A Role of RIP3-Mediated Macrophage Necrosis in Atherosclerosis Development

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Highlights? RIP3 deficiency in macrophages reduces advanced atherosclerotic lesions ? RIP3 deficiency reduces primary necrosis of macrophages in advanced lesions ? RIP3-dependent macrophage necrosis is not postapoptotic cell death ? Increased RIP3 converts apoptosis to necrosis in advanced lesional macrophages     

Improving the fermentation performance of saccharomyces cerevisiae by laccase during ethanol production from steam‐exploded wheat straw at high‐substrate loadings

Operating the saccharification and fermentation processes at high‐substrate loadings is a key factor for making ethanol production from lignocellulosic biomass economically viable. However, increasing the substrate loading presents some disadvantages, including a higher concentration of inhibitors (furan derivatives, weak acids, and phenolic compounds) in the media, which negatively affect the fermentation performance. One strategy to eliminate soluble inhibitors is filtering and washing the pretreated material. In this study, it was observed that even if the material was previously washed, inhibitory compounds were released during the enzymatic hydrolysis step. Laccase enzymatic treatment was evaluated as a method to reduce these inhibitory effects. The laccase efficiency was analyzed in a presaccharification and simultaneous saccharification and fermentation process at high‐substrate loadings. Water‐insoluble solids fraction from steam‐exploded wheat straw was used as substrate and Saccharomyces cerevisiae as fermenting microorganism. Laccase supplementation reduced strongly the phenolic content in the media, without affecting weak acids and furan derivatives. This strategy resulted in an improved yeast performance during simultaneous saccharification and fermentation process, increasing significantly ethanol productivity. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013     

Impacts of large mammals on movements of the pouched mouse (Saccostomus mearnsi) in central Kenya

Populations of large wild mammals are declining worldwide, while the abundance of livestock is increasing. The absence of large mammals frequently leads to increases in the abundance of small mammals such as rodents, but little is known about how the loss of large mammals affects the behaviour of small mammals. To investigate this question, we analysed long‐term data collected at the Kenya Long‐term Exclosure Experiment, which excludes different combinations of large mammals from a savannah ecosystem in central Kenya. We investigated the effects of excluding large mammals, both wild and domestic, on the movements of the pouched mouse (Saccostomus mearnsi), the most common species of small mammal in this habitat. Mice moved ~20% more in the presence of wildlife, but their movements were not significantly affected by the presence of cattle. An index of intraspecific contacts between mice was higher at higher mouse densities, and these high densities were more likely when wildlife and cattle were absent. The results suggest that the absence of large mammals led to higher densities of small mammals, which resulted in a greater probability of intraspecific contacts, despite lower average movement distances.     

Conservation of the Native Orchids Through Seedling Culture and Reintroduction—A Singapore Experience

Singapore is located near the equator, off the southern tip of the Malay Peninsula. The whole country consists mostly of lowland. It has many interesting types of natural habitats such as primary rain forest, freshwater swamp forest, mangroves, secondary forests, shrub, grasslands, and urban parks and fields. The climate is equatorial with relatively uniform temperature and high humidity. Unfortunately, many of the natural habitats and the native orchids which thrive there have disappeared due to habitat destruction. Some 226 species of native orchids have been recorded in Singapore. However, of these 178 are considered to be extinct, and only five are common. The orchid conservation programme aims to monitor existing species, explore ways to conserve their germplasm, and increase their numbers in natural, semi-natural, and urban environments through ex-situ seedling culture and subsequent re-introduction into appropriate habitats, including roadside trees, parks and natural areas. In the first phase of the programme, we have successfully propagated and carried out experiments of re-introduction on five species of native orchids, namely, Grammatophyllum speciosum, Bulbophyllum vaginatum, Bulbophyllum membranaceum, Cymbidium finlaysonianum and Cymbidium bicolor. Survival percentages 8-yr after the reintroduction events ranged from 10 to 95 for G. speciosum, the target species of the earliest re-introduction experiments. Size of the seedlings at reintroduction, host trees, and relative humidity seemed to play significant roles in the success rate of the reintroductions.     

Ectopic expression of an amino acid transporter (VfAAP1) in seeds of Vicia narbonensis and pea increases storage proteins

Storage protein synthesis is dependent on available nitrogen in the seed, which may be controlled by amino acid import via specific transporters. To analyze their rate-limiting role for seed protein synthesis, a Vicia faba amino acid permease, VfAAP1, has been ectopically expressed in pea (Pisum sativum) and Vicia narbonensis seeds under the control of the legumin B4 promoter. In mature seeds, starch is unchanged but total nitrogen is 10% to 25% higher, which affects mainly globulin, vicilin, and legumin, rather than albumin synthesis. Transgenic seeds in vitro take up more [14C]-glutamine, indicating increased sink strength for amino acids. In addition, more [14C] is partitioned into proteins. Levels of total free amino acids in growing seeds are unchanged but with a shift toward higher relative abundance of asparagine, aspartate, glutamine, and glutamate. Hexoses are decreased, whereas metabolites of glycolysis and the tricarboxylic acid cycle are unchanged or slightly lower. Phosphoenolpyruvate carboxylase activity and the phosphoenolpyruvate carboxylase-to-pyruvate kinase ratios are higher in seeds of one and three lines, indicating increased anaplerotic fluxes. Increases of individual seed size by 20% to 30% and of vegetative biomass indicate growth responses probably due to improved nitrogen status. However, seed yield per plant was not altered. Root application of [15N] ammonia results in significantly higher label in transgenic seeds, as well as in stems and pods, and indicates stimulation of nitrogen root uptake. In summary, VfAAP1 expression increases seed sink strength for nitrogen, improves plant nitrogen status, and leads to higher seed protein. We conclude that seed protein synthesis is nitrogen limited and that seed uptake activity for nitrogen is rate limiting for storage protein synthesis.     

Transmission of MRSA between companion animals and infected human patients presenting to outpatient medical care facilities

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in both human and veterinary medicine. The importance of companion animals as reservoirs of human infections is currently unknown. The companion animals of 49 MRSA-infected outpatients (cases) were screened for MRSA carriage, and their bacterial isolates were compared with those of the infected patients using Pulsed-Field Gel Electrophoresis (PFGE). Rates of MRSA among the companion animals of MRSA-infected patients were compared to rates of MRSA among companion animals of pet guardians attending a “veterinary wellness clinic” (controls). MRSA was isolated from at least one companion animal in 4/49 (8.2%) households of MRSA-infected outpatients vs. none of the pets of the 50 uninfected human controls. Using PFGE, patient-pets MRSA isolates were identical for three pairs and discordant for one pair (suggested MRSA inter-specie transmission p-value = 0.1175). These results suggest that companion animals of MRSA-infected patients can be culture-positive for MRSA, representing a potential source of infection or re-infection for humans. Further studies are required to better understand the epidemiology of MRSA human-animal inter-specie transmission.     

Widespread gamma-secretase activity in the cell, but do we need it at the mitochondria?

gamma-Secretase cleavage of the amyloid precursor protein already subjected to a prior beta-secretase cleavage generates beta-amyloid (Abeta) peptide fragments, which are major constituents of the amyloid plagues found in Alzheimer's disease brain tissues. gamma-Secretase activity and components of the gamma-secretase complex are found in the endoplasmic reticulum-Golgi intermediate compartment, the Golgi, the trans-Golgi network, the plasma membrane, the endosomal-lysosomal system and recently, the mitochondria. Abeta fragments have been shown to be neurotoxic, leading to mitochondrial dysfunction and enhanced apoptotic cell death. However, if Abeta fragments are indeed detrimental to neurons, the widespread presence of enzymatic activity that would result in their generation in the cell appears to make little sense. The presence of a gamma-secretase complex in the mitochondrion, an organelle that is particularly susceptible to Abeta toxicity, is even more puzzling. Emerging evidence suggests that both secreted and intracellular Abeta fragments have endogenous functions. Also, while the fibrillogenic Abeta1-42 is clearly neurotoxic, the more abundant and soluble Abeta1-40 is an antioxidant and could potentially be neuroprotective in several ways. A "physiological" amount of Abeta1-40 production by cellular gamma-secretase activity may be part of the neuron's natural counter against oxidative damage, in addition to endogenous roles in neuronal survival and modulation of synaptic transmission. In any case, whether Abeta is produced locally in the mitochondria and the function for mitochondrial Abeta, if produced, is yet unclear.