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Li Q, Cui M, Yang F, Li N, Jiang B, Yu Z, Zhang D, Wang Y, Zhu X, Hu H, Li PS, Ning SL, Wang S, Qi H, Song H, He D, Lin A, Zhang J, Liu F, Zhao J, Gao L, Yi F, Xue T, Sun JP, Gong Y, Yu X. A cullin 4B-RING E3 ligase complex fine-tunes pancreatic δ cell paracrine interactions. J Clin Invest 2017; 127:2631-2646. [PMID: 28604389 DOI: 10.1172/jci91348] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 04/20/2017] [Indexed: 12/24/2022] Open
Abstract
Somatostatin secreted by pancreatic δ cells mediates important paracrine interactions in Langerhans islets, including maintenance of glucose metabolism through the control of reciprocal insulin and glucagon secretion. Disruption of this circuit contributes to the development of diabetes. However, the precise mechanisms that control somatostatin secretion from islets remain elusive. Here, we found that a super-complex comprising the cullin 4B-RING E3 ligase (CRL4B) and polycomb repressive complex 2 (PRC2) epigenetically regulates somatostatin secretion in islets. Constitutive ablation of CUL4B, the core component of the CRL4B-PRC2 complex, in δ cells impaired glucose tolerance and decreased insulin secretion through enhanced somatostatin release. Moreover, mechanistic studies showed that the CRL4B-PRC2 complex, under the control of the δ cell-specific transcription factor hematopoietically expressed homeobox (HHEX), determines the levels of intracellular calcium and cAMP through histone posttranslational modifications, thereby altering expression of the Cav1.2 calcium channel and adenylyl cyclase 6 (AC6) and modulating somatostatin secretion. In response to high glucose levels or urocortin 3 (UCN3) stimulation, increased expression of cullin 4B (CUL4B) and the PRC2 subunit histone-lysine N-methyltransferase EZH2 and reciprocal decreases in Cav1.2 and AC6 expression were found to regulate somatostatin secretion. Our results reveal an epigenetic regulatory mechanism of δ cell paracrine interactions in which CRL4B-PRC2 complexes, Cav1.2, and AC6 expression fine-tune somatostatin secretion and facilitate glucose homeostasis in pancreatic islets.
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Affiliation(s)
- Qing Li
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Min Cui
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Fan Yang
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Na Li
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Baichun Jiang
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Genetics, and
| | - Zhen Yu
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Daolai Zhang
- Department of Biochemistry, Shandong University School of Medicine, Jinan, Shandong, China
| | - Yijing Wang
- Department of Biochemistry, Shandong University School of Medicine, Jinan, Shandong, China
| | - Xibin Zhu
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Huili Hu
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Genetics, and
| | - Pei-Shan Li
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Genetics, and
| | - Shang-Lei Ning
- Department of Biochemistry, Shandong University School of Medicine, Jinan, Shandong, China
| | - Si Wang
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Haibo Qi
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Hechen Song
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
| | - Dongfang He
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology.,Department of Biochemistry, Shandong University School of Medicine, Jinan, Shandong, China
| | - Amy Lin
- Duke University, School of Medicine, Durham, North Carolina, USA
| | - Jingjing Zhang
- The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Feng Liu
- The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China
| | - Ling Gao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China
| | - Fan Yi
- Department of Pharmacology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Tian Xue
- Hefei National Laboratory for Physical Science at Microscale, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Jin-Peng Sun
- Department of Biochemistry, Shandong University School of Medicine, Jinan, Shandong, China.,Duke University, School of Medicine, Durham, North Carolina, USA
| | - Yaoqin Gong
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Genetics, and
| | - Xiao Yu
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology
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Jansson L, Barbu A, Bodin B, Drott CJ, Espes D, Gao X, Grapensparr L, Källskog Ö, Lau J, Liljebäck H, Palm F, Quach M, Sandberg M, Strömberg V, Ullsten S, Carlsson PO. Pancreatic islet blood flow and its measurement. Ups J Med Sci 2016; 121:81-95. [PMID: 27124642 PMCID: PMC4900068 DOI: 10.3109/03009734.2016.1164769] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Pancreatic islets are richly vascularized, and islet blood vessels are uniquely adapted to maintain and support the internal milieu of the islets favoring normal endocrine function. Islet blood flow is normally very high compared with that to the exocrine pancreas and is autonomously regulated through complex interactions between the nervous system, metabolites from insulin secreting β-cells, endothelium-derived mediators, and hormones. The islet blood flow is normally coupled to the needs for insulin release and is usually disturbed during glucose intolerance and overt diabetes. The present review provides a brief background on islet vascular function and especially focuses on available techniques to measure islet blood perfusion. The gold standard for islet blood flow measurements in experimental animals is the microsphere technique, and its advantages and disadvantages will be discussed. In humans there are still no methods to measure islet blood flow selectively, but new developments in radiological techniques hold great hopes for the future.
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Affiliation(s)
- Leif Jansson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- CONTACT Leif Jansson, Department of Medical Cell Biology, Biomedical Centre, Box 571, Husargatan 3, SE-75123 Uppsala, Sweden
| | - Andreea Barbu
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Birgitta Bodin
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Carl Johan Drott
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Daniel Espes
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Xiang Gao
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Liza Grapensparr
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Örjan Källskog
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Joey Lau
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Hanna Liljebäck
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Fredrik Palm
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - My Quach
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Monica Sandberg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | | - Sara Ullsten
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Per-Ola Carlsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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