The interleukin-4 -34TT and -590TT genotype is correlated with increased expression and protein production in aggressive periodontitis

Loricrin and Cytokeratin Disorganisation in Severe Forms of Periodontitis

OBJECTIVE

The aim of this research was to investigate the role of the cornified epithelium, the outermost layer of the oral mucosa, engineered to prevent water loss and microorganism invasion, in severe forms of periodontitis (stage III or IV, grade C).

METHODS

Porphyromonas gingivalis, a major periodontal disease pathogen, can affect cornified epithelial protein expression through chronic activation of signal transducer and activator of transcription 6 (Stat6). We used a mouse model, Stat6VT, that mimics this to determine the effects of barrier defect on P gingivalis-induced inflammation, bone loss, and cornified epithelial protein expression, and compared histologic and immunohistologic findings with tissues obtained from human controls and patients with stage III and IV, grade C disease. Alveolar bone loss in mice was assessed using micro-computerised tomography, and soft tissue morphology was qualitatively and semi-quantitatively assessed by histologic examination for several proteins, including loricrin, filaggrin, cytokeratin 1, cytokeratin 14, a proliferation marker, a pan-leukocyte marker, as well as morphologic signs of inflammation. Relative cytokine levels were measured in mouse plasma by cytokine array.

RESULTS

In the tissues from patients with periodontal disease, there were greater signs of inflammation (rete pegs, clear cells, inflammatory infiltrates) and a decrease and broadening of expression of loricrin and cytokeratin 1. Cytokeratin 14 expression was also broader and decreased in stage IV. P gingivalis-infected Stat6VT mice showed greater alveolar bone loss in 9 out of 16 examined sites, and similar patterns of disruption to human patients in expression of loricrin and cytokeratins 1 and 14. There were also increased numbers of leukocytes, decreased proliferation, and greater signs of inflammation compared with P gingivalis-infected control mice.

CONCLUSIONS

Our study provides evidence that changes in epithelial organisation can exacerbate the effects of P gingivalis infection, with similarities to the most severe forms of human periodontitis.

Association between genetic variants in TREM1, CXCL10, IL4, CXCL8 and TLR7 genes with the occurrence of congenital Zika syndrome and severe microcephaly

Congenital Zika syndrome (CZS) is a cluster of malformations induced by Zika virus (ZIKV) infection and the underline mechanisms involved in its occurrence are yet not fully understood. Along with epidemiological and environmental factors, the genetic host factors are suggested as important to the CZS occurrence and development, however, few studies have evaluated this. This study enrolled a total of 245 individuals in a case-control association study compound a cohort of high specific interest constituted by 75 mothers who had delivered CZS infants, their 76 infants, and 47 mothers that had delivered healthy infants, and their 47 infants. Sixteen single-nucleotide polymorphisms on TREM1, CXCL10, IL4, CXCL8, TLR3, TLR7, IFNR1, CXCR1, IL10, CCR2 and CCR5 genes were genotyped to investigate their association as risk factors to CZS. The results show an association between C allele at TREM1 rs2234246 and C allele at IL4 rs224325 in mothers infected with ZIKV during pregnancy, with the increased susceptibility to CZS occurrence in their infants and the SNP CXCL8 rs4073 and the G allele at CXCL10 rs4508917 with presence of CZS microcephaly in the infants. Furthermore, the T allele at CXCL8 rs4073 and TRL7 rs179008 SNPs were associated with the severity of microcephaly in children with CZS. These results suggest that these polymorphisms in genes of innate immune responses addressed here are associated to increased risk of occurrence and severity of CZS in pregnant mothers infected with ZIKV and their CZS infants.

