Several lines of evidence indicate that brain cytokines, principally interleukin-1beta (IL-1beta) and IL-1 receptor antagonist may have a role in the biology of major depression, and that they might additionally be involved in the pathophysiology and somatic consequences of depression as well as in the effects of antidepressant treatment.
Our findings suggest that the IL1B-511C/T polymorphism may be related to age at manifestation among individuals vulnerable to depression, but they do not affect the basic vulnerability to or severity of depression in elderly Chinese adults.
In this study, we tested the leukocyte mRNA expression levels of genes belonging to glucocorticoid receptor (GR) function (FKBP-4, FKBP-5, and GR), inflammation (interleukin (IL)-1α, IL-1β, IL-4, IL-6, IL-7, IL-8, IL-10, macrophage inhibiting factor (MIF), and tumor necrosis factor (TNF)-α), and neuroplasticity (brain-derived neurotrophic factor (BDNF), p11 and VGF), in healthy controls (n=34) and depressed patients (n=74), before and after 8 weeks of treatment with escitalopram or nortriptyline, as part of the Genome-based Therapeutic Drugs for Depression study.
A higher number of pro-inflammatory cytokine risk alleles, and IL-1β-511T/T genotype individually, were independently associated with both prevalent depression at baseline and persistent depression at one year follow-up.
In a 2-year prospective study of a community sample of 521 older people, information on number of physical disorders, diagnosis of depression (Geriatric Mental State), and genotypes for 6 pro-inflammatory (tumor necrosis factor-α -850C/T and -308G/A, interleukin (IL)-1β-511C/T and +3953C/T, IL-6 -174G/C, IL-8 -251T/A) and 2 anti-inflammatory (IL-4 +33T/C, IL-10 -1082G/A) cytokine polymorphisms were ascertained.
Findings across the literature suggest that functional allelic variants of genes for interleukin-1beta (IL)-1β, tumor necrosis factor-alpha (TNF-α) and C-reactive protein (CRP), as well as genetic variations affecting T-cell function, may increase the risk for depression.
We demonstrated that prenatal stress leads to depression-like behavior, decreased IGF-1, increased IL-1β, TNF-α and IFN-γ release and disturbed SOCS-1, SOCS-2 and SOCS-3 expression in the hippocampus and frontal cortex of adult offspring.
TNF-α -308G/A and IL-8 -251T/A were significantly associated with AD and IL-1β +3953C/T with late-life depression, while the significance of these associations was lost after Bonferroni correction.
TNF-α -308G/A and IL-8 -251T/A were significantly associated with AD and IL-1β+3953C/T with late-life depression, while the significance of these associations was lost after Bonferroni correction.
Chronic peripheral inflammation mediated by cytokines such as TNFα, IL-1β, and IL-6 is associated with psychiatric disorders like depression and anxiety.
Previously, we reported that IL-1 receptor antagonist (IL-1Ra) knockout (KO) mice, which lacked IL-1Ra molecules that antagonize the IL-1 receptor, showed anti-depression-like behavior via adrenergic modulation at the age of 8 weeks.
We sought to assess the prevalence of -889C>T IL-1α, -31T>C and -511C>T IL-1β, -330T>G IL-2 and -174G>C IL-6 genes and their association with adiposity and depression in Polish subjects.
These findings are consistent with a previously reported association between reduced serum IL-1β levels and reduced depression severity following 12 weeks of physical exercise in 105 depressed adults.
Correlation analysis revealed that depression severity negatively correlated with IL-12 in males, and positively correlated with IL-1β and tumor necrosis factor (TNF)-α in females.
Patients who were symptomatic had the highest depression and anxiety scores, together with increased intestinal expression of IL-1β, IL-6 and matrix metalloproteinase-9, increased circulating IL-6 and CRP, and an increased circulating kynurenine:tryptophan ratio.