Human placenta-derived mesenchymal stem cell (hPMSC), a promising source of MSCs, has biological characteristics similar to those of BMSC and is readily available from a rich source through noninvasive methods, is free of ethical issues, and has a higher differentiation capacity and lower immunogenicity, as well as other advantages [11-14].
In this study, we used hPMSCs with green fluorescent protein ([GFP.sup.+] hPMSCs) and the corresponding imaging modality to provide a novel approach to continuously track and quantify the fate of hPMSCs in vivo, investigated the effect of [GFP.sup.+] hPMSCs on hepatic fibrosis in a carbon tetrachloride(C[Cl.sub.4-]) induced fibrotic rat model , and provided an experimental and theoretical basis for the clinical use of hPMSC transplantation for the treatment of liver diseases.
The animals were randomly divided into three groups as follows: group I (saline control group, n = 24), which received saline instead of carbon tetrachloride injection and cell transplantation (passages 3 to 6; 2.0 x [10.sup.6] hPMSCs in 1 mL saline) by caudal vein injection; group II (hPMSC-treated group, n = 24), fibrosis models with hPMSC transplantation via the caudal vein (passages 3 to 6; 2.0 x [10.sup.6] hPMSCs in 1 mL saline); and group III (untreated fibrosis group, n = 24), which received saline by caudal vein injection instead of cell transplantation.
Human AFP, ALB, and CK18 mRNA were not detected in the livers at 1 week after hPMSC transplantation, which was also confirmed by immunohistochemistry.
As shown in Figure 5, in group II, positive staining for AFP, ALB, and CK18 was not observed in any liver specimen at 1 week after hPMSC transplantation.
In the present study, levels of [alpha]-SMA in the rat liver significantly decreased after hPMSC transplantation.
Caption: FIGURE 1: Human placental mesenchymal stem cell (hPMSC) morphology and phenotype profile.
TABLE 1: Candidate metabolites with significant changes between the hPMSC and [GFP.sup.+]hPMSC samples detected by isotope labeling liquid (a) chromatography-mass spectrometry (CIL LC-MS) analysis.
Our previous studies showed that transfection of human placental mesenchymal stem cells (hPMSCs) with the GFP gene did not affect their viability, phenotype profile, or pluripotency .
Here, we report the development and application of an effective metabolite extraction protocol, along with a highly sensitive metabolomic profiling method based on chemical isotope labeling liquid chromatography-mass spectrometry (CIL LC-MS) to investigate whether GFP gene transduction and expression impacts the metabolism of hPMSCs. High coverage of metabolites was achieved, which allowed better understanding of the potential cellular disturbances induced by GFP labeling.
The culture and labeling of hPMSCs were performed according to previously reported protocols [5, 10].