β-Cell-specific ablation of sirtuin 4 does not affect nutrient-stimulated insulin secretion in mice.
Journal Article (Journal Article)
Sirtuins are a family of proteins that regulate biological processes such as cellular stress and aging by removing posttranslational modifications (PTMs). We recently identified several novel PTMs that can be removed by sirtuin 4 (SIRT4), which is found in mitochondria. We showed that mice with a global loss of SIRT4 [SIRT4-knockout (KO) mice] developed an increase in glucose- and leucine-stimulated insulin secretion, and this was followed by accelerated age-induced glucose intolerance and insulin resistance. Because whole body SIRT4-KO mice had alterations to nutrient-stimulated insulin secretion, we hypothesized that SIRT4 plays a direct role in regulating pancreatic β-cell function. Thus, we tested whether β-cell-specific ablation of SIRT4 would recapitulate the elevated insulin secretion seen in mice with a global loss of SIRT4. Tamoxifen-inducible β-cell-specific SIRT4-KO mice were generated, and their glucose tolerance and glucose- and leucine-stimulated insulin secretion were measured over time. These mice exhibited normal glucose- and leucine-stimulated insulin secretion and maintained normal glucose tolerance even as they aged. Furthermore, 832/13 β-cells with a CRISPR/Cas9n-mediated loss of SIRT4 did not show any alterations in nutrient-stimulated insulin secretion. Despite the fact that whole body SIRT4-KO mice demonstrated an age-induced increase in glucose- and leucine-stimulated insulin secretion, our current data indicate that the loss of SIRT4 specifically in pancreatic β-cells, both in vivo and in vitro, does not have a significant impact on nutrient-stimulated insulin secretion. These data suggest that SIRT4 controls nutrient-stimulated insulin secretion during aging by acting on tissues external to the β-cell, which warrants further study.
Full Text
Duke Authors
Cited Authors
- Huynh, FK; Peterson, BS; Anderson, KA; Lin, Z; Coakley, AJ; Llaguno, FMS; Nguyen, T-TN; Campbell, JE; Stephens, SB; Newgard, CB; Hirschey, MD
Published Date
- October 1, 2020
Published In
Volume / Issue
- 319 / 4
Start / End Page
- E805 - E813
PubMed ID
- 32865009
Pubmed Central ID
- PMC7750516
Electronic International Standard Serial Number (EISSN)
- 1522-1555
Digital Object Identifier (DOI)
- 10.1152/ajpendo.00170.2020
Language
- eng
Conference Location
- United States