Does Risk of Hyperhomocysteinemia Depend on Thiol-Disulfide Exchange Reactions of Albumin and Homocysteine?

Significance: Increased plasma concentrations of total homocysteine (tHcy; mild-moderate hyperhomocysteinemia: 15-50 μM tHcy) are considered an independent risk factor for the onset/progression of various diseases, but it is not known about how the increase in tHcy causes pathological conditions. Recent Advances: Reduced homocysteine (HSH ∼1% of tHcy) is presumed to be toxic, unlike homocystine (∼9%) and mixed disulfide between homocysteine and albumin (HSS-ALB; homocysteine [Hcy]-albumin mixed disulfide, ∼90%). This and other notions make it difficult to explain the pathogenicity of Hcy because: (i) lowering tHcy does not improve pathological outcomes; (ii) damage due to HSH usually emerges at supraphysiological doses; and (iii) it is not known why tiny increments in plasma concentrations of HSH can be pathological. Critical Issues: Albumin may have a role in Hcy toxicity, because HSS-ALB could release toxic HSH via thiol-disulfide (SH/SS) exchange reactions in cells. Similarly, thiol-disulfide exchange processes of reduced albumin (albumin with free SH group of Cys34 [HS-ALB]) or N-homocysteinylated albumin are plausible alternatives for initiating Hcy pathological events. Adverse effects of albumin and other data reviewed here suggest the hypothesis of a role of albumin in Hcy toxicity. Future Directions: HSS-ALB might be involved in disruption of the antioxidant/oxidant balance in critical tissues (brain, liver, kidney). Since homocysteine-albumin mixed disulfide is a possible intermediate of thiol-disulfide exchange reactions, we suggest that homocysteinylated albumin could be a new pathological factor, and that studies on the redox role of albumin and mixed disulfide production via thiol-disulfide exchange reactions could offer new therapeutic insights for reducing Hcy toxicity.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:38

Enthalten in:

Antioxidants & redox signaling - 38(2023), 13-15 vom: 16. Mai, Seite 920-958

Sprache:

Englisch

Beteiligte Personen:

Coppo, Lucia [VerfasserIn]
Scheggi, Simona [VerfasserIn]
DeMontis, Graziella [VerfasserIn]
Priora, Raffaella [VerfasserIn]
Frosali, Simona [VerfasserIn]
Margaritis, Antonio [VerfasserIn]
Summa, Domenico [VerfasserIn]
Di Giuseppe, Danila [VerfasserIn]
Ulivelli, Monica [VerfasserIn]
Di Simplicio, Paolo [VerfasserIn]

Links:

Volltext

Themen:

0LVT1QZ0BA
462-10-2
Albumin
Cysteine-homocysteine mixed disulfide
Disulfides
Homocysteine
Homocysteine-albumin mixed disulfide
Homocysteine-thiolactone
Homocystine
Journal Article
Research Support, Non-U.S. Gov't
Review
Sulfhydryl Compounds
Thiol exchange processes

Anmerkungen:

Date Completed 08.05.2023

Date Revised 08.05.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1089/ars.2021.0269

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM348664370