Platelet-derived growth factor receptor α (PDGFRα)-expressing "fibroblast-like cells" in diabetic and idiopathic gastroparesis of humans.
BACKGROUND
Emerging evidence suggests that "fibroblast-like cells" (FLC) may play a role in the regulation of gastrointestinal (GI) motor function. FLC are ultrastructurally distinct from other interstitial cells, including interstitial cells of Cajal (ICC), and express small-conductance Ca(2+) -activated K(+) channels (SK3). In mice, platelet-derived growth factor receptor α (PDGFRα) antibody has also been shown to label FLC. The aims of this study were to determine the morphology and distribution of PDGFRα-immunoreactive (ir) FLC in human gastric muscle and to determine if FLC are altered in gastroparesis, where ICC are reduced.


METHODS
Full thickness gastric body biopsies from five healthy subjects, 10 diabetic, and 10 idiopathic gastroparesis patients were immunolabeled using SK3 and PDGFRα staining for FLC and Kit staining for ICC. Intramuscular FLC and ICC were quantified.


RESULTS
Intramuscular PDGFRα-ir cells had slender cell bodies and long, thin processes and were more abundant in the longitudinal compared with the circular muscle. In the region of myenteric plexus, FLC had smaller, rounder cell bodies with 3-4 processes and formed networks, often around ganglia. All SK3-ir cell structures showed complete overlap with PDGFRα-ir. FLC were in close proximity to ICC, but their cell bodies did not overlap. No differences were seen in the distribution, morphology, or overall numbers of FLC in gastroparesis patients.


CONCLUSIONS
In conclusion, PDGFRα identifies FLC in human gastric smooth muscle. FLC were not altered in distribution or overall numbers in gastroparesis. Additional studies are required to determine their role in human GI function.
Mayo Clinic, Rochester, MN, USA.
M
M
Grover
C E
CE
Bernard
P J
PJ
Pasricha
H P
HP
Parkman
T L
TL
Abell
L A
LA
Nguyen
W
W
Snape
K R
KR
Shen
M
M
Sarr
J
J
Swain
M
M
Kendrick
S
S
Gibbons
T
T
Ordog
G
G
Farrugia
D000328:Adult; D016022:Case-Control Studies; D048909:Diabetes Complications / Q000378:metabolism*; D005260:Female; D005746:Gastric Emptying; D005753:Gastric Mucosa / Q000378:metabolism; D018589:Gastroparesis / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism; D009197:Myenteric Plexus / Q000378:metabolism; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000378:metabolism*; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism; D013270:Stomach / Q000166:cytology
C406328:KCNN3 protein, human; D051640:Small-Conductance Calcium-Activated Potassium Channels; D020796:Receptor, Platelet-Derived Growth Factor alpha