Recent Advances in Function-based Metagenomic Screening / 基因组蛋白质组与生物信息学报·英文版

Metagenomes from uncultured microorganisms are rich resources for novel enzyme genes. The methods used to screen the metagenomic libraries fall into two categories, which are based on sequence or function of the enzymes. The sequence-based approaches rely on the known sequences of the target gene families. In contrast, the function-based approaches do not involve the incorporation of metagenomic sequencing data and, therefore, may lead to the discovery of novel gene sequences with desired functions. In this review, we discuss the function-based screening strategies that have been used in the identification of enzymes from metagenomes. Because of its simplicity, agar plate screening is most commonly used in the identification of novel enzymes with diverse functions. Other screening methods with higher sensitivity are also employed, such as microtiter plate screening. Furthermore, several ultra-high-throughput methods were developed to deal with large metagenomic libraries. Among these are the FACS-based screening, droplet-based screening, and the in vivo reporter-based screening methods. The application of these novel screening strategies has increased the chance for the discovery of novel enzyme genes.

Identification of zebrafish shield organizer-specific genes / 中国实验动物学报

Objective During zebrafish gastrulation, dramatic movements rearrange cells into three germ layers and contribute to the formation of the shield organizer, which acts as a dorsal signal center to pattern the body axis.Global identification of shield organizer-specific genes in early gastrulas will be valuable for studying the regulatory cascades during organizer formation and body axis establishment.Methods Tg( gsc:GFP) transgenic embryos express GFP in the shield organizer, which is controlled by a 1.8 kb gsc promoter.Flow cytometry technology and RNA deep sequencing analysis were applied to isolate GFP positive cells from the Tg( gsc:GFP) transgenic embryos and systematically uncover the genes highly expressed in the dorsal organizer.Subsequently, the expression of shield organizer-specific genes was further con-firmed by quantitative real-time PCR and whole mount in situ hybridization method during zebrafish embryonic develop-ment.Results GFP-positive cells exceeding 96%purity were isolated from shield-stage Tg(gsc:GFP) transgenic embryos and 657 organizer highly expressed genes were identified through RNA deep sequencing analysis.The results of in situ hy-bridization experiments revealed that a number of genes including KIAA1324, ripply1, twist2, isthmin1, nme4, zgc174153 and rrbp1b were expressed in shield organizer during zebrafish gastrulation.Conclusions The identification of these shield organizer-specific genes in the current study provides useful clues to explore the zebrafish developmental functions in further studies.

Antiangiogenic and Proapoptotic Activity of Averrhoa Carambola L. Fruit Extract on Ehrlich Ascites Carcinoma Treated Mice.

Aim: Accumulation of fluid containing cancer cells in the abdomen particularly, in ovarian cancer, forms malignant ascites rendering poor prognosis at this stage. We investigated the tumor inhibitory activity of Averrhoa carambola L. fruit extract on EAC cells administered mice targeting angiogenesis and apoptosis, and the bioactive compounds responsible. Main Methods: Body weight, ascites volume and peritoneal angiogenesis were monitored. Giemsa staining on EAC cells, DNA fragmentation assay and FACS analysis to determine the growth arrest were conducted. VEGF count was monitored using ELISA. Phytochemical screening and HPLC analysis were conducted to determine the bioactive compounds. Key Findings: The fruit extract expressed direct cytotoxicity to EAC cells by inducing apoptosis as evidenced by decrease in tumor volume, viable cell count and body weight of EAC bearing mice; characteristic apoptotical features, DNA fragmentation of apoptosis, and growth arrest taking place at G2/M phase of the cell cycle. Significant decrease in density of microvessel network in peritoneal lining and VEGF count in treated cells indicated that the fruit extract curbed malignancy of tumor through its antiangiogenic activity also. All these can be attributed to catechin, epicatechin and ferulic acid present in the extract. The total phenolic, flavanoids, proancthocyanidin and condensed tannins content were 1.216 mgGAE/g extract, 767 mgCE/g extract, 586 mgCE/ g extract and 18.35 mgCE/g extract respectively. Significance: The present study is the first to provide direct evidence that Averrhoa carambola L. has potent proapoptotic and antiangiogenic activity which may contribute to its well- documented clinical activity as a pharmaceutical drug.

