We previously showed that Wnt3a could stimulate human embryonic stem (hES) cell proliferation and affect cell fate determination. In the absence of feeder cell--derived factors, hES cells cultured under a feeder-fre...We previously showed that Wnt3a could stimulate human embryonic stem (hES) cell proliferation and affect cell fate determination. In the absence of feeder cell--derived factors, hES cells cultured under a feeder-free condition survived and proliferated poorly. Adding recombinant Wnt3a in the absence of feeder cell derived-factors stimulated hES cell proliferation but also differentiation. In the present study, we further extended our analysis to other Wnt ligands such as Wntl and Wnt5a. While Wntl displayed a similar effect on hES cells as Wnt3a, Wnt5a had little effect in this system. Wnt3a and Wntl enhanced proliferation of undifferentiated hES cells when feeder-derived self-renewal factors and bFGF are also present. To explore the possibility to promote the proliferation of undifferentiated hES cells by activating the Wnt signaling, we overexpressed Wnt3a or Wntl gene in immortalized human adult fibroblast (HAFi) cells that are superior in supporting long-term growth of undifferentiated hES cells than primary mouse embryonic fibroblasts. HAFi cells with or without a Wnt tmnsgene can be propagated indefinitely. Over-expression of the Wnt3a gene significantly enhanced the ability of HAFi feeder cells to support the undifferentiated growth of 3 different hES cell lines we tested. Co-expression of three commonly-used drug selection genes in Wnt3a-overpressing HAFi cells further enabled us to select rare hES clones after stable transfection or transduction. These immortalized engineered feeder cells (W3R) that co-express growth-promoting genes such as Wnt3a and three drug selection genes should empower us to efficiently make genetic modified hES cell lines for basic and translational research.展开更多
Classical methyl-CpG binding proteins contain the conserved DNA binding motif methyl-cytosine binding domain(MBD), which preferentially binds to methylated CpG dinucleotides. These proteins serve as transcriptional re...Classical methyl-CpG binding proteins contain the conserved DNA binding motif methyl-cytosine binding domain(MBD), which preferentially binds to methylated CpG dinucleotides. These proteins serve as transcriptional repressors,mediating gene silencing via DNA cytosine methylation. Mutations in methyl-CpG binding protein 2 (MeCP2) have beenlinked to the human mental retardation disorder Rett syndrome, suggesting an important role for methyl-CpG bindingproteins in brain development and function. This mini-review summarizes the recent advances in studying the diversefunctions of MeCP2 as a prototype for other methyl-CpG binding proteins in the development and function of thevertebrate nervous system.展开更多
Endothelial cells (TEC_3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × 10~6 smooth muscle cells (...Endothelial cells (TEC_3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × 10~6 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC_3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.展开更多
AIM: To detect distribution and relative frequency of endocrine cells in gastrointestinal tract of flower fish (Pseudophoxinus antalyae). METHODS: The intestinal tract of flower fish was divided into four portions...AIM: To detect distribution and relative frequency of endocrine cells in gastrointestinal tract of flower fish (Pseudophoxinus antalyae). METHODS: The intestinal tract of flower fish was divided into four portions from proximal to distal; the enlarged area after oesophagus and anterior, middle and posterior intestine. Immunohistochemical method using the peroxidase anti-peroxidase complex was employed. All antisera between four portions of flower fish were compared using ANOVA. RESULTS: Eleven types of gut endocrine cells were determined; they were immunoreactive for calcitonin gene related peptide, substance P, vasoactive intestinal peptide, bombesin, somatostatin-14, secretin, TrkA, TrkB, TrkC, neurotensin, neuropeptide Y, which were found in almost all portions of the gastrointestinal tract. CONCLUSION: The regional frequency of immunoreactive distribution and relative cells in the flower fish, Pseudophoxinus antalyae, are essentially similar to those of other fish.展开更多
AIM: To investigate the expression patterns of human differentiated embryo chondrocyte 1 (DEC1) in hepatocellular carcinoma (HCC) and corresponding adjacent non-tumor and the normal liver tissues, the association betw...AIM: To investigate the expression patterns of human differentiated embryo chondrocyte 1 (DEC1) in hepatocellular carcinoma (HCC) and corresponding adjacent non-tumor and the normal liver tissues, the association between DEC1 expression and histopathological variables and the role of DEC1 in hepatocarcinogenesis. METHODS: The expression of DEC1 was detected immunohistochemically in 176 paraffin-embedded sections from 63 patients with HCC and 50 subjects with normal liver tissues. RESULTS: DEC1 protein was persistently expressed in the cytoplasm of hepatocytes in normal liver and HCC tissues. Compared with adjacent non-tumor liver tissues, HCC tissues showed high nuclear expression of DEC1 protein. However, high DEC1 nuclear expression was more frequently detected in well-differentiated (83.3%) than in moderately (27.3%) and poorly differentiated HCC (16.7%). Low DEC1 expression was associated with poor histological differentiation and malignancy progression. A correlation was found between the nuclear expression of DEC1 protein and histological differentiation (r = 0.376, P = 0.024). CONCLUSION: DEC1 is expressed in the cytoplasm of hepatocytes and because nuclear DEC1 expression is decreased with decreasing differentiation status of HCC, nuclear DEC1 might be a marker of HCC differentiation.展开更多
DNA barcoding provides accurate stages. Single-gene-targeted metagenomic analysis identification of zooplankton species through all life based on DNA barcode databases can facilitate long- term monitoring of zooplankt...DNA barcoding provides accurate stages. Single-gene-targeted metagenomic analysis identification of zooplankton species through all life based on DNA barcode databases can facilitate long- term monitoring of zooplankton communities. With the help of the available zooplankton databases, the zooplankton community of the Changjiang (Yangtze) River estuary was studied using a single-gene-targeted metagenomic method to estimate the species richness of this community. A total of 856 mitocbondrial cytochrome oxidase subunit 1 (coxl) gene sequences were determined. The environmental barcodes were clustered into 70 molecular operational taxonomic units (MOTUs). Forty-two MOTUs matched barcoded marine organisms with more than 90% similarity and were assigned to either the species (similarity〉96%) or genus level (similarity〈96%). Sibling species could also be distinguished. Many species that were overlooked by morphological methods were identified by molecular methods, especially gelatinous zooplankton and merozooplankton that were likely sampled at different life history phases. Zooplankton community structures differed significantly among all of the samples. The MOTU spatial distributions were influenced by the ecological habits of the corresponding species. In conclusion, single-gene-targeted metagenomic analysis is a useful tool for zooplankton studies, with which specimens from all life history stages can be identified quickly and effectively with a comprehensive database.展开更多
AtCRE1 is known to be a cytokinin receptor in Arabidopsis. The AtCRE1 protein contains CHASE domain at the N-terminal part, followed by a transmitter (histidine kinase) domain and two receiver domains. The N-terminal...AtCRE1 is known to be a cytokinin receptor in Arabidopsis. The AtCRE1 protein contains CHASE domain at the N-terminal part, followed by a transmitter (histidine kinase) domain and two receiver domains. The N-terminal CHASE domain of AtCRE1 contains putative recognition sites for cytokinin. Five CHASE domains containing proteins were found in rice, OsCRL1a, OsCRL1b, OsCRL2, OsCRL3, and OsCRL4. OsCRL1a, OsCRL1b, OsCRL2 and OsCRL3 contain the four domains existing in CRE1, whereas OsCRL4 only contains the CHASE domain and a putative Ser/Thr protein kinase domain. The authors cloned the encoding gene OsCRL4 and found that it represents a new member of the cytokinin receptor protein in rice.展开更多
Recent advances in the evolutionary genetics of sex determination indicate that the only molecular similarity in sex determination found so far among phyla is between the fly doublesex, worm mab-3 and vertebrate DMRTI...Recent advances in the evolutionary genetics of sex determination indicate that the only molecular similarity in sex determination found so far among phyla is between the fly doublesex, worm mab-3 and vertebrate DMRTI(dsx- and mab3-related transcription factor 1)/DMY genes. Each of these factors encodes a zinc-finger-like DNA-binding motif, DM domain. Insights into the evolution and functions of human DMRT1 gene could reveal evolutionary mechanisms of sexual development. Here we report the identification and characterization of multiple isoforms of human DMRT1 in the testis. These transcripts encode predicted proteins with 373,275 and 175 amino acids and they were generated by alternative splicing at 3' region. Expression level of DMRTla is higher than those of both DMRTlb and c, and the DMR Tlc expression was the lowest in testis, based on comparisons of mean values from real-time fluorescent quantitative RT-PCR analysis. Both DMRTlb and c result from exonization of intronic sequences, including the exonization of an Alu element. A further search for Alu elements within the DMRT1 gene demonstrated that all 99 Alu elements are non-randomly distributed among the non-coding regions on both directions. These new characteristics of DMRT1 would have an important impact on the evolution of sexual development mechanisms.展开更多
As a fundamental component of the host cellular cytoskeleton, actin is routinely engaged by infecting viruses. Furthermore, viruses from diverse groups, and infecting diverse hosts, have convergently evolved an array ...As a fundamental component of the host cellular cytoskeleton, actin is routinely engaged by infecting viruses. Furthermore, viruses from diverse groups, and infecting diverse hosts, have convergently evolved an array of mechanisms for manipulating the actin cytoskeleton for efficacious infection. An ongoing chorus of research now indicates that the actin cytoskeleton is critical for viral replication at many stages of the viral life cycle, including binding, entry, nuclear localization, genomic transcription and reverse transcription, assembly, and egress/dissemination. Specifically, viruses subvert the force-generating and macromolecular scaffolding properties of the actin cytoskeleton to propel viral surfing, internalization, and migration within the cell. Additionally, viruses utilize the actin cytoskeleton to support and organize assembly sites, and eject budding virions for cell-to-cell transmission. It is the purpose of this review to provide an overview of current research, focusing on the various mechanisms and themes of virus-mediated actin modulation described therein.展开更多
