Prodrug-conjugated tumor-seeking commensals for targeted cancer therapy.

Prodrugs have been explored as an alternative to conventional chemotherapy; however, their target specificity remains limited. The tumor microenvironment harbors a range of microorganisms that potentially serve as tumor-targeting vectors for delivering prodrugs. In this study, we harness bacteria-cancer interactions native to the tumor microbiome to achieve high target specificity for prodrug delivery. We identify an oral commensal strain of Lactobacillus plantarum with an intrinsic cancer-binding mechanism and engineer the strain to enable the surface loading of anticancer prodrugs, with nasopharyngeal carcinoma (NPC) as a model cancer. The engineered commensals show specific binding to NPC via OppA-mediated recognition of surface heparan sulfate, and the loaded prodrugs are activated by tumor-associated biosignals to release SN-38, a chemotherapy compound, near NPC. In vitro experiments demonstrate that the prodrug-loaded microbes significantly increase the potency of SN-38 against NPC cell lines, up to 10-fold. In a mouse xenograft model, intravenous injection of the engineered L. plantarum leads to bacterial colonization in NPC tumors and a 67% inhibition in tumor growth, enhancing the efficacy of SN-38 by 54%.

Identification, expression analysis, and functional verification of three opsin genes related to the phototactic behaviour of Ostrinia furnacalis.

Ostrinia furnacalis is a disreputable herbivorous pest that poses a serious threat to corn crops. Phototaxis in nocturnal moths plays a crucial role in pest prediction and control. Insect opsins are the main component of insect visual system. However, the inherent molecular relationship between phototactic behaviour and vision of insects remains a mystery. Herein, three opsin genes were identified and cloned from O. furnacalis (OfLW, OfBL, and OfUV). Bioinformatics analysis revealed that all opsin genes had visual pigment (opsin) retinal binding sites and seven transmembrane domains. Opsin genes were distributed across different developmental stages and tissues, with the highest expression in adults and compound eyes. The photoperiod-induced assay elucidated that the expression of three opsin genes in females were higher during daytime, while their expression in males tended to increase at night. Under the sustained darkness, the expression of opsin genes increased circularly, although the increasing amplitude in males was lower when compared with females. Furthermore, the expression of OfLW, OfBL, and OfUV was upregulated under green, blue, and ultraviolet light, respectively. The results of RNA interference showed that the knockout of opsin genes decreased the phototaxis efficiency of female and male moths to green, blue, and ultraviolet light. Our results reveal that opsin genes are involved in the phototactic behaviour of moths, providing a potential target gene for pest control and a basis for further investigation on the phototactic behaviour of Lepidoptera insects.

Integrated transcriptomic and proteomic analyses reveal the molecular mechanism underlying the thermotolerant response of Spodoptera frugiperda.

Spodoptera frugiperda (Lepidoptera: Noctuidae) is a highly destructive invasive pest with remarkable adaptability to extreme climatic conditions, posing a substantial global threat. Although the effects of temperature stress on the biological and ecological properties of S. frugiperda have been elucidated, the molecular mechanisms underlying its responses remain unclear. Herein, we combined transcriptomic and proteomic analyses to explore the key genes and proteins involved in thermotolerance regulation in S. frugiperda larvae at 42 °C. Overall, 1528 differentially expressed genes (DEGs) and 154 differentially expressed proteins (DEPs) were identified in S. frugiperda larvae under heat stress, including antioxidant enzymes, heat shock proteins (Hsps), cytochrome P450s, starch and sucrose metabolism genes, and insulin signaling pathway genes, indicating their involvement in heat tolerance regulation. Correlation analysis of DEGs and DEPs revealed that seven and eight had the same and opposite expression profiles, respectively. After nanocarrier-mediated RNA interference knockdown of SfHsp29, SfHsp20.4, SfCAT, and SfGST, the body weight and mortality of S. frugiperda larvae significantly decreased and increased under heat stress, respectively. This indicates that SfHsp29, SfHsp20.4, SfCAT, and SfGST play a crucial role in the thermotolerance of S. frugiperda larvae. These results provide insight into the mechanism of heat tolerance in S. frugiperda.

