Nanoparticle-delivered RNAi-based pesticide target screening for the rice pest white-backed planthopper and risk assessment for a natural predator

Vacuolar-type (H+)-ATPase (vATPase) is a conserved multi-subunit eukaryotic enzyme composed of 14 subunits that form a functional complex consisting of an ATP-hydrolytic domain (V1) and a proton-translocation domain (V0). ATP hydrolysis and subsequent H+ translocation rely heavily on a fully assembled V1/V0 complex. Since vATPase is crucial for insect survival, it is a viable molecular target for pest control. However, detailed functional analyses of the 14 subunits and their suitability for pest control have not been fully explored in a single insect species. In this study, we identified 22 vATPase subunit transcripts that correspond to 13 subunits (A1, A2, B, C, D, E, F, G, H, a1, a2, c and d) in the white-backed planthopper (WBPH), Sogatella furcifera, a major hemipteran pest of rice. RNAi screens using microinjection and spray-based methods revealed that the SfVHA-F, SfVHA-a2 and SfVHA-c2 subunits are critical. Furthermore, star polymer (SPc) nanoparticles were utilized to conduct spray-induced and nanoparticle-delivered gene silencing (SI-NDGS) to evaluate the pest control efficacy of RNAi targeting the SfVHA-F, SfVHA-a2 and SfVHA-c2 transcripts. Target mRNA levels and vATPase enzymatic activity were both reduced. Honeydew excreta was likewise reduced in WBPH treated with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. To assess the environmental safety of the nanoparticle-wrapped dsRNAs, Cyrtorhinus lividipennis Reuter, a major natural enemy of planthoppers, was also sprayed with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. Post-spray effects of dsSfVHA-a2 and dsSfVHA-c2 on C. lividipennis were innocuous. This study identifies SfVHA-a2 and SfVHA-c2 as promising targets for biorational control of WBPH and lays the foundation for developing environment-friendly RNAi biopesticides.

Increasing maternal glucose concentrations is insufficient to restore placental glucose transfer in chorionic somatomammotropin RNA interference pregnancies

We previously demonstrated impaired placental nutrient transfer in chorionic somatomammotropin (CSH) RNA interference (RNAi) pregnancies, with glucose transfer being the most impacted. Thus, we hypothesized that despite experimentally elevating maternal glucose, diminished umbilical glucose uptake would persist in CSH RNAi pregnancies, demonstrating the necessity of CSH for adequate placental glucose transfer. Trophectoderm of sheep blastocysts (9 days of gestational age; dGA) were infected with a lentivirus expressing either nontargeting control (CON RNAi; n = 5) or CSH-specific shRNA (CSH RNAi; n = 7) before transfer into recipient sheep. At 126 dGA, pregnancies were fitted with vascular catheters and underwent steady-state metabolic studies (3H2O transplacental diffusion) at 137 ± 0 dGA, before and during a maternal hyperglycemic clamp. Umbilical glucose and oxygen uptakes, as well as insulin and IGF1 concentrations, were impaired (P ≤ 0.01) in CSH RNAi fetuses and were not rescued by elevated maternal glucose. This is partially due to impaired uterine and umbilical blood flow (P ≤ 0.01). However, uteroplacental oxygen utilization was greater (P ≤ 0.05) during the maternal hyperglycemic clamp, consistent with greater placental oxidation of substrates. The relationship between umbilical glucose uptake and the maternal-fetal glucose gradient was analyzed, and while the slope (CON RNAi, Y = 29.54X +74.15; CSH RNAi, Y = 19.05X + 52.40) was not different, the y-intercepts and elevation were (P = 0.003), indicating reduced maximal glucose transport during maternal hyperglycemia. Together, these data suggested that CSH plays a key role in modulating placental metabolism that ultimately promotes maximal placental glucose transfer.NEW & NOTEWORTHY The current study demonstrated a novel, critical autocrine role for chorionic somatomammotropin in augmenting placental glucose transfer and maintaining placental oxidative metabolism. In pregnancies with CSH deficiency, excess glucose in maternal circulation is insufficient to overcome fetal hypoglycemia due to impaired placental glucose transfer and elevated placental metabolic demands. This suggests that perturbations in glucose transfer in CSH RNAi pregnancies are due to compromised metabolic efficiency along with reduced placental mass.

Lethal and sublethal effects of orally delivered double-stranded RNA on the cabbage stem flea beetle, Psylliodes chrysocephala

BACKGROUND

The cabbage stem flea beetle (Psylliodes chrysocephala) is one of the most important insect pests of oilseed rape (Brassica napus) in northern Europe. The emergence of insecticide-resistant populations and the ban on neonicotinoid seed treatments have made the management of this pest challenging and research is needed to develop alternative strategies such as RNA interference (RNAi). We investigated lethal and sublethal effects of orally delivered double-stranded (ds)RNAs targeting P. chrysocephala orthologs of Sec23 and vacuolar adenosine triphosphatase subunit G (VatpG), which are involved in endoplasmic reticulum-Golgi transport and organelle acidification, respectively.

RESULTS

Feeding bioassays on P. chrysocephala adults showed that the highest concentration (200 ng/leaf disk) of dsSec23 caused mortalities of 76% and 56% in pre-aestivating and post-aestivating beetles, respectively, while the same concentration of dsVatpG led to mortality rates of ~34% in both stages. Moreover, sublethal effects, such as decreased feeding rates and attenuated locomotion were observed. Small RNA sequencing and gene expression measurements following the delivery of dsRNAs demonstrated the generation of ~21 nucleotide-long small interfering RNAs and a systemic RNAi response in P. chrysocephala.

CONCLUSION

We demonstrate that P. chrysocephala is a promising candidate for developing RNAi-based pest management strategies. Further research is necessary to identify more effective target genes and to assess potential non-target effects. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Identification of an active RNAi pathway in Candida albicans

RNA interference (RNAi) is a fundamental regulatory pathway with a wide range of functions, including regulation of gene expression and maintenance of genome stability. Although RNAi is widespread in the fungal kingdom, well-known species, such as the model yeast Saccharomyces cerevisiae, have lost the RNAi pathway. Until now evidence has been lacking for a fully functional RNAi pathway in Candida albicans, a human fungal pathogen considered critically important by the World Health Organization. Here, we demonstrated that the widely used C. albicans reference strain (SC5314) contains an inactivating missense mutation in the gene encoding for the central RNAi component Argonaute. In contrast, most other C. albicans isolates contain a canonical Argonaute protein predicted to be functional and RNAi-active. Indeed, using high-throughput small and long RNA sequencing combined with seamless CRISPR/Cas9-based gene editing, we demonstrate that an active C. albicans RNAi machinery represses expression of subtelomeric gene families. Thus, an intact and functional RNAi pathway exists in C. albicans, highlighting the importance of using multiple reference strains when studying this dangerous pathogen.

Structural Characterization and Physiological Role of Bombyx mori Fibroinase in the Silk Gland Development

Silkworm is a highly valuable insect that produces silk through secretion by a silk gland. Within this gland, a type of cathepsin L protease called Fibroinase was identified as an enzyme for hydrolyzing the primary components of silk, including fibroin and sericin. Here, we determined the crystal structure of Fibroinase fromBombyx mori at a resolution of 1.56 Å. Comparative structural analysis revealed that Fibroinase adopted a similar structural pattern with papain-type cathepsin, consisting of an N-terminal domain and a C-terminal domain. The interface between the domains forms a substrate-binding cleft, where the E64 inhibitor noncovalently binds in a novel manner. Additionally, computational simulations combined with biochemical analysis allowed us to define the binding mode and inhibition mechanism of physiological inhibitor Bombyx cysteine protease inhibitor (BCPI) with Fibroinase. Moreover, the expression profiles and RNA interference of Fibroinase indicated its critical role in removing silk proteins in the silk gland lumen and the destruction of silk gland tissue during the larval-pupal metamorphosis. These findings enhance our understanding of the structural and biochemical features of Fibroinase and its inhibitors, while also providing evidence for the physiological role of Fibroinase in silk gland development.

Molecular identification and related functional characterization of the FKBP52 gene in immunity of Locusta migratoria manilensis (Orthoptera: Oedipodidae)

Metarhizium anisopliae is an important class of entomopathogenic fungi used for the biocontrol of insects, but its virulence is affected by insect immunity. We identified a novel FK506 binding protein gene that was differentially expressed between control and Metarhizium-treated Locusta migratoria manilensis. We hypothesized that this protein played an important role in Metarhizium infection of L. migratoria and could provide new insights for developing highly efficient entomopathogenic fungi. We, therefore, cloned the specific gene and obtained its purified protein. The gene was then named FKBP52, and its dsRNA (dsFKBP52) was synthesized and used for gene interference. Bioassay results showed that the mortality of L. migratoria treated with dsFKBP52 + Metarhizium was significantly lower than that of other treatments. Furthermore, immune-related genes (MyD88, Dorsal, Cactus, and Defensin) in L. migratoria treated with dsFKBP52 + Metarhizium showed significant upregulation compared to that treated with Metarhizium only. However, the activities of peroxidase (POD), superoxide dismutase (SOD), and calcineurin (CaN) showed fluctuations. These results suggest that the FKBP52 gene may play a crucial role in the innate immunity of L. migratoria. The effect of its silencing indicated that this immunity-related protein might be a potential target for insect biocontrol.

Exploring the mechanism of nonylphenol-induced ovarian developmental delay of manila clams, Ruditapes philippinarum: Applying RNAi to toxicological analysis

Nonylphenol (NP) contamination in the coastal environment of China poses ecological risks to aquatic organisms. However, the endocrine disruptive impacts of NP on bivalves, particularly on ovarian development, remain poorly understood. In this study, Manila clams Ruditapes philippinarum at the developing stage of gonad were exposed to 1.0 μg/L NP for 21 days. Utilizing RNA interference (RNAi) to suppress ER gene expression, we observed a delay in ovarian development as evidenced by histological observations under both NP and NPRi (NP with ER-RNAi) treatment, with Vtg elevation exclusive to the NP group. Comprehensive analyses encompassing transcriptomics, real-time quantitative PCR, and steroid hormone measurement revealed significant alterations in aldosterone synthesis, estrogen signaling, and thyroid hormone synthesis. These pathways showed similar perturbations in both NP and NPRi groups compared to controls. Notably, the NPRi group exhibited distinct enrichment in PPAR and insulin signaling pathways, may implicating these in ER function suppression. Steroid hormone biosynthesis was notably reduced in both treatments, pointing to a profound impact on hormone synthesis. The contrast between in vivo and in vitro findings suggests that NP's detrimental effects on ovarian development may primarily involve neuroendocrine regulation of steroidogenesis. This investigation highlights the complex dynamics of NP-induced endocrine disruption in bivalves, emphasizing the pivotal role of ER and associated pathways.

Molecular mechanisms of cytochrome P450-mediated detoxification of tetraniliprole, spinetoram, and emamectin benzoate in the fall armyworm, Spodoptera frugiperda (J.E. Smith)

The fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) is a highly damaging invasive omnivorous pest that has developed varying degrees of resistance to commonly used insecticides. To investigate the molecular mechanisms of tolerance to tetraniliprole, spinetoram, and emamectin benzoate, the enzyme activity, synergistic effect, and RNA interference were implemented in S. frugiperda. The functions of cytochrome P450 monooxygenase (P450) in the tolerance to tetraniliprole, spinetoram, and emamectin benzoate in S. frugiperda was determined by analysing changes in detoxification metabolic enzyme activity and the effects of enzyme inhibitors on susceptibility to the three insecticides. 102 P450 genes were screened via transcriptome and genome, of which 67 P450 genes were differentially expressed in response to tetraniliprole, spinetoram, and emamectin benzoate and validated by quantitative real-time PCR. The expression patterns of CYP9A75, CYP340AA4, CYP340AX8v2, CYP340L16, CYP341B15v2, and CYP341B17v2 were analysed in different tissues and at different developmental stages in S. frugiperda. Silencing CYP340L16 significantly increased the susceptibility of S. frugiperda to tetraniliprole, spinetoram, and emamectin benzoate. Furthermore, knockdown of CYP340AX8v2, CYP9A75, and CYP341B17v2 significantly increased the sensitivity of S. frugiperda to tetraniliprole. Knockdown of CYP340AX8v2 and CYP340AA4 significantly increased mortality of S. frugiperda to spinetoram. Knockdown of CYP9A75 and CYP341B15v2 significantly increased the susceptibility of S. frugiperda to emamectin benzoate. These results may help to elucidate the mechanisms of tolerance to tetraniliprole, spinetoram and emamectin benzoate in S. frugiperda.

Functional Analysis of β-Carotene Oxygenase 2 (BCO2) Gene in Yesso Scallop (Patinopecten yessoensis)

Carotenoids are essential nutrients for humans and animals, and carotenoid coloration represents an important meat quality parameter for many farmed animals. Increasingly, studies have demonstrated that vertebrate carotenoid cleavage oxygenases (CCOs) are essential enzymes in carotenoid metabolism and are therefore potential candidate genes for improving carotenoid deposition. However, our understanding of carotenoid bioavailability and CCOs functions in invertebrates, particularly marine species, is currently quite limited. We previously identified that a CCO homolog, PyBCO-like 1, was the causal gene for carotenoid coloration in the 'Haida golden scallop', a variety of Yesso scallop (Patinopecten yessoensis) characterized by carotenoid enrichment. Here, we found that another CCO-encoding gene named PyBCO2 (β-carotene oxygenase 2) was widely expressed in P. yessoensis organs/tissues, with the highest expression in striated muscle. Inhibiting BCO2 expression in P. yessoensis through RNA interference led to increased carotenoid (pectenolone and pectenoxanthin) deposition in the striated muscle, and the color of the striated muscle changed from white to light orange. Our results indicate that PyBCO2 might be a candidate gene used for improving carotenoid content in normal Yesso scallops, and also in 'Haida golden scallops'.

A novel safer CD19CAR with shRNA interference of IFN-γ can reduce multiple cytokine levels without significantly compromising its killing efficacy

Cytokine release syndrome (CRS) is a great challenge for the application of anti-CD19 CAR-T cell therapy. The aim of this study was to investigate the effect of knocking down interferon gamma (IFN-γ) by shRNA as a potential strategy to reduce the cytokine storms. A newly designed short hairpin interference RNA of IFN-γ (shIFN-γ) in CD19CAR gene was constructed. Several cellular model systems of approach using Nalm-6 cell lines including Nalm-6CD19pos and Nalm-6CD19neg with or without monocytes and endothelial cells were used to analyze the different levels of cytokines after shIFN-γ-anti-CD19CAR-T cell targeted therapy. The activity of this novel CD19CAR-T was evaluated both in vitro and in NSG mouse model. The killing efficacy of shIFN-γ-anti-CD19CAR-T at the E:T ratio of 2:1 was similar to that of regular anti-CD19CAR-T at the E:T ratio of 1:1. The IFN-γ level in the shIFN-γ-anti-CD19CAR-T cell group was (2673.1 ± 307.4) pg/ml at the E:T ratio of 2:1 which was significantly lower than that ((8261.5 ± 345.5) pg/ml) in the regular anti-CD19CAR-T group at the E:T ratio of 1:1. Cytotoxicity experiments in vitro showed significantly reduced concentrations of IFN-γ, IL-6 and TNFα in the shIFN-γ-anti-CD19CAR-T cell group compared to regular anti-CD19CAR-T cell group. Both regular anti-CD19CAR and shIFN-γ-CD19CAR-T exerted bystander killing effect in vitro. We conclude that shIFN-γ-anti-CD19CAR-T cells can reduce the generation of cytokine storms without significantly compromising their therapeutic efficacy in the preclinical setting. In mouse model, 3 × 106 shIFN-γ-anti-CD19CAR-T cells/mouse generated the similar killing efficacy to that with 2 × 106 regular anti-CD19CAR-T cells/mouse.

Vutrisiran: a new drug in the treatment landscape of hereditary transthyretin amyloid polyneuropathy

INTRODUCTION

Hereditary transthyretin (ATTRv) amyloidosis is a progressive, fatal disorder caused by mutations in the transthyretin (TTR) gene leading to deposition of the misfolded protein in amyloid fibrils. The main phenotypes are peripheral neuropathy (PN) and cardiomyopathy (CM).

AREAS COVERED

Gene silencing therapy, by dramatically reducing liver production of TTR, has transformed ATTRv-PN patient care in the last decade. In this drug discovery case history, the authors discuss the treatment history of ATTRv-PN and focus on the latest siRNA therapy: vutrisiran. Vutrisiran is chemically enhanced and N-acetylgalactosamin-conjugated, allowing increased stability and specific liver delivery. HELIOS-A, a phase III, multicenter randomized study, tested vutrisiran in ATTRv-PN and showed significant improvement in neuropathy impairment, disability, quality of life (QoL), gait speed, and nutritional status. Tolerance was acceptable, no safety signals were raised.

EXPERT OPINION

Vutrisiran offers a new treatment option for patients with ATTRv-PN. Vutrisian's easier delivery and administration route, at a quarterly frequency, as well as the absence of premedication, are major improvements to reduce patients' disease burden and improve their QoL. Its place in the therapeutic strategy is to be determined, considering affordability.

Functional characteristics of Dicer genes in Plutella xylostella

BACKGROUND

Dicer is an endonuclease that belongs to the RNase III family and can specifically recognize and cleave double-stranded RNA (dsRNA). In most insects, there are two Dicer genes, Dicer-1 (Dcr-1) and Dicer-2 (Dcr-2), which are involved in the micro-RNA and small-interfering RNA pathways in many species, respectively. The function of Dicer in Plutella xylostella remains unknown.

