Lysosomal membrane protein Sidt2 knockout induces apoptosis of human hepatocytes in vitro independent of the autophagy-lysosomal pathway / 南方医科大学学报

OBJECTIVE@#To explore the regulatory mechanism of human hepatocyte apoptosis induced by lysosomal membrane protein Sidt2 knockout.@*METHODS@#The Sidt2 knockout (Sidt2-/-) cell model was constructed in human hepatocyte HL7702 cells using Crispr-Cas9 technology.The protein levels of Sidt2 and key autophagy proteins LC3-II/I and P62 in the cell model were detected using Western blotting, and the formation of autophagosomes was observed with MDC staining.EdU incorporation assay and flow cytometry were performed to observe the effect of Sidt2 knockout on cell proliferation and apoptosis.The effect of chloroquine at the saturating concentration on autophagic flux, proliferation and apoptosis of Sidt2 knockout cells were observed.@*RESULTS@#Sidt2-/- HL7702 cells were successfully constructed.Sidt2 knockout significantly inhibited the proliferation and increased apoptosis of the cells, causing also increased protein expressions of LC3-II/I and P62(P < 0.05) and increased number of autophagosomes.Autophagy of the cells reached a saturated state following treatment with 50 μmol/L chloroquine, and at this concentration, chloroquine significantly increased the expressions of LC3B and P62 in Sidt2-/- HL7702 cells.@*CONCLUSION@#Sidt2 gene knockout causes dysregulation of the autophagy pathway and induces apoptosis of HL7702 cells, and the latter effect is not mediated by inhibiting the autophagy-lysosomal pathway.

Preliminary study for integrating DPRA with h-CLAT to predict skin sensitizers / 中国实验动物学报

Objective To establish a detection method integrating DPRA ( direct peptide reactivity assay) with h?CLAT ( human cell line activation test) to screen the skin sensitization potency of chemicals and plant extracts. Methods 12 chemicals and 7 plant extracts were chosen as the test substances. Firstly, the test substances were incubated together with two different peptides ( cysteine and lysine) respectively for reaction for 24 h. The peptide consumptions were analyzed by HPLC. Simultaneously, THP?1 cells were cultured in vitro and then exposed to different concentrations of test sub?stances for 24 h to examine the cell viability, cell surface markers CD54 and CD86 were assessed by flow cytometry. The predicting results were compared further between DPRA and h?CLAT. Results 12 chemicals were distinguished correctly by DPRA classified as 2 non?sensitizers and 10 sensitizers. The results of DPRA were in accordance with h?CLAT. Predic?ting the sensitization potency of plant extracts by DPRA showed that 6 plant extracts were determined as suspected sensiti?zers except for green tea extract. But using the method of h?CLAT, 4 plant extracts were examined as suspected sensitizers except for green tea extract, herba portulacae extract and ginseng fruit extract. The coherence of DPRA and h?CLAT was 0?57. Conclusion This detection method integrating DPRA with h?CLAT can predict single compound accurately. As for complex compound, it can achieve preliminary prediction and need other integrating methods to make a further identifica?tion.