Change in DNA methylation patterns of SLC6A4 gene in the gastric mucosa in functional dyspepsia

Level of Foxp3, DNMTs, methylation of Foxp3 promoter region, and CD4 + CD25 + CD127low regulatory T cells in vulvar lichen sclerosus

This study is to investigate the pathogenesis of vulvar lichen sclerosus (VLS) by analyzing the level of Foxp3, DNMTs, methylation of Foxp3 promoter region, and CD4 + CD25 + CD127low Regulatory T cells (Tregs). This study enrolled 15 VLS patients and 25 controls. Lesional and extralesional vulvar skin tissues, normal vulvar skin tissues and peripheral blood were collected. Compared with the control group, Foxp3 protein in the lesional and extralesional skin of VLS group was significantly reduced. The levels of DNMT1 and DNMT3b proteins in lesional skin of VLS group were significantly increased. There was no difference in the total methylation rates of the promoter region of the Foxp3 gene. The methylation rates of CpG1, CpG4, CpG9, and CpG10 were significantly higher in lesional skin of VLS group than in control group. There was no correlation between the total methylation rates of 10 CpG sites and the level of Foxp3 and DNMT1 proteins; there was a positive correlation between Foxp3 and DNMT1 protein in lesional skin of VLS group (r = 0.675, p < 0.05), and a negative correlation (r = -0.665, p < 0.05) in extralesional skin of VLS group. However, there was no correlation of Foxp3 with DNMT3b. The number of CD4 + CD25 + CD127low Tregs VLS decreased significantly. The expression of Foxp3 protein and the quantity of CD4 + CD25 + CD127low Tregs in patients with VLS decreased, which may cause local or systemic abnormal immunosuppression of Tregs, leading to the occurrence of VLS. This may be related with methylation or DNMT1, which needs further verification.

Promoter Activity-Based Case-Control Association Study on SLC6A4 Highlighting Hypermethylation and Altered Amygdala Volume in Male Patients With Schizophrenia

Associations between altered DNA methylation of the serotonin transporter (5-HTT)-encoding gene SLC6A4 and early life adversity, mood and anxiety disorders, and amygdala reactivity have been reported. However, few studies have examined epigenetic alterations of SLC6A4 in schizophrenia (SZ). We examined CpG sites of SLC6A4, whose DNA methylation levels have been reported to be altered in bipolar disorder, using 3 independent cohorts of patients with SZ and age-matched controls. We found significant hypermethylation of a CpG site in SLC6A4 in male patients with SZ in all 3 cohorts. We showed that chronic administration of risperidone did not affect the DNA methylation status at this CpG site using common marmosets, and that in vitro DNA methylation at this CpG site diminished the promoter activity of SLC6A4. We then genotyped the 5-HTT-linked polymorphic region (5-HTTLPR) and investigated the relationship among 5-HTTLPR, DNA methylation, and amygdala volume using brain imaging data. We found that patients harboring low-activity 5-HTTLPR alleles showed hypermethylation and they showed a negative correlation between DNA methylation levels and left amygdala volumes. These results suggest that hypermethylation of the CpG site in SLC6A4 is involved in the pathophysiology of SZ, especially in male patients harboring low-activity 5-HTTLPR alleles.

Immunopathological and molecular basis of functional dyspepsia and current therapeutic approaches

INTRODUCTION

Functional dyspepsia (FD) is widespread with 20% prevalence worldwide and a significant economic burden due to health care cost and constraints on daily activities of patients. Despite extensive investigation, the underlying causes of dyspepsia in a majority of patients remain unknown. Common complaints include abdominal discomfort, pain, burning, nausea, early satiety, and bloating. Motor dysfunction of the gut was long considered a major cause, but recent investigations suggest immune-based pathophysiological and molecular events in the duodenum are more probable contributing factors. Areas Covered: Inflammatory mediators and immune cells including duodenal eosinophils, intraepithelial lymphocytes, and T-cells have been implicated in the underlying cause of disease process, as have genetic factors. In this article, we critically reviewed findings, identified gaps in knowledge and suggested future directions for further investigation to identify targets and develop better therapeutic approaches. Expert commentary: Impaired gastric accommodation, slow gastric emptying, and increased visceral sensitivity have long been thought of as main causal factors of FD. However, more recent identification of eosinophilic degranulation and recruitment of T cells that induce mild duodenal inflammation are giving rise to new insights into immune-mediated pathophysiology. These insights offer promising avenues to explore for immune-mediated therapy in the future.

New Medical Approach to Functional Dyspepsia, from Core Symposium 3, Japan Gastroenterological Association 2015-2017

In the annual meeting of the Japan Gastroenterological Association (JGA), the scientific organizing committee selected the serial topics for the core symposium. One of the core symposia held during 2015-2017 was entitled "New medical approach to functional dyspepsia (FD)." In 2015, the subtitle of this symposium was "Helicobacter pylori gastritis and FD." In 2016, the subtitle of this symposium was "overlap with other functional GI disorders." In 2017, the subtitle was "therapeutic approach to FD." During these 3 years, a total of 24 presentations were included in Core Symposium 3 and deep and intensive discussions were carried out.

An integrative review of methylation at the serotonin transporter gene and its dialogue with environmental risk factors, psychopathology and 5-HTTLPR

Gene-environment (G×E) interactions have largely been regarded as the root of many complex disorders, including several psychiatric disorders. In this regard, it has been hypothesized that epigenetic mechanisms may be the main mediators of such interactions. Of particular interest is the previously described interaction between psychosocial stress and genetic variability of the serotonin transporter gene (SLC6A4) in its polymorphic region 5-HTTLPR. Here we review the literature concerning SLC6A4 methylation in association with environmental, clinical or genetic variables. While SLC6A4 hypermethylation has typically been described to be independently associated with both early life stress and depressive disorders, only a few papers address whether methylation could mediate the interaction between stress and 5-HTTLPR in predicting psychopathological risk. Nevertheless, research preliminarily indicates a methylation-driven increased vulnerability of carriers of the short allele of 5-HTTLPR to psychiatric disorders when exposed to early stress or soon after exposure to stress.