Steroid sex hormones, such as estradiol-17β （E2） and testosterone （T）, are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gon...Steroid sex hormones, such as estradiol-17β （E2） and testosterone （T）, are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gonadal differentiation in the olive flounder Paralichtbys olivaceus using histology and radioimmunoassay （RIA）. Flounder larvae were divided into five groups （G0~G4）, and fed with 0 （control）, 0.2, 2, 20 and 100 mg E2/kg feed from 35 to 110 day post hatching （dph）. Fish growth in the G1 and G2 groups was not significantly different from that of the control group （P〉0.05）, while fish in the G3 and G4 groups were less active and showed growth depression and high mortality. The gonads of fish in the G3 and G4 groups were smaller and surrounded by hyperplastic connective tissue. The frequency of females in the G0-G4 groups was 54.5%, 75.0%, 100%, 100% and 93.3%, respectively. The RIA analyses of E2 and T showed that T levels decreased during gonadal differentiation, and increased slightly at the onset of ovarian differentiation, while E2 levels increased gradually and peaked at the onset of ovarian differentiation in the control group. In the E2-treated groups, T levels decreased before the onset of ovarian differentiation. E2 levels were high on the 48 dph, but declined to a lower level on the 54 dph, and then increased gradually during gonadal differentiation. And a sharp increase of E2 levels were observed in all E2-treated groups at the onset of ovarian differentiation. The data suggest that T and E2 play important roles during gonadal differentiation, and an E2 dose of 2 mg/kg feed could induce sex reversal in P olivaceus.展开更多
AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in v...AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in vivo.METHODS YLG-1 is a novel photosensitizer extracted from spirulina. Its phototoxicity, cellular uptake and localization, as well as its effect on reactive oxygen species(ROS) production, apoptosis, and expression of apoptosis-associated proteins were detected in vitro. An in vivo imaging system(IVIS), the Lumina K imaging system, and mouse models of subcutaneous Panc-1-bearing tumors were exploited to evaluate the drug delivery pathway and pancreatic cancer growth in vivo.RESULTS YLG-1 was localized to the mitochondria, and the appropriate incubation time was 6 h. Under 650 nm light irradiation, YLG-1-PDT exerted a potent cytotoxic effect on pancreatic cancer cells in vitro, which could be abolished by the ROS scavenger N-acetyl-L-cysteine(NAC). The death mode caused by YLG-1-PDT was apoptosis, accompanied by upregulated Bax and cleaved Caspase-3 and decreased Bcl-2 expression. The results from the IVIS images suggested that the optimal administration route was intratumoral(IT) injection and that the best time to conduct YLG-1-PDT was 2 h post-IT injection. Consistent with the results in vitro, YLG-1-PDT showed great growth inhibition effects on pancreatic cancer cells in a mouse model.CONCLUSION YLG-1 is a potential photosensitizer for pancreatic cancer PDT via IT injection, the mechanisms of which are associated with inducing ROS and promoting apoptosis.展开更多
基金Supported by the National Natural Science Foundation of China(No.30571445)the National High Technology Research and Development Program of China(863 Program)(No.2006AA10A404)the Earmarked Fund for Modern Agro-Industry Technology Research System,China(No.nycytx-50)
文摘Steroid sex hormones, such as estradiol-17β （E2） and testosterone （T）, are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gonadal differentiation in the olive flounder Paralichtbys olivaceus using histology and radioimmunoassay （RIA）. Flounder larvae were divided into five groups （G0~G4）, and fed with 0 （control）, 0.2, 2, 20 and 100 mg E2/kg feed from 35 to 110 day post hatching （dph）. Fish growth in the G1 and G2 groups was not significantly different from that of the control group （P〉0.05）, while fish in the G3 and G4 groups were less active and showed growth depression and high mortality. The gonads of fish in the G3 and G4 groups were smaller and surrounded by hyperplastic connective tissue. The frequency of females in the G0-G4 groups was 54.5%, 75.0%, 100%, 100% and 93.3%, respectively. The RIA analyses of E2 and T showed that T levels decreased during gonadal differentiation, and increased slightly at the onset of ovarian differentiation, while E2 levels increased gradually and peaked at the onset of ovarian differentiation in the control group. In the E2-treated groups, T levels decreased before the onset of ovarian differentiation. E2 levels were high on the 48 dph, but declined to a lower level on the 54 dph, and then increased gradually during gonadal differentiation. And a sharp increase of E2 levels were observed in all E2-treated groups at the onset of ovarian differentiation. The data suggest that T and E2 play important roles during gonadal differentiation, and an E2 dose of 2 mg/kg feed could induce sex reversal in P olivaceus.
基金Supported by National Natural Science Foundation of China,No.81472844
文摘AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in vivo.METHODS YLG-1 is a novel photosensitizer extracted from spirulina. Its phototoxicity, cellular uptake and localization, as well as its effect on reactive oxygen species(ROS) production, apoptosis, and expression of apoptosis-associated proteins were detected in vitro. An in vivo imaging system(IVIS), the Lumina K imaging system, and mouse models of subcutaneous Panc-1-bearing tumors were exploited to evaluate the drug delivery pathway and pancreatic cancer growth in vivo.RESULTS YLG-1 was localized to the mitochondria, and the appropriate incubation time was 6 h. Under 650 nm light irradiation, YLG-1-PDT exerted a potent cytotoxic effect on pancreatic cancer cells in vitro, which could be abolished by the ROS scavenger N-acetyl-L-cysteine(NAC). The death mode caused by YLG-1-PDT was apoptosis, accompanied by upregulated Bax and cleaved Caspase-3 and decreased Bcl-2 expression. The results from the IVIS images suggested that the optimal administration route was intratumoral(IT) injection and that the best time to conduct YLG-1-PDT was 2 h post-IT injection. Consistent with the results in vitro, YLG-1-PDT showed great growth inhibition effects on pancreatic cancer cells in a mouse model.CONCLUSION YLG-1 is a potential photosensitizer for pancreatic cancer PDT via IT injection, the mechanisms of which are associated with inducing ROS and promoting apoptosis.
