1.Identification of autoinducer-2 in Streptococcus mutans membrane vesicles and effect of membrane vesicles on biofilm formation
TU Ye ; HUANG Zhengwei ; CHEN Zhanyi ; NIU Chenguang
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(2):119-128
Objective:
To investigate whether membrane vesicles (MVs) of Streptococcus mutans (S.mutans) contain autoinducer-2 (AI-2) and to preliminarily explore the effects of these MVs on the growth and biofilm formation of S. mutans.
Methods:
MVs were isolated from the S. mutans UA159 strain using differential centrifugation. The isolated MVs were characterized by nanoparticle tracking analysis for particle size and concentration and observed by transmission electron microscopy. The presence of AI-2 was identified using the Vibrio harveyi BB170 bioluminescence assay: the BB170 diluent was supplemented with AB medium (control group), MV extract (MVs group), pre-ultrafiltration supernatant (Sup group), or post-ultrafiltration supernatant (Sup-af group). The effects of MVs on growth and biofilm formation were assessed using the S.mutans UA159 strain or a luxS deletion mutant as the control group, compared with experimental groups stimulated with gradient concentrations of MVs (MVs-2.0E+7, MVs-2.0E+8, and MVs-2.0E+9 groups). Growth curves, MTT assay, and colony-forming unit (CFU) counts were used to determine changes in growth capacity. Biofilm formation was evaluated using crystal violet staining, confocal laser scanning microscopy, and the anthrone method for polysaccharide quantification.
Results:
Enriched S. mutans MVs were successfully obtained, with an average particle size of approximately 94.19 nm and a concentration of 1.87E+11 particles/mL. The bioluminescence assay showed that the luminescence intensity of the Sup group was higher than that of the Sup-af group, and the MVs group exhibited higher intensity than the control group. Assessments via growth curves, MTT assay, and CFU counts indicated no significant differences in the growth capacity of the various S. mutans strains after treatment with different concentrations of MVs. Crystal violet staining quantification and confocal laser scanning microscopy observations revealed that high-concentration MV treatment (2.0E+9 particles/mL group) resulted in lower biofilm mass compared to the control. The anthrone method showed that the production of both water-soluble and water-insoluble polysaccharides was significantly lower in the high-concentration MV group than in the control.
Conclusion
S. mutans MVs contain the quorum sensing signal molecule AI-2. These MVs do not significantly affect the growth of S. mutans, but they can regulate biofilm formation and exhibit an inhibitory effect at high concentrations.
2.Osteomodulin modulates the inflammatory responses via the interleukin-1 receptor 1/nuclear factor-κB signaling pathway in dental pulpitis.
Yueyi YANG ; Xuchen HU ; Meiling JING ; Xiaohan ZHU ; Xiaoyu LIU ; Wenduo TAN ; Zhanyi CHEN ; Chenguang NIU ; Zhengwei HUANG
International Journal of Oral Science 2025;17(1):41-41
Pulpitis is a common infective oral disease in clinical situations. The regulatory mechanisms of immune defense in pulpitis are still being investigated. Osteomodulin (OMD) is a small leucine-rich proteoglycan family member distributed in bones and teeth. It is a bioactive protein that promotes osteogenesis and suppresses the apoptosis of human dental pulp stem cells (hDPSCs). In this study, the role of OMD in pulpitis and the OMD-induced regulatory mechanism were investigated. The OMD expression in normal and inflamed human pulp tissues was detected via immunofluorescence staining. Intriguingly, the OMD expression decreased in the inflammatory infiltration area of pulpitis specimens. The cellular experiments demonstrated that recombined human OMD could resist the detrimental effects of lipopolysaccharide (LPS)-induced inflammation. A conditional Omd knockout mouse model with pulpal inflammation was established. LPS-induced inflammatory impairment significantly increased in conditional Omd knockout mice, whereas OMD administration exhibited a protective effect against pulpitis. Mechanistically, the transcriptome alterations of OMD overexpression showed significant enrichment in the nuclear factor-κB (NF-κB) signaling pathway. Interleukin-1 receptor 1 (IL1R1), a vital membrane receptor activating the NF-κB pathway, was significantly downregulated in OMD-overexpressing hDPSCs. Additionally, the interaction between OMD and IL1R1 was verified using co-immunoprecipitation and molecular docking. In vivo, excessive pulpal inflammation in Omd-deficient mice was rescued using an IL1R antagonist. Overall, OMD played a protective role in the inflammatory response via the IL1R1/NF-κB signaling pathway. OMD may optimize the immunomodulatory functions of hDPSCs and can be used for regenerative endodontics.
