Publications by authors named "Hong-Bo Hu"

27 Publications

  • Page 1 of 1

Epidemiology and Clinical Characteristics of Henoch-Schönlein Purpura Associated with Epstein-Barr Virus Infection.

Mediterr J Hematol Infect Dis 2021 1;13(1):e2021064. Epub 2021 Nov 1.

Medical department, The first people's Hospital of Guangshui, China.

Background: Henoch-Schönlein purpura (HSP) is an immune-mediated vasculitis, and the formation of immune complexes may be triggered by exposure to Epstein-Barr virus (EBV) infection.

Methods: We performed a five-year case-control study to evaluate the epidemiology and clinical characteristics of HSP associated with EBV infection.

Results: The incidence of EBV-triggered HSP was 4.2%, while EBV infection in children with HSP was 0.9%; The EBV-triggered HSP cases had a significantly higher frequency of abdominal pain than the (MP)-triggered HSP group (χ2 = 8.024, p = 0.005); Significant differences were observed in the duration of abdominal pain (Z = -1.935, = 0.027) between the two groups; C3 (t = 9.709, < 0.001), IgA (t = 20.39, < 0.001) and IgG (t = 6.407, < 0.001) were significantly increased in the EBV infection group than those in the healthy control group. Notably, significantly higher proportion of CD19 (t = 6.773, < 0.001) and lower proportion of CD56 (t = 11.13, < 0.001) was found in EBV infection group compared with healthy control group. The IgA level was higher than that of the non-infectious group (t = 2.162, = 0.032), but their CD4/CD8 ratio (t = 10.070, < 0.001) and CD56 proportion (t = 2.096, = 0.037) were significantly lower.

Conclusions: Both cellular and humoral immunity were involved in the pathogenesis of EBV-triggered HSP, leading to increased production of inflammatory mediators and immunoglobulins. Those events may cause or promote the development of systemic vessel vasculitis.
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http://dx.doi.org/10.4084/MJHID.2021.064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8577555PMC
November 2021

rpeA, a global regulator involved in mupirocin biosynthesis in Pseudomonas fluorescens NCIMB 10586.

Appl Microbiol Biotechnol 2021 Nov 18. Epub 2021 Nov 18.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.

Mupirocin, a polyketide antibiotic produced by Pseudomonas fluorescens, is used as a topical antimicrobial treatment to cure various skin infections. Quorum sensing system plays an important role in regulation of mupirocin biosynthesis in P. fluorescens NCIMB 10586. In Pseudomonas, the RpeA/RpeB two-component signal transduction (TCST) system regulates quorum sensing system. However, the influences of the RpeA/RpeB TCST system on mupirocin production or other cell activities have not been studied. In this work, the homologous genes of rpeA and rpeB in P. fluorescens NCIMB 10586 were identified and inactivated in the chromosome, respectively. The deletion of rpeA reduced the mupirocin production from 160 in the wild-type to 21.3 mg/L along with slightly decreased cell growth, while no significant effected on mupirocin production in the rpeB mutant. Next, it was found that the RpeA/RpeB TCST system regulated the biosynthesis of mupirocin by modulating the quorum sensing system. Furthermore, untargeted metabolomics analysis was employed to detect the influences of RpeA on other cell activities modulated by quorum sensing system. Combined with quantitative real-time PCR, the results demonstrated that RpeA also regulated other cell activities including central carbon, amino acids, fatty acids, and purine metabolism. Overall, this study expands the current understanding of the RpeA/RpeB TCST system and provides several targets for increasing yields of mupirocin. KEY POINTS: • In P. fluorescens, the RpeA/RpeB TCST system regulates the biosynthesis of mupirocin. • RpeA modulates the cell activities through effecting the central carbon metabolism.
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http://dx.doi.org/10.1007/s00253-021-11683-3DOI Listing
November 2021

Epidemiology and Clinical Characteristics of Henoch-Schönlein Purpura Associated with Infection in 131 Children in Hubei Province, China.

Mediterr J Hematol Infect Dis 2021 1;13(1):e2021037. Epub 2021 May 1.

Department of Laboratory, Maternal and Child Health Hospital of Hubei Province, China.

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http://dx.doi.org/10.4084/MJHID.2021.037DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8114884PMC
May 2021

Characterization and Engineering of LX24 with High Production of 2-Hydroxyphenazine.

J Agric Food Chem 2021 Apr 13;69(16):4778-4784. Epub 2021 Apr 13.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.

The take-all disease of wheat is one of the most serious diseases in the field of food security in the world. There is no effective biological pesticide to prevent the take-all disease of wheat. 2-Hydroxyphenazine (2-OH-PHZ) was reported to possess a better inhibitory effect on the take-all disease of wheat than phenazine-1-carboxylic acid, which was registered as "Shenqinmycin" in China in 2011. The aim of this study was to construct a 2-OH-PHZ high-producing strain by strain screening, genome sequencing, genetic engineering, and fermentation optimization. First, the metabolites of the previously screened new phenazine-producing sp. strain were identified, and the taxonomic status of the new sp. strain was confirmed through 16S rRNA and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Then, the new sp. strain was named subsp. LX24, which is a new subspecies of that can synthesize 2-OH-PHZ. Next, the draft genome of strain LX24 was determined, and clusters of orthologous group (COG) analysis, KEGG analysis, and gene ontology (GO) analysis of strain LX24 were performed. Furthermore, the production of 2-OH-PHZ increased to 351.7 from 158.6 mg/L by deletion of the phenazine synthesis negative regulatory genes and in strain LX24. Finally, the 2-OH-PHZ production of strain LX24 reached 677.1 mg/L after fermentation optimization, which is the highest production through microbial fermentation reported to date. This work provides a reference for the efficient production of other pesticides and antibiotics.
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http://dx.doi.org/10.1021/acs.jafc.1c00434DOI Listing
April 2021

Biosynthesis and Characterization of Medium-Chain-Length Polyhydroxyalkanoate with an Enriched 3-Hydroxydodecanoate Monomer from a Cell Factory.

