Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicellulose an...Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicellulose and lignin.To dissect the roles of hemicellulosic polysaccharides during fiber development,four IRREGULAR XYLEM 15(IRX15)genes,GhIRX15-1/-2/-3/-4,were functionally characterized in cotton.These genes encode DUF579 domain-containing proteins,which are homologs of AtIRX15 involved in xylan biosynthesis.The four GhIRX15 genes were predominantly expressed during fiber secondary wall thickening,and the encoded proteins were localized to the Golgi apparatus.Each GhIRX15 gene could restore the xylan deficient phenotype in the Arabidopsis irx15irx15l double mutant.Silencing of GhIRX15s in cotton resulted in shorter mature fibers with a thinner cell wall and reduced cellulose content as compared to the wild type.Intriguingly,GhIRX15-2 and GhIRX15-4 formed homodimers and heterodimers.In addition,the GhIRX15s showed physical interaction with glycosyltransferases GhGT43C,GhGT47A and GhGT47B,which are responsible for synthesis of the xylan backbone and reducing end sequence.Moreover,the GhIRX15s can form heterocomplexes with enzymes involved in xylan modification and side chain synthesis,such as GhGUX1/2,GhGXM1/2 and GhTBL1.These findings suggest that GhIRX15s participate in fiber xylan biosynthesis and modulate fiber development via forming large multiprotein complexes.展开更多
The present study was carried out to evaluate the pollution and its effect on the quality of catfish. Four sites in Eygpt were chosen for the research, Ras El-Bar (Site 1) as control, Shatta (Site 2), Kafr El-Bateekh ...The present study was carried out to evaluate the pollution and its effect on the quality of catfish. Four sites in Eygpt were chosen for the research, Ras El-Bar (Site 1) as control, Shatta (Site 2), Kafr El-Bateekh (Site 3), and Talkha (Site 4). The research was carried out on water, sediments and catfish (serum and muscles). Nitrite, nitrate and ammonia were determined in water and sediment. Also, RNA and DNA were determined in serum samples and the muscles of the catfish. In addition, the concentrations of heavy metals (Pb, Cd, Fe, Zn and Cu) were estimated in water, sediments and the muscles of catfish. Also, hepatosomatic index, liver water content, condition factor, lipid and protein contents were determined in the fish. The concentrations of nitrite, nitrate and ammonia in water and sediment of Site 4 and the levels of heavy metals especially Pb and Cd in water, sediment and muscle of catfish from Sites 3 and 4 were highly elevated compared to those of the control. On the other hand, DNA, RNA and protein contents in the catfish of Sites 3 and 4 decreased. The results illustrated that, Cd and Pb levels in the muscle of catfish were negatively correlated with DNA, RNA and with the protein contents. In conclusion, the accumulation of heavy metals in catfish tissues therefore, can cause health problems in human after catfish intake.展开更多
INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 a...INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer .展开更多
Phosphorus（P） is one of the key nutrients for the growth of phytoplankton. In this study, we used a method coupling label-free quantitation with liquid chromatography–mass spectrometry（LFQ–LC–MS/MS） to track th...Phosphorus（P） is one of the key nutrients for the growth of phytoplankton. In this study, we used a method coupling label-free quantitation with liquid chromatography–mass spectrometry（LFQ–LC–MS/MS） to track the change of relative protein abundance between P-replete and P-deficient treatments in a non-model diatom, Thalassiosira weissflogii. Out of the 631 proteins identified, 132 were found to have significant changes in abundance（〉1.5 folds） between the two treatments, especially those proteins involved in macromolecular biosynthesis pathways. For example, the up-regulation of sulfolipid biosynthesis protein in the P-deficient culture suggested a switch from using phospholipids to sulfolipids. In addition, the ribosome subunits and tRNA synthetases were down-regulated, which might explain the decrease in protein content in the P-deficient culture. A vacuolar sorting receptor homologous protein was found to be 9.2-folds up-regulated under P-deficiency, indicating an enhancement in the vacuolar sorting pathway for protein degradation. Our results show that T. weissflogii has sophisticated responses in multiple macromolecular metabolism pathways under P-deficiency, a mechanism which can be critical for this species to survive under various levels of P availability in the environment展开更多
