Enantioselective Self-Assembly of a Homochiral Tetrahedral Cage Comprising Only Achiral Precursors.

How Nature synthesizes enantiomerically pure substances from achiral or racemic resources remains a mystery. In this study, we aimed to emulate this natural phenomenon by constructing chiral tetrahedral cages through self-assembly, achieved by condensing two achiral compounds-a trisamine and a trisaldehyde. The occurrence of intercomponent CH⋅⋅⋅π interactions among the phenyl building blocks within the cage frameworks results in twisted conformations, imparting planar chirality to the tetrahedrons. In instances where the trisaldehyde precursor features electron-withdrawing ester side chains, we observed that the intermolecular CH⋅⋅⋅π forces are strong enough to prevent racemization. To attain enantioselective self-assembly, a chiral amine was introduced during the imine formation process. The addition of three equivalents of chiral amino mediator to one equivalent of the achiral trisaldehyde precursor formed a trisimino intermediate. This chiral compound was subsequently combined with the achiral trisamino precursor, leading to an imine exchange reaction that releasing the chiral amino mediator and formation of the tetrahedral cage with an enantiomeric excess (ee) of up to 75 %, exclusively composed of achiral building blocks. This experimental observation aligns with theoretical calculations based on the free energies of related cage structures. Moreover, since the chiral amine was not consumed during the imine exchange cycle, it enabled the enantioselective self-assembly of the tetrahedral cage for multiple cycles when new batches of the achiral trisaldehyde and trisamino precursors were successively added.

Effects of Sous-Vide on Quality, Structure and Flavor Characteristics of Tilapia Fillets.

To investigate the effects of traditional high-temperature cooking and sous-vide cooking on the quality of tilapia fillets, muscle microstructure, texture, lipid oxidation, protein structure, and volatile compounds were analyzed. In comparison with samples subjected to traditional high-temperature cooking, sous-vide-treated samples exhibited less protein denaturation, a secondary structure dominated by α-helices, a stable and compact structure, a significantly higher moisture content, and fewer gaps in muscle fibers. The hardness of the sous-vide-treated samples was higher than that of control samples, and the extent of lipid oxidation was significantly reduced. The sous-vide cooking technique resulted in notable changes in the composition and relative content of volatile compounds, notably leading to an increase in the presence of 1-octen-3-ol, α-pinene, and dimethyl sulfide, and a decrease in the levels of hexanal, D-limonene, and methanethiol. Sous-vide treatment significantly enhanced the structural stability, hardness, and springiness of muscle fibers in tilapia fillets and reduced nutrient loss, enriched flavor, and mitigated effects on taste and fishy odor.

[Aucubin combined with ADSCs-exos protects TBHP-induced nucleus pulposus cells via TLR4/NF-κB pathway].

This paper aims to investigate the effects and mechanisms of adipose-derived stem cells-exosomes(ADSCs-exos) toge-ther with aucubin in protecting human-derived nucleus pulposus cells(NPCs) from inflammatory injury, senescence, and apoptosis. The tert-butyl hydroperoxide(TBHP)-induced NPCs were assigned into normal, model, aucubin, ADSCs-exos, and aucubin+ADSCs-exos groups. The cell viability was examined by cell counting kit-8(CCK-8), cell proliferation by EdU staining, cell senescence by senescence-associated-ß-galactosidase(SA-ß-Gal), and cell cycle and apoptosis by flow cytometry. Enzyme-linked immunosorbent assay was employed to examine the expression of interleukin-1ß(IL-1ß), IL-10, and tumor necrosis factor-α(TNF-α). Real-time fluorescence quantitative PCR and Western blot were employed to determine the mRNA and protein levels of aggregated proteoglycan(aggrecan), type Ⅱ collagen alpha 1(COL2A1), Toll-like receptor 4(TLR4), and nuclear factor-kappa B(NF-κB). The results showed that compared with the model group, the aucubin or ADSCs-exos group showed enhanced viability and proliferation of NPCs, decreased proportion of G_0/G_1 phase cells, increased proportion of S phase cells, reduced apoptosis and proportion of cells in senescence, lowered IL-1ß and TNF-α levels, elevated IL-10 level, down-regulated mRNA and protein levels of TLR4 and NF-κB, and up-regulated mRNA and protein levels of aggrecan and COL2A1. Compared with the aucubin or ADSCs-exos group, the aucubin+ADSCs-exos combination further increased the viability and proliferation of NPCs, decreased the proportion of G_0/G_1 phase cells, increased the proportion of S phase cells, reduced the apoptosis and proportion of cells in senescence, lowered the IL-1ß and TNF-α levels, elevated the IL-10 level, down-regulated the mRNA and protein levels of TLR4 and NF-κB, and up-regulated the mRNA and protein levels of aggrecan and COL2A1. In summary, both aucubin and ADSCs-exos could exert protective effects by inhibiting inflammatory responses, reducing apoptosis and senescence of NPCs, improving cell viability and proliferation as well as extracellular matrix synthesis, which may be associated with the inhibition of TLR4/NF-κB signaling pathway activation. The combination of both plays a synergistic role in the protective effects.