J Agric Food Chem 2021 Apr 24;69(13):3895-3903. Epub 2021 Mar 24.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.

Polyhydroxyalkanoates (PHAs) have been reported with agricultural and medical applications in virtue of their biodegradable and biocompatible properties. Here, we systematically engineered three modules for the enhanced biosynthesis of medium-chain-length polyhydroxyalkanoate (mcl-PHA) in HT66. The , , and genes were deleted to block the native phenazine pathway and weaken the fatty acid β-oxidation pathway. Additionally, a PHA depolymerase gene was knocked out to prevent the degradation of mcl-PHA. Three genes involved in the mcl-PHA biosynthesis pathway were co-overexpressed to increase carbon flux. The engineered strain HT4Δ:: exhibited an 18.2 g/L cell dry weight with 84.9 wt % of mcl-PHA in a shake-flask culture, and the 3-hydroxydodecanoate (3HDD) monomer was increased to 71.6 mol %. Thermophysical and mechanical properties of mcl-PHA were improved with an enriched ratio of 3HDD. This study demonstrated a rational metabolic engineering approach to enhance the production of mcl-PHA with the enriched dominant monomer and improved material properties.
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http://dx.doi.org/10.1021/acs.jafc.1c00500DOI Listing
April 2021

Identification of a Novel Bioactive Phenazine Derivative and Regulation of on Its Production in S015.

J Agric Food Chem 2021 Jan 14;69(3):974-981. Epub 2021 Jan 14.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.

Natural phenazines are a class of multifunctional secondary metabolites of bacteria that play an important role in the biocontrol of plant pathogens. In this paper, a novel bioactive phenazine derivative was isolated from S015 through silica gel chromatography and preparative high-performance liquid chromatography (HPLC). The structure was identified as 1-carboxyl-6-formyl-4,7,9-trihydroxy-phenazine (CFTHP) by NMR spectroscopy in combination with ultraperformance liquid chromatography & mass spectrometry (UPLC-MS). CFTHP could inhibit , , , and f. sp. with minimal inhibitory concentration (MIC) values of 16, 32, 16, and 16 μg/mL, respectively. A global regulatory gene could positively regulate CFTHP biosynthesis since its production was 3.0-fold enhanced by overexpression and inhibited by deletion in S015. These studies illustrated the potential of CFTHP as a promising biopesticide and provided a reference for phenazine production improvement.
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http://dx.doi.org/10.1021/acs.jafc.0c06498DOI Listing
January 2021

LncRNA HOTTIP promotes the proliferation and invasion of ovarian cancer cells by activating the MEK/ERK pathway.

Mol Med Rep 2020 Nov 21;22(5):3667-3676. Epub 2020 Aug 21.

Department of Gynaecology, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China.

Recent studies have revealed that long non‑coding RNAs (lncRNAs) serve important roles in carcinogenesis and that this type of gene may be used as biomarkers in cancer. A high level of lncRNA HOXA distal transcript antisense RNA (HOTTIP) is associated with unfavorable prognosis for patients with ovarian cancer (OC), but the mechanism of HOTTIP involved in OC development remains to be elucidated. The present study aimed to investigate the mechanism of HOTTIP in metastasis‑associated OC cell behaviors. HOTTIP levels in ovarian cells were quantified by reverse transcription‑quantitative PCR, cell proliferation was analyzed by colony formation assay, and apoptosis was assessed by flow cytometry. Cell migratory and invasive abilities were evaluated by wound healing and Transwell assays, respectively. The expression levels of mitogen‑activated protein kinase kinase (MEK)/ERK pathway‑associated proteins were detected by western blotting. The results demonstrated that knockdown of HOTTIP in OC cells significantly reduced the phosphorylation levels of MEK and ERK, inhibited the proliferation and invasion of OC cells and promoted their apoptosis. Furthermore, the effects of HOTTIP on cell migration and invasion were partly associated with the epithelial‑mesenchymal transition (EMT) process. Proliferation, invasion and EMT of OC cells were enhanced following overexpression of HOTTIP; however, these effects were reversed by the MEK/ERK pathway inhibitor U0126. In conclusion, HOTTIP was demonstrated to promote the proliferation, migration and invasion of OC cells by activating the MEK/ERK pathway. Therefore, HOTTIP may serve as a potential therapeutic target for OC.
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http://dx.doi.org/10.3892/mmr.2020.11452DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7533522PMC
November 2020

Engineering of glycerol utilization in Pseudomonas chlororaphis GP72 for enhancing phenazine-1-carboxylic acid production.

World J Microbiol Biotechnol 2020 Mar 10;36(3):49. Epub 2020 Mar 10.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.

