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Abstract Urea’s transmembrane transport through urea transporters (UT) is a fundamental physiological behavior for life activities. Here, we present 11 cryo-EM structures of four UT members in resting states, urea transport states, or inactive states bound with synthetic competitive, uncompetitive or noncompetitive inhibitor. Our results indicate that the binding of urea via a conserved urea recognition motif (URM) and the urea transport via H-bond transfer along the QPb-T5b-T5a-QPa motif among different UT members. Moreover, distinct binding modes of the competitive inhibitors 25a and ATB3, the uncompetitive inhibitor CF11 and the noncompetitive inhibitor HQA2 provide different mechanisms for blocking urea transport and achieved selectivity through L-P pocket, UCBP region and SCG pocket, respectively. In summary, our study not only allows structural understanding of urea transport via UTs but also afforded a structural landscape of hUT-A2 inhibition by competitive, uncompetitive and noncompetitive inhibitors, which may facilitate developing selective human UT-A inhibitors as a new class of salt-sparing diuretics.

Abstract Background and aims The older people bears a severe burden of disease due to frailty and depressive symptoms, however, the results of association between the two in the older Chinese people have been conflicting. Therefore, this study aimed to investigate the developmental trajectories and interactions of frailty and depressive symptoms in the Chinese middle-aged and older adults. Methods The study used four waves of data from 2011, 2013, 2015 and 2018 in the China Health and Retirement Longitudinal Study (CHARLS) database, focused on middle-aged and older people ≥ 45 years of age, and analyzed using latent growth models and cross-lagged models. Results The parallel latent growth model showed that the initial level of depressive symptoms had a significant positive predictive effect on the initial level of frailty. The rate of change in depressive symptoms significantly positively predicted the rate of change in frailty. The initial level of frailty had a significant positive predictive effect on the initial level of depressive symptoms, but a significant negative predictive effect on the rate of change in depressive symptoms. The rate of change in frailty had a significant positive predictive effect on the rate of change in depressive symptoms. The results of the cross-lagged analysis indicated a bidirectional causal association between frailty and depressive symptoms in the total sample population. Results for the total sample population grouped by age and gender were consistent with the total sample. Conclusions This study recommends advancing the age of concern for frailty and depressive symptoms to middle-aged adults. Both men and women need early screening and intervention for frailty and depressive symptoms to promote healthy aging.

Abstract Background The catenin beta 1 gene (CTNNB1) plays a crucial role in the malignant progression of various cancers. Recent studies have suggested that CTNNB1 hyperactivation is closely related to the occurrence and development of bladder cancer (BCa). As a member of the deubiquitinating enzyme (DUB) family, ubiquitin C-terminal hydrolase L3 (UCHL3) is abnormally expressed in various cancers. In this study, we discovered that UCHL3 is a novel oncogene in bladder cancer, suggesting it is a promising target against bladder cancer. Methods We utilized CRISPR‒Cas9 technology to construct cell lines with UCHL3 stably overexpressed or knocked out. The successful overexpression or knockout of UCHL3 was determined using Western blotting. Then, we performed CCK-8, colony formation, soft agar and Transwell migration assays to determine the impact of the UCHL3 gene on cell phenotype. RNA-seq was performed with UCHL3-depleted T24 cells (established via CRISPR–Cas9-mediated genomic editing). We analyzed differences in WNT pathway gene expression in wild-type and UCHL3-deficient T24 cell lines using a heatmap and by gene set enrichment analysis (GSEA). Then, we validated the effect of UCHL3 on the Wnt pathway using a dual fluorescence reporter. We then analyzed the underlying mechanisms involved using Western blots, co-IP, and immunofluorescence results. We also conducted nude mouse tumor formation experiments. Moreover, conditional UCHL3-knockout mice and bladder cancer model mice were established for research. Results We found that the overexpression of UCHL3 boosted bladder cancer cell proliferation, invasion and migration, while the depletion of UCHL3 in bladder cancer cells delayed tumor tumorigenesis in vitro and in vivo. UCHL3 was highly associated with the Wnt signaling pathway and triggered the activation of the Wnt signaling pathway, which showed that its functions depend on its deubiquitination activity. Notably, Uchl3-deficient mice were less susceptible to bladder tumorigenesis. Additionally, UCHL3 was highly expressed in bladder cancer cells and associated with indicators of advanced clinicopathology. Conclusion In summary, we found that UCHL3 is amplified in bladder cancer and functions as a tumor promoter that enhances proliferation and migration of tumor cells in vitro and bladder tumorigenesis and progression in vivo. Furthermore, we revealed that UCHL3 stabilizes CTNNB1 expression, resulting in the activation of the oncogenic Wnt signaling pathway. Therefore, our findings strongly suggest that UCHL3 is a promising therapeutic target for bladder cancer.

