Fig 2: SPS increases mitochondrial reactive oxygen species (mtROS) and its colocalization with AT1R- and FOSL1-expressing cells in the PVN of SD rats. (A–C) Representative fluorescent images depicting the distribution of mtROS (in red) across PVN subdivisions, including the Pa, Me, and Ma regions. Colocalization of mtROS with AVP (A), AT1R (B), and FOSL1 (C) was evaluated, as indicated by white arrows. (D) Total fluorescence of MitoProbe in different PVN subregions was quantified and normalized to that in the Pa region of control groups. Data points represent average fluorescent intensities from multiple microscopic fields within the PVN region. The two-way Student’s unpaired t test was used for statistical analysis. Scale bar = 50 µm. Data are represented as mean ± SEM. * indicates p < 0.05, ** p < 0.01, *** p < 0.001.

Fig 3: SPS increases mRNA expression and immunofluorescence of AVP, AT1R, and FOSL1 in the hypothalamic paraventricular nucleus (PVN) of male SD rats. The mRNA levels of AVP (A), AT1R (B), and FOSL1 (C) were measured in the PVN of male SD rats with and without SPS exposure. mRNA expression was semi-quantified using real-time PCR and normalized to GAPDH, comparing control and SPS groups. Each data point represents individual values from one rat (n = 7–8 per group). Statistical analysis was performed using a two-way unpaired Student’s t-test. (D–F) Representative fluorescent images show AVP ((D), red), AT1R ((E), green), and FOSL1 ((F), green) within the PVN. Scale bar = 200 µm. The total fluorescent areas of AVP (G), AT1R (H), and FOSL1 (I) were quantified in the parvocellular (Pa), intermediocellular (Me), and posterior magnocellular lateral (Ma) subregions of the PVN and normalized to control values. Each data point represents a microscopic view of a PVN region. Statistical analysis was conducted using a one-way unpaired Student’s t-test. Data are presented as mean ± SEM. * indicates p < 0.05, ** p < 0.01, *** p < 0.001 and ns indicates p > 0.05.