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Spermidine is a natural polyamine which was shown to prolong lifespan of organisms and to improve cardiac and cognitive function. Spermidine was also reported to reduce inflammation and modulate T-cells. Autophagy is one of the mechanisms that spermidine exerts its effect. Autophagy is vital for β-cell homeostasis and autophagy deficiency was reported to lead to exacerbated diabetes in mice. The effect of spermidine in type 1 diabetes pathogenesis remains to be elucidated. Therefore, we examined the effect of spermidine treatment in non-obese diabetic (NOD) mice, a mouse model for type 1 diabetes. NOD mice were given untreated or spermidine-treated water ad libitum from 4 weeks of age until diabetes onset or 35 weeks of age. We found that treatment with 10 mM spermidine led to higher diabetes incidence in NOD mice despite unchanged pancreatic insulitis. Spermidine modulated tissue polyamine levels and elevated signs of autophagy in pancreas. Spermidine led to increased proportion of pro-inflammatory T-cells in pancreatic lymph nodes (pLN) in diabetic mice. Spermidine elevated the proportion of regulatory T-cells in early onset mice, whereas it reduced the proportion of regulatory T-cells in late onset mice. In summary spermidine treatment led to higher diabetes incidence and elevated proportion of T-cells in pLN.

BACKGROUND In precision oncology ex vivo drug screening systems have the potential to improve clinical outcomes. Traditionally, cancer drugs are tested on cancer cell line models, but these cannot represent an individual patient and are biologically too distinct. Drug screening systems usually rely on viability assays and correlations to genomic alterations. Beside genomic alterations, the cellular metabolism is significantly altered which may lead to drug resistance. Here we aim to establish a drug screening platform using tumor cells derived directly from the individual patient glial tumor tissue, create patient derived tumor cells (PDCs) and combine the outcomes from standardized viability- and genetic-assays with a new developed metabolomics platform. Materials and METHODS Fresh native tissue from patients harbouring low- and high-grade glioma are collected (n=46). Tumor tissue used for NMR-based metabolomic analyses and targeted sequencing analyses as well as PDC isolation. To preserve the original tumor similarity, tissue is short term cultured for two weeks, and PDCs are seeded and treated with a panel of clinical- and preclinical drugs followed by viability assessment, sequencing and metabolomic profiling. RESULTS Culturing of PDCs is successful in ≥ 85% of patient cases, provided that at least 2 g of tumor tissue is available. The automatized high throughput ex vivo drug response identifies drug candidates, which might become relevant for therapeutic approaches in future. It is possible to distinguish between IDH1-wild-type and IDH1-mutant tumors based on the metabolomic profile, which is confirmed by immunohistochemical staining and molecular analysis of IDH1 R132H-mutation. Strong metabolomic variations have been identified, including GABA, lactate, and myo-inositol levels between tumor and healthy tissue. CONCLUSION Entangling drug screening and genetic assays with metabolomic profiling of glial tumors enriches the information about cellular drug response and paves the way for future clinical studies and better understanding of underlying drug resistance mechanisms in gliomas.

The loss of lipid homeostasis can lead to lipid overload and is associated with a variety of disease states. However, little is known as to how the disruption of lipid regulation or lipid overload affects cell survival. In this study we investigated how excess diacylglycerol (DG), a cardinal metabolite suspected to mediate lipotoxicity, compromises the survival of yeast cells. We reveal that increased DG achieved by either genetic manipulation or pharmacological administration of 1,2-dioctanoyl-sn-glycerol (DOG) triggers necrotic cell death. The toxic effects of DG are linked to glucose metabolism and require a functional Rim101 signaling cascade involving the Rim21-dependent sensing complex and the activation of a calpain-like protease. The Rim101 cascade is an established pathway that triggers a transcriptional response to alkaline or lipid stress. We propose that the Rim101 pathway senses DG-induced lipid perturbation and conducts a signaling response that either facilitates cellular adaptation or triggers lipotoxic cell death. Using established models of lipotoxicity, i.e., high-fat diet in Drosophila and palmitic acid administration in cultured human endothelial cells, we present evidence that the core mechanism underlying this calpain-dependent lipotoxic cell death pathway is phylogenetically conserved.