[Show abstract][Hide abstract] ABSTRACT: To investigate intraperitoneal transplantation of microencapsulated hepatic-like cells from human umbilical cord blood for treatment of hepatic failure in rats.
CD34+ cells in umbilical cord blood cells were isolated by magnetic cell sorting. In the in vitro experiment, sorted CD34+ cells were amplified and induced into hepatic-like cells by culturing with a combination of fibroblast growth factor 4 and hepatocyte growth factor. Cultures without growth factor addition served as controls. mRNA and protein levels for hepatic-like cells were analyzed by reverse transcription-polymerase chain reaction, immunohistochemistry and immunofluorescence. In the in vivo experiment, the hepatic-like cells were encapsulated and transplanted into the abdominal cavity of acute hepatic failure (AHF) rats at 48 h after D-galactosamine induction of acute hepatic failure. Transplantation with PBS and unencapsulated hepatic-like cells served as controls. The mortality rate, hepatic pathological changes and serum biochemical indexes were determined. The morphology and structure of microcapsules in the greater omentum were observed.
Human albumin, alpha-fetoprotein and GATA-4 mRNA and albumin protein positive cells were found among cultured cells after 16 d. Albumin level in culture medium was significantly increased after culturing with growth factors in comparison with culturing without growth factor addition (P < 0.01). Compared with the unencapsulated group, the mortality rate of the encapsulated hepatic-like cell-transplanted group was significantly lower (P < 0.05). Serum biochemical parameters, alanine aminotransferase, aspartate aminotransferase and total bilirubin in the encapsulated group were significantly improvement compared with the PBS control group (P < 0.01). Pathological staining further supported these findings. At 1-2 wk post-transplantation, free microcapsules with a round clear structure and a smooth surface were observed in peritoneal lavage fluid, surviving cells inside microcapsules were found by trypan blue staining, but some fibrous tissue around microcapsules was also detected in the greater omentum of encapsulated group by hematoxylin and eosin staining.
Transplantation of microencapsulated hepatic-like cells derived from umbilical cord blood cells could preliminarily alleviate the symptoms of AHF rats.
Preview · Article · Feb 2011 · World Journal of Gastroenterology
[Show abstract][Hide abstract] ABSTRACT: To investigate the stepwise development and germ cell gene expression in allografted neonatal mouse testes and the differentiation of immature human testicular cells in xenografted human testes.
Immunodeficient nude mice were used as hosts for allografting of neonatal mouse testes and xenografting of human fetal testicular tissues. Stepwise development and stage-specific gene expression of germ cells in allografts were systematically evaluated and parallel compared with those in intact mice by periodically monitoring the graft status with measurement of graft weight, histological analysis and determination of five stage-specific genes. Human testicular tissues from 20 and 26 weeks fetuses were used for the xenografting study. Histological analysis of xenografts was performed 116 and 135 d after the grafting procedure.
In the allografting study, progressive increase in tissue volume and weight as well as in tubule diameter in grafts was observed; the appearance time of various germ cells in seminiferous tubules, including spermatogonia, spermatocytes, round and elongate spermatids and sperm, was comparable with that in intact donors; the initiation of gene transcription in grafts showed a similar trend as in normal mice. Graft weight ceased to increase after 7-8 weeks and degradation of grafts was observed after 5 weeks with progressive damage to seminiferous epithelium. In the xenografting study using immature human testicular tissues, graft survival and development was indicated by increasing graft weight, Sertoli cells differentiation into advanced stage, germ cells migration and location to the basal lamina and formation of a niche-like structure.
The developmental course and gene expression pattern of germ cells in allografts were similar to those in intact mice. The best time point for retrieval of mouse sperm from grafts was 5-7 weeks after grafting procedure. An accelerated development of immature human testicular cells could be achieved by ectopic xenografting of human testes.
No preview · Article · Aug 2006 · Asian Journal of Andrology
[Show abstract][Hide abstract] ABSTRACT: To explore the effect of the microenvironment induced by damaged mouse hepatic cells on the conversion of human umbilical cord blood-derived cells into hepatocyte-like cells.
A hepatic injury-like microenvironment was mimicked using carbon tetrachloride damaged mouse hepatic cells, where mononuclear cells (MNC) from human umbilical cord blood were cultured in a compartment separated by trans-well membrane. Histochemical staining, reversed transcription-polymerase chain reaction (RT-PCR) and gene sequencing were performed for the information on the conversion of human umbilical cord blood MNC.
A number of PAS positive stained cells in MNC co-cultured with damaged mouse hepatic cells were observed after 72 h. Cells expressing mature hepatocyte markers, human albumin (hALB) and human GATA-4 (hGATA-4) mRNA were detected by RT-PCR, which was further confirmed with sequencing. Relevant control groups, MNC co-cultured with normal mouse hepatic cells and MNC cultured alone remained negative.
The culture system using damaged mouse hepatic cells as stimulator could be a potential in vitro system for the conversion of human umbilical cord blood-derived cells into hepatocyte-like cells.
No preview · Article · Sep 2005 · Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences
[Show abstract][Hide abstract] ABSTRACT: To establish an in vitro model for the development of mouse spermatogenic cells into sperm by using the immunodefective mouse as the incubator.
Tissue grafting was performed using testis from 1-2 days old Kun-ming mice as donor tissue and immunodefective mice as recipients; the expression of TESK1 mRNA in grafts was determined by RT-PCR and the spermatogenesis further observed with histological analysis of grafts.
Molecular biological and histological analyses showed that grafts post-grafting not only expressed TESK1 mRNA as in normal mouse testis, but also exhibited similarities in the structure of seminiferous tubules and component of spermatogenic cells, including sperms.
Spermatogenic cells heterotopically grafted in vitro could continuously grow and complete spermatogenesis and finally develop into sperm.
No preview · Article · Jan 2005 · Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences