Apoptotic process of porcine intestinal M cells.
Membranous (M) cells of the follicle-associated epithelium (FAE) are believed to sample antigens from the gut lumen. However, the origin, differentiation mechanism, and cell death of M cells are still a matter of controversy. Therefore, we investigated the process of M cell differentiation and determined their fate in the intestine of three-way crossbred female pigs. We used anti-cytokeratin 18 and anti-PCNA antibodies to distinguish M cells and proliferative cells and performed immunohistochemistry, enzyme histochemistry, and scanning electron microscopy on fresh ileal Peyer's patches. Cell migration and apoptotic cells were detected by BrdU labeling and the TUNEL method, respectively. The turnover of the FAE was similar to that of the villi. M cells were mostly observed from the FAE crypt to the FAE periphery, but not in the FAE apex. As proliferative M cells (cytokeratin 18(+)/PCNA(+) cells) have previously been detected in the FAE crypt, porcine M cells may be directly derived from intestinal epithelial stem cells and committed as a distinct cell lineage in the crypts. M cells from the FAE periphery were unstained or only weakly stained for alkaline phosphatase, whereas cytokeratin 18(+)/alkaline phosphatase(+) cells lying near to the FAE apex showed a columnar shape similar to that of adjacent enterocytes. These data suggest that the committed M cells differentiate to mature M cells by contact with lymphocytes at the FAE periphery, and that they trans-differentiate to enterocytes and are finally excluded near the FAE apex.
Miyazawa
Kohtaro
K
Laboratory of Functional Morphology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, 981-8555, Sendai, Japan.
Aso
Hisashi
H
Kanaya
Takashi
T
Kido
Taketomo
T
Minashima
Takeshi
T
Watanabe
Kouichi
K
Ohwada
Shyuichi
S
Kitazawa
Haruki
H
Rose
Michael T
MT
Tahara
Koji
K
Yamasaki
Tadashi
T
Yamaguchi
Takahiro
T
D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D019070:Cell Lineage; D002465:Cell Movement; D020895:Enterocytes / Q000166:cytology / Q000648:ultrastructure; D004847:Epithelial Cells / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D005260:Female; D006651:Histocytochemistry; D007082:Ileum / Q000166:cytology* / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000166:cytology* / Q000648:ultrastructure; D053538:Keratin-18 / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010581:Peyer's Patches / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D013552:Swine
D053538:Keratin-18; D018809:Proliferating Cell Nuclear Antigen