Necrotic cell death occur via JNK pathway with the activity of transcription factor c-Jun by 4-MC in INS-1 cell line

Area of Science:

• Biochemistry
• Cell Biology
• Toxicology

Background:

• 4-methylcatechol is a catechol derivative with potential cellular toxicity.
• Understanding the mechanisms of chemical-induced cell death is crucial for toxicology and disease research.

Purpose of the Study:

• Determine 4-methylcatechol doses causing cell death in rat insulinoma β-cells (INS-1).
• Identify the type of cell death induced by 4-methylcatechol.
• Investigate the molecular pathways involved in 4-methylcatechol-induced cell death.

Main Methods:

• Treatment of INS-1 cells with varying doses of 4-methylcatechol (350, 400, 450 μM).
• Assays for lactate dehydrogenase, reactive oxygen species, mitochondrial potential, ATP, and GTP.
• Western blot analysis to assess JNK and ERK pathway activation (p-RAF1, JNK, c-Jun, ATF2, ERK, Elk1).

Main Results:

• Necrotic cell death predominated over apoptosis at tested 4-methylcatechol doses.
• Increased lactate dehydrogenase, reactive oxygen species, and loss of mitochondrial potential, ATP, and GTP were observed.
• Activation of the JNK pathway via phosphorylated RAF1 and c-Jun, alongside alterations in ERK pathway components, was noted.

Conclusions:

• 4-methylcatechol induces necrotic cell death in INS-1 cells.
• The JNK pathway is activated by phosphorylated RAF1 and transcription factor c-Jun.
• Heat shock proteins Hsp 70 and Hsp 90 do not appear to inhibit the JNK pathway in this context.