Intestinal inflammation can destroy the integrity of the intestinal barrier and disrupt immune homeostasis, increasing the risks of developing fatal diseases. Enterohemorrhagic Escherichia coli (EHEC) O157:H7, a prominent pathogen primarily transmitted through contaminated food, is known to trigger intestinal inflammation and subsequent infections. Temporin-GHbK (GHbK) and temporin-GHb3K (GHb3K), derived from temporin-GHb of Hylarana guentheri, were synthesized and demonstrated antimicrobial and anti-biofilm activities against EHEC in vitro. They also exhibited efficacy in preventing EHEC infection in vivo. GHbK and GHb3K significantly decreased the disease activity index (DAI) in EHEC-infected mice in comparison with the untreated model group. The derived peptides exhibited barrier-protective effects by preserving structural integrity, reducing inflammatory infiltrates in the intestinal epithelium, and maintaining gut microbiota diversity. Taken together, GHbK and GHb3K exhibit promising anti-inflammatory and anti-infection potential against EHEC infection. These findings lay a foundation for exploring the application of antibacterial peptides in the treatment of EHEC infection.

Peel color is an important indicator of pitaya appearance, quality, and commercial value, yet its formation mechanism remains unclear. In this study, four pitaya cultivars were selected, and peel samples were collected at the green, color-transition, and mature stages. Integrated metabolomic and transcriptomic analyses were performed to elucidate the molecular basis of peel color formation. The results revealed significant differences in metabolite composition and gene expression among cultivars. Red-peel cultivars exhibited higher betalain contents, with key biosynthetic genes (CYP76AD1, DODA, and GT) significantly upregulated during fruit maturation, closely associated with red coloration. In 'Wucihuanglong', betalains and related genes were also upregulated but at lower levels than in red cultivars, while carotenoids and flavonoids accumulated at relatively higher levels, likely jointly influencing peel color. In contrast,'Yanwoguo' showed substantial accumulation of carotenoids and flavonoids, whereas betalain contents and biosynthetic gene expression were low, indicating that carotenoids and flavonoids are the main pigments responsible for yellow peel formation. Additionally, genes involved in chlorophyll biosynthesis (HEMA, POR, and DVR) were downregulated, while chlorophyll degradation genes (SGR and PAO) were upregulated during fruit maturation, further promoting peel color changes. Overall, this study identified key metabolites and candidate genes associated with pitaya peel color through integrated multi-omics analysis, providing a theoretical basis for elucidating coloration mechanisms and supporting breeding research.

Background Cutaneous wound healing proceeds through a tightly regulated sequence of four phases. Disruption of this process, particularly prolonged inflammation, often leads to delayed repair and the development of chronic wounds. Materials and methods In this study, we focused on the Fejervarin (Fej) family peptides, which were isolated from the skin secretions of Fejervarya moodiei , Fejervarya multistriata , Hylarana cubitalis , and Duttaphrynus melanostictus . By integrating molecular cloning, in vitro cellular functional assays, animal models, molecular interaction studies, and multi-omics technologies, we established a research framework encompassing: molecular identification - druggability evaluation - in vivo efficacy - target validation - pathway analysis. Results In murine models of full-thickness wounds, Fej peptides exhibit regulatory efficacy during both the inflammatory and proliferative phases, achieving 99% re-epithelialization by day 12, compared to 91% with human epidermal growth factor (EGF) gel (REFOO®). Biophysical analyses revealed that Fej-1a and Fej-1b directly bind to the transforming growth factor-β receptor II (TGFBR2) with dissociation constants (Kd) of 0.387 µM and 5.78 µM, respectively. During the inflammatory phase, Fej-1a and Fej-1b modulate inflammatory responses through the TGF-β-activated kinase 1 - nuclear factor-kappa B (TAK1-NF-κB) axis, thereby suppressing M1 macrophage activation while promoting M2 polarization, which accelerates the transition to the proliferative phase of wound healing. Concurrently, these peptides enhance fibroblast migration and collagen deposition by activating the TGF-β/Smad2/3 signaling pathway. Notably, Fej peptides exhibit negligible hemolytic activity and no detectable cytotoxicity in vitro and in vivo , underscoring their biocompatibility for topical application. Conclusion Our findings elucidate a dual-functioning family of amphibian anionic octapeptides that effectively bridge immune resolution and tissue remodeling, highlighting promising prospects for the development of peptide-based therapeutics in wound healing.

