734 research outputs found

    TRPV4, TRPC1, and TRPP2 assemble to form a flow-sensitive heteromeric channel

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    Transient receptor potential (TRP) channels, a superfamily of ion channels, can be divided into 7 subfamilies, including TRPV, TRPC, TRPP, and 4 others. Functional TRP channels are tetrameric complexes consisting of 4 pore-forming subunits. The purpose of this study was to explore the heteromerization of TRP subunits crossing different TRP subfamilies. Two-step coimmunoprecipitation (co-IP) and fluorescence resonance energy transfer (FRET) were used to determine the interaction of the different TRP subunits. Patch-clamp and cytosolic Ca2+ measurements were used to determine the functional role of the ion channels in flow conditions. The analysis demonstrated the formation of a heteromeric TRPV4-C1-P2 complex in primary cultured rat mesenteric artery endothelial cells (MAECs) and HEK293 cells that were cotransfected with TRPV4, TRPC1, and TRPP2. In functional experiments, pore-dead mutants for each of these 3 TRP isoforms nearly abolished the flow-induced cation currents and Ca2+ increase, suggesting that all 3 TRPs contribute to the ion permeation pore of the channels. We identified the first heteromeric TRP channels composed of subunits from 3 different TRP subfamilies. Functionally, this heteromeric TRPV4- C1-P2 channel mediates the flow-induced Ca2+ increase in native vascular endothelial cells.-Du, J., Ma, X., Shen, B., Huang, Y., Birnbaumer, L., Yao, X. TRPV4, TRPC1, and TRPP2 assemble to form a flowsensitive heteromeric channel.Fil: Du, Juan. Chinese University Of Hong Kong; Hong Kong. Anhui Medical University; ChinaFil: Ma, Xin. Chinese University Of Hong Kong; Hong KongFil: Shen, Bing. Chinese University Of Hong Kong; Hong Kong. Anhui Medical University; ChinaFil: Huang, Yu. Chinese University Of Hong Kong; Hong KongFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. National Institutes of Health; Estados UnidosFil: Yao, Xiaoqiang. Chinese University Of Hong Kong; Hong Kon

    Apoptosis of Endothelial Cells Contributes to Brain Vessel Pruning of Zebrafish During Development

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    During development, immature blood vessel networks remodel to form a simplified and efficient vasculature to meet the demand for oxygen and nutrients, and this remodeling process is mainly achieved via the pruning of existing vessels. It has already known that the migration of vascular endothelial cells (ECs) is one of the mechanisms underlying vessel pruning. However, the role of EC apoptosis in vessel pruning remains under debate, especially in the brain. Here, we reported that EC apoptosis makes a significant contribution to vessel pruning in the brain of larval zebrafish. Using in vivo long-term time-lapse confocal imaging of the brain vasculature in zebrafish larvae, we found that EC apoptosis was always accompanied with brain vessel pruning and about 15% of vessel pruning events were resulted from EC apoptosis. In comparison with brain vessels undergoing EC migration-associated pruning, EC apoptosis-accompanied pruned vessels were longer and showed higher probability that the nuclei of neighboring vessels’ ECs occupied their both ends. Furthermore, we found that microglia were responsible for the clearance of apoptotic ECs accompanying vessel pruning, though microglia themselves were dispensable for the occurrence of vessel pruning. Thus, our study demonstrates that EC apoptosis contributes to vessel pruning in the brain during development in a microglial cell-independent manner

    Do we really need temporal convolutions in action segmentation?

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    Action classification has made great progress, but segmenting and recognizing actions from long untrimmed videos remains a challenging problem. Most state-of-the-art methods focus on designing temporal convolution-based models, but the inflexibility of temporal convolutions and the difficulties in modeling long-term temporal dependencies restrict the potential of these models. Transformer-based models with adaptable and sequence modeling capabilities have recently been used in various tasks. However, the lack of inductive bias and the inefficiency of handling long video sequences limit the application of Transformer in action segmentation. In this paper, we design a pure Transformer-based model without temporal convolutions by incorporating temporal sampling, called Temporal U-Transformer (TUT). The U-Transformer architecture reduces complexity while introducing an inductive bias that adjacent frames are more likely to belong to the same class, but the introduction of coarse resolutions results in the misclassification of boundaries. We observe that the similarity distribution between a boundary frame and its neighboring frames depends on whether the boundary frame is the start or end of an action segment. Therefore, we further propose a boundary-aware loss based on the distribution of similarity scores between frames from attention modules to enhance the ability to recognize boundaries. Extensive experiments show the effectiveness of our model

    Effects of levothyroxine therapy on bone mineral density and bone turnover markers in premenopausal women with thyroid cancer after thyroidectomy

