Journal: Military Medical Research
Article Title: USP18 exacerbates myocardial I/R injury by inhibiting Parkin mitophagy through the deubiquitinase PTEN-L
doi: 10.1016/j.mmr.2026.100004
Figure Lengend Snippet: Overexpression of USP18 in the heart exacerbates mitochondrial dysfunction, acute cardiac injury, and cardiac remodeling following I/R in mice. a TTC staining of heart tissue 24 h post-I/R in each group ( n= 5). Scale bar=0.5 cm. ⁎⁎⁎ P <0.001. b Mitochondrial DNA levels ( n= 6) and mitochondrial complexes I and II–III activity ( n= 5) 24 h post-I/R in each group. ⁎⁎ P <0.01, ⁎⁎⁎ P <0.001, ⁎⁎⁎⁎ P <0.0001. c Representative electron microscopy images of heart sections 24 h post-I/R. Quantitative analysis of mitochondrial volume density and the percent of mitochondria with cristae loss in each group ( n= 5). Scale bar=10 μm (top) and 6 μm (bottom). Red arrows indicate mitochondria with cristae loss. ⁎⁎⁎ P <0.001, ⁎⁎⁎⁎ P <0.0001. d Oxygen consumption rate (OCR) and quantitative statistical analysis of basal respiration, ATP-related respiration, maximal respiration, and spare respiratory capacity in mitochondria in the indicated groups ( n= 4). ⁎ P <0.05, ⁎⁎⁎ P <0.001, ⁎⁎⁎⁎ P <0.0001. e H&E staining, PSR staining, and quantitative statistical analysis of cell size and left ventricl e (LV) fibrotic area in AAV9-USP18-transfected mice at 4 weeks after I/R injury ( n= 5). Scale bar=1 mm (left), 50 μm (middle), and 100 μm (right). ⁎⁎⁎ P <0.001, ⁎⁎⁎⁎ P <0.0001. f Representative B-mode and M-mode echocardiographic images of LV from AAV9-USP18-transfected mice 4 weeks after I/R injury. g Cardiac function of AAV9-USP18-transfected mice after I/R injury at the indicated time points ( n= 6). ⁎⁎ P <0.01, ⁎⁎⁎ P <0.001, ⁎⁎⁎⁎ P <0.0001 vs . AAV9-NC, ns non-significant. USP18. Ubiquitin-specific protease 18; I/R. Ischemia/reperfusion; NC. Negative control; AAV9. Adeno-associated virus serotype 9; AAV9-USP18. Adeno-associated virus serotype 9 encoding USP18; TTC. 2,3,5-triphenyltetrazolium chloride; ATP. Adenosine triphosphate; H&E. Hematoxylin and eosin; PSR. picrosirius red; FCCP. Carbonyl cyanide p-trifluoromethoxyphenylhydrazone; LVIDd. Left ventricle internal diameter at diastole; LVISd. Left ventricle internal diameter at systole; LVEF. Left ventricle ejection fraction; LVFS. Left ventricle fractional shortening.
Article Snippet: To establish a cardiac-specific USP18 knockout mice model (USP18-cKO), USP18 flox/flox mice (C57BL/6 J; Shanghai Model Organisms, NM-cKO-215042) were bred with α-MHC-MerCreMer mice (C57BL/6 J; Jackson Laboratory, stock No. 024992).
Techniques: Over Expression, Staining, Activity Assay, Electron Microscopy, Transfection, Ubiquitin Proteomics, Negative Control, Virus