Pulpitis/metabolism*
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NF-kappa B/metabolism*
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Animals
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Signal Transduction
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Humans
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Mice
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Mice, Knockout
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Dental Pulp/metabolism*
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Disease Models, Animal
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Lipopolysaccharides
3.Two decomposition algorithms of dual-energy cone beam CT and their dependence on the phantom sizes
Chenguang LI ; Tianye NIU ; Li ZHOU ; Jun DENG ; Chengyuan ZOU ; Sha LI ; Hongjia LIU ; Zhengkun DONG ; Ling HUA ; Yichen PU ; Liangzi QU ; Qiao LI ; Yibao ZHANG
Chinese Journal of Radiological Medicine and Protection 2022;42(4):269-276
Objective:To analyze the effects of two decomposition algorithms of dual-energy cone beam CT (DECBCT) (direct decomposition and iterative decomposition) on the image quality and material decomposition accuracy of different sizes of phantoms.Methods:Different sizes of imaging parts of patients were simulated using the combination of CatPhan604 phantoms and customized annuluses. CBCT with high energy of 140 kVp and low energy of 100 kVp were acquired using the Varian Edge CBCT system. Then the material decomposition of DECBCT images was performed using the two algorithms. The electron density (ED) and contrast-to-noise ratio (CNR) of each material in the CTP682 module were calculated. They were used to assess the decomposition accuracy and image quality of the two algorithms.Results:Based on the values in the Catphan604 manual, both algorithms have high ED accuracy. Only the ED accuracy of four materials of the smallest sized phantom showed statistical difference ( z = -4.21, 4.30, 2.87, 5.45, P < 0.05), but the average relative error was less than 1%. The CNR of the iterative decomposition algorithm was significantly higher than that of the direct decomposition, increasing by 51.8%-703.47%. The increase in the phantom size significantly reduced the accuracy of ED, and the increased amplitude of the relative error was up to a maximum of 2.52%. The large phantom size also reduced the image quality of iterative decomposition, and the decreased amplitude of CNR was up to a maximum of 39.71. Conclusions:Compared with the direct decomposition, the iterative decomposition algorithm can significantly reduce the image noise and improve the contrast without losing the accuracy of electron density in the DECBCT construction of different sizes of phantoms.
4.Development of a predictive model of pulmonary hemorrhage in patients after CT-guided coaxial core needle lung biopsy
Linyun YANG ; Ting LIANG ; Yonghao DU ; Chenguang GUO ; Jin SHANG ; Pokharel SAUGAT ; Gang NIU
Journal of Xi'an Jiaotong University(Medical Sciences) 2021;42(5):747-754
【Objective】 To establish a predictive model for patients with hemorrhage after CT-guided coaxial core needle lung biopsy (CCNB) based on logistic regression. 【Methods】 A total of 489 patients who had undergone CCNB were retrospectively recruited. The potential risk factors of hemorrhage after lung biopsy were analyzed by univariate and multivariate logistic regression, through which we screened the independent risk factors and established a prediction model for hemorrhage. We evaluated the discrimination, calibration and clinical usefulness of the model. 【Results】 There were 141 cases (42.6%) of hemorrhage in the development group and 66 cases (41.8%) of hemorrhage in the validation group; there was no case of severe hemorrhage or hemothorax. Multivariate logistic regression analysis showed that fibrinogen degradation products, pulmonary interstitial fibrosis, largest diameter and puncture depth were independent predictive factors of hemorrhage. Hemorrhage prediction model was established and presented in the form of a nomogram. Discrimination of the model: the AUC was 0.837 in the development group and 0.777 in the validation group. The calibration curve showed good agreement between predicted probability and actual probability of hemorrhage. The unreliability test yielded a P value of 0.849 in the development group and 0.147 in the validation group. The DCA curve showed that the hemorrhage predictive model could increase the benefit of patients. 【Conclusion】 The predictive model of hemorrhage in patients after CCNB based on logistic regression can be used in clinical practice.
