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

Objective To explore the inhibitory effect of Xinhui tangerine peel polysaccharides on the mouse skin fibroblasts so as to understand the underlying molecular mechanism.Methods We separated and purified the components of tangerine peel polysaccharides from Xinhui tangerine peel.C57BL/6 mouse skin fibroblasts were isolated and cultured for the cellular experimental study.We set up a blank control group(normal culture)and low-,medium-and high-dose experimental groups(50,100 and 200 μg/mL tangerine peel polysaccharides).After 24 hours of treatment,cell survival rate was assessed by CCK-8 assay.The mRNA and protein expression levels of collagen type Ⅰ(Col1a1),collagen type Ⅲ(Col1a3),TGF-β1 and ACTA2 in fibroblasts were examined by RT-qPCR and Western blotting.Smad3 was examined by Western blotting.Results The cell survival rate in the blank control group,the medium-and high-dose experimental groups was 100％,(90.54±6.74)％,and(78.90±4.24)％,respectively.The relative expression level of Col1a1 protein was 1.13±0.15,0.57±0.16,and 0.48±0.05,respectively;the relative expression level of Col3a1 protein was 0.81±0.13,0.49±0.11 and 0.50±0.03;the relative expression level of TGF-β1 protein was 1.11±0.15,0.60±0.13,and 0.33±0.11;the relative expression level of p-Smad3/Smad3 proteins was 0.96±0.05,0.75±0.06 and 0.71±0.03.The mRNA expression level of Col1a1 was 1.01±0.17,0.58±0.11,and 0.52±0.12;the mRNA expression level of Col3a1 was 1.01±0.12,0.56±0.19,and 0.65±0.14;the expression level of ACTA2 mRNA was 1.01±0.13,0.24±0.04,and 0.22±0.07;the mRNA expression level of TGF-β1 was 1.00±0.09,0.50±0.10,and 0.49±0.15.The relative expression levels of p-Smad3/Smad3 proteins were 0.86±0.06,0.66±0.06,0.55±0.13,0.43±0.09,0.35±0.06,and 0.27±0.12,respectively,after time-related treatment with high-dose tangerine peel polysaccharides.The above indicators in medium-and high-dose tangerine peel polysaccharide groups showed statistically significant differences compared to those in the blank control group(P＜0.05).Conclusion Tangerine peel polysaccharides can inhibit the cell proliferation and the synthesis of keloid-related genes on fibroblasts by inhibiting TGF-β1/Smad3 signaling pathway.

Objective To evaluate the effects of transcatheter aortic valve replacement(TAVR)on left ventricular reverse remodeling(LVRR)and outcomes in patients with mixed aortic valve disease(MAVD)and predominant aortic stenosis(AS).Methods Patients undergoing TAVR at our center between January 2020 and December 2022 were enrolled consecutively.Propensity score matching(PSM)(1∶1 ratio)was used to reduce selection bias.Transthoracic echocardiography(TTE)was used to monitor left ventricular ejection fraction(LVEF)and other structural parameters over time.The study outcome was a composite of cardiovascular death and rehospitalization due to cardiovascular causes.Linear mixed-effects models and logistic regression were utilized for comparing echocardiographic changes across groups and identifying independent risk factors for no-LVRR,respectively.Results After PSM,126 patients were included.MAVD group exhibited larger structural parameters(left ventricular end-systolic/end-diastolic diameter and volume,left ventricular mass index)and a lower left ventricular ejection fraction(LVEF)(all P＜0.05).However,more pronounced improvements in left ventricular structure and hemodynamics were observed during follow-up.Multivariate logistic regression analysis indicated that the left ventricular mass index(LVMI)was an independent predictor of left ventricular reverse remodeling(LVRR)after TAVR,whereas persistent moderate or greater mitral regurgitation(MR)and paravalvular leak(PVL)significantly reduced the incidence of LVRR.During a median follow-up period of 23 months,a total of 31 endpoint events occurred,and there was no statistically significant difference in long-term prognosis between the two groups(Log-rank P=0.330).Conclusions Compared to patients in the AS group,those in the MAVD group exhibited more severe left ventricular remodeling before TAVR.However,more significant LVRR was observed during postoperative follow-up.Additionally,the long-term prognosis was comparable between the two groups.

Solid-phase extraction(SPE)combined with surface-enhanced Raman spectroscopy(SERS)has emerged as a promising analytical technique for detection and analysis of trace components in complex sample matrices.SPE enriches analytes through selective adsorption and solvent elution,effectively increasing the concentration and signal intensity.SERS enables ultra-sensitive and highly selective molecular analysis through the use of SERS-active substrates engineered to amplify Raman signals.The integration of these two techniques overcomes the limitations of conventional Raman spectroscopy in low-concentration detection field,while significantly improving sample preparation efficiency and analytical accuracy.This review provided a comprehensive overview of the characteristics of three SPE-SERS coupling modes,including two-step,one-step,and online integration.Special emphasis was placed on recent advancements in one-step SPE-SERS approaches based on novel functional adsorbent materials such as graphene,metal-organic frameworks,covalent organic frameworks,and molecularly imprinted polymers.Furthermore,future directions and development prospects of SPE-SERS technology were discussed.