Methicillin-resistant Staphylococcus aureus (MRSA) causes life-threatening skin and systemic infections, necessitating novel antimicrobial strategies. The Temporin-GHb (GHb) derived peptides GHbR, GHbK, GHb3K, GHb11K, and GHbK4R were demonstrated effective bactericidal activity against both planktonic and biofilm state of MRSA, without inducing detectable bacterial resistance in vitro. Additionally, the peptides have high biocompatibility, with GHb3K exhibiting the lowest cytotoxicity in HaCaT cells and promoting cell migration. In vivo, GHbR and GHb3K effectively accelerated MRSA-infected skin wound healing by reducing bacterial burden, suppressing pro-inflammatory cytokines, and promoting tissue regeneration and remodeling. In mouse model of MRSA pneumonia, they reduced bacterial loads, mitigated lung inflammation, and accelerated pulmonary tissue recovery. These findings highlight the therapeutic potential of Temporin-derived peptides as promising alternatives for combating MRSA infections.

IntroductionGlobally, cat allergens are a common cause of allergic rhinitis and asthma. Fel d 1 is the primary allergen among cat allergens and can induce a broad range of allergies through airborne transmission.MethodsIn our study, we constructed layered double hydroxide (LDH) nanoparticles loaded with PADRE-rFel d 1, aiming to address allergies triggered by Fel d 1. We utilized a mouse model sensitized with purified rFel d 1 and then immunized them subcutaneously with LDH nanoparticles loaded with PADRE-rFel d 1.ResultsOur results indicated that this nanoparticle vaccine effectively restored the balance of Th1/Th2 and Th17/ Treg cells, which led to a reduction in inflammatory cell infiltration, mitigated local and systemic stress responses induced by rFel d 1, decreased airway hyperresponsiveness, and lowered serum IgE levels.DiscussionConsequently, the LDH loaded with PADRE-rFel d 1 vaccine shows promise as an effective treatment for cat allergies.

3,4-Dihydroxyphenylacetaldehyde synthase (DHPAAS) catalyzes oxygen-dependent conversion of 3,4-dihydroxyphenylalanine (dopa) to 3,4-dihydroxyphenylacetaldehyde (DHPAA), a likely cross-linking agent precursor of the insect cuticle. In the current study, extensive in vivo experiments in Aedes aegypti show that DHPAAS is essential for abdominal integrity, egg development and cuticle structure formation. Solid-state 13C nuclear magnetic resonance analysis of the Ae. aegypti cuticle molecular structure shows chemical shifts of 115 to 145 ppm, suggesting the presence of catechols derived from DHPAA. The crystal structure of insect DHPAAS was then solved, revealing an active site that is divergent from that of the homologous enzyme dopa decarboxylase. In the DHPAAS crystal structure, stabilization of the flexible 320-350 region accompanies the positioning of the 350-360 loop relatively close to the catalytic Asn192 residue while the conserved active site residue Phe103 adopts an open conformation away from the active center; these distinct features participate in the formation of a specific hydrophobic tunnel which potentially facilitates delivery of oxygen to pyridoxal 5'-phosphate in the conversion of dopa to DHPAA.

Dental caries, the most prevalent oral infectious disease, is closely associated with Streptococcus mutans. This study investigates the antimicrobial properties of the temporin-GHb peptide and its derivatives (GHbR, GHbK, and GHb3K) against S. mutans. These peptides exhibited potent anti-S. mutans activity through a membrane-disruptive mechanism, confirmed by flow cytometry and fluorescence staining assays while showing lower bactericidal effects on beneficial probiotic bacteria. Additionally, they inhibited the biofilm matrix formation by disrupting extracellular polysaccharide (EPS) synthesis, as demonstrated by zymography, qRT-PCR, and sucrose metabolism experiments. In a rat model of S. mutans-induced dental caries, treatment with these peptides significantly reduced the incidence of dental lesions. H&E staining analysis of rat oral tissues confirmed the biosafety of GHb and GHb3K. These findings suggest that temporin-derived peptides effectively target EPS, inhibiting biofilm formation and virulence, offering a promising strategy for preventing dental caries and promoting oral health. The findings suggest potential applications for peptide-based interventions to mitigate biofilm-related issues across various fields, including agriculture, food processing, and healthcare.

