Objective The myocardial injury was induced by hypobaric hypoxia through regulating the expression of various proteins.The expression of proteins was mainly detected by western blot,but the selection of internal reference proteins and their variations have not been systematically studied.Methods Myocardial injury was induced in a low-pressure,low-oxygen chamber simulating an altitude of 6000 m,for 24 and 72 h.Establishment of the myocardial injury model was confirmed by hematoxylin eosin(HE)staining.Expression levels of internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor-5(EIF5),β-actin,glyceraldehyde-3-phosphate dehydrogenase(GAPDH),cyclophilin B,and cofilin,were detected by Western Blot and total protein expression was detected by Ponceau S and Coomassie Blue staining.An adult mouse cardiomyocytes(AMCMs)injury model was induced by hypoxia for 12 and 24 h and confirmed by terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL staining).Internal control proteins were detected by Western Blot,as in the in vivo model,and total protein expression was detected by Ponceau S and Coomassie Blue staining.Results A myocardial injury model was established by hypobaric hypoxia for 24 and 72 h,the total protein expression levels remained consistent.The expression of internal control proteins including vinculin,EIF5,β-actin,cyclophilin B,and cofilin was consistent between the control and model groups.Expression levels of α-tubulin were similar in the plain control and 24 h hypobaric hypoxia group,but were significantly lower in the 72 h hypobaric hypoxia group compared with the plain control group.GAPDH expression was significantly higher in the 24 and 72 h hypobaric hypoxia groups than in the plain control group.An AMCM injury model was established by hypoxia for 12 and 24 h.Total protein levels and expression levels of the internal control proteins EIF5 and β-actin were consistent,but vinculin,α-tubulin,GAPDH,cyclophilin B,and cofilin expression levels were higher in both hypoxia groups compared with the normoxic control group.Conclusions EIF5 and β-actin may be the suitable loading control proteins for studies of hypobaric hypoxia-induced myocardial injury using Western Blot.Total protein is also a good choice for hypobaric hypoxia studies.

Objective The pathophysiological process of acute high-altitude hypoxia-induced lung injury affects protein expression levels,which are mainly evaluated by Western blot.No systematic study has investigated changes in internal control proteins as calibration loading amounts.Methods Lung injury at an altitude of 6000 m was induced in a low-pressure,low-oxygen chamber for 8,24,and 72 h using C57BL/6J mice.Establishment of the model was confirmed by hematoxylin and eosin staining.Expression levels of various internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor 5(EIF5),β-actin,and glyceraldehyde 3-phosphate dehydrogenase(GAPDH)were detected by Western blot,and total protein expression was detected by Coomassie blue staining.Furthermore,the lung injury model in vitro was establised by using,Bronchial epithelial cell(BZAS-2B)andhunman umbilical vein endothelial cells(HUVECS)confirmed by TUNEL staining.Expression levels of internal control proteins were detected by Western blot,and total protein expression was detected by Coomassie Blue staining.Results Acute 8,24,and 72 h hypoxic models were successfully established in lung tissue,demonstrating consistent total protein expression and stable levels of the internal reference proteins vinculin,α-tubulin,EIF5,andβ-actin.GAPDH expression was elevated in the HH8 h,HH24 h,and HH72 h groups compared with the normoxia(Nor)group,but only the increase at HH72 h groups was significant.Similarly,8,24,and 48 h hypoxic models were successfully established in BEAS-2B cells and HUVECs,with consistent total protein expression.In BEAS-2B cells,expression levels of the internal reference proteins β-actin and GAPDH were consistent with the normoxic control(NC)group,while vinculin,α-tubulin,and EIF5 expression levels were significantly reduced under hypoxic conditions for up to 24 h.In HUVECs,vinculin and α-tubulin expression levels were also consistent with the NC group,while EIF5,β-actin,and GAPDH expression levels were significantly reduced at 8 h and increased at 48 h.Conclusions Acute hypoxia induces lung tissue injury,and protein expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,and β-actin are stable,making them suitable internal references for Western blot.Additionally,Western blot detected differential expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,β-actin,and GAPDH in BEAS-2B cells and HUVECs,as the most important in vitro lung tissue models of hypoxia-induced injury.

