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1.
Nat Commun ; 15(1): 3884, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719909

ABSTRACT

Only a minority of cancer patients benefit from immune checkpoint blockade therapy. Sophisticated cross-talk among different immune checkpoint pathways as well as interaction pattern of immune checkpoint molecules carried on circulating small extracellular vesicles (sEV) might contribute to the low response rate. Here we demonstrate that PD-1 and CD80 carried on immunocyte-derived sEVs (I-sEV) induce an adaptive redistribution of PD-L1 in tumour cells. The resulting decreased cell membrane PD-L1 expression and increased sEV PD-L1 secretion into the circulation contribute to systemic immunosuppression. PD-1/CD80+ I-sEVs also induce downregulation of adhesion- and antigen presentation-related molecules on tumour cells and impaired immune cell infiltration, thereby converting tumours to an immunologically cold phenotype. Moreover, synchronous analysis of multiple checkpoint molecules, including PD-1, CD80 and PD-L1, on circulating sEVs distinguishes clinical responders from those patients who poorly respond to anti-PD-1 treatment. Altogether, our study shows that sEVs carry multiple inhibitory immune checkpoints proteins, which form a potentially targetable adaptive loop to suppress antitumour immunity.


Subject(s)
B7-1 Antigen , B7-H1 Antigen , Extracellular Vesicles , Programmed Cell Death 1 Receptor , Extracellular Vesicles/metabolism , Extracellular Vesicles/immunology , Programmed Cell Death 1 Receptor/metabolism , Humans , B7-1 Antigen/metabolism , B7-H1 Antigen/metabolism , B7-H1 Antigen/immunology , Animals , Mice , Cell Line, Tumor , Female , Neoplasms/immunology , Neoplasms/pathology , Immune Checkpoint Inhibitors/therapeutic use , Immune Checkpoint Inhibitors/pharmacology , Immune Tolerance , Mice, Inbred C57BL , Male , Tumor Microenvironment/immunology
2.
Int J Mol Sci ; 24(17)2023 Aug 23.
Article in English | MEDLINE | ID: mdl-37685910

ABSTRACT

Oral squamous cell carcinoma (OSCC) is the most prevalent subtype of head and neck tumors, highly prone to lymph node metastasis. This study aims to examine the expression pattern of Ras-related protein Rab-27A (RAB27A) and explore its potential implications in OSCC. The expression of RAB27A was assessed through immunohistochemical analysis utilizing tissue microarrays. In vitro experiments were conducted using RAB27A-knockdown cells to investigate its impact on OSCC tumor cells. Additionally, transcriptome sequencing was performed to elucidate potential underlying mechanisms. RAB27A was significantly overexpressed in OSCC, and particularly in metastatic lymph nodes. It was positively correlated with the clinical progression and poor survival prognosis. Silencing RAB27A notably decreased the proliferation, migration, and invasion abilities of OSCC cells in vitro. A Gene Ontology (GO) enrichment analysis indicated a strong association between RAB27A and the epidermal growth factor receptor (EGFR) signaling pathway. Further investigations revealed that RAB27A regulated the palmitoylation of EGFR via zinc finger DHHC-type containing 13 (ZDHHC13). These findings provide insights into OSCC progression and highlight RAB27A as a potential therapeutic target for combating this aggressive cancer.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Carcinoma, Squamous Cell/genetics , Mouth Neoplasms/genetics , Squamous Cell Carcinoma of Head and Neck/genetics , ErbB Receptors/genetics , rab27 GTP-Binding Proteins
3.
Anal Chem ; 95(22): 8735-8743, 2023 06 06.
Article in English | MEDLINE | ID: mdl-37218037

ABSTRACT

Liquid biopsy technology involves taking samples from body fluids in a minimally invasive way and analyzing tumor markers to achieve early diagnosis and efficacy evaluation of tumors. The development of real-time cancer diagnosis and treatment strategies based on liquid biopsy technology is of great significance to cancer management. This paper described an extracorporeal circulation based on a three-dimensional (3D) magnetic chip (3DMC-system) for in vivo detection and real-time monitoring of circulating tumor cells (CTCs). Utilizing biofunctionalized magnetic nanospheres (MNs) with CTC recognition function, this 3DMC-system could effectively achieve the real-time monitoring of CTCs in vivo with good stability and strong anti-interference. Compared with in vitro CTC detection, in vivo detection could not only detect more CTCs but also detect the presence of CTCs in the blood at an early stage of the tumor, when tumor metastasis is not observed in imaging. In addition, due to the flexibility of the chip design, the system can easily add a treatment module to integrate cancer diagnosis and treatment together. With good biocompatibility and high stability, this 3DMC-system is expected to provide a new personalized medical program for cancer patients.


