). CD36-/- mice also had significantly higher serum insulin concentration and HOMA-IR than WT mice (P < 0.05). Western blotting showed that the p-AKT/AKT ratio in the muscle tissues was significantly decreased in CD36-/- mice as compared with the WT mice (P < 0.01). No significant differences were found in mRNA and protein levels of IR, IRS1 and IRS2 in the muscle tissues between WT and CD36-/- mice (P>0.05). In the muscle tissue of CD36-/- mice, tyrosine phosphorylation levels of IR and IRS1 were significantly decreased (P < 0.05), and the mRNA and protein levels of PTP1B (P < 0.05) and histone acetylation level of PTP1B promoters (P < 0.01) were significantly increased as compared with those in the WT mice. Intraperitoneal injection of claramine, a PTP1B inhibitor, effectively improved the impairment of insulin sensitivity in CD36-/- mice.@*CONCLUSION@#CD36 is essential for maintaining muscle insulin sensitivity under physiological conditions, and CD36 gene deletion in mice causes impaired insulin sensitivity by up-regulating muscle PTP1B expression, which results in detyrosine phosphorylation of IR and IRS1.

Characterization of highly active tyrosine ammonia lyase and its application in biosynthesis of p-coumaric acid / 生物工程学报

p-coumaric acid is one of the aromatic compounds that are widely used in food, cosmetics and medicine due to its properties of antibacterium, antioxidation and cardiovascular disease prevention. Tyrosine ammonia-lyase (TAL) catalyzes the deamination of tyrosine to p-coumaric acid. However, the lack of highly active and specific tyrosine ammonia lyase limits cost-effective microbial production of p-coumaric acid. In order to improve biosynthesis efficiency of p-coumaric acid, two tyrosine ammonia-lyases, namely Fc-TAL2 derived from Flavobacterium columnare and Fs-TAL derived from Flavobacterium suncheonense, were selected and characterized. The optimum temperature (55 ℃) and pH (9.5) for Fs-TAL and Fc-TAL2 are the same. Under optimal conditions, the specific enzyme activity of Fs-TAL and Fc-TAL2 were 82.47 U/mg and 13.27 U/mg, respectively. Structural simulation and alignment analysis showed that the orientation of the phenolic hydroxyl group of the conserved Y50 residue on the inner lid loop and its distance to the substrate were the main reasons accounting for the higher activity of Fs-TAL than that of Fc-TAL2. The higher activity and specificity of Fs-TAL were further confirmed via whole-cell catalysis using recombinant Escherichia coli, which could convert 10 g/L tyrosine into 6.2 g/L p-coumaric acid with a yield of 67.9%. This study provides alternative tyrosine ammonia-lyases and may facilitate the microbial production of p-coumaric acid and its derivatives.

Azeliragon ameliorates Alzheimer's disease via the Janus tyrosine kinase and signal transducer and activator of transcription signaling pathway

OBJECTIVES: TTP488, an antagonist of the receptor for advanced glycation end-products, was evaluated as a potential treatment for patients with mild-to-moderate Alzheimer's disease (AD). However, the mechanism underlying the protective action of TTP488 against AD has not yet been fully explored. METHODS: Healthy male rats were exposed to aberrant amyloid β (Aβ) 1-42. Lipopolysaccharide (LPS) and the NOD-like receptor family pyrin domain containing 1 (NLRP1) overexpression lentivirus were injected to activate the NLRP1 inflammasome and exacerbate AD. TTP488 was administered to reverse AD injury. Finally, tofacitinib and fludarabine were used to inhibit the activity of Janus tyrosine kinase (JAK) and signal transducer and activator of transcription (STAT) to prove the relationship between the JAK/STAT signaling pathway and TTP488. RESULTS: LPS and NLRP1 overexpression significantly increased the NLRP1 levels, reduced neurological function, and aggravated neuronal damage, as demonstrated by the impact latency time of, time spent by, and length of the platform covered by, the mice in the Morris water maze assay, Nissl staining, and immunofluorescence staining in rats with AD. CONCLUSIONS: TTP488 administration successfully reduced AD injury and reversed the aforementioned processes. Additionally, tofacitinib and fludarabine administration could further reverse AD injury after the TTP488 intervention. These results suggest a new potential mechanism underlying the TTP488-mediated alleviation of AD injury.

Application of tyrosine phosphoproteomics in biomedical research: a review / 生物工程学报

The enrichment of tyrosine phosphorylation sites plays an important role in the study of tyrosine phosphoproteomics and the commonly used enrichment methods are antibody affinity enrichment and SH2 superbinder enrichment. In addition, in order to achieve large-scale identification of tyrosine phosphorylation sites, biological mass spectrometry and bioinformatics have been applied in tyrosine phosphoproteomics. In-depth coverage research of tyrosine phosphoproteomics, revealing the dysregulated kinases in cancer process, may help us understanding the occurrence and development process of cancer. According to literature reports, three quarters of the oncogenes are tyrosine kinase genes. Therefore, tyrosine kinase inhibitors have received more and more attention as anticancer drugs. The application of tyrosine phosphoproteomics technology can identify tyrosine kinases related to cancer and other major diseases, so as to help finding tyrosine kinase inhibitors. In short, tyrosine phosphoproteomics technology can be applied in biomedical fields such as tyrosine kinase identification, tyrosine kinase inhibitor research, and tyrosine phosphorylation signal pathway research.

Advances and application of enrichment technology in SH2 superbinder-based tyrosine phosphoproteomics / 生物工程学报

Tyrosine phosphorylation is one of the important protein phosphorylations in eukaryotes responsible for a variety of biological processes including cell signaling transduction, cell migration, and apoptosis. In the study of phosphoproteomics, due to the low stoichiometry of tyrosine phosphorylation (pTyr) proteins and sometimes limited initial sample, traditional phosphoproteomics enrichment technology is inefficient for the enrichment of pTyr peptides. Here, we review the substantial progress in tyrosine phosphoproteomics by preparation of limited amount sample and the newly introduced SH2 superbinder.

High-throughput screening of Saccharomyces cerevisiae efficiently producing tyrosine / 生物工程学报

Tyrosine is an important aromatic amino acid. Besides its nutritional value, tyrosine is also an important precursor for the synthesis of coumarins and flavonoids. Previously, our laboratory constructed a Saccharomyces cerevisiae strain LTH0 (ARO4K229L, ARO7G141S, Δaro10, Δzwf1, Δura3) where tyrosine feedback inhibition was released. In the present study, heterologous expression of betaxanthins synthesis genes DOD (from Mirabilis jalapa) and CYP76AD1 (from sugar beet B. vulgaris) in strain LTH0 enabled production of yellow fluorescence. The engineered strain LTH0-DOD-CYP76AD1 was subjected to UV combined with ARTP mutagenesis, followed by flow cytometry screening. Among the mutants screened, the fluorescence intensity of the mutant strain LTH2-5-DOD-CYP76AD1 at the excitation wavelength of 485 nm and emission wavelength of 505 nm was (5 941±435) AU/OD, which was 8.37 times higher than that of strain LTH0-DOD-CYP76AD1. Fourteen mutant strains were subjected to fermentation to evaluate their tyrosine producing ability. The highest extracellular tyrosine titer reached 26.8 mg/L, which was 3.96 times higher than that of strain LTH0-DOD-CYP76AD1. Heterologous expression of the tyrosine ammonia lyase FjTAL derived from Flavobacterium johnsoniae further increased the titer of coumaric acid to 119.8 mg/L, which was 1.02 times higher than that of the original strain LTH0-FjTAL.

Infecção por SARS-CoV-2 em paciente com agamaglobulinemia ligada ao X tratado com altas doses de imunoglobulina endovenosa e plasma de convalescente / SARS-CoV-2 infection in a patient with X-linked agammaglobulinemia treated with high doses of intravenous immunoglobulin and convalescent plasma

A pandemia pelo vírus SARS-CoV-2 atingiu adultos, crianças e penalizou indivíduos idosos e com comorbidades como diabetes, doença cardíaca, hipertensão e obesidade. A maioria dos infectados são assintomáticos ou têm sintomas leves, entretanto 15% podem apresentar pneumonia e 5% síndrome respiratória aguda grave. Apresentamos um caso de agamaglobulinemia ligada ao X (XLA) em paciente masculino de 27 anos que se infectou com SARS-CoV-2. Os pacientes com XLA não possuem linfócitos B e não produzem anticorpos devido a uma mutação no gene Bruton tirosino-quinase (BTK), responsável pela maturação dos linfócitos B. Ele infectou-se e foi internado em hospital de Ivoti/RS. A evolução da pneumonia foi rápida, necessitando transferência para o Hospital de Clínicas de Porto Alegre (HCPA) no 10° dia de evolução. Iniciou com infusão de imunoglobulinas, tendo utilizado o total de 400 gramas devido ao intenso catabolismo da IgG, mantendo-se sua concentração entre 700-900 mg/dL. Necessitou de ventilação mecânica, oxigenação por membrana extracorpórea (ECMO) e hemodiálise. Foi administrado plasma de convalescente (PC), 300 mL, por duas vezes, com melhora clínico-radiológica e retirada da ventilação mecânica. Piorou e repetiu outras 4 infusões de PC (total de 1717 mL), negativando o vírus na orofaringe (RT-PCR). Em 3 ocasiões teve sepse, debelada rapidamente. Apresentou anemia, com necessidade de transfusão frequente. Identificou-se linfopenia de CD3, CD4, CD8, NK e ausência de linfócitos B. A linfopenia foi revertida com a recuperação clínica e a alta hospitalar aconteceu no 70° dia de internação.

