Function were noted in mice that were fed G. hollisae and E. coli-TOPO-tdh. These patterns are similar to those observed in mice treated with Gh-rTDH. There was no pathological damage to the liver parenchyma in mice treated with E. coli-TOPO (Figure 8D). By contrast, spotty liver cell damage around the portal vein was noted in mice that were treated with G. hollisae (Figure 8E) or E. coli-TOPO-tdh (Figure 8F). The 18F-FDG PET/CT images revealed that the mice treated with G. hollisae (Figure 9D) or E. coli-TOPO-tdh (Figure 9E) exhibited much less 18 F-FDG hepatic uptake than those treated with E. coli-TOPOHepatotoxicity of Thermostable Direct HemolysinFigure 7. Gh-rTDH might not cause cardiotoxicity and nephrotoxicity. The levels of (A) creatinine, (B) CK-MB, and (C) troponin I did not significantly increase when mice were treated with different doses of Gh-rTDH. doi:10.1371/journal.pone.0056226.g(Figure 9F). Overall, the patterns of hepatotoxicity were notably similar between mice infected with G. hollisae or treated with GhrTDH. E. coli-TOPO did not cause significant liver injury.DiscussionIn this study, both human and mouse liver cells were treated with G. hollisae TDH, and the in vitro hepatotoxicity was demonstrated by direct observation and the MTT assay. The hepatotoxicity caused by Gh-rTDH was both dose- and timedependent. Very low concentrations of TDH (.1026 mg/ml) damaged liver cells. We also noted that the MTT assays yielded a similar pattern over 12, 16, 24, and 48 hr under different toxin concentrations. One possible explanation is that when the concentration of toxin increased, cells were not only killed by this toxin but also probably suffered cell division suppression. Therefore, when we prolonged the treatment durations, the number of surviving cells did not clearly differ between the 4 time points. Naim et al. reported that V. parahaemolyticus TDH caused Rat-1 cell Title Loaded From File injury and that TDH might induce cytotoxicity by acting inside the cells [24]. In this study, we noted that the GhrTDH-FITC was taken up by liver cells via binding around the margin of the cell and was translocated to the nucleus within a short time period. Therefore, the destruction caused by G. hollisae TDH is notably quick and lethal to the liver cells. Morros et al. firstly reported an account of a patient suffering a G. hollisae infection who presented with liver cirrhosis and hepaticencephalopathy in 1982 [25]. Previous studies demonstrated that Vibrio species infections could be more severe in patients with a history of impaired liver function [1,9]. However, evidence of hepatotoxicity caused by G. hollisae TDH has never been provided. In this study, we found that the GOT and GPT levels in mice treated with Gh-rTDH obviously increased, and acute liver injury was strongly suspected. Muscle injury was not favored as the major reason for the elevation of GOT/GPT, as a 18F-FDG PET/CT scan did not show muscle injury. Moreover, liver biopsy revealed that the periportal areas of the livers were damaged and that the severity of the damage was associated with the dosage of GhrTDH. The periportal area in the liver is functionally well-known for its oxidative energy metabolism of fatty acids and amino acids, glucose Chebulagic acid site release and glycogen formation, ammonia detoxification, protective metabolism, and the synthesis of albumin [26?8]. Therefore, mice with periportal area injury caused by Gh-rTDH might also suffer complications, which include malnutrition, protective.Function were noted in mice that were fed G. hollisae and E. coli-TOPO-tdh. These patterns are similar to those observed in mice treated with Gh-rTDH. There was no pathological damage to the liver parenchyma in mice treated with E. coli-TOPO (Figure 8D). By contrast, spotty liver cell damage around the portal vein was noted in mice that were treated with G. hollisae (Figure 8E) or E. coli-TOPO-tdh (Figure 8F). The 18F-FDG PET/CT images revealed that the mice treated with G. hollisae (Figure 9D) or E. coli-TOPO-tdh (Figure 9E) exhibited much less 18 F-FDG hepatic uptake than those treated with E. coli-TOPOHepatotoxicity of Thermostable Direct HemolysinFigure 7. Gh-rTDH might not cause cardiotoxicity and nephrotoxicity. The levels of (A) creatinine, (B) CK-MB, and (C) troponin I did not significantly increase when mice were treated with different doses of Gh-rTDH. doi:10.1371/journal.pone.0056226.g(Figure 9F). Overall, the patterns of hepatotoxicity were notably similar between mice infected with G. hollisae or treated with GhrTDH. E. coli-TOPO did not cause significant liver injury.DiscussionIn this study, both human and mouse liver cells were treated with G. hollisae TDH, and the in vitro hepatotoxicity was demonstrated by direct observation and the MTT assay. The hepatotoxicity caused by Gh-rTDH was both dose- and timedependent. Very low concentrations of TDH (.1026 mg/ml) damaged liver cells. We also noted that the MTT assays yielded a similar pattern over 12, 16, 24, and 48 hr under different toxin concentrations. One possible explanation is that when the concentration of toxin increased, cells were not only killed by this toxin but also probably suffered cell division suppression. Therefore, when we prolonged the treatment durations, the number of surviving cells did not clearly differ between the 4 time points. Naim et al. reported that V. parahaemolyticus TDH caused Rat-1 cell injury and that TDH might induce cytotoxicity by acting inside the cells [24]. In this study, we noted that the GhrTDH-FITC was taken up by liver cells via binding around the margin of the cell and was translocated to the nucleus within a short time period. Therefore, the destruction caused by G. hollisae TDH is notably quick and lethal to the liver cells. Morros et al. firstly reported an account of a patient suffering a G. hollisae infection who presented with liver cirrhosis and hepaticencephalopathy in 1982 [25]. Previous studies demonstrated that Vibrio species infections could be more severe in patients with a history of impaired liver function [1,9]. However, evidence of hepatotoxicity caused by G. hollisae TDH has never been provided. In this study, we found that the GOT and GPT levels in mice treated with Gh-rTDH obviously increased, and acute liver injury was strongly suspected. Muscle injury was not favored as the major reason for the elevation of GOT/GPT, as a 18F-FDG PET/CT scan did not show muscle injury. Moreover, liver biopsy revealed that the periportal areas of the livers were damaged and that the severity of the damage was associated with the dosage of GhrTDH. The periportal area in the liver is functionally well-known for its oxidative energy metabolism of fatty acids and amino acids, glucose release and glycogen formation, ammonia detoxification, protective metabolism, and the synthesis of albumin [26?8]. Therefore, mice with periportal area injury caused by Gh-rTDH might also suffer complications, which include malnutrition, protective.