Search

Insect chitinases have been proposed as potential targets for pest control. In this work, a novel group IV chitinase gene, MdCht9, from Musca domestica was found to have multiple functions in the physiological activity, including chitin regulation, development and antifungal immunity. The MdCht9 gene was cloned and sequenced, its phylogeny was analysed and its expression was determined in normal and 20E treated larvae. Subsequently, RNA interference (RNAi)‐mediated MdCht9 knockdown was performed, followed by biochemical assays, morphological observations and transcriptome analysis. Finally, the recombinant protein MdCht9 (rMdCht9) was purified and tested for anti‐microbial activity and enzyme characteristics. The results showed that MdCht9 consists of three domains, highly expressed in a larval salivary gland. RNAi silencing of MdCht9 resulted in significant down‐regulation of chitin content and expression of 15 chitin‐binding protein (CBP) genes, implying a new insight that MdCht9 might regulate chitin content by influencing the expression of CBPs. In addition, more than half of the lethality and partial wing deformity appeared due to the dsMdCht9 treatment. In addition, the rMdCht9 exhibited anti‐microbial activity towards Candida albicans (fungus) but not towards Escherichia coli (G−) or Staphylococcus aureus (G+). Our work expands on previous studies of chitinase while providing a potential target for pest management. [ABSTRACT FROM AUTHOR]

Neurodegeneration is linked to the progressive loss of neural function and is associated with several diseases. Hypoxia is a hallmark in many of these diseases, and several therapies have been developed to treat this disease, including gene expression therapies that should be tightly controlled to avoid side effects. Cells experiencing hypoxia undergo a series of physiological responses that are induced by the activation of various transcription factors. Modulation of microRNA (miRNA) expression to alter transcriptional regulation has been demonstrated to be beneficial in treating multiple diseases, and in this study, we therefore explored potential miRNA candidates that could influence hypoxia-induced nerve cell death. Our data suggest that in mouse neuroblasts Neuro-2a cells with hypoxia/reoxygenation (H/R), miR-337-3p is downregulated to increase the expression of Potassium channel tetramerization domain containing 11 (KCTD11) and subsequently promote apoptosis. Here, we demonstrate for the first time that KCTD11 plays a role in the cellular response to hypoxia, and we also provide a possible regulatory mechanism by identifying the axis of miR-337-3p/KCTD11 as a promising candidate modulator of nerve cell survival after H/R exposure. [ABSTRACT FROM AUTHOR]

