43 research outputs found
Kinetics and protective role of autophagy in a mouse cecal ligation and puncture-induced sepsis
INTRODUCTION: It is not well understood whether the process of autophagy is accelerated or blocked in sepsis, and whether it is beneficial or harmful to the immune defense mechanism over a time course during sepsis. Our aim was to determine both the kinetics and the role of autophagy in sepsis. METHODS: We examined autophagosome and autolysosome formation in a cecal ligation and puncture (CLP) mouse model of sepsis (in C57BL/6N mice and GFP-LC3 transgenic mice), using western blotting, immunofluorescence, and electron microscopy. We also investigated the effect of chloroquine inhibition of autophagy on these processes. RESULTS: Autophagy, as demonstrated by increased LC3-II/LC3-I ratios, is induced in the liver, heart, and spleen over 24 h after CLP. In the liver, autophagosome formation peaks at 6 h and declines by 24 h. Immunofluorescent localization of GFP-LC3 dots (alone and with lysosome-associated membrane protein type 1 (LAMP1)), as well as electron microscopic examination, demonstrate that both autophagosomes and autolysosomes are increased after CLP, suggesting that intact autophagy mechanisms operate in the liver in this model. Furthermore, inhibition of autophagy process by chloroquine administration immediately after CLP resulted in elevated serum transaminase levels and a significant increase in mortality. CONCLUSIONS: All autophagy-related processes are properly activated in the liver in a mouse model of sepsis; autophagy appears to play a protective role in septic animals
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Publisher Correction: Genetic tool development in marine protists: emerging model organisms for experimental cell biology.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
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Genetic tool development in marine protists: emerging model organisms for experimental cell biology
Abstract: Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways
Genetic tool development in marine protists: emerging model organisms for experimental cell biology
Abstract: Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways
Persistent Differences in Horizontal Gradients in Phytoplankton Concentration Maintained by Surf Zone Hydrodynamics
The article of record as published may be located at http://link.springer.com/article/10.1007/s12237-017-0278-2Surf zones, regions of breaking waves, are at the
interface between the shore and coastal ocean. Surf zone hydrodynamics
may affect delivery of phytoplankton subsidies
to the intertidal zone. Over a month of daily sampling at an
intermediate surf zone with bathymetric rip currents and a
reflective surf zone, we measured surf zone hydrodynamics
and compared concentrations of coastal phytoplankton taxa in
the surf zones to concentrations offshore. At the intermediate
surf zone, ~80% of the variability in the concentration of
coastal phytoplankton taxa within the surf zone was explained
by their variation offshore; however, concentrations were
much higher and lower than those offshore in samples from
a bathymetric rip current and over the adjacent shoal, respectively.
Hydrodynamics at this intermediate surf zone did not
hinder the delivery of coastal phytoplankton to the surf zone,
but the bathymetric rip current system appeared to redistribute phytoplankton concentrating them within eddies. At the reflective
shore, we sampled surf zones at a beach and two
adjacent rocky intertidal sites. Concentrations of typical coastal
phytoplankton taxa were usually an order of magnitude or
more lower than those offshore, even when offshore samples
were collected just 20 m beyond the breakers. The phytoplankton
assemblages inside and outside the surf zone often
appeared to be disconnected. Surf zone hydrodynamics at the
steep, reflective shore coupled with low phytoplankton concentrations
in near-surface water appeared to limit delivery of
phytoplankton subsidies to the surf zone. Surf zone hydrodynamics
may be a key factor in the alongshore variation in
phytoplankton subsidies to coastal communities.NSF-OCE no. 09273
IÎşBNS enhances T follicular helper cell differentiation and function as downstream of Ascl2
IÎşBNS plays an important role in Tfh cell differentiation and function