The connection between intestinal microbiota and host physiology is increasingly becoming recognized. The details of this dynamic interaction, however, remain to be explored. Toll-like receptor 2 (Tlr2) is important for its role in bacterial recognition, intestinal inflammation, and obesity-related metabolic changes. Therefore, we sought to determine the epigenomic and metagenomic consequences of Tlr2 deficiency in the colonic mucosa of mice to gain insights into biological pathways that shape the interface between the gut microbiota and the mammalian host. Colonic mucosa from wild type (WT) and Tlr2(-/-) C57BL/6 mice was interrogated by microarrays specific for DNA methylation and gene expression. The mucosal microbiome was studied by next-generation pyrosequencing of bacterial 16S rRNA. The expression of genes involved in immune processes was significantly modified by the absence of Tlr2, a number of which correlated with DNA methylation changes. The epigenomic and transcriptomic modifications associated with alteration in mucosal microbial composition. Several bacterial species, including members of the Firmicutes were significantly different in abundance between WT and Tlr2(-/-) animals. This manuscript highlights the intimate interrelationships between expression of immune-related genes and immunity pathways in the host with compositional and functional differences of the mammalian microbiome.

Brooke-Spiegler syndrome (BSS), familial cylindromatosis (FC), and multiple familial trichoepithelioma (MFT), originally described as distinct inherited disorders, are characterized by a variety of skin appendage neoplasms. Mutations in the CYLD gene are found in individuals with these syndromes. We describe a single family with affected members exhibiting either the FC or the MFT phenotypes associated with a mutation in the CYLD gene. These findings support the notion that BSS, FC, and MFT represent phenotypic variation of a single defect. Of interest, one of the affected individuals described in this report exhibits a severe phenotype illustrating the morbidity of the disorder.

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a rare T-cell lymphoma that arises around breast implants. Most patients manifest with periprosthetic effusion, whereas a subset of patients develops a tumor mass or lymph node involvement (LNI). The aim of this study is to describe the pathologic features of lymph nodes from patients with BI-ALCL and assess the prognostic impact of LNI. Clinical findings and histopathologic features of lymph nodes were assessed in 70 patients with BI-ALCL. LNI was defined by the histologic demonstration of ALCL in lymph nodes. Fourteen (20%) patients with BI-ALCL had LNI, all lymph nodes involved were regional, the most frequent were axillary (93%). The pattern of involvement was sinusoidal in 13 (92.9%) cases, often associated with perifollicular, interfollicular, and diffuse patterns. Two cases had Hodgkin-like patterns. The 5-year overall survival was 75% for patients with LNI and 97.9% for patients without LNI at presentation (P=0.003). Six of 49 (12.2%) of patients with tumor confined by the capsule had LNI, compared with LNI in 8/21 (38%) patients with tumor beyond the capsule. Most patients with LNI achieved complete remission after various therapeutic approaches. Two of 14 (14.3%) patients with LNI died of disease compared with 0/56 (0%) patients without LNI. Twenty percent of patients with BI-ALCL had LNI by lymphoma, most often in a sinusoidal pattern. We conclude that BI-ALCL beyond capsule is associated with a higher risk of LNI. Involvement of lymph nodes was associated with decreased overall survival. Misdiagnosis as Hodgkin lymphoma is a pitfall.

