大鼠移植骨髓细胞向肝细胞转化的实验研究

目的 探讨体内骨髓细胞向肝细胞转化的可行性。方法 将雌性SD大鼠随机分为3组，每组15只。①R BMT(全身照射 骨髓移植)；②2—AAF R BMT；③2—AAF PH(部分肝切) BMT。进行交叉性别骨髓细胞移植，雄性骨髓植入雄性受体，分别于第5、10、20天处死雌鼠。以雄性性别决定基因sry作为细胞标记，用原位杂交和FISH作为检测方法对骨髓细胞的肝细胞转化进行分析。结果 PCR移植效果初步分析可见，R BMT组11例中有10例PCR阳性；2AAF PH BMT组11例中有7例阳性，2AAF B BMT组10例中有6例阳性。sry原位杂交染色发现，第5天各组雌性受体肝索中均未见sry阳性的肝细胞。第10天R BMT组可见1例sry阳性的细胞位于肝细胞索,FISH染色可见这一细胞白蛋白mRNA阳性。第20天各组PCR阳性各例均可在肝索中检测到sry阳性的细胞。FISH染色可见白蛋白mRNA阳性。经统计学分析第20天各组sry阳性细胞数无明显差异。结论 在B BMT、2—AAF PH BMT和2—AAF R BMT模型中移植的骨髓细胞均可以植入肝脏，并存在于肝细胞索。植入肝索的骨髓细胞最早可见于移植后第10天，并发生转分化，表达白蛋白mRNA。不经过全身照射的2—AAF PH BMT组，移植的骨髓细胞也可以进入肝脏发生转分化，因此全身照射并不一定是移植骨髓细胞活化、植入和转化的必须条件。     

结缔组织生长因子对人Tenon囊成纤维细胞中E-cadherin蛋白表达的促进作用

背景 青光眼滤过手术后滤过通道的瘢痕化是手术失败的主要原因,其主要病理机制是成纤维细胞的异常增生、间质-上皮转分化及细胞外基质的重塑.结缔组织生长因子(CTGF)是促进瘢痕形成的关键因子,而CTGF是否能促进人Tenon囊成纤维细胞(HTFs)的间质-上皮转分化尚不清楚.目的 观察CTGF对HTFs间质-上皮转分化的影响.方法 用体积分数10％胎牛血清的DMEM高糖型培养液进行HTFs体外常规培养和传代,取3～6代细胞用于实验.将培养的HTFs分为空白对照组和CTGF处理组,空白对照组用DMEM完全培养液培养细胞,CTGF处理组在培养液中加入CTGF,使终质量浓度为50 ng/ml.细胞培养后48 h,采用细胞免疫荧光染色技术鉴定HTFs中上皮钙黏素(E-cadherin)蛋白的表达,采用Western blot法对HTFs中E-cadherin蛋白的表达量进行检测.结果 空白对照组及CTGF处理组HTFs均生长良好,呈长梭形,漩涡状排列.细胞免疫荧光染色显示,CTGF处理组HTFs细胞质呈红色荧光,细胞核呈蓝色荧光;空白对照组HTFs仅见DAPI蓝染的细胞核,无E-cadherin表达的红色荧光.Western blot法检测结果显示,空白对照组HTFs中E-cadherin蛋白无表达,而CTGF处理组HTFs中E-cadherin蛋白的相对表达量为0.63±0.08.结论 间叶组织来源的成纤维细胞本身不表达E-cadherin,在CTGF的刺激下成纤维细胞能够表达E-cadherin,CTGF促进HTFs的间质-上皮转分化.     

马兜铃酸促进肾小管上皮细胞转分化的发生及温阳活血方干预作用研究

目的：探讨马兜铃酸（aristolochic acid,AA）在大鼠近端肾小管上皮细胞（NRK-52E）转分化中的可能作用,及温阳活血方拮抗转分化机制。方法：（1）MTT法检测不同浓度温阳活血方含药血清对NRK-52E细胞增殖的影响。（2）免疫细胞化学法检测不同浓度AA（0、5、10、20、40μg/ml）对NRK-52E细胞表达α-平滑肌肌动蛋白的影响。（3）ELISA法检测AA刺激下Col-Ⅰ的表达及温阳活血方对其调控作用。（4）Real-Time PCR法检测温阳活血方对TGF-β1mRNA、ET-1mRNA、VEGF mRNA等肾间质纤维化相关因子的调控作用。结果：（1）AA5μg/ml、AA10μg/ml、AA20μg/ml、AA40μg/ml均可刺激NRK-52E表达α-平滑肌肌动蛋白,AA10μg/ml浓度下α-平滑肌肌动蛋白表达较强。（2）AA刺激NRK-52E细胞12h、24h、48h后,Col-Ⅰ的表达水平随着时间的延长而增强。（3）马兜铃酸刺激NRK-52E细胞24h后,TGF-β1mRNA表达上调（P〈0.05）,VEGF mRNA表达显著下调（P〈0.01）,ET-1mRNA的表达显著上调（P〈0.01）,Col-Ⅰ表达水平显著高于正常对照组（P〈0.01）,温阳活血方干预下,TGF-β1mRNA表达下调（P〈0.05）,VEGF mRNA表达显著上调（P〈0.01）,ET-1mRNA有下调趋势,Col-Ⅰ表达水平显著下调。结论：（1）马兜铃酸可促进肾小管上皮细胞转分化的发生。（2）温阳活血方具有拮抗肾小管上皮细胞转分化作用。     

MicroRNAs, development of Barrett��s esophagus, and progression to esophageal adenocarcinoma

Barrett’s esophagus is a premalignant condition caused by gastroesophageal reflux. Once developed, it can progress through varying grades of dysplasia to esophageal adenocarcinoma. Whilst it is well accepted that Barrett’s esophagus is caused by gastroesophageal reflux, the molecular mechanisms of its pathogenesis and progression to cancer remain unclear. MicroRNAs (miRNAs) are short segments of RNA that have been shown to control the expression of many human genes. They have been implicated in most cellular processes, and the role of miRNAs in disease development is becoming increasingly evident. Understanding altered miRNA expression is likely to help unravel the molecular mechanisms that underpin the development of Barrett’s esophagus and its progression to cancer.     