5.Nasal feeding nutritional tube capable of carrying 125I particles: its preparation and preliminary clinical application
Dechao JIAO ; Chenguang PANG ; Xinwei HAN ; Rongfang NIU ; Zongming LI ; Ming ZHU ; Huibin LU
Journal of Interventional Radiology 2017;26(11):1004-1008
Objective To design a kind of nasal feeding nutritional tube that can carry 125I particles,to use this tube for the treatment of upper digestive tract malignant occlusive disease in order to achieve double effect of nasal feeding nutrition and brachytherapy.Methods 125I particles were put into a 3F catheter,then both ends of the catheter were sealed off to make 125I particle chain.By using binding technology,the 125I particle chain was fixed on the nasal feeding tube.Under DSA guidance,the nasal feeding tube carrying 125I particle chain was inserted into the esophagus,with the 125I particle chain segment crossing over the section of esophageal stenosis or occlusion to conduct brachytherapy.This technique was employed in 6 patients with advanced esophageal carcinoma.The technical success rate,operation time and complications were recorded.Two months after the treatment,the Karnofsky score,visual analogue scale (VAS) pain score,Neuhaus dysphagia grading,esophagus patency on esophageal radiography,and local tumor control rate were determined.Results The preparation of nasal feeding nutritional tube carrying 125I particle chain was simple.The technical success rate was 100%,the mean operation time was 15.5 min,no serious complications such as bleeding or infection occurred.Two months after the treatment,the Karnofsky score,VAS pain score and Neuhaus dysphagia grading were significantly improved when compared with the preoperative data (P<0.O1).On esophageal radiography,the contrast agent passed through the narrow area smoothly.Partial remission (PR) of local tumor was obtained in all patients,and the local tumor control rate was 100%.The patients were followed up for 2-6 months,one patient developed recurrent obstruction.Conclusion It is simple and easy to prepare a nasal feeding nutritional tube carrying 125I particle chain,the use of this kind of tube can achieve both parenteral nutrition and brachytherapy at the same time.Therefore,this technique opens a new way for the treatment of esophageal malignant tumor.
6.Application of optic coherent tomography in assessing visual performance of idiopathic macular epiretinal membrane patients
Bin MENG ; Ang JI ; Hongxia NIU ; Lijuan YAN ; Xu CHEN ; Ying PENG ; Chenguang ZHANG
Tianjin Medical Journal 2016;44(7):884-886,887
Objective To investigate the correlation between retinal deformation degree and retina thickness (RT) detected by optic coherent tomography (OTC) in patients with idiopathic macular epiretinal membrane (IMEM). Methods The 66 eyes (56 patients) with IMEM diagnosed by OCT were retrospectively analyzed in this study. After best corrected visual acuity (BCVA), ocular fundus and OCT examination, patients were divided into three groups (mild, medium and severe) according to retinal deformation degrees. The RT value was measured manually. Results There were significant differences in RT values between mild, moderate and severe groups:(311.95 ±51.78) μm, (447.13±41.95) μm and (560.00± 58.23) μm (P<0.05). The values of BCVA were 0.78±0.16, 0.38±0.12 and 0.27±0.14 for mild, moderate and severe groups, there were significant differences between them (P<0.05). There was no significant correlation between RT and BCVA in mild group (r=-0.352,P=0.128). There was negative correlation between RT and BCVA in medium group and serious group (r=-0.768 and-0.482,P<0.05). Conclusion The retinal deformation degree and RT are two objective indicators to assess visual performance in patients of IMEM. When RT is more than 400 μm, it can be used as objective criteria for surgical intervention.