The SARS-CoV-2 pandemic has affected adults and children and penalized older people and those with comorbidities such as diabetes, heart disease, hypertension and obesity. Most of those infected are asymptomatic or have mild symptoms, but 15% may have pneumonia and 5% acute respiratory distress syndrome. We report a case of X-linked agammaglobulinemia (XLA) in a 27-yearold man who was infected with SARS-CoV-2. XLA patients do not have B lymphocytes and do not produce antibodies because of mutations in the Bruton tyrosine-kinase gene, responsible for the maturation of B cells. This patient was infected and then admitted to a hospital in Ivoti, southern Brazil. Pneumonia progressed rapidly, requiring transfer to the Hospital de Clínicas de Porto Alegre on the 10th day. Intravenous immunoglobulin infusions were initiated, using a total of 400 grams because of an intense catabolism of IgG, and the concentration was kept around 700- 900 mg/dL. Mechanical ventilation, extracorporeal membrane oxygenation and hemodialysis were necessary. Convalescent plasma (CP) was administered (2x300 mL) and then followed by clinical and radiological improvement and interruption of mechanical ventilation. Then he got sicker and had to return to invasive support and received 4 extra CP infusions (total of 1717 mL), until a negative reverse-transcriptase polymerase chain reaction (RT-PCR) for SARS-CoV-2 was obtained. On 3 occasions he had sepsis, promptly managed. He had anemia, requiring frequent transfusion, and lymphopenia (CD3, CD4, CD8, NK), with absence of B lymphocytes. Lymphopenia was reverted during recovery, and he was discharged from the hospital on the 70th day.

Dietary intake of tyrosine and phenylalanine, and p-cresyl sulfate plasma levels in non-dialyzed patients with chronic kidney disease / Ingestão dietética de tirosina e fenilalanina e níveis plasmáticos de p-cresil sulfato em pacientes com doença renal crônica não dialisados

ABSTRACT Background: Patients with chronic kidney disease (CKD) present an imbalance of the gut microbiota composition, leading to increased production of uremic toxins like p-cresyl sulfate (PCS), product from bacterial fermentation of the amino acids tyrosine (Tyr) and phenylalanine (Phe) from the diet. Thus, diet may be a determinant in the uremic toxins levels produced by the gut microbiota. The aim of this study was to evaluate the possible relationship between Tyr and Phe intake and PCS plasma levels in non-dialysis CKD patients. Methods: Twenty-seven non-dialysis CKD patients (stages 3 and 4) without previous nutritional intervention were evaluated. The dietary intake was evaluated using a 24-hour recall, 3-day food record and protein intake was also estimated by Protein Nitrogen Appearance (PNA). The plasma levels of PCS were measured using reverse phase high performance liquid chromatography. Results: The evaluated patients (GRF, 34.8 ± 12.4 mL/min, 54.2 ± 14.3 years, BMI, 29.3 ± 6.1 kg/m2) presented mean protein intake of 1.1 ± 0.5 g/kg/day), Tyr of 4.5 ± 2.4 g/day and Phe of 4.6 ± 2.5 g/day. PCS plasma levels (20.4 ± 15.5 mg/L) were elevated and positively associated with both, Tyr (r = 0.58, p = 0.002) and Phe intake (r = 0.53, p = 0.005), even after adjustments for eGFR and age. Conclusion: This study suggests that the diet is an important modulator of the uremic toxins plasma levels produced by the gut microbiota, in non-dialysis CKD patients.

RESUMO Introdução: Pacientes com doença renal crônica (DRC) apresentam desequilíbrio na composição da microbiota intestinal, gerando toxinas urêmicas, como o p-cresil sulfato (PCS), pela fermentação bacteriana dos aminoácidos tirosina (Tyr) e fenilalanina (Phe) da dieta. Assim, a dieta pode ser determinante nos níveis de toxinas urêmicas produzidos pela microbiota intestinal. O objetivo deste estudo foi avaliar a possível relação entre a ingestão de Tyr e Phe e os níveis plasmáticos de PCS em pacientes com DRC não dialisados. Métodos: Foram avaliados 27 pacientes com DRC em tratamento conservador (estágios 3 e 4), sem intervenção nutricional prévia. A ingestão alimentar foi avaliada pelo recordatório alimentar de 24h (R-24h) de 3 dias, e a ingestão proteica também foi verificada através do Protein Nitrogen Appearance (PNA). Os níveis plasmáticos de PCS foram determinados por cromatografia líquida de fase reversa. Resultados: Os pacientes avaliados (TFG, 34,8 ± 12,4 mL/min, 54,2 ± 14,3 anos, IMC 29,3 ± 6,1 kg/m2) apresentaram ingestão média de proteína de 1,1 ± 0,5 g/kg/dia, Tyr de 4,5 ± 2,4 g/dia e Phe de 4,6 ± 2,5 g/dia. Os níveis plasmáticos de PCS (20,4 ± 15,5 mg/L) foram elevados e positivamente associados à ingestão de Tyr (r = 0,58, p = 0,002) e Phe (r = 0,53, p = 0,005), mesmo após ajustes pela TFG e idade. Conclusão: Este estudo sugere que a dieta é um importante modulador dos níveis plasmáticos de toxinas urêmicas produzidas pela microbiota intestinal em pacientes com DRC não dialisados.

