1.Chufeng Yisuntang Ameliorates PM2.5-induced Dry Eye via ROS/p38 MAPK Signaling Pathway
Yuan ZHONG ; Pan ZHAO ; Shi TAN ; Yu TANG ; Dongdong LI ; Lihao CHEN ; Jun PENG ; Qinghua PENG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(7):191-200
ObjectiveTo establish a mouse model of particulate matter 2.5 (PM2.5)-induced dry eye and investigate whether Chufeng Yisuntang can ameliorate the PM2.5-induced ocular surface damage by regulating the reactive oxygen species (ROS)/p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway. MethodsSixty 8-week-old male C57BL/6J mice were used. Ten were randomly selected as the control group. The remaining 50 mice received topical instillation of 1 drop (0.1 mL) of 5 g·L-1 PM2.5 suspension in both eyes, four times daily. Successfully modeled mice were randomized into four groups (n=10): Model, p38 MAPK inhibitor, Chufeng Yisuntang, and combination (Chufeng Yisuntang at 7.3 g·kg-1 + p38 MAPK inhibitor SB203580 at 5 mg·kg-1). Chufeng Yisuntang was administered via gavage, and the inhibitor group via intraperitoneal injection. The control and model groups received equal volumes of distilled water by gavage. All treatments lasted for 4 weeks. General conditions were dynamically observed. Tear secretion, tear film break-up time, and corneal fluorescein staining were assessed. After intervention for 4 weeks, hematoxylin and eosin (HE) staining was used to examine the histopathological changes. Enzyme-linked immunosorbent assay (ELISA) was adopted to measure serum levels of ROS, malondialdehyde (MDA), superoxide dismutase (SOD) 1, and SOD2. Western blot and Real-time PCR were employed to determine the protein and gene levels, respectively, of p38 MAPK, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), and cysteinyl aspartate-specific proteinase-3 (Caspase-3) in the corneal tissue. ResultsCompared with the control group, the model group exhibited reduced tear secretion volume and tear film breakup time, along with increased corneal fluorescein staining scores (P<0.01). Compared with the model group, the Chufeng Yisuntang group, p38 MAPK inhibitor group, and combination group demonstrated increased tear secretion volume and tear film breakup time, along with decreased corneal fluorescein staining scores (P<0.01). HE staining revealed that compared with the control group, the model group exhibited marked increases in corneal epithelial cell layers and epithelial thickness, along with reduced meibomian gland acini and intensely stained, densely packed nuclei around the acini. Compared with the model group, the Chufeng Yisuntang group, p38 MAPK inhibitor group, and combination group showed intact corneal structure, improved cell morphology, and reduced damage severity. ELISA revealed elevated ROS and MDA levels (P<0.01) and decreased SOD1 and SOD2 levels (P<0.01) in the model group compared with the control group. Compared with the model group, Chufeng Yisuntang, p38 MAPK inhibitor, and the combination lowered ROS and MDA levels (P<0.01), while raising SOD1 and SOD2 levels (P<0.05, P<0.01). Western blot revealed that compared with the control group, the model group exhibited increased protein levels of p38 MAPK, Bax, and Caspase-3 (P<0.01) and reduced protein level of Bcl-2 (P<0.01). Compared with the model group, Chufeng Yisuntang, p38 MAPK inhibitor, and the combination down-regulated the protein levels of p38 MAPK, Bax, and Caspase-3 (P<0.01), while up-regulating the protein level of Bcl-2 (P<0.01). Compared with the Chufeng Yisuntang group, the combination group exhibited decreased protein levels of p38 MAPK, Bax, and Caspase-3 (P<0.01) and increased protein level of Bcl-2 (P<0.01). Real-time PCR revealed that compared with the control group, the model group exhibited upregulated mRNA levels of p38 MAPK, Bax, and Caspase-3 (P<0.01), and downregulated mRNA level of Bcl-2 (P<0.01). Compared with the model group, Chufeng Yisuntang, p38 MAPK inhibitor, and the combination down-regulated the mRNA levels of p38 MAPK, Bax, and Caspase-3 (P<0.01), while up-regulating the mRNA level of Bcl-2 (P<0.05, P<0.01). Compared with the Chufeng Yisuntang group, the combination group exhibited decreased mRNA levels of p38 MAPK, Bax, and Caspase-3 expression (P<0.05, P<0.01) and increased mRNA level of Bcl-2 (P<0.01). ConclusionChufeng Yisuntang may partially protect against PM2.5-induced corneal injury by inhibiting the ROS/p38 MAPK pathway, enhancing antioxidant defense, and reducing epithelial apoptosis.