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Monozygotic twin and other epidemiologic studies indicate that epigenetic processes may play an important role in the pathogenesis of inflammatory bowel diseases that commonly affect the colonic mucosa. The peak onset of these disorders in young adulthood suggests that epigenetic changes normally occurring in the colonic mucosa shortly before adulthood could be important etiologic factors. We assessed developmental changes in colitis susceptibility during the physiologically relevant period of childhood in mice [postnatal day 30 (P30) to P90] and concurrent changes in DNA methylation and gene expression in murine colonic mucosa. Susceptibility to colitis was tested in C57BL/6J mice with the dextran sulfate sodium colitis model. Methylation specific amplification microarray (MSAM) was used to screen for changes in DNA methylation, with validation by bisulfite pyrosequencing. Gene expression changes were analyzed by microarray expression profiling and real time RT-PCR. Mice were more susceptible to chemically induced colitis at P90 than at P30. DNA methylation changes, however, were not extensive; of 23 743 genomic intervals interrogated, only 271 underwent significant methylation alteration during this developmental period. We found an excellent correlation between the MSAM and bisulfite pyrosequencing at 11 gene associated intervals validated (R(2) = 0.89). Importantly, at the genes encoding galectin-1 (Lgals1), and mothers against decapentaplegic homolog 3 or Smad3, both previously implicated in murine colitis, developmental changes in DNA methylation from P30 to P90 were inversely correlated with expression. Colonic mucosal epigenetic maturation continues through early adulthood in the mouse, and may contribute to the age-associated increase in colitis susceptibility. Transcript Profiling: Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/), accession numbers: GSE18031 (DNA methylation arrays), GSE19506 (gene expression arrays).

Inflammatory bowel diseases (IBD) are emerging globally, indicating that environmental factors may be important in their pathogenesis. Colonic mucosal epigenetic changes, such as DNA methylation, can occur in response to the environment and have been implicated in IBD pathology. However, mucosal DNA methylation has not been examined in treatment-naïve patients. We studied DNA methylation in untreated, left sided colonic biopsy specimens using the Infinium HumanMethylation450 BeadChip array. We analyzed 22 control (C) patients, 15 untreated Crohn’s disease (CD) patients, and 9 untreated ulcerative colitis (UC) patients from two cohorts. Samples obtained at the time of clinical remission from two of the treatment-naïve UC patients were also included into the analysis. UC-specific gene expression was interrogated in a subset of adjacent samples (5 C and 5 UC) using the Affymetrix GeneChip PrimeView Human Gene Expression Arrays. Only treatment-naïve UC separated from control. One-hundred-and-twenty genes with significant expression change in UC (> 2-fold, P < 0.05) were associated with differentially methylated regions (DMRs). Epigenetically associated gene expression changes (including gene expression changes in the IFITM1, ITGB2, S100A9, SLPI, SAA1, and STAT3 genes) were linked to colonic mucosal immune and defense responses. These findings underscore the relationship between epigenetic changes and inflammation in pediatric treatment-naïve UC and may have potential etiologic, diagnostic, and therapeutic relevance for IBD.

Decreased consumption of dietary fibers, such as cellulose, has been proposed to promote the emergence of inflammatory bowel diseases (IBD: Crohn disease [CD] and ulcerative colitis [UC]) where intestinal microbes are recognized to play an etiologic role. However, it is not known if transient fiber consumption during critical developmental periods may prevent consecutive intestinal inflammation. The incidence of IBD peaks in young adulthood indicating that pediatric environmental exposures may be important in the etiology of this disease group. We studied the effects of transient dietary cellulose supplementation on dextran sulfate sodium (DSS) colitis susceptibility during the pediatric period in mice. Cellulose supplementation stimulated substantial shifts in the colonic mucosal microbiome. Several bacterial taxa decreased in relative abundance (e.g., Coriobacteriaceae [p = 0.001]), and other taxa increased in abundance (e.g., Peptostreptococcaceae [p = 0.008] and Clostridiaceae [p = 0.048]). Some of these shifts persisted for 10 days following the cessation of cellulose supplementation. The changes in the gut microbiome were associated with transient trophic and anticolitic effects 10 days following the cessation of a cellulose-enriched diet, but these changes diminished by 40 days following reversal to a low cellulose diet. These findings emphasize the transient protective effect of dietary cellulose in the mammalian large bowel and highlight the potential role of dietary fibers in amelioration of intestinal inflammation.

Darier disease (DD) and Hailey-Hailey disease (HHD) are the only known autosomal-dominant Ca2+ ATPase disorders. Epidermal symptoms selectively occur in the affected individuals, the precise reason for which is still not fully understood. Here, we review the clinical, epidermal, and molecular features of the two genodermatoses. It is concluded that epidermal Ca2+ regulation disturbances and epigenetic factors may play an even more prominent role in the pathogenesis of DD and HHD than earlier appreciated.