Co-localization of nestin and PDX-1 in small evaginations of the main pancreatic duct in adult rats.
OBJECTIVE
Pancreatic stem cells are powerful tools for future gene/cell therapy for diabetes, pancreatic carcinoma and chronic pancreatitis. However, it is unclear where the pancreatic stem cells exist in adult pancreas. To identify the pancreatic stem cells, we have focused on a homeodomain-containing transcription factor, pancreatic/duodenal homeobox-1 (PDX-1), and an intermediate filament protein, nestin, which are important candidates of pancreatic stem cell markers.


RESULTS
We investigated the immunohistological localization for PDX-1 and nestin in adult rat pancreas. PDX-1 staining was detected in small evaginations of the main pancreatic duct and in nuclei of islet cells. Nestin staining was also detected in small evaginations of the main duct, islets and spindle-shaped cells in the connective tissue around the main duct. These spindle-shaped cells were also positive for alpha-smooth muscle actin, the marker of myofibroblasts. Confocal laser microscopy study showed that nestin and PDX-1 are co-localized not only in a subset of cells in small evaginations of the main duct but also in a few cells in the islets. These cells of the main duct were also positive for the ductal cell marker, cytokeratin 19.


CONCLUSIONS
Our results suggest that the double positive cells for PDX-1 and nestin might be important candidates for pancreatic stem cells in adult rats.
Taguchi
Masashi
M
Third Department of Internal Medicine, University of Occupational and Environmental Health, Japan 5 School of Medicine, Kitakyushu 807-8555, Japan.
Otsuki
Makoto
M
D000818:Animals; D015415:Biomarkers; D018398:Homeodomain Proteins / Q000378:metabolism*; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D064231:Nestin; D010183:Pancreatic Ducts / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism*
D015415:Biomarkers; D018398:Homeodomain Proteins; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein