OBJECTIVE: To explore the changes of CKLF-like MARVEL transmembrane domain-containing 6 (CMTM6) and programmed death-ligand 1 (PD-L1) expression in gastric mucosal epithelial cells after Helicobacter pylori infection and the regulation of CMTM6 on PD-L1, and to analyze the mRNA expression differences before and after CMTM6 gene knock-out in helicobacter pylori infected gastric epithelial cells by microarray analysis. METHODS: The standard Helicobacter pylori strain ATCC 26695 was co-cultured with human gastric epithelial cell GES-1 for 6, 24 and 48 hours, and the mRNA and protein levels of CMTM6 and PD-L1 were detected by real-time quantitative PCR and Western blot. Using CRISPR/Cas9 to construct CMTM6 gene knockout plasmid and knockout CMTM6 gene of GES-1 cells. Helicobacter pylori was co-cultured with CMTM6 gene knockout and wild type GES-1 cells for 48 hours to detect PD-L1 transcription and protein level changes, and CMTM6 gene knockout GES-1 cells were treated with the proteasome inhibitor MG-132 to detect the changes in PD-L1 protein levels. Agilent Human ceRNA Microarray 2019 was used to detect the differentially expressed genes in CMTM6 gene knockout and wild-type GES-1 cells co-cultured with Hp for 48 hours, and the signal pathway of differentially expressed genes enrichment was analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) database. RESULTS: The mRNA and protein levels of CMTM6 and PD-L1 in GES-1 cells were significantly up-regulated after Helicobacter pylori infection, and CMTM6 mRNA was most significantly up-regulated 48 hours after infection. After CMTM6 gene knockout, the CD274 gene transcription level of Helicobacter pylori infected GES-1 cells did not change significantly, but PD-L1 protein level was significantly down-regulated, and the PD-L1 level increased after the application of proteasome inhibitor MG-132. After CMTM6 gene knockout, 67 genes had more than two times of differential expression. The transcription levels of TMEM68, FERMT3, GPR142, ATP6V1FNB, NOV, UBE2S and other genes were significantly down-regulated. The transcription levels of PCDHGA6, CAMKMT, PDIA2, NTRK3, SPOCK1 and other genes were significantly up-regulated. After CMTM6 gene knockout, ubiquitin-conjugating enzyme E2S (UBE2S) gene expression was significantly down-regulated, which might affect protein ubiquitination degradation. After CMTM6 gene knockout, adrenoceptor alpha 1B (ADRA1B), cholinergic receptor muscarinic 1 (M1), CHRM1, platelet activating factor receptor (PTAFR) gene expression was significantly up-regulated. CONCLUSION Helicobacter pylori infection up-regulates the expression level of CMTM6 in gastric mucosa cells, and CMTM6 can stabilize PD-L1 and maintain the protein level of PD-L1. CMTM6 gene knockout may affect biological behaviors such as protein ubiquitination and cell surface receptor expression.
Humans ; MARVEL Domain-Containing Proteins/metabolism* ; Helicobacter pylori/physiology* ; B7-H1 Antigen/genetics* ; Helicobacter Infections/metabolism* ; Epithelial Cells/metabolism* ; Gastric Mucosa/metabolism* ; Chemokines/metabolism* ; Cell Line ; Gene Knockout Techniques ; Myelin Proteins

