Mitochondrial Protein Nfu1 Influences Homeostasis of Essential Metals in the Human Fungal Pathogen Cryptococcus neoformans

Mitochondrial protein Nfu1 plays an important role in the assembly of mitochondrial Fe-S clusters and intracellular iron homeostasis in the model yeast Saccharomyces cerevisiae. In this study, we identified the Nfu1 ortholog in the human fungal pathogen Cryptococcus neoformans. Our data showed that C. neoformans Nfu1 localized in the mitochondria and influenced homeostasis of essential metals such as iron, copper and manganese. Marked growth defects were observed in the mutant lacking NFU1, which suggests a critical role of Nfu1 in Fe-S cluster biosynthesis and intracellular metal homeostasis in C. neoformans.

Nicotinamide enhances the effect of none focused ultrasound to kill human pulmonary carcinoma cell line GLC-82 / 基础医学与临床

Objective To determine the sensitization of Nicotinamide (NA) on None Focused Ultrasound (NFU) on GLC-82 cells in vitro. Methods The subjectives were divided into A、B、C and D four groups, group A was negative control, group B was treated with NA, group C was irradiated with NFU, group D was treated with both NFU and NA; MTT assay was used to evaluate the cytotoxicity of NA and its sensitivity for NFU on GLC-82 cells quantified by calculating the sensitive enhancement ratios (SER); Morphologic change of cells was observed with light microscope, fluorescence microscope and scanning electron microscope;Flow cytometry was performed to determine the percentage changes of apoptosis and distributional percentage of the cell cycle of GLC-82 cells in response to NFU, NA and the effect of its intervention to NFU. Results The cytotoxicity of NA increased in a dose-dependent manner after 24-hour treatment, with the optimal dose range of 1 mg/mL～5 mg/mL. A sub-toxic dose of NA at 3 mg/ml was used in the subsequent experiments; After treatment with NA plus NFU, microvilli and filipodium of GLC-82 cells reduced, shortened and shrunk into corpuscule-shape; The apoptosis rate of group D was more than that in group B and C, with cell cycle arrested at phase S and G2.Conclusion NA can significantly enhance the effect of NFU on GLC-82 cells, which provides evidence for NA as a sensitization to NFU in clinic.