USP15 stabilizes MDM2 to mediate cancer-cell survival and inhibit antitumor T cell responses.

Deubiquitinases (DUBs) are a new class of drug targets, although the physiological function of only few DUBs has been characterized. Here we identified the DUB USP15 as a crucial negative regulator of T cell activation. USP15 stabilized the E3 ubiquitin ligase MDM2, which in turn negatively regulated T cell activation by targeting the degradation of the transcription factor NFATc2. USP15 deficiency promoted T cell activation in vitro and enhanced T cell responses to bacterial infection and tumor challenge in vivo. USP15 also stabilized MDM2 in cancer cells and regulated p53 function and cancer-cell survival. Our results suggest that inhibition of USP15 may both induce tumor cell apoptosis and boost antitumor T cell responses.

A vaccine targeting the RBD of the S protein of SARS-CoV-2 induces protective immunity.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a respiratory disease called coronavirus disease 2019 (COVID-19), the spread of which has led to a pandemic. An effective preventive vaccine against this virus is urgently needed. As an essential step during infection, SARS-CoV-2 uses the receptor-binding domain (RBD) of the spike protein to engage with the receptor angiotensin-converting enzyme 2 (ACE2) on host cells1,2. Here we show that a recombinant vaccine that comprises residues 319-545 of the RBD of the spike protein induces a potent functional antibody response in immunized mice, rabbits and non-human primates (Macaca mulatta) as early as 7 or 14 days after the injection of a single vaccine dose. The sera from the immunized animals blocked the binding of the RBD to ACE2, which is expressed on the cell surface, and neutralized infection with a SARS-CoV-2 pseudovirus and live SARS-CoV-2 in vitro. Notably, vaccination also provided protection in non-human primates to an in vivo challenge with SARS-CoV-2. We found increased levels of RBD-specific antibodies in the sera of patients with COVID-19. We show that several immune pathways and CD4 T lymphocytes are involved in the induction of the vaccine antibody response. Our findings highlight the importance of the RBD domain in the design of SARS-CoV-2 vaccines and provide a rationale for the development of a protective vaccine through the induction of antibodies against the RBD domain.

GmEID1 modulates light signaling through the Evening Complex to control flowering time and yield in soybean.

Soybean (Glycine max) morphogenesis and flowering time are accurately regulated by photoperiod, which determine the yield potential and limit soybean cultivars to a narrow latitudinal range. The E3 and E4 genes, which encode phytochrome A photoreceptors in soybean, promote the expression of the legume-specific flowering repressor E1 to delay floral transition under long-day (LD) conditions. However, the underlying molecular mechanism remains unclear. Here, we show that the diurnal expression pattern of GmEID1 is opposite to that of E1 and targeted mutations in the GmEID1 gene delay soybean flowering regardless of daylength. GmEID1 interacts with J, a key component of circadian Evening Complex (EC), to inhibit E1 transcription. Photoactivated E3/E4 interacts with GmEID1 to inhibit GmEID1-J interaction, promoting J degradation resulting in a negative correlation between daylength and the level of J protein. Notably, targeted mutations in GmEID1 improved soybean adaptability by enhancing yield per plant up to 55.3% compared to WT in field trials performed in a broad latitudinal span of more than 24°. Together, this study reveals a unique mechanism in which E3/E4-GmEID1-EC module controls flowering time and provides an effective strategy to improve soybean adaptability and production for molecular breeding.

A novel mechanoeffector role of fibroblast S100A4 in myofibroblast transdifferentiation and fibrosis.

Fibroblast to myofibroblast transdifferentiation mediates numerous fibrotic disorders, such as idiopathic pulmonary fibrosis (IPF). We have previously demonstrated that non-muscle myosin II (NMII) is activated in response to fibrotic lung extracellular matrix, thereby mediating myofibroblast transdifferentiation. NMII-A is known to interact with the calcium-binding protein S100A4, but the mechanism by which S100A4 regulates fibrotic disorders is unclear. In this study, we show that fibroblast S100A4 is a calcium-dependent, mechanoeffector protein that is uniquely sensitive to pathophysiologic-range lung stiffness (8-25 kPa) and thereby mediates myofibroblast transdifferentiation. Re-expression of endogenous fibroblast S100A4 rescues the myofibroblastic phenotype in S100A4 KO fibroblasts. Analysis of NMII-A/actin dynamics reveals that S100A4 mediates the unraveling and redistribution of peripheral actomyosin to a central location, resulting in a contractile myofibroblast. Furthermore, S100A4 loss protects against murine in vivo pulmonary fibrosis, and S100A4 expression is dysregulated in IPF. Our data reveal a novel mechanosensor/effector role for endogenous fibroblast S100A4 in inducing cytoskeletal redistribution in fibrotic disorders such as IPF.

Targeting YAP/TAZ mechanosignaling to ameliorate stiffness-induced Schlemm's canal cell pathobiology.

Pathological alterations in the biomechanical properties of the Schlemm's canal (SC) inner wall endothelium and its immediate vicinity are strongly associated with ocular hypertension in glaucoma due to decreased outflow facility. Specifically, the underlying trabecular meshwork is substantially stiffer in glaucomatous eyes compared with that from normal eyes. This raises the possibility of a critical involvement of mechanotransduction processes in driving SC cell dysfunction. Yes-associated protein (YAP) has emerged as a key contributor to glaucoma pathogenesis. However, the molecular underpinnings of SC cell mechanosignaling via YAP and transcriptional coactivator with PDZ-binding motif (TAZ) in response to glaucomatous extracellular matrix (ECM) stiffening are not well understood. Using a novel biopolymer hydrogel that facilitates dynamic and reversible stiffness tuning, we investigated how ECM stiffening modulates YAP/TAZ activity in primary human SC cells, and whether disruption of YAP/TAZ mechanosignaling attenuates SC cell pathobiology and increases ex vivo outflow facility. We demonstrated that ECM stiffening drives pathologic YAP/TAZ activation and cytoskeletal reorganization in SC cells, which was fully reversible by matrix softening in a distinct time-dependent manner. Furthermore, we showed that pharmacologic or genetic disruption of YAP/TAZ mechanosignaling abrogates stiffness-induced SC cell dysfunction involving altered cytoskeletal and ECM remodeling. Finally, we found that perfusion of the clinically used, small molecule YAP/TAZ inhibitor verteporfin (without light activation) increases ex vivo outflow facility in normal mouse eyes. Collectively, our data provide new evidence for a pathologic role of aberrant YAP/TAZ mechanosignaling in SC cell dysfunction and suggest that YAP/TAZ inhibition has therapeutic value for treating ocular hypertension in glaucoma.NEW & NOTEWORTHY Pathologically altered biomechanical properties of the Schlemm's canal (SC) inner wall microenvironment were recently validated as the cause for increased outflow resistance in ocular hypertensive glaucoma. However, the involvement of specific mechanotransduction pathways in these disease processes is largely unclear. Here, we demonstrate that Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) are central regulators of glaucoma-like SC cell dysfunction in response to extracellular matrix stiffening and that targeted disruption of YAP/TAZ mechanosignaling attenuates SC cell pathobiology and enhances outflow function.

ZmXYL modulates auxin-induced maize growth.

Plant architecture, lodging resistance, and yield are closely associated with height. In this paper, we report the identification and characterization of two allelic EMS-induced mutants of Zea mays, xyl-1, and xyl-2 that display dwarf phenotypes. The mutated gene, ZmXYL, encodes an α-xylosidase which functions in releasing xylosyl residue from a ß-1,4-linked glucan chain. Total α-xylosidase activity in the two alleles is significantly decreased compared to wild-type plants. Loss-of-function mutants of ZmXYL resulted in a decreased xylose content, an increased XXXG content in xyloglucan (XyG), and a reduced auxin content. We show that auxin has an antagonistic effect with XXXG in promoting cell divisions within mesocotyl tissue. xyl-1 and xyl-2 were less sensitive to IAA compared to B73. Based on our study, a model is proposed that places XXXG, an oligosaccharide derived from XyG and the substrate of ZmXYL, as having a negative impact on auxin homeostasis resulting in the dwarf phenotypes of the xyl mutants. Our results provide a insight into the roles of oligosaccharides released from plant cell walls as signals in mediating plant growth and development.

Combined analysis of mRNA and miRNA transcriptomes reveals the regulatory mechanism of Xanthomonas arboricola pv pruni resistance in Prunus persica.