Objective: To detect the different morphologic features, developmental regulation, potential of proliferation and differentiation of neonatal rat cochlea progenitor spheres. Methods: We isolated the cochlea sensory ep...Objective: To detect the different morphologic features, developmental regulation, potential of proliferation and differentiation of neonatal rat cochlea progenitor spheres. Methods: We isolated the cochlea sensory epithelium cells from neonatal rats and cultured them in nonadherent conditions to acquire different morphologic spheres. Then we observed the diameter and compositional change of cell colonies in distinct sphere types on day 3, 6, 9 and 12, and summarized the regularity of development and their conversion. We also detected the proliferative activity of distinct spheres by immunohistochemical staining of Abcg2, Nestin and BrdU. After induced spontaneous differentiation, the spheres were detected in the changes of the marker of hair cell, MyosinVIIA; by immunocytochemical staining, we revealed the potential of how different spheres were converted into hair cell-like cells. Results: The acquired three types of suspended spheres are solid, transitional, and hollow. There's morphologic significance among them and they can covert into the other type of spheres among them. The ability of self-renewing and proliferation in distinct spheres vary and all of them have the potential of spontaneously differentiation into hair cell-like cells. Conclusion: All the type of spheres not only has the potential of proliferation and differentiation, but also hasthe potential of spontaneous differentiation into hair cell-like cells. Distinct types of cell spheres neither originate from different progenitor cell subcolonies nor are different stages of the same cell spheres. Solid spheres are most practically useful.展开更多
The purpose of the given work was the experimental analysis of features of Arg-X proteolysis in proteom of supramolecular structures of bacterial cells during their life cycle. The basic attention was devoted to relax...The purpose of the given work was the experimental analysis of features of Arg-X proteolysis in proteom of supramolecular structures of bacterial cells during their life cycle. The basic attention was devoted to relaxation of Arg-X sites of proteom in association with the evolutionary significance ofArg-rich histones in the eukaryotic kingdom. These properties were not studied in the prokaryotes. Cells ofE. coli were grown to the stationary phase, collected by centrifugation and washed. All cells were taken over from 50 min to 430 min at intervals of 20 min and were preserved in glycerol. The supramolecular structures were fractionated from bacterial cells by increasing ionic strength of solution. The Arg-Xactivity was assessed by cleavage of Arg-Xbonds in the arginine-enriched protein protamine in all cell fractions. We have shown that during the stationary phase in the life cycle of E. coli, there are a high continuous activity of the Arg-X processing at the level of"cytoskeleton" of the cell and bright cyclic activity in the cytoplasm.展开更多
Radix Adenophorae, a traditional Chinese medicine, has been reported to have a variety of biological functions. In the present study, a polysaccharide component, Radix Adenophorae Polysaccharide (RAPS), was purified...Radix Adenophorae, a traditional Chinese medicine, has been reported to have a variety of biological functions. In the present study, a polysaccharide component, Radix Adenophorae Polysaccharide (RAPS), was purified from Radix Adenophorae by decoloring with ADS-7 macroporous adsorption resin, DEAE-52 cellulose ion-exchange chromatography, and Sephacryl S-300HR gel chromatography, with the purity of 98.3% and a molecular weight of 1.8 × 104 Da. The cell viability assay and microscopic examination revealed that RAPS promoted the proliferation and activation of macrophages. At 400 μg·mL-1, RAPS stimulated RAW264.7 cell proliferation by 1.91-fold compared with the control. Meanwhile, RAPS significantly increased the secretion of pro-inflammatory cytokines (TNF-a and IL-6) in a dose-dependent manner in the supernatant of RAW264.7 cell culture as determined by ELISA. At 400 μg·mL-1, the production of TNF-a was 20.8-fold higher than that of the control. Simultaneously, the production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) were increased in RAW264.7 cells incubated with RAPS, as measured by Griess assay and Western blot analysis. The NO production of cells treated with RAPS (400 μg·mL-1) reached 15.8 μmol·L-L, which was 30.4-fold higher than that of the control (0.53 μmol·L-1). These data suggested that RAPS may enhance the immune function and protect against exogenous pathogens by activating macrophages.展开更多
