再生障碍性贫血患者骨髓单个核细胞端粒长度及P53、P21的表达

Telomere length and expression of P53 and P21 in BMMNC of patients with aplastic anemia

目的:研究再生障碍性贫血(AA)患者骨髓单个核细胞(BMMNC)的端粒长度以及P53和P21表达水平,探讨它们与AA发病的关系。方法:采用实时荧光定量聚合酶链反应(RT-qPCR)检测60例AA患者[其中非重型再障(NSAA)38例,重型再障(SAA)22例]和25例对照者BMMNC中端粒长度以及P53和P21的mRNA表达情况;采用Western blot法检测P53和P21蛋白表达情况;并进行相关性比较。骨髓活检术检测骨髓造血细胞成分分布情况;流式细胞术检测CD34^+细胞占有核细胞百分比情况。结果:AA患者端粒长度较对照组明显缩短骨髓造血细胞成分及CD34^+细胞占有核细胞百分比较对照组明显减少(P<0.05);NSAA、SAA患者与对照组相比端粒长度均明显缩短,骨髓造血细胞成分及CD34^+细胞占有核细胞百分比均明显减少(P<0.05);SAA与NSAA比较,端粒长度明显缩短,骨髓造血细胞成分及CD34^+细胞占有核细胞百分比明显减少(P<0.05)。AA患者P53和P21的mRNA及蛋白表达水平均较对照组明显升高(P<0.05);NSAA和SAA患者P53和P21的mRNA及蛋白表达水平与对照组相比均明显升高(P<0.05);SAA患者P53和P21的mRNA及蛋白表达水平较NSAA明显升高(P<0.05)。端粒长度与P53表达水平或P21表达水平之间没有相关性(P>0.05);P53表达水平与P21表达水平之间呈正相关(P<0.05)。结论:端粒长度的改变以及P53和P21可能参与了再障的发病经过,推测可能是通过抑制造血干细胞的增殖和分化,从而引发造血细胞凋亡。

AIM：To investigate the pathogenesis of aplastic anemia （ AA） through the expression of P 53 and P21, and the telomere length in the bone marrow mononuclear cells （BMMNC） of patients with AA.METHODS： The BMMNC were collected from 60 cases of AA, including 38 non-severe aplastic anemia （NSAA） and 22 severe aplastic ane-mia （SAA）, and 25 healthy controls.The mRNA expression of P53 and P21, and the telomere length were detected by real-time quantitative polymerase chain reaction （RT-qPCR）, while the protein expression of P53 and P21 was determined by Western blot.The correlations among P53, P21 and telomere length were analyzed .Hematopoietic components of bone marrow were measured by bone marrow biopsy .CD34 ＋cells proportion in nuclear cells were assessed by flow cytometry . RESULTS：Telomere length in the patients with AA , including NSAA and SAA , was significantly lower than that in con-trol group （P〈0.05）.The same results of the hematopoietic components of bone marrow and the CD 34＋cells proportion in nuclear cells were observed .Telomere length in SAA group was shorter than that in NSAA group （ P〈0.05 ） , while the hematopoietic components of bone marrow and the CD 34 ＋cells proportion in nuclear cells also showed the same results . The expression of P53 and P21 at both mRNA and protein levels in the AA patients , including NSAA and SAA , was signi-ficantly higher than that in control group （P〈0.05）.The expression of P53 and P21 in the SAA patients was higher signi-ficantly than that in the NSAA patients （ P〈0.05 ） .No correlation between the expression of P 53 or P21 and telomere length was found . There was significant positive correlation between the expression of P 53 and P21 （ P 〈0.05 ） . CONCLUSION：Telomere length, P53 and P21 may be involved in the pathogenesis of AA by inhibiting the proliferation and differentiation of hematopoietic stem cells , and triggering cell apoptosis .