RESULTS

The full-length open reading frames of P. xylostella Dicer-1 (PxDcr-1) and Dicer-2 (PxDcr-2) were cloned and sequenced. Dcr-1 and Dcr-2 proteins shared similar structural domains with the Dicer-Partner Binding Domain (Dicer-PBD) and the double-strand RNA binding domain (dsRBD) present only in Dcr-1. The phylogenetic trees showed that lepidopteran Dcr-1s or Dcr-2s clustered in one branch, with PxDcr-1 in the basal position and PxDcr-2 closest to Plodia interpunctella Dicer. Two homozygous knockout lines, ΔPxDcr-1 and ΔPxDcr-2, were obtained by using the CRISPR-Cas9 technique. The ΔPxDcr-1 strain exhibited a high mortality rate, a low eclosion rate, a low egg-laying rate, a low hatching rate, and a shriveled ovariole without mature eggs. The ΔPxDcr-2 strain showed no significant difference from the wild-type in terms of survival, development and reproduction, but the RNA interference (RNAi) efficiency caused by dsRNA was significantly reduced.

CONCLUSION

These findings demonstrate the involvement of PxDcr-1 in the development and reproduction of P. xylostella, specifically in the formation of ovarioles and eggs, and PxDcr-2 is indispensable for RNAi. These findings shed light on the function of Dcr-1 and Dcr-2 in Lepidoptera. © 2023 Society of Chemical Industry.

Effect of four chitinase genes on the female fecundity in Sogatella furcifera (Horváth)

BACKGROUND

The white-backed planthopper (WPH), Sogatella furcifera (Horváth), is a destructive rice pest with strong reproductive capacity. To gain insights into the roles of chitinases in the reproductive process of this insect species, this study represents the first-ever endeavor to conduct an in-depth exploration into the reproductive functions of four chitinase genes.

RESULTS

In this study, it was observed that four chitinase genes were expressed in female adults, with a relatively high expression level in the ovaries. SfCht2 and SfIDGF1 were highly expressed during later ovarian development. while SfENGase increased and then decreased with ovarian development. SfCht2, SfCht6-2 and SfENGase were highly expressed in fat body on the first and second days after eclosion, whereas SfIDGF1 highest on day 7. Compared with control group, Silencing four chitinase genes inhibited ovarian development and significantly shortened the oviposition period of S. furcifera, reducing egg-laying capacity but not affecting egg hatching. The detection demonstrated that the expression levels of SfVg, SfVgR and 70-90% juvenile hormone (JH) signaling pathway-related reproductive genes was significantly down-regulated. Moreover, SfCht6-2 and SfENGase significantly affected the expression levels of Target of Rapamycin (TOR) signaling pathway genes. SfENGase had the ability to impact nutrient signaling pathways and fatty acid metabolism, repressing vitellogenin synthesis and ultimately influencing ovarian development of S. furcifera.

CONCLUSIONS

Overall, this study provides insight into the function of chitinases in insect fecundity and is of great significance for enriching the cognition of insect chitinase function. They will become the suitable target genes for controlling the most destructive rice planthoppers. © 2023 Society of Chemical Industry.

RNA Interference Effectors Selectively Silence the Pathogenic Variant GNAO1 c.607 G > A In Vitro

RNA interference (RNAi)-based therapeutics hold the potential for dominant genetic disorders, enabling sequence-specific inhibition of pathogenic gene products. We aimed to direct RNAi for the selective suppression of the heterozygous GNAO1 c.607 G > A variant causing GNAO1 encephalopathy. By screening short interfering RNA (siRNA), we showed that GNAO1 c.607G>A is a druggable target for RNAi. The si1488 candidate achieved at least twofold allelic discrimination and downregulated mutant protein to 35%. We created vectorized RNAi by incorporating the si1488 sequence into the short hairpin RNA (shRNA) in the adeno-associated virus (AAV) vector. The shRNA stem and loop were modified to improve the transcription, processing, and guide strand selection. All tested shRNA constructs demonstrated selectivity toward mutant GNAO1, while tweaking hairpin structure only marginally affected the silencing efficiency. The selectivity of shRNA-mediated silencing was confirmed in the context of AAV vector transduction. To conclude, RNAi effectors ranging from siRNA to AAV-RNAi achieve suppression of the pathogenic GNAO1 c.607G>A and discriminate alleles by the single-nucleotide substitution. For gene therapy development, it is crucial to demonstrate the benefit of these RNAi effectors in patient-specific neurons and animal models of the GNAO1 encephalopathy.

The temporal-spatial expression and functional analysis of three gustatory receptor genes in Solenopsis invicta using sweet and bitter compounds

The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds. During this process, gustatory receptors (GRs) recognize feeding stimulant and deterrent compounds. However, the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant, Solenopsis invicta, remain unknown. Therefore, we conducted a study on the genes SinvGR1, SinvGR32b, and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds. In this current study, we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent. The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds. Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1, SinvGR32b, and SinvGR28a genes were highly expressed in fire ant workers. Tissue-specific expression profiles indicated that SinvGR1, SinvGR32b, and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers, whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae. Furthermore, the silencing of SinvGR1 or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose. The results also showed that SinvGR28a is required for avoiding quinine, as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine. This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds. This study could provide potential target gustatory genes for the control of the fire ant.

Targeting lncRNA16 by GalNAc-siRNA conjugates facilitates chemotherapeutic sensibilization via the HBB/NDUFAF5/ROS pathway

Chemoresistance is a significant barrier to effective cancer treatment. Potential mechanisms for chemoresistance include reactive oxygen species (ROS) accumulation and expression of chemoresistance-promoting genes. Here, we report a novel function of lncRNA16 in the inhibition of ROS generation and the progression of chemoresistance. By analyzing the serum levels of lncRNA16 in a cohort of 35 patients with non-small cell lung cancer (NSCLC) and paired serum samples pre- and post-treatment from 10 NSCLC patients receiving neoadjuvant platinum-based chemotherapy, performing immunohistochemistry (IHC) assays on 188 NSCLC tumor samples, using comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) assays, as well as RNA immunoprecipitation (RIP) and RNA pull-down analyses, we discovered that patients with increased serum levels of lncRNA16 exhibited a poor response to platinum-based chemotherapy. The expression of hemoglobin subunit beta (HBB) and NDUFAF5 significantly increases with the development of chemoresistance. LncRNA16 binds to HBB and promotes HBB accumulation by inhibiting autophagy. LncRNA16 can also inhibit ROS generation via the HBB/NDUFAF5 axis and function as a scaffold to facilitate the colocalization of HBB and NDUFAF5 in the mitochondria. Importantly, preclinical studies in mouse models of chemo-resistant NSCLC have suggested that lncRNA16 targeting by trivalent N-acetylgalactosamine (GalNAc)-conjugated siRNA restores chemosensitivity and results in tumor growth inhibition with no detectable toxicity in vivo. Overall, lncRNA16 is a promising therapeutic target for overcoming chemoresistance, and the combination of first-line platinum-based chemotherapy with lncRNA16 intervention can substantially enhance anti-tumor efficacy.

Effect of short neuropeptide F signaling on larval feeding in Mythimna separata

Mythimna separata is a notorious phytophagous pest which poses serious threats to cereal crops owing to the gluttony of the larvae. Because short neuropeptide F (sNPF) and its receptor sNPFR are involved in a diversity of physiological functions, especially in functions related to feeding in insects, it is a molecular target for pest control. Herein, an sNPF and 2 sNPFRs were identified and cloned from M. separata. Bioinformatics analysis revealed that the sNPF and its receptors had a highly conserved RLRFamide C-terminus and 7 transmembrane domains, respectively. The sNPF and its receptor genes were distributed across larval periods and tissues, but 2 receptors had distinct expression patterns. The starvation-induced assay elucidated that sNPF and sNPFR expression levels were downregulated under food deprivation and recovered with subsequent re-feeding. RNA interference knockdown of sNPF, sNPFR1, and sNPFR2 by injection of double-stranded RNA into larvae not only suppressed food consumption and increased body size and weight, but also led to decrease of glycogen and total lipid contents, and increase of trehalose compared with double-stranded green fluorescent protein injection. Furthermore, molecular docking was performed on the interaction mode between sNPFR protein and its ligand sNPF based on the 3-dimensional models constructed by AlphaFold; the results indicated that both receptors were presumably activated by the mature peptide sNPF-2. These results revealed that sNPF signaling played a considerably vital role in the feeding regulation of M. separata and represents a potential control target for this pest.

