title: Distribution and possible role of PDGF-AA and PDGFR-alpha in the gastrointestinal tract of adult guinea pigs.
abstract: 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.
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.
authors.forename: Fangxiao
authors.initials: F
authors.lastname: Chan
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Haimei
authors.initials: H
authors.lastname: Sun
authors.forename: Xiaoshuang
authors.initials: X
authors.lastname: Li
authors.forename: Hongwei
authors.initials: H
authors.lastname: Shang
authors.forename: Dongying
authors.initials: D
authors.lastname: Fan
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.forename: Deshan
authors.initials: D
authors.lastname: Zhou
mesh_terms: 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
chemical_list: D010982:Platelet-Derived Growth Factor; C075278:platelet-derived growth factor A; D020796:Receptor, Platelet-Derived Growth Factor alpha