Automatic accurate longitudinal location of structural defects in sewer pipes via monocular ranging.

Rough manual interpretation distance cannot keep up with the intelligent detection and interpretation of sewer pipe defects. We present an automatic location method for the accurate longitudinal distance of the structural defects in sewer pipes via a pinhole-based defect monocular ranging model via image processing of pipe diameters. Then the model verification experiment is undertaken through a comparison with the actual data of the pipe size and the camera parameters. The results of the experiment demonstrate an improved accuracy of this method of defect spatial location and the robustness and stability of the model of the accurate acquisition of the longitudinal distance based on the monocular ranging between the inspection robot and the pipe defect.

Long non-coding RNAs involved in cancer metabolic reprogramming.

Metabolic reprogramming has now been accepted as a hallmark of cancer. Compared to normal cells, cancer cells exhibit different metabolic features, including increased glucose uptake, aerobic glycolysis, enhanced glutamine uptake and glutaminolysis, altered lipid metabolism, and so on. Cancer metabolic reprogramming, which supports excessive cell proliferation and growth, has been widely regulated by activation of oncogenes or loss of tumor suppressors. Here, we review that long non-coding RNAs (lncRNAs) can affect cancer metabolism by mutual regulation with oncogenes or tumor suppressors. Additionally, the interaction of lncRNAs with crucial transcription factors, metabolic enzymes or microRNAs can also effectively modulate the processes of cancer metabolism. LncRNAs-derived metabolism reprogramming allows cancer cells to maintain deregulated proliferation and withstand hostile microenvironment such as energy stress. Understanding the functions of lncRNAs in cancer metabolic reprogramming that contributes to carcinogenesis and cancer development may help to develop novel and effective strategies for cancer diagnosis, prognosis and treatment.

Guidance of circular RNAs to proteins' behavior as binding partners.

Circular RNAs (circRNAs) are single-stranded and covalently closed back-splicing products of pre-mRNAs. They can be derived from exons, introns, or exons with intron retained between exons of transcripts, as well as antisense transcripts. CircRNAs have been reported to function as microRNA sponges, regulate gene transcription mediated by RNA polymerase II, and modulate the splicing or stability of mRNA. However, emerging studies demonstrate that they affect the behavior of proteins via direct interactions with them. Here, we summarize that by binding directly with proteins; circRNAs can facilitate their nuclear or cytoplasmic localizations, regulate their functions or stability, promote or inhibit the interactions between them, or influence the interactions between them and DNA. Furthermore, these circRNA-binding proteins contain transcription factors, RNA processing proteins, proteases, and some other RNA-binding proteins. As a consequence, circRNAs are involved in the regulation of multiple physiological or pathological processes, including tumorigenesis, atherosclerosis, wound repair, cardiac senescence, myocardial ischemia/reperfusion injury, and so forth. Nonetheless, it is worthwhile to further explore more types of proteins that interact with circRNAs, which would be helpful in revealing other unknown biological functions of circRNAs that guide the variation in behavior of cellular proteins.

Aucubin inhibits IL-1ß- or TNF-α-induced extracellular matrix degradation in nucleus pulposus cell through blocking the miR-140-5p/CREB1 axis.

