ABSTRACT
To investigate the effects of HIV-1 infection on the expression of host factors TSG101 (Tumor Susceptibility Gene 101) and Alix (ALG-2-interacting protein X). HIV-1 infectious clone pNL4-3 was used to infect TZM-bl, PM1, Jurkat cell lines and human peripheral blood mononuclear cells (PBMC). Twenty-four hours post-infection, the infected or uninfected cells were harvested respectively for extraction of total RNAs and total cellular proteins, which were subsequently used in RT-PCR and Western-blotting respectively to quantify TSG101 and Alix, respectively. Our data showed that HIV-1 infection resulted in various influences on the expression of TSG101 and Alix in the cell lines and the primary PBMC. A down-regulation was mainly observed in the cell lines, whereas an up-regulation of TSG101 was identified in primary PBMC. Three patterns were observed for down-regulation, including dual down-regulation of TSG101 and Alix for Jurkat cells, single down-regulation of Alix for TZM-bl cells and marginal or no influence on PM1 cells. The dual down-regulation of Alix and TSG101 in Jurkat cells coincided with less expression of HIV-1 p24 protein. This is the first-line evidence that HIV-1 infection affects the expression of host factors TSG101 and Alix, the down-regulation of these molecules may influence the HIV-1 replication. The underlying mechanism remains to be addressed.
Subject(s)
Humans , Calcium-Binding Proteins , Genetics , Metabolism , Cell Cycle Proteins , Genetics , Metabolism , DNA-Binding Proteins , Genetics , Metabolism , Endosomal Sorting Complexes Required for Transport , Genetics , Metabolism , Gene Expression Regulation , HEK293 Cells , HIV-1 , Physiology , Jurkat Cells , Leukocytes, Mononuclear , Metabolism , Virology , RNA, Messenger , Genetics , Metabolism , Transcription Factors , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of emodin on apoptosis induction and proliferation inhibition in human apoptosis and on c-myc protein and mRNA expression in human myeloid leukemia cell line HL-60 cells.</p><p><b>METHODS</b>HL-60 cells were exposed to emodin at different dosages. Growth inhibition was detected by MTT assay and colony formation assay, and cell apoptosis by flow cytometry, TUNEL labeling method, DNA fragmentation and MitoCapture apoptosis detection. The expression of c-myc was detected by RT-PCR and Western-blot.</p><p><b>RESULTS</b>Emodin remarkably inhibited the cell proliferation, with an IC(50) value of 20 micromol/L. HL-60 cells apoptosis could be efficiently induced by emodin in a dose dependent manner. The c-myc protein and mRNA expressions on HL-60 cells were decreased after emodin treatment.</p><p><b>CONCLUSION</b>Emodin could efficiently induce growth inhibition and apoptosis in HL-60 cells. c-myc may be involved in this process.</p>