Circulating concentration of interleukin-37 in Helicobacter pylori-infected patients with peptic ulcer: Its association with IL-37 related gene polymorphisms and bacterial virulence factor CagA.

The immunopathologic responses play a major role in the development of H. pylori (HP)-related gastrointestinal diseases. IL-37 is an anti-inflammatory cytokine with potent suppressive effects on innate and adaptive immune responses. Here, we investigated the IL-37 levels and two single nucleotide polymorphisms (SNPs) including rs3811047 and rs2723176 in IL-37 gene in HP-infected peptic ulcer (PU) patients to identify any relationship. Three groups, including 100 HP-infected PU patients, 100 HP-infected asymptomatic (AS) subjects and 100 non-infected healthy control (NHC) subjects were enrolled to study. Serum IL-37 levels and the genotyping at rs3811047 and rs2723176 were determined using ELISA and SSP-PCR methods, respectively. Significantly higher IL-37 levels were observed in PU patients compared with AS and NHC groups (P < 0.0001). In both PU and AS groups, the CagA+ HP-infected participants displayed higher IL-37 levels compared with those infected with CagA- strains (P < 0.0001). There were significant differences between PU, AS and NHC groups regarding the distribution of genotypes and alleles at rs3811047 and rs2723176 SNPs. The genotype GG and allele G at IL-37 rs3811047 SNP, and the genotype CC and allele C at IL-37 rs2723176 SNP more frequently expressed in PU patients than total healthy subjects (AS + NHC groups) and were associated with an increased risk of PU development (genotype GG: RR = 3.08, P < 0.009; allele G: RR = 2.94, P < 0.01; genotype CC: RR = 5, P < 0.01; and allele C: RR = 5.0, P < 0.02, respectively). The PU patients with allele A at IL-37 rs2723176 SNP expressed higher amounts of IL-37 compared with patients carried allele C at the same position (P < 0.05). In AS carriers and NHC individuals, the IL-37 levels in subjects carried genotype AA or allele A at IL-37 rs2723176 SNP were higher than those carried genotype CC or allele C at the same location (P < 0.01 and P < 0.02 for AS group; P < 0.0001 and P < 0.001 for NHC subjects, respectively). The increased IL-37 levels may be considered as a valuable marker of PU development in HP-infected individuals. The SNPs rs3811047 and rs2723176 were associated with PU development. The CagA status of HP and IL-37 rs2723176 SNP may affect the IL-37 levels.

Are gold nanoparticles and microplastics mixtures more toxic to the marine microalgae Tetraselmis chuii than the substances individually?

The widespread use of microplastics and nanomaterials resulting in environmental contamination is of high concern. Microplastics have been found to modulate the toxicity of other environmental contaminants. Thus, the hypothesis that microplastics increase the toxicity of gold nanoparticles to the marine microalgae Tetraselmis chuii was tested. In a laboratory bioassay, T. chuii cultures were exposed for 96 h to ∼5 nm diameter gold nanoparticles (AuNP) and to virgin 1-5 µm diameter microplastics (MP), alone and in mixture. The treatments were: control; citrate-control; AuNP alone (0.1, 0.3 and 3 mg/L); MP alone (0.3, 0.9 and 4 mg/L) and mixture of the two substances in three different concentrations (0.1 mg/L AuNP + 0.3 mg/L MP; 0.3 mg/L AuNP + 0.9 mg/L MP; 3 mg/l AuNP + 4 mg/L MP). The effect criterion was the inhibition of the average specific growth rate. AuNP alone and MP alone did not cause significant decrease of T. chui average specific growth rate up to 3 mg/L and 4 mg/L, respectively. The mixture containing 3 mg/L AuNP + 4 mg/L MP significantly reduced the average specific growth rate of the microalgae. Therefore, this mixture was more toxic to T. chuii than its components individually. Overall, the results of the present study indicated that the MP and AuNP tested have a relatively low toxicity to T. chuii, but the toxicity increases when they are in mixtures containing high concentrations of both substances. These proof-of-concept findings stress the need of more research on the toxicity of mixtures containing microplastics and nanomaterials.