Identification of Growth-Related Gene BAMBI and Analysis of Gene Structure and Function in the Pacific White Shrimp Litopenaeus vannamei

As one of the most important aquaculture species in the world, the improvement of growth traits of the Pacific white shrimp (Litopenaeus vannamei), has always been a primary focus. In this study, we conducted SNP-specific locus analysis and identified a growth-related gene, BAMBI, in L. vannamei. We analyzed the structure and function of LvBAMBI using genomic, transcriptomic, metabolomic, and RNA interference (RNAi) assays. The LvBAMBI possessed highly conserved structural domains and widely expressed in various tissues. Knockdown of LvBAMBI significantly inhibited the gain of body length and weight of the shrimp, underscoring its role as a growth-promoting factor. Specifically, knockdown of LvBAMBI resulted in a significant downregulation of genes involved in lipid metabolism, protein synthesis, catabolism and transport, and immunity. Conversely, genes related to glucose metabolism exhibited significant upregulations. Analysis of differential metabolites (DMs) in metabolomics further revealed that LvBAMBI knockdown may primarily affect shrimp growth by regulating biological processes related to lipid and glucose metabolism. These results suggested that LvBAMBI plays a crucial role in regulating lipid metabolism, glucose metabolism, and protein transport in shrimp. This study provides valuable insights for future research and utilization of BAMBI genes in shrimp and crustaceans.

Advances in discovery of novel investigational agents for functional cure of chronic hepatitis B: A comprehensive review of phases II and III therapeutic agents

Chronic hepatitis B virus (HBV) infection affects over 295 million people globally and an estimated 1.6 million people in the United States. It is associated with significant morbidity and mortality due to cirrhosis, liver failure, and liver cancer. Antiviral therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression, which in turn has been associated with a decreased risk of liver complications. However, current antiviral regimens are limited by concerns with adverse effects, adherence, resistance, long-term treatment, and ongoing risk for liver events. Novel investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis B surface antigen (HBsAg) loss and suppression of HBV DNA. Herein we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis B, including core/capsid inhibitors, entry inhibitors, RNA interference (siRNA/ASO), HBsAg inhibitors, Toll-like receptor agonists, checkpoint inhibitors, and therapeutic vaccines.

An anti-GD2 aptamer-based bifunctional spherical nucleic acid nanoplatform for synergistic therapy targeting MDM2 for retinoblastoma

Retinoblastoma (RB) is a type of pediatric solid tumor in the fundus. The lack of precision therapies combined with the difficulty of delivering small interfering RNA (siRNA) into the eyes means that there is currently no nucleic acid-based therapy for RB in clinical practice. Here, we reported on anti-GD2 and glutathione-responsive spherical nucleic acids (SNAs), loaded with siRNA and the inhibitor NVP-CGM097, which jointly blocked the oncogenic factor n in RB cells (Y79 and WERI-RB-1). The SNAs were formed through the self-assembly of bifunctional cholesterol amphiphiles containing aptamers that specifically targeted GD2-positive RB cells, allowing for the formation of an SNA with a dense DNA shell. The aptamer/siRNA component functioned both as a carrier and a payload, enhancing the specific recognition and delivery of both components and constituting an active agent for MDM2 regulation. Following SNA endocytosis by RB cells, siRNA and NVP-CGM097 were released from the SNA particles by glutathione, which synergistically blocked the MDM2-p53 pathway, increasing p53 protein content and inducing cell apoptosis. This study showed a potent antitumor effect following intravitreal injection of SNAs in Y79 tumor-bearing mice through clinical manifestation and tumor pathological analysis. In hematological analysis and hepatotoxicity assays, SNAs were safer for mice than melphalan, the favored drug for treating RB in clinical practice. Our results illustrated the potential of intravitreally injected SNAs as a precision medicine for treating RB.

Impact of Baseline Neuropathy Severity on Vutrisiran Treatment Response in the Phase 3 HELIOS-A Study

INTRODUCTION

Hereditary transthyretin (ATTRv, v for variant) amyloidosis is a rare, progressive, fatal disease with multisystem manifestations, caused by pathogenic variants in the transthyretin (TTR) gene. Vutrisiran, an RNA interference therapeutic that results in rapid TTR knockdown, improved neuropathy and quality of life (QOL) versus external placebo in patients with ATTRv amyloidosis with polyneuropathy in the phase 3 HELIOS-A study (NCT03759379). This post hoc analysis evaluates the impact of baseline neuropathy severity on response to vutrisiran treatment.

METHODS

Patients were randomized (3:1) to vutrisiran (n = 122; 25 mg subcutaneous injection once every 3 months) or patisiran (n = 42; 0.3 mg/kg intravenous infusion once every 3 weeks), which served as a reference group. In this post hoc analysis, patients were grouped into quartiles of increasing baseline Neuropathy Impairment Score (NIS): Quartile (Q)1 ≥ 5.0 to ≤ 20.5; Q2 > 20.5 to ≤ 44.1; Q3 > 44.1 to ≤ 73.1; Q4 > 73.1 to ≤ 127.0. Mean change from baseline to Month 18 was summarized by quartile for a range of efficacy endpoints.

RESULTS

Across all baseline NIS quartiles, vutrisiran demonstrated benefit versus external placebo in measures of neuropathy severity (modified NIS + 7), QOL (Norfolk Quality of Life-Diabetic Neuropathy), disability (Rasch-built Overall Disability Scale), gait speed (10-m walk test), and nutritional status (modified body mass index). Overall, patients in lower versus higher NIS quartiles (less severe neuropathy) at baseline maintained better scores at Month 18. The external placebo group progressively worsened in all measures at Month 18.

CONCLUSIONS

Vutrisiran demonstrated benefit in neurologic function and other key efficacy measures versus external placebo across all four baseline neuropathy severity quartiles. Patients initiating vutrisiran earlier in their disease course retained the highest neurologic function level after 18 months, highlighting the importance of early diagnosis and treatment.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT03759379.

Binding Properties of Odorant Binding Protein 37 in Plagiodera versicolora to Host Volatile, o-Cymene

The chemosensory system plays an important role in the host plants location. Plagiodera versicolora (Coleoptera: Chrysomelidae) is a worldwide leaf-eating forest pest that feeds exclusively on salicaceous trees. There is no function study of odorant binding proteins (OBPs) in P. versicolora. In the current study, we found that PverOBP37 has a high expression in male and female antennae, heads, and legs by quantitative real-time PCR. The binding properties of PverOBP37 to 18 host plant volatiles were determined by fluorescence competition binding assays. The results showed that PverOBP37 could bind to the host plant volatile, o-cymene. Furthermore, four candidate key amino acid residues (F8, Y50, F103, and R107) of PverOBP37 to o-cymene were identified by molecular docking. The functional assay to confirm Y50, F103, and R107 mutations were key amino acid residues of PverOBP37 involved in the binding to o-cymene. Knockdown of PverOBP37 and Y-tube behavioral bioassays of mated females led to a significantly reduced attraction to o-cymene. This study not only revealed the molecular mechanism of PverOBP37 but also suggested that PverOBP37 is essential to detect host plant volatiles as cues to search for egg-laying sites in P. versicolora.

Transcriptomic Identification and Characterization of Trehalose-6-Phosphate Synthase in Fat Body of the Oriental Fruit Fly, Bactrocera dorsalis

The destructive agricultural pest oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), has been causing huge damage to the fruits and vegetable industry. Although many pertinent studies have been conducted on B. dorsalis, the functions of fat body still remain largely unknown. To this end, the comparative transcriptome analysis between fat body and carcass was performed in an attempt to provide insights into functions of fat body of B. dorsalis in the present study. A total of 1431 upregulated and 2511 downregulated unigenes were discovered in the fat body vs carcass comparison, respectively. The enrichment analysis of differentially expressed genes (DEG) revealed that most of the enriched pathways were related to metabolism. The reliability of DEG analysis was validated by qRT-PCR measurements of 12 genes in starch and sucrose metabolism pathway, including the trehalose-6-phosphate synthase (BdTPS) which was highly expressed in eggs, 5 d-old adults, and fat body. The RNAi of BdTPS significantly affected trehalose and chitin metabolism, larval growth, and larva-pupa metamorphosis. Collectively, the findings in this study enriched our understanding of fat body functions in metabolism and demonstrated the indispensable roles of BdTPS in trehalose-related physiological pathways.

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.

The small heat shock protein Hsp20.8 imparts tolerance to high temperatures in the leafminer fly, Liriomyza trifolii (Diptera: Agtomyzidae)

As an environmental factor, temperature impacts the distribution of species and influences interspecific competition. The molecular chaperones encoded by small heat shock proteins (sHsps) are essential for rapid, appropriate responses to environmental stress. This study focuses on Hsp20.8, which encodes a temperature-responsive sHsp in Liriomyza trifolii, an insect pest that infests both agricultural and ornamental crops. Hsp20.8 expression was highest at 39℃ in L. trifolii pupae and adults, and expression levels were greater in pupae than in adults. Recombinant Hsp20.8 was expressed in Escherichia coli and conferred a higher survival rate than the empty vector to bacterial cells exposed to heat stress. RNA interference experiments were conducted using L. trifolii adults and prepupae and the knockdown of Hsp20.8 expression increased mortality in L. trifolii during heat stress. The results expand our understanding of sHsp function in Liriomyza spp. and the ongoing adaptation of this pest to climate change. In addition, this study is also important for predicting the distribution of invasive species and proposing new prevention and control strategies based on temperature adaptation.

