Detoxification of Aflatoxin B1 by Phytochemicals in Agriculture and Food Science.

Aflatoxin B1 (AFB1), the most toxic and harmful mycotoxin, has a high likelihood of occurring in animal feed and human food, which seriously affects agriculture and food safety and endangers animal and human health. Recently, natural plant products have attracted widespread attention due to their low toxicity, high biocompatibility, and simple composition, indicating significant potential for resisting AFB1. The mechanisms by which these phytochemicals resist toxins mainly involve antioxidative, anti-inflammatory, and antiapoptotic pathways. Moreover, these substances also inhibit the genotoxicity of AFB1 by directly influencing its metabolism in vivo, which contributes to its elimination. Here, we review various phytochemicals that resist AFB1 and their anti-AFB1 mechanisms in different animals, as well as the common characteristics of phytochemicals with anti-AFB1 function. Additionally, the shortcomings of current research and future research directions will be discussed. Overall, this comprehensive summary contributes to the better application of phytochemicals in agriculture and food safety.

A ribosomal gene panel predicting a novel synthetic lethality in non-BRCAness tumors.

Poly (ADP-ribose) polymerase (PARP) inhibitors are one of the most exciting classes of targeted therapy agents for cancers with homologous recombination (HR) deficiency. However, many patients without apparent HR defects also respond well to PARP inhibitors/cisplatin. The biomarker responsible for this mechanism remains unclear. Here, we identified a set of ribosomal genes that predict response to PARP inhibitors/cisplatin in HR-proficient patients. PARP inhibitor/cisplatin selectively eliminates cells with high expression of the eight genes in the identified panel via DNA damage (ATM) signaling-induced pro-apoptotic ribosomal stress, which along with ATM signaling-induced pro-survival HR repair constitutes a new model to balance the cell fate in response to DNA damage. Therefore, the combined examination of the gene panel along with HR status would allow for more precise predictions of clinical response to PARP inhibitor/cisplatin. The gene panel as an independent biomarker was validated by multiple published clinical datasets, as well as by an ovarian cancer organoids library we established. More importantly, its predictive value was further verified in a cohort of PARP inhibitor-treated ovarian cancer patients with both RNA-seq and WGS data. Furthermore, we identified several marketed drugs capable of upregulating the expression of the genes in the panel without causing HR deficiency in PARP inhibitor/cisplatin-resistant cell lines. These drugs enhance PARP inhibitor/cisplatin sensitivity in both intrinsically resistant organoids and cell lines with acquired resistance. Together, our study identifies a marker gene panel for HR-proficient patients and reveals a broader application of PARP inhibitor/cisplatin in cancer therapy.

Copper chaperone antioxidant 1: multiple roles and a potential therapeutic target.

Copper (Cu) was recently demonstrated to play a critical role in cellular physiological and biochemical processes, including energy production and maintenance, antioxidation and enzymatic activity, and signal transduction. Antioxidant 1 (ATOX1), a chaperone of Cu previously named human ATX1 homologue (HAH1), has been found to play an indispensable role in maintaining cellular Cu homeostasis, antioxidative stress, and transcriptional regulation. In the past decade, it has also been found to be involved in a variety of diseases, including numerous neurodegenerative diseases, cancers, and metabolic diseases. Recently, increasing evidence has revealed that ATOX1 is involved in the regulation of cell migration, proliferation, autophagy, DNA damage repair (DDR), and death, as well as in organism development and reproduction. This review summarizes recent advances in the research on the diverse physiological and cytological functions of ATOX1 and the underlying mechanisms of its action in human health and diseases. The potential of ATOX1 as a therapeutic target is also discussed. This review aims to pose unanswered questions related to ATOX1 biology and explore the potential use of ATOX1 as a therapeutic target.

[Practices of integrating the undergraduate and graduate teaching of Biochemistry and Molecular Biology].

Biochemistry and Molecular Biology are the cornerstone courses of talent training in the field of life science. Taking these course as an example, this study explored reconstructing the knowledge framework, developing teaching cases, sharing teaching resources, innovating teaching means and establishing ideological education patterns. Supported by the scientific research achievements with discipline characteristics and online teaching platform, this research explored and practiced an integrated curriculum reform mode. This mode is guided by scientific research and education, based on the course development, and driven by communication and cooperation. A shared space of "exchange, practice, openness and informatization" was developed to achieve free and independent integration of undergraduate and graduate teaching motivated by learning knowledge, resulting in an effective student training.

MiR-18 inhibitor promotes the differentiation of bovine skeletal muscle-derived satellite cells by increasing MEF2D expression.

Skeletal muscle is composed of muscle fibers formed from myoblast differentiation. Recently, numerous researchers have demonstrated that microRNAs (miRNAs) play an essential role in modulating the proliferation and differentiation of myoblasts. Our previous study has shown that among the miR-17-92 cluster members, miR-17 and miR-20a together with miR-19b can efficiently promote the differentiation of murine C2C12 and bovine primary myoblasts. However, the role of miR-18 in this process remains elusive. In this study, we revealed that miR-18 inhibited the differentiation of bovine skeletal muscle-derived satellite cells (bMDSCs), whereas an miR-18 inhibitor significantly promoted cell differentiation (p < 0.001). Then, a target gene of miR-18 was found to be myocyte enhancer factor 2D (MEF2D), which is critical for myoblast differentiation. Furthermore, we found that the combination of the miR-18 inhibitor and miR-19 significantly improved the formation of bMDSCs-derived muscle fibers (p < 0.001). This study revealed the role of miR-18 in bovine skeletal muscle differentiation and contributed to the understanding of the regulatory mechanism of mammalian myogenic differentiation.

Beef is a beneficial food source, and improving muscle yield and quality has become a hot topic in the beef industry. Therefore, our study aimed to explore effective methods to improve bovine muscle cell differentiation to increase beef production. The study revealed that microRNA-18 (miR-18) inhibitor could promote the differentiation of bovine skeletal muscle-derived satellite cells (bMDSCs) by increasing the expression of myocyte enhancer factor 2D (MEF2D), a critical gene for myoblast differentiation. Furthermore, we found that combined inhibitors of miR-18 and miR-19 could significantly improve bMDSCs differentiation. Our study demonstrated the role of a new regulatory factor that may enhance beef production level and contributed to elucidating the mechanism of muscle differentiation.

Study on Lgr5 expression in pancreas tissues and organoids by lineage tracing.

Leucine rich repeat containing G protein-coupled receptor 5(Lgr5) is widely expressed in multiple tissues and can be used as a stem cell marker in a variety of epithelial organs (including the small intestine, colon, stomach and hair follicles). In this study, we used Lgr5-CreERT2+/- and Rosa26-mTmG hybridized transgenic mice to investigate the expression of Lgr5 in both ductal epithelial cells during pancreas development and in vitro cultured pancreatic duct organoids. After induction with Tamoxifen, the Lgr5 expression was analyzed by detecting the enhanced green fluorescence protein in the pancreatic tissue sections in adult animals and embryos at different developmental stages. The results showed that Lgr5 expression was detected neither in adult pancreatic duct epithelia nor in the embryonic pancreatic tissues at day 15.5 or in newborn mice. However, when 4-hydroxy-Tamoxifen was supplemented to the culture medium, EGFP could be detected in the primary pancreatic duct organoids from Lgr5-Cre ERT2+/-; Rosa26-mTmG mice. These results suggested that Lgr5 was not expressed in adult and embryonic pancreatic tissues; but could be expressed in the cultured pancreas ductal organoids. The research lays the foundation for exploring specific gene expression patterns in stem/progenitor cells during pancreatic development.

A saponin from astragalus promotes pancreatic ductal organoids differentiation into insulin-producing cells.