In intervertebral disc degeneration (IDD), increased proinflammatory molecules secreted by human nucleus pulposus cells (HNPCs) could promote the expression of extracellular matrix (ECM)-degrading enzymes. IDD could be affected by both genetic and environmental factors, including microRNAs (miRNAs). Aucubin, the active ingredient of a traditional Chinese medicine herb Du Zhong, has been reported to promote osteogenic differentiation; however, the role of aucubin in IDD and the underlying mechanism remain unclear. Herein, we evaluated the effect of aucubin on TNF-α- or IL-1ß-induced ECM degradation in HNPCs. By using online tools, miR-140 was selected as a candidate miRNA that is related to TNF-α or IL-1ß signaling. Overexpression of miR-140 enhanced the effect of aucubin on ECM degradation. Moreover, cAMP responsive element binding protein 1 (CREB1), a major transcriptional factor in immune-related signaling, was a direct downstream target of miR-140. CREB1 knockdown mimicked the function of miR-140 overexpression on ECM degradation. In summary, aucubin might ameliorate IL-1ß- or TNF-α-induced ECM degradation in HNPCs through regulating miR-140/CREB1.

Bu-Shen-Huo-Xue-Fang modulates nucleus pulposus cell proliferation and extracellular matrix remodeling in intervertebral disk degeneration through miR-483 regulation of Wnt pathway.

Intervertebral disk degeneration (IDD) has been widely considered as one of the main causes for low back pain, which can cause a severe impact to human health and huge economic burden to worldwide society. IDD pathogenesis can be affected by extensive degradation of extracellular matrix (ECM) and the hyperproliferation of nucleus pulposus (NP) cells. During the IDD process, expression of the ECM degradation enzymes matrix metalloproteinase and ADAMTS increases, whereas expression of ECM synthesis-related aggrecan and COL2A1 decreases. In addition, the Wnt signaling pathway is reportedly involved in the process of IDD. Bu-Shen-Huo-Xue-Fang (BSHXF), a Chinese traditional medicine formula that contains six Chinese traditional medicinal herbs, is widely used in the treatment of IDD. Herein, we obtained the serum containing BSHXF from BSHXF-fed rat and demonstrated that the BSHXF promoted NP cell proliferation and ECM synthesis through the Wnt signaling pathway. By using DIANA online tools and luciferase reporter gene assays, we confirmed that miR-483-3p and miR-23c regulated CTNNB1 and GSK3B, respectively, through direct targeting, thereby affecting the effect of BSHXF on NP cell proliferation and ECM synthesis through the Wnt signaling pathway. Taken together, we demonstrated the function and mechanism of BSHXF in regulating NP cell proliferation and ECM remodeling through the Wnt signaling pathway during IDD.

CUE domain-containing protein 2 promotes the Warburg effect and tumorigenesis.

Cancer progression depends on cellular metabolic reprogramming as both direct and indirect consequence of oncogenic lesions; however, the underlying mechanisms are still poorly understood. Here, we report that CUEDC2 (CUE domain-containing protein 2) plays a vital role in facilitating aerobic glycolysis, or Warburg effect, in cancer cells. Mechanistically, we show that CUEDC2 upregulates the two key glycolytic proteins GLUT3 and LDHA via interacting with the glucocorticoid receptor (GR) or 14-3-3ζ, respectively. We further demonstrate that enhanced aerobic glycolysis is essential for the role of CUEDC2 to drive cancer progression. Moreover, using tissue microarray analysis, we show a correlation between the aberrant expression of CUEDC2, and GLUT3 and LDHA in clinical HCC samples, further demonstrating a link between CUEDC2 and the Warburg effect during cancer development. Taken together, our findings reveal a previously unappreciated function of CUEDC2 in cancer cell metabolism and tumorigenesis, illustrating how close oncogenic lesions are intertwined with metabolic alterations promoting cancer progression.

Regulation of RNA decay and cellular function by 3'-5' exoribonuclease DIS3L2.

