1.Mechanism of Naoxintong Capsules in treatment of rats with multiple cerebral infarctions and myocardial injury based on HIF-1α/VEGF pathway.
Xiao-Lu ZHANG ; Jin-Feng SHANG ; Yin-Lian WEN ; Gui-Jin-Feng HUANG ; Bo-Hong WANG ; Wan-Ting WEI ; Wen-Bin CHEN ; Xin LIU
China Journal of Chinese Materia Medica 2025;50(7):1889-1899
This study aims to explore whether Naoxintong Capsules improve multiple cerebral infarctions and myocardial injury via promoting angiogenesis, thereby exerting a simultaneous treatment effect on both the brain and heart. Male SD rats were randomly divided into six groups: sham-operated group, model group, high-dose, medium-dose, and low-dose groups of Naoxintong Capsules(440, 220, and 110 mg·kg~(-1)), and nimodipine group(10.8 mg·kg~(-1)). Rat models of multiple cerebral infarctions were established by injecting autologous thrombus, and samples were collected and tested seven days after modeling. Evaluations included multiple cerebral infarction model assessments, neurological function scores, grip strength tests, and rotarod tests, so as to evaluate neuromotor functions. Morphological structures of brain and heart tissue were observed using hematoxylin-eosin(HE) staining, Nissl staining, and Masson staining. Network pharmacology was employed to screen the mechanisms of Naoxintong Capsules in improving multiple cerebral infarctions and myocardial injury. Neuronal and myocardial cell ultrastructures were observed using transmission electron microscopy. Apoptosis rate in brain neuronal cells was detected by TdT-mediated dUTP nick end labeling(TUNEL) staining, and reactive oxygen species(ROS) levels in myocardial cells were measured. Immunofluorescence was used to detect the expression of platelet endothelial cell adhesion molecule-1(CD31), antigen identified by monoclonal antibody Ki67(Ki67), hematopoietic progenitor cell antigen CD34(CD34), and hypoxia inducible factor-1α(HIF-1α) in brain and myocardial tissue. Western blot, and real-time quantitative polymerase chain reaction(RT-qPCR) were used to detect the expression of HIF-1α, vascular endothelial growth factor(VEGF), vascular endothelial growth factor receptor 2(VEGFR2), sarcoma(Src), basic fibroblast growth factor(bFGF), angiopoietin-1(Ang-1), and TEK receptor tyrosine kinase(Tie-2). Compared with the model group, the medium-dose group of Naoxintong Capsules showed significantly lower neurological function scores, increased grip strength, and prolonged time on the rotarod. Pathological damage in brain and heart tissue was reduced, with increased and more orderly arranged mitochondria in neurons and cardiomyocytes. Apoptosis in brain neuronal cells was decreased, and ROS levels in cardiomyocytes were reduced. The microvascular density and endothelial cells of new blood vessels in brain and heart tissue increased, with increased overlapping regions of CD31 and Ki67 expression. The relative protein and mRNA expression levels of HIF-1α, VEGF, VEGFR2, Src, Ang-1, Tie-2, and bFGF were elevated in brain tissue and myocardial tissue. Naoxintong Capsules may improve multiple cerebral infarctions and myocardial injury by mediating HIF-1α/VEGF expression to promote angiogenesis.
Animals
;
Male
;
Drugs, Chinese Herbal/administration & dosage*
;
Rats, Sprague-Dawley
;
Rats
;
Cerebral Infarction/genetics*
;
Hypoxia-Inducible Factor 1, alpha Subunit/genetics*
;
Vascular Endothelial Growth Factor A/genetics*
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Capsules
;
Signal Transduction/drug effects*
;
Humans
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Brain/metabolism*
;
Myocardium/metabolism*
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Apoptosis/drug effects*
2.Tanreqing Capsules protect lung and gut of mice infected with influenza virus via "lung-gut axis".
