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β cell regeneration is necessary to cure patients with type 1 diabetes (T1D) whose β cells are destroyed by immune cells. Although insulin therapy can control blood glucose levels, it must be administered throughout life and occurs several side effects such as hypoglycemia. New β cell can be generated through neogenesis, β cell replication or transdifferentiation from other cells in diabetic animals. In addition to β cell regeneration, immunosuppression is another important mechanism to prevent β cell destruction, but currently any drugs haven’t been approved as immunosuppressants for T1D treatments yet. A novel 9-mer peptide, Shiloah 1000 (S1K) , has dual functions of β cell regeneration and immunosuppression. In streptozotocin-induced hyperglycemic mouse model, the number of mice recovered to normoglycemia was increased by the combined treatment of S1K and insulin compared to S1K or insulin alone. In addition, the combined treatment more increased the number of β cells than S1K or insulin alone. Interestingly, insulin/glucagon double-positive cells were increased by both combined and S1K alone treatments. The increase in the number of mice recovered to normoglycemia is considered to be due to β cell regeneration through α- to β-cell transdifferentiation by S1K. In the NOD mouse model, the combined treatment of S1K and insulin suppressed hyperglycemia more than insulin alone. In addition, the serum C-peptide levels were increased by both combined and S1K treatments, but not by insulin treatment. The increase in the serum C-peptide level suggest that β cells remain undestroyed by immunosuppression. Taken together, our data show that S1K, as a drug candidate for T1D treatment in combination with insulin reduces blood glucose levels in the T1D mouse models through β cell regeneration and immunosuppression, suggesting a potential role in preventing and curing T1D. Disclosure Y. Lee: Employee; Ensolbiosciences. H. Kim: Employee; Ensolbiosciences. J. Kim: Employee; Ensol Bioscience. Y. Jang: Employee; Ensolbiosciences.

Studies in rats, monkeys, and humans have found action-value signals in multiple regions of the brain. These findings suggest that action-value signals encoded in these brain structures bias choices toward higher expected rewards. However, previous estimates of action-value signals might have been inflated by serial correlations in neural activity and also by activity related to other decision variables. Here, we applied several statistical tests based on permutation and surrogate data to analyze neural activity recorded from the striatum, frontal cortex, and hippocampus. The results show that previously identified action-value signals in these brain areas cannot be entirely accounted for by concurrent serial correlations in neural activity and action value. We also found that neural activity related to action value is intermixed with signals related to other decision variables. Our findings provide strong evidence for broadly distributed neural signals related to action value throughout the brain.

Choices of humans and non-human primates are influenced by both actually experienced and fictive outcomes. To test whether this is also the case in rodents, we examined rat's choice behavior in a binary choice task in which variable magnitudes of actual and fictive rewards were delivered. We found that the animal's choice was significantly influenced by the magnitudes of both actual and fictive rewards in the previous trial. A model-based analysis revealed, however, that the effect of fictive reward was more transient and influenced mostly the choice in the next trial, whereas the effect of actual reward was more sustained, consistent with incremental learning of action values. Our results suggest that the capacity to modify future choices based on fictive outcomes might be shared by many different animal species, but fictive outcomes are less effective than actual outcomes in the incremental value learning system.