Subject(s)
Neoplastic Cells, Circulating , Humans , Neoplastic Cells, Circulating/pathology , Magnetic Phenomena , Extracorporeal Circulation , Biomarkers, Tumor
4.
J Vasc Access ; : 11297298231154303, 2023 Feb 16.
Article in English | MEDLINE | ID: mdl-36797823

ABSTRACT

A 38-year-old male patient was diagnosed as acute non-ST-segment elevation myocardial infarction on Apr 21st 2021 and he received percutaneous transluminal coronary angioplasty for RCA via transradial artery access. He sought for second percutaneous coronary intervention in our center for frequently exertional angina on Sep 13th 2021. Proximal right radial artery pulsation can not be touched in physical examination, indicating right radial artery occlusion (RAO). Distal transradial access was applied and RAO was confirmed via angiography. With balloon pre-dilation, the guidewire and guiding catheter crossed the occlusion and coronary intervention was successfully completed. A Reewarm 2.5 × 220 mm paclitaxel drug-coated balloon (Endovastec, China) was released at 12 atm in radial arterial lesion with 90 s. Pulsation of radial artery can be well palpated 24 h after PCI. No oral anticoagulant was added. The right radial artery remained patent after 8-month and 14-month follow-up and there was no abnormal sensation or obstacle of right hand.

5.
Adv Sci (Weinh) ; 10(7): e2205566, 2023 03.
Article in English | MEDLINE | ID: mdl-36599707

ABSTRACT

Extracellular vesicles (EVs) are cell-derived membrane-enclosed structures that deliver biomolecules for intercellular communication. Developing visualization methods to elucidate the spatiotemporal dynamics of EVs' behaviors will facilitate their understanding and translation. With a quantum dot (QD) labeling strategy, a single particle tracking (SPT) platform is proposed here for dissecting the dynamic behaviors of EVs. The interplays between tumor cell-derived small EVs (T-sEVs) and endothelial cells (ECs) are specifically investigated based on this platform. It is revealed that, following a clathrin-mediated endocytosis by ECs, T-sEVs are transported to the perinuclear region in a typical three-stage pattern. Importantly, T-sEVs frequently interact with and finally enter lysosomes, followed by quick release of their carried miRNAs. This study, for the first time, reports the entire process and detailed dynamics of T-sEV transportation and cargo-release in ECs, leading to better understanding of their proangiogenic functions. Additionally, the QD-based SPT technique will help uncover more secrets of sEV-mediated cell-cell communication.


Subject(s)
Extracellular Vesicles , MicroRNAs , MicroRNAs/analysis , Endothelial Cells , Extracellular Vesicles/chemistry , Cell Communication , Endocytosis
6.
Int J Clin Pract ; 2022: 8975396, 2022.
Article in English | MEDLINE | ID: mdl-35814306

ABSTRACT

Objective: The present study aims to investigate the relationship between vitamin D deficiency and renin-angiotensin-aldosterone levels in patients with essential hypertension. Methods: The present study observed two groups of patients from Urumqi, Xinjiang, China, from April 2017 to March 2018. There were two subject groups: the hypertension group (80 patients with essential hypertension selected by random cluster sampling) and the control group (76 healthy adults). The 25-hydroxyvitamin D (25(OH)D or vitamin D) levels were measured through electrolytes; fasting blood glucose, blood lipids, and other biochemical indicators were detected using immune chemiluminescence; and plasma renin activity and angiotensin II concentrations were detected with radio-immunity. Results: Comparison between the hypertension group and control group showed statistically significant differences in the systolic pressure and levels of 25(OH)D, renin, and triglycerides (P < 0.05). The correlation analysis showed that 25(OH)D was negatively correlated with renin (r = -0.185; P=0.021) and positively correlated with systolic pressure (r = -0.105; P=0.035). There were no statistically significant differences in diastolic pressure, fasting blood glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides between the two groups. Conclusions: The results of the present study show that vitamin D deficiency is common in Urumqi, Xinjiang, China and vitamin D levels are negatively correlated with renin levels. Vitamin D plays an important role in regulating blood pressure by affecting renin levels through the renin-angiotensin-aldosterone system.