DIS3L2, in which mutations have been linked to Perlman syndrome, is an RNA-binding protein with 3'-5' exoribonuclease activity. It contains two CSD domains and one S1 domain, all of which are RNA-binding domains, and one RNB domain that is responsible for the exoribonuclease activity. The 3' polyuridine of RNA substrates can serve as a degradation signal for DIS3L2. Because DIS3L2 is predominantly localized in the cytoplasm, it can recognize, bind, and mediate the degradation of cytoplasmic uridylated RNA, including pre-microRNA, mature microRNA, mRNA, and some other non-coding RNAs. Therefore, DIS3L2 plays an important role in cytoplasmic RNA surveillance and decay. DIS3L2 is involved in multiple biological and physiological processes such as cell division, proliferation, differentiation, and apoptosis. Nonetheless, the function of DIS3L2, especially its association with cancer, remains largely unknown. We summarize here the RNA substrates degraded by DIS3L2 with its exonucleolytic activity, together with the corresponding biological functions it is implicated in. Furthermore, we discuss whether DIS3L2 can function independently of its 3'-5' exoribonuclease activity, as well as its potential tumor-suppressive or oncogenic roles during cancer progression.

Aberrant Regulation of mRNA m6A Modification in Cancer Development.

N6-methyladenosine (m6A) is the most prevalent internal modification of eukaryotic messenger RNAs (mRNAs). The m6A modification in RNA can be catalyzed by methyltransferases, or removed by demethylases, which are termed m6A writers and erasers, respectively. Selective recognition and binding by distinct m6A reader proteins lead mRNA to divergent destinies. m6A has been reported to influence almost every stage of mRNA metabolism and to regulate multiple biological processes. Accumulating evidence strongly supports the correlation between aberrant cellular m6A level and cancer. We summarize here that deregulation of m6A modification, resulting from aberrant expression or function of m6A writers, erasers, readers or some other protein factors, is associated with carcinogenesis and cancer progression. Understanding the regulation and functional mechanism of mRNA m6A modification in cancer development may help in developing novel and efficient strategies for the diagnosis, prognosis and treatment of human cancers.

Reprogramming of glucose, fatty acid and amino acid metabolism for cancer progression.

Metabolic reprogramming is widely observed during cancer development to confer cancer cells the ability to survive and proliferate, even under the stressed, such as nutrient-limiting, conditions. It is famously known that cancer cells favor the "Warburg effect", i.e., the enhanced glycolysis or aerobic glycolysis, even when the ambient oxygen supply is sufficient. In addition, deregulated anabolism/catabolism of fatty acids and amino acids, especially glutamine, serine and glycine, have been identified to function as metabolic regulators in supporting cancer cell growth. Furthermore, extensive crosstalks are being revealed between the deregulated metabolic network and cancer cell signaling. These exciting advancements have inspired new strategies for treating various malignancies by targeting cancer metabolism. Here we review recent findings related to the regulation of glucose, fatty acid and amino acid metabolism, their crosstalk, and relevant cancer therapy strategy.

Noncoding RNAs in Regulation of Cancer Metabolic Reprogramming.

Since the description of the Warburg effect 90 years ago, metabolic reprogramming has been gradually recognized as a major hallmark of cancer cells. Mounting evidence now indicates that cancer is a kind of metabolic disease, quite distinct from conventional perception. While metabolic alterations in cancer cells have been extensively observed in glucose, lipid, and amino acid metabolisms, its underlying regulatory mechanisms are still poorly understood. Noncoding RNA, also known as the "dark matter in life," functions through various mechanisms at RNA level regulating different biological pathways. The last two decades have witnessed the booming of noncoding RNA study on microRNA (miRNA), long noncoding RNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), etc. In this chapter, we will discuss the regulatory roles of noncoding RNAs on cancer metabolism.

A plasma microRNA panel for early detection of colorectal cancer.

Colonoscopy remains the standard screening method for detecting colorectal cancer (CRC) at an early stage. However, many people avoid having a colonoscopy because of the fear for its potential complications. Our study aimed to identify plasma microRNAs for preliminarily screening CRC in general population, so that some unnecessary colonoscopies can be avoided. We investigated plasma microRNA expression in three independent cohorts including the discovery (n = 80), training (n = 112), and validation (n = 49) phases recruited at two medical centers. Microarrays were used for screening 723 microRNAs in 80 plasma samples to identify candidate microRNAs. Quantitative reverse-transcriptase PCR was performed on the 161 training and validation plasma samples to evaluate the candidate microRNAs discovered from microarrays. A logistic regression model was constructed based on the training cohort and then verified by using the validation dataset. Area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic accuracy. We identified a panel of miR-409-3p, miR-7, and miR-93 that yielded high diagnostic accuracy in discriminating CRC from healthy group (AUC: 0.866 and 0.897 for training and validation dataset, respectively). Moreover, the diagnostic performance of the microRNA panel persisted in nonmetastasis CRC stages (Dukes' A-B, AUC: 0.809 and 0.892 for training and validation dataset, respectively) and in metastasis CRC stages (Dukes' C-D, AUC: 0.917 and 0.865 for training and validation dataset, respectively). In conclusion, our study reveals a plasma microRNA panel that has potential clinical value in early CRC detection and would play a critical role on preliminarily screening CRC in general population.

