Osteoclasts are the bone resorbing cells essential for bone remodeling.Osteoclasts are formed from hematopoietic progenitors in the monocyte/macrophage lineage.Osteoclastogenesis is composed of several steps including...Osteoclasts are the bone resorbing cells essential for bone remodeling.Osteoclasts are formed from hematopoietic progenitors in the monocyte/macrophage lineage.Osteoclastogenesis is composed of several steps including progenitor survival,differentiation to mononuclear pre-osteoclasts,fusion to multi-nuclear mature osteoclasts,and activation to bone resorbing osteoclasts.The regulation of osteoclastogenesis has been extensively studied,in which the receptor activator of NF-κB ligand(RANKL)-mediated signaling pathway and downstream transcription factors play essential roles.However,less is known about osteoclast fusion,which is a property of mature osteoclasts and is required for osteoclasts to resorb bone.Several proteins that affect cell fusion have been identified.Among them,dritic cell-specific transmembrane protein(DC-STAMP)is directly associated to osteoclast fusion in vivo.Cytokines and factors influence osteoclast fusion through regula-tion of DC-STAMP.Here we review the recently discovered new factors that regulate osteoclast fusion with specific focus on DC-STAMP.A better understanding of the mechanistic basis of osteoclast fusion will lead to the development of a new therapeutic strategy for bone disorders due to elevated osteoclast bone resorption.Cell-cell fusion is essential for a variety of cellular biological processes.In mammals,there is a limited number of cell types that fuse to form multinucleated cells,such as the fusion of myoblasts for the formation of skeletal muscle and the fusion of cells of the monocyte/macrophage lineage for the formation of multinucleated osteoclasts and giant cells.In most cases,cellcell fusion is beneficial for cells by enhancing function.Myoblast fusion increases myofiber size and diameter and thereby increases contractile strength.Multinucleated osteoclasts have far more bone resorbing activity than their mono-nuclear counterparts.Multinucleated giant cells are much more efficient in the removal of implanted materials and bacteria due to chronic infection than macr展开更多
AIM: To investigate dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin(DC-SIGN) expression in intestinal epithelial cells(IECs) in inflammatory bowel disease(IBD).METHODS: The expression o...AIM: To investigate dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin(DC-SIGN) expression in intestinal epithelial cells(IECs) in inflammatory bowel disease(IBD).METHODS: The expression of DC-SIGN in IECs was examined by immunohistochemistry of intestinal mucosal biopsies from 32 patients with IBD and 10 controls.Disease activity indices and histopathology scores were used to assess the tissue lesions and pathologic damage.Animal studies utilized BALB/c mice with dextran sodium sulfate(DSS)-induced colitis treated with anti-P-selectin lectin-EGF domain monoclonal antibody(PsL-EGFmA b).Controls,untreated and treated mice were sacrificed after 7 d,followed by isolation of colon tissue and IECs.Colonic expression of DC-SIGN,CD80,CD86 and MHC Ⅱ was examined by immunohistochemistry or flow cytometry.The capacity of mouse enterocytes or dendritic cells to activate T cells was determined by coculture with naive CD4+ T cells.Culture supernatant and intracellular levels of interleukin(IL)-4 and interferon(IFN)-γ were measured by enzyme-linked immunosorbent assay and flow cytometry,respectively.The ability of IECs to promote T cell proliferation was detected by flow cytometry staining with carboxyfluorescein diacetate succinimidyl ester.RESULTS: Compared with controls,DC-SIGN expression was significantly increased in IECs from patients with Crohn's disease(P < 0.01) or ulcerative colitis(P < 0.05).DC-SIGN expression was strongly correlated with disease severity in IBD(r = 0.48; P < 0.05).Similarly,in the DSS-induced colitis mouse model,IECs showed upregulated expression of DC-SIGN,CD80,CD86 and MHC,and DC-SIGN expression was positively correlated with disease activity(r = 0.62: P < 0.01).IECs from mouse colitis stimulated naive T cells to generate IL-4(P < 0.05).Otherwise,dendritic cells promoted a T-helper-1-skewing phenotype by stimulating IFN-γ secretion.However,DC-SIGN expression and T cell differentiation were suppressed following treatment of mice with DSS-induced colitis with Ps L-E展开更多
Serine/arginine-rich splicing factor 7(SRSF7),a known splicing factor,has been revealed to play oncogenic roles in multiple cancers.However,the mechanisms underlying its oncogenic roles have not been well addressed.He...Serine/arginine-rich splicing factor 7(SRSF7),a known splicing factor,has been revealed to play oncogenic roles in multiple cancers.However,the mechanisms underlying its oncogenic roles have not been well addressed.Here,based on N6-methyladenosine(m^(6)A)co-methylation network analysis across diverse cell lines,we find that the gene expression of SRSF7 is positively correlated with glioblastoma(GBM)cell-specific m^(6)A methylation.We then indicate that SRSF7 is a novel m^(6)A regulator,which specifically facilitates the m^(6)A methylation near its binding sites on the mRNAs involved in cell proliferation and migration,through recruiting the methyltransferase complex.Moreover,SRSF7 promotes the proliferation and migration of GBM cells largely dependent on the presence of the m^(6)A methyltransferase.The two m^(6)A sites on the mRNA for PDZ-binding kinase(PBK)are regulated by SRSF7 and partially mediate the effects of SRSF7 in GBM cells through recognition by insulin-like growth factor 2 mRNA-binding protein 2(IGF2BP2).Together,our discovery reveals a novel role of SRSF7 in regulating m^(6)A and validates the presence and functional importance of temporal-and spatial-specific regulation of m^(6)A mediated by RNA-binding proteins(RBPs).展开更多
