Identification of antennal alternative splicing by combining genome and full-length transcriptome analysis in Bactrocera dorsalis.

Alternative splicing is an essential post-transcriptional regulatory mechanism that diversifies gene function by generating multiple protein isoforms from a single gene and act as a crucial role in insect environmental adaptation. Olfaction, a key sense for insect adaptation, relies heavily on the antennae, which are the primary olfactory organs expressing most of the olfactory genes. Despite the extensive annotation of olfactory genes within insect antennal tissues facilitated by high-throughput sequencing technology advancements, systematic analyses of alternative splicing are still relatively less. In this study, we focused on the oriental fruit fly (Bactrocera dorsalis), a significant pest of fruit crops. We performed a detailed analysis of alternative splicing in its antennae by utilizing the full-length transcriptome of its antennal tissue and the insect's genome. The results revealed 8600 non-redundant full-length transcripts identified in the oriental fruit fly antennal full-length transcriptome, spanning 4,145 gene loci. Over 40% of these loci exhibited multiple isoforms. Among these, 161 genes showed sex-biased isoform switching, involving seven different types of alternative splicing. Notably, events involving alternative transcription start sites (ATSS) and alternative transcription termination sites (ATTS) were the most common. Of all the genes undergoing ATSS and ATTS alternative splicing between male and female, 32 genes were alternatively spliced in protein coding regions, potentially affecting protein function. These genes were categorized based on the length of the sex-biased isoforms, with the highest difference in isoform fraction (dIF) associated with the ATSS type, including genes such as BdorABCA13, BdorCAT2, and BdorTSN3. Additionally, transcription factor binding sites for doublesex were identified upstream of both BdorABCA13 and BdorCAT2. Besides being expressed in the antennal tissues, BdorABCA13 and BdorCAT2 are also expressed in the mouthparts, legs, and genitalia of both female and male adults, suggesting their functional diversity. This study reveals alternative splicing events in the antennae of Bactrophora dorsalis from two aspects: odorant receptor genes and other types of genes expressed in the antennae. This study not only provides a research foundation for understanding the regulation of gene function by alternative splicing in the oriental fruit fly but also offers new insights for utilizing olfaction-based behavioral manipulation techniques to manage this pest.

CRISPR/Cas9-Based Functional Characterization of SfUGT50A15 Reveals Its Roles in the Resistance of Spodoptera frugiperda to Chlorantraniliprole, Emamectin Benzoate, and Benzoxazinoids.

UDP-glycosyltransferases (UGTs) are a diverse superfamily of enzymes. Insects utilize uridine diphosphate-glucose (UDP-glucose) as a glycosyl donor for glycosylation in vivo, involved in the glycosylation of lipophilic endosymbionts and xenobiotics, including phytotoxins. UGTs act as second-stage detoxification metabolizing enzymes, which are essential for the detoxification metabolism of insecticides and benzoxazine compounds. However, the UGT genes responsible for specific glycosylation functions in S. frugiperda are unclear at present. In this study, we utilized CRISPR/Cas9 to produce a SfUGT50A15-KO strain to explore its possible function in governing sensitivity to chemical insecticides or benzoxazinoids. The bioassay results suggested that the SfUGT50A15-KO strain was significantly more sensitive to chlorantraniliprole, emamectin benzoate, and benzoxazinoids than the wild-type strains. This finding suggests that the overexpression of the SfUGT50A15 gene may be linked to S. frugiperda resistance to pesticides (chlorantraniliprole and emamectin benzoate) as well as benzoxazinoids (BXDs).

Odorant Receptor BdorOR49b Mediates Oviposition and Attraction Behavior of Bactrocera dorsalis to Benzothiazole.

The ability to recognize a host plant is crucial for insects to meet their nutritional needs and locate suitable sites for laying eggs. Bactrocera dorsalis is a highly destructive pest in fruit crops. Benzothiazole has been found to induce oviposition behavior in the gravid B. dorsalis. However, the ecological roles and the olfactory receptor responsible for benzothiazole are not yet fully understood. In this study, we found that adults were attracted to benzothiazole, which was an effective oviposition stimulant. In vitro experiments showed that BdorOR49b was narrowly tuned to benzothiazole. The electroantennogram results showed that knocking out BdorOR49b significantly reduced the antennal electrophysiological response to benzothiazole. Compared with wild-type flies, the attractiveness of benzothiazole to BdorOR49b knockout adult was significantly attenuated, and mutant females exhibited a severe decrease in oviposition behavior. Altogether, our work provides valuable insights into chemical communications and potential strategies for the control of this pest.

Intracranial delivery of synthetic mRNA to suppress glioblastoma.

Owing to messenger RNA's unique biological advantages, it has received increasing attention to be used as a therapeutic, known as mRNA-based gene therapy. It is critical to have an ideal strategy of mRNA gene therapy for glioma, which grows in a special environment. In the present study, we screened out a safe and efficient transfection reagent for intracranial delivery of synthetic mRNA in mouse brain. First, in order to analyze the effect of different transfection reagents on the intracranial delivery of mRNA, the synthetic luciferase mRNA was wrapped with two different transfection reagents and microinjected into the brain at the fixed point. The expression status of delivered mRNA was monitored by a small animal imaging system. The possible reagent-induced biological toxicity was evaluated by behavioral and blood biochemical measurements. Then, to test the therapeutic effect of our intracranial delivery mRNA model on glioma, synthetic modified tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA was used as an example of therapeutic application. This model demonstrated that synthetic mRNA could be successfully delivered into the brain using commercially available transfection reagents, and TransIT-mRNA showed better results than in vivo-jetPEI kit. This model can be applied in precise targeting and personalized gene therapy of glioma.

