Overexpression of Lysyl Oxidase to Increase Matrix Crosslinking and Improve Tissue Strength in Dermal Wound Healing

Abstract

In this study, we aimed to increase crosslinking in collagen and elastin in the extracellular matrix through overexpression of lysyl oxidase (LO) in order to improve mechanical strength in dermal wounds during healing. We had used a gene activated matrix (GAM) approach to locally deliver plasmid DNA (pDNA) complexed with polyethylenimine (PEI) in collagen gels at the wound site for localized and sustained transfection of cells involved in the healing process. We first demonstrated in vitro that PEI-pDNA complexes in collagen gels could be taken up and expressed by cultured fibroblasts for at least 20 days. In vitro studies showed that fibroblast-seeded GAMs with the LO transgene exhibited over a 3-fold increase in mechanical strength as compared with a green fluorescent protein (GFP)-transgene control. Addition of an inhibitor of LO abolished this increase. We applied this system in a rat dermal wound healing model and showed that treatment with LO-producing GAMs led to significantly enhanced mechanical strength of the wound site.

Molecular events surrounding collagen fibril assembly in the early healing rabbit medial collateral ligament—failure to recapitulate normal ligament development

“…LOX is responsible for oxidizing lysine residues and initiating collagen cross-linking [36]. The increased LOX mRNA levels detected at 3 weeks postinjury is consistent with in vivo experiments showing that over-expression of LOX improves the mechanical strength of the matrix in rat dermal wound healing by catalyzing the formation of cross-links between collagen fibrils [21,46]. This upregulation of LOX mRNA could potentially result from the upregulation of TGF-β1 mRNA during healing because a previous in vitro cell culture study showed that LOX steady-state mRNA levels were increased when rat lung fibroblasts were exposed to TGF-β1 [24].…”

Stimulus responsive elastin biopolymers: applications in medicine and biotechnology

“…The maximum shear modulus of these materials (310 kPa) [16,45,46] compares favorably with that of normal cartilage of (~440 kPa). We also investigated a bioinspired, in situ crosslinking method to form ELP hydrogels by covalent cross-linking between lysine and glutamine guest residues catalyzed by tissue transglutaminase [44•].…”

An Exploratory Pathways Analysis of Temporal Changes Induced by Spinal Cord Injury in the Rat Bladder Wall: Insights on Remodeling and Inflammation

“…In the networks, LOX shows a direct relation with elastin (Figure 1), but in addition, it has been shown to be involved in the organization of collagen fibrils [31]. Over-expression of LOX in a rat dermal wound healing model resulted in significantly enhanced mechanical strength of the wound site, indicating increased cross-linking of the extracellular matrix[31].…”