In recent years, the bacteriophage Φ29 (Phi29) DNA polymerase has garnered increasing attention due to its high-fidelity amplification capacity at constant temperatures. To advance the industrial application of this type of isothermal polymerases, this study mined and characterized new enzymes from the microbial metagenome based on the known Phi29 DNA polymerase sequence. The results revealed that a new enzyme, Php29 DNA polymerase, was identified in the microbial metagenome with plants as the hosts. This enzyme exhibited higher strand displacement activity, with a 59.5% similarity to bacteriophage Φ29. Experimental validation demonstrated that the enzyme had 3'→5' exonuclease activity, and its amplification products can serve as substrates for further catalytic reactions. The discovery and validation of Php29 DNA polymerase gives insights into the future industrial application of isothermal polymerases.
DNA-Directed DNA Polymerase/metabolism* ; Bacillus Phages/genetics* ; Metagenome

The enterotoxigenic Escherichia coli (ETEC) infection is a major factor restricting the development of animal husbandry. However, the abuse of antibiotics will lead to the antibiotic residues and emergence of antibiotic-resistant bacteria. The existing vaccines face challenges in stimulating intestinal immunity, demonstrating limited prevention effects. Therefore, it is indispensable to develop a new vaccine that is safe and suitable as a feed additive to activate intestinal immunity. This study constructed yeast-cell microcapsules (YCM) carrying the DNA vaccine against ETEC by genetic engineering. Furthermore, animal experiments were carried out to explore the regulatory effects of feeding YCM on the intestinal immune system and intestinal microbiota. Saccharomyces cerevisiae was selected as the oral delivery vehicle (microcapsules) of the DNA vaccine. The codon-optimized nucleic acid sequence of K88, the main antigen of mammal-derived ETEC, was synthesized, and the yeast shuttle vector containing the corresponding DNA vaccine expression cassette was constructed by DNA recombination. The recombinant strain of YCM was prepared by transforming JMY1. Additionally, the characteristics of the YCM strain and its feasibility as an oral vaccine were comprehensively evaluated by the fluorescence reporter assay, gastrointestinal fluid tolerance assay, intestinal epithelial cell adhesion assay, intestinal retention assessment, antiserum detection, and intestinal microbiota detection. The experimental results showed that the DNA vaccine expression cassette was expressed in mammals, and the recombinant strain of YCM could tolerate up to 8 hours of gastrointestinal fluid digestion and had good adhesion to intestinal epithelial cells. The results of mouse feeding experiments indicated that the recombinant strain of YCM could stay in the intestinal tract for at least two weeks, and the DNA vaccine expression cassette carried by YCM entered the intestinal immune system and triggered an immune response to induce the production of specific antibodies. Moreover, feeding YCM recombinant bacteria also improved the abundance of gut microbiota in mice, demonstrating a positive effect in regulating intestinal flora. In summary, we prepared the recombinant strain of YCM carrying the DNA vaccine against ETEC and comprehensively evaluated its characteristics and feasibility as an oral vaccine. Feeding the recombinant YCM could induce specific immune responses and regulate intestinal microbiota. The findings provide a reference for the immunoprevention of ETEC-related animal diseases.
