RESUMO
The mature mammalian brain connectome emerges during development via the extension and pruning of neuronal connections. Glial cells have been identified as key players in the phagocytic elimination of neuronal synapses and projections. Recently, phosphatidylserine has been identified as neuronal "eat-me" signal that guides elimination of unnecessary input sources, but the associated transduction systems involved in such pruning are yet to be described. Here, we identified Xk-related protein 8 (Xkr8), a phospholipid scramblase, as a key factor for the pruning of axons in the developing mammalian brain. We found that mouse Xkr8 is highly expressed immediately after birth and required for phosphatidylserine exposure in the hippocampus. Mice lacking Xkr8 showed excess excitatory nerve terminals, increased density of cortico-cortical and cortico-spinal projections, aberrant electrophysiological profiles of hippocampal neurons, and global brain hyperconnectivity. These data identify phospholipid scrambling by Xkr8 as a central process in the labeling and discrimination of developing neuronal projections for pruning in the mammalian brain.
Assuntos
Proteínas Reguladoras de Apoptose , Proteínas de Transferência de Fosfolipídeos , Animais , Camundongos , Proteínas de Transferência de Fosfolipídeos/genética , Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Fosfatidilserinas/metabolismo , Axônios/metabolismo , Plasticidade Neuronal , Mamíferos , Proteínas de Membrana/metabolismoRESUMO
We developed and applied 4 extrusion regimens (moisture content between 30 % and 60 % and temperature from 110 °C to 120 °C) with twin-screw extruder for valorising soy press cakes, byproduct of soy drink (Soyd) and tofu (Soyt) manufacturing processes, by varying physical conditions of extrusion for improving their morphological, functional, and sensory parameters. The valorised soy press cakes were compared to their respective control samples (Soyd or Soyt) both before and after extrusion. Two quantities (3%-6%) of untreated and extruded soy press cakes were utilised to develop meat analogues. Extrusion introduced striations and reduced flakiness on the surface of extruded press cake samples. Press cakes extruded at higher moisture indicated improved water holding and oil holding capacity. Interestingly, the same press cake samples also scored higher for positive indicators (e.g., juiciness) during sensory assessment. Compared with meat analogue control matrix, all meat analogue samples containing varying amounts of extruded press cake exhibited reduced chewiness, with other parameters relatively unchanged. Our results indicate that extrusion of soy press cakes of both Soyd and Soyt origin at 120 °C with 60 % moisture results in improving the morphological, functional, and sensory properties of press cakes, making them suitable for development of meat analogues.
RESUMO
The effect of the incorporation of rice bran wax (5%; 7%) or candelilla wax (3%; 7%) for production of hemp-oil-based oleogels was analyzed in this study. The experiment was carried out to replace between 0 and 100% of animal fat in meat patties with oleogels. Free fatty acids (FFAs), acid value (AV), oxidative stability index (OSI), conjugated diene value, malondialdehyde value, physicochemical properties, and the sensory properties of oleogels and meat patties were studied. The results indicated that hemp oil had more polyunsaturated fatty acids and lower oxidative stability when compared to oleogels. The OSI for oil was 3.1 h, while for oleogels it was 3.4-3.6 (candelilla case) or 3.7-3.9 (rice bran). Oleogels were able to match pork fat texture properties such as spreadability and adhesiveness in meat patties. However, sensory data for cooked meat patties with animal fat fully replaced by oleogels revealed that samples with 100% pork fat had higher juiciness and taste intensity. Our results showed that a wax-based oleogel had a higher oxidative stability and nutritional profile, but further investigations to mimic pork fat properties in meat patties are necessary.