The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more a...The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.展开更多
BACKGROUND Pancreatic cancer tissues mainly consist of fibrotic and dense stroma,which limits their therapeutic efficacy.The stromal fibroblasts of pancreatic tumors frequently express the secreted protein acidic and ...BACKGROUND Pancreatic cancer tissues mainly consist of fibrotic and dense stroma,which limits their therapeutic efficacy.The stromal fibroblasts of pancreatic tumors frequently express the secreted protein acidic and rich in cysteine(SPARC).AIM To assess the impact of SPARC and its oncological relevance in patients undergoing pancreatic cancer resection.METHODS Ninety-one pancreatic ductal adenocarcinoma specimens were obtained from patients with curative resection between January 2009 and December 2015 as a retrospective study.SPARC expression patterns were analyzed using immunohistochemistry.Oncological outcomes were analyzed based on SPARC expression patterns.Oncological outcomes,based on SPARC expression,were analyzed in The Cancer Genome Atlas-Pancreatic Adenocarcinoma cohort(retrieved from a public database).RESULTS Patients with stromal SPARC expression(sSPARC+)had poorer overall survival than that in those without it(sSPARC-)(P=0.035).However,among patients who received adjuvant treatment,no difference was observed in survival between the sSPARC+and the sSPARC-groups(P=0.14).In The Cancer Genome Atlas-Pancreatic Adenocarcinoma samples,the high SPARC expression group exhibited noticeably lower overall survival than that in the low expression group(cutoff:14.1295,P=0.0222).Furthermore,SPARC expression was strongly correlated with the percentage the CD10+stromal component(R2=0.804,P<0.001).CONCLUSION Adjuvant chemotherapy improves survivals in sSPARC+pancreatic cancer patients,indicating suggesting sSPARC expression as a prognostic biomarker and potential indicator for neoadjuvant treatment planning.展开更多
Objective Microcystin-leucine-arginine(MC-LR)exposure induces lipid metabolism disorders in the liver.Secreted frizzled-related protein 5(SFRP5)is a natural antagonist of winglesstype MMTV integration site family,memb...Objective Microcystin-leucine-arginine(MC-LR)exposure induces lipid metabolism disorders in the liver.Secreted frizzled-related protein 5(SFRP5)is a natural antagonist of winglesstype MMTV integration site family,member 5A(Wnt5a)and an anti-inflammatory adipocytokine.In this study,we aimed to investigate whether MC-LR can induce lipid metabolism disorders in hepatocytes and whether SFRP5,which has anti-inflammatory effects,can alleviate the effects of hepatic lipid metabolism by inhibiting the Wnt5a/Jun N-terminal kinase(JNK)pathway.Methods We exposed mice to MC-LR in vivo to induce liver lipid metabolism disorders.Subsequently,mouse hepatocytes that overexpressed SFRP5 or did not express SFRP5 were exposed to MC-LR,and the effects of SFRP5 overexpression on inflammation and Wnt5a/JNK activation by MC-LR were observed.Results MC-LR exposure induced liver lipid metabolism disorders in mice and significantly decreased SFRP5 mRNA and protein levels in a concentration-dependent manner.SFRP5 overexpression in AML12cells suppressed MC-LR-induced inflammation.Overexpression of SFRP5 also inhibited Wnt5a and phosphorylation of JNK.Conclusion MC-LR can induce lipid metabolism disorders in mice,and SFRP5 can attenuate lipid metabolism disorders in the mouse liver by inhibiting Wnt5a/JNK signaling.展开更多
Fusarium graminearum,the primary pathogenic fungus responsible for Fusarium head blight(FHB)in wheat,secretes abundant chemical compounds that interact with host plants.In this study,a secreted protein FgHrip1,isolate...Fusarium graminearum,the primary pathogenic fungus responsible for Fusarium head blight(FHB)in wheat,secretes abundant chemical compounds that interact with host plants.In this study,a secreted protein FgHrip1,isolated from the culture filtrate of F.graminearum,was found to induce typical cell death in tobacco.The FgHrip1 gene was then cloned and expressed in Escherichia coli.Further bioassay analysis showed that the recombinant FgHrip1 induced early defense induction events,such as reactive oxygen species(ROS)production,callose deposition,and up-regulation of defense-related genes in tobacco.Furthermore,FgHrip1 significantly enhanced immunity in tobacco seedlings against Pseudomonas syringae pv.tabaci 6605(Pst.6605)and tobacco mosaic virus(TMV).FgHrip1-treated wheat spikes also exhibited defense-related transcript accumulation and developed immunity against FHB infection.Whereas the expression of FgHrip1 was induced during the infection process,the deletion of the gene impaired the virulence of F.graminearum.Our results suggest that FgHrip1triggers immunity and induces disease resistance in tobacco and wheat,thereby providing new insight into strategy for biocontrol of FHB.展开更多
[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided the...[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.展开更多
[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase （SAMS） in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was ...[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase （SAMS） in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was amplified by PCR and inserted into the secreted expression vector pPIC9K to get recombinant plasmid. The recombinant plasmid pPIC9K-sarr~ was integrated into Pichia pastoris GSl15 genome by electroporation and induced by methanol. The activity of the recombinant enzyme was measured using high-pedormance liquid chroma- tography （HPLC） by determining the production of S-adenosy-L-methionine （SAM） with the enzyme secreted. [ ResultJ The molecular weight of the expression protein identified by SDS-PAGE was about 50 kD, being larger than the theoretical molecular mass of SAMS, which might be due to the glycosytation in the process of secretion. Methanol-induction as well as preliminary purification could enhance the enzyme activity, espe- cially the latter, after which the specific activity of SAMS was improved to 61.48 U/rng. [Conclusion] SAMS with biological activity was secreted successfully in Pichia pastoris GSl15 for the first time. And it is the start for the genetic engineering strains to open up prospects for industrial production.展开更多
AIM： To investigate the functions of promoter hypermethylation of secreted frizzled-related proteins （sFRPs） genes in colorectal tumorigenesis and progression. METHODS： The promoter hypermethylation and expression...AIM： To investigate the functions of promoter hypermethylation of secreted frizzled-related proteins （sFRPs） genes in colorectal tumorigenesis and progression. METHODS： The promoter hypermethylation and expression of sFRP genes in 72 sporadic colorectal carcinomas, 33 adenomas, 18 aberrant crypt foci （ACF） and colorectal cancer cell lines RKO, HCT116 and SW480 were detected by methylation-specific PCR and reverse transcription PCR, respectively. RESULTS： None of the normal colorectal mucosa tissues showed methylated bands of any of four sFRP genes, sFRP1, 2, 4 and 5 were frequently methylated in colorectal carcinoma, adenoma and ACF （sFRP1 〉 85%, sFRP2 〉75%, sFRP5 〉 50%）, and the differences between three colorectal tissues were not significant （P 〉 0.05）. IVlethylation in colorectal tumors was more frequent than in normal mucosa and adjacent normal mucosa. The mRNA of sFRP1-5 genes was expressed in all normal colorectal mucosa samples. Expression of sFRP1, 2, 4 and 5 and sFRP1, 2 and 5 was downregulated in carcinoma and adenoma, respectively. The downregulation of sFRP2, 4 and 5 was more frequent in carcinoma than in adenoma. Expression of sFRP3 which promoter has no CpG island was downregulated in only a few of colorectal tumor samples （7/105）. The downregulation ofsFRP1, 2, 4 and 5 expression was significantly associated with promoter hypermethylation in colorectal tumor. After cells were treated by DAC/TSA combination, the silenced sFRP mRNA expression could be effectively re-expressed in colorectal cancer cell lines. CONCLUSION： Hypermethylation of sFRP genes is a common early event in the evolution of colorectal tumor, occurring frequently in ACF, which is regarded as the earliest lesion of multistage colorectal carcinogenesis. It appears to functionally silence sFRP genes expression. Methylation of sFRP1, 2 and 5 genes might serve as indicators for colorectal tumor.展开更多