Subject(s)
Angiotensins , Essential Hypertension , Renin , Vitamin D Deficiency , Adult , Aldosterone/blood , Angiotensins/blood , Asian People , Blood Pressure , Essential Hypertension/blood , Essential Hypertension/complications , Essential Hypertension/physiopathology , Female , Humans , Male , Middle Aged , Renin/blood , Vitamin D Deficiency/complications
7.
Anal Chem ; 93(31): 10862-10870, 2021 08 10.
Article in English | MEDLINE | ID: mdl-34328732

ABSTRACT

Circulating small extracellular vesicles (sEVs) are naturally occurring nanosized membrane vesicles that convey bioactive molecules between cells. Conventionally, to evaluate their behaviors in vivo, circulating sEVs have to be isolated from the bloodstream, then labeled with imaging materials in vitro, and finally injected back into the circulation of animals for subsequent detection. The tedious isolation-labeling-reinfusion procedures might have an undesirable influence on the natural properties of circulating sEVs, thereby changing their behaviors and the detected kinetics in vivo. Herein, we proposed an in situ biotinylation strategy to directly label circulating sEVs with intravenously injected DSPE-PEG-Biotin, aiming to evaluate the in vivo kinetics of circulating sEVs more biofriendly and accurately. Such an analysis strategy is free of isolation-labeling-reinfusion procedures and has no unfavorable influence on the natural behaviors of sEVs. The results showed that the lifetime of generic circulating sEVs in mice was around 3 days. Furthermore, we, for the first time, revealed the distinct in vivo kinetics of circulating sEV subpopulations with different cell sources, among which erythrocyte-derived sEVs showed the longest lifespan. Moreover, compared with circulating sEVs in situ or used as autograft, circulating sEVs used as allograft had the shortest lifetime. In addition, the in situ biotinylation strategy also provides a way for the enrichment of biotinylated circulating sEVs. In summary, this study provides a novel strategy for in situ labeling of circulating sEVs, which would facilitate the accurate characterization of their kinetics in vivo, thereby accelerating their future application as biomarkers and theranositic vectors.


Subject(s)
Extracellular Vesicles , Animals , Biomarkers/metabolism , Biotinylation , Extracellular Vesicles/metabolism , Kinetics , Mice
8.
J Mol Histol ; 52(3): 511-520, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33394292

ABSTRACT

Cav3.1, a subfamily of T-type calcium channel, is overexpressed in various human cancers and exerts important functions in tumor progression. This study is to identify the expression pattern and clinical significance of Cav3.1 in oral squamous cell carcinoma (OSCC). Firstly, the expression levels of Cav3.1 in oral mucosa (OM), dysplasia and oral squamous cell carcinoma (OSCC) were determined and compared by real-time quantitative PCR and Western blot analysis. After that, human tissue microarrays, containing 29 OM, 23 dysplasia and 122 primary OSCC samples, were applied to investigate the expression levels of Cav3.1, proliferation markers [Ki-67, proliferating cell nuclear antigen (PCNA)] and cellular anti-apoptosis markers [B cell lymphoma 2 (Bcl-2)] by immunohistochemistry and digital pathology analysis. In addition, we determined the function of Cav3.1 using knockdown assays of Cav3.1 in vitro. The results demonstrated that the mRNA and protein expression of Cav3.1 were significantly higher in OSCC specimens, and Cav3.1 expression in primary OSCCs was correlated with tumor size and pathological grade. Statistical analysis of immunohistochemical staining showed that Cav3.1 was closely correlated with Ki-67, PCNA and Bcl-2. Functional studies showed that the knockdown of Cav3.1 in OSCC cell lines using RNA interference influenced cell proliferation and apoptosis in vitro. Taken together, these findings suggested that Cav3.1 is overexpressed in OSCC tissues, also associated with proliferative and anti-apoptotic activity in oral squamous cell carcinoma.


