Differential effects of PDGF-BB on matrix metalloproteases and cytokine release in fibroblasts of Type 2 diabetic patients and normal controls in vitro.
OBJECTIVE
The complex process of wound healing is regulated by various growth factors. The systemic character of diabetes mellitus favors the chronification of diabetic wounds. In this study, the in vitro effects of platelet-derived growth factor (PDGF)-BB on the expression of cytokines and matrix metalloproteases (MMPs) in fibroblasts of Type 2 diabetic patients and healthy controls were investigated.


METHODS
We studied six Type 2 diabetic patients (mean Hba1(c)=7.5%) and six healthy controls. For proliferation studies, cultivated fibroblasts, prepared from biopsies taken from the thigh, were stimulated with different concentrations of PDGF. After 48 h, the expression of MMPs and cytokines was measured. We analysed the mRNA expression by RT-PCR (TaqMan), tissue protein levels by zymography, and cell supernatant levels by ELISA.


RESULTS
Levels of MMP-mRNA were elevated in diabetic fibroblasts compared with healthy controls. At baseline, MMP-2 protein levels were significantly increased in the fibroblast of diabetic patients (P=.019). For MMP-9, a trend towards higher levels (P=.3) was found. After incubation with PDGF, a significant reduction of MMP-9 (P=.01) and MMP-13 (P=.04) was found. Analysis of cytokine release in cell culture supernatant showed elevated levels of interleukin (IL)-8 at baseline conditions. MMP-1 and MMP-2 levels in the supernatant were concentration-dependently reduced.


CONCLUSIONS
This study, for the first time, demonstrates elevated MMPs in cultivated fibroblasts (derived from intact skin and not from an open wound) of diabetic patients compared with healthy controls under in vitro conditions. Therefore, our data support the hypothesis of alterations of wound healing in diabetic patients on the cellular level, reflecting the systemic character of the disease.
Lobmann
Ralf
R
Department of Endocrinology and Metabolism, Magdeburg University Medical School, Magdeburg 39120, Germany. ralf.lobmann@medizin.uni-magdeburg.de
Pap
Thomas
T
Ambrosch
Andreas
A
Waldmann
Katrin
K
König
Wolfgang
W
Lehnert
Hendrik
H
D000077214:Becaplermin; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000503:physiopathology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology
D016207:Cytokines; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D000077214:Becaplermin; D020782:Matrix Metalloproteinases