In recent studies, samples of human bone marrow were obtained by Lumbar Puncture (LP), human adipose tissue were obtained from abdominal subcutaneous adipose tissue of gastric cancer patients or liposuction patients, human peripheral blood were obtained from patients with HBV or healthy adult blood donors, in accordance with the local ethics committee.

Most laboratory data showed that BMSCs could be prepared through the density degree of centrifuge, flow cytometry sorting, and sidewall sieve method (11–14). side-wall sieve method has become popular one for its simple operation, lower cost, less injury to cell (15). Adipose tissue was minced with scissors and scalpels into less than 3mm pieces and isolation of ADSCs proceeded as previously described (16, 17). Generally, human peripheral blood monocytes isolated from donors were isolated by density gradient centrifugation and further purified by adherence separation. In order to obtain more PBSCs in shortly time, PBMCs were mobilized with recombinant G-CSF at 5∼10 μg/kg/d, administered subcutaneously daily to mobilize PBMCs from bone marrow to peripheral blood (18, 19). Then PBMCs were collected by means of aphaeresis.

Flow Cytometer was used to identify the surface marker of the adult stem cells. Conget et al indicated that the BMSCs express many surface agents including CD13, CD44, CD29, CD105, but didn’t express CD1a, CD14, CD31, CD34, CD56, CD45 (20). ASCs derived from all three sources displayed no expression of hematopoietic markers (CD14, CD34, CD45), of the stem cell marker CD133, or the marker for endothelial cells CD144. More than 90% of MSCs derived from the three sources expressed the typical MSC marker proteins CD44, CD73, CD29, and CD90. However, the intensity of expression of CD90 of PBSCs was significantly below that of the other tissues. More than 90% of the ASCs derived from all three sources expressed HLA I; however, none of the MSCs expressed HLA II. CD105 was expressed by a significantly lower percentage of PBSCs compared with BM- or AD-SCs, whereas, more PB- and BM-SCs expressed CD106 than ADSCs. ADSCs expressed similar surface markers to BMSCs (21, 22). Besides the fact, that they are more heterogeneous (23), they reveal a surface antigen marker profile (22, 24–26), and differentiation potential similar to BMSCs (27–32). ADSCs are characterized as CD45−, CD34+, CD105+, CD31-(33) (Table 1).

Some studies indicated that functional hepatocytes could be induced from ASCs by some cytokines or through coculture with other cell types. However, the potential of the ASCs’ transdifferentiation is generally low. Therefore, researchers are keen to explore new methods to induce ASCs differentiate into functional hepatocytes in vitro currently. The current protocols used in different ASCs are summarized in Table 2.

The hepatocyte-like cells from ASCs were confirmed from the gene and protein expression. Gene expressions were identified by RT-PCR, using the common markers of hepatocytes, including ALB, AFP, CK18, CK19, and CYP3A4 (34). Protein expressions were usually identified by immunohistochemistry or mmunofluorescence, western blot, from the expression of albumin, CK18, CYP3A4, CYP1A1, CYP2C9 and NADPH-P450 (35–38). To compare the potential of hepatogenic differentiation of the different adult stem cells in vitro, researches indicated ADSCs have a similar differentiation potential towards the hepatic lineage, similar to BMSCs. However, their longer culture period and proliferation capacity differ from the BMSCs (39–41).