GATA-2过表达对小鼠胎肝造血干细胞功能的影响

本研究探讨GATA-2过表达对小鼠胎肝造血干细胞功能的影响。应用带GFP绿荧光的逆转录病毒载体介导的病毒感染实验将GATA-2基因引入小鼠胎肝细胞,通过流式免疫荧光术、细胞周期检测及集落形成实验等技术手段研究这些GATA-2过表达胎肝造血干细胞的生物学功能变化。研究结果表明:过表达GATA-2的胎肝细胞中Lin-Sca1+C-Kit+(LSK)细胞比例显著增加,LSK细胞周期未受太大影响,但其定向克隆形成能力受抑。结论:过表达GATA-2引起小鼠胎肝造血干细胞LSK比例增加,并抑制其定向分化能力,其机制可能与HES-1表达上调导致细胞在干/祖细胞阶段受阻滞有关。     

Rictor在胚胎期肝脏造血干细胞中的作用研究

目的:观察Rictor在血细胞特异敲除后对胎肝造血的影响。方法:取实验组Vav-Cre;Rictorf/f小鼠和对照组Rictorf/+或Rictorf/f小鼠E12.5 0.08ee胎肝细胞进行骨髓重建移植实验,观察Rictor敲除对造血干细胞重建造血能力的影响。同时,实验组和对照组小鼠分选E14.5胎肝细胞0, 10, 20, 40, 60, 80个造血干细胞进行极限稀释移植实验,检测Rictor敲除后具有重建造血能力的造血干细胞的数量。进一步进行细胞周期实验以及流式细胞术分选E12.5通过一次移植成功重建造血的供体细胞进行二次移植实验,检测Rictor敲除对造血干细胞自我更新能力的影响。结果:骨髓重建造血实验结果显示,移植后4个月对照组Rictorf/+或Rictorf/f 8只受体小鼠全部重建造血功能,重建率为77.2%±11.1%,每个胎肝有57个LT-RU,实验组Vav-Cre;Rictorf/f 8只受体全部重建,重建率为37.0%±16.3%,每个胎肝8个LT-RU。极限稀释移植实验显示,移植后4个月对照组每17个SLAM细胞,实验组每39个SLAM细胞有1个具有重建造血能力的造血干细胞。二次移植实验证明,每只受体移植4×10~5供体细胞,1个月后对照组4只受体有2只重建,实验组0只重建。并且进一步证明实验组S/G2/M期细胞比率增加。结论:在胎肝造血过程中,特异敲除血细胞Rictor会导致重建造血能力降低,具有重建造血能力的造血干细胞数量下降,造血干细胞自我更新能力降低。     

内皮祖细胞对野百合碱诱导的肝静脉闭塞病的防治作用研究

目的:探讨内皮祖细胞对野百合碱诱导的小鼠肝静脉闭塞病的防治作用。方法:将C57BL/6小鼠随机分为3组:生理盐水组(n=15)、野百合碱组(n=15)、野百合碱+内皮祖细胞输注组(n=15)。灌胃后d 8检测各组小鼠肝功能(TBIL、ALT、AST)、肝脏指数及TNF-α、IL-6水平;HE染色及免疫组织化学染色观察肝血窦内皮细胞、肝中央静脉内皮细胞及肝细胞的损伤情况,Masson染色了解肝脏纤维化的程度。结果:在光学显微镜下可见野百合碱组小鼠肝脏中至重度肝血窦内皮细胞、中央静脉内皮细胞损伤及肝小静脉淤血;Masson染色可见中至重度肝中央静脉、肝血窦纤维化。野百合碱+内皮祖细胞组在光学显微镜下可见小鼠肝血窦内皮细胞和中央静脉内皮细胞损伤;Masson染色可见肝中央静脉和肝血窦纤维化为轻度至中度,肝小静脉淤血减轻。与野百合碱+内皮祖细胞组小鼠相比,野百合碱组小鼠肝脏指数升高,肝功能异常明显,且野百合碱组小鼠的血清TNFα、IL-6表达水平更高。结论:野百合碱诱导的肝血窦内皮及中央静脉内皮细胞损伤是肝静脉闭塞病的始发因素,内皮祖细胞输注可以起到防治肝静脉闭塞病的作用。     