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    Introduction: We investigated the impact of long-term levothyroxine (LT4) treatment on bone mineral density (BMD) and bone turnover markers (BTMs) in premenopausal women with differentiated thyroid cancer (DTC) after thyroidectomy. Material and methods: Sixty-five premenopausal women who received LT4 therapy at least one year (range, 1.5–9.0 years) after thyroidectomy for DTC and 50 premenopausal women without thyroid diseases were enrolled in this study. We measured the Z-scores of lumbar and hip BMD, serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), intact parathyroid hormone (iPTH), N-terminal propeptide of type 1 N procollagen (P1NP), C terminal telopeptide of type 1 collagen (CTX-1), calcium (Ca), phosphorus (P), vitamin D3, and alkaline phosphatase (ALP) in all participants. Results: In DTC subjects, serum TSH levels were lower, and serum FT4, P1NP, CTX-1, and ALP levels were higher compared with controls. The prevalence of low BMD was higher in DTC subjects than in controls. Multivariate logistic regression analysis showed that serum TSH levels were negatively associated with CTX-1 and ALP. Conclusions: We found a high prevalence of low BMD among premenopausal women who received long-term LT4 therapy for DTC after thyroidectomy. Long-term TSH suppression therapy was a significant risk factor for decreased bone strength, mainly by increasing bone turnover.

    Synergistic anti-atherosclerotic effect of Yerba Maté (Illex Paraguariensis) polyphenols and Lox-1 silencing in foam cell model

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    Purpose: To elucidate the anti-atherosclerotic effect of Yerba Mate polyphenols (MP) as well as the anti-atherosclerotic effect of a combination of MP and silencing of lectin-like oxidized low-density lipoprotein receptor-1 interference group (LOX)-1.Methods: The anti-atherosclerotic effects of control group (CG), simvastatin group (SG), MP group (MP), LOX-1 interference group (LOX) and MP + LOX-1 interference group (MP-LOX) were determined using Oil Red O staining, enzyme-linked immunosorbent assay (ELISA) and Western blot assay.Results: The levels of foam cells, intracellular lipids, viz, total cholesterol (TC), free cholesterol (FC), cholesterol ester (CE) and acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1); LOX-1, inflammation (TNF-alpha, IL-6 and pNF-κB/NF-κB); adhesion molecular status (ICAM-1 and VCAM-1), and monocyte chemotactic protein-1 in SG and in MP, LOX and MP-LOX groups were significantly decreased, when compared with CG (p < 0.01). The levels of these parameters were much lower in MPLOX group than in SG (p < 0.01). However, they were synergistically reduced in MP-LOX group, relative to MP group or LOX group (p < 0.01). Combination of LOX-1 gene silencing with MP produced synergistic anti-atherosclerotic effect which was reflected in decreases in foam cell formation, intracellular lipids, inflammatory status, adhesion molecular status, and MCP-1-mediated migration and infiltration of macrophages in foam cells.Conclusion: The synergistic anti-atherosclerotic effects of MP and LOX-1 gene silencing may be potential tools for development of anti-atherosclerotic agents

    2,2′-Diamino-4,4′-bi-1,3-thia­zolium bis­(3-nitro­benzoate)

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    In the title salt, C6H8N4S2 2+·2C7H4NO4 −, the diprotonated diamino­bithia­zole dication is located on an inversion center. The carboxyl­ate group of the anion is twisted with respect to the benzene ring, with a dihedral angle of 13.6 (4)°. N—H⋯O hydrogen bonds involving the amino and ammonium groups of the dication and the carboxyl­ate functionality of the anion generate supra­molecular chains in the crystal

    Penetration and pharmacokinetics of ferulic acid after dermal administration

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    Purpose: To study the in vitro penetration and in vivo pharmacokinetics of ferulic acid (FA), and the correlation between them after dermal administration. Methods: Franz diffusion cell was used to study in vitro penetration of FA. The concentration of FA in the Franz receiver solution was assessed by high performance liquid chromatography (HPLC). Prior to in vivo pharmacokinetics experiments, probe recovery was validated with respect to influencing factors such as flow rate, FA concentration, within-day stability and reproducibility of the probes. In in vivo pharmacokinetic experiment, six male CD-1 hairless mice were used. The micro-dialysis (MD) probe was implanted in the dermis of the rat skin, and dialysates from probe outlet were quantified directly by HPLC. In in vivo studies, deconvolution methods were used to determine the relationship between in vitro and in vivo data, and the correlation coefficient of linear equations. Results: There was significant effect of pH (5 ~ 8) on the penetration of FA. Increase in pH caused commensurate decrease in permeability. The Cmax of FA was 300.74 ± 31.86 ng/mL while Tmax was 138.00 ± 22.80 min after dermal administration of 1 mg/mL FA dissolved in phosphate buffered saline (PBS). The correlation coefficient (r) between in vitro and in vivo data was 0.9905. Conclusion: Both in vivo and in vitro experiments demonstrate that FA permeates the stratum corneum of skin rapidly. The unionized form of FA shows better penetration than the ionic form. In addition, results from correlation analysis indicate that the in vitro penetration characteristics of FA can be applied to predict its in vivo pharmacokinetics
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