Connective Tissue Growth Factor/IGF-Binding Protein-Related Protein-2 Is a Mediator in the Induction of Fibronectin by Advanced Glycosylation End-Products in Human Dermal Fibroblasts

Abstract

Expansion of extracellular matrix with fibrosis occurs in many tissues, including skin, as part of the end-organ complications in diabetes. Advanced glycosylation end-products (AGEs) have been implicated as a pathogenic factor in diabetic tissue fibrosis. Connective tissue growth factor (CTGF), also known as IGF-binding protein-related protein-2, induces extracellular matrix. We have recently shown that CTGF mRNA and protein are up-regulated by AGE treatment of cultured human dermal fibroblasts. The aim of this study was to determine whether CTGF is an autocrine mediator in the induction of fibronectin (FN) by AGE. Primary cultures of nonfetal human dermal fibroblasts in confluent monolayer were treated with synthesized soluble AGE BSA, 0-200 microg/ml. Analysis of mRNA, by quantitative real-time RT-PCR and conditioned media from treated cultures, showed that FN mRNA was increased by approximately 4-fold at 48 h, and FN protein levels by Western immunoblot and FN ELISA were doubled, compared with control. In the same system, added recombinant human CTGF (0-500 ng/ml) induced FN mRNA and protein levels dose dependently and in a rapid time course. To test whether AGE BSA acts through cell-derived CTGF to induce FN, a CTGF neutralizing antibody was shown to significantly attenuate, but not fully inhibit, the AGE induction of FN mRNA. A pan-specific PKC inhibitor, GF109203X, at 0.2 microM, inhibited the induction of FN mRNA by AGE BSA. Although the same inhibitor did not significantly affect the induction of CTGF mRNA by AGE, it blocked the induction of FN mRNA by recombinant human CTGF. In summary, the induction of FN by AGE is partly mediated by the AGE-induced up-regulation of cell-derived CTGF and is dependent on PKC activity. These results have potential implications for the expansion of extracellular matrix in diabetes mellitus by advanced glycosylation end products.

Differential expression of connective tissue growth factor in microglia and pericytes in the human diabetic retina

“…18 19 AGEs induce fibronectin, a component of the retinal BM, 38 in dermal fibroblasts via upregulation of CTGF. 39 Thus, CTGF may well be involved in BM thickening in preclinical DR, and this notion is supported by our finding that CTGF is overexpressed in pericytes in the human diabetic retina, irrespective of changes related to clinical DR like vascular leakage.…”

Acellular dermal matrix scaffolds coated with connective tissue growth factor accelerate diabetic wound healing by increasing fibronectin through PKC signalling pathway

“…Previous literature reported that chronic wounds in diabetes mainly occur due to the lack of different macromolecular proteins of the ECM (Maione et al, ; Pankov & Yamada, ). FN, as one composition of ECM, has been proved to be induced by CTGF through PKC signalling pathway in human dermal fibroblasts (Twigg et al, ).Therefore, we determined whether CTGF loaded on ADM scaffolds increases the expression of FN for accelerated diabetic wound healing through the PKC signalling pathway in this experiment. For comparison, CTGF + PKC inhibitor was loaded on ADM scaffolds to treat dorsal skin wounds in STZ‐induced diabetic mice with ADM as a control.…”

Endogenous Hydrogen Sulfide Regulates Pulmonary Artery Collagen Remodeling in Rats with High Pulmonary Blood Flow

“…It was reported that an imbalance between gene expression of interstitial collagenases and gene expression of TIMP-1 contributed to extracellular matrix accumulation (26). Connective tissue growth factor (CTGF), a potent stimulator of collagen synthesis (27), consists of 349 amino acids with four distinct domains and induced by mechanical shear stress in vitro (28,29). As mentioned above, the balance of MMP and TIMP-1 is involved in the regulation of collagen degradation and CTGF contributed to collagen synthesis.…”