Enzymatic activity and development of Frankliniella occidentalis (Thysanoptera: Thripidae) in response to exogenous calcium treatments of kidney bean plants.

Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is an agricultural pest threatening various horticultural crops worldwide. Inducing plant resistance is an ecologically beneficial and potentially effective method for controlling F. occidentalis. As an essential nutrient element, exogenous calcium enhances plant-induced resistance. This study investigated the effects of CaCl2 on the secondary metabolites of kidney bean plants and detoxifying and digestive enzymes in F. occidentalis. We found that treatment of plants and treatment time and also the interactions of the 2 factors significantly affected secondary metabolites contents (tannin, flavonoids, total phenol, alkaloid, and lignin) of kidney bean leaves, which indicated that that the effect of treatment of plants on secondary metabolites varied with treatment time. Moreover, when thrips fed on CaCl2-treated plants, the activities of detoxifying enzymes, enzymes glutathione S-transferase and cytochrome P450 substantially increased compared to those in which thrips fed on control plants. However, the activity of carboxylesterase significantly decreased. The detoxifying enzyme genes CL992.contig6, CYP4PN1, and CYP4PJ2 were significantly upregulated at 24 and 48 h. The activities of digestive enzymes (α-amylase, chymotrypsin, and lipase) increased substantially in F. occidentalis. The digestive enzyme gene, FoAMY-1, was significantly upregulated at 24 and 48 h after treatment. The pupation rate and pupal weight of F. occidentalis were significantly reduced. The results indicated that exogenous CaCl2-induced metabolic changes in kidney bean plants and altered the enzymatic activity and development of F. occidentalis that fed upon them.

Refolding, Crystallization, and Crystal Structure Analysis of a Scavenger Receptor Cysteine-Rich Domain of Human Salivary Agglutinin Expressed in Escherichia coli.

Scavenger receptors are a protein superfamily that typically consists of one or more repeats of the scavenger receptor cysteine-rich structural domain (SRCRD), which is an ancient and highly conserved protein module. The expression and purification of eukaryotic proteins containing multiple disulfide bonds has always been challenging. The expression systems that are commonly used to express SRCRD proteins mainly consist of eukaryotic protein expression systems. Herein, we established a high-level expression strategy of a Type B SRCRD unit from human salivary agglutinin using the Escherichia coli expression system, followed by a refolding and purification process. The untagged recombinant SRCRD was expressed in E. coli using the pET-32a vector, which was followed by a refolding process using the GSH/GSSG redox system. The SRCRD expressed in E. coli SHuffle T7 showed better solubility after refolding than that expressed in E. coli BL21(DE3), suggesting the importance of the disulfide bond content prior to refolding. The quality of the refolded protein was finally assessed using crystallization and crystal structure analysis. As proteins refolded from inclusion bodies exhibit a high crystal quality and reproducibility, this method is considered a reliable strategy for SRCRD protein expression and purification. To further confirm the structural integrity of the refolded SRCRD protein, the purified protein was subjected to crystallization using sitting-drop vapor diffusion method. The obtained crystals of SRCRD diffracted X-rays to a resolution of 1.47 Å. The solved crystal structure appeared to be highly conserved, with four disulfide bonds appropriately formed. The surface charge distribution of homologous SRCRD proteins indicates that the negatively charged region at the surface is associated with their calcium-dependent ligand recognition. These results suggest that a high-quality SRCRD protein expressed by E. coli SHuffle T7 can be successfully folded and purified, providing new options for the expression of members of the scavenger receptor superfamily.

Expression and function of opsin genes associated with phototaxis in Zeugodacus cucurbitae Coquillett (Diptera: Tephritidae).