AIM： To identify the methylation of secreted frizzled-related protein 1 （SFRP1） in gastric cancer and to investigate the aberrant expression of SFRP1 and its correlation with the clinical pathological features of p...AIM： To identify the methylation of secreted frizzled-related protein 1 （SFRP1） in gastric cancer and to investigate the aberrant expression of SFRP1 and its correlation with the clinical pathological features of patients. METHODS： We determined SFRP1 methylation and SFRP1 mRNA expression in 3 gastric cancer cell lines SGC-7901, BGC-823, HGC-27, from 52 primary gastric cancer specimens and matched tumor adjacent tissue specimens by methylation-specific （MSP） PCR and RT-PCR respectively. Fisher＇s exact test was used to analyze the statistical association between clinical pathological data and aberrant expression of SFRP1. RESULTS： In 3 cancer cell lines, BGC-823 and HGC-27 had methylated SFRP1 and lost SFRP1 mRNA expression. After treatment of BGC-823 and HGC-27 with the demethylating agent, 5-aza-2′-deoxycytidine, SFRP1 was re-expressed. In 52 primary gastric cancer specimens and matched tumor adjacent tissue specimens, hypermethylation of SFRP1 was detected in 23 （44%） and 8 （15%） specimens respectively （x^2= 10.34, P 〈 0.01）. Loss of SFRP1 expression was detected in 17（33%） and 6 （12%） specimens respectively （x^2= 6.75, P 〈 0.01）. There was a significant correlation between SFRP1 hypermethylation and SFRP1 expression loss. SFRP1 expression was also correlated significantly with tumor stage and lymph node status, but not with patient sex, age and histological type. CONCLUSION： SFRP1 inactivation is a common and early event caused mainly by hypermethylation in gastric cancer. SFRP1 expression loss may be correlated with tumor metastasis in primary gastric cancer.展开更多
Objective Obstructive sleep apnea (OSA) is closely related to obesity, insulin resistance and inflammation. Secreted frizzled-related protein 5 (SFRP5) is a recently discovered adipokine. It is involved in insulin res...Objective Obstructive sleep apnea (OSA) is closely related to obesity, insulin resistance and inflammation. Secreted frizzled-related protein 5 (SFRP5) is a recently discovered adipokine. It is involved in insulin resistance and inflammation in obesity. This study aimed at evaluating the association between SFRP5and sleeping characteristics as well as biochemical parameters of OSA patients.Methods This was a prospective case control study. Nondiabetic OSA patients and controls were consecutively recruited and divided into three groups: OSA group, apnea–hypopnea Index (AHI)≥5/h; healthy controls with normal body mass index (BMI); obese controls without OSA, and BMI > 24.0 kg/m2. All participants underwent polysomnography (PSG). Plasma SFRP5 was examined using enzyme-linked immunosorbent assay (ELISA). Blood biochemical examinations, including fasting blood glucose (FBG), lipid profile, hypersensitive Creactive protein (hsCRP), were performed early in the morning after PSG. Patients with severe OSA were treated with nasal continuous positive airway pressure (nCPAP), and plasma SFRP5 was repeatedly measured for comparison.Results Sixty-eight subjects were enrolled in the study, including 38 patients of OSA, whose medium AHI was 58.70 /h (36.63, 71.15), 20 obese controls, and 10 healthy controls. The plasma SFRP5 level of OSA patients was not significantly different from that of healthy controls or obese controls. In OSA patients, SFRP5 level correlated positively with triglyceride level (r=0.447, P=0.005) and negatively with LDL-cholesterol level and HDLcholesterol level (r=?0.472 and P=0.003; r=?0.478 and P=0.002; respectively). SFRP5 level was not found correlating with FBG, AHI, or any of nocturnal hypoxia parameters. After overnight nCPAP treatment, plasma SFRP5 levels of OSA patients did not change significantly (t=1.557, P = 0.148) compared to that of pretreatment.Conclusions In nondiabetic OSA patients, plasma SFRP5 is associated with the lipid profile. However,no correlation was observed between SFRP5 and FBG or sleep parameters. The SFRP5 level of OSA patients did not differ from that of non-OSA individuals in our study.展开更多
Secreted protein acidic and rich in cysteine(SPARC)is a matricellular protein highly expressed in bone tissue that acts as achemoattractant factor promoting the arrival of prostate cancer(PCa)cells to the bone marrow....Secreted protein acidic and rich in cysteine(SPARC)is a matricellular protein highly expressed in bone tissue that acts as achemoattractant factor promoting the arrival of prostate cancer(PCa)cells to the bone marrow.However,the contribution of SPARCduring the early stages of tumor progression remains unclear.In this study,we show that SPARC is highly expressed in PCa tissueswith a higher Gleason score.Through stable knockdown and overexpression of SPARC in PC3 and LNCaP cells,respectively,here wedem on strate that en doge nous SPARC induces the epithelial-mesenchymal tran sition(EMT),decreasing E-cadheri n and cytokeratin18 and increasing N-cadheri n and vime ntin.Moreover,SPARC in duces the expression of EMT regulatory tran scription factors Snailfamily transcriptional repressor 1(Snail),Snail family transcriptional repressor 2(Slug),and zinc finger E-box binding homeobox 1(Zeb1).In addition,SPARC knockdown in PC3 cells decreases migration and invasion in vitro,without modifying cell proliferation.Our results indicate that SPARC might facilitate tumor progression by modifying the cellular phenotype in cancer cells.展开更多
AIM：To determine the methylation status and aberrant expression of some secreted frizzled-related protein（SFRP） genes in pancreatic cancer and explore their role in pancreatic carcinogenesis.METHODS：Methylation st...AIM：To determine the methylation status and aberrant expression of some secreted frizzled-related protein（SFRP） genes in pancreatic cancer and explore their role in pancreatic carcinogenesis.METHODS：Methylation status and expression of SFRP genes were detected by methylation-specific PCR（MSPCR） and reverse-transcription PCR（RT-PCR） respectively.RESULTS：The frequencies of methylation for SFRP genes 1,2,4,5 were 70%,48.3%,60% and 76.7% in pancreatic cancer samples,and 21.7%,20%,10% and 36.7% in matched cancer adjacent normal tissue samples,respectively（χ^2 = 28.23,P 〈 0.0001 for SFRP gene 1;χ^2 = 10.71,P = 0.001 for SFRP gene 2;χ^2 = 32.97,P 〈 0.0001 for SFRP gene 4;χ^2 = 19.55,P 〈 0.0001 for SFRP gene 5）.Expression loss of SFRP genes 1,2,4 and 5 was found in 65%,40%,55% and 71.7% of 60 pancreatic cancer samples,and 25%,15%,18.3% and 31.7% of matched cancer adjacent normal tissue samples,respectively（χ^2 = 19.39,P 〈 0.0001 for SFRP gene 1;χ^2 = 9.40,P = 0.002 for SFRP gene 2;χ^2 = 17.37,P 〈 0.0001 for SFRP gene 4;χ^2 = 19.22,P 〈 0.0001 for SFRP gene 5）.SFRP gene 1 was methylated but not expressed in PC-3 and PANC-1,SFRP gene 2 was methylated but not expressed in PANC-1 and CFPAC-1,SFRP gene 4 was methylated but not expressed in PC-3,and SFRP gene 5was methylated but not expressed in CFPAC-1.CONCLUSION： Hypermethylation and aberrant expression of SFRP genes are common in pancreatic cancer, which may be involved in pancreatic carcinogenesis.展开更多