Effect of aging on repair capability of lung stem cells / 中国比较医学杂志

Objective To study the impact of aging on the capability of lung stem cell steady-state maintaining and bronchial epithelial cells regeneration and differentiation during the repair of lung epithelial cells after naphthalene induced bronchial epithelialium injury.Methods The proportion of lung stem cells in mice after naphthalene treatment was analyzed by immunohistochemistry and FACS.The repair efficiency of lung epithelial cell in young and old mice was examined by immunohistochemistry staining and FACS.Results The data suggested that aging didn ’ t change the proportion of lung stem cells ( including the distal lung epithelial stem cells/progenitor cells and lung mesenchymal stem cells/progenitor cells) under normal physiological conditions.After naphthalene injury, more serious injury and decreased repairing capacity was observed in old group.Lung progenitor cells /total lung cells decreased during the repair process of lung bronchial epithelialium ( clara cell) injury.The ratio of regenerated cell to lung progenitor and stem cells were also significantly decreased in old group.Conclusion The regenerated capability of lung stem cells after lung bronchial epithelialium injury decreased with aging.This might be the reason of more incidence of lung injury and worse therapeutic results in the elder in clinic.

Pluripotent lineage of CD133 stem cells isolated from human skin samples.

Skin stem cells are very important in cosmetics, pharmacological and regenerative medicine and burn cases. Foreskin samples surgically removed after circumcision from boys below 7 years were collected and primary epidermal cells were prepared by enzymatic and mechanical tituration method. Selecting CD133 (prominin-1) multipotent stem cell marker, enriched stem cells were analyzed by MACS using CD133 antibodies conjugated with magnetic beads. CD133 positive and negative cells with specific skin stem cells markers like - CD34 (Universal stem cells marker), CD29 (integrin beta-1) and CD49f (integrin alpha-6) immunophenotypes were screened and sorted in flowcytometer. Further the expression of four embryonic genes or transcription factors of pluripotent stem cells were analyzed for pluripotent character of sorted cells. It was found that skin stem cell markers associated with CD133 cells, differentially expressed CD34, CD29 and CD49f immunophenotyes on both positive and negative CD133 cells in FACS analysis. The embryonic stem cell markers (induced pluripotent stem cell markers) like Oct4, SOX2, Notch-2 and K19 genes were expressed in CD133 positive epidermal cells. It is therefore evident that foreskin derived epidermal stem cells showed pluripotent or multipotent nature. This finding opens up avenues for new uses of these stem cells for direct cell seeding in wound healing, surgical suturing and drug screening.

D8/17 Expression on B Lymphocytes of Children and Adolescents with Tic Disorder

OBJECTIVES: It has been reported that higher percentage of B cells react with monoclonal D8/17 antibody in patients with rheumatic fever, childhood onset obsessive-compulsive disorder, Tourette's disorder, or prepubertal anorexia nervosa. The purpose of this study is to replicate the previous studies in a Korean young population with tic disorder and to identify any relationship between D8/17 and clinical symptoms. METHODS: The binding of D8/17 to B cells was determined in patients with tic disorder (N=21) and healthy controls (N=9) by Fluorescence-Activated Cell Sorter analysis. RESULTS: In the sample examined by this study, the average percentage of B cells expressing D8/17 in tic disorder was 2.05%; healthy controls was 3.15%. No statistically significant differences were found in the mean percentages of D8/17 between the two groups. CONCLUSION: The expression of D8/17 in B cells was very low in this study. No subjects with tic disorder or healthy controls was above 12% in D8/17 positive proportion. Further studies, including higher number of patients and control group members, should be performed.

Radiomodulation by Hoechst 33258 against radiation- induced damage in murine splenocytes.