BACKGROUND: Peach bacterial shot hole, caused by Xanthomonas arboricola pv pruni (Xap), is a global bacterial disease that poses a threat to the yield and quality of cultivated peach trees (Prunus persica). RESULTS: This study compared the mRNA and miRNA profiles of two peach varieties, 'Yanbao' (resistant) and 'Yingzui' (susceptible), after inoculation with Xap to identify miRNAs and target genes associated with peach tree resistance. mRNA sequencing results revealed that in the S0-vs-S3 comparison group, 1574 genes were upregulated and 3975 genes were downregulated. In the R0-vs-R3 comparison group, 1575 genes were upregulated and 3726 genes were downregulated. Through miRNA sequencing, a total of 112 known miRNAs belonging to 70 miRNA families and 111 new miRNAs were identified. Notably, some miRNAs were exclusively expressed in either resistant or susceptible varieties. Additionally, 59 miRNAs were downregulated and 69 miRNAs were upregulated in the R0-vs-R3 comparison group, while 46 miRNAs were downregulated and 52 miRNAs were upregulated in the S0-vs-S3 comparison group. Joint analysis of mRNA and miRNA identified 79 relationship pairs in the S0-vs-S3 comparison group, consisting of 48 miRNAs and 51 target genes. In the R0-vs-R3 comparison group, there were 58 relationship pairs, comprising 28 miRNAs and 20 target genes. Several target genes related to resistance, such as SPL6, TIFY6B, and Prupe.4G041800_v2.0.a1 (PPO), were identified through literature reports and GO/KEGG enrichment analysis. CONCLUSION: In conclusion, this study discovered several candidate genes involved in peach tree resistance by analyzing differential expression of mRNA and miRNA. These findings provide valuable insights into the mechanisms underlying resistance to Xap in peach trees.

Coping with extremes: the rumen transcriptome and microbiome co-regulate plateau adaptability of Xizang goat.

The interactions between the rumen microbiota and the host are crucial for the digestive and absorptive processes of ruminants, and they are heavily influenced by the climatic conditions of their habitat. Owing to the harsh conditions of the high-altitude habitat, little is known about how ruminants regulate the host transcriptome and the composition of their rumen microbiota. Using the model species of goats, we examined the variations in the rumen microbiota, transcriptome regulation, and climate of the environment between high altitude (Lhasa, Xizang; 3650 m) and low altitude (Chengdu, Sichuan, China; 500 m) goats. The results of 16 S rRNA sequencing revealed variations in the abundance, diversity, and composition of rumen microbiota. Papillibacter, Quinella, and Saccharofermentans were chosen as potential microbes for the adaptation of Xizang goats to the harsh climate of the plateau by the Spearman correlation study of climate and microbiota. Based on rumen transcriptome sequencing analysis, 244 genes were found to be differentially expressed between Xizang goats and low-altitude goats, with 127 genes showing up-regulation and 117 genes showing down-regulation. SLC26A9, GPX3, ARRDC4, and COX1 were identified as potential candidates for plateau adaptation in Xizang goats. Moreover, the metabolism of fatty acids, arachidonic acids, pathway involving cytokines and their receptors could be essential for adaptation to plateau hypoxia and cold endurance. The expression of GPX3, a gene linked to plateau acclimatization in Xizang goats, was linked to the abundance of Anaerovibrio, and the expression of SLC26A9 was linked to the quantity of Selenomonas, according to ruminal microbiota and host Spearman correlation analysis. Our findings imply that in order to adapt harsh plateau conditions, Xizang goats have evolved to maximize digestion and absorption as well as to have a rumen microbiota suitable for the composition of their diet.

The Carthamus tinctorius L. genome sequence provides insights into synthesis of unsaturated fatty acids.

