Effect of IGF-I on Hair Growth Is Related to the Anti-Apoptotic Effect of IGF-I and Up-Regulation of PDGF-A and PDGF-B

BACKGROUND: Insulin-like growth factor-I (IGF-I) shares a high degree of structural and functional homology with insulin and is a potent mitogen supporting cell growth and survival in many kinds of the tissues and cells. It also plays a role in some differentiation and anti-apoptotic functions. In previous reports, it has been shown that IGF-I stimulates hair follicle (HF) growth, maintains the anagen stage, and postpones the catagen stage. OBJECTIVE: The exact mechanism of the effect of IGF-I on HF growth is not yet established. Therefore, we investigated the relationships between IGF-I and various other factors (i.e. apoptosis related molecules, pro-inflammatory cytokines, other growth factors, etc.) in the control of HF growth. METHODS: The effect of IGF-I on human hair growth was measured using an organ culture model of human HFs and compared with a control group that did not receive IGF-I. We also measured mRNA expression of factors related to hair growth and apoptosis (which was determined by reverse transcription polymerase chain reaction (RT-PCR). RT-PCR was done on days 2, 4, 6, and 8 of organ culture. RESULTS: In organ cultured human hair follicles, IGF-I had a positive effect on the rate of linear hair growth. IGF-I maintained the anagen phase. IGF-I increased the expression of platelet-derived growth factor (PDGF)-A, PDGF-B and the expression ratio of Bcl-2/Bax. CONCLUSION: The effect of IGF-I on hair growth appears to be related to the upregulation of PDGF-A and PDGF-B and to the anti-apoptotic effect of IGF-I.

FGF-2, TGFâ-1, PDGF-A and respective receptors expression in pleomorphic adenoma myoepithelial cells: an in vivo and in vitro study

Myoepithelial cells have an important role in salivary gland tumor development, contributing to a low grade of aggressiveness of these tumors. Normal myoepithelial cells are known by their suppressor function presenting increased expression of extracellular matrix genes and protease inhibitors. The importance of stromal cells and growth factors during tumor initiation and progression has been highlighted by recent literature. Many tumors result from the alteration of paracrine growth factors pathways. Growth factors mediate a wide variety of biological processes such as development, tissue repair and tumorigenesis, and also contribute to cellular proliferation and transformation in neoplastic cells. OBJECTIVES: This study evaluated the expression of fibroblast growth factor-2 (FGF-2), transforming growth factor â-1 (TGFâ-1), platelet-derived growth factor-A (PDGF-A) and their respective receptors (FGFR-1, FGFR-2, TGFâR-II and PDGFR-á) in myoepithelial cells from pleomorphic adenomas (PA) by in vivo and in vitro experiments. MATERIAL AND METHODS: Serial sections were obtained from paraffin-embedded PA samples obtained from the school's files. Myoepithelial cells were obtained from explants of PA tumors provided by surgery from different donors. Immunohistochemistry, cell culture and immunofluorescence assays were used to evaluate growth factor expression. RESULTS: The present findings demonstrated that myoepithelial cells from PA were mainly positive to FGF-2 and FGFR-1 by immunohistochemistry and immunofluorescence. PDGF-A and PDGFR-á had moderate expression by immunohistochemistry and presented punctated deposits throughout cytoplasm of myoepithelial cells. FGFR-2, TGFâ-1 and TGFâR-II were negative in all samples. CONCLUSIONS: These data suggested that FGF-2 compared to the other studied growth factors has an important role in PA benign myoepithelial cells, probably contributing to proliferation of ...

Construction and identification of recombinant adenovirus expressing hPDGF-A and hBD-2 / 第三军医大学学报

Objective To further determine their possible synergistic effect on accelerating wound healing, adenovirus vector containing recombinant human hPDGF-A and hBD2 genes was constructed and the expression of exogenous genes in transformed mesenchymal stem cells derived from rat bone marrow was observed. Methods By putting IRES in the middle of hPDGF-A and hBD2, these two genes were expected to be expressed individually. The shuttle vector was named as pAdTrack-hPDGF-A-IRES2-hBD2, which homologously recombinated with Adeasy-1 in BJ5183 cells and formed the mammalian expression vector pAdeasy-hPDGF-A-IRES2-hBD2. Furthermore, the recombinant vector was packaged in 293 cells into infectious recombinant adenovirus, which were used to infect BMSCs. The expression of hPDGF-A and hBD2 in BMSCs was detected by RT-PCR. Results We successfully constructed recombinant adenovirus vector that simultaneously expressed hPDGF-A and hBD2. The expressions of hPDGF-A and hBD2 were confirmed by RT-PCR on transformed BMSCs. Conclusion The established BMSCs that overexpressed hPDGF-A and hBD2 provide a new strategy of combining cell therapy and gene therapy to promote wound healing, especially the chronic one.

Effect of Unilateral Ureteral Obstruction(UUO) on the Expression of Platelet-Derived Growth Factor(PDGF) in the Sprague-Dawley Rat / 대한신장학회잡지

Unilateral ureteral obstruction(UUO) results in severe renal vascular constriction through the activation of renin-angiotensin system, which causes progressive tubulointerstitial fibrosis. Platelet-derived growth factor(PDGF) plays an important role in stimulating myofibroblasts and regulating synthesis of extracellular matrix in renal interstitial proliferation and fibrosis. This study was designed to investigate the relationship between unilateral ureteral obstruction and PDGF expression in tubulointerstitial fibrosis of the kidney. Eleven adult male Spraugue-Dawley rats were carried out unilateral ureteral ligation and sham operation. After 14 days, control kidney, UUO kidney and intact opposite(IO) kidney were harvested. Tissue fibrosis was quantified morphologically using the point detection method after Masson-Trichrome stain. Expression of PDGF-A and B was determined by immunohistochemical staining, RT-PCR and Western blot assay. Results were as follows: 1) UUO and IO group resulted in reduced kidney weight compared with control group(p<0.05). 2) Collagen deposition was increased in the renal cortex of UUO group(p<0.05). 3) PDGF-A and B mRNA expression was increased significantly compared with control and IO group(p< 0.05). 4) PDGF-A and B protein expression were increased in UUO and IO group(p<0.05). 5) On the immunohistochemical staining for PDGF- A and B, staining intensity was increased significantly at the renal cortex, interstitium and tubular epithelial cells in the UUO group. This results indicated that PDGF-A and B plays important role in tubulointerstitial fibrosis developed after unilateral ureteral obstruction and compensatory fibroproliferative growth in contralateral kidney.