Characterization of a new megakaryocytic cell line: the Dami cell

A new human megakaryocytic cell line (Dami) has been established from the blood of a patient with megakaryoblastic leukemia. The Dami cells grow primarily in suspension with a doubling time of 24 to 30 hours. By light and electron microscopy, the Dami cells range in size from 12 to 120 micron in diameter and have lobulated nuclei characteristic of megakaryocytes. At least 89% of the cells react with monoclonal antibodies against platelet glycoproteins (GP) Ib and IIB/IIIa, and glycophorin. The cells do not react with antibodies against lymphoid, monocyte, granulocyte, or macrophage antigens. Thirteen percent of the cells become polyploid, spontaneously achieving greater than 4N DNA ploidy levels. In response to phorbol myristate acetate (PMA), the proportion of cells with ploidy levels greater than 4N increased threefold and could be separated into discrete ploidy groups. PMA also increased the expression of GPIb, the GPIIb/GPIIIa complex,l and von Willebrand factor. Cytogenetic analysis revealed a human male hyperdiploid karyotype with a modal chromosome number of 54 to 64 and several consistent clonal chromosomal abnormalities. These included a partial deletion of chromosome 5 and a translocation involving chromosome 3. In contrast to other megakaryocytic cell lines in which only a small portion of the cells express the megakaryocytic phenotype, nearly all of the Dami cells express platelet glycoproteins. Thus, the Dami cells provide a superior model in which to study human megakaryocyte biochemistry and differentiation.     

糖尿病视网膜病变易感性与相关基因多态性研究进展

糖尿病视网膜病变是糖尿病的并发症之一,在糖尿病患者中,有血糖控制不良且病程较长但未发生糖尿病视网膜病变的情况,也有血糖控制良好且病程较短的但发生严重糖尿病视网膜病变的患者。通过大量的流行病学调查发现,糖尿病视网膜病变的发生、发展除了与血糖控制的情况、病程长短等因素有关外,还与每个人的个体差异有关。     

过氧化物酶体增殖物激活受体γ及其配体对早期细胞滋养细胞MMP-2、MMP-9表达的调控

目的:探讨过氧化物酶体增殖物激活型受体γ(PPARγ)及其配体(15-脱氧-前列腺素J2,15-d-PGJ2)对细胞滋养细胞表达基质金属蛋白酶-2(MMP-2)和MMP-9的调控作用。方法:采用免疫荧光细胞化学方法检测细胞滋养细胞中PPARγ的表达;利用免疫荧光共聚焦技术观察15-d-PGJ2作用前后细胞滋养细胞MMP-2和MMP-9表达强度的变化;通过荧光定量PCR(Real-timePCR)和Westernblot方法定量检测MMP-2和MMP-9mRNA和蛋白的表达变化。结果:在细胞滋养细胞中有PPARγ蛋白表达,且主要定位在细胞滋养细胞核中;15-d-PGJ2作用后细胞滋养细胞中MMP-2和MMP-9的表达明显下降,与对照组相比差异显著(P<0.01);15-d-PGJ2对MMP-2的作用强于MMP-9。结论:PPARγ及其配体15-d-PGJ2调节滋养细胞浸润作用可能是通过调节MMP-2和MMP-9的表达实现的。     

特应性皮炎与丝聚蛋白基因突变相关性研究进展

特应性皮炎(AD)是一种常见的慢性反复性炎症性皮肤疾病.遗传因素是特应性皮炎发生、发展的重要因素.丝聚蛋白基因(FLG)被定位于人类染色体1q21的EDC区域内,该基因发生突变后导致丝聚蛋白功能缺失进而皮肤屏障发生破坏,与AD的发生密切相关.研究表明,不同种族和不同区域间AD患者FLG基因突变位点可能不同.FLG基因突变与AD发病关系的研究有利于进一步加深对AD发病机制的认识,并可能为AD的治疗提供新的方向.