In this study modulatory effect of Hoechst 33258 on radiation induced membrane related signaling events which ultimately leads to apoptosis has been investigated. Splenocytes from swiss albino mice were irradiated in air at room temperature in a gamma chamber (240 TBq 60Co Model 4000 A) at the dose-rate of 0.052 Gys-1. Membrane lipid peroxidation, fluidity, specific activities of antioxidant enzymes, levels of nitric oxide, glutathione and apoptosis in presence and absence of different concentrations of Hoechst 33258 has been assayed. DNA binding activity of nuclear factor kappa B and activator protein–1 was also assayed by electrophoretic mobility shift assay. Modulatory effect of Hoechst 33258 was examined at 3 and 5 Gy using different concentrations (10, 20 and 30 µM). Hoechst 33258 was found to inhibit radiation induced peroxidative damage and fluidity and lowered the level of nitric oxide and apoptosis - as evident by DNA ladder assay and FACS, indicating free radicals scavenging potential. Dot plot diagramme clearly showed that 30 µM Hoechst 33258 caused 14% and 19% decrease in apoptotic cells at 3 Gy and 5 Gy of radiation respectively (compared to irradiated control group). Further DNA binding activity of nuclear factor kappa B and activator protein–1 was also inhibited but the antioxidant potential of the cells was enhanced. These findings support that Hoechst 33258 protects the cell from undergoing apoptosis. Hoechst 33258 may have interacted and has an ability to protect splenocytes against radiation induced apoptosis through modulation of membrane-related signaling events and antioxidant status.

Pro-inflammatory Cytokine Expression of Spleen Dendritic Cells in Mouse Toxoplasmosis

Dendritic cells have been known as a member of strong innate immune cells against infectious organelles. In this study, we evaluated the cytokine expression of splenic dendritic cells in chronic mouse toxoplasmosis by tissue cyst-forming Me49 strain and demonstrated the distribution of lymphoid dendritic cells by fluorescence-activated cell sorter (FACS). Pro-inflammatory cytokines, such as IL-1alpha, IL-1beta, IL-6, and IL-10 increased rapidly at week 1 post-infection (PI) and peaked at week 3 PI. Serum IL-10 level followed the similar patterns. FACS analysis showed that the number of CD8alpha+/CD11c+ splenic dendritic cells increased at week 1 and peaked at week 3 PI. In conclusion, mouse splenic dendritic cells showed early and rapid cytokine changes and may have important protective roles in early phases of murine toxoplasmosis.

Preliminary findings of immunological characteristics in primary human corneal endothelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To evaluate the function of primary human corneal endothelial cells(HCEC) serving as immunological cells. ·METHODS: Expression of HLA-DP, -DQ, -DR, CD40, CD80, and CD86 was determined by immunohistochemical methods. Meanwhile, purified peripheral blood mononuclear cells(PBMC) were cocultured with primary HCEC which were pre-treated with and without γ-IFN respectively; activation of lymphocytes was determined by FACS analysis.·RESULTS: In coculture system, T lymphocyte was activated by primary HCEC, HLA-DP, -DQ, -DR and CD40 expression were increased by γ-IFN induction. Costimulatory molecular CD80 was shown on the endothelial cells. ·CONCLUSION: Primary HCEC were assumed to be involved in the corneal transplantation rejection process as potential antigen presenting cells(APC).

A New Reporter Vector System Based on Flow-Cytometry to Detect Promoter Activity

In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity.

