A Flow Cytometric Study of ER Stress and Autophagy

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Endoplasmic reticulum (ER) stress, autophagy, and cell death are critical cellular processes.
• The interplay between these pathways influences cell fate decisions.
• Understanding these mechanisms is crucial for developing targeted therapies.

Purpose of the Study:

• To elucidate the mechanistic link between ER stress, autophagy, and cell death.
• To investigate how modulating autophagy and apoptosis affects the ER stress response.
• To determine the impact of drug treatment sequence and concentration on cell death pathways.

Main Methods:

• Utilized Thapsigargin (Tg) and Chloroquine (CQ) to induce ER stress and modulate autophagy/apoptosis.
• Employed flow cytometry to measure cell death, cell cycle arrest, ER stress markers (PERK), misfolded proteins, and autophagy markers (LC3B).
• Investigated effects of prior induction/blockade of autophagy and apoptosis before ER stress induction.

Main Results:

• Tg and CQ treatments induced necrosis and apoptosis, G1 cell cycle arrest, ER stress, and autophagy.
• Prior autophagy induction amplified cell death, up-regulated autophagy, and reduced PERK.
• Drug sequence and concentration modulated ER stress, autophagy, and cell death, with CQ reducing misfolded proteins and Tg increasing reticulophagy.

Conclusions:

• A profound link exists between ER stress, autophagy, and cell death.
• The sequence and concentration of drug interventions critically modulate these interconnected biological processes.
• These findings highlight the potential for targeted manipulation of these pathways to control cell fate.