Mutation spectrum of FLT3 and significance of non-canonical FLT3 mutations in haematological malignancy.

Fms-like tyrosine kinase 3 (FLT3) is frequently mutated in haematological malignancies. Although canonical FLT3 mutations including internal tandem duplications (ITDs) and tyrosine kinase domains (TKDs) have been extensively studied, little is known about the clinical significance of non-canonical FLT3 mutations. Here, we first profiled the spectrum of FLT3 mutations in 869 consecutively newly diagnosed acute myeloid leukaemia (AML), myelodysplastic syndrome and acute lymphoblastic leukaemia patients. Our results showed four types of non-canonical FLT3 mutations depending on the affected protein structure: namely non-canonical point mutations (NCPMs) (19.2%), deletion (0.7%), frameshift (0.8%) and ITD outside the juxtamembrane domain (JMD) and TKD1 regions (0.5%). Furthermore, we found that the survival of patients with high-frequency (>1%) FLT3-NCPM in AML was comparable to those with canonical TKD. In vitro studies using seven representative FLT3-deletion or frameshift mutant constructs showed that the deletion mutants of TKD1 and the FLT3-ITD mutant of TKD2 had significantly higher kinase activity than wild-type FLT3, whereas the deletion mutants of JMD had phosphorylation levels comparable with wild-type FLT3. All tested deletion mutations and ITD were sensitive to AC220 and sorafenib. Collectively, these data enrich our understanding of FLT3 non-canonical mutations in haematological malignancies. Our results may also facilitate prognostic stratification and targeted therapy of AML with FLT3 non-canonical mutations.

Synthesis and evaluation of new potential anti-pseudo-allergic agents.

Pseudo-allergic reactions frequently occur following clinical drug use and sometimes even cause mortal danger. Mas-related G-protein-coupled receptor member X2 (MRGPRX2) is a novel receptor that mediates pseudo-allergy and is an important target in the treatment of allergies. However, to date, there are no synthetic small-molecule inhibitors that prevent anaphylactoid reactions through this pathway. Our preliminary research suggested that B10-S and mubritinib effectively inhibited LAD2 cells. Therefore, two novel derivatives were synthesized by integrating the active substructures of B10-S and mubritinib, according to the molecular docking results. The antiallergic inhibitory effects of the two compounds were preliminarily evaluated in vitro using ß-hexosaminidase release, histamine release, and intracellular Ca2+ mobilization assays, and their binding sites on MRGPRX2 were analyzed by molecular docking. Both substances inhibited ß-hexosaminidase and histamine release in LAD2 cells and decreased intracellular Ca2+ by inhibiting MRGPRX2 in MRGPRX2-HEK293 cells treated with C48/80 in a dose-dependent manner. The docking results suggested that the molecules could competitively bind to the active site on MRGPRX2 and Glu141, which were combined by C48/80. Our study indicated that the two compounds have potential anti-allergic properties, which may provide evidence that will facilitate the development of synthetic molecules with anti-pseudo-allergic activity for clinical use in the future.

Application of mammography-based radiomics signature for preoperative prediction of triple-negative breast cancer.

