RESUMEN

There is an unmet clinical need for pharmacologic treatment for metabolic dysfunction-associated steatotic liver disease (MASLD). Hepatocyte cell death is a hallmark of this highly prevalent chronic liver disease, but the dominant type of cell death remains uncertain. Here we report that ferroptosis, an iron-catalyzed mode of regulated cell death, contributes to MASLD. Unsupervised clustering in a cohort of biopsy-proven MASLD patients revealed a subgroup with hepatic ferroptosis signature and lower glutathione peroxidase 4 (GPX4) levels. Likewise, a subgroup with reduced ferroptosis defenses was discerned in public transcriptomics datasets. Four weeks of choline-deficient L-amino acid-defined high-fat diet (CDAHFD) induced MASLD with ferroptosis in mice. Gpx4 overexpression did not affect steatohepatitis, instead CDAHFD protected from morbidity due to hepatocyte-specific Gpx4 knockout. The ferroptosis inhibitor UAMC-3203 attenuated steatosis and alanine aminotransferase in CDAHFD and a second model, i.e., the high-fat high-fructose diet (HFHFD). The effect of monounsaturated and saturated fatty acids supplementation on ferroptosis susceptibility was assessed in human HepG2 cells. Fat-laden HepG2 showed a drop in ferroptosis defenses, increased phosphatidylglycerol with two polyunsaturated fatty acid (PUFA) lipid tails, and sustained ferroptosis sensitivity. In conclusion, this study identified hepatic ferroptosis as a detrimental factor in MASLD patients. Unexpectedly, non-PUFA supplementation to hepatocytes altered lipid bilayer composition to maintain ferroptosis sensitivity. Based on findings in in vivo models, ferroptosis inhibition represents a promising therapeutic target in MASLD.

Asunto(s)

RESUMEN

Key Clinical Message: Myeloma of the thyroid cartilage is a rare but important differential diagnosis of a laryngeal mass. Although hoarseness as the initial presenting symptom in multiple myeloma is extremely rare, a clinician should always consider it. Abstract: Multiple myeloma (MM) is a malignant plasma cell disorder characterized by an uncontrolled proliferation of monoclonal plasma cells. Although the clinical presentation at diagnosis can be quite variable, thyroid cartilage infiltration in MM is rare. Here we discuss a 65-year-old Caucasian male presenting to the ENT doctor with continuous hoarseness for 3 months. The initial clinical examination showed a tangible mass at the left lymph node level II-III. Further examination with fiber-optic laryngoscopy showed a bulging of the aryepiglottic and ventricular fold. Neck and chest CT scan revealed multiple osteolytic bone lesions in addition to the large lesion in the left thyroid cartilage. Laboratory work-up, PET-CT scan and biopsy of the thyroid cartilage were performed and eventually all confirmed the presence of a new diagnosis of IgA kappa MM. The patient was referred to the department of hematology to start with chemotherapy.