56 research outputs found
Demographic characteristics, clinical information, and neuropsychological tests of three participating groups.
Demographic characteristics, clinical information, and neuropsychological tests of three participating groups.</p
Assessent of executive functions for SCZ, Unaffected siblings and HCS groups.
TC = the total number of correct responses; TE = the total number of error responses,PR = the number of persistent responses;PE = the number of persistent errors; TCFC = the number of trials to complete the first category;* Significant at P<0.017 ((α = 0.05/3)).</p
Correlation analysis between WCST and Clinical symptoms in patients with SCZ.
Correlation analysis between WCST and Clinical symptoms in patients with SCZ.</p
S1 Data -
IntroductionSchizophrenia (SCZ) is characterized by widespread cognitive impairments, such as executive functions. Most of the available research indicate that executive impairment has a certain genetic predisposition. Shared neuropathological characteristics of patients with SCZ and their siblings may reveal intermediate behavioral phenotypes that can be used to further characterize the illness.MethodsOur study involved 32 SCZ patients, 32 unaffected siblings (US), and 33 persons as healthy controls (HCS). These three groups underwent a computerized version of the Wisconsin Card Sorting Test (WCST), and a battery of cognitive neuropsychological assessments. These tests also evaluate executive function and several cognitive domains.ResultsThe performed study on SCZ patients and their unaffected siblings showed an inferior WCST performance to the HCS subjects, further indicating that unaffected siblings have a functional impairment, and they also performed poorly on the neuropsychological assessment compared with the HCS.ConclusionThis result supports the claim that the development of functional impairment is not limited to SCZ patients and unaffected siblings may also have a certain level of abnormal brain function. Consequently. neurological abnormalities lead to the abnormal functioning in siblings and patients, suggesting that genetics plays a considerable role in such results.</div
Flow chart.
IntroductionSchizophrenia (SCZ) is characterized by widespread cognitive impairments, such as executive functions. Most of the available research indicate that executive impairment has a certain genetic predisposition. Shared neuropathological characteristics of patients with SCZ and their siblings may reveal intermediate behavioral phenotypes that can be used to further characterize the illness.MethodsOur study involved 32 SCZ patients, 32 unaffected siblings (US), and 33 persons as healthy controls (HCS). These three groups underwent a computerized version of the Wisconsin Card Sorting Test (WCST), and a battery of cognitive neuropsychological assessments. These tests also evaluate executive function and several cognitive domains.ResultsThe performed study on SCZ patients and their unaffected siblings showed an inferior WCST performance to the HCS subjects, further indicating that unaffected siblings have a functional impairment, and they also performed poorly on the neuropsychological assessment compared with the HCS.ConclusionThis result supports the claim that the development of functional impairment is not limited to SCZ patients and unaffected siblings may also have a certain level of abnormal brain function. Consequently. neurological abnormalities lead to the abnormal functioning in siblings and patients, suggesting that genetics plays a considerable role in such results.</div
Correlation analysis between WCST and neuropsychological tests in patients and unaffected siblings.
Correlation analysis between WCST and neuropsychological tests in patients and unaffected siblings.</p
Quantification of microRNA by DNA–Peptide Probe and Liquid Chromatography–Tandem Mass Spectrometry-Based Quasi-Targeted Proteomics
The distorted and unique expression
of microRNAs (miRNAs) in cancer
makes them an attractive source of biomarkers. However, one of prerequisites
for the application of miRNAs in clinical practice is to accurately
profile their expression. Currently available assays normally require
pre-enrichment, amplification, and labeling steps, and most of them
are semiquantitative. In this study, we converted the signal of target
miR-21 into reporter peptide by a DNA-peptide probe and the reporter
peptide was ultimately quantified using LC-MS/MS-based targeted proteomics.