BACKGROUND: Islet transplantation is an effective treatment for the type 1 and severe type 2 diabetes, but it is restricted by the severe lack of pancreas donors. In vitro differentiation of pancreatic progenitors into insulin-secreting cells is one of the hopeful strategies in the cell transplantation therapy of diabetes. Isoastragaloside I is one of the saponin molecules found in Astragalus membranaceus, which has been demonstrated to alleviate insulin resistance and glucose intolerance in obese mice. STUDY DESIGN: We established mouse pancreatic ductal organoids (mPDOs) with progenitor characteristics and an insulin promoter-driven EGFP reporter system to screen astragalus saponin components for monomers that can promote insulin-producing cell differentiation. METHODS: mPDOs treated with or without astragalus saponin monomers were investigated by the insulin promoter-driven EGFP reporter, quantitative PCR, immunofluorescence and flow cytometry to evaluate the expression of endocrine progenitor and ß-cell markers. RESULTS: Isoastragaloside I significantly promoted the expression of ß-cell differentiation genes, which was demonstrated by the activation of the insulin promoter-driven EGFP reporter, as well as the significant increase of mRNA levels of the endocrine progenitor marker Ngn3 and the ß-cell markers insulin1 and insulin2. Immunostaining studies indicated that the ß-cell-specific C-peptide was upregulated in isoastragaloside I-treated mPDOs. FACS analysis revealed that the ratio of C-peptide-secreting cells in isoastragaloside I-treated mPDOs was over 40%. Glucose tolerance tests demonstrated that the differentiated mPDOs could secrete C-peptide in response to glucose stimulation. CONCLUSIONS: We discover a novel strategy of inducing pancreatic ductal progenitors to differentiate into insulin-producing cells using isoastragaloside I. This approach can be potentially applied to ß-cell transplantation in diabetes therapies.

A histidine cluster determines YY1-compartmentalized coactivators and chromatin elements in phase-separated enhancer clusters.

As an oncogenic transcription factor, Yin Yang 1 (YY1) regulates enhancer and promoter connection. However, gaps still exist in understanding how YY1 coordinates coactivators and chromatin enhancer elements to assemble enhancers and super-enhancers. Here, we demonstrate that a histidine cluster in YY1's transactivation domain is essential for its formation of phase separation condensates, which can be extended to additional proteins. The histidine cluster is also required for YY1-promoted cell proliferation, migration, clonogenicity and tumor growth. YY1-rich nuclear puncta contain coactivators EP300, BRD4, MED1 and active RNA polymerase II, and colocalize with histone markers of gene activation, but not that of repression. Furthermore, YY1 binds to the consensus motifs in the FOXM1 promoter to activate its expression. Wild-type YY1, but not its phase separation defective mutant, connects multiple enhancer elements and the FOXM1 promoter to form an enhancer cluster. Consistently, fluorescent in situ hybridization (FISH) assays reveal the colocalization of YY1 puncta with both the FOXM1 gene locus and its nascent RNA transcript. Overall, this study demonstrates that YY1 activates target gene expression through forming liquid-liquid phase separation condensates to compartmentalize both coactivators and enhancer elements, and the histidine cluster of YY1 plays a determinant role in this regulatory mechanism.

Copper enhances genotoxic drug resistance via ATOX1 activated DNA damage repair.

Copper is involved in various biochemical and physiological processes. The absorbed copper ions are transported to the intracellular destination via copper chaperones, such as ATOX1. Previous studies have demonstrated that neoplastic cells have a high demand for copper; however, its role in cancer cells has not been fully elucidated. Here, we reveal that the high level of copper contributes to drug resistance and repair of damaged DNA in cancer cells at least partially via ATOX1-induced expression of MDC1, a crucial protein involved in double-strand DNA damage repair. Specifically, ATOX1 enters into nuclear to target MDC1 promoter after treatments of various genotoxic agents, thus promoting the transcription of MDC1 in a copper-dependent manner. Therefore, knockout or blockage of ATOX1 conferred sensitivity to Gemcitabine in transplanted tumor mouse models. Together, our findings gain new insight into the role of copper in DNA damage repair and provide a novel strategy for clinical cancer therapy of drug-resistance cancers.

Comparative transcriptome analysis of rainbow trout gonadal cells (RTG-2) infected with U and J genogroup infectious hematopoietic necrosis virus.