Objective To investigate biological markers associated with psychotic symptoms in patients with bipolar disorder(BD)based on electronic medical records of patients,and to develop an interpretable risk prediction model that supports the identification of high-risk individuals and that facilitates decision-making for providing clinical intervention in a timely manner.Methods A total of 2 352 patients diagnosed with BD and admitted to West China Hospital,Sichuan University were enrolled using the electronic medical records system of the hospital.The participants were divided into two subgroups,the bipolar disorder depression(BDD)group and the bipolar disorder mania(BDM)group.The logistic regression algorithm was used to train and validate the prediction model,and interpretability methods were used to analyze the contribution of each feature to individuals and the effect of the features on specific target prediction decisions.Results The logistic regression model demonstrated robust predictive performance across the BD,BDD,and BDM cohorts,with areas under the curve(AUC)of the receiver operating characteristic curves always exceeding 81.6%.The core predictive features included platelet distribution width(PDW),fibrinogen(FIB),platelet large cell ratio(P-LCR),activated partial thromboplastin time(APTT),prothrombin time(PT),and triglyceride(TG).The logistic regression model exhibited strong interpretability and was combined with nomograms for intuitive risk quantification and individualized prediction.Conclusion The logistic regression model enables rapid and simple screening of BD patients with psychotic symptoms.Distinct patterns of changes observed in blood biomarkers of BDD and BDM subgroups enrich the understanding of the underlying pathophysiological mechanisms and highlight the importance of considering subtypes in the intervention and management of patients.

Objective To explore the inhibitory effect of Xinhui tangerine peel polysaccharides on the mouse skin fibroblasts so as to understand the underlying molecular mechanism.Methods We separated and purified the components of tangerine peel polysaccharides from Xinhui tangerine peel.C57BL/6 mouse skin fibroblasts were isolated and cultured for the cellular experimental study.We set up a blank control group(normal culture)and low-,medium-and high-dose experimental groups(50,100 and 200 μg/mL tangerine peel polysaccharides).After 24 hours of treatment,cell survival rate was assessed by CCK-8 assay.The mRNA and protein expression levels of collagen type Ⅰ(Col1a1),collagen type Ⅲ(Col1a3),TGF-β1 and ACTA2 in fibroblasts were examined by RT-qPCR and Western blotting.Smad3 was examined by Western blotting.Results The cell survival rate in the blank control group,the medium-and high-dose experimental groups was 100％,(90.54±6.74)％,and(78.90±4.24)％,respectively.The relative expression level of Col1a1 protein was 1.13±0.15,0.57±0.16,and 0.48±0.05,respectively;the relative expression level of Col3a1 protein was 0.81±0.13,0.49±0.11 and 0.50±0.03;the relative expression level of TGF-β1 protein was 1.11±0.15,0.60±0.13,and 0.33±0.11;the relative expression level of p-Smad3/Smad3 proteins was 0.96±0.05,0.75±0.06 and 0.71±0.03.The mRNA expression level of Col1a1 was 1.01±0.17,0.58±0.11,and 0.52±0.12;the mRNA expression level of Col3a1 was 1.01±0.12,0.56±0.19,and 0.65±0.14;the expression level of ACTA2 mRNA was 1.01±0.13,0.24±0.04,and 0.22±0.07;the mRNA expression level of TGF-β1 was 1.00±0.09,0.50±0.10,and 0.49±0.15.The relative expression levels of p-Smad3/Smad3 proteins were 0.86±0.06,0.66±0.06,0.55±0.13,0.43±0.09,0.35±0.06,and 0.27±0.12,respectively,after time-related treatment with high-dose tangerine peel polysaccharides.The above indicators in medium-and high-dose tangerine peel polysaccharide groups showed statistically significant differences compared to those in the blank control group(P＜0.05).Conclusion Tangerine peel polysaccharides can inhibit the cell proliferation and the synthesis of keloid-related genes on fibroblasts by inhibiting TGF-β1/Smad3 signaling pathway.

