BACKGROUND Cases of myelin oligodendrocyte glycoprotein(MOG)antibody-related disease have a history of coronavirus disease 2019 infection or its vaccination before disease onset.Severe acute respiratory syndrome virus...BACKGROUND Cases of myelin oligodendrocyte glycoprotein(MOG)antibody-related disease have a history of coronavirus disease 2019 infection or its vaccination before disease onset.Severe acute respiratory syndrome virus 2(SARS-CoV-2)infection has been considered to be a trigger of central nervous system autoimmune diseases.CASE SUMMARY Here we report a 20-year male with MOG-associated transverse myelitis after a SARS-CoV-2 infection.The patient received a near-complete recovery after standard immunological treatments.CONCLUSION Attention should be paid to the evaluation of typical or atypical neurological symptoms that may be triggered by SARS-CoV-2 infection.展开更多
Nasopharyngeal carcinoma(NPC)is a malignant tumor arising from the nasopharyngeal epithelium.It consists of undifferentiated squamous cells in the nasopharynx.This type of epithelial cell neoplasm is globally distribu...Nasopharyngeal carcinoma(NPC)is a malignant tumor arising from the nasopharyngeal epithelium.It consists of undifferentiated squamous cells in the nasopharynx.This type of epithelial cell neoplasm is globally distributed,with the highest prevalence observed in certain regions of the world.It has been known since ancient times.The incidence of NPC is steadily decreasing as data on the molecular factors involved in the pathogenesis of NPC accumulate.Glycoproteins are characterized by polymers of saccharides attached to the amino acid sequences of proteins during the process of glycosylation.They are present in all animal cells and are especially abundant on the surface of tumor cells.Alterations in expression of cellular glycoproteins have recently attracted attention as a key component of neoplastic progression.Tumor-associated glycoproteins may serve as a hallmark of cancer cells and thus represent novel diagnostic and even therapeutic targets.Interest in the role of glycoproteins in cancer in general and specifically in NPC pathology has steadily increased over the past fifty years,reaching over thousands and two hundred publications in the last five years,respectively.Here,data on a specific class of proteins,glycoproteins,involved in tumorigenesis of NPCs are summarized,with a focus on a few of the best-studied ones.Relevant studies performed mainly in the last five years were retrieved and collected through the PubMed system.展开更多
介绍了一个新的基于优化推导出的核偏最小二乘(kernel partial least squares,K-PLS)的算法原理和实现步骤,并且给出了利用K-PLS法构建P-糖蛋白(P-glycoprotein,P-gp)黄酮类抑制剂的定量构效关系(QSAR)模型.利用该方法结合几个简单的分...介绍了一个新的基于优化推导出的核偏最小二乘(kernel partial least squares,K-PLS)的算法原理和实现步骤,并且给出了利用K-PLS法构建P-糖蛋白(P-glycoprotein,P-gp)黄酮类抑制剂的定量构效关系(QSAR)模型.利用该方法结合几个简单的分子拓扑参数,构建了具有高准确率的预测模型.该模型将有助于P-gp黄酮类抑制剂的虚拟筛选和理性设计.结果证明K-PLS是一个十分稳定可靠的方法,将会在化学计量学领域得到较好的应用和推广.展开更多
肿瘤多药耐药性(multiple drug resistance,MDR)的发生往往伴随着多药耐药基因如MDR1、MRP1和BCRP等高表达,其中MDR1基因编码的P-糖蛋白(P-glycoprotein,P-gp)是目前公认可以诱发癌细胞发生MDR的重要分子。传统研究认为P-gp主要是作为...肿瘤多药耐药性(multiple drug resistance,MDR)的发生往往伴随着多药耐药基因如MDR1、MRP1和BCRP等高表达,其中MDR1基因编码的P-糖蛋白(P-glycoprotein,P-gp)是目前公认可以诱发癌细胞发生MDR的重要分子。传统研究认为P-gp主要是作为一个药物泵将化疗药物从细胞内排出从而导致MDR。然而系列研究发现,除了介导MDR以外,P-gp还能够调节癌细胞的生长、增殖、凋亡、迁移和侵袭等其他生物学行为;而且研究表明P-gp的这些作用可以依赖,也可以不依赖于其药物泵的功能。这些结果表明P-gp能够通过一些新的机制促进肿瘤的进展。本文主要针对P-gp在促进肿瘤进展中的作用进行综述。展开更多
Myelin-associated glycoprotein(MAG) inhibits the growth of neurites from nerve cells. Extraction and purification of MAG require complex operations; therefore, we attempted to determine whether commercially availabl...Myelin-associated glycoprotein(MAG) inhibits the growth of neurites from nerve cells. Extraction and purification of MAG require complex operations; therefore, we attempted to determine whether commercially available MAG-Fc can replace endogenous MAG for research purposes. Immunofluorescence using specific antibodies against MAG, Nogo receptor(NgR) and paired immunoglobulin-like receptor B(PirB) was used to determine whether MAG-Fc can be endocytosed by neuro-2a cells. In addition, neurite outgrowth of neuro-2a cells treated with different doses of MAG-Fc was evaluated. Enzyme linked immunosorbent assays were used to measure RhoA activity. Western blot assays were conducted to assess Rho-associated protein kinase(ROCK) phosphorylation. Neuro-2a cells expressed NgR and PirB, and MAG-Fc could be endocytosed by binding to NgR and PirB. This activated intracellular signaling pathways to increase RhoA activity and ROCK phosphorylation, ultimately inhibiting neurite outgrowth. These findings not only verify that MAG-Fc can inhibit the growth of neural neurites by activating RhoA signaling pathways, similarly to endogenous MAG, but also clearly demonstrate that commercial MAG-Fc is suitable for experimental studies of neurite outgrowth.展开更多
