Unraveling the metabolic landscape of alkaptonuria through a human-relevant in vitro liver disease model
- 1Vrije Universiteit Brussel
Abstract
Alkaptonuria (AKU) is a rare inherited metabolic disorder of tyrosine catabolism caused by a deficient homogentisate 1,2-dioxygenase (HGD) enzyme. This results in the accumulation of homogentisic acid (HGA), driving a progressive multisystem pathology characterized by debilitating early-onset osteoarthritis due to connective tissue degeneration. While previous in vitro studies have primarily relied on exogenous HGA exposure in osteoarticular cell models, the direct metabolic consequences of endogenous HGD deficiency within its native hepatic context remain poorly understood. Here, we established the first human-relevant HGD knockout hepatic in vitro model using a universal in-house-developed homology-directed repair approach. Integrative multi-omic analysis revealed that HGD deficiency induces widespread metabolic rewiring extending beyond disrupted tyrosine catabolism. HGD-deficient hepatocytes exhibited elevated oxidative stress accompanied by impaired mitochondrial respiration and a pseudohypoxic metabolic adaptation toward increased glycolytic dependency. Despite this glycolytic shift, the cells displayed reduced anabolic and translational activity alongside attenuated proliferation, consistent with a chronic stress-adaptive survival state rather than a proliferative metabolic phenotype. This study provides systems-level insights into the pathophysiology of AKU and establishes a versatile platform for mechanistic and therapeutic investigation.
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BibTeX
@misc{rombaut2026unraveling,
title = {{Unraveling the metabolic landscape of alkaptonuria through a human-relevant in vitro liver disease model}},
author = {M. Rombaut and G. Del'haye and S. Lequeue and B. P. Norman and L. Desmet and N. Salvi and A. Heymans and J. Neuckermans and J. H. Hughes and G. Ates and A. Massie and T. Vanhaecke and G. Bou-Gharios and J. De Kock},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.27.754319},
url = {https://www.biorxiv.org/content/10.64898/2026.09.27.754319v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Unraveling the metabolic landscape of alkaptonuria through a human-relevant in vitro liver disease model
AU - M. Rombaut
AU - G. Del'haye
AU - S. Lequeue
AU - B. P. Norman
AU - L. Desmet
AU - N. Salvi
AU - A. Heymans
AU - J. Neuckermans
AU - J. H. Hughes
AU - G. Ates
AU - A. Massie
AU - T. Vanhaecke
AU - G. Bou-Gharios
AU - J. De Kock
PY - 2026
DA - 2026/09/27
PB - bioRxiv
DO - 10.64898/2026.09.27.754319
UR - https://www.biorxiv.org/content/10.64898/2026.09.27.754319v1
AB - Alkaptonuria (AKU) is a rare inherited metabolic disorder of tyrosine catabolism caused by a deficient homogentisate 1,2-dioxygenase (HGD) enzyme. This results in the accumulation of homogentisic acid (HGA), driving a progressive multisystem pathology characterized by debilitating early-onset osteoarthritis due to connective tissue degeneration. While previous in vitro studies have primarily relied on exogenous HGA exposure in osteoarticular cell models, the direct metabolic consequences of endogenous HGD deficiency within its native hepatic context remain poorly understood. Here, we established the first human-relevant HGD knockout hepatic in vitro model using a universal in-house-developed homology-directed repair approach. Integrative multi-omic analysis revealed that HGD deficiency induces widespread metabolic rewiring extending beyond disrupted tyrosine catabolism. HGD-deficient hepatocytes exhibited elevated oxidative stress accompanied by impaired mitochondrial respiration and a pseudohypoxic metabolic adaptation toward increased glycolytic dependency. Despite this glycolytic shift, the cells displayed reduced anabolic and translational activity alongside attenuated proliferation, consistent with a chronic stress-adaptive survival state rather than a proliferative metabolic phenotype. This study provides systems-level insights into the pathophysiology of AKU and establishes a versatile platform for mechanistic and therapeutic investigation.
ER -