Isolation of Subtype Spermatogonia in Juvenile Rats / 华中科技大学学报（医学）（英德文版）

The present study was aimed at finding an effective method to isolate and purify the subtype of type A spermatogonial stem cells (SSCs) in juvenile rats. Testes from 9-days-old rats were used to isolate germ cells by using two-step enzymatic digestion. The expression of c-kit in the testes of the rats was immunohistochemically detected. After isolation, cell suspension was enriched further by discontinuous density gradient centrifugation. Then type A1-A4 spermatogonia was isolated from the purified spermatogonia with c-kit as the marker by using fluorescence-activated cell sorting(FACS). Electron microscopy was used to observe their ultrastructure. Finally, highly purified and viable subtype of SSCs was obtained. Cells separation with discontinuous density gradient centrifugation significantly increased the concentration of c-kit positive cells [(18.65±1.69)% after the centrifugation versus (3.16±0.84)% before the centrifugation, P＜0.01]. Furthermore, the recovery and viability were also high [(65.9±1.24)% and (85.6±1.14)%]. It is concluded that FACS with c-kit as the marker in combination with discontinuous density gradient centrifugation can well enrich type A1-A4spermatogonia from the testes of 9-days-old rats.

Dual effect of Molt-4 cell lines onset with Roscovitine / 肿瘤研究与临床

Objective To investigate the effect of Mlot-4 cells onset with Roscovitine (ROSC)as some Cyclin-dependent kinases(CDK),inhibitor.Methods The logarithmic growth phase Molt-4 cells treated with ROSC at a final concentration ranging between 1～20 μmol/L and harvested in different time point,DNA assay of single cells by flow cytometry was used to detect the effect of cell cycle arrest and Annexin-V/FITC assay was used to detect the effect of cell apoptosis. Results It showed that ROSC exerted strong inhibitory effect on proliferation and cell cycle progression of Molt-4 Accumulation of G2/M arrested cells starting 6 h after onset of 10 μmol/L and 20 μmol/L ROSC;at the same time,the cell apoptosis of Molt-4 would be detected,According with the time and concentration changing,the cell apoptosis rate would rise.Conclusion It is concluded that Roscovitine(ROSC)as some Cyclin-dependent kinases(CDK),inhibitor,It has dual effects to Molt-4 cells,not only the effect of cell cycle arrest but also the effect of cell apoptosis.

Establishment of B-1 cell-derived polyreactive monoclonal antibodies and expression of costimulators by B-cell to antigenic stimulation / 대한치주과학회지

No abstract available.

TAF to The Hypoimmunity Mice on Effect of T Cell Polarization / 浙江中医药大学学报

[Objective]To study the effect of T cell groups of CD4+,CD8+,CD4+/CD8+,IL-4,IFN-? in the hypoimmunitymice induced by hydrocortisone to discuss its function of regulating the immune function and CD4+TH cell’s inferior change of group,have offered the experiment basis for clinical practice of TAF.[Method] FACS measured the T lymphocyte phenotype;the level of cytokine IFN-r and IL-4 was detected by ELISA.[Result] TAF can raise CD4+T lymphocyte of hypoimmunitymice,suppress CD8+ T lymphocyte expression,raise CD4+/CD8+ ratio;And can make the level of serum IFN-r obviously enhanced in hypoimmunitymice,and the level of IL-4 was very low.[Conclusion] TAF can rebuild immune function of hypoimmunitymice,promote organism Th0 to split up to Th1,maintain the advantage state of TH1,and strengthen the function of cellular mediated immunoresponse.

