1.The Role and Regulatory Mechanisms of FOXO1 in Hepatic Lipid Deposition
Meng JIA ; Fang-Hui LI ; Shi-Zhan YAN ; Ai-Ju LI ; Yi-Le WANG ; Pin-Shi NI ; Jia-Han HE ; Yin-Lu LI
Progress in Biochemistry and Biophysics 2026;53(4):905-919
Metabolic associated fatty liver disease (MAFLD) is fundamentally driven by an imbalance in hepatic fatty-acid flux: the influx of fatty acids exceeds the liver’s capacity for disposal, resulting in excessive hepatic lipid accumulation, predominantly in the form of triglycerides (TGs). The occurrence and progression of MAFLD depend on disordered regulation across multiple metabolic steps, including fatty-acid uptake, de novo lipogenesis (DNL), fatty-acid oxidation (FAO), and very low-density lipoprotein (VLDL) export. Forkhead box protein O1 (FOXO1) is a key transcriptional regulator within the hepatic network coordinating glucose and lipid metabolism. Under metabolic stress and insulin resistance (IR), FOXO1 expression is frequently increased, whereas its inhibitory phosphorylation is reduced. These changes enhance FOXO1 nuclear localization and transcriptional activity, thereby reprogramming the expression of genes related to metabolism in the liver. Because hepatic lipid deposition is the central pathological feature of MAFLD, the functional status of FOXO1 directly influences hepatic lipid homeostasis. Growing evidence suggests that FOXO1 can exert bidirectional, environment-dependent effects on hepatic lipid accumulation; however, the molecular basis for this functional switch remains incompletely understood. This review systematically summarizes the biological functions and regulatory mechanisms of FOXO1 and its roles in hepatic lipid metabolism, with a particular focus on its crosstalk with insulin signaling. FOXO1 expression is shaped by RNA modifications and epigenetic regulation mediated by non-coding RNAs. Its transcriptional output is precisely governed by post-translational modifications—such as phosphorylation and acetylation—as well as by coordinated nucleocytoplasmic shuttling. Notably, these regulatory patterns vary markedly across nutritional states, degrees of insulin resistance, and stages of disease. In the fed state, insulin/IGF-1 signaling activates the PI3K-AKT pathway, promoting the inhibitory phosphorylation of FOXO1 and facilitating additional modifications, including acetylation, methylation, and ubiquitination. Together, these events drive FOXO1 export from the nucleus and dampen its transcriptional activity, suppressing gluconeogenesis and constraining lipogenic programs. Conversely, during fasting or when insulin signaling is weakened, FOXO1 inhibition is relieved. FOXO1 accumulates in the nucleus, binds to DNA, and regulates the transcription of downstream target genes. Mechanistically, FOXO1 can aggravate hepatic lipid accumulation by activating genes involved in TG synthesis while repressing FAO-related pathways, thereby favoring storage over oxidation. However, under specific conditions, FOXO1 may also alleviate the hepatic lipid burden by promoting TG hydrolysis and enhancing VLDL secretion, thereby reducing the net hepatic lipid load. In addition, lipotoxic signals mediated by ceramides and diacylglycerols (Cer/DAG) activate atypical protein kinase C (aPKC), further exacerbating the disruption of the AKT-FOXO1 axis. This vicious cycle ultimately produces a metabolic paradox in which increased hepatic glucose output coexists with persistent, insulin-independent lipogenesis, accelerating MAFLD progression. Importantly, FOXO1 regulation is not uniform: during early metabolic overload, insulin-mediated suppression may remain effective, whereas in advanced insulin resistance, the loss of AKT control permits sustained FOXO1 activity. Such stage-dependent dynamics may help explain why FOXO1 can either promote steatosis or, in certain contexts, support programs that facilitate lipid turnover. Accordingly, interventions should be liver-specific and tuned to the disease stage, aiming to curb maladaptive FOXO1 signaling while preserving its capacity to promote triglyceride hydrolysis and VLDL secretion when advantageous. Overall, this review offers an important perspective on MAFLD pathogenesis, emphasizing FOXO1 as a potential therapeutic target and providing a theoretical basis for developing liver-specific, disease-course-dependent precision interventions.
2.Expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells in children with bronchial asthma.
Hui-Ling SHI ; Jie-Bo LIU ; Ai-Pin LU
Chinese Journal of Contemporary Pediatrics 2016;18(7):614-617
OBJECTIVETo study the expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells (PBMCs) in children with bronchial asthma, as well as their roles in the pathogenesis of asthma.
METHODSThirty children with acute exacerbation of bronchial asthma were enrolled as the asthma group, and 20 healthy children were enrolled as the control group. RT-PCR and Western blot were used to measure the mRNA and protein expression levels of PI3K, NF-κB, and STAT1 in PBMCs. A spirometer was used to compare the pulmonary function between the two groups. The correlations between the mRNA expression of PI3K, NF-κB, and STAT1 and pulmonary function in children with bronchial asthma were analyzed.
RESULTSThe asthma group had significantly higher mRNA and protein expression levels of PI3K, NF-κB, and STAT1 than the control group (P<0.05). Compared with the control group, the asthma group showed significant reductions in pulmonary function indices such as FEV1%, FEV1/FVC, and PEF% (P<0.05). In children with bronchial asthma, the mRNA expression levels of PI3K, NF-κB, and STAT1 were negatively correlated with FEV1%, FEV1/FVC, and PEF% (P<0.05).
CONCLUSIONSThe expression levels of PI3K, NF-κB, and STAT1 increase in children with asthma, and are negatively correlated with pulmonary function indices, suggesting that PI3K, NF-κB and STAT1 are involved in the development and progression of bronchial asthma in children.
Asthma ; blood ; etiology ; physiopathology ; Child ; Child, Preschool ; Female ; Forced Expiratory Volume ; Humans ; Leukocytes, Mononuclear ; chemistry ; Male ; NF-kappa B ; blood ; genetics ; physiology ; Phosphatidylinositol 3-Kinases ; blood ; genetics ; physiology ; RNA, Messenger ; analysis ; STAT1 Transcription Factor ; blood ; genetics ; physiology

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