Genetic Variants of Interleukin-4 in Romanian Patients with Idiopathic Nephrotic Syndrome

Background and objectives: One of the most frequent glomerular diseases in the pediatric population is represented by the idiopathic nephrotic syndrome (INS). The exact mechanisms mediating the disease are still unknown, but several genetic factors have been studied for possible implications. Cytokines are considered to play a pivotal role in mediating INS disease progression, interleukin-4 (IL-4) exhibiting particular interest. The objective of this research project was to investigate the association between two IL-4 gene single-nucleotide polymorphisms (SNPs) and INS susceptibility as well as response to steroid therapy, in a group of Romanian children. Materials and Methods: In total, 75 patients with INS and 160 healthy controls of Romanian origin were genotyped for IL-4 rs2243250/−590C/T and rs2070874/−34C/T using real-time polymerase chain reaction. Association tests were performed using the DeFinetti program and Plink 1.07 software and p-values < 0.05 were considered statistically significant. Results: The analysis of INS patients and controls revealed a similar genotype distribution of the studied SNPs. The minor T alleles were less frequent in the INS group, but not statistically significant (p = 0.1, OR = 0.68 and p = 0.2, OR = 0.74). Regarding the response to steroids, a low frequency of 590*T allele in steroid-resistant patients (7.7%), compared with steroid-sensitive patients (14%) and controls (17.5%), was obtained, but the difference did not reach the statistical significance threshold. The same result was obtained for −34C/T SNP. Conclusions: This is the first study examining the relationship between the IL-4 gene and INS susceptibility conducted in a European population, and particularly in Romania. The investigated SNPs were found to not be associated with disease susceptibility or response to the steroid treatment of pediatric INS.

Polymorphisms PSCA rs2294008, IL-4 rs2243250 and MUC1 rs4072037 are associated with gastric cancer in a high risk population

Genetic variants are considered risk factors for gastric cancer. To date, 61 polymorphisms have been identified as associated with this disease. The aim of the present study was to analyze the association of some of those polymorphisms with GC in Chile. We performed a case-control study including 310 gastric cancer cases and 311 controls to assess the association of 36 single-nucleotide polymorphisms genotyped by Global Screening Array (GSA). Three polymorphisms was significantly associated: PSCA rs2294008 (allele model, OR = 1.49, 95%CI 1.17-1.88, P = 1.08 × 10-3), IL-4 rs2243250 (allele model, OR = 1.28, 95%CI 1.01-1.62, P = 0.04), and MUC1 rs4072037 (allele model, OR = 0.78, 95%CI 0.61-0.99, P = 0.04).PSCA rs2294008, IL-4 rs2243250 and MUC1 rs4072037 are associated with gastric cancer in Chile. It suggests that those polymorphisms could be used as biomarkers to assess the genetic risk for this cancer outside of the previously studied populations, not only for East Asians and Caucasians populations.

Interleukin-4 -590C/T gene polymorphism in Egyptian children with acute lower respiratory infection: A multicenter study

BACKGROUND

Acute lower respiratory infection (ALRI) is the leading cause of child mortality, especially in the developing world. Polymorphisms in the interleukin 4 (IL-4) gene have been linked to a variety of human diseases.

OBJECTIVES

To investigate whether the IL-4 -590C/T (rs2243250) polymorphism could be a genetic marker for susceptibility to ALRIs in young Egyptian children.

METHODS

This was a multicenter study conducted on 480 children diagnosed with pneumonia or bronchiolitis, and 480 well-matched healthy control children. Using PCR-RFLP analysis, we genotyped a -590C/T (rs2243250) single nucleotide polymorphism of the IL-4 gene promoter, meanwhile the serum IL-4concentration was measured by ELISA.

RESULTS

The frequency of the IL-4 -590 T/T genotype and T allele were overrepresented in patients with ALRIs in comparison to the control group (OR = 2.0; [95% confidence interval [CI]: 1.38-2.96]; for the T/T genotype) and (OR: 1.3; [95%CI: 1.07-1.56]; for the T allele; P < 0.01). The IL-4 -590 T/T genotype was associated with significantly higher mean serum IL-4 concentration (58.7 ± 13.4 pg/mL) compared to the C/T genotype (47.6 ± 11 pg/mL) and the C/C genotype (34.8 ± 9.6 pg/mL); P < 0.01.

