1.Enriching Vitamin C in Tomato Fruits by CRISPR/Cas9-Mediated SlCSN5B Gene Editing
Xuan-Sen AN ; Yan-Wei WANG ; Wen-Chao TIAN ; Ya-Juan REN ; Peng-Fei AI
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):460-469
Subunit 5B of constitutively photomorphogenic 9 signalosome(CSN5B)is an inhibitory factor for the biosynthesis of vitamin C in the L-galactose synthesis pathway in plants.To create mutants with richer vitamin C in tomato fruits,a dual-target vector of pKSE402-SlCSN5Bwas constructed and trans-formed into the breeding parent of 1912.Based on the molecular biological assay and DNA sequencing,17 transgenic positive lines were determined,and 6 lines of them were genetically mutated at the target site of SlCSN5B,with an editing efficiency of 35.3%.Among the mutants,2 lines were homozygous mu-tants,csn5b-6 with 180 bp deletion and csn5b-8 with 3 bp deletion.The biological traits of two types of deficiency homozygotes without exogenous T-DNA insertion derived from the T1 generation were observed,and there were no significant differences in phenotypes of the plant and fruit.Through physiological tes-ting of red-ripe fruits from T,generation lines of csn5b-6,the GMPase activity and the vitamin C content significantly increased by 43%and 37.8%,respectively,the content of hydrogen peroxide significantly decreased by 25.9%,and the content of soluble solids did not obviously change,compared with the wild type.There were no significant differences in plant traits and physiological characteristics between T1 gen-eration lines of csn5b-8 and the wild type.Based on gene expression analysis and protein structure predic-tion,the results showed that the gene of SlCSN5B normally transcribed,and the loss of large peptide seg-ments of CSN5B encoded by SlCSN5B caused changes in its structure to affect functioning,which led to an increase of vitamin C content in the line of csn5b-6-1 1.The findings suggest that the vitamin C content of tomato fruit can be improved by CRISPR/Cas9-mediated SlCSN5B gene editing,which provides the valuable resources for high-quality breeding in tomato.
2.Enriching Vitamin C in Tomato Fruits by CRISPR/Cas9-Mediated SlCSN5B Gene Editing
Xuan-Sen AN ; Yan-Wei WANG ; Wen-Chao TIAN ; Ya-Juan REN ; Peng-Fei AI
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):460-469
Subunit 5B of constitutively photomorphogenic 9 signalosome(CSN5B)is an inhibitory factor for the biosynthesis of vitamin C in the L-galactose synthesis pathway in plants.To create mutants with richer vitamin C in tomato fruits,a dual-target vector of pKSE402-SlCSN5Bwas constructed and trans-formed into the breeding parent of 1912.Based on the molecular biological assay and DNA sequencing,17 transgenic positive lines were determined,and 6 lines of them were genetically mutated at the target site of SlCSN5B,with an editing efficiency of 35.3%.Among the mutants,2 lines were homozygous mu-tants,csn5b-6 with 180 bp deletion and csn5b-8 with 3 bp deletion.The biological traits of two types of deficiency homozygotes without exogenous T-DNA insertion derived from the T1 generation were observed,and there were no significant differences in phenotypes of the plant and fruit.Through physiological tes-ting of red-ripe fruits from T,generation lines of csn5b-6,the GMPase activity and the vitamin C content significantly increased by 43%and 37.8%,respectively,the content of hydrogen peroxide significantly decreased by 25.9%,and the content of soluble solids did not obviously change,compared with the wild type.There were no significant differences in plant traits and physiological characteristics between T1 gen-eration lines of csn5b-8 and the wild type.Based on gene expression analysis and protein structure predic-tion,the results showed that the gene of SlCSN5B normally transcribed,and the loss of large peptide seg-ments of CSN5B encoded by SlCSN5B caused changes in its structure to affect functioning,which led to an increase of vitamin C content in the line of csn5b-6-1 1.The findings suggest that the vitamin C content of tomato fruit can be improved by CRISPR/Cas9-mediated SlCSN5B gene editing,which provides the valuable resources for high-quality breeding in tomato.