Background Understanding how plants and pathogens regulate each other's gene expression during their interactions is key to revealing the mechanisms of disease resistance and controlling the development of pathogens. Despite extensive studies on the molecular and genetic basis of plant immunity against pathogens, the influence of pitaya immunity on N. dimidiatum metabolism to restrict pathogen growth is poorly understood, and how N. dimidiatum breaks through pitaya defenses. In this study, we used the RNA-seq method to assess the expression profiles of pitaya and N. dimidiatum at 4 time periods after interactions to capture the early effects of N. dimidiatum on pitaya processes. Results The study defined the establishment of an effective method for analyzing transcriptome interactions between pitaya and N. dimidiatum and to obtain global expression profiles. We identified gene expression clusters in both the host pitaya and the pathogen N. dimidiatum . The analysis showed that numerous differentially expressed genes (DEGs) involved in the recognition and defense of pitaya against N. dimidiatum , as well as N. dimidiatum ’s evasion of recognition and inhibition of pitaya. The major functional groups identified by GO and KEGG enrichment were responsible for plant and pathogen recognition, phytohormone signaling (such as salicylic acid, abscisic acid). Furthermore, the gene expression of 13 candidate genes involved in phytopathogen recognition, phytohormone receptors, and the plant resistance gene ( PG ), as well as 7 effector genes of N. dimidiatum , including glycoside hydrolases, pectinase, and putative genes, were validated by qPCR. By focusing on gene expression changes during interactions between pitaya and N. dimidiatum , we were able to observe the infection of N. dimidiatum and its effects on the expression of various defense components and host immune receptors. Conclusion Our data show that various regulators of the immune response are modified during interactions between pitaya and N. dimidiatum . Furthermore, the activation and repression of these genes are temporally coordinated. These findings provide a framework for better understanding the pathogenicity of N. dimidiatum and its role as an opportunistic pathogen. This offers the potential for a more effective defense against N. dimidiatum .

Self-incompatible pitaya varieties have low fruit-setting rates under natural conditions, leading to higher production costs and hindering industrial prosperity. Through transcriptome sequencing, we obtained the 36,900 longest transcripts (including 9167 new transcripts) from 60 samples of flowers. Samples were collected pre- and post-pollination (at 0 h, 0.5 h, 2 h, 4 h, and 12 h) from two varieties of pitaya (self-compatible Jindu No. 1 and self-incompatible Cu Sha). Using the RNA-Seq data and comparison of reference genomes, we annotated 28,817 genes in various databases, and 1740 genes were optimized in their structure for annotation. There were significant differences in the expression of differentially expressed genes (DEGs) in the pitaya stigmas under different pollination types, especially at the late post-pollination stage, where the expression of protease genes increasedal significantly under cross-pollination. We identified DEGs involved in the ribosomal, ubiquitination-mediated, and phyto-signaling pathways that may be involved in pitaya SI regulation. Based on the available transcriptome data and bioinformatics analysis, we tentatively identified HuS-RNase2 as a candidate gynogenetic S gene in the pitaya GSI system.

Background Temporin is one family of the shortest antimicrobial peptides found in Ranidae frogs. Staphylococcus aureus is one of the main pathogens of suppurative diseases and food contamination, causing severe local or systemic infections in humans. Temporin-GHa (GHa) was previously obtained from Hylarana guentheri, showing weak antibacterial activity against S. aureus. Most temporin peptides are positively charged by arginine and lysine; however, GHa contains histidine. Objective In order to investigate the impact of positively charged amino acid on its antibacterial and antibiofilm activity, GHa4R was designed and synthesized by replacing histidine with arginine in GHa. Methods The antibacterial activity and efficacy against S. aureus were detected by minimum inhibitory concentration, minimum bactericidal concentration, and time-killing kinetics assays. The action mechanism was determined by propidium iodide uptake and scanning electron microscopy assays. The antibiofilm activity was measured by the MTT method. Eradication of biofilm was observed by fluorescence microscope. Results Compared to GHa, GHa4R had stronger antibacterial activity and bactericidal efficacy against S. aureus. Impressively, GHa4R presented antibacterial activity against methicillin-resistant S. aureus (MRSA). It was barely affected by temperature, pH, and storage period, showing high stability. Furthermore, it increased the permeability of the cell membrane and damaged the membrane integrity, leading to cell death. In addition, GHa4R did not induce antibiotic resistance in S. aureus in 30 days, but the MIC of vancomycin was doubled. It not only inhibited S. aureus biofilm formation but also eradicated 24 h-biofilms. Conclusion The above-mentioned characteristics make GHa4R a promising candidate for the treatment of S. aureus infections.

