Deletion of the PDGFR-beta gene affects key fibroblast functions important for wound healing.
This study provides new perspectives of the unique aspects of platelet-derived growth factor beta-receptor (PDGFR-beta) signaling and biological responses through the establishment of a mutant mouse strain in which two loxP sequences were inserted into the introns of PDGFR-beta genome sequences. Isolation of skin fibroblasts from the mutant mice and Cre recombinase transfection in vitro induced PDGFR-beta gene deletion (PDGFR-betaDelta/Delta). The resultant depletion of the PDGFR-beta protein significantly attenuated platelet-derived growth factor (PDGF)-BB-induced cell migration, proliferation, and protection from H2O2-induced apoptosis of the cultured PDGFR-betaDelta/Delta dermal fibroblasts. PDGF-AA and fetal bovine serum were mitogenic and anti-apoptotic but were unable to induce the migration in PDGFR-beta Delta/Delta fibroblasts. Concerning the PDGF signaling, PDGF-BB-induced phosphorylation of Akt, ERK1/2, and JNK, but not p38, decreased in PDGFR-betaDelta/Delta fibroblasts, but PDGF-AA-induced signaling was not altered. Overexpression of the phospholipid phosphatases, SHIP2 and/or PTEN, inhibited PDGF-BB-induced phosphorylation of Akt and ERK1/2 in PDGFR-betaDelta/Delta fibroblasts but did not affect that of JNK and p38. These results indicate that disruption of distinct PDGFR-beta signaling pathways in PDGFR-betaDelta/Delta dermal fibroblasts impaired their proliferation and survival, but completely inhibits migratory response, and that PDGF-BB-induced phosphorylation of Akt and ERK1/2 possibly mediated by PDGFR-alpha is regulated, at least in part, by the lipid phosphatases SHIP2 and/or PTEN. Thus, the PDGFR-beta function on dermal fibroblasts appears to be critical in PDGF-BB action for skin wound healing and is clearly distinctive from that of PDGFR-alpha in the ligand-induced biological responses and the underlying properties of cellular signaling.
Gao
Zhiyang
Z
Department of Pathology, Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan.
Sasaoka
Toshiyasu
T
Fujimori
Toshihiko
T
Oya
Takeshi
T
Ishii
Yoko
Y
Sabit
Hemragul
H
Kawaguchi
Makoto
M
Kurotaki
Yoko
Y
Naito
Maiko
M
Wada
Tsutomu
T
Ishizawa
Shin
S
Kobayashi
Masashi
M
Nabeshima
Yo-Ichi
Y
Sasahara
Masakiyo
M
D000818:Animals; D017931:DNA Primers; D005347:Fibroblasts / Q000502:physiology*; D017353:Gene Deletion; D005838:Genotype; D006801:Humans; D019426:Integrases / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000172:deficiency / Q000235:genetics*; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012867:Skin; D014162:Transfection; D014945:Wound Healing / Q000502:physiology*; D014947:Wounds and Injuries / Q000235:genetics / Q000473:pathology*
D017931:DNA Primers; D011994:Recombinant Proteins; D020797:Receptor, Platelet-Derived Growth Factor beta; C045073:Cre recombinase; D019426:Integrases