The endosymbiont Wolbachia manipulates host reproduction by several strategies, one of the most important of which is cytoplasmic incompatibility (CI). CI can be rescued when Wolbachia‐infected males mate with females infected with the same Wolbachia strain. However, the potential rescue mechanism of CI in the small brown planthopper Laodelphax striatellus is unclear. In this study, comparative transcriptome analysis was applied to explore the effect of Wolbachia on L. striatellus eggs. A total of 1387 differentially expressed genes were identified. RNA interference of 7 Wolbachia‐upregulated key planthopper genes reduced egg reproduction, suggesting that Wolbachia might improve fecundity in L. striatellus by affecting these 7 genes. Suppressing the expression of another upregulated gene, NDUFA8 (encoding NADH dehydrogenase [ubiquinone] 1 α subcomplex subunit 8‐like) by RNA interference significantly increased the mortality of early embryos without affecting the number of deposited eggs. Wolbachia infection upregulated the mRNA level of NDUFA8, and dsNDUFA8 treatment of Wolbachia‐infected females recreated CI‐like symptoms, suggesting that NDUFA8 is associated with the rescue phenotype. Because all L. striatellus populations worldwide are infected with Wolbachia, NDUFA8 is a potential pest control target. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cruciferous black rot is caused by Xanthomonas campestris pv. campestris (Xcc) infection and is a widespread disease worldwide. Excessive and repeated use of bactericide is an important cause of the development of bacterial resistance. It is imperative to take new approaches to screening compounds that target virulence factors rather than kill bacterial pathogens. The type III secretion system (T3SS) invades a variety of cells by transporting virulence effector factors into the cytoplasm and is an attractive antitoxic target. Toward the search of new T3SS inhibitors, an alternative series of novel pyrimidin‐4‐one derivatives were designed and synthesized and assessed for their effect in blocking the virulence. RESULTS: All of the target compounds were characterized by proton (1H) nuclear magnetic resonance (NMR), carbon‐13 (13C) NMR, fluorine‐19 (19F) NMR and high‐resolution mass spectrometry (HRMS). All compounds were evaluated using high‐throughput screening systems against Xcc. The results of the biological activity test revealed that the compound SPF‐9 could highly inhibit the activity of xopN gene promoter and the hypersensitivity (HR) of tobacco without affecting bacterial growth. Moreover, messenger RNA (mRNA) level measurements showed that compound SPF‐9 inhibited the expression of some representative genes (hrp/hrc genes). Compound SPF‐9 weakened the pathogenicity of Xcc to Raphanus sativus L. CONCLUSION: Compound SPF‐9 has good potential for further development as a novel T3SS inhibitor against Xcc. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Aim: Progesterone resistance is an epigenetic factor that reduces endometrial receptivity and causes implantation failure in women with endometriosis. In addition, dysregulated miRNAs contribute to the underlying pathogenic mechanisms of endometriosis. This study aimed to determine the effect of miR‐297 on the progesterone receptor (PR) expression and on insufficient decidualization of endometrial stromal cells (ESCs) within the eutopic endometria of infertile women with minimal or mild endometriosis. Methods: ESCs were isolated from infertile endometriosis and normal patients and were transfected with miR‐297 mimic or miR‐297 inhibitor or respective control. qRT‐PCR and western blot were conducted to quantify the expression of miR‐297 and PR. The effect of miR‐297 on ESCs decidualization was investigated by induced decidualization in vitro. Results: We observed an increase in miR‐297 expression and a decrease in the expression of PR in the ESCs from endometriosis patients. Moreover, the expression of PR, most notably PRB, was found to be downregulated following transfection with miR‐297 mimic and upregulated following treatment with miR‐297 inhibitor. In addition, overexpressed miR‐297 inhibited the decidualization of ESCs in vitro. We further determined that miR‐297 exerts direct regulatory effects on PR expression. Conclusions: We demonstrated that miR‐297 interferes with fertility by repressing the expression of PR and preventing efficient decidualization in eutopic endometria. Further, miR‐297 directly contributes to progesterone resistance in minimal or mild cases of endometriosis. Thus, regulation of miR‐297 may prove to be a promising therapeutic strategy for endometriosis. [ABSTRACT FROM AUTHOR]

The effect of genistein (GEN) on the gene expression level of stromal cell‐derived factor‐1/CXCL‐12 and early growth response gene‐1 was studied in ovarian tissue of young and initially ageing (early stages in the ageing process) female rats. Forty, young female Sprague Dawley (SD) rats of 2–3 months old (200 ±20 g) and forty, initially ageing female SD rats of 10–12 months (490 ± 20 g) old were selected. According to the weight, rats were divided into control group, low‐dose group (L), medium‐dose group (M) and a high‐dose group (H) and were given 15, 30 and 60 mg/kg GEN respectively. The positive control (Oestrogen) group was given 0.5 mg/kg diethylstilbestrol. The treatment lasted for 30 days. The mRNA expression of C‐X‐C motif chemokine ligand 12 (CXCL‐12) and early growth response factor‐1 (EGR‐1) was measured by real‐time PCR, and protein expression of EGR‐1 was detected by Western blot. When compared to the negative control group (NC), the ovary/body weight ratio in the young rats decreased in the GEN group, but the difference was not significant. Similarly, compared with NC, the ovary/body weight ratio in the initially ageing rats also decreased with the increase in GEN concentration, but the decrease was significant in M and H groups (p <.01). The administration of GEN enhanced both the gene and protein expression levels of CXCL‐12 and EGR‐1 in the ovary. Pearson's correlation analysis showed a synergistic effect between CXCL‐12 and EGR‐1. Thus, we conclude that the effect of GEN on CXCL‐12 and EGR‐1 in the initially ageing group was obvious than that in the younger group. [ABSTRACT FROM AUTHOR]

In this study, we cloned the complementary (c)DNA sequences of tumour necrosis factor receptor (TNFR)‐associated factor 3 (traf3) in Nile tilapia, Oreochromis niloticus. The expression patterns of the traf3 gene were investigated and preliminary functional analyses were performed. In healthy fish, traf3 transcript was broadly expressed in all examined tissues, with the highest expression level in the blood and the lowest in the liver. The traf3 gene reached its highest expression at 8 days post‐fertilisation (dpf) during embryonic development. Moreover, we found that expression of traf3 was clearly altered following stimulation with Streptococcus agalactiae in vivo and that traf3 could be induced by lipopolysaccharides (LPS), Poly I: C and S. agalactiae WC1535 in Nile tilapia macrophages. Overexpression in 293T cells showed that Traf3 protein was mainly distributed in the cytoplasm and could significantly increase nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) activation. Taken together, these results implied that traf3 could play important roles in the immune response to pathogen invasion. [ABSTRACT FROM AUTHOR]

Six new cell lines were established from embryonic tissues of the diamondback moth, Plutella xylostella (L.). The cell lines showed differential characteristics, including growth in attachment or in suspension, susceptibility to a baculovirus infection and expression of genes involved in the glucosinolate detoxification pathway in P. xylostella larvae. Five of the cell lines grew attached to the culture flask and one cell line grew unattached as a suspension cell line. The cell lines had population doubling times ranging from 18 to 23 h. Among five of the P. xylostella cell lines examined for infection of a nucleopolyhedrovirus from Autographa californica, AcMNPV, four cell lines were highly susceptible to AcMNPV infection, but one was only semi‐permissive to AcMNPV infection. The production of two recombinant proteins, a β‐galactosidase of bacterial origin and a secreted alkaline phosphatase of eukaryotic origin, in the P. xylostella cell lines was examined in comparison with that in the cell line Sf9 which is commonly used for recombinant protein production. In the P. xylostella cell lines, expression of three important midgut genes involved in the glucosinolate detoxification pathway, including the glucosinolate sulfatase genes GSS1 and GSS2 and the sulfatase modifying factor gene SUMF1, was detected. The P. xylostella cell lines developed in this study could be useful in in vitro research systems for studying insec–virus interactions and complex molecular mechanisms in glucosinolate detoxification and insect–plant interactions. [ABSTRACT FROM AUTHOR]

The diamondback moth, Plutella xylostella (L.), uses sulfatases (SULF) to counteract the glucosinolate–myrosinase defensive system that cruciferous plants have evolved to deter insect feeding. Sulfatase activity is regulated by post‐translational modification of a cysteine residue by sulfatase modifying factor 1 (SUMF1). We identified 12 SULF genes (PxylSulfs) and two SUMF1 genes (PxylSumf1s) in the P. xylostella genome. Phylogenetic analysis of SULFs and SUMFs from P. xylostella, Bombyx mori, Manduca sexta, Heliconius melpomene, Danaus plexippus, Drosophila melanogaster, Tetranychus urticae and Homo sapiens showed that the SULFs were clustered into five groups, and the SUMFs could be divided into two groups. Profiling of the expression of PxylSulfs and PxylSumfs by RNA‐seq and by quantitative real‐time polymerase chain reaction showed that two glucosinolate sulfatase genes (GSS), PxylSulf2 and PxylSulf3, were primarily expressed in the midgut of 3rd‐ and 4th‐instar larvae. Moreover, expression of sulfatases PxylSulf2, PxylSulf3 and PxylSulf4 were correlated with expression of the sulfatases modifying factor PxylSumf1a. The findings from this study provide new insights into the structure and expression of SUMF1 and PxylSulf genes that are considered to be key factors for the evolutionary success of P. xylostella as a specialist herbivore of cruciferous plants. [ABSTRACT FROM AUTHOR]

Hepatitis B virus core protein (HBc) has been implicated in hepatocarcinogenesis through several mechanisms. Resistance of hepatitis B virus (HBV)-infected hepatocytes to apoptosis is considered one of the major contributors to the progression of chronic hepatitis to cirrhosis and ultimately to hepatocellular carcinoma. The Fas receptor/ligand (Fas/FasL) system plays a prominent role in hepatocyte death during HBV infection. Here we report that HBc mediates resistance of hepatoma cells to agonistic anti-Fas antibody (CH11)-induced apoptosis. When HBc was introduced into human hepatoma cells, the cells became resistant to CH11 cyto-toxicity in a p53-dependent manner. HBc significantly down-regulated the expression of p53, total Fas, and membrane-bound Fas at the mRNA and protein levels and reduced FasL mRNA expression. In contrast, HBc up-regulated the expression of soluble forms of Fas by increasing Fas alternative mRNA splicing. Mechanistically, HBc-mediated Fas alternative mRNA splicing was associated with up-regulation of polypyrimidine tract-binding protein 1 and down-regulation of Fas-activated serine/ threonine kinase. These results indicated that HBc may prevent hepatocytes from Fas-induced apoptosis by the dual effects of reducing the expression of the proapoptotic form of Fas and enhancing the expression of the antiapoptotic form of the receptor, which may contribute to the survival and persistence of infected hepatocytes during chronic infection. [ABSTRACT FROM AUTHOR]

Aim: 5-Fluorouracil (5-FU) is one of the most commonly used chemotherapeutic drugs. Resistance to 5-FU is a major cause of chemotherapy failure in advanced-stage hepatocellular carcinoma (HCC). Green tea polyphenol Epigallocatechin-3-gallate (EGCG) plays a critical role in growth inhibition and apoptotic induction in HCC cell lines. The aim of this study is to investigate whether EGCG can enhance 5-FU-induced cell growth inhibition and to explore its potential mechanisms. Methods: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate cell growth. Western blotting analysis was performed to detect the proteins expression in Hep3B cells. Small interfering RNA was used to suppress cyclooxygenase-2 (COX-2) expression. Furthermore, enzyme linked immunosorbent assay was used to test the prostaglandin E2 (PGE2) production in cell cultures. Results: Epigallocatechin-3-gallate augmented the anti-tumor effect of 5-FU in Hep3B cells. Significant difference was observed between the treated groups and the control group ( P < 0.05). EGCG (its concentrations at over 5 µmol/L) combined with 5-FU presented a synergic effect. Furthermore, the combination of EGCG and 5-FU abrogated the COX-2 overexpression and PGE2 secretion induced by 5-FU. The upregulation of COX-2 expression decreased the phosphorylation of Akt (Thr308) expression. These appeared to be followed by the AMPK hyperactivation. Conclusion: Epigallocatechin-3-gallate sensitizes HCC cells to 5-FU antitumor activity, and the combination of EGCG and 5-FU exhibits synergism in chemo-resistant cancer cells. The results suggest potential novel therapies for the treatment of advanced-stage liver cancer. [ABSTRACT FROM AUTHOR]

In the myelodysplastic syndromes (MDS), the haematopoietic cells show various levels of abnormal maturation and differentiation, which can be detected by flow cytometry. Testing the anomalies of stage- or lineage-specific surface antigens in CD34+ blasts can distinguish MDS from non-clonal cytopenic diseases, and also reflect the pathological characteristics of MDS as a class of clonal diseases for providing new clues to basic research. The present study established a flow cytometric scoring system (FCMSS) based on theproportion and antigenic co-expression of CD34+ blasts. This FCMSS showed good sensitivity and specificity (77·8% and 100%) in the assisted diagnosis of low-risk MDS without chromosome anomalies, ringed sideroblasts and excess marrow blasts. Moreover, we explored and reported different modes of abnormal expression of CD34+ blasts antigens in different disease stages and analyzed the biological significance of the immunotypes for the first time. We found expression of mature myeloid antigens and lymphoid antigens gradually decreased, and early functional antigens gradually increased from low-risk MDS with normal karytype to low-risk MDS with abnormal karyotype then to high-risk MDS. The patients with higher FCM scores were generally accompanied with HLA-DR15 allele or hypocellular marrow. Evolution of clones and immunological factors might have influence on expression of antigens in CD34+ blasts. [ABSTRACT FROM AUTHOR]

Cell-wall invertase plays an important role in sucrose partitioning between source and sink organs in higher plants. To investigate the role of cell-wall invertases for seed development in rice ( Oryza sativa L.), cDNAs of three putative cell-wall invertase genes OsCIN1, OsCIN2 and OsCIN3 were isolated. Semi-quantitative reverse transcription-polymerase chain reaction analysis revealed different expression patterns of the three genes in various rice tissues/organs. In developing caryopses, they exhibited similar temporal expression patterns, expressed highly at the early and middle grain filling stages and gradually declined to low levels afterward. However, the spatial expression patterns of them were very different, with OsCIN1 primarily expressed in the caryopsis coat, OsCIN2 in embryo and endosperm, and OsCIN3 in embryo. Further RNA in situ hybridization analysis revealed that a strong signal of OsCIN2 mRNA was detected in the vascular parenchyma surrounding the xylem of the chalazal vein and the aleurone layer, whereas OsCIN3 transcript was strongly detected in the vascular parenchyma surrounding the phloem of the chalazal vein, cross-cells, the aleurone layer and the nucellar tissue. These data indicate that the three cell-wall invertase genes play complementary/synergetic roles in assimilate unloading during the grain filling stage. In addition, the cell type-specific expression patterns of OsCIN3 in source leaf blades and anthers were also investigated, and its corresponding physiological roles were discussed. [ABSTRACT FROM AUTHOR]