200 research outputs found
The alpha 7 nicotinic receptor agonist PHA-543613 hydrochloride inhibits <i>Porphyromonas gingivalis</i>-induced expression of interleukin-8 by oral keratinocytes
Objective:
The alpha 7 nicotinic receptor (α7nAChR) is expressed by oral keratinocytes. α7nAChR activation mediates anti-inflammatory responses. The objective of this study was to determine if α7nAChR activation inhibited pathogen-induced interleukin-8 (IL-8) expression by oral keratinocytes.<p></p>
Materials and methods:
Periodontal tissue expression of α7nAChR was determined by real-time PCR. OKF6/TERT-2 oral keratinocytes were exposed to <i>Porphyromonas gingivalis</i> in the presence and absence of a α7nAChR agonist (PHA-543613 hydrochloride) alone or after pre-exposure to a specific α7nAChR antagonist (α-bungarotoxin). Interleukin-8 (IL-8) expression was measured by ELISA and real-time PCR. Phosphorylation of the NF-κB p65 subunit was determined using an NF-κB p65 profiler assay and STAT-3 activation by STAT-3 in-cell ELISA. The release of ACh from oral keratinocytes in response to <i>P. gingivalis</i> lipopolysaccharide was determined using a GeneBLAzer M3 CHO-K1-blacell reporter assay.<p></p>
Results:
Expression of α7nAChR mRNA was elevated in diseased periodontal tissue. PHA-543613 hydrochloride inhibited <i>P. Gingivalis</i>-induced expression of IL-8 at the transcriptional level. This effect was abolished when cells were pre-exposed to a specific α7nAChR antagonist, α-bungarotoxin. PHA-543613 hydrochloride downregulated NF-κB signalling through reduced phosphorylation of the NF-κB p65-subunit. In addition, PHA-543613 hydrochloride promoted STAT-3 signalling by maintenance of phosphorylation. Furthermore, oral keratinocytes upregulated ACh release in response to <i>P. Gingivalis</i> lipopolysaccharide.<p></p>
Conclusion:
These data suggest that α7nAChR plays a role in regulating the innate immune responses of oral keratinocytes.<p></p>
RNA localization in neurite morphogenesis and synaptic regulation: current evidence and novel approaches
It is now generally accepted that RNA localization in the central nervous system conveys important roles both during development and in the adult brain. Of special interest is protein synthesis located at the synapse, as this potentially confers selective synaptic modification and has been implicated in the establishment of memories. However, the underlying molecular events are largely unknown. In this review, we will first discuss novel findings that highlight the role of RNA localization in neurons. We will focus on the role of RNA localization in neurotrophin signaling, axon outgrowth, dendrite and dendritic spine morphogenesis as well as in synaptic plasticity. Second, we will briefly present recent work on the role of microRNAs in translational control in dendrites and its implications for learning and memory. Finally, we discuss recent approaches to visualize RNAs in living cells and their employment for studying RNA trafficking in neurons
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
Observation of B(s)0→J/ψpp¯ decays and precision measurements of the B(s)0 masses
The first observation of the decays
B
0
(
s
)
→
J
/
ψ
p
¯
p
is reported, using proton-proton collision data corresponding to an integrated luminosity of
5.2
fb
−
1
, collected with the LHCb detector. These decays are suppressed due to limited available phase space, as well as due to Okubo-Zweig-Iizuka or Cabibbo suppression. The measured branching fractions are
B
(
B
0
→
J
/
ψ
p
¯
p
)
=
[
4.51
±
0.40
(
stat
)
±
0.44
(
syst
)
]
×
10
−
7
,
B
(
B
0
s
→
J
/
ψ
p
¯
p
)
=
[
3.58
±
0.19
(
stat
)
±
0.39
(
syst
)
]
×
10
−
6
. For the
B
0
s
meson, the result is much higher than the expected value of
O
(
10
−
9
)
. The small available phase space in these decays also allows for the most precise single measurement of both the
B
0
mass as
5279.74
±
0.30
(
stat
)
±
0.10
(
syst
)
MeV
and the
B
0
s
mass as
5366.85
±
0.19
(
stat
)
±
0.13
(
syst
)
MeV
Test of lepton universality in decays
The first simultaneous test of muon-electron universality using
and decays is performed, in two ranges of the dilepton
invariant-mass squared, . The analysis uses beauty mesons produced in
proton-proton collisions collected with the LHCb detector between 2011 and
2018, corresponding to an integrated luminosity of 9 . Each
of the four lepton universality measurements reported is either the first in
the given interval or supersedes previous LHCb measurements. The
results are compatible with the predictions of the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-046.html (LHCb
public pages
Precision measurement of violation in the penguin-mediated decay
A flavor-tagged time-dependent angular analysis of the decay
is performed using collision data collected
by the LHCb experiment at % at TeV, the center-of-mass energy of
13 TeV, corresponding to an integrated luminosity of 6 fb^{-1}. The
-violating phase and direct -violation parameter are measured
to be rad and
, respectively, assuming the same values
for all polarization states of the system. In these results, the
first uncertainties are statistical and the second systematic. These parameters
are also determined separately for each polarization state, showing no evidence
for polarization dependence. The results are combined with previous LHCb
measurements using collisions at center-of-mass energies of 7 and 8 TeV,
yielding rad and . This is the most precise study of time-dependent violation
in a penguin-dominated meson decay. The results are consistent with
symmetry and with the Standard Model predictions.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-001.html (LHCb
public pages
Observation of Two New Excited Ξb0 States Decaying to Λb0 K-π+
Two narrow resonant states are observed in the Λb0K-π+ mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6 fb-1. The minimal quark content of the Λb0K-π+ system indicates that these are excited Ξb0 baryons. The masses of the Ξb(6327)0 and Ξb(6333)0 states are m[Ξb(6327)0]=6327.28-0.21+0.23±0.12±0.24 and m[Ξb(6333)0]=6332.69-0.18+0.17±0.03±0.22 MeV, respectively, with a mass splitting of Δm=5.41-0.27+0.26±0.12 MeV, where the uncertainties are statistical, systematic, and due to the Λb0 mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξb(6327)0]<2.20(2.56) and Γ[Ξb(6333)0]<1.60(1.92) MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξb0 resonances
First observation of a doubly charged tetraquark and its neutral partner
A combined amplitude analysis is performed for the decays and , which are
related by isospin symmetry. The analysis is based on data collected by the
LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8
and 13. The full data sample corresponds to an integrated
luminosity of 9. Two new resonant states with masses of
and widths of
are observed, which decay to and
respectively. The former state indicates the first observation of
a doubly charged open-charm tetraquark state with minimal quark content
, and the latter state is a neutral tetraquark composed of
quarks. Both states are found to have spin-parity ,
and their resonant parameters are consistent with each other, which suggests
that they belong to an isospin triplet.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-026.html (LHCb
public pages
Observation of a resonant structure near the threshold in the decay
An amplitude analysis of the decay is carried out to
study for the first time its intermediate resonant contributions, using
proton-proton collision data collected with the LHCb detector at centre-of-mass
energies of 7, 8 and 13 TeV. A near-threshold peaking structure, referred to as
, is observed in the invariant-mass spectrum with
significance greater than 12 standard deviations. The mass, width and the
quantum numbers of the structure are measured to be MeV,
MeV and , respectively, where the first
uncertainties are statistical and the second systematic. The properties of the
new structure are consistent with recent theoretical predictions for a state
composed of quarks. Evidence for an additional structure is
found around 4140 MeV in the invariant mass, which might be
caused either by a new resonance with the assignment or by a coupled-channel effect.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-018.html (LHCb
public pages
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