DIC患者的血浆可溶性E-选择素水平

像白细胞一样,细胞激素如TNF-α和IL-1β通过激活内皮细胞对败血症的发病机理非常重要。这些细胞激素增加组织因子的表达,组织因子在内皮细胞表面激活外凝血系统途径,减少血栓调节蛋白活性及氨基葡聚糖含量,和减少内皮细胞抗血栓形成能力。内皮细胞E-选择素(E-Selectin),一种能激活中性粒细胞粘附到内皮细胞的内皮白细胞粘稠分子表达也增加。在中性粒细胞引起内皮细胞损伤中,E-选择素介导激活的中性粒细     

小鼠肝窦内皮细胞损伤在肝静脉闭塞病中的作用研究

本研究探讨野百合碱诱导的小鼠肝窦内皮细胞损伤在肝静脉闭塞病中的作用。将BALB/c小鼠随机分为2组,即生理盐水组(n=15)和野百合碱组(n=15),分别按10 ml/kg和200 mg/kg灌胃,连续3 d。灌胃后第3、4、6、8和10天检测各组小鼠肝功能(总胆红素、丙氨酸转氨酶、碱性磷酸酶)、肝脏指数及活化血小板比例;HE染色、Masson染色及免疫组织化学染色观察肝细胞及肝窦内皮细胞的损伤情况、肝脏纤维化程度等;电子显微镜观察肝窦内皮细胞损伤、炎细胞浸润及血小板聚集情况。结果显示,野百合碱组与生理盐水组相比在光学显微镜和电子显微镜下均可见肝窦内皮细胞损伤、大量血小板黏附和聚集、中央静脉和肝血窦纤维化;与生理盐水组相比,野百合碱组外周血活化血小板比例升高(P<0.05),肝脏指数升高(P<0.05),肝功能异常并有腹水形成。结论:野百合碱诱导的肝窦内皮细胞损伤是肝静脉闭塞病的始动因素,且该肝窦内皮细胞损伤可能具有自限性,但纤维化持续存在。     

Wnt、Notch信号参与造血微环境调控造血机制的研究

目的 探讨造血发育过程中Wnt和Notch信号通路参与造血微环境调控造血的机制.方法 磁珠分选法分离小鼠骨髓c-kit~+造血干/祖细胞(HSPC).贴壁培养法分离小鼠孕10.5 d主动脉-中肾-肾上腺(AGM)区,孕12.5 d、14.5 d、16.5 d胎肝以及骨髓来源的基质细胞.通过Transwell共培养以及流式细胞术计数,比较不同来源基质细胞支持HSPC增殖的能力.通过实时定量PCR和免疫荧光动态检测各发育阶段基质细胞中Wnt、Notch Mrna和蛋白的表达.结果 体外培养7 d,AGM区和胎肝基质细胞培养体系中c-kit~+细胞数由0.4×10~5/孔分别扩增为(19.2±3.2)×10~5/孔和(26.8±5.4)×10~5/孔,明显高于骨髓基质细胞培养体系的(9.6 ± 2.9)×10~5/孔(P＜0.05);其中,AGM区和骨髓基质细胞培养体系中c-kit~+细胞比例分别为(75.2 ± 7.1)%和(74.1 ± 6.2)%,明显高于胎肝基质细胞培养体系的(63.4±5.3)%(P＜0.05).Wnt、Notch在各阶段基质细胞均有表达,Wnt在AGM区和胎肝基质细胞表达水平较高,Notch在AGM区及骨髓基质细胞表达水平较高(P＜0.05).结论 造血发育过程中,造血微环境通过Wnt与Notch信号通路协作、交替、整合,精密调控HSPC的发育.     