7.Study on Effects of Podophyllotoxin Derivative QW-83 on Human Cervical Cancer HeLa Cell Apoptosis and Its Mechanism
Ling LENG ; Chenguang GAO ; Hong CHEN ; Cong NIU ; Bo CAO
China Pharmacy 2016;27(7):892-895
OBJECTIVE:To study the effects of podophyllotoxin derivative QW-83 on human cervical cancer HeLa cell apopto-sis and its mechanism. METHODS:After treated with 0(negative control),0.01,0.1,1 and 10 μmol/L QW-83 and positive drug etoposide(VP-16)for 48 h,proliferation inhibition rate and IC50 of HeLa cell were determined by MTT assay. The morphological changes of HeLa cell were observed by Hochest 33342 staining after treated with QW-83 [0(negative control),2.5,5,10μmol/L] for 48 h;flow cytometry was used to detect apoptosis rate;semi quantitative RT-PCR was adopted to detect the expression of apop-tosis related gene P53,Bax,Casepase-3,Casepase-8,Casepase-9 and Bcl-2 mRNA. RESULTS:Compared with negative control, 1,10 μmol/L VP-16 and QW-83 had obvious proliferation inhibition effect on HeLa cells (P<0.05 or P<0.01),and IC50 were (5.11±0.43)μmol/L and(4.96±0.54)μmol/L. Hochest 33342 staining results showed QW-83 could obviously induce cells apopto-sis and nuclear pyknosis. Flow cytometry showed QW-83 could increase apoptosis rate in concentration-dependent manner,being 16.89%-62.56%. RT-PCR showed mRNA expression of P53,Bax,Caspase-3,Casepase-8 and Casepase-9,Bcl-2/Bax increased, while mRNA expression of Bcl-2 decreased after treated with QW-83(P<0.05). CONCLUSIONS:Podophyllotoxin derivative QW-83 can induce HeLa cell apoptosis,and its mechanism may be associated with regulate mRNA expression of apoptosis related gene.
8.Compartive study of giant cell tumor in vertebral column with MSCT and 3.0T MRI
Fuye NIU ; Chenguang WANG ; Yanqing MA ; Jiehua ZHANG ; Caiguo XU ; Un YINXUEJ
Journal of Practical Radiology 2015;(1):110-112,120
Objective To study the imaging features of spinal giant cell tumors (GCTs)including multi-slice spiral CT (MSCT) and MRI in order to improve the diagnosis.Methods A retrospective study was conducted in 27 patients with GCTs in the spine at our institute.The data of MSCT and 3.0T MRI were recorded and analyzed.Results Of the 27 patients,4 were found in the cervi-cal spine,12 in the thoracic spine,5 in the lumbar spine and 6 in the sacral spine.Typical imaging features showed eccentric,expan-sive and lytic bone destruction of the involved vertebra.The tumor showed soft-tissue density on CT with inner visible cystic change, necrosis and trabecula remnants in most tumors,without calcification and periosteal reaction.Most lesions showed hypointensity or isointensity on T1 WI and hypointensity,isointersity or heterogeneous high signal on T2 WI.When aneurysmal bone cyst (ABC)was detected,MRI revealed hyperintensity with a fluid-fluid interface.Conclusion Radiographic features of the GCTs in the spine are specific for diagnosis to some extent.CT and MRI may contribute to the accuracy of preoperative diagnosis.The methods have a good value in GCT diagnosis,clinical staging,surgical strategies and postoperative evaluation.
