A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent （BVS）, a new method whi...A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent （BVS）, a new method which combines 3D bio-printing and electrospinning to prepare the composite bioabsorbable vascular stent （CBVS） is proposed. The inner layer of the CBVS can be obtained through 3D bio- printing using poly-p-dioxanone （PPDO）. The thin nanofiber film that serves as the outer layer can be built through electrospinning using mixtures of chitosan-PVA （poly （vinyl alcohol））. Tests of mechanical properties show that the stent prepared through 3D bio-printing combined with electrospinning is better than that prepared through 3D bio- printing alone. Cells cultivated on the CBVS adhere and proliferate better due to the natural, biological chitosan in the outer layer. The proposed complex process and method can provide a good basis for preparing a controllable drug-carrying vascular stent. Overall, the CBVS can be a good candidate for treating stenotic vessels.展开更多
In order to understand the microtubule change of monocotyls stem-tip during mitosis, the arrangement, transformation of microtubule array and its relation with chromosome movement during mitosis were studied with free...In order to understand the microtubule change of monocotyls stem-tip during mitosis, the arrangement, transformation of microtubule array and its relation with chromosome movement during mitosis were studied with freezing microtome, indirect immunofluoreseenee, DAPI staining and fluorescence microscopy. The results showed that nucleolus was intact when the cortical microtubules formed; cortical microtubules were changed into phramoplast microtubules bands at mitosis prophase. When phramoplast microtubules came into being, nuclear membrane was ruptured and chromosome was arranged at the position of cell plate ; subsequently, phramoplast microtubules were changed into phragmoplast microtubules, phramoplast microtubules were shortening and microtubules on the sides of cell plate were increasing gradually, during this course sister ehromatid was separated by microtubules at cell plate and tract to the two poles, forming phragmoplast microtubules. Then the nucleolus of two daughter cells formed and separated in the end with the increase of cells numbers. Therefore, cell division orientation could be judged from the arrangement of cell microtubules in different periods in order to understand its growth status.展开更多
The origin of cytoskeleton and the origin of relevant intracellular transportation system are big problems for understanding the emergence of eukaryotic cells. The present article summarized relevant information of ev...The origin of cytoskeleton and the origin of relevant intracellular transportation system are big problems for understanding the emergence of eukaryotic cells. The present article summarized relevant information of evidences and molecular traces on the origin of actin, tubulin, the chaperonin system for folding them, myosins, kinesins, axonemal dyneins and cytoplasmic dyneins. On this basis the authors proposed a series of works, which should be done in the future, and indicated the ways for reaching the targets. These targets are mainly: 1) the reconstruction of evolutionary path from MreB protein of archaeal ancestor of eukaryotic cells to typical actin; 2) the finding of the MreB or MreB-related proteins in crenarchaea and using them to examine J. A. Lake's hypothesis on the origin of eukaryote from "eocytes" (crenarchaea); 3) the examinations of the existence and distribution of cytoskeleton made of MreB-related protein within coccoid archaea, especially in amoeboid archaeon Thermoplasm acidophilum; 4) using Thermoplasma as a model of archaeal ancestor of eukaryotic cells; 5) the searching for the homolog of ancestral dynein in present-day living archaea. During the writing of this article, Margulis' famous spirochaete hypothesis on the origin of flagella and cilia was unexpectedly involved and analyzed from aspects of tubulins, dyneins and spirochaetes. Actually, spirochaete cannot be reasonably assumed as the ectosymbiotic ancestor of eukaryotic flagella and cilia, since their swing depends upon large amount of bacterial flagella beneath the flexible outer wall, but not depends upon their intracellular tubules and the assumed dyneins. In this case, if they had "evolved" into cilia and lost their bacterial flagella, they would immediately become immobile! In fact, tubulin and dynein-like proteins have not been found in any spirochaete.展开更多
