Related Experiment Video
Updated: Jun 8, 2025
Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway
Published on: August 23, 2024
Monocrotaline-mediated autophagy via inhibiting PI3K/AKT/mTOR pathway induces apoptosis in rat hepatocytes
Yazhou Guo1,2, Yang Yuan2, Ruibo Wang2
1Shaanxi Engineering Research Center of the Prevention and Control for Animal Disease, Yangling Vocational and Technical College, Yangling, Shaanxi, China.
Abstract:
Monocrotaline (MCT), a major pyrrolizidine alkaloid, is well-known for its high liver toxicity. Dysregulation of autophagy induced apoptosis can lead to various liver diseases, including those induced by chemical compounds. Therefore, we aim to explore whether autophagy might serve as a potential strategy for addressing liver apoptosis caused by MCT. In primary rat hepatocytes (PRHs), MCT significantly increased the number of autophagosomes and the expression levels of LC3II, Becline-1, and Atg5, while it decreased the expression of p62 in a concentration-dependent manner at doses of 100, 200, 300, and 400 μM. Western blot assays revealed MCT inhibited the phosphorylation levels of the PI3K/AKT/mTOR pathway. To elucidate the role of autophagy in mediating MCT-induced apoptosis, we further pretreated PRHs with the autophagy agonist Rapamycin and the inhibitors Bafilomycin A1 and Chloroquine, respectively, and assessed the apoptosis of PRHs induced by MCT. The results displayed that Rapamycin increased the apoptosis rate and the expression of cleaved caspase-3, whereas Bafilomycin A1 and Chloroquine reduced the apoptosis and the expression of cleaved caspase-3 in PRHs. This study confirms that autophagy enhances PRHs apoptosis induced by MCT. In summary, this study demonstrates that MCT-induced autophagy via inhibition of the PI3K/AKT/mTOR pathway can lead to apoptosis in PRHs.
Insights
Monocrotaline (MCT) triggers autophagy, a cellular process, which exacerbates liver cell apoptosis. Inhibiting this autophagy pathway may offer a therapeutic strategy for MCT-induced liver injury.
Area of Science:
- Hepatology
- Cell Biology
- Toxicology
Background:
- Pyrrolizidine alkaloids, like Monocrotaline (MCT), are known hepatotoxins.
- Autophagy dysregulation is implicated in chemical-induced liver injury and apoptosis.
- Understanding MCT's effect on autophagy is crucial for developing therapeutic interventions.
Purpose of the Study:
- To investigate the role of autophagy in Monocrotaline (MCT)-induced liver cell apoptosis.
- To determine if modulating autophagy can mitigate MCT-induced hepatotoxicity.
Main Methods:
- Primary rat hepatocytes (PRHs) were treated with varying concentrations of MCT (100–400 μM).
- Autophagy markers (LC3II, Beclin-1, Atg5, p62) and PI3K/AKT/mTOR pathway phosphorylation were assessed via Western blot.
- PRHs were pretreated with autophagy modulators (Rapamycin, Bafilomycin A1, Chloroquine) before MCT exposure to evaluate apoptosis.
Main Results:
- MCT significantly increased autophagosome formation and key autophagy markers (LC3II, Beclin-1, Atg5) while decreasing p62.
- MCT inhibited the PI3K/AKT/mTOR signaling pathway.
- Autophagy activation (Rapamycin) enhanced MCT-induced apoptosis, while inhibition (Bafilomycin A1, Chloroquine) reduced it.
Conclusions:
- Autophagy is significantly induced by MCT in primary rat hepatocytes.
- MCT induces autophagy through the inhibition of the PI3K/AKT/mTOR pathway.
- Autophagy activation exacerbates, rather than protects against, MCT-induced hepatocyte apoptosis, suggesting it as a potential therapeutic target.
Related Concept Videos
01:22PI3K/mTOR/AKT Signaling Pathway
03:03mTOR Signaling and Cancer Progression
The mTOR pathway or the...
01:31The Intrinsic Apoptotic Pathway