Domesticated safflower (Carthamus tinctorius L.) is a widely cultivated edible oil crop. However, despite its economic importance, the genetic basis underlying key traits such as oil content, resistance to biotic and abiotic stresses, and flowering time remains poorly understood. Here, we present the genome assembly for C. tinctorius variety Jihong01, which was obtained by integrating Oxford Nanopore Technologies (ONT) and BGI-SEQ500 sequencing results. The assembled genome was 1,061.1 Mb, and consisted of 32,379 protein-coding genes, 97.71% of which were functionally annotated. Safflower had a recent whole genome duplication (WGD) event in evolution history and diverged from sunflower approximately 37.3 million years ago. Through comparative genomic analysis at five seed development stages, we unveiled the pivotal roles of fatty acid desaturase 2 (FAD2) and fatty acid desaturase 6 (FAD6) in linoleic acid (LA) biosynthesis. Similarly, the differential gene expression analysis further reinforced the significance of these genes in regulating LA accumulation. Moreover, our investigation of seed fatty acid composition at different seed developmental stages unveiled the crucial roles of FAD2 and FAD6 in LA biosynthesis. These findings offer important insights into enhancing breeding programs for the improvement of quality traits and provide reference resource for further research on the natural properties of safflower.

PAK inhibitor FRAX486 decreases the metastatic potential of triple-negative breast cancer cells by blocking autophagy.

BACKGROUND: Triple-negative breast cancer (TNBC) is a unique breast cancer subtype with a high risk of metastasis and recurrence and a poor prognosis. Epithelial-mesenchymal transition (EMT) endows epithelial cells with the ability to move to distant sites, which is essential for the metastasis of TNBC to organs, including the lung. Autophagy, an intracellular degradation process that involves formation of double-layered lipid autophagosomes that transport cytosolic cargoes into lysosomes via autophagosome-lysosome fusion, is involved in various diseases, including cancer and neurodegenerative, metabolic, cardiovascular, and infectious diseases. The relationship between autophagy and cancer has become relatively clear. However, research on pharmacological drugs that block cancer EMT by targeting autophagy is still in the initial stages. Therefore, the re-evaluation of old drugs for their potential in blocking both autophagy and EMT was conducted. METHODS: More than 2000 small molecule chemicals were screened for dual autophagy/EMT inhibitors, and FRAX486 was identified as the best candidate inhibitor of autophagy/EMT. The functions of FRAX486 in TNBC metastasis were detected by CCK-8, migration and wound healing assays. The effects of FRAX486 on autophagy and its target PAK2 were determined by immunoblotting, immunofluorescence, immunoprecipitation analysis and transmission electron microscopy. The findings were validated in mouse models. RESULTS: Here, we report that FRAX486, a potent P21-activated kinase 2 (PAK2) inhibitor, facilitates TNBC suppression both in vitro and in vivo by blocking autophagy. Mechanistically, FRAX486 inhibits autophagy in TNBC cells by targeting PAK2, leading to the ubiquitination and proteasomal degradation of STX17, which mediates autophagosome-lysosome fusion. The inhibition of autophagy by FRAX486 causes upregulation of the epithelial marker protein E-cadherin and thus suppresses the migration and metastasis of TNBC cells. CONCLUSIONS: The effects of FRAX486 on TNBC metastasis suppression were verified to be dependent on PAK2 and autophagy inhibition. Together, our results provide a molecular basis for the application of FRAX486 as a potential treatment for inhibiting the metastasis of TNBC.

SOX9 Modulates the Transformation of Gastric Stem Cells Through Biased Symmetric Cell Division.

BACKGROUND & AIMS: Transformation of stem/progenitor cells has been associated with tumorigenesis in multiple tissues, but stem cells in the stomach have been hard to localize. We therefore aimed to use a combination of several markers to better target oncogenes to gastric stem cells and understand their behavior in the initial stages of gastric tumorigenesis. METHODS: Mouse models of gastric metaplasia and cancer by targeting stem/progenitor cells were generated and analyzed with techniques including reanalysis of single-cell RNA sequencing and immunostaining. Gastric cancer cell organoids were genetically manipulated with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) for functional studies. Cell division was determined by bromodeoxyuridine-chasing assay and the assessment of the orientation of the mitotic spindles. Gastric tissues from patients were examined by histopathology and immunostaining. RESULTS: Oncogenic insults lead to expansion of SOX9+ progenitor cells in the mouse stomach. Genetic lineage tracing and organoid culture studies show that SOX9+ gastric epithelial cells overlap with SOX2+ progenitors and include stem cells that can self-renew and differentiate to generate all gastric epithelial cells. Moreover, oncogenic targeting of SOX9+SOX2+ cells leads to invasive gastric cancer in our novel mouse model (Sox2-CreERT;Sox9-loxp(66)-rtTA-T2A-Flpo-IRES-loxp(71);Kras(Frt-STOP-Frt-G12D);P53R172H), which combines Cre-loxp and Flippase-Frt genetic recombination systems. Sox9 deletion impedes the expansion of gastric progenitor cells and blocks neoplasia after Kras activation. Although Sox9 is not required for maintaining tissue homeostasis where asymmetric division predominates, loss of Sox9 in the setting of Kras activation leads to reduced symmetric cell division and effectively attenuates the Kras-dependent expansion of stem/progenitor cells. Similarly, Sox9 deletion in gastric cancer organoids reduces symmetric cell division, organoid number, and organoid size. In patients with gastric cancer, high levels of SOX9 are associated with recurrence and poor prognosis. CONCLUSION: SOX9 marks gastric stem cells and modulates biased symmetric cell division, which appears to be required for the malignant transformation of gastric stem cells.

