OBP83b and OBP49a Involved in the Perception of Female-Derived Pheromones in Bactrocera dorsalis (Hendel).

In Bactrocera dorsalis, both males and females release chemical signals to attract mates. In our previous study, we identified ethyl laurate, ethyl myristate, and ethyl palmitate as potent female-derived pheromones that contribute to mate attraction. However, the mechanisms underlying the olfactory recognition remain unclear. In this study, we observed strong antennal and behavioral responses in male B. dorsalis to these female-derived pheromones, and further investigation revealed significant upregulation of OBP49a and OBP83b following exposure to these compounds. Through fluorescence competitive binding assays and RNA interference techniques, we demonstrated the crucial roles of OBP49a and OBP83b in detecting female-derived pheromones. Finally, molecular docking analysis identified key residues, including His134 in OBP83b and a lysine residue in OBP49a, which formed hydrogen bonds with female-derived pheromones, facilitating their binding. These findings not only advance our understanding of olfactory recognition of pheromones in B. dorsalis but also offer potential targets for developing olfaction-interfering techniques for pest control.

Breast cancer mortality in Chinese women and men from 1990 to 2019: Analysis of trends in risk factors.

OBJECTIVE: This study aimed to examine the relative risk of risk factor in male and female breast cancer (BC) deaths in China and analyzed the changing trends in BC mortality rates from 1990 to 2019. METHODS: Open data from the Global Burden of Disease database from 1990 to 2019 were analyzed to assess the number of BC deaths and age-standardized mortality rates (ASMR) in China. The age-period-cohort model was employed to study age effects, period effects, cohort effects, as well as local drift and net drift of the data, determining the impact of changing risk factors on crude mortality rates and ASMR of BC. RESULTS: In 2019, the number of BC deaths across all age groups in China increased by 130.38% compared to 1990, with an increase of 125.68% in females and 648.80% in males. The ASMR for BC and male BC increased in 2019, while female BC ASMR declined. Overall, alcohol consumption and smoking as risk factors contributed to increased mortality rates of BC with advancing age. Over the entire study period, the net drift of alcohol consumption in females for BC was 0.06% (95% confidence interval [CI]: -0.24% to 0.36%), while for smoking it was -0.64% (95% CI: -0.83% to -0.45%). For males, the net drift of alcohol consumption for BC was 6.75% (95% CI: 5.55% to 7.96%), and for smoking, it was 6.09% (95% CI: 2.66% to 9.64%). CONCLUSION: Hence, improving awareness of BC-related risk factors and implementing prevention strategies are necessary to alleviate future BC burdens.

Physical, rheological and microscopic properties of AAT nanomaterial/crumb rubber powder composite-modified asphalt and SBS-modified asphalt.

This research was based on a nano-AAT (American Advanced Technology)-modified asphalt to which CRP (crumb rubber powder), a rubber waste, was introduced to explore the influence of CRP on AAT performance. The changes in the performance of AAT-modified asphalt after the addition of CRP were analyzed. The rubber powder with the raw material of waste tire was added to the asphalt instead of SBS modifier. While achieving waste recycling, the asphalt material has good performance. Physical analysis methods, rheological performance tests, rolling thin-film oven tests and Fourier transform infrared spectroscopy tests were used to investigate the performance of the composite-modified asphalt. The rheological properties of the composite-modified asphalt were analyzed by means of DSR, BBR and MSCR tests, and the microscopic mechanism of the modified asphalt was investigated by means of FTIR tests. The optimal nano-AAT-composite-modified formulation A3C3 (AAT-3.5%SBS-3%CRP) was selected by evaluating the overall performance. Additionally, the performances of the AAT/CRP-composite-modified asphalt and SBS-modified asphalt were compared using physical indicators, the rutting factor, creep flexibility and the stiffness modulus. The results show that the A3C3-modified asphalt had better stiffness, high-temperature (HT) performance and aging resistance than the SBS-modified asphalt, but it was less effective at low temperatures (LTs). According to FTIR, the absorption curves of A3C3 and SBS are essentially equal, with A3C3 only having a variation at 1104 cm-1.