Isolation of Putative Corneal Epithelial Stem Cells from Cultured Limbal Tissue

PURPOSE: To investigate methods of isolating putative corneal epithelial stem cells from cultured limbal tissue. METHODS: Three extraction techniques were compared to identify an efficient method of obtaining a large number of viable corneal epithelial stem cells from the limbus. Limbal tissues were extracted by incubation at 37 degrees C or 4 degrees C for 1 or 16 hours, respectively, with 1.2U/ml dispase/trypsin or by treatment with 0.05% trypsin and 0.01% ethyldiaminetetraacetic acid (EDTA) at 37 degrees C in single procedure. Collected cells were cultured on NIH/3T3-seeded plates, and colony forming efficiency (CFE) was evaluated. Fluorescence activated cell sorting (FACS) was performed with a Coulter EPICS 753 after incubation with Hoechst 33342 and propidium iodide (PI). Hoechst negative cells were obtained using gates exhibiting low Hoechst blue with a 424/44 nm BP filter. Gated cells of each fraction were re-cultured to assess the capability of colony formation. RESULTS: The mean numbers of viable cells obtained from treatment with dispase and trypsin was 3x10(4) cell/ml and 8.06x10(5) cell/ml at 37 degrees C and 4 degrees C incubations; the number increased to 1.21x10(6) cell/ml with a trypsin/EDTA treatment (p<0.05). CFE was 9.67+/-2.13% and 6.63+/-2.35% in rabbit and human cells, respectively. Likewise, the Hoechst negative fraction was 3.61+/-0.42% and 5.21+/-4.91% in rabbit and human cells, respectively. The sorted Hoechst negative cells were cultured through four passages, forming small round colonies. In rabbit cells, the CFEs of Hoechst negative and positive fractions after FACS, were 12.67+/-2.24% and 1.17+/-6.13%, respectively (p<0.05). CONCLUSIONS: Putative corneal epithelial stem cells were efficiently isolated from limbal tissue using a trypsin/EDTA extraction and FACS. This technique may be very useful in tissue engineered stem cell therapy.

The immune reaction in mucosal and systemic immune system was induced after intranasal immunization with bivalent Shigella vaccines / 中国免疫学杂志

Objective:To observe the effect on different mucosal sites and system immune sites after intranasal immunization with bivalent Shigella vaccines Methods:BALB/c mice were divided into three groups at random , 10 mice per group Mice were intranasally immunized respectively with FSM 2117or FS 5416 (4?10 7CFU) three doses with an interval of two weeks The NALT, NP, spleen, PP, MLN, lymphocytes were isolated on the seventh day after the last immunization to assay the change of the cell phenotype with FACS The nasal ?lung?intestine?genital tract lavage fluid and serum were taken to assay the specific IgA or IgG against F2a or Sonni LPS with ELISA Results:The specific IgA and IgG in different mucosal sites and serum increased significantly after intranasal immunization with two Shigella vaccines compared with the control (P

Characteristics of B Cell proliferation by polysaccharide fraction of Paeonia japonica miyabe

BACKGROUND: Paeonia j ap onica Miyabe is a medicinal plant which has been widely used as a component of blood-building decoctions (Chinese medicinal concept : Bu-Xie). The immunopharmacological characteristics of the extract of Paeonia j ap onica (PJ) were investigated. METHODS: The effects of fractions of PJ extract on lymphocyte proliferation were measured by H3 -thymidine incorporation assay . The proliferated lymphocyte subsets were analyzed in flow cytometry . The subset cell populations of spleen cells were separated by magnetic cell separation system, and their proliferation by the extract were investigated. The effect of the extract on antibody production was determined in mice challenged with sheep red blood cells (SRBC) using hemolytic plaque forming cell assay. RESULTS: Spleen cells were proliferated by water extract of PJ. Polysaccharide fraction (PJ-P) of the extract was most active in the proliferation. It was found in flow cytometry that the lymphocyte subset proliferated by PJ-P was B cell population. Among the separated subset cell populations, T cell-depleted cell population and macrophage-depleted cell population were most proliferated by PJ-P. However, positively selected populations of B cells and T cells were not proliferated by PJ-P. These result s indicate that B cell proliferation by PJ-P may require the assistance of macrophages or T cells. These result s suggest that firstly PJ-P may stimulate macrophages or T cells, and then B cells are activated. The number of antibody-secreting cells was increased by administration of PJ-P in mice immunized with SRBC as a T-dependent antigen. CONCLUSION: These result s suggest that macrophages and accessory cells are directly activated by PJ-P and then helper T cells and B cells are indirectly activated. As the results, immune responses might be coordinately improved. In conclusion, PJ-P, a polysaccharide of P. j ap onica, may be a characteristic immunostimulator, which is analogous to polysaccharides such as lentinan, PSK and ginsan.