Objective To evaluate the effects of transcatheter aortic valve replacement(TAVR)on left ventricular reverse remodeling(LVRR)and outcomes in patients with mixed aortic valve disease(MAVD)and predominant aortic stenosis(AS).Methods Patients undergoing TAVR at our center between January 2020 and December 2022 were enrolled consecutively.Propensity score matching(PSM)(1∶1 ratio)was used to reduce selection bias.Transthoracic echocardiography(TTE)was used to monitor left ventricular ejection fraction(LVEF)and other structural parameters over time.The study outcome was a composite of cardiovascular death and rehospitalization due to cardiovascular causes.Linear mixed-effects models and logistic regression were utilized for comparing echocardiographic changes across groups and identifying independent risk factors for no-LVRR,respectively.Results After PSM,126 patients were included.MAVD group exhibited larger structural parameters(left ventricular end-systolic/end-diastolic diameter and volume,left ventricular mass index)and a lower left ventricular ejection fraction(LVEF)(all P＜0.05).However,more pronounced improvements in left ventricular structure and hemodynamics were observed during follow-up.Multivariate logistic regression analysis indicated that the left ventricular mass index(LVMI)was an independent predictor of left ventricular reverse remodeling(LVRR)after TAVR,whereas persistent moderate or greater mitral regurgitation(MR)and paravalvular leak(PVL)significantly reduced the incidence of LVRR.During a median follow-up period of 23 months,a total of 31 endpoint events occurred,and there was no statistically significant difference in long-term prognosis between the two groups(Log-rank P=0.330).Conclusions Compared to patients in the AS group,those in the MAVD group exhibited more severe left ventricular remodeling before TAVR.However,more significant LVRR was observed during postoperative follow-up.Additionally,the long-term prognosis was comparable between the two groups.

Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.

Ubiquitination, a diverse post-translational modification, is carried out by enzymes including E1-activating enzymes, E2-conjugating enzymes, E3 ligases, and deubiquitinating enzymes (DUBs). Ubiquitin itself possesses 7 lysine residues and N-terminal methionine, allowing for the formation of polyubiquitin chains with different lengths and linkages. These chains exhibit various topologies that can be recognized by proteins containing ubiquitin-binding domain, thereby transmitting distinct cellular signals. To unravel the physiological mechanisms associated with ubiquitin, numerous ubiquitin probes have been developed. This review provides an overview of recent advancements in the field of ubiquitin probes, focusing on activity-based and affinity-based probes. Activity-based probes are designed to covalently bind to DUBs, E1s, or E3s, enabling the identification and characterization of these enzymes. Affinity-based probes, on the other hand, selectively bind to ubiquitin-binding domains, facilitating the identification of proteins that interact with ubiquitin. Moreover, this review comprehensively discusses the synthetic methodologies employed for the acquisition of ubiquitin probes. These includes meticulous discussions on the synthesis of individual monomeric modules, the establishment of isopeptide linkages, as well as the incorporation of reactive functional groups. Additionally, the review explores the emerging area of cell-penetrating ubiquitin probes and highlights their latest applications in living cells. These probes incorporate cell-penetrating peptides to enable their internalization into cells, allowing for direct visualization and manipulation of ubiquitin-modified proteins within their native environment. Overall, this review offers insights into the design, synthesis, and applications of ubiquitin probes, highlighting their significance in elucidating ubiquitin-mediated cellular processes.

[Objective] To investigate the role of miR-199a-3p on mouse skin scar fibroblasts and the potential target of miR-199a-3p. [Methods] A mouse skin keloid model was established. The mRNA levels of miR-199a-3p, Smad1 and keloid related genes in keloid tissues and normal skin tissues were detected by Real-time quantitative PCR. C57BL/6 mouse skin fibroblasts were isolated and cultured for the cellular experimental study. miR-199a-3p mimic and Smad1 siRNA matter were transiently transfected into mouse skin fibroblasts by liposome reagent. the interaction between miR-199a-3p and the 3′-UTR of Smad1 was confirmed by the dual luciferase reporter assay. The expressions of Smad1 and keloid-related genes at mRNA and protein levels after transfection of miR-199a-3p mimic were determined. The expressions of Smad1 and keloid-related genes at protein level after transfection of miR-199a-3p mimic and Smad1 siRNA were determined by Western blot assay. [Results] Compared with normal skin tissues, the expressions of Smad1 (t=-4.403, P=0.010) and keloid related genes, Col1a1(t=-3.334, P=0.016), Col3a1(t=-5.927, P=0.001) and ACTA2(t=-3.673, P=0.010), were significantly increased in keloid tissues, while miR-199a-3p (t=7.059, P<0.001) expression was significantly decreased. Over-expression of miR-199a-3p could significantly decrease the expressions of keloid-related genes, Col1a1 (t=5.514, P=0.005), Col3a1 (t=5.132, P=0.014) and ACTA2 (t=4.136, P=0.026), in mouse skin fibroblasts. Moreover, the dual luciferase reporter assay revealed that miR-199a-3p could interact with the 3′-UTR of Smad1. miR-199a-3p was observed to inhibit Smad1 at mRNA expression level (t=3.556, P=0.024), and at the post-transcriptional level (t=3.781, P=0.019). Meanwhile, miR-199a-3p mimic, in parallel to Smad1 siRNA, decreased the expressions of keloid-related genes, Col1a1 (F=18.804; P=0.003, 0.022), Col3a1 (F=33.212; P=0.001, 0.001) and α-SMA (F=10.181; P=0.020, 0.028), and decreased the proliferation of skin fibroblasts (F=18.622; P=<0.001, <0.001). [Conclusion] miR-199a-3p inhibits the formation of keloid by targeting Smad1.