Estrus-associated glycoprotein (EGP) is a special protein in oviductal fluid which appears before ovulation and fertilization and disappears after the embryo passes into the uterus. One-and two dimensional SDS-PAGE an...Estrus-associated glycoprotein (EGP) is a special protein in oviductal fluid which appears before ovulation and fertilization and disappears after the embryo passes into the uterus. One-and two dimensional SDS-PAGE and Western blotting with monoclonal antibody or peanut agglutinin were used to characterize the glycoprotein,The specificity of the marking agents enabled the study to proceed without purification. EGP was found to include two proteins: one is acidic with a pH of 4.5 while the other is basic with a pH of 8.0 The molecular weights of their subunits are the same, that is 110 kD. This study may shed light on the mechanism of reproductive Process and be helpful to the development of a more cffective culture medium for in vitro culture of early embryo.展开更多
During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spe...During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four (ZP1, ZP2, ZP3 and ZP4). ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans (in addition to ZP3), ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the Gi-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels (VOCCs), whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans (in addition to ZP3), ZP1 and ZP4 also participate in these stages of fertilisation.展开更多
Gynogenetic silver crucian carp, Carassius auratus gibelio, is an intriguing model system. In the present work, a systemic study has been initiated by introducing suppression subtractive hybridization technique into t...Gynogenetic silver crucian carp, Carassius auratus gibelio, is an intriguing model system. In the present work, a systemic study has been initiated by introducing suppression subtractive hybridization technique into this model system to identify the differentially expressed genes in oocytes between gynogenetic silver crucian carp and its closely related gonochoristic color crucian carp. Five differential cDNA fragments were identified from the preliminary screening, and two of them are ZP3 homologues. Moreover, the full length ZP3 cDNAs were cloned from their oocyte cDNA libraries. The length of ZP3 cDNAs were 1378 bp for gyno-carp and 1367 bp for gono-carp, and they can be translated into proteins with 435 amino acids. Obvious differences are not only in the composition of amino acids, but also in the number of potential O-linked oligosaccharide sites. In addition, gyno-carp ZP3 amino acid sequence has an unexpected higher identity value with common carp (83.5%) than that with the closely related gono-carp (74.7%). The unique homology may be originated from the ancient hybridization. Northern blot analysis confirmed that expression of the ZP3 gene occurred exclusively in the oocytes. Because O-linked oligosaccharides on ZP3 have been demonstrated to play very important roles in fertilization, it is suggested that the extra O-linked glycosylation sites may be related to the unique sperm-egg recognition mechanism in gynogenesis.展开更多
Glycoprotein from Ginkgo biloba kernel may be allergic. In this paper, the allergic proteins were identified with Western blotting, and the 32 kDa glycoprotein was purified with ion exchange chromatography and gel chr...Glycoprotein from Ginkgo biloba kernel may be allergic. In this paper, the allergic proteins were identified with Western blotting, and the 32 kDa glycoprotein was purified with ion exchange chromatography and gel chromatography. With Western blotting, there were 3 allergic proteins with molecular weight 21, 32, and 36 kDa. With SDS-PAGE analysis and measurements of the protein and sugar contents, the isolation and purification technology of 32 kDa was confirmed. Ginkgo crude protein extract was precipitated with ammonium sulphate (saturation gradient: 40-80%). The precipitate was purified by chromatography with DEAE-cellulose 52, then chromatography with Sephadex G-200 and the target glycoprotein was finally obtained. The analysis results showed the molecule of the glycoprotein was 32.12 kDa and the ratio of protein to sugar was 20.56:1. In conclusion, the purification method could be used in preparation of the glycoprotein, and the study could provide a basis for the further research of the glycoprotein.展开更多
The glycoprotein H (gH) gene homologue of duck plague virus (DPV) was cloned by degenerate polymerase chain reaction (PCR) and sequenced. It was located immediately downstream from the thymidine kinase gene (TK...The glycoprotein H (gH) gene homologue of duck plague virus (DPV) was cloned by degenerate polymerase chain reaction (PCR) and sequenced. It was located immediately downstream from the thymidine kinase gene (TK). In addition, the 3'-end of the gene homologue to herpesvirus UL21 was located downstream from the gH gene. DPV gH gene open reading frame (ORF) was 2 505 bp in length and its primary translation product was a polypeptide of 834 amino acids long. It possessed several characteristics of membrane glycoproteins, including an N-terminal hydrophobic signal sequence, an external domain containing eight putative N-linked glycosylation sites, a C-terminal transmembrane domain, and a charged cytoplasmic tail. Comparison with other herpesvirus revealed identities of 20.2, 25.1, 23.0, 23.0, 26.5 and 26.0% with the gH counterparts of the human herpesvirus virus 1 (HSV1), equine herpesvirus 4 (EHV4), bovine herpesvirus 1 (BHV1), pseudorabies virus (PRV), gallid herpesvirus 2 (GHV2) and gallid herpesvirus 3 (GHV3), respectively.展开更多