透明质酸支架构建工程化肝组织小块的初步研究

目的探索肝窦血管内皮细胞和肝细胞与透明质酸支架复合后构建工程化肝组织小块的可行性。方法分离小鼠肝细胞和肝窦血管内皮细胞，分别种植于透明质酸海绵状支架上培养，形成支架材料-细胞复合体，植于小鼠肝包膜下肝组织表面。2周后将支架取出观察植入效果。结果分离获得的肝细胞和肝窦血管内皮细胞活力较高。构建的支架-细胞复合物植入体内后与宿主肝组织紧密融合，可见移植物内有微血管形成，血管周围肝细胞聚集生长，结构类似正常肝组织。结论利用透明质酸支架复合肝窦血管内皮细胞和肝细胞构建工程化肝组织小块的方法可行。     

E-选择素与消化道肿瘤关系的研究进展

E-选择素是黏附分子选择素家族成员之一,为内皮细胞选择素,仅于活化内皮细胞表面表达,是炎症过程中最初出现的黏附分子,E-选择素介导活化的内皮细胞与中性粒细胞黏附的作用,还能介导内皮细胞与单核细胞、记忆T细胞、嗜酸及嗜碱粒细胞、血液树突状淋巴细胞、前T细胞、成人T细胞性白血病细胞等的合成;内皮细胞上E-选择素可锚定白细胞,继而介导其活     

VEGFA、VEGFC及其受体和angiopoietin-1/angiopoietin-2及其受体在发育第3-12周人胚胎肝的表达

本研究观察VEGFA和VEGFC及其受体和angiopoietin-1／angiopoietin-2及其受体在发育第3—12周人胚胎肝的表达。在征得意外流产孕妇同意并签字后，收集其意外流产受精龄为第3—12周的人胚胎，4％多聚甲醛固定，石蜡包埋切片，HE和免疫组织化学染色，光镜观察。结果表明：在发育第4周，肝由少量肝索组成，肝内未见造血细胞和血细胞。肝内大、圆、有核的原始血细胞于发育第5周开始出现，并强表达VEGFA、flt-4和Tie-2，其数量在发育第7周达高峰。第11—12周，阳性细胞数量减少。这类细胞仅于发育第6周时短暂表达Flk-1。第7—12周，肝细胞表达VEGFC和flt-1，阳性反应产物积聚在细胞质中。发育第5周到第12周胚胎肝血管内，有angiopoie—tin-1和angiopoietin-2阳性反应的细胞存在，细胞形态同上述VEGFA、fkt-4和Tie-2阳性细胞。angiopoietin-1和angiopoietin-2阳性反应较弱，Tie-2的免疫反应强。发育各期，肝细胞也弱表达angiopoietin-1和angiopoiefin-2和Tie-2。发育各期血管内皮细胞为上述各种因子和受体阴性反应。结论：发育第7周之前和第7周之后，VEGF家族及其受体在肝内造血灶的细胞表达模式不同。胎肝造血与肝细胞的发育可能相关。     

Adhesion molecule behavior during rejection and infection episodes after heart transplantation.

In cardiac transplant recipients the release of soluble cellular adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-Selectin into serum is pronounced during immune activation. It is uncertain whether there is a specific pattern of release during infection or cardiac allograft rejection. In a prospective study, 30 consecutive cardiac allograft recipients were followed for a median period of 11.4 months (range 1-34). Soluble ICAM-1 (sICAM-1), soluble VCAM-1 (sVCAM-1) and soluble E-Selectin (sE-Selectin) were measured in addition to acute phase proteins (C-reactive protein, alpha1-antitrypsin), complement factors (C3, C4) and beta2-microglobulin. The measured serum levels were correlated with the clinical status of the transplant recipient: 1) uneventful clinical status; 2) asymptomatic infection; 3) symptomatic infection and 4) rejection. Forty age-matched healthy subjects served as controls. Six days before biopsy-proven cardiac allograft rejection sICAM-1-release started to increase (p < 0.05) as compared to uneventful clinical status. The peak concentration of sICAM-1 was measured three days before rejection. On the day of rejection, serum concentrations of sICAM-1 (p < 0.001) and sVCAM-1 (p < 0.05) were increased, whereas sE-Selectin was not markedly elevated. In symptomatic infections, the serum concentrations of sICAM-1 (p < 0.001) and sVCAM-1 (p < 0.05) were elevated at the day of diagnosis and both parameters reached peak levels three days after onset of chemotherapy. In multivariate analysis soluble adhesion molecules only weakly discriminated between rejection and infection (sensitivity: 13%, specificity: 95%). Although, in combination with routine blood parameters the discriminatory power could be improved (sensitivity: 85%, specificity: 85%) the clinical utility of these markers in non-invasive monitoring is limited.     