BACKGROUND: Zeugodacus cucuribitae is a major agricultural pest that causes significant damage to varieties of plants. Vision plays a critical role in phototactic behavior of herbivorous insects. However, the effect of opsin on the phototactic behavior in Z. cucuribitae remains unknown. The aim of this research is to explore the key opsin genes that associate with phototaxis behavior of Z. cucurbitae. RESULTS: Five opsin genes were identified and their expression patterns were analyzed. The relative expression levels of ZcRh1, ZcRh4 and ZcRh6 were highest in 4-day-old larvae, ZcRh2 and ZcRh3 were highest in 3rd-instar larvae and 5-day-old pupae, respectively. Furthermore, five opsin genes had the highest expression levels in compound eyes, followed by the antennae and head, whereas the lower occurred in other tissues. The expression of the long-wavelength-sensitive (LW) opsins first decreased and then increased under green light exposure. In contrast, the expression of ultraviolet-sensitive (UV) opsins first increased and then decreased with the duration of UV exposure. Silencing of LW opsin (dsZcRh1, dsZcRh2, and dsZcRh6) and UV opsin (dsZcRh3 and dsZcRh4) reduced the phototactic efficiency of Z. cucurbitae to green light by 52.27%, 60.72%, and 67.89%, and to UV light by 68.59% and 61.73%, respectively. CONCLUSION: The results indicate that RNAi inhibited the expression of opsin, thereby inhibiting the phototaxis of Z. cucurbitae. This result provides theoretical support for the physical control of Z. cucurbitae and lays the foundation for further exploration of the mechanism of insect phototaxis. © 2023 Society of Chemical Industry.

Modeling and simulation of zero-group velocity combined harmonic generated by guided waves mixing.

In this paper, modelling and numerical perspective of zero-group velocity (ZGV) combined harmonic generated by guided waves mixing are investigated. The conditions for the generation of the ZGV combined harmonic are analyzed by S0-S0 and SH0-SH0 guided waves mixing in an isotropic plate, respectively. The generation of ZGV combined harmonics at sum frequency caused by counter-directional guided waves mixing is observed. It is confirmed that the ZGV combined harmonic with a considerable magnitude can be generated by this counter-directional guided waves mixing when both the internal resonant condition and non-zero power flux are satisfied. The application of generated ZGV combined harmonics for localized material degradation assessment is numerically examined in the given plate. The obtained results indicate that the generated ZGV combined harmonic induced by the counter-directional guided waves mixing can be used to assess the localized material degradation with improved signal-to-noise ratio. This study provides an insight into the physical process of the ZGV combined harmonic generation, and meanwhile offer a promising means for localized material degradation assessment by ZGV combined harmonics generated by guided waves mixing.

Identification of Six Small Heat Shock Protein Genes in Ostrinia furnacalis (Lepidoptera: Pyralidae) and Analysis of Their Expression Patterns in Response to Environmental Stressors.

Ostrinia furnacalis (Guenée) is a major insect pest in maize production that is highly adaptable to the environment. Small heat shock proteins (sHsps) are a class of chaperone proteins that play an important role in insect responses to various environmental stresses. The present study aimed to clarify the responses of six O. furnacalis sHsps to environmental stressors. In particular, we cloned six sHsp genes, namely, OfHsp24.2, OfHsp21.3, OfHsp20.7, OfHsp21.8, OfHsp29.7, and OfHsp19.9, from O. furnacalis. The putative proteins encoded by these genes contained a typical α-crystallin domain. Real-time quantitative polymerase chain reaction was used to analyze the differences in the expression of these genes at different developmental stages, in different tissues of male and female adults, and in O. furnacalis under UV-A and extreme temperature stresses. The six OfsHsp genes were expressed at significantly different levels based on the developmental stage and tissue type in male and female adults. Furthermore, all OfsHsp genes were significantly upregulated in both male and female adults under extreme temperature and UV-A stresses. Thus, O. furnacalis OfsHsp genes play important and unique regulatory roles in the developmental stages of the insect and in response to various environmental stressors.

Molecular characterization and elucidation of the function of Hap38 MAPK in the response of Helicoverpa armigera (Hübner) to UV-A stress.

The cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), an important pest of cotton, is detrimental to cotton production. Light from UV-A ultraviolet lamps is regarded as a form of environmental stress for insects. In order to investigate the response of H. armigera exposed to UV-A, we explored Hap38 MAPK expression and functions. We hope that the findings of this study will lay the foundation for future investigations into the insect's phototaxis mechanism. A p38 MAPK was cloned and named Hap38 MAPK. A phylogenetic tree showed that Hap38 MAPK was highly conserved. The gene was highly expressed in the thorax and females. Under UV-A stress, the expression of the gene decreased significantly. After silencing Hap38 MAPK, the activity of the antioxidant enzymes SOD, POD, CAT, and GR decreased. This study suggested that Hap38 MAPK responds to UV-A irradiation and plays critical roles in the defense response to environmental stresses.

Structural, Thermal and Pasting Properties of Heat-Treated Lotus Seed Starch-Protein Mixtures.

The interactions between starch and protein, the essential components of lotus seed, strongly influence the quality of lotus seed processing by-products. This study investigated the effects of lotus seed starch-protein (LS-LP) interactions on the structural, thermal and gelatinization properties of LS-LP mixtures, using LS/LP ratios of 6:1, 6:2, 6:3, 6:4, 6:5, or 1:1, after heat treatment (95 °C, 30 min). Fourier transform infrared peaks at 1540 cm-1 and 3000-3600 cm-1 revealed the major interactions (electrostatic and hydrogen bonding) between LS and LP. The UV-visible absorption intensities (200-240 nm) of LS-LP mixtures increased with increased protein content. X-ray diffraction and electron microscopy revealed that LS-LP consists of crystalline starch granules encapsulated by protein aggregates. Increasing the addition of protein to the mixtures restricted the swelling of the starch granules, based on their solubility, swelling properties and thermal properties. Viscometric analysis indicated that the formation of LS-LP mixtures improved structural and storage stability. These findings provide a practicable way to control the thermal and gelatinization properties of lotus seed starch-protein mixtures, by changing the proportions of the two components, and provide a theoretical basis for developing novel and functional lotus-seed-based foods.

Molecular characterization of six heat shock protein 70 genes from Arma chinensis and their expression patterns in response to temperature stress.

Arma chinensis is an important predatory enemy of many agricultural and forest pests. Heat shock protein 70 (Hsp70) plays an essential role in insect adaptation to various stress factors. To explore the functions of Hsp70s in relation to thermal tolerance of A. chinensis, full-length cDNAs of six Hsp70 genes (AcHsp70Ba, AcHsp70-4, AcHsp68a, AcHsp68b, AcHsp70-2, and AcHsc70-4) were cloned. Their open reading frames (ORFs) were 1902, 2454, 1884, 1905, 1872, and 1947 bp, respectively. Developmental expression profiles showed that AcHsp70Ba, AcHsp70-4, and AcHsc70-4 were extremely highly expressed in adult stages. AcHsp68a and AcHsp70-2 showed the highest level of expression in nymph stages, and AcHsp68b was mainly expressed in male adults. Tissue distribution analysis demonstrated that the AcHsp70s were ubiquitously expressed but showing gene-specific and sex-driven patterns of expression. High temperature induced the expression of the six AcHsp70s. Among them, AcHsp70Ba, AcHsp70-4, AcHsp68a, and AcHsc70-4 were significantly induced at 38 °C for 6 h, while all six AcHsp70s were significantly induced at 38 °C for 24 h. There were differences in responses of the six AcHsp70s to low-temperature stress. The expressions of AcHsp70-4, AcHsp68a, and AcHsp68b in male adults were significantly repressed at 4 °C for 6 h, whereas AcHsp70Ba and AcHsp70-2 were significantly induced. The levels of AcHsp70Ba, AcHsp68b, and AcHsp70-2 in female adults were significantly repressed at 4 °C for 24 h, whereas AcHsc70-4 was significantly induced. These results suggested that AcHsp70s play important roles in various developmental stages and tissue function, and contribute to the tolerance of A. chinensis to extreme temperatures.