3.Expert consensus on visualized tele-round and quality control management based on the improvement of clinical practice ability
Wanhong YIN ; Xiaoting WANG ; Ran ZHOU ; Dawei LIU ; Yan KANG ; Yaoqing TANG ; Xiaochun MA ; Jianguo LI ; Zhenjie HU ; Haitao ZHANG ; Wei HE ; Lixia LIU ; Wenjin CHEN ; Ran ZHU ; Jun WU ; Hongmin ZHANG ; Lina ZHANG ; Wenzhao CHAI ; Shihong ZHU ; Wangbin XU ; Rongqing SUN ; Xiangyou YU ; Tianjiao SONG ; Ying ZHU ; Hong REN ; Ai SHANMU ; Qing ZHANG ; Wei FANG ; Xiuling SHANG ; Liwen LYU ; Shuhan CAI ; Xin DING ; Heng ZHANG ; Guang FENG ; Lipeng ZHANG ; Bo HU ; Dong ZHANG ; Weidong WU ; Feng SHEN ; Xiaojun YANG ; Zhenguo ZENG ; Qibing HUANG ; Xueying ZENG ; Tongjuan ZOU ; Milin PENG ; Yulong YAO ; Mingming CHEN ; Hui LIAN ; Jingmei WANG ; Yong LI ; Feng QU ; Gang YE ; Rongli YANG ; Xiukai CHEN ; Suwei LI ; Juxiang WANG ; Yangong CHAO
Chinese Journal of Internal Medicine 2025;64(2):101-109
Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.
4.Dimethyloxalylglycine improves functional recovery through inhibiting cell apoptosis and enhancing blood-spinal cord barrier repair after spinal cord injury.
Wen HAN ; Chao-Chao DING ; Jie WEI ; Dan-Dan DAI ; Nan WANG ; Jian-Min REN ; Hai-Lin CHEN ; Ling XIE
Chinese Journal of Traumatology 2025;28(5):361-369
PURPOSE:
The secondary damage of spinal cord injury (SCI) starts from the collapse of the blood spinal cord barrier (BSCB) to chronic and devastating neurological deficits. Thereby, the retention of the integrity and permeability of BSCB is well-recognized as one of the major therapies to promote functional recovery after SCI. Previous studies have demonstrated that activation of hypoxia inducible factor-1α (HIF-1α) provides anti-apoptosis and neuroprotection in SCI. Endogenous HIF-1α, rapidly degraded by prolylhydroxylase, is insufficient for promoting functional recovery. Dimethyloxalylglycine (DMOG), a highly selective inhibitor of prolylhydroxylase, has been reported to have a positive effect on axon regeneration. However, the roles and underlying mechanisms of DMOG in BSCB restoration remain unclear. Herein, we aim to investigate pathological changes of BSCB restoration in rats with SCI treated by DOMG and evaluate the therapeutic effects of DMOG.
METHODS:
The work was performed from 2022 to 2023. In this study, Allen's impact model and human umbilical vein endothelial cells were employed to explore the mechanism of DMOG. In the phenotypic validation experiment, the rats were randomly divided into 3 groups: sham group, SCI group, and SCI + DMOG group (10 rats for each). Histological analysis via Nissl staining, Basso-Beattie-Bresnahan scale, and footprint analysis was used to evaluate the functional recovery after SCI. Western blotting, TUNEL assay, and immunofluorescence staining were employed to exhibit levels of tight junction and adhesion junction of BSCB, HIF-1α, cell apoptosis, and endoplasmic reticulum (ER) stress. The one-way ANOVA test was used for statistical analysis. The difference was considered statistically significant at p < 0.05.
RESULTS:
In this study, we observed the expression of HIF-1α reduced in the SCI model. DMOG treatment remarkably augmented HIF-1α level, alleviated endothelial cells apoptosis and disruption of BSCB, and enhanced functional recovery post-SCI. Besides, the administration of DMOG offset the activation of ER stress induced by SCI, but this phenomenon was blocked by tunicamycin (an ER stress activator). Finally, we disclosed that DMOG maintained the integrity and permeability of BSCB by inhibiting ER stress, and inhibition of HIF-1α erased the protection from DMOG.
CONCLUSIONS
Our findings illustrate that the administration of DMOG alleviates the devastation of BSCB and HIF-1α-induced inhibition of ER stress.
Spinal Cord Injuries/pathology*
;
Animals
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Apoptosis/drug effects*
;
Amino Acids, Dicarboxylic/therapeutic use*
;
Recovery of Function/drug effects*
;
Rats
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Rats, Sprague-Dawley
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Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
;
Male
;
Spinal Cord/blood supply*
5.Quercetin Confers Protection against Sepsis-Related Acute Respiratory Distress Syndrome by Suppressing ROS/p38 MAPK Pathway.
