LKB1/ AMPK deficiency aggravates mitochondrial DNA leakage via mTOR-dependent mitophagy damage in liver injury sensitized by trichloroethylene.
Impaired mitophagy due to TCE exposure may lead to liver inflammation through mitochondrial DNA leakage and activation of immune pathways.
Where it sits
this study against the rest of the aicar (acadesine) corpusSummary and findings
This study investigated the effects of trichloroethylene (TCE) sensitization on liver injury in a mouse model, focusing on the LKB1/AMPK/mTOR signaling pathway and mitophagy. AICAR was used to assess its impact on mitochondrial DNA leakage and inflammatory responses. The findings suggest a link between impaired mitophagy and exacerbated liver inflammation.
Abstract
Occupational medicamentosa-like dermatitis induced by trichloroethylene (OMDT) is a severe systemic allergic disease, often accompanied by acute liver injury. However, the underlying mechanisms linking metabolic disorders and immune damage remain unclear. In a TCE-sensitized mouse model, we demonstrated that TCE sensitization inhibited LKB1/AMPK/mTOR signaling pathway (LKB1 overexpression, AICAR, rapamycin) or autophagy (3-MA) in hepatocytes, resulting in defective mitophagy. This mitochondrial dysfunction leads to leakage of mitochondrial DNA (mtDNA) into the cytoplasm, where mtDNA acts as a damage-associated molecular pattern (DAMP) to activate the cGAS-STING pathway, driving the production of proinflammatory cytokines (IL-1β, IL-6, TNF-α), and exacerbating liver inflammation. Restoration of LKB1/AMPK signaling or inhibition of mTOR rescued mitophagi, reduced mitochondrial DNA leakage, inhibited cGAS-STING activation, and alleviated liver pathology, while inhibition of autophagy alone recapitulated the TCE-induced phenotype. Taken together, our findings demonstrate that failure of TCE via LKB1/AMPK/mTOR mediated mitophagy destroys hepatocyte homeostasis, leading to mtDNA-driven cGAS-STING activation and immune-mediated liver injury in the pathogenesis of OMDT, thus providing a potential therapeutic target for OMDT-related liver injury.
Background
The paper addresses the mechanisms linking metabolic disorders and immune damage in occupational medicamentosa-like dermatitis induced by trichloroethylene (OMDT). Previous research has identified liver injury as a significant complication of TCE exposure, but the specific pathways involved remain poorly understood. This study is important as it explores the role of LKB1/AMPK/mTOR signaling in mitochondrial dysfunction and its impact on liver inflammation.
Methods
The study utilized a TCE-sensitized mouse model to examine the effects of various interventions on liver injury. Specific doses of AICAR and other compounds were administered, although exact dosages and durations are not reported in the abstract. The primary outcome measures included mitochondrial DNA leakage and proinflammatory cytokine production.
Results
The study demonstrated that TCE sensitization led to inhibition of the LKB1/AMPK/mTOR signaling pathway, resulting in defective mitophagy and increased mitochondrial DNA leakage. Specific numeric findings are not reported in the abstract.
Interpretation
The findings suggest a significant role of mitochondrial dysfunction in the pathogenesis of liver injury related to TCE exposure. However, the clinical relevance of these findings is uncertain, as the effect sizes and direct implications for human health are not clearly established. Confounding factors include the use of a rodent model and the lack of human data.
Key findings
- TCE sensitization inhibited LKB1/AMPK/mTOR signaling pathway.
- Restoration of LKB1/AMPK signaling reduced mitochondrial DNA leakage.
- Inhibition of autophagy recapitulated the TCE-induced phenotype.
Limitations
- rodent-only evidence, no human data
- mechanistic study without clinical outcomes
- small sample size not specified