Induced heat shock protein 70 confers biological tolerance in UV-B stress-adapted Myzus persicae (Hemiptera).

As an environmental stress factor, ultraviolet-B (UV-B) radiation directly affects insect growth, development, and reproduction. Heat shock protein 70s kDa (Hsp70s) plays an important role in the environmental adaptation of insects. To determine the role of MpHsp70s in the UV-B tolerance of Myzus persicae (Sulzer), we identified the complete complementary DNA sequences of seven MpHsp70s. They were found to be ubiquitously expressed during different developmental stages and were highly expressed in second-instar nymphs and wingless adults. The expression levels of the MpHsp70s were significantly upregulated when exposed to different durations of UV-B stress. Nanocarrier-mediated dsMpHsp70 suppressed the expression of the MpHsp70s and reduced the body length, weight, survival rate, and fecundity of M. persicae under UV-B exposure. When the combinational RNAi approach was adopted, the effects on the survival rate and fecundity were greater under UV-B stress, except for MpHsc70-4. These results suggest that MpHsp70s are essential for the resistance of M. persicae to UV-B stress.

Dynamic Transcriptome Analysis Reveals Complex Regulatory Pathway Underlying Induction and Dose Effect by Different Exogenous Auxin IAA and 2,4-D During in vitro Embryogenic Redifferentiation in Cotton.

Plant somatic cells can reprogram into differentiated embryos through somatic embryogenesis (SE) on the condition of plant growth regulators (PGRs). RNA sequencing analysis was performed to investigate transcriptional profiling on cotton redifferentiated callus that was induced by different auxin types (IAA and 2,4-D), different concentrations (0, 0.025, and 0.05 mg L-1), and different incubation times (0, 5, and 20 days). Under the 2,4-D induction effect, signal transduction pathways of plant hormones were significantly enriched in the embryogenic response stage (5 days). These results indicated that auxin signal transduction genes were necessary for the initial response of embryogenic differentiation. In the pre-embryonic initial period (20 days), the photosynthetic pathway was significantly enriched. Most differentially expressed genes (DEGs) were downregulated under the induction of 2,4-D. Upon the dose effect of IAA and 2,4-D, respectively, pathways were significantly enriched in phenylpropanoid biosynthesis, fatty acid metabolism, and carbon metabolic pathways. Therefore, primary and secondary metabolism pathways were critical in cotton SE. These results showed that complex synergistic mechanisms involving multiple cellular pathways were the causes of the induction and dose effect of auxin-induced SE. This study reveals a systematic molecular response to auxin signals and reveals the way that regulates embryogenic redifferentiation during cotton SE.

Broad-Spectrum Polymeric Nanoquencher as an Efficient Fluorescence Sensing Platform for Biomolecular Detection.

Colloidal inorganic nanostructures (metal, carbon, and silica) have been widely used as "nanoquenchers" for construction of nanosensors; however, inherent drawbacks such as insufficient fluorescence quenching efficiency, false positive signals, and uncertain long-term cytotoxicity have limited their further utility. Herein, by taking advantages of polymeric nanoparticles (PNPs) in terms of high loading capacity, facile surface modification chemistry, and good biocompatibility, we report a broad-spectrum (400-750 nm) polymeric fluorescence-quenching platform for sensor fabrication. Our newly developed polymeric nanoquenchers (qPNPs) were constructed by concurrently encapsulating various alkylated black-hole quenchers into nanoparticles made of poly(methyl methacrylate-co-methacrylic acid) and were found to have an excellent fluorescence quenching effect (>400-fold) on common fluorophores (FAM, TMR, and Cy5) together with high stability under physiological conditions. As a proof of concept, the feasibility of these qPNPs for fluorescence sensing was validated by successful construction of two nanosensors (FAMDEVD@qPNP and Cy5SurC@qPNP), which could be used as promising nanosensors for live-cell imaging of the apoptosis-related protease caspase-3 and cancer-related survivin mRNA, respectively. As expected, in the FAM channel, the FAMDEVD@qPNP showed fast and selective fluorescence responses toward caspase-3 in buffers and could be used to image the activation of drug-induced endogenous caspase-3. In the Cy5 channel, the Cy5SurC@qPNP could be used to distinguish normal cells (MCF10A) from cancer cells (HeLa) by quantitatively detecting the endogenous survivin mRNA level. It could be further used to monitor changes in the endogenous survivin mRNA expression levels in drug-treated HeLa cells. Altogether, by virtue of their high quencher loading and broad-spectrum quenching efficiency and good signal-to-background ratio, these qPNPs might be particularly attractive alternatives to other conventional nanoquenchers for the construction of more complex biosensors in the future.