Abstract Spatial transcriptomics technologies developed in recent years can provide various information including tissue heterogeneity, which is fundamental in biological and medical research, and have been making significant breakthroughs. Single-cell RNA sequencing (scRNA-seq) cannot provide spatial information, while spatial transcriptomics technologies allow gene expression information to be obtained from intact tissue sections in the original physiological context at a spatial resolution. Various biological insights can be generated into tissue architecture and further the elucidation of the interaction between cells and the microenvironment. Thus, we can gain a general understanding of histogenesis processes and disease pathogenesis, etc. Furthermore, in silico methods involving the widely distributed R and Python packages for data analysis play essential roles in deriving indispensable bioinformation and eliminating technological limitations. In this review, we summarize available technologies of spatial transcriptomics, probe into several applications, discuss the computational strategies and raise future perspectives, highlighting the developmental potential.

Abstract Background Compound Turkish gall ointment (CTGO) has a long history of being widely used as a folk medicine in Xinjiang for the treatment of eczema. CTGO is currently in the pre-investigational new drug application stage, but its pharmacological mechanisms of action have not yet been clarified. Methods First, a sensitive and reliable ultra-high performance liquid chromatography-Q exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry (UHPLC-Q-Orbitrap HRMS) technique was established. Second, an integrative strategy of network analysis and molecular docking based on identified and retrieved ingredients was implemented to investigate the potential targets and pathways involved in the treatment of eczema with CTGO. Finally, Sprague–Dawley (SD) rats with eczema were prepared to verify the predicted results. The skin conditions of the rats were observed, evaluated, and scored. Skin tissues were observed by hematoxylin–eosin (HE) staining, and the levels of serum interferon-γ (IFN-γ) and interleukin-4 (IL-4) were determined by enzyme-linked immunosorbent assay (ELISA). The expression levels of toll-like receptor 4 (TLR4), nuclear factor kappa-B p65 (NF-κB p65), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Results A total of 29 compounds were identified. We found 38 active components and 58 targets for the treatment of eczema, which included 118 signaling pathways related to inflammation, immunity, and apoptosis. CTGO significantly improved the skin surface and histopathological characteristics of eczema-affected rats, downregulated the expression of IL-4, TLR4, NF-κB (p65), IL-1β, and TNF-α, and upregulated the expression level of IFN-γ. Conclusion We predicted and validated our prediction that CTGO may be used to treat eczema by affecting the TLR4/NF-κB signaling pathway, which provides guidance for future experimental studies.

The interaction between human serum albumin (HSA) and hispidin, a polyketide abundantly present in both edible and therapeutic mushrooms, was explored through multispectral methods, hydrophobic probe assays, location competition trials, and molecular docking simulations. The results of fluorescence quenching analysis showed that hispidin quenched the fluorescence of HSA by binding to it via a static mechanism. The binding of hispidin and HSA was validated further by synchronous fluorescence, three-dimensional fluorescence, and UV/vis spectroscopy analysis. The apparent binding constant (Ka) at different temperatures, the binding site number (n), the quenching constants (Ksv), the dimolecular quenching rate constants (Kq), and the thermodynamic parameters (∆G, ∆H, and ∆S) were calculated. Among these parameters, ∆H and ∆S were determined to be 98.75 kJ/mol and 426.29 J/(mol·K), respectively, both exhibiting positive values. This observation suggested a predominant contribution of hydrophobic forces in the interaction between hispidin and HSA. By employing detergents (SDS and urea) and hydrophobic probes (ANS), it became feasible to quantify alterations in Ka and surface hydrophobicity, respectively. These measurements confirmed the pivotal role of hydrophobic forces in steering the interaction between hispidin and HSA. Site competition experiments showed that there was an interaction between hispidin and HSA molecules at site I, which situates the IIA domains of HSA, which was further confirmed by the molecular docking simulation.

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.