Infectious hematopoietic necrosis virus (IHNV) is the causative pathogen of infectious hematopoietic necrosis, outbreaks of which are responsible for significant losses in rainbow trout aquaculture. Strains of IHNV isolated worldwide have been classified into five major genogroups, J, E, L, M, and U. To date, comparative transcriptomic analysis has only been conducted individually for the J and M genogroups. In this study, we compared the transcriptome profiles in U genogroup and J genogroup IHNV-infected RTG-2 cells with mock-infected RTG-2 cells. The RNA-seq results revealed 17,064 new genes, of which 7,390 genes were functionally annotated. Differentially expressed gene (DEG) analysis between U and J IHNV-infected cells revealed 2,238 DEGs, including 1,011 downregulated genes and 1,227 upregulated genes. Among the 2,238 DEGs, 345 new genes were discovered. The DEGs related to immune responses, cellular signal transduction, and viral diseases were further analyzed. RT-qPCR validation confirmed that the changes in expression of the immune response-related genes trpm2, sting, itgb7, ripk2, and irf1, cellular signal transduction-related genes irl, cacnb2, bmp2l, gadd45α, and plk2, and viral disease-related genes mlf1, mtor, armc5, pik3r1, and c-myc were consistent with the results of transcriptome analysis. Taken together, our findings provide a comprehensive transcriptional analysis of the differential virulence of the U and J genogroups of IHNV, and shed new light on the pathogenic mechanisms of IHNV strains.

[The value of diversifying blackboard writing in college education: taking Biochemistry teaching as an example].

Blackboard writing undertakes the dual task of knowledge transmission and classroom culture inheritance. Well-designed blackboard writing will not only help students to better memorize, understand and construct knowledge framework, but also create a serious but lively classroom atmosphere, strengthen the soul of moral education in the classroom, leading to improved quality of education. Taking the practice of blackboard writing in teaching the Biochemistry course as an example, the authors categorized the blackboard writing approaches according to the teaching objectives to be achieved, and discussed the necessity and application scope of each type of blackboard writing approach in the multimedia era. Our goal was to make blackboard writing, a conventional teaching approach, play an important role in the new era of classroom education.

Establishment of a specific in vivo Cu(â ) reporting system based on metallothionein screening.

Copper is one of the indispensable trace metal elements in organisms, but excess copper means cytotoxicity. Cells protect themselves by storing excess copper in copper-binding proteins. Metallothioneins (MTs) are a group of low-molecular-weight, cysteine-rich proteins, which are well known for sensing and binding the overcharged Zn(Ⅱ), Cd(Ⅱ), and Cu(Ⅰ) in cells. However, there are only few reports on MTs that can specifically respond to intracellular copper ions in mammals in real-time. Here, we screened copper-response MTs in pancreatic cancer cells through data-mining, RNA-seq, and qPCR analysis. We found that MT1E, MT1F, and MT1X mRNA were significantly upregulated after exogenous copper ion induction. By constructing the stable cell lines with MT1E, MT1F, or MT1X promoter-driven EGFP as reporters, we found that only PMT1F-EGFP could specifically and stably report the intracellular Cu(Ⅰ) changes in multiple cell lines including Panc-1, 8988T, 293T, HepG2, and normal hepatic cells, indicating that PMT1F-EGFP is an ideal in vivo Cu(Ⅰ) reporter. Using the PMT1F-EGFP reporter, we found that MEK inhibitors (U0126) and Astragaloside IV could significantly increase intracellular copper ions. According to these results, PMT1F-EGFP reporter can sense intracellular copper change and can be used to screen copper-target drugs and study copper-related cellular physiology and pathology.

MiR-7 mediates mitochondrial impairment to trigger apoptosis and necroptosis in Rhabdomyosarcoma.