Group housing enhances mating and increases the sensitization of chemical cues in Bactrocera dorsalis.

BACKGROUND: Changes in population density have profound impacts on mating behaviors in group-living animals. The plasticity of mating behavior enables insects to respond to social signals and adjust mating frequency in accordance with rival competition and reproductive opportunity. RESULTS: In this study, we found that low levels of cis-vaccenyl acetate (cVA), a Drosophila pheromone, increased mating rates of Bactrocera dorsalis, but high concentrations of cVA inhibited mating, indicating a functional role of cVA in regulating mating behaviors in insect species other than Drosophila. Moreover, we demonstrated that group housing conditions had positive effects for B. dorsalis on their mating rates, responses toward cVA and cVA-mediated mating behaviors, which are dependent on the activity of c-AMP reponse element binding protein (CREB) binding protein (CBP). CONCLUSIONS: Our data suggest that CBP-mediated plasticity in mating behavior and chemical recognition enables insects to adapt to different housing conditions and highlight the potential of cVA as an efficient agent in regulating mating behaviors in insect species other than Drosophila. © 2022 Society of Chemical Industry.

The modulatory effects of biogenic amines on male mating performance in Bactrocera dorsalis.

In insects, the emergence of mating behavior requires the interplay among sex-determination hierarchy mechanisms that regulate sex-specific differentiation, perception and integration of different sensory cues, and precisely patterned behavioral outputs. Biogenic amines, including octopamine (OA), dopamine (DA), tyramine (TA), serotonin and histamine, have been identified and proposed as putative neurotransmitters, neurohormones and/or neuromodulators in the central nervous system of insects to influence multiple physiologies and behaviors. The current study provides the physiological roles and pharmacology of these biogenic amines in the mating performance of Bactrocera dorsalis. Silencing gene expressions coding for biosynthetic enzymes of DA and serotonin in male flies could decrease mating rates, while OA, TA and histamine had no such effects on mating. Furthermore, injection of DA or the DA receptor antagonist chlorpromazine could affect mating rate, as well as injection of serotonin. Pharmacological treatments with other biogenic amines or their receptor antagonists in male flies have no roles in regulating mating performance. We conclude that DA and its receptors are involved in regulating male mating behaviors in B. dorsalis, while changes in serotonin levels in male flies could also affect mating rates. In the current study, the modulatory effects of these biogenic amines on mating performance were investigated, and these results will be helpful in providing a new strategy for controlling B. dorsalis.

Crystal structure of suboptimal viral fragments of Epstein Barr Virus Rta peptide-HLA complex that stimulate CD8 T cell response.

Peptides presented by Human leukocyte antigen (HLA) class-I molecules are generally 8-10 amino acids in length. However, the predominant pool of peptide fragments generated by proteasomes is less than 8 amino acids in length. Using the Epstein - Barr virus (EBV) Rta-epitope (ATIGTAMYK, residues 134-142) restricted by HLA-A*11:01 which generates a strong immunodominant response, we investigated the minimum length of a viral peptide that can constitute a viral epitope recognition by CD8 T cells. The results showed that Peripheral blood mononuclear cells (PBMCs) from healthy donors can be stimulated by a viral peptide fragment as short as 4-mer (AMYK), together with a 5-mer (ATIGT) to recapitulate the full length EBV Rta epitope. This was confirmed by generating crystals of the tetra-complex (2 peptides, HLA and ß2-microglobulin). The solved crystal structure of HLA-A*11:01 in complex with these two short peptides revealed that they can bind in the same orientation similar to parental peptide (9-mer) and the free ends of two short peptides acquires a bulged conformation that is directed towards the T cell receptor. Our data shows that suboptimal length of 4-mer and 5-mer peptides can complement each other to form a stable peptide-MHC (pMHC) complex.

Chiral acid-catalysed enantioselective C-H functionalization of toluene and its derivatives driven by visible light.

Toluene and its derivatives are petroleum-derived raw materials produced from gasoline by catalytic reformation. These abundant chemical feedstocks are commonly used as solvents in organic synthesis. The C(sp3)-H functionalization of these unactivated substrates has been widely used to directly introduce benzylic motifs into diverse molecules to furnish important compounds. Despite these advances, progress in asymmetric catalysis remains underdeveloped. Here, we report photoinduced radical-based enantioselective C(sp3)-C(sp3) coupling reactions of activated ketones with toluene and its derivatives by means of chiral acid catalysis. With a La(OTf)3/pybox complex catalyst, a variety of chiral 3-hydroxy-3-benzyl-substituted 2-oxindoles, including many conventionally difficult-to-access variants, are obtained directly from isatins in high yields with good to excellent enantioselectivities. Acenaphthoquinone is also compatible with the use of a chiral phosphoric acid (CPA) catalyst, leading to another series of important enantioenriched tertiary alcohols.

Regulating Fast Anionic Redox for High-Voltage Aqueous Hydrogen-Ion-based Energy Storage.

The ionic conductivity and small size of the hydrogen ion make it an ideal charge carrier for hydrogen-ion energy storage (HES); however, high-voltage two-electrode configurations are difficult to construct as the result of the lack of efficient cathodic energy storage. Herein, the high potential fast anionic redox at the cathode of reduced graphene oxide (rGO) was applied by introducing redox additive electrolytes. By coupling the storing hydrogen ion in the Ti3 C2 Tx at the anode, a HES with a voltage of 1.8 V and a plateau voltage at 1.2 V was constructed. Compared with 2.2 Wh kg-1 for the low-voltage Ti3 C2 Tx //Ti3 C2 Tx , the specific energy of asymmetric rGO//Ti3 C2 Tx reaches 34.4 Wh kg-1 . Furthermore, it possesses an energy density of 23.7 Wh kg-1 at high power density of 22.5 kW kg-1 . Thus, this study provides a novel guideline for constructing high-voltage fast HES full cells.

Dual non-contiguous peptide occupancy of HLA class I evoke antiviral human CD8 T cell response and form neo-epitopes with self-antigens.

Host CD8 T cell response to viral infections involves recognition of 8-10-mer peptides presented by MHC-I molecules. However, proteasomes generate predominantly 2-7-mer peptides, but the role of these peptides is largely unknown. Here, we show that single short peptides of <8-mer from Latent Membrane Protein 2 (LMP2) of Epstein Barr Virus (EBV) can bind HLA-A*11:01 and stimulate CD8+ cells. Surprisingly, two peptide fragments between 4-7-mer derived from LMP2(340-349) were able to complement each other, forming combination epitopes that can stimulate specific CD8+ T cell responses. Moreover, peptides from self-antigens can complement non-self peptides within the HLA binding cleft, forming neoepitopes. Solved structures of a tetra-complex comprising two peptides, HLA and ß2-microglobulin revealed the free terminals of the two peptides to adopt an upward conformation directed towards the T cell receptor. Our results demonstrate a previously unknown mix-and-match combination of dual peptide occupancy in HLA that can generate vast combinatorial complexity.

Intrahaplotypic Variants Differentiate Complex Linkage Disequilibrium within Human MHC Haplotypes.

Distinct regions of long-range genetic fixation in the human MHC region, known as conserved extended haplotypes (CEHs), possess unique genomic characteristics and are strongly associated with numerous diseases. While CEHs appear to be homogeneous by SNP analysis, the nature of fine variations within their genomic structure is unknown. Using multiple, MHC-homozygous cell lines, we demonstrate extensive sequence conservation in two common Asian MHC haplotypes: A33-B58-DR3 and A2-B46-DR9. However, characterization of phase-resolved MHC haplotypes revealed unique intra-CEH patterns of variation and uncovered 127 single nucleotide variants (SNVs) which are missing from public databases. We further show that the strong linkage disequilibrium structure within the human MHC that typically confounds precise identification of genetic features can be resolved using intra-CEH variants, as evidenced by rs3129063 and rs448489, which affect expression of ZFP57, a gene important in methylation and epigenetic regulation. This study demonstrates an improved strategy that can be used towards genetic dissection of diseases.

