Rational Design of Bioorthogonally Activatable PROTAC for Tumor-Targeted Protein Degradation.

Protein degradation mediated by the proteolysis-targeting chimera (PROTAC) has emerged as an efficient strategy to accurately control intracellular protein levels. However, the development of PROTACs is limited by their systemic toxicity. Herein, we report a bioorthogonally activatable prodrug (BT-PROTAC) strategy to accurately control the activity of PROTACs. As a proof of concept, we introduced the highly reactive trans-cyclooctene into PROTAC molecule MZ1, the structure-acitivity relationships of which were well characterized previously, to construct the bioorthogonally activatable prodrug BT-PROTAC. Compared with MZ1, BT-PROTAC is incapable of degradation of BRD4 protein. However, BT-PROTAC can be activated by highly active tetrazine compound BODIPY-TZ in vitro. Furthermore, we could selectively degrade BRD4 protein in tumor tissue enabled by tumor-targeted tetrazine compound IR808-TZ. This strategy may represent an alternative to existing strategies and may be widely applied in the design of BT-PROTAC targeting other proteins.

The effect of customer satisfaction on floral product purchase behavior, evidence from Shanghai, China.

China's flower industry is developing rapidly, and the size of the retail market is increasing year by year. Studying the factors influencing residents' flower purchasing behavior and understanding their flower needs can help promote the sustainable development of the flower industry. Based on customer satisfaction theory, this paper uses 838 consumer research questionnaires from 15 districts in Shanghai to analyze the influence of customer satisfaction on residents' flower purchasing behavior by conducting a binary logit model and to investigate the moderating effect of flower purchasing purpose on the influence of satisfaction. The results show that price satisfaction and satisfaction with promotional methods have a significant negative effect on flower purchasing behavior, service satisfaction has a significant positive effect on purchasing behavior, and different customer purchase purposes lead to different intensities of the effect of satisfaction on purchasing behavior. According to the conclusion of the study, three countermeasures are proposed: to popularize the knowledge of flower culture, guide the concept of flower consumption, and promote the transformation of flower consumption to daily consumption; to conduct regular research on consumers by flower merchants to clarify consumers' needs and improve their satisfaction; to clarify consumers' purchase intention, increase the investment in the research and development and cultivation of flower products, and improve the supply level of flowers.

Circular RNA circFAT1(e2) Facilitates Cell Progression through the miR-30e-5P/MYBL2 Pathway in Glioma.

Objective: To explore the mechanism of glioma from MYB family genes from the perspective of the circRNA-miRNA-mRNA regulatory network. Methods: First, the MYB family genes were analyzed by multiple bioinformatics analyses to identify one gene most associated with glioma. Then, the prognostic value and clinical characteristics of the gene were evaluated by bioinformatics analysis and experiments in glioma cells. Next, the target miRNA and circRNA were predicted and verified by dual-luciferase reporter assays. Besides, the functions of target circRNA in glioma were investigated by CCK-8 and Transwell assays. At last, the relation between the screened MYB gene, miRNA, and circRNA in glioma was identified by rescue experiments. Results: After expression and Cox and survival analysis of six MYB family genes, MYBL2 was identified as the gene most associated with glioma. Then, we found that MYBL2 expression in primary gliomas was higher than those in other histologies, and it had variable expression according to clinical features. Furthermore, MYBL2 knockdown in glioma cells impairs cell growth, invasion, and migration in functional studies. Then, miR-30e-5p and circFAT1(e2) were identified as targets of MYBL2 by bioinformatics prediction and experimental verification. Finally, the relationship between circFAT1(e2), MYBL2, and miR-30e-5p was elucidated by rescue experiments. Conclusion: circFAT1(e2) could promote glioma development by regulating MYBL2 and miR-30e-5p, and MYBL2 has diagnostic and prognostic values in glioma.

Food Safety Governance in the Age of COVID-19: How Does Employees' Attitude on Public-Private Governance System Affect Their Willingness to Blow the Whistle on Food Violations?

