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Aminoguanidine inhibits advanced glycation end products formation on beta2-microglobulin
F F Hou1, J Boyce, G M Chertow
1Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Abstract:
Because advanced glycation end products (AGE)-modified beta2-microglobulin (AGE-beta2M) is a dominant constituent of amyloid in dialysis-related amyloidosis (DRA), AGE-beta2M may be directly involved in the pathobiology of DRA. In experimental diabetes mellitus, blocking the formation of AGE prevents AGE-mediated tissue damage. In this study, it is postulated that similar pharmacologic intervention may be beneficial in DRA. Aminoguanidine, a nucleophilic hydrazine compound that prevents AGE formation on collagen, may have a similar effect on the advanced glycation of beta2M. To test this hypothesis, beta2M was incubated in vitro with 50 or 100 mM D-glucose for 3 wk in the presence and absence of incremental concentrations of aminoguanidine. On the basis of enzyme-linked immunosorbent assay and immunoblots using anti-AGE-keyhole limpet hemocyanin antibody, aminoguanidine inhibited glucose-induced N(epsilon)-(carboxymethyl)lysine formation on beta2M. At aminoguanidine-glucose molar ratios of 1:8 to 1:1, 26 to 53% inhibition occurred. Fluorospectrometry examination showed that aminoguanidine also inhibited the formation of fluorescent AGE on beta2M in a dose-dependent manner. At aminoguanidine-glucose molar ratios of 1:8 to 1:1, fluorescent product generation was inhibited by 30 to 70%. Furthermore, aminoguanidine suppressed the AGE formation on beta2M bound to AGE-modified collagen. If aminoguanidine is similarly active in vivo, this compound may be of clinical utility for treating DRA in patients on maintenance dialysis.
Insights
Aminoguanidine effectively inhibits the formation of advanced glycation end products (AGEs) on beta2-microglobulin (beta2M), a key component in dialysis-related amyloidosis (DRA). This finding suggests aminoguanidine may be a potential therapeutic agent for treating DRA.
Area of Science:
- Biochemistry
- Nephrology
- Pharmacology
Background:
- Dialysis-related amyloidosis (DRA) is characterized by amyloid deposits of advanced glycation end product-modified beta2-microglobulin (AGE-beta2M).
- Inhibition of AGE formation has shown promise in preventing tissue damage in experimental diabetes mellitus.
- Aminoguanidine is a compound known to inhibit AGE formation on collagen.
Purpose of the Study:
- To investigate the potential of aminoguanidine to inhibit the formation of AGEs on beta2-microglobulin.
- To assess the efficacy of aminoguanidine in preventing AGE modification of beta2M, a crucial step in DRA pathogenesis.
Main Methods:
- In vitro incubation of beta2-microglobulin (beta2M) with D-glucose in the presence of varying concentrations of aminoguanidine.
- Enzyme-linked immunosorbent assay (ELISA) and immunoblots using anti-AGE antibody to quantify N(epsilon)-(carboxymethyl)lysine formation.
- Fluorospectrometry to measure the formation of fluorescent AGEs.
- Assessment of aminoguanidine's effect on AGE formation on AGE-modified collagen-bound beta2M.
Main Results:
- Aminoguanidine significantly inhibited glucose-induced N(epsilon)-(carboxymethyl)lysine formation on beta2M, with 26-53% inhibition at aminoguanidine-glucose molar ratios of 1:8 to 1:1.
- Aminoguanidine dose-dependently inhibited the formation of fluorescent AGEs on beta2M, showing 30-70% inhibition at the same molar ratios.
- The compound also suppressed AGE formation on beta2M when it was bound to AGE-modified collagen.
Conclusions:
- Aminoguanidine effectively inhibits the formation of AGEs on beta2-microglobulin in vitro.
- These findings suggest that aminoguanidine may hold clinical utility in the treatment of dialysis-related amyloidosis.
- Further in vivo studies are warranted to confirm the therapeutic potential of aminoguanidine for DRA patients.