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Research reveals that heme group is bound tightly at the active site of rabbit cytochrome P450-4B1 (CYP4B1) and base treatment of rabbit CYP4A human CYP4F subfamilies of heme-containing monooxygenases release a polar heme derivative. The general structural feature of mammalian CYP4 proteins may contain a covalently linked heme.

Although long noncoding RNAs (lncRNAs) have significant tissue specificity, their expression and variability in single cells remain unclear. Here, we developed ColorCells (http://rna.sysu.edu.cn/colorcells/), a resource for comparative analysis of lncRNAs expression, classification and functions in single-cell RNA-Seq data. ColorCells was applied to 167 913 publicly available scRNA-Seq datasets from six species, and identified a batch of cell-specific lncRNAs. These lncRNAs show surprising levels of expression variability between different cell clusters, and has the comparable cell classification ability as known marker genes. Cell-specific lncRNAs have been identified and further validated by in vitro experiments. We found that lncRNAs are typically co-expressed with the mRNAs in the same cell cluster, which can be used to uncover lncRNAs' functions. Our study emphasizes the need to uncover lncRNAs in all cell types and shows the power of lncRNAs as novel marker genes at single cell resolution. [ABSTRACT FROM AUTHOR]

Research has been conducted on CYP4B1. The authors report their investigation of the heme ester link site in CYP4B1, and their study of the functional consequences of the active site mutations.

Hanzhou Citizen Center is a complex connected tall building, in which six hexadic-towers are connected to each other through six skybridges. The finite element model updating of the steel skybridge was conducted using the sensitivity-based and Bayesian estimation updating methods. The relative error of the frequencies and Modal Assurance Criterion (MAC) values of the modal shapes were firstly computed, then the dynamic characteristic differences between numerical model and real structure were obtained by comparing the calculated modal parameters and the estimated modal parameters through dynamic testing under the ambient excitation. The sensitivity matrix was constructed through differential computation for modal parameters with respect to all selected structural parameters and then the insensitive parameters were sieved. The parameter weighting matrix and response weighting matrix were obtained using the Bayesian estimation method. Based on the confidence values of initial designed parameters, the allowable lower and upper bounds were applied for the parameters values. The iterative updating procedure was conducted according to the convergence criterion. From the updating results, it is, found that there was a good correlation between the dynamic characteristics of updated model and estimated dynamic characteristics through dynamic testing. The updated model can then be used for vibration control, response prediction and condition assessment of the skybridge in future. [ABSTRACT FROM AUTHOR]

During the summer of 2024, COVID-19 cases surged globally, driven by variants derived from JN.1 subvariants of SARS-CoV-2 that feature new mutations, particularly in the N-terminal domain (NTD) of the spike protein. In this study, we report on the neutralizing antibody (nAb) escape, infectivity, fusion, and stability of these subvariants-LB.1, KP.2.3, KP.3, and KP.3.1.1. Our findings demonstrate that all of these subvariants are highly evasive of nAbs elicited by the bivalent mRNA vaccine, the XBB.1.5 monovalent mumps virus-based vaccine, or from infections during the BA.2.86/JN.1 wave. This reduction in nAb titers is primarily driven by a single serine deletion (DelS31) in the NTD of the spike, leading to a distinct antigenic profile compared to the parental JN.1 and other variants. We also found that the DelS31 mutation decreases pseudovirus infectivity in CaLu-3 cells, which correlates with impaired cell-cell fusion. Additionally, the spike protein of DelS31 variants appears more conformationally stable, as indicated by reduced S1 shedding both with and without stimulation by soluble ACE2, and increased resistance to elevated temperatures. Molecular modeling suggests that the DelS31 mutation induces a conformational change that stabilizes the NTD and strengthens the NTD-Receptor-Binding Domain (RBD) interaction, thus favoring the down conformation of RBD and reducing accessibility to both the ACE2 receptor and certain nAbs. Additionally, the DelS31 mutation introduces an N-linked glycan modification at N30, which shields the underlying NTD region from antibody recognition. Our data highlight the critical role of NTD mutations in the spike protein for nAb evasion, stability, and viral infectivity, and suggest consideration of updating COVID-19 vaccines with antigens containing DelS31., Competing Interests: DECLARATION OF INTERESTS The authors do not declare any competing interests.