Dereplication of known nucleobase and nucleoside compounds in natural product extracts by capillary electrophoresis-high resolution mass spectrometry.

Nucleobase and nucleoside compounds exist widely in various organisms. An often occurring problem in the discovery of new bioactive compounds from natural products is reisolation of known nucleobase and nucleoside compounds. To resolve this problem, a capillary electrophoresis-high resolution mass spectrometry (CE-HR-MS) method providing both rapid separation and accurate mass full-scan MS data was developed for the first time to screen and dereplicate known nucleobase and nucleoside compounds in crude extracts of natural products. Instrumental parameters were optimized to obtain optimum conditions for CE separation and electrospray ionization-time-of-flight mass spectrometry (ESI-TOF/MS) detection. The proposed method was verified to be precise, reproducible, and sensitive. Using this method, known nucleobase and nucleoside compounds in different marine medicinal organisms including Syngnathus acus Linnaeus; Hippocampus japonicus Kaup and Anthopleura lanthogrammica Berkly were successfully observed and identified. This work demonstrates that CE-HR-MS combined with an accurate mass database may be used as a powerful tool for dereplicating known nucleobase and nucleoside compounds in different types of natural products. Rapid dereplication of known nucleobase and nucleoside compounds allows researchers to focus on other leads with greater potential to yield new substances.

Immobilization of Cyclooxygenase-2 on Silica Gel Microspheres: Optimization and Characterization.

In this study, immobilized COX-2 was successfully constructed through glutaraldehyde-mediated covalent coupling on functional silica gel microspheres. The optimum conditions, properties, and morphological characteristics of the immobilized COX-2 were investigated. The optimal immobilization process was as follows: about 0.02 g of aminated silica gel microspheres was activated by 0.25% GA solution for 6 h and mixed with 5 U of free recombinant COX-2 solution. Then, the mixture was shaken for 8 h at 20 °C. Results showed that the immobilized COX-2 produced by this method exhibited excellent biocatalytic activity, equivalent to that of free COX-2 under the test conditions employed. The best biocatalytic activity of immobilized COX-2 appeared at pH 8.0 and still maintained at about 84% (RSD < 7.39%, n = 3) at pH 10.0. For temperature tolerance, immobilized COX-2 exhibited its maximum biocatalytic activity at 40 °C and about 68% (RSD < 6.99%, n = 3) of the activity was maintained at 60 °C. The immobilized COX-2 retained over 85% (RSD < 7.26%, n = 3) of its initial biocatalytic activity after five cycles, and after 10 days storage, the catalytic activity of immobilized COX-2 still maintained at about 95% (RSD < 3.08%, n = 3). These characteristics ensured the convenient use of the immobilized COX-2 and reduced its production cost.

Quality control method for commercially available wild Jujube leaf tea based on HPLC characteristic fingerprint analysis of flavonoid compounds.

Flavonoids are the main active components of natural medicinal plants with many physiological functions. In this study, an HPLC fingerprinting method based on the distribution and relative amount of 11 bioactive flavonoids was established for the quality evaluation of commercially available wild Jujube leaf tea (JLT) from China. Separation of the crude flavonoid extract was achieved on a column filled with C18 material with a high carbon content. The flavonoids in wild JLT were identified based on UV spectroscopy and accurate mass measurements by TOF-MS. Twenty-one batches of practical samples collected from different habitats were analyzed by using the developed HPLC method to construct the HPLC characteristic fingerprint of wild JLT. Then, combined with clustering and similarity analyses, the HPLC characteristic fingerprint was used for the authentication and quality evaluation of commercial wild JLT. Results indicated that the proposed HPLC characteristic fingerprint reflected the inherent characteristics of wild JLT collected from different regions. Authenticity identification and quality control of commercially available wild Jujube tea were achieved based on the HPLC characteristic fingerprint analysis. This new approach to bioactive component profiling provided a promising reference method for the quality evaluation of commercial wild flower and plant tea.

