The cause of the development of age-related systemic inflammation has been established
As living organisms age, the functionality of their immune system fades with age. This process is associated with the so-called age-related inflammatory status (systemic inflammation) and chronic inflammatory diseases, as well as with many types of cancer. The reasons underlying the development of age-associated inflammation are largely unclear today.
Researchers at the Carnegie Institute, working under the guidance of Dr. Yixian Zheng, in experiments on fruit flies drosophila found that one of the elements of the mechanism that triggers age-related inflammation and decreased immunity is the protein lamin B.
Insects have an immune organ known as the adipose body, which is roughly a functional analogue of mammalian adipose tissue and liver. It is responsible for performing many immune functions. The authors found that the fatty body of aging fruit flies is characterized by a pronounced inflammatory status. This inflammation is accompanied by the secretion of proteins that suppress immune responses in the intestines of insects. Such a local decrease in immunity leads to excessive division and abnormal differentiation of intestinal stem cells with the development of hyperplasia, a condition similar to the formation of precancerous polyps in the human intestine.
Researchers have demonstrated that the cause of inflammation of the adipose body and hyperplasia of the intestinal mucosa, which fully fit into the picture of age-related immunosuppression, is a gradual decrease in the concentration of lamin B protein in the fat bodies of aging fruit flies.
Comparison of the state of lamin B in the cells of fat bodies of 10-day and 50-day drosophila.
Lamin B protein belongs to the family of lamins forming the main structural component of the material lining the inner surface of cell nuclei. Lamins are found in many tissues and organs and perform a variety of functions, including suppression of gene expression. In humans, lamin mutations cause diseases known as laminopathies, which include premature aging.
Researchers have long attributed to type B lamins the ability to suppress gene expression by binding to certain DNA segments. The experiments carried out by the authors showed that the removal of lamin B from the cells of the drosophila fat body reversed the suppression of genes involved in the formation of immune responses, in a way that would occur with bacterial infection or injury. As a result, uncontrolled immune reactions developing in the absence of an adequate cause triggered the inflammatory process and the development of hyperplasia of the intestinal mucosa.
The authors believe that the patterns they have identified also apply to mammals, since it is known that lamin proteins are also attached to the DNA sections corresponding to the genes of the human immune response. However, additional research is needed to confirm this hypothesis.
Article by Haiyang Chen et al. Age-Associated Loss of Lamin-B Leads to Systemic Inflammation and Gut Hyperplasia published in the journal Cell.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the Carnegie Institution: A cause of age-related inflammation found.
12.11.2014