Haplotype-dependent differential activation of the human IL-10 gene promoter in macrophages and trophoblasts: implications for placental IL-10 deficiency and pregnancy complications

Association of IL-10 and TGF-beta cytokine gene polymorphisms with autoimmune hepatitis

BACKGROUND AND AIMS

Autoimmune hepatitis is a chronic immune-mediated liver injury caused by dysregulated immune response to liver antigens. Genetic susceptibility is affected by multiple single nucleotide polymorphisms in immune-related genes. There are few reports on the association of TGF-β and IL-10 genetic variants with autoimmune hepatitis.

METHODS

Allele frequency and genotype status of IL-10 -1082, -819, -592 and TGF-β +869 and +915 polymorphisms were investigated in 57 unrelated patients with autoimmune hepatitis and 140 healthy controls by polymerase chain reaction with sequence-specific primers.

RESULTS

IL-10 -592 and -819 allele frequencies and genotypes were not associated with autoimmune hepatitis in our population, while IL-10 -1082 genotypes were. IL-10 -1082/-819/-592 "high-producing" haplotype GCC was significantly less frequent in patients. TGF-β +869 "high-producing" allele C and genotype CC were significantly more in autoimmune hepatitis, compared to controls; whereas, TGF-β +915 "low-producing" allele C and genotype CC were significantly more in autoimmune hepatitis compared to control. TGF-β +869/+915 haplotype TG was significantly less frequent in patients while CC haplotype was significantly more frequently observed in patients.

CONCLUSION

We identified a significant association between IL-10 -1082/-819 and TGF-β +869/+915 genotypes and haplotypes with autoimmune hepatitis in Iranians.

Polychlorinated biphenyls target Notch/Dll and VEGF R2 in the mouse placenta and human trophoblast cell lines for their anti-angiogenic effects

The intrauterine environment is particularly vulnerable to environmental exposures. We previously established a mouse model that provided evidence for pregnancy complications and placental anti-angiogenesis in response to Aroclor 1254 (A-1254), a mixture of polychlorinated biphenyls (PCBs). Importantly, these effects were observed in IL-10^-/-, but not wild type, mice, suggesting that IL-10 deficiency predisposes to pregnancy disruptive effects of environmental toxicants. However, the mechanisms by which PCBs cause anti-angiogenic effects are unclear. Here, we evaluated PCB-mediated anti-angiogenic effects by diverse but complementary approaches, including HUVEC-mediated trophoblast invasion in nude mice, in vitro three-dimensional capillary tube formation involving HUVEC and/or HTR8 trophoblasts, and aortic ring endothelial cell outgrowth/sprouting. Taken together, our data suggest that PCBs act as potent anti-angiogenic agents. Importantly, we show that treatment of pregnant IL-10^-/- mice with A-1254 resulted in placental activation of the Notch/Delta-like ligand (Dll) pathway, a master regulator of cell-cell interaction and vascular patterning. Similar results were obtained with HUVEC and HTR8 trophoblasts. Rescue of A-1254-induced disruption of HUVEC-based tube formation by γ-secretase inhibitor L1790 confirmed the critical role of the Notch/Dll pathway. Our data suggest that PCBs impart pregnancy disruptive functions by activating the Notch/Dll pathway and by inducing anti-angiogenic effects at the maternal-fetal interface.

Association of interleukin-10 gene promoter polymorphisms with recurrent pregnancy loss: a meta-analysis

PURPOSE

It has been reported single-nucleotide polymorphisms (SNPs) of the IL-10 promoter might be associated with the susceptibility to recurrent pregnancy loss (RPL). Owing to the inconclusive results, we conducted a meta-analysis to systematically summarize and clarify the association between the IL-10 promoter SNPs and RPL risk.

METHODS

A systematic search of studies on the association of the three SNPs with RPL was conducted in PubMed and Embase. Odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were used to pool the effect size.

RESULT

Eleven case-control studies on rs1800896, seven studies on rs1800871, and eight studies on rs1800872 were included. A significant association was identified between IL-10 rs1800896 with RPL risk (G versus A: OR = 1.21, 95 % CI 1.09-1.35). No evidence of association was found between rs1800871 and RPL when restricted to those studies in Hardy-Weinberg equilibrium in controls (T versus C: OR = 1.25, 95 % CI 0.76-2.06). No statistical association was demonstrated between rs1800872 and RPL (C versus A: OR = 1.08, 95 % CI 0.83-1.42).

CONCLUSIONS

IL-10 rs1800896 significantly increases the risk of RPL, while rs1800872 is not correlated with RPL risk. No significant association is demonstrated between rs1800871 and RPL risk but this requires further investigation.

