Regulation of NLRP3 and AIM2 inflammasome gene expression levels in gingival fibroblasts by oral biofilms
CELLULAR IMMUNOLOGY
Authors: Bostanci, Nagihan; Meier, Andre; Guggenheim, Bernhard; Belibasakis, Georgios N.
Abstract
Periodontal disease is an inflammatory condition that destroys the tooth-supporting tissues. The inflammation is initiated by oral bacteria in the form of multi-species biofilms, and is dominated by cytokines of the IL-1 family. IL-1 activation and processing is regulated by Caspase-1, within intracellular protein complexes, known as "inflammasomes". The present study employed culture supernatants of in vitro supragingival and subgingival biofilms, to challenge human GF cultures for 6 h. The gene expression of inflammasome complex components was investigated by TaqMan qPCR. NLRP1 expression was not affected, whereas NLRP2 was not expressed. SupragingiVal biofilm challenge increased the expression of Caspase-1, the adaptor ASC, AIM2, as well as IL-1 beta and IL-18, but did not affect NLRP3 expression. Subgingival biofilm challenge enhanced Caspase-1, ASC, AIM2, IL-1 beta and IL-18 gene expression at lower concentrations, followed by their down-regulation at higher concentrations, which was also evident for NLRP3 expression. Hence, supragingival and subgingival biofilms differentially regulate the gene expressions of NLRP3 and AIM2 inflammasomes and their down-stream IL-1 targets. Increased inflammasome transcription in response to supragingival biofilms is commensurate with early inflammatory events in periodontal disease, whereas decreased transcription in response to subgingival biofilms corroborates the dampening of host immune responses, in favour of pathogen survival and persistence. (C) 2011 Elsevier Inc. All rights reserved.
Characterization of multi-locus imprinting disturbances and underlying genetic defects in patients with chromosome 11p15.5 related imprinting disorders
EPIGENETICS
Authors: Fontana, L.; Bedeschi, M. F.; Maitz, S.; Cereda, A.; Fare, C.; Motta, S.; Seresini, A.; D'Ursi, P.; Orro, A.; Pecile, V.; Calvello, M.; Selicorni, A.; Lalatta, F.; Milani, D.; Sirchia, S. M.; Miozzo, M.; Tabano, S.
Abstract
The identification of multilocus imprinting disturbances (MLID) appears fundamental to uncover molecular pathways underlying imprinting disorders (IDs) and to complete clinical diagnosis of patients. However, MLID genetic associated mechanisms remain largely unknown. To characterize MLID in Beckwith-Wiedemann (BWS) and Silver-Russell (SRS) syndromes, we profiled by MassARRAY the methylation of 12 imprinted differentially methylated regions (iDMRs) in 21 BWS and 7 SRS patients with chromosome 11p15.5 epimutations. MLID was identified in 50% of BWS and 29% of SRS patients as a maternal hypomethylation syndrome. By next-generation sequencing, we searched for putative MLID-causative mutations in genes involved in methylation establishment/maintenance and found two novel missense mutations possibly causative of MLID: one in NLRP2, affecting ADP binding and protein activity, and one in ZFP42, likely leading to loss of DNA binding specificity. Both variants were paternally inherited. In silico protein modelling allowed to define the functional effect of these mutations. We found that MLID is very frequent in BWS/SRS. In addition, since MLID-BWS patients in our cohort show a peculiar pattern of BWS-associated clinical signs, MLID test could be important for a comprehensive clinical assessment. Finally, we highlighted the possible involvement of ZFP42 variants in MLID development and confirmed NLRP2 as causative locus in BWS-MLID.D