Glycerol is a by-product of biodiesel, and it has a great application prospect to be transformed to synthesize high value-added compounds. Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere is a plant growth promoting rhizobacteria that can utilize amount of glycerol to synthesize phenazine-1-carboxylic acid (PCA). PCA has been commercially registered as "Shenqinmycin" in China due to its characteristics of preventing pepper blight and rice sheath blight. The aim of this study was to engineer glycerol utilization pathway in P. chlororaphis GP72. First, the two genes glpF and glpK from the glycerol metabolism pathway were overexpressed in GP72ANO separately. Then, the two genes were co-expressed in GP72ANO, improving PCA production from 729.4 mg/L to 993.4 mg/L at 36 h. Moreover, the shunt pathway was blocked to enhance glycerol utilization, resulting in 1493.3 mg/L PCA production. Additionally, we confirmed the inhibition of glpR on glycerol metabolism pathway in P. chlororaphis GP72. This study provides a good example for improving the utilization of glycerol to synthesize high value-added compounds in Pseudomonas.
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http://dx.doi.org/10.1007/s11274-020-02824-3DOI Listing
March 2020

Enhanced Production of 2-Hydroxyphenazine from Glycerol by a Two-Stage Fermentation Strategy in GP72AN.

J Agric Food Chem 2020 Jan 31;68(2):561-566. Epub 2019 Dec 31.

2-Hydroxyphenazine (2-OH-PHZ) is an effective biocontrol antibiotic secreted by GP72AN and is transformed from phenazine-1-carboxylic acid (PCA). PCA is the main component of the recently registered biopesticide "Shenqinmycin". Previous research showed that 2-OH-PHZ was better in controlling wheat take-all disease than PCA; however, 2-OH-PHZ production was low under natural conditions. Herein, we confirmed that PCA induced reactive oxygen species in its host GP72AN and that the addition of DTT improved PCA production by 1.8-fold, whereas the supplementation of K[Fe(CN)] and HO increased the conversion rate of PCA to 2-OH-PHZ. Finally, a two-stage fermentation strategy combining the addition of DTT at 12 h and HO at 24 h enhanced 2-OH-PHZ production. Taken together, the two-stage fermentation strategy was designed to enhance 2-OH-PHZ production for the first time, and it provided a valuable reference for the fermentation of other antibiotics.
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http://dx.doi.org/10.1021/acs.jafc.9b05033DOI Listing
January 2020

Synthesis of cinnabarinic acid by metabolically engineered Pseudomonas chlororaphis GP72.

Biotechnol Bioeng 2019 11 26;116(11):3072-3083. Epub 2019 Jul 26.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.

Cinnabarinic acid is a valuable phenoxazinone that has broad applications in the pharmaceutical, chemical, and dyeing industries. However, few studies have investigated the production of cinnabarinic acid or its derivatives using genetically engineered microorganisms. Herein, an efficient synthetic pathway of cinnabarinic acid was designed and constructed in Pseudomonas chlororaphis GP72 for the first tim, which was more straightforward and robust than the known eukaryotic biosynthetic pathways. First, we screened and identified trans-2,3-dihydro-3-hydroxyanthranilic acid (DHHA) dehydrogenases from Escherichia coli MG1655 (encoded by entA), Streptomyces sp. NRRL12068 (encoded by bomO) and Streptomyces chartreusis NRRL3882 (encoded by calB ) based on the structural similarity of the substrate and product, and the DHHA dehydrogenase encoded by calB was selected for the synthesis of cinnabarinic acid due to its high DHHA conversion rate. Subsequently, cinnabarinic acid was synthesized by the expression of the DHHA dehydrogenase CalB and the phenoxazinone synthase CotA in the DHHA-producing strain P. chlororaphis GP72, resulting in a cinnabarinic acid titer of 20.3 mg/L at 48 hr. Further fermentation optimization by the addition of Cu , H O , and with adding glycerol increased cinnabarinic acid titer to 136.2 mg/L in shake flasks. The results indicate that P. chlororaphis GP72 may be engineered as a microbial cell factory to produce cinnabarinic acid or its derivatives from renewable bioresources.
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http://dx.doi.org/10.1002/bit.27118DOI Listing
November 2019

Novel Three-Component Phenazine-1-Carboxylic Acid 1,2-Dioxygenase in Sphingomonas wittichii DP58.

Appl Environ Microbiol 2017 05 17;83(9). Epub 2017 Apr 17.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.

Phenazine-1-carboxylic acid, the main component of shenqinmycin, is widely used in southern China for the prevention of rice sheath blight. However, the fate of phenazine-1-carboxylic acid in soil remains uncertain. DP58 can use phenazine-1-carboxylic acid as its sole carbon and nitrogen sources for growth. In this study, dioxygenase-encoding genes, , were found using transcriptome analysis to be highly upregulated upon phenazine-1-carboxylic acid biodegradation. PcaA1 shares 68% amino acid sequence identity with the large oxygenase subunit of anthranilate 1,2-dioxygenase from DSM 44675. The dioxygenase was coexpressed in with its adjacent reductase-encoding gene, , and ferredoxin-encoding gene, , and showed phenazine-1-carboxylic acid consumption. The dioxygenase-, ferredoxin-, and reductase-encoding genes were expressed in KT2440 or BL21, and the three recombinant proteins were purified. A phenazine-1-carboxylic acid conversion capability occurred only when all three components were present. However, KT2440 transformed with obtained phenazine-1-carboxylic acid degradation ability, suggesting that phenazine-1-carboxylic acid 1,2-dioxygenase has low specificities for its ferredoxin and reductase. This was verified by replacing PcaA3 with RedA2 in the enzyme assay. High-performance liquid chromatography-mass spectrometry (HPLC-MS) and nuclear magnetic resonance (NMR) analysis showed that phenazine-1-carboxylic acid was converted to 1,2-dihydroxyphenazine through decarboxylation and hydroxylation, indicating that PcaA1A2A3A4 constitutes the initial phenazine-1-carboxylic acid 1,2-dioxygenase. This study fills a gap in our understanding of the biodegradation of phenazine-1-carboxylic acid and illustrates a new dioxygenase for decarboxylation. Phenazine-1-carboxylic acid is widely used in southern China as a key fungicide to prevent rice sheath blight. However, the degradation characteristics of phenazine-1-carboxylic acid and the environmental consequences of the long-term application are not clear. DP58 can use phenazine-1-carboxylic acid as its sole carbon and nitrogen sources. In this study, a three-component dioxygenase, PcaA1A2A3A4, was determined to be the initial dioxygenase for phenazine-1-carboxylic acid degradation in DP58. Phenazine-1-carboxylic acid was converted to 1,2-dihydroxyphenazine through decarboxylation and hydroxylation. This finding may help us discover the pathway for phenazine-1-carboxylic acid degradation.
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http://dx.doi.org/10.1128/AEM.00133-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394328PMC
May 2017

