In vitro transformation of adult rat hepatic progenitor cells into pancreatic endocrine hormone-producing cells.
OBJECTIVE
Pancreatic and duodenal homeobox factor 1 (Pdx-1) plays an important role in initiating differentiation toward pancreatic endocrine cells. The transdifferentiation or transformation of hepatocytes into pancreatic endocrine cells could be feasible, due to their similar cellular origins. Our goal in this study was to see if small hepatocytes (SHs) could give rise to pancreatic endocrine cells via exogenous Pdx-1 gene expression.


METHODS
SHs were cultured for 10 days before adenovirus (Adt)-mediated Pdx-1 gene transfection. We performed western blot analysis for pancreatic transcription factors in the nuclei and reverse-transcription polymerase chain reaction (RT-PCR) for the gene expression of pancreatic endocrine hormones. Confocal laser microscanning analysis was used to observe the transformation of SHs.


RESULTS
Pancreatic transcription factors such as Pdx-1, Ngn3, NeuroD, Nkx2.2, and Pax6 were induced after Adt-Pdx-1 gene transfection. The mRNA expression of pancreatic endocrine hormones (insulin, glucagon, and somatostatin) was induced after the gene transfection. Pdx-1 was expressed in the nucleus, where the cells were positive for one or more of the hormones and cytokeratin (CK) 8. Some cells were positive for multiple hormones. The insulin level increased while the glucagon level decreased after the glucose loading test, depending on the glucose concentration.


CONCLUSIONS
SHs are transformed into functional pancreatic endocrine cells after Pdx-1 gene transfection.
First Department of Surgery, Sapporo Medical University School of Medicine, S-1, W-16, Chuo-ku, Sapporo, Hokkaido 060-8543, Japan.
Hiroyuki
H
Kawasaki
Toru
T
Mizuguchi
Yamato
Y
Kikkawa
Hideki
H
Oshima
Yasushi
Y
Sasaki
Takashi
T
Tokino
Yasuo
Y
Kokai
Jun-Ichi
J
Miyazaki
Tadashi
T
Katsuramaki
Toshihiro
T
Mitaka
Koichi
K
Hirata
D000818:Animals; D002454:Cell Differentiation; D015870:Gene Expression; D005934:Glucagon / Q000032:analysis; D022781:Hepatocytes / Q000166:cytology*; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins / Q000235:genetics; D007150:Immunohistochemistry; D007328:Insulin / Q000032:analysis; D053533:Keratin-8 / Q000032:analysis; D008297:Male; D018613:Microscopy, Confocal; D010179:Pancreas / Q000166:cytology*; D010187:Pancreatic Hormones / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000032:analysis; D014162:Transfection / Q000379:methods
D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D007328:Insulin; D053533:Keratin-8; C000715628:Nkx2-2 protein, rat; D010187:Pancreatic Hormones; D015534:Trans-Activators; D014157:Transcription Factors; C084010:pancreatic and duodenal homeobox 1 protein; D005934:Glucagon