Human albumin mRNA was specifically expressed after injury in the human stem cell–engrafted NOD/SCID mouse liver.
Total cellular RNA was extracted from the human-mouse chimeric hepatocytes plus injured and noninjured controls, and Oligo (dT) was used to prime first-strand synthesis from equivalent levels of RNA. Human-specific albumin primers were used for PCR in comparison with human and murine-specific β2M, and amplifications were halted in log phase. Nontransplanted NOD/SCID mouse liver, including injured (CCl4-treated) mouse liver, did not express human albumin. There was no albumin expression in human cord blood mononuclear cells, or in the purified CD34+38−or CD34+ starting populations. There was no albumin expression in the human-mouse chimeric liver, marrow, or spleen in the absence of injury. However, in the human-mouse chimeric liver, CCl4 treatment induced human albumin expression. There was increased albumin expression after rhHGF was injected into mice that underwent stem cell transplantation that had received liver damage. HepG2 was used as positive control. Human β2M (Hβ2M) and murine β2M (Mβ2M) were internal controls for densitometry. RNA analyses were repeated 4 times, using different samples, with the same results. The first lane shows molecular weight markers.