上皮型钙粘蛋白在小鼠胚胎干细胞体外分化中动态表达及与细胞黏附状态关系

背景:体内胚胎期,上皮型钙粘蛋白对肝脏组织的发育起到决定作用,探讨其在胚胎干细胞分化中的动态表达对于肝脏组织的体外发育可行性具有重要意义.目的:观察上皮型钙粘蛋白在小鼠胚胎干细胞体外分化过程中的动态表达,及其与细胞间黏附状态的关系.设计、时间及地点:细胞学体外观察,于2007-12/2098-12在中山大学附属第一医院外科实验室完成.材料:BALB/c系小鼠胚胎干细胞由中山大学眼科中心黄冰教授建系和保存.清洁级BALB/c系孕13 d小鼠20只,由中山大学实验动物中心提供.方法:BALB/c系小鼠胚胎干细胞克隆经胰酶消化后,利用含胎牛血清、2-巯基乙醇、HEPES、青霉素、链霉素的DMEM培养基悬浮培养,使其自然发育5 d形成拟胚体,第6天转至培养板使其贴壁生长.取BALB/c系孕13 d小鼠,取其胎鼠肝脏组织制备胎肝细胞及冰冻切片,作为对照组.主要观察指标:按胚胎干细胞初分化、拟胚体形成、细胞分化群落形成等阶段,于细胞分化第1,5,9,13,17天利用RT-PCR和免疫细胞化学法检测上皮型钙粘蛋白的表达,观察其表达水平与细胞黏附状态的关系.结果:RT-PCR检测结果显示,在胚胎干细胞自然分化系统中,上皮型钙粘蛋白mRNA于分化第1天未表达,在第5天拟胚体形成后表达最强,其后表达能力逐渐降低,至17 d时不再表达,作为对照的BALB/c系小鼠胎肝细胞表达较强的上皮型钙粘蛋白mRNA.免疫细胞化学检测结果亦体现相同规律.胚胎干细胞在形态学上由单细胞发育为致密的包含3胚层结构的拟胚体,再继续分化为松散的细胞群落.结论:上皮型钙粘蛋白在胚胎干细胞体外培养系统中的表达水平与分化细胞间黏附状态变化呈一定的相关性,其在体外环境中丧失表达可能是分化细胞不能组织化的一个重要原因.     

Circulating levels of adhesion molecules and markers of endothelial activation in acute inflammation induced by prolonged brisk exercise

OBJECTIVES: To investigate circulating levels of adhesion molecules and markers of endothelial activation in acute inflammation induced by prolonged brisk exercise. DESIGN AND METHODS: The circulating levels of adhesion molecules E-, L- and P-selectins, intercellular and vascular adhesion molecule-1 (ICAM-1 and VCAM-1), along with those of thrombomodulin (TM), N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and cardiac troponin T, were measured before, at the end of and at 48 h post-race, in athletes participating in this extreme physical stress paradigm. RESULTS: Levels of L- and P-selectins remained the same before and at the end of the "Spartathlon" race, presenting a similar decline at 48 h post-race. E-Selectin, ICAM-1 and TM reached a maximum value at the end of the race and returned to normal 48 h after the race. A similar profile was observed for VCAM-1 and NT-pro-BNP, with a tendency for a decrease at 48 h post-race, while troponin T was not detected. CONCLUSIONS: The indices of endothelial activation are strongly affected during "Spartathlon" race, suggesting that, although prolonged brisk exercise activates the endothelium, it rapidly recovers.     

慢性乙型肝炎血清可溶性L-选择素及细胞间粘附分子-1与肝功能损害的相关性研究

目的：探讨乙型肝炎患者血清可溶性L-选择素(L-Selectin)、可溶性细胞间粘附分子-1(ICAM-1)水平与肝功能损害的相关性。方法：应用ELISA法检测50例慢性乙型肝炎和10例正常人血清可溶性L-Selectin、ICAM-1的水平,同时检测肝功相关生化指标。结果：慢性乙型肝炎患者血清L-选择素和细胞间粘附分子-1水平均明显高于正常人,均与肝功能损害呈不同程度的正相关。结论：L-选择素和细胞间粘附分子-1均参与乙肝病毒感染后的肝功能损害过程,血清L-选择素和细胞间粘附分子-1特别是后者的水平可作为反映慢性乙肝患者肝功能损害程度的指标之一。     