Background： The expression of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin （DC-SIGN） in renal tubular epithelial cells has been thought to be highly correlated with the occurrence ...Background： The expression of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin （DC-SIGN） in renal tubular epithelial cells has been thought to be highly correlated with the occurrence of several kidney diseases, but whether it takes place in renal tissues during hemorrhagic shock （HS） is unknown. The present study airned to investigate this phenomenon and the inhibitory effect of Vitamin C （VitC）. Methods： A Sprague Dawley rat HS model was established in vivo in this study. The expression level and location of DC-SIGN were observed in kidneys. Also, the degree of histological damage, the concentrations of tumor necrosis factor-or and interleukin-6 in the renal tissues, and the serum concentration of blood urea nitrogen and creatinine at different times （2-24 h） alter HS （six rats in each group）, with or without VitC treatment belbre resuscitation, were evaluated. Results： HS induced DC-SIGN expression in rat tubular epithelial cells. The proinflarnmatory cytokine concentration, histological damage scores, and functional injury of kidneys had increased. All these phenornena induced by HS were relieved when the rats were treated with VitC before resuscitation. Conclusions： The results of the present study illustrated that HS could induce tubular epithelial cells expressing DC-SIGN, and the levels of proinflarnmatory cytokines in the kidney tissues improved correspondingly. The results also indicated that VitC could suppress the DC-SIGN expression in the tubular epithelial cells induced by HS and alleviate the inflammation and functional injury in the kidney.展开更多
Background： Dendritic cells （DCs） play an important role in host defense against pathogen infection. DC-specific intercellular adhesion moleeule-3-grabbing nonintegrin （SIGN） is a group II C-type lectin receptor ...Background： Dendritic cells （DCs） play an important role in host defense against pathogen infection. DC-specific intercellular adhesion moleeule-3-grabbing nonintegrin （SIGN） is a group II C-type lectin receptor and specifically expressed on the surface of DCs. This study aimed to determine whether DC-SIGN affects intracellular signaling activation, Th1/Th2 imbalance and aspergillus immune evasion in aspergillus infection, and explore the application of DC-SIGN-modified DCs in immunotherapy. Methods： DCs were first obtained from the mononuelear ceils of peripheral blood. The interferon （IFN）-γand dexamethasone （Dex） were used to stimulate DCs. The expression ofDC-SIGN, Th 1 and Th2 cytokines, and the capacity of DCs in stimulating T cells proliferation and phagocytosis, and nuclear factor （NF）-κB activation were analyzed. In addition, adenovirus expression vector Ad-DC-SIGN was generated to transfect DCs. Mannan was used to block DC-SIGN signaling for confirming the involvement of DC-SIGN function in Aspergillus fumigatus （Af）-induced DCs maturation. The unpaired, two-tailed Student＇s t-test was used in the comparisons between two groups. Results： Exogenous IFN-y could activate Af-induced DCs and promote the Th0 cells toward Th 1 profile （interleukin [IL]- 12 in I FN-y/Af group： 50.96 ± 4.38 pg/ml; control/Afgroup： 29.70 ±2.00 pg/ml, t = 10.815, P 〈 0.001 ）. On the other hand, Dex inhibited the secretion of Th2 cytokines （IL- 10 in Dex/Af group： 5.27 ± 0.85 pg/ml; control/Af group： 15.14 ± 1.40 pg/ml, t = 14.761, P 〈 0.001 ））, and successfully caused immunosuppression. Alier transfection with Ad-DC-SIGN, DCs have improved phagocytosis （phagocytosis rates in Ad-DC-SIGN group： 74.0% ± 3.4%; control group： 64.7% ± 6.8%, t = 3.104, P = 0.013）. There was more Thl cytokine secreted in the Af-induced DC-SIGN modified DCs （IL-12 in Ad-DC-SIGN/Af group： 471.98 ± 166.31 pg/ml; control/Af group： 33.35 ± 5.98 pg/ml, t = 6.456, P = 0.001 ）, correl展开更多
The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breedin...The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breeding Japanese and Chinese original strains are usually used for the large-scale breeding of silkworms,but this may result in uncontrolled transgene dispersal during the popularization and application of the F1 hybrid transgenic eggs.To address this issue,we developed a safe and efficient strategy using the GAL4/Upstream activating sequence(UAS)system,the FLP/flippase recognition target(FRT)system,and the gonad-specific expression gene promoters(RSHP1p and Nanosp)for the germ cell-specific automatic excision of foreign DNA in the F1 hybrid transgenic silkworms.We established 2 types of activator strains,R1p::GAL4-Gr and Nsp::GAL4-Gr,containing the testis-specific GAL4 gene expression cassettes driven by RSHP1p or Nanosp,respectively,and 1 type of effector strain,UAS::FLP-Rg,containing the UAS-linked FLP gene expression cassette.The FLP recombinase-mediated sperm-specific complete excision of FRT-flanked target DNA in the F1 double-transgenic silkworms resulting from the hybridization of R1p::GAL4-Gr and UAS::FLP-Rg was 100%,whereas the complete excision efficiency resulting from the hybridization of Nsp::GAL4-Gr and UAS::FLP-Rg ranged from 13.73%to 80.3%.Additionally,we identified a gene,sw11114,that is expressed in both testis and ovary of Bombyx mori,and can be used to establish novel gonad-specific expression systems in transgenic silkworms.This strategy has the potential to fundamentally solve the safety issue in the production of F1 transgenic silkworm eggs and provides an important reference for the safety of transgenic technology in other insect species.展开更多
