Page 119 - 南京医科大学自然版

第46卷第5期 刘 敏，步丹丹，钱 旭. 微量元素硒与肿瘤风险及预后的研究进展［J］.
2026年5月 南京医科大学学报（自然科学版），2026，46（5）：739-750，761 ·741 ·

Sources
Diet Distribution & Selenoproteins
& Supplements Peripheral tissues
Liver ·GPX
（hepatic selenium ·TXRND
metabolism） ·TDI
·SELENOP
Intake & Absorption
Selenium is absorded
in the intestine
in organic and inorganic SELENOP⁃mediated distribution
forms
Selenoproteins：
eg.，GPX，TXRND，SELENOP
Liver
（hepatic selenium Metabolism & Excretion
metabolism）
· Selenoprotein synthesis
· Methylation pathway
Excretion via urine
and exhalation
Selenium from food and supplements is absorbed in the intestines and distributed throughout the circulatory system，primarily bound to SELENOP.
The liver plays a key role in regulating selenium metabolism and the availability of selenoproteins for synthesis. Selenium⁃dependent enzymes，such as
GPX and TXNRD，contribute to antioxidant defense and redox homeostasis，while TDI regulates thyroid hormone metabolism. Through these mecha⁃
nisms，selenium status may influence susceptibility to oxidative stress⁃related cancers. Selenium is ultimately excreted via the kidneys and respiratory
tract to maintain physiological balance.
图1 人体中硒摄入、吸收与代谢过程的示意图
Figure 1 Schematic diagram of selenium intake，absorption，and metabolic processes in the human body

表1 硒蛋白的主要生物学功能及其相关生理作用
Table 1 The primary biological functions of selenoproteins and their related physiological effects

Name Symbol Main function Application/Mechanism/Physiological role
Glutathione peroxidase 1 GPX1 Removes intracellular H 2O2 Reduces ROS via glutathione ⁃ dependent antioxidant reac⁃
and small ⁃ molecule perox⁃ tions；protective in the cardiovascular system，pancreatic β⁃
ides；maintains redox homeo⁃ cells，and nervous system；closely associated with oxidative
stasis stress⁃related disease risk
Glutathione peroxidase 2 GPX2 Antioxidant defense in intes⁃ Maintains intestinal mucosal barrier function and limits in⁃
tinal epithelium flammation⁃related ROS production；involved in inflammatory
bowel disease and colorectal carcinogenesis
Glutathione peroxidase 3 GPX3 Antioxidant enzyme in body Serves as a circulating antioxidant defense and biomarker of
fluids and plasma selenium nutritional status；associated with cardiovascular
disease，chronic inflammation，and myocardial fibrosis
Glutathione peroxidase 4 GPX4 Eliminates membrane phos⁃ Core executor of ferroptosis inhibition；maintains membrane
pholipid peroxides；suppress⁃ stability by blocking polyunsaturated fatty acid⁃phospholipid
es lipid peroxidation peroxidation；closely related to neurodegenerative diseases，
myocardial injury，and tumor drug resistance
Glutathione peroxidase 6 GPX6 Antioxidant function（tissue ⁃ Function not fully elucidated；may participate in local oxida⁃
specific） tive stress regulation；associated with nervous system homeo⁃
stasis and degenerative changes
Thioredoxin reductase 1 TXNRD1 Maintains the reduced state Regulates redox signaling，DNA synthesis，and protein re⁃
of the cellular thioredoxin pair；plays a key role in tumorigenesis and ferroptosis resis⁃
system tance
Thioredoxin reductase 2 TXNRD2 Mitochondrial redox homeo⁃ Protects mitochondrial function；regulates energy metabolism
stasis regulation and apoptosis；associated with cardiovascular disease and
metabolic disorders