Diabetes mellitus, characterized by the impaired metabolism of insulin secretion in β cells, is becoming one of the most prevalent diseases around the world. Recently, cell replacement based on differentiation of var...Diabetes mellitus, characterized by the impaired metabolism of insulin secretion in β cells, is becoming one of the most prevalent diseases around the world. Recently, cell replacement based on differentiation of various pluripotent stem cells, including embryonic stern cells, induced pluripo- tent stem cells and multipotent stem cells, such as bone mar- row mesenchymal stem cells, adipose-derived stem cells and gnotobiotic porcine skin-derived stem cells, is becoming a promising therapeutic strategy. Cells derived from pancreatic tissues or other tissues that are relevant to β cell differentiation have also been used as cell source. However, in spite of hopeful experimental results, cell therapy in diabetes still confronts certain obstacles, such as purity of cells, functional differentiation of stem cells and possible tumorigenesis, which, in turn, lead to the seeking of new-generation tools, such as xenogenetic materials. In this review, we will sum- marize the current knowledge and future prospects of cell therapy in diabetes mellitus.展开更多
Objective: To differentiate rat adipose tissue-derived mesenchymal stem cells (ADSCs) into cells with a nucleus pulposus-like phenotype in vitro, so as to lay a foundation for the cell-based transplantation therapy...Objective: To differentiate rat adipose tissue-derived mesenchymal stem cells (ADSCs) into cells with a nucleus pulposus-like phenotype in vitro, so as to lay a foundation for the cell-based transplantation therapy of degenerated intervertebral discs. Methods: Rat ADSCs were isolated only from the subcutaneous inguinal region and purified by limited dilution. ADSCs of the third passages were analyzed by fluorescence activated cell sorter (FACS) to detect the cell surface markers (Sca-1, CD44, CD45, CDI lb). To induce ADSCs to- wards a nucleus pulposus-like phenotype, ADSCs were immobilized in 3-dimensional alginate hydrogels and cultured in an inducing medium containing transforming growth factor-beta1 (TGF- β1) under hypoxia (2% O2), while control groups under normoxia (21% O2) in alginate beads in medium with or without the presence of TGF-β 1. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was carried out to evaluate phenotypic and biosynthetic activities in the process of differentiation. Meanwhile, Alcian blue staining were used to detect the formation of sulfated glycosaminoglycans (GAGs) in the differentiated cells. Results: The purified ADSCs were fibroblast-like and proliferated rapidly in vitro. The flow cytometry showed that ADSCs were positive for Sca-1 and CD44, negative for CD45 and CD11b. The results of RT-PCR manifested that the gene expressions of Sox-9, aggrecan and collagen Ⅱ, which were chondrocyte specific, were upregulated in medium containing TGF-β1 under hypoxia (2% O2). Likewise, gene expression of HIF-1 a, which was characteristics of in- tervertebral discs, was also upregulated. Simultaneously, Alcian blue staining exhibited the formation of many GAGs. Conclusions: The approach in our experiment is a simple and effective way to acquire a large quantity of homogenous ADSCs. Rat ADSCs can be differentiated into nucleus pulposus-like cells. ADSCs may replace bone marrow mesenchymal stem cells as a new kind of seed cells in regeneration of degenerated intervertebral discs using cell transolantation therarw.展开更多
Bucky ball(Buc)is involved in germ plasm(GP)assembly during early zebrafish development by regulating GP mRNA expression via an unknown mechanism.The present study demonstrates that an m^(6)A reader Igf2bp3 interacts ...Bucky ball(Buc)is involved in germ plasm(GP)assembly during early zebrafish development by regulating GP mRNA expression via an unknown mechanism.The present study demonstrates that an m^(6)A reader Igf2bp3 interacts and colocalizes with Buc in the GP.Similar to the loss of Buc,the genetic deletion of maternal igf2bp3 in zebrafish leads to abnormal GP assembly and insufficient germ cell specification,which can be partially restored by the injection of igf2 bp3 mRNA.Igf2bp3 binds to m^(6)A-modified GPorganizer and GP mRNAs in an m^(6)A-dependent manner and prevents their degradation.These findings indicate that the functions of Igf2bp3,a direct effector protein of Buc,in GP mRNA expression and GP assembly involve m^(6)A-dependent regulation;these results emphasize a critical role of m^(6)A modification in the process of GP assembly.展开更多
Long non-coding RNAs(lncRNAs)are defined as a class of nonprotein-coding transcripts greater than 200 nucleotides in length,which have diverse functions in development and diseases including hematopoiesis.Recent advan...Long non-coding RNAs(lncRNAs)are defined as a class of nonprotein-coding transcripts greater than 200 nucleotides in length,which have diverse functions in development and diseases including hematopoiesis.Recent advances have revealed that lncRNAs regulate hematopoietic development at almost every stage,including differentiation of the myelocyte,lymphocyte,and erythrocyte.Abnormal regulation of the lncRNAs may block aspects of blood development,which can lead to different types of hematopoietic disorders.These findings highlight the role of lncRNAs as potential therapeutic tools in malignant hematopoiesis.In this review,we summarize recent progress in the study of functional lncRNAs associated with blood development,as well as dysregulated lncRNAs involved in diverse blood diseases by interacting with crucial susceptibility genes in different pathways.In addition,we discuss genome-wide studies on lncRNAs,which are helpful for genome screening and in-depth functional study of lncRNAs associated with blood development and disease.展开更多
