GC–MS analysis of 4-hydroxyproline: elevated proline hydroxylation in metformin-associated lactic acidosis and metformin-treated Becker muscular dystrophy patients

Abstract Metformin (N,N-dimethylbiguanide), an inhibitor of gluconeogenesis and insulin sensitizer, is widely used for the treatment of type 2 diabetes. In some patients with renal insufficiency, metformin can accumulate and cause lactic acidosis, known as metformin-associated lactic acidosis (MALA, defined as lactate ≥ 5 mM, pH < 7.35, and metformin concentration > 38.7 µM). Here, we report on the post-translational modification (PTM) of proline (Pro) to 4-hydroxyproline (OH-Pro) in metformin-associated lactic acidosis and in metformin-treated patients with Becker muscular dystrophy (BMD). Pro and OH-Pro were measured simultaneously by gas chromatography–mass spectrometry before, during, and after renal replacement therapy in a patient admitted to the intensive care unit (ICU) because of MALA. At admission to the ICU, plasma metformin concentration was 175 µM, with a corresponding lactate concentration of 20 mM and a blood pH of 7.1. Throughout ICU admission, the Pro concentration was lower compared to healthy controls. Renal excretion of OH-Pro was initially high and decreased over time. Moreover, during the first 12 h of ICU admission, OH-Pro seems to be renally secreted while thereafter, it was reabsorbed. Our results suggest that MALA is associated with hyper-hydroxyprolinuria due to elevated PTM of Pro to OH-Pro by prolyl-hydroxylase and/or inhibition of OH-Pro metabolism in the kidneys. In BMD patients, metformin, at the therapeutic dose of 3 × 500 mg per day for 6 weeks, increased the urinary excretion of OH-Pro suggesting elevation of Pro hydroxylation to OH-Pro. Our study suggests that metformin induces specifically the expression/activity of prolyl-hydroxylase in metformin intoxication and BMD..

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:56

Enthalten in:

Amino acids - 56(2024), 1 vom: 10. März

Sprache:

Englisch

Beteiligte Personen:

Baskal, Svetlana [VerfasserIn]
Posma, Rene A. [VerfasserIn]
Bollenbach, Alexander [VerfasserIn]
Dieperink, Willem [VerfasserIn]
Bakker, Stephan J. L. [VerfasserIn]
Nijsten, Maarten W. [VerfasserIn]
Touw, Daan J. [VerfasserIn]
Tsikas, Dimitrios [VerfasserIn]

Links:

Volltext [kostenfrei]

BKL:

35.76

Themen:

4-Hydroxyproline
Amino acids
BMD
Dialysis
GC–MS
Intoxication
Kidney injury
MALA
Mass spectrometry
PTM
Renal replacement therapy (RTR)

Anmerkungen:

© The Author(s) 2024

doi:

10.1007/s00726-024-03383-9

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

SPR055090966