Vitamin D is becoming increasingly accepted as an important physiological regulator outside of its classical role in skeletal homeostasis. A growing body of evidence connects vitamin D with hepatic disease. This review summarises the role of vitamin D in liver homeostasis and disease and discusses the therapeutic potential of vitamin D-based treatments to protect against hepatic disease progression and to improve response to treatment. While pre-clinical experimental data is promising, clinical trials around liver diseases have mostly been under-powered, and further studies will be required to clarify whether vitamin D or vitamin D analogues have beneficial effects on liver disease.
Epstein-Barr virus (EBV) infection may be necessary for the development of Multiple sclerosis (MS). Earlier we had identified six MS risk loci that are co-located with binding sites for the EBV transcription factor Epstein-Barr Nuclear Antigen 2 (EBNA2) in EBV-infected B cells (lymphoblastoid cell lines – LCLs). We used an allele-specific chromatin immunoprecipitation PCR assay to assess EBNA2 allelic preference. We treated LCLs with a peptide inhibitor of EBNA2 (EBNA2-TAT), reasoning that inhibiting EBNA2 function would alter gene expression at these loci if it was mediated by EBNA2. We found that EBNA2 binding was dependent on the risk allele for five of these six MS risk loci (p < 0·05). Treatment with EBNA2-TAT significantly altered the expression of TRAF3 (p < 0·05), CD40 (p < 0·001), CLECL1 (p <0·0001), TNFAIP8 (p < 0·001) and TNFRSF1A (p < 0·001). These data suggest that EBNA2 can enhance or reduce expression of the gene depending on the risk allele, likely promoting EBV infection. This is consistent with the concept that these MS risk loci affect MS risk through altering the response to EBNA2. Together with the extensive data indicating a pathogenic role for EBV in MS, this study supports targeting EBV and EBNA2 to reduce their effect on MS pathogenesis. Funding was provided by grants from MS Research Australia, National Health and Medical Research Council of Australia, Australian Government Research Training Program, Multiple Sclerosis International Federation, Trish Multiple Sclerosis Research Foundation.
Although the causes of Multiple Sclerosis (MS) still remain largely unknown, multiple lines of evidence suggest that Epstein–Barr virus (EBV) infection may contribute to the development of MS. Here, we aimed to identify the potential contribution of EBV-encoded and host cellular miRNAs to MS pathogenesis. We identified differentially expressed host miRNAs in EBV infected B cells (LCLs) and putative host/EBV miRNA interactions with MS risk loci. We estimated the genotype effect of MS risk loci on the identified putative miRNA:mRNA interactions in silico. We found that the protective allele of MS risk SNP rs4808760 reduces the expression of hsa-mir-3188-3p. In addition, our analysis suggests that hsa-let-7b-5p may interact with ZC3HAV1 differently in LCLs compared to B cells. In vitro assays indicated that the protective allele of MS risk SNP rs10271373 increases ZC3HAV1 expression in LCLs, but not in B cells. The higher expression for the protective allele in LCLs is consistent with increased IFN response via ZC3HAV1 and so decreased immune evasion by EBV. Taken together, this provides evidence that EBV infection dysregulates the B cell miRNA machinery, including MS risk miRNAs, which may contribute to MS pathogenesis via interaction with MS risk genes either directly or indirectly.
To investigate the molecular mechanisms through which Epstein-Barr virus (EBV) may contribute to Systemic Lupus Erythematosus (SLE) pathogenesis, we interrogated SLE genetic risk loci for signatures of EBV infection. We first compared the gene expression profile of SLE risk genes across 459 different cell/tissue types. EBV-infected B cells (LCLs) had the strongest representation of highly expressed SLE risk genes. By determining an SLE risk allele effect on gene expression (expression quantitative trait loci, eQTL) in LCLs and 16 other immune cell types, we identified 79 SLE risk locus:gene pairs putatively interacting with EBV infection. A total of 10 SLE risk genes from this list (CD40, LYST, JAZF1, IRF5, BLK, IKZF2, IL12RB2, FAM167A, PTPRC and SLC15A) were targeted by the EBV transcription factor, EBNA2, differentially expressed between LCLs and B cells, and the majority were also associated with EBV DNA copy number, and expression level of EBV encoded genes. Our final gene network model based on these genes is suggestive of a nexus involving SLE risk loci and EBV latency III and B cell proliferation signalling pathways. Collectively, our findings provide further evidence to support the interaction between SLE risk loci and EBV infection that is in part mediated by EBNA2. This interplay may increase the tendency towards EBV lytic switching dependent on the presence of SLE risk alleles. These results support further investigation into targeting EBV as a therapeutic strategy for SLE.