Increased concentrations of interleukin 1 (IL-1) in the cerebrospinal fluid and serum of patients with Alzheimer disease (AD) reduced phagocytic capacity point to an inflammatory activation of mononuclear phagocytes in AD.
Compared with the sham operation group, the spatial learning and memory abilities of AD rats were signifificantly decreased (P<0.05 or P<0.01; Expressions of IL-1, TNF-α, Aβ and apoptosis-signaling proteins caspase-3, -8, -9, -12 were signifificantly up-regulated (P<0.05 or P<0.01).
In this review, we summarize the polymorphisms of both pro- and anti-inflammatory cytokines related to AD, primarily interleukin-1 (IL-1), IL-6, tumor necrosis factor alpha, IL-4, IL-10, and transforming growth factor beta, as well as their functional activity in AD pathology.
A number of genetic risk factors have been identified for Alzheimer's disease (AD) including genes involved in the inflammatory response (interleukin 1A, [IL-1α (-889)], interleukin 1B (IL-1β [+3953]), and tumor necrosis factor (TNF [-308 and -850]).
Interleukin-33 (IL-33), a newly described member of the IL-1 family, is located on chromosome 9p24, a chromosomal region of interest in Alzheimer's disease (AD) defined by many genome-wide studies.
In conclusion, this meta-analysis supports the idea that IL-1A-889C/T polymorphism is capable of causing AD and LOAD susceptibility in Caucasians but not in Asians.
Interactions have been reported between the low-activity -1021T allele (rs1611115) of DBH and polymorphisms of the pro-inflammatory cytokine genes, IL1A and IL6, contributing to the risk of AD.
Interleukin (IL)-18 is a potent pro-inflammatory cytokine of the IL-1 superfamily, and increasing evidences indicate a crucial role for it in the pathogenesis of AD.
Despite the small sample size and the possibility of a false negative finding, our preliminary data support the hypothesis the IL1Ars1800587 variants are not associated with AD.
Further studies of the associations between other IL-1A genetic polymorphisms and AD should be performed in a larger population and biologic functional analysis of IL-1A gene is required to verify the underlying roles of IL-IA in LOAD.
(i) The risk of developing AD in our population was associated with the IL-1 beta (-511 C/T) promoter polymorphism; (ii) such risk was independent of the risk factor allele in the APOE gene (APOE4); and (iii) the IL-1 alpha promoter polymorphism (-889 C/T) was not associated with the disease.
PARP-1 -410 and PARP-1 -1672 haplotypes were associated with an increased risk for AD (global haplotype association p value=0.019), and, in addition, PARP-1 haplotypes increased the risk of AD by interaction with the IL-1A -889 allele 2.
Most genes conferring susceptibility to AD are related to amyloid-beta deposition (APP; PS1; PS2; APOE; Cystatin-C; ubiquilin-1), oxidative stress (NOS2; NOS3) and inflammatory response (IL-1 alpha; IL-1 beta; IL-6; TNF-alpha).
In this study, the frequency of polymorphisms in the genes coding for interleukin (IL)-1alpha, IL-1beta and the IL-1 receptor antagonist (RN) and their genotype associations with late-onset AD and VaD were determined in a Japanese-American cohort of men (n=931) participating in the Honolulu-Asia Aging Study (HAAS).