Case Report: Primary Pulmonary Angiosarcoma With Brain Metastasis.

Primary pulmonary angiosarcoma (PPA) is a rare malignant vascular tumor, of which early diagnosis is challenging due to lack of specific clinical manifestations and a low level of suspicion. Here, we report a case of PPA presented with advanced brain metastasis. A 21-year-old patient with 1 week history of headache and mild cough was hospitalized for a head injury. Head MRI showed multiple intracranial lesions with brain edema. Chest CT displayed bilateral pulmonary infiltrates with mediastinal lymph node enlargement. After 2 months of anti-tuberculosis treatment, the patient was readmitted for persistent headache and cough with occasional hemosputum along with worsening pulmonary and intracranial lesions. Despite seizure prophylaxis and control of intracranial pressure and brain edema, his symptoms progressively aggravated, accompanied by cough with bloody sputum, frequent epileptic seizures, and hypotension. He eventually developed coma and died within 3 months of onset of symptoms. An autopsy confirmed PPA with brain metastasis.

Protective effect of microRNA-138 against cerebral ischemia/reperfusion injury in rats.

MicroRNAs (miRs) serve a regulatory function in oxidative radical-mediated inflammation and apoptosis during ischemia/reperfusion (IR) injury. Lipocalin 2 (Lcn-2), a target protein of miR-138, is widely involved in the systemic response to IR injury. The aim of the present study was to investigate the association between miR-138 and Lcn-2 in a rat model of cerebral ischemia/reperfusion (CIR) injury and to verify the interaction between miR-138 and Lcn-2 in a PC12 cell model of hypoxia/reoxygenation injury. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect the mRNA and protein expression levels of miR-138 and Lcn-2. Cell proliferation was determined by MTT assay. The results suggested that the expression of miR-138 was inversely correlated with the expression of Lcn-2 in the CIR rat model and the PC12 cells subjected to hypoxia and reoxygenation. The expression of Lcn-2 was inhibited by miR-138 mimics and enhanced by miR-138 inhibitors, thereby indicating that miR-138 functions as a negative regulator for Lcn-2 expression. This study provides an experimental basis for the further study of miR-138-based therapy for CIR injury.

Induction of proline-rich tyrosine kinase 2 activation-mediated C6 glioma cell invasion after anti-vascular endothelial growth factor therapy.

BACKGROUND: Anti-angiogenic therapy inhibits tumor growth and is considered as a potential clinical therapy for malignant glioma. However, inevitable recurrences and unexpected tumor resistance, particularly increased invasion ability of glioma cell, were observed after anti-angiogenic treatment. The underlying mechanism remains undetermined. Focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) are closely associated with cell migration; therefore, we investigated the possible role of these kinases in rat C6 glioma cell invasion induced by bevacizumab, a recombinant monoclonal antibody against vascular endothelial growth factor (VEGF). METHODS: The effects of bevacizumab on migration and invasion of C6 glioma cells were investigated in vitro and in vivo. The cells proliferation, migration, and invasion were determined by MTT assay, wound healing, and transwell assay, respectively. Invasive potential of glioma cells in vivo was assessed by counting vimentin-positive cells crossing the solid tumor rim by immunohistochemical staining. The total and phosphorylated protein levels of FAK and Pyk2 were detected by Western blotting. RESULTS: Bevacizumab exposure increased migration and invasion of cultured C6 cells in a concentration-dependent manner. In addition, the continuous bevacizumab treatment also promoted tumor invasion in rat C6 intracranial glioma models. Bevacizumab treatment enhanced Pyk2 phosphorylation at Tyr402, but no effect on FAK phosphorylation at Tyr397 both in vitro and in vivo. Knockdown of Pyk2 by siRNA or inhibition of Pyk2 phosphorylation by Src kinase specific inhibitor PP1 partially inhibited bevacizumab-induced cell invasion in cultured C6 glioma cells. Furthermore, the combined administration of bevacizumab and PP1 significantly suppressed glioma cell invasion into surrounding brain tissues compared to bevacizumab treatment alone in experimental rats. CONCLUSIONS: These results suggest that anti-VEGF treatment promotes glioma cell invasion via activation of Pyk2. Inhibition of Pyk2 phosphorylation might be a potential target to ameliorate the therapeutic efficiency of anti-VEGF treatment.

Nanoparticle-coated separators for lithium-ion batteries with advanced electrochemical performance.

We report a simple, scalable approach to improve the interfacial characteristics and, thereby, the performance of commonly used polyolefin based battery separators. The nanoparticle-coated separators are synthesized by first plasma treating the membrane in oxygen to create surface anchoring groups followed by immersion into a dispersion of positively charged SiO(2) nanoparticles. The process leads to nanoparticles electrostatically adsorbed not only onto the exterior of the surface but also inside the pores of the membrane. The thickness and depth of the coatings can be fine-tuned by controlling the ζ-potential of the nanoparticles. The membranes show improved wetting to common battery electrolytes such as propylene carbonate. Cells based on the nanoparticle-coated membranes are operable even in a simple mixture of EC/PC. In contrast, an identical cell based on the pristine, untreated membrane fails to be charged even after addition of a surfactant to improve electrolyte wetting. When evaluated in a Li-ion cell using an EC/PC/DEC/VC electrolyte mixture, the nanoparticle-coated separator retains 92% of its charge capacity after 100 cycles compared to 80 and 77% for the plasma only treated and pristine membrane, respectively.