Gene regulatory networks play pivotal roles in our understanding of biological processes/mechanisms at the molecular level.Many studies have developed sample-specific or cell-type-specific gene regulatory networks fro...Gene regulatory networks play pivotal roles in our understanding of biological processes/mechanisms at the molecular level.Many studies have developed sample-specific or cell-type-specific gene regulatory networks from single-cell transcriptomic data based on a large amount of cell samples.Here,we review the state-of-the-art computational algorithms and describe various applications of gene regulatory networks in biological studies.展开更多
Zwitterionic polymers are known to interact with cells and have been shown to reveal cancer cell specificity.In this work,the importance of the chemistry of the polymer backbone for the cellular specificity of amino-a...Zwitterionic polymers are known to interact with cells and have been shown to reveal cancer cell specificity.In this work,the importance of the chemistry of the polymer backbone for the cellular specificity of amino-acid-derived polyzwitterions is demonstrated.A series of glutamic acid(Glu)-based vinyl monomers(i.e.,an acrylate,a methacrylate,an acrylamide,and a methacrylamide)were prepared and used for reversible addition-fragmentation chain-transfer(RAFT)polymerisation,yielding defined polymers with narrow size distribution(Ð<1.3).All Glu-functionalised,zwitterionic polymers revealed high cytocompatibility;however,differences in cellular association and specificity were observed.In particular,the methacrylamide-derived polymers showed high association with both,breast cancer cells and non-cancerous dendritic cells and,consequently,lack specificity.In contrast,high specificity to only breast cancer cells was observed for polyacrylates,-methacrylates,and-acrylamides.Detailed analysis of the polymers revealed differences in hydrophobicity,zeta potential,and potential side chain hydrolysis,which are impacted by the polymer backbone and might be responsible for the altered the cell association of these polymers.It is shown that a slightly negative net charge is preferred over a neutral charge to retain cell specificity.This was also confirmed by association experiments in the presence of competitive amino acid transporter substrates.The affinity of slightly negatively charged Glu-derived polymers to the xCT Glu/cystine cell membrane antiporter was found to be higher than that of neutrally charged polymers.Our results emphasise the importance of the polymer backbone for the design of cell-specific polymers.This study further highlights the potential to tailor amino-acid-derived zwitterionic materials beyond their side chain functionality.展开更多
t The rapid advancement of single-cell technologies has shed new light on the complex mechanisms of cellular heterogeneity.However,compared to bulk RNA sequencing(RNA-seq),single-cell RNA-seq(scRNA-seq)suffers from hi...t The rapid advancement of single-cell technologies has shed new light on the complex mechanisms of cellular heterogeneity.However,compared to bulk RNA sequencing(RNA-seq),single-cell RNA-seq(scRNA-seq)suffers from higher noise and lower coverage,which brings new computational difficulties.Based on statistical independence,cell-specific network(CSN)is able to quantify the overall associations between genes for each cell,yet suffering from a problem of overestimation related to indirect effects.To overcome this problem,we propose the c-CSN method,which can construct the conditional cell-specific network(CCSN)for each cell.c-CSN method can measure the direct associations between genes by eliminating the indirect associations.c-CSN can be used for cell clustering and dimension reduction on a network basis of single cells.Intuitively,each CCSN can be viewed as the transformation from less“reliable”gene expression to more“reliable”gene–gene associations in a cell.Based on CCSN,we further design network flow entropy(NFE)to estimate the differentiation potency of a single cell.A number of scRNA-seq datasets were used to demonstrate the advantages of our approach.1)One direct association network is generated for one cell.2)Most existing scRNA-seq methods designed for gene expression matrices are also applicable to c-CSN-transformed degree matrices.3)CCSN-based NFE helps resolving the direction of differentiation trajectories by quantifying the potency of each cell.c-CSN is publicly available at https://github.com/LinLi-0909/c-CSN.展开更多
Aim： To characterize mouse capping protein α3 （CPα3） during spermatogenesis and sperm maturation. Methods： We produced rat anti-CPα3 antiserum and examined the expression of CPα3 in various mouse tissues using...Aim： To characterize mouse capping protein α3 （CPα3） during spermatogenesis and sperm maturation. Methods： We produced rat anti-CPα3 antiserum and examined the expression of CPα3 in various mouse tissues using Western blot analysis and the localization of CPα3 in testicular and epididymal sperm using immunohistochemical analyses. We also examined how the localization of CPα3 and β-actin （ACTB） in sperm changed after the acrosomal reaction by performing immunohistochemical analyses using anti-CPα3 antiserum and anti-actin antibody. Results： Western blot analysis using specific antiserum revealed that CPα3 was expressed specifically in testes. Interestingly, the molecular weight of CPα3 changed during sperm maturation in the epididymis. Furthermore, the subcellular localization of CPα3 in sperm changed dynamically from the flagellum to the post-acrosomal region of the head during epididymal maturation. The distribution of ACTB was in the post-acrosomal region of the head and the flagellum. After inducing the acrosomal reaction, the CPα3 and ACTB localization was virtually identical to the localization before the acrosomal reaction. Conclusion： CPα3 might play an important role in sperm morphogenesis and/or sperm function.展开更多