2.Analysis of gene expression in synovial fluid and blood of patients with knee osteoarthritis of Yang deficiency and blood stasis type.
Hao-Tian HUA ; Zhong-Yi ZHANG ; Zhao-Kai JIN ; Peng-Qiang LOU ; Zhuo MENG ; An-Qi ZHANG ; Yang ZHANG ; Pei-Jian TONG
China Journal of Orthopaedics and Traumatology 2025;38(8):792-799
OBJECTIVE:
To reveal the molecular basis of knee osteoarthritis (KOA) with Yang deficiency and blood stasis syndrome by analyzing the gene expression profiles in synovial fluid and blood of KOA patients with this syndrome.
METHODS:
A total of 80 KOA patients were recruited from October 2022 to June 2024, including 40 cases in the non-Yang deficiency and blood stasis group (27 males and 13 females), with an average age of (61.75±3.45) years old;and 40 cases in the Yang deficiency and blood stasis group (22 males and 18 females), with an average age of (62.00±2.76) years old. The levels of body mass index (BMI), high-density lipoprotein (HDL), low-density lipoprotein (LDL), fibrinogen, total cholesterol, and D-dimer were recorded and summarized. Blood and synovial fluid samples from patients were collected for gene expression profile microarray sequencing, and then PCR and immunohistochemistry were used for clinical verification on the patients' synovial fluid and cartilage samples.
RESULTS:
Logistic regression analysis showed that compared with KOA patients with non-Yang deficiency and blood stasis syndrome, those with Yang deficiency and blood stasis syndrome had increased BMI, LDL, fibrinogen, total cholesterol, and D-dimer, and decreased HDL, with a clear correlation between the two groups. There were 562 differential genes in the blood, among which 322 were up-regulated and 240 were down-regulated;755 differential genes were found in the synovial fluid, with 350 up-regulated and 405 down-regulated. KEGG signaling pathway analysis of synovial fluid revealed changes in lipid metabolism-related pathways, including cholesterol metabolism, fatty acid metabolism, and PPARG signaling pathway. Analysis of the involved differential genes identified 6 genes in synovial fluid that were closely related to lipid metabolism, namely LRP1, LPL, ACOT6, TM6SF2, DGKK, and PPARG. Subsequently, PCR and immunohistochemical verification were performed using synovial fluid and cartilage samples, and the results were consistent with those of microarray sequencing.
CONCLUSION
This study explores the clinical and genomic correlation between traditional Chinese medicine syndromes and knee osteoarthritis from the perspective of lipid metabolism, and proves that abnormal lipid metabolism is closely related to KOA with Yang deficiency and blood stasis syndrome from both clinical and basic aspects.
Humans
;
Male
;
Female
;
Middle Aged
;
Synovial Fluid/metabolism*
;
Osteoarthritis, Knee/metabolism*
;
Yang Deficiency/complications*
;
Aged
3.Novel biallelic MCMDC2 variants were associated with meiotic arrest and nonobstructive azoospermia.
