Aging-dependent reduction in glyoxalase 1 delays wound healing.

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.

First detection of the Anaplasma phagocytophilum groEL-A genotype in man.

OBJECTIVE: Human Granulocytic Anaplasmosis (HGA) is an emerging disease caused by the gram-negative bacterium Anaplasma phagocytophilum which is transmitted by ticks of the genus Ixodes ricinus. For molecular detection of the pathogen by PCR, a conserved portion of the groEL gene within the groESL operon is frequently used as a target. A single G/A polymorphism in this region allows to discriminate between two genotypes, groEL-G and groEL-A. METHODS: Total DNA from peripheral blood samples of two HGA patients was analysed by RealTime PCR, employing a protocol designed for genotyping groEL-G- and groEL-A variants of A. phagocytophilum. RESULTS: We confirmed two clinical cases of HGA by PCR; in one patient, and for the first time in a human host, the groEL-A variant was detected, in the other case the pathogen was recognised as the groEL-G variant, up to now representing the only genotype reported in man. CONCLUSIONS: It is documented that HGA infections can be caused by two A. phagocytophilum groEL genotypes. At present, the preference of the A. phagocytophilum groEL-G genotype in humans remains unclear, as we describe the first patient with HGA caused by the groEL-A variant. For a conclusive interpretation, more data from HGA patients will be required.