To separate the proteins related to pigment synthesis in green colored fiber （GCF）, we performed a comparative proteomic analysis to identify the differentially expressed proteins between green cotton fiber and a wh...To separate the proteins related to pigment synthesis in green colored fiber （GCF）, we performed a comparative proteomic analysis to identify the differentially expressed proteins between green cotton fiber and a white near-isogenic line （NIL）. One differential spot identified as phenylocumaran benzylic ether redutase-like protein （PCBER） was expressed only in GCF, but was not found in white colored fiber （WCF） at any time points. Since PCBER was a key enzyme in lignans biosynthesis, total lignans were extracted from GCF and WCF and their content was determined by using a chromotropic acid spectrophotometric method. The results showed that total lignans content in GCF was significantly higher than that in WCF. The qPCR analysis for two PLR genes associated with lignans biosynthesis showed that the expression level of two genes was much higher in GCF than that in WCF at 24 and 27 days post anthesis （DPA）, which may be responsible for the higher lignans content in GCF. Our study suggested that PCBER and lignans may be responsible for the color difference between GCF and WCF. Additionally, p-dimethylaminocinnamaldehyde （DMACA） staining demonstrated that the pigment in GCF was not proanthocyanidins, and was different from that in brown colored fiber （BCF）. This study provided new clues for uncovering the molecular mechanisms related to pigment biosynthesis in GCF.展开更多
AIM: To investigate the relationship between mutations of rearranged during transfection (RET) proto-oncogene and Chinese patients with Hirschsprung's disease (HD), and to elucidate the genetic mechanism of famili...AIM: To investigate the relationship between mutations of rearranged during transfection (RET) proto-oncogene and Chinese patients with Hirschsprung's disease (HD), and to elucidate the genetic mechanism of familial HD patient at the molecular level.METHODS: Genomic DNA was extracted from venous blood of probands and their relatives in two genealogies.Polymerase chain reaction (PCR) products, which were amplified using specific primers (RET, exons 11, 13, 15and 17), were electrophoresed to analyze the single-strand conformational polymorphism (SSCP) patterns. The positive amplified products were sequenced. Forty-eight sporadic HD patients and 30 normal children were screened for mutations of RET proto-oncogene simultaneously.RESULTS: Three cases with HD in one family were found to have a G heterozygous insertion at nucleotide 18 974 in exon 13 of RET cDNA (18 974insG), which resulted in a frameshift mutation. In another family, a heterozygosity for T to G transition at nucleotide 18 888 in the same exon which resulted in a synonymous mutation of Leu at codon 745 was detected in the proband and his father. Eight RET mutations were confirmed in 48 sporadic HD patients.CONCLUSION: Mutations of RET proto-oncogene may play an important role in the pathogenesis of Chinese patients with HD. Detection of mutated RET proto-oncogene carriers may be used for genetic counseling of potential risk for HD in the affected families.展开更多
AIM: To study the epitope distribution of hepatitis G virus (HGV) and to seek for the potential recombinant antigens for the development of HGV diagnostic reagents. METHODS: Fourteen clones encompassing HGV gene fragm...AIM: To study the epitope distribution of hepatitis G virus (HGV) and to seek for the potential recombinant antigens for the development of HGV diagnostic reagents. METHODS: Fourteen clones encompassing HGV gene fragments from core to NS3 and NS5 were constructed using prokaryotic expression vector pRSET and (or) pGEX, and expressed in E.coli. Western blotting and ELISA were used to detect the immunoreactivity of these recombinant proteins. RESULTS: One clone with HGV fragment from core to E1 (G1), one from E2 (G31), three from NS3 (G6, G61, G7), one from NS5B (G821) and one chimeric fragment from NS3 and NS5B (G61-821) could be expressed well and showed obvious immunoreactivity by Western blotting. One clone with HGV framment from NS5B (G82) was also well expressed, but could not show immunoreactivity by Western blotting. No obvious expression was found in the other six clones. All the expressed recombinant proteins were in inclusion body form, except the protein G61 which could be expressed in soluble form. Further purified recombinant proteins G1, G31, G61, G821 and G61-821 were detected in indirected ELISA as coating antigen respectively. Only recombinant G1 could still show immunoreactivity, and the other four recombinant proteins failed to react to the HGV antibody positive sera. Western blotting results indicated that the immunoactivity of these four recombinant proteins were lost during purification. CONCLUSION: Core to E1, E2, NS3 and NS5 fragment of HGV contain antigenic epitopes, which could be produced in prokaryotically expressed recombinant proteins. A high-yield recombinant protein (G1) located in HGV core to E1 could remain its epitope after purification, which showed the potential that G1 could be used as a coating antigen to develop an ELISA kit for HGV specific antibody diagnosis.展开更多
The recombinant plasmid PGC was constructed for transcription unit of c-myc gene with diorientation in vitro, to make RNA probes for detection of c-myc mRNA and antisence RNA expression of tranfectant HL-9,which was o...The recombinant plasmid PGC was constructed for transcription unit of c-myc gene with diorientation in vitro, to make RNA probes for detection of c-myc mRNA and antisence RNA expression of tranfectant HL-9,which was obtained from HL60 cells transfected with inducible c-myc antisense RNA expression plasmid. The results from HL-9 cells induced by Cd2+ indicated that expression of c-myc antisense RNA increased with Cd2+ concentration and exposure time, while c-myc mRNA expression progressively reduced. Using immunohistochemical technique no c-myc P62 protein expression was detected. The incorporation of 3H-TdR, 3H-UR and 3H-Leu revealed significant suppression of DNA, RNA and protein biosynthesis. It is suggested that the reversion changes previously reported in malignant Phenotypes of HL-9 cells and the inhibition of macromolecular biosynthesis mentioned above were associated with the blockade of c-myc gene expression by its antisense RNA.展开更多
The tea plant cultivar‘Zhonghuang 2'(ZH2)possesses albino-induced yellow leaves that contain low levels of catechins but high contents of amino acids.However,the molecular mechanism underlying the yellow leaf phe...The tea plant cultivar‘Zhonghuang 2'(ZH2)possesses albino-induced yellow leaves that contain low levels of catechins but high contents of amino acids.However,the molecular mechanism underlying the yellow leaf phenotype of ZH2 has not been elucidated clearly.In the current research,the yellow shoots(ZH2-Y)and naturally converted green shoots(ZH2-G)of ZH2 were studied using metabolic and proteomic profiling for a better understanding of the mechanism underlying phenotype formation.In total,107 differentially changed metabolites(DCMs)were identified from the GC-MS-based metabolomics,and 189 differentially accumulated proteins(DAPs)were identified from the tandem mass tag(TMT)-based quantitative proteomics.Subsequently,integrated analysis revealed that‘porphyrin and chlorophyll metabolism',‘carbon fixation in photosynthetic organisms',and‘phenylpropanoid biosynthesis'pathways were commonly enriched for DAPs and DCMs.We further found that the inhibition of chlorophyll biosynthesis,the deficiency of photosynthetic proteins and the imbalance of the ROS-scavenging system were the crucial reasons responsible for the chlorosis,chloroplast abnormality and photooxidative damage of ZH2 leaves.Altogether,our research combines metabolomics and proteomics approaches to uncover the molecular mechanism leading to the yellow leaf phenotype of tea plants.展开更多
Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role...Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.展开更多
AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS: Rats for sleep disruption were placed...AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500mL.L(-1), i.g.) was used to induce gastric mucosa damage. RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L(-1) ethanol challenge, the ulcer area found in the rats with 7d sleep deprivation (19.15 +/- 4.2)mm(2) was significantly lower (P【0.01) than the corresponding control (53.7 +/- 8.1) mm(2). CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.展开更多
Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods:...Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods: Using streptavidinbiotin complex (SABC)method, c-erbB-2 oncongene protein, we examinedimmunohistochemically EGFR and TGF-β1 expres-sions in wax-tissue sections from 10 individuals withnormal pancreas (NP), 13 patients with chronic pan-creatitis (CP) and 36 patients with pancreatic ductaladenocarcinoma (PC).Results: The positive expression rates of c-cerbB-2oncogene protein, EGFR and TGF-β1 in the NP, CPand PC groups were 0, 0, 10%; 7.7%, 7.7%,7.7%; and 41.7%, 50.0%, 44.4%, respectively.The positive expression rates of the three specific pro-teins increased more significantly in the PC groupthan in the NP and CP groups (P【0.05). The indi-vidual expression of c-erbB-2, EGFR and TGF-β1was not related to the age and sex of the patients aswell as the site, size and histopathological grade oftumors (P】0.05), but to the clinical stage of tumors(P【0.01). The coexpression rate of the three pro-teins was 27.8 % (10/36). This coexpression in thePC group was correlated with the histopathologicalgrades and clinical stages of tumors (P【0.01).Conclusion: Detection of c-erbB-2 oncogene protein,EGFR, and TGF-β1 expressions in pancreatic tissueis helpful to judge the malignancy, progression, andmetastasis of PC.展开更多
Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometr...Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.展开更多
Proteins are one of the major classes of biomolecules that execute biological functions for maintenance of life.Various kinds of nanostructures self-assembled from proteins have been created in nature over millions of...Proteins are one of the major classes of biomolecules that execute biological functions for maintenance of life.Various kinds of nanostructures self-assembled from proteins have been created in nature over millions of years of evolution,including protein nanowires,layers and nanocages.These protein nanostructures can be reconstructed and equipped with desired new functions.Learning from and manipulating the self-assembly of protein nanostructures not only help to deepen our understanding of the nature of life but also offer new routes to fabricate novel nanomaterials for diverse applications.This review summarizes the recent research progress in this field,focusing on the characteristics,functionalization strategies,and applications of protein nanostructures.展开更多
基金supported by the National Natural Science Foundation of China(31970516 and 32372104)the Foundation of Hubei Hongshan Laboratory(2021hszd014).
文摘Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicellulose and lignin.To dissect the roles of hemicellulosic polysaccharides during fiber development,four IRREGULAR XYLEM 15(IRX15)genes,GhIRX15-1/-2/-3/-4,were functionally characterized in cotton.These genes encode DUF579 domain-containing proteins,which are homologs of AtIRX15 involved in xylan biosynthesis.The four GhIRX15 genes were predominantly expressed during fiber secondary wall thickening,and the encoded proteins were localized to the Golgi apparatus.Each GhIRX15 gene could restore the xylan deficient phenotype in the Arabidopsis irx15irx15l double mutant.Silencing of GhIRX15s in cotton resulted in shorter mature fibers with a thinner cell wall and reduced cellulose content as compared to the wild type.Intriguingly,GhIRX15-2 and GhIRX15-4 formed homodimers and heterodimers.In addition,the GhIRX15s showed physical interaction with glycosyltransferases GhGT43C,GhGT47A and GhGT47B,which are responsible for synthesis of the xylan backbone and reducing end sequence.Moreover,the GhIRX15s can form heterocomplexes with enzymes involved in xylan modification and side chain synthesis,such as GhGUX1/2,GhGXM1/2 and GhTBL1.These findings suggest that GhIRX15s participate in fiber xylan biosynthesis and modulate fiber development via forming large multiprotein complexes.
文摘The present study was carried out to evaluate the pollution and its effect on the quality of catfish. Four sites in Eygpt were chosen for the research, Ras El-Bar (Site 1) as control, Shatta (Site 2), Kafr El-Bateekh (Site 3), and Talkha (Site 4). The research was carried out on water, sediments and catfish (serum and muscles). Nitrite, nitrate and ammonia were determined in water and sediment. Also, RNA and DNA were determined in serum samples and the muscles of the catfish. In addition, the concentrations of heavy metals (Pb, Cd, Fe, Zn and Cu) were estimated in water, sediments and the muscles of catfish. Also, hepatosomatic index, liver water content, condition factor, lipid and protein contents were determined in the fish. The concentrations of nitrite, nitrate and ammonia in water and sediment of Site 4 and the levels of heavy metals especially Pb and Cd in water, sediment and muscle of catfish from Sites 3 and 4 were highly elevated compared to those of the control. On the other hand, DNA, RNA and protein contents in the catfish of Sites 3 and 4 decreased. The results illustrated that, Cd and Pb levels in the muscle of catfish were negatively correlated with DNA, RNA and with the protein contents. In conclusion, the accumulation of heavy metals in catfish tissues therefore, can cause health problems in human after catfish intake.
基金Supported by the Medical Research Foundation of Guangdong Province,No.1997423
文摘INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer .
基金The National Natural Science Foundation of China(NSFC)under contract No.40925018the National Basic Research Program(973 Program)under contract No.2011CB403603
文摘Phosphorus（P） is one of the key nutrients for the growth of phytoplankton. In this study, we used a method coupling label-free quantitation with liquid chromatography–mass spectrometry（LFQ–LC–MS/MS） to track the change of relative protein abundance between P-replete and P-deficient treatments in a non-model diatom, Thalassiosira weissflogii. Out of the 631 proteins identified, 132 were found to have significant changes in abundance（〉1.5 folds） between the two treatments, especially those proteins involved in macromolecular biosynthesis pathways. For example, the up-regulation of sulfolipid biosynthesis protein in the P-deficient culture suggested a switch from using phospholipids to sulfolipids. In addition, the ribosome subunits and tRNA synthetases were down-regulated, which might explain the decrease in protein content in the P-deficient culture. A vacuolar sorting receptor homologous protein was found to be 9.2-folds up-regulated under P-deficiency, indicating an enhancement in the vacuolar sorting pathway for protein degradation. Our results show that T. weissflogii has sophisticated responses in multiple macromolecular metabolism pathways under P-deficiency, a mechanism which can be critical for this species to survive under various levels of P availability in the environment
基金supported by the National Natural Science Foundation of China (31460360)the National Key Research and Development Program,China (2016YFD0101900)the Foundation Research Funds for Advanced Talents of Shihezi University,China (RCZX201316)
文摘To separate the proteins related to pigment synthesis in green colored fiber （GCF）, we performed a comparative proteomic analysis to identify the differentially expressed proteins between green cotton fiber and a white near-isogenic line （NIL）. One differential spot identified as phenylocumaran benzylic ether redutase-like protein （PCBER） was expressed only in GCF, but was not found in white colored fiber （WCF） at any time points. Since PCBER was a key enzyme in lignans biosynthesis, total lignans were extracted from GCF and WCF and their content was determined by using a chromotropic acid spectrophotometric method. The results showed that total lignans content in GCF was significantly higher than that in WCF. The qPCR analysis for two PLR genes associated with lignans biosynthesis showed that the expression level of two genes was much higher in GCF than that in WCF at 24 and 27 days post anthesis （DPA）, which may be responsible for the higher lignans content in GCF. Our study suggested that PCBER and lignans may be responsible for the color difference between GCF and WCF. Additionally, p-dimethylaminocinnamaldehyde （DMACA） staining demonstrated that the pigment in GCF was not proanthocyanidins, and was different from that in brown colored fiber （BCF）. This study provided new clues for uncovering the molecular mechanisms related to pigment biosynthesis in GCF.