Hao-Wei BAI ; Na LI ; Yu-Xiang ZHANG ; Jia-Qiang LUO ; Ru-Hui TIAN ; Peng LI ; Yu-Hua HUANG ; Fu-Rong BAI ; Cun-Zhong DENG ; Fu-Jun ZHAO ; Ren MO ; Ning CHI ; Yu-Chuan ZHOU ; Zheng LI ; Chen-Cheng YAO ; Er-Lei ZHI
Asian Journal of Andrology 2025;27(2):268-275
Nonobstructive azoospermia (NOA), one of the most severe types of male infertility, etiology often remains unclear in most cases. Therefore, this study aimed to detect four biallelic detrimental variants (0.5%) in the minichromosome maintenance domain containing 2 ( MCMDC2 ) genes in 768 NOA patients by whole-exome sequencing (WES). Hematoxylin and eosin (H&E) demonstrated that MCMDC2 deleterious variants caused meiotic arrest in three patients (c.1360G>T, c.1956G>T, and c.685C>T) and hypospermatogenesis in one patient (c.94G>T), as further confirmed through immunofluorescence (IF) staining. The single-cell RNA sequencing data indicated that MCMDC2 was substantially expressed during spermatogenesis. The variants were confirmed as deleterious and responsible for patient infertility through bioinformatics and in vitro experimental analyses. The results revealed four MCMDC2 variants related to NOA, which contributes to the current perception of the function of MCMDC2 in male fertility and presents new perspectives on the genetic etiology of NOA.
Humans
;
Male
;
Azoospermia/genetics*
;
Meiosis/genetics*
;
Spermatogenesis/genetics*
;
Adult
;
Exome Sequencing
;
Microtubule-Associated Proteins/genetics*
;
Alleles
;
Infertility, Male/genetics*
4.Two cases of creatine deficiency syndrome caused by GAMT gene mutations and literature review.
Ting-Ting ZHAO ; Zou PAN ; Jian-Min ZHONG ; Hai-Yun TANG ; Fei YIN ; Jing PENG ; Chen CHEN
Chinese Journal of Contemporary Pediatrics 2025;27(3):340-346
OBJECTIVES:
To summarize the clinical manifestations and genetic characteristics of creatine deficiency syndrome (CDS) caused by GAMT gene mutations.
METHODS:
A retrospective analysis was conducted on the clinical and genetic data of two children diagnosed with GAMT deficiency-type CDS at the Children's Medical Center of Xiangya Hospital, Central South University, from December 2020 to December 2024.
RESULTS:
The two patients presented with symptoms in infancy, and both had compound heterozygous mutations in the GAMT gene. Case 1 exhibited seizures and intellectual disability, while Case 2 had intellectual disability and attention-deficit hyperactivity disorder. Magnetic resonance spectroscopy of cranial MRI in both patients indicated reduced creatine peaks. After creatine treatment, seizures in Case 1 were controlled, but both patients continued to experience intellectual disabilities and behavioral issues. As of December 2024, a total of 21 cases have been reported in China (including this study), and 115 cases have been reported abroad. All patients exhibited developmental delay or intellectual disabilities, with 66.9% (91/136) experiencing seizures, 33.8% (46/136) presenting with motor disorders, and 36.8% (50/136) having behavioral problems. Seventy-five percent (102/136) of patients received creatine treatment, leading to significant improvements in seizures and motor disorders, although cognitive improvement was not substantial.
CONCLUSIONS
GAMT deficiency-type CDS is rare and presents with nonspecific clinical features. Timely diagnosis facilitates targeted treatment, which can partially improve prognosis.
Child
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Female
;
Humans
;
Male
;
Creatine/deficiency*
;
Guanidinoacetate N-Methyltransferase/deficiency*
;
Intellectual Disability/genetics*
;
Mutation
;
Retrospective Studies
;
Rhabdomyolysis/genetics*
;
Language Development Disorders
;
Movement Disorders/congenital*
5.Analysis of Hormone Levels in Patients with Hematological Diseases Before and After Hematopoietic Stem Cell Tansplantation.
Fen LI ; Yu-Jin LI ; Jie ZHAO ; Zhi-Xiang LU ; Xiao-Li GAO ; Hai-Tao HE ; Xue-Zhong GU ; Feng-Yu CHEN ; Hui-Yuan LI ; Qi SA ; Lin ZHANG ; Peng HU
Journal of Experimental Hematology 2025;33(5):1443-1452
OBJECTIVE:
By analyzing the hormone secretion of the adenohypophysis, thyroid glands, gonads, and adrenal cortex in patients with hematological diseases before and after hematopoietic stem cell transplantation (HSCT), this study aims to preliminarily explore the effect of HSCT on patients' hormone secretion and glandular damage.