Pancreatic cancer(Pa C) shows a clear tendency to increase in the next years and therefore represents an important health and social challenge. Currently, there is an important need to find biomarkers for PaC early de...Pancreatic cancer(Pa C) shows a clear tendency to increase in the next years and therefore represents an important health and social challenge. Currently, there is an important need to find biomarkers for PaC early detection because the existing ones are not useful for that purpose. Recent studies have indicated that there is a large window of time for PaC early detection, which opens the possibility to find early biomarkers that could greatly improve the dismal prognosis of this tumor. The present manuscript reviews the state of the art of the existing PaC biomarkers. It focuses on the anomalous glycosylation process and its role in PaC. Glycan structures of glycoconjugates such as glycoproteins are modified in tumors and these modifications can be detected in biological fluids of the cancer patients. Several studies have found serum glycoproteins with altered glycan chains in PaC patients, but they have not shown enough specificity for PaC. To find more specific cancer glycoproteins we propose to analyze the glycan moieties of a battery of glycoproteins that have been reported to increase in PaC tissues and that can also be found in serum. The combination of these new candidate glycoproteins with their aberrant glycosylation together with the existing biomarkers could result in a panel, which would expect to give better results as a new tool for early diagnosis of PaC and to monitor the disease.展开更多
BACKGROUND Acute pancreatitis(AP) is rapid-onset pancreatic inflammation that causes local and systemic inflammatory response syndrome(SIRS) with high morbidity and mortality, but no approved therapies are currently a...BACKGROUND Acute pancreatitis(AP) is rapid-onset pancreatic inflammation that causes local and systemic inflammatory response syndrome(SIRS) with high morbidity and mortality, but no approved therapies are currently available. P-selectin glycoprotein ligand 1(PSGL-1) is a transmembrane glycoprotein to initiate inflammatory responses. We hypothesized that PSGL-1 may be involved in the development of AP and would be a new target for the treatment of AP.AIM To investigate the role and mechanism of PSGL-1 in the development of AP.METHODS The PSGL-1 expression on leukocytes was detected in peripheral blood of AP patients and volunteers. Pancreatic injury, inflammatory cytokines expression, and inflammatory cell infiltration was measured in AP mouse models induced with PSGL-1 knockout(PSGL-1-/-) and wild-type(PSGL-1+/+) mice. Leukocyteendothelial cell adhesion was measured in a peripheral blood mononuclear cell(PBMC)-endothelial cell coculture system.RESULTS The expression of PSGL-1 on monocytes and neutrophils was significantly increased in AP patients. Compared with PSGL-1+/+ mice, PSGL-1-/-AP mice induced by caerulein exhibited lower serum amylase, less Interleukin-1 beta(IL-1 beta) and Interleukin-6(IL-6) expression, less neutrophil and macrophage infiltration, and reduced peripheral neutrophil and monocyte accounts. PSGL-1 deficiency alleviated leukocyte-endothelial cell adhesion via IL-6 but not IL-1 beta.CONCLUSION PSGL-1 deficiency effectively inhibits the development of AP by preventing leukocyte-endothelial cell adhesion via IL-6 stimulation and may become a potential therapeutic target for treating AP.展开更多
Many mammalian herpes viruses utilize heparan sulfate (HS) moieties present on cell surface proteoglycans as receptors for cell entry, and this process also requires viral glycoprotein C (gC) homologues. However, ...Many mammalian herpes viruses utilize heparan sulfate (HS) moieties present on cell surface proteoglycans as receptors for cell entry, and this process also requires viral glycoprotein C (gC) homologues. However, our understanding of the role of gC in facilitating attachment of other alpha-herpes viruses such as the duck plague virus (DPV) remains preliminary. To study the role of gC during DPV infection, we used a gC-deleted mutant virus (DPV-AgC-EGFP). Examination of the viral copy number by real-time PCR, as well as time course studies of viral adsorption and proliferation revealed that gC was involved in the viral binding to the cell surface. The affinity of viral glycoproteins (gB-DPV, gC-DPV, and gE-DPV) to HS was assessed using a prokaryotic expression system and HJTrapTM HeparJn HP column chromatography. In addition, to confirm that gC played a role in the interaction between DPV and HS, viruses were treated with the HS analogue heparin and host cells were treated with its inhibitors heparinase prior to exposure to DPV-△gC-EGFP or wild-type strain Chinese virulent duck plague virus (DPV-CHv). The effects of heparin and heparinase on virus infectivity demonstrated that function of gC on Viral adsorption is independent of interactions between gC and heparin sulfate on cell surface. All in all, this study demonstrated that the gC of DPV can mediate viral adsorption in an HS-independent manner, which distinguish it from the gC of some other alpha-herpes viruses. Future studies will be required to identify the receptors involved in gC protein binding to cells. This work provides us a foundation for further studies of examining the roles of gC in the adsorption during duck plague virus infection.展开更多