Wei-Chao DING ; Juan CHEN ; Quan LI ; Yi REN ; Meng-Meng WANG ; Wei ZHANG ; Xiao-Hang JI ; Xin-Yao WU ; Shi-Nan NIE ; Chang-Bao HUANG ; Zhao-Rui SUN
Chinese journal of integrative medicine 2025;31(11):1011-1020
OBJECTIVE:
To identify the underlying mechanism by which quercetin (Que) alleviates sepsis-related acute respiratory distress syndrome (ARDS).
METHODS:
In vivo, C57BL/6 mice were assigned to sham, cecal ligation and puncture (CLP), and CLP+Que (50 mg/kg) groups (n=15 per group) by using a random number table. The sepsisrelated ARDS mouse model was established using the CLP method. In vitro, the murine alveolar macrophages (MH-S) cells were classified into control, lipopolysaccharide (LPS), LPS+Que (10 μmol/L), and LPS+Que+acetylcysteine (NAC, 5 mmol/L) groups. The effect of Que on oxidative stress, inflammation, and apoptosis in mice lungs and MH-S cells was determined, and the mechanism with reactive oxygen species (ROS)/p38 mitogen-activated protein kinase (MAPK) pathway was also explored both in vivo and in vitro.
RESULTS:
Que alleviated lung injury in mice, as reflected by a reversal of pulmonary histopathologic changes as well as a reduction in lung wet/dry weight ratio and neutrophil infiltration (P<0.05 or P<0.01). Additionally, Que improved the survival rate and relieved gas exchange impairment in mice (P<0.01). Que treatment also remarkedly reduced malondialdehyde formation, superoxide dismutase and catalase depletion, and cell apoptosis both in vivo and in vitro (P<0.05 or P<0.01). Moreover, Que treatment diminished the release of inflammatory factors interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 both in vivo and in vitro (P<0.05 or P<0.01). Mechanistic investigation clarifified that Que administration led to a decline in the phosphorylation of p38 MAPK in addition to the suppression of ROS expression (P<0.01). Furthermore, in LPS-induced MH-S cells, ROS inhibitor NAC further inhibited ROS/p38 MAPK pathway, as well as oxidative stress, inflammation, and cell apoptosis on the basis of Que treatment (P<0.05 or P<0.01).
CONCLUSION
Que was found to exert anti-oxidative, anti-inflammatory, and anti-apoptotic effects by suppressing the ROS/p38 MAPK pathway, thereby conferring protection for mice against sepsis-related ARDS.
Animals
;
Sepsis/drug therapy*
;
Quercetin/therapeutic use*
;
Respiratory Distress Syndrome/enzymology*
;
p38 Mitogen-Activated Protein Kinases/metabolism*
;
Mice, Inbred C57BL
;
Reactive Oxygen Species/metabolism*
;
Apoptosis/drug effects*
;
Male
;
Oxidative Stress/drug effects*
;
MAP Kinase Signaling System/drug effects*
;
Lung/drug effects*
;
Mice
;
Lipopolysaccharides
;
Macrophages, Alveolar/pathology*
;
Inflammation/pathology*
;
Protective Agents/therapeutic use*
6.Expert consensus on visualized tele-round and quality control management based on the improvement of clinical practice ability
Wanhong YIN ; Xiaoting WANG ; Ran ZHOU ; Dawei LIU ; Yan KANG ; Yaoqing TANG ; Xiaochun MA ; Jianguo LI ; Zhenjie HU ; Haitao ZHANG ; Wei HE ; Lixia LIU ; Wenjin CHEN ; Ran ZHU ; Jun WU ; Hongmin ZHANG ; Lina ZHANG ; Wenzhao CHAI ; Shihong ZHU ; Wangbin XU ; Rongqing SUN ; Xiangyou YU ; Tianjiao SONG ; Ying ZHU ; Hong REN ; Ai SHANMU ; Qing ZHANG ; Wei FANG ; Xiuling SHANG ; Liwen LYU ; Shuhan CAI ; Xin DING ; Heng ZHANG ; Guang FENG ; Lipeng ZHANG ; Bo HU ; Dong ZHANG ; Weidong WU ; Feng SHEN ; Xiaojun YANG ; Zhenguo ZENG ; Qibing HUANG ; Xueying ZENG ; Tongjuan ZOU ; Milin PENG ; Yulong YAO ; Mingming CHEN ; Hui LIAN ; Jingmei WANG ; Yong LI ; Feng QU ; Gang YE ; Rongli YANG ; Xiukai CHEN ; Suwei LI ; Juxiang WANG ; Yangong CHAO
Chinese Journal of Internal Medicine 2025;64(2):101-109
Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.