Modulating Visible-Light Driven NIR Lanthanide Polymer Photocatalysis for Amplification Detection of Exosomal Proteins and Cancer Diagnosis.

Near-infrared (NIR) luminescent lanthanide materials hold great promise for bioanalysis, as they have anti-interference properties. The approach of efficient luminescence is sensitization through a reasonable chromophore to overcome the obstacle of the aqueous phase. The involvement of the surfactant motif is an innovative strategy to arrange the amphiphilic groups to be regularly distributed near the polymer to form a closed sensitized space. Herein, a lanthanide polymer (TCPP-PEI70K-FITC@Yb/SDBS) is designed in which the meso-tetra(4-carboxyphenyl)porphine (TCPP) ligand serves as both a sensitizer and photocatalytic switch. The surfactant sodium dodecyl benzenesulfonate (SDBS) wraps the photosensitive polymers to form a hydrophobic layer, which augments the light-harvesting ability and expedites its photocatalysis. TCPP-PEI70K-FITC@Yb/SDBS is subsequently applied as an amplified photocatalysis toolbox for universally regulating the generation of reactive oxygen species (ROS). Boosting 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to produce blue products, a dual-mode biosensor is fabricated for improving the diagnosis of programmed death ligand-1-positive (PDL1) cancer exosomes. Exosomes were captured by Fe3O4 modified by the PDL1 aptamer, enabling replacement of alkaline phosphatase (ALP)-labeled multiple hybridized chains; then, the isolated ALP triggered a hydrolysis reaction to block the generation of oxTMB. Detection sensitivity improves by 1 order of magnitude through SDBS modulation, down to 104 particles/mL. The sensor performed well clinically in distinguishing cancer patients from healthy individuals, expanding physiological applications of near-infrared lanthanide luminescence.

Greenhouse covering cultivation promotes chlorophyll accumulation of tea plant (Camellia sinensis) by activating relevant gene expression and enzyme activity.

BACKGROUND: The tea plant (Camellia sinensis (L.) O. Kuntze) is one of the most economically important woody crops. Plastic greenhouse covering cultivation has been widely used in tea areas of northern China. Chlorophyll is not only the crucial pigment for green tea, but also plays an important role in the growth and development of tea plants. Currently, little is known about the effect of plastic greenhouse covering cultivation on chlorophyll in tea leaves. RESULTS: To investigate the effect of plastic greenhouse covering cultivation on chlorophyll in tea leaves, color difference values, chlorophyll contents, gene expression, enzyme activities and photosynthetic parameters were analyzed in our study. Sensory evaluation showed the color of appearance, liquor and infused leaves of greenhouse tea was greener than field tea. Color difference analysis for tea liquor revealed that the value of ∆L, ∆b and b/a of greenhouse tea was significantly higher than field tea. Significant increase in chlorophyll content, intracellular CO2, stomatal conductance, transpiration rate, and net photosynthetic rate was observed in greenhouse tea leaves. The gene expression and activities of chlorophyll-metabolism-related enzymes in tea leaves were also activated by greenhouse covering. CONCLUSION: The higher contents of chlorophyll a, chlorophyll b and total chlorophyll in greenhouse tea samples were primarily due to higher gene expression and activities of chlorophyll-metabolism-related enzymes especially, chlorophyll a synthetase (chlG), pheophorbide a oxygenase (PAO) and chlorophyllide a oxygenase (CAO) in tea leaves covered by greenhouse. In general, our results revealed the molecular basis of chlorophyll metabolism in tea leaves caused by plastic greenhouse covering cultivation, which had great significance in production of greenhouse tea.