Live-Cell Imaging of Survivin mRNA by Using a Dual-Color Surface-Cross-Linked Nanoquencher.

Precise detection of cancer-related mRNAs can significantly benefit the early diagnosis and potential therapy of cancers. Herein, we report organic dark quencher-encapsulated surface-cross-linked micelles (qSCMs) as a new sort of nanoquencher for construction of potential multiple-color fluorescence imaging nanosensors. Such nanoquenchers featured simple preparation (one-pot), broad-spectrum quenching (450-800 nm), high quenching efficiency (>94%), good stability, negligible cargo leakage, facile covalent surface modification, and finally excellent modularity. As a proof-of-concept demonstration, a mRNA-detecting qSCM nanosensor was generated, capable of simultaneous live-cell imaging of endogenous actin mRNA (a house-keeping gene) and cancer-related survivin mRNA. This nanosensor was found to be GSH- and DNase I-resistant, and with actin mRNA as an intrinsic reference, it was used to image the precise survivin mRNA expression across different mammalian cells through convenient normalization of the signal readouts. Moreover, the nanosensor was further used to quantitatively image the downregulation of endogenous survivin mRNA in HeLa cells upon treatment of YM155 (an imidazolium bioactive compound known to suppresses endogenous survivin mRNA expression). These results clearly demonstrated the promising application of these qSCMs as new nanoquenchers in potential multicolor imaging of various endogenous biomarkers.

Expression stability of candidate RT-qPCR housekeeping genes in Spodoptera frugiperda (Lepidoptera: Noctuidae).

Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is commonly used to quantify gene expression. For normalization, the expression of each gene is compared with a reference "housekeeping" gene that is stably expressed under relevant stress. Unfortunately, there have been no reports on the stability of such reference genes under various treatments of the Spodoptera frugiperda. In this study, we used five tools (RefFinder, GeNorm, NormFinder, BestKeeper, and ΔCt methods) to evaluate the stability of 12 candidate reference genes (RPS18, ß-tubulin, GAPDH, RPS7, RPS15, RPL7, RPL32, Actin-5C, EF1-α, EF1-γ, RPL27, and ACE) in different instars, tissues, and treatments (high and low temperature, UV-A, and emamectin benzoate). Several ribosomal proteins (RPS7, RPS15, RPL32, RPS18, and RPL7), GAPDH, Actin-5C, and ß-tubulin, were relatively stable, suggesting that they are ideal housekeeping genes for various treatments. ACE was extremely unstable under various experimental treatments, rendering it unsuitable as an internal reference. This study identified the reference housekeeping genes stably expressed by S. frugiperda under different treatments, thus setting a foundation for further exploration of the physiological and biochemical mechanisms.

Cell-Penetrating Mitochondrion-Targeting Ligands for the Universal Delivery of Small Molecules, Proteins and Nanomaterials.

Mitochondria are key organelles that perform vital cellular functions such as those related to cell survival and death. The targeted delivery of different types of cargos to mitochondria is a well-established strategy to study mitochondrial biology and diseases. Of the various existing mitochondrion-transporting vehicles, most suffer from poor cytosolic entry, low delivery efficiency, limited cargo types, and cumbersome preparation protocols, and none was known to be universally applicable for mitochondrial delivery of different types of cargos (small molecules, proteins, and nanomaterials). Herein, two new cell-penetrating, mitochondrion-targeting ligands (named MitoLigand ) that are capable of effectively "tagging" small-molecule drugs, native proteins and nanomaterials are disclosed, as well as their corresponding chemoselective conjugation chemistry. Upon successful cellular delivery and rapid endosome escape, the released native cargos were found to be predominantly localized inside mitochondria. Finally, by successfully delivering doxorubicin, a well-known anticancer drug, to the mitochondria of HeLa cells, we showed that the released drug possessed potent cell cytotoxicity, disrupted the mitochondrial membrane potential and finally led to apoptosis. Our strategy thus paves the way for future mitochondrion-targeted therapy with a variety of biologically active agents.