Changes of tyrosine phosphorylation in liver and kidney of polycystic ovarian rats induced by letrozole / Cambios de fosforilación de tirosina en hígado y riñón de ratas ováricas poliquísticas inducidas por letrozol

Letrozole (Letro) is a drug commonly used for breast cancer treatment since it can decrease estrogen level. In experimental animal, the Letro has been used to induce the polycystic ovarian syndrome (PCOS) model. Tyrosine phosphorylation (TyrPho) is an essential process in various biological functions both normal and abnormal conditions especially reproduction. Although some side effects of Letro are reported, the alterations of TyrPho responsible for liver and kidney functions have never been demonstrated. In this study, the blood serum, liver, and kidney of control and PCOS rats induced with Letro (orally, 1 mg/ KgBW) for consecutive 21 days were used to determine the serum biochemical components and to investigate the TyrPho expression using western blot analysis. Histopathology of such tissues was observed by Masson's trichrome staining. The results showed that Letro did not affect histological structures but significantly increased the serum levels of urea nitrogen, cholesterol, triglyceride, HDL, LDL, ALT, AST, and alkaline phosphatase. Additionally, the TyrPho protein expressions of 32 and 27 kDas in liver and of 55 and 43 kDas in kidney were increased while of a kidney 26 kDa was decreased as compared to those of control. In conclusion, this recent study indicated that the changes of TyrPho proteins in liver and kidney induced with Letro associated with their functions by alteration of serum biochemical levels.

El letrozol (Letro) es un medicamento utilizado comúnmente para el tratamiento del cáncer de mama, debido a que puede disminuir el nivel de estrógeno. En animales de experimentación, el Letro se ha utilizado para inducir el modelo de síndrome de ovario poliquístico (PCOS). La fosforilación de tirosina (TyrPho) es un proceso esencial en diversas funciones biológicas, tanto en condiciones normales como anormales, especialmente en la reproducción. A pesar de informes que indican algunos efectos secundarios de Letro, no se han demostrado las alteraciones de TyrPho responsables de las funciones hepáticas y renales. En este estudio, el suero sanguíneo, el hígado y el riñón control y las ratas PCOS inducidas con Letro (por vía oral, 1 mg / KgBW) durante 21 días consecutivos se usaron para determinar los componentes bioquímicos del suero y para investigar la expresión de TyrPho usando análisis de transferencia Western. La histopatología de los tejidos se observó mediante la tinción tricrómica de Masson. Los resultados mostraron que Letro no afectó las estructuras histológicas, pero aumentó significativamente los niveles séricos de urea, colesterol, triglicéridos, HDL, LDL, ALT, AST y fosfatasa alcalina. Además, las expresiones de la proteína TyrPho de 32 y 27 kDas en el hígado y de 55 y 43 kDas en el riñón aumentaron mientras que en un riñón disminuyeron 26 kDa en comparación con el control. En conclusión, este estudio indicó que los cambios de las proteínas TyrPho en el hígado y los riñones inducidos con Letro se asociaron con sus funciones mediante la alteración de los niveles bioquímicos en suero.

Importancia clínica y diagnóstica de la relación receptor de tirosin-quinasa tipo 1 en su forma soluble y el factor de crecimiento placentario / Clinical and diagnostic importance of the type 1 receptor tyrosine-kinase ratio in its soluble form and placental growth factor / Importância clínica e diagnóstica da relação receptor de tirosina-quinase tipo 1 em sua forma solúvel e o fator de crescimento placentário