iTRAQ-based quantitative proteomic analysis reveals potential factors associated with the enhancement of phenazine-1-carboxamide production in Pseudomonas chlororaphis P3.

Sci Rep 2016 06 7;6:27393. Epub 2016 Jun 7.

State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.

Phenazine-1-carboxamide (PCN), a phenazine derivative, is strongly antagonistic to fungal phytopathogens. Pseudomonas chlororaphis HT66 is a PCN-producing, non-pathogenic biocontrol strain, and we obtained the mutant P. chlororaphis P3, which produces 4.7 times more PCN than the wild-type HT66 strain. To reveal the cause of PCN production enhancement in P3 and find potential factors related to PCN biosynthesis, an iTRAQ-based quantitative proteomic analysis was used to study the expression changes between the two strains. Of the 452 differentially expressed proteins, most were functionally mapped into PCN biosynthesis pathway or other related metabolisms. The upregulation of proteins, including PhzA/B, PhzD, PhzF, PhzG, and PhzH, involved in PCN biosynthesis was in agreement with the efficient production of PCN in P3. A number of proteins that function primarily in energy production, amino acid metabolism, and secondary metabolism played important roles in PCN biosynthesis. Notably, proteins involved in the uptake and conversion of phosphate, inorganic nitrogen sources, and iron improved the PCN production. Furthermore, the type VI secretion system may participate in the secretion or/and indirect biosynthetic regulation of PCN in P. chlororaphis. This study provides valuable clues to better understand the biosynthesis, excretion and regulation of PCN in Pseudomonas and also provides potential gene targets for further engineering high-yield strains.
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http://dx.doi.org/10.1038/srep27393DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4895345PMC
June 2016

Human umbilical cord mesenchymal stem cell transplantation restores damaged ovaries.

J Cell Mol Med 2015 Sep 29;19(9):2108-17. Epub 2015 Apr 29.

Department of Obstetrics and Gynaecology, Zhujiang Hospital, Southern Medical University, Guangzhou, GuangDong, China.

Ovarian injury because of chemotherapy can decrease the levels of sexual hormones and potentia generandi of patients, thereby greatly reducing quality of life. The goal of this study was to investigate which transplantation method for human umbilical cord mesenchymal stem cells (HUMSCs) can recover ovarian function that has been damaged by chemotherapy. A rat model of ovarian injury was established using an intraperitoneal injection of cyclophosphamide. Membrane-labelled HUMSCs were subsequently injected directly into ovary tissue or tail vein. The distribution of fluorescently labelled HUMSCs, estrous cycle, sexual hormone levels, and potentia generandi of treated and control rats were then examined. HUMSCs injected into the ovary only distributed to the ovary and uterus, while HUMSCs injected via tail vein were detected in the ovary, uterus, kidney, liver and lung. The estrous cycle, levels of sex hormones and potentia generandi of the treated rats were also recovered to a certain degree. Moreover, in some transplanted rats, fertility was restored and their offspring developed normally. While ovary injection could recover ovarian function faster, both methods produced similar results in the later stages of observation. Therefore, our results suggest that transplantation of HUMSCs by tail vein injection represents a minimally invasive and effective treatment method for ovarian injury.
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http://dx.doi.org/10.1111/jcmm.12571DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4568915PMC
September 2015

Comparison of cell proliferation, apoptosis, cellular morphology and ultrastructure between human umbilical cord and placenta-derived mesenchymal stem cells.

Neurosci Lett 2013 Apr 21;541:77-82. Epub 2013 Mar 21.

Medical College of Shaoguan University, Shaoguan, Guangdong, PR China.

Research in mesenchymal stem cells (MSCs) is mainly focused on applications for treatments of brain and spinal cord injury as well as mechanisms underlying effects of MSCs. However, due to numerous limitations, there is little information on selection of appropriate sources of MSCs for transplantation in clinical applications. Therefore, in this study we compared various properties of human umbilical cord-derived MSCs (HUCMSCs) with human placenta-derived MSCs (HPDMSCs), including cell proliferation, apoptosis, cellular morphology, ultrastructure, and their ability to secrete various growth factors (i.e. vascular endothelial growth factor, insulin-like growth factors-1, and hepatocyte growth factor), which will allow us to select appropriate MSC sources for cellular therapy. Cell culture, flow cytometry, transmission electron microscope (TEM) and atomic force microscope (AFM) were used for assessment of HUCMSCs and HPDMSCs. Results showed that the two types of cells appeared slightly different when they were observed under AFM. HUCMSCs appeared more fibroblast-like, whereas HPDMSCs appeared as large flat cells. HUCMSCs had higher proliferative rate and lower rate of apoptosis than HPDMSCs (p<0.05). However, HPDMSCs secreted more of the three growth factors than HUCMSCs (p<0.05). Results of TEM revealed that the two types of MSCs underwent active metabolism and had low degree of differentiation, especially HUCMSCs. Results of AFM showed that HUCMSCs had stronger ability of mass transport and cell migration than HPDMSCs. However, HPDMSCs displayed stronger adhesive properties than HUCMSCs. Our findings indicate that different sources of MSCs have different properties, and that care should be taken when choosing the appropriate sources of MSCs for stem cell transplantation.
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http://dx.doi.org/10.1016/j.neulet.2013.03.018DOI Listing
April 2013

Microbial transformation of ursolic acid by Syncephalastrum racemosum (Cohn) Schroter AS 3.264.

