TY - JOUR N1 - This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ TI - TGF?-1 Induced Cross-Linking of the Extracellular Matrix of Primary Human Dermal Fibroblasts Y1 - 2021/01/20/ VL - 22 UR - https://doi.org/10.3390/ijms22030984 A1 - Semkova, ME A1 - Hsuan, JJ AV - public JF - International Journal of Molecular Science N2 - Excessive cross-linking is a major factor in the resistance to the remodelling of the extracellular matrix (ECM) during fibrotic progression. The role of TGF? signalling in impairing ECM remodelling has been demonstrated in various fibrotic models. We hypothesised that increased ECM cross-linking by TGF? contributes to skin fibrosis in Systemic Sclerosis (SSc). Proteomics was used to identify cross-linking enzymes in the ECM of primary human dermal fibroblasts, and to compare their levels following treatment with TGF?-1. A significant upregulation and enrichment of lysyl-oxidase-like 1, 2 and 4 and transglutaminase 2 were found. Western blotting confirmed the upregulation of lysyl hydroxylase 2 in the ECM. Increased transglutaminase activity in TGF?-1 treated ECM was revealed from a cell-based assay. We employed a mass spectrometry-based method to identify alterations in the ECM cross-linking pattern caused by TGF?-1. Cross-linking sites were identified in collagens I and V, fibrinogen and fibronectin. One cross-linking site in fibrinogen alpha was found only in TGF?-treated samples. In conclusion, we have mapped novel cross-links between ECM proteins and demonstrated that activation of TGF? signalling in cultured dermal fibroblasts upregulates multiple cross-linking enzymes in the ECM. ID - discovery10121706 KW - TGF?-1 KW - dermal fibroblasts KW - extracellular matrix KW - lysyl hydroxylase 2 KW - lysyl-oxidase-like enzymes KW - transglutaminase cross-linking KW - transglutaminases IS - 3 ER -