Objective The pathophysiological process of acute high-altitude hypoxia-induced lung injury affects protein expression levels,which are mainly evaluated by Western blot.No systematic study has investigated changes in internal control proteins as calibration loading amounts.Methods Lung injury at an altitude of 6000 m was induced in a low-pressure,low-oxygen chamber for 8,24,and 72 h using C57BL/6J mice.Establishment of the model was confirmed by hematoxylin and eosin staining.Expression levels of various internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor 5(EIF5),β-actin,and glyceraldehyde 3-phosphate dehydrogenase(GAPDH)were detected by Western blot,and total protein expression was detected by Coomassie blue staining.Furthermore,the lung injury model in vitro was establised by using,Bronchial epithelial cell(BZAS-2B)andhunman umbilical vein endothelial cells(HUVECS)confirmed by TUNEL staining.Expression levels of internal control proteins were detected by Western blot,and total protein expression was detected by Coomassie Blue staining.Results Acute 8,24,and 72 h hypoxic models were successfully established in lung tissue,demonstrating consistent total protein expression and stable levels of the internal reference proteins vinculin,α-tubulin,EIF5,andβ-actin.GAPDH expression was elevated in the HH8 h,HH24 h,and HH72 h groups compared with the normoxia(Nor)group,but only the increase at HH72 h groups was significant.Similarly,8,24,and 48 h hypoxic models were successfully established in BEAS-2B cells and HUVECs,with consistent total protein expression.In BEAS-2B cells,expression levels of the internal reference proteins β-actin and GAPDH were consistent with the normoxic control(NC)group,while vinculin,α-tubulin,and EIF5 expression levels were significantly reduced under hypoxic conditions for up to 24 h.In HUVECs,vinculin and α-tubulin expression levels were also consistent with the NC group,while EIF5,β-actin,and GAPDH expression levels were significantly reduced at 8 h and increased at 48 h.Conclusions Acute hypoxia induces lung tissue injury,and protein expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,and β-actin are stable,making them suitable internal references for Western blot.Additionally,Western blot detected differential expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,β-actin,and GAPDH in BEAS-2B cells and HUVECs,as the most important in vitro lung tissue models of hypoxia-induced injury.

Objective The myocardial injury was induced by hypobaric hypoxia through regulating the expression of various proteins.The expression of proteins was mainly detected by western blot,but the selection of internal reference proteins and their variations have not been systematically studied.Methods Myocardial injury was induced in a low-pressure,low-oxygen chamber simulating an altitude of 6000 m,for 24 and 72 h.Establishment of the myocardial injury model was confirmed by hematoxylin eosin(HE)staining.Expression levels of internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor-5(EIF5),β-actin,glyceraldehyde-3-phosphate dehydrogenase(GAPDH),cyclophilin B,and cofilin,were detected by Western Blot and total protein expression was detected by Ponceau S and Coomassie Blue staining.An adult mouse cardiomyocytes(AMCMs)injury model was induced by hypoxia for 12 and 24 h and confirmed by terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL staining).Internal control proteins were detected by Western Blot,as in the in vivo model,and total protein expression was detected by Ponceau S and Coomassie Blue staining.Results A myocardial injury model was established by hypobaric hypoxia for 24 and 72 h,the total protein expression levels remained consistent.The expression of internal control proteins including vinculin,EIF5,β-actin,cyclophilin B,and cofilin was consistent between the control and model groups.Expression levels of α-tubulin were similar in the plain control and 24 h hypobaric hypoxia group,but were significantly lower in the 72 h hypobaric hypoxia group compared with the plain control group.GAPDH expression was significantly higher in the 24 and 72 h hypobaric hypoxia groups than in the plain control group.An AMCM injury model was established by hypoxia for 12 and 24 h.Total protein levels and expression levels of the internal control proteins EIF5 and β-actin were consistent,but vinculin,α-tubulin,GAPDH,cyclophilin B,and cofilin expression levels were higher in both hypoxia groups compared with the normoxic control group.Conclusions EIF5 and β-actin may be the suitable loading control proteins for studies of hypobaric hypoxia-induced myocardial injury using Western Blot.Total protein is also a good choice for hypobaric hypoxia studies.

