Intergenerational inheritance of paternal metabolic disorder: miR-29a/c-3p/glucose-6-phosphatase 1 axis in glucose intolerance propagation.

The escalating global burden of obesity and diabetes underscores the need to elucidate generational effects of parental metabolic health. This study investigates the generational inheritance of paternal obesity and glucose dysregulation in offspring, along with its underlying epigenetic mechanisms. Four-week-old male C57BL/6 J mice were randomly assigned to either a control diet (CON) or high-glucose/high-fat (HGF) group. After 4 weeks, these males were mated with healthy females to produce F1 male offspring, with the same breeding strategy applied to generate F2 males. Metabolic phenotyping revealed impaired glucose tolerance and insulin sensitivity in HGF-fed F0 males and F1/F2 male offspring, demonstrating intergenerational transmission of paternal HGF-induced metabolic dysfunction. Liver transcriptomic profiling identified elevated expression of the gluconeogenic enzyme glucose-6-phosphatase 1 (G6pc1) and reduced levels of miR-29a/c-3p in HGF males across three generations. Luciferase assay and molecular studies confirmed that G6pc1 is a direct target of miR-29a/c-3p, and miR-29a/c-3p negatively regulates G6pc1 expression. Functional analyses showed that hepatic miR-29a-3p knockdown in wild-type mice increased G6pc1 expression, inducing glucose intolerance and insulin resistance. Conversely, miR-29a-3p overexpression in HGF offspring suppressed G6pc1 and restored glucose homeostasis. Notably, sperm miR-29a/c-3p levels were consistently reduced in HGF-fed males, suggesting its role as an epigenetic carrier mediating intergenerational metabolic dysregulation. This study uncovers a paternal intergenerational inheritance mechanism whereby HGF-induced glucose dysregulation propagates intergenerationally through the miR-29a/c-3p-G6pc1 axis. These findings advance our understanding of the origins of metabolic disorders and highlight potential miRNA-targeted strategies for mitigating intergenerational metabolic risks.