Fig. 1: CPT1A regulates mitochondrial dynamics through MFF.

a Representative confocal microscopy images of the mitochondria in SKOV-3 and OVCAR-3 cells with control or CPT1A knockdown (left, scale bar = 10 μm). The proportion of cells with different mitochondrial morphologies was quantified (n = 3 samples, each sample contains 100 cells, right). The white arrow represents fragmented mitochondria, the blue arrow represents elongated mitochondria, and the yellow arrow represents hyperfused mitochondria. b Representative images of the mitochondrial network in SKOV-3 cells with empty vector or exogenous CPT1A overexpression (HA-CPT1A) (left, scale bar = 10 μm). The proportion of cells (n = 3 samples, each sample contains 100 cells) with fragmented, elongated, and hyperfused mitochondria was quantified (right). c Representative images showing mitochondrial morphology in SKOV-3 cell with ctrl-sh, CPT1A knockdown by transmission electron microscopy (n = 10 for each group). Scale bars = 500 nm. d CPT1A-WT and CPT1A-G710E overexpression rescued CPT1A downregulation-induced mitochondrial fusion and restored mitochondrial fragmentation in SKOV-3 cells, n = 3 samples, each sample contains 100 cells. Scale bar = 10 μm. Data represent the mean ± SD. *p < 0.05, **p < 0.01 and n.s. indicates no significant difference compared with the control groups. e CPT1A was knocked down by CPT1A-sh2 in SKOV-3 or OVCAR-3 cells. Mitochondrial fission- and fusion-related proteins were examined by western blotting. Bands are derived from the different gels. f CPT1A was exogenously overexpressed in SKOV-3 cells. CPT1A, DRP1 and MFF were examined. β-Tubulin was included as a protein loading control. g Representative confocal microscopy images of the mitochondrial network in SKOV-3 and OVCAR-3 cells exogenously overexpressed MFF in the background of CPT1A knockdown (upper, scale bar = 10 μm). The proportion of cells with different mitochondrial morphologies was quantified (n = 3 samples, each sample contains 100 cells, lower). All data represent the mean ± SD; *p < 0.05, **p < 0.01, ***p < 0.001; n.s. indicates no significant difference compared with the control groups. Scale bar = 10 μm.