Objective:To explore the influence of EBP50(ezrin-radixin-moesin-binding phospho-protein-50) on microfilament cytoskeleton content and distribution in cultured Hela cells, and to investigate the relationship between t...Objective:To explore the influence of EBP50(ezrin-radixin-moesin-binding phospho-protein-50) on microfilament cytoskeleton content and distribution in cultured Hela cells, and to investigate the relationship between the changes in microfilament cytoskeleton localization and EBP50 after PDGF(platelet-derived growth factor) stimulation, and to further clarify the molecular mechanism by which EBP50 suppresses tumor cell proliferation and migration.Methods:pBK-CMV-HAEBP50 wild type recombinant plasmid and pBK-CMV-HA empty vector were transfected into Hela cells.G418 at 350 mg/L was used to screen for cell clones stably expressing EBP50.Western blot was carried out to detect EBP50 expression.Similarities and differences in microfilament cytoskeleton content and distribution in Hela cells transfected with pBK-CMV-HA-EBP50 wild type recombinant plasmid and pBK-CMV-HA empty vector were also treated with PDGF(10 ng/mL and 20 ng/mL, 37 ℃, 15 min) and stained by rhodamine-labeled phalloidin to observe the distribution of microfilament cytoskeleton in the two groups.EBP50 protein distribution in PDGF-stimulated Hela cells was detected by immunofluorescence.Results:Western blot results confirmed that the EBP50 cDNA fragment could express EBP50 in cultured Hela cell lines and that cell lines stably expressing EBP50 were successfully obtained.Western blot and fluorescence results showed that in the cell line transfected with empty vector, the microfilament cytoskeleton was thick, loose, multidirectional and displayed crossing arrangements.The content of microfilament cytoskeleton in the cell line transfected with pBK-CMV-HA-EBP50 was different from that found in the cell line transfected with empty vector.EBP50 expression enhanced microfilament cytoskeleton polymerization into compact thin filaments.Under the stimulation of PDGF, EBP50 migrated to the cell membrane from the cytosol together with microfilament cytoskeleton and co-localized there.Conclusion:EBP50 can change the distribution of microfilament cytoskeleton in cultured Hela cells and can also bind the microfilament cytoskeleton to the cell membrane under the stimulation of PDGF.EBP50 may play a role in the proliferation and migration of tumor cells by influencing the distribution and localization of microfilament cytoskeleton.展开更多
基金The National Natural Science Foundation of China(No.51475281,51375292)the National Natural Science Foundation for Young Scholar of China(No.51105239)
文摘A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent （BVS）, a new method which combines 3D bio-printing and electrospinning to prepare the composite bioabsorbable vascular stent （CBVS） is proposed. The inner layer of the CBVS can be obtained through 3D bio- printing using poly-p-dioxanone （PPDO）. The thin nanofiber film that serves as the outer layer can be built through electrospinning using mixtures of chitosan-PVA （poly （vinyl alcohol））. Tests of mechanical properties show that the stent prepared through 3D bio-printing combined with electrospinning is better than that prepared through 3D bio- printing alone. Cells cultivated on the CBVS adhere and proliferate better due to the natural, biological chitosan in the outer layer. The proposed complex process and method can provide a good basis for preparing a controllable drug-carrying vascular stent. Overall, the CBVS can be a good candidate for treating stenotic vessels.
基金Supported by the National Natural Science Foundation of China(30060038)~~
文摘In order to understand the microtubule change of monocotyls stem-tip during mitosis, the arrangement, transformation of microtubule array and its relation with chromosome movement during mitosis were studied with freezing microtome, indirect immunofluoreseenee, DAPI staining and fluorescence microscopy. The results showed that nucleolus was intact when the cortical microtubules formed; cortical microtubules were changed into phramoplast microtubules bands at mitosis prophase. When phramoplast microtubules came into being, nuclear membrane was ruptured and chromosome was arranged at the position of cell plate ; subsequently, phramoplast microtubules were changed into phragmoplast microtubules, phramoplast microtubules were shortening and microtubules on the sides of cell plate were increasing gradually, during this course sister ehromatid was separated by microtubules at cell plate and tract to the two poles, forming phragmoplast microtubules. Then the nucleolus of two daughter cells formed and separated in the end with the increase of cells numbers. Therefore, cell division orientation could be judged from the arrangement of cell microtubules in different periods in order to understand its growth status.
