A critical region of A20 unveiled by missense variations that lead to autoinflammation.

A20 haploinsufficiency (HA20) is an autoinflammatory disease caused by heterozygous loss-of-function variations in , the gene encoding the A20 protein. Diagnosis of HA20 is challenging due to its heterogeneous clinical presentation and the lack of pathognomonic symptoms. While the pathogenic effect of truncating variations is clearly established, that of missense variations is difficult to determine.

De Novo Gain-Of-Function Variations in LYN Associated With an Early-Onset Systemic Autoinflammatory Disorder.

Objective: To identify the molecular basis of a severe systemic autoinflammatory disorder (SAID) and define its main phenotypic features, and to functionally assess the sequence variations identified in LYN, a gene encoding a nonreceptor tyrosine kinase.

Methods: We used targeted next-generation sequencing and in vitro functional studies of Lyn phosphorylation state and Lyn-dependent NF-κB activity after expression of recombinant Lyn isoforms carrying different sequence variations.

Results: We identified a de novo LYN variation (p.

Neutrophilic dermatoses.

Neutrophilic dermatoses (ND) are a group of inflammatory skin conditions characterized by a neutrophilic infiltrate on histopathology with no evidence of infection. ND are classified based upon the localization of neutrophils within the skin and clinical features. Recent findings suggest that ND are due to two main mechanisms: i) a polyclonal hereditary activation of the innate immune system (polygenic or monogenic); or ii) a clonal somatic activation of myeloid cells such as encountered in myelodysplastic syndrome or VEXAS syndrome.

Mosaic variants in TNFRSF1A: an emerging cause of tumour necrosis factor receptor-associated periodic syndrome.

Objective: To identify the molecular basis of a systemic autoinflammatory disorder (SAID) evocative of TNF receptor-associated periodic syndrome (TRAPS).

Methods: (i) Deep next generation sequencing (NGS) through a SAID gene panel; (ii) variant allele distribution in peripheral blood subpopulations; (iii) in silico analyses of mosaic variants using TNF receptor superfamily 1A (TNFRSF1A) crystal structure; (iv) review of the very rare TNFRSF1A mosaic variants reported previously.

Results: In a 36-year-old man suffering from recurrent fever for 12 years, high-depth NGS revealed a TNFRSF1A mosaic variant, c.

Identification of IgG1 isotype phosphorylcholine antibodies for the treatment of inflammatory cardiovascular diseases.

Background: Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti-inflammatory and anti-atherosclerotic properties.

NLRP3-associated autoinflammatory diseases: Phenotypic and molecular characteristics of germline versus somatic mutations.

Background: NLRP3-associated autoinflammatory diseases (NLRP3-AIDs) include conditions of various severities, due to germline or somatic mosaic NLRP3 mutations.

Objective: To identify mosaic- versus germline-specific NLRP3 mutations' characteristics, we reinterpreted all the mutations reported in NLRP3-AIDs and performed an in-depth study of 3 novel patients.

Methods: The pathogenicity of all reported mosaic/germline mutations was reassessed according to international recommendations and their location on the NLRP3 3-dimensional structure.

Somatic Mosaic NLRP3 Mutations and Inflammasome Activation in Late-Onset Chronic Urticaria.

Chronic urticaria is a common skin disorder with heterogeneous causes. In the absence of physical triggers, chronic urticarial rash is called idiopathic or spontaneous. The objective of this study was to identify the molecular and cellular bases of a disease condition displayed by two unrelated patients aged over 60 years who presented for two decades with a chronic urticaria resistant to standard therapy that occurred in the context of systemic inflammation not triggered by cold.

Expression of SAA1, SAA2 and SAA4 genes in human primary monocytes and monocyte-derived macrophages.

Circulating serum amyloid A (SAA) is increased in various inflammatory conditions. The human SAA protein family comprises the acute phase SAA1/SAA2, known to activate a large set of innate and adaptive immune cells, and the constitutive SAA4. The liver synthesis of SAA1/SAA2 is well-established but there is still an open debate on extrahepatic SAA expression especially in macrophages.