胚胎干细胞源性肝干细胞肝内移植对宿主肝功能的影响及安全性评估

背景:体外诱导胚胎干细胞分化为肝细胞已有不少成功的报道,但其体内移植后能否有效整合入宿主肝板、在肝内能否进一步生长分化并表达肝细胞功能以及成瘤的风险等情况目前还不清楚.目的:应用治疗性肝再生模型进行胚胎干细胞源性肝干细胞肝内移植, 观察其在肝组织替代、体内的生长分化及成瘤性情况.设计:随机对照动物实验.单位:中山大学附属第二医院小儿外科.材料:选用BALB/c小鼠24只为受体,鼠龄6～8周,体质量20～ 35 g,雌雄不拘购自广州市实验动物中心.实验所用胚胎干细胞源性肝干细胞由作者所在课题组诱导胚胎干细胞分化而成.小鼠胚胎干细胞株E14由本院干细胞中心提供.方法:实验于2006-07/2007-06在中山大学附属第二医院干细胞研究中心完成.将24只小鼠随机分为2组:肝再生模型 干细胞移植组和肝切除 干细胞移植组,每组12只.前组分两次按50 mg/kg剂量腹腔内注射倒千里光碱(retrorsine) ,间隔2周,第2次注射4周后行70%肝部分切除制造肝损伤;然后经门静脉分别移植1×105羟基荧光素乙酰乙酸(CFDA-SE)荧光标记的细胞入小鼠肝内进行胚胎干细胞源性肝干细胞移植.后组在行70%肝部分切除制造肝损伤模型后进行胚胎干细胞源性肝干细胞移植.主要观察指标:荧光显微镜下观察移植细胞组受体鼠肝脏内分布、整合与体内生长分化情况.2周后行白蛋白荧光免疫组化(双荧光染色)、血清白蛋白水平检测其功能状况.将胚胎干细胞源性肝干细胞注入治疗性肝再生小鼠肝内,将未分化的胚胎干细胞移植入小鼠腋区皮下作为对照,观察胚胎干细胞源性肝干细胞体内成瘤情况.结果:①肝干细胞在受体鼠肝内生长情况:CFDA SE标记的胚胎干细胞源性肝干细胞肝内移植1周,受体小鼠肝实质内可见散在绿色荧光分布.2周后,肝实质内绿色荧光分布区域明显扩大,且可见类似肝索样结构排列.②肝功能:共焦白蛋白荧光免疫组化(双荧光染色)结果表明,受体小鼠肝组织内可见标记细胞表达白蛋白阳性信号(呈黄色荧光),肝再生模型 干细胞移植组和肝切除 干细胞移植组血清白蛋白水平则无明显差异(P > 0.05).③肝干细胞移植安全性:6周内未见畸胎瘤形成,而将未分化的胚胎干细胞移植入小鼠腋区皮下6周后则可见畸胎瘤形成.结论:胚胎干细胞源性肝干细胞移植入治疗性肝再生模型小鼠肝内后可有效在肝内能进一步生长分化并部分表达肝细胞功能;且此移植安全性较好.     

Certain batches of albumin solutions influence the expression of endothelial cell adhesion molecules

Objective: Increased levels of soluble adhesion molecules, a decreased PO₂/FIO₂ ratio and a tendency to worsened outcome have been reported following the use of human albumin in critical illness. The reasons are not yet understood. Since albumin solutions have previously been shown to contain proinflammatory mediators, a direct upregulation of adhesion molecules by contaminated batches may explain these findings. To examine this, we studied the effects of different albumin preparations on endothelial cell adhesion molecules in vitro. Design: Experimental study. Setting: Laboratory for cell biology. Methods: Human umbilical venous endothelial cell cultures (n = 4) were incubated for 6 h at 5 mg/ml with four different human albumin solutions (HA1–4) from different manufacturers. Medium served as the control. Using flow cytometry, the effects on E-selectin, ICAM-1 and VCAM-1 expression were determined on unstimulated cells and on cells stimulated with tumour necrosis factor α at 0.5 ng/ml for 4 h. Measurements and results: On unstimulated cells, HA1 and HA4, two different batches from the same manufacturer, increased ICAM-1 by 22 % and 15 %, respectively. After stimulation, both solutions resulted in a 19 % increased expression of E-Selectin. In addition, HA4 decreased VCAM-1 on stimulated cells (p≤ 0.05). Two albumin preparations from other manufacturers did not produce significant effects. Conclusions: Some albumin solutions directly modulate adhesion molecule expression on endothelial cells. This may, at least in part, explain the previous finding of increased soluble adhesion molecules and a decreased PO₂/FIO₂ ratio in critically ill patients undergoing volume replacement with human albumin. Received: 28 May 1999*Accepted: 14 September 1999     

