Author: Flora Date: 2018-04-28
Why is immunity weaker when you are older? Why does the aging rate of the immune system vary from person to person? Why does the environment have a greater impact on the immune system than genetics? Recently, scientists have found new clues to answer these questions by analyzing the differences in chromatin in individual cells.
Image source: Pixabay
Scientists from the Stanford University School of Medicine have completed this vast work and analyzed a large number of immune cells. They found that the immune cells of the elderly carry more chromatin modifications than younger people. Moreover, these differences in modification are mainly derived from the environment.
The research team's focus is on the modification of histones (protein structures tightly bound to DNA in the nucleus), which is an important part of epigenetics, which has a status that cannot be ignored in the fields of health and disease. Related research results are published online in the latest issue of Cell.
Doi.org/10.1016/j.cell.2018.03.079
1. The influence of epigenetics
Protein is the main force in performing cellular activities. The identity and function of a cell are closely related to the type and amount of protein it expresses. In fact, every cell in the body contains the same DNA, but the proteins expressed by skin cells, fat cells, and nerve cells are very different, so they perform different functions. By specifying gene expression or not, epigenetic marks on the DNA sequence largely guide and define the overall behavior of the cell.
"Without mutations or wear on the ends of the chromosomes, DNA remains essentially unchanged during aging, but the degree of gene expression may undergo major changes," said Paul J. Utz, professor of immunology and rheumatology.
In addition, epigenetic modifications are constantly changing along with cell division and senescence. Among them, the gene expression level of a large number of white blood cells in the immune system will change significantly with aging.
With this in mind, the team speculates that changes in immune cells that are associated with aging may be due to changes in histone modifications. They want to know the extent to which different immune cell types are affected by changes in epigenetic markers, and this pattern of influence varies from person to person or from cell to cell.
2 , aging immune cells
Paul J. Utz collaborated with Purvesh Khatri, assistant professor of bioinformatics, Alex Kuo, associate researcher in basic life sciences, and Francesco Vallania, postdoctoral fellow, to analyze the chromatin modification of immune cells from single cell levels using mass cytometry. . They analyzed 40 different types of epigenetic markers in 22 different immune cells, accumulated a total of approximately 21.7 billion data points, and performed specialized data analysis.
It was found that many aging immune cells carry more histone marks than younger immune cells. In addition, histone modifications between older immune cells are more diverse than in younger adults.
Image source: Cell
3 , the change is mainly due to the environment
To assess differences in the effects of environmental and genetic patterns on histone marks, the researchers obtained blood samples from identical twins and fraternal twins. Among them, identical twins share the same DNA sequence and share a common intrauterine environment. Although there are differences in fraternal twin DNA, the intrauterine environment and the growing environment (grow together) are the same.
The results showed that the histone modifications between the older identical twins were significantly different compared to the young identical twins. And these differences are equivalent to two people who are completely unrelated. Further data analysis showed that the epigenetic differences exhibited by the elderly were mainly due to non-genetic factors, including diet, sleep, exercise, infection, work, place of residence, and physical and psychological stress.
References: 1) Key differences in young, older people's immune cells attributed to environment
Source: Bio-Exploration
Household Gloves,Gloves Microfiber,Flock Lined Glove,Household Latex Work Glove
ZHANGJIAGANG DINSHENGLIN TRADING CO.,LTD , https://www.dslhouse.com