The succinct metaphor,‘the immune system＇s loaded gun＇, has been used to describe the role of mast cells （MCs） due to their storage of a wide range of potent pro-inflammatory and antimicrobial mediators in secret...The succinct metaphor,‘the immune system＇s loaded gun＇, has been used to describe the role of mast cells （MCs） due to their storage of a wide range of potent pro-inflammatory and antimicrobial mediators in secretory granules that can be released almost instantly on demand to fight invaders. Located at host-environment boundaries and equipped with an arsenal of pattern recognition receptors, MCs are destined to be rapid innate sensors of pathogens penetrating endothelial and epithelial surfaces. Although the importance of MCs in antimicrobial and antiparasitic defense has long been appreciated, their role in raising the alarm against viral infections has been noted only recently. Work on cytomegalovirus （CMV） infection in the murine model has revealed MCs as players in a novel cross-talk axis between innate and adaptive immune surveillance of CMV, in that infection of MCs, which is associated with MC degranulation and release of the chemokine CCL5, enhances the recruitment of protective CD8 T cells to extravascular sites of virus replication, specifically to lung interstitium and alveolar epithelium. Here, we have expanded on these studies by investigating the conditions for MC activation and the consequent degranulation in response to host infection. Surprisingly, the data revealed two temporally and mechanistically distinct waves of MC activation： an almost instant indirect activation that depended on TLR3/TRIF signaling and delayed activation by direct infection of MCs that did not involve TLR3/rRIF signaling. Cell type-specific Cre-recombination that yielded eGFP-expressing reporter virus selectively originating from MCs identified MC as a new in vivo, first-hit target cell of productive murine CMV infection.展开更多
NES1 gene is thought to be a tumor-suppressor gene.Our previous study found that overexpression of NES1 gene in PC3 cell line could slow down the tumor proliferation rate,associated with a mild decrease in BCL-2 expre...NES1 gene is thought to be a tumor-suppressor gene.Our previous study found that overexpression of NES1 gene in PC3 cell line could slow down the tumor proliferation rate,associated with a mild decrease in BCL-2 expression.The BCL-2 decrease could increase the sensitivity of radiotherapy to tumors.Thus,we supposed to have an“enhanced firepower”effect by combining overexpressed NES1 gene therapy and 131I radiation therapy uptake by overexpressed hNIS protein.We found a weak endogenous expression of hNIS protein in PC3 cells and demonstrated that the low expression of hNIS protein in PC3 cells might be the reason for the low iodine uptake.By overexpressing hNIS in PC3,the radioactive iodine uptake ability was significantly increased.Results of in vitro and in vivo tumor proliferation experiments and 18F-fluorothymidine(18F-FLT)micro-positron emission tomography/computed tomography(micro-PET/CT)imaging showed that the combined NES1 gene therapy and 131I radiation therapy mediated by overexpressed hNIS protein had the best tumor proliferative inhibition effect.Immunohistochemistry showed an obvious decrease of Ki-67 expression and the lowest BCL-2 expression.These data suggest that via inhibition of BCL-2 expression,overexpressed NES1 might enhance the effect of radiation therapy of 131I uptake in hNIS overexpressed PC3 cells.展开更多
Some germ cell marker genes, such as vasa, nanos, and dead end( dnd), have been identified in fish. Recently, lymphocyte antigen 75(Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker i...Some germ cell marker genes, such as vasa, nanos, and dead end( dnd), have been identified in fish. Recently, lymphocyte antigen 75(Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker in several fish species. In this study, the Japanese flounder Paralichthys olivaceus ly75 homolog( ly75) was cloned and its expression pattern in gonads was analyzed. The full-length c DNA of ly75 was 7 346 bp, with an open reading frame(ORF) of 5 229 bp. The ORF encoded a protein containing 1 742 amino acids with a predicted molecular mass of 196.89 k Da. In adult tissues, ly75 transcripts were detected in all analyzed tissues but abundantly in the testis. In in-situ hybridization analyses, ly75 mRNA was predominantly localized in oocytes in the ovary and spermatogonia in the testis, but ly75 mRNA was not detected in oogonia, spermatocytes, spermatids, or spermatozoa. These results indicated that ly75 could be a potential germ cell-specific marker in P. olivaceus, as in other fishes.展开更多