CONCLUSION

The IL-4 -590C/T (rs2243250) polymorphism may contribute to susceptibility to ALRIs in young Egyptian children.

Functionality and opposite roles of two interleukin 4 haplotypes in immune cells

Cytokines expression can be influenced by polymorphisms in their respective coding genes. We associated the CTI/TTD haplotype (Hap-1) and TCI/CCI haplotype (Hap-2) in the IL4 gene formed by the -590, +33 and variable number of tandem repeat polymorphisms with the severity of chronic periodontitis in humans. The functionality of these IL4 haplotypes in the response of immune cells to phorbol 12-myristate 13-acetate (PMA) with Ionomycin and IL-1β (as inflammatory stimuli) was evaluated. Gene expression (quantitative real-time PCR), profile of secreted cytokines (multiplex) and phenotypic polarization of T cells (flow cytometry) were the outcomes assessed. Green fluorescent protein reporter plasmid constructs containing specific IL4 haplotype were transiently transfected into JM cells to assess the influence of the individual haplotypes on promoter activity. In response to inflammatory stimuli the immune cells from Hap-1 haplotype had increased expression of anti-inflammatory IL4; conversely, the Hap-2 haplotype showed higher levels of pro-inflammatory cytokines. The haplotype CTI proved to be the most important for the regulation of IL4 promoter, regardless of the nature of the inflammatory stimulation; whereas the polymorphism in the promoter region had the least functional effect. In conclusion, IL4 haplotypes studied are functional and trigger opposite immune responses: anti-inflammatory (Hap-1) and pro-inflammatory (Hap-2). In addition, we identified the CTI haplotype as the main responsible for the regulation of IL4 transcriptional activity.

Association of interleukin-4 polymorphisms with multiple sclerosis in southeastern Iranian patients

BACKGROUND AND OBJECTIVES

Immune system-related factors are important in the pathogenesis of multiple sclerosis (MS). Interleukin 4 (IL-4) as a helper T cell (2TH) cytokine is involved in the regulation of immune responses. Hence, this study was designed to explore the association between MS and polymorphisms in the -590 region of IL-4.

DESIGN AND SETTING

A descriptive study at Rafsanjan University of Medical Sciences, Rafsnajan from September 2009 to August 2010.

PATIENTS AND METHODS

Blood samples were collected from 100 MS patients and 150 healthy controls on EDTA precoated tubes. DNA was extracted and analyzed for IL-4 polymorphisms using restricted fragment length polymorphism in patients and controls. Demographic data were also collected by a questionnaire that was designed specifically for this study.

RESULTS

We observed a significant difference in the C/C, T/C, and T/T genotypes of the -590 region of IL-4 between patients with MS and healthy controls (P<.001).

CONCLUSIONS

We conclude that functional polymorphisms of IL-4 possibly play a crucial role in the pathogenesis of MS.

The genetic impact of the Q551R interleukin-4 receptor alpha polymorphism for aggressive or chronic periodontitis and the occurrence of periodontopathic bacteria

OBJECTIVE

The Q551R polymorphism of the gene encoded for the α chain of the interleukin-4 receptor (IL-4RA) could influence both IL-4 and IL-13 signalling. Since both cytokines could be important in the pathogenesis of periodontitis the aim of this study was to evaluate putative associations of the Q551R polymorphism to generalized aggressive or chronic periodontitis and five periodontopathogens.

DESIGN

154 patients with severe generalized periodontitis (chronic: n=68, mean age=48.7 ± 9.4 years; aggressive: n=86, mean age=40.4 ± 9.8 years) and controls without periodontitis (n=89, mean age=46.2 ± 10.8 years) were included. The Q551R polymorphism was analysed by PCR-SSP CTS-Kit, Heidelberg, Germany. Subgingival bacteria were determined molecular biologically using micro-Ident test (HainLifescience, Nehren, Germany). Distributions of single alleles and genotypes were calculated by Chi(2)-test with Yates correction or Fisher's exact test. Adjusted odds ratios were generated by logistic regression with respect to established cofactors for periodontitis.

