Fig. 6. Effects of SQOR expression in the brain of mice.

a Structures of AAV containing mouse SQOR and enhanced GFP sequence under hSYN1 promoter (AAV-SQOR) and control AAV (AAV-GFP). SV40, simian virus 40. Relative SQOR mRNA expression levels in brains of 8-week-old b male (n = 6, 10) and c female (n = 7, 5) CD-1 mice transfected with AAV-GFP or AAV-SQOR on postnatal day 0. Survival curves of 8-week-old d male and e female CD-1 mice transfected with AAV-GFP or AAV-SQOR on postnatal day 0 and breathing 5.5% oxygen and 4.5% oxygen, respectively. Levels of f sulfide (n = 6, 7, 6, 6), g persulfide (n = 5 each), h the ratios of NADH/NAD⁺ (n = 6 each), i lactate/pyruvate (n = 6 each), and j succinate/fumarate (n = 6 each) in male mice transfected with AAV-GFP or AAV-SQOR and breathed 21% or 5.5% oxygen for 3 min. k Representative photomicrographs of Fluoro-Jade B (FJB)-stained brain sections focusing on hippocampal CA1 and CA3 regions of male mice transfected with AAV-GFP (n = 4) or AAV-SQOR (n = 6) and subjected to 2VO and reperfusion. Number of dead neurons in l CA1 and m CA3 regions of mice transfected with AAV-GFP or AAV-SQOR and subjected to 2VO (n = 4, 6). n Representative photomicrographs of FJB-stained brain sections focusing on cerebral cortex region of male mice transfected with AAV-GFP (n = 4) or AAV-SQOR (n = 6) and subjected to 2VO and reperfusion. o Number of dead neurons in the cerebral cortex of mice transfected with AAV-GFP or AAV-SQOR and subjected to 2VO (n = 4, 6). p Neurofunctional impairment score of male CD-1 mice transfected with AAV-GFP or AAV-SQOR and subjected to sham surgery or 12 or 20 min of 2VO (n = 6, 6, 7, 6, 6, 7). Data are presented as mean and individual values. A two-tailed unpaired t-test was performed for b, c, l, m, and o. Survival rates were estimated using the Kaplan–Meier method and a log-rank test was used to compare the survival curves between groups in d and e. Two-way ANOVA followed by Sidak’s correction for post-hoc comparisons were performed for f–j and p.