Animals ; Enterotoxigenic Escherichia coli/genetics* ; Saccharomyces cerevisiae/metabolism* ; Vaccines, DNA/genetics* ; Mice ; Escherichia coli Infections/immunology* ; Escherichia coli Vaccines/genetics* ; Capsules ; Mice, Inbred BALB C ; Female

Geminiviruses cause substantial crop yield losses worldwide. The replication initiator protein (Rep) encoded by geminiviruses is indispensable for geminiviral replication. The Rep protein encoded by beet severe curly top virus (BSCTV, genus Curtovirus, family Geminiviridae) induces VARIANT IN METHYLATION 5 (VIM5) expression in Arabidopsis leaves upon BSCTV infection. VIM5 functions as a ubiquitination-related E3 ligase to promote the proteasomal degradation of methyltransferases, resulting in reduction of methylation levels in the BSCTV C2-3 promoter. However, the specific domains of Rep responsible for VIM5 induction remain poorly characterized. Although Rep proteins from several geminiviruses act as viral suppressors of RNA silencing (VSRs), whether BSCTV Rep also possesses VSR activity remains to be illustrated. In this study, we employed a transient expression system in the 16c-GFP transgenic and the wild-type Nicotiana benthamiana plants to analyze the VSR and the VIM5-inducing activities of different truncated Rep proteins haboring distinct domains. We found that the N-terminal domain (amino acids 1-180) of Rep suppressed GFP silencing in 16c-GFP transgenic N. benthamiana leaves. The minimal N-terminal fragment (amino acids 1-104) induced VIM5 expression upon co-infiltration, while C-terminal truncations lacked VIM5-inducing activity. Our results indicate that the N-terminal domain of Rep encoded by BSCTV mediates the suppression of RNA silencing and induces VIM5 expression. Thus, our findings contribute to a better understanding of interactions between geminiviral Rep and plant hosts.
Geminiviridae/genetics* ; Nicotiana/metabolism* ; Arabidopsis/metabolism* ; RNA Interference ; Viral Proteins/metabolism* ; Arabidopsis Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Protein Domains ; Plant Diseases/virology* ; Methyltransferases/metabolism* ; Ubiquitin-Protein Ligases/metabolism* ; DNA Helicases/genetics*

OBJECTIVE: To explore the effect and mechanism of DNA methyltransferase 1 (DNMT1) knockout on the inhibition of acute myeloid leukemia (AML) by natural killer (NK) cells. METHODS: The peripheral blood NK cells of AML patients and controls were collected, and the mRNA and protein level of DNMT1 were measured by PCR and Western blot, respectively. The DNMT1 knockout mice were constructed to obtain NK^DNMT1-/- cells. The NK cells were stimulated with interleukin (IL)-12, IL-15, and IL-18 to construct memory NK cells, and then the interferon-γ (IFN-γ) levels were measured by ELISA. After co-culturing with memory NK cells and HL60 cells, the killing effect of NK^DNMT1-/- cells on HL60 cells was detected by LDH assay. Then, the HL60 cell apoptosis and NK cell NKG2D level were measured by flow cytometry. The perforin and granzyme B protein levels of NK cells were measured by Western blot. The AML model mice were constructed by injecting HL60 cells into the tail vein, meanwhile, memory NK cells were also injected, and then the mouse weights, CD33 positive rates, and survival time were detected. RESULTS: The mRNA and protein levels of DNMT1 in NK cells of AML patients were significantly higher than those in the control group (both P < 0.01), while the IFN-γ level induced by interleukin was significantly lower than that in the control group (P < 0.05). Compared with NK^DNMT1+/+ cells, the ability of NK^DNMT1-/- cells to secrete IFN-γ after interleukin stimulation was significantly increased (P < 0.05). The killing and apoptosis-inducing effects of NK^DNMT1-/- cells on HL60 cells were significantly stronger than those of NK^DNMT1+/+ cells (both P < 0.05). The NKG2D level and expression of perforin and granzyme B of NK^DNMT1-/- cells were significantly increased compared with NK^DNMT1+/+ cells (all P < 0.05). Compared with AML mice injected with NK^DNMT1+/+ cells, AML mice injected with NK^DNMT1-/- cells showed significantly increased body weight, decreased CD33 positive rate, and prolonged survival time (all P < 0.05). CONCLUSION Knocking out DNMT1 can enhance the inhibitory effect of NK cells on AML, which may be related to enhancing NK cell memory function.