BACKGROUND Sepsis is a major medical challenge.Magnolol is an active constituent of Houpu that improves tissue function and exerts strong anti-endotoxin and anti-inflammatory effects,but the mechanism by which it redu...BACKGROUND Sepsis is a major medical challenge.Magnolol is an active constituent of Houpu that improves tissue function and exerts strong anti-endotoxin and anti-inflammatory effects,but the mechanism by which it reduces intestinal inflammation in sepsis is yet unclear.AIM To assess the protective effect of magnolol on intestinal mucosal epithelial cells in sepsis and elucidate the underlying mechanisms.METHODS Enzyme-linked immunosorbent assay was used to measure tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6,and regulated on activation,normal T-cell expressed and secreted(RANTES)levels in serum and ileal tissue in animal studies.The histopathological changes of the ileal mucosa in different groups were observed under a microscope.Cell Counting Kit-8 and cell permeability assays were used to determine the concentration of drug-containing serum that did not affect the activity of Caco2 cells but inhibited lipopolysaccharide(LPS)-induced decrease in permeability.Immunofluorescence and Western blot assays were used to detect the levels of RANTES,inhibitor of nuclear factor kappa-B kinaseβ(IKKβ),phosphorylated IKKβ(p-IKKβ),inhibitor of nuclear factor kappa-B kinaseα(IκBα),p65,and p-p65 proteins in different groups in vitro.RESULTS In rats treated with LPS by intravenous tail injection in the presence or absence of magnolol,magnolol inhibited the expression of proinflammatory cytokines,IL-1β,IL-6,and TNF-αin a dose-dependent manner.In addition,magnolol suppressed the production of RANTES in LPS-stimulated sepsis rats.Moreover,in vitro studies suggested that magnolol inhibited the increase of p65 nucleation,thereby markedly downregulating the production of the phosphorylated form of IKKβin LPS-treated Caco2 cells.Specifically,magnolol inhibited the translocation of the transcription factor nuclear factor-kappa B(NF-κB)from the cytosol into the nucleus and down-regulated the expression level of the chemokine RANTES in LPS-stimulated Caco2 cells.CONCLUSION Magnolol down-regulates RANTES levels by inhibiting the LPS/NF-κB signaling pathways,thereby suppressing IL-1β,IL-6,and TNF-αexpression to alleviate the mucosal barrier dysfunction in sepsis.展开更多
Total RNA was isolated from mycelium of T. harzianum by Total RNA extraction kit, and two clear bands of rRNA （28S and 18S） were observed in agarose electrophoresis. By joining the 3＇end sequence with the known SA7...Total RNA was isolated from mycelium of T. harzianum by Total RNA extraction kit, and two clear bands of rRNA （28S and 18S） were observed in agarose electrophoresis. By joining the 3＇end sequence with the known SA76 EST from cDNA library of T. harzianum, a full-length cDNA sequence of 2019bp was obtained, whose open reading frame contained 1593bp, a stop codon TAA, a 5＇untranslated region （5＇UTR） of 266bp, a 3＇untranslated region （3＇UTR） of 201bp, and poly （A） 29 encoded a protein of 530 amino acids, had a signal peptide. T. harzianum shared 53% identity of secreted aspartic proteinase gene with G. zeae, 37% with N. crassa and 36% with C. globosum. The full-length cDNA sequence of secreted aspartic proteinase gene from T. harzianum was cloned for the first time by using BD SMART RACE technique, which provides a foundation to obtain and validate functional genes of T. harzianum.展开更多
Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in...Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome of Saccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, and they were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secreted proteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secreted proteins included all the three domains. There were differences in the constitution of signal peptides between the secreted proteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides were similar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and the homology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECES and CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignment result indicated that homology of these sequences with the same signal peptide was very highly conservative in amino acid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secreted proteins is discussed in this paper.展开更多
The fine-tuned expression dynamics of the effector genes are pivotal for the transition from vegetative growth to host colonization of pathogenic filamentous fungi.However,mechanisms underlying the dynamic regulation ...The fine-tuned expression dynamics of the effector genes are pivotal for the transition from vegetative growth to host colonization of pathogenic filamentous fungi.However,mechanisms underlying the dynamic regulation of these genes remain largely unknown.Here,through comparative transcriptome and chromatin immunoprecipitation sequencing(ChIP-seq)analyses of the methyltransferase PoKmt6 in rice blast fungus Pyricularia oryzae(syn.Magnaporthe oryzae),we found that PoKmt6-mediated H3K27me3 deposition was enriched mainly at fast-evolving regions and contributed to the silencing of a subset of secreted proteins(SP)and transposable element(TE)families during the vegetative growth of P.oryzae.Intriguingly,we observed that a group of SP genes,which were depleted of H3K27me3 modification,could also be silenced via the H3K27me3-mediated repression of the nearby TEs.In conclusion,our results indicate that H3K27me3 modification mediated by PoKmt6 regulates the expression of some SP genes in fast-evolving regions through the suppression of nearby TEs.展开更多
BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its ab...BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its aberrant methylation in gastric cancer(GC)is still inadequate.In the present research,we performed fundamental research to clarify the precise function of methylation on SPARC and its significance in GC.AIM To investigate promoter methylation and the effects of the SPARC gene in GC cells and tissues and to evaluate its clinical significance.METHODS Plasmids that overexpressed the SPARC gene were transfected into human GC BGC-823 cells;non-transfected cells were used as a control group(NC group).Quantitative real-time polymerase chain reaction and western blotting(WB)were then used to detect the expression of SPARC.Methylation-specific polymerase chain reaction was executed to analyze the gene promoter methylation status.Cell viability was measured by the cell counting kit-8 assay.The migration and invasion ability of cells were detected by scratch assays and transwell chamber assays,respectively.Cell cycle events and apoptosis were observed with a flow cytometer.RESULTS The expression of SPARC mRNA in GC tissues and cells was significantly lower and showed differing degrees of hypermethylation,respectively,than that in normal adjacent tissues and control cells.Treatment with 5-Aza-2’-deoxycytidine(5-Aza-Cdr)was able to restore the expression of SPARC and reverse promoter hypermethylation.Overexpression of the SPARC gene significantly inhibited proliferation,migration,and invasion of GC cells,while also causing cell cycle arrest and apoptosis;the NC group exhibited the opposite effects.CONCLUSION This study demonstrated that SPARC could function as a tumor suppressor and might be silenced by promoter hypermethylation.Furthermore,in GC cells,SPARC inhibited migration,invasion,and proliferation,caused cell cycle arrest at the G0/G1 phase,and promoted apoptosis.展开更多
BACKGROUND： It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells （BMSCs） can in vitro induce and differentiate into t...BACKGROUND： It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells （BMSCs） can in vitro induce and differentiate into the cells possessing the properties of nerve cells. But the functions of BMSCs-derived neural stem cells（NSCs） and the differentiated neuron-like cells are still unclear. OBJECTIVE： To observe whether bone marrow-derived NSCs can secrete norepinephrine （NE） under the condition of in vitro culture, induce and differentiation, and analyze the biochemical properties of BMSCs-derived NSCs. DESIGN： A non-randomized and controlled experimental observation SETTING ： Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University MATERIALS： This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5- month-old healthy New Zealand white rabbits. METHODS： This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5 month-old healthy New Zealand white rabbits. BMSCs of rabbits were isolated and performed in vitro culture, induce and differentiation with culture medium of NSCs and differentiation-inducing factor, then identified with immunocytochemical method. Experimental grouping： ①Negative control group： L-02 hepatic cell and RPMI1640 culture medium were used. ② Background culture group： Only culture medium of NSCs as culture solution was added into BMSCs to perform culture, and 0.1 volume fraction of imported fetal bovine serum was supplemented 72 hours