El objetivo del trabajo fue evaluar la utilidad clínica de la relación factor de crecimiento placentario/receptor de tirosin-quinasa tipo 1 soluble (sFlt-1/ PlGF) para el diagnóstico de preeclampsia (PE) en embarazadas de alto riesgo y con diagnóstico clínico de PE en un centro de salud de Córdoba, Argentina. Se procesaron 135 muestras de embarazadas: 39 con diagnóstico clínico de PE (Grupo I), 72 con riesgo de PE (Grupo II), y 24 de grupo control (Grupo III). Se utilizó una técnica automatizada de electroquimioluminiscencia (Roche). Valores <38 se consideraron sin riesgo de PE, entre 38 y 85 (< semana 34) o 38 y 110 (> semana 34) con riesgo moderado o alto riesgo dentro de las 4 semanas posteriores a la realización de dichos marcadores y >85 en embarazadas con síntomas de aparición temprana o >110 en embarazadas con síntomas de aparición tardía, PE confirmada. En el Grupo I, 33 muestras dieron relación >38 y 6 fueron menores. De 72 muestras del Grupo II 69 dieron <38 y 3 >38. Todas las muestras del Grupo III dieron relación <38. La razón de verosimilitud positiva (LR+) fue de 20,31 y la razón negativa (LR-) fue de 0,16. La relación fue >38 en la mayoría de las embarazadas con diagnóstico de PE. La determinación es útil en aquellas mujeres embarazadas que son de alto riesgo, ya sea porque tienen hipertensión o proteinuria o algún antecedente previo, en las cuales puede ser fundamental para decidir el correcto diagnóstico.

The objective of this work was to evaluate the clinical usefulness of the relation placental growth factor/soluble tyrosine-kinase type 1 receptor (sFlt-1/PlGF) for the diagnosis of PE (preeclampsia) in pregnant women at high risk and with clinical diagnosis of PE in a health center of Córdoba, Argentina. A total of 135 samples of pregnant women were processed: 39 with clinical diagnosis of PE (Group I), 72 with risk of PE (Group II), and 24 of control group (Group III). An automated electrochemiluminescence technique (Roche) was used. Ratio sFlt-1/PlGF <38 was considered without risk of PE. Between 38 and 85 (< week 34) or 38 and 110 (> week 34), with moderate risk or high risk within 4 weeks after performing these markers. To confirm diagnosis, relationships >85 in pregnant women were considered with symptoms of early onset and >110 in pregnant women with symptoms of late onset. In Group I, 33 samples reported >38 and 6 were lower. Of 72 samples from Group II, 69 gave <38 and 3, >38. All samples from Group III gave a ratio <38. The positive likelihood ratio (LR+) was 20.31 and the negative likelihood ratio (LR-), 0.16. The ratio was >38 in the majority of women already diagnosed as PE. The test is useful in those pregnant women who are at high risk of PE, either because they have hypertension or proteinuria or a previous history. In those cases it can be fundamental to decide the correct diagnosis.

O objetivo do estudo é avaliar a utilidade clínica da relação fator de crescimento placentário/receptor de tirosina-quinase tipo 1 solúvel (sFlt-1/PIGF) para o diagnóstico de pré-eclâmpsia (PE) em grávidas de alto risco e com diagnóstico clínico de PE em um centro de saúde de Córdoba, Argentina. Foram processadas 135 amostras de gestantes, sendo 39 com diagnóstico clínico de PE (Grupo I), 72 com risco de PE (Grupo II) e 24 de grupo controle (Grupo III). Foi utilizada uma técnica automatizada de eletroquimioluminescência (Roche). Valores <38 foram considerados sem risco de PE, entre 38 e 85 (

Directed evolution of tyrosine ammonia-lyase to improve the production of p-coumaric acid in Escherichia coli / 生物工程学报

p-coumaric acid is an important natural phenolic compound with a variety of pharmacological activities, and also a precursor for the biosynthesis of many natural compounds. It is widely used in foods, cosmetics and medicines. Compared with the chemical synthesis and plant extraction, microbial production of p-coumaric acid has many advantages, such as energy saving and emission reduction. However, the yield of p-coumaric acid by microbial synthesis is too low to meet the requirements of large-scale industrial production. Here, to further improve p-coumaric acid production, the directed evolution of tyrosine ammonia lyase (TAL) encoded by Rhodotorula glutinis tal gene was conducted, and a high-throughput screening method was established to screen the mutant library for improve the property of TAL. A mutant with a doubled TAL catalytic activity was screened from about 10,000 colonies of the mutant library. There were three mutational amino acid sites in this TAL, namely S9Y, A11N, and E518A. It was further verified by a single point saturation mutation. When S9 was mutated to Y, I or N, or A11 was mutated to N, T or Y, the catalytic activity of TAL increased by more than 1-fold. Through combinatorial mutation of three types of mutations at the S9 and A11, the TAL catalytic activity of S9Y/A11N or S9N/A11Y mutants were significantly higher than that of other mutants. Then, the plasmid containing S9N/A11Y mutant was transformed into CP032, a tyrosine-producing E. coli strain. The engineered strain produced 394.2 mg/L p-coumaric acid, which is 2.2-fold higher than that of the control strain, via shake flask fermentation at 48 h. This work provides a new insight for the biosynthesis study of p-coumaric acid.