Objective: To determine skin whitening and wrinkle improvement efficacy, glycoprotein fractions were extracted from liquid extracts of boiled sea cucumber and their effects on tyrosine and elastase inhibitory activiti...Objective: To determine skin whitening and wrinkle improvement efficacy, glycoprotein fractions were extracted from liquid extracts of boiled sea cucumber and their effects on tyrosine and elastase inhibitory activities were assayed. Methods: Fractions above and below 50 k Da(>50 kD a and <50 kD a) were extracted via a series of steps invovling: boiling, filtering, desalting and freeze drying. Cytotoxicity, skin whitening and wrinkle-removing effects of boiled liquid were determined. Results: Our MTT data showed that neither glycoprotein fraction of boiled liquid induces cellular cytotoxicity up to a concentration of 10 mg/m L treatment of the mouse melanoma cell line, B16F10, with 10 mg/m L >50 kDa enhanced tyrosinase and elastase inhibitory activities by 50.84% and 28.78%, respectively. Correlations of the >50 kD a concentration with tyrosinase inhibitory(R^2=0.968) and elastase inhibitory(R2=0.983) efficacy were significant. Conclusions: >50 kD a glycoprotein fraction isolated from liquid extracts of boiled sea cucumber, which can serve as a functional cosmetic ingredient for whitening and wrinkle improvement of skin.展开更多
Aberrations in protein glycosylation and polysaccharides play a pivotal role in pancreatic tumorigenesis, influencing cancer progression, metastasis, immunoresponse and chemoresistance. Abnormal expression in sugar mo...Aberrations in protein glycosylation and polysaccharides play a pivotal role in pancreatic tumorigenesis, influencing cancer progression, metastasis, immunoresponse and chemoresistance. Abnormal expression in sugar moieties can impact the function of various glycoproteins, including mucins, surface receptors, adhesive proteins, proteoglycans, as well as their effectors and binding ligands, resulting in an increase in pancreatic cancer invasiveness and a cancerfavored microenvironment. Recent advance in glycoproteomics, glycomics and other chemical biology techniques have been employed to better understand the complex mechanism of glycosylation events and how they orchestrate molecular activities in genomics, proteomics and metabolomics implicated in pancreatic adenocarcinoma. A variety of strategies have been demonstrated targeting protein glycosylation and polysaccharides for diagnostic and therapeutic development.展开更多
The effects of spraying rare earths(RE) on composition and activities of tea polysaccharide were measured by inductively coupled plasma mass spectrometry (ICP-MS), gas chromatography(GC), amino acid analyzer and anima...The effects of spraying rare earths(RE) on composition and activities of tea polysaccharide were measured by inductively coupled plasma mass spectrometry (ICP-MS), gas chromatography(GC), amino acid analyzer and animal models. The results show that there are rare earth elements binding glycoprotein in tea (REE-TGP). The effects of RE on composition and content of saccharides in REE-TGP are not obvious. The contents of Hypro and Ser in REE-TGP are evidently enhanced in comparison with that in control (not treated with rare earth), but the content of Glu is smaller than that from control. The content of La in REE-TGP from the tea garden sprayed rare earth is 193% higher than that in control. REE-TGP declines content of blood sugar in mice and enhances immunization of rat, which are very evident when the animals are treated by REE-TGP from the tea garden sprayed RE.展开更多
This study aimed to isolate and characterize the structures of glycoproteins from peas and determine their hypoglycemic activity.The crude pea glycoproteins(PGP)were extracted by hot water and purified by diethylamino...This study aimed to isolate and characterize the structures of glycoproteins from peas and determine their hypoglycemic activity.The crude pea glycoproteins(PGP)were extracted by hot water and purified by diethylaminoethyl(DEAE)-Sepharose chromatography and Sephadex G-100 size-exclusion chromatography in sequence.Then three main fractions were obtained,namely PGP1,PGP2 and PGP3,with molecular weights of 897615,846740 and 1194692 Da,respectively.The physical and chemical properties of the three fractions were evaluated and compared by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),scanning electron microscope(SEM),high performance liquid chromatography(HPLC)and other analytical techniques.The fraction PGP2 with the highest hypoglycemic activity,was screened using the Caco-2 monolayer cell model.It can inhibit the uptake of glucose in the small intestine,as well as the activities of maltase and sucrase.After simulated gastrointestinal digestion,PGP2 signifi cantly enhanced the inhibitory effect of α-glucosidase,and slightly reduced the inhibitory ability ofα-amylase.In summary,PGP2 possessed strong hypoglycemic activity after digestion.These results indicated that PGP2 has the potential to be developed into a functional food or natural medicine for the treatment of type 2 diabetes mellitus.展开更多
基金Supported by the Shenzhen University Teaching Reform Fund,No.JG2023166the Shenzhen Science and Technology Innovation Commission Fund,No.JCYJ2022081802810022the Shenzhen Science and Technology Innovation Commission Basic Research Key Projects Fund,No.JCYJ20210324115800003.