Glycosylation is one of the most extensive post-translation modifications of proteins. Although lots of computational models have been developed to predict the glycosylation sites, none of them considered the tissue a...Glycosylation is one of the most extensive post-translation modifications of proteins. Although lots of computational models have been developed to predict the glycosylation sites, none of them considered the tissue and cell specificity of glycosylation. Here, we built a two-step computational method GlycoCell to predict the cell-specific O-GalNAc glycosylation, the most complex type of O-glycosylation reported so far, in 12 human cell types. The first step predicted whether a site had the potential to be O-glycosylated. The model achieved an accuracy of 0.83. The second step predicted whether a potential glycosite would be O-glycosylated in the given cell type. For 12 cell types, a model was built for each cell type. The accuracies for these models ranged from 0.78 to 0.87. To facilitate the usage of GlycoCell for the public, a web server was built which is available at http://www.biomedcloud.com.cn/GlyoCell/main.htm. It could be useful for investigating the cell-specific O-glycosylation in human.展开更多
基金Supported by(in part)Grants R01-AR43510 to Boyce BF and R01-AR48697 to Xing L from the National Institute of Arthritis and Musculoskeletal and Skin Diseases,United States
文摘Osteoclasts are the bone resorbing cells essential for bone remodeling.Osteoclasts are formed from hematopoietic progenitors in the monocyte/macrophage lineage.Osteoclastogenesis is composed of several steps including progenitor survival,differentiation to mononuclear pre-osteoclasts,fusion to multi-nuclear mature osteoclasts,and activation to bone resorbing osteoclasts.The regulation of osteoclastogenesis has been extensively studied,in which the receptor activator of NF-κB ligand(RANKL)-mediated signaling pathway and downstream transcription factors play essential roles.However,less is known about osteoclast fusion,which is a property of mature osteoclasts and is required for osteoclasts to resorb bone.Several proteins that affect cell fusion have been identified.Among them,dritic cell-specific transmembrane protein(DC-STAMP)is directly associated to osteoclast fusion in vivo.Cytokines and factors influence osteoclast fusion through regula-tion of DC-STAMP.Here we review the recently discovered new factors that regulate osteoclast fusion with specific focus on DC-STAMP.A better understanding of the mechanistic basis of osteoclast fusion will lead to the development of a new therapeutic strategy for bone disorders due to elevated osteoclast bone resorption.Cell-cell fusion is essential for a variety of cellular biological processes.In mammals,there is a limited number of cell types that fuse to form multinucleated cells,such as the fusion of myoblasts for the formation of skeletal muscle and the fusion of cells of the monocyte/macrophage lineage for the formation of multinucleated osteoclasts and giant cells.In most cases,cellcell fusion is beneficial for cells by enhancing function.Myoblast fusion increases myofiber size and diameter and thereby increases contractile strength.Multinucleated osteoclasts have far more bone resorbing activity than their mono-nuclear counterparts.Multinucleated giant cells are much more efficient in the removal of implanted materials and bacteria due to chronic infection than macr
基金Supported by Grants from the National Natural Science Foundation of China No.81000163,No.81070567,and No.81170363
文摘AIM: To investigate dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin(DC-SIGN) expression in intestinal epithelial cells(IECs) in inflammatory bowel disease(IBD).METHODS: The expression of DC-SIGN in IECs was examined by immunohistochemistry of intestinal mucosal biopsies from 32 patients with IBD and 10 controls.Disease activity indices and histopathology scores were used to assess the tissue lesions and pathologic damage.Animal studies utilized BALB/c mice with dextran sodium sulfate(DSS)-induced colitis treated with anti-P-selectin lectin-EGF domain monoclonal antibody(PsL-EGFmA b).Controls,untreated and treated mice were sacrificed after 7 d,followed by isolation of colon tissue and IECs.Colonic expression of DC-SIGN,CD80,CD86 and MHC Ⅱ was examined by immunohistochemistry or flow cytometry.The capacity of mouse enterocytes or dendritic cells to activate T cells was determined by coculture with naive CD4+ T cells.Culture supernatant and intracellular levels of interleukin(IL)-4 and interferon(IFN)-γ were measured by enzyme-linked immunosorbent assay and flow cytometry,respectively.The ability of IECs to promote T cell proliferation was detected by flow cytometry staining with carboxyfluorescein diacetate succinimidyl ester.RESULTS: Compared with controls,DC-SIGN expression was significantly increased in IECs from patients with Crohn's disease(P < 0.01) or ulcerative colitis(P < 0.05).DC-SIGN expression was strongly correlated with disease severity in IBD(r = 0.48; P < 0.05).Similarly,in the DSS-induced colitis mouse model,IECs showed upregulated expression of DC-SIGN,CD80,CD86 and MHC,and DC-SIGN expression was positively correlated with disease activity(r = 0.62: P < 0.01).IECs from mouse colitis stimulated naive T cells to generate IL-4(P < 0.05).Otherwise,dendritic cells promoted a T-helper-1-skewing phenotype by stimulating IFN-γ secretion.However,DC-SIGN expression and T cell differentiation were suppressed following treatment of mice with DSS-induced colitis with Ps L-E
基金supported by the National Key R&D Program of China(Grant No.2018YFA0107200)to JWthe National Natural Science Foundation of China(Grant Nos.81830082,82030078,and 81621004 to JL+1 种基金Grant Nos.31771446 and 31970594 to JWGrant No.32100452 to XS).
文摘Serine/arginine-rich splicing factor 7(SRSF7),a known splicing factor,has been revealed to play oncogenic roles in multiple cancers.However,the mechanisms underlying its oncogenic roles have not been well addressed.Here,based on N6-methyladenosine(m^(6)A)co-methylation network analysis across diverse cell lines,we find that the gene expression of SRSF7 is positively correlated with glioblastoma(GBM)cell-specific m^(6)A methylation.We then indicate that SRSF7 is a novel m^(6)A regulator,which specifically facilitates the m^(6)A methylation near its binding sites on the mRNAs involved in cell proliferation and migration,through recruiting the methyltransferase complex.Moreover,SRSF7 promotes the proliferation and migration of GBM cells largely dependent on the presence of the m^(6)A methyltransferase.The two m^(6)A sites on the mRNA for PDZ-binding kinase(PBK)are regulated by SRSF7 and partially mediate the effects of SRSF7 in GBM cells through recognition by insulin-like growth factor 2 mRNA-binding protein 2(IGF2BP2).Together,our discovery reveals a novel role of SRSF7 in regulating m^(6)A and validates the presence and functional importance of temporal-and spatial-specific regulation of m^(6)A mediated by RNA-binding proteins(RBPs).
文摘Background： The expression of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin （DC-SIGN） in renal tubular epithelial cells has been thought to be highly correlated with the occurrence of several kidney diseases, but whether it takes place in renal tissues during hemorrhagic shock （HS） is unknown. The present study airned to investigate this phenomenon and the inhibitory effect of Vitamin C （VitC）. Methods： A Sprague Dawley rat HS model was established in vivo in this study. The expression level and location of DC-SIGN were observed in kidneys. Also, the degree of histological damage, the concentrations of tumor necrosis factor-or and interleukin-6 in the renal tissues, and the serum concentration of blood urea nitrogen and creatinine at different times （2-24 h） alter HS （six rats in each group）, with or without VitC treatment belbre resuscitation, were evaluated. Results： HS induced DC-SIGN expression in rat tubular epithelial cells. The proinflarnmatory cytokine concentration, histological damage scores, and functional injury of kidneys had increased. All these phenornena induced by HS were relieved when the rats were treated with VitC before resuscitation. Conclusions： The results of the present study illustrated that HS could induce tubular epithelial cells expressing DC-SIGN, and the levels of proinflarnmatory cytokines in the kidney tissues improved correspondingly. The results also indicated that VitC could suppress the DC-SIGN expression in the tubular epithelial cells induced by HS and alleviate the inflammation and functional injury in the kidney.
基金The study was supported by a grant from the National Natural Science Foundation of China （No. 30772019）.
文摘Background： Dendritic cells （DCs） play an important role in host defense against pathogen infection. DC-specific intercellular adhesion moleeule-3-grabbing nonintegrin （SIGN） is a group II C-type lectin receptor and specifically expressed on the surface of DCs. This study aimed to determine whether DC-SIGN affects intracellular signaling activation, Th1/Th2 imbalance and aspergillus immune evasion in aspergillus infection, and explore the application of DC-SIGN-modified DCs in immunotherapy. Methods： DCs were first obtained from the mononuelear ceils of peripheral blood. The interferon （IFN）-γand dexamethasone （Dex） were used to stimulate DCs. The expression ofDC-SIGN, Th 1 and Th2 cytokines, and the capacity of DCs in stimulating T cells proliferation and phagocytosis, and nuclear factor （NF）-κB activation were analyzed. In addition, adenovirus expression vector Ad-DC-SIGN was generated to transfect DCs. Mannan was used to block DC-SIGN signaling for confirming the involvement of DC-SIGN function in Aspergillus fumigatus （Af）-induced DCs maturation. The unpaired, two-tailed Student＇s t-test was used in the comparisons between two groups. Results： Exogenous IFN-y could activate Af-induced DCs and promote the Th0 cells toward Th 1 profile （interleukin [IL]- 12 in I FN-y/Af group： 50.96 ± 4.38 pg/ml; control/Afgroup： 29.70 ±2.00 pg/ml, t = 10.815, P 〈 0.001 ）. On the other hand, Dex inhibited the secretion of Th2 cytokines （IL- 10 in Dex/Af group： 5.27 ± 0.85 pg/ml; control/Af group： 15.14 ± 1.40 pg/ml, t = 14.761, P 〈 0.001 ））, and successfully caused immunosuppression. Alier transfection with Ad-DC-SIGN, DCs have improved phagocytosis （phagocytosis rates in Ad-DC-SIGN group： 74.0% ± 3.4%; control group： 64.7% ± 6.8%, t = 3.104, P = 0.013）. There was more Thl cytokine secreted in the Af-induced DC-SIGN modified DCs （IL-12 in Ad-DC-SIGN/Af group： 471.98 ± 166.31 pg/ml; control/Af group： 33.35 ± 5.98 pg/ml, t = 6.456, P = 0.001 ）, correl
基金This work was supported by the National Natural Science Foundation of China(31801126)the Chongqing Talents:Exceptional Young Talents Project(cstc2022ycjhbgzxm0019)the Doctoral Start-up Foundation of Southwest University(SWU120010).
