[Sensory neuropeptide SP modulating expression of EGF, FGF-2 and their receptors in fibroblasts of granulation in vivo and in vitro].
OBJECTIVE
To study the modulating effect of sensory neuropeptide substance P (SP) on gene expression of epidermal growth factor (EGF), fibroblast growth factor-2 (FGF-2) and EGF receptor (EGFR), FGF receptor-1 (FGFR-1) in granulation fibroblast.


METHODS
The study consisted of two parts, in vivo and in vitro. In vivo, fifty wistar rats were randomly arranged into capsaicin group and control group. The rats in capsaicin group were subcutaneously injected with neurotoxin dose of capsaicin (50 mg/kg) on the back of the rats to chemically destroy sensory nerves to prevent the release of SP. After one week, full-thickness skin wounds were created on the rats' back. SP content and EGF, EGFR, FGF-2, FGFR-1 gene expression in the granulation tissue were observed using immunohistochemistry and in situ hybridization combined with image analysis on 3rd, 6th, 9th 12th after skin injury, respectively. The experimental procedure in control group were similar with that in capsaicin group except injection with capsaicin. In vitro, SP (10(-9)-10(-5) mol/L) was added into culture medium for cultured fibroblasts from granulation and mRNA expressions of EGF, FGF-2 and their receptors were assayed with RT-PCR.


RESULTS
In the present study, immunoreactive stain for SP in granulation tissue were correlated with gene expression of EGF, FGF-2 and their receptors using in situ hybridization in vivo. Once sensory nerves were destroyed and SP release was inhibited in capsaicin group, the gene expression of above growth factors and their receptors were attenuated. SP concentrations in culture medium for upregulation of mRNA expressions of EGF and EGFR in cultured fibroblasts were from 10(-8) mol/L to 10(-6) mol/L and from 10(-6) mol/L to 10(-5) mol/L, respectively. SP concentration was from 10(-9) mol/L to 10(-5) mol/L for upregulation of FGF-2 mRNA expression in cultured fibroblasts and from 10(-6) mol/L to 10(-5) mol/L for upregulation of FGFR-1.


CONCLUSIONS
Sensory neuropeptide SP released from sensory nerve participates in upregulation of gene expressions of EGF, EGF-2 and their receptors in granulation fibroblasts during wound healing.
Lai
Xi-nan
XN
Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China.
Wang
Zheng-guo
ZG
Wei
Li
L
Zhu
Jin-ming
JM
Wang
Li-li
LL
D000818:Animals; D004815:Epidermal Growth Factor / Q000235:genetics*; D066246:ErbB Receptors / Q000235:genetics*; D016222:Fibroblast Growth Factor 2 / Q000235:genetics*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics*; D013373:Substance P / Q000032:analysis / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000378:metabolism
D017468:Receptors, Fibroblast Growth Factor; D018808:Transcription Factor AP-1; D016222:Fibroblast Growth Factor 2; D013373:Substance P; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; C496350:Fgfr1 protein, rat; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D020928:Mitogen-Activated Protein Kinases