CHAC1 exacerbates arsenite cytotoxicity by lowering intracellular glutathione levels

Area of Science:

• Cell Biology
• Toxicology
• Biochemistry

Background:

• Arsenite (As(III)) is a toxic metalloid known to induce cytotoxicity and apoptosis in various cell types.
• Glutathione (GSH) plays a critical role in cellular defense against oxidative stress and toxic insults.
• CHAC1 (also known as AIG1) is a gene induced by endoplasmic reticulum stress and implicated in apoptosis.

Purpose of the Study:

• To investigate the role of CHAC1 in arsenite (As(III))-induced cytotoxicity and apoptosis in HaCaT cells.
• To determine the relationship between CHAC1 expression, intracellular GSH levels, and As(III) sensitivity.

Main Methods:

• HaCaT cells were transfected with CHAC1 siRNA to reduce CHAC1 expression.
• Cells were treated with arsenite (As(III)) and/or buthionine sulfoximine (BSO), an inhibitor of GSH biosynthesis.
• Intracellular GSH levels, cell viability, and apoptosis (caspase-3 cleavage) were assessed.

Main Results:

• Downregulation of CHAC1 led to decreased sensitivity to As(III)-induced cytotoxicity.
• Elevated intracellular GSH levels in CHAC1-depleted cells correlated with reduced As(III) sensitivity.
• As(III) exposure increased CHAC1 expression and induced apoptosis, which was abrogated in CHAC1 siRNA-transfected cells.

Conclusions:

• CHAC1 is involved in regulating intracellular GSH levels, thereby modulating HaCaT cell sensitivity to arsenite.
• CHAC1 plays a significant role in As(III)-induced apoptosis in HaCaT cells.
• Targeting CHAC1 may offer a strategy to mitigate arsenite toxicity.