Engineering carotenoid production in mammalian cells for nutritionally enhanced cell-cultured foods.

Metabolic engineering of mammalian cells has to-date focused primarily on biopharmaceutical protein production or the manipulation of native metabolic processes towards therapeutic aims. However, significant potential exists for expanding these techniques to diverse applications by looking across the taxonomic tree to bioactive metabolites not synthesized in animals. Namely, cross-taxa metabolic engineering of mammalian cells could offer value in applications ranging fromfood and nutrition to regenerative medicine and gene therapy. Towards the former, recent advances in meat production through cell culture suggest the potential to produce meat with fine cellular control, where tuning composition through cross-taxa metabolic engineering could enhance nutrition and food-functionality. Here we demonstrate this possibility by engineering primary bovine and immortalized murine muscle cells with prokaryotic enzymes to endogenously produce the antioxidant carotenoids phytoene, lycopene and ß-carotene. These phytonutrients offer general nutritive value and protective effects against diseases associated with red and processed meat consumption, and so offer a promising proof-of-concept for nutritional engineering in cultured meat. We demonstrate the phenotypic integrity of engineered cells, the ability to tune carotenoid yields, and the antioxidant functionality of these compounds in vitro towards both nutrition and food-quality objectives. Our results demonstrate the potential for tailoring the nutritional profile of cultured meats. They further lay a foundation for heterologous metabolic engineering of mammalian cells for applications outside of the clinical realm.

Quantitative label-free mass spectrometry reveals content and signaling differences between neonatal and adult platelets.

BACKGROUND: Recent clinical studies have shown that transfusions of adult platelets increase morbidity and mortality in preterm infants. Neonatal platelets are hyporesponsive to agonist stimulation, and emerging evidence suggests developmental differences in platelet immune functions. OBJECTIVES: This study was designed to compare the proteome and phosphoproteome of resting adult and neonatal platelets. METHODS: We isolated resting umbilical cord blood-derived platelets from healthy full-term neonates (n = 8) and resting blood platelets from healthy adults (n = 6) and compared protein and phosphoprotein contents using data-independent acquisition mass spectrometry. RESULTS: We identified 4770 platelet proteins with high confidence across all samples. Adult and neonatal platelets were clustered separately by principal component analysis. Adult platelets were significantly enriched in immunomodulatory proteins, including ß2 microglobulin and CXCL12, whereas neonatal platelets were enriched in ribosomal components and proteins involved in metabolic activities. Adult platelets were enriched in phosphorylated GTPase regulatory enzymes and proteins participating in trafficking, which may help prime them for activation and degranulation. Neonatal platelets were enriched in phosphorylated proteins involved in insulin growth factor signaling. CONCLUSION: Using label-free data-independent acquisition mass spectrometry, our findings expanded the known neonatal platelet proteome and identified important differences in protein content and phosphorylation between neonatal and adult platelets. These developmental differences suggested enhanced immune functions for adult platelets and presence of molecular machinery related to platelet activation. These findings are important to understanding mechanisms underlying key platelet functions as well as the harmful effects of adult platelet transfusions given to preterm infants.

Hemostatic and Immunologic Effects of Platelet Transfusions in Neonates.

Liberal platelet transfusions are associated with increased morbidity and mortality among preterm neonates, and it is now recognized that platelets are both hemostatic and immune cells. Neonatal and adult platelets are functionally distinct, and adult platelets have the potential to be more immuno-active. Preclinical studies suggest that platelet transfusions (from adult donors) can trigger dysregulated immune responses in neonates, which might mediate the increased morbidity and mortality observed in clinical studies. More research is needed to understand how neonatal and adult platelets differ in their immune functions and the consequences of these differences in the setting of neonatal platelet transfusions.