Differential effects of PDGF-BB on matrix metalloproteases and cytokine release in fibroblasts of Type 2 diabetic patients and normal controls in vitro

Lobmann, Ralf; Pap, Thomas; Ambrosch, Andreas; Waldmann, Katrin; König, Wolfgang; Lehnert, Hendrik

doi:10.1016/j.jdiacomp.2005.05.013

« Previous Next »Journal of Diabetes and Its Complications
Volume 20, Issue 2 , Pages 105-112, March 2006

Differential effects of PDGF-BB on matrix metalloproteases and cytokine release in fibroblasts of Type 2 diabetic patients and normal controls in vitro

Ralf Lobmann
- Department of Endocrinology and Metabolism, Magdeburg University Medical School, Magdeburg 39120, Germany
- Corresponding author. Department of Endocrinology and Metabolism, Magdeburg University Medical School, Leipziger Strasse 44, Magdeburg 39120, Germany. Tel.: +49 391 67 15445; fax: +49 391 67 15448.
Thomas Pap
- Institute of Experimental Rheumatology, Magdeburg University Medical School, Magdeburg 39120, Germany
Andreas Ambrosch
- Department of Clinical Microbiology, Magdeburg University Medical School, Magdeburg 39120, Germany
Katrin Waldmann
- Department of Endocrinology and Metabolism, Magdeburg University Medical School, Magdeburg 39120, Germany
Wolfgang König
- Department of Clinical Microbiology, Magdeburg University Medical School, Magdeburg 39120, Germany
Hendrik Lehnert
- Department of Endocrinology and Metabolism, Magdeburg University Medical School, Magdeburg 39120, Germany

Received 21 December 2004; received in revised form 26 May 2005; accepted 31 May 2005.

Abstract

Aims/hypothesis

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.

Keywords: Wound healing, Diabetic fibroblasts, PDGF, Proliferation