Objective To construct models of viral transfection and hypoxia/reoxygenation induced cellular injury in adult mouse cardiomyocytes(AMCMs)isolated using a non-Langendorff method.Methods AMCMs were isolated,extracted,sedimented,and plated using a non-Langendorff method.The morphology and survival rate of the isolated cells were evaluated 2,24,48 and 72 h after plating,and their integrity was observed by immunofluorescence staining for α-actinin.The isolated AMCMs were infected with adenoviruses carrying an RFP-expressing vector and fluorescence images were obtained at 36 and 48 h post-infection and used to calculate transfection efficiency.The cells were cultured under hypoxic conditions for 45 min,reoxygenated for 24 h,and then stained with propidium iodide(PI)to verify establishment of the hypoxia/reoxygenation injury model.Results The survival rates of AMCMs at 2,24 and 48 h after plating were comparable,but survival was significantly reduced at 72 h.The integrity of the AMCMs was good and＞80%of the cells were transfected with adenovirus at 48 h.After hypoxia/reoxygenation treatment,42%of cells were stained by PI,suggesting successful establishment of the AMCM injury model.Conclusions In this study,we developed a non-Langendorff method for the fast and easy isolation of AMCMs with high cell viability.The isolated cells can be efficiently infected with adenovirus and respond to hypoxia/reoxygenation injury.These findings provide a systematic method for isolating AMCMs and for applying gene modification and hypoxia/reoxygenation injury in these cells.

This study aimed to investigate the effects of concentration, intestinal section and borneol on the intestinal absorption of salvianolic acids. The experiment not only studied the intestinal absorption properties of three concentrations of rosmarinic acid, salvianolic acid B and salvianolic acid A at duodenum, jejunum and ileum, but also of salvianolic acids compatible with borneol at different concentrations using single-pass intestinal perfusion model in rat with phenol red as the marker. The results showed that salvianolic acids was stable under weak-acid condition and affected by metabolism enzyme; The Peff and Ka significantly different among three concentrations of rosmarinic acid and salvianolic acid B, whose intestinal absorption were saturated in high concentration, suggesting that the transport mechanisms of rosmarinic acid and salvianolic acid B were similar to active transport or facilitated diffusion; However, there was inconspicuousness in the Peff and Ka of salvianolic acid A at different concentrations, whose absorption was not saturated in high concentration, indicating that the transport mechanisms of salvianolic acid A was passive diffusion; The Peff and Ka in the ileum obviously higher than those in the duodenum and jejunum, namely the ileum was the best absorption section; When concentration of borneol increased, the enhancing effect of intestinal absorption of salvianolic acids increased, but significantly decreased when borneol increased to some degree. The enhancing effect of medium borneol concentration was the optimum. This implied that borneol can enhance the intestinal absorption of salvianolic acids, and the capacity of enhancing effect was influenced by the concentration of borneol.

Objective To select an optimal non-specific antigen blocking method by using immuno-infiltration assay so as to suit protein chip preparation. Methods Human papillomavirus type 16 L1 protein expressed by insect-baculovirus espressin system was incubated with skimmed milk powder, calf serum, bovine serum albumin (BSA) combinations of five kinds of methods to block the non-specific antigen. PBS was used as control. The effect of eliminating non-specific stain was detected by immuno-infiltration assay. Results After repeated tests, the results showed that the stability and repeatability of blocking effects were poor for the fixing up antigen first and then blocking method, and the blank control was prone to false positive. The infiltration rate of NC membrane would be affected by using skimmed milk powder as a blocking agent because the pore of NC membrane was easily plugged by milk powder particles. The use of calf serum as a blocking agent made it very difficult to determine the result because the calf serum absorbed by NC membrane produced the background; however, when 20g/L BSA was used to blocking before fixing up antibody, the results became satisfactory. Conclusion Fixing up antibody after blocking in immuno-infiltration assay showed that the blocking effect against non-specific antigen was satisfactory, stable and repeatable, indicating this method is a novel optimal blocking method compared with others.

OBJECTIVETo develop an efficient expression, purification system of recombinant Escherichia coli heat-labile enterotoxin B subunit (rLTB) and study its activity against mucosal immunoadjuvant by nasal immunization.

METHODSA recombinant, pMMB68-LTB was generated by cloning the LTB cDNA fragment into an expression vector (pMMB68) and transformed it into the host strain marine vibrio VSP60. The relevant target protein was identified using SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Sephacryl S-100 gel filtration chromatography was carried out for purification of rLTB in engineering bacteria VSP60. BALB/c mice received hen egg lysozyme (HEL) alone or combined with rLTB by nasal administration. After three times immunization, IgG and IgA antibody levels in serum or small intestine wash samples were determined using ELISA.