白细胞介素-18促肾小管上皮细胞转分化的机制研究

目的探讨白细胞介素-18（IL-18）诱导体外培养的人近端肾小管上皮细胞转分化的细胞内信号的转导机制。方法应用细胞培养技术培养HK-2细胞。予不同浓度的p38MAPK通路特异性阻断剂SB203580预孵育细胞30min后,再加入IL-18共同培养。应用RT—PCR方法检测α-SMA mRNA的表达水平,ELISA方法测定细胞胞浆中α—SMA的表达水平。结果SB203580可呈剂量依赖性地抑制IL—18诱导的HK-2细胞α-SMA基因和蛋白的表达。结论阻断p38MAPK信号通路可明显抑制IL—18诱导的HK-2细胞转分化作用：p38MAPK通路可能是调控IL-18诱导的HK-2细胞转分化的主要信号通路之一。     

MicroRNAs, development of Barrett’s esophagus, and progression to esophageal adenocarcinoma

Barrett's esophagus is a premalignant condition caused by gastroesophageal reflux. Once developed, it can progress through varying grades of dysplasia to esoph-ageal adenocarcinoma. Whilst it is well accepted that Barrett's esophagus is caused by gastroesophageal reflux, the molecular mechanisms of its pathogenesis and progression to cancer remain unclear. MicroRNAs (miRNAs) are short segments of RNA that have been shown to control the expression of many human genes. They have been implicated in most cellul...     

Biology of human bone marrow stem cells

Abstract. The bone marrow is constituted of two separate and distinct stem cells. The hematopoietic stem cells (HSC) are responsible for the production and maintenance of all the mature blood cells. The mesenchymal stem cells constituted the bone marrow stroma. In this report we review our current understanding on both stem cell populations. We also discuss the recent unexpected degree of differentiation plasticity that have been reported recently and the impacts these new discoveries may have in stem cell therapy.     

Phenotypic characterization of multi-functional somatotropes, mammotropes and gonadotropes of the mouse anterior pituitary

The existence of bihormonal anterior pituitary (AP) cells co-storing growth hormone and either prolactin (mammosomatotrope) or gonadotropins (somatogonadotrope) has been described. These cells have been proposed to be involved in paradoxical secretion [secretion of an AP hormone induced by a non-related hypothalamic releasing factor (HRH) and transdifferentiation (a phenotypic switch between different cell types without cell division]. Here we combine calcium imaging (to assess HRH responsiveness) and multiple sequential immunoassay of the six AP hormones to perform a single-cell phenotypic study of multifunctional somatotropes, mammotropes and gonadotropes in the normal male and female mouse pituitaries. AP cell phenotypes differed from the classic view, showing multiple HRH-receptor expression and/or hormone storage. Mammosomatotropes represented only 5–6% of somatotropes and were poorly responsive to HRHs, suggesting that their contribution to paradoxical secretion should be very limited. Somatogonadotropes were present only in females and contained adrenocorticotropic hormone. They responded to growth hormone-releasing hormone but failed to respond to gonadotropin-releasing hormone (LHRH). Other polyhormonal cells identified include (1) gonadocorticotropes, restricted to females, where they make up more than 50% of all the gonadotropes and contain other AP hormones; (2) gonadomammotropes, which are present preferentially in female cells and respond to LHRH; and (3) gonadothyrotropes, which are present similarly in male and female pituitaries.     

混合培养对骨髓基质细胞转分化为神经元的影响

目的　研究神经干细胞(NSCs)与骨髓基质细胞(BMSCs)混合培养对骨髓基质细胞转分化为神经元的 影响。　方法　将BMSCs传代培养2d,10μg LbFGF预诱导过夜,DAPI标记后加入到已贴壁分化2d的NSCs中,神 经元培养基混合培养7d后进行神经元特异性烯醇化酶(Nse)染色。对照组于BMSCs传代2d后,一组加bFGF处理 过夜,另一组不加,神经元培养基培养7d后NSE染色。　结果　实验组中部分BMSCs呈NSE染色强阳性,比例为 (13.38±5.79)%,对照组呈NSE阴性　结论　NSCs与BMSCs混合培养可诱导BMSCs转分化为神经元。     

缬沙坦抑制人类肾小管上皮细胞转分化的初步研究

目的：探讨血管紧张素ⅡⅠ型受体拮抗剂缬沙坦（ｖａｌｓａｒｔａｎ,Ｖａｌ）在人类肾小管上皮细胞系（ＨＫＣ）转分化中的作用。方法将培养的ＨＫＣ细胞分为（１）无血清培养培养对照组;（２）阳性对照组（ＭＣＰ－１＋ＡＡＩ组）：培养液中加入马兜铃酸－Ｉ（ＡＡＩ）和单核细胞趋化蛋白－１）ＭＣＰ－１）：（３）Ｖａｌ组：培养液中加入Ｖａｌ;（４）ＭＣＰ－１＋ＡＡＩ＋Ｖａｌ组。应用间接酶标免疫组织化学方法（ＩＥＩ）检