Biological function of protein tyrosine phosphatase H-type receptor and its progress in tumor / 中南大学学报(医学版)

Protein tyrosine phosphatase H-type receptor (PTPRH) gene encodes a gastric cancer associated protein, which exerts its biological function through tyrosine phosphorylation in the post-translational COOH- terminal region. PTPRH is abnormally expressed in a variety of tumors, and its biological function is closely related to the occurrence, development and prognosis of tumors.

Mimosine increases the expressions of tyrosine phosphorylated protein in mouse seminal vesicles / La mimosina aumenta la expresión de la proteína tirosina fosforilada en las vesículas seminales del ratón

Acute effect of purified mimosine (MiMo) extracted from Leucaena leucocephala on testicular histopathology has been documented with seminal vesicle (SV) atrophy. Since protein phosphorylation and seminal secretions play important roles in sperm physiology, this study aimed to study the alteration of substances including tyrosine phosphorylated (TyrPho) proteins in seminal vesicle treated with MiMo. Male mice were divided into a control and experimental groups treated with purified MiMo at 3 doses of 15, 30, and 60 mg/KgBW, respectively for 35 consecutive days. The morphology and weights of SV were compared among groups. The levels of magnesium and fructosamine in SV fluid were assayed. The profiles of equally SV total proteins were compared using SDS-PAGE. The expression of seminal TyrPho proteins was detected by western blotting. Recent results showed the decreased weights of SV in MiMo treated mice compared to control. However MiMo in all doses did not affect the levels of magnesium and fructosamine in SV fluid. The SV protein expression of 130 and 55 kDas was obviously decreased in a high dose MiMo. In dose-dependent response, the expressions of 72 and 55 kDas TyrPho proteins of SV were increased. In conclusion, MiMo could affect SV morphological size and protein secretions especially TyrPho proteins.

El efecto agudo de la mimosina purificada (MiMo) extraída de Leucaena leucocephala en la histopatología testicular se ha documentado con atrofia de vesícula seminal (VS). Debido a que la fosforilación de proteínas y las secreciones seminales tienen un papel importante en la fisiología de los espermatozoides, este estudio tuvo como objetivo estudiar la alteración de sustancias como la proteína tirosina fosforilada (TyrPho) en vesículas seminales tratadas con MiMo. Los ratones se dividieron en un grupo control y un grupo experimental y se trataron con MiMo purificado en 3 dosis de 15, 30 y 60 mg / KgBW, respectivamente, durante 35 días seguidos. La morfología y los pesos de VS se compararon entre los grupos. Fueron analizados los niveles de magnesio y fructosamina en el fluido VS. Los perfiles de las proteínas totales de VS se compararon utilizando SDS-PAGE. La expresión de la proteína TyrPho en las vesículas seminales se detectó mediante transferencia de Western blot. Los resultados recientes muestran la disminución del peso de las VS en ratones tratados con MiMo, en comparación con el grupo control. Sin embargo, en ninguna de las dosis se vieron afectados por mimosina purificada los niveles de magnesio y fructosamina en el líquido de las VS. La expresión de la proteína en VS de 130 y 55 kDas disminuyó notablemente en una dosis alta de MiMo. En la respuesta dependiente de la dosis, aumentaron las expresiones de 72 y 55 kDas de las proteínas TyrPho en las VS. En conclusión, la mimosina purificada podría afectar el tamaño morfológico de las VS y la expresión de proteínas, especialmente las proteínas TyrPho.

Fenilcetonuria de diagnóstico precoz: Bases fisiopatológicas del daño neuronal y opciones terapéuticas / Early diagnosis of phenylketonuria. Physiopathology of the neuronal damage and therapeutic options

La fenilcetonuria, también conocida como PKU, es el error congénito más frecuente del metabolismo de los aminoácidos. La forma grave o PKU clásica no tratada, causa una discapacidad intelectual, aunque los programas de detección en el período neonatal, el diagnóstico y el tratamiento evitan la aparición de los síntomas. A pesar de un diagnóstico y tratamiento temprano hemos observado cierta neurotoxicidad en los pacientes con PKU tratados. Analizamos los demás factores implicados, aparte de la toxicidad por las elevadas concentraciones cerebrales de fenilalanina (Phe), se revisan los defectos de síntesis de neurotransmisores, las alteración de la mielinización cerebral, el efecto de la elevación de Phe en los procesos de transporte y distribución de los aminoácidos neutros con una síntesis anómala de proteínas cerebrales, la deficiencia plasmática y cerebral de tirosina, la neurotoxicidad de los metabolitos de Phe, el defecto de la biosíntesis del colesterol o el aumento del estrés oxidativo. Las alteraciones de la sustancia blanca en los pacientes con PKU tienen un papel importante en las manifestaciones neurológicas. El tratamiento de la PKU es para toda la vida y se basa en la reducción del aporte de alimentos que contienen Phe combinado con la administración de una fórmula especial, o en el tratamiento con tetrahidrobiopterina (BH4). Se analizan nuevas opciones terapéuticas.

