Fig. 2

Fig. 2

Analysis of the impact of P. gingivalis OMVs on the cardiac system. (A) Schematic diagram of the operation of the P. gingivalis OMVs for zebrafish treatment. Approximately 4 nL of PBS or OMVs were injected into the common cardinal vein of zebrafish larvae at 30 hpf using an Eppendorf microinjector (FemtoJet 4i, Eppendorf). (B) Mortality of zebrafish treated with P. gingivalis OMVs with different concentrations (0, 1.25, 2.5 and 4.5 µg/µL) at 2, 24 and 48 h post injection (hpi). n = 30, each group being replicated thrice. (C) Representative diagram of cardiac phenotype of zebrafish larvae at 48 hpi. Red arrow indicates pericardial position. The zebrafish larvae treated with OMVs showed three degrees of pericardial edema, that is normal, slight pericardial edema and severe pericardial edema. Scale bar: 0.5 mm. (D) Heartbeat statistics for different treatment groups (0, 1.25, 2.5 and 4.5 µg/µL) at 48 hpi. The unit is beats/min. n = 15, each group being replicated thrice. ***p ≤ 0.001. (E) Percentage of pericardial edema at concentrations of 0, 1.25, 2.5 and 4.5 µg/µL in 2 hpi. n = 30, each group being replicated thrice. (F) Percentage of pericardial edema at concentrations of 0, 1.25, 2.5 and 4.5 µg/µL in 24 hpi. n = 30, each group being replicated thrice. (G) Percentage of pericardial edema at concentrations of 0, 1.25, 2.5 and 4.5 µg/µL in 48 hpi. n = 30, each group being replicated thrice. (H) Expression results of gata4 and nkx 2.5 genes in 48 hpi zebrafish larvae. The relative change of mRNA levels was calculated by the 2 − ΔΔCt method and β-actin. Data were shown as the mean ± standard deviation (SD), and P values < 0.05 were considered statistically significant, ***p ≤ 0.001