7.Micro-segmention analysis of 20 benzodiazepines in multiple hairs and case application
Linxi XIE ; Dingchang XUE ; Zhaochen GUO ; Fei REN ; Jing LI ; Keming YUN ; Zhiwen WEI ; Chao ZHANG ; Guobin XIN
Chinese Journal of Forensic Medicine 2024;39(6):717-723
Objective To establish an analytical method of LC-MS/MS based on micro-segmentation analysis of multiple hairs,verify the detection of 20 benzodiazepines in 1mm hair,and finally use it for case detection analysis.Methods 5 hairs were cut into 1mm long segments each,and the corresponding segments were immersed and sonicated in an extract containing dithiothreitol,methanol,etc.Mobile phase A was 0.1%formic acid in water,and mobile phase B was acetonitrile.Data were collected using electrospray ion source positive ion mode in multiple reaction monitoring mode.Results The 20 benzodiazepines in multiple hairs had a good linear relationship(r>0.99),detection limit of 0.2~5 pg/mm,minimum quantification limit of 0.5 to 20 pg/mm,the intro-day and inter-day precisions of 2.03%to 13.81%,the intro-day and inter-day accuracies of 87.98%~111.29%,matrix effect of 71.15%~110.43%,and extraction recovery of 69.34%to 99.94%.Using this method,hair samples were analyzed in volunteers taking a single dose of clonazepam for 20 days,and the detected location of clonazepam in 15 hairs was located in segment 6~11 from the hair root,with the concentration range of 1.06~3.45 pg/mm.By this method,the hair of the victims suspected of having taken sleeping pills in the case was analyzed.In 15 hairs,clonazepam was detected in segments 9~13 of the hair root.The quantitative results were 1.07~19.06 pg/mm.The experimental results were basically consistent with the medication time of the victim.Conclusion The micro-segmentation analysis technique of multiple hairs can be applied to the investigation of drug-assisted crime cases,and can roughly estimate the medication time.
8.Antimicrobial resistance profile of clinical isolates in hospitals across China:report from the CHINET Antimicrobial Resistance Surveillance Program,2023
Yan GUO ; Fupin HU ; Demei ZHU ; Fu WANG ; Xiaofei JIANG ; Yingchun XU ; Xiaojiang ZHANG ; Fengbo ZHANG ; Ping JI ; Yi XIE ; Yuling XIAO ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Jingyong SUN ; Qing CHEN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yunmin XU ; Sufang GUO ; Yanyan WANG ; Lianhua WEI ; Keke LI ; Hong ZHANG ; Fen PAN ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Wei LI ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Qian SUN ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanqing ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Hua FANG ; Penghui ZHANG ; Bixia YU ; Ping GONG ; Haixia SHI ; Kaizhen WEN ; Yirong ZHANG ; Xiuli YANG ; Yiqin ZHAO ; Longfeng LIAO ; Jinhua WU ; Hongqin GU ; Lin JIANG ; Meifang HU ; Wen HE ; Jiao FENG ; Lingling YOU ; Dongmei WANG ; Dong'e WANG ; Yanyan LIU ; Yong AN ; Wenhui HUANG ; Juan LI ; Quangui SHI ; Juan YANG ; Abulimiti REZIWAGULI ; Lili HUANG ; Xuejun SHAO ; Xiaoyan REN ; Dong LI ; Qun ZHANG ; Xue CHEN ; Rihai LI ; Jieli XU ; Kaijie GAO ; Lu XU ; Lin LIN ; Zhuo ZHANG ; Jianlong LIU ; Min FU ; Yinghui GUO ; Wenchao ZHANG ; Zengguo WANG ; Kai JIA ; Yun XIA ; Shan SUN ; Huimin YANG ; Yan MIAO ; Jianping WANG ; Mingming ZHOU ; Shihai ZHANG ; Hongjuan LIU ; Nan CHEN ; Chan LI ; Cunshan KOU ; Shunhong XUE ; Jilu SHEN ; Wanqi MEN ; Peng WANG ; Xiaowei ZHANG ; Xiaoyan ZENG ; Wen LI ; Yan GENG ; Zeshi LIU
Chinese Journal of Infection and Chemotherapy 2024;24(6):627-637
Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0% were gram-positive and 71.0% were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6%,81.9% and 78.5%,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9% of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4% of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1% in the isolates from children and and 95.9% in the isolates from adults.The resistance rate to carbapenems was lower than 15.0% for most Enterobacterales species except for Klebsiella,22.5% and 23.6% of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6% to 10.0%.The resistance rate to imipenem and meropenem was 21.9% and 17.4% for Pseudomonas aeruginosa,respectively,and 67.5% and 68.1% for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.
