RESUMEN
Chitosan is a natural biopolymer and is made up of D-glucosamine subunits linked by beta-(1,4) glycosidic bond. In recent years, the application of chitosan has attracted more and more attention because of its good biological function in cell biology. The properties of chitosan-based biomaterial are attributed to the physical properties and chemical composition of chitosan. The author of this paper summarized recent related studies and progresses of the influence of physical properties of chitosan on cell activity and cell mechanics property at home and abroad. The findings show that most studies mainly focused on the influence of chitosan and cell activity, while few were on cell mechanics property. The related studies of the influence of chitosan on cell will contribute to the explanation for the mechanism of the interaction between chitosan and cell, and provide the theoretical support for the further study.
Asunto(s)
Animales , Humanos , Adhesión Celular , Diferenciación Celular , Movimiento Celular , Proliferación Celular , Fenómenos Químicos , Quitosano , Química , Farmacología , Ingeniería de Tejidos , Andamios del Tejido , QuímicaRESUMEN
The plasmodium of Physarum polycephalum is a suitable eukaryotic cell for cell cycle investigation, but there is no compatible transient expression system for the plasmodium. Using the promoter and terminator of ardC actin of Physarum polycephalum substituted the CMV IE and SV40 polyA of plasmid pDsRedl-N1, using cassette PardC-MCS-DsRed1-TardC substituted the cassette PardC-hph-TardC of plasmid pTB38, we constructed plasmids pXM1 and pXM2 for transient expression of red fluorescent protein (RFP) in Physarum polycephalum respectively. After reconstituting the transcription elongation factor homologous gene (pelf1) of Physarum polycephalum into the pXM2, we generated a plasmid pXM2-pelf1. After the plasmid pXM1, pXM2 and pXM2-pelf1 were electroporated into the plasmodium of Physarum polycephalum, we observed optimum RFP and PELF1-RFP expression under fluoroscope and confocal microscope between 24-48 h after electroporation, and found that ELF1-RFP expression was accumulated in nucleus of microplasmodium, the optimum electroporation parameters were 40 V/cm electric field, 1 ampere current, and 70 micros electric shock time. The results suggest that this expression system is qualified for transient expression of specific protein in plasmodium of Physarum polycephalum.
Asunto(s)
Actinas , Genética , Metabolismo , Electroporación , Proteínas Luminiscentes , Genética , Physarum polycephalum , Genética , Metabolismo , Plásmidos , Genética , Metabolismo , Factores de Elongación Transcripcional , GenéticaRESUMEN
To better understand the cleavage efficiency of muhiribozyme system on its RNA substrate in the presence and absence of divalent magnesium and monovalent sodium ions.we constructed pGEM-Coat'A,pGEM-Coat'A196Rz plasmids and pGEM-MDRl target plasmid.They were applied to transcribe RNAs with SP6/T7 transcription kit.Cleavage reactions were carried out in cell-free system and reaction products were analyzed by electrophoresis on 6% denaturing polyacrylamide gels in TBS buffer.The gels were dried and exposed to X-ray films for autoradiography.The Image J software was employed to analyze the dried gels.The results indicated that the cleavage efficiency of the muhiribozyme was dependent on the concentration of divalent Mg2+.The cleavage products increased with the concentrations of divalent Mg2+ and were Mg2+ concentration and time dependent.No cleavage product was obtained in the presence of lower than 200 mmol/L Na+ alone.On the contrary,monovalent Na+ inhibited the Mg2+ -induced cleavage reaction in Na+ and Mg2+ coexistance.The cleavage rate was significantly lower than that observed with divalent Mg2+ alone.These results suggested that divalent Mg2+ was required for muhiribozyme on substrate cleavage reaction in the physical condition,whereas monovalent Na+ was not.
RESUMEN
Three pSIREN-siRNA plasmids were constructed using a pSIREN-RetroQ vector to silence the expression of muhidrug resistance-associated protein (MRP1) gene, and subsequently characterized by restriction endonuclease digestion and DNA sequencing. A truncated MRP1 and a full-length MRP1 were cloned into pEGFP-N2 and PeDNA3.1 respectively as pEGFP-MRP1T and pcDNA-MRP1. The plasmid pEGFP-MRP1T was co-transferred with each of the three pSIREN-siRNAs into HEK293 cells for MRP1T-GFP targeted silencing, and pSIREN-siRNA1 was used as the negative control, pSIREN-siRNA2 and pSIREN-siRNA3 appeared to be more effective to silence MRP1T-GFP compared to pSIREN-siRNA1 as shown by fluorescence microscopy. For the silencing of full-length MRP1 expression, HEK293 ceils were co-transferred with pcDNA-MRP1 and either of the three pSIREN-siRNAs, then subjected for Western blot analysis and MTT assays, pSIREN-siRNA2 and pSIREN-siRNA3 were able to inhibit the expression of 190 kD MRP1, but not pSIREN-siRNA1. The MDR of MRP1-transfected HEK293 ceils was abolished with pSIREN-siRNA2 or pSIREN-siRNA3 transfections. RNA secondary structure predictions demonstrated that the mRNA local free energy (△G) of the siRNA1 targeted sequence was lower, as the GC content and Tm value of siRNA1 were higher than those of siRNA2 and siRNA3. These data suggest that the local structure siRNAs and target mRNA may influence the silencing efficiency of MRP1 expression.
RESUMEN
To investigate the effect of Yisui Jiedu Recipe (YSJDR), a compound traditional Chinese herbal medicine, on cytokines and their corresponding just another kinase 2-signal transducers and activators of transcription 5 (JAK2-STAT5) signal transduction pathway in bone marrow hematopoietic cells from patients with myelodysplastic syndrome-refractory anemia (MDS-RA).