later. ③Differentiation inducing factor group： After culture for 72 hours, retinoic acid and glial cell line-derived neurotrophic factors were added in the culture medium of BMSCs and NSCs as corresponding inducing factors. The level of NE in each group was detected on the day of culture and 5, 7, 14 and 20 days after culture with high performance liquid chromatography （HPLC）. The procedure was conducted 3 times in each group.Standard working curve was made according to the corresponding relationship of NE concentration and peak area. The concentration of NE every 1×10^7 cells was calculated according to standard curve and cell counting. MAIN OUTCOME MEASURES ： The level of NE of cultured cells was detected with HPLC; immunocytochemistrical identification of Nestin and neuron specific nuclear protein was performed. RESULTS： ① On the 14^th day after cell culture, BMSCs turned into magnus and round cells which presented Nestin-positive antigen, then changed into neuron-like cells with long processus and presented neuron specific nuclear protein -positive antigen at the 20^th day following culture. ② The ratio of NE concentration and peak area has good linear relationship, and regression equation was Y=1.168 36＋0.000 272 8X,r=-0.998 4. Coefficient variation （CV） was 〈 5% and the recovery rate was 92.39%（ Y referred to concentration and X was peak area）.③NE was well detached within 10 minutes under the condition of this experiment. ④ NE was detected in NSCs and their culture mediums, which were cultured for 7, 14 and 20 days respectively, but no NE in BMSCs, NSCs-free culture medium and L-02 hepatic cell which were as negative control under the HPLC examination. Analysis of variance showed that the level of NE gradually increased following the elongation of culture time （P 〈 0.01 ）. No significant difference in the level of NE existed at the same time between differentiation inducing factor group and basic culture group（P 〉 0.05）. CONCLUSION ： BMSCs of rabbits can proliferate in vitro and express Nestin antigen; They can differentiate into neuron-like cells, express specific neucleoprotein of mature neurons, synthesize and secrete NE as a kind of neurotransmitter.展开更多
Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria v...Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria via various secretion systems. These proteins are essential for the virulence of bacteria, so it is crucial to study them for the pathogenesis of diseases and the development of drugs. Using amino acid composition (AAC), position-specific scoring matrix (PSSM) and N-terminal signal peptides, two different substitution models are firstly constructed to transform protein sequences into numerical vectors. Then, based on support vector machine (SVM) and the “one to one”?algorithm, a hybrid multi-classifier named SecretP v.2.2 is proposed to rapidly and accurately?distinguish different types of Gram-negative?bacterial secreted proteins. When performed on the same test set for a comparison with other methods, SecretP v.2.2 gets the highest total sensitivity of 93.60%. A public independent dataset is used to further test the power of SecretP v.2.2 for predicting NCSPs, it also yields satisfactory results.展开更多
Objective：The aim of this study was to investigate the af ecting of Rg3 to secreted VEGF of human laryngeal carcinoma Hep-2 cells and its mechanism of inhibition to tumor angiogenesis. Methods：Cultured human larynge...Objective：The aim of this study was to investigate the af ecting of Rg3 to secreted VEGF of human laryngeal carcinoma Hep-2 cells and its mechanism of inhibition to tumor angiogenesis. Methods：Cultured human laryngeal cancer cellline Hep-2 and human vascular endothelial cells in vitro, cells got into the period of exponential phase of growth, was diviced into 3 groups：group I （control group）, group II （DDP group）, group III （Rg3 group）. Added to the Hep-2 cells Rg3 and DDP, made Rg3 final concentration was 300μg/mL, and DDP was 3μg/mL. 48 h later, specimens from sample to be done immunocytochemistry, and the protein of VEGF in Hep-2 cells to be detected. Col ecting Hep-2 cells supernatant, some was used to measure the protein level of VEGF in Hep-2 cells supernatant by ELISA. Some was used to culture HVEC. 24 h later, cellgrowth inhibition rate of human vascular endothelial was determined by MTT. Results：The protein level of VEGF was evi-dently higher in group I compared to group II and group III, it was not only in Hep-2 cells, but also in supernatant of Hep-2 cells. There was no significantly dif erent between group II and group III. MTT results showed that, the human vascular endothelial cellgrowth inhibition rate of group I was significantly lower than that of group II and group III （P〈0.05）. At the same time the HVEC growth inhibition rate of group II was significantly lower than that of group III （P〈0.05）. Conclusion：The inhibition to tumor angiogenesis of Rg3 is stronger than traditional chemotherapy drug cisplatin. It worke by reducing the biological ef ects of secreted VEGF, But the ef ecting worke by reducing the activity of secreted VEGF itself or af ecting endothelial function of VEGF receptor or some other ways to be further studied.展开更多
BACKGROUND Previously,we have successfully constructed replication-competent hepatitis B virus(HBV)vectors by uncoupling the P open reading frame(ORF)from the preC/C ORF to carefully design the transgene insertion sit...BACKGROUND Previously,we have successfully constructed replication-competent hepatitis B virus(HBV)vectors by uncoupling the P open reading frame(ORF)from the preC/C ORF to carefully design the transgene insertion site to overcome the compact organization of the HBV genome and maintain HBV replication competence.Consequently,the replication-competent HBV vectors carrying foreign genes,including pCH-BsdR,carrying blasticidin resistance gene(399 bp),and pCH-hrGFP,carrying humanized renilla green fluorescent protein gene(720 bp),were successfully obtained.However,the replication efficiency of the former is higher but it is tedious to use,while that of the latter is poor and cannot be quantified.Hence,we need to search for a new reporter gene that is convenient and quantifiable for further research.AIM To establish a helpful tool for intracellular HBV replication and anti-viral drugs screening studies.METHODS We utilized the replication-competent HBV viral vectors constructed by our laboratory,combined with the secreted luciferase reporter gene,to construct replication-competent HBV vectors expressing the reporter gene secretory Nanoluc Luciferase(SecNluc).HepG2.TA2-7 cells were transfected with this vector to obtain cell lines with stably secreted HBV particles carrying secNluc reporter gene.RESULTS The replication-competent HBV vector carrying the SecNluc reporter gene pCHsNLuc could produce all major viral RNAs and a full set of envelope proteins and achieve high-level secreted luciferase expression.HBV replication intermediates could be produced from this vector.Via transfection with pTRE-sNLuc and selection by hygromycin,we obtained isolated cell clones,named HBV-NLuc-35 cells,which could secrete secNLuc recombinant viruses,and were sensitive to existing anti-HBV drugs.Using differentiated HepaRG cells,it was verified that recombinant HBV possessed infectivity.CONCLUSION Our research demonstrated that a replication-competent HBV vector carrying a secreted luciferase transgene possesses replication and expression ability,and the established HBV replication and expression cell lines could stably secrete viral particles carrying secNluc reporter gene.More importantly,the cell line and the secreted recombinant viral particles could be used to trace HBV replication or infection.展开更多
基金supported by the Youth Foundation of Beijing Academy of Agriculture and Forestry Sciences[Grant No.QNJJ202242]the Excellent Young Scholars of Beijing Academy of Agriculture and Forestry Sciences[Grant No.YXQN202205]+3 种基金the Beijing Nova Program[Grant No.20220484052]the National Natural Science Foundation of China[Grant No.31801852]the Collaborative Innovation Center of Beijing Academy of Agriculture and Forestry Sciences[Grant No.KJCX201907-2]the Earmarked Fund for China Agriculture Research System[Grant No.CARS-23-A-05].
