Fig. 7: Exogenous expression of RRBP1 rescues rough ER—mitochondria interactions in obesity.

A Immunoblotting and quantification analysis of RRBP1 protein in total liver lysates of indicated conditions. n = 3 in each group. B Immunoblot analysis of RRBP1 in total liver lysates from mice exogenously expressing LacZ (n = 2) or GFP-RRBP1 (n = 2) through Adenovirus gene delivery. C Representative TEM images from obese mice exogenously expressing LacZ or RRBP1 though adenovirus (Ad). Scale bars: 500 nm. D FIB-SEM imaging and 3D segmentation and rendering of liver volume from obese mice expressing RRBP1 depicting ER morphology. Scale bar: 500 nm. E FIB-SEM imaging and 3D segmentation and rendering of liver volume from obese mice expressing either LacZ (left) and RRBP1 (right), depicting mitochondria surface covered by ER at 25-56 nm distance. Scale bars: 1 µm. F Quantification of mitochondria surface covered by ER at 25-80 nm distance. G Mitochondria surface covered by ER at 25-80 nm distance frequency distribution. H, I Mitochondria sphericity and frequency distribution in liver tissue from LacZ and RRBP1 overexpression. J, K Mitochondria volume and frequency distribution in liver tissue from LacZ and RRBP1 overexpression. For F–K, n = 23550 mitochondria for LacZ and n = 29235 for RRBP1. Mitochondria were quantified in the entire data set imaged and not segregated by cell. For the bar graphs data are shown as mean ± s.e.m; For F and H, two-tailed unpaired t-test. ****p < 0.0001.