Phytochemistry 2012 Oct 15;82:56-60. Epub 2012 Jul 15.

State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, China.

Biotransformation of ursolic acid by the filamentous fungus Syncephalastrum racemosum (Cohn) Schroter AS 3.264 yielded five metabolites. Their structures were identified as 3β,21β-dihydroxy-urs-11-en-28-oic acid-13-lactone, 3β,7β,21β-trihydroxy-urs-11-en-28-oic acid-13-lactone, 1β,3β-dihydroxy-urs-12-en-21-one-28-oic acid, 1β,3β,21β-trihydroxy-urs-12-en-28-oic acid and 11,26-epoxy-3β,21β-dihydroxy-urs-12-en-28-oic acid based on NMR and MS spectroscopic analyses. The condensation reactions to form 28-oic acid-13-lactone ring and 11,26-epoxy ring are not frequently seen for the biotransformation of triterpenoids. One compound showed moderate inhibitory activity against protein tyrosine phosphatase 1B (PTP1B).
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http://dx.doi.org/10.1016/j.phytochem.2012.06.020DOI Listing
October 2012

[Laboratory diagnosis of HIV/AIDS patients complicated with Pneumocystis jirovecii pneumonia].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2011 Jun;29(3):176-8

Department of Clinical Laboratory, Longtan Hospital, Liuzhou 545005, China.

Pneumocystis jirovecii was detected in sputum samples and bronchoalveolar lavage fluid (BALF) obtained from HIV/AIDS patients complicated with Pneumocystis jirovecii pneumonia by Giemsa staining. CD4+ T lymphocytes of 500 patients were counted by flow cytometer. P. jirovecii positive rate in sputum samples (46.8%, 845/1 806) significantly lower than that of BALF (55.8%, 10(6)/190) (P < 0.05). The proportion of patients developing clinical symptoms in P. jirovecii positive cases (96.6%, 816/845) was higher than that of P. jirovecii negative cases (64.0%, 615/961) (P < 0.05). P. jirovecii positive rate increased with the decrease of CD4+ T lymphocyte number. P. jirovecii positive rates in cases with CD4+ > 200 x 10(6)/L, CDC 200 x 10(6)/L-100 x 10(6)n/L, and CD4+ < 100x10(6)/12.0% (6/50), 39.0%( 39/100), 54.6% (191/350), respectively (P < 0.05). Giemsa staining is an efficient, simple and feasible method for P. jirovecii detection, relying on the experience and skill of the operator.
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June 2011

Biotransformation of bufadienolides by cell suspension cultures of Saussurea involucrata.

Phytochemistry 2011 Oct 1;72(14-15):1779-85. Epub 2011 Jun 1.

The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.

The biotransformation of three bioactive bufadienolides, namely, bufotalin (1), telocinobufagin (2), and gamabufotalin (3) by cell suspension cultures of Saussurea involucrata yielded 11 products. Bufotalin yielded 3-epi-bufotalin (1a), 3-epi-desacetylbufotalin (1b), 3-epi-bufotalin 3-O-β-D-glucoside (1c), 1β-hydroxybufotalin (1d), and 5β-hydroxybufotalin (1e); telocinobufagin yielded 3-dehydroscillarenin (2a), 3-dehydrobufalin (2b), and 3-epi-telocinobufagin (2c); and gamabufotalin yielded 3-epi-gamabufotalin (3a), 3-dehydrogamabufotalin (3b), and 3-dehydro-Δ¹-gamabufotalin (3c), respectively. Among these 11 products, 1a, 1b, 1c, 1d, 3a and 3c are previously unreported. The structures of these metabolites were elucidated based on NMR spectroscopic analyses and mass spectrometry. Most metabolites showed significant cytotoxic activities against human hepatoma (HepG2) and breast cancer (MCF-7) cell lines. In addition, the time course for the biotransformation of 3 was investigated.
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http://dx.doi.org/10.1016/j.phytochem.2011.05.004DOI Listing
October 2011

[ID4 methylation patterns in childhood T line and B line lymphocytic leukemia].

Authors:
Hong-Bo Hu Qun Hu

Zhongguo Dang Dai Er Ke Za Zhi 2010 Dec;12(12):940-2

Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. Email:

Objective: To study the relationship of methylation of inhibitor of DNA binding 4 (ID4) gene core promoter region with childhood T line, B line and T/B acute lymphocytic leukemia (ALL).

Methods: Methylation-specific polymerase chain reaction (MS-PCR) was used to detect the methylation status of ID4 promoter region in 18 children with newly-diagnosed ALL (2 cases of T-ALL, 13 cases of B-ALL and 3 cases of T/B-ALL). Thirty-four hospitalized children with non-tumor disease served as the control group.

