93 research outputs found
An Analytical Pipeline for Quantitative Characterization of Dietary Intake:Application To Assess Grape Intake
Lack
of accurate dietary assessment in free-living populations
requires discovery of new biomarkers reflecting food intake qualitatively
and quantitatively to objectively evaluate effects of diet on health.
We provide a proof-of-principle for an analytical pipeline to identify
quantitative dietary biomarkers. Tartaric acid was identified by nuclear
magnetic resonance spectroscopy as a dose-responsive urinary biomarker
of grape intake and subsequently quantified in volunteers following
a series of 4-day dietary interventions incorporating 0 g/day, 50
g/day, 100 g/day, and 150 g/day of grapes in standardized diets from
a randomized controlled clinical trial. Most accurate quantitative
predictions of grape intake were obtained in 24 h urine samples which
have the strongest linear relationship between grape intake and tartaric
acid excretion (r<sup>2</sup> = 0.90). This new methodological pipeline
for estimating nutritional intake based on coupling dietary intake
information and quantified nutritional biomarkers was developed and
validated in a controlled dietary intervention study, showing that
this approach can improve the accuracy of estimating nutritional intakes
Molecular Aspects of Secretory Granule Exocytosis by Neurons and Endocrine Cells
Neuronal communication and endocrine signaling are fundamental for integrating
the function of tissues and cells in the body. Hormones released by endocrine
cells are transported to the target cells through the circulation. By contrast, transmitter
release from neurons occurs at specialized intercellular junctions, the synapses.
Nevertheless, the mechanisms by which signal molecules are synthesized,
stored, and eventually secreted by neurons and endocrine cells are very similar.
Neurons and endocrine cells have in common two different types of secretory
organelles, indicating the presence of two distinct secretory pathways. The synaptic
vesicles of neurons contain excitatory or inhibitory neurotransmitters, whereas the
secretory granules (also referred to as dense core vesicles, because of their electron
dense content) are filled with neuropeptides and amines. In endocrine cells, peptide
hormones and amines predominate in secretory granules. The function and content
of vesicles, which share antigens with synaptic vesicles, are unknown for most
endocrine cells. However, in B cells of the pancreatic islet, these vesicles contain
GABA, which may be involved in intrainsular signaling.'
Exocytosis of both synaptic vesicles and secretory granules is controlled by
cytoplasmic calcium. However, the precise mechanisms of the subsequent steps,
such as docking of vesicles and fusion of their membranes with the plasma membrane,
are still incompletely understood. This contribution summarizes recent observations
that elucidate components in neurons and endocrine cells involved in
exocytosis. Emphasis is put on the intracellular aspects of the release of secretory
granules that recently have been analyzed in detail
The Role of Rab3a in Secretory Vesicle Docking Requires Association/Dissociation of Guanidine Phosphates and Munc18-1
Rab3a is a small GTPase that binds selectively to secretory vesicles and switches between active, GTP-bound and inactive, GDP-bound conformations. In yeast, Rab and SM-genes interact genetically to promote vesicle targeting/fusion. We tested different Rab3a conformations and genetic interactions with the SM-gene munc18-1 on the docking function of Rab3a in mammalian chromaffin cells. We expressed Rab3a mutants locked in the GTP- or GDP-bound form in wild-type and munc18-1 null mutant cells and analyzed secretory vesicle distribution. We confirmed that wild-type Rab3a promotes vesicle docking in wild-type cells. Unexpectedly, both GTP- and GDP-locked Rab3a mutants did not promote docking. Furthermore, wild-type Rab3a did not promote docking in munc18-1 null cells and GTP- and GDP-Rab3a both decreased the amount of docked vesicles. The results show that GTP- and GDP-locked conformations do not support a Munc18-1 dependent role of Rab3a in docking. This suggests that nucleotide cycling is required to support docking and that this action of Rab3a is upstream of Munc18-1
Serum interferon alpha receptor 2 mRNA may predict efficacy of interferon alpha with/without low-dose sorafenib for metastatic clear cell renal cell carcinoma
TSG101, a tumor susceptibility gene, bidirectionally modulates cell invasion through regulating MMP-9 mRNA expression
Comparison between polyethylene glycol- and polyethylenimine-mediated transformation of Aspergillus nidulans
ArticleCURRENT GENETICS. 54(2):95-103(2008)journal articl
Different antibacterial actions of isoflavones isolated from Erythrina poeppigiana against methicillin-resistant Staphylococcus aureus
INHIBITORS OF CAMP PHOSPHODIESTERASE IN MEDICINAL-PLANTS .16. INHIBITION OF ADENOSINE 3',5'-CYCLIC-MONOPHOSPHATE PHOSPHODIESTERASE BY FLAVONOIDS .3.
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