Online food delivery increases dramatically during the COVID-19 era and has grown into a global marketplace worth more than $150 billion dollars, necessitating a more effective and responsive governance system. Public-private governance systems with whistleblowing to the public are seen as an effective tool for addressing the formidable challenges of food security in modern society. Accordingly, this study aims to explore the determinants of whistleblowing intentions and to propose policy policies for the whistleblowing system to fully utilize the advantages of public-private governance systems. Through empirical research, this paper finds that employees' perceived effectiveness of government authorities, as well as their familiarity with whistleblowing systems, positively affect their intentions to blow the whistle. However, the whistleblowing intent of restaurant employees is adversely affected by the online platform's focus. The root cause lies in the employee's trust in both the government sector and corporate sector. This study thus argues that a suite of measures to promote individual trust in public-private governance systems is desired and that this is an effective means of better mitigating food safety governance challenges in terms of capacity and resources.

How Has the COVID-19 Pandemic Changed Urban Consumers' Ways of Buying Agricultural Products? Evidence from Shanghai, China.

The COVID-19 pandemic has had a huge impact on people's consumption behavior and habits. This paper takes Shanghai, China as a case study and uses a questionnaire survey of urban residents in all districts in Shanghai from April to May in 2022. Herein, we empirically analyze the factors affecting shopping modes for agricultural products, describe how things have changed compared to before the outbreak of the pandemic, and explore the underlying mechanism. This paper can provide a policy reference for how to ensure the safety of people's food supply in the context of the COVID-19 pandemic. The results show that urban residents pay more attention to the basic attributes of agricultural products such as the quantity guarantee and health safety, and will adjust their consumption modes for agricultural products according to the needs of families and management. Compared with shopping malls and supermarkets, the quantity and quality assurance of community groups and e-commerce platforms can better meet the consumption situation of agricultural products during the pandemic period. The moderating effect of consumer commodity preference in the positive influence of safety evaluation on the transformation of shopping mode is significant. In general, online e-commerce platforms and community group buying have played a significant role in ensuring the acquisition of supplies needed by people during the COVID-19 pandemic. However, it remains to be determined whether the changes in the shopping modes for agricultural products of urban consumers brought by the current COVID-19 pandemic are long term or solidified.

Uncovering the Mechanisms of Active Components from Toad Venom against Hepatocellular Carcinoma Using Untargeted Metabolomics.

Toad venom, a dried product of secretion from Bufo bufo gargarizans Cantor or Bufo melanostictus Schneider, has had the therapeutic effects of hepatocellular carcinoma confirmed. Bufalin and cinobufagin were considered as the two most representative antitumor active components in toad venom. However, the underlying mechanisms of this antitumor effect have not been fully implemented, especially the changes in endogenous small molecules after treatment. Therefore, this study was designed to explore the intrinsic mechanism on hepatocellular carcinoma after the cotreatment of bufalin and cinobufagin based on untargeted tumor metabolomics. Ultraperformance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) was performed to identify the absorbed components of toad venom in rat plasma. In vitro experiments were determined to evaluate the therapeutic effects of bufalin and cinobufagin and screen the optimal ratio between them. An in vivo HepG2 tumor-bearing nude mice model was established, and a series of pharmacodynamic indicators were determined, including the body weight of mice, tumor volume, tumor weight, and histopathological examination of tumor. Further, the entire metabolic alterations in tumor after treating with bufalin and cinobufagin were also profiled by UHPLC-MS/MS. Twenty-seven active components from toad venom were absorbed in rat plasma. We found that the cotreatment of bufalin and cinobufagin exerted significant antitumor effects both in vitro and in vivo, which were reflected in inhibiting proliferation and inducing apoptosis of HepG2 cells and thereby causing cell necrosis. After cotherapy of bufalin and cinobufagin for twenty days, compared with the normal group, fifty-six endogenous metabolites were obviously changed on HepG2 tumor-bearing nude mice. Meanwhile, the abundance of α-linolenic acid and phenethylamine after the bufalin and cinobufagin intervention was significantly upregulated, which involved phenylalanine metabolism and α-linolenic acid metabolism. Furthermore, we noticed that amino acid metabolites were also altered in HepG2 tumor after drug intervention, such as norvaline and Leu-Ala. Taken together, the cotreatment of bufalin and cinobufagin has significant antitumor effects on HepG2 tumor-bearing nude mice. Our work demonstrated that the in-depth mechanism of antitumor activity was mainly through the regulation of phenylalanine metabolism and α-Linolenic acid metabolism.