9.Surveillance of bacterial resistance in tertiary hospitals across China:results of CHINET Antimicrobial Resistance Surveillance Program in 2022
Yan GUO ; Fupin HU ; Demei ZHU ; Fu WANG ; Xiaofei JIANG ; Yingchun XU ; Xiaojiang ZHANG ; Fengbo ZHANG ; Ping JI ; Yi XIE ; Yuling XIAO ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Jingyong SUN ; Qing CHEN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yunmin XU ; Sufang GUO ; Yanyan WANG ; Lianhua WEI ; Keke LI ; Hong ZHANG ; Fen PAN ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Wei LI ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Qian SUN ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanqing ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Wenhui HUANG ; Juan LI ; Quangui SHI ; Juan YANG ; Abulimiti REZIWAGULI ; Lili HUANG ; Xuejun SHAO ; Xiaoyan REN ; Dong LI ; Qun ZHANG ; Xue CHEN ; Rihai LI ; Jieli XU ; Kaijie GAO ; Lu XU ; Lin LIN ; Zhuo ZHANG ; Jianlong LIU ; Min FU ; Yinghui GUO ; Wenchao ZHANG ; Zengguo WANG ; Kai JIA ; Yun XIA ; Shan SUN ; Huimin YANG ; Yan MIAO ; Mingming ZHOU ; Shihai ZHANG ; Hongjuan LIU ; Nan CHEN ; Chan LI ; Jilu SHEN ; Wanqi MEN ; Peng WANG ; Xiaowei ZHANG ; Yanyan LIU ; Yong AN
Chinese Journal of Infection and Chemotherapy 2024;24(3):277-286
Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5%were gram-positive and 70.5%were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3%,76.7%and 77.9%,respectively.Overall,94.0%of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8%of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2%in the isolates from children and 95.7%in the isolates from adults.The resistance rate to carbapenems was lower than 13.1%in most Enterobacterales species except for Klebsiella,21.7%-23.1%of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1%to 13.3%.The prevalence of meropenem-resistant strains decreased from 23.5%in 2019 to 18.0%in 2022 in Pseudomonas aeruginosa,and decreased from 79.0%in 2019 to 72.5%in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.
10.Effect of quercetin on Erastin-induced ferroptosis in chondrocytes
Hao WANG ; Fu-Li ZHOU ; Ren-Di ZHU ; Ying-Jie ZHAO ; Ren-Peng ZHOU ; Wei HU ; Chao LU
Chinese Pharmacological Bulletin 2024;40(10):1945-1952
Aim To explore the effect of quercetin(Que)on ferroptosis and the potential mechanisms in an Erastin-induced ferroptosis model in chondrocytes.Methods A model of Erastin-induced ferroptosis was established in C28/I2 chondrocytes.Cells were treated with different concentrations of Que.Cell viability and cytotoxicity were assessed by MTT and LDH assays.The expression levels of Prdx6 and ferroptosis-related proteins ACSL4 and GPX4 in chondrocytes were deter-mined by Western blot.Lipid ROS production in chon-drocytes was measured by flow cytometry,while the changes in mitochondrial membrane potential were de-tected by RH123 staining.Prdx6 mRNA expression in chondrocytes was quantified by RT-qPCR.The chan-ges in the expression of the ferroptosis-related proteins ACSL4 and GPX4 were detected by immunofluores-cence staining.Results Compared to the Erastin-in-duced ferroptosis model group,Que significantly im-proved the viability of C28/I2 chondrocytes and re-duced cell cytotoxicity.It decreased the expression of the ferroptosis-related protein ACSL4 and increased the expression of GPX4.Que also inhibited the production of lipid ROS in chondrocytes and strengthened their mitochondrial membrane potential.In addition,the ex-pression of Prdx6 was significantly reduced in the Eras-tin group compared to the control group,while Que treatment upregulated the expression of Prdx6.Mean-while,the inhibitory effect of Que on chondrocyte fer-roptosis was reduced by the use of MJ33,an inhibitor of Prdx6.Conclusion Que can inhibit Erastin-induced ferroptosis of C28/I2 chondrocytes,possibly by upregu-lating Prdx6,and thus play a protective role in chon-drocytes.

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