BACKGROUND: Rhabdomyosarcoma (RMS) is a pediatric cancer with rhabdomyoblastic phenotype and mitochondria act as pivotal regulators of its growth and progression. While miR-7-5p (miR-7) is reported to have a tumor-suppressive role, little is yet known about its antitumor activity in RMS. METHODS: The effects of miR-7 on RMS were analyzed both in vitro and in vivo. Cell death modalities induced by miR-7 were identified. Influence on mitochondria was evaluated through RNA sequencing data, morphological observation and mitochondrial functional assays, including outer membrane permeability, bioenergetics and redox balance. Dual-luciferase assay and phenotype validation after transient gene silencing were performed to identify miR-7 targets in RMS. RESULTS: MiR-7 executed anti-tumor effect in RMS beyond proliferation inhibition. Morphologic features and molecular characteristics with apoptosis and necroptosis were found in miR-7-transfected RMS cells. Chemical inhibitors of apoptosis and necroptosis were able to prevent miR-7-induced cell death. Further, we identified that mitochondrial impairment mainly contributed to these phenomena and mitochondrial proteins SLC25A37 and TIMM50 were crucial targets for miR-7 to induce cell death in RMS. CONCLUSION: Our results extended the mechanism of miR-7 antitumor role in rhabdomyosarcoma cancer, and provided potential implications for its therapy.

Copper promotes sheep pancreatic duct organoid growth by activation of an antioxidant protein 1-dependent MEK-ERK pathway.

Proper amounts of copper supplemented in livestock feed improve the physical growth and traits of farm animals. The pancreas is an important organ with both exocrine and endocrine portions. To investigate the role and mechanism of copper in the sheep pancreas, we first established sheep pancreatic duct organoids (sPDOs). We found that an appropriate amount of copper benefited the formation and growth of sPDOs, whereas excess or deficient copper damaged sPDOs. We found that the proliferation-stimulating effect of copper was related to the copper chaperone antioxidant protein 1 (ATOX1)-dependent activation of MEK-ERK1/2 signaling. Atox1 knockdown suppressed the cell proliferation of sPDOs, even in the presence of the MEK activator. These results indicate that moderate concentrations of copper promote sPDO growth through ATOX1-regulated cell proliferation by activation of MEK-ERK. Moreover, our study indicates that organoids may be a useful model to study organ growth mechanisms in livestock.

Molecular chaperone HspB2 inhibited pancreatic cancer cell proliferation via activating p53 downstream gene RPRM, BAI1, and TSAP6.

Heat shock proteins (HSPs) were known as the molecular chaperones, which play a pivotal role in the protein quality control system, ensuring correct folding of proteins, and facilitating the correct refolding of damaged proteins via the transient interaction with their substrate proteins. They also practice in the regulation of cell cycles and are involved in apoptosis. We found that HspB2 was almost completely silent in pancreatic cancer and few studies investigated the role of HspB2 in cancer cells, particularly in pancreatic cancer. Here, we reported that HspB2 effectively inhibited cell proliferation in Panc-1 cells. Specifically, we demonstrated that HspB2 could combine mut-p53 and change the DNA binding site of mutant p53, subsequently upregulated the expression of RPRM, BAI-1, and TSAP6 which were the downstream genes of wt-p53, participate in mediating downstream responses to p53, including inhibiting cell proliferation and angiogenesis. The main aim of this study is to investigate the relationship between HspB2 and p53, and provide a novel treatment strategy for pancreatic cancer.

EGF suppresses the expression of miR-124a in pancreatic ß cell lines via ETS2 activation through the MEK and PI3K signaling pathways.

Diabetes mellitus is characterized by pancreatic ß cell dysfunction. Previous studies have indicated that epidermal growth factor (EGF) and microRNA-124a (miR-124a) play opposite roles in insulin biosynthesis and secretion by beta cells. However, the underlying mechanisms remain poorly understood. In the present study, we demonstrated that EGF could inhibit miR-124a expression in beta cell lines through downstream signaling pathways, including mitogen-activated protein kinase kinase (MEK) and phosphatidylinositol 3-kinase (PI3K) cascades. Further, the transcription factor ETS2, a member of the ETS (E26 transformation-specific) family, was identified to be responsible for the EGF-mediated suppression of miR-124a expression, which was dependent on ETS2 phosphorylation at threonine 72. Activation of ETS2 decreased miR-124a promoter transcriptional activity through the putative conserved binding sites AGGAANA/TN in three miR-124a promoters located in different chromosomes. Of note, ETS2 played a positive role in regulating beta cell function-related genes, including miR-124a targets, Forkhead box a2 (FOXA2) and Neurogenic differentiation 1 (NEUROD1), which may have partly been through the inhibition of miR-124 expression. Knockdown and overexpression of ETS2 led to the prevention and promotion of insulin biosynthesis respectively, while barely affecting the secretion ability. These results suggest that EGF may induce the activation of ETS2 to inhibit miR-124a expression to maintain proper beta cell functions and that ETS2, as a novel regulator of insulin production, is a potential therapeutic target for diabetes mellitus treatment.