Results: The complete methylation rate of ID4 gene promoter region (15/18, 83%) was significantly higher than the partial methylation rate (3/18, 17%) in the 18 ALL children (P<0.05). The complete methylation rate of ID4 gene promoter region in children with T-ALL, B-ALL and T/B-ALL (50%, 85% and 100% respectively) was significantly higher than that in the control group (18%; P<0.05). In contrast, the partial methylation rate and non-methylation rate in the three ALL groups were significantly lower than those in the control group (P<0.05). There were no statistically significant differences in the methylation patterns among the B-ALL, T-ALL and T/B-ALL cases.

Conclusions: The methylation of ID4 promoter region may be related to the pathogenesis of childhood ALL. The methylation patterns of ID4 promoter region are identical in B-ALL, T-ALL and T/B-ALL.
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December 2010

Enhanced production of 2-hydroxyphenazine in Pseudomonas chlororaphis GP72.

Appl Microbiol Biotechnol 2011 Jan 21;89(1):169-77. Epub 2010 Sep 21.

Key Laboratory of Microbial Metabolism, Ministry of Education, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.

Pseudomonas chlororaphis GP72 is a root-colonizing biocontrol strain isolated from the green pepper rhizosphere that synthesizes two phenazine derivatives: phenazine-1-carboxylic acid (PCA) and 2-hydroxyphenazine (2-OH-PHZ). The 2-OH-PHZ derivative shows somewhat stronger broad-spectrum antifungal activity than PCA, but its conversion mechanism has not yet been clearly revealed. The aim of this study was to clone and analyze the phenazine biosynthesis gene cluster in this newly found strain and to improve the production of 2-OH-PHZ by gene disruption and precursor addition. The conserved phenazine biosynthesis core operon in GP72 was cloned by PCR, and the unknown sequences located upstream and downstream of the core operon were detected by random PCR gene walking. This led to a complete isolation of the phenazine biosynthesis gene cluster phzIRABCDEFG and phzO in GP72. Gene rpeA and phzO were insertionally mutated to construct GP72AN and GP72ON, respectively, and GP72ANON collectively. The inactivation of rpeA resulted in a fivefold increase in the production of PCA, as well as 2-OH-PHZ. The addition of exogenous precursor PCA to the broth culture, to determine the conversion efficiency of PCA to 2-OH-PHZ under current culture conditions, revealed that PCA had a positive feedback effect on its own accumulation, leading to enhanced synthesis of both PCA and 2-OH-PHZ. The production of 2-OH-PHZ by GP72AN increased to about 170 μg ml(-1), compared with just 5 μg ml(-1) for the wild type. The hypothesis of biosynthetic pathway for 2-OH-PHZ from PCA was confirmed by identification of 2-hydroxyphenazine-1-carboxylic acid as an intermediate in the culture medium of the high-phenazine producing GP72AN mutant.
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http://dx.doi.org/10.1007/s00253-010-2863-1DOI Listing
January 2011

[Value of detecting p16 gene methylation in the diagnosis of malignant pleural effusion].

Nan Fang Yi Ke Da Xue Xue Bao 2010 Sep;30(9):2148-50

Department of Respiratory Diseases, Liutie Central Hospital, Liuzhou 545007, China.

Objective: To investigate aberrant methylation in the promoter of p16 gene in the sediment cells of pleural effusion and evaluate its clinical significance in the differentiating benign and malignant pleural effusion.

Methods: Using methylation-specific PCR (MSP), aberrant promoter methylation of p16 gene was detected in the sedimental cells of pleural effusion samples from 66 patients with pleural effusion.

Results: Of the 66 patients with pleural effusion, 36 had a definite diagnosis of malignant pleural effusion, and the rest were confirmed to have benign pleural effusion. The positivity rate of p16 gene promoter methylation was 69.4% (25/36) in malignant pleural effusion and 13.3% (4/30) in benign pleural effusion specimens, showing a significant difference between them (χ² = 20.915, P < 0.01). The diagnostic sensitivity, specificity and accuracy of aberrant promoter methylation of p16 gene in the 36 malignant cases were 69.4%, 86.7% and 77.3%, respectively. The positive expression of p16 gene promoter methylation in malignant pleural effusion was not correlated to the histological type or the pathological grade of the tumor (P > 0.05).

Conclusion: Detection of aberrant methylation in p16 gene promoter in the sediment cells of pleural effusion specimens by MSP method allows differentiation between benign and malignant pleural effusion.
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September 2010

Prospective study of colonization and infection because of Pseudomonas aeruginosa in mechanically ventilated patients at a neonatal intensive care unit in China.

Am J Infect Control 2010 Nov 3;38(9):746-50. Epub 2010 Jun 3.

Department of Microbiology, Tongji Medical College, Huazhong University of Technology and Science, Wuhan, China.

Background: Ventilator-associated pneumonia (VAP) is an important nosocomial infection at neonatal intensive care units (NICU), frequently caused by Pseudomonas aeruginosa. A 6-month prospective study from January 2009 through June 2009 was performed to investigate the respective contribution of endogenous and exogenous transmission of P aeruginosa in the respiratory colonization or/and infection in the mechanically ventilated patients at a NICU to identify routes of lung infection with P aeruginosa and to assess risk factors for colonization or respiratory infection with P aeruginosa.

Methods: Samples from oropharyngeal swab, tracheobronchial aspirates, gastric aspirate, and rectal swab were obtained in each patient after intubation and then twice a week. Surveillance cultures for the presence of P aeruginosa from environmental surfaces of the ICU were taken once every 5 days during the study period. Pulsed-field gel electrophoresis was used to characterize the clonal relatedness of the strains by SpeI-digested genomic DNA.

Results: Eighteen patients (78.3%) had colonization of the upper respiratory tract. Sixteen (69.6%) patients with colonization of the respiratory tract were infected from other patients or environmental surfaces, which was considered exogenous, and, among strains causing pulmonary infection, there were 4 (50%) patients with exogenous infection. Eight of these developed VAP after a mean of 9 ± 3.4 days. The incidence of P aeruginosa VAP on the unit was 6.2%. The respiratory tract was the earliest site of colonization in all patients of VAP. Low birth weight, duration of mechanical ventilation, previous ampicillin group use, and previous second-generation cephalosporins use were independently associated with patient-related acquisition of P aeruginosa.

Conclusion: Our results confirm that the upper respiratory tract acts as an important reservoir of P aeruginosa colonization and infection in the mechanically ventilated patients and emphasize the importance of exogenous acquisition of P aeruginosa. A combination of early identification and eradication of airways colonization by P aeruginosa plus infection control measures may be the basis to prevent pulmonary infection.
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http://dx.doi.org/10.1016/j.ajic.2010.02.012DOI Listing
November 2010

[Proliferation apoptotic influence of crocin on human bladder cancer T24 cell line].

Zhongguo Zhong Yao Za Zhi 2008 Aug;33(15):1869-73

Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Chongqing Medical University, Chongqing 400016, China.

Objective: To investigate the proliferation, apoptosis and mechanisms on T24 cell of transitional cell carcinoma of bladder (TCCB) by crocin.

Method: MTT assay was used to evaluate the proliferation of T24 cells. The changes of cell cycle and cell apoptotic percentage were measured by flow cytometry. T24 cells were inoculated into BALB/c nude mice to establish model of carcinoma of bladder. The mice were randomly divided into control group and experimental group. After treatment with 50 mmol x L(-1) crocin, the inhibited growth of tumor was observed. Electronic microscope was used to observe the morphological changes. The expressions of Bcl-2, Bax, Survivin and Cyclin D1 were detected by immunohistochemistry.

Result: The growth of T24 cells was remarkably inhibited after treatment of crocin. Flow cytometric profiles revealed that crocin led to the increase of the cells in G0/G1 phase, the percentage of cell apoptosis was also increased. Crocin could inhibit the growth of BALB/c xenograft tumor. The morphology changes of cell apoptosis were observed. Bcl-2, Cyclin D1 and survivin expressions determined by immunohistochemical staining were down-regulated after treatment with Bax expression up-regulated.

Conclusion: Crocin exerts both in vitro and in vivo anti-cancer effect on TCCB T24 cell line. The mechanisms may change tumour cell cycle and induce tumour cell apoptosis by down-regulating the expression of Bcl-2, Survivin, Cyclin D1 and up-regulating the expression of Bax.
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August 2008

Isolation, identification, and degradation characteristics of phenazine-1-carboxylic acid-degrading strain Sphingomonas sp. DP58.

Curr Microbiol 2007 Oct 13;55(4):284-7. Epub 2007 Aug 13.

Key Laboratory of Microbial Metabolism, Ministry of Education, College of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.

A phenazine-1-carboxylic acid (PCA)-degrading bacterium, strain DP58, was isolated from pimiento rhizosoil. Based on morphology, physiologic tests, 16S rDNA sequence, and phylogenetic characteristics, it was identified as Sphingomonas sp. The PCA-degradation experiments were conducted both in Luria-Bertani and inorganic salt medium at 28 degrees C. The relationship between bacterium growth and PCA degradation suggested that strain DP58 could use PCA as the sole source of carbon and nitrogen and was able to completely degrade PCA in 40 hours. Newly isolated strain DP58 represents the first bacterium that can degrade PCA.
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http://dx.doi.org/10.1007/s00284-006-0522-7DOI Listing
October 2007

An improved method for purification of recombinant truncated heme oxygenase-1 by expanded bed adsorption and gel filtration.

Bioprocess Biosyst Eng 2007 Mar 12;30(2):87-90. Epub 2006 Dec 12.

Key Laboratory of Microbial Metabolism, Ministry of Education, College of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.

Recombinant truncated human heme oxygenase-1 (hHO-1) expressed in Escherichia coli was efficiently separated and purified from feedstock by DEAE-ion exchange expanded bed adsorption. Protocol optimization of hHO-1 on DEAE adsorbent resulted in adsorption in 0 M NaCl and elution in 150 mM NaCl at a pH of 8.5. The active enzyme fractions separated from the expanded bed column were further purified by a Superdex 75 gel filtration step. The specific hHO-1 activity increased from 0.82 +/- 0.05 to 24.8 +/- 1.8 U/mg during the whole purification steps. The recovery and purification factor of truncated hHO-1 of the whole purification were 72.7 +/- 4.7 and 30.2 +/- 2.3%, respectively. This purification process can decrease the demand on the preparation of feedstock and simplify the purification process.
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http://dx.doi.org/10.1007/s00449-006-0103-yDOI Listing
March 2007

[Isolation and characterization of a new Pseudomonas strain against Phytophthora capsici].

Wei Sheng Wu Xue Bao 2006 Aug;46(4):516-21

School of Life Science & Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China.

