133 research outputs found
Association of Toll-Like Receptor 4 Gene Polymorphism and Expression with Urinary Tract Infection Types in Adults
Background: Innate immunity of which Toll-like receptor (TLR) 4 and CXCR1 are key elements plays a central role in the development of urinary tract infection (UTI). Although the relation between the genetics of TLR4 and CXCR1 and UTI is investigated partly, the polymorphisms and expression of TLR4 and CXCR1 in different types of UTI in adults are not extremely clear. Methodology/Principal Findings: This study investigates the presence of TLR4 A (896) G and CXCR1 G (2608) C polymorphisms in 129 UTI patients using RFLP-PCR. Gene and allelic prevalence were compared with 248 healthy controls. Flow cytometry was used to detect TLR4 and CXCR1 expression in the monocytes of UTI patients and healthy controls. TLR4 (896) AG genotype and TLR4 (896) G allele had higher prevalence in UTI (especially in acute cystitis and urethritis) patients, whereas CXCR1 (2608) GC genotype and CXCR1 (2608) C allele had lower prevalence in UTI patients than controls. TLR4 expression was significantly lower in chronic UTI patients than in acute pyelonephritis or healthy controls. CXCR1 expression was similar in both controls and patients. TLR4 expression in chronic UTI patients after astragalus treatment was higher than pre-treatment. Conclusions: The results indicate the relationship between the carrier status of TLR4 (896) G alleles and the development of UTI, especially acute cystitis and urethritis, in adults. TLR4 expression levels are correlated with chronic UTI
Effects of PRPS1 I72 mutations on drug resistance in acute lymphoblastic leukemia and its mechanisms
Objective·To study whether mutations at the I72 site of phosphoribosyl pyrophosphate synthetase 1 (PRPS1) can induce resistance in acute lymphoblastic leukemia (ALL) cells to thiopurine chemotherapy drugs 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG), and explain their mechanisms of action.Methods·The PRPS1 gene mutations (I72F, R177S and V316L) found in clinical practice and PRPS1 gene mutations (V208A and V289A) present in two ALL cell lines (KOPN72bi and RS4;11) were constructed into the vector pGV303 fused with green fluorescent protein (GFP), respectively. The PRPS1 A190T mutation that has been proven to be resistant to thiopurine chemotherapy drugs was used as the positive control, and the empty vector pGV303 (Vector), PRPS1 wild-type (WT) and PRPS1 I72V were used as the negative controls. The various mutants of PRPS1 were transiently transfected into HEK-293T cells (referred to as 293T cells), and the expression of these exogenous PRPS1 was detected by Western blotting. The half maximal inhibitory concentration (IC50) of 6-MP or 6-TG on the above 293T cell lines transiently transfected with PRPS1 mutants was detected and calculated by drug sensitivity experiments. Subsequently, in addition to PRPS1 I72F and I72V, multiple mutations I72M, I72L, I72N, I72S and I72T were constructed into the vector pGV303, respectively, by changing the isoleucine (I) at position 72 into other amino acids. The various mutants were transiently transfected into 293T cells, respectively, and the protein expression of each mutant and IC50 values of 6-MP or 6-TG were detected by Western blotting and drug sensitivity experiments. PRPS1 WT, I72F, I72V, A190T and pGV303 vectors were transfected into REH cell lines by lentivirus infection, and GFP-positive cells were sorted by flow cytometry to obtain cells with stable expression of PRPS1 mutants. The protein expression of each mutant in REH cells and IC50 values of 6-MP or 6-TG were detected by Western blotting and drug sensitivity experiments to verify the results of drug sensitivity experiments obtained by 293T cells. Annexin V/DAPI double staining was used to evaluate the apoptosis of each REH cell line, and Western blotting was used to detect the levels of DNA damage-related proteins [phosphorylation at S139 of histone H2AX (phosphorylated H2AX-S139, γ-H2AX), phosphorylated check point kinase 2 (pCHK2)], and apoptosis-related protein cleaved poly (ADP-ribose) polymerase (cleaved PARP) in each REH cell line. The diagrams of amino acid residues and spatial conformations of I72 locus, I72V and I72F were predicted and drawn through three-dimensional imaging and PyMOL software by using the crystal structure data of PRPS1-numbered 2HCR (PDB code 2HCR) in the PDB (Protein Data Bank) database.Results·Western blotting results showed that the transiently transfected exogenous PRPS1-mutated proteins were successfully expressed in 293T cells. The drug sensitivity experiment results showed that the IC50 values of 6-MP or 6-TG in 293T cells expressing PRPS1 I72F, R177S, V316L, V208A and the positive control A190T were much higher