Background: Lenvatinib is the most common multitarget receptor tyrosine kinase inhibitor for the treatment of advanced hepatocellular carcinoma (HCC). Acquired resistance to lenvatinib is one of the major factors leading to the failure of HCC treatment, but the underlying mechanism has not been fully characterized. Methods: We established lenvatinib-resistant cell lines, cell-derived xenografts (CDXs) and patient-derived xenografts (PDXs) and obtained lenvatinib-resistant HCC tumor tissues for further study. Results: We found that ubiquitin-specific protease 14 (USP14) was significantly increased in lenvatinib-resistant HCC cells and tumors. Silencing USP14 significantly attenuated lenvatinib resistance in vitro and in vivo . Mechanistically, USP14 directly interacts with and stabilizes calcium- and integrin-binding protein 1 (CIB1) by reversing K48-linked proteolytic ubiquitination at K24, thus facilitating the P21-activated kinase 1 (PAK1)-ERK1/2 signaling axis. Moreover, in vivo adeno-associated virus 9 mediated transduction of CIB1 promoted lenvatinib resistance in PDXs, whereas CIB1 knockdown resensitized the response of PDXs to lenvatinib. Conclusions: These findings provide new insights into the role of CIB1/PAK1-ERK1/2 signaling in lenvatinib resistance in HCC. Targeting CIB1 and its pathways may be a novel pharmaceutical intervention for the treatment of lenvatinib-resistant HCC., Competing Interests: Competing Interests: Hui-Chuan Sun has received speaker fees from Hengrui, Bayer, and Eisai. The other authors declare that they have no known competing financial interests., (© The author(s).)

SARS-CoV-2 variants derived from the immune evasive JN.1 are on the rise worldwide. Here, we investigated JN.1-derived subvariants SLip, FLiRT, and KP.2 for their ability to be neutralized by antibodies in bivalent-vaccinated human sera, XBB.1.5 monovalent-vaccinated hamster sera, sera from people infected during the BA.2.86/JN.1 wave, and class III monoclonal antibody (Mab) S309. We found that compared to parental JN.1, SLip and KP.2, and especially FLiRT, exhibit increased resistance to COVID-19 bivalent-vaccinated human sera and BA.2.86/JN.1-wave convalescent sera. Interestingly, antibodies in XBB.1.5 monovalent vaccinated hamster sera robustly neutralized FLiRT and KP.2 but had reduced efficiency for SLip. These JN.1 subvariants were resistant to neutralization by Mab S309. In addition, we investigated aspects of spike protein biology including infectivity, cell-cell fusion and processing, and found that these subvariants, especially SLip, had a decreased infectivity and membrane fusion relative to JN.1, correlating with decreased spike processing. Homology modeling revealed that L455S and F456L mutations in SLip reduced local hydrophobicity in the spike and hence its binding to ACE2. In contrast, the additional R346T mutation in FLiRT and KP.2 strengthened conformational support of the receptor-binding motif, thus counteracting the effects of L455S and F456L. These three mutations, alongside D339H, which is present in all JN.1 sublineages, alter the epitopes targeted by therapeutic Mabs, including class I and class III S309, explaining their reduced sensitivity to neutralization by sera and S309. Together, our findings provide insight into neutralization resistance of newly emerged JN.1 subvariants and suggest that future vaccine formulations should consider JN.1 spike as immunogen, although the current XBB.1.5 monovalent vaccine could still offer adequate protection., Competing Interests: The authors have no competing interests to disclose. S.-L.L. conceived and directed the project. R.J.G led the clinical study/experimental design and implementation. P.L. performed the experiments and data processing and analyses. K.X. performed molecular modeling and data analyses. D.J. led SARS-CoV-2 variant genotyping and DNA sequencing ana- lyses. C.C., J.S.B., J.C.H., R.M., and R.J.G. provided clinical samples and related information. C.C.H, M.C., and J.L. provided hamster serum samples and associated information. P.L., J.N.F. and S.-L.L. wrote the paper. Y.-M.Z, L.J.S., E.M.O. provided insightful discussion and revision of the manuscript. DECLARATION OF INTERESTS The authors do not declare any competing interests.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible coronavirus responsible for the global COVID-19 pandemic. Herein, we provide evidence that SARS-CoV-2 spreads through cell-cell contact in cultures, mediated by the spike glycoprotein. SARS-CoV-2 spike is more efficient in facilitating cell-to-cell transmission than is SARS-CoV spike, which reflects, in part, their differential cell-cell fusion activity. Interestingly, treatment of cocultured cells with endosomal entry inhibitors impairs cell-to-cell transmission, implicating endosomal membrane fusion as an underlying mechanism. Compared with cell-free infection, cell-to-cell transmission of SARS-CoV-2 is refractory to inhibition by neutralizing antibody or convalescent sera of COVID-19 patients. While angiotensin-converting enzyme 2 enhances cell-to-cell transmission, we find that it is not absolutely required. Notably, despite differences in cell-free infectivity, the authentic variants of concern (VOCs) B.1.1.7 (alpha) and B.1.351 (beta) have similar cell-to-cell transmission capability. Moreover, B.1.351 is more resistant to neutralization by vaccinee sera in cell-free infection, whereas B.1.1.7 is more resistant to inhibition by vaccinee sera in cell-to-cell transmission. Overall, our study reveals critical features of SARS-CoV-2 spike-mediated cell-to-cell transmission, with important implications for a better understanding of SARS-CoV-2 spread and pathogenesis., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