Common Carp mef2 Genes: Evolution and Expression.

The MEF2 (myocyte enhancer factor 2) family belongs to the MADS-box superfamily of eukaryotic transcription factors. The vertebrate genes compose four distinct subfamilies designated MEF2A, -B, -C, and -D. There are multiple mef2 genes in the common carp (Cyprinus carpio). So far, the embryonic expression patterns of these genes and the evolution of fish mef2 genes have been barely investigated. In this study, we completed the coding information of C. carpio mef2ca2 and mef2d1 genes via gene cloning and presented two mosaic mef2 sequences as evidence for recombination. We also analyzed the phylogenetic relationship and conserved synteny of mef2 genes and proposed a new evolutionary scenario. In our version, MEF2B and the other three vertebrate subfamilies were generated in parallel from the single last ancestor via two rounds of whole genome duplication events that occurred at the dawn of vertebrates. Moreover, we examined the expression patterns of C. carpio mef2 genes during embryogenesis, by using whole-mount in situ hybridization, and found the notochord to be a new expression site for these genes except for mef2ca1&2. Our results thus provide new insights into the evolution and expression of mef2 genes.

Expansion and Maintenance of CD133-Expressing Pancreatic Ductal Epithelial Cells by Inhibition of TGF-ß Signaling.

Restoring ß-cell mass by the transplantation of pancreatic islets is an effective diabetes treatment, but it is limited by the shortage of donor organs. CD133-expressing pancreatic ductal epithelial cells (PDECs) have the ability to generate insulin-producing cells. The expansion of these cells is dependent on extrinsic niche factors, but few of those signals have been identified. In this study, CD133-expressing PDECs were purified by sorting from adult wild-type C57BL/6 mice and TGFßRIInull/null mice. Furthermore, using immunofluorescence and transplantation assays, we found that the inhibition of the transforming growth factor-ß (TGF-ß) pathway promoted the expansion of CD133-expressing PDECs for many generations and maintained the ability of CD133-expressing PDECs to generate insulin-producing cells. Moreover, western blot, qRT-PCR, and dual luciferase assays using TGF-ß inhibitors were performed to identify the mechanisms by which TGF-ß signaling regulates proliferation and differentiation. The results showed that the inhibition of TGF-ß signaling enhanced Id2 binding to the promoter region of the cell proliferation repressor p16 and promoted the expansion of CD133-expressing PDECs, and the increased Id2 binding to NeuroD1 decreased the transcription of Pax6 to maintain CD133-expressing PDECs in the Pdx1-expression stage. Taken together, the effect of TGF-ß antagonists on CD133-expressing PDECs reveals a novel paradigm of signaling that explains the balance between the expansion and differentiation of pancreatic duct epithelial progenitors.

miR-19 family: A promising biomarker and therapeutic target in heart, vessels and neurons.

The miR-19 family, including miR-19a, miR-19b-1 and miR-19b-2, arises from two different paralogous clusters miR-17-92 and miR-106a-363. Although it is identified as oncogenic miRNA, the miR-19 family has also been found to play important roles in regulating normal tissue development. The precise control of miR-19 family level is essential for keeping tissue homeostasis and normal development of organisms. Its dysregulation leads to dysplasia, disease and even cancer. Therefore, this review focuses on the roles of miR-19 family in the development and disease of heart, vessels and neurons to estimate the potential value of miR-19 family as diagnostic biomarker or therapeutic target of cardiac, neurological, and vascular diseases.