文摘We previously showed that Wnt3a could stimulate human embryonic stem (hES) cell proliferation and affect cell fate determination. In the absence of feeder cell--derived factors, hES cells cultured under a feeder-free condition survived and proliferated poorly. Adding recombinant Wnt3a in the absence of feeder cell derived-factors stimulated hES cell proliferation but also differentiation. In the present study, we further extended our analysis to other Wnt ligands such as Wntl and Wnt5a. While Wntl displayed a similar effect on hES cells as Wnt3a, Wnt5a had little effect in this system. Wnt3a and Wntl enhanced proliferation of undifferentiated hES cells when feeder-derived self-renewal factors and bFGF are also present. To explore the possibility to promote the proliferation of undifferentiated hES cells by activating the Wnt signaling, we overexpressed Wnt3a or Wntl gene in immortalized human adult fibroblast (HAFi) cells that are superior in supporting long-term growth of undifferentiated hES cells than primary mouse embryonic fibroblasts. HAFi cells with or without a Wnt tmnsgene can be propagated indefinitely. Over-expression of the Wnt3a gene significantly enhanced the ability of HAFi feeder cells to support the undifferentiated growth of 3 different hES cell lines we tested. Co-expression of three commonly-used drug selection genes in Wnt3a-overpressing HAFi cells further enabled us to select rare hES clones after stable transfection or transduction. These immortalized engineered feeder cells (W3R) that co-express growth-promoting genes such as Wnt3a and three drug selection genes should empower us to efficiently make genetic modified hES cell lines for basic and translational research.
文摘Classical methyl-CpG binding proteins contain the conserved DNA binding motif methyl-cytosine binding domain(MBD), which preferentially binds to methylated CpG dinucleotides. These proteins serve as transcriptional repressors,mediating gene silencing via DNA cytosine methylation. Mutations in methyl-CpG binding protein 2 (MeCP2) have beenlinked to the human mental retardation disorder Rett syndrome, suggesting an important role for methyl-CpG bindingproteins in brain development and function. This mini-review summarizes the recent advances in studying the diversefunctions of MeCP2 as a prototype for other methyl-CpG binding proteins in the development and function of thevertebrate nervous system.
基金supported by the national“973”tissue engineering project of China(G1999054300)Shanghai Science and Technology Development Foundation(03DJ14021)
文摘Endothelial cells (TEC_3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × 10~6 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC_3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.
文摘AIM: To detect distribution and relative frequency of endocrine cells in gastrointestinal tract of flower fish (Pseudophoxinus antalyae). METHODS: The intestinal tract of flower fish was divided into four portions from proximal to distal; the enlarged area after oesophagus and anterior, middle and posterior intestine. Immunohistochemical method using the peroxidase anti-peroxidase complex was employed. All antisera between four portions of flower fish were compared using ANOVA. RESULTS: Eleven types of gut endocrine cells were determined; they were immunoreactive for calcitonin gene related peptide, substance P, vasoactive intestinal peptide, bombesin, somatostatin-14, secretin, TrkA, TrkB, TrkC, neurotensin, neuropeptide Y, which were found in almost all portions of the gastrointestinal tract. CONCLUSION: The regional frequency of immunoreactive distribution and relative cells in the flower fish, Pseudophoxinus antalyae, are essentially similar to those of other fish.
基金Supported by The National Natural Science Foundation ofChina, No. 81000869the "Spring City Scholars" ConstructionProject of Jinan City (Q2-06)+1 种基金the Key Projects of Science andTechnology of Jinan City, No. 200807027the Youth Sci-ence and Technology Star Project of Jinan City, No. 20080210
文摘AIM: To investigate the expression patterns of human differentiated embryo chondrocyte 1 (DEC1) in hepatocellular carcinoma (HCC) and corresponding adjacent non-tumor and the normal liver tissues, the association between DEC1 expression and histopathological variables and the role of DEC1 in hepatocarcinogenesis. METHODS: The expression of DEC1 was detected immunohistochemically in 176 paraffin-embedded sections from 63 patients with HCC and 50 subjects with normal liver tissues. RESULTS: DEC1 protein was persistently expressed in the cytoplasm of hepatocytes in normal liver and HCC tissues. Compared with adjacent non-tumor liver tissues, HCC tissues showed high nuclear expression of DEC1 protein. However, high DEC1 nuclear expression was more frequently detected in well-differentiated (83.3%) than in moderately (27.3%) and poorly differentiated HCC (16.7%). Low DEC1 expression was associated with poor histological differentiation and malignancy progression. A correlation was found between the nuclear expression of DEC1 protein and histological differentiation (r = 0.376, P = 0.024). CONCLUSION: DEC1 is expressed in the cytoplasm of hepatocytes and because nuclear DEC1 expression is decreased with decreasing differentiation status of HCC, nuclear DEC1 might be a marker of HCC differentiation.
