Scholarlink

Background <p>Hypoxia disrupts corneal stromal physiology and alters cellular energy metabolism. This study aimed to elucidate the molecular role of the cellular energy sensor AMP-activated protein kinase (AMPK) in modulating the energy metabolism of human keratocytes (HKs) under hypoxic conditions and to explore a potential therapeutic strategy.</p> Methods <p><i>In vitro</i>, HKs were exposed to 1% O₂ for 2&#xa0;h and 24&#xa0;h to simulate hypoxia.&#xa0;In vivo, a mouse corneal alkali burn model was established, in which hypoxia is recognized as an important contributing factor to tissue injury.&#xa0;The expression of AMPK and its influence on downstream pathways related to mitochondrial metabolism were investigated. The AMPK agonist AICAR was administered in these models to assess its effects. Key molecular pathways, including AMPK/MFF/DRP1, AMPK/MTFR1L/OPA1 (mitochondrial dynamics), and AMPK/ULK1/PINK1/PARKIN (mitophagy), were analyzed to understand the mechanisms of action.</p> Results <p><i>In vitro</i>, hypoxia shifted HKs energy production from oxidative phosphorylation to anaerobic glycolysis over time, accompanied by AMPK upregulation. AICAR restored mitochondrial function, increased OCR, reduced ECAR and ROS, and improved mitochondrial membrane potential. AMPK knockdown abolished these protective effects. In vivo, AICAR treatment of alkali-burned mouse corneas significantly reduced corneal opacity and fluorescein staining scores, restored mitochondrial respiration and glycolysis balance. Mechanistically, AICAR activated AMPK to regulate mitochondrial dynamics via the AMPK/MFF/DRP1 and AMPK/MTFR1L/OPA1 pathways and enhanced mitophagy through the AMPK/ULK1/PINK1/PARKIN axis. This coordinated action increased mitochondrial oxidative phosphorylation capacity.</p> Conclusions <p>Activation of AMPK via AICAR ameliorates hypoxia‑induced energy imbalance in HKs in vitro and in mouse corneal alkali burn in vivo by restoring mitochondrial homeostasis. This mechanism represents a novel therapeutic target for hypoxia-related keratopathy and suggests a promising approach for energy replacement therapy.</p> Graphical Abstract <p>The graphical abstract was created with BioGDP.com, illustrating that AICAR activates the AMPK signaling pathway in HKs under hypoxic conditions. This activation inhibits mitochondrial fusion while enhancing mitochondrial fission, thereby facilitating downstream mitophagy processes. Consequently, these mechanisms contribute to the rejuvenation of mitochondrial state and the restoration of energy metabolic homeostasis</p> <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

AMPK orchestrates mitochondrial homeostasis via dynamics and mitophagy to combat hypoxia-induced energetic crisis in keratocytes

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月1日

查看全文
  • Xinlin Yan,
  • Yi Guan,
  • Guozhen Chen,
  • Shumei Yang,
  • Zhengyu Cao,
  • Xuan Li

摘要

Background

Hypoxia disrupts corneal stromal physiology and alters cellular energy metabolism. This study aimed to elucidate the molecular role of the cellular energy sensor AMP-activated protein kinase (AMPK) in modulating the energy metabolism of human keratocytes (HKs) under hypoxic conditions and to explore a potential therapeutic strategy.

Methods

In vitro, HKs were exposed to 1% O₂ for 2 h and 24 h to simulate hypoxia. In vivo, a mouse corneal alkali burn model was established, in which hypoxia is recognized as an important contributing factor to tissue injury. The expression of AMPK and its influence on downstream pathways related to mitochondrial metabolism were investigated. The AMPK agonist AICAR was administered in these models to assess its effects. Key molecular pathways, including AMPK/MFF/DRP1, AMPK/MTFR1L/OPA1 (mitochondrial dynamics), and AMPK/ULK1/PINK1/PARKIN (mitophagy), were analyzed to understand the mechanisms of action.

Results

In vitro, hypoxia shifted HKs energy production from oxidative phosphorylation to anaerobic glycolysis over time, accompanied by AMPK upregulation. AICAR restored mitochondrial function, increased OCR, reduced ECAR and ROS, and improved mitochondrial membrane potential. AMPK knockdown abolished these protective effects. In vivo, AICAR treatment of alkali-burned mouse corneas significantly reduced corneal opacity and fluorescein staining scores, restored mitochondrial respiration and glycolysis balance. Mechanistically, AICAR activated AMPK to regulate mitochondrial dynamics via the AMPK/MFF/DRP1 and AMPK/MTFR1L/OPA1 pathways and enhanced mitophagy through the AMPK/ULK1/PINK1/PARKIN axis. This coordinated action increased mitochondrial oxidative phosphorylation capacity.

Conclusions

Activation of AMPK via AICAR ameliorates hypoxia‑induced energy imbalance in HKs in vitro and in mouse corneal alkali burn in vivo by restoring mitochondrial homeostasis. This mechanism represents a novel therapeutic target for hypoxia-related keratopathy and suggests a promising approach for energy replacement therapy.

Graphical Abstract

The graphical abstract was created with BioGDP.com, illustrating that AICAR activates the AMPK signaling pathway in HKs under hypoxic conditions. This activation inhibits mitochondrial fusion while enhancing mitochondrial fission, thereby facilitating downstream mitophagy processes. Consequently, these mechanisms contribute to the rejuvenation of mitochondrial state and the restoration of energy metabolic homeostasis