文摘BACKGROUND Cases of myelin oligodendrocyte glycoprotein(MOG)antibody-related disease have a history of coronavirus disease 2019 infection or its vaccination before disease onset.Severe acute respiratory syndrome virus 2(SARS-CoV-2)infection has been considered to be a trigger of central nervous system autoimmune diseases.CASE SUMMARY Here we report a 20-year male with MOG-associated transverse myelitis after a SARS-CoV-2 infection.The patient received a near-complete recovery after standard immunological treatments.CONCLUSION Attention should be paid to the evaluation of typical or atypical neurological symptoms that may be triggered by SARS-CoV-2 infection.
文摘Nasopharyngeal carcinoma(NPC)is a malignant tumor arising from the nasopharyngeal epithelium.It consists of undifferentiated squamous cells in the nasopharynx.This type of epithelial cell neoplasm is globally distributed,with the highest prevalence observed in certain regions of the world.It has been known since ancient times.The incidence of NPC is steadily decreasing as data on the molecular factors involved in the pathogenesis of NPC accumulate.Glycoproteins are characterized by polymers of saccharides attached to the amino acid sequences of proteins during the process of glycosylation.They are present in all animal cells and are especially abundant on the surface of tumor cells.Alterations in expression of cellular glycoproteins have recently attracted attention as a key component of neoplastic progression.Tumor-associated glycoproteins may serve as a hallmark of cancer cells and thus represent novel diagnostic and even therapeutic targets.Interest in the role of glycoproteins in cancer in general and specifically in NPC pathology has steadily increased over the past fifty years,reaching over thousands and two hundred publications in the last five years,respectively.Here,data on a specific class of proteins,glycoproteins,involved in tumorigenesis of NPCs are summarized,with a focus on a few of the best-studied ones.Relevant studies performed mainly in the last five years were retrieved and collected through the PubMed system.
文摘介绍了一个新的基于优化推导出的核偏最小二乘(kernel partial least squares,K-PLS)的算法原理和实现步骤,并且给出了利用K-PLS法构建P-糖蛋白(P-glycoprotein,P-gp)黄酮类抑制剂的定量构效关系(QSAR)模型.利用该方法结合几个简单的分子拓扑参数,构建了具有高准确率的预测模型.该模型将有助于P-gp黄酮类抑制剂的虚拟筛选和理性设计.结果证明K-PLS是一个十分稳定可靠的方法,将会在化学计量学领域得到较好的应用和推广.