恒河猴移植肝组织内细胞间黏附分子1与急性排斥反应的关系

背景:在急性排斥反应发生时会伴有移植组织中细胞间黏附分子1表达水平的增高。目的:探讨恒河猴移植肝组织内细胞间黏附分子1与急性排斥反应的关系。方法:建立恒河猴同种异体肝移植模型,随机分为实验组(移植后不给予抗排斥处理)和对照组(移植中及移植后均给予抗排斥处理)。结果与结论:实验组移植后24,72h血清丙氨酸氨基转移酶及血清总胆红素水平明显高于对照组(P<0.05或<0.001)。移植后12h实验组移植肝即表现为轻度急性排斥反应,说明急性排斥反应时肝功能变化滞后于肝组织病理学检查,移植后24,72h表现为中重度急性排斥反应。移植后6h实验组肝组织中血管内皮细胞、肝细胞膜、胆管上皮细胞上细胞间黏附分子1的表达呈持续增强,并显著高于对照组(P<0.05),随细胞间黏附分子1的表达增强,排斥反应加剧,说明在急性排斥反应早期,肝功能、病理学仅有轻微改变时,细胞间黏附分子1水平即显著升高。提示移植肝组织中细胞间黏附分子1表达的检测对肝移植后急性排斥反应的早期诊断具重要意义。     

Trauma-hemorrhagic shock-induced up-regulation of endothelial cell adhesion molecules is blunted by mesenteric lymph duct ligation

OBJECTIVE: Previous studies have shown that mesenteric lymph duct ligation prevents trauma-hemorrhagic shock-induced lung injury and neutrophil activation. Since endothelial cells rapidly express adhesion molecules, such as P-selectin and intercellular adhesion molecule-1, after shock, and because trauma-hemorrhagic shock-induced lung injury appears to involve neutrophil-endothelial cell interactions, we tested the hypothesis that lymph duct ligation would diminish trauma-hemorrhagic shock-induced P-selectin and intercellular adhesion molecule-1 expression in the lung and other organs. DESIGN: Prospective animal study with concurrent control. SETTING: Small animal laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: Four groups of male rats were studied: trauma (laparotomy) plus sham shock, trauma-sham shock plus lymph duct ligation, trauma-hemorrhagic shock (90 mins of shock at 30 mm Hg), and trauma-hemorrhagic shock plus lymph duct ligation. At 3 or 24 hrs after trauma-hemorrhagic shock or trauma-sham shock, lung, heart, liver, kidney, intestinal, and other visceral concentrations of P-selectin and intercellular adhesion molecule-1 expression were measured using the dual radiolabeled monoclonal antibody technique. MEASUREMENTS AND MAIN RESULTS: At 3 and 24 hrs, trauma-hemorrhagic shock increased endothelial cell P-selectin and intercellular adhesion molecule-1 adhesion molecule expression in the lung and liver. At 3 and 24 hrs after trauma-hemorrhagic shock, intercellular adhesion molecule-1 expression was increased in the heart, spleen, pancreas, intestine, and kidney, whereas at 24 hrs, but not 3 hrs, P-selectin expression also was increased in these organs. Lymph duct ligation prevented trauma-hemorrhagic shock-induced increased adhesion molecule expression in all of these organs with the exception of intestinal P-selectin expression. CONCLUSIONS: Trauma-hemorrhagic shock-induced increases in endothelial cell P-selectin and intercellular adhesion molecule-1 expression in the lung and liver as well as other tissues appear to be related to factors liberated from the ischemic gut and carried in intestinal lymph.     

