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Grieco GE, Brusco N, Fignani D, Nigi L, Formichi C, Licata G, Marselli L, Marchetti P, Salvini L, Tinti L, Po A, Ferretti E, Sebastiani G, Dotta F. Reduced miR-184-3p expression protects pancreatic β-cells from lipotoxic and proinflammatory apoptosis in type 2 diabetes via CRTC1 upregulation. Cell Death Dis 2022; 8:340. [PMID: 35906204 PMCID: PMC9338237 DOI: 10.1038/s41420-022-01142-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022]
Abstract
The loss of functional β-cell mass in type 2 diabetes (T2D) is associated with molecular events that include β-cell apoptosis, dysfunction and/or dedifferentiation. MicroRNA miR-184-3p has been shown to be involved in several β-cell functions, including insulin secretion, proliferation and survival. However, the downstream targets and upstream regulators of miR-184-3p have not been fully elucidated. Here, we show reduced miR-184-3p levels in human T2D pancreatic islets, whereas its direct target CREB regulated transcription coactivator 1 (CRTC1) was increased and protects β-cells from lipotoxicity- and inflammation-induced apoptosis. Downregulation of miR-184-3p in β-cells leads to upregulation of CRTC1 at both the mRNA and protein levels. Remarkably, the protective effect of miR-184-3p is dependent on CRTC1, as its silencing in human β-cells abrogates the protective mechanism mediated by inhibition of miR-184-3p. Furthermore, in accordance with miR-184-3p downregulation, we also found that the β-cell-specific transcription factor NKX6.1, DNA-binding sites of which are predicted in the promoter sequence of human and mouse MIR184 gene, is reduced in human pancreatic T2D islets. Using chromatin immunoprecipitation analysis and mRNA silencing experiments, we demonstrated that NKX6.1 directly controls both human and murine miR-184 expression. In summary, we provide evidence that the decrease in NKX6.1 expression is accompanied by a significant reduction in miR-184-3p expression and that reduction of miR-184-3p protects β-cells from apoptosis through a CRTC1-dependent mechanism.
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Affiliation(s)
- Giuseppina E Grieco
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Noemi Brusco
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Daniela Fignani
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Laura Nigi
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Caterina Formichi
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Giada Licata
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | | | - Laura Tinti
- TLS-Toscana Life Sciences Foundation, Siena, Italy
| | - Agnese Po
- Department of Experimental Medicine, Sapienza University, 00161, Rome, Italy
| | - Elisabetta Ferretti
- Department of Experimental Medicine, Sapienza University, 00161, Rome, Italy
| | - Guido Sebastiani
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy.
| | - Francesco Dotta
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Fondazione Umberto Di Mario ONLUS c/o Toscana Life Science, Siena, Italy.,Tuscany Centre for Precision Medicine (CReMeP), Siena, Italy
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