OBJECTIVE: This study is aimed to explore the value of mammography-based radiomics signature for preoperative prediction of triple-negative breast cancer (TNBC). MATERIALS AND METHODS: Initially, the clinical and X-ray data of patients (n = 319, age of 54 ± 14) with breast cancer (triple-negative-65, non-triple-negative-254) from the First Affiliated Hospital of Soochow University (n = 211, as a training set) and Suzhou Municipal Hospital (n = 108, as a verification set) from January 2018 to February 2021 are retrospectively analyzed. Comparing the mediolateral oblique (MLO) and cranial cauda (CC) mammography images, the mammography images with larger lesion areas are selected, and the image segmentation and radiomics feature extraction are then performed by the MaZda software. Further, the Fisher coefficients (Fisher), classification error probability combined average correlation coefficients (POE + ACC), and mutual information (MI) are used to select three sets of feature subsets. Moreover, the score of each patient's radiomics signature (Radscore) is calculated. Finally, the receiver operating characteristic curve (ROC) is analyzed to calculate the AUC, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of TNBC. RESULTS: A significant difference in the mammography manifestation between the triple-negative and the non-triple-negative groups (P < 0.001) is observed. The (POE + ACC)-NDA method showed the highest accuracy of 88.39%. The Radscore of triple-negative and non-triple-negative groups in the training set includes - 0.678 (- 1.292, 0.088) and - 2.536 (- 3.496, - 1.324), respectively, with a statistically significant difference (Z = - 6.314, P < 0.001). In contrast, the Radscore in the validation set includes - 0.750 (- 1.332, - 0.054) and - 2.223 (- 2.963, - 1.256), with a statistically significant difference (Z = - 4.669, P < 0.001). In the training set, the AUC, accuracy, sensitivity, specificity, positive predictive value and negative predictive value of TNBC include 0.821 (95% confidence interval 0.752-0.890), 74.4%, 82.5%, 72.5%, 41.2%, and 94.6%, respectively. In the validation set, the AUC, accuracy, sensitivity, specificity, positive predictive value and negative predictive value of TNBC are of 0.809 (95% confidence interval 0.711-0.907), 80.6%, 72.0%, 80.7%, 55.5%, and 93.1%, respectively. CONCLUSION: In summary, we firmly believe that this mammography-based radiomics signature could be useful in the preoperative prediction of TNBC due to its high value.

Astemizole as a drug to inhibit the effect of SARS-COV-2 in vitro.

Since the beginning of December 2019, a novel Coronavirus severe respiratory disease, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) which also been termed 2019-new CoV (2019-nCoV), has continued to spread worldwide. As of August 27, 2020, a total of 24,232,429 people have been infected and 826,518 people have died. In our study, we found that astemizole can antagonize ACE2 and inhibit the entry of SARS-COV-2 spike pseudovirus into ACE2-expressed HEK293T cells (ACE2hi cells). We analysied the binding character of astemizole to ACE2 by molecular docking and surface plasmon resonance (SPR) assays and molecule docking, SARS-COV-2 spike pseudotype virus was also taken to investigate the suppression viropexis effect of astemizole. The results showed that astemizole can bind to the ACE2 receptor and inhibit the invasion of SARS-COV-2 Spike pseudoviruses. Thus astemizole represent potential drug candidates that can be re-used in anti-coronavirus therapies.

MRGPRX2 is critical for clozapine induced pseudo-allergic reactions.

BACKGROUND: Clozapine is one of the most widely used second-generation antipsychotics in clinic. However, allergy-like symptoms such as rash and angioedema have been reported frequently, and the mechanism is still not clear. Mas-related G protein-coupled receptor X2 (MRGPRX2) expressed on mast cells is a crucial receptor for drug induced pseudo-allergic reactions. Therefore, we explored whether the symptoms induced by clozapine were associated with allergic reaction through MRGPRX2. METHODS: The effects of clozapine on pseudo-allergic reactions were evaluated by mast cells degranulation and calcium mobilization assay in vitro, and mice hindpaw swelling, serum histamine detection, avidin and H&E staining assay in vivo. The overexpressed MRGPRX2 cells membrane chromatography (MRGPRX2-HEK293/CMC), MRGPRX2-HEK293 cells calcium mobilization assay and molecular docking were applied to research the correlation between clozapine and MRGPRX2. RESULTS: The study showed that clozapine induced the release of ß-hexosaminidase, histamine and monocyte chemoattractant protein-1 (MCP-1), and trigged calcium mobilization in mast cells. In vivo, clozapine induced paw swelling, degranulation and vasodilation. Furthermore, clozapine could activate the calcium mobilization obviously in MRGPRX2-HEK293 cells, not in NC-HEK293 cells. Clozapine also had a good retention characteristic on MRGPRX2-HEK293/CMC column and the K D value is (2.33 ± 0.21)×10-01M. CONCLUSIONS: Our findings demonstrated that clozapine could induce pseudo-allergic reactions and MRGPRX2 might be the critical receptor for it.

Roxithromycin inhibits compound 48/80-induced pseudo-allergy via the MrgprX2 pathway both in vitro and in vivo.