Specifically, substrate peptide GDKAVLGVDPFR containing reporter peptide
AVLGVDPFR and tryptic cleavage site (lysine at position 3) was first
designed, followed by the conjugation with DNA sequence that was complementary
to miR-21. The newly formed DNA-peptide probe was then hybridized
with miR-21, which was biotinylated and attached to streptavidin agarose
in advance. After trypsin digestion, the reporter peptide was released
and monitored by a targeted proteomics assay. The obtained limit of
quantification (LOQ) was 1 pM, and the detection dynamic range spanned
∼5 orders of magnitude. Using this assay, the developed quasi-targeted
proteomics approach was applied to determine miR-21 level in breast
cells and tissue samples. Finally, qRT-PCR was also performed for
a comparison. This report grafted the strategy of targeted proteomics
into miRNA quantification
Compositional Analysis of Asymmetric and Symmetric Dimethylated H3R2 Using Liquid Chromatography–Tandem Mass Spectrometry-Based Targeted Proteomics
Protein
arginine methylation is one of the common post-translational
modifications in cellular processes. To date, two isomeric forms of
dimethylated arginine have been identified: asymmetric <i>N</i><sup>G</sup>,<i>N</i><sup>G</sup>-dimethylarginine (aDMA),
and symmetric <i>N</i><sup>G</sup>,<i>N</i>′<sup>G</sup>-dimethylarginine (sDMA). Evidence indicated that these isomers
can coexist and have different or even opposite functions, with aDMA
and sDMA forms of arginine 2 on histone H3 (i.e., H3R2me2a and H3R2me2s)
being an example. Thus, specific detection and quantification of each
isomeric form is important. Current methods are capable of predicting
and detecting thousands of methylarginine sites in proteins, whereas
differentiation and stoichiometric measurement of dimethylated protein
isomers are still challenging. Liquid chromatography coupled with
tandem mass spectrometry (LC–MS/MS)-based targeted proteomics
has emerged as a promising technique for site-specific quantification
of protein methylation using enzymatic peptides as surrogates of target
proteins. However, it should be pointed out that a routine targeted
proteomics strategy cannot easily distinguish sDMA- and aDMA-containing
surrogate peptides due to their common nature. The estimated amount
should be considered as the sum of both arginine dimethylated isomers.
In this study, compositional analysis based on a linear algebra algorithm
as an add-on to targeted proteomics was employed to quantify H3R2me2a
and H3R2me2s (i.e., surrogate peptides of ARÂ(me2a)ÂTKÂ(me1/2)ÂQT and
ARÂ(me2s)ÂTKÂ(me1/2)ÂQT). To achieve this simultaneous quantification,
a targeted proteomics assay was developed and validated for each isomer
first. With the slope and intercept of their calibration curves for
each multiple reaction monitoring (MRM) transition, linear algebraic
equations were derived. Using a series of mock mixtures consisting
of isomers in varying concentrations, the reliability of the method
was confirmed. Finally, the H3R2 dimethylation status was analyzed
in normal MCF-10A cells, parental drug-sensitive MCF-7/WT cancer cells,
and drug-resistant MCF-7/ADR cancer cells. Dimethylated H3R2 was also
monitored in MCF-7/WT cells with the treatment of doxorubicin (DOX)
for confirmation
Additional file 2: of Genome-wide association study of eating and cooking qualities in different subpopulations of rice (Oryza sativa L.)
Table S2. The sources of the rice varieties used in this study. (DOC 32 kb
Acid-Sensitive Peptide-Conjugated Doxorubicin Mediates the Lysosomal Pathway of Apoptosis and Reverses Drug Resistance in Breast Cancer
The extended use of doxorubicin (DOX)
could be limited because
of the emergence of drug resistance associated with its treatment.
To reverse the drug resistance, two thiol-modified peptide sequences
HAIYPRHGGC and THRPPMWÂSPVWPGGC were, respectively, conjugated
to DOXO-EMCH, forming a maleimide bridge in this study (i.e., T10-DOX
and T15-DOX). The structures and properties of peptide–DOX
conjugates were characterized using <sup>1</sup>H NMR, <sup>13</sup>C NMR, mass spectrometry, and high-performance liquid chromatography.
Their stability was also evaluated. By using MCF-7/ADR cells as an <i>in vitro</i> model system and nude mice bearing MCF-7/ADR xenografts
as an <i>in vivo</i> model, the ability of these novel peptide–DOX
conjugates to reverse drug resistance was accessed as compared with
free DOX. As a result, the IC<sub>50</sub> values for T10-DOX and
T15-DOX significantly decreased (31.6 ± 1.6 μM and 27.2
± 0.8 μM), whereas the percentage of apoptotic cell population
increased (35.4% and 39.3%). The <i>in vivo</i> extent of
inhibition was more evident in the mice groups treated with peptide–DOX
conjugates (59.6 ± 8.99% and 46.4 ± 6.63%), which had DOX
primarily accumulated in tumor. These conjugates also showed a longer
half-life in plasma and cleared much more slowly from the body. Furthermore,
T10-DOX may be more effective than T15-DOX with a higher efficacy
and a lower side effect. Most importantly, evidence was provided to
support the enhanced intracellular drug accumulation and the induction
of lysosomal pathway of apoptosis underlying the drug resistance.
As an endosomal/lysosomal marker, cathepsin D permealized the destabilized
organelle membrane and was detected in the cytoplasm, leading to the
activation of the effector caspase-3 in cell apoptosis. This report
is among the first to demonstrate that peptide–DOX-like conjugates
promote apoptosis through the initiation of the lysosomal pathway
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