Gualou-Xiebai-Banxia-Tang regulates liver-gut axis to ameliorate Metabolic Syndrome in HFD-fed mice.

BACKGROUND: Metabolic syndrome (MetS), characterized by obesity, hyperglycemia, and abnormal blood lipid levels, is the pathological basis of many cardiovascular diseases. Gualou-Xiebai-Banxia-Tang decoction (GT) was first described in the Synopsis of the Golden Chamber, the earliest traditional Chinese medicine (TCM) monograph on diagnosis and treatment of miscellaneous diseases in China. According to TCM precepts, based on its ability to activate yang to release stagnation, activate qi to reduce depression, remove phlegm, and broaden the chest, GT has been used for more than 2,000 years to treat cardiovascular ailments. However, the molecular bases of its therapeutic mechanisms remain unclear. PURPOSE: The aim of this study was to identify lipid- and glucose-related hepatic genes differentially regulated by GT, and to assess GT impact on gut microbiota composition, in mice with high-fat diet (HFD)-induced MetS. STUDY DESIGN AND METHODS: ApoE-/- mice were fed with an HFD for 24 weeks, with or without concurrent GT supplementation, to induce MetS. At the study's end, body weight, visceral fat weight, blood lipid levels, and insulin sensitivity were measured, and histopathological staining was used to evaluate hepatosteatosis and intestinal barrier integrity. Liver transcriptomics was used for analysis of differentially expressed genes in liver and prediction of relevant regulatory pathways. Hepatic lipid/glucose metabolism-related genes and proteins were detected by RT-qPCR and western blotting. Gut microbial composition was determined by 16S rRNA gene sequencing. RESULTS: GT administration reduced MetS-related liver steatosis and weight gain, promoted insulin sensitivity and lipid metabolism, and beneficially modulated gut microbiota composition by decreasing the relative abundance of g_Lachnospiraceae_NK4A136_group and increasing the relative abundance of g_Alistipes. Liver transcriptomics revealed that GT regulated the expression of genes related to lipid and glucose metabolism (Pparγ, Igf1, Gpnmb, and Trem2) and of genes encoding chemokines/chemokine receptors (e.g. Cxcl9 and Cx3cr1). Significant, positive correlations were found for Ccr2, Ccl4, Ccr1, and Cx3cr1 and the g_Lachnospiraceae_NK4A136_group, and between Cxcl9, Ccr2, Ccl4, and Cx3cr1 and g_Desulfovibrio. GT treatment downregulated the protein expressions of SCD1 and CX3CR1 and upregulated the expression of PCK1 protein. CONCLUSION: GT supplementation alleviates HFD-induced MetS in mice by improving hepatic lipid and glucose metabolism. The anti-metabolic syndrome effects of GT may be related to the regulation of the gut-liver axis.

miR-218 directs a Wnt signaling circuit to promote differentiation of osteoblasts and osteomimicry of metastatic cancer cells.

MicroRNAs (miRNAs) negatively and post-transcriptionally regulate expression of multiple target genes to support anabolic pathways for bone formation. Here, we show that miR-218 is induced during osteoblast differentiation and has potent osteogenic properties. miR-218 promotes commitment and differentiation of bone marrow stromal cells by activating a positive Wnt signaling loop. In a feed forward mechanism, miR-218 stimulates the Wnt pathway by down-regulating three Wnt signaling inhibitors during the process of osteogenesis: Sclerostin (SOST), Dickkopf2 (DKK2), and secreted frizzled-related protein2 (SFRP2). In turn, miR-218 expression is up-regulated in response to stimulated Wnt signaling and functionally drives Wnt-related transcription and osteoblast differentiation, thereby creating a positive feedback loop. Furthermore, in metastatic breast cancer cells but not in normal mammary epithelial cells, miR-218 enhances Wnt activity and abnormal expression of osteoblastic genes (osteomimicry) that contribute to homing and growth of cells metastatic to bone. Thus, miR-218/Wnt signaling circuit amplifies both the osteoblast phenotype and osteomimicry-related tumor activity.