Fig. 4

Depletion of HIGD2A induces mitochondrial stress. A, C Intercellular ATP level in HepG2 (A) and Huh7 (C) transfected with shCtrl or shHIGD2A.1. B, D Immunofluorescent (IF) images showing mitochondria morphology in HepG2 (B) and Huh7 (D) cells transfected with shCtrl or shHIGD2A.1. Left, representative IF images (magenta, MitoTracker; yellow, DAPI) and 3D mitochondria reconstruction of shCtrl- and shHIGD2A-infected HepG2 and Huh7 cell. Scale bar, 5 μm; Sphericity heat map, 0.326–0.915. Right, sphericity analysis of 3D reconstructed mitochondria (results are presented as mean ± SD). E Immunoblot analysis of mitochondrial fusion-related protein (Mfn1 and OPA1) in HepG2 (left) and Huh7 (right) transfected with shCtrl or shHIGD2A.1. F ATF5 mRNA level in in HepG2 (left) and Huh7 (right) transfected with shCtrl or shHIGD2A.1 measured by real-time PCR. Results shown are mean ± SEM. The Mann–Whitney test was used for statistical analyses. *P < 0.05 and **P < 0.01