文摘肿瘤多药耐药性(multiple drug resistance,MDR)的发生往往伴随着多药耐药基因如MDR1、MRP1和BCRP等高表达,其中MDR1基因编码的P-糖蛋白(P-glycoprotein,P-gp)是目前公认可以诱发癌细胞发生MDR的重要分子。传统研究认为P-gp主要是作为一个药物泵将化疗药物从细胞内排出从而导致MDR。然而系列研究发现,除了介导MDR以外,P-gp还能够调节癌细胞的生长、增殖、凋亡、迁移和侵袭等其他生物学行为;而且研究表明P-gp的这些作用可以依赖,也可以不依赖于其药物泵的功能。这些结果表明P-gp能够通过一些新的机制促进肿瘤的进展。本文主要针对P-gp在促进肿瘤进展中的作用进行综述。
基金supported by the National Natural Science Foundation of China,No.81171178
文摘Myelin-associated glycoprotein(MAG) inhibits the growth of neurites from nerve cells. Extraction and purification of MAG require complex operations; therefore, we attempted to determine whether commercially available MAG-Fc can replace endogenous MAG for research purposes. Immunofluorescence using specific antibodies against MAG, Nogo receptor(NgR) and paired immunoglobulin-like receptor B(PirB) was used to determine whether MAG-Fc can be endocytosed by neuro-2a cells. In addition, neurite outgrowth of neuro-2a cells treated with different doses of MAG-Fc was evaluated. Enzyme linked immunosorbent assays were used to measure RhoA activity. Western blot assays were conducted to assess Rho-associated protein kinase(ROCK) phosphorylation. Neuro-2a cells expressed NgR and PirB, and MAG-Fc could be endocytosed by binding to NgR and PirB. This activated intracellular signaling pathways to increase RhoA activity and ROCK phosphorylation, ultimately inhibiting neurite outgrowth. These findings not only verify that MAG-Fc can inhibit the growth of neural neurites by activating RhoA signaling pathways, similarly to endogenous MAG, but also clearly demonstrate that commercial MAG-Fc is suitable for experimental studies of neurite outgrowth.
文摘Estrus-associated glycoprotein (EGP) is a special protein in oviductal fluid which appears before ovulation and fertilization and disappears after the embryo passes into the uterus. One-and two dimensional SDS-PAGE and Western blotting with monoclonal antibody or peanut agglutinin were used to characterize the glycoprotein,The specificity of the marking agents enabled the study to proceed without purification. EGP was found to include two proteins: one is acidic with a pH of 4.5 while the other is basic with a pH of 8.0 The molecular weights of their subunits are the same, that is 110 kD. This study may shed light on the mechanism of reproductive Process and be helpful to the development of a more cffective culture medium for in vitro culture of early embryo.
文摘During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four (ZP1, ZP2, ZP3 and ZP4). ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans (in addition to ZP3), ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the Gi-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels (VOCCs), whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans (in addition to ZP3), ZP1 and ZP4 also participate in these stages of fertilisation.
文摘Gynogenetic silver crucian carp, Carassius auratus gibelio, is an intriguing model system. In the present work, a systemic study has been initiated by introducing suppression subtractive hybridization technique into this model system to identify the differentially expressed genes in oocytes between gynogenetic silver crucian carp and its closely related gonochoristic color crucian carp. Five differential cDNA fragments were identified from the preliminary screening, and two of them are ZP3 homologues. Moreover, the full length ZP3 cDNAs were cloned from their oocyte cDNA libraries. The length of ZP3 cDNAs were 1378 bp for gyno-carp and 1367 bp for gono-carp, and they can be translated into proteins with 435 amino acids. Obvious differences are not only in the composition of amino acids, but also in the number of potential O-linked oligosaccharide sites. In addition, gyno-carp ZP3 amino acid sequence has an unexpected higher identity value with common carp (83.5%) than that with the closely related gono-carp (74.7%). The unique homology may be originated from the ancient hybridization. Northern blot analysis confirmed that expression of the ZP3 gene occurred exclusively in the oocytes. Because O-linked oligosaccharides on ZP3 have been demonstrated to play very important roles in fertilization, it is suggested that the extra O-linked glycosylation sites may be related to the unique sperm-egg recognition mechanism in gynogenesis.
基金supported by Research Fund for the Doctoral Program of Higher Education of China(200802980004 and 20070298008)the National Natural Science Fundation of China (30872055)
文摘Glycoprotein from Ginkgo biloba kernel may be allergic. In this paper, the allergic proteins were identified with Western blotting, and the 32 kDa glycoprotein was purified with ion exchange chromatography and gel chromatography. With Western blotting, there were 3 allergic proteins with molecular weight 21, 32, and 36 kDa. With SDS-PAGE analysis and measurements of the protein and sugar contents, the isolation and purification technology of 32 kDa was confirmed. Ginkgo crude protein extract was precipitated with ammonium sulphate (saturation gradient: 40-80%). The precipitate was purified by chromatography with DEAE-cellulose 52, then chromatography with Sephadex G-200 and the target glycoprotein was finally obtained. The analysis results showed the molecule of the glycoprotein was 32.12 kDa and the ratio of protein to sugar was 20.56:1. In conclusion, the purification method could be used in preparation of the glycoprotein, and the study could provide a basis for the further research of the glycoprotein.