基金Supported by the National Natural Science Foundation of China(No.41230963)the National Basic Research Program of China(973 Program)(No.2011CB403604)+2 种基金the"135"Fund of Institute of Oceanology,Chinese Academy of Sciences(No.2012I0060102)the Innovative Research Group Funding of the National Natural Science Foundation of China(No.41121064)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020305)
文摘DNA barcoding provides accurate stages. Single-gene-targeted metagenomic analysis identification of zooplankton species through all life based on DNA barcode databases can facilitate long- term monitoring of zooplankton communities. With the help of the available zooplankton databases, the zooplankton community of the Changjiang (Yangtze) River estuary was studied using a single-gene-targeted metagenomic method to estimate the species richness of this community. A total of 856 mitocbondrial cytochrome oxidase subunit 1 (coxl) gene sequences were determined. The environmental barcodes were clustered into 70 molecular operational taxonomic units (MOTUs). Forty-two MOTUs matched barcoded marine organisms with more than 90% similarity and were assigned to either the species (similarity〉96%) or genus level (similarity〈96%). Sibling species could also be distinguished. Many species that were overlooked by morphological methods were identified by molecular methods, especially gelatinous zooplankton and merozooplankton that were likely sampled at different life history phases. Zooplankton community structures differed significantly among all of the samples. The MOTU spatial distributions were influenced by the ecological habits of the corresponding species. In conclusion, single-gene-targeted metagenomic analysis is a useful tool for zooplankton studies, with which specimens from all life history stages can be identified quickly and effectively with a comprehensive database.
基金Project supported by the National Natural Science Foundation of China
文摘AtCRE1 is known to be a cytokinin receptor in Arabidopsis. The AtCRE1 protein contains CHASE domain at the N-terminal part, followed by a transmitter (histidine kinase) domain and two receiver domains. The N-terminal CHASE domain of AtCRE1 contains putative recognition sites for cytokinin. Five CHASE domains containing proteins were found in rice, OsCRL1a, OsCRL1b, OsCRL2, OsCRL3, and OsCRL4. OsCRL1a, OsCRL1b, OsCRL2 and OsCRL3 contain the four domains existing in CRE1, whereas OsCRL4 only contains the CHASE domain and a putative Ser/Thr protein kinase domain. The authors cloned the encoding gene OsCRL4 and found that it represents a new member of the cytokinin receptor protein in rice.
基金The work was supported by the National Natural Science Foundation of China, and the National Key Basic Research project (2004CB117400)the Program for New Century Excellent Talents in University and the Key Project of Chinese Ministry of Education (No. 2004.28).
文摘Recent advances in the evolutionary genetics of sex determination indicate that the only molecular similarity in sex determination found so far among phyla is between the fly doublesex, worm mab-3 and vertebrate DMRTI(dsx- and mab3-related transcription factor 1)/DMY genes. Each of these factors encodes a zinc-finger-like DNA-binding motif, DM domain. Insights into the evolution and functions of human DMRT1 gene could reveal evolutionary mechanisms of sexual development. Here we report the identification and characterization of multiple isoforms of human DMRT1 in the testis. These transcripts encode predicted proteins with 373,275 and 175 amino acids and they were generated by alternative splicing at 3' region. Expression level of DMRTla is higher than those of both DMRTlb and c, and the DMR Tlc expression was the lowest in testis, based on comparisons of mean values from real-time fluorescent quantitative RT-PCR analysis. Both DMRTlb and c result from exonization of intronic sequences, including the exonization of an Alu element. A further search for Alu elements within the DMRT1 gene demonstrated that all 99 Alu elements are non-randomly distributed among the non-coding regions on both directions. These new characteristics of DMRT1 would have an important impact on the evolution of sexual development mechanisms.
