The interleukin-1 receptor antagonist protein (IL-1RN) is a
protein that in humans is encoded by the ''IL1RN''
gene.
IL-1RN was initially called the IL-1 inhibitor and was discovered separately in 1984 by two independent laboratories.
IL-1RN is an agent that binds non-productively to the cell surface
interleukin-1 receptor (IL-1R), the same receptor that binds
interleukin 1 family (IL-1), preventing IL-1's from sending a signal to that cell.
Function
IL-1RA is a member of the interleukin 1
cytokine family. IL1Ra is secreted by various types of cells including immune cells, epithelial cells, and adipocytes, and is a natural inhibitor of the pro-inflammatory effect of IL1β.
This protein inhibits the activities of interleukin 1, alpha (
IL1A) and interleukin 1, beta (
IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses. This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. Four alternatively spliced transcript variants encoding distinct isoforms have been reported.
Clinical significance
A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures
and
gastric cancer
Stomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lymph ...
.
Mutations in the IL1RN gene results in a
rare disease called
deficiency of the interleukin-1–receptor antagonist
Deficiency of the interleukin-1–receptor antagonist (DIRA) is an autosomal recessive, genetic autoinflammatory syndrome resulting from mutations in '' IL1RN'', the gene encoding the interleukin 1 receptor antagonist. The mutations result in an ...
(DIRA).
Variants of the IL1RN gene is also associated with risk of schizophrenia.
Elevated levels of IL1RN has been found in serum of schizophrenia patients.
A recombinant, slightly modified version of interleukin 1 receptor antagonist called
anakinra is used in the treatment of
rheumatoid arthritis, an
autoimmune disease in which IL-1 plays a key role.
Anakinra differs from native human IL-1Ra in that it has the addition of a single methionine residue at its amino terminus
Use in horses
Interleukin 1 receptor antagonist is used in horses for the
treatment of equine lameness secondary to joint and soft-tissue injury.
References
Further reading
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External links
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{{Interleukin receptor modulators
Cytokines