Does a Traceability System Help to Regulate Pig Farm Households' Veterinary Drug Use Behavior? Evidence from Pig Farms in China.

In China, there is a renewed interest in traceability systems as an efficient tool to guarantee pork safety. One of the pathways through which a traceability system can benefit consumers is by easing information asymmetry. However, past literature on the traceability system in China pays more attention to theoretical analysis and less to empirical analysis. Using a large-scale survey of pig farms in China, we investigate the effects influencing farmers' participation in the traceability system. Findings show that a traceability system can influence the safety of pork indirectly through its impacts on farmers' production behaviors. Another important finding is that unsafe pork is a result of non-standard use of veterinary drugs, and the traceability system works well for farmers by pushing them to take stricter safety measurements.

ZWZ-3, a Fluorescent Probe Targeting Mitochondria for Melanoma Imaging and Therapy.

The increased drug resistance and metastasis of melanoma resulted in poor prognosis of patients. Here, we designed and synthesized a novel hemicyanine-based fluorescent probe ZWZ-3, and investigated its application for melanoma imaging and treatment both in vitro and in vivo. ZWZ-3 preferentially accumulated in melanoma cells via a process that depended on the organic anion-transporting polypeptide (OATP), which targeted mitochondria on the hemicyanine cationic nitrogen. In addition, we investigated the effect and molecular mechanism of ZWZ-3 in melanoma. In vitro studies showed that ZWZ-3 promoted the generation of reactive oxygen species and induced mitochondrial-mediated cell apoptosis by upregulating Bax and activating caspase-3, caspase-9, and PARP. Importantly, ZWZ-3 also induced autophagy by upregulating LC-3II and Atg5 and downregulating P62. It significantly suppressed tumor growth of A375 xenograft tumor in mice without notable side effects. Histological and immunohistochemical analyses revealed that ZWZ-3 induced apoptosis and inhibited tumor cell proliferation. Thus, ZWZ-3 represents a novel theranostic agent that can be used to effectively targeting, detecting, and treating melanoma. It could also help monitoring disease progression and response to treatment.

Research on hybrid intrusion detection method based on the ADASYN and ID3 algorithms.

Intrusion detection system plays an important role in network security. Early detection of the potential attacks can prevent the further network intrusion from adversaries. To improve the effectiveness of the intrusion detection rate, this paper proposes a hybrid intrusion detection method that utilizes ADASYN (Adaptive Synthetic) and the decision tree based on ID3 algorithm. At first, the intrusion detection dataset is transformed by coding technology and normalized. Subsequently, the ADASYN algorithm is applied to implement oversampling on the training set, and the ID3 algorithm is employed to build a decision tree model. In addition, the model proposed by the research is evaluated by accuracy, precision, recall, and false alarm rate. Besides, a performance comparison is conducted with other models. Consequently, it is found that the combined model based on ADASYN and ID3 decision tree proposed in this research possesses higher accuracy as well as lower false alarm rate, which is more suitable for intrusion detection tasks.

Influencing Factors and Group Differences of Urban Consumers' Willingness to Pay for Low-Carbon Agricultural Products in China.

Developing low-carbon agriculture has become a development goal for low-carbon economies in various countries, and consumers' awareness and willingness to pay (WTP) for low-carbon agricultural products is an important link in achieving the sustainable development of low-carbon agriculture. The theory of planned behavior is a widely used framework to explain consumers' food choices. Considering the intrinsic norms of consumers, their perceptions of low-carbon agricultural products, and shifts in consumer behavior, our study adds the influence of environmental awareness and consumer preferences to the theoretical framework of analysis. We choose the contingent valuing method (CVM) and use 532 consumer questionnaires in Shanghai to validate Chinese urban consumers' WTP for low-carbon products and its influencing factors. The findings show that Chinese urban consumers have a high overall awareness of low-carbon agricultural products and, after strengthening the conceptual information of consumers, most consumers agree that low-carbon vegetables are more conducive to ecological environment protection, quality, and safety guarantees than conventional vegetables. The existing analysis showed that some variables such as bid price, behavioral attitudes, subjective norms, and consumption preferences significantly influenced consumers' willingness to pay for low-carbon leafy greens, while the effect of the environmental awareness variable was not significant. Further research found that consumers' WTP for low-carbon leafy greens showed significant group differences across income, gender, age, and education. Therefore, to promote the consumption of low-carbon agricultural products in China, we should attach importance to the publicity and guidance of low-carbon vegetables and strengthen the certification of low-carbon vegetable products. This study can provide policy reference for reasonably regulating and subdividing China's low-carbon agricultural products market.

