A New Risk Polymorphism rs10403848 of CARD8 Significantly Associated with Psoriasis Vulgaris in Northeastern China

CARD8: A Novel Inflammasome Sensor with Well-Known Anti-Inflammatory and Anti-Apoptotic Activity

Inflammasomes comprise a group of protein complexes with fundamental roles in the induction of inflammation. Upon sensing stress factors, their assembly induces the activation and release of the pro-inflammatory cytokines interleukin (IL)-1β and -18 and a lytic type of cell death, termed pyroptosis. Recently, CARD8 has joined the group of inflammasome sensors. The carboxy-terminal part of CARD8, consisting of a function-to-find-domain (FIIND) and a caspase activation and recruitment domain (CARD), resembles that of NLR family pyrin domain containing 1 (NLRP1), which is recognized as the main inflammasome sensor in human keratinocytes. The interaction with dipeptidyl peptidases 8 and 9 (DPP8/9) represents an activation checkpoint for both sensors. CARD8 and NLRP1 are activated by viral protease activity targeting their amino-terminal region. However, CARD8 also has some unique features compared to the established inflammasome sensors. Activation of CARD8 occurs independently of the inflammasome adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC), leading mainly to pyroptosis rather than the activation and secretion of pro-inflammatory cytokines. CARD8 was also shown to have anti-inflammatory and anti-apoptotic activity. It interacts with, and inhibits, several proteins involved in inflammation and cell death, such as the inflammasome sensor NLRP3, CARD-containing proteins caspase-1 and -9, nucleotide-binding oligomerization domain containing 2 (NOD2), or nuclear factor kappa B (NF-κB). Single nucleotide polymorphisms (SNPs) of CARD8, some of them occurring at high frequencies, are associated with various inflammatory diseases. The molecular mechanisms underlying the different pro- and anti-inflammatory activities of CARD8 are incompletely understood. Alternative splicing leads to the generation of multiple CARD8 protein isoforms. Although the functional properties of these isoforms are poorly characterized, there is evidence that suggests isoform-specific roles. The characterization of the functions of these isoforms, together with their cell- and disease-specific expression, might be the key to a better understanding of CARD8's different roles in inflammation and inflammatory diseases.

Macrophage Subsets and Death Are Responsible for Atherosclerotic Plaque Formation

Cardiovascular diseases, the notorious killer, are mainly caused by atherosclerosis (AS) characterized by lipids, cholesterol, and iron overload in plaques. Macrophages are effector cells and accumulate to the damaged and inflamed sites of arteries to internalize native and chemically modified lipoproteins to transform them into cholesterol-loaded foam cells. Foam cell formation is determined by the capacity of phagocytosis, migration, scavenging, and the features of phenotypes. Macrophages are diverse, and the subsets and functions are controlled by their surrounding microenvironment. Generally, macrophages are divided into classically activated (M1) and alternatively activated (M2). Recently, intraplaque macrophage phenotypes are recognized by the stimulation of CXCL4 (M4), oxidized phospholipids (Mox), hemoglobin/haptoglobin complexes [HA-mac/M(Hb)], and heme (Mhem). The pro-atherogenic or anti-atherosclerotic phenotypes of macrophages decide the progression of AS. Besides, apoptosis, necrosis, ferroptosis, autophagy and pyrotopsis determine plaque formation and cardiovascular vulnerability, which may be associated with macrophage polarization phenotypes. In this review, we first summarize the three most popular hypotheses for AS and find the common key factors for further discussion. Secondly, we discuss the factors affecting macrophage polarization and five types of macrophage death in AS progression, especially ferroptosis. A comprehensive understanding of the cellular and molecular mechanisms of plaque formation is conducive to disentangling the candidate targets of macrophage-targeting therapies for clinical intervention at various stages of AS.

Association of Polymorphisms of Metabolism-Related Genes with Psoriasis Vulgaris in Han Chinese

Aim

Psoriasis is a chronic inflammatory disease with a complex etiology, and psoriasis vulgaris (PsV) is the most common type of psoriasis. Recent studies suggest the relationship between psoriasis and metabolic syndrome in different ethnicities. This study is aimed at evaluating the association of metabolism-related gene variants with the risk of PsV in Chinese Han population. Material and Methods. PsV patients (1030) and healthy controls (965) were enrolled in this study. Eighteen single-nucleotide polymorphisms (SNPs) previously reported to be significantly associated with metabolic syndrome were selected. SNPs were detected by next-generation sequencing.

