The effects of a novel immunosuppressive agent FTY720 on proliferation inhibition and apoptosis of acute leukemia cell lines HL-60 and U937, and the role of extracellular regulated protein kinase (ERK) in the course of proliferation inhibition and apoptosis induced by FTY720 were studied. The proliferation inhibition rate of HL-60 and U937 cells by various concentrations of FTY720 was detected by MTT assay. Cell apoptosis was detected by DNA fragment analysis and flow cytometry. The phosphorylated ERK1/2 protein expression was observed by Western blotting. The change of intracellular distribution of ERK1/2 protein was identified by SP immunohistochemical staining. The results showed that FTY720 could inhibit the growth of HL-60 and U937 cells effectively in a dose-dependent manner. After incubation with FTY720 for 24 h, apoptosis was observed in HL-60 and U937 cells. The intracellular expression of phosphorylated ERK1/2 protein was also down-regulated and the distribution of ERK1/2 protein in cell nuclear was reduced during FTY720-induced apoptosis. So, that FTY720 inhibited ERK1/2 phosphorylation might mediate the role of FTY720-induced apoptosis and proliferation inhibition of leukemia cells.
The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made.In vitro, DBM and bone marrow stromal cell (BMSC) from rabbits were co-cultured for 3–7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM).In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as control. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culturein vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. Thein vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts, trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the surface of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good biocompatibility and ectopic induced osteogenic activity.
The effects of ligustrazine on the expression of LFA-1, ICAM-1 in bone marrow tissue and the mechanism promoting hematopoietic reconstitution following bone marrow transplantation (BMT) were investigated. The 150 mice were randomly divided into 3 groups: normal group, saline group and ligustrazine group. The normal group received no treatment, while in the saline group and ligustrazine group, the mice were subjected to normal saline (0.2 ml, twice a day) and ligustrazine (0.2 ml, twice a day) respectively through a gastric tube. At the 7th, 14th, 21st and 28th day after BMT, survival rate, colony forming unit of spleen (CFU-S), peripheral blood cells and bone marrow mononuclear cells (BMMNC) were measured, histological changes in bone marrow tissue were observed and the expression level of LFA-1, ICAM-1 was detected. In ligustrazine group CFU-S counts on the 10th day and the peripheral blood WBC, PLT. BMMNC counts, hematopoietic tissue volume as well as the expression level of LFA-1 on the 7th, 14th, 21st, 28th day after BMT were higher than in saline group (P<0.01or P<0.05). Mature RBC volume and the expression level of ICAM-1 were significantly lower in the ligustrazine group than in the saline group (P<0.01orP<0.05). In the ligustrazine group, fat tissue volume was higher on the 7th, 14th day after BMT (P<0.01) and was lower on the 21st, 28th day (P<0.01) after BMT than in the saline group. It was concluded that Ligustrazine could improve bone marrow microenvironment and promote hematopoietic reconstitution.
To investigate the relationship of bcl-2, p53, proliferating cell nuclear antigen (PCNA) to cell proliferation, apoptosis and pathological parameters, the patterns of cell growth and turnover in renal cell carcinoma (RCC), formalin-fixed and paraffin-embedded tissue blocks from 34 patients with RCC were examined. Cell proliferation activity was detected by PCNA immunostaining and the proliferation index (PI) was expressed as a percentage of the PCNA-positive cells in the tumor cells. Apoptosis was detected by terminal deoxy-nucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells. Expressions of bcl-2 and p53 were assessed immunohistochemically. Our results showed that the PI ranged from 6.0% to 24.0% (median 12. 3%) and the AI from 2.0% to 8.0% (median 5.4%) in RCC. The expression of the bcl-2 protein was demonstrated in 15 cases (44.1%); the expression of the p53 protein, however, was seen in only 3 case. bcl-2 positivity was not associated with PI or AI or any pathological parameters. There were close associations between PI and tumor grade and stage, and a significant relationship between AI and the tumor grade of RCC. Our study suggests that bcl-2 positivity was not associated with PI or AI or any pathological parameters. There are close associations between PI and AI and tumor grade and stage of RCC. Active cell proliferation may be accompanied by frequent apoptosis in RCC.
In order to determine whether the variations in the calpain-10 gene constitutes risk of type 2 diabetes (T2DM) in Chinese, the frequency of UCSNP-43, 44 in 268 adults newly diagnosed with T2DM (according to the 1999 ADA criteria) and 153 non-diabetic control subjects was investigated. For all subjects, the height, weight, waist-to-hip ratio (W/H) and blood pressure, as well as following parameters were measured: (1) 75-g oral glucose tolerance test with insulin, C-peptide, HbAlc and blood lipid profiles; (2) Genomic DNA extracted from peripheral blood lymphocytes was genotyped for UCSNP-43 (calpain-10-g. 4852 G/A) and UCSNP-44 (calpain-10-g. 4841 T/C by sequencing a polymerase chain reaction (PCR)-amplified fragment. PCR product was selected by single strand conformation polymorphism (SSCP) and then sequenced. The results showed that there was significant difference between T2DM group and normal control group in allele frequencies, haplotype frequencies, or haplotype combinations of UCSNP-43 and-44 either. But in newly diagnosed T2DM group, it was found that the individuals with the genotype UCSNP-44 T/C+C/C had significantly increased fasting and post-challenge insulin levels (FIns and P2hIns), consistent with reduced insulin sensitivity. In the BMI>25 subgroup, the differences were even more significant. It was demonstrated that the Calpain-10 gene polymorphism UCSNP-44 was associated with insulin sensitivity and FIns and P2hIns in newly diagnosed T2DM, although Calpain-10 doesn't appear as a major diabetes susceptible gene in this population.