文摘The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breeding Japanese and Chinese original strains are usually used for the large-scale breeding of silkworms,but this may result in uncontrolled transgene dispersal during the popularization and application of the F1 hybrid transgenic eggs.To address this issue,we developed a safe and efficient strategy using the GAL4/Upstream activating sequence(UAS)system,the FLP/flippase recognition target(FRT)system,and the gonad-specific expression gene promoters(RSHP1p and Nanosp)for the germ cell-specific automatic excision of foreign DNA in the F1 hybrid transgenic silkworms.We established 2 types of activator strains,R1p::GAL4-Gr and Nsp::GAL4-Gr,containing the testis-specific GAL4 gene expression cassettes driven by RSHP1p or Nanosp,respectively,and 1 type of effector strain,UAS::FLP-Rg,containing the UAS-linked FLP gene expression cassette.The FLP recombinase-mediated sperm-specific complete excision of FRT-flanked target DNA in the F1 double-transgenic silkworms resulting from the hybridization of R1p::GAL4-Gr and UAS::FLP-Rg was 100%,whereas the complete excision efficiency resulting from the hybridization of Nsp::GAL4-Gr and UAS::FLP-Rg ranged from 13.73%to 80.3%.Additionally,we identified a gene,sw11114,that is expressed in both testis and ovary of Bombyx mori,and can be used to establish novel gonad-specific expression systems in transgenic silkworms.This strategy has the potential to fundamentally solve the safety issue in the production of F1 transgenic silkworm eggs and provides an important reference for the safety of transgenic technology in other insect species.
基金supported by the National Key Research and Development Program of China(2017YFA0505500)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB38040400)+1 种基金National Science Foundation of China(31771476 and 31930022)Shanghai Municipal Science and Technology Major Project(2017SHZDZX01)。
文摘Gene regulatory networks play pivotal roles in our understanding of biological processes/mechanisms at the molecular level.Many studies have developed sample-specific or cell-type-specific gene regulatory networks from single-cell transcriptomic data based on a large amount of cell samples.Here,we review the state-of-the-art computational algorithms and describe various applications of gene regulatory networks in biological studies.
文摘Zwitterionic polymers are known to interact with cells and have been shown to reveal cancer cell specificity.In this work,the importance of the chemistry of the polymer backbone for the cellular specificity of amino-acid-derived polyzwitterions is demonstrated.A series of glutamic acid(Glu)-based vinyl monomers(i.e.,an acrylate,a methacrylate,an acrylamide,and a methacrylamide)were prepared and used for reversible addition-fragmentation chain-transfer(RAFT)polymerisation,yielding defined polymers with narrow size distribution(Ð<1.3).All Glu-functionalised,zwitterionic polymers revealed high cytocompatibility;however,differences in cellular association and specificity were observed.In particular,the methacrylamide-derived polymers showed high association with both,breast cancer cells and non-cancerous dendritic cells and,consequently,lack specificity.In contrast,high specificity to only breast cancer cells was observed for polyacrylates,-methacrylates,and-acrylamides.Detailed analysis of the polymers revealed differences in hydrophobicity,zeta potential,and potential side chain hydrolysis,which are impacted by the polymer backbone and might be responsible for the altered the cell association of these polymers.It is shown that a slightly negative net charge is preferred over a neutral charge to retain cell specificity.This was also confirmed by association experiments in the presence of competitive amino acid transporter substrates.The affinity of slightly negatively charged Glu-derived polymers to the xCT Glu/cystine cell membrane antiporter was found to be higher than that of neutrally charged polymers.Our results emphasise the importance of the polymer backbone for the design of cell-specific polymers.This study further highlights the potential to tailor amino-acid-derived zwitterionic materials beyond their side chain functionality.
基金the National Key R&D Program of China(Grant No.2017YFA0505500)the National Natural Science Foundation of China(Grant Nos.31771476 and 31930022)the Shanghai Municipal Science and Technology Major Project,China(Grant No.2017SHZDZX01).
文摘t The rapid advancement of single-cell technologies has shed new light on the complex mechanisms of cellular heterogeneity.However,compared to bulk RNA sequencing(RNA-seq),single-cell RNA-seq(scRNA-seq)suffers from higher noise and lower coverage,which brings new computational difficulties.Based on statistical independence,cell-specific network(CSN)is able to quantify the overall associations between genes for each cell,yet suffering from a problem of overestimation related to indirect effects.To overcome this problem,we propose the c-CSN method,which can construct the conditional cell-specific network(CCSN)for each cell.c-CSN method can measure the direct associations between genes by eliminating the indirect associations.c-CSN can be used for cell clustering and dimension reduction on a network basis of single cells.Intuitively,each CCSN can be viewed as the transformation from less“reliable”gene expression to more“reliable”gene–gene associations in a cell.Based on CCSN,we further design network flow entropy(NFE)to estimate the differentiation potency of a single cell.A number of scRNA-seq datasets were used to demonstrate the advantages of our approach.1)One direct association network is generated for one cell.2)Most existing scRNA-seq methods designed for gene expression matrices are also applicable to c-CSN-transformed degree matrices.3)CCSN-based NFE helps resolving the direction of differentiation trajectories by quantifying the potency of each cell.c-CSN is publicly available at https://github.com/LinLi-0909/c-CSN.
文摘Aim： To characterize mouse capping protein α3 （CPα3） during spermatogenesis and sperm maturation. Methods： We produced rat anti-CPα3 antiserum and examined the expression of CPα3 in various mouse tissues using Western blot analysis and the localization of CPα3 in testicular and epididymal sperm using immunohistochemical analyses. We also examined how the localization of CPα3 and β-actin （ACTB） in sperm changed after the acrosomal reaction by performing immunohistochemical analyses using anti-CPα3 antiserum and anti-actin antibody. Results： Western blot analysis using specific antiserum revealed that CPα3 was expressed specifically in testes. Interestingly, the molecular weight of CPα3 changed during sperm maturation in the epididymis. Furthermore, the subcellular localization of CPα3 in sperm changed dynamically from the flagellum to the post-acrosomal region of the head during epididymal maturation. The distribution of ACTB was in the post-acrosomal region of the head and the flagellum. After inducing the acrosomal reaction, the CPα3 and ACTB localization was virtually identical to the localization before the acrosomal reaction. Conclusion： CPα3 might play an important role in sperm morphogenesis and/or sperm function.