Antimicrobial peptides (AMPs) show broad-spectrum microbicidal activity against bacteria, fungi, and viruses, and have been considered as one of the most promising candidates to overcome bacterial antimicrobial resistance. Structural modification of AMPs is an effective strategy to develop high-efficiency and low-toxicity antibacterial agents. A series of peptides GHaR6R, GHaR7R, GHaR8R, and GHaR9W with arginine replacement of histidine (His) derived from temporin-GHa of Hylarana guentheri were designed and synthesized. These derived peptides exhibit antibacterial activity against Staphylococcus aureus, and GHaR8R exerts bactericidal effect within 15 min at 4 x MIC (25 mu m). The derived peptides caused rapid depolarization of bacteria, and the cell membrane damage was monitored using quartz crystal microbalance with dissipation assay, which suggests that they target cell membranes to exert antibacterial effects. The derived peptides can effectively eradicate mature biofilms of S. aureus. Taken together, the derived peptides are promising antibacterial agent candidates against S. aureus.

With the continuous development of drug resistance in bacteria to traditional antibiotics, the demand for novel antibacterial agents is urgent. Antimicrobial peptides (AMPs) are promising candidates because of their unique mechanism of action and low tendency to induce drug resistance. Previously, we cloned temporin-GHb (hereafter referred to simply as "GHb") from Hylarana guentheri. In this study, a series of derived peptides were designed, namely, GHbR, GHbK, GHb3K, GHb11K, and GHbK4R. The five derived peptides had stronger antibacterial activities against Staphylococcus aureus than the parent peptide GHb and could effectively inhibit the formation of biofilms and eradicate mature biofilms in vitro. GHbR, GHbK, GHb3K, and GHbK4R exerted bactericidal effects by disrupting membrane integrity. However, GHb11K exhibited bacteriostatic efficacy with toroidal pore formation on the cell membrane. In comparison to GHbK4R, GHb3K showed much lower cytotoxicity against A549 alveolar epithelial cells, with an IC50 > 200 μM, which was much higher than its minimal inhibitory concentration (MIC = 3.1 μM) against S. aureus. The anti-infection potential of GHbK4R and GHb3K was investigated in vivo. Compared with vancomycin, the two peptides displayed significant efficacy in a mouse model of acute pneumonia infected with S. aureus. Both GHbK4R and GHb3K also had no obvious toxicity to normal mice after intraperitoneal administration (15 mg/kg) for 8 days. Our results indicate that GHb3K and GHbK4R might be promising candidates for the treatment of bacterial pneumonia infected with S. aureus.

Introduction Temporin-GHa obtained from the frog Hylarana guentheri showed bactericidal efficacy against Streptococcus mutans . To enhance its antibacterial activity, the derived peptides GHaR and GHa11R were designed, and their antibacterial performance, antibiofilm efficacy and potential in the inhibition of dental caries were evaluated. Methods Bacterial survival assay, fluorescent staining assay and transmission electron microscopy observation were applied to explore how the peptides inhibited and killed S. mutans . The antibiofilm efficacy was assayed by examining exopolysaccharide (EPS) and lactic acid production, bacterial adhesion and cell surface hydrophobicity. The gene expression level of virulence factors of S. mutans was detected by qRT-PCR. Finally, the impact of the peptides on the caries induced ability of S. mutans was measured using a rat caries model. Results It has been shown that the peptides inhibited biofilm rapid accumulation by weakening the initial adhesion of S. mutans and reducing the production of EPS. Meanwhile, they also decreased bacterial acidogenicity and aciduricity, and ultimately prevented caries development in vivo. Conclusion GHaR and GHa11R might be promising candidates for controlling S. mutans infections.

