再生障碍性贫血患者血清对脐血CD34+细胞cyclin D关键亚型表达的影响

目的：确定控制脐血造血干/祖细胞增殖的细胞周期蛋白D(cyclin D)关键亚型，体外观察再生障碍性贫血（再障）患者血清对脐血造血干/祖细胞cyclin D关键亚型表达的影响，以探讨再障的发病机制。 方法:用免疫磁珠阳性分选的方法分离脐带血CD34+细胞，用RT-PCR和Western blotting方法检测其cyclin D各亚型的表达以筛选其关键亚型；用甲基纤维素半固体培养方法，观察再障血清对脐血CD34+细胞粒单系-集落形成单位(CFU-GM)形成的影响；再用半定量RT-PCR和Western blotting方法检测再障血清对脐血CD34+细胞cyclin D关键亚型表达的影响。结果： RT-PCR和Western blotting结果显示：控制脐血CD34+细胞增殖的cyclin D关键亚型为cyclin D3；再障血清可以显著抑制脐血CFU-GM的形成，并分别可以从mRNA和蛋白质水平抑制cyclin D3亚型的表达。 结论:Cyclin D3是控制脐血CD34+细胞增殖的关键cyclin D亚型，再障血清可以抑制其表达，这可能是再障造血抑制的一种机制。

Effects of aplastic anemia patient serum on the expression of the crucial cyclin D isoform in cord blood CD34+ cells

AIM: To explore the pathogenesis of aplastic anemia (AA), we identified the crucial isoform of cyclin D that determine the proliferation of the cord blood CD34~+ cells and observed effects of AA serum on the expression of crucial cyclin D isoform in umbilical cord blood CD34~+ cells. METHODS: The CD34~+ cells were isolated with MIDI-MACS system. The isoforms of cyclin D were detected by RT-PCR and Western blotting. Methylcellulose culture system was used to measure the formation of CFU-GM. The expression level of crucial cyclin D isoform was assayed by RT-PCR and Western blotting after the CD34~+ cells were incubated in AA serum. RESULTS: The crucial cyclin D isoform in CD34~+ cells was cyclin D3. The AA serum inhibited the formation of CFU-GM and down-regulated expression level of the cyclin D3 from the mRNA to protein level, respectively. CONCLUSION: The AA serum inhibits the proliferation of CD34~+ cells and down-regulates level of cyclin D3, this may be one of hematopoiesis inhibition mechanisms in AA.