[Initial research for effects of vasoactive intestinal polypeptide (VIP) on differentiation of human umbilical cord blood derived CD34+ cells into hepatic related cells].
OBJECTIVE
To investigate the effect of vasoactive intestinal polypeptide (VIP) on differentiation of hematopoietic stem cells (HSC) into hepatic related cells and probe into the possibility that VIP affects HSC transdifferentiation.


METHODS
Mini MACS assay was used to purify human CD34+ cells from mononuclear cell (MNC), the purity of the CD34+ cells was evaluated by flow cytometry. Alpha fetal proteins(AFP) in cultured CD34+ cells and their supernatant were measured with ELISA assay. Liver tissue markers on CD34+ cells, AFP, albumin (ALB) and CK-19, were measured by immunohistochemistry. Western blot assay was used to detect the expression of ALB on CD34+ cells. Nest RT-PCR was used to measure the expression of AFP mRNA and ALB mRNA on CD34+ cells, the product of ALB was chosen to measure the sequence.


RESULTS
Immunohistochemistry showed that human CD34+ cell contained AFP and albumin but no CK-19 protein. When human CD34+ cells were cultured with VIP for 14 days, the concentration of AFP within CD34+ cells was decreased from (270.00 +/- 11.37) pg/mL to (165.00 +/- 8.51) pg/mL (P < 0.05). Western blot revealed that albumin in CD34+ cells treated with VIP faded, compared to that of control. Both human cord blood MNC and CD34+ cells expressed AFP mRNA and albumin mRNA; the sequence of the product of nest RT-PCR for albumin matched completely with the sequence of albumin in GenBank.


CONCLUSIONS
Human cord blood CD34+ cells have been note to express hepatocyte related markers such as AFP and albumin, although there is no evidence of CK-19 expression. These findings suggests the possibility that human HSC could be transdifferentiated into hepatocyte. The expressions of AFP and albumin on human CD34+ cells depressed by VIP indicate that VIP might inhibit the transdifferentiation of HSC.
Wang
Li
L
Division of Peptides Related with Human Diseases, State Key Laboratory of Biotherapy of Human Disease, West China Hospital, Sichuan University, Chengdu 610041, China.
Tang
Cheng-wei
CW
Wang
Chun-hui
CH
Li
Xian
X
Qiang
Ou
O
Huang
Ming-hui
MH
D000418:Albumins / Q000096:biosynthesis / Q000235:genetics; D018952:Antigens, CD34 / Q000378:metabolism*; D001483:Base Sequence; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D022781:Hepatocytes / Q000166:cytology*; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*; D000509:alpha-Fetoproteins / Q000096:biosynthesis / Q000235:genetics
D000418:Albumins; D018952:Antigens, CD34; D012333:RNA, Messenger; D000509:alpha-Fetoproteins; D014660:Vasoactive Intestinal Peptide