基金Supported by the Fund for Excellent Young Talented Persons by Public Health Ministry of China, and Analysis and Testing Foundation of Zhejiang Province, No. 99075
文摘AIM: To investigate the relationship between mutations of rearranged during transfection (RET) proto-oncogene and Chinese patients with Hirschsprung's disease (HD), and to elucidate the genetic mechanism of familial HD patient at the molecular level.METHODS: Genomic DNA was extracted from venous blood of probands and their relatives in two genealogies.Polymerase chain reaction (PCR) products, which were amplified using specific primers (RET, exons 11, 13, 15and 17), were electrophoresed to analyze the single-strand conformational polymorphism (SSCP) patterns. The positive amplified products were sequenced. Forty-eight sporadic HD patients and 30 normal children were screened for mutations of RET proto-oncogene simultaneously.RESULTS: Three cases with HD in one family were found to have a G heterozygous insertion at nucleotide 18 974 in exon 13 of RET cDNA (18 974insG), which resulted in a frameshift mutation. In another family, a heterozygosity for T to G transition at nucleotide 18 888 in the same exon which resulted in a synonymous mutation of Leu at codon 745 was detected in the proband and his father. Eight RET mutations were confirmed in 48 sporadic HD patients.CONCLUSION: Mutations of RET proto-oncogene may play an important role in the pathogenesis of Chinese patients with HD. Detection of mutated RET proto-oncogene carriers may be used for genetic counseling of potential risk for HD in the affected families.
基金Supported by National 863 Project,No.102-07-02-079th Five-Year Sci-Tech Plan,No.96-906A-03-08
文摘AIM: To study the epitope distribution of hepatitis G virus (HGV) and to seek for the potential recombinant antigens for the development of HGV diagnostic reagents. METHODS: Fourteen clones encompassing HGV gene fragments from core to NS3 and NS5 were constructed using prokaryotic expression vector pRSET and (or) pGEX, and expressed in E.coli. Western blotting and ELISA were used to detect the immunoreactivity of these recombinant proteins. RESULTS: One clone with HGV fragment from core to E1 (G1), one from E2 (G31), three from NS3 (G6, G61, G7), one from NS5B (G821) and one chimeric fragment from NS3 and NS5B (G61-821) could be expressed well and showed obvious immunoreactivity by Western blotting. One clone with HGV framment from NS5B (G82) was also well expressed, but could not show immunoreactivity by Western blotting. No obvious expression was found in the other six clones. All the expressed recombinant proteins were in inclusion body form, except the protein G61 which could be expressed in soluble form. Further purified recombinant proteins G1, G31, G61, G821 and G61-821 were detected in indirected ELISA as coating antigen respectively. Only recombinant G1 could still show immunoreactivity, and the other four recombinant proteins failed to react to the HGV antibody positive sera. Western blotting results indicated that the immunoactivity of these four recombinant proteins were lost during purification. CONCLUSION: Core to E1, E2, NS3 and NS5 fragment of HGV contain antigenic epitopes, which could be produced in prokaryotically expressed recombinant proteins. A high-yield recombinant protein (G1) located in HGV core to E1 could remain its epitope after purification, which showed the potential that G1 could be used as a coating antigen to develop an ELISA kit for HGV specific antibody diagnosis.
文摘The recombinant plasmid PGC was constructed for transcription unit of c-myc gene with diorientation in vitro, to make RNA probes for detection of c-myc mRNA and antisence RNA expression of tranfectant HL-9,which was obtained from HL60 cells transfected with inducible c-myc antisense RNA expression plasmid. The results from HL-9 cells induced by Cd2+ indicated that expression of c-myc antisense RNA increased with Cd2+ concentration and exposure time, while c-myc mRNA expression progressively reduced. Using immunohistochemical technique no c-myc P62 protein expression was detected. The incorporation of 3H-TdR, 3H-UR and 3H-Leu revealed significant suppression of DNA, RNA and protein biosynthesis. It is suggested that the reversion changes previously reported in malignant Phenotypes of HL-9 cells and the inhibition of macromolecular biosynthesis mentioned above were associated with the blockade of c-myc gene expression by its antisense RNA.