OBJECTIVES: The purinergic receptor P2X2 (P2RX2) encodes an ATP-gated ion channel permeable to Na⁺, K⁺, and especially Ca²⁺. Loss-of-function mutations in P2RX2 are known to cause autosomal dominant nonsyndromic deafness 41 (DFNA41), which manifests as high-frequency hearing loss, accelerated presbycusis, and increased susceptibility to noise-induced damage. Zebrafish, owing to their small size, rapid development, high fecundity, transparent embryos, and high gene conservation with humans, provide an ideal model for studying human diseases and developmental mechanisms. This study aims to generate a p2rx2 knockout zebrafish model using CRISPR/Cas9 gene editing system to investigate the effect of p2rx2 deficiency on the auditory system, providing a basis for understanding P2RX2-related hearing loss and developing gene therapy strategies. METHODS: Two CRISPR targets (sgRNA1 and sgRNA2) spaced 47 bp apart were designed within the zebrafish p2rx2 gene. Synthesized sgRNAs and Cas9 protein were microinjected into single-cell stage Tübingen (TU)-strain zebrafish embryos. PCR and gel electrophoresis verified editing efficiency at 36 hours post-fertilization (hpf). Surviving embryos were raised to adulthood (F0), tail-clipped, genotyped, and screened for positive mosaics. F1 heterozygotes were generated by outcrossing, and F2 homozygous mutants were obtained by intercrossing. Polymerase chain reaction (PCR) combined with sequencing verified mutation type and heritability. At 5 days post-fertilization (dpf), YO-PRO-1 staining was used to examine hair cell morphology and count in lateral line neuromasts and the otolith region. Auditory evoked potential (AEP) thresholds at 600, 800, 1 000, and 2 000 Hz were measured in nine 4-month-old wild type and mutant zebrafish per group. RESULTS: A stable p2rx2 knockout zebrafish line was successfully established. Sequencing revealed a 66 bp insertion at the first target site introducing a premature stop codon (TAA), leading to early termination of protein translation and loss of function. Embryos developed normally with no gross malformations. At 5 dpf, mutants exhibited significantly reduced hair cell density in the otolith region compared with wild type, although lateral line neuromasts were unaffected. AEP testing showed significantly elevated auditory thresholds at all 4 frequencies in homozygous mutants compared with wild type (all P<0.001), indicating reduced hearing sensitivity. CONCLUSIONS We successfully generated a p2rx2 loss-of-function zebrafish model using CRISPR/Cas9 technology. p2rx2 deficiency caused hair cell defects in the otolith region and increased auditory thresholds across frequencies, indicating its key role in maintaining zebrafish auditory hair cell function and hearing perception. The phenotype's restriction to the otolith region suggests tissue-specific roles of p2rx2 in sensory organs. This model provides a valuable tool for elucidating the molecular mechanisms of P2RX2-related hearing loss and for screening otoprotective drugs and developing gene therapies.
Animals ; Zebrafish/genetics* ; Receptors, Purinergic P2X2/deficiency* ; CRISPR-Cas Systems/genetics* ; Gene Knockout Techniques ; Phenotype ; Zebrafish Proteins/genetics* ; Disease Models, Animal

OBJECTIVES: To study the effect of CDC20 knockdown on proliferation, migration and invasion of cervical cancer cells and its underlying mechanism. METHODS: CDC20 expression in cervical cancer tissues was analyzed using the TCGA database, and the protein expressions of CDC20 and β-Catenin in clinical specimens of cervical cancer and adjacent tissues were detected using immunohistochemistry. A dual target sgRNA2&7 sequence for CDC20 gene was designed for CDC20 gene knockdown in cervical cancer C33A cells using CRISPR/Cas9 technology, and CDC20 mRNA and protein expression levels in the transfected cells were detected using qRT-PCR and Western blotting. The changes in proliferation, cell cycle, apoptosis, migration and invasiveness of the transfected cells were evaluated using colony-forming assay, fluorescence activated cell sorting (FACS) and Transwell assay. In the animal experiment, naïve C33A cells and the cells with CDC20 knockdown were injected subcutaneously into the left and right axillae of nude mice (n=5) to observe tumor growth. The expressions of CDC20 and β-Catenin proteins in transfected cells and the xenograft were analyzed using Western blotting, and their interaction was confirmed by co-immunoprecipitation (CoIP) and immunofluorescence co-localization assays. RESULTS: Cervical cancer tissues expressed significantly higher CDC20 and β‑Catenin levels than the adjacent tissues. C33A cells with CDC20 knockdown showed reduced proliferation, increased apoptosis, and lowered migration and invasion abilities. CDC20 knockdown significantly suppressed the growth of C33A cell xenograft in nude mice, and the tumor-bearing mice did not exhibit obvious body mass changes. CDC20 and β-Catenin levels were both significantly lowered in C33A cells with CDC20 knockdown. Co-immunoprecipitation and co-localization assays confirmed the interaction between CDC20 and β‑Catenin. CONCLUSIONS CDC20 is highly expressed in cervical cancer tissues, and CDC20 knockdown can suppress proliferation, invasion, and metastasis while enhancing apoptosis of C33A cells, which is closely related with the regulation of the Wnt/β-Catenin signaling pathway.
Humans ; Uterine Cervical Neoplasms/metabolism* ; Female ; Cdc20 Proteins/genetics* ; Cell Proliferation ; Animals ; Cell Movement ; Neoplasm Invasiveness ; Apoptosis ; Mice, Nude ; beta Catenin/metabolism* ; CRISPR-Cas Systems ; Mice ; Cell Line, Tumor ; Gene Knockout Techniques ; Neoplasm Metastasis

