Efficacy of diacetyl hexamethylene diamine in treatment of patients with high risk myelodysplastic syndrome / 中国实验血液学杂志

The aim of this study was to investigate the efficacy of diacetyl hexamethylene diamine (CAHB) for patients with high risk myelodysplastic syndrome (MDS), and to explore the effect of CAHB on HL-60 cells in vitro and its possible mechanism. 8 patients with high risk MDS were treated with CAHB by continuous intravenous infusion for 10 days, and repeated once after an interval of 28 days. The count of the granulo- and mono-blasts in bone marrow (BM) aspirate was measured before and after treatment. HL-60 cells were treated with different concentrations of CAHB for 72 hours in vitro. The inhibitory effect of CAHB on proliferation of HL-60 cells in vitro was measured by MTT assay. Differentiation of HL-60 cells was detected by the changes of CD11b and CD14 expression on cell surface. Apoptosis of HL-60 cells was detected by double staining of Annexin V and PI. The cell cycle distribution change of HL-60 cells was analyzed by flow-cytometry. The results indicated that the granulo- and mono-blasts in BM decreased in all the 8 patients after CAHB treatment. The main side effect of CAHB on hematological system was thrombocytopenia. After being treated with 1, 2, 3, 4 mmol/L CAHB for 72 hours in vitro, the result of MTT assay showed the inhibitory effect of CAHB on the proliferation of HL-60 cells in dose-dependent manner. After being treated manner 1, 2, 3, 4 mmol/L CAHB for 72 hours, the CD11b positive HL-60 cells were 22.39+/-3.97%, 33.12+/-4.46%, 49.25+/-5.27%, 78.05+/-5.66%, respectively, which were significantly different from the control group (CD11b positive HL-60 cells was 5.89+/-2.94%) (p<0.01). The CD14 expression was negative in all the 5 groups. These results suggested that CAHB could induce HL-60 cells to differentiate into mature granulocytes, and the effect of CAHB appeared in dose-dependent manner. After being treated for 72 hours by 1, 2, 3, 4 mmol/L CAHB, the apoptotic cells (Annexin V(+)/PI(-) cells) increased mildly, which suggested that CAHB only weakly induces HL-60 cells to apoptosis at the concentration of 1 to 4 mmol/L. Along with the concentration increase of CAHB, the ratio of cells in G(0)/G(1) phase increased, and ratio of cells in S phase and G(2)/M phase decreased correspondingly, it indicated that CAHB could arrest HL-60 cells in G(0)/G(1) phase in a dose-dependent manner. It is concluded that induction of cell differentiation may be the primary effect of CAHB on MDS. Cell cycle arrest may be essential to the effect of CAHB as well. Side effect of CAHB on platelet count may correlated with its inhibitory effect on hematopoiesis.

Regulation of G protein-coupled receptor kinase 5 mRNA and protein level in rat brain by addictive drugs / 生理学报

G protein-coupled receptor kinase 5 (GRK5) plays an important role in the regulation of GPCR-transduced signals. Our previous study showed that acute administration of morphine could significantly increase GRK5 mRNA level in the cerebral cortex and hippocampus of the rat brain. The current study investigated the potential effects of acute administration of addictive drugs including morphine, heroine and cocaine on GRK5 mRNA level in the rat brain using in situ hybridization and analyzed the effects of acute and chronic morphine treatments on GRK5 protein level in the rat brain using Western blotting assay. Our results showed that 2 h after the initial morphine (10 mg/kg), cocaine (15 mg/kg) and heroine (1 mg/kg) treatment, the mRNA level of GRK5 in the parietal cortex increased about 110% (P<0.01), 70% (P<0.05) and 100% (P<0.01), respectively. In the temporal cortex, GRK5 mRNA level increased about 90% (P<0.01), 40% (P<0.05) and 80.0% (P<0.01), respectively . In the hippocampus, the mRNA level of GRK5 increased about 60% (P<0.01), 30% (P<0.05) and 80% (P<0.01). However, the mRNA level of GRK5 remained unchanged after acute morphine, cocaine or heroine treatment. In the cerebral cortex of the rat brain, the acute administration of morphine (NS-Mor) increased GRK5 protein level by about 60% while the chronic morphine treatment (Mor-Mor) increased GRK5 protein level even higher [about 130% compared with the control group (chronic saline treatment, NS-NS) group, P<0.01]. In the hippocampus, GRK5 protein level remained unchanged after acute administration of morphine (P>0.1),while the level of GRK5 protein tended to decrease after chronic morphine treatment (P=0.098). In the thalamus, acute morphine treatment caused no change in GRK5 protein level (P>0.1) while after chronic morphine treatment, GRK5 protein level decreased significantly (more than 90%, P<0.01), Taken together, our results indicate that addictive drugs can regulate GRK5 in the rat brain on protein level as well as on mRNA level and suggest that GRK5 may play a role in addiction of psychoactive substances.