Subject(s)
Apoptosis , Calcium Channels, T-Type/metabolism , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Mouth Neoplasms/metabolism , Mouth Neoplasms/pathology , Apoptosis/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Humans , Mouth Mucosa/metabolism , Mouth Mucosa/pathology , Mouth Neoplasms/genetics , Up-Regulation/genetics
9.
J Interv Cardiol ; 2020: 1031675, 2020.
Article in English | MEDLINE | ID: mdl-33192184

ABSTRACT

AIM: Based on optical coherence tomography (OCT), we aimed to determine the diagnosis, clinical characteristics, and interventions of braid-like coronary arteries, which are rare and tend to be diagnosed as a woven coronary artery (WCA) anomaly. METHODS AND RESULTS: We identified braid-like lesions on coronary angiography (CAG) in 7 patients (6 men; median age 47 years; age range 26 to 57 years). All patients were heavy smokers. Four patients were diagnosed with an old myocardial infarction and the other 3 with unstable angina. The braid-like lesions were located in the left anterior descending arteries in 2 patients and in the right coronary arteries in the other 5. TIMI grade 2 flow was observed in all involved vessels. OCT findings of all lesions were consistent with recanalization of organized thrombi, which consisted of septa that divided the lumen into multiple small cavities communicating with each other. No separate three-layered structure could be defined. Based on the significance of the stenosis and its related symptoms, drug-eluting stents were implanted in all of the lesions. All patients experienced symptomatic improvement after the intervention and were followed up event-free for 12 months. CONCLUSIONS: Braid-like coronary arteries are likely to undergo recanalization of organized thrombi rather than WCA according to our OCT findings. The majority of cases affect men who smoke heavily. Percutaneous stent implantation may be beneficial in selected patients when feasible.


Subject(s)
Coronary Angiography/methods , Coronary Vessel Anomalies , Coronary Vessels , Percutaneous Coronary Intervention , Tomography, Optical Coherence/methods , Coronary Vessel Anomalies/diagnosis , Coronary Vessel Anomalies/surgery , Coronary Vessels/diagnostic imaging , Coronary Vessels/pathology , Diagnosis, Differential , Drug-Eluting Stents , Female , Humans , Male , Middle Aged , Myocardial Ischemia/diagnosis , Myocardial Ischemia/psychology , Myocardial Ischemia/surgery , Percutaneous Coronary Intervention/instrumentation , Percutaneous Coronary Intervention/methods , Risk Factors , Smoking/epidemiology , Treatment Outcome
10.
Acta Pharmacol Sin ; 39(9): 1473-1482, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29645002

ABSTRACT

Berberine8998 is a newly synthesized berberine derivative with better lipid-lowering activity and improved absorption. The objective of this study was to investigate the effects of berberine8998 on serum cholesterol and lipid levels in vivo and to examine the mechanisms involved. Hamsters on high-fat diet (HFD) were administered berberine or berberine8998 (50 mg·kg-1·d-1, ig) for 3 weeks. Berberine8998 administration significantly lowered the total cholesterol, triglycerides and LDL-C levels in HFD hamsters. Bioinformatics revealed that berberine and berberine8998 shared similar metabolic pathways and fatty acid metabolism was the predominant pathway. Western blot validation results showed that peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) and long-chain fatty acid-CoA ligase 1 (ACSL1), two proteins involved in fatty acid metabolism, were expressed differently in the berberine8998 group than in the untreated group and the berberine treatment group. Biochemistry results showed that berberine8998 significantly lowered the non-esterified fatty acid (NEFA) levels, which may lead to a reduction in TG levels in the berberine8998 treatment group and the differences observed in proteomics analyses. Pharmacokinetic analysis conducted in rats. After administration of berberine or berberine8998 (50 mg/kg, ig), berberine8998 exhibited a remarkably improved absorption with increasing bioavailability by 6.7 times compared with berberine. These findings suggest that berberine8998 lowers cholesterol and lipid levels via different mechanisms than berberine, and its improved absorption makes it a promising therapeutic candidate for the treatment of hypercholesterolemia and obesity.


