Journal: bioRxiv
Article Title: Pancreatic islets undergo functional and morphological adaptation during development of Barth Syndrome
doi: 10.1101/2024.06.28.601122
Figure Lengend Snippet: ( A ) Generation of a new mouse (shTaz x Mito-roGFP2-Orp1) model that expresses an shRNA against Taz and the mitochondrial H 2 O 2 sensor roGFP2-Orp1. The mice are lifelong feed with doxy. Figure created with Biorender.com. ( B ) Schematic protocol of redox histology to measure in vivo redox state. Before pancreas isolation, shTaz x Mito-roGFP2-Orp1 mice are perfused with NEM via the cardiovascular system. Isolated pancreas is fixed in PFA und cryocuts are staining against insulin to localize the pancreatic islets. Imaged intensity ratio (excitation: 405/488 nm and emission: 500 – 530 nm) of the mito-roGFP2-Orp1 sensor in pancreatic islets reflects the in vivo redox status. ( C ) Representative ratiometric image (ImageJ Lookup table: “Fire”) of mito-roGFP2-Orp1/WT (left) and mito-roGFP2-Orp1/ Taz -KD (right) pancreatic islets at 20 (top) or 50 wo (bottom). Scale bar: 100 µm. ( D ) Normalized percentage change in ratio of the redox state of the mito-roGFP2-Orp1 sensor in pancreatic islets of 20 (left) and 50 (right) wo mito-roGFP2-Orp1/WT and mito-roGFP2-Orp1/ Taz -KD mice. DTT was used as a reductive control (blue). N (WT, 20 wo) = 7, N ( Taz -KD, 20 wo) = 7, N (DTT, 20 wo) = 8, N (WT, 50 wo) = 4, N ( Taz -KD, 50 wo) = 4, N (DTT, 50 wo) = 6. ( E ) Real-time H 2 O 2 imaging of ex vivo 20 wo mito-roGFP2-Orp1/WT and mito-roGFP2-Orp1/ Taz -KD pancreatic islets. Pancreatic islets were incubated with RPMI 1640 at 5% CO 2 and 37 °C, in presence or absence of 1 µM Auranofin and 100 µM exogenously added H 2 O 2 , N = 5. A schematic figure illustrates the CD7 redox measurement with isolated islets, created with Biorender.com. ( F ) Representative western blot and quantification of Prx3 (left), Cat (middle) and GPX4 (right) normalized to β-actin in pancreatic islets of 20 wo Taz -KD mice, N (Prx3) = 4, N (Cat) = 3, N (GPX4) = 4. Data represent mean ± SEM (indicated by error bars); N and n numbers indicate number of animals and experiments, respectively; statistical significance was determined by unpaired Student t test: *p < 0.05, **p < 0.01. Abbreviations: Mitochondria-redox-sensitive- GFP2-Orp1 (Mito-roGFP2-Orp1), doxycycline (doxy), weeks of age (wo), Tafazzin -Knockdown ( Taz -KD), Wildtype (WT), Dithiothreitol (DTT), glucose (Glu, G), catalase (Cat), peroxiredoxin 3 (Prx3), glutathionperoxidase 4 (GPX4), area under the curve (AUC).
Article Snippet: Doxycycline (doxy) in a concentration of 625 mg of doxy/kg was added to the standard rodent chow (A153D70623, Ssniff, Germany) leading to induction of short hairpin RNA (shRNA)-mediated knockdown of Taz , as described previously ( ).
Techniques: shRNA, In Vivo, Isolation, Staining, Control, Imaging, Ex Vivo, Incubation, Western Blot, Knockdown