METHODS:
The baseline data of 209 hematological disease patients who underwent HSCT in our hospital from January 2019 to December 2023, as well as the data on the levels of hormones secreted by the adenohypophysis, thyroid glands, gonads and adrenal cortex before and after HSCT were collected, and the changes in hormone levels before and after transplantation were analyzed.
RESULTS:
After allogeneic HSCT, the levels of thyroid-stimulating hormone (TSH), triiodothyronine (T3), free triiodothyronine (FT3) and estradiol (E2) decreased, while the levels of luteinizing hormone (LH) and follicle- stimulating hormone (FSH) increased. The T3 level of patients with decreased TSH after transplantation was lower than that of those with increased TSH after transplantation. In female patients, the levels of prolactin (PRL), progesterone (Prog), and testosterone (Testo) decreased after HSCT. Testo and PRL decreased when there was a donor-recipient sex mismatch, and the levels of adrenocorticotropic hormone (ACTH) and cortisol (COR) decreased when the HLA matching was haploidentical. The levels of T3, FT3, and PRL decreased after autologous HSCT. In allogeneic HSCT patients, the levels of TSH, T4, T3, FT3, and ACTH in the group with graft-versus-host disease (GVHD) were significantly lower than those in the group without GVHD. Logistic regression analysis showed the changes in hormone levels after transplantation were not correlated with factors such as the patient's sex, age, or whether the blood types of the donor and the recipient are the same.
CONCLUSION
HSCT can affect the endocrine function of patients with hematological diseases, mainly affecting target glandular organs such as the thyroid, gonads, and adrenal glands, while the secretory function of the adenohypophysis is less affected.
Humans
;
Hematopoietic Stem Cell Transplantation
;
Female
;
Male
;
Hematologic Diseases/blood*
;
Follicle Stimulating Hormone/blood*
;
Triiodothyronine/blood*
;
Luteinizing Hormone/blood*
;
Thyroid Gland/metabolism*
;
Estradiol/blood*
;
Thyrotropin/blood*
;
Gonads/metabolism*
;
Adult
;
Middle Aged
;
Adrenocorticotropic Hormone/blood*
;
Hormones/metabolism*
;
Adrenal Cortex/metabolism*
;
Prolactin
6.Influences of LncRNA MALAT1/miR-876-5p/FOXM1 axis on TNF-α-induced proliferation,apoptosis and inflammatory response of HaCaT cells
Zhao JIN ; Zhong LIU ; Jing PENG ; Rongyi HU ; Juan WU ; Qinsi HUANG ; Fei WANG
Chinese Journal of Immunology 2025;41(3):582-588,594
Objective:To investigate the influences of long non-coding RNA metastasis-associated lung adenocarcinoma tran-script 1(lncRNA MALAT1)/miR-876-5p/forkhead box protein M1(FOXM1)axis on TNF-α-induced proliferation,apoptosis and in-flammatory response of HaCaT cells.Methods:HaCaT cells were grouped into Ct group,Model group,si-NC group,si-MALAT1 group,mimic NC group,miR-876-5p mimic group,si-MALAT1+inhibitor NC group,and si-MALAT1+miR-876-5p inhibitor group.Except for the Ct group,cells in other groups were treated with 25 μg/L TNF-α to induce the in vitro cell model of psoriasis,and after 24 hours of TNF-α induction,the corresponding transfectants were transfected for 48 hours for subsequent experiments.qRT-PCR was applied to detect the expression of MALAT1 and miR-876-5p in cells;CCK-8 method and EdU staining were applied to detect cell pro-liferation;flow cytometry was applied to detect apoptosis;ELISA method was applied to detect the levels of IL-6,TNF-α,and IL-1β in cell supernatant;Western blot was applied to detect the protein expressions of FOXM1,proliferating cell nuclear antigen(PCNA),Bcl-2-associated X protein(Bax)and B-lymphocytoma-2(Bcl-2);dual-luciferase reporter gene assay was applied to verify the rela-tionship