than those in cells expressing V289A and the negative control Vector, PRPS1 WT and I72V (all P =0.000). After mutating the isoleucine (I) at position 72 with other amino acids, Western blotting results showed successful expression of exogenous PRPS1-mutated proteins at position I72 after transient transfection in 293T cells. Drug sensitivity experiments revealed the IC50 values of 6-MP or 6-TG in 293T cells expressing PRPS1 I72M, I72F, I72L, I72N, I72S, I72T and positive control A190T were much higher than those in cells expressing negative control Vector, PRPS1 WT and I72V (all P=0.000). Western blotting results showed that the protein expression levels of PRPS1 WT, A190T, I72F and I72V in the REH stable cell lines constructed by lentivirus were high and similar. The drug sensitivity experiment results showed that the IC50 values of 6-MP or 6-TG in REH cells expressing PRPS1 I72F and positive control A190T were much higher than those in cells expressing negative control Vector, PRPS1 WT and I72V (all P=0.000), which was consistent with the drug sensitivity results obtained by transient transfection in 293T cells. The results of Annexin V/DAPI double staining method and the detection of DNA damage and apoptosis-related proteins by Western blotting showed that after 6-MP treatment, the DNA damage and apoptosis rates of REH cell lines expressing PRPS1 A190T and I72F were significantly lower than those of cells expressing negative control Vector, PRPS1 WT and I72V (all P=0.000). The protein structure analysis results showed that PRPS1 I72F could change the conformation of PRPS1.Conclusion·The PRPS1 I72F, R177S, V316L, V208A, I72M, I72L, I72N, I72S and I72T mutations can confer drug resistance to the thiopurine chemotherapy drugs in cells, while the PRPS1 V289A and I72V mutations do not affect cell sensitivity to the thiopurine chemotherapy drugs. The drug sensitivity experiment results in 293T cells are consistent with those in REH cells, demonstrating that 293T cells can serve as a rapid research model for detecting the resistance of PRPS1 mutations to thiopurine chemotherapy drugs. The effects of the PRPS1 I72 mutations on the resistance of the thiopurine chemotherapy drugs may be related to changes in the structure of PRPS1
Effects of treatment with Astragalus Membranaceus on function of rat leydig cells
Background
Astragalus membranaceus (AM) is a Chinese traditional herb which has been reported to have broad positive effects on many diseases, including hepatitis, heart disease, diabetes and skin disease. AM can promote cell proliferation, increase the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and inhibit apoptosis by regulating the transcription of proto-oncogenes controlling cell death. While AM is included in some commercially available “testosterone boosting supplements”, studies directly testing ability of AM to modulate testosterone production are lacking. In the present study, we examined the effects of AM on Leydig cell function in vitro. Methods
Rat Leydig cells were purified and treated with AM at different concentrations (0 ÎĽg/mL, 10 ÎĽg/mL, 20 ÎĽg/mL, 50 ÎĽg/mL, 100 ÎĽg/mL and 150 ÎĽg/mL) and cell counting-8 (CCK-8) assay, Enzyme-linked immunosorbent assay, quantitative real time PCR and analysis of activities of SOD and GPx were done respectively. Results
Treatment with 100 μg/mL (P \u3c 0.05) and 150 μg/mL AM (P \u3c 0.01) significantly increased Leydig cell numbers. Treatment with AM (20 μg/mL, 50 μg/mL and 100 μg/mL) significantly increased testosterone production (P \u3c 0.01). In addition, increased Leydig cell SOD and GPx activities were observed in response to 20 μg/mL and 50 μg/mL AM treatment (P \u3c 0.01). Furthermore, expression of Bax mRNA was significantly decreased (P \u3c 0.01), and the ratio of Bcl-2/Bax mRNA was significantly increased in response to 20 μg/mL AM in the culture medium (P \u3c 0.05). Conclusions
Results supported a beneficial effect of AM on multiple aspects of rat Leydig cell function in vitro including testosterone production
Biomimetic three-dimensional glioma model printed in vitro for the studies of glioma cells and neurons interactions
The interactions between glioma cells and neurons are important for glioma
progression but are rarely mimicked and recapitulated in in vitro three-dimensional
(3D) models, which may affect the success rate of relevant drug research and
development. In this study, an in vitro bioprinted 3D glioma model consisting of
an outer hemispherical shell with neurons and an inner hemisphere with glioma
cells is proposed to simulate the natural glioma. This model was produced by
extrusion-based 3D bioprinting technology. The cells survival rate, morphology, and
intercellular Ca2+ concentration studies were carried out up to 5 days of culturing.
