Distribution and possible role of PDGF-AA and PDGFR-alpha in the gastrointestinal tract of adult guinea pigs.
It was reported that a signaling pathway of platelet-derived growth factors (PDGFs) and their receptors (PDGFRs) played a critical role in the developing gut of mice. Overexpression of the PDGFR-alpha gene in gastrointestinal stromal tumors (GISTs) indicated that parts of tumor cells originated from PDGFR-alpha-positive cells, but a more detailed distribution of PDGFR-alpha and possible role in the adult mammalian gut are still unclear. In the present study, we examined the expression of both PDGF-AA and its receptor PDGFR-alpha in the gastrointestinal (GI) tract of adult guinea pigs using western blotting and immunohistochemistry. PDGF-AA-immunoreactive cells were mainly distributed in the mucosal epithelium of the stomach, small intestine, and large intestine. Only a few PDGF-AA-positive cells were seen in the longitudinal muscle layer of the large intestine. In contrast, PDGFR-alpha-positive cells were widely distributed throughout the GI tract, including the lamina propria, muscular layer, and subserosa. Double staining showed that the distribution of the PDGFR-alpha-positive cells in the muscular layer were similar to those of the interstitial cells of Cajal (ICCs), and they were associated with ICCs and enteric nerves, but no double-labeled cells were observed by anti-PDGFR or Kit antibody. It was noted that PDGFR-alpha-positive cells were also stained with a vimentin monoclonal antibody. Based on the double staining and morphological features, we consider the PDGFR-alpha-positive cells belong to a subtype of fibroblast. Our results not only provide a roadmap for understanding the function of the PDGF/PDGFR signaling pathway in both normal adult mammals and during gut injury and repair but also might help in understanding the growth and development of GISTs in the clinic.
Chan
Fangxiao
F
Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.
Liu
Yong
Y
Sun
Haimei
H
Li
Xiaoshuang
X
Shang
Hongwei
H
Fan
Dongying
D
An
Jing
J
Zhou
Deshan
D
D000818:Animals; D015153:Blotting, Western; D005260:Female; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D007150:Immunohistochemistry; D056885:Interstitial Cells of Cajal / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000096:biosynthesis*; D015398:Signal Transduction / Q000502:physiology
D010982:Platelet-Derived Growth Factor; C075278:platelet-derived growth factor A; D020796:Receptor, Platelet-Derived Growth Factor alpha