文摘The glycoprotein H (gH) gene homologue of duck plague virus (DPV) was cloned by degenerate polymerase chain reaction (PCR) and sequenced. It was located immediately downstream from the thymidine kinase gene (TK). In addition, the 3'-end of the gene homologue to herpesvirus UL21 was located downstream from the gH gene. DPV gH gene open reading frame (ORF) was 2 505 bp in length and its primary translation product was a polypeptide of 834 amino acids long. It possessed several characteristics of membrane glycoproteins, including an N-terminal hydrophobic signal sequence, an external domain containing eight putative N-linked glycosylation sites, a C-terminal transmembrane domain, and a charged cytoplasmic tail. Comparison with other herpesvirus revealed identities of 20.2, 25.1, 23.0, 23.0, 26.5 and 26.0% with the gH counterparts of the human herpesvirus virus 1 (HSV1), equine herpesvirus 4 (EHV4), bovine herpesvirus 1 (BHV1), pseudorabies virus (PRV), gallid herpesvirus 2 (GHV2) and gallid herpesvirus 3 (GHV3), respectively.
基金Supported by the Spanish Ministry of Economy and Competitivity,No.BIO 2015-66356-Rthe Generalitat de Catalunya Grant,No.2017SGR673
文摘Pancreatic cancer(Pa C) shows a clear tendency to increase in the next years and therefore represents an important health and social challenge. Currently, there is an important need to find biomarkers for PaC early detection because the existing ones are not useful for that purpose. Recent studies have indicated that there is a large window of time for PaC early detection, which opens the possibility to find early biomarkers that could greatly improve the dismal prognosis of this tumor. The present manuscript reviews the state of the art of the existing PaC biomarkers. It focuses on the anomalous glycosylation process and its role in PaC. Glycan structures of glycoconjugates such as glycoproteins are modified in tumors and these modifications can be detected in biological fluids of the cancer patients. Several studies have found serum glycoproteins with altered glycan chains in PaC patients, but they have not shown enough specificity for PaC. To find more specific cancer glycoproteins we propose to analyze the glycan moieties of a battery of glycoproteins that have been reported to increase in PaC tissues and that can also be found in serum. The combination of these new candidate glycoproteins with their aberrant glycosylation together with the existing biomarkers could result in a panel, which would expect to give better results as a new tool for early diagnosis of PaC and to monitor the disease.
基金Supported by National Natural Science Foundation of China,No. 81670387,No. 31671440,and No. 81800402。
文摘BACKGROUND Acute pancreatitis(AP) is rapid-onset pancreatic inflammation that causes local and systemic inflammatory response syndrome(SIRS) with high morbidity and mortality, but no approved therapies are currently available. P-selectin glycoprotein ligand 1(PSGL-1) is a transmembrane glycoprotein to initiate inflammatory responses. We hypothesized that PSGL-1 may be involved in the development of AP and would be a new target for the treatment of AP.AIM To investigate the role and mechanism of PSGL-1 in the development of AP.METHODS The PSGL-1 expression on leukocytes was detected in peripheral blood of AP patients and volunteers. Pancreatic injury, inflammatory cytokines expression, and inflammatory cell infiltration was measured in AP mouse models induced with PSGL-1 knockout(PSGL-1-/-) and wild-type(PSGL-1+/+) mice. Leukocyteendothelial cell adhesion was measured in a peripheral blood mononuclear cell(PBMC)-endothelial cell coculture system.RESULTS The expression of PSGL-1 on monocytes and neutrophils was significantly increased in AP patients. Compared with PSGL-1+/+ mice, PSGL-1-/-AP mice induced by caerulein exhibited lower serum amylase, less Interleukin-1 beta(IL-1 beta) and Interleukin-6(IL-6) expression, less neutrophil and macrophage infiltration, and reduced peripheral neutrophil and monocyte accounts. PSGL-1 deficiency alleviated leukocyte-endothelial cell adhesion via IL-6 but not IL-1 beta.CONCLUSION PSGL-1 deficiency effectively inhibits the development of AP by preventing leukocyte-endothelial cell adhesion via IL-6 stimulation and may become a potential therapeutic target for treating AP.
基金supported by the grants from the National Natural Science Foundation of China(31072157)the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2015BAD12B05)+1 种基金the Foundation of China Agricultural Research System(CARS-43-8)the Major Project of Education Department in Sichuan,China(16ZA0027)
文摘Many mammalian herpes viruses utilize heparan sulfate (HS) moieties present on cell surface proteoglycans as receptors for cell entry, and this process also requires viral glycoprotein C (gC) homologues. However, our understanding of the role of gC in facilitating attachment of other alpha-herpes viruses such as the duck plague virus (DPV) remains preliminary. To study the role of gC during DPV infection, we used a gC-deleted mutant virus (DPV-AgC-EGFP). Examination of the viral copy number by real-time PCR, as well as time course studies of viral adsorption and proliferation revealed that gC was involved in the viral binding to the cell surface. The affinity of viral glycoproteins (gB-DPV, gC-DPV, and gE-DPV) to HS was assessed using a prokaryotic expression system and HJTrapTM HeparJn HP column chromatography. In addition, to confirm that gC played a role in the interaction between DPV and HS, viruses were treated with the HS analogue heparin and host cells were treated with its inhibitors heparinase prior to exposure to DPV-△gC-EGFP or wild-type strain Chinese virulent duck plague virus (DPV-CHv). The effects of heparin and heparinase on virus infectivity demonstrated that function of gC on Viral adsorption is independent of interactions between gC and heparin sulfate on cell surface. All in all, this study demonstrated that the gC of DPV can mediate viral adsorption in an HS-independent manner, which distinguish it from the gC of some other alpha-herpes viruses. Future studies will be required to identify the receptors involved in gC protein binding to cells. This work provides us a foundation for further studies of examining the roles of gC in the adsorption during duck plague virus infection.
