| Objective 1.To observe the expression of heme oxygenase(NO)gene mRNA in bone marrow of patients with iron deficiency /megaloblastic anemia (IDA/MA),aplastic anemia(AA),myelodysplastic syndrome(MDS)and acute non-lymphocytic leukemia(ANLL).2.To approach the relationship between HO and signal transduction pathway in hematopoietic regulation.3.To discuss the mechanism and significance of NO-1 expression in hematologic diseases.Methods 1.The expression levels of HO-1,STAT5,Raf-1 gene mRNA in marrow mononuclear cells from IDA/MA(20 cases),AA(20 cases),MDS(30 cases)and ANLL(20 cases)were measured by semi-quantitive RT-PCR,all of these cases were primary.Healthy groups(10 cases)were taken as comparison groups.2.Bone marrow mononuclear cells(BMNCs),isolated by density gradient centrifugation,from patients with MDS-RAEB bone marrow aspirates,were cultured and separately incubated with Hemin of different concentrations(0,1μmol/L,5μmol/L and 10μmol/L).The expression levels of HO-1,STAT5,Raf-1 gene mRNA in BMSCs were measured by semi-quantitive RT-PCR,the expression levels of VEGF,IL-1β,TNF-αwere determined by ELISA.3,Values presented are means±SEM.The result were analyzed with spss11.5 statistics software package.Statistical comparisons of absorbance differences were performed by the ANOVA test and the Newman-Keuls test.The correlation test was Spearman rank correlation. A probability level P≤0.05 was accepted as significant.Results 1,①There was significant difference between the expression levels of HO-1 SWAT5 and Raf-1 mRNA in IDA/MA and comparison groups (p＜0.05),the expression levels in nutritional anemia group were higher.②There was significant difference between the expression levels of HO-1 STAT5 and Raf-1 mRNA in AA and comparison groups(p＜0.05),the expression levels in AA group were lower.③There was significant difference between the expression levels of HO-1 SWAT5 and Raf-1 mRNA in MDS and comparison groups(p＜0.05),the expression levels in MDS group were higher.④There was significant difference between the expression levels of HO-1 STAT5 and Raf-1 mRNA in ANLL and comparison groups (p＜0.05),the expression levels in ANLL group were higher.⑤There was positive correlation between the expression level of STAT5,Raf-1 and HO-1(Raf-1 r_s=0.334,P＜0.01;SWAT5 r_s=0.287,P＜0.05).2,the expression level of HO-1 in groups incubated with hemin were higher than group incubated with no hemin and there was positive correlation between the expression level and the hemin concentration(r_s=0.763,P＜0.02).the expression Level of Raf-1 mRNA in groups incubated with hemin were lower than group incubated without hemin. there was negative correlation between the expression Level of Raf-1 and HO-1(r_s=0.371,P＜0.05).There was no significant difference of SWAT5 expression level among all groups,the expression levels of VEGF,IL-1β,TNF-αdetermined by ELISA were lower in groups incubated with hemin. there was negative correlation between the three cytokines and HO-1 (VEGF r_s=0.447,P＜0.02;IL-1βr_s=0.382,P＜0.05;TNF-αr_s=0.459, P＜0.02).In group incubated with hemin concentration of 10μmol/L, contrasted with group incubated with no hemin,,the decreased rates of VEGF,IL-1β,TNF-αexpressiong levels were 56.8%,43.7%and 48.4%.Conclusion The expression level of HO gene mRNA is abnormal in MDS and especially the HO-1 expression level is significantly increased, perhaps HO-1 has protecting effection in MDS.The abnormal expression of STAT5,Raf-1 mRNA demonstrates that signal transduction pathway of Ras-MAPK and JAK-STAT must have done something in MDS.HO-1 perhaps performs its protecting effect through Ras-MAPK signal transduction pathway in BMSCs of MDS.
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