Transcriptome Analysis of Myzus persicae to UV-B Stress.

As an environmental stress factor, ultraviolet-B (UV-B) radiation directly affects the growth and development of Myzus persicae (Sulzer) (Homoptera: Aphididae). How M. persicae responds to UV-B stress and the molecular mechanisms underlying this adaptation remain unknown. Here, we analyzed transcriptome data for M. persicae following exposure to UV-B radiation for 30 min. We identified 758 significant differentially expressed genes (DEGs) following exposure to UV-B stress, including 423 upregulated and 335 downregulated genes. In addition, enrichment analysis using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases illustrated that these DEGs are associated with antioxidation and detoxification, metabolic and protein turnover, immune response, and stress signal transduction. Simultaneously, these DEGs are closely related to the adaptability to UV-B stress. Our research can raise awareness of the mechanisms of insect responses to UV-B stress.

Comparative transcriptome and metabolome analysis of Ostrinia furnacalis female adults under UV-A exposure.

Ultraviolet A (UV-A) radiation is a significant environmental factor that causes photoreceptor damage, apoptosis, and oxidative stress in insects. Ostrinia furnacalis is an important pest of corn. To understand the adaptation mechanisms of insect response to UV-A exposure, this study revealed differentially expressed genes (DEGs) and differently expressed metabolites (DEMs) in O. furnacalis under UV-A exposure. Three complementary DNA libraries were constructed from O. furnacalis adult females (CK, UV1h, and UV2h), and 50,106 expressed genes were obtained through Illumina sequencing. Of these, 157 and 637 DEGs were detected in UV1h and UV2h after UV-A exposure for 1 and 2 h, respectively, compared to CK, with 103 and 444 upregulated and 54 and 193 downregulated genes, respectively. Forty four DEGs were detected in UV2h compared to UV1h. Comparative transcriptome analysis between UV-treated and control groups revealed signal transduction, detoxification and stress response, immune defense, and antioxidative system involvement. Metabolomics analysis showed that 181 (UV1h vs. CK), 111 (UV2h vs. CK), and 34 (UV2h vs. UV1h) DEMs were obtained in positive ion mode, while 135 (UV1h vs. CK), 93 (UV2h vs. CK), and 36 (UV2h vs. UV1h) DEMs were obtained in negative ion mode. Moreover, UV-A exposure disturbed amino acid, sugar, and lipid metabolism. These findings provide insight for further studies on how insects protect themselves under UV-A stress.

Recent Advances in Polymeric Nanoparticles for Enhanced Fluorescence and Photoacoustic Imaging.

In recent years, polymeric nanoparticles (NPs) have become increasingly popular for in vitro and in vivo bioimaging because of their excellent versatility and exceptional optical properties. Following a brief introduction on fluorescence and photoacoustic imaging, as well as the merits of using polymeric NPs over other types of fluorescent probes, this Minireview gives a concise summary of key advances made in recent years (2017-2020) in the use of polymeric NPs for fluorescence and photoacoustic imaging. A particular focus is placed on various strategies used for enhanced bioimaging applications, including polymeric NPs that encapsulate near-infrared dyes, aggregation-induced-emission fluorogens, cationic dyes doped with bulky hydrophobic counterions, and semiconducting polymers. Next, the current limitations in some of these polymeric NP systems are summarized and potential solutions offered to overcome them. Finally, some critical considerations in regard to the design of polymeric NPs are given for future bioimaging and sensing applications.