Abstract3,4-Dihydroxyphenylacetaldehyde synthase (DHPAAS) catalyzes the direct conversion of 3,4-dihydroxyphenylalanine to 3,4-dihydroxyphenylacetaldehyde (DHPAA), an important intermediate in the formation of flexible insect cuticle. In order to clarify the precise roles DHPAAS plays in insect development and survival, DHPAAS was characterized throughout the physiological to the molecular levels. Extensive in vivo experiments inAedes aegypticonfirm that DHPAAS is essential for blood feeding, egg development and cuticle structure formation. The crystal structure of insect DHPAAS was then solved to reveal the structural basis underlying the catalytic production of the key cuticle intermediate DHPAA. The molecular view shows a DHPAAS active site that is distinct from that of the homologous enzyme 3,4-dihydroxyphenylalanine decarboxylase. Stabilization of the flexible 320–350 region is observed to position the 350–360 loop towards the catalytic asparagine residue, and these distinct features are suggested to promote pyridoxal 5'-phosphate-dependent amine oxidation. Additional molecular dynamics simulations further support the involvement of Phe82, Tyr83 and Asn195 in substrate binding and catalysis, and also shows increased fluctuations limited to loop residues 330–345 inAedes aegyptiDHPAAS.

Oxidative stress is one of the elements causing aging and related diseases. Inhibiting Nrf2 activity or increasing oxidative pressure can replicate the deficits of premature aging. SIRT6 is one of the few proteins that can regulate both life span and aging. Deletion of SIRT6 in human cells impairs the antioxidant capacity of cells, which results in the accumulation of intracellular reactive oxygen species and DNA oxidation products. Characterization of the binding of Nrf2 with SIRT6 is critical for understanding the modulation of Nrf2-correlated cell activities by SIRT6. The yeast two-hybrid experiments showed that the binding of Nrf2 with SIRT6 is mediated by Neh1 and Neh3 domains. The elimination of the Neh1 and Neh3 domains decreased the binding stability and free energy, according to the molecular dynamic analysis. The roles of theses domains in mediating the binding were confirmed by co-immunoprecipitation. In cells transfected with the small interfering RNA (siRNA) targeting the Nrf2 Neh1 domain and plasmids overexpressing domain-mutant Nrf2, it was discovered that Nrf2 lost its activity to stimulate the transcription of antioxidant genes in the absence of Neh1 and Neh3 domains.

ABSTRACT Neoscytalidium dimidiatum (class Dothideomycetes) is a fungus responsible for canker disease in pitaya stems and fruits, leading to significant economic losses. However, little is known about the pathogenesis, family evolution, and genetic variants of this species. In this study, we report a high-quality genome sequence of N. dimidiatum based on the Nanopore sequencing technology platform for sequencing and Hi-C assembly technology for genome assembly. The genome contains 12 chromosomes (2n = 2× = 12; diploid), with a sequencing depth of 186.1×, encoding 12,349 proteins. Molecular phylogenetic analysis showed that N. dimidiatum is evolutionarily close to Botryosphaeria dothidea. Compared to other fungi, the N. dimidiatum genome contains many carbohydrate-active enzymes and secondary metabolites. Additionally, we predict that N. dimidiatum contains 121 candidate effectors that may play important roles in infection and colonization, promoting pathogenicity in pitaya. Nine of these effectors were confirmed to contain signal peptides and inhibit BAX/INF1-induced necrosis in Nicotiana benthamiana, demonstrating their importance during infection. Finally, we also confirm that N. dimidiatum does not form an appressorium or infection thread but instead infects pitaya via open stomata. In conclusion, the results provide a foundation for future research on N. dimidiatum and the control of pitaya canker. IMPORTANCE Pitaya canker is a significant disease in the pitaya industry in China, causing significant economic losses. Therefore, systematic research on Neoscytalidium dimidiatum, the fungus implicated in pitaya canker, is essential for comprehending the pathogenesis of this disease and developing effective control strategies. We applied comparative genomics to reveal the genetic evolution, metabolic diversity, environmental adaptation, and pathogenicity of N. dimidiatum, providing ideal targets for studies of pathogenesis and molecular targets for fungicide development. Moreover, the systematic study of the N. dimidiatum growth cycle, morphological characteristics, and molecular phylogenetic analysis can promote a comprehensive understanding of its genetic basis.

