P-231

Effect of Nrf2 (nuclear factor erythroid2-related factor1)-Keap1 (Kelch ECH Associating protein1) signaling pathway on islet isolation

H. Ichii¹, S. Li¹, M. Alexander¹, M. Lamb¹, C. Foster¹, J.R.T. Lakey¹, N.D.. Vaziri^2
1 Universtiy of California Irvine, Surgery, Orange, USA; ² University of California Irvine, Medicine, Orange, USA

Objective: To improve islet transplantation outcomes, it is critical to protect the islets against various insults during the isolation process. Nrf2 (nuclear factor erythroid2-related factor1)-Keap1(Kelch ECH Associating protein1) signaling pathway plays a major role in protecting the cells against oxidants, carcinogens and environmental and cytotoxic agents by mediating expression of numerous genes encoding anti-oxidant and cytoprotective molecules. The aim of this study was to investigate the effects of pretreatment with an Nrf2 inducer on the quality of the islet cells following islet isolation.

Methods: Lewis rats (7wks) were fed with diets containing Nrf2-Keap1 inducer or regular diet for 72 hours before islet isolation. Islet yields, beta-cell content and insulin secretion were compared. Beta cell viability (apoptosis, necrosis) was assessed by Flow cytometry using three dyes (Newport green, TMRE, 7AAD). Additionally, viable beta-cell mass was calculated using the formula (IEQ x % beta cell X % beta cell viability).

Results: The Islet yield was significantly greater in the treated compared to the control group (1978±156 vs. 1609±125 IEQ, P<0.05). The stimulation index in the treated group was significantly higher when compared with that in the control group (6.0 ±1.2 vs. .2.7±0.5, P<0.05, respectively). In addition, islets harvested from the treated animals contained higher amount of beta cells when compared to the control group (88.4±1.6%, vs. 79.4±3.7, P<0.05, respectively). Flow cytometry analysis showed higher beta cell viability (76.0±2.5 vs. 72.8±1.6), lower cell death (16.2±1.3 vs. 20.9±4.7) and viable beta cell mass (1329.3±210.3, 930.1±185.2 vbIEQ, P<0.05).in the treated group compared to the Control group

Conclusions: Our study indicated that administration of Nrf2 inducer significantly improved islet yield, beta cell content, viability and function in rat isolation model. The results suggest that treatment with Nrf2 inducer may enhance the quality and quantity of the islets and as such may improve the islet transplant outcomes.

P-231

Effect of Nrf2 (nuclear factor erythroid2-related factor1)-Keap1 (Kelch ECH Associating protein1) signaling pathway on islet isolation

H. Ichii¹, S. Li¹, M. Alexander¹, M. Lamb¹, C. Foster¹, J.R.T. Lakey¹, N.D.. Vaziri^2
1 Universtiy of California Irvine, Surgery, Orange, USA; ² University of California Irvine, Medicine, Orange, USA

Objective: To improve islet transplantation outcomes, it is critical to protect the islets against various insults during the isolation process. Nrf2 (nuclear factor erythroid2-related factor1)-Keap1(Kelch ECH Associating protein1) signaling pathway plays a major role in protecting the cells against oxidants, carcinogens and environmental and cytotoxic agents by mediating expression of numerous genes encoding anti-oxidant and cytoprotective molecules. The aim of this study was to investigate the effects of pretreatment with an Nrf2 inducer on the quality of the islet cells following islet isolation.

Methods: Lewis rats (7wks) were fed with diets containing Nrf2-Keap1 inducer or regular diet for 72 hours before islet isolation. Islet yields, beta-cell content and insulin secretion were compared. Beta cell viability (apoptosis, necrosis) was assessed by Flow cytometry using three dyes (Newport green, TMRE, 7AAD). Additionally, viable beta-cell mass was calculated using the formula (IEQ x % beta cell X % beta cell viability).

Results: The Islet yield was significantly greater in the treated compared to the control group (1978±156 vs. 1609±125 IEQ, P<0.05). The stimulation index in the treated group was significantly higher when compared with that in the control group (6.0 ±1.2 vs. .2.7±0.5, P<0.05, respectively). In addition, islets harvested from the treated animals contained higher amount of beta cells when compared to the control group (88.4±1.6%, vs. 79.4±3.7, P<0.05, respectively). Flow cytometry analysis showed higher beta cell viability (76.0±2.5 vs. 72.8±1.6), lower cell death (16.2±1.3 vs. 20.9±4.7) and viable beta cell mass (1329.3±210.3, 930.1±185.2 vbIEQ, P<0.05).in the treated group compared to the Control group

Conclusions: Our study indicated that administration of Nrf2 inducer significantly improved islet yield, beta cell content, viability and function in rat isolation model. The results suggest that treatment with Nrf2 inducer may enhance the quality and quantity of the islets and as such may improve the islet transplant outcomes.