Killer Cells, Natural/metabolism* ; Animals ; Leukemia, Myeloid, Acute ; Humans ; DNA (Cytosine-5-)-Methyltransferase 1 ; Mice ; Mice, Knockout ; HL-60 Cells ; Apoptosis ; Interferon-gamma/metabolism* ; Granzymes/metabolism* ; Perforin/metabolism* ; NK Cell Lectin-Like Receptor Subfamily K/metabolism*

OBJECTIVE: To investigate the expression levels of EZH2 and KMT2D in patients with diffuse large B-cell lymphoma (DLBCL) and their relationship with pathological features. METHODS: 84 patients with DLBCL treated in our hospital from January 2021 to June 2022 were selected as the study subjects, and clinical characteristics such as sex, age and pathological classification of the patients were collected. Immunohistochemistry was used to detecet the expression of KMT2D and EZH2 proteins in tumor tissue cells of the DLBCL patients. The differential expression of KMT2D and EZH2 in subgroups of different sexes, ages, primary sites, clinical stages, Hans subtypes, etc. were compared. The correlation between the expression of KMT2D and EZH2 protein and BCL-6, CD79A was analyzed and validated through the interaction of protein molecular structures. We followed up and recorded the survival status of the patients for 12 months, and analyzed the factors that affect the mortality of DLBCL patients. RESULTS: The positive rate of KMT2D and EZH2 was high (over 95%) in DLBCL patients. There was no significant difference in the expression of EZH2 and KMT2D among subgroups of different sexes, ages and stages (P >0.05). However, patients with different levels of BCL-6 and CD79A expression showed differences in EZH2 and KMT2D expression (P < 0.05). EZH2 and KMT2D were positively correlated with BCL-6 (r =0.391, r =0.332) and CD79A (r =0.309, r =0.258), respectively, and there were interactions in the protein molecular structures. The risk factors for mortality in DLBCL patients include male sex (OR =1.106, 95%CI : 1.082-1.130, P < 0.001), stage II (OR =1.778, 95%CI : 1.567-2.016, P < 0.001), stage IV (OR =2.233, 95%CI : 2.021-2.467, P < 0.001), EZH2 positive (OR =2.762, 95%CI : 1.304-5.850, P =0.008), BCL-6 positive (OR =7.309, 95%CI : 1.340-39.859, P =0.022), age≥74 years (OR =3.080, 95%CI : 1.658-5.723, P < 0.001), and 63-73 years old (OR =2.400, 95%CI : 1.564-3.682, P < 0.001), while KMT2D positive (OR =0.180, 95%CI : 0.054-0.608, P =0.006) and 41-51 years old (OR =0.406, 95%CI : 0.274-0.603, P < 0.001) were factors which could reduce the risk of mortality. CONCLUSION EZH2 and KMT2D are highly expressed in patients with DLBCL, and they are positively correlated with BCL-6 and CD79A, and affect the prognosis of DLBCL patients.
Humans ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Lymphoma, Large B-Cell, Diffuse/metabolism* ; DNA-Binding Proteins/metabolism* ; Female ; Male ; Middle Aged ; Adult ; Neoplasm Proteins/metabolism* ; Aged ; Immunohistochemistry ; Proto-Oncogene Proteins c-bcl-6/metabolism* ; Prognosis

BACKGROUND: Abnormalities of the switch/sucrose nonfermentable (SWI/SNF) chromatin-remodeling complex are closely related to various cancers, and ARID1B (AT-rich interaction domain 1B) is one of the core subunits of the SWI/SNF complex. Mutations or copy number deletions of the ARID1B gene are associated with impaired DNA damage response and altered chromatin accessibility. However, whether ARID1B deficiency affects the proliferation, migration and invasion abilities of non-small cell lung cancer (NSCLC) cells and its molecular mechanisms remain poorly understood. This study aims to reveal the regulatory role of ARID1B gene deletion on the malignant phenotype of NSCLC cells and its molecular mechanism. METHODS: Online databases were used to analyze the relationship between ARID1B and the prognosis of patients with lung cancer, and the expression levels of ARID1B in lung cancer tissues. The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat) technology was employed to construct stable ARID1B gene knockout (KO) cell lines. The plate colony formation assay was used to detect cell proliferation, and the Transwell cell migration and invasion assays were used to detect changes in cell migration ability. RNA-Seq was utilized for the expression and enrichment analysis of differentially expressed genes. Western blot (WB) was used to verify the knockout effect of the