Roxithromycin (ROX) is a macrolide antibiotic with a variety of immunological effects. Mast cells (MCs) play a key role in host defense, mediating hypersensitivity and pseudo-allergic reactions. Mas-related G protein-coupled receptor X2 (MrgprX2) is the main receptor related to pseudo-allergy. In this study, we investigated the anti-pseudo-allergy effect of ROX and its underlying mechanism. The effects of ROX on passive cutaneous anaphylaxis (PCA) and active systemic allergy were examined, degranulation, Ca2+ influx, and cytokine release were studied in vivo and in vitro. Interactions between ROX and MrgprX2 protein were also detected through surface plasmon resonance. The PCA and active systemic allergy induced by compound 48/80 were inhibited by ROX. An intermolecular interaction was detected between the ROX and MrgprX2 protein. In conclusion, ROX could inhibit pseudo-allergic reactions, and this effect involves the Ca2+/PLC/IP3 pathway of MrgprX2. This study provides new insight into the anti-pseudo-allergy effects of ROX.

Isoimperatorin reduces the effective dose of dexamethasone in a murine model of asthma by inhibiting mast cell activation.

Adverse effects that result from dexamethasone (DEX) use are common and serious in patients with asthma. Therefore, alternative anti-inflammatory treatments are being investigated. Isoimperatorin (ISO), an active natural furocoumarin, possesses multiple pharmacological properties, including an anti-inflammation effect. In this study, investigations were conducted on the effect of ISO on mast cell (MC) activation in vitro and whether ISO could reduce the effective dose of DEX in a mast cell-dependent murine model of asthma in vivo. Calcium imaging was used to assess intracellular Ca2+ mobilization. Enzyme-linked immunosorbent assay was used to measure the chemokines release. Western blot analysis was conducted to investigate the underlying pathway. Airway inflammation and hyperresponsiveness (AHR) were examined in an asthma model. ISO inhibited Ca2+ flux and MC degranulation via Lyn/PLCγ1/PKC, ERK, and P38 MAPK pathways. In the asthma model, ISO, in combination with DEX, showed an additive inhibitory effect on AHR, inflammation, and the number of activated MCs in the lungs and decreased the levels of interleukin (IL)-4, IL-5, IL-6, IL-13, tumor necrosis factor (TNF)-a, and C-C motif chemokine ligand (CCL)-2 in bronchoalveolar lavage fluid. A combination of DEX and ISO may be appropriate if a decrease in the steroid dose is desired owing to dose-dependent adverse effects.

Changes in volatile flavor compounds of peppers during hot air drying process based on headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS).

BACKGROUND: Flavor plays a critical role in defining sensory and consumer acceptance of dried pepper, and it can be affected by temperature and moisture content during hot air drying (HAD). Thus, headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was used to analyze changes in volatile compounds of pepper during the HAD process with different drying temperatures. RESULTS: A total of 45 volatile flavor compounds were identified, including 11 esters, 11 aldehydes, nine alcohols, five ketones, three furans, three acids, two pyrazines, and one ether. The results showed that with the loss of moisture during drying, aldehydes and alcohols decreased, esters initially increased and then decreased. However, propyl acetate, 2,3-butanediol, 2-acetylfuran, and 2-methylpyrazine increased. Moreover, drying temperature was closely related to the change of volatile flavor compounds. Aldehydes, alcohols, and some other volatile flavor compounds (methyl salicylate, ethyl acetate, 2-methylpyrazine, dipropyl disulfide) decreased with an increase of temperature (60-80 °C) at the same moisture content, while high temperature could promote the formation of ethyl octanoate, methyl octanoate, benzaldehyde, furfurol, acetal, 5-methylfurfural, and 2-acetylfuran. Based on principal components analysis and heat map clustering analysis, peppers dried at 70 or 80 °C presented similar composition, and the loss of volatile flavor compounds was more than samples died at 60 °C during the HAD process. CONCLUSION: Overall, the flavor quality of peppers dried at 60 °C was better than that of other treatments during the HAD process. HS-GC-IMS was a reliable and effective means of analyzing volatile flavor compounds in peppers during the drying process. © 2020 Society of Chemical Industry.

