Aging-Dependent Reduction in Glyoxalase 1 Delays Wound Healing

Abstract

Methylglyoxal (MG), the major dicarbonyl substrate of the enzyme glyoxalase 1 (GLO1), is a reactive metabolite formed via glycolytic flux. Decreased GLO1 activity in situ has been shown to result in an accumulation of MG and increased formation of advanced glycation endproducts, both of which can accumulate during physiological aging and at an accelerated rate in diabetes and other chronic degenerative diseases. To determine the physiological consequences which result from elevated MG levels and the role of MG and GLO1 in aging, wound healing in young (≤12 weeks) and old (≥52 weeks) wild-type mice was studied. Old mice were found to have a significantly slower rate of wound healing compared to young mice (74.9 ± 2.2 vs. 55.4 ± 1.5% wound closure at day 6; 26% decrease; p < 0.0001). This was associated with decreases in GLO1 transcription, expression and activity. The importance of GLO1 was confirmed in mice by inhibition of GLO1. Direct application of MG to the wounds of young mice, decreased wound healing by 24% compared to untreated mice, whereas application of BSA modified minimally by MG had no effect. Treatment of either young or old mice with aminoguanidine, a scavenger of free MG, significantly increased wound closure by 16% (66.8 ± 1.6 vs. 77.2 ± 3.1%; p < 0.05) and 64% (40.4 ± 7.9 vs. 66.4 ± 5.2%; p < 0.05), respectively, by day 6. As a result of the aminoguanidine treatment, the overall rate of wound healing in the old mice was restored to the level observed in the young mice. These findings were confirmed in vitro, as MG reduced migration and proliferation of fibroblasts derived from young and old, wild-type mice. The data demonstrate that the balance between MG and age-dependent GLO1 downregulation contributes to delayed wound healing in old mice.

Glycative stress and glyoxalase in kidney disease and aging

“…Our data regarding the effect of Glo1 on kidney and vascular aging are consistent with a recent study showing that age-dependent delay of wound healing is associated with the lowering of Glo1 activity with age [7]. Other studies also indicate that the Glo1 activity of Caenorhabditis elegans decreased by 10% by aging and Glo1 overexpression enhanced their lifespan and, in contrast, Glo1 knockdown significantly shortened the lifespan [8].…”

Glyoxalase I inhibition induces apoptosis in irradiated MCF-7 cells via a novel mechanism involving Hsp27, p53 and NF-κB

“…Untreated cells were incubated for the same time periods. Independent experiments were also performed by pretreating cells with N -acetyl- L -cysteine (NAC, 10 m M , for 0.5 h), a known antioxidant that increases cellular GSH levels, aminoguanidine bicarbonate (AG, 1 m M , for 2 h), a scavenger of free MG (Fleming et al , 2013) and MG-derived AGEs (Thornalley et al , 2000), the specific wild-type p53 inhibitor, pifithrin- α (PFT- α , 20  μ M in DMSO, for 2 h), the specific NF-κB inhibitor BAY 11-7082 (10  μ M in DMSO, for 0.5 h, Santa Cruz Biotechnology, Inc., Heidelberg, Germany), the ER α anti-oestrogen ICI 182,780 (100 n M in DMSO, for 4 h), ERK-1/2 inhibitor U-0126 (10  μ M in DMSO, for 1 h), and then irradiated in the conditions above described. Unless otherwise stated, these reagents were from Sigma-Aldrich (Milan, Italy) and used at concentrations producing no significant toxicity to MCF-7 cells.…”

Dicarbonyl stress in cell and tissue dysfunction contributing to ageing and disease

“…MG-derived AGEs increased in human lens with age and was linked to cataract formation [3]. Decreased Glo1 activity was associated with impaired wound healing [24]. Dicarbonyl stress is also likely involved in senescence of plants.…”