Proteasomal degradation of NOD2 by NLRP12 in monocytes promotes bacterial tolerance and colonization by enteropathogens.

Mutations in the nucleotide-binding oligomerization domain protein 12 (NLRP12) cause recurrent episodes of serosal inflammation. Here we show that NLRP12 efficiently sequesters HSP90 and promotes K48-linked ubiquitination and degradation of NOD2 in response to bacterial muramyl dipeptide (MDP). This interaction is mediated by the linker-region proximal to the nucleotide-binding domain of NLRP12.

A thioredoxin-mimetic peptide exerts potent anti-inflammatory, antioxidant, and atheroprotective effects in ApoE2.Ki mice fed high fat diet.

Aims: Oxidative stress and inflammation play a pathogenic role in atherosclerosis. Thioredoxin-1 (Trx-1) is an anti-oxidative, anti-inflammatory protein with atheroprotective effects. However, in vivo cleavage of Trx-1 generates a truncated pro-inflammatory protein, Trx-80, which compromises the therapeutic use of Trx-1.

Photoaging and skin cancer: Is the inflammasome the missing link?

Photoaging and epithelial skin tumorigenesis are complex processes triggered mainly by UV radiation from chronic sun exposure. This leads to DNA damage and reactive oxygen species (ROS) production, which initiate an inflammatory response that alters cell structure and function. Changes in cell homeostasis and ROS production activate intracellular multiprotein platforms called inflammasomes.

Inflammasome biology, molecular pathology and therapeutic implications.

Inflammasomes are intracellular multiprotein signaling complexes, mainly present in myeloid cells. They commonly assemble around a cytoplasmic receptor of the nucleotide-binding leucine-rich repeat containing receptor (NLR) family, although other cytoplasmic receptors like pyrin have been shown to form inflammasomes. The nucleation of the multiprotein scaffolding platform occurs upon detection of a microbial, a danger or a homeostasis pattern by the receptor that will, most commonly, associate with the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD) through homotypic domain interactions resulting in recruitment of procaspase-1.

Impact of human monocyte and macrophage polarization on NLR expression and NLRP3 inflammasome activation.

Inflammasomes are multiprotein complexes nucleating around an NLR (Nucleotide-binding domain and Leucine-rich Repeat containing protein), which regulate the secretion of the pro-inflammatory interleukin (IL)-1β and IL-18 cytokines. Monocytes and macrophages, the main cells expressing the inflammasome genes, adapt to their surrounding microenvironment by a phenotypic polarization towards a pro-inflammatory M1 phenotype that promotes inflammation or an anti-inflammatory M2 phenotype important for resolution of inflammation. Despite the importance of inflammasomes in health and disease, little is known about inflammasome gene expression in relevant human cells and the impact of monocyte and macrophage polarization in inflammasome gene expression.

Role of lipid phosphate phosphatase 3 in human aortic endothelial cell function.

Aims: Lipid phosphate phosphatase 3; type 2 phosphatidic acid phosphatase β (LPP3; PPAP2B) is a transmembrane protein dephosphorylating and thereby terminating signalling of lipid substrates including lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P). Human LPP3 possesses a cell adhesion motif that allows interaction with integrins. A polymorphism (rs17114036) in PPAP2B is associated with coronary artery disease, which prompted us to investigate the possible role of LPP3 in human endothelial dysfunction, a condition promoting atherosclerosis.

Plasma PAFAH/PLA2G7 Genetic Variability, Cardiovascular Disease, and Clinical Trials.

PAFAH is specific for short acyl groups esterified at the sn-2 position of glycerol in phospholipids, and apart from PAF, it hydrolyzes oxidized phospholipids produced during LDL oxidation. As the majority of the plasma PAFAH activity is bound in humans to LDL, it is also called the lipoprotein-associated phospholipase A2 (Lp-PLA2), and it was associated with the proinflammatory processes in atherosclerosis. The epidemiological studies in Caucasian populations demonstrated that high PAFAH levels might be a risk factor for cardiovascular disease through generation of proinflammatory lysoPC/lysoPAF and oxidized fatty free acids and led to the development of darapladib, a reversible PAFAH inhibitor.