RESULTS

The mutant allele R551 (p(Y)=0.013) and the genotypes QR+RR (p(B)=0.024) occurred more frequently amongst patients with chronic periodontitis vs. controls. Carriers of the Q551R polymorphism had an increased adjusted odds ratio for chronic periodontitis (OR=3.2, 95%CI 1.5-6.5, p=0.002) and severe periodontitis (chronic+aggressive) in general (OR=2.0, 95%CI 1.1-3.6, p=0.003). Moreover, in the total study cohort the Q551R polymorphism was associated with the presence of Tannerella forsythia (90.3% vs. 78.0%, p(Y)=0.01).

CONCLUSIONS

The Q551R IL-4RA polymorphism is a putative risk indicator for severe chronic periodontitis, but was not significant associated to AP.

Congenital toxoplasmosis: candidate host immune genes relevant for vertical transmission and pathogenesis

Toxoplasma gondii infects a variety of vertebrate hosts, including humans. Transplacental passage of the parasite leads to congenital toxoplasmosis. A primary infection during the first weeks of gestation causes vertical transmission at low rate, although it causes major damage to the embryo. Transmission frequency increases to near 80% by the end of pregnancy, but the proportion of ill newborns is low. For transmission and pathogenesis, the parasite genetics is certainly important. Several host innate and adaptative immune response genes are induced during infection in adults, which control the rapidly replicating tachyzoite. The T helper 1 (Th1) response is protective, although it has to be modulated to avoid inflammatory damage. Paradoxical observations on this response pattern in congenital toxoplasmosis have been reported, as it may be protective or deleterious, inducing sterile abortion or favoring parasite transplacental passage. Regarding pregnancy, an early Th1 microenvironment is important for control of infectious diseases and successful implantation, although it has to be regulated to support trophoblast survival. Polymorphism of genes involved in these parallel phenomena, such as Toll-like receptors (TLRs), adhesins, cytokines, chemokines or their receptors, immunoglobulins or Fc receptors (FcRs), might be important in susceptibility for T. gondii vertical transmission, abortion or fetal pathology. In this study some examples are presented and discussed.

FAM5C contributes to aggressive periodontitis

Aggressive periodontitis is characterized by a rapid and severe periodontal destruction in young systemically healthy subjects. A greater prevalence is reported in Africans and African descendent groups than in Caucasians and Hispanics. We first fine mapped the interval 1q24.2 to 1q31.3 suggested as containing an aggressive periodontitis locus. Three hundred and eighty-nine subjects from 55 pedigrees were studied. Saliva samples were collected from all subjects, and DNA was extracted. Twenty-one single nucleotide polymorphisms were selected and analyzed by standard polymerase chain reaction using TaqMan chemistry. Non-parametric linkage and transmission distortion analyses were performed. Although linkage results were negative, statistically significant association between two markers, rs1935881 and rs1342913, in the FAM5C gene and aggressive periodontitis (p = 0.03) was found. Haplotype analysis showed an association between aggressive periodontitis and the haplotype A-G (rs1935881-rs1342913; p = 0.009). Sequence analysis of FAM5C coding regions did not disclose any mutations, but two variants in conserved intronic regions of FAM5C, rs57694932 and rs10494634, were found. However, these two variants are not associated with aggressive periodontitis. Secondly, we investigated the pattern of FAM5C expression in aggressive periodontitis lesions and its possible correlations with inflammatory/immunological factors and pathogens commonly associated with periodontal diseases. FAM5C mRNA expression was significantly higher in diseased versus healthy sites, and was found to be correlated to the IL-1β, IL-17A, IL-4 and RANKL mRNA levels. No correlations were found between FAM5C levels and the presence and load of red complex periodontopathogens or Aggregatibacter actinomycetemcomitans. This study provides evidence that FAM5C contributes to aggressive periodontitis.