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Objective: To explore the influence of tanshinone 11 A on the expressions of molecular chape rone Cosmc. advanced oxidation protein products (AOPP) in the kidney tissue of the allergic purpura nephritis mice and the levels of extracellular signal-regulated kinase/mitogen activated protein kinase (ERK/MAPK) signaling pathway proteins, and to clarify mechanism of tanshinone 11 A in the treatment of allergic purpura nephritis. Methods: A total of 38 mice were divided into control group∗ model group (allergic purpura nephritis model) and tanshinone 11 A group (allergic purpura nephritis model • tanshinone 11 A treatment), with 12 in each group; the other 2 mice were used to verify the success of modeling. The urine red blood cell counts and urine protein levels of the mice in various groups were measured, and the pathomorphology of kidney tissue of the mice in various groups were observed by periodate schiff-reaction (PAS) staining. The AOPP protein levels in the kidney tissue of the mice were determined by enzyme linked immunosorbent assay (ELISA), and the ERK and phosphorylated ERK (p-ERk) protein expression levels were determined by Western blotting method. The expression levels of ERK. p-ERK and Cosmc mRNA in kidney tissue of the mice were determined by RT-PCR. Results: In control group, there was no hyperplasia of glomerular basement membrane and no glomerular sclerosis; in model group, the proliferation of glomerular basement membrane was obvious∗ the inflammatory cells were infiltrated, and glomerular sclerosis appeared; in tanshinone 11 A group, glomerular basement membrane hyperplasia and inflammatory infiltration were not obvious in the mice, there was only small amount of infiltrated inflammatory cells. Compared with control group, the urine red blood cell count, the 24 h urine protein level, the p ERK mRNA and AOPP protein levels of the mice in model group and tanshinone 11 A group were increased ( P<0. 05 or P<0. 01); the Cosmc mRNA expression levels were decreased (P<0. 01). Compared with model group, the urine red blood cell count. 24 h urine protein level, the p-ERK and AOPP protein levels in the kidney tissue of the mice in tanshinone 11 A group were decreased (P<0. 05 or P<0. 01). and the Cosmc mRNA expression level was increased (P
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Objective:In the present study,Bac-to-Bac baculovirus expression system was used to obtain recombinant human Cosmc extracellular domain protein,which can lay the foundation for the research about the structure and function of Cosmc protein in vitro,and simultaneously provide ideas for the research of O-glycosylation and related diseases. Methods: The Cosmc extracellular domain ( Cosmc-ED) gene was cloned into a transfer vector pFastBac1 to form the recombinant donor plasmid pFastBac1-Cosmc ED, which was transformed into competent cells DH10Bac. By using blue-white selection and PCR analysis,we could obtain recombinant shuttle vector rBacmid-Cosmc ED. Then, the recombinant gene DNA of rBacmid-Cosmc ED was used to transfect Sf-9 mediated by cationic lipid formulation,and the recombinant baculovirus bacmid was obtained,which was further used to infect the serum-free cell Sf-9 to express Cosmc-ED in the supernatant. Then the protein of interest was detected by SDS-PAGE and Western blot and purified with Ni-NTA affinity column. Results:SDS-PAGE and Western blot analysis showed a specific band about 33 kD,consistent with the interest protein. Mass spectrometry results further prove that the protein was Cosmc extracellular domain protein. Conclusion: Human Cosmc-ED protein can be successfully expressed in Sf-9 insect cells and laid basis for subsequent studies.
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Objective To explore the mechanism of Tn antigen expression in colon cancer cells HT-29.Methods Tn(+) and Tn(-) cells were separated from human colon cancer cell line HT-29 by im-mune magnetic beads.Total RNA, genomic DNA ( gDNA) and cytoplasmic proteins in these cells were ex-tracted by using Trizol, DNA preparation kit and nuclear and cytoplasmic extraction reagents respectively.T-synthase activity was measured by a fluorescent assay.Cosmc and T-synthase transcriptional levels were ana-lyzed by RT-PCR using mRNA as the templates.The coding sequence ( CDS) and CpG islands of Cosmc were amplified by PCR using gDNA as the templates.Amplified products were analyzed on 1%agarose gel. The expected bands were purified, and then sequenced to examine Cosmc mutation.Wild type Cosmc ( Wt-Cosmc) were transfected into tumor cell lines and normal cells to define the function of Cosmc.The expres-sions of Cosmc protein in these cells were then examined by Western blot.Results Although no mutation appeared in HT-29-Tn(-) cells, the deletion of CDS and inactivity of T-synthase were observed in HT-29-Tn(+) cells.Additionally, transfected WtCosmc restored T-synthase activity and then decreased Tn antigen expression in Tn antigen positive cells.Conclusion The absence of CDS in Cosmc gene resulted in the loss of T-synthase activity and consequent Tn antigen expression in HT-29-Tn(+) cells.
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Objective To explore the mutation in corel β3-galactosyl-transferase specific molecular chaperone(Cosmc、no-coding region and it's effects on the transcription level of Cosmc in Tn antigen positive tumor cells.Methods The Tn antigen positive(Tn+)and negative(Tn-)cells were separated from tumor tissues by immune magnetic bead,then the genomic DNA(gDNA),total RNA were prepared by Qiagen AllPrep DNA/RNA mini kit. In these cells.the transcription levels of T-synthase and Cosmc mRNA were tested by RT-PCR.the DNA of Cosmc non-coding region was amplified by PCR,the mutation in Cosmc non-coding region were further detected by sequencing.Results There are no mutation appearing in Tn-cells,one or more mosaic sequence allele appearing in portion of patient's Tn-cells.Almost of the Tn+cells which separated from tumor tissues and Jurkat T cell exists mutation.but the mutation style and mutation point were not saine in different tumor.Thtee patient's Tn+cells have loss of hetemzygosity(LOH),four patient's Tn+cells and Jurkat T cell have point mutation.Although no difference of transcription level of T-synthase mRNA in Tn+ and Tn-cells.but the transcription level of Cosmc mRNA in Tn+ cell was much lower than that in Tn-cell.The ratio of T-synthase/Cosmc mRNA in Tn+ tumor cells was hiigher than that in Tn-cell.Conclusion The tumor Tn antigen arise from mutation in Cosmc non-coding region maybe result from transcription level decreased of Cosmc mRNA.
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Objective To clarify whether the Cosmc gene down-regnhtion in lgA nephropathy (IgAN) patients is resulted from genetic disorders or external suppressions. Methods Forty IgAN patients, 16 non-IgAN glomerulonephritis patients and 21 healthy controls were enrolled in the study. Genomie DNA was extracted and then Cosmc gene was amplified and sequenced. Peripheral B lymphoeytes were isolated and cultured with RPMI-1640 alone or plus lipopolysaecharide (LPS). The Cosmc mRNA expression levels at baseline, after RPMI-1640 culture or RPMI-1640+LPS treatment were measured respectively by real-time RT-PCR. Results (1) Only 2 missense mutations and 2 silent mutations were detected in coding frame region of Cosine gene in 2 IgAN patients. (2) The baseline Cosmc gene expression level was significantly lower in IgAN patients (31% of that in healthy controls) than that in healthy controls. (3) Relative quantification PCR indicated that Cosmc mRNA expression level was significantly increased (219% of baseline) after RPMI-1640 culture, and treatment of LPS could strongly inhibit this effect. (4) The Cosmc gene expression of healthy control was not affected by RPMI-1640 or LPS. Conclusion It is not genetic disorders but external suppression to cause the down-regulation of Cosmc gene mRNA expression in IgAN.