The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics* ; Glutamic Acid/biosynthesis* ; Fermentation ; Metabolic Engineering ; Bacterial Proteins/metabolism* ; Bioreactors/microbiology* ; Gene Knockout Techniques

The protein kinase A/protein kinase G/protein kinase C-family (AGC kinase family) of eukaryotes is involved in regulating numerous biological processes. The 3-phosphoinositide- dependent protein kinase 1 (PDK1), is a conserved serine/threonine kinase in eukaryotes. To understand the roles of PDK1 homologous genes in cell death and immunity in tetraploid Nicotiana tabacum, the previuosly generated transgenic CRISPR/Cas9 lines, in which 5-7 alleles of the 4 homologous PDK1 genes (NtPDK1a/1b/1c/1d homologs) simultaneously knocked out, were used in this study. Our results showed that the hypersensitive response (HR) triggered by transient overexpression of active Pto (Pto^Y207D) or soybean GmMEKK1 was significantly delayed, whereas the resistance to Pseudomonas syrangae pv. tomato DC3000 (Pst DC3000) and tobacco mosaic virus (TMV) was significantly elevated in these partial knockout lines. The elevated resistance to Pst DC3000 and TMV was correlated with the elevated activation of NtMPK6, NtMPK3, and NtMPK4. Taken together, our results indicated that NtPDK1s play a positive role in cell death but a positive role in disease resistance, likely through negative regulation of the MAPK signaling cascade.
Nicotiana/virology* ; Disease Resistance/genetics* ; Plant Diseases/immunology* ; Plants, Genetically Modified/genetics* ; Gene Knockout Techniques ; Plant Proteins/genetics* ; CRISPR-Cas Systems ; Protein Serine-Threonine Kinases/genetics* ; 3-Phosphoinositide-Dependent Protein Kinases/genetics* ; Pyruvate Dehydrogenase Acetyl-Transferring Kinase ; Tobacco Mosaic Virus/pathogenicity*

This study established the mouse podocyte clone-5 (MPC5) with Smad3 knockout and studied the effect of transforming growth factor-beta 1 (TGF-β1) on the dedifferentiation of the MPC5 cells with Smad3 knockout, aiming to provide a cell tool for studying the role of Smad3 in mouse podocytes. The single-guide RNA (sgRNA) sequence targeting Smad3 was designed according to the principles of CRISPR/Cas9 design. The pX458-Smad3 vector was constructed and introduced into competent cells, and then the vector was extracted and used to transfect MPC5 cells. The successfully transfected cells were sorted by a flow cytometer. After single-cell clone expansion, PCR amplification of sequences adjacent to the edition site of Smad3 and sequencing were performed to identify potential cells with gene knockout. Western blotting was employed to verify the knockout efficiency of Smad3. Finally, the effect of Smad3 knockout on TGF-β1-induced dedifferentiation of MPC5 cells was analyzed by reverse transcription-polymerase chain reacting (RT-PCR), Western blotting, and the immunofluorescence method. The sgRNA was designed to target the fifth exon of Smad3. EGFP expression was observed 24 h after transfection of the pX458-Smad3 plasmid into MPC5 cells, with the transfection efficiency of 0.1% as determined by flow cytometry. From the transfected cells, 21 cell clones were obtained through flow cytometric sorting and single-cell clone expansion. PCR amplification and sequencing of the region around the sgRNA target site in Smad3 identified two cell clones with biallelic frameshift mutations. Western blotting results confirmed the absence of Smad3 expression in these clones, indicating successful establishment of the MPC5 cell line with Smad3 knockout. In normal MPC5 cells, TGF-β1 stimulation promoted the expression of fibrosis-related genes fibronectin and Col1a1 (collagen I) and inhibited the expression of the podocyte marker proteins synaptopodin and podocin, which suggested epithelial-mesenchymal transition and podocyte injury. However, in the two MPC5 cell lines with Smad3 knockout, TGF-β1-induced expression of epithelial-mesenchymal transition markers was significantly suppressed. The MPC5 cell lines with Smad3 knockout that were constructed by CRISPR/Cas9 provide a valuable cell model for functional studies of Smad3 protein and highlight the critical role of Smad3 in cell dedifferentiation.
Animals ; Smad3 Protein/genetics* ; CRISPR-Cas Systems/genetics* ; Mice ; Podocytes/metabolism* ; Transforming Growth Factor beta1/pharmacology* ; Cell Line ; Gene Knockout Techniques ; RNA, Guide, CRISPR-Cas Systems/genetics*

