Cardiometabolic Risk Unit, Institute of Clinical Physiology, CNR, 56121 Pisa, Italy.
Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland.
Cell Rep Med. 2024 Nov 19;5(11):101820. doi: 10.1016/j.xcrm.2024.101820.
Metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (MASH) are associated with a high prevalence of type 2 diabetes (T2D). Individuals with MASLD exhibit insulin resistance (IR) and hyperglycemia, but it is unclear whether hepatic glucose production (HGP) is increased with MASLD severity. We evaluated HGP in a cohort of histologically characterized individuals with MASL/MASH using stable isotope infusion (6,6-H-glucose, U-H-glycerol) and liver-specific genome-scale metabolic models (GEMs). Tracer-measured HGP is increased with liver fibrosis and inflammation, but not steatosis, and is associated with lipolysis and IR. The GEM-derived gluconeogenesis is elevated due to high glucogenic/energy metabolite uptakes (lactate, glycerol, and free fatty acid [FFA]), and the expression of insulin action genes (IRS1, IRS2, and AKT2) is reduced in MASH with fibrosis F2-F4, with/without T2D, suggesting these as putative mechanisms for increased fasting HGP and hyperglycemia. In conclusion, elevated HGP, lipolysis, and IR help to explain the mechanisms for the increased risk of hyperglycemia and T2D in MASH.
代谢功能障碍相关脂肪性肝病 (MASLD) 和脂肪性肝炎 (MASH) 与 2 型糖尿病 (T2D) 的高发率相关。MASLD 患者表现出胰岛素抵抗 (IR) 和高血糖,但尚不清楚 MASLD 严重程度是否会导致肝葡萄糖生成 (HGP) 增加。我们使用稳定同位素输注 (6,6-H-葡萄糖、U-H-甘油) 和肝脏特异性基因组规模代谢模型 (GEM) 对具有 MASL/MASH 的组织学特征个体进行了 HGP 评估。示踪剂测量的 HGP 随着肝纤维化和炎症而增加,但与脂肪变性无关,并且与脂肪分解和 IR 相关。由于高糖生成/能量代谢物摄取 (乳酸、甘油和游离脂肪酸 [FFA]),GEM 衍生的糖异生增加,并且纤维化 F2-F4 伴/不伴 T2D 的 MASH 中胰岛素作用基因 (IRS1、IRS2 和 AKT2) 的表达降低,这表明这些是增加空腹 HGP 和高血糖的潜在机制。总之,升高的 HGP、脂肪分解和 IR 有助于解释 MASH 中高血糖和 T2D 风险增加的机制。