文摘The origin of cytoskeleton and the origin of relevant intracellular transportation system are big problems for understanding the emergence of eukaryotic cells. The present article summarized relevant information of evidences and molecular traces on the origin of actin, tubulin, the chaperonin system for folding them, myosins, kinesins, axonemal dyneins and cytoplasmic dyneins. On this basis the authors proposed a series of works, which should be done in the future, and indicated the ways for reaching the targets. These targets are mainly: 1) the reconstruction of evolutionary path from MreB protein of archaeal ancestor of eukaryotic cells to typical actin; 2) the finding of the MreB or MreB-related proteins in crenarchaea and using them to examine J. A. Lake's hypothesis on the origin of eukaryote from "eocytes" (crenarchaea); 3) the examinations of the existence and distribution of cytoskeleton made of MreB-related protein within coccoid archaea, especially in amoeboid archaeon Thermoplasm acidophilum; 4) using Thermoplasma as a model of archaeal ancestor of eukaryotic cells; 5) the searching for the homolog of ancestral dynein in present-day living archaea. During the writing of this article, Margulis' famous spirochaete hypothesis on the origin of flagella and cilia was unexpectedly involved and analyzed from aspects of tubulins, dyneins and spirochaetes. Actually, spirochaete cannot be reasonably assumed as the ectosymbiotic ancestor of eukaryotic flagella and cilia, since their swing depends upon large amount of bacterial flagella beneath the flexible outer wall, but not depends upon their intracellular tubules and the assumed dyneins. In this case, if they had "evolved" into cilia and lost their bacterial flagella, they would immediately become immobile! In fact, tubulin and dynein-like proteins have not been found in any spirochaete.
基金Supported by grants from the National Natural Science Foundation ofChina (No. 30572183 and 30772573)Beijing Educational Committee Foundation (No. KZ200610025013)+2 种基金the New Century Excellent Talentsin University of China (No. NCEF-06-0184)Excellent Talents Foundation in Beijing (No. 20071D0501800253)Beijing Novagramme Foundation (No. 2008B58 [MS1]).
文摘Objective:To explore the influence of EBP50(ezrin-radixin-moesin-binding phospho-protein-50) on microfilament cytoskeleton content and distribution in cultured Hela cells, and to investigate the relationship between the changes in microfilament cytoskeleton localization and EBP50 after PDGF(platelet-derived growth factor) stimulation, and to further clarify the molecular mechanism by which EBP50 suppresses tumor cell proliferation and migration.Methods:pBK-CMV-HAEBP50 wild type recombinant plasmid and pBK-CMV-HA empty vector were transfected into Hela cells.G418 at 350 mg/L was used to screen for cell clones stably expressing EBP50.Western blot was carried out to detect EBP50 expression.Similarities and differences in microfilament cytoskeleton content and distribution in Hela cells transfected with pBK-CMV-HA-EBP50 wild type recombinant plasmid and pBK-CMV-HA empty vector were also treated with PDGF(10 ng/mL and 20 ng/mL, 37 ℃, 15 min) and stained by rhodamine-labeled phalloidin to observe the distribution of microfilament cytoskeleton in the two groups.EBP50 protein distribution in PDGF-stimulated Hela cells was detected by immunofluorescence.Results:Western blot results confirmed that the EBP50 cDNA fragment could express EBP50 in cultured Hela cell lines and that cell lines stably expressing EBP50 were successfully obtained.Western blot and fluorescence results showed that in the cell line transfected with empty vector, the microfilament cytoskeleton was thick, loose, multidirectional and displayed crossing arrangements.The content of microfilament cytoskeleton in the cell line transfected with pBK-CMV-HA-EBP50 was different from that found in the cell line transfected with empty vector.EBP50 expression enhanced microfilament cytoskeleton polymerization into compact thin filaments.Under the stimulation of PDGF, EBP50 migrated to the cell membrane from the cytosol together with microfilament cytoskeleton and co-localized there.Conclusion:EBP50 can change the distribution of microfilament cytoskeleton in cultured Hela cells and can also bind the microfilament cytoskeleton to the cell membrane under the stimulation of PDGF.EBP50 may play a role in the proliferation and migration of tumor cells by influencing the distribution and localization of microfilament cytoskeleton.