Activating killer cell immunoglobulin-like receptor 2DS2 binds to HLA-A*11.

Inhibitory killer cell Ig-like receptors (KIRs) are known to recognize HLA ligands mainly of the HLA-C and Bw4 groups, but the ligands for KIRs are poorly understood. We report here the identification of the cognate ligand for the activating KIR 2DS2 as HLA-A*11:01. The crystal structure of the KIR2DS2-HLA-A*11:01 complex was solved at 2.5-Å resolution and revealed residue-binding characteristics distinct from those of inhibitory KIRs with HLA-C and the critical role of residues Tyr45 and Asp72 in shaping binding specificity to HLA-A*11:01. Using KIR2DS2 tetramers, binding to surface HLA-A*11:01 on live cells was demonstrated and, furthermore, that binding can be altered by residue changes at p8 of the peptide, indicating the influence of peptide sequence on KIR-HLA association. In addition, heteronuclear single quantum coherence NMR was used to map the involvement of critical residues in HLA binding at the interface of KIR and HLA, and validates the data observed in the crystal structure. Our data provide structural evidence of the recognition of A*11:01 by the activating KIR2DS2 and extend our understanding of the KIR-HLA binding spectrum.

hnRNP K suppresses apoptosis independent of p53 status by maintaining high levels of endogenous caspase inhibitors.

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related deaths globally. One of the cellular hallmarks of this disease is dysregulation of apoptosis, and a better understanding of this process is important if progress is to be made toward effectively treating HCC. Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a RNA-binding protein that is implicated in apoptosis and is upregulated in various cancers, including HCC. In this study, we report new evidence for a crucial role of hnRNP K in suppressing apoptosis in HCC cells. We used the chemotherapeutic agent 5-fluorouracil to induce apoptosis in HCC cell lines and found that hnRNP K was downregulated, independent of both p53 and caspases. Prolonged downregulation of hnRNP K using small interfering RNA (siRNA) significantly decreased cell viability and increased apoptosis in HCC cell lines in a p53-independent manner. Moreover, enhanced tumor necrosis factor-related apoptosis-inducing ligand potency, independent of BH3-interacting domain death agonist (BID) cleavage, was also observed in hnRNP K siRNA-treated cells. Examination of the underlying mechanism revealed that hnRNP K suppresses the activity of various caspases through controlling transcription of the caspase inhibitor XIAP. Taken together, this study establishes that hnRNP K plays an antiapoptotic role in HCC cell lines, independent of p53 status, via the maintenance of high levels of endogenous caspase inhibitors, and also identifies hnRNP K as a possible therapeutic marker for cancer treatment.

The p53 response element and transcriptional repression.

p53 tumor suppressor has been widely recognized as the "Guardian of the Genome", reflecting its importance in ensuring the proper functioning of the cell. It is well-known for its function as a transcription factor, capable of mediating both transcriptional activation and repression, which brings about many cellular outcomes such as cell cycle arrest, apoptosis, cellular senescence and DNA repair. The canonical p53 response element (p53RE), which contains two repeats of a decamer motif "RRRCWWGYYY" separated by a spacer of 0 to 13 base-pairs, has been characterized as the regulatory region on the target genes that p53 binds for transcriptional activation. It was thought that p53 generally represses genes that lack this canonical p53RE, presumably through the sequestration of basal transcriptional machinery components or transcription activators. However, characterization of individual genes as well as genome-wide studies utilizing gene expression profiling and chromatin immunoprecipitation uncovered a large number of potential p53-repressed targets. Taken together, there appears to be multiple modes of gene repression by p53 with some being mediated through direct binding of p53 to DNA. The aim of this review is to assess the evidence of p53 mediated transcriptional repression and discuss its role in cellular function.

