47 research outputs found
Y27, a novel derivative of 4-hydroxyquinoline-3-formamide, prevents the development of murine systemic lupus erythematosus-like diseases in MRL/lpr autoimmune mice and BDF1 hybrid mice
INTRODUCTION: Naturally occurring CD4(+)CD25(+ )regulatory T (Treg) cells are central to the maintenance of peripheral tolerance. Impaired activity and/or a lower frequency of these cells lead to systemic lupus erythematosus (SLE). Manipulating the number or activity of Treg cells is to be a promising strategy in treating it and other autoimmune diseases. We have examined the effects of Y27, a novel derivative of 4-hydroxyquinoline-3-formamide, on SLE-like symptoms in MRL/lpr autoimmune mice and BDF1 hybrid mice. Whether the beneficial effect of Y27 involves modulation of CD4(+)CD25(+ )Treg cells has also been investigated. METHODS: Female MRL/lpr mice that spontaneously develop lupus were treated orally by gavage with Y27 for 10 weeks, starting at 10 weeks of age. BDF1 mice developed a chronic graft-versus-host disease (GVHD) by two weekly intravenous injections of parental female DBA/2 splenic lymphocytes, characterized by immunocomplex-mediated glomerulonephritis resembling SLE. Y27 was administered to chronic GVHD mice for 12 weeks. Nephritic symptoms were monitored and the percentage of CD4(+)CD25(+)FoxP3(+ )Treg peripheral blood leukocyte was detected with mouse regulatory T cell staining kit by flowcytometry. Purified CD4(+)CD25(+ )Tregs were assessed for immune suppressive activity using the mixed lymphocyte reaction. RESULTS: The life-span of MRL/lpr mice treated with Y27 for 10 weeks was significantly prolonged, proteinuria and renal lesion severity were ameliorated, and blood urea nitrogen, triglyceride and serum anti-double-stranded DNA antibodies were decreased. Similar results were found in chronic GVHD mice. Administration of Y27 had little impact on percentage of the peripheral blood lymphocyte CD4(+)CD25(+)Foxp3(+ )Treg cells in both groups of mice. In contrast, the suppressive capacity of CD4(+)CD25(+ )Treg cells in splenocytes was markedly augmented in Y27-treated mice ex vivo. CONCLUSIONS: Experimental evidence of the protect effects of Y27 against autoimmune nephritis has been shown. The mechanism may involve enhancement of the suppressive capacity of CD4(+)CD25(+ )Treg cells
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MAPK-dependent hormonal signaling plasticity contributes to overcoming Bacillus thuringiensis toxin action in an insect host
The arms race between entomopathogenic bacteria and their insect hosts is an excellent model for decoding the intricate coevolutionary processes of host-pathogen interaction. Here, we demonstrate that the MAPK signaling pathway is a general switch to trans-regulate differential expression of aminopeptidase N and other midgut genes in an insect host, diamondback moth (Plutella xylostella), thereby countering the virulence effect of Bacillus thuringiensis (Bt) toxins. Moreover, the MAPK cascade is activated and fine-tuned by the crosstalk between two major insect hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH) to elicit an important physiological response (i.e. Bt resistance) without incurring the significant fitness costs often associated with pathogen resistance. Hormones are well known to orchestrate physiological trade-offs in a wide variety of organisms, and our work decodes a hitherto undescribed function of these classic hormones and suggests that hormonal signaling plasticity is a general cross-kingdom strategy to fend off pathogens
CloudBrain-MRS: An Intelligent Cloud Computing Platform for in vivo Magnetic Resonance Spectroscopy Preprocessing, Quantification, and Analysis
Magnetic resonance spectroscopy (MRS) is an important clinical imaging method
for diagnosis of diseases. MRS spectrum is used to observe the signal intensity
of metabolites or further infer their concentrations. Although the magnetic
resonance vendors commonly provide basic functions of spectra plots and
metabolite quantification, the widespread clinical research of MRS is still
limited due to the lack of easy-to-use processing software or platform. To
address this issue, we have developed CloudBrain-MRS, a cloud-based online
platform that provides powerful hardware and advanced algorithms. The platform
can be accessed simply through a web browser, without the need of any program
installation on the user side. CloudBrain-MRS also integrates the classic
LCModel and advanced artificial intelligence algorithms and supports batch
preprocessing, quantification, and analysis of MRS data from different vendors.
Additionally, the platform offers useful functions: 1) Automatically
statistical analysis to find biomarkers for diseases; 2) Consistency
verification between the classic and artificial intelligence quantification
algorithms; 3) Colorful three-dimensional visualization for easy observation of
individual metabolite spectrum. Last, both healthy and mild cognitive
impairment patient data are used to demonstrate the functions of the platform.
