Human pancreatic β cell incRNAs control cell-specific regulatory networks

Recent studies have uncovered thousands of long non-coding RNAs (lncRNAs) in human pancreatic β cells. β cell lncRNAs are often cell type specific and exhibit dynamic regulation during differentiation or upon changing glucose concentrations. Although these features hint at a role of lncRNAs in β cell gene regulation and diabetes, the function of β cell lncRNAs remains largely unknown. In this study, we investigated the function of β cell-specific lncRNAs and transcription factors using transcript knockdowns and co-expression network analysis. This revealed lncRNAs that function in concert with transcription factors to regulate β cell-specific transcriptional networks. We further demonstrate that the lncRNA PLUTO affects local 3D chromatin structure and transcription of PDX1, encoding a key β cell transcription factor, and that both PLUTO and PDX1 are downregulated in islets from donors with type 2 diabetes or impaired glucose tolerance. These results implicate lncRNAs in the regulation of β cell-specific transcription factor networks

A genome-wide association study identifies susceptibility loci for primary central nervous system lymphoma at 6p25.3 and 3p22.1: a LOC network study.

Background Primary central nervous system lymphoma (PCNSL) is a rare form of extra-nodal non-Hodgkin lymphoma. PCNSL is a distinct subtype of non-Hodgkin lymphoma, with over 95% of tumors belonging to the diffuse large B-cell lymphoma (DLBCL) group. We have conducted a genome-wide association study (GWAS) on immunocompetent patients to address the possibility that common genetic variants influence the risk of developing PCNSL.Methods We performed a meta-analysis of two new genome-wide association studies of PCNSL totaling 475 cases and 1,134 controls of European ancestry. To increase genomic resolution, we imputed >10 million single-nucleotide polymorphisms (SNPs) using the 1000 Genomes Project combined with UK10K as reference. In addition we performed a transcription factor binding disruption analysis and investigated the patterns of local chromatin patterns by capture Hi-C data.Results We identified independent risk loci at 3p22.1 (rs41289586, ANO10, P = 2.17 x 10-8) and 6p25.3 near EXOC2 (rs116446171, P = 1.95 x 10-13). In contrast the lack of an association between rs41289586 and DLBCL, suggests distinct germline predisposition to PCNSL and DLBCL. We found looping chromatin interactions between non-coding regions at 6p25.3 (rs11646171) with the IRF4 promoter and at 8q24.21 (rs13254990) with the MYC promoter, both genes with strong relevance to B-cell tumorigenesis.Conclusion To our knowledge this is the first study providing insight into the genetic predisposition to PCNSL. Our findings represent an important step in defining the contribution of common genetic variation to the risk of developing PCNSL

Nutrient regulation of ß-cell function: what do islet cell/animal studies tell us?

Diabetes mellitus is widely recognised as one of the most serious metabolic diseases worldwide, and its incidence in Asian countries is growing at an alarming rate. Type 2 diabetes (T2DM) is closely associated with age, sedentary lifestyle and poor diet. In T2DM, ß-cell dysfunction will occur before hyperglycaemia develops. Excessive levels of glucose, lipid and various inflammatory factors interact at the level of the pancreatic islet to promote ß-cell dysfunction. Pancreatic ß-cell lines have been widely utilised since the early 1980s and have contributed a large volume of important information regarding molecular, metabolic and genetic mechanisms that regulate insulin secretion. The purpose of this review is to describe the origin and characteristics of the most commonly used ß-cell lines and their contribution to discovery of fundamental regulatory processes that control insulin production and release. Pancreatic islets obtained from rodents as well as other animals have additionally provided information on the architecture and three-dimensional design of this endocrine tissue that allows precise regulation of hormone release. Understanding the nature of failure of physiologic and metabolic processes leading to insufficient insulin release and subsequent diabetes has allowed development of novel anti-diabetic therapeutics, now in common use, worldwide.European Journal of Clinical Nutrition advance online publication, 19 April 2017; doi:10.1038/ejcn.2017.49