between MALAT1 and miR-876-5p,miR-876-5p and FOXM1;and RNA pull down experiments were applied to verify the re-lationship between MALAT1 and miR-876-5p.Results:Compared with the control group,the expressions of MALAT1 and FOXM1 protein expression in the experimental group were increased,and the expression of miR-876-5p was decreased(P<0.05);compared with Ct group,the expressions of MALAT1 and FOXM1 protein expression in HaCaT cells,A450 value,EdU positive rate,the levels of IL-6,TNF-α,IL-1β,and the protein expressions of PCNA and Bcl-2 in cell supernatant in Model group increased,the expression of miR-876-5p,apoptosis rate and the protein expression of Bax were decreased(P<0.05);silencing MALAT1 or overexpressing miR-876-5p could inhibit the proliferation and inflammatory response of HaCaT cells induced by TNF-α,and promote cell apoptosis;miR-876-5p inhibitor attenuated the inhibitory effects of silencing MALAT1 on TNF-α-induced HaCaT cell proliferation and inflammatory response,and the promotion on cell apoptosis;MALAT1 targeted and regulated the miR-876-5p/FOXM1 axis.Conclusion:Silencing MALAT1 may inhibit the expression of FOXM1 by up-regulating miR-876-5p,thereby inhibiting the proliferation and inflammatory re-sponse of HaCaT cells induced by TNF-α,and promoting cell apoptosis.
7.Biomimetic dual-cell membrane nanoprobes employed for bimodal fluorescence-MR imaging of pancreatic cancer
Yanqi ZHONG ; Yingying MA ; Wenzheng LU ; Heng ZHANG ; Yuxi GE ; Peng WANG ; Jing ZHAO ; Jianying QIAN ; Jingxiao CHEN ; Shudong HU
Chinese Journal of Nuclear Medicine and Molecular Imaging 2025;45(2):88-93
Objective:To construct fused cancer cell/neutrophil membrane-coated polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNP@FMs) and explore the potential for targeted pancreatic cancer fluorescence imaging and MRI.Methods:Cancer cell membranes fused with neutrophil membranes were encapsulated on the surface of polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNPs) to prepare PMNP@FMs. The morphology, structure, and MRI performance of the product were characterized. The cytotoxicity of PMNP@FMs towards human pancreatic cancer cells (PANC-1) and normal human pancreatic ductal epithelial cells (hTERT-HPNE) was evaluated using cell counting kit (CCK)-8, and in vivo toxicity was assessed in healthy mice. PANC-1 pancreatic cancer xenograft nude mouse models were established for in vivo fluorescence imaging and MRI. Data were analyzed using the independent-sample t test, repeated measures analysis of variance and the least significance difference method. Results:PMNP@FMs exhibited a core-shell structure with a diameter of (112.81±8.64) nm, negative surface charge, and good dispersibility. The T 1 relaxivity of PMNPs was 18.81±0.22, which was 4.1 times higher than that of gadopentetate dimeglumine (Gd-DTPA) (4.55±0.24; t=75.54, P<0.001). Co-culture of PMNPs and PMNP@FMs with hTERT-HPNE and PANC-1 cells for 24 h resulted in cell viability above 90% within the concentration range of 0-500 μg/ml. PMNP@FMs did not affect mouse survival and showed no apparent organ damage. In vivo fluorescence imaging and MRI revealed that PMNP@FMs accumulated highly in tumors and reached the peak 24 h post intravenous administration (relative MR signal: 1.35±0.01, fluorescence intensity: (1.20±0.25)×10 10), surpassing the peak observed in the control group (1.22±0.01, (3.87±0.50)×10 9;F values: 11.03-188.01, t values: 18.20, 5.64, all P<0.05), with hepatic metabolism being the primary route of clearance. Conclusion:PMNP@FMs demonstrate a potential for targeted pancreatic cancer fluorescence imaging and MRI, offering promising prospect for precise diagnosis of early-stage pancreatic cancer.