Molluscicidal effect mechanism study on metaldehyde to Pomacea canaliculate at low temperature

BACKGROUND

Metaldehyde is a molluscicide commonly used to control Pomacea canaliculate. Its efficacy is significantly impacted by water temperature, although the underlying mechanisms have not been fully explored.

RESULTS

In this study, we systematically investigated the temperature effect and molecular mechanisms of metaldehyde on P. canaliculata. The molluscicidal effect at various temperatures indicated that metaldehyde's molluscicidal activity significantly decreases with a drop in temperature. The LC50 value was only 458.8176 mg/L at 10 °C, while it surged to a high of 0.8249 mg/L at 25 °C. The impact of low temperature (10 °C) on metaldehyde's molluscicidal activity was analyzed via transcriptomics. The results revealed that the effect of low temperature primarily influences immunity, lipid synthesis, and oxidative stress. The expression of stress and immune-related genes, such as MANF, HSP70, Cldf7, HSP60, and PclaieFc, significantly increased. Furthermore, we studied the function of five target genes using RNA interference (RNAi) and discovered that Cldf7 and HSP70 could notably affect metaldehyde's molluscicidal effect. The mortality of P. canaliculata increased by 36.17% (72 h) after Cldf7 interference and by 48.90% (72 h) after HSP70 interference.

CONCLUSION

Our findings demonstrate that low temperature can induce the extensive expression of the Cldf7 and HSP70 genes, resulting in a substantial reduction in metaldehyde's molluscicidal activity. © 2024 Society of Chemical Industry.

Inhibition of AMPK activation in Echinococcus granulosus sensu stricto limits the parasite's glucose metabolism and survival

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by larvae of the Echinococcus granulosus sensu lato (s.l.) cluster. There is an urgent need to develop new drug targets and drug molecules to treat CE. Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a serine/threonine protein kinase consisting of α, β, and γ subunits, plays a key role in the regulation of energy metabolism. However, the role of AMPK in regulating glucose metabolism in E. granulosus s.l. and its effects on parasite viability is unknown. In this study, we found that targeted knockdown of EgAMPKα or a small-molecule AMPK inhibitor inhibited the viability of E. granulosus sensu stricto (s.s.) and disrupted the ultrastructure. The results of in vivo experiments showed that the AMPK inhibitor had a significant therapeutic effect on E. granulosus s.s.-infected mice and resulted in the loss of cellular structures of the germinal layer. In addition, the inhibition of the EgAMPK/EgGLUT1 pathway limited glucose uptake and glucose metabolism functions in E. granulosus s.s.. Overall, our results suggest that EgAMPK can be a potential drug target for CE and that inhibition of EgAMPK activation is an effective strategy for the treatment of disease.

Current RNA strategies in treating cardiovascular diseases

Cardiovascular disease (CVD) continues to impose a significant global health burden, necessitating the exploration of innovative treatment strategies. Ribonucleic acid (RNA)-based therapeutics have emerged as a promising avenue to address the complex molecular mechanisms underlying CVD pathogenesis. We present a comprehensive review of the current state of RNA therapeutics in the context of CVD, focusing on the diverse modalities that bring about transient or permanent modifications by targeting the different stages of the molecular biology central dogma. Considering the immense potential of RNA therapeutics, we have identified common gene targets that could serve as potential interventions for prevalent Mendelian CVD caused by single gene mutations, as well as acquired CVDs developed over time due to various factors. These gene targets offer opportunities to develop RNA-based treatments tailored to specific genetic and molecular pathways, presenting a novel and precise approach to address the complex pathogenesis of both types of cardiovascular conditions. Additionally, we discuss the challenges and opportunities associated with delivery strategies to achieve targeted delivery of RNA therapeutics to the cardiovascular system. This review highlights the immense potential of RNA-based interventions as a novel and precise approach to combat CVD, paving the way for future advancements in cardiovascular therapeutics.

Calcineurin contributes to RNAi-mediated transgene silencing and small interfering RNA production in the human fungal pathogen Cryptococcus neoformans

Adaptation to external environmental challenges at the cellular level requires rapid responses and involves relay of information to the nucleus to drive key gene expression changes through downstream transcription factors. Here, we describe an alternative route of adaptation through a direct role for cellular signaling components in governing gene expression via RNA interference-mediated small RNA production. Calcium-calcineurin signaling is a highly conserved signaling cascade that plays central roles in stress adaptation and virulence of eukaryotic pathogens, including the human fungal pathogen Cryptococcus neoformans. Upon activation in C. neoformans, calcineurin localizes to P-bodies, membraneless organelles that are also the site for RNA processing. Here, we studied the role of calcineurin and its substrates in RNAi-mediated transgene silencing. Our results reveal that calcineurin regulates both the onset and the reversion of transgene silencing. We found that some calcineurin substrates that localize to P-bodies also regulate transgene silencing but in opposing directions. Small RNA sequencing in mutants lacking calcineurin or its targets revealed a role for calcineurin in small RNA production. Interestingly, the impact of calcineurin and its substrates was found to be different in genome-wide analysis, suggesting that calcineurin may regulate small RNA production in C. neoformans through additional pathways. Overall, these findings define a mechanism by which signaling machinery induced by external stimuli can directly alter gene expression to accelerate adaptative responses and contribute to genome defense.

Host RNAi-mediated silencing of Fusarium oxysporum f. sp. lycopersici specific-fasciclin-like protein genes provides improved resistance to Fusarium wilt in Solanum lycopersicum

MAIN CONCLUSION

Tomato transgenics expressing dsRNA against FoFLPs act as biofungicides and result in enhanced disease resistance upon Fol infection, by downregulating the endogenous gene expression levels of FoFLPs within Fol. Fusarium oxysporum f. sp. lycopersici (Fol) hijacks plant immunity by colonizing within the host and further instigating secondary infection causing vascular wilt disease in tomato that leads to significant yield loss. Here, RNA interference (RNAi) technology was used to determine its potential in enduring resistance against Fusarium wilt in tomato. To gain resistance against Fol infection, host-induced gene silencing (HIGS) of Fol-specific genes encoding for fasciclin-like proteins (FoFLPs) was done by generating tomato transgenics harbouring FoFLP1, FoFLP4 and FoFLP5 RNAi constructs confirmed by southern hybridizations. These tomato transgenics were screened for stable siRNA production in T0 and T1 lines using northern hybridizations. This confirmed stable dsRNAhp expression in tomato transgenics and suggested durable trait heritability in the subsequent progenies. FoFLP-specific siRNAs producing T1 tomato progenies were further selected to ascertain its disease resistance ability using seedling infection assays. We observed a significant reduction in FoFLP1, FoFLP4 and FoFLP5 transcript levels in Fol, upon infecting their respective RNAi tomato transgenic lines. Moreover, tomato transgenic lines, expressing intended siRNA molecules in the T1 generation, exhibit delayed disease onset with improved resistance. Furthermore, reduced fungal colonization was observed in the roots of Fol-infected T1 tomato progenies, without altering the plant photosynthetic efficiency of transgenic plants. These results substantiate the cross-kingdom dsRNA or siRNA delivery from transgenic tomato to Fol, leading to enhanced resistance against Fusarium wilt disease. The results also demonstrated that HIGS is a successful approach in rendering resistance to Fol infection in tomato plants.

Neutrophils and NADPH Oxidases Are Major Contributors to Mild but Not Severe Ischemic Acute Kidney Injury in Mice

Upregulation of free radical-generating NADPH oxidases (NOX), xanthine oxidoreductase (XOR), and neutrophil infiltration-induced, NOX2-mediated respiratory burst contribute to renal ischemia-reperfusion injury (IRI), but their roles may depend on the severity of IRI. We investigated the role of NOX, XOR, and neutrophils in developing IRI of various severities. C57BL/6 and Mcl-1ΔMyelo neutrophil-deficient mice were used. Oxidases were silenced by RNA interference (RNAi) or pharmacologically inhibited. Kidney function, morphology, immunohistochemistry and mRNA expression were assessed. After reperfusion, the expression of NOX enzymes and XOR increased until 6 h and from 15 h, respectively, while neutrophil infiltration was prominent from 3 h. NOX4 and XOR silencing or pharmacological XOR inhibition did not protect the kidney from IRI. Attenuation of NOX enzyme-induced oxidative stress by apocynin and neutrophil deficiency improved kidney function and ameliorated morphological damage after mild but not moderate/severe IRI. The IR-induced postischemic renal functional impairment (BUN, Lcn-2), tubular necrosis score, inflammation (TNF-α, F4/80), and decreases in the antioxidant enzyme (GPx3) mRNA expression were attenuated by both apocynin and neutrophil deficiency. Inhibition of NOX enzyme-induced oxidative stress or the lack of infiltration by NOX2-expressing neutrophils can attenuate reperfusion injury after mild but not moderate/severe renal IR.

