Protein misfolding and dysregulated protein homeostasis in autoinflammatory diseases and beyond.

Cells have a number of mechanisms to maintain protein homeostasis, including proteasome-mediated degradation of ubiquitinated proteins and autophagy, a regulated process of ‘self-eating’ where the contents of entire organelles can be recycled for other uses. The unfolded protein response prevents protein overload in the secretory pathway. In the past decade, it has become clear that these fundamental cellular processes also help contain inflammation though degrading pro-inflammatory protein complexes such as the NLRP3 inflammasome. Signaling pathways such as the UPR can also be co-opted by toll-like receptor and mitochondrial reactive oxygen species signaling to induce inflammatory responses. Mutations that alter key inflammatory proteins, such as NLRP3 or TNFR1, can overcome normal protein homeostasis mechanisms, resulting in autoinflammatory diseases. Conversely, Mendelian defects in the proteasome cause protein accumulation, which can trigger interferon-dependent autoinflammatory disease. In non-Mendelian inflammatory diseases, polymorphisms in genes affecting the UPR or autophagy pathways can contribute to disease, and in diseases not formerly considered inflammatory such as neurodegenerative conditions and type 2 diabetes, there is increasing evidence that cell intrinsic or environmental alterations in protein homeostasis may contribute to pathogenesis

The touchscreen operant platform for testing learning and memory in rats and mice.

An increasingly popular method of assessing cognitive functions in rodents is the automated touchscreen platform, on which a number of different cognitive tests can be run in a manner very similar to touchscreen methods currently used to test human subjects. This methodology is low stress (using appetitive rather than aversive reinforcement), has high translational potential and lends itself to a high degree of standardization and throughput. Applications include the study of cognition in rodent models of psychiatric and neurodegenerative diseases (e.g., Alzheimer's disease, schizophrenia, Huntington's disease, frontotemporal dementia), as well as the characterization of the role of select brain regions, neurotransmitter systems and genes in rodents. This protocol describes how to perform four touchscreen assays of learning and memory: visual discrimination, object-location paired-associates learning, visuomotor conditional learning and autoshaping. It is accompanied by two further protocols (also published in this issue) that use the touchscreen platform to assess executive function, working memory and pattern separation

Effect of Aging on Healthcare Costs of Inflammatory Bowel Disease: A Glimpse into the Future

Background:Population aging is expected to result in a substantial additional burden on healthcare resources in the near future. We aimed to assess the current and future impact of aging on direct healthcare costs (DHC) attributed to inflammatory bowel disease (IBD).Methods:Patients with IBD from a Dutch multicenter cohort filled out 3-monthly questionnaires for 2 years. Elderly (60 yr) and younger patients (18-60 yr) IBD were analyzed for differences in 3-monthly DHC, productivity losses, and out-of-pocket costs. Prevalence rates were obtained from a health insurance database. Estimates of annual DHC and prevalence rates were applied to the total Dutch adult population in 2011 and then projected to 2040, using predicted changes in population demography, prices, and volume.Results:IBD-attributable DHC were lower in elderly than in younger patients with IBD with respect to 3-monthly DHC (Euro359 versus Euro978, P < 0.01), productivity losses (Euro108 versus Euro456, P < 0.01), and out-of-pocket costs (Euro40 versus Euro57, P < 0.01). Between 2011 and 2040, the percentage of elderly IBD patients in the Netherlands has been projected to rise from 24% to 35%. Between 2011 and 2040, DHC of the total IBD population in the Netherlands are projected to increase from Euro161 to Euro661 million. Population aging accounted for 1% of this increase, next to rising prices (29%), and volume growth (70%).Conclusions:Population aging has a negligible effect on IBD-attributable DHC of the IBD population in the near future, because the average costs incurred by elderly patients with IBD are considerably lower than those incurred by younger patients with IBD

Cold-induced urticarial autoinflammatory syndrome related to factor XII activation

Hereditary autoinflammatory diseases are caused by gene mutations of the innate immune pathway, e.g. nucleotide receptor protein 3 (NLRP3). Here, we report a four-generation family with cold-induced urticarial rash, arthralgia, chills, headache and malaise associated with an autosomal-dominant inheritance. Genetic studies identify a substitution mutation in gene F12 (T859A, resulting in p.W268R) which encodes coagulation factor XII (FXII). Functional analysis reveals enhanced autocatalytic cleavage of the mutated protein and spontaneous FXII activation in patient plasma and in supernatant of transfected HEK293 cells expressing recombinant W268R-mutated proteins. Furthermore, we observe reduced plasma prekallikrein, cleaved high molecular weight kininogen and elevated plasma bradykinin. Neutrophils are identified as a local source of FXII. Interleukin-1β (IL-1β) is upregulated in lesional skin and mononuclear donor cells exposed to recombinant mutant proteins. Treatment with icatibant (bradykinin-B2-antagonist) or anakinra (interleukin-1-antagonist) reduces disease activity in patients. In conclusion, our findings provide a link between contact system activation and cytokine-mediated inflammation