胚胎干细胞源性肝干细胞肝内移植对宿主肝功能的影响及安全性评估

背景：体外诱导胚胎干细胞分化为肝细胞已有不少成功的报道，但其体内移植后能否有效整合入宿主肝板、在肝内能否进一步生长分化并表达肝细胞功能以及成瘤的风险等情况目前还不清楚。 目的：应用治疗性肝再生模型进行胚胎干细胞源性肝干细胞肝内移植．观察其在肝组织替代、体内的生长分化及成瘤性情况。 设计：随机对照动物实验。 单位：中山大学附属第二医院小儿外科。 材料：选用BALB／c小鼠24只为受体，鼠龄6～8周，体质量20～352，雌雄不拘购自广州市实验动物中心。实验所用胚胎干细胞源性肝干细胞由作者所在课题组诱导胚胎干细胞分化而成。小鼠胚胎干细胞株E14由本院干细胞中心提供。 方法：实验于2006-07／2007-06在中山大学附属第二医院干细胞研究中心完成。将24只小鼠随机分为2组：肝再生模型＋干细胞移植组和肝切除＋干细胞移植组，每组12只。前组分两次按50mg／kg剂量腹腔内注射倒千里光碱（retrorsine），间隔2周，第2次注射4周后行70％肝部分切除制造肝损伤；然后经门静脉分别移植1×10^5羟基荧光素乙酰乙酸（CFDA-SE）荧光标记的细胞入小鼠肝内进行胚胎干细胞源性肝干细胞移植。后组在行70％肝部分切除制造肝损伤模型后进行胚胎干细胞源性肝干细胞移植。 主要观察指标：荧光显微镜下观察移植细胞组受体鼠肝脏内分布、整合与体内生长分化情况。2周后行白蛋白荧光免疫组化（双荧光染色）、血清白蛋白水平检测其功能状况。将胚胎干细胞源性肝干细胞注入治疗性肝再生小鼠肝内，将未分化的胚胎干细胞移植入小鼠腋区皮下作为对照，观察胚胎干细胞源性肝干细胞体内成瘤情况。 结果：①肝干细胞在受体鼠肝内生长情况：CFDASE标记的胚胎干细胞源性肝干细胞肝内移植1周，受体小鼠肝实质内可见散     

Bovine gamma/delta T cells bind E-selectin via a novel glycoprotein receptor: first characterization of a lymphocyte/E-selectin interaction in an animal model

E-Selectin is an inducible adhesion protein expressed by endothelial cells and recognized by leukocytes during their extravasation from the blood into inflamed tissues. Originally, E-selectin was defined as a myeloid cell-specific adhesion protein, but recent studies have shown it to be recognized by human lymphocytes as well. These lymphocytes represent a memory T cell subset and have been shown to express the HECA-452 carbohydrate epitope (CLA+ lymphocytes). We extend these findings and show that ruminant gamma/delta T cells bind E-selectin as well; and we provide preliminary evidence that this interaction is mediated by a novel glycoprotein receptor on the lymphocyte. Unlike conventional T cells (alpha/beta T cells), gamma/delta T cells from neonatal and mature animals bind E-selectin, suggesting that prior antigen stimulation and differentiation to a memory lymphocyte are not required for this interaction. Neuraminidase treatment of the gamma/delta T cells or addition of ethylenediaminetetraacetic acid (EDTA) to the assay abrogates binding, demonstrating the importance of sialic acid and divalent cations, which is consistent with other E- selectin-mediated adhesion events. However, previously defined E- selectin carbohydrate ligands, such as sialyl Lewis x on neutrophils and the HECA-452 epitope on human memory lymphocytes, are antigenically different than the carbohydrates on ruminant gamma/delta T cells since the mAbs CSLEX and HECA-452 do not recognize these cells. Protease treatment of gamma/delta T cells significantly inhibits their binding to E-selectin; however, previously characterized adhesion glycoproteins, such as L-selectin, CD44, and CD18, are not involved in the adhesive event. An E-selectin affinity column purifies a single glycoprotein of 250 kD (280 kD under reducing conditions) from gamma/delta T cell detergent lysates. Neuraminidase digestion of the 250-kD product as well as EDTA abolishes binding to E-selectin. Finally, E-selectin expression in vivo appears to mediate gamma/delta T cell accumulation. Stimulation of bovine skin with tumor necrosis factor alpha induced an increase in E-selectin expression that was associated with an influx of gamma/delta T cells at the same site.