A far-red-emitting fluorescence probe for selective and sensitive detection of no in live cells and in C. elegans.

Nitric oxide (NO), a ubiquitous intracellular and intercellular messenger molecule, plays vital roles in many physiological processes and is closely related to many diseases. Although a lot of fluorescent probes have been developed for real-time detection of NO successfully, the probes still suffer from poor tissue permeability and limited selectivity. In this study, a novel far-red fluorescent probe ZJL-3 based on rhodamine fluorescent dye was designed, synthesized, and used for NO determination. The probe contains a rhodamine as fluorophore and o-phenylenediamino as recognition unit. Upon addition of NO, the probe ZJL-3 showed an obvious far-red emission at 637 nm. The results of fluorescence spectrum experiments indicated that probe ZJL-3 exhibited desirable selectivity to NO. Furthermore, probe ZJL-3 has low cytotoxicity and was applied for the detection of exogenous and endogenous NO in RAW264.7 cells and C. elegans with satisfactory results.

Nitroso-Caged Rhodamine: A Superior Green Light-Activatable Fluorophore for Single-Molecule Localization Super-Resolution Imaging.

The evolution of super-resolution imaging techniques, especially single-molecule localization microscopy, demands the engineering of switchable fluorophores with labeling functionality. Yet, the switching of these fluorophores depends on the exterior conditions of UV light and enhancing buffers, which is bioincompatible for living-cell applications. Herein, to surpass these limitations, a nitroso-caging strategy is employed to cage rhodamines into leuco forms, which for the first time, is discovered to uncage highly bright zwitterions by green light. Further, clickable construction grants the specificity and versatility for labeling various components in living cells. The simultaneous photoactivation and excitation of these novel probes allow for single-laser super-resolution imaging without any harmful additives. Super-resolution imaging of microtubules in fixed cells or mitochondria and the distribution of glycans and H2B proteins in living cells are achieved at a molecular scale with robust integrity. We envision that our nitroso-caging probes would set a platform for the development of future visible-activatable probes.

Epigenetic targeting of SLC30A3 by HDAC1 is related to the malignant phenotype of glioblastoma.

The epigenetic abnormality is believed as a major driver for cancer initiation. Histone modification plays a vital role in tumor formation and progression. Particularly, alteration in histone acetylation has been highly associated with gene expression, cell cycle, as well as carcinogenesis. By analyzing glioblastoma (GBM)-related microarray from the GEO database and conducting chromatin immunoprecipitation-sequencing (ChIP-seq), we discovered that solute carrier family 30 member 3 (SLC30A3), a super enhancer (SE)-regulated factor, was significantly reduced in GBM tissues. Furthermore, histone deacetylase 1 (HDAC1), overexpressed in GBM tissues, could inhibit SLC30A3 expression by promoting histone H3K27ac deacetylation modification of the SE region of SLC30A3. Our functional validation revealed that SLC30A3 can inhibit the growth and metastatic spread of GBM cells in vitro and in vivo, and can activate the MAPK signaling pathway to promote apoptosis of GBM cells. Moreover, overexpression of HDAC1 resulted in a significant increase in DNA replication activity, a significant decline in apoptosis and cell cycle arrest in GBM cells. In a word, these findings indicate that combined epigenetic targeting of SLC30A3 by HDAC1 and SE is potentially therapeutically feasible in GBM.

E2F2 drives glioma progression via PI3K/AKT in a PFKFB4-dependent manner.

