Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2014 Nov 25;111(47):16760-5. doi: 10.1073/pnas.1419240111. Epub 2014 Nov 10.

Mapping of long-range INS promoter interactions reveals a role for calcium-activated chloride channel ANO1 in insulin secretion.

Author information

1
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
2
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892 gary.felsenfeld@nih.gov.

Abstract

We used circular chromatin conformation capture (4C) to identify a physical contact in human pancreatic islets between the region near the insulin (INS) promoter and the ANO1 gene, lying 68 Mb away on human chromosome 11, which encodes a Ca(2+)-dependent chloride ion channel. In response to glucose, this contact was strengthened and ANO1 expression increased, whereas inhibition of INS gene transcription by INS promoter targeting siRNA decreased ANO1 expression, revealing a regulatory effect of INS promoter on ANO1 expression. Knockdown of ANO1 expression caused decreased insulin secretion in human islets, establishing a physical proximity-dependent feedback loop involving INS transcription, ANO1 expression, and insulin secretion. To explore a possible role of ANO1 in insulin metabolism, we carried out experiments in Ano1(+/-) mice. We observed reduced serum insulin levels and insulin-to-glucose ratios in high-fat diet-fed Ano1(+/-) mice relative to Ano1(+/+) mice fed the same diet. Our results show that determination of long-range contacts within the nucleus can be used to detect novel and physiologically relevant mechanisms. They also show that networks of long-range physical contacts are important to the regulation of insulin metabolism.

KEYWORDS:

chloride channel; diabetes; insulin secretion

PMID:
25385647
PMCID:
PMC4250121
DOI:
10.1073/pnas.1419240111
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center