Search

BACKGROUND Human placental mesenchymal stem cells (hPMCs) are thought to be multipotent, but their fate after in utero transplantation is not known. METHODS hPMCs isolated from term placenta were assessed for their phenotype markers, mutilineage capacity, and immunomodulatory properties. Their engraftment potential was analyzed in a pregnant rat model after in utero transplantation at embryonic day 17. Immunohistochemistry, tracing of labeled cells, fluorescence in situ hybridization and real-time PCR were used to assess post-transplant chimerism. RESULTS In vitro, lineage-negative, CD34-negative hPMCs differentiated into osteocytes, adipocytes, hepatocytes and endothelial cells with tube formation, and actively suppressed the rat lymphocyte proliferative response to allogeneic lymphocyte stimulation (P in utero transplantation into pregnant rats, a low level of engraftment was achieved in various fetal tissues. Engraftment occurred in more than 60% of the fetal rats. Cells persisted for at least 12 weeks after delivery and evidence was obtained to suggest differentiation into specific lineages, including hepatocytes and hematopoietic cells. However, a greater number of hPMCs migrated to the placenta than to the fetus, thus limiting the degree of cell engraftment in fetal organs. CONCLUSIONS We conclude that hPMCs are mutipotent cells that can be engrafted long-term in immunocompetent rats after in utero transplantation. [ABSTRACT FROM AUTHOR]

Purpose: Zoledronic acid (ZOL), an effective nitrogen-containing bisphosphonate used to prevent excessive bone loss in clinical practice, has been shown to affect the development of dendritic cells by redirecting differentiation toward a state of atypical maturation. The study was aimed to examine whether ZOL can reduce acute rejection of skin allografts. Methods: A skin transplantation model using C57BL/6 to BALB/c mice was used. ZOL was injected intraperitoneally into transplant recipients post-surgically. Graft survival, body weight, leukocyte count, hepatic and renal functions were assessed. Results: ZOL treatment significantly prolonged skin allograft survival in mice. In terms of toxicity, there were no significant differences in body weight, leukocyte count, plasma alanine aminotransferase or creatinine levels between the ZOL-treated and control groups. Histopathology showed that the loss of skin integrity seen in control group was prevented by ZOL treatment. In draining lymph nodes and spleen, the number and clustering extent of mononuclear cells were markedly declined by ZOL treatment. The plasma IL-6 levels were reduced by treatment of ZOL. Conclusion: ZOL can prolong skin allograft survival without major toxicity. [ABSTRACT FROM AUTHOR]