5 research outputs found
Peroxisome proliferator-activated receptors (PPARs) and related transcription factors in differentiating astrocyte cultures
Peroxisome proliferator-activated receptors (PPARs),
retinoid X receptors (RXRs), CCAAT/enhancer binding proteins
(C/EBPs) and -catenin are transcription factors involved
in cell differentiation. The aim of this work was to
investigate the occurrence and variations of these proteins
during astrocyte differentiation. Primary cultures of mouse
cortical astrocytes were characterized using nestin, A2B5
and glial fibrillary acidic protein (GFAP) as differentiation
markers, during a period of 21 days in vitro (DIV). Glycogen
and triglyceride accumulation were also studied.
At 3 DIV the cultures were mainly constituted by neural
progenitor cells, as assessed by their immunofluorescent
pattern. At this time PPARs and -catenin were localized to
the cytoplasm. Interestingly, some cells contained Oil Red
O-positive lipid droplets. Between 7 and 21 DIV, nestin decreased,
while GFAP increased, indicating ongoing astroglial
differentiation. -catenin, predominantly nuclear at 7 DIV,
later localized to membranes. Redistribution of all three
PPAR isotypes from the cytoplasm to the nucleus was observed
starting from 7 DIV. Between 7 and 14 DIV, C/EBP,
PPAR, RXR and glycogen content increased. Between 14
and 21 DIV, PPAR/ decreased, while PPAR, C/EBP and
and lipid droplet-containing cells increased. At 21 DIV both
A2B5/GFAP and A2B5/GFAP cells were predominantly
observed, indicating differentiation toward type-1 and type-2
astrocytes, although the presence of GFAP cells demonstrates
the persistence of neural precursors in the culture
even at this time point.
In conclusion, our results, reporting modifications of
PPARs, RXRs, C/EBPs and -catenin during culture time,
strongly suggest the involvement of these transcription factors
in astrocyte differentiation. Specifically, -catenin translocation
from the nucleus to plasma membrane, together with
PPAR/ decrease and C/EBP increase, could be related to
decreased proliferation at confluence, while PPAR and
and all C/EBPs could participate in differentiation processes,
such as glycogenesis and lipidogenesis
Redistribution of iron and hydrogen peroxide in Pinus sylvestris roots in response to trophically diverse fungi
Truffles and Morels: Two Different Evolutionary Strategies of Fungal-Plant Interactions in the Pezizales
Pezizales are a widespread group of fungi, basal to the other filamentous ascomycetes. Most species live in soil as saprobes, in a mycorrhizal relationship with a wide range of plants, or as plant parasites. The lineage Morchellaceae–Discinaceae–Helvellaceae–Tuberaceae includes most of the commercially valuable species in the order. The truffles in the genus Tuber and morels in the genus Morchella arguably command more interest in culinary circles than any other groups of mushrooms. In recent years, the interactions of these fungi with plants have been thoroughly researched although many aspects still need to be clarified. In this chapter, we describe and compare these two groups of mushrooms and take a look at the evidence as to whether there are real trophic differences from those traditionally held and if things are not quite as simple as our forebears would have had us believe. We explore the range of host plants involved in the interactions, the morpho-anatomy of symbiotic structures, the molecular mechanisms of symbiosis, and the influence of other microbial species