Achieving Cross Time-Domain Multiplexed Signal Cascade and Cancer Exosomes Identification by Bridging Long Lifetime Phosphor to NIR-II Lanthanide Energy Transfer.

Designing lanthanide luminescence lifetime sensors in the second near-infrared (NIR-II) window holds great potentials for physiological studies. However, the single lifetime signal is confined to one or two orders of magnitude of signal variation, which limits the sensitivity of lifetime probes. In this study, a lifetime cascade system, i.e., ZGO:Mn, Eu-DNA-1/TCPP-PEI70K@Yb-AptEpCAM, with a variety of signals (τm, τn, τµ, τm/τn and τm/τµ) is constructed for exosome identification using time-domain multiplexing. The sensitized ligand TCPP acts as both target-modulated switch and a bridge for connecting long lifetime ZGO:Mn, Eu-DNA-1 emitter to lanthanide Yb3+. This drives successive dual-path energy transfer and forms two D(donor)-A(acceptor) pairs. The lifetime variation is dominantly modulated by arranging TCPP as energy intermediate relay to covert milliseconds to nanoseconds to microseconds. It enables a broad lifetime range of six orders of magnitude. The presence of exosome specifically recognizes aptamers on TCPP-PEI70K@Yb-AptEpCAM to impede D-A pairs and reverse multiplexed response signals of the lifetime cascade system. The ratio lifetime signals τm/τn and τm/τµ achieve prominent exosome quantification and exosome type differentiation attributed to signal amplification. The cascade system relying on lifetime criteria can realize precise quantization and provide an effective strategy for subsequent physiological study.

IQ domain-containing protein ZmIQD27 modulates water transport in maize.

Plant metaxylem vessels provide physical support to promote upright growth and the transport of water and nutrients. A detailed characterization of the molecular network controlling metaxylem development is lacking. However, knowledge of the events that regulate metaxylem development could contribute to the development of germplasm with improved yield. In this paper, we screened an EMS-induced B73 mutant library, which covers 92% of maize (Zea mays) genes, to identify drought-sensitive phenotypes. Three mutants were identified, named iqd27-1, iqd27-2, and iqd27-3, and genetic crosses showed that they were allelic to each other. The causal gene in these 3 mutants encodes the IQ domain-containing protein ZmIQD27. Our study showed that defective metaxylem vessel development likely causes the drought sensitivity and abnormal water transport phenotypes in the iqd27 mutants. ZmIQD27 was expressed in the root meristematic zone where secondary cell wall deposition is initiated, and loss-of-function iqd27 mutants exhibited a microtubular arrangement disorder. We propose that association of functional ZmIQD27 with microtubules is essential for correct targeted deposition of the building blocks for secondary cell wall development in maize.

High-efficiency single-frequency DBR fiber laser at 1091 nm utilizing a Yb:YAG crystal-derived silica fiber.

A single-frequency distributed Bragg Reflector (DBR) fiber laser operating at 1091 nm was demonstrated by using a Yb:YAG crystal-derived silica fiber (YDSF). The YDSF was prepared via the molten core (MC) method, with a Yb2O3 doping concentration of 5.60 wt.% in the core, resulting in a gain coefficient of 1.45 dB/cm at 1091 nm. Employing 0.8 cm of the YDSF, we attained a single-frequency laser with a maximum output power of 145 mW and a slope efficiency of 31.8%. The laser exhibited an optical signal-to-noise ratio (OSNR) exceeding 71 dB, a linewidth of ∼34 kHz, and a stabilized relative intensity noise (RIN) at -132 dB/Hz for frequencies over 4.5 MHz. The fiber laser could serve as an outstanding seed source for high-power, narrow-linewidth fiber amplifiers operating at 1091 nm.

A novel endolysin from an Enterococcus faecalis phage and application.