基金supported by the Project for Collaborative Promotion of Agricultural Major Technology of Zhejiang Province(Grant No.2022XTTGCY01-02)the National Natural Science Foundation of China(Grant Nos.31700615,32172633)+1 种基金the China Agriculture Research System of MOF and MARA(Grant No.CARS19-01A)the Special Project of Zhejiang Province(Grant No.2020R52036)。
文摘The tea plant cultivar‘Zhonghuang 2'(ZH2)possesses albino-induced yellow leaves that contain low levels of catechins but high contents of amino acids.However,the molecular mechanism underlying the yellow leaf phenotype of ZH2 has not been elucidated clearly.In the current research,the yellow shoots(ZH2-Y)and naturally converted green shoots(ZH2-G)of ZH2 were studied using metabolic and proteomic profiling for a better understanding of the mechanism underlying phenotype formation.In total,107 differentially changed metabolites(DCMs)were identified from the GC-MS-based metabolomics,and 189 differentially accumulated proteins(DAPs)were identified from the tandem mass tag(TMT)-based quantitative proteomics.Subsequently,integrated analysis revealed that‘porphyrin and chlorophyll metabolism',‘carbon fixation in photosynthetic organisms',and‘phenylpropanoid biosynthesis'pathways were commonly enriched for DAPs and DCMs.We further found that the inhibition of chlorophyll biosynthesis,the deficiency of photosynthetic proteins and the imbalance of the ROS-scavenging system were the crucial reasons responsible for the chlorosis,chloroplast abnormality and photooxidative damage of ZH2 leaves.Altogether,our research combines metabolomics and proteomics approaches to uncover the molecular mechanism leading to the yellow leaf phenotype of tea plants.
基金Major State BasicResearch (973) Program of China, (G1999053905).
文摘Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.
文摘AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500mL.L(-1), i.g.) was used to induce gastric mucosa damage. RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L(-1) ethanol challenge, the ulcer area found in the rats with 7d sleep deprivation (19.15 +/- 4.2)mm(2) was significantly lower (P【0.01) than the corresponding control (53.7 +/- 8.1) mm(2). CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.
文摘Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods: Using streptavidinbiotin complex (SABC)method, c-erbB-2 oncongene protein, we examinedimmunohistochemically EGFR and TGF-β1 expres-sions in wax-tissue sections from 10 individuals withnormal pancreas (NP), 13 patients with chronic pan-creatitis (CP) and 36 patients with pancreatic ductaladenocarcinoma (PC).Results: The positive expression rates of c-cerbB-2oncogene protein, EGFR and TGF-β1 in the NP, CPand PC groups were 0, 0, 10%; 7.7%, 7.7%,7.7%; and 41.7%, 50.0%, 44.4%, respectively.The positive expression rates of the three specific pro-teins increased more significantly in the PC groupthan in the NP and CP groups (P【0.05). The indi-vidual expression of c-erbB-2, EGFR and TGF-β1was not related to the age and sex of the patients aswell as the site, size and histopathological grade oftumors (P】0.05), but to the clinical stage of tumors(P【0.01). The coexpression rate of the three pro-teins was 27.8 % (10/36). This coexpression in thePC group was correlated with the histopathologicalgrades and clinical stages of tumors (P【0.01).Conclusion: Detection of c-erbB-2 oncogene protein,EGFR, and TGF-β1 expressions in pancreatic tissueis helpful to judge the malignancy, progression, andmetastasis of PC.
文摘Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.
基金supported by the National Natural Science Foundation of China(21890743,31771103,and 91527302)the National Key Research and Development Program of China(2017YFA0205503)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB29050100)CAS Emergency Project of ASF Research(KJZD-SWL06 and KJZD-SWL07)Youth Innovation Promotion Association of CAS(2014308)Wuhan Huanghe Talents Program of Science and Technology。
文摘Proteins are one of the major classes of biomolecules that execute biological functions for maintenance of life.Various kinds of nanostructures self-assembled from proteins have been created in nature over millions of years of evolution,including protein nanowires,layers and nanocages.These protein nanostructures can be reconstructed and equipped with desired new functions.Learning from and manipulating the self-assembly of protein nanostructures not only help to deepen our understanding of the nature of life but also offer new routes to fabricate novel nanomaterials for diverse applications.This review summarizes the recent research progress in this field,focusing on the characteristics,functionalization strategies,and applications of protein nanostructures.