文摘The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.
基金Supported by Faculty Research Grant from Yonsei University College of Medicine,No.6-2017-0155.
文摘BACKGROUND Pancreatic cancer tissues mainly consist of fibrotic and dense stroma,which limits their therapeutic efficacy.The stromal fibroblasts of pancreatic tumors frequently express the secreted protein acidic and rich in cysteine(SPARC).AIM To assess the impact of SPARC and its oncological relevance in patients undergoing pancreatic cancer resection.METHODS Ninety-one pancreatic ductal adenocarcinoma specimens were obtained from patients with curative resection between January 2009 and December 2015 as a retrospective study.SPARC expression patterns were analyzed using immunohistochemistry.Oncological outcomes were analyzed based on SPARC expression patterns.Oncological outcomes,based on SPARC expression,were analyzed in The Cancer Genome Atlas-Pancreatic Adenocarcinoma cohort(retrieved from a public database).RESULTS Patients with stromal SPARC expression(sSPARC+)had poorer overall survival than that in those without it(sSPARC-)(P=0.035).However,among patients who received adjuvant treatment,no difference was observed in survival between the sSPARC+and the sSPARC-groups(P=0.14).In The Cancer Genome Atlas-Pancreatic Adenocarcinoma samples,the high SPARC expression group exhibited noticeably lower overall survival than that in the low expression group(cutoff:14.1295,P=0.0222).Furthermore,SPARC expression was strongly correlated with the percentage the CD10+stromal component(R2=0.804,P<0.001).CONCLUSION Adjuvant chemotherapy improves survivals in sSPARC+pancreatic cancer patients,indicating suggesting sSPARC expression as a prognostic biomarker and potential indicator for neoadjuvant treatment planning.
基金supported by the Natural Science Research Project of colleges and Universities in Anhui Province[2022AH052336]High Level Talent Research Initiation Fund Of Anhui Medical College[2023RC004]。
文摘Objective Microcystin-leucine-arginine(MC-LR)exposure induces lipid metabolism disorders in the liver.Secreted frizzled-related protein 5(SFRP5)is a natural antagonist of winglesstype MMTV integration site family,member 5A(Wnt5a)and an anti-inflammatory adipocytokine.In this study,we aimed to investigate whether MC-LR can induce lipid metabolism disorders in hepatocytes and whether SFRP5,which has anti-inflammatory effects,can alleviate the effects of hepatic lipid metabolism by inhibiting the Wnt5a/Jun N-terminal kinase(JNK)pathway.Methods We exposed mice to MC-LR in vivo to induce liver lipid metabolism disorders.Subsequently,mouse hepatocytes that overexpressed SFRP5 or did not express SFRP5 were exposed to MC-LR,and the effects of SFRP5 overexpression on inflammation and Wnt5a/JNK activation by MC-LR were observed.Results MC-LR exposure induced liver lipid metabolism disorders in mice and significantly decreased SFRP5 mRNA and protein levels in a concentration-dependent manner.SFRP5 overexpression in AML12cells suppressed MC-LR-induced inflammation.Overexpression of SFRP5 also inhibited Wnt5a and phosphorylation of JNK.Conclusion MC-LR can induce lipid metabolism disorders in mice,and SFRP5 can attenuate lipid metabolism disorders in the mouse liver by inhibiting Wnt5a/JNK signaling.
基金financed by the National Key Research and Development Program of China(2017YFD0200900)。
文摘Fusarium graminearum,the primary pathogenic fungus responsible for Fusarium head blight(FHB)in wheat,secretes abundant chemical compounds that interact with host plants.In this study,a secreted protein FgHrip1,isolated from the culture filtrate of F.graminearum,was found to induce typical cell death in tobacco.The FgHrip1 gene was then cloned and expressed in Escherichia coli.Further bioassay analysis showed that the recombinant FgHrip1 induced early defense induction events,such as reactive oxygen species(ROS)production,callose deposition,and up-regulation of defense-related genes in tobacco.Furthermore,FgHrip1 significantly enhanced immunity in tobacco seedlings against Pseudomonas syringae pv.tabaci 6605(Pst.6605)and tobacco mosaic virus(TMV).FgHrip1-treated wheat spikes also exhibited defense-related transcript accumulation and developed immunity against FHB infection.Whereas the expression of FgHrip1 was induced during the infection process,the deletion of the gene impaired the virulence of F.graminearum.Our results suggest that FgHrip1triggers immunity and induces disease resistance in tobacco and wheat,thereby providing new insight into strategy for biocontrol of FHB.
基金Supported by National Natural Science Foundation of China(31370613)Major State Basic Research Development Program of China(973 Program)(2011CB403202)Fundamental Research Funds for the Central Universities(DL12CA01)~~
文摘[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.
文摘[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase （SAMS） in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was amplified by PCR and inserted into the secreted expression vector pPIC9K to get recombinant plasmid. The recombinant plasmid pPIC9K-sarr~ was integrated into Pichia pastoris GSl15 genome by electroporation and induced by methanol. The activity of the recombinant enzyme was measured using high-pedormance liquid chroma- tography （HPLC） by determining the production of S-adenosy-L-methionine （SAM） with the enzyme secreted. [ ResultJ The molecular weight of the expression protein identified by SDS-PAGE was about 50 kD, being larger than the theoretical molecular mass of SAMS, which might be due to the glycosytation in the process of secretion. Methanol-induction as well as preliminary purification could enhance the enzyme activity, espe- cially the latter, after which the specific activity of SAMS was improved to 61.48 U/rng. [Conclusion] SAMS with biological activity was secreted successfully in Pichia pastoris GSl15 for the first time. And it is the start for the genetic engineering strains to open up prospects for industrial production.