Redefining the p53 response element.

The tumor suppressor p53 is a master transcriptional regulator that affects a diverse range of cellular events. Surprisingly, even with >100 validated p53 response element (RE) sequences available, the effect of p53 binding on transcriptional behavior is seldom predictable and no functional rules have been described. Here, we report a systematic study on the role of specific nucleotides within the p53RE by using p21, a well-known target for p53 activation and contrasting it with Lasp1, a gene recently identified to be repressed by p53. Functional assays revealed a specific dinucleotide core combination within the CWWG motif of the p53RE to be the key factor that determines whether p53 transcriptionally activates or represses a target gene. The triplet RRR and YYY sequences flanking the core CWWG motif were also shown to play an important role in modulating the transcriptional behavior of p53. With the establishment of a set of predictive rules, we were able to reassess 162 published p53REs and showed that the attributed function for 20/162 p53REs studied were in fact erroneous. A significant proportion of p53REs (39/162) were found to be repressive, which is substantially higher than what is currently thought. Hence this clearer definition of the transcriptional behavior of p53 interaction with its RE will provide better insight toward the understanding of its fundamental role in cellular networks.

Designed DNA probes from the neocarzinostatin family: impact of glycosyl linkage stereochemistry on bulge base binding.

Bulged sites in DNA and RNA have become targets for rational drug design due to their suspected involvement in a number of key biomolecular processes. A lead compound, derived from the enediyne natural product NCS-chrom has been used to inform chemical synthesis of a family of designed probes of DNA bulges, one of which shows 80 nM affinity for a two base bulged target. Key contributors to binding of these spirocyclic compounds have been studied in order to correlate affinity and specificity with structural features. Herein, we demonstrate that the glycosyl linkage stereochemistry of the pendant aminofucosyl group plays a pivotal role in binding, and coupled with insight obtained with various bulged targets, will allow rational design of second generation ligands.

LIM and SH3 protein 1 (Lasp1) is a novel p53 transcriptional target involved in hepatocellular carcinoma.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide with poor prognosis associated with tumor invasion and metastasis. The tumor suppressor p53 plays critical roles in tumor development, but there is increasing evidence for its involvement in tumor metastasis with the underlying mechanisms largely unexplored. METHODS: Using combinatorial analysis of a p53 binding database with HCC microarray expression profile, we identified a novel metastasis-related gene Lasp1 as a potential p53 target. RESULTS: In this study, we demonstrate that Lasp1 is indeed a bona fide p53 target by validating the functional repression effect of p53 on Lasp1 via a p53 response element. Transient transfection of wild-type p53 but not the mutant form suppressed Lasp1 in Hep3B (p53-/-) cells, while p53 siRNA up-regulated its expression in HepG2 (p53+/+) cells. p53 mutations at key residues involved in DNA binding abrogates the p53-mediated suppression of Lasp1 expression. In addition, Lasp1 regulates HCC cell growth as well as cell migration and invasion ability. CONCLUSIONS: p53 transcriptionally represses Lasp1, which is a partner protein in affecting HCC cell motility. This suggests that p53 may play a role in influencing tumor metastasis through Lasp1.

Congeners of the enediyne neocarzinostatin chromophore: designed agents for bulged nucleic acid targets.

Of the commonly recognized structural elements within nucleic acids, bulges are among the least developed as targets for small molecules. Bulges in DNA and RNA have been linked to biomolecular processes involved in numerous diseases, thus probes with affinity for these targets would be of considerable utility to chemical biologists and medicinal chemists. Despite such opportunity, there is a dearth of small molecules available with affinity for bulges, which has hampered exploitation of these key targets. We have used guided chemical synthesis to prepare small molecules capable of binding to DNA and RNA bulges. Our design is based on a template which mimics a metabolite of the enediyne neocarzinostatin. The key spirocylic building block was formed through an intramolecular aldol process and the parent template shows pronounced affinity for 2 base bulges. Functionalization with specific aminosugar moieties confers nanomolar binding affinity for selected bulged DNA targets, and installation of reactive functional groups allows covalent modification of bulges. These rationally designed agents can now be used to study the stereochemistry and architecture of bulge-drug complexes and investigate the molecular biology of bulge induced processes. Members of this class have been shown to induce slipped synthesis of DNA, suggesting the agents, in addition to recognizing and binding to pre-formed bulges, can also induce bulge formation on demand.

