Isolation of mesenchymal stem cells from human vermiform appendix.
BACKGROUND
Recent findings have shown that pluripotent stem cells exist in areas outside the bone marrow (BM). Moreover, it has been demonstrated that the appendix is important for the development of mucosal gut immunity, and hematopoietic progenitors have been isolated from animal and human appendices.


METHODS
Non-inflamed appendices removed during laparotomy were processed and cultured until the appearance of adherent cells. Differentiations (performed under osteogenic, adipogenic, and myogenic conditions) were confirmed by immunohistochemistry and cytochemistry. Polymerase chain reaction and cytofluorimetric analyses were performed to evidence the presence of genes and protein specific lineages in appendix-derived mesenchymal stem cells (ADMCs).


RESULTS
ADMCs were present in non-inflamed appendices. ADMCs under osteogenic conditions differentiated in osteoblasts and showed increased alkaline phosphatase expression; at the gene level, we observed the expression of Core binding factor alpha 1 (Cbfa1) and osteocalcin in osteogenic induced ADMCs. Under adipogenic conditions, lipidic drops in the cytoplasm, expression of lipoprotein lipase (LpL), and peroxisome proliferator-activated receptor gamma were observed; under myogenic conditions, myotubes expressing muscle specific proteins like desmin were formed. Myogenic regulatory factor 4 and MyoD were selectively induced in the ADMCs under myogenic conditions.


CONCLUSIONS
This study shows for the first time that mesenchymal stem cells can be isolated from normal appendices obtained from a pediatric and adult age group (0-18 years of age). This finding not only may further knowledge of the maturation of the intestinal immunesystem but also could indicate a new physiological role of the human vermiform appendix.
De Coppi
Paolo
P
Laboratorio Trapianto del Midollo Osseo and Banca del Sangue di Cordone Ombelicale, Dipartimento di Oncoematologia Pediatrica, Padova, Italy. pdecoppi@hotmail.com
Pozzobon
Michela
M
Piccoli
Martina
M
Gazzola
Maria Vittoria
MV
Boldrin
Luisa
L
Slanzi
Elisa
E
Destro
Roberta
R
Zanesco
Luigi
L
Zanon
Giovanni Franco
GF
Gamba
Piergiorgio
P
D000293:Adolescent; D001065:Appendix / Q000166:cytology* / Q000254:growth & development / Q000601:surgery*; D002454:Cell Differentiation; D002455:Cell Division; D019070:Cell Lineage; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D019902:Chondrocytes / Q000166:cytology; D042783:Endothelial Cells / Q000166:cytology; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007231:Infant, Newborn; D007813:Laparotomy; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D032342:Muscle Cells / Q000166:cytology; D010006:Osteoblasts / Q000166:cytology