One Pseudomonas strain GP72, which was against Phytophthora capsici, was isolated from green pepper rhizosphere in Jiangsu province. It had distinctively inhibitive effect on several kinds of pathogenic fungi; mostly of them are soilborne pathogens. Therefore, this strain may be used for an effective biocontrol strain in the crop protection. The morphological, biochemical and physiological characteristics, Biolog GN, G + C mol% content and 16S rDNA sequence analysis of this strain were studied. In comparison and conclusion of all the experimental data, GP72 is identified as Pseudomonas chlororaphis. The strain is single-cellular and motile by means of single polar flagellum. It was not able to accumulate ploy-beta-hydroxybutyrate. Compared to P. aureofaciens 30-84, the strain was able to survive at the concentration of 5% NaCl. It could strongly utilize 45 of 95 carbon-substrates; weakly utilize 6 of the whole carbon-substrates and never utilize 43 of the whole carbon-substrates resulting from analysis of Biolog GN, bearing the similarity probability of 98% with Pseudomonas chlororaphis and with the similarity index 0.72. The G + C content of the strain DNA was 65.1 mol% using the thermal denaturation method. A phylogenetic tree was constructed by comparing with the validly published 16S rDNA sequences of the related type strains from GenBank, using the Neighbor-Joining method of Saitou and Nei and the Clustal X program to do the multiple alignments. The tree topology was tested by a bootstrap analysis of 1000 samplings. The overall similarity value between strain GP72 and typical is the closest in the phylogenetic tree. For the latest taxonomical development has put genus Pseudomonas aureofaciens to the genus Pseudomonas chlororaphis, then it is appropriate to say that GP72 belongs to the genus Pseudomonas chlororaphis. This is the first time in China to report that a strain of Pseudomonas chlororaphis was isolated from green pepper rhizosphere, having a strong inhibitive effect on Phytophthora capsici and other soilborne pathogenic fungus. The other characteristics and the biocontrol mechanism are yet to be further studied.
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August 2006

Quantitative analysis of pyoluteorin in anti-fungal fermentation liquor of Pseudomonas species by capillary zone electrophoresis with UV-vis detector.

J Chromatogr B Analyt Technol Biomed Life Sci 2005 Nov 1;826(1-2):252-6. Epub 2005 Sep 1.

Laboratory of Analytical Biochemistry and Bioseparation, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Rd. Minhang, 200240 Shanghai, PR China.

This paper investigated potential utility of capillary zone electrophoresis (CZE) for very succinct but robust quantitative analysis of pyoluteorin (Plt) in anti-fungal fermentation liquor of Pseudomonas species. The experimental conditions for the separation and quantification of Plt were optimized at first. The optimized conditions are: 80 mmol/L pH 8.40 Gly-NaOH buffer, 51 cm total length (42 cm effective) and 75 microm I.D. capillary, 230 nm wavelength, 25 kV, 13 mbar 10s pressure sample injection and 24 degrees C air-cooling. Under the optimized conditions, the migration times of Plt and the internal standard phenobarbital are 2.09 and 2.49 min, respectively, the linear response of Plt concentration ranges from 5.0 to 1000 microg/mL with high correlation coefficient (r=0.99977, n=9), the limits of detection (LOD) and quantification (LOQ) for Plt are 0.66 and 2.2 microg/mL, the precision values (expressed as R.S.D.) of intra- and inter-day are 1.19-1.94% and 1.55-6.21%, respectively, the recoveries of Plt at three concentration levels of 750, 250 and 50 microg/mL range from 90.31% to 97.85% and to 98.96%, respectively. The developed method can be well used for the quantification of Plt in the fermentation liquor.
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http://dx.doi.org/10.1016/j.jchromb.2005.07.047DOI Listing
November 2005

[Recovery of platinum with immobilized Citrobacter freudii XP05 biomass].

Sheng Wu Gong Cheng Xue Bao 2003 Jul;19(4):456-61

School of Life Sciences, Xiamen University, Xiamen 361005, China.

The objective of this work was to develop a valuable adsorbent for recovery of platinum by studying the properties of Pt4+ -adsorption with immobilized Citrobacter freudii XP05 biomass. Five methods for immobilization of Citrobacter freudii XP05 biomass were compared. The method with gelatin-alginate sodium as entrapment matrix was considered to be the optimal. Spherical and uniform beads were produced and the SEM micrograph indicated that the cell of strain XP08 were uniformly dispersed within the matrix. The adsorption of Pt4+ by immobilized XP05 biomass was affected with adsorptive time, pH value of the solution, immobilized biomass concentration, Pt4+ initial concentration The adsorption was a rapid process. The optimal pH value for Pt4+ adsorption was 1.5, and its adsorptive capacity increased linearly with increasing Pt4+ initial concentrations in the range of 50 - 250 mg/L. The experimental data could be fitted to Langmuir and Freundlich models of adsorption isotherm. The adsorptive capacity reached 35.2 mg/g under the conditions of 250 Pt4+ mg/L, 2.0 g/L immobilized biomass, pH 1.5 and 30 degrees C for 60 min. 98.7% of Pt4+ adsorbed on immobilized biomass could be desorbed with 0.5 mol HC1/L. The characteristics of dynamic adsorption and desorption of immobilized XP05 biomass in packed-bed reactor were investigated. The saturation uptake was 24.66 mg Pt4+ /g under the conditions of flow rate 1.2 mL/min, pH 1.5, 50 mg Pt4+/L and 1.85 g biomass(dry weight) . Adsorptive efficiency of Pt4 + by the immobilized XP05 biomass was above 78% for 4 cycles of adsorption and desorption. The recovery of platinum from waste platinum catalyst was studied. The adsorptive capacity was 20.94 mg Pt4+/g immobilized biomass under the conditions of 4.0 g/L immobilized XP05 biomass, 117.76 mg Pt4+/L and pH 1.5 for 60 min. The immobilized XP05 biomass is potentially applicable to the recovery of platinum from waste and wastewater containing platinum.
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July 2003
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