Hepatitis B virus X protein modifies invasion, proliferation and the inflammatory response in an HTR-8/SVneo cell model

Mother-to-infant transmission of hepatitis B virus (HBV) can occur as an intrauterine, intrapartum or postpartum infection. In the present study, we induced a multifunctional viral regulator of HBV gene products, HBx, and its different fragments to overexpress in a tropho-blast cell line, HTR-8/SVneo. We then identified the biological effects of HBx on HTR-8/SVneo cells. Our results indicated that HBx inhibited apoptosis and induced invasion as detected using Annexin V/propidium iodide (PI) double staining and Transwell assay, respectively. Furthermore, we carried out western blot analysis to analyze the possible related signaling pathway. We confirmed that HBx and its different fragments can activate the Smad signaling pathway, accompanied by downregulation of E-cadherin, and upregulation of vimentin and N-cadherin. TGF‑β1 was used as a control to activate the Smad signaling pathway in HTR-8/SVneo cells. HBx activated the Smad signaling pathway in the HTR-8/SVneo cells. After the signaling pathway was activated, reduced apoptosis, higher invasive ability and enhanced inflammatory response were observed in the HTR-8/SVneo cells.

Interleukin-10: a pleiotropic regulator in pregnancy

Pregnancy is a unique and well-choreographed physiological process that involves intricate interplay of inflammatory and anti-inflammatory milieu, hormonal changes, and cellular and molecular events at the maternal-fetal interface. IL-10 is a pregnancy compatible cytokine that plays a vital role in maintaining immune tolerance. A wide array of cell types including both immune and non-immune cells secret IL-10 in an autocrine and paracrine manner. IL-10 binds to a specific receptor complex and activates JAK-STAT and PI3K-Akt signaling pathways while inhibiting NF-κB signaling pathway. IL-10 exerts its anti-inflammatory effects mainly by decreasing pro-inflammatory cytokines such as IL-1, IL-6, IL-12, and TNF-α, by inducing heme oxygenase-1, and by inhibiting antigen presentation via blocking major histocompatibility complex (MHC) class II expression. Prior studies from our group and others have shown that IL-10 also functions as a potent protector against vascular dysfunction, and enhancement of IL-10 may serve as an immunotherapeutic intervention to treat adverse pregnancy outcomes. This review seeks to critically evaluate the archetypal functions of IL-10 as an immune suppressive factor as well as its novel functions as a vascular protector and modulator of endoplasmic reticulum (ER) stress and autophagy in the context of normal and adverse pregnancy outcomes.

ATA homozigosity in the IL-10 gene promoter is a risk factor for schizophrenia in Spanish females: a case control study

Background

Three IL-10 gene promoter single nucleotide polymorphisms -1082G > A, -819C > T and -592C > A and the haplotypes they define in Caucasians, GCC, ACC, ATA, associated with different IL-10 production rates, have been linked to schizophrenia in some populations with conflicting results. On the basis of the evidence of the sex-dependent effect of certain genes in many complex diseases, we conducted a sex-stratified case-control association study to verify the linkage of the IL-10 gene promoter SNPs and haplotypes with schizophrenia and the possible sex-specific genetic effect in a Spanish schizophrenic population.

Methods

241 DSM-IV diagnosed Spanish schizophrenic patients and 435 ethnically matched controls were genotyped for -1082G > A and -592C > A SNPs. Chi squared tests were performed to assess for genetic association of alleles, genotypes and haplotypes with the disease.

Results

The -1082A allele (p = 0.027), A/A (p = 0.008) and ATA/ATA (p = 0.003) genotypes were significantly associated with schizophrenia in females while neither allelic nor genotypic frequencies reached statistical significance in the male population.

Conclusions

Our results highlight the hypothesis of an imbalance towards an inflammatory syndrome as the immune abnormality of schizophrenia. Anyway, a better understanding of the involvement of the immune system would imply the search of immune abnormalities in endophenotypes in whose sex and ethnicity might be differential factors. It also reinforces the need of performing complex gene studies based on multiple cytokine SNPs, including anti and pro-inflammatory, to clarify the immune system abnormalities direction in the etiology of schizophrenia.

Vascular IL-10: a protective role in preeclampsia

IL-10 is a pregnancy compatible cytokine that plays a vital role in maintaining the balance of anti-inflammatory and pro-inflammatory milieu at the maternal-fetal interface. Recent evidence now suggests that IL-10 is a potent vascular cytokine that can blunt hypertension and inflammation-mediated vascular dysfunction. Thus, a re-evaluation of IL-10 as a cytokine supporting endovascular interactions and angiogenesis as well as blunting hypoxic-injury and preeclampsia-like features is warranted. In this review, we highlight these novel functions of IL-10 and propose that its immune-modulating and vascular functions are mutually inclusive, particularly in the context of normal gestation.