Chronic myelomonocytic leukemia as a cause of fatal uncontrolled inflammation in familial Mediterranean fever.

We report on a familial Mediterranean fever (FMF) patient homozygous for p.M694V in the MEFV gene who developed chronic myelomonocytic leukemia (CMML) leading to an uncontrolled and fatal inflammatory syndrome. Plasma levels of IL-6 and IL-18 were found to be very high, as compared to healthy controls and CMML-free FMF patients.

PLA2G10 Gene Variants, sPLA2 Activity, and Coronary Heart Disease Risk.

Background: Observational studies report that secretory phospholipase A2 (sPLA2) activity is a marker for coronary heart disease (CHD) risk, and activity measures are thought to represent the composite activity of sPLA2-IIA, -V, and -X. The aim of this study was to use genetic variants of PLA2G10, encoding sPLA2-X, to investigate the contribution of sPLA2-X to the measure of sPLA2 activity and coronary heart disease (CHD) risk traits and outcome.

Methods And Results: Three PLA2G10 tagging single-nucleotide polymorphisms (rs72546339, rs72546340, and rs4003232) and a previously studied PLA2G10 coding single-nucleotide polymorphism rs4003228, R38C, were genotyped in a nested case: control cohort drawn from the prospective EPIC-Norfolk Study (2175 cases and 2175 controls).

Induction of dendritic cell-mediated T-cell activation by modified but not native low-density lipoprotein in humans and inhibition by annexin a5: involvement of heat shock proteins.

Objective: Atherosclerosis is an inflammatory disease, where activated immunocompetent cells, including dendritic cells (DCs) and T cells are abundant in plaques. Low-density lipoprotein modified either by oxidation (oxLDL) or by human group X-secreted phospholipase A2 (LDLx) and heat shock proteins (HSP), especially HSP60 and 90, have been implicated in atherosclerosis. We previously reported that Annexin A5 inhibits inflammatory effects of phospholipids, decreases vascular inflammation and improves vascular function in apolipoprotein E(-/-) mice.

Brief Report: Involvement of TNFRSF11A molecular defects in autoinflammatory disorders.

Objective: Autoinflammatory disorders are caused by a primary dysfunction of the innate immune system. Among these disorders are hereditary recurrent fevers, which are characterized by recurrent episodes of fever and inflammatory manifestations affecting multiple tissues. Hereditary recurrent fevers often lack objective diagnostic criteria, thereby hampering the identification of disease-causing genes.

Involvement of the same TNFR1 residue in mendelian and multifactorial inflammatory disorders.

Objectives: TNFRSF1A is involved in an autosomal dominant autoinflammatory disorder called TNFR-associated periodic syndrome (TRAPS). Most TNFRSF1A mutations are missense changes and, apart from those affecting conserved cysteines, their deleterious effect remains often questionable. This is especially true for the frequent R92Q mutation, which might not be responsible for TRAPS per se but represents a susceptibility factor to multifactorial inflammatory disorders.

The risk of familial Mediterranean fever in MEFV heterozygotes: a statistical approach.

Background: Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder due to MEFV mutations and one of the most frequent Mediterranean genetic diseases. The observation of many heterozygous patients in whom a second mutated allele was excluded led to the proposal that heterozygosity could be causal. However, heterozygosity might be coincidental in many patients due to the very high rate of mutations in Mediterranean populations.

A diet containing soybean oil heated for three hours increases adipose tissue weight but decreases body weight in C57BL/6 J mice.

Background: Our previous work showed that dietary oxidized linoleic acid given, as a single fatty acid, to LDL receptor knockout mice decreased weight gain as compared to control mice. Other studies have also reported that animals fed oils heated for 24 h or greater showed reduced weight gain. These observations, while important, have limited significance since fried foods in the typical human diet do not contain the extreme levels of oxidized lipids used in these studies.