To establish a new quantitative method for simultaneous determination of multi-components in Scrophularia root by using high performance liquid chromatography (HPLC) and validate its feasibilities．Meanwhile,using catalpol as one chemical reference substance to establish the relative correct factors and relative retention values of aucubin,harpagide,acteoside,angoroside C,harpagoside and cinnamic acid．Then using the quantitative analysis of multi-components by single-marker (QAMS)model,the six analytes can be quantitatively determined in Scrophularia root．The method was evaluated by comparison of the quantitative results to external standard method．No significant differences were observed between the quantitative results of the two methods．The obtained RCFs were credible．It is feasible and suitable to evaluate the quality of Scrophularia root., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

To explore the optimum conditions of β-glucosidase activity in Scrophularia root by using pNPG method. The extraction conditions and reaction conditions (such as extraction liquid type, reaction system, reaction time, temperature, and substrate concentration) were screened by using monofactorial experiment and homogeneous design. Then the changes of β-glucosidase activity in Scrophularia root were detected at the drying temperature of 40-100 ℃. The results showed that citric acid phosphate buffer had better extraction effect, and the maximum absorbance produced by enzymatic reaction was present at 50 ℃ environment after reaction for 30 min. Homogeneous design experiment determined that the optimal conditions were as follows: optimal extraction liquid pH 7.0; enzymatic reaction system pH 6.0; substrate concentration 20 mmol•L⁻¹. The change of enzyme activity was affected by drying temperature and water loss rate. In the drying temperature of 60-100 ℃, the enzyme activity was reduced rapidly with the increase in water loss rate, while the activity was seen even with 0% of water at 40 and 50 ℃. This study has laid the theoretical foundation for research of hydrolysis mechanism of iridoid glycosides and optimum drying process., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Hepatitis C virus is a major cause of chronic liver disease worldwide. Xanthohumol, a prenylated flavonoid from hops, has various biological activities including an antiviral effect. It was previously characterized as a compound that inhibits bovine viral diarrhea virus, a surrogate model of hepatitis C virus. In the present work, xanthohumol was examined for its ability to inhibit hepatitis C virus replication in a cell culture system carrying replicating hepatitis C virus RNA replicon. 0.2 % DMSO and 500 units/mL interferon-alpha treatments were set as a negative and positive control, respectively. The inhibitory effect by xanthohumol was determined by the luciferase activity of the infected Huh7.5 cell lysates and the hepatitis C virus RNA levels in the culture. Xanthohumol at 3.53 µM significantly decreased the luciferase activity compared to the negative control (p < 0.01). Xanthohumol at 7.05 µM further decreased the luciferase activity compared to xanthohumol at 3.53 µM (p = 0.015). Xanthohumol at 7.05 µM or 14.11 µM achieved an inhibitory effect similar to that of interferon-alpha 2b (p > 0.05). Xanthohumol at 3.53 µM significantly reduced the hepatitis C virus RNA level compared to the negative control (p = 0.001). Although the results of xanthohumol at 7.05 µM had a higher variation, xanthohumol at the 7.05 µM and 14.11 µM decreased the hepatitis C virus RNA level to that achieved by interferon-alpha (p > 0.05). In conclusion, xanthohumol displays anti-hepatitis C virus activity in a cell culture system and may be potentially used as an alternative or complementary treatment against the hepatitis C virus., (Georg Thieme Verlag KG Stuttgart · New York.)