Enterococcus faecalis is the primary species detected in cases of secondary persistent infection resulting from root canal therapy failure. Due to the overuse of antibacterial agents, E. faecalis has developed resistance to these drugs, making it challenging to treat clinical diseases caused by E. faecalis infection. Therefore, there is an urgent need to explore new alternative drugs for treating E. faecalis infections. We aimed to clone and express the genes of phage endolysins, purify the recombinant proteins, and analyze their antibacterial activity, lysis profile, and ability to remove biofilm. The crude enzyme of phage endolysin pEF51 (0.715 mg/mL), derived from phage PEf771 infecting E. faecalis, exhibited superior bacterial inhibitory activity and a broader bactericidal spectrum than its parental phage PEf771. Furthermore, pEF51 demonstrated high efficacy in eliminating E. faecalis biofilm. Therapeutic results of the infected Sprague-Dawley (SD) rat model indicated that among 10 SD rats, only one developed a thoracic peritoneal abscess and splenic peritoneal abscess after 72 h of treatment with pEF51. This suggests that pEF51 could provide protection against E. faecalis infection in SD rats. Based on the 16S rDNA metagenomic data of the intestinal microbial community of SD rats, endolysin pEF51 exerted a certain influence on the diversity of intestinal microorganisms at the genus level. Thus, pEF51 may serve as a promising alternative to antibiotics in the management of E. faecalis infection.

Phage therapy: A renewed approach against oral diseases caused by Enterococcus faecalis infections.

Antibiotics play an important role in the treatment of infectious diseases. Long-term overuse or misuse of antibiotics, however, has triggered the global crisis of antibiotic resistance, bringing challenges to treating clinical infection. Bacteriophages (phages) are the viruses infecting bacterial cells. Due to high host specificity, high bactericidal activity, and good biosafety, phages have been used as natural alternative antibacterial agents to fight against multiple drug-resistant bacteria. Enterococcus faecalis is the main species detected in secondary persistent infection caused by failure of root canal therapy. Due to strong tolerance and the formation of biofilm, E. faecalis can survive the changes in pH, temperature, and osmotic pressure in the mouth and thus is one of the main causes of periapical lesions. This paper summarizes the advantages of phage therapy, its applications in treating oral diseases caused by E. faecalis infections, and the challenges it faces. It offers a new perspective on phage therapy in oral diseases.

A novel holin from an Enterococcus faecalis phage and application in vitro and in vivo.

Enterococcus faecalis, a conditional pathogenic bacterium, is prevalent in the intestinal, oral, and reproductive tracts of humans and animals, causing a variety of infectious diseases. E. faecalis is the main species detected in secondary persistent infection from root canal therapy failure. Due to the abuse of antibacterial agents, E. faecalis has evolved its resistant ability. Therefore, it is difficult to treat clinical diseases infected by E. faecalis. Exploring new alternative drugs for treating E. faecalis infection is urgent. We cloned and expressed the gene of phage holin, purified the recombinant protein, and analyzed the antibacterial activity, lysis profile, and ability to remove bacterial biofilm. It showed that the crude enzyme of phage holin pEF191 exhibited superior bacterial inhibiting activity and a broader lysis host range compared to the parent phage PEf771. In addition, pEF191 demonstrated high efficacy in eliminating E. faecalis biofilm. The therapeutic results of the Sprague-Dawley (SD) rats model infected showed that pEf191 did not affect SD rats, indicating that pEF191 provided greater protection against E. faecalis infection in SD rats. Based on the 16 S rDNA data of SD rats intestinal microorganism population, holin pEF191 exhibited no impact on the diversity of intestinal microorganisms at the phylum and genus levels and improved the relative abundance of favorable bacteria. Thus, pEF191 may serve as a promising alternative to antibiotics in the management of E. faecalis infection.

Modulating ß-Keto-enamine-Based Covalent Organic Frameworks for Photocatalytic Atom-Transfer Radical Addition Reaction.

The atom-transfer radical addition (ATRA) reaction simultaneously forges carbon-carbon and carbon-halogen bonds. However, frequently-used photosensitizers such as precious transition metal complexes, or organic dyes have limitations in terms of their potential toxicity and recyclability. Three ß-ketoenamine-linked covalent organic frameworks (COFs) from 1,3,5-triformylphloroglucinol and 1,4-phenylenediamines with variable transient photocurrent and photocatalytic activity have been prepared. A COF bearing electron-deficient Cl atoms displayed the highest photocatalytic activity toward the ATRA reaction of polyhalogenated alkanes to give halogenated olefins under visible light at room temperature. This heterogeneous photocatalyst exhibited good functional group tolerance and could be recycled without significant loss of activity.