P-237

Zip1 knockout mice display altered zinc transporter gene expression profiles in pancreatic tissue

C. Mee¹, P. Zalewski², C. Lang², C. Drogemuller¹, C. Milner¹, D. Mohanasundaram¹, P.T.H. Coates^1
1 Royal Adelaide Hospital, CNARTS, Adelaide, Australia; ² Bazil Hetzel Institute for Medical Research, Adelaide, Australia

Zinc is essential for the secretion, storage and synthesis of insulin. Two families of zinc transporters exist that are critical in maintaining zinc homeostasis: SLC39 (ZIP) and SLC30 (ZnT). The ZIP family control cellular uptake of zinc from the extracellular matrix and the ZnT family control both the efflux of zinc and zinc-insulin hexamer packaging in intracellular vesicles.

Objective: In this study, the gene expression profile of both families of zinc transporters (22 in total) was assessed in a ZIP1 knockout mouse model.

Methods: Cryostat sectioning, RNA extraction, analysis and cDNA synthesis was performed from the native pancreata of ZIP1-/- mice and control C57B6 mice. Real Time PCR was performed using gene specific Taqman® primers and analysed using the ∆∆Ct method.

Results: The absence of ZIP1 gene expression in the knockout mice resulted in the suppression of gene expression in the majority of the ZIP family members, with ZIP3 being reduced more than 5 fold. However, the majority of the ZnT family remained unaffected, except for ZnT2 which also showed greater than 5 fold reduction in expression. Interestingly, Insulin expression also appeared to be reduced in the knockout mice. The islet specific ZnT8 transporter showed wide variation in expression levels in both the knockout and control mice with a trend towards higher expression in the knockout. Further studies are ongoing to determine if this altered expression profile has a functional effect both in vitro and in vivo.

Conclusions: These results suggest that knocking out the expression of one zinc transporter may impact the expression profiles of other critical zinc transporters of the mouse pancreas. This suggests that there may be cross regulation of zinc transporter expression. These findings warrant further investigation into the significance of this altered expression profile on the viability and function of islets.

P-237

Zip1 knockout mice display altered zinc transporter gene expression profiles in pancreatic tissue

C. Mee¹, P. Zalewski², C. Lang², C. Drogemuller¹, C. Milner¹, D. Mohanasundaram¹, P.T.H. Coates^1
1 Royal Adelaide Hospital, CNARTS, Adelaide, Australia; ² Bazil Hetzel Institute for Medical Research, Adelaide, Australia

Zinc is essential for the secretion, storage and synthesis of insulin. Two families of zinc transporters exist that are critical in maintaining zinc homeostasis: SLC39 (ZIP) and SLC30 (ZnT). The ZIP family control cellular uptake of zinc from the extracellular matrix and the ZnT family control both the efflux of zinc and zinc-insulin hexamer packaging in intracellular vesicles.

Objective: In this study, the gene expression profile of both families of zinc transporters (22 in total) was assessed in a ZIP1 knockout mouse model.

Methods: Cryostat sectioning, RNA extraction, analysis and cDNA synthesis was performed from the native pancreata of ZIP1-/- mice and control C57B6 mice. Real Time PCR was performed using gene specific Taqman® primers and analysed using the ∆∆Ct method.

Results: The absence of ZIP1 gene expression in the knockout mice resulted in the suppression of gene expression in the majority of the ZIP family members, with ZIP3 being reduced more than 5 fold. However, the majority of the ZnT family remained unaffected, except for ZnT2 which also showed greater than 5 fold reduction in expression. Interestingly, Insulin expression also appeared to be reduced in the knockout mice. The islet specific ZnT8 transporter showed wide variation in expression levels in both the knockout and control mice with a trend towards higher expression in the knockout. Further studies are ongoing to determine if this altered expression profile has a functional effect both in vitro and in vivo.

Conclusions: These results suggest that knocking out the expression of one zinc transporter may impact the expression profiles of other critical zinc transporters of the mouse pancreas. This suggests that there may be cross regulation of zinc transporter expression. These findings warrant further investigation into the significance of this altered expression profile on the viability and function of islets.