Target-specific requirements for RNA interference can arise through restricted RNA amplification despite the lack of specialized pathways

Since double-stranded RNA (dsRNA) is effective for silencing a wide variety of genes, all genes are typically considered equivalent targets for such RNA interference (RNAi). Yet, loss of some regulators of RNAi in the nematode C. elegans can selectively impair the silencing of some genes. Here we show that such selective requirements can be explained by an intersecting network of regulators acting on genes with differences in their RNA metabolism. In this network, the Maelstrom domain-containing protein RDE-10, the intrinsically disordered protein MUT-16, and the Argonaute protein NRDE-3 work together so that any two are required for silencing one somatic gene, but each is singly required for silencing another somatic gene, where only the requirement for NRDE-3 can be overcome by enhanced dsRNA processing. Quantitative models and their exploratory simulations led us to find that (1) changing cis-regulatory elements of the target gene can reduce the dependence on NRDE-3, (2) animals can recover from silencing in non-dividing cells and (3) cleavage and tailing of mRNAs with UG dinucleotides, which makes them templates for amplifying small RNAs, is enriched within 'pUG zones' matching the dsRNA. Similar crosstalk between pathways and restricted amplification could result in apparently selective silencing by endogenous RNAs.

Reduction in 99mTc-DPD myocardial uptake with therapy of ATTR cardiomyopathy

Aims: Novel ribonucleic acid interference (RNAi) therapeutics such as patisiran and inotersen have been shown to benefit neurologic disease course and quality of life in patients with hereditary transthyretin amyloidosis (ATTRv). We aimed to determine the impact of RNAi therapeutics on myocardial amyloid load using quantitative single photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with ATTRv-related cardiomyopathy (ATTRv-CM). We furthermore compared them with wild-type ATTR-CM (ATTRwt-CM) patients treated with tafamidis.Methods and results: ATTRv-CM patients underwent [99mTc]-radiolabeled diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy and quantitative SPECT/CT imaging before and after 12 months (IQR: 11.0-12.0) of treatment with RNAi therapeutics (patisiran: n = 5, inotersen: n = 4). RNAi treatment significantly reduced quantitative myocardial uptake as measured by standardised uptake value (SUV) retention index (baseline: 5.09 g/mL vs. follow-up: 3.19 g/mL, p = .028) in ATTRv-CM patients without significant improvement in cardiac function. Tafamidis treatment resulted in a significant reduction in SUV retention index (4.96 g/mL vs. 3.27 g/mL, p < .001) in ATTRwt-CM patients (historical control cohort: n = 40) at follow-up [9.0 months (IQR: 7.0-10.0)] without beneficial impact on cardiac function.Conclusions: RNAi therapeutics significantly reduce quantitative myocardial uptake in ATTRv-CM patients, comparable to tafamidis treatment in ATTRwt-CM patients, without impact on cardiac function. Serial 99mTc-DPD SPECT/CT imaging may be a valuable tool to quantify and monitor response to disease-specific therapies in both ATTRv-CM and ATTRwt-CM.

Tyrosine hydroxylase plays crucial roles in larval cuticle formation and larval-pupal tanning in the rice stem borer, Chilo suppressalis

The striped stem borer, Chilo suppressalis (Walker), a notorious pest infesting rice, has evolved a high level of resistance to many commonly used insecticides. In this study, we investigate whether tyrosine hydroxylase (TH), which is required for larval development and cuticle tanning in many insects, could be a potential target for the control of C. suppressalis. We identified and characterized the full-length cDNA (CsTH) of C. suppressalis. The complete open reading frame of CsTH (MW690914) was 1683 bp in length, encoding a protein of 560 amino acids. Within the first to the sixth larval instars, CsTH was high in the first day just after molting, and lower in the ensuing days. From the wandering stage to the adult stage, levels of CSTH began to rise and reached a peak at the pupal stage. These patterns suggested a role for the gene in larval development and larval-pupal cuticle tanning. When we injected dsCsTH or 3-iodotyrosine (3-IT) as a TH inhibitor or fed a larva diet supplemented with 3-IT, there were significant impairments in larval development and larval-pupal cuticle tanning. Adult emergence was severely impaired, and most adults died. These results suggest that CsTH might play a critical role in larval development as well as larval-pupal tanning and immunity in C. suppressalis, and this gene could form a potential novel target for pest control.

From sequences to therapeutics: Using machine learning to predict chemically modified siRNA activity

Small interfering RNAs (siRNAs) exemplify the promise of genetic medicine in the discovery of novel therapeutic modalities. Their ability to selectively suppress gene expression makes them ideal candidates for the development of oligonucleotide pharmaceuticals. Recent advancements in machine learning (ML) have facilitated the design of unmodified siRNA and efficacy prediction. However, a model trained to predict the silencing activity of siRNAs with diverse chemical modification patterns is yet to be published despite the importance of such modifications in designing siRNAs with the potential to reach the level of clinical use. This study presents the first application of ML to efficiently classify chemically modified siRNAs on the basis of sequence and chemical modification patterns alone. Three algorithms were evaluated at three classification thresholds and compared according to sensitivity, specificity, consistency of feature weights with empirical knowledge, and performance using an external validation dataset. Finally, possible directions for future research were proposed.

RNAi-mediated silencing of Mediterranean fruit fly (Ceratitis capitata) endogenous genes using orally-supplied double-stranded RNAs produced in Escherichia coli

BACKGROUND

The Mediterranean fruit fly (medfly), Ceratitis capitata Wiedemann, is a major pest affecting fruit and vegetable production worldwide, whose control is mainly based on insecticides. Double-stranded RNA (dsRNA) able to down-regulate endogenous genes, thus affecting essential vital functions via RNA interference (RNAi) in pests and pathogens, is envisioned as a more specific and environmentally-friendly alternative to traditional insecticides. However, this strategy has not been explored in medfly yet.

RESULTS

Here, we screened seven candidate target genes by injecting in adult medflies gene-specific dsRNA hairpins transcribed in vitro. Several genes were significantly down-regulated, resulting in increased insect mortality compared to flies treated with a control dsRNA targeting the green fluorescent protein (GFP) complementary DNA (cDNA). Three of the dsRNAs, homologous to the beta subunit of adenosine triphosphate (ATP) synthase (ATPsynbeta), a vacuolar ATPase (V-ATPase), and the ribosomal protein S13 (RPS13), were able to halve the probability of survival in only 48 h after injection. We then produced new versions of these three dsRNAs and that of the GFP control as circular molecules in Escherichia coli using a two-self-splicing-intron-based expression system and tested them as orally-delivered insecticidal compounds against medfly adults. We observed a significant down-regulation of V-ATPase and RPS13 messenger RNAs (mRNAs) (approximately 30% and 90%, respectively) compared with the control medflies after 3 days of treatment. No significant mortality was recorded in medflies, but egg laying and hatching reduction was achieved by silencing V-ATPase and RPS13.

CONCLUSION

In sum, we report the potential of dsRNA molecules as oral insecticide in medfly. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of silencing the E74B gene on the development and metamorphosis of Helicoverpa armigera

BACKGROUND

The growth and development transition of insects are mainly mediated by ecdysone. As one of the ecdysone-induced transcription factors, E74 is involved in many physiological processes of insect growth and development. However, E74 and its function in Helicoverpa armigera remains unclear.

RESULTS

In this study, E74B, a subtype of the E74, was identified for the first time in H. armigera. Bioinformatics analysis showed that H. armigera E74B shared the highest homology with E74B in Bombyx mori, which belongs to the E26 transformation-specific (ETS) superfamily. The expression profile showed that the transcription level of HaE74B increased in the late stages of fourth to sixth instars compared with the early stages; it was also high in the pupa and midgut. Moreover, we investigated the function of HaE74B through RNA interference and 20E rescue experiments. The results showed silencing of E74B affected the molting and growth of larvae, resulting in the death of more than 60% of larvae. In addition, it also seriously affected the metamorphosis of H. armigera, which reduced the pupae rate, the eclosion rate of the pupae, and fecundity. Application of 20E partially restored the defects in the molting, development and pupae rate of H. armigera.

CONCLUSION

Taken together, these results demonstrated that HaE74B plays a critical role in the growth, development, and metamorphosis of H. armigera, which serves as a molecular target and sets out a theoretical foundation for RNAi-mediated control of this key pest. © 2023 Society of Chemical Industry.