Gold induces a pseudo-allergic reaction via MRGPRX2 both in vitro and in vivo.

The traditional mast cell (MC) degranulation pathway is mediated by crossing-linking of high-affinity IgE receptor (FcεRI), whereas a non-traditional, but analogous, pseudo-allergic way was recently reported to occur via Mas-Related G Protein-Coupled Receptor X2 (MRGPRX2). Severe contact hypersensitivity to metallic gold, typically considered non-sensitizing, has been reported. However, whether gold induces IgE-independent allergy remains unclear. Therefore, this study assessed the effects of gold chloride (CA) on MC activation and its relation to MRGPRX2. Our data show that CA acted on MRGPRX2 to increase cellular calcium levels and induced the release of inflammatory mediators in vitro. Compared to Mrgprb2-knockout (KO) mice, CA dose-dependently induced passive cutaneous anaphylaxis (PCA) in wild-type (WT) mice. Furthermore, peritoneal mast cells (MPMCs) were extracted from WT and Mrgprb2-KO mice and stimulated by CA, but only MPMCs from WT mice could be activated. Our results suggest that CA-induced pseudo-allergic responses are MRGPRX2 dependent.

1-MCP treatment improves the postharvest quality of Jinxiu yellow peach by regulating cuticular wax composition and gene expression during cold storage.

This study aimed to analyze the effect of 1-methylcyclopropene (1-MCP) treatment on the postharvest quality, epidermal wax morphology, composition, and gene expression of Jinxiu yellow peach during cold storage. The results showed that 1-MCP treatment could maintain the postharvest quality of peach fruit as compared to control (CK) during cold storage. The wax crystals of peach fruit were better retained by 1-MCP, and they still existed in 0.6 and 0.9 µL/L 1-MCP treated fruit at 36 days. The total wax content in all the fruit increased first and then decreased during cold storage. Meanwhile, n-alkanes and primary alcohols were the main wax components. Compared to CK, 1-MCP treatment could delay the reduction of wax content during cold storage. The correlation analysis indicated that the postharvest quality of yellow peach was mainly affected by the contents of fatty acids and triterpenoids in cuticular wax. The transcriptomics results revealed PpaCER1, PpaKCS, PpaKCR1, PpaCYP86B1, PpaFAR, PpaSS2, and PpaSQE1 played the important roles in the formation of peach fruit wax. 1-MCP treatment upregulated PpaCER1 (18785414, 18786441, and 18787644), PpaKCS (18774919, 18789438, and 18793503), PpaKCR1 (18790432), and PpaCYP86B1 (18789815) to deposit more n-alkanes and fatty acids during cold storage. This study could provide a new perspective for regulating the postharvest quality of yellow peach in view of the application of cuticular wax. PRACTICAL APPLICATION: 'Jinxiu' yellow peach fruit is favorable among consumers because of its high commercial value. However, it ripens and deteriorates rapidly during storage, leading to serious economic loss and consumer disappointment. The effect of 1-methylcyclopropene (1-MCP) treatment on the postharvest quality, epidermal wax morphology, composition, and genes regulation of 'Jinxiu' yellow peach during cold storage was assessed. Compared to control, 1-MCP treatment could retain the storage quality of yellow peach by affecting cuticular wax composition and gene expression. This study could provide new perspective for regulating the postharvest quality of yellow peach in view of the application of cuticular wax.

Grafting chlorogenic acid enhanced the antioxidant activity of curdlan oligosaccharides and modulated gut microbiota.

In this study, the effects of grafting chlorogenic acid (CA) on the antioxidant and probiotic activities of curdlan oligosaccharides (CDOS) were investigated. CDOS with degrees of polymerization of 3-6 was first obtained by degradation of curdlan with hydrogen peroxide and then grafted with CA using a free radical-mediated method under an ultrasonication-assisted Fenton system. The thermal stability and antioxidant ability of CDOS were enhanced after grafting with CA. In vitro fermentation, supplementation of CDOS-CA stimulated the proliferation of Prevotella and Faecalibacterium while inhibiting the growth of harmful microbiota. Notably, the concentration of total short-chain fatty acids and the relative abundance of beneficial bacteria markedly increased after fermentation of CDOS-CA, indicating that CA grafting could improve the probiotic activity of CDOS. Overall, the covalent binding of CDOS and CA could enhance the antioxidant and probiotic activities of CDOS, suggesting potential improvements in gastrointestinal and colonic health.