8.Preliminary clinical study of a novel FAP-targeted PET tracer 64Cu-FAPI-XT117 in malignant solid tumors: a comparative study with 18F-FDG
Xi HE ; Meijuan ZHOU ; Peng HOU ; Kaixiang ZHONG ; Youcai LI ; Jie LYU ; Miao KE ; Ruiyue ZHAO ; Shaoyu LIU ; Yimin FU ; Huizhen ZHONG ; Xinlu WANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2025;45(12):708-713
Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.
9.Mechanism of action of Guizhi Fuling Pill in treating chronic prostatitis based on network pharmacology and molecular docking
Ji SUN ; Xinfeng XIA ; Peng JIN ; Wei ZHONG ; Yanlin ZHAO ; Qinglei HANG ; Guohui ZHU
Journal of Clinical Medicine in Practice 2025;29(20):72-77
Objective To investigate the mechanism of action of Guizhi Fuling pill in treating chro-nic prostatitis(CP)using network pharmacology and molecular docking techniques.Methods Compo-nents of Guizhi Fuling pill were collected from the Traditional Chinese Medicines Systems Pharmacolo-gy Platform(TCMSP),and target information was obtained from the SwissTarget database.Targets for chronic prostatitis were screened from the GeneCards,OMIM,CTD,and DisGeNET disease data-bases.A protein-protein interaction(PPI)network was established and analyzed.Gene ontology(GO)functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway en-richment analysis were performed using the DAVID database.The Cytoscape software was employed to construct an association network linking the components of Guizhi Fuling Pill,their targets,and the targets of chronic prostatitis.Molecular docking was conducted using AutoDock Vina software to verify the binding stability between the components of Guizhi Fuling pill and their targets.Results After screening and deduplication in the TCMSP database,76 components of Guizhi Fuling Pill were iden-tified,and 655 component targets were retrieved from the SwissTarget database.There were 190 intersecting targets between GuizhiFuling Pill and chronic prostatitis.GO analysis indicated that Guizhi Fuling Pill may treat chronic prostatitis by participating in processes such asapoptosis,ATP binding,and signal transduction.KEGG analysis suggested that Guizhi Fuling Pill can regulate pathways such as phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)and mitogen-acti-vated protein kinase(MAPK)to intervene in chronic prostatitis.Molecular docking data demonstra-ted that the components of Guizhi Fuling pill exhibited stable conformations with their targets.Con-clusion The components of Guizhi Fuling Pill can stably bind to their targets and exert therapeutic effects on chronic prostatitis through multiple targets and pathways.
10.Phenotypic Function of Legionella pneumophila Type I-F CRISPR-Cas.
Ting MO ; Hong Yu REN ; Xian Xian ZHANG ; Yun Wei LU ; Zhong Qiu TENG ; Xue ZHANG ; Lu Peng DAI ; Ling HOU ; Na ZHAO ; Jia HE ; Tian QIN
Biomedical and Environmental Sciences 2025;38(9):1105-1119
OBJECTIVE:
CRISPR-Cas protects bacteria from exogenous DNA invasion and is associated with bacterial biofilm formation and pathogenicity.
METHODS:
We analyzed the type I-F CRISPR-Cas system of Legionella pneumophila WX48, including Cas1, Cas2-Cas3, Csy1, Csy2, Csy3, and Cas6f, along with downstream CRISPR arrays. We explored the effects of the CRISPR-Cas system on the in vitro growth, biofilm-forming ability, and pathogenicity of L. pneumophila through constructing gene deletion mutants.
RESULTS:
The type I-F CRISPR-Cas system did not affect the in vitro growth of wild-type or mutant strains. The biofilm formation and intracellular proliferation of the mutant strains were weaker than those of the wild type owing to the regulation of type IV pili and Dot/Icm type IV secretion systems. In particular, Cas6f deletion strongly inhibited these processes.
CONCLUSION
The type I-F CRISPR-Cas system may reduce biofilm formation and intracellular proliferation in L. pneumophila.
Legionella pneumophila/pathogenicity*
;
CRISPR-Cas Systems
;
Biofilms/growth & development*
;
Phenotype
;
Bacterial Proteins/metabolism*
;
Gene Deletion

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