文摘The succinct metaphor,‘the immune system＇s loaded gun＇, has been used to describe the role of mast cells （MCs） due to their storage of a wide range of potent pro-inflammatory and antimicrobial mediators in secretory granules that can be released almost instantly on demand to fight invaders. Located at host-environment boundaries and equipped with an arsenal of pattern recognition receptors, MCs are destined to be rapid innate sensors of pathogens penetrating endothelial and epithelial surfaces. Although the importance of MCs in antimicrobial and antiparasitic defense has long been appreciated, their role in raising the alarm against viral infections has been noted only recently. Work on cytomegalovirus （CMV） infection in the murine model has revealed MCs as players in a novel cross-talk axis between innate and adaptive immune surveillance of CMV, in that infection of MCs, which is associated with MC degranulation and release of the chemokine CCL5, enhances the recruitment of protective CD8 T cells to extravascular sites of virus replication, specifically to lung interstitium and alveolar epithelium. Here, we have expanded on these studies by investigating the conditions for MC activation and the consequent degranulation in response to host infection. Surprisingly, the data revealed two temporally and mechanistically distinct waves of MC activation： an almost instant indirect activation that depended on TLR3/TRIF signaling and delayed activation by direct infection of MCs that did not involve TLR3/rRIF signaling. Cell type-specific Cre-recombination that yielded eGFP-expressing reporter virus selectively originating from MCs identified MC as a new in vivo, first-hit target cell of productive murine CMV infection.
文摘NES1 gene is thought to be a tumor-suppressor gene.Our previous study found that overexpression of NES1 gene in PC3 cell line could slow down the tumor proliferation rate,associated with a mild decrease in BCL-2 expression.The BCL-2 decrease could increase the sensitivity of radiotherapy to tumors.Thus,we supposed to have an“enhanced firepower”effect by combining overexpressed NES1 gene therapy and 131I radiation therapy uptake by overexpressed hNIS protein.We found a weak endogenous expression of hNIS protein in PC3 cells and demonstrated that the low expression of hNIS protein in PC3 cells might be the reason for the low iodine uptake.By overexpressing hNIS in PC3,the radioactive iodine uptake ability was significantly increased.Results of in vitro and in vivo tumor proliferation experiments and 18F-fluorothymidine(18F-FLT)micro-positron emission tomography/computed tomography(micro-PET/CT)imaging showed that the combined NES1 gene therapy and 131I radiation therapy mediated by overexpressed hNIS protein had the best tumor proliferative inhibition effect.Immunohistochemistry showed an obvious decrease of Ki-67 expression and the lowest BCL-2 expression.These data suggest that via inhibition of BCL-2 expression,overexpressed NES1 might enhance the effect of radiation therapy of 131I uptake in hNIS overexpressed PC3 cells.
基金Supported by the National Natural Science Foundation of China(Nos.31372514,31472264,31572602)the China Agriculture Research System(No.CARS-47)+1 种基金the Scientific and Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(Nos.2015ASKJ02,2015ASKJ02-03-03)the Youth Innovation Promotion Association CAS and Chinese Academy of Science and Technology Service Network Planning(No.KFJ-EW-STS-060)
文摘Some germ cell marker genes, such as vasa, nanos, and dead end( dnd), have been identified in fish. Recently, lymphocyte antigen 75(Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker in several fish species. In this study, the Japanese flounder Paralichthys olivaceus ly75 homolog( ly75) was cloned and its expression pattern in gonads was analyzed. The full-length c DNA of ly75 was 7 346 bp, with an open reading frame(ORF) of 5 229 bp. The ORF encoded a protein containing 1 742 amino acids with a predicted molecular mass of 196.89 k Da. In adult tissues, ly75 transcripts were detected in all analyzed tissues but abundantly in the testis. In in-situ hybridization analyses, ly75 mRNA was predominantly localized in oocytes in the ovary and spermatogonia in the testis, but ly75 mRNA was not detected in oogonia, spermatocytes, spermatids, or spermatozoa. These results indicated that ly75 could be a potential germ cell-specific marker in P. olivaceus, as in other fishes.
文摘Glycosylation is one of the most extensive post-translation modifications of proteins. Although lots of computational models have been developed to predict the glycosylation sites, none of them considered the tissue and cell specificity of glycosylation. Here, we built a two-step computational method GlycoCell to predict the cell-specific O-GalNAc glycosylation, the most complex type of O-glycosylation reported so far, in 12 human cell types. The first step predicted whether a site had the potential to be O-glycosylated. The model achieved an accuracy of 0.83. The second step predicted whether a potential glycosite would be O-glycosylated in the given cell type. For 12 cell types, a model was built for each cell type. The accuracies for these models ranged from 0.78 to 0.87. To facilitate the usage of GlycoCell for the public, a web server was built which is available at http://www.biomedcloud.com.cn/GlyoCell/main.htm. It could be useful for investigating the cell-specific O-glycosylation in human.