Development of a chitosan/pectin-based multi-active food packaging with both UV and microbial defense functions for effectively preserving of strawberry.

Multi-active food packaging was prepared for strawberry fruit preservation where epigallocatechin gallate (EGCG)-containing pectin matrix and natamycin (NATA)-containing chitosan (CS) matrix were utilized to complete LBL electrostatic self-assembly. The results showed that the physicochemical properties of the multi-active packaging were closely related to the addition of NATA and EGCG. It was found that NATA and EGCG were embedded in the CS/pectin matrix through intermolecular hydrogen bonding interactions. The CN/PE 15 % multi-active films prepared based on the spectral stacking theory formed a barrier to UV light in the outer layer, exhibited excellent NATA protection under UV light exposure conditions at different times, and provided long-lasting and sustained bacterial inhibition in the inner layer. In addition, the CN/PE 15 % multi-active packaging extended the shelf life of strawberry at room temperature compared with the control samples. In conclusion, the developed CN/PE 15 % packaging provided potential applications for multi-active food packaging materials.

Citrus oil gland and cuticular wax inspired multifunctional gelatin film of OSA-starch nanoparticles-based nanoemulsions for preserving perishable fruit.

Inspired by the citrus oil gland and cuticular wax, a multifunctional material that stably and continuously released the carvacrol and provided physical defenses was developed to address issues of fresh-cut fruits to microbial infestation and moisture loss. The results confirmed that low molecular weight and loose structure of starch nanoparticles prepared by the ultrasound-assisted Fenton system were preferable for octenyl succinic anhydride modification compared to native starch, achieving a higher degree of substitution (increased by 18.59 %), utilizing in preparing nanoemulsions (NEs) for encapsulating carvacrol (at 5 % level: 81.58 %). Furthermore, the NEs-based gelatin (G) film improved with surface hydrophobic modification by myristic acid (MA) successfully replicated the citrus oil gland and cuticular wax, providing superior antioxidant (enhanced by 3-4 times) and antimicrobial properties (95.99 % and 84.97 % against Staphylococcus aureus and Escherichia coli respectively), as well as the exceptional UV shielding (nearly 0 transmittance in the UV region), mechanical (72 % increase in tensile strength), and hydrophobic (WCA 133.63°). Moreover, the 5%NE-G@MA film inhibited foodborne microbial growth (reduced by 50 %) and water loss (controlled below 15 %), extending the shelf life of fresh-cut navel orange and kiwi. Thus, the multifunctional film was a potential shield for preserving perishable fresh-cut products.

Visible light-responsive TiO2-based hybrid nanofiller reinforced multifunctional chitosan film for effective fruit preservation.

In this study, we developed a multifunctional chitosan film with visible light-responsive photocatalytic properties by incorporating a novel nanofiller-a nanohybrid particle of poly(tannic acid) (PTA) and TiO2 (TP-NPs). Firstly, the hybridization of TiO2 with PTA not only improved its dispersion but also obtained TP-NPs with smaller band gaps (from 3.11 eV to 1.55 eV) and higher separation efficiency of photogenerated e--h+ (about 1.5-fold enhancement), thereby producing more reactive oxygen species and enhancing the antibacterial efficacy (compared with TiO2, the antibacterial effect of TP-NPs on Staphylococcus aureus and Escherichia coli was heightened by about 2 times under visible light for 1 h). Secondly, TP-NPs were hydrogen bonded with chitosan, strengthening its mechanical and barrier properties, while imparting exceptional antibacterial efficacy. Moreover, the multifunctional properties enabled the active film to effectively delay the quality deterioration of grapes and kiwifruit. Hence, this study presented a multifunctional active packaging film tailored for fruit preservation.

The combination of metabolome and transcriptome clarifies the inhibition of the Alternaria toxin accumulation by methyl ferulate.