基金Supported by the Special-purpose Scientific Research Foundation for University Doctorate Project of the Ministry of Education of China, No. 301090255
文摘AIM： To investigate the functions of promoter hypermethylation of secreted frizzled-related proteins （sFRPs） genes in colorectal tumorigenesis and progression. METHODS： The promoter hypermethylation and expression of sFRP genes in 72 sporadic colorectal carcinomas, 33 adenomas, 18 aberrant crypt foci （ACF） and colorectal cancer cell lines RKO, HCT116 and SW480 were detected by methylation-specific PCR and reverse transcription PCR, respectively. RESULTS： None of the normal colorectal mucosa tissues showed methylated bands of any of four sFRP genes, sFRP1, 2, 4 and 5 were frequently methylated in colorectal carcinoma, adenoma and ACF （sFRP1 〉 85%, sFRP2 〉75%, sFRP5 〉 50%）, and the differences between three colorectal tissues were not significant （P 〉 0.05）. IVlethylation in colorectal tumors was more frequent than in normal mucosa and adjacent normal mucosa. The mRNA of sFRP1-5 genes was expressed in all normal colorectal mucosa samples. Expression of sFRP1, 2, 4 and 5 and sFRP1, 2 and 5 was downregulated in carcinoma and adenoma, respectively. The downregulation of sFRP2, 4 and 5 was more frequent in carcinoma than in adenoma. Expression of sFRP3 which promoter has no CpG island was downregulated in only a few of colorectal tumor samples （7/105）. The downregulation ofsFRP1, 2, 4 and 5 expression was significantly associated with promoter hypermethylation in colorectal tumor. After cells were treated by DAC/TSA combination, the silenced sFRP mRNA expression could be effectively re-expressed in colorectal cancer cell lines. CONCLUSION： Hypermethylation of sFRP genes is a common early event in the evolution of colorectal tumor, occurring frequently in ACF, which is regarded as the earliest lesion of multistage colorectal carcinogenesis. It appears to functionally silence sFRP genes expression. Methylation of sFRP1, 2 and 5 genes might serve as indicators for colorectal tumor.
基金Supported by Liaoning Education Divison Foundation, No.05L557
文摘AIM： To identify the methylation of secreted frizzled-related protein 1 （SFRP1） in gastric cancer and to investigate the aberrant expression of SFRP1 and its correlation with the clinical pathological features of patients. METHODS： We determined SFRP1 methylation and SFRP1 mRNA expression in 3 gastric cancer cell lines SGC-7901, BGC-823, HGC-27, from 52 primary gastric cancer specimens and matched tumor adjacent tissue specimens by methylation-specific （MSP） PCR and RT-PCR respectively. Fisher＇s exact test was used to analyze the statistical association between clinical pathological data and aberrant expression of SFRP1. RESULTS： In 3 cancer cell lines, BGC-823 and HGC-27 had methylated SFRP1 and lost SFRP1 mRNA expression. After treatment of BGC-823 and HGC-27 with the demethylating agent, 5-aza-2′-deoxycytidine, SFRP1 was re-expressed. In 52 primary gastric cancer specimens and matched tumor adjacent tissue specimens, hypermethylation of SFRP1 was detected in 23 （44%） and 8 （15%） specimens respectively （x^2= 10.34, P 〈 0.01）. Loss of SFRP1 expression was detected in 17（33%） and 6 （12%） specimens respectively （x^2= 6.75, P 〈 0.01）. There was a significant correlation between SFRP1 hypermethylation and SFRP1 expression loss. SFRP1 expression was also correlated significantly with tumor stage and lymph node status, but not with patient sex, age and histological type. CONCLUSION： SFRP1 inactivation is a common and early event caused mainly by hypermethylation in gastric cancer. SFRP1 expression loss may be correlated with tumor metastasis in primary gastric cancer.
文摘Objective Obstructive sleep apnea (OSA) is closely related to obesity, insulin resistance and inflammation. Secreted frizzled-related protein 5 (SFRP5) is a recently discovered adipokine. It is involved in insulin resistance and inflammation in obesity. This study aimed at evaluating the association between SFRP5and sleeping characteristics as well as biochemical parameters of OSA patients.Methods This was a prospective case control study. Nondiabetic OSA patients and controls were consecutively recruited and divided into three groups: OSA group, apnea–hypopnea Index (AHI)≥5/h; healthy controls with normal body mass index (BMI); obese controls without OSA, and BMI > 24.0 kg/m2. All participants underwent polysomnography (PSG). Plasma SFRP5 was examined using enzyme-linked immunosorbent assay (ELISA). Blood biochemical examinations, including fasting blood glucose (FBG), lipid profile, hypersensitive Creactive protein (hsCRP), were performed early in the morning after PSG. Patients with severe OSA were treated with nasal continuous positive airway pressure (nCPAP), and plasma SFRP5 was repeatedly measured for comparison.Results Sixty-eight subjects were enrolled in the study, including 38 patients of OSA, whose medium AHI was 58.70 /h (36.63, 71.15), 20 obese controls, and 10 healthy controls. The plasma SFRP5 level of OSA patients was not significantly different from that of healthy controls or obese controls. In OSA patients, SFRP5 level correlated positively with triglyceride level (r=0.447, P=0.005) and negatively with LDL-cholesterol level and HDLcholesterol level (r=?0.472 and P=0.003; r=?0.478 and P=0.002; respectively). SFRP5 level was not found correlating with FBG, AHI, or any of nocturnal hypoxia parameters. After overnight nCPAP treatment, plasma SFRP5 levels of OSA patients did not change significantly (t=1.557, P = 0.148) compared to that of pretreatment.Conclusions In nondiabetic OSA patients, plasma SFRP5 is associated with the lipid profile. However,no correlation was observed between SFRP5 and FBG or sleep parameters. The SFRP5 level of OSA patients did not differ from that of non-OSA individuals in our study.
文摘Secreted protein acidic and rich in cysteine(SPARC)is a matricellular protein highly expressed in bone tissue that acts as achemoattractant factor promoting the arrival of prostate cancer(PCa)cells to the bone marrow.However,the contribution of SPARCduring the early stages of tumor progression remains unclear.In this study,we show that SPARC is highly expressed in PCa tissueswith a higher Gleason score.Through stable knockdown and overexpression of SPARC in PC3 and LNCaP cells,respectively,here wedem on strate that en doge nous SPARC induces the epithelial-mesenchymal tran sition(EMT),decreasing E-cadheri n and cytokeratin18 and increasing N-cadheri n and vime ntin.Moreover,SPARC in duces the expression of EMT regulatory tran scription factors Snailfamily transcriptional repressor 1(Snail),Snail family transcriptional repressor 2(Slug),and zinc finger E-box binding homeobox 1(Zeb1).In addition,SPARC knockdown in PC3 cells decreases migration and invasion in vitro,without modifying cell proliferation.Our results indicate that SPARC might facilitate tumor progression by modifying the cellular phenotype in cancer cells.
基金The Fund for University Science and Technology Research from Education Office of Liaoning Province,No.05L557
文摘AIM：To determine the methylation status and aberrant expression of some secreted frizzled-related protein（SFRP） genes in pancreatic cancer and explore their role in pancreatic carcinogenesis.METHODS：Methylation status and expression of SFRP genes were detected by methylation-specific PCR（MSPCR） and reverse-transcription PCR（RT-PCR） respectively.RESULTS：The frequencies of methylation for SFRP genes 1,2,4,5 were 70%,48.3%,60% and 76.7% in pancreatic cancer samples,and 21.7%,20%,10% and 36.7% in matched cancer adjacent normal tissue samples,respectively（χ^2 = 28.23,P 〈 0.0001 for SFRP gene 1;χ^2 = 10.71,P = 0.001 for SFRP gene 2;χ^2 = 32.97,P 〈 0.0001 for SFRP gene 4;χ^2 = 19.55,P 〈 0.0001 for SFRP gene 5）.Expression loss of SFRP genes 1,2,4 and 5 was found in 65%,40%,55% and 71.7% of 60 pancreatic cancer samples,and 25%,15%,18.3% and 31.7% of matched cancer adjacent normal tissue samples,respectively（χ^2 = 19.39,P 〈 0.0001 for SFRP gene 1;χ^2 = 9.40,P = 0.002 for SFRP gene 2;χ^2 = 17.37,P 〈 0.0001 for SFRP gene 4;χ^2 = 19.22,P 〈 0.0001 for SFRP gene 5）.SFRP gene 1 was methylated but not expressed in PC-3 and PANC-1,SFRP gene 2 was methylated but not expressed in PANC-1 and CFPAC-1,SFRP gene 4 was methylated but not expressed in PC-3,and SFRP gene 5was methylated but not expressed in CFPAC-1.CONCLUSION： Hypermethylation and aberrant expression of SFRP genes are common in pancreatic cancer, which may be involved in pancreatic carcinogenesis.