基金supported by the Public Welfare & Safety Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science,ICT & Future Planning (NRF-2013M3A2A1067529)
文摘Objective: To determine skin whitening and wrinkle improvement efficacy, glycoprotein fractions were extracted from liquid extracts of boiled sea cucumber and their effects on tyrosine and elastase inhibitory activities were assayed. Methods: Fractions above and below 50 k Da(>50 kD a and <50 kD a) were extracted via a series of steps invovling: boiling, filtering, desalting and freeze drying. Cytotoxicity, skin whitening and wrinkle-removing effects of boiled liquid were determined. Results: Our MTT data showed that neither glycoprotein fraction of boiled liquid induces cellular cytotoxicity up to a concentration of 10 mg/m L treatment of the mouse melanoma cell line, B16F10, with 10 mg/m L >50 kDa enhanced tyrosinase and elastase inhibitory activities by 50.84% and 28.78%, respectively. Correlations of the >50 kD a concentration with tyrosinase inhibitory(R^2=0.968) and elastase inhibitory(R2=0.983) efficacy were significant. Conclusions: >50 kD a glycoprotein fraction isolated from liquid extracts of boiled sea cucumber, which can serve as a functional cosmetic ingredient for whitening and wrinkle improvement of skin.
文摘Aberrations in protein glycosylation and polysaccharides play a pivotal role in pancreatic tumorigenesis, influencing cancer progression, metastasis, immunoresponse and chemoresistance. Abnormal expression in sugar moieties can impact the function of various glycoproteins, including mucins, surface receptors, adhesive proteins, proteoglycans, as well as their effectors and binding ligands, resulting in an increase in pancreatic cancer invasiveness and a cancerfavored microenvironment. Recent advance in glycoproteomics, glycomics and other chemical biology techniques have been employed to better understand the complex mechanism of glycosylation events and how they orchestrate molecular activities in genomics, proteomics and metabolomics implicated in pancreatic adenocarcinoma. A variety of strategies have been demonstrated targeting protein glycosylation and polysaccharides for diagnostic and therapeutic development.
文摘The effects of spraying rare earths(RE) on composition and activities of tea polysaccharide were measured by inductively coupled plasma mass spectrometry (ICP-MS), gas chromatography(GC), amino acid analyzer and animal models. The results show that there are rare earth elements binding glycoprotein in tea (REE-TGP). The effects of RE on composition and content of saccharides in REE-TGP are not obvious. The contents of Hypro and Ser in REE-TGP are evidently enhanced in comparison with that in control (not treated with rare earth), but the content of Glu is smaller than that from control. The content of La in REE-TGP from the tea garden sprayed rare earth is 193% higher than that in control. REE-TGP declines content of blood sugar in mice and enhances immunization of rat, which are very evident when the animals are treated by REE-TGP from the tea garden sprayed RE.
基金The authors would like to show deepest gratitude tothe Earmarked Fund for Jiangsu Agricultural Industry Technology System(JATS[2020]413)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX19_0682)forfinancial assistance.
文摘This study aimed to isolate and characterize the structures of glycoproteins from peas and determine their hypoglycemic activity.The crude pea glycoproteins(PGP)were extracted by hot water and purified by diethylaminoethyl(DEAE)-Sepharose chromatography and Sephadex G-100 size-exclusion chromatography in sequence.Then three main fractions were obtained,namely PGP1,PGP2 and PGP3,with molecular weights of 897615,846740 and 1194692 Da,respectively.The physical and chemical properties of the three fractions were evaluated and compared by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),scanning electron microscope(SEM),high performance liquid chromatography(HPLC)and other analytical techniques.The fraction PGP2 with the highest hypoglycemic activity,was screened using the Caco-2 monolayer cell model.It can inhibit the uptake of glucose in the small intestine,as well as the activities of maltase and sucrase.After simulated gastrointestinal digestion,PGP2 signifi cantly enhanced the inhibitory effect of α-glucosidase,and slightly reduced the inhibitory ability ofα-amylase.In summary,PGP2 possessed strong hypoglycemic activity after digestion.These results indicated that PGP2 has the potential to be developed into a functional food or natural medicine for the treatment of type 2 diabetes mellitus.