The Critical Role of Methylglyoxal and Glyoxalase 1 in Diabetic Nephropathy

  1. Paul J. Thornalley
  1. Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, University Hospital, Coventry, U.K.
  1. Corresponding author: Paul J. Thornalley, p.j.thornalley{at}

The discovery of increased formation of methylglyoxal (MG) by cell metabolism in high glucose concentration in vitro suggested possible relevance to diabetes and diabetes complications (1,2). MG is the precursor of quantitatively important advanced glycation end products (AGEs) of protein and DNA- and MG-derived AGEs increase in experimental and clinical diabetes (3,4). Increased MG and its metabolism by glyoxalase 1 (Glo1) was linked to clinical microvascular complications (nephropathy, retinopathy, and neuropathy) (5). Current clinical treatment decreasing MG and MG-derived AGEs, such as insulin lispro (6,7), has some clinical benefit in diabetic nephropathy (8), although the decrease in MG-derived AGE exposure is minor—∼17% (7). Greater benefits may be achieved with specific and effective anti-MG targeted therapy. An outstanding research problem is to gain unequivocal evidence that MG glycation is a key mediator of vascular complications and, if possible, provide some pointers as to how MG glycation could be effectively countered. In this issue, the study by Giacco et al. (9) provides key evidence by a functional genomic approach manipulating expression of Glo1 to increase or decrease endogenous MG glycation. The outcomes show that development of experimental diabetic nephropathy is driven by increased levels of MG glycation and increasing renal expression of Glo1 prevents this. Recent research has shown Glo1 expression may be increased …

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