It was found that neurons could promote the proliferation of glioma cells around
them, associate the morphological changes of glioma cells to be neuron-like, and
increase the expression of intracellular Ca2+ of glioma cells. Conversely, the presence
of glioma cells could maintain the neuronal survival rate and promote the neurite
outgrowth. The results indicated that glioma cells and neurons facilitated each other
implying a symbiotic pattern established between two types of cells during the early
stage of glioma development, which were seldom found in the present artificial
glioma models. The proposed bioprinted glioma model can mimic the natural
microenvironment of glioma tissue, provide an in-depth understanding of cellâ cell
interactions, and enable pathological and pharmacological studies of glioma.The work was supported by the Program of the National Natural Science Foundation of China [52275291],
[51675411], [81972359], the Fundamental Research Funds for the Central Universities, and the Youth Innovation
Team of Shaanxi Universities
Ultrafast manipulation of topologically enhanced surface transport driven by mid-infrared and terahertz pulses in Bi2Se3
Topology-protected surface transport of ultimate thinness in three-dimensional topological insulators (TIs) is breaking new ground in quantum science and technology. Yet a challenge remains on how to disentangle and selectively control surface helical spin transport from the bulk contribution. Here we use the mid-infrared and terahertz (THz) photoexcitation of exclusive intraband transitions to enable ultrafast manipulation of surface THz conductivity in Bi2Se3. The unique, transient electronic state is characterized by frequency-dependent carrier relaxations that directly distinguish the faster surface channel than the bulk with no complication from interband excitations or need for reduced bulk doping. We determine the topological enhancement ratio between bulk and surface scattering rates, i.e., γBS/γSS ~3.80 in equilibrium. The ultra-broadband, wavelength-selective pumping may be applied to emerging topological semimetals for separation and control of the protected transport connected with the Weyl nodes from other bulk bands
Light control of surface–bulk coupling by terahertz vibrational coherence in a topological insulator
The demand for disorder-tolerant quantum logic and spin electronics can be met by generating and controlling dissipationless spin currents protected by topology. Dirac fermions with helical spin-locking surface transport offer a way of achieving such a goal. Yet, surface-bulk coupling can lead to strong Dirac electron scattering with bulk carriers and phonons as well as impurities, assisted by such dissipative channel, which results in “topological breakdown”. Here, we demonstrate that coherent lattice vibrations periodically driven by a single-cycle terahertz (THz) pulse can significantly suppress such dissipative channel in topological insulators. This is achieved by reducing the phase space in the bulk available for Dirac fermion scattering into during coherent lattice oscillations in Bi2Se3. This light-induced suppression manifests as a remarkable transition exclusively in surface transport, absent for bulk, above the THz electric fields for driving coherent phonons, which prolongs the surface transport lifetime. These results, together with simulations, identify the critical role of spin–orbit coupling for the “phase space contraction” mechanism that suppresses the surface-bulk coupling. Imposing vibrational quantum coherence into topological states of matter may become a universal light control principle for reinforcing the symmetry-protected helical transport
Ultrafast nonthermal terahertz electrodynamics and possible quantum energy transfer in the Nb3Sn superconductor
We report terahertz (THz) electrodynamics of a moderately clean A15 superconductor (SC) following ultrafast excitation to manipulate quasiparticle (QP) transport. In the Martensitic normal state, we observe a photo enhancement in the THz conductivity using optical pulses, while the opposite is observed for the THz pump. This demonstrates wavelength-selective nonthermal control of conductivity distinct from sample heating. The photo enhancement persists up to an additional critical temperature, above the SC one, from a competing electronic order. In the SC state, the fluence dependence of pair-breaking kinetics together with an analytic model provides an implication for a “one photon to one Cooper pair” nonresonant energy transfer during the 35-fs laser pulse; i.e., the fitted photon energy ℏω absorption to create QPs set by 2ΔSC/ℏω=0.33%. This is more than one order of magnitude smaller than in previously studied BCS SCs, which we attribute to strong electron-phonon coupling and possible influence of phonon condensation
A Missense Mutation in PPARD Causes a Major QTL Effect on Ear Size in Pigs
Chinese Erhualian is the most prolific pig breed in the world. The breed exhibits exceptionally large and floppy ears. To identify genes underlying this typical feature, we previously performed a genome scan in a large scale White Duroc × Erhualian cross and mapped a major QTL for ear size to a 2-cM region on chromosome 7. We herein performed an identical-by-descent analysis that defined the QTL within a 750-kb region. Historically, the large-ear feature has been selected for the ancient sacrificial culture in Erhualian pigs. By using a selective sweep analysis, we then refined the critical region to a 630-kb interval containing 9 annotated genes. Four of the 9 genes are expressed in ear tissues of piglets. Of the 4 genes, PPARD stood out as the strongest candidate gene for its established role in skin homeostasis, cartilage development, and fat metabolism. No differential expression of PPARD was found in ear tissues at different growth stages between large-eared Erhualian and small-eared Duroc pigs. We further screened coding sequence variants in the PPARD gene and identified only one missense mutation (G32E) in a conserved functionally important domain. The protein-altering mutation showed perfect concordance (100%) with the QTL genotypes of all 19 founder animals segregating in the White Duroc × Erhualian cross and occurred at high frequencies exclusively in Chinese large-eared breeds. Moreover, the mutation is of functional significance; it mediates down-regulation of β-catenin and its target gene expression that is crucial for fat deposition in skin. Furthermore, the mutation was significantly associated with ear size across the experimental cross and diverse outbred populations. A worldwide survey of haplotype diversity revealed that the mutation event is of Chinese origin, likely after domestication. Taken together, we provide evidence that PPARD G32E is the variation underlying this major QTL
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
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