We knocked out the retinoic acid-inducible gene I (RIG-I) in HEK293 cells via CRISPR/Cas9 to reveal the effects of RIG-I knockout on the key factors in the type I interferon signaling pathway. Three single guide RNAs (sgRNAs) targeting RIG-I were designed, and the recombination vectors were constructed on the basis of the pX459 vector and used to transfect HEK293 cells, which were screened by puromycin subsequently. Furthermore, a mimic of virus, poly I: C, was used to transfect the cells screened out. RIG-I knockout was checked by sequencing, real-time quantitative PCR, Western blotting, and immunofluorescence assay. Meanwhile, the expression levels of key factors of type I interferon signaling pathway such as melanoma differentiation-associated gene 5 (MDA5), interferonβ1 (IFNβ1), and nuclear factor-kappa B p65 [NF-κB(p65)], as well as cell viability, were determined. The results showed that two HEK293 cell lines (S1 and S3) with RIG-I knockout were obtained, which exhibited lower mRNA and protein levels of RIG-I than the wild type HEK293 cells (P < 0.05). The mRNA levels of MDA5 and IFNβ1 in S1 and S3 cells and the protein level of NF-κB(p65) in S3 cells were lower than those in the wild type (P < 0.05). More extranuclear NF-κB(p65) protein was detected in S1 cells than in the wild type after transfection with poly I: C. Plus, the wild-type and S1 cells transfected with poly I: C for 48 h showcased reduced viability (P < 0.05), while S3 cells did not display the reduction in cell viability. In summary, the present study obtained two HEK293 cell lines with RIG-I knockout via CRISPR/Cas9, which provided a stable cell model for exploring the mechanism of type I interferon signaling pathway.
Humans ; HEK293 Cells ; CRISPR-Cas Systems ; DEAD Box Protein 58/metabolism* ; Signal Transduction ; Receptors, Immunologic/metabolism* ; Gene Knockout Techniques ; Transfection ; DEAD-box RNA Helicases/metabolism* ; RNA, Guide, CRISPR-Cas Systems/genetics* ; Interferon-Induced Helicase, IFIH1/metabolism* ; Transcription Factor RelA/metabolism* ; Interferon-beta/metabolism*

OBJECTIVE: To construct a modABC gene knockout strain of Proteus mirabilis and explore the effect of modABC gene deletion on biological characteristics of Proteus mirabilis. METHODS: Fusion PCR was used to obtain the fusion gene of modABC and the kanamycin-resistant gene Kn, which was ligated with the suicide vector pCVD442 and transduced into Proteus mirabilis. The modABC gene knockout strain of Proteus mirabilis was obtained after homologous recombination with the suicide vector. PCR and Sanger sequencing were used to identify genomic deletion of modABC gene in the genetically modified strain. The concentration of molybdate in the wild-type and gene knockout strains was determined using inductively coupled plasma mass spectrometry (ICP-MS), and their survival ability in LB medium was compared under both aerobic and anaerobic conditions. RESULTS: PCR and sanger sequencing confirmed genomic deletion of modABC gene in the obtained Proteus mirabilis strain. The concentration of intracellular molybdenum in the modABC gene knockout strain was 1.22 mg/kg, significantly lower than that in the wild-type strain (1.46 mg/kg, P < 0.001). Under the aerobic condition, the modABC gene knockout strain grown in LB medium showed no significant changes in survival ability compared with the wild-type strain, but its proliferation rate decreased significantly under the anaerobic condition and also when cultured in nitrate-containing LB medium under anaerobic condition. CONCLUSION Homologous recombination with the suicide vector can be used for modABC gene knockout in Proteus mirabilis. modABC gene participates in molybdate uptake and is associated with anaerobic growth of Proteus mirabilis in the presence of nitrate.
Humans ; Gene Deletion ; Nitrates ; Proteus mirabilis/genetics* ; Gene Knockout Techniques