Subject(s)
Anticholesteremic Agents/therapeutic use , Berberine/analogs & derivatives , Berberine/therapeutic use , Hypercholesterolemia/drug therapy , Proteomics , Animals , Anticholesteremic Agents/pharmacokinetics , Berberine/pharmacokinetics , Biological Availability , Cholesterol, LDL/blood , Cholesterol, LDL/metabolism , Cricetinae , Diet, High-Fat , Hep G2 Cells , Humans , Male , Rats, Sprague-Dawley , Triglycerides/blood , Triglycerides/metabolism
11.
Med Sci Monit ; 20: 1274-83, 2014 Jul 23.
Article in English | MEDLINE | ID: mdl-25064492

ABSTRACT

BACKGROUND: Accumulating evidence suggests that low concentrations of serum 25(OH)D is coupled with increased risks of hypertension, obesity, and cardiovascular disease. However, this relationship has not been established in populations with very low levels of 25(OH)D. Therefore, the aim of our study was to clarify the associations between 25(OH)D and blood pressure, obesity, sex, and lipid profiles in the Kazak ethnic population, who have an extremely low level of 25(OH)D. MATERIAL/METHODS: A multistage-cluster sampling survey was carried out for residents with Kazak ethnicity in Xinjiang, China. Anthropometric measurements of each participant were taken and the concentrations of 25(OH)D, calcium, alkaline phosphatase, and lipid profiles were measured. Individuals were classified into different groups in terms of vitamin D status, degree of adiposity, presence of hypertension, and other comorbidities. RESULTS: The madian concentration of 25(OH)D was 16.2 (11.8-20.5) ng/mL and the prevalence of vitamin D deficiency was 72.4% in this Kazak population (n=928, 59.0% women). Females had a lower 25(OH)D concentration than males - 14.6 (10.5-19.4) ng/mL vs. 17.7 (14.8-22.5) ng/mL, P<0.001. The subjects were classified into 3 groups according to their vitamin D status. There were significant differences in BMI (P=0.046), waist circumference (P=0.037), hip circumference (P=0.003), systolic BP (P=0.035), and LDL cholesterol (P=0.008) among the groups after adjustment for sex and age. On the other hand, there was no significant difference in vitamin D levels between groups with or without hypertension (P=0.586), and groups with or without obesity (P=0.639). A multifactor-regression analysis revealed that every increment of 1mg/dL in LDL cholesterol was associated with a 1.0 ng/mL decline in serum 25(OH)D. CONCLUSIONS: The insufficiency of vitamin D is highly prevalent in Kazaks. Sex, LDL cholesterol, and hip circumference are 3 variables strongly associated with serum 25(OH)D concentration. In a population with low levels of 25(OH)D, the negative relationship between obesity and serum 25(OH)D, a common finding from most previous studies, could not be established.


Subject(s)
Blood Pressure/physiology , Cholesterol, LDL/blood , Ethnicity/statistics & numerical data , Obesity/epidemiology , Vitamin D Deficiency/complications , Vitamin D Deficiency/epidemiology , Analysis of Variance , Anthropometry , China/epidemiology , Female , Humans , Male , Obesity/complications , Prevalence , Regression Analysis , Sex Factors , Vitamin D Deficiency/blood
12.
Zhongguo Gu Shang ; 27(9): 712-6, 2014 Sep.
Article in Chinese | MEDLINE | ID: mdl-25571650