A case of allogeneic bone marrow transplantation in Gaucher's disease type III and recovery of enzyme activity documented by Fluorescence-Activated Cell Sorter (FACS) analysis / 대한내과학회지

Gaucher's disease (GD) is the most common inherited lysosomal storage disease, manifested by generalized accumulation of glucocerebroside in macrophages of the reticuloendothelial system due to a deficient lysosomal beta-glucocerebrosidase (GC). It is inherited by an autosomal recessive pattern in which three clinical phenotypes have been described based on the presence and severity of neurologic involvement. GD is treated possible by GC enzyme replacement therapy, allogeneic bone marrow transplantation (BMT), and gene therapy. We here report the exprience of successful allogeneic BMT in a 16-year-old female patient with GD type III which was demostrated markedly increased Gaucher cells in bone marrow and absence of GC activity in peripheral blood monocytes by FACS using 5'- pentafluorobenzoylaminofluorescein-di-beta-D-glucoside (PFBFDGlu) as substrate. Donor marrow engraftment was confirmed by chromosome analysis using microsatellite and by bone marrow examination. Assay of GC activity using FACS revealed normal level of enzyme activity. She remains alive and well after 12 months of BMT.

Studies on the characterization of a molecule expressed on murine thymic stromalcells and activated thymocytes / 中国免疫学杂志

To identify the expression of the molecule recognized by Pf18-3 mAb (Pf18-3 molecule) on various cells. Meth-ods: The expression of pr18-3 molecule was assayed by flow cytometry and confocal laser scanning microscope . Result: The molecule recog-nized by Pf18-3 mAb expressed on TSC and other stromal cells. Whereas, fresh thymocytes were Pf18-3 negative. Interestingly, the expressionof Pf18-3 molecule was gradually up-regulated on thymocytes after activation by ConA. This molecule mainly expressed on CD4+ CD8+ andCD4+ CD8- cells. Under confocal laser scanning microscope, the staining of fluorescence showed as ring around the cell, it changed grsduallystronger and thicker with activation. Conclusion: This study indicated that the Pf18-3 molecule was co-expressive molecule of MTSC and acti-vated tlymocytes,it was concemed closely about the activation of CD4+ C D8+ and CD4+ CD8- cells.

Inhibition of Interleukin-1 Signal by Annexin-1 in Phorbol Myristate Acetate Stimulated Lymphocytes / 대한면역학회지

Annexin-1 (ANX1) is a 37 kDa protein that is induced and secreted by glucocorticosteroid hormone. The secreted ANX1 has been believed to exert its function by binding to its putative rnembrane receptor. In this report we demonstrate that ANXl receptor (ANX1R) signal blocks the interleukin-1B (IL-1B) receptor signal pathway in human peripheral blood mononuclear cells (PBMCs). When PBMCs were treated with both IL-1B (100 ng/ml) and PMA (10 ng/ml) in the absence or presence of dexamethasone for 5 days, dexamethasone (100 nM) suppressed lymphocyte proliferation to 24% of the control. However addition of anti-ANX1 polyclonal antibody of 1:200 and 1:1,000 dilution to this system induced recovery of proliferation to 80% and 40%, respectively, when compared to the control. In the mixed lymphocyte reaction, dexamethasone suppressed lymphocyte proliferation to 9% of that of control when stimulated with IL-1B (100 ng/ml) and phorbol myristate acetate (10 ng/ml). Addition of anti-ANX1 polyclonal antibody (1:1,000) to this system also recovered the proliferation to 20% of that of the control system. In the ANX1 receptor induction experiment using flow cytometry, ANX1 receptor expression on lymphocytes, CD4+ T cells, CD8+ T cells and monocytes increased depending on the externally added IL-1B ranging from 10 to 1,000 ng/ml. From these results, it is evident that dexamethasone induces ANX1 secretion into the culture medium and anti-ANX1 polyclonal antibody abolishes the effects of dexamethasone. Furthermore these results imply that extracellular ANX1 exerts its effects by binding to the receptor on the cell membrane and the activated signal(s) of ANX1R block IL-1B receptor signal in the lymphocytes.