Phenylketonuria, also known as PKU, is the most frequent congenital inborn error of metabolism. The severe form or classic PKU untreated causes intellectual disability, although with the early detection programs in the neonatal period, diagnosis and treatment prevent the appearance of the symptoms. Despite early diagnosis and treatment we have observed some neurotoxicity in treated PKU patients. We analyzed the factors involved apart from the toxicity due to the high cerebral concentrations of phenylalanine (Phe), the defects of synthesis of neurotransmitters, the alteration of cerebral myelination, the effect of the elevation of Phe in the processes of transport and distribution of neutral amino acids with an abnormal synthesis of brain proteins, plasma and cerebral tyrosine deficiency, the neurotoxicity of Phe metabolites, the defect of cholesterol biosynthesis or the increase of oxidative stress. White matter alterations in early treated PKU patients have an important role in neurological manifestations. The treatment of PKU is for life and is based on the reduction of foods containing Phe combined with the administration of a special formula or tetrahydrobiopterin (BH4) treatment. New therapeutic options will be analyzed.

Miopatía nemalínica tratada con L-tirosina para aliviar los síntomas en un recién nacido / Nemaline rod myopathy treated with L-tyrosine to relieve symptoms in a neonate

La miopatía nemalínica es un trastorno heterogéneo definido por la presencia de estructuras con forma de bastones, conocidas como cuerpos nemalínicos (o bastones de nemalina). El diagnóstico se funda en la debilidad muscular, además de la visualización de cuerpos nemalínicos en la biopsia muscular. La miopatía nemalínica no tiene cura. Las estrategias terapéuticas para este trastorno son sintomáticas y empíricas. En este artículo, presentamos el caso de una recién nacida con insuficiencia respiratoria grave y debilidad muscular generalizada, a la que se le diagnosticó miopatía nemalínica a través de la biopsia muscular. La paciente tuvo una notable disminución de la sialorrea y una mejora de los movimientos espontáneos después del tratamiento con L-tirosina. Este caso se presenta para destacar la importancia de la biopsia muscular en el diagnóstico diferencial de la hipotonía grave durante el período neonatal y el posible beneficio del aporte suplementario de L-tirosina para disminuir la sialorrea y restaurar la fuerza muscular.

Nemaline myopathy (NM) is a heterogeneous disorder defined by the presence of rod-shaped structures known as nemaline bodies or rods. The diagnosis is based on muscle weakness, combined with visualization of nemaline bodies on muscle biopsy. There is no curative treatment for nemaline myopathy. Therapeutic strategies for this condition are symptomatic and empirical. Herein, we present a newborn with severe respiratory failure and generalized muscle weakness, who was diagnosed as NM by muscle biopsy. The patient experienced remarkable decrease in sialorrhea and improvement of spontaneous movements after L-tyrosine treatment. This case is presented to emphasize the importance of muscle biopsy in the differential diagnosis of severe hypotonia during neonatal period and a possible benefit of L-tyrosine supplementation for decreasing sialorrhea and restoring muscle strength.

Cáncer de tiroides en estadios avanzados tratados con inhibidores de tirosina quinasa (SORAFENIB) / Advanced stage thyroid cancer treated with tyrosine kinase inhibitors (SORAFENIB)

OBJETIVO: Este estudio pretende evaluar la sobrevida global en los pacientes con carcinoma diferenciado de tiroides localmente avanzado yodo refractario. MÉTODO: Son 8 casos tratados con inhibidores de tirosina quinasa (Sorafenib) en el período comprendido entre 2014-2017. Las variables estudiadas fueron: Epidemiológicas, laboratorios tiroideos, histología, tratamiento, supervivencia posterior al tratamiento. Se tomó como significativo una P<0,05. RESULTADOS: Edad media entre los pacientes fue 51 años ± 22,1 años, el sexo prevaleciente fue femenino (75 %). El lugar de procedencia más incidente fue Estado Miranda (50 %). Los valores de laboratorio al momento del diagnóstico fueron tiroglobulina (290,2 ± 250,7), la TSH (11,3 ± 13,9) y la antitiroglobulina solo fue positiva en un paciente (87,5 %). La T predominante fue T3 (50 %), la N que prevaleció fue N1B (62 %) y M1 (62,5 %). El estadio predominante fue IVC (50 %). El grupo histológico predominante fue papilar (62,5 %). Se les realizó tiroidectomía total con vaciamiento bilateral al 75 % de los pacientes. Posteriormente recibieron 131I, para los cuales se obtuvieron una dosis media de 227,5 mCi con desviación de estándar: 188,1 mCi. La mayoría recibió radioterapia externa a región cervical (87,50 %). La sobrevida global 3 años posteriores al tratamiento fue 87,5 %. CONCLUSIONES. El control de la enfermedad a largo plazo en estos pacientes avanzados puede obtenerse con Sorafenib. En nuestro estudio evidenciamos que es un fármaco adecuado para controlar la enfermedad en pacientes con cáncer de tiroides yodo refractarios.(AU)