RESULTSrLTB protein was highly expressed in VSP60. After gel filtration with Sephacryl S-100, the purity of rLTB reached 98.1%, the yield rate was about 52%. After immunization, IgG and IgA antibody responses specific to HEL in system and mucosa of HEL + rLTB groups were significantly increased, compared with the HEL alone group (P < 0.001).

CONCLUSIONSA set of protocols for large-scale rLTB preparation has been established, which is simple, efficient and applicable. The rLTB protein we prepared was proved to be a powerful mucocal adjuvant, which could greatly enhance systemic and mucosal immune responses to nasally co-administered antigen.

Adjuvants, Immunologic ; administration & dosage ; pharmacology ; Administration, Intranasal ; Animals ; Bacterial Toxins ; administration & dosage ; isolation & purification ; pharmacology ; Blotting, Western ; Electrophoresis, Polyacrylamide Gel ; Enterotoxins ; administration & dosage ; isolation & purification ; pharmacology ; Escherichia coli ; Escherichia coli Proteins ; Immunization ; Mice ; Mice, Inbred BALB C ; Nasal Mucosa ; immunology ; Recombinant Proteins ; administration & dosage ; isolation & purification ; pharmacology

OBJECTIVETo investigate which of the two immunoglobulin (Ig)-like domains, the immunoglobulin variable region homologous domain IgV (hB7.2 IgV) and the immunoglobulin constant region homologous domain IgC (hB7.2 IgC) on the human B7.2 molecule contains receptor binding sites, and to evaluate whether the B7.2 protein expressed in bacteria has biological activity in vitro.

METHODSThree fragments of hB7.2 IgV,hB7.2 IgC and the complete extracellular region of human B7.2 containing both the IgV and IgC domains,hB7.2 Ig (V+C), were amplified by PCR and subcloned into pGEM-Teasy. Three recombinants,pGEX-4T-3-hB7.2 IgV,pGEX-4T-3-hB7.2 IgC and pGEX-4T-3-hB7.2 Ig (V+C), were generated by cloning the fragments into a prokaryote expression plasmid (pGEX-4T-3) and transformed into the host strain E. coli DH5alpha. The relevant target fusion proteins consisting of GST and hB7.2 IgV,hB7.2 IgC and hB7.2 Ig (V+C), were identified by SDS-PAGE and Western blotting. With the presence of the first signal imitated by anti-CD3 antibody, T cell activation was observed by exposing purified T lymphocytes to each soluble form of the three bacterially-produced human B7.2 fusion proteins by [(3)H]-TdR incorporation.

RESULTSThree recombinant fusion proteins of human B7.2, GST-hB7.2 IgV, GST-hB7.2 IgC and GST-hB7.2 Ig (V+C) were produced and detected in inclusion body form from engineered bacteria. With the first signal present,T lymphocytes proliferated when co-stimulated by bacterially-produced either GST-hB7.2 Ig (V+C) or GST-hB7.2 IgV fusion proteins, but not by GST-hB7.2 IgC.

CONCLUSIONSFunctional human B7.2 fusion protein can be produced in bacteria. The IgV-like domain of human B7.2 is sufficient for B7.2 to interact with its counter-receptors and co-stimulate T lymphocytes.

Antigens, CD ; pharmacology ; B7-2 Antigen ; Escherichia coli ; genetics ; Humans ; Immunoglobulin Constant Regions ; pharmacology ; Immunoglobulin Variable Region ; pharmacology ; Lymphocyte Activation ; Membrane Glycoproteins ; pharmacology ; Plasmids ; Recombinant Fusion Proteins ; pharmacology ; T-Lymphocytes ; immunology

Objective To construct the human interleukin-18(hIL-18) DNA plasmids vaccine and to express the eukaryotic plasmids vaccine in mammalian cell lines Cos-7 and D5.Methods Gene recombinant technique was used to construct hIL-18 eukaryotic expression vectors.Calcium phosphate method was performed to transect recombinant hIL-18 eukaryotic expression vectors into Cos-7 and D5 cells.In situ hybridization and Western Blot were implemented to verify the transient expression of recombinant hIL-18 in Cos-7 and D5.Results The eukaryotic expression plasmid pVAX1-IL 18 was constructed successfully.hIL-18 was transiently expressed in Cos-7 and D5.Conclusion The eukaryotic expression plasmid pVAX1-IL 18 was constructed.In situ hybridization and Western Blot results proved the successful transient expression of pVAX1-IL 18 in Cos-7 and D5.Therefore,the work has settled the foundation for further biological research on hIL-18,including immunogene therapy through hIL-18.