Oral Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2017

Abrogation of adenosine receptor A1R signalling potentiates VCP746 dependent beta-cell proliferation (#83)

Tharun B Mysore 1 , Sarah White 1 , Lauren T May 2 , Karen M Dwyer 1
  1. Deakin University, Geelong, VICTORIA, Australia
  2. Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia

Background

Adenosine receptor signalling is implicated in β-cell survival, insulin production and proliferation. The non-specific adenosine receptor agonist NECA promotes β-cell regeneration in zebrafish1. The novel adenosinergic compound VCP746 activate adenosine receptor (AR) subtypes A1R, A2AR and A2BR with similar potency to adenosine but with minimal side effects on heart rate or systolic blood pressure2. VCP746 utilises the unique pharmacological property of biased agonism, a new paradigm of G-protein coupled receptor (GPCR) drug action to examine its efficacy in the regeneration of β-cells.

 

Aim

To investigate the effect of VCP746 on β-cell viability in vitro and development  in vivo  using Tg(ins:CFP-NTR);Tg(ins:Kaede) (NTR)  zebrafish regeneration model.  

 

Methods

INS-1 cells were cultured in serum-free DMEM media for 24h, and β-cells ablated NTR fish embryos in fish water for 48h, with either buffer only (DMSO) or with VCP746 ± 25nM SLV320 (A1R specific antagonist). In vitro INS-1 viability/proliferation was quantified by MTT assay and in vivo β-cell development by measuring relative area of insulin (RAI) expression in the embryos using whole mount in situ hybridisation (WISH).

 

Results

 591e4230f1de4-ADSfig1.tif

(A) VCP746 inhibited INS-1 cell proliferation at all concentrations tested, which was ameliorated with A1R antagonist, SLV320 in a dose dependent manner. (B) RAI following ablation and treatment was reduced significantly with VCP746 treatment and increased with NECA in NTR fish embryos.

  

Conclusions

VCP746 increased INS-1 cells proliferation, but only when treated with SLV320 to block A1R receptor signalling in vitro. The preliminary data suggests possible involvement of A2AR and A2BR signalling in proliferation. Further in vivo studies to decipher VCP746 role in β-cell proliferation including, receptor signalling pathways and gene expression is underway.   

 

References

  1. Andersson O, et al. Cell Metab. 2012;15(6):885-94
  2. Valant C, et al. Proc Natl Acad Sci U S A. 2014; 111(12):4614-9.