ZnT8 Haploinsufficiency Impacts MIN6 Cell Zinc Content and β-Cell Phenotype via ZIP-ZnT8 Coregulation.
Rebecca LawsonWolfgang MaretChrister HogstrandPublished in: International journal of molecular sciences (2019)
The zinc transporter ZnT8 (SLC30A8) localises to insulin secretory granules of β-cells where it facilitates zinc uptake for insulin crystallisation. ZnT8 abundance has been linked to β-cell survival and functional phenotype. However, the consequences of ZnT8 haploinsufficiency for β-cell zinc trafficking and function remain unclear. Since investigations in human populations have shown SLC30A8 truncating polymorphisms to decrease the risk of developing Type 2 Diabetes, we hypothesised that ZnT8 haploinsufficiency would improve β-cell function and maintain the endocrine phenotype. We used CRISPR/Cas9 technology to generate ZnT8 haploinsufficient mouse MIN6 β-cells and showed that ZnT8 haploinsufficiency is associated with downregulation of mRNAs for Slc39a8 and Slc39a14, which encode for the zinc importers, Znt- and Irt-related proteins 8 (ZIP8) and 14 (ZIP14), and with lowered total cellular zinc content. ZnT8 haploinsufficiency disrupts expression of a distinct array of important β-cell markers, decreases cellular proliferation via mitogen-activated protein (MAP) kinase cascades and downregulates insulin gene expression. Thus, ZnT8 cooperates with zinc importers of the ZIP family to maintain β-cell zinc homeostasis. In contrast to the hypothesis, lowered ZnT8 expression reduces MIN6 cell survival by affecting zinc-dependent transcription factors that control the β-cell phenotype.
Keyphrases
- type diabetes
- single cell
- cell therapy
- gene expression
- oxide nanoparticles
- crispr cas
- induced apoptosis
- endothelial cells
- poor prognosis
- magnetic resonance
- glycemic control
- signaling pathway
- adipose tissue
- computed tomography
- dna methylation
- transcription factor
- high resolution
- high throughput
- metabolic syndrome
- oxidative stress
- insulin resistance
- weight loss
- genome editing
- binding protein
- tyrosine kinase
- genetic diversity
- dna binding