Diabetic skin may have deficient wound healing properties but little is known of its intrinsic biomechanical properties. blot analysis. At baseline both murine and human diabetic skin was biomechanically inferior compared to D-106669 nondiabetic skin with decreased maximum stress and decreased modulus (< 0.001 and < 0.05 respectively). Surprisingly the expression of genes involved in collagen synthesis were significantly up-regulated and genes involved in collagen degradation were significantly down-regulated in murine diabetic skin (< 0.01). In addition MMP-2 and MMP-9/TIMP-1 protein ratios were significantly lower in murine diabetic skin (< 0.05). Collagen I levels and I:III ratios were lower in diabetic skin (< 0.05). These findings suggest that the predisposition of diabetics to wounds may be the result of impaired tissue integrity at baseline and are due in part to a defect in the regulation of collagen protein synthesis at the post-transcriptional level. Diabetes is usually associated with increased morbidity and mortality 1 as well as impaired wound healing.2 Diabetes-related admissions accounted for 22% of all hospital inpatient days in 2007 and diabetic foot ulcers account for 20% of all hospital admissions in diabetic patients which are the leading cause of lower extremity amputations.2 Improvements made in diabetic wound management and prevention clearly have the potential D-106669 to affect a large number of patients and decrease diabetic-related health care expenditures. More than 100 factors have been determined that donate to the impairment in diabetic wound curing.3 Decreased angiogenesis 4 impaired growth aspect creation 5 an altered inflammatory and immune system response 5 a reduced price of wound contraction 6 and an imbalance between your accumulation of extracellular elements and their redecorating by matrix metalloproteinases (MMPs)7 8 possess all been demonstrated in diabetic wounds. MMP-2 and MMP-9 have already been been shown to be present in better focus in wounded diabetic pets than their non-diabetic littermates which is comparable to findings from sufferers with nonhealing ulcers.9 Diabetes is seen as a significantly increased mix linking and non-enzymatic glycation of collagen aswell as elevated degrees of advanced glycation end products (AGEs).10 11 Blockade from the receptor for advanced glycation end items (RAGEs) can restore the wound healing D-106669 properties of diabetic (Db/Db) mice.12 Hyperglycemic animals have been shown to have significantly higher concentrations of glycated Rabbit Polyclonal to ITCH (phospho-Tyr420). collagen and higher levels of collagenase activity.9 13 Furthermore diabetic (Db/Db) mice have also been shown to have a prolonged inflammatory phase with sustained expression of the inflammatory cytokines macrophage chemoattractant protein 1 (MPC-1) and macrophage inflammatory protein 2 (MIC-2).14 The biomechanical properties of diabetic skin are another critical aspect of wound-healing physiology. Diabetic hyperglycemic rats were found to have inferior biomechanical properties than euglycemic rats after injury.15 Other studies confirm inferior properties after wounding but few have assessed these properties at baseline. We hypothesize that there exist inherently inferior biomechanical properties of diabetic skin at baseline. D-106669 Furthermore we propose that these inferior biomechanical properties are the result of imbalances in collagen synthesis and degradation in diabetic compared to nondiabetic skin. Materials and Methods Animals The animals were 6-week- to 8-week-old genetically diabetic female C57BKS.Cg-m+/+= 5 for each group) were morcellized and D-106669 subsequently homogenized in a solution of 750 μL of tissue lysis buffer (Qiagen Inc. Valencia CA). All subcutaneous tissue was removed prior to homogenization. This answer was then centrifuged at 10 0 rpm for 10 minutes. The supernatant was collected and frozen at ?80°C for further analysis. Protein concentration was quantified using a bicinchoninic acid protein assay (Thermo Scientific Rockford IL) that uses a standard curve generated from known concentrations of bovine serum albumin (Thermo Scientific). All samples were run in duplicate. Enzyme-linked immunosorbent assay (ELISA) was then used to quantify the concentration of MMP-2 MMP-9 and tissue inhibitor metalloproteinase-1 (TIMP-1) protein levels (R&D Systems Minneapolis MN). The ELISA kits that were used quantified the total amounts.