OBJECTIVE: This study aimed evaluates overall survival in patients with locally advanced thyroid iodine refractory differentiated carcinoma. METHOD: 8 cases treated with inhibitors of tyrosine kinase (Sorafenib) in the period 2014-2017. The variables studied were: epidemiological, laboratory thyroid histology, treatment, post-treatment survival. P was taken as meaningful < 0.05. RESULTS: Mean age among patients was 51 years ± 22.1 year, prevailing sex female (75 %). Place of origin more incident was Miranda State (50 %). At the time of the diagnostic laboratory values were thyroglobulin (290.2 ± 250.7), TSH (3 ± 13.9 11) and the single antithyroglobulin was positive in one patient (87.5 %). The predominant T was T3 (50 %), the N that prevailed was N1B (62 %) and M1 (62.5 %). The predominant stadium was IVC (50 %). The predominant histological group was papillary (62.5 %). The predominant stadium was IVC (50 %). The predominant histological group was papillary (62.5 %). He was performed in total thyroidectomy with bilateral clearing to 75 % of patients. Subsequently received 131I, for which an average dose of 227.5 mCi with standard deviation were obtained: 188.1 mCi. Most received radiotherapy external cervical region (87.50 %). Global survival 3 years after treatment was 87.5 %. CONCLUSIONS: The control of disease in long run in these advanced patients can get with Sorafenib. In our study we showed that it is a suitable drug to control the disease in patients with cancer of thyroid iodine refractory. (AU)

Effect of gene knockout of L-tyrosine transport system on L-tyrosine production in Escherichia coli / 生物工程学报

L-tyrosine is one of three aromatic amino acids that are widely used in food, pharmaceutical and chemical industries. The transport system engineering provides an important research strategy for the metabolic engineering of Escherichia coli to breed L-tyrosine producing strain. The intracellular transport of L-tyrosine in E. coli is mainly regulated by two distinct permeases encoded by aroP and tyrP genes. The aroP and tyrP gene knockout mutants were constructed by CRISPR-Cas technique on the basis of L-tyrosine producing strain HGXP, and the effects of regulating transport system on L-tyrosine production were investigated by fermentation experiments. The fermentation results showed that the aroP and tyrP knockout mutants produced 3.74 and 3.45 g/L L-tyrosine, respectively, which were 19% and 10% higher than that of the original strain. The optimum induction temperature was determined to be 38 °C. Fed-batch fermentation was carried out on a 3-L fermentor. The L-tyrosine yields of aroP and tyrP knockout mutants were further increased to 44.5 and 35.1 g/L, respectively, which were 57% and 24% higher than that of the original strain. The research results are of great reference value for metabolic engineering of E. coli to produce L-tyrosine.

Helicobacter pylori inhibited cell proliferation in human periodontal ligament fibroblasts through the Cdc25C/CDK1/cyclinB1 signaling cascade

PURPOSE: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. METHODS: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. RESULTS: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. CONCLUSIONS: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.

The Risk of Herpes Zoster in Patients with Non-small Cell Lung Cancer according to Chemotherapy Regimens: Tyrosine Kinase Inhibitors versus Cytotoxic Chemotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Despite the successful use of tyrosine kinase inhibitors (TKIs) in cancer patients, their effect on herpes zoster development has not been studied. The aim of this study was to evaluate and compare the effects of epidermal growth factor receptor (EGFR) TKI and cytotoxic chemotherapy on the risk of herpes zoster development in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: We conducted a medical review of all eligible NSCLC patients in Seoul National University hospital between 2002 and 2015. We classified patients based on whether they previously underwent EGFR TKI therapy into either the TKI group or the cytotoxic group. We compared the incidence rates of herpes zoster during TKI therapy and cytotoxic chemotherapy. Additionally, the longitudinal risk of herpes zoster from TKIs was analyzed using the incidence rate ratio (IRR) of the TKI group to the cytotoxic group and the log-rank test of the Kaplan-Meier method. RESULTS: Of the 2,981 NSCLC patients, 54 patients (1.54%) developed herpes zoster. In the TKI group (2,002 patients), the IRR of herpes zoster during TKI therapy compared to that during cytotoxic chemotherapy was 1.05 (95% confidence interval [CI], 0.53 to 2.09). The IRR of the TKI group compared to the cytotoxic group was 1.33 (95% CI, 0.64 to 2.76). The Kaplan-Meier cumulative risk of both groups was not significantly different. CONCLUSION: Our results show that the incidence rate of herpes zoster in the TKI group was not statistically different from the incidence in the cytotoxic group during and after chemotherapy in NSCLC patients.