基金Basic Public Welfare Research Foundation of Zhejiang Province,China,No.GD21H290001and Traditional Chinese Medicine Science and Technology Project Foundation of Zhejiang Province,China,No.2020ZB072.
文摘BACKGROUND Sepsis is a major medical challenge.Magnolol is an active constituent of Houpu that improves tissue function and exerts strong anti-endotoxin and anti-inflammatory effects,but the mechanism by which it reduces intestinal inflammation in sepsis is yet unclear.AIM To assess the protective effect of magnolol on intestinal mucosal epithelial cells in sepsis and elucidate the underlying mechanisms.METHODS Enzyme-linked immunosorbent assay was used to measure tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6,and regulated on activation,normal T-cell expressed and secreted(RANTES)levels in serum and ileal tissue in animal studies.The histopathological changes of the ileal mucosa in different groups were observed under a microscope.Cell Counting Kit-8 and cell permeability assays were used to determine the concentration of drug-containing serum that did not affect the activity of Caco2 cells but inhibited lipopolysaccharide(LPS)-induced decrease in permeability.Immunofluorescence and Western blot assays were used to detect the levels of RANTES,inhibitor of nuclear factor kappa-B kinaseβ(IKKβ),phosphorylated IKKβ(p-IKKβ),inhibitor of nuclear factor kappa-B kinaseα(IκBα),p65,and p-p65 proteins in different groups in vitro.RESULTS In rats treated with LPS by intravenous tail injection in the presence or absence of magnolol,magnolol inhibited the expression of proinflammatory cytokines,IL-1β,IL-6,and TNF-αin a dose-dependent manner.In addition,magnolol suppressed the production of RANTES in LPS-stimulated sepsis rats.Moreover,in vitro studies suggested that magnolol inhibited the increase of p65 nucleation,thereby markedly downregulating the production of the phosphorylated form of IKKβin LPS-treated Caco2 cells.Specifically,magnolol inhibited the translocation of the transcription factor nuclear factor-kappa B(NF-κB)from the cytosol into the nucleus and down-regulated the expression level of the chemokine RANTES in LPS-stimulated Caco2 cells.CONCLUSION Magnolol down-regulates RANTES levels by inhibiting the LPS/NF-κB signaling pathways,thereby suppressing IL-1β,IL-6,and TNF-αexpression to alleviate the mucosal barrier dysfunction in sepsis.
基金This paper was supported by Development Program (863) of China (No. 2003AA241140)
文摘Total RNA was isolated from mycelium of T. harzianum by Total RNA extraction kit, and two clear bands of rRNA （28S and 18S） were observed in agarose electrophoresis. By joining the 3＇end sequence with the known SA76 EST from cDNA library of T. harzianum, a full-length cDNA sequence of 2019bp was obtained, whose open reading frame contained 1593bp, a stop codon TAA, a 5＇untranslated region （5＇UTR） of 266bp, a 3＇untranslated region （3＇UTR） of 201bp, and poly （A） 29 encoded a protein of 530 amino acids, had a signal peptide. T. harzianum shared 53% identity of secreted aspartic proteinase gene with G. zeae, 37% with N. crassa and 36% with C. globosum. The full-length cDNA sequence of secreted aspartic proteinase gene from T. harzianum was cloned for the first time by using BD SMART RACE technique, which provides a foundation to obtain and validate functional genes of T. harzianum.
基金This work is supported by the National Natural Science Foundation of China （30360061）Natural Science Foundation of Yunnan Province of China （1999C0008Z） National 863 Program of China （2003AA211020）.
文摘Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome of Saccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, and they were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secreted proteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secreted proteins included all the three domains. There were differences in the constitution of signal peptides between the secreted proteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides were similar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and the homology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECES and CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignment result indicated that homology of these sequences with the same signal peptide was very highly conservative in amino acid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secreted proteins is discussed in this paper.
基金the grants from the National Natural Science Foundation of China(U1805232,31770156,and 32172365)the China Postdoctoral Science Foundation(2021M690637)。
文摘The fine-tuned expression dynamics of the effector genes are pivotal for the transition from vegetative growth to host colonization of pathogenic filamentous fungi.However,mechanisms underlying the dynamic regulation of these genes remain largely unknown.Here,through comparative transcriptome and chromatin immunoprecipitation sequencing(ChIP-seq)analyses of the methyltransferase PoKmt6 in rice blast fungus Pyricularia oryzae(syn.Magnaporthe oryzae),we found that PoKmt6-mediated H3K27me3 deposition was enriched mainly at fast-evolving regions and contributed to the silencing of a subset of secreted proteins(SP)and transposable element(TE)families during the vegetative growth of P.oryzae.Intriguingly,we observed that a group of SP genes,which were depleted of H3K27me3 modification,could also be silenced via the H3K27me3-mediated repression of the nearby TEs.In conclusion,our results indicate that H3K27me3 modification mediated by PoKmt6 regulates the expression of some SP genes in fast-evolving regions through the suppression of nearby TEs.
基金Supported by the Natural Science Foundation of Liaoning Province,No.201602817
文摘BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its aberrant methylation in gastric cancer(GC)is still inadequate.In the present research,we performed fundamental research to clarify the precise function of methylation on SPARC and its significance in GC.AIM To investigate promoter methylation and the effects of the SPARC gene in GC cells and tissues and to evaluate its clinical significance.METHODS Plasmids that overexpressed the SPARC gene were transfected into human GC BGC-823 cells;non-transfected cells were used as a control group(NC group).Quantitative real-time polymerase chain reaction and western blotting(WB)were then used to detect the expression of SPARC.Methylation-specific polymerase chain reaction was executed to analyze the gene promoter methylation status.Cell viability was measured by the cell counting kit-8 assay.The migration and invasion ability of cells were detected by scratch assays and transwell chamber assays,respectively.Cell cycle events and apoptosis were observed with a flow cytometer.RESULTS The expression of SPARC mRNA in GC tissues and cells was significantly lower and showed differing degrees of hypermethylation,respectively,than that in normal adjacent tissues and control cells.Treatment with 5-Aza-2’-deoxycytidine(5-Aza-Cdr)was able to restore the expression of SPARC and reverse promoter hypermethylation.Overexpression of the SPARC gene significantly inhibited proliferation,migration,and invasion of GC cells,while also causing cell cycle arrest and apoptosis;the NC group exhibited the opposite effects.CONCLUSION This study demonstrated that SPARC could function as a tumor suppressor and might be silenced by promoter hypermethylation.Furthermore,in GC cells,SPARC inhibited migration,invasion,and proliferation,caused cell cycle arrest at the G0/G1 phase,and promoted apoptosis.
