Low protein

About: Low protein is a research topic. Over the lifetime, 8139 publications have been published within this topic receiving 213225 citations.

Maternal Protein Restriction Affects Postnatal Growth and the Expression of Key Proteins Involved in Lifespan Regulation in Mice

Abstract: We previously reported that maternal protein restriction in rodents influenced the rate of growth in early life and ultimately affected longevity. Low birth weight caused by maternal protein restriction followed by catch-up growth (recuperated animals) was associated with shortened lifespan whereas protein restriction and slow growth during lactation (postnatal low protein: PLP animals) increased lifespan. We aim to explore the mechanistic basis by which these differences arise. Here we investigated effects of maternal diet on organ growth, metabolic parameters and the expression of insulin/IGF1 signalling proteins and Sirt1 in muscle of male mice at weaning. PLP mice which experienced protein restriction during lactation had lower fasting glucose (P = 0.038) and insulin levels (P = 0.046) suggesting improved insulin sensitivity. PLP mice had higher relative weights (adjusted by body weight) of brain (P = 0.0002) and thymus (P = 0.031) compared to controls suggesting that enhanced functional capacity of these two tissues is beneficial to longevity. They also had increased expression of insulin receptor substrate 1 (P = 0.021) and protein kinase C zeta (P = 0.046). Recuperated animals expressed decreased levels of many insulin signalling proteins including PI3 kinase subunits p85alpha (P = 0.018), p110beta (P = 0.048) and protein kinase C zeta (P = 0.006) which may predispose these animals to insulin resistance. Sirt1 protein expression was reduced in recuperated offspring. These observations suggest that maternal protein restriction can affect major metabolic pathways implicated in regulation of lifespan at a young age which may explain the impact of maternal diet on longevity.

Computational methodologies for modelling, analysis and simulation of signalling networks

Abstract: This article is a critical review of computational techniques used to model, analyse and simulate signalling networks. We propose a conceptual framework, and discuss the role of signalling networks in three major areas: signal transduction, cellular rhythms and cell-to-cell communication. In order to avoid an overly abstract and general discussion, we focus on three case studies in the areas of receptor signalling and kinase cascades, cell-cycle regulation and wound healing. We report on a variety of modelling techniques and associated tools, in addition to the traditional approach based on ordinary differential equations (ODEs), which provide a range of descriptive and analytical powers. As the field matures, we expect a wider uptake of these alternative approaches for several reasons, including the need to take into account low protein copy numbers and noise and the great complexity of cellular organisation. An advantage offered by many of these alternative techniques, which have their origins in computing science, is the ability to perform sophisticated model analysis which can better relate predicted behaviour and observations.

Sediment properties and bacterial community in burrows of the ghost shrimp Pestarella tyrrhena (Decapoda: Thalassinidea)

Abstract: Chemical properties of burrow wall sediment from burrows of the thalassinidean shrimp Pestarella (=Callianassa) tyrrhena located at Vravrona Bay (Aegean Sea, Greece) were studied and found to be very different from the sediment surface and ambient anoxic sediment. P. tyrrhena burrow walls had significantly higher amounts of silt and clay, while total organic carbon (TOC) was up to 6 times higher than in surrounding sediment. Chlorophyll a (chl a) accounted for a small frac- tion of TOC and showed similar values in burrow walls and surface sediment, whereas the low chl a: chl a + phaeopigment ratio indicated the presence of more fresh material in the latter. Biopolymers (carbohydrates, proteins and lipids) were 4 to 11 times higher in burrow walls than in the surround- ing sediment, accounting for 47% of TOC. The low protein:carbohydrate ratio indicated that the high TOC in the burrow walls was caused by the presence of aged detritus of low nutritional quality, such as seagrass detritus. The distinct conditions along the burrow wall also affected the bacterial community and resulted in a 10-fold increase of bacterial abundance. Molecular fingerprints of the bacterial communities showed that the bacterial composition of the burrow wall was more similar to the ambient anoxic sediment and showed less seasonal change than the sediment surface. These results suggest that burrow walls have distinct properties and should not be considered merely as a simple extension of the sediment surface.