Lupp A, Lucas N, Lindström-Seppä P, Koponen K, Hänninen O, Danz M, Klinger W
Institute of Pharmacology and Toxicology, Friedrich Schiller University Jena, Germany.
Exp Toxicol Pathol. 1998 Mar;50(1):41-51. doi: 10.1016/S0940-2993(98)80064-X.
In the present study, the developmental expression of three cytochrome P450 (P450) isoforms, 1A1, 2B1 and 3A2, and the ability to store glycogen was investigated in intrasplenic liver cell explants in comparison to adult and fetal liver. Fetal liver tissue suspensions were transplanted into the spleens of adult male syngenic Fisher inbred rats. Animals were sacrificed at 3 days, 1, 2, 4 weeks, 2, 4, 6 months and 1 year after transplantation. Spleens and livers of transplant recipients were compared to those of sham operated and control rats. Three days after transplantation little bulks of hepatocytes and only few bile ducts were seen in the red pulp of the transplant containing spleens. A massive hypertrophy and proliferation of bile ducts and also an augmentation in the number of hepatocytes were observed 4 weeks after transplantation. One month later, however, the bile ducts had become more and more atrophic, while instead the number of hepatocytes continuously increased. One year after surgery large masses of hepatocytes with apparent cord structure and only few but well preserved bile ducts were seen. Within the livers of adult rats, P450 1A1 was only slightly expressed by some hepatocytes around the central veins. P450 2B1 and 3A2 isoforms expression was much stronger, but also predominantly located in the hepatocytes of the central zone of the liver lobule. Hepatocytes of fetal livers displayed a moderate P450 1A1 expression. In some cells also a very mild staining for P450 2B1 and 3A2 was observed. Within the hepatocytes of the intrasplenic liver cell explants P450 1A1 was still expressed 3 days after transplantation, disappeared at 1 week after surgery, but reappeared at 4 weeks after transplantation. After 2, 4 and 6 months no staining for P450 1A1 was detectable any more. One year after transplantation again a slight P450 1A1 expression appeared. With P450 2B1 and 3A2 a mild to moderate expression was seen already at 3 days after transplantation. Four weeks after surgery nearly all of the hepatocytes were stained for P450 2B1 and 3A2, but there were marked differences between the individual cells in the extent of the expression of these two P450 subtypes, like it was also the case with normal adult liver. Within hepatocytes of the fetal livers strongly stained glycogen granules were seen, which, in comparison to adult livers, were rather coarse-grained. Three days after transplantation the glycogen granules in the transplanted hepatocytes were still coarse-grained, but from 1 week after transplantation on, they became more and more fine-grained. As it was also the case with normal adult liver cells, there were marked differences between the individual transplanted hepatocytes in their glycogen content. These results demonstrate that transplanted liver cells originating from syngenic fetal liver tissue suspensions can survive in host organs like the spleen for at least 1 year. They proliferate, differentiate, are able to store glycogen, and express different P450 isoforms, like normal adult liver cells.
在本研究中，与成年和胎儿肝脏相比，研究了三种细胞色素P450（P450）同工型1A1、2B1和3A2在脾内肝细胞外植体中的发育表达以及储存糖原的能力。将胎儿肝脏组织悬液移植到成年雄性同基因Fisher近交系大鼠的脾脏中。在移植后3天、1周、2周、4周、2个月、4个月、6个月和1年处死动物。将移植受体的脾脏和肝脏与假手术和对照大鼠的脾脏和肝脏进行比较。移植后3天，在含有移植组织的脾脏红髓中可见少量肝细胞团，仅有少数胆管。移植后4周观察到胆管大量肥大和增生，肝细胞数量也增加。然而，1个月后，胆管变得越来越萎缩，而肝细胞数量持续增加。手术后1年，可见大量具有明显索状结构的肝细胞，仅有少数但保存良好的胆管。在成年大鼠肝脏中，P450 1A1仅在中央静脉周围的一些肝细胞中轻微表达。P450 2B1和3A2同工型的表达更强，但也主要位于肝小叶中央区的肝细胞中。胎儿肝脏细胞显示出中等程度的P450 1A1表达。在一些细胞中也观察到P450 2B1和3A2的非常轻微的染色。在脾内肝细胞外植体的肝细胞中，P450 1A1在移植后3天仍有表达，手术后1周消失，但在移植后4周再次出现。在2个月、4个月和6个月后，不再能检测到P450 1A1的染色。移植后1年，再次出现轻微的P450 1A1表达。对于P450 2B1和3A2，在移植后3天就可见轻度至中度表达。手术后4周，几乎所有肝细胞都被P450 2B1和3A2染色，但这两种P450亚型在个体细胞中的表达程度存在显著差异，正常成年肝脏也是如此。在胎儿肝脏细胞中可见强烈染色的糖原颗粒，与成年肝脏相比，这些颗粒相当粗大。移植后3天，移植肝细胞中的糖原颗粒仍然粗大，但从移植后1周开始，它们变得越来越细小。与正常成年肝细胞一样，个体移植肝细胞的糖原含量也存在显著差异。这些结果表明，源自同基因胎儿肝脏组织悬液的移植肝细胞能够在脾脏等宿主器官中存活至少1年。它们增殖、分化，能够储存糖原，并表达不同的P450同工型，如同正常成年肝细胞一样。