基金supported by US Public Health Service grant 1R01MH102144 from NIMH to Y. W
文摘As a fundamental component of the host cellular cytoskeleton, actin is routinely engaged by infecting viruses. Furthermore, viruses from diverse groups, and infecting diverse hosts, have convergently evolved an array of mechanisms for manipulating the actin cytoskeleton for efficacious infection. An ongoing chorus of research now indicates that the actin cytoskeleton is critical for viral replication at many stages of the viral life cycle, including binding, entry, nuclear localization, genomic transcription and reverse transcription, assembly, and egress/dissemination. Specifically, viruses subvert the force-generating and macromolecular scaffolding properties of the actin cytoskeleton to propel viral surfing, internalization, and migration within the cell. Additionally, viruses utilize the actin cytoskeleton to support and organize assembly sites, and eject budding virions for cell-to-cell transmission. It is the purpose of this review to provide an overview of current research, focusing on the various mechanisms and themes of virus-mediated actin modulation described therein.
基金Supported by the National Natural Science Foundation of China (Grant No.30973300)
文摘Objective: To detect the different morphologic features, developmental regulation, potential of proliferation and differentiation of neonatal rat cochlea progenitor spheres. Methods: We isolated the cochlea sensory epithelium cells from neonatal rats and cultured them in nonadherent conditions to acquire different morphologic spheres. Then we observed the diameter and compositional change of cell colonies in distinct sphere types on day 3, 6, 9 and 12, and summarized the regularity of development and their conversion. We also detected the proliferative activity of distinct spheres by immunohistochemical staining of Abcg2, Nestin and BrdU. After induced spontaneous differentiation, the spheres were detected in the changes of the marker of hair cell, MyosinVIIA; by immunocytochemical staining, we revealed the potential of how different spheres were converted into hair cell-like cells. Results: The acquired three types of suspended spheres are solid, transitional, and hollow. There's morphologic significance among them and they can covert into the other type of spheres among them. The ability of self-renewing and proliferation in distinct spheres vary and all of them have the potential of spontaneously differentiation into hair cell-like cells. Conclusion: All the type of spheres not only has the potential of proliferation and differentiation, but also hasthe potential of spontaneous differentiation into hair cell-like cells. Distinct types of cell spheres neither originate from different progenitor cell subcolonies nor are different stages of the same cell spheres. Solid spheres are most practically useful.
文摘The purpose of the given work was the experimental analysis of features of Arg-X proteolysis in proteom of supramolecular structures of bacterial cells during their life cycle. The basic attention was devoted to relaxation of Arg-X sites of proteom in association with the evolutionary significance ofArg-rich histones in the eukaryotic kingdom. These properties were not studied in the prokaryotes. Cells ofE. coli were grown to the stationary phase, collected by centrifugation and washed. All cells were taken over from 50 min to 430 min at intervals of 20 min and were preserved in glycerol. The supramolecular structures were fractionated from bacterial cells by increasing ionic strength of solution. The Arg-Xactivity was assessed by cleavage of Arg-Xbonds in the arginine-enriched protein protamine in all cell fractions. We have shown that during the stationary phase in the life cycle of E. coli, there are a high continuous activity of the Arg-X processing at the level of"cytoskeleton" of the cell and bright cyclic activity in the cytoplasm.
基金supported by the National Science and Technology Major Project Foundation of China(No.2012ZX09102301-003)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Radix Adenophorae, a traditional Chinese medicine, has been reported to have a variety of biological functions. In the present study, a polysaccharide component, Radix Adenophorae Polysaccharide (RAPS), was purified from Radix Adenophorae by decoloring with ADS-7 macroporous adsorption resin, DEAE-52 cellulose ion-exchange chromatography, and Sephacryl S-300HR gel chromatography, with the purity of 98.3% and a molecular weight of 1.8 × 104 Da. The cell viability assay and microscopic examination revealed that RAPS promoted the proliferation and activation of macrophages. At 400 μg·mL-1, RAPS stimulated RAW264.7 cell proliferation by 1.91-fold compared with the control. Meanwhile, RAPS significantly increased the secretion of pro-inflammatory cytokines (TNF-a and IL-6) in a dose-dependent manner in the supernatant of RAW264.7 cell culture as determined by ELISA. At 400 μg·mL-1, the production of TNF-a was 20.8-fold higher than that of the control. Simultaneously, the production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) were increased in RAW264.7 cells incubated with RAPS, as measured by Griess assay and Western blot analysis. The NO production of cells treated with RAPS (400 μg·mL-1) reached 15.8 μmol·L-L, which was 30.4-fold higher than that of the control (0.53 μmol·L-1). These data suggested that RAPS may enhance the immune function and protect against exogenous pathogens by activating macrophages.