As one of the most typical pathogens in fruit postharvest diseases, Alternaria alternata (A. alternata) can produce Alternaria toxins (ATs) aggravating fruit decay and harming human health. In this study, ATs (tenuazonic acid, alternariol monomethyl ether, and alternariol) production was inhibited effectively by 200 and 8000 mg/L MF (methyl ferulate) in vitro and in vivo. 1-Octen-3-ol and 3-octanol were the potential iconic volatile organic compounds of ATs (R2 > 0.99). MF induced oxidative stress, resulting in physiological and metabolic disorders, membrane lipid oxidation and cell damage. It decreased precursors and energy supply by disturbing amino acid metabolism, ABC transporters, citrate cycle, pentose and glucuronate interconversions to regulate ATs synthesis. MF down-regulated the genes related to ATs synthesis (PksJ, AaTAS1, and OmtI), transport (AaMFS1 and MFS), and pathogenicity to affect ATs production and virulence. This study provided a theoretical basis for the control of ATs production.

Investigations of the prognostic value of RUNX1 mutation in acute myeloid leukemia patients: Data from a real-world study.

RUNX1 is one of the recurrent mutated genes in newly diagnosed acute myeloid leukemia (AML). Although historically recognized as a provisional distinct entity, the AML subtype with RUNX1 mutations (AML-RUNX1mut) was eliminated from the 2022 WHO classification system. To gain more insight into the characteristics of AML-RUNX1mut, we retrospectively analyzed 1065 newly diagnosed adult AML patients from the First Affiliated Hospital of Soochow University between January 2017 and December 2021. RUNX1 mutations were identified in 112 patients (10.5%). The presence of RUNX1 mutation (RUNX1mut) conferred a lower composite complete remission (CRc) rate (40.2% vs. 58.4%, P＜0.001), but no significant difference was observed in the 5-year overall survival (OS) rate (50.2% vs. 53.9%; HR=1.293; P=0.115) and event-free survival (EFS) rate (51.5% vs. 49.4%; HR=1.487, P=0.089), even within the same risk stratification. Multivariate analysis showed that RUNX1mut was not an independent prognostic factor for OS (HR=1.352, P=0.068) or EFS (HR=1.129, P=0.513). When patients were stratified according to induction regimen, RUNX1mut was an unfavorable factor for CRc both on univariate and multivariate analysis in patients receiving conventional chemotherapy, and higher risk stratification predicted worse OS. In those who received venetoclax plus hypomethylating agents, RUNX1mut was not predictive of CRc and comparable OS and EFS were seen between intermediate-risk and adverse-risk groups. The results of this study revealed that the impact of RUNX1mut is limited. Its prognostic value depended more on treatment and co-occurrent abnormalities. VEN-HMA may abrogate the prognostic impact of RUNX1, which merits a larger prospective cohort to illustrate.

Screening of CPT1A-Targeting Lipid Metabolism Modulators Using Mitochondrial Membrane Chromatography.

Carnitine palmitoyltransferase 1A (CPT1A), which resides on the mitochondrial outer membrane, serves as the rate-limiting enzyme of fatty acid ß-oxidation. Identifying the compounds targeting CPT1A warrants a promising candidate for modulating lipid metabolism. In this study, we developed a CPT1A-overexpressed mitochondrial membrane chromatography (MMC) to screen the compounds with affinity for CPT1A. Cells overexpressing CPT1A were cultured, and subsequently, their mitochondrial membrane was isolated and immobilized on amino-silica gel cross-linked by glutaraldehyde. After packing the mitochondrial membrane column, retention components of MMC were performed with LC/MS, whose analytic peaks provided structural information on compounds that might interact with mitochondrial membrane proteins. With the newly developed MMC-LC/MS approach, several Chinese traditional medicine extracts, such as Scutellariae Radix and Polygoni Cuspidati Rhizoma et Radix (PCRR), were analyzed. Five noteworthy compounds, baicalin, baicalein, wogonoside, wogonin, and resveratrol, were identified as enhancers of CPT1A enzyme activity, with resveratrol being a new agonist for CPT1A. The study suggests that MMC serves as a reliable screening system for efficiently identifying modulators targeting CPT1A from complex extracts.