Nai-Fan DUAN ; Yuan-Yuan YU ; Yu-Rong HE ; Feng CHEN ; Lin-Qiong ZHOU ; Ya-Lan LI ; Shi-Qi SUN ; Yan XUE ; Xing ZHANG ; Gui-Hua XU ; Yue-Juan ZHENG ; Wei ZHANG
China Journal of Chinese Materia Medica 2025;50(8):2270-2281
This study aims to explore the mechanism of lung and gut protection by Tanreqing Capsules on the mice infected with influenza virus based on "the lung-gut axis". A total of 110 C57BL/6J mice were randomized into control group, model group, oseltamivir group, and low-and high-dose Tanreqing Capsules groups. Ten mice in each group underwent body weight protection experiments, and the remaining 12 mice underwent experiments for mechanism exploration. Mice were infected with influenza virus A/Puerto Rico/08/1934(PR8) via nasal inhalation for the modeling. The lung tissue was collected on day 3 after gavage, and the lung tissue, colon tissue, and feces were collected on day 7 after gavage for subsequent testing. The results showed that Tanreqing Capsules alleviated the body weight reduction and increased the survival rate caused by PR8 infection. Compared with model group, Tanreqing Capsules can alleviate the lung injury by reducing the lung index, alleviating inflammation and edema in the lung tissue, down-regulating viral gene expression at the late stage of infection, reducing the percentage of neutrophils, and increasing the percentage of T cells. Tanreqing Capsules relieved the gut injury by restoring the colon length, increasing intestinal lumen mucin secretion, alleviating intestinal inflammation, and reducing goblet cell destruction. The gut microbiota analysis showed that Tanreqing Capsules increased species diversity compared with model group. At the phylum level, Tanreqing Capsules significantly increased the abundance of Firmicutes and Actinobacteria, while reducing the abundance of Bacteroidota and Proteobacteria to maintain gut microbiota balance. At the genus level, Tanreqing Capsules significantly increased the abundance of unclassified_f_Lachnospiraceae while reducing the abundance of Bacteroides, Eubacterium, and Phocaeicola to maintain gut microbiota balance. In conclusion, Tanreqing Capsules can alleviate mouse lung and gut injury caused by influenza virus infection and restore the balance of gut microbiota. Treating influenza from the lung and gut can provide new ideas for clinical practice.
Animals
;
Drugs, Chinese Herbal/administration & dosage*
;
Mice
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Lung/metabolism*
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Mice, Inbred C57BL
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Capsules
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Orthomyxoviridae Infections/virology*
;
Gastrointestinal Microbiome/drug effects*
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Male
;
Humans
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Female
;
Influenza A virus/physiology*
;
Influenza, Human/virology*
3.Effect and mechanism of Xintong Granules in ameliorating myocardial ischemia-reperfusion injury in rats by regulating gut microbiota.
Yun-Jia WANG ; Ji-Dong ZHOU ; Qiu-Yu SU ; Jing-Chun YAO ; Rui-Qiang SU ; Guo-Fei QIN ; Gui-Min ZHANG ; Hong-Bao LIANG ; Shuai FENG ; Jia-Cheng ZHANG
China Journal of Chinese Materia Medica 2025;50(14):4003-4014
This study investigates the mechanism by which Xintong Granules improve myocardial ischemia-reperfusion injury(MIRI) through the regulation of gut microbiota and their metabolites, specifically short-chain fatty acids(SCFAs). Rats were randomly divided based on body weight into the sham operation group, model group, low-dose Xintong Granules group(1.43 g·kg~(-1)·d~(-1)), medium-dose Xintong Granules group(2.86 g·kg~(-1)·d~(-1)), high-dose Xintong Granules group(5.72 g·kg~(-1)·d~(-1)), and metoprolol group(10 mg·kg~(-1)·d~(-1)). After 14 days of pre-administration, the MIRI rat model was established by ligating the left anterior descending coronary artery. The myocardial infarction area was assessed using the 2,3,5-triphenyltetrazolium chloride(TTC) staining method. Apoptosis in tissue cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL) assay. Pathological changes in myocardial cells and colonic tissue were observed using hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), creatine kinase MB isoenzyme(CK-MB), and cardiac troponin T(cTnT) in rat serum were quantitatively measured using enzyme-linked immunosorbent assay(ELISA) kits. The activities of lactate dehydrogenase(LDH), creatine kinase(CK), and superoxide dismutase(SOD) in myocardial tissue, as well as the level of malondialdehyde(MDA), were determined using colorimetric assays. Gut microbiota composition was analyzed by 16S rDNA sequencing, and fecal SCFAs were quantified using gas chromatography-mass spectrometry(GC-MS). The results show that Xintong Granules significantly reduced the myocardial infarction area, suppressed cardiomyocyte apoptosis, and decreased serum levels of pro-inflammatory cytokines(TNF-α, IL-1β, and IL-6), myocardial injury markers(CK-MB, cTnT, LDH, and CK), and oxidative stress marker MDA. Additionally, Xintong Granules significantly improved intestinal inflammation in MIRI rats, regulated gut microbiota composition and diversity, and increased the levels of SCFAs(acetate, propionate, isobutyrate, etc.). In summary, Xintong Granules effectively alleviate MIRI symptoms. This study preliminarily confirms that Xintong Granules exert their inhibitory effects on MIRI by regulating gut microbiota imbalance and increasing SCFA levels.
Animals
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Gastrointestinal Microbiome/drug effects*
;
Rats
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Male
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Myocardial Reperfusion Injury/genetics*
;
Drugs, Chinese Herbal/administration & dosage*
;
Rats, Sprague-Dawley
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Apoptosis/drug effects*
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Humans
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Tumor Necrosis Factor-alpha/metabolism*
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Interleukin-6/genetics*
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Malondialdehyde/metabolism*
4.Correlation of IGF2 levels with sperm quality, inflammation, and DNA damage in infertile patients.
Jing-Gen WU ; Cai-Ping ZHOU ; Wei-