What Are Nucleosomes?
Nucleosomes are the basic structural units of chromatin formed by DNA and histones. Each nucleosome is formed by 146 bp DNA winding 1.75 circles of histone octamer. The nucleosome core particles are connected by a connecting DNA of about 50bp. The shape of a nucleosome resembles a flat dish or a cylinder. At this time, the length of the DNA is compressed 7 times, which is called chromatin fiber. Chromatin is a series of nucleosomes. When a series of nucleosomes are arranged in a spiral shape to form a filament shape, the compression packaging ratio of DNA is about 40. When the filament itself is further compressed and becomes a state of normal chromatin, the compression packing ratio of DNA is about 1,000. During mitosis, chromatin is further compressed into chromosomes, and the compression-packing ratio is as high as 8,400, which is only one ten thousandth of the length in the extended state.
Nucleosome
- Nucleosomes are the basic structural units of chromatin formed by DNA and histones. Each nucleosome is formed by 146 bp DNA winding 1.75 circles of histone octamer. The nucleosome core particles are connected by a connecting DNA of about 50bp. The shape of a nucleosome resembles a flat dish or a cylinder. At this time, the length of the DNA is compressed 7 times, which is called chromatin fiber.
- Nucleosomes are
- People then use
- Nucleosomes are
- Anti-nucleosome antibodies are better than anti-dsDNA antibodies,
- AnuA is defined as exposure to tissue proteins during
- Two important comments about AnuA suggest that this antibody is sensitive and specific to SLE and DIL, and that the presence of AnuA is often associated with SLE and glomerulonephritis patients. AnuA is more sensitive than anti-DNA. If the yin-positive segmentation point is raised, the anti-nucleosomes can be made more sensitive to lupus. The improvement of nucleosome antigen purification technology has improved the diagnostic specificity of AnuA in patients with SLE. The results show that the detection of AnuA by ELISA has high sensitivity and specificity in SLE patients. According to foreign reports, the sensitivity and specificity of AnuA detection in SLE patients are 56.0% ~ 64.2% and 97.0% ~ 98.8%, respectively. Domestic Su Yin et al. Proposed that AnuA can appear at various stages of the course of SLE disease. High sensitivity (69.9%) and strong specificity (97.9%) may be one of the labeled antibodies of SLE, but Xu Kuai et al. Reported low sensitivity (55.8%) and low specificity (95.3%). It is considered to be related to the different sources of AnuA, the detection population and disease activity, and the actual use, but compared with dsDNA antibodies and anti-Sm antibodies, the sensitivity has been greatly improved, and it has good specificity, which can be used for SLE The diagnosis and the appearance of a variety of commercial detection kits make it possible to apply the autoantibody to the diagnosis and differential diagnosis of connective tissue diseases such as clinical SLE.
- Many different techniques have been used to detect AnuA, in addition to the LE cell test, there are also
- A few hospitals in China have launched AnuA testing and several related reports have been published. It has been reported in the literature that the study of a murine lupus model treated with a nucleosomal peptide-specific antigen found that the nucleosome-polypeptide-specific antigen can inhibit the activation of TH cells and B cells, thus bringing new insights into the treatment of SLE Dawning [20]. However, it should be pointed out that the detection of AnuA is of great significance for the diagnosis of SLE. Different nucleosome sources, different detection populations and disease activity levels, as well as detection reagents and methods will bring about different results. This antibody is different from an anti-Sm antibody and is not a SLE-labeled antibody. Although AnuA has been found to be more sensitive and specific for the diagnosis of SLE than anti-dsDNA antibodies, there are still inconsistent results. As for the situation in China, a large sample and multi-center test should be conducted to obtain more reasonable and accurate conclusions. The diagnosis of SLE cannot be affirmed or denied only by the positive or negative of a certain antibody. Before establishing the antibody test, its clinical significance must be clarified. Secondly, false positive or false negative results should be avoided, just like other autoantibody tests. Clinicians must closely combine the clinical data of patients in the diagnosis and treatment, treat the test results correctly, and never substitute laboratory tests for everything. [1]