Abstract
BackgroundOne of the well-defined and characterized protein modifications usually produced by oxidation is carbonylation, an irreversible non-enzymatic modification of proteins. However, carbonyl groups can be introduced into proteins by non-oxidative mechanisms. Reactive carbonyl compounds have been observed to have increased in patients with renal failure. In the present work we have described a procedure designed as aldehyde capture to calculate the protein carbonyl stress derived solely from lipid peroxidation.MethodsAcrolein-albumin adduct was prepared as standard at alkaline pH. Rat liver microsomal membranes and serum samples from patients with diabetic nephropathy were subjected to the aldehyde capture procedure and aldol-protein formation. Before alkalinization and incubation, samples were precipitated and redisolved in 6M guanidine. The absorbances of the samples were read with a spectrophotometer at 266 nm against a blank of guanidine.ResultsEvidence showed abundance of unsaturated aldehydes derived from lipid peroxidation in rat liver microsomal membranes and in the serum of diabetic patients with advanced chronic kidney disease. Carbonyl protein and aldol-proteins resulted higher in the diabetic nephropathy patients (p < 0.004 and p < 0.0001 respectively).ConclusionThe aldehyde-protein adduct represents a non oxidative component of carbonyl stress, independent of the direct amino acid oxidation and could constitute a practical and novelty strategy to measure the carbonyl stress derived solely from lipid peroxidation and particularly in diabetic nephropathy patients. In addition, we are in a position to propose an alternative explanation of why alkalinization of urine attenuates rhabdomyolysis-induced renal dysfunction.
Highlights
One of the well-defined and characterized protein modifications usually produced by oxidation is carbonylation, an irreversible non-enzymatic modification of proteins
Carbonyl groups can be introduced into proteins by reaction with molecules such as acrolein, 4-hydroxy-2nonenal (HNE) and other alpha-beta unsaturated aldehydes derived from lipid peroxidation that react with protein residues via several kinds of reactions, included Schiff base formation and Michael addition reactions [11]
Lipid peroxidation catalyzed by the hemoprotein’s radicals is probably the more documented explanation for the oxidative damage associated with rhabdomyolysis [19], and this condition constitutes another potential source of the alpha beta unsaturated aldehydes and carbonyl stress in the kidney
Summary
One of the well-defined and characterized protein modifications usually produced by oxidation is carbonylation, an irreversible non-enzymatic modification of proteins. Reactive carbonyl compounds derived from lipids and carbohydrates by both oxidative and non-oxidative routes have been observed to have increased in patients with renal damage. These compounds react with proteins, resulting in the condition described as “carbonyl stress”, which underlies the development of uremic complications [15]. Uremic plasma contains elevated levels of low weight molecular carbonyl compounds [16] These do not seem to be secondary products of protein glycation nor do they depend on glucose plasma concentration, but more probably are reactive carbonyl compounds derived from carbohydrates, lipids and amino acids [16,17]. Lipid peroxidation catalyzed by the hemoprotein’s radicals is probably the more documented explanation for the oxidative damage associated with rhabdomyolysis [19], and this condition constitutes another potential source of the alpha beta unsaturated aldehydes and carbonyl stress in the kidney
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
