Mtb-induced endoplasmic reticulum (ER) stress modulates MFN2 production in macrophages. (A,B) Raw264.7 cells and BMDMs were infected with Mtb at a MOI of 1 for 3 h and CHOP, p-eIF2α, and BiP were detected by western blotting. β-actin was used as the loading control. BMDMs were pretreated with (C) tunicamycin (Tm, 500 ng/mL), (D) 4-phenylbutyric acid (4-PBA, 10 mM), or (E) ER stress inhibitors (10 µM GSK2606414, 5 µM IREstatin, 500 µM AEBSF) for 1 h and infected with Mtb for 3 h. At 48 h after Mtb infection, western blotting for Parkin, MFN2, CHOP, and β-actin was performed. Data are representative of three independent experiments.