基金the National Natural Science Foundation of China, No. 30270491 the Natural Science Foundation of Guangdong Province, No. 04020422 Science and Technology Plan Program of Guangdong Province, No. 2003A3020304
文摘BACKGROUND： It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells （BMSCs） can in vitro induce and differentiate into the cells possessing the properties of nerve cells. But the functions of BMSCs-derived neural stem cells（NSCs） and the differentiated neuron-like cells are still unclear. OBJECTIVE： To observe whether bone marrow-derived NSCs can secrete norepinephrine （NE） under the condition of in vitro culture, induce and differentiation, and analyze the biochemical properties of BMSCs-derived NSCs. DESIGN： A non-randomized and controlled experimental observation SETTING ： Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University MATERIALS： This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5- month-old healthy New Zealand white rabbits. METHODS： This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5 month-old healthy New Zealand white rabbits. BMSCs of rabbits were isolated and performed in vitro culture, induce and differentiation with culture medium of NSCs and differentiation-inducing factor, then identified with immunocytochemical method. Experimental grouping： ①Negative control group： L-02 hepatic cell and RPMI1640 culture medium were used. ② Background culture group： Only culture medium of NSCs as culture solution was added into BMSCs to perform culture, and 0.1 volume fraction of imported fetal bovine serum was supplemented 72 hours later. ③Differentiation inducing factor group： After culture for 72 hours, retinoic acid and glial cell line-derived neurotrophic factors were added in the culture medium of BMSCs and NSCs as corresponding inducing factors. The level of NE in each group was detected on the day of culture and 5, 7, 14 and 20 days after culture with high performance liquid chromatography （HPLC）. The procedure was conducted 3 times in each group.Standard working curve was made according to the corresponding relationship of NE concentration and peak area. The concentration of NE every 1×10^7 cells was calculated according to standard curve and cell counting. MAIN OUTCOME MEASURES ： The level of NE of cultured cells was detected with HPLC; immunocytochemistrical identification of Nestin and neuron specific nuclear protein was performed. RESULTS： ① On the 14^th day after cell culture, BMSCs turned into magnus and round cells which presented Nestin-positive antigen, then changed into neuron-like cells with long processus and presented neuron specific nuclear protein -positive antigen at the 20^th day following culture. ② The ratio of NE concentration and peak area has good linear relationship, and regression equation was Y=1.168 36＋0.000 272 8X,r=-0.998 4. Coefficient variation （CV） was 〈 5% and the recovery rate was 92.39%（ Y referred to concentration and X was peak area）.③NE was well detached within 10 minutes under the condition of this experiment. ④ NE was detected in NSCs and their culture mediums, which were cultured for 7, 14 and 20 days respectively, but no NE in BMSCs, NSCs-free culture medium and L-02 hepatic cell which were as negative control under the HPLC examination. Analysis of variance showed that the level of NE gradually increased following the elongation of culture time （P 〈 0.01 ）. No significant difference in the level of NE existed at the same time between differentiation inducing factor group and basic culture group（P 〉 0.05）. CONCLUSION ： BMSCs of rabbits can proliferate in vitro and express Nestin antigen; They can differentiate into neuron-like cells, express specific neucleoprotein of mature neurons, synthesize and secrete NE as a kind of neurotransmitter.
文摘Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria via various secretion systems. These proteins are essential for the virulence of bacteria, so it is crucial to study them for the pathogenesis of diseases and the development of drugs. Using amino acid composition (AAC), position-specific scoring matrix (PSSM) and N-terminal signal peptides, two different substitution models are firstly constructed to transform protein sequences into numerical vectors. Then, based on support vector machine (SVM) and the “one to one”?algorithm, a hybrid multi-classifier named SecretP v.2.2 is proposed to rapidly and accurately?distinguish different types of Gram-negative?bacterial secreted proteins. When performed on the same test set for a comparison with other methods, SecretP v.2.2 gets the highest total sensitivity of 93.60%. A public independent dataset is used to further test the power of SecretP v.2.2 for predicting NCSPs, it also yields satisfactory results.
文摘Objective：The aim of this study was to investigate the af ecting of Rg3 to secreted VEGF of human laryngeal carcinoma Hep-2 cells and its mechanism of inhibition to tumor angiogenesis. Methods：Cultured human laryngeal cancer cellline Hep-2 and human vascular endothelial cells in vitro, cells got into the period of exponential phase of growth, was diviced into 3 groups：group I （control group）, group II （DDP group）, group III （Rg3 group）. Added to the Hep-2 cells Rg3 and DDP, made Rg3 final concentration was 300μg/mL, and DDP was 3μg/mL. 48 h later, specimens from sample to be done immunocytochemistry, and the protein of VEGF in Hep-2 cells to be detected. Col ecting Hep-2 cells supernatant, some was used to measure the protein level of VEGF in Hep-2 cells supernatant by ELISA. Some was used to culture HVEC. 24 h later, cellgrowth inhibition rate of human vascular endothelial was determined by MTT. Results：The protein level of VEGF was evi-dently higher in group I compared to group II and group III, it was not only in Hep-2 cells, but also in supernatant of Hep-2 cells. There was no significantly dif erent between group II and group III. MTT results showed that, the human vascular endothelial cellgrowth inhibition rate of group I was significantly lower than that of group II and group III （P〈0.05）. At the same time the HVEC growth inhibition rate of group II was significantly lower than that of group III （P〈0.05）. Conclusion：The inhibition to tumor angiogenesis of Rg3 is stronger than traditional chemotherapy drug cisplatin. It worke by reducing the biological ef ects of secreted VEGF, But the ef ecting worke by reducing the activity of secreted VEGF itself or af ecting endothelial function of VEGF receptor or some other ways to be further studied.
基金Supported by the National Natural Science Foundation of China,No.81672041the National Major Science and Technology Special Project for Infectious Diseases of China,No.2012ZX10004503-012
文摘BACKGROUND Previously,we have successfully constructed replication-competent hepatitis B virus(HBV)vectors by uncoupling the P open reading frame(ORF)from the preC/C ORF to carefully design the transgene insertion site to overcome the compact organization of the HBV genome and maintain HBV replication competence.Consequently,the replication-competent HBV vectors carrying foreign genes,including pCH-BsdR,carrying blasticidin resistance gene(399 bp),and pCH-hrGFP,carrying humanized renilla green fluorescent protein gene(720 bp),were successfully obtained.However,the replication efficiency of the former is higher but it is tedious to use,while that of the latter is poor and cannot be quantified.Hence,we need to search for a new reporter gene that is convenient and quantifiable for further research.AIM To establish a helpful tool for intracellular HBV replication and anti-viral drugs screening studies.METHODS We utilized the replication-competent HBV viral vectors constructed by our laboratory,combined with the secreted luciferase reporter gene,to construct replication-competent HBV vectors expressing the reporter gene secretory Nanoluc Luciferase(SecNluc).HepG2.TA2-7 cells were transfected with this vector to obtain cell lines with stably secreted HBV particles carrying secNluc reporter gene.RESULTS The replication-competent HBV vector carrying the SecNluc reporter gene pCHsNLuc could produce all major viral RNAs and a full set of envelope proteins and achieve high-level secreted luciferase expression.HBV replication intermediates could be produced from this vector.Via transfection with pTRE-sNLuc and selection by hygromycin,we obtained isolated cell clones,named HBV-NLuc-35 cells,which could secrete secNLuc recombinant viruses,and were sensitive to existing anti-HBV drugs.Using differentiated HepaRG cells,it was verified that recombinant HBV possessed infectivity.CONCLUSION Our research demonstrated that a replication-competent HBV vector carrying a secreted luciferase transgene possesses replication and expression ability,and the established HBV replication and expression cell lines could stably secrete viral particles carrying secNluc reporter gene.More importantly,the cell line and the secreted recombinant viral particles could be used to trace HBV replication or infection.