To explore the effect of Mlk3 (mixed lineage kinase 3) deficiency on blood pressure, Mlk3 gene knockout (Mlk3KO) mice were generated. Activities of sgRNAs targeted Mlk3 gene were evaluated by T7 endonuclease I (T7E1) assay. CRISPR/Cas9 mRNA and sgRNA were obtained by in vitro transcription, microinjected into zygote, followed by transferring into a foster mother. Genotyping and DNA sequencing confirmed the deletion of Mlk3 gene. Real- time PCR (RT-PCR), Western blotting or immunofluorescence analysis showed that Mlk3KO mice had an undetectable expression of Mlk3 mRNA or Mlk3 protein. Mlk3KO mice exhibited an elevated systolic blood pressure compared with wild-type mice as measured by tail-cuff system. Immunohistochemistry and Western blotting analysis showed that the phosphorylation of MLC (myosin light chain) was significantly increased in aorta isolated from Mlk3KO mice. Together, Mlk3KO mice was successfully generated by CRISPR/Cas9 system. MLK3 functions in maintaining blood pressure homeostasis by regulating MLC phosphorylation. This study provides an animal model for exploring the mechanism by which Mlk3 protects against the development of hypertension and hypertensive cardiovascular remodeling.
Animals ; Mice ; Mice, Knockout ; CRISPR-Cas Systems ; Blood Pressure ; Gene Knockout Techniques ; Zygote

OBJECTIVE: To investigate the effects of CACNA1H gene knockout (KO) on autistic-like behaviors and the morphology of hippocampal neurons in mice. METHODS: In the study, 25 CACNA1H KO mice of 3-4 weeks old and C57BL/6 background were recruited as the experimental group, and 26 wild type (WT) mice of the same age and background were recruited as the control group. Three-chamber test and open field test were used to observe the social interaction, anxiety, and repetitive behaviors in mice. After that, their brain weight and size were measured, and the number of hippocampal neurons were observed by Nissl staining. Furthermore, the CACNA1H heterozygote mice were interbred with Thy1-GFP-O mice to generate CACNA1H^-/--Thy1⁺(KO-GFP) and CACNA1H^+/+-Thy1⁺ (WT-GFP) mice. The density and maturity of dendritic spines of hippocampal neurons were observed. RESULTS: In the sociability test session of the three-chamber test, the KO mice spent more time in the chamber of the stranger mice than in the object one (F_{1, 14}=95.086, P < 0.05; Post-Hoc: P < 0.05), without any significant difference for the explored preference index between the two groups (t=1.044, P>0.05). However, in the social novelty recognition test session, no difference was observed between the time of the KO mice spend in the chamber of new stranger mice and the stranger one (F_{1, 14}=18.062, P < 0.05; Post-Hoc: P>0.05), and the explored preference index of the KO mice was less than that of the control group (t=2.390, P < 0.05). In the open field test, the KO mice spent less time in the center of the open field apparatus than the control group (t=2.503, P < 0.05), but the self-grooming time was significantly increased compared with the control group (t=-2.299, P < 0.05). Morphological results showed that the brain weight/body weight ratio (t=0.356, P>0.05) and brain size (t=-0.660, P>0.05) of the KO mice were not significantly different from those of the control group, but the number of neurons were significantly reduced in hippocampal dentate gyrus compared with the control group (t=2.323, P < 0.05). Moreover, the density of dendritic spine of dentate gyrus neurons in the KO-GFP mice was significantly increased compared with the control group (t=-2.374, P < 0.05), without any significant difference in spine maturity (t=-1.935, P>0.05). CONCLUSION CACNA1H KO mice represent autistic-like behavior, which may be related to the decrease in the number of neurons and the increase in the density of dendritic spine in the dentate gyrus.
Animals ; Autistic Disorder/genetics* ; Calcium Channels, T-Type/genetics* ; Gene Knockout Techniques ; Hippocampus ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Neurons