F-box基因家族作为植物中最大的基因家族之一,在调控植物发育、生殖及非生物胁迫反应等方面,发挥至关重要的作用.本研究以火龙果的自交亲和品种'金都一号'和自交不亲和品种'粗砂'为材料,对火龙果花器官转录组中的F-box基因家族进行鉴定,对与花发育和亲和性识别相关基因亚族的理化性质、亚细胞定位、保守结构域、基因在染色体的定位、系统进化关系和遗传结构进行分析,通过RT-qPCR分析其在火龙果花器官的不同组织、授粉前后不同时期的基因表达差异.结果表明:火龙果的F-box基因可被分成11个亚群;根据拟南芥UFO基因聚类结果,鉴定出了 10个与花发育相关的火龙果F-box基因,他们的蛋白分子量为40～52 kD,其中70％呈碱性,90％属于不稳定蛋白,80％定位在细胞膜上;10个基因的保守基序组成相似度较高,均含有motif 1;基因系统发育树和遗传结构对比表明,基因的亲缘关系越近,其遗传结构越接近;RT-qPCR验证出8个基因在火龙果在授粉2 h后显著差异表达,HU11G01721基因和HU07G00057基因在自交亲和品种和自交不亲和品种的花授粉时期中存在显著性差异,他们在自交亲和品种中显著上调,表明其与花发育和亲和性识别有关.

Background: In tropical and subtropical areas, allergens from the dust mite species Blomia tropicalis are common causes of allergic rhinitis and asthma. Blomia tropicalis has two main allergens: Blo t 5 and Blo t 21.Aim: To generate a chimeric virus-like particle containing HBcAg, Blo t 5 and Blo t 21 that can treat allergies caused by Blomia tropicalis. Methods: To produce allergic asthma in mice, prokaryotic expression and purification of Blomia tropicalis allergens rBlo t 5, rBlo t 21, and recombinant fusion allergen rBlo t 5-21 were utilized in the study. We created a hepatitis B core antigen (HBcAg) and rBlo t 5-21 fusion prokaryotic expression plasmid. HBcAg-rBlo t 5-21 was purified after expression and tested by transmission electron microscopy (TEM). Furthermore, the protein HBcAg-rBlo t 5-21 was employed as a protein vaccination.Results: In allergy-induced mouse model experiments, the fusion allergen rBlo t 5-21 was more effective than the individual allergens rBlo t 5 and rBlo t 21 at inducing allergy. We found that vaccinating allergic mice with the recombinant fusion protein vaccine HBcAg-rBlo t 5-21 alleviated allergy symptoms elicited by the rBlo t 5-21 allergen. Vaccination with HBcAg-rBlo t 5-21 resulted in a decrease in total serum IgE levels, suppression of anaphylaxis, and reduction of inflammatory cell infiltration into lung tissue as compared to the PBS group.Conclusion: HBcAg-rBlo t 5-21, a protein vaccine containing both the hepatitis B core antigen and the Blomia tropicalis fusion allergen rBlo t 5-21, could be a suitable vaccination for preventing allergy disorders caused by Blomia tropicalis.

Translocation of RNA across the nuclear envelope relies on transport receptors. Receptor nuclear transport factor 2 (NTF2)-like export protein 1 (NXT1 [also called p15 or p15-1]) shuttles between the nucleus and cytoplasm of metazoan cells and contributes to the nuclear export of a diverse spectrum of RNAs. NXT2 (also called p15-2), a paralog of NXT1 in eutherians, also has implications for RNA nuclear export. A comprehensive description is currently lacking as to the genetic signature of these molecules. In this study, we analyzed genetic changes in the NXT1 and NXT2 genes in primates and murine rodents, including the commonly used model organisms Macaca spp., Mus musculus, and Rattus norvegicus. The results show that NXT1 has been subject to functional constraints in both phylogenetic lineages. Conversely, NXT2 exhibits discrepant patterns of genetic changes between these taxa. Murine NXT2 has evolved conservatively; by contrast, adaptive selection has frequently contributed to genetic changes in primate NXT2. The genetic discrepancy of the NXT2 orthologs leads to the suggestion that they had experienced quite different evolutionary fates potentially constituting different functional implementations in these taxa. These findings raise awareness of further study on different organisms to comprehensively understand their functional characteristics.