Results

Seven SNPs were significantly associated with PsV: rs805303 (P = 0.012, OR = 0.85), rs3177928 (P = 1.37 × 10⁻¹⁵, OR = 2.51), and rs2247056 (P = 3.73 × 10⁻⁴, OR = 0.67) located in the HLA gene region; rs1047781 (P = 0.012, OR = 1.18), rs281379 (P = 0.014, OR = 1.71), and rs492602 (P = 0.005, OR = 1.86) located in the FUT2 region; and rs2303138 (P = 0.014, OR = 1.18) located in the LNPEP region. After stratified analysis, rs805303 (P = 0.017, OR = 0.74) and rs2303138 (P = 0.041, OR = 1.30) were associated with PsVs when HLA-C^∗06 : 02 was positive, and rs805303 (P = 5.62 × 10⁻⁵, OR = 0.68), rs3177928 (P = 0.003, OR = 1.75), rs281379 (P = 0.034, OR = 1.96), and rs492602 (P = 0.025, OR = 2.04) were associated with PsVs when HLA-C^∗06 : 02 was negative.

Conclusion

PsV and metabolic syndrome may have overlapped susceptible genes in Chinese Han population.

Single-Nucleotide Polymorphism LncRNA AC008392.1/rs7248320 in CARD8 is Associated with Kawasaki Disease Susceptibility in the Han Chinese Population

Background

Kawasaki disease (KD) is a multisystem vasculitis in infants and young children and involved in the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome activation. Genetic factors may increase the risk of KD. To assess the association between rs7248320 in long noncoding RNA (lncRNA) AC008392.1 located in the upstream region of CARD8 and the risk of KD, a case–control study was conducted in the Han Chinese population.

Methods

This study genotyped the polymorphism rs7248320 in the lncRNA AC008392.1 gene using the TaqMan real-time polymerase chain reaction assay. The genetic contribution of rs7248320 was evaluated using odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis. The association between rs7248320 and KD susceptibility was analyzed by performing a hospital-based case–control study including 559 KD patients and 1055 non-KD controls.

Results

In this study, a significant relationship between rs7248320 and KD risk was observed in the genotype/allele frequency distribution. The rs7248320 polymorphism was associated with a significantly decreased risk of KD after adjustment for age and sex (AG vs AA: adjusted OR = 0.80, 95% CI: 0.64–0.99, P = 0.0421; GG vs AA: adjusted OR = 0.71, 95% CI: 0.51–1.00, P = 0.0492; AG/GG vs AA: adjusted OR = 0.78, 95% CI: 0.63–0.96, P = 0.0186). Moreover, the rs7248320 G allele also exhibited a decreased risk for KD (adjusted OR = 0.83, 95% CI: 0.72–0.97, P = 0.0193) compared with the A allele. In the stratification analysis, compared to the rs7248320 AA genotype, AG/GG genotypes were more protective for males (OR = 0.71, 95% CI: 0.55–0.93, P = 0.0122).

Conclusion

This study suggests for the first time that the lncRNA AC008392.1 rs7248320 polymorphism may be involved in KD susceptibility in the Han Chinese population.

The polymorphism of the CARD8 inflammasome-related gene is associated with glutamic-acid-decarboxylase-antibody positivity in patients with type 1 diabetes mellitus

Background

This study sought to examine the correlation between 2 single-nucleotide polymorphisms (SNPs; rs10403848 and rs2043211) in the caspase recruitment domain-containing protein 8 (CARD8) gene and the risks and clinical features of patients with type 1 diabetes mellitus (T1DM) in the Han Chinese population.

Methods

A case-control study involving the Han Chinese population was designed, and individuals diagnosed with classical T1DM and healthy controls were enrolled in this study. MassARRAY genotyped the SNPs of rs10403848 and rs2043211. Logistic regression and chi-square analyses were conducted to compare the allele distributions and genotypes of the T1DM and healthy control participants. A Kruskal-Wallis 1-way analysis of variance was used to perform the genotype-phenotype analysis for the T1DM patients.

Results

In total, 510 participants with classical T1DM and 531 sex-matched healthy control participants participated in this study. The CARD8 SNP of rs2043211 was significantly associated with the rate of glutamic-acid-decarboxylase-antibody (GADA) positivity among T1DM patients (P=0.021). However, no significant differences in the distributions of alleles or the genotypes of rs10403848 and rs2043211 were observed between the case and control groups, and these 2 SNPs were not associated with T1DM under various inheritance models.

Conclusions

The rs10403848 and rs2043211 polymorphisms of CARD8 were not associated with susceptibility to T1DM. However, rs2043211 was found to be correlated with GADA positivity in participants with T1DM.