9.The clinical value of 3.0T MRI diffusion weighted imaging in diagnosing active sacroiliitis of ankylosing spondylitis
Fuye NIU ; Yi XIAO ; Weiwei ZOU ; Caiguo XU ; Nxuejun YI ; Chenguang WANG
Journal of Practical Radiology 2015;(4):616-620
Objective To evaluate the value of diffusion weighted imaging (DWI)in diagnosing active sacroiliitis of ankylosing spondylitis(AS)Methods 63 cases with AS confirmed clinically were included.The patients were evaluated by Bath ankylosing spondylitis disease activity index (BASDAI)score and examined by MRI with oblique coronal DWI and STIR sequence in the sacroili-ac joint.The ADC value and Spondyloarthritis Research Consortium of Canada (SPARCC)score were measured in all patients.Cor-relative analysis was performed among BASDAI score,SPARCC score and ADC value.Patients were divided into activity and stability group according to the condition,which were compared with the ADC features of the sacroiliac joint in healthy volunteers.Results The Spearman correlation analysis showed that in patients SPARCC score and ADC values (r =0.781,P <0.001 ),BASDAI score and ADC values (r=0.854,P <0.001),SPARCC score and BASDAI score (r =0.805,P <0.001)were positively correlated.The median ADC values in the sacroiliac joint of activity group (0.704×10 -3 mm2/s)was higher than that in the stable group(0.543× 10 -3 mm2/ s )and the control group (0.431×10 -3 mm2/ s).The ADC values between the activity、stability and control group were statistically significant differences.Conclusion SPARCC score and DWI are important indexes for MRI evaluation of sacroiliac ar-thritis activity.DWI is a fast imaging sequence,can be quantified by measuring the ADC value of the lesion area,and is the ideal choice for sacroiliac joint imaging.
10.The synergistic effect of amygdalin and HSYA on the IL-1beta induced endplate chondrocytes of rat intervertebral discs.
Kai NIU ; Yongjian ZHAO ; Lei ZHANG ; Chenguang LI ; Yongjun WANG ; Weichao ZHENG
Acta Pharmaceutica Sinica 2014;49(8):1136-42
The effect of amygdalin joint hydroxysafflor yellow A (HSYA) on the endplate chondrocytes derived from intervertebral discs of rats induced by IL-1beta and the possible mechanism were studied and explored. Chondrocytes were obtained from endplate of one-month SD rat intervertebral discs and cultured primary endplate chondrocytes. After identification, they were divided into normal group, induced group, amygdalin group, HSYA group and combined group. CCK-8 kit was adopted to detect the proliferation of the endplate chondrocytes. FCM was measured to detect the apoptosis. Real-time PCR method was adopted to observe the mRNA expression of Aggrecan, Col 2 alpha1, Col 10 alpha1, MMP-13 and the inflammatory cytokines IL-1beta. The protein expression of Col II, Col X was tested through immunofluorescence. Compared with the normal group, the proliferation of the endplate chondrocytes decreased while the apoptosis increased (P < 0.05). With down regulation of the mRNA expressions of Aggrecan, Col 2 alpha1 and up regulation of the mRNA expressions of Col 10 alpha1, MMP-13, IL-1beta (P < 0.05), the protein expression of Col II decreased while the protein expression of Col X increased. Compared with the induced group, amygdalin group, HSYA group, the combined group could inhibit the apoptosis and promote the proliferation (P < 0.05). They could increase the mRNA expressions of Aggrecan and Col 2 alpha1 while decrease the mRNA expressions of Col 10 alpha1, MMP-13 and IL-1beta (P < 0.05). They could also enhance the protein expression of Col II while reduce the protein expression of Col X. The effect of the combined group was significantly better than that of amygdalin and HSYA. Amygdalin joint HSYA could inhibit the degeneration of the endplate chondrocytes derived from intervertebral discs of rats induced by IL-1beta and better than the single use of amygdalin or HSYA.


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