ABSTRACT

OBJECTIVE: To explore the clinical effects of unilateral pedicle screw fixation and transforaminal lumbar interbody fusion (TLIF) through paraspinal muscle approach for recurrent lumbar disc herniation combined with lumbar instability. METHODS: A total of 35 patients with recurrent lumbar disc herniation combined with lumbar instability were treated between March 2008 and May 2010, including 15 patients managed by the paraspinal muscle approach with unilateral pedicle screw fixation and transforaminal lumbar interbody fusion (TLIF) (unilateral fixation group) and 20 patients by the posterior midline approach with bilateral pedicle screw fixation and posterior lumbar interbody fusion (bilateral fixation group). Operation time and intraoperative blood loss were observed, preoperative and postoperative JOA score and VAS score in low back pain and legs pain, the interbody fusion condition were compared between two groups. RESULTS: All patients were followed up from 6 to 30 months with an average 16.8 months. All clinical symptoms had obviously improved postoperatively. X-rays showed good interbody fusion (only 1 case did not obtain fusion in bilateral fixation group) without cage displacement or settlement and implant loosening or breakage. There was significant difference in operation time and the intraoperative blood loss between two groups (P < 0.05). Postoperative JOA score had obviously decreased than preoperative one (P < 0.05). At 1 week after surgery, there was significant difference in VAS score of low back pain between two groups and there was no significant difference in VAS score of legs pain between two groups (P > 0.05); at final follow-up, there was no significant difference in VAS score of low back pain and legs pain between two groups (P > 0.05). CONCLUSION: Two methods both can obtain satisfactory effect in treating recurrent lumbar disc herniation combined with lumbar instability. Through the paraspinal muscle approach with unilateral pedicle screw fixation and TLIF has advantages of smaller surgical incision, shorter operation time, less intraoperative blood loss, faster relief in low back pain after operation, etc.


Subject(s)
Intervertebral Disc Displacement/surgery , Lumbar Vertebrae/surgery , Pedicle Screws , Spinal Fusion/methods , Aged , Female , Humans , Intervertebral Disc Displacement/physiopathology , Lumbar Vertebrae/physiopathology , Male , Middle Aged , Recurrence
13.
Talanta ; 76(2): 276-81, 2008 Jul 15.
Article in English | MEDLINE | ID: mdl-18585277

ABSTRACT

Natural phenazines in secondary metabolites of bacteria have been receiving increasing attention in recent years due to their potential usage as antibiotics. In the present study, a rapid and reliable capillary zone electrophoresis (CZE) method was developed and validated for monitoring for the first time dynamic phenazine-1-carboxylic acid (PCA) and the 2-hydroxyphenazine (2-OH-PHZ) production of Pseudomonas chlororaphis GP72 during the entire fermentation cycle. The paper begins with the optimization of separate conditions for 2-OH-PHZ and PCA together with phenazine (PHZ), which is used as internal standard. The optimized conditions are: 10mM, pH 7.3 phosphate buffer, a fused-silica capillary with a total length of 49 cm x 75 microm ID, 375 microm OD with an effective length of 40 cm, 25 kV, 13 mbar 10s pressure sample injection and 25 degrees C air-cooling. The three compounds could be separated within 2 min under optimized conditions. The validation of the newly developed study shows the linear response of 2-OH-PHZ and PCA ranging from 10 to 250 microg mL(-1) with high correlation coefficient (r=0.9997 and 0.9993, n=7), low limits of detection (0.47 and 0.38 microg mL(-1)) and quantification (1.56 and 1.28 microg mL(-1)), respectively. Good precision values for intra- and inter-day detection and acceptable individual recovery ranges for 2-OH-PHZ and PCA are indicated. The newly developed method was also validated through monitoring dynamic PCA and 2-OH-PHZ production of P. chlororaphis GP72 during an 84 h growth cycle.


Subject(s)
Electrophoresis, Capillary/methods , Pseudomonas/metabolism , Culture Media/analysis , Electrophoresis, Capillary/standards , Fermentation , Methods , Phenazines/analysis , Reproducibility of Results
14.
Wei Sheng Wu Xue Bao ; 46(4): 516-21, 2006 Aug.
Article in Chinese | MEDLINE | ID: mdl-17037046

ABSTRACT

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.


Subject(s)
Pest Control, Biological/methods , Phytophthora/growth & development , Pseudomonas/isolation & purification , Pseudomonas/physiology , Base Composition/genetics , Capsicum/microbiology , Phylogeny , Plant Roots/microbiology , Pseudomonas/classification , Pseudomonas/genetics , RNA, Ribosomal, 16S/genetics
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