ABSTRACT
SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjögren's syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52's role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52(low) HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H(2)O(2)- or diamide-induced oxidative stress, IFN-α, IFN-γ and anti-Fas antibody, etoposide, or γ-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.
Subject(s)
Apoptosis/immunology , Oxidative Stress/immunology , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Ribonucleoproteins/physiology , Active Transport, Cell Nucleus , Apoptosis/genetics , Cell Nucleus/enzymology , Diamide/pharmacology , Gene Knockdown Techniques , HeLa Cells , Humans , Hydrogen Peroxide/pharmacology , Interferon-alpha/pharmacology , Interferon-gamma/pharmacology , Oxidative Stress/genetics , Ribonucleoproteins/genetics , Ribonucleoproteins/metabolismABSTRACT
Indonesia is one of the high burden tuberculosis (TB) countries. The utilization of molecular diagnostic has been setting over the country, however there are still a lot of remote areas that only depend on microscopic smear. Bleach might be used to increase the value of microscopy diagnostic. The study aimed to evaluate the added value of 1% bleach to increase the positivity rate of TB compared to conventional stain. This study was conducted on 70 subjects who were suspected as TB from various primary care centers in West Java and Banten, Indonesia. The sputum was 2-3 mL, and divided into two parts, both of them were stained using Ziehl-Neelsen (ZN), however the first was only stained and the second added 1% bleach. Bleach was added in same volume with sputum and incubated for 10 minutes. After 10 minutes, the sputum was stained with ZN. The positivity rate for ZN only was 39 (55.7%) compared to 1% bleach was 63 (90%), and significantly different (P=0.000) using Mann-Whitney U test. Bleach can be used as an alternative agent to improve the TB smear in setting that only depends on microscopy diagnostic.