RLP1.1, a novel wheat receptor-like protein gene, is involved in the defence response against Puccinia striiformis f. sp. tritici.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most serious diseases of wheat; therefore, exploring effective resistance-related genes is critical for breeding and studying resistance mechanisms. However, only a few stripe rust resistance genes and defence-related genes have been cloned. Moreover, transgenic wheat with enhanced stripe rust resistance has rarely been reported. Receptor-like proteins (RLPs) are known to be involved in defence and developmental pathways. In this research, a novel RLP gene TaRLP1.1 was characterized as an important stripe rust defence gene. TaRLP1.1 was screened by GeneChip and was found to be induced by Pst specifically in the resistant variety. Knock down of TaRLP1.1 in the stripe rust-resistant plants resulted in increased susceptibility to Pst, and phenolic autofluorogen accumulation at the pathogen-host interaction sites, usually correlated with the hypersensitive response, was decreased dramatically. However, when the TaRLP1.1 gene was transformed into the susceptible wheat variety Yangmai158, the transgenic plants showed highly increased resistance to Pst, and the hypersensitive response was enhanced at the infection sites. Meanwhile, the expression of pathogenesis-related genes decreased in the TaRLP1.1-silenced plants and increased in the TaRLP1.1-overexpressing plants. Thus, it was proposed that TaRLP1.1 greatly contributed to the hypersensitive response during the pathogen-host interaction. Along with the functional analysis, an evolutionary study of the TaRLP1 family was performed. Characterization of TaRLP1.1 may facilitate breeding for stripe rust resistance and better understanding of the evolution of the RLP genes in wheat.

Transcriptomics and gas chromatography-mass spectrometry metabolomics reveal the mechanism of heat shock combined with 1-methylcyclopropene to regulate the cuticle wax of jujube fruit during storage.

Cuticle wax is closely related to fruit quality during storage. In this study, changes in epidermal wax morphology, composition, and genes regulation induced by heat shock (HT), 1-methylcyclopropene (1-MCP) or their combination (HT + 1-MCP) were investigated in jujube fruit during cold storage. HT, 1-MCP, or HT + 1-MCP caused a smoother wax layer and fewer micro-cracks compared to the control (CK) during cold storage. It was confirmed that acids and terpenoids were the main wax components by gas chromatography-mass spectrometry. HT + 1-MCP and 1-MCP treatments could significantly increase (p < 0.05) the wax content at 45 d of cold storage. The transcriptomics results indicated that HT + 1-MCP treatment up-regulated FATB, FATB, FAB2, FAD2 and CYP716A, and maintained the wax content of jujube fruit during cold storage. These results could provide new perspective for regulating the cuticle characteristics to extend the shelf life of jujube fruit.

Site-Specific Covalent Immobilization of SMA-Stabilized ACE2 for SARS-CoV-2 Recognition and Drug Screening.

Membrane protein (MP)-based biomaterials have a wide range of applications in drug screening, antigen detection, and ligand-receptor interaction analysis. Traditional MP immobilization methods have the disadvantage of disordered protein immobilization orientation, leading to the shielded binding domain and unreliable binding pattern. Herein, we describe a site-specific covalent immobilization of MPs, which utilizes the styrene maleic acid (SMA) detergent-free extraction method of MPs as well as the covalent reaction between His-tag and divinyl sulfone (DVS). As an example, we covalently immobilized angiotensin-converting enzyme 2 (ACE2) on a cell membrane chromatography system (ACE2-His-SMALPs/CMC) in a site-specific manner and verified the specificity and stability of this system. This technique significantly improves the service life compared to the physisorption CMC column. The improved protein immobilization strategies of the ACE2-His-SMALPs/CMC system enable it to effectively recognize SARS-CoV-2 pseudoviral particles as well as detect viral particles in ambient air once combined with an aerosol collector; as a powerful ligand biosensor, the ACE2-His-SMALPs/CMC system was used to screen for compounds with anti-SARS-CoV-2 pseudovirus activity. In conclusion, the optimized MP immobilization strategy has been successfully applied to CMC technology, showing enhanced stability and sensitivity, which can provide an efficient and convenient membrane protein immobilization method for biomaterials.