基金supported by the National Basic Research Program of China(2013CB967102)the National Natural Science Foundation of China(31201112)
文摘Diabetes mellitus, characterized by the impaired metabolism of insulin secretion in β cells, is becoming one of the most prevalent diseases around the world. Recently, cell replacement based on differentiation of various pluripotent stem cells, including embryonic stern cells, induced pluripo- tent stem cells and multipotent stem cells, such as bone mar- row mesenchymal stem cells, adipose-derived stem cells and gnotobiotic porcine skin-derived stem cells, is becoming a promising therapeutic strategy. Cells derived from pancreatic tissues or other tissues that are relevant to β cell differentiation have also been used as cell source. However, in spite of hopeful experimental results, cell therapy in diabetes still confronts certain obstacles, such as purity of cells, functional differentiation of stem cells and possible tumorigenesis, which, in turn, lead to the seeking of new-generation tools, such as xenogenetic materials. In this review, we will sum- marize the current knowledge and future prospects of cell therapy in diabetes mellitus.
文摘Objective: To differentiate rat adipose tissue-derived mesenchymal stem cells (ADSCs) into cells with a nucleus pulposus-like phenotype in vitro, so as to lay a foundation for the cell-based transplantation therapy of degenerated intervertebral discs. Methods: Rat ADSCs were isolated only from the subcutaneous inguinal region and purified by limited dilution. ADSCs of the third passages were analyzed by fluorescence activated cell sorter (FACS) to detect the cell surface markers (Sca-1, CD44, CD45, CDI lb). To induce ADSCs to- wards a nucleus pulposus-like phenotype, ADSCs were immobilized in 3-dimensional alginate hydrogels and cultured in an inducing medium containing transforming growth factor-beta1 (TGF- β1) under hypoxia (2% O2), while control groups under normoxia (21% O2) in alginate beads in medium with or without the presence of TGF-β 1. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was carried out to evaluate phenotypic and biosynthetic activities in the process of differentiation. Meanwhile, Alcian blue staining were used to detect the formation of sulfated glycosaminoglycans (GAGs) in the differentiated cells. Results: The purified ADSCs were fibroblast-like and proliferated rapidly in vitro. The flow cytometry showed that ADSCs were positive for Sca-1 and CD44, negative for CD45 and CD11b. The results of RT-PCR manifested that the gene expressions of Sox-9, aggrecan and collagen Ⅱ, which were chondrocyte specific, were upregulated in medium containing TGF-β1 under hypoxia (2% O2). Likewise, gene expression of HIF-1 a, which was characteristics of in- tervertebral discs, was also upregulated. Simultaneously, Alcian blue staining exhibited the formation of many GAGs. Conclusions: The approach in our experiment is a simple and effective way to acquire a large quantity of homogenous ADSCs. Rat ADSCs can be differentiated into nucleus pulposus-like cells. ADSCs may replace bone marrow mesenchymal stem cells as a new kind of seed cells in regeneration of degenerated intervertebral discs using cell transolantation therarw.
基金supported by the National Key R&D Program of China(2018YFD0901201 and 2019YFA0802801)China Agricultural Research System(CARS-46)+3 种基金the National Natural Science Foundation of China(31870820)the Innovative Research Group Program of Hubei Province(2020CFA017)the Medical Science Advancement Program of Wuhan University(TFJC2018004)the Fundamental Research Funds for the Central Universities(2042019kf0207)。
文摘Bucky ball(Buc)is involved in germ plasm(GP)assembly during early zebrafish development by regulating GP mRNA expression via an unknown mechanism.The present study demonstrates that an m^(6)A reader Igf2bp3 interacts and colocalizes with Buc in the GP.Similar to the loss of Buc,the genetic deletion of maternal igf2bp3 in zebrafish leads to abnormal GP assembly and insufficient germ cell specification,which can be partially restored by the injection of igf2 bp3 mRNA.Igf2bp3 binds to m^(6)A-modified GPorganizer and GP mRNAs in an m^(6)A-dependent manner and prevents their degradation.These findings indicate that the functions of Igf2bp3,a direct effector protein of Buc,in GP mRNA expression and GP assembly involve m^(6)A-dependent regulation;these results emphasize a critical role of m^(6)A modification in the process of GP assembly.
基金supported by the National Basic Research Program of China(2011CB8113015,2011CBA0110)National Natural Science Foundation of China(81270629)
文摘Long non-coding RNAs(lncRNAs)are defined as a class of nonprotein-coding transcripts greater than 200 nucleotides in length,which have diverse functions in development and diseases including hematopoiesis.Recent advances have revealed that lncRNAs regulate hematopoietic development at almost every stage,including differentiation of the myelocyte,lymphocyte,and erythrocyte.Abnormal regulation of the lncRNAs may block aspects of blood development,which can lead to different types of hematopoietic disorders.These findings highlight the role of lncRNAs as potential therapeutic tools in malignant hematopoiesis.In this review,we summarize recent progress in the study of functional lncRNAs associated with blood development,as well as dysregulated lncRNAs involved in diverse blood diseases by interacting with crucial susceptibility genes in different pathways.In addition,we discuss genome-wide studies on lncRNAs,which are helpful for genome screening and in-depth functional study of lncRNAs associated with blood development and disease.