AIMS: The effects of PFKFB4 on glycolysis during the cancer progression has been investigated, while its role in glioma remains unclear. The present study evaluated the molecular mechanism of PFKFB4 in glycolysis of glioma progression. MATERIALS AND METHODS: The pan-cancer platform SangerBox was inquired to investigate the E2F2 expression in tumors. The E2F2 expression was studied by qRT-PCR and immunohistochemistry in collected glioma and normal brain tissues and by qRT-PCR and western blot in glioma cells. The relationship between the E2F2 expression in glioma tissues and patients' prognosis was analyzed. The cell malignant phenotype, glycolysis, growth and metastasis were examined by CCK-8, EdU, colony formation, flow cytometry, wound healing, Transwell assays, ELISA kits, and tumorigenesis and metastasis assays. Downstream targets of E2F2 were searched in hTFtarget, followed by pathway enrichment analysis. The expression of these targets and their correlation with E2F2 expression in gliomas were investigated through the GEPIA website. After ChIP and luciferase assays, the effect of the target on glioma was investigated. KEY FINDINGS: E2F2 was overexpressed in glioma patients and predicted poor prognoses. E2F2 promoted cell proliferation, colony formation, DNA synthesis, migration, invasion and glycolysis, and inhibited apoptosis. Meanwhile, inhibition of E2F2 suppressed the growth and metastasis of gliomas. E2F2 elevated the PFKFB4 expression transcriptionally by binding to its promoter and activated PI3K/AKT pathway. The promotion of glioma metastasis and glycolysis by E2F2 was mitigated by PFKFB4 knockdown. SIGNIFICANCE: E2F2-mediated transcriptional enhancement of PFKFB4 expression regulated the phosphorylation of PI3K/AKT to promote glioma malignancy progression.

Circular RNA CircHIPK3 Elevates CCND2 Expression and Promotes Cell Proliferation and Invasion Through miR-124 in Glioma.

As a malignant tumor of the central nervous system, glioma exhibits high incidence and poor prognosis. Circular RNA HIPK3 (circHIPK3) is a circular RNA (circRNA) related to cancer progression. However, the role of circHIPK3 in gliomas remains unclear. The purpose of this study was to investigate the role of circHIPK3 in gliomas and its mechanism. The qRT-PCR method was used to determine the expression pattern of circHIPK3 in glioma cell lines. CCK-8 assay was used to detect cell proliferation. Cell migration and invasion were evaluated using the Transwell assay. Our results showed that circHIPK3 expression was significantly up-regulated in glioma tissues and cell lines. In vitro, the down-regulation of circHIPK3 significantly inhibited the proliferation, migration and invasion of glioma cells. Besides, we demonstrated that circHIPK3 acted as a sponge to absorb miR-124 and promoted CCND2 expression. In summary, our results indicated that circHIPK3 had carcinogenic effects by regulating the expression of CCND2 in glioma by sponging miR-124. These findings provided favorable evidence to reveal the role of circHIPK3 in the development of gliomas.

A mitochondria-targeted two-photon fluorescent probe for sensing and imaging pH changes in living cells.

A novel two-photon pH probe, 3-benzimidazole-7-hydroxycoumarin (BHC), was designed and synthesized based on the structures of hydroxycoumarin and benzimidazole. BHC showed good linearity in the pH ranges of 3.30-5.40 (pKa = 4.20) and 6.50-8.30 (pKa = 7.20) at a maximum emission wavelength of 480 nm. BHC in acidic and alkaline media could be distinguished by an obvious spectral shift of the maximum absorption wavelength from 390 nm to 420 nm. In addition, BHC was well localized to mitochondria and successfully applied to one-photon and two-photon imaging of pH changes in the mitochondria of HeLa cells. The findings presented herein suggest that BHC can serve as an excellent fluorescent probe for selectively sensing mitochondrial pH changes with remarkable photostability and low cytotoxicity.

A Polymer Responsive to Reactive Oxygen Species for Safe, Efficient Chemo-Photodynamic Combined Cancer Therapy.

Combining photodynamic therapy (PDT) and chemotherapy can improve anti-cancer efficacy. In this study, a novel copolymer PTPP combining thioketal and protoporphyrin was synthesized and tested for antitumor activity. Self-assembled PTPP micelles loaded with doxorubicin (DOX) showed uniform size, narrow particle size distribution and greater antitumor activity in vivo and in vivo than DOX-loaded micelles made from the commonly used material mPEG-PCL. Under laser irradiation, the photosensitizing protoporphyrin of DOX/PTPP produces abundant reactive oxygen species (ROS) that directly kill tumor cells as well as destroy the micelles themselves, leading to drug release. The ROS and DOX then act synergistically against the tumors. These ROS-responsive, laser-sensitive polymeric micelles may be useful for combining PDT and chemotherapy.