Novel RNA molecular bioengineering technology efficiently produces functional miRNA agents

Genome-derived microRNAs (miRNA or miR) govern posttranscriptional gene regulation and play important roles in various cellular processes and disease progression. While chemo-engineered miRNA mimics or biosimilars made in vitro are widely available and used, miRNA agents produced in vivo are emerging to closely recapitulate natural miRNA species for research. Our recent works have demonstrated the success of high-yield, in vivo production of recombinant miRNAs by using human tRNA (htRNA) fused precursor miRNA (pre-miR) carriers. In this study, we aim to compare the production of bioengineered RNA (BioRNA) molecules with glycyl versus leucyl htRNA fused hsa-pre-miR-34a carriers, namely BioRNAGly and BioRNALeu, respectively, and perform initial functional assessment. We designed, cloned, overexpressed, and purified a total of 48 new BioRNA/miRNAs, and overall expression levels, final yields, and purities were revealed to be comparable between BioRNAGly and BioRNALeu molecules. Meanwhile, the two versions of BioRNA/miRNAs showed similar activities to inhibit non-small cell lung cancer cell viability. Interestingly, functional analyses using model BioRNA/miR-7-5p demonstrated that BioRNAGly/miR-7-5p exhibited greater efficiency to regulate a known target gene expression (EGFR) than BioRNALeu/miR-7-5p, consistent with miR-7-5p levels released in cells. Moreover, BioRNAGly/miR-7-5p showed comparable or slightly greater activities to modulate MRP1 and VDAC1 expression, compared with miRCURY LNA miR-7-5p mimic. Computational modeling illustrated overall comparable 3D structures for exemplary BioRNA/miRNAs with noticeable differences in htRNA species and payload miRNAs. These findings support the utility of hybrid htRNA/hsa-pre-miR-34a as reliable carriers for RNA molecular bioengineering, and the resultant BioRNAs serve as functional biologic RNAs for research and development.

Unclassified glutathione-S-transferase AiGSTu1 confers chlorantraniliprole tolerance in Agrotis ipsilon

BACKGROUND

Chlorantraniliprole (CAP) is a diamide insecticide with high efficacy against many pest insects, including the black cutworm, Agrotis ipsilon. Agrotis ipsilon is a serious pest causing significant yield losses in crops. Glutathione-S-transferases (GSTs) belong to a family of metabolic enzymes that can detoxify a wide range of pesticides. However, little is known about the functions of GSTs in CAP tolerance in A. ipsilon.

RESULTS

A cDNA sequence (designated AiGSTu1) encoding an unclassified GST was identified from A. ipsilon. AiGSTu1 is highly expressed during the 3rd -instar larval and the pupal stages. Most of the mRNA transcripts were found in larval Malpighian tubules. Exposure to CAP strongly enhanced AiGSTu1 expression, GST activity, hydrogen peroxide (H2 O2 ) and malondialdehyde levels in larvae. H2 O2 treatment upregulated the transcription level of AiGSTu1, suggesting that CAP-induced oxidative stress may activate AiGSTu1 expression. The activity of recombinant AiGSTu1 was inhibited by CAP in a dose-dependent manner. Metabolism assay results demonstrated that AiGSTu1 is capable of depleting CAP. Overexpression of AiGSTu1 enhanced the tolerance of Escherichia coli cells to H2 O2 and the oxidative stress inducer, cumene hydroperoxide. Silencing of AiGSTu1 by RNA interference increased the susceptibility of A. ipsilon larvae to CAP.

CONCLUSION

The findings of this study provide valuable insights into the potential role of AiGSTu1 in CAP detoxification and will improve our understanding of CAP tolerance in A. ipsilon. © 2023 Society of Chemical Industry.

C1QBP is a critical component in the immune response of large yellow croaker (Larimichthys crocea) against visceral white spot disease caused by Pseudomonas plecoglossicida

The large yellow croaker (Larimichthys crocea) stands as a cornerstone of mariculture in China due to its significant value. However, the threat of Pseudomonas plecoglossicida infection looms large, capable of triggering "visceral white spot disease" and subsequently inflicting severe economic ramifications. Through a prior genome-wide association analysis (GWAS) aimed at understanding the resistance of the large yellow croaker to this ailment, a pivotal player emerged: the complement component 1q binding protein, aptly named LcC1qbp. This protein assumes a crucial role in the activation of the complement system. This study delves deeper into the immune response by examining the expression patterns of LcC1QBP when confronted with P. plecoglossicida. The investigation into gene expression patterns reveals LcC1qbp's widespread presence, with its highest transcriptional abundance identified in the kidney tissues. Upon infection by P. plecoglossicida, the up-regulation of LcC1qbp in major immune organs manifests at both the transcriptional and translational levels. In the context of RNA interference, transcriptome analysis of C1qbp in HEK 293T cells uncovers 1327 differentially expressed genes (DEGs), featuring 41 significant immune genes. This includes pivotal components such as C1S and C3 of the complement system, along with IL11, IL12RB2, and Myd88, among others. The outcomes of enrichment analysis spotlight the prevalence of DEGs within key pathways like immune system development, myeloid leukocyte-mediated immunity, MAPK signaling, and other immune-related routes. By unveiling the immune response mechanisms of the large yellow croaker to P. plecoglossicida infection, this study bolsters our understanding. Furthermore, it lays the groundwork for pursuing effective strategies in both preventing and treating "visceral white spot disease" in the large yellow croaker.

Control of two insect pests by expression of a mismatch corrected double-stranded RNA in plants

RNA interference (RNAi) has emerged as an efficient technology for pest control by silencing the essential genes of targeted insects. Owing to its nucleotide sequence-guided working mechanism, RNAi has a high degree of species-specificity without impacts on non-target organisms. However, as plants are inevitably under threat by two or more insect pests in nature, the species-specific mode of RNAi-based technology restricts its wide application for pest control. In this study, we artificially designed an intermediate dsRNA (iACT) targeting two β-Actin (ACT) genes of sap-sucking pests Bemisia tabaci and Myzus persicae by mutual correction of their mismatches. When expressing hairpin iACT (hpiACT) from tobacco nuclear genome, transgenic plants are well protected from both B. tabaci and M. persicae, either individually or simultaneously, as evidenced by reduced fecundity and suppressed ACT gene expression, whereas expression of hpRNA targeting BtACT or MpACT in transgenic tobacco plants could only confer specific resistance to either B. tabaci or M. persicae, respectively. In sum, our data provide a novel proof-of-concept that two different insect species could be simultaneously controlled by artificial synthesis of dsRNA with sequence optimization, which expands the range of transgenic RNAi methods for crop protection.

Berberine and RNAi-Targeting Telomerase Reverse Transcriptase (TERT) and/or Telomerase RNA Component (TERC) Caused Oxidation in Colorectal Cancer Cell Line, HCT 116: An Integrative Approach using Molecular and Metabolomic Studies

Colorectal cancer (CRC) is the most common cancer in both men and women and is associated with increased telomerase levels and activity. The potential downstream effects of TERT and/or TERC downregulation by berberine (a telomerase inhibitor) or RNA interference (RNAi) on various target RNAs, proteins, relative telomerase activity (RTA), relative telomere length (RTL), hydrogen peroxide concentration [H2O2], percentage of cell cycle distribution, cell size and granularity as well as cellular metabolites were explored in HCT 116 cell line. Knockdown of TERT decreased TERC. The downregulation of TERT and/or TERC caused increment of [H2O2], G0/G1 phase arrest in addition to decreased S and G2/M phases, as well as diminished cell size. RTL was later reduced as a result of TERT, TERT and/or TERC downregulation which decreased RTA. It was discovered that xanthine oxidase (XO) was significantly and positively correlated at FDR-adjusted p value < 0.05 with RTA, TERT, TERT, TERC, and RTL. HCT 116 with decreased RTA was closely clustered in the Principal Component Analysis (PCA) indicating similarity of the metabolic profile. A total of 55 metabolites were putatively annotated in this study, potentially associated with RTA levels. The Debiased Sparse Partial Correlation (DSPC) Network revealed that RTA was directly correlated to TERT. There were 4 metabolic pathways significantly affected by low level of RTA which include (1) purine metabolism, (2) glycine, serine, and threonine metabolism, (3) glyoxylate and dicarboxylate metabolism, and (4) aminoacyl-tRNA biosynthesis. The Gene-Metabolite Interaction Network implied that reduced RTA level was related to the mechanism of oxidative stress. This study reveals the linkages between RTA to various selected RNAs, proteins, metabolites, oxidative stress mechanism and subsequently phenotypic changes in HCT 116 which is valuable to understand the intricate biological interactions and mechanism of telomerase in CRC.

Improvement of qualitative and quantitative traits in cotton under normal and stressed environments using genomics and biotechnological tools: A review

Due to the increasing demand for high-quality and high fiber-yielding cotton (Gossypium spp.), research into the development of stress-resilient cotton cultivars has acquired greater significance. Various biotic and abiotic stressors greatly affect cotton production and productivity, posing challenges to the future of the textile industry. Moreover, the content and quality of cottonseed oil can also potentially be influenced by future environmental conditions. Apart from conventional methods, genetic engineering has emerged as a potential tool to improve cotton fiber quality and productivity. Identification and modification of genome sequences and the expression levels of yield-related genes using genetic engineering approaches have enabled to increase both the quality and yields of cotton fiber and cottonseed oil. Herein, we evaluate the significance and molecular mechanisms associated with the regulation of cotton agronomic traits under both normal and stressful environmental conditions. In addition, the importance of gossypol, a toxic phenolic compound in cottonseed that can limit consumption by animals and humans, is reviewed and discussed.