ARID1B gene and to detect the expression changes of epithelial-mesenchymal transition (EMT) markers and mitogen-activated protein kinases (MAPK) signaling pathway-related proteins. Nude mouse tumor models were constructed and the tumorigenic abilities of control and ARID1B-deficient cells were compared. RESULTS: Patients with low ARID1B expression have poor overall survival. ARID1B is differentially expressed in lung cancer and normal tissues, and its expression level being lower in cancer cells. ARID1B-deficient cells had significantly enhanced in vitro proliferation, migration and invasion abilities. In animal experiments, the tumor formation speed of ARID1B gene deficient cells was significantly accelerated. Enrichment analysis of RNA-Seq results revealed that the differentially expressed genes were mainly enriched in MAPK, phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) and other signaling pathways. WB experiments demonstrated that the expressions of E-cadherin, N-cadherin and Vimentin changed in ARID1B gene deficient cells, and the expressions of MAPK and p-MAPK was increased. CONCLUSIONS The A549-ARID1B KO and PC9-ARID1B KO cell lines were successfully established. The ARID1B-deficient cell lines demonstrated high migration, invasion and proliferation potential at both in vitro and in vivo biological behavior levels and at the transcriptome sequencing level. The changes in the expression of EMT markers and the activation of the MAPK signaling pathway suggest possible metastasis mechanisms of ARID1B-deficient NSCLC.
Humans ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Lung Neoplasms/metabolism* ; Animals ; Carcinoma, Non-Small-Cell Lung/physiopathology* ; Transcription Factors/metabolism* ; Neoplasm Invasiveness ; Mice ; DNA-Binding Proteins/metabolism* ; Gene Deletion ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition ; Mice, Nude ; Gene Expression Regulation, Neoplastic

BACKGROUND: Lung adenocarcinoma (LUAD) is the predominant subtype of non-small cell lung cancer (NSCLC). Damage-specific DNA binding protein 1 (DDB1), as a core protein of the CUL4-DDB1 ubiquitin ligase complex, is involved in the regulation of DNA damage repair, epigenetic modification, and cell cycle checkpoint activation. While the involvement of DDB1 in tumour progression through DNA repair and RNA transcriptional regulation has been reported, its expression and role in LUAD remain to be elucidated. This study aims to investigate the expression and role of DDB1 in LUAD. METHODS: The expression, clinicopathological features and prognosis of DDB1 in LUAD were analysed using databases such as UALCAN, Kaplan-Meier Plotter and GEPIA; The interaction network and enriched functional pathways were constructed by GeneMANIA and Metascape; the correlation between DDB1 and immune cells by combining with TISIDB infiltration was evaluated, and the clustering results of cell subtypes and the expression of DDB1 in different immune cell subpopulations were analysed by single-cell sequencing; finally, tissue microarrays were used to further verify the expression and prognostic value of DDB1 in LUAD. RESULTS: The mRNA and protein expression of DDB1 in LUAD tissues were significantly higher than those in normal tissues (P<0.01), and the high expression correlated with later clinical stage (P<0.001), lymph node metastasis (P<0.001) and poor prognosis (P<0.001). Functional enrichment showed that DDB1 was involved in DNA repair and RNA transcriptional regulation, and TISIDB evaluation revealed that DDB1 was negatively correlated with the expression level of immune cells, suggesting the potential regulation of the immune microenvironment. Single cell analysis showed that DDB1 was mainly expressed in T cells, alveolar macrophages and dendritic cells. Tissue microarrays confirmed that overall survival was shorter in the DDB1 high expression group (P<0.001), and Cox multifactorial analysis showed that DDB1 was an independent predictor of LUAD prognosis. CONCLUSIONS DDB1 is highly expressed in LUAD, which is associated with poor prognosis, and is closely related to tumor immune cell infiltration, and is involved in tumourigenesis and development through DNA repair and RNA transcriptional regulation. DDB1 can be used as a potential prognostic marker and therapeutic target for LUAD.