To the best of our knowledge, this is the first cloud computing platform for in
vivo MRS with artificial intelligence processing. We have shared our cloud
platform at MRSHub, providing free access and service for two years. Please
visit https://mrshub.org/software_all/#CloudBrain-MRS or
https://csrc.xmu.edu.cn/CloudBrain.html.Comment: 11 pages, 12 figure
Metabolomic profiles of bovine mammary epithelial cells stimulated by lipopolysaccharide
Bovine mammary epithelial cells (bMECs) are the main cells of the dairy cow mammary gland. In addition to their role in milk production, they are effector cells of mammary immunity. However, there is little information about changes in metabolites of bMECs when stimulated by lipopolysaccharide (LPS). This study describes a metabolomics analysis of the LPS-stimulated bMECs to provide a basis for the identification of potential diagnostic screening biomarkers and possible treatments for bovine mammary gland inflammation. In the present study, bMECs were challenged with 500 ng/mL LPS and samples were taken at 0 h, 12 h and 24 h post stimulation. Metabolic changes were investigated using high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF MS) with univariate and multivariate statistical analyses. Clustering and metabolic pathway changes were established by MetaboAnalyst. Sixty-three differential metabolites were identified, including glycerophosphocholine, glycerol-3-phosphate, L-carnitine, L-aspartate, glutathione, prostaglandin G2, α-linolenic acid and linoleic acid. They were mainly involved in eight pathways, including D-glutamine and D-glutamic acid metabolism; linoleic acid metabolism; α-linolenic metabolism; and phospholipid metabolism. The results suggest that bMECs are able to regulate pro-inflammatory, anti-inflammatory, antioxidation and energy-producing related metabolites through lipid, antioxidation and energy metabolism in response to inflammatory stimuli
One for Multiple: Physics-informed Synthetic Data Boosts Generalizable Deep Learning for Fast MRI Reconstruction
Magnetic resonance imaging (MRI) is a principal radiological modality that
provides radiation-free, abundant, and diverse information about the whole
human body for medical diagnosis, but suffers from prolonged scan time. The
scan time can be significantly reduced through k-space undersampling but the
introduced artifacts need to be removed in image reconstruction. Although deep
learning (DL) has emerged as a powerful tool for image reconstruction in fast
MRI, its potential in multiple imaging scenarios remains largely untapped. This
is because not only collecting large-scale and diverse realistic training data
is generally costly and privacy-restricted, but also existing DL methods are
hard to handle the practically inevitable mismatch between training and target
data. Here, we present a Physics-Informed Synthetic data learning framework for
Fast MRI, called PISF, which is the first to enable generalizable DL for
multi-scenario MRI reconstruction using solely one trained model. For a 2D
image, the reconstruction is separated into many 1D basic problems and starts
with the 1D data synthesis, to facilitate generalization. We demonstrate that
training DL models on synthetic data, integrated with enhanced learning
techniques, can achieve comparable or even better in vivo MRI reconstruction
compared to models trained on a matched realistic dataset, reducing the demand
for real-world MRI data by up to 96%. Moreover, our PISF shows impressive
generalizability in multi-vendor multi-center imaging. Its excellent
adaptability to patients has been verified through 10 experienced doctors'
evaluations. PISF provides a feasible and cost-effective way to markedly boost
the widespread usage of DL in various fast MRI applications, while freeing from
the intractable ethical and practical considerations of in vivo human data
acquisitions.Comment: 22 pages, 9 figures, 1 tabl
MAPK-activated transcription factor PxJun suppresses PxABCB1 expression and confers resistance to Bacillus thuringiensis Cry1Ac toxin in Plutella xylostella (L.)
Deciphering the molecular mechanisms underlying insect resistance to Cry toxins produced by Bacillus thuringiensis (Bt) is pivotal for the sustainable utilization of Bt biopesticides and transgenic Bt crops. Previously, we identified that MAPK-mediated reduced expression of the PxABCB1 gene is associated with Bt Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.). However, the underlying transcriptional regulation mechanism remains enigmatic. Herein, the PxABCB1 promoter in Cry1Ac-susceptible and Cry1Ac-resistant P. xylostella strains was cloned and analyzed and found to contain a putative Jun binding site (JBS). A dual-luciferase reporter assay and yeast one-hybrid assay (Y1H) demonstrated that the transcription factor PxJun repressed PxABCB1 expression by interacting with this JBS. The expression levels of PxJun were increased in the midguts of all resistant strains compared to the susceptible strain. Silencing of PxJun expression significantly elevated PxABCB1 expression and Cry1Ac susceptibility in the resistant NIL-R strain, and silencing of PxMAP4K4 expression decreased PxJun expression and also increased PxABCB1 expression. These results indicate that MAPK-activated PxJun suppresses PxABCB1 expression to confer Cry1Ac resistance in P. xylostella, deepening our understanding of the transcriptional regulation of midgut Cry receptor genes and the molecular basis of insect resistance to Bt Cry toxins.ImportanceThe transcriptional regulation mechanisms underlying reduced expression of Bt toxin receptor genes in Bt-resistant insects remain elusive. This study unveils that a transcription factor PxJun activated by the MAPK signaling pathway represses PxABCB1 expression and confers Cry1Ac resistance in P. xylostella Our results provide new insights into the transcriptional regulation mechanisms of midgut Cry receptor genes and deepen our understanding of the molecular basis of insect resistance to Bt Cry toxins. To our knowledge, this study identified the first transcription factor that can be involved in the transcriptional regulation mechanisms of midgut Cry receptor genes in Bt-resistant insects
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data