TY - JOUR
T1 - The dysregulation of the DLK1-MEg3 locus in islets from patients with type 2 diabetes is mimicked by targeted epimutation of its promoter with TALE-DNMT constructs
AU - Kameswaran, Vasumathi
AU - Golson, Maria L.
AU - Ramos-Rodríguez, Mireia
AU - Ou, Kristy
AU - Wang, Yue J.
AU - Zhang, Jia
AU - Pasquali, Lorenzo
AU - Kaestner, Klaus H.
N1 - Funding Information:
Acknowledgments. The authors thank the University of Pennsylvania Diabetes Research Center for the use of the Functional Genomics Core. Funding. This work was supported by the National Institutes of Health (R01-DK-088383 and UC4-DK-104119). The University of Pennsylvania Diabetes Research Center Functional Genomics Core was supported by the National Institutes of Health (P30-DK-19525). Duality of Interest. No potential conflicts of interest relevant to this article were reported. Author Contributions. V.K. wrote the manuscript and researched data. M.L.G., M.R.-R., K.O., Y.J.W., J.Z., and L.P. researched data. K.H.K. contributed to discussion and reviewed and edited the manuscript. K.H.K. is the guarantor of this work and, as such, had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Publisher Copyright:
© 2018 by the American Diabetes Association.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Type 2 diabetes mellitus (T2DM) is characterized by the inability of the insulin-producing b-cells to overcome insulin resistance. We previously identified an imprinted region on chromosome 14, the DLK1-MEG3 locus, as being downregulated in islets from humans with T2DM. In this study, using targeted epigenetic modifiers, we prove that increased methylation at the promoter of Meg3 in mouse bTC6 b-cells results in decreased transcription of the maternal transcripts associated with this locus. As a result, the sensitivity of b-cells to cytokine-mediated oxidative stress was increased. Additionally, we demonstrate that an evolutionarily conserved intronic region at the MEG3 locus can function as an enhancer in bTC6 b-cells. Using circular chromosome conformation capture followed by high-throughput sequencing, we demonstrate that the promoter of MEG3 physically interacts with this novel enhancer and other putative regulatory elements in this imprinted region in human islets. Remarkably, this enhancer is bound in an allele-specific manner by the transcription factors FOXA2, PDX1, and NKX2.2. Overall, these data suggest that the intronic MEG3 enhancer plays an important role in the regulation of allele-specific expression at the imprinted DLK1-MEG3 locus in human b-cells, which in turn impacts the sensitivity of b-cells to cytokine-mediated oxidative stress.
AB - Type 2 diabetes mellitus (T2DM) is characterized by the inability of the insulin-producing b-cells to overcome insulin resistance. We previously identified an imprinted region on chromosome 14, the DLK1-MEG3 locus, as being downregulated in islets from humans with T2DM. In this study, using targeted epigenetic modifiers, we prove that increased methylation at the promoter of Meg3 in mouse bTC6 b-cells results in decreased transcription of the maternal transcripts associated with this locus. As a result, the sensitivity of b-cells to cytokine-mediated oxidative stress was increased. Additionally, we demonstrate that an evolutionarily conserved intronic region at the MEG3 locus can function as an enhancer in bTC6 b-cells. Using circular chromosome conformation capture followed by high-throughput sequencing, we demonstrate that the promoter of MEG3 physically interacts with this novel enhancer and other putative regulatory elements in this imprinted region in human islets. Remarkably, this enhancer is bound in an allele-specific manner by the transcription factors FOXA2, PDX1, and NKX2.2. Overall, these data suggest that the intronic MEG3 enhancer plays an important role in the regulation of allele-specific expression at the imprinted DLK1-MEG3 locus in human b-cells, which in turn impacts the sensitivity of b-cells to cytokine-mediated oxidative stress.
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U2 - 10.2337/db17-0682
DO - 10.2337/db17-0682
M3 - Article
C2 - 30084829
AN - SCOPUS:85052688337
SN - 0012-1797
VL - 67
SP - 1807
EP - 1815
JO - Diabetes
JF - Diabetes
IS - 9
ER -