Humans ; Adenocarcinoma of Lung/immunology* ; DNA-Binding Proteins/metabolism* ; Lung Neoplasms/diagnosis* ; Gene Expression Regulation, Neoplastic ; Prognosis ; Male ; Female ; Middle Aged

OBJECTIVE: To investigate the correlation of seminal plasma oxidation reduction potential (ORP), normalized oxidation-reduction potential (nORP) and sperm DNA fragmentation index (DFI) to sperm motion parameters, and their clinical predictive value for oligoasthenozoospermia (OAZ). METHODS: This study included 433 male subjects visiting the Clinic of Andrology in our hospital from March to May 2024. According to sperm concentration and the percentage of progressively motile sperm (PMS), we divided them into a normal control (n = 119), an oligozoospermia (OZ, n = 118), an athenozoospermia (AZ, n = 119) and an OAZ group (n = 77). Using the electrode method, we measured the seminal plasma ORP, calculated nORP=ORP/sperm concentration (mV/［10⁶/ml］), and determined DFI and high DNA chromatin sperm (HDS) by flow cytometry based on sperm chromatin structure assay (SCSA), followed by comparison among the four groups in age, abstinence days, semen volume, total sperm count, sperm concentration, PMS, non-progressively motile sperm (NPMS), immotile sperm (IMS), curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), straightness(STR), wobble (WOB), DFI, HDS, ORP and nORP. Using the receiver operating characteristic (ROC) curve, we assessed the predictive value of DFI, ORP and nORP for OAZ, and analyzed the correlation of DFI, ORP and nORP to sperm motion parameters by Pearson and Spearman analyses. RESULTS: Statistical analysis revealed statistically significant differences among the four groups in semen volume, abstinence days, total sperm count, sperm concentration, PMS, NPMS, IMS, total sperm motility, VCL, VSL, VAP, STR, DFI, HDS, ORP and nORP (P < 0.05), but not in age, LIN and WOB (P > 0.05). The area under the ROC curve (AUC) for the predictive value of DFI for OAZ was 0.880, with the critical value of 8.920, sensitivity of 74.8% and specificity of 88.2%; that of ORP for AZ was 0.698, with the critical value of 155.375, sensitivity of 70.6% and specificity of 64.7%; and that of nORP for OZ was 0.999, with the critical value of 9.844, sensitivity of 98.3% and specificity of 99.2%. Pearson and Spearman correlation analyses showed that DFI was correlated positively with age, abstinence days, semen volume, IMS, HDS and ORP, but negatively with PMS, NPMS, total sperm motility, VCL, VSL, VAP and STR; ORP positively with abstinence days, semen volume, IMS, DFI and nORP, but negatively with PMS, NPMS, total sperm motility, VSL, LIN and STR; and nORP positively with HDS, but negatively with abstinence days, total sperm count, sperm concentration, PMS and NPMS. CONCLUSION Oxidative stress (OS) may be an important pathological factor for elevated ORP, increased DFI and changes of routine sperm motion parameters, consequently leading to OAZ. As OS markers, DFI and ORP have a high predictive value for OS-induced OAZ.