RNA Interference-based Therapies for the Reduction of Cardiovascular Risk

Globally, there remains an unwavering increase in the incidence of cvd - from 271 million in 1990 to 523 million in 2019. Among the several modifiable and non-modifiable risk factors of heart disease, dyslipidemia is an important and prevalent risk factor mediated by both genetics and lifestyle factors. Hence, lowering lipid levels, specifically, ldl-c levels (low-density lipoprotein cholesterol), is a key strategy in decreasing the risk of cardiovascular disease. A reduction of 20 mg/dl in ldl-c levels has been found to prevent 2-3 cases of coronary artery disease (cad) for every 1000 individuals. Studies have also found reductions in ldl-c levels to be associated with a mortality benefit. However, ldl-c levels reduction may not eliminate the risk of significant cardiovascular events.

Optimized protocols for RNA interference in Macrostomum lignano

Macrostomum lignano, a marine free-living flatworm, has emerged as a potent invertebrate model in developmental biology for studying stem cells, germline, and regeneration processes. In recent years, many tools have been developed to manipulate this worm and to facilitate genetic modification. RNA interference is currently the most accessible and direct technique to investigate gene functions. It is obtained by soaking worms in artificial seawater containing dsRNA targeting the gene of interest. Although easy to perform, the original protocol calls for daily exchange of dsRNA solutions, usually until phenotypes are observed, which is both time- and cost-consuming. In this work, we have evaluated alternative dsRNA delivery techniques, such as electroporation and osmotic shock, to facilitate the experiments with improved time and cost efficiency. During our investigation to optimize RNAi, we demonstrated that, in the absence of diatoms, regular single soaking in artificial seawater containing dsRNA directly produced in bacteria or synthesized in vitro is, in most cases, sufficient to induce a potent gene knockdown for several days with a single soaking step. Therefore, this new and highly simplified method allows a very significant reduction of dsRNA consumption and lab work. In addition, it enables performing experiments on a larger number of worms at minimal cost.

Functional Characterization and Putative Regulatory Mechanism of an RNAi Efficiency-Related Nuclease (REase) in the Fall Armyworm, Spodoptera frugiperda

The lepidopteran-specific RNAi efficiency-related nuclease (REase) has been shown to contribute to double-strand RNA (dsRNA) degradation in several lepidopteran insects. However, little is known about its regulatory mechanism. In this study, we identified and characterized SfREase in Spodoptera frugiperda. The exposure of the third-instar larvae to dsEGFP and high temperature led to the upregulation of SfREase, whereas starvation treatment resulted in the downregulation of SfREase. Further experiments revealed that dsRNA degraded more slowly in the hemolymph or midgut fluid extracted from dsSfREase-injected or dsSfREase-ingested larvae compared with those from dsEGFP-treated larvae, and the recombinant SfREase degraded dsRNA in a concentration-dependent manner. Additionally, the knockdown of SfREase improved RNAi efficiency. Finally, both RNAi and dual-luciferase reporter assay in Sf9 cells revealed that SfREase is negatively regulated by FOXO. These data provide insights into the function and regulatory mechanism of REase and have applied implications for the development of an RNAi-based control strategy of S. frugiperda.

Functional characterization of a catalase gene PtCat associated with sclerotia formation in Pleurotus tuber-regium

Pleurotus tuber-regium (Fr.) Sing. can evade oxygen by forming sclerotia under oxidative stress, consequently averting the development of hyperoxidative state, during which the expression level of catalase gene (PtCat) is significantly up-regulated. To investigate the relationship between the catalase gene and sclerotia formation, over-expression and interference strains of the PtCat gene were obtained by Agrobacterium tumefaciens-mediated transformation for phenotypic analysis. In the absence of hydrogen peroxide (H2O2) stress, a minor difference was observed in the mycelial growth rate and the activity of antioxidant enzymes between the over-expression and interference strains. However, when exposed to 1-2 mM H2O2, the colony diameter of the over-expression strain was approximately 2-3× that of the interference strain after 8 days of culturing. The catalase activity of the over-expression strain increased by 1000 U/g under 2 mM H2O2 stress, while the interference strain increased by only 250 U/g. After one month of cultivation, the interference strain formed an oval sclerotium measuring 3.5 cm on the long axis and 2 cm on the short axis, while the over-expression strain did not form sclerotia. Therefore, it is concluded that catalase activity regulates the formation of sclerotia in P. tuber-regium.

The Impact of SLC2A8 RNA Interference on Glucose Uptake and the Transcriptome of Human Trophoblast Cells

While glucose is the primary fuel for fetal growth, the placenta utilizes the majority of glucose taken up from the maternal circulation. Of the facilitative glucose transporters in the placenta, SLC2A8 (GLUT8) is thought to primarily function as an intracellular glucose transporter; however, its function in trophoblast cells has not been determined. To gain insight into the function of SLC2A8 in the placenta, lentiviral-mediated RNA interference (RNAi) was performed in the human first-trimester trophoblast cell line ACH-3P. Non-targeting sequence controls (NTS RNAi; n = 4) and SLC2A8 RNAi (n = 4) infected ACH-3P cells were compared. A 79% reduction in SLC2A8 mRNA concentration was associated with an 11% reduction (p ≤ 0.05) in ACH-3P glucose uptake. NTS RNAi and SLC2A8 RNAi ACH-3P mRNA were subjected to RNAseq, identifying 1525 transcripts that were differentially expressed (|log2FC| > 1 and adjusted p-value < 0.05), with 273 transcripts derived from protein-coding genes, and the change in 10 of these mRNAs was validated by real-time qPCR. Additionally, there were 147 differentially expressed long non-coding RNAs. Functional analyses revealed differentially expressed genes involved in various metabolic pathways associated with cellular respiration, oxidative phosphorylation, and ATP synthesis. Collectively, these data indicate that SLC2A8 deficiency may impact placental uptake of glucose, but that its likely primary function in trophoblast cells is to support cellular respiration. Since the placenta oxidizes the majority of the glucose it takes up to support its own metabolic needs, impairment of SLC2A8 function could set the stage for functional placental insufficiency.

Calcium stress reduces the reproductive capacity and pathogenicity of the pine wood nematode (Bursaphelenchus xylophilus) by inhibiting oxidative phosphorylation reaction

The continuous use of chemical pesticides to control nematodes could result in the developing of pesticide-resistant nematodes. Novel nucleic acid pesticides are becoming the focus of pesticide research due to their strong specificity, high efficiency, and environmental friendliness. However, the limited known biochemical targets restrict the development of target pesticides for nematodes. The calcium stress experiments on pine wood nematodes (PWN) showed that 100 mmol/L Ca2+ resulted in longitudinal depression on the PWN body wall, reduced oviposition, and increased corrected mortality. To enrich the biological targets of nematode pesticides, we further investigated the response mechanism of PWN to calcium stress at the molecular level. Differentially expressed gene analysis showed that genes involved in the oxidative phosphorylation (OXPHOS) pathway were significantly enriched. RNA interference results of 6 key genes belonging to four mitochondrial complex I (BXNDUFA2), III (BXQCR8), IV (BXCOX17), V (BXV-ATPaseB, BXV-ATPaseE, BXV-ATPaseε) in non-stressed nematodes showed reduction in PWN oviposition, population size, feeding ability, and pathogenicity. The BXNDUFA2 gene interference had the highest inhibitory impact by decreasing the oviposition from 31.00 eggs to 6.75 eggs and PWN population size from 8.27 × 103 nematodes to 1.64 × 103 nematodes, respectively. Interestingly, RNA interference of these 6 key genes in calcium-stressed nematodes also led to increased mortality and decreased oviposition of PWN. In summary, calcium stress inhibited the reproductive capacity of PWN by down-regulating key genes BXNDUFA2, BXQCR8, BXV-ATPaseB, BXV-ATPaseE, BXV-ATPaseε, and BXCOX17, thereby reducing the pathogenicity. The current results enrich the RNAi targets in PWN and provide a scientific basis for developing novel nucleic nematicides.

Using RNA interference targeting a nicotinic acetylcholine receptor subunit to counteract insecticide accommodation mechanisms: example of the β1 subunit in the imidacloprid-accommodated American cockroach, Periplaneta americana

Insecticide accommodation and resistance are limiting factors to the much-needed increase in agricultural production. Various physiological and cellular modifications, such as the changes of insecticide molecular targets, have been linked to these events. Thus, a previous study demonstrated that the imidacloprid accommodation set up by the cockroach Periplaneta americana after an exposure to a sublethal dose of this insecticide involves functional alterations of two nicotinic acetylcholine receptor (nAChR) subtypes. As RNA interference (RNAi) is one of the most promising strategies for controlling pest insects, we evaluated, in this study, the use of RNAi that targets the β1 nAChR subunit to counteract the imidacloprid accommodation phenomenon in cockroaches. Interestingly, we showed that ingestion of dsRNA-β1 increased the sensitivity to imidacloprid of accommodated cockroaches. Thus, we have demonstrated for the first time that RNAi that targets an nAChR subunit can counteract the accommodation mechanism to insecticide targeting nAChRs set up by an insect.