Solution structure of a designed spirocyclic helical ligand binding at a two-base bulge site in DNA.

The solution structure of the complex formed between an oligodeoxynucleotide containing a two-base bulge (5'-CCATCGTCTACCTTTGGTAGGATGG) and SCA-alpha2, a designed spirocyclic helical molecule, has been elucidated. SCA-alpha2, a close mimic of the metabolite, NCSi-gb, of the DNA bulge-specific enediyne antibiotic neocarzinostatin, differs in possessing a more stable spirocyclic ring system and in lacking certain bulky groupings that compromise bulged DNA binding. This study provides a detailed comparison of the binding modes of the two complexes and provides new insights into the importance of shape and space, as opposed to simple nucleotide sequence, in complex formation at the bulge site. The two rigidly held aromatic rings of SCA-alpha2 form a right-handed helical molecular wedge that specifically penetrates the bulge-binding pocket and immobilizes the two bulge residues (GT), which point toward the minor groove, rather than the major groove as in the NCSi-gb.bulged DNA complex. The ligand aromatic ring systems stack on the DNA bulge-flanking base pairs that define the long sides of the triangular prism binding pocket. Like NCSi-gb, SCA-alpha2 possesses the natural N-methylfuranose moiety, alpha-linked to the benzindanol (BI) moiety. The amino sugar anchors in the major groove of the DNA and points toward the 3'-bulge-flanking base pair. Lacking the bulky cyclocarbonate of NCSi-gb, the SCA-alpha2.bulged DNA complex has a much less twisted and buckled 3'-bulge-flanking base pair (dG20.dC8), and the G20 residue stacks directly above the BI ring platform. Also, the absence of the methyl group and the free rotation of the methoxy group on the dihydronaphthanone (NA) moiety of SCA-alpha2 allow better stacking geometry of the NA ring above the 5'-bulge-flanking dG21.dC5 base pair. These and other considerations help to explain why NCSi-gb binds very poorly to bulged RNA and are consistent with the recent observation of good binding with SCA-alpha2. Thus, although the two complexes resemble each other closely, they differ in important local environmental details. SCA-alpha2 has a better hand-in-glove fit at the bulge site, making it an ideal platform for the placement of moieties that can react covalently with the DNA and for generating congeners specific for bulges in RNA.

Molecular probes of DNA bulges: functional assay and spectroscopic analysis.

Bulged structures in DNA and RNA have been linked to biomolecular processes involved in numerous diseases, thus probes with affinity for these nucleic acid targets would be of considerable utility to chemical biologists. Herein, we report guided chemical synthesis of small molecules capable of binding to DNA bulges by virtue of their unique (spirocyclic) geometry. The agents, modeled on a natural product congener, show pronounced selectivity for specific bulged motifs and are able to enhance slipped DNA synthesis, a hallmark functional assay of bulge binding. Significantly, bulge-agent complexes demonstrate characteristic fluorescent signatures depending on bulge and flanking sequence in the oligo. It is anticipated that these signature patterns can be harnessed as molecular probes of bulged hotspots in DNA and RNA.

Spirocyclic helical compounds as binding agents for bulged RNA, including HIV-2 TAR.

Based on fluorescence binding studies and 1D 1H NMR studies, designed synthetic analogues of NCSi-gb bind specifically with two-base bulged RNA, including HIV-2 TAR RNA, making them potential lead compounds for antiviral drug development.