Male ; Humans ; DNA Fragmentation ; Semen/metabolism* ; Sperm Motility ; Spermatozoa ; Oxidation-Reduction ; Adult ; Oligospermia ; Sperm Count ; Semen Analysis ; Asthenozoospermia

OBJECTIVES: To investigate the efficacy of Qihuang Jianpi Zishen Granules (QJZ) for inhibiting renal B cell differentiation in MRL/lpr mice and explore its underlying mechanism. METHODS: Thirty 8-week-old female MRL/lpr mice were randomly divided into model group, QJZ group, prednisone (Pred) group, QJZ+Pred group, and AIM2 inhibitor group (n=6), with 6 8-week-old female C57BL/6 mice as the normal control group. After treatments with normal saline, QJZ, Pred, or AIM2 inhibitor for 8 weeks, the mice were examined for urinary total protein-to-creatinine ratio (TPCR) and albumin-to-creatinine ratio (ACR), serum creatinine (Cr) and blood urea nitrogen (BUN) levels, and renal histopathology (with HE, Masson, and PAS staining) and ultrastructural changes (with electron microscopy). ELISA, immunohistochemistry, immunofluorescence staining and flow cytometry were used to detect blood levels of anti-dsDNA antibodies, cytokines and chemokines, renal deposition of complement components C3 and C4, renal expressions of AIM2, CD19, CD27 and CD138, and changes in splenic B lymphocyte subsets. The effect of QJZ on the AIM2/Blimp-1/Bcl-6 signaling axis was examined using Western blotting. RESULTS: QJZ treatment significantly improved Cr, BUN, TPCR and ACR in MRL/lpr mice, ameliorated renal pathologies, reduced the expressions of ds-DNA, BAFF, IL-21, CXCL12, CXCL13, C3 and C4, and increased IL-10 levels. QJZ significantly downregulated renal expressions of the key B-cell transcription factors Blimp-1 and XBP-1, upregulated Bcl-6 and PAX5 expressions, inhibited B-cell differentiation, and lowered the expressions of AIM2, CD27, CD138 and CD69. Inhibition of AIM2 similarly reduced renal Blimp-1 and XBP-1 expressions, increased Bcl-6 and PAX5 levels, suppressed B-cell differentiation, decreased IgG production, reduced C3 and C4 deposition, and alleviated renal pathology in MRL/lpr mice. CONCLUSIONS QJZ inhibits B cell differentiation and alleviates renal damage in systemic lupus erythematosus possibly by suppressing the AIM2/Blimp-1/Bcl-6 signaling pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Mice, Inbred MRL lpr ; Female ; Mice ; Mice, Inbred C57BL ; Cell Differentiation/drug effects* ; B-Lymphocytes/drug effects* ; Proto-Oncogene Proteins c-bcl-6/metabolism* ; Kidney/drug effects* ; DNA-Binding Proteins/metabolism* ; Signal Transduction ; Lupus Nephritis

Loss-of-function variants in CSDE1 have been strongly linked to neuropsychiatric disorders, yet the precise role of CSDE1 in neurogenesis remains elusive. In this study, we demonstrate that knockout of Csde1 during cortical development in mice results in impaired neural progenitor proliferation, leading to abnormal cortical lamination and embryonic lethality. Transcriptomic analysis revealed that Csde1 upregulates the transcription of genes involved in the cell cycle network. Applying a dual thymidine-labelling approach, we further revealed prolonged cell cycle durations of neuronal progenitors in Csde1-knockout mice, with a notable extension of the G1 phase. Intersection with CLIP-seq data demonstrated that Csde1 binds to the 3' untranslated region (UTR) of mRNA transcripts encoding cell cycle genes. Particularly, we uncovered that Csde1 directly binds to the 3' UTR of mRNA transcripts encoding Cdk6, a pivotal gene in regulating the transition from the G1 to S phases of the cell cycle, thereby maintaining its stability. Collectively, this study elucidates Csde1 as a novel regulator of Cdk6, sheds new light on its critical roles in orchestrating brain development, and underscores how mutations in Csde1 may contribute to the pathogenesis of neuropsychiatric disorders.
Animals ; Neurogenesis/genetics* ; Cell Cycle/genetics* ; Mice, Knockout ; Mice ; Neural Stem Cells/metabolism* ; DNA-Binding Proteins/metabolism* ; Cyclin-Dependent Kinase 6/genetics* ; Cell Proliferation ; 3' Untranslated Regions ; Cerebral Cortex/embryology* ; RNA-Binding Proteins ; Mice, Inbred C57BL