3-HK介导双酚F致小鼠抑郁的机制及亮氨酸的干预作用

The mechanism of 3-hydroxykynurenine in the depression-like changes induced by bisphenol F in mice and the intervention effect of leucine

摘要

目的：探究犬尿氨酸（kynurenine，Kyn）代谢通路中的关键神经毒性代谢物3-羟基犬尿氨酸（3-hydroxy-kynurenine，3-HK）在双酚F（bisphenol F，BPF）暴露引起小鼠抑郁样行为中的作用及机制，并评估亮氨酸干预该通路所产生的神经保护效应，从而为寻找潜在干预靶点提供实验依据。方法：构建BPF暴露小鼠模型，通过悬尾实验、强迫游泳、旷场实验等行为学实验观察小鼠抑郁样行为改变，检测小鼠海马体和前额皮层中3-HK、5-羟色胺（5-hydroxytryptamine，5-HT）、Kyn等抑郁相关神经递质水平的改变以及干扰素-γ（interferon gamma，IFN-γ）、白介素-1β（interleukin-1β，IL-1β）等促炎因子和犬尿氨酸单加氧酶（kynurenine-3-monooxygenase，KMO）表达水平的改变；设置亮氨酸联合干预组，观察BPF诱导的小鼠抑郁样行为是否改善，并检测神经递质水平、促炎因子和KMO表达水平的变化；采用荧光探针法观察3-HK在BPF引起原代神经元活性氧（reactive oxygen species，ROS）生成中的作用。结果：BPF暴露引起小鼠明显的抑郁样行为，小鼠海马和皮层中5-HT含量无明显变化，而Kyn含量显著减少；BPF显著上调海马和皮层中KMO表达水平，促进3-HK的累积同时引发IFN-γ、IL-1β等促炎因子增加，加剧神经损伤；亮氨酸干预后BPF诱导的小鼠抑郁样行为得到改善，显著逆转了BPF诱导的KMO及促炎因子的异常表达，3-HK水平显著降低，其余神经递质水平变化不明显；同时，竞争性抑制3-HK转运或抑制KMO明显逆转BPF引起的ROS。结论：BPF暴露可上调海马和皮层KMO表达，引起3-HK异常蓄积，继而触发ROS过度生成和神经炎症，这些病理变化可能协同参与神经损伤和抑郁样行为。亮氨酸则能抑制该代谢偏移，减轻氧化应激与炎症，从而缓解抑郁样行为。

Abstract

Objective：To explore the role and mechanism of 3-hydroxy-kynurenine（3-HK），a key neurotoxic metabolite in the kynurenine pathway，in bisphenol F（BPF）-induced depressive-like changes in mice and evaluate the intervention effect of leucine by intervening this pathway，thereby providing experimental evidence for identifying potential intervention targets. Methods：The BPF exposure mouse model was established to investigate its neurotoxic effects，and the depression-like behaviors were assessed through behavioral tests such as the tail-suspension test，forced swimming test，and open-field test. Concurrently，the levels of depression-related neurotransmitters，including 3-HK，5-hydroxytryptamine（5-HT），and kynurenine were measured in the hippocampus and prefrontal cortex. Alterations in the expression levels of pro-inflammatory cytokines，including interferon-gamma（IFN-γ）and interleukin-1β（IL-1β），as well as kynurenine 3-monooxygenase（KMO），were also detected. Furthermore，a leucine combined intervention group was established to assess whether BPF-induced depression-like behaviors improved，with additional measurements of neurotransmitter levels，pro-inflammatory factors，and KMO expression. The role of 3-HK in BPF-induced reactive oxygen species（ROS）generation in primary neurons was investigated using a fluorescent probe assay. Results：BPF exposure induced depressive-like behaviors in mice. While 5-HT levels in the hippocampus and cortex showed no significant change，the content of kynurenine was markedly reduced. BPF exposure significantly increased the expression levels of KMO in the hippocampus and cortex，and promoted the accumulation of 3-HK，which facilitated the production of pro-inflammatory factors such as IFN-γ and IL-1β by activating the inflammatory pathway. Leucine intervention alleviated BPF-induced depressive-like behavior，significantly reversing the abnormal expression of KMO and pro-inflammatory factors，and notably reducing 3-HK levels，though other neurotransmitter levels remained largely unchanged. Meanwhile，competitive inhibition of 3-HK transport or inhibition of KMO significantly reversed the ROS caused by BPF. Conclusion：BPF exposure upregulates KMO expression in the hippocampus and cortex，leading to abnormal accumulation of 3-HK，which subsequently triggers excessive ROS generation and neuroinflammation. These pathological changes may collectively contribute to neural damage and depression-like behaviors. In contrast，leucine inhibits this metabolic shift，alleviates oxidative stress and inflammation，thereby mitigating depression-like behaviors.

关键词

双酚F / 3-羟基犬尿氨酸 / 亮氨酸 / 抑郁 / 海马体 / 大脑皮层

Key words

bisphenol F / 3-hydroxy-hynurenine / leucine / depression / hippocampus / cerebral cortex

参考文献

[1] NEUTEBOOM D, ZANTVOORD J B, GOYA—MALDONADO R, et al. Accelerated intermittent theta burst stimulation in major depressive disorder: a systematic review[J]. Psychiatry Res, 2023, 327:115429

[2] LIU J C, ZHANG L Y, LU G H, et al. Occurrence, toxicity and ecological risk of bisphenol A analogues in aquatic environment—a review[J]. Ecotoxicol Environ Saf, 2021, 208:111481

[3] CULL M E, WINN L M. Bisphenol A and its potential mechanism of action for reproductive toxicity[J]. Toxicology, 2025, 511:154040

[4] MICHAŁOWICZ J. Bisphenol A—sources, toxicity and biotransformation[J]. Environ Toxicol Pharmacol, 2014, 37(2):738-758

[5] WILLHITE C C, DASTON G P. Bisphenol exposure, hazard and regulation[J]. Toxicology, 2019, 425:152243

[6] LU S Y, YU Y L, REN L, et al. Estimation of intake and uptake of bisphenols and triclosan from personal care products by dermal contact[J]. Sci Total Environ, 2018, 621:1389-1396

[7] MENG Z Y, WANG D Z, LIU W, et al. Perinatal exposure to Bisphenol S (BPS) promotes obesity development by interfering with lipid and glucose metabolism in male mouse offspring[J]. Environ Res, 2019, 173:189-198

[8] GAO C Z, HE H H, QIU W H, et al. Oxidative stress, endocrine disturbance, and immune interference in humans showed relationships to serum bisphenol concentrations in a dense industrial area[J]. Environ Sci Technol, 2021, 55(3):1953-1963

[9] KRUPA M M, PIENKOWSKI T, TANKIEWICZ—KWEDLO A, et al. Targeting the kynurenine pathway in gliomas: insights into pathogenesis, therapeutic targets, and clinical advances[J]. Biochim Biophys Acta BBA Rev Cancer, 2025, 1880(3):189343

[10] YE Z H, YANG S R, LU L, et al. Unlocking the potential of the 3—hydroxykynurenine/kynurenic acid ratio: a promising biomarker in adolescent major depressive disorder[J]. Eur Arch Psychiatry Clin Neurosci, 2025, 275(4):1049-1061

[11] BARANYI A, AMOUZADEH—GHADIKOLAI O, VON LEWINSKI D, et al. Branched—chain amino acids as new biomarkers of major depression—a novel neurobiology of mood disorder[J]. PLoS One, 2016, 11(8):e0160542

[12] WALKER A K, WING E E, BANKS W A, et al. Leucine competes with kynurenine for blood—to—brain transport and prevents lipopolysaccharide—induced depression—like behavior in mice[J]. Mol Psychiatry, 2019, 24(10):1523-1532

[13] YU Z, LIN Y X, WU L L, et al. Bisphenol F exposure induces depression—like changes: roles of the kynurenine metabolic pathway along the "liver—brain" axis[J]. Environ Pollut, 2024, 346:123356

[14] SEKINE A, OKAMOTO M, KANATANI Y, et al. Amino acids inhibit kynurenic acid formation via suppression of kynurenine uptake or kynurenic acid synthesis in rat brain in vitro[J]. Springerplus, 2015, 4(1):48

[15] WINKLER J, LIU P Y, PHONG K, et al. Bisphenol A replacement chemicals, BPF and BPS, induce protumorigenic changes in human mammary gland organoid morphology and proteome[J]. Proc Natl Acad Sci USA, 2022, 119(11):e2115308119

[16] HUO S M, LI B, DU J Y, et al. Neurotoxic effects of perinatal exposure to Bisphenol F on offspring mice[J]. Environ Pollut, 2024, 362:124932

[17] BARONE P. The 'Yin' and the 'Yang' of the kynurenine pathway: excitotoxicity and neuroprotection imbalance in stress—induced disorders[J]. Behav Pharmacol, 2019, 30(2 and 3):163-186

[18] HAN Q, CAI T, TAGLE D A, et al. Structure, expression, and function of kynurenine aminotransferases in human and rodent brains[J]. Cell Mol Life Sci, 2010, 67(3):353-368

[19] OKUDA S, NISHIYAMA N, SAITO H, et al. 3—hydroxykynurenine, an endogenous oxidative stress generator, causes neuronal cell death with apoptotic features and region selectivity[J]. J Neurochem, 1998, 70(1):299-307

[20] LI Y Q, UNIVERSITY J, ZHANG L Y, et al. Kynurenic acid, a small foodborne molecule with the potential to affect human health[J]. J Agric Food Chem, 2025, 73(15):8729-8739

[21] DRYER S E. Glutamate receptors in the kidney[J]. Nephrol Dial Transplant, 2015, 30(10):1630-1638

[22] KNAUS L S, BASILICO B, MALZL D, et al. Large neutral amino acid levels tune perinatal neuronal excitability and survival[J]. Cell, 2023, 186(9):1950-1967

[23] WHIPP A M, HEINONEN—GUZEJEV M, PIETILÄINEN K H, et al. Branched—chain amino acids linked to depression in young adults[J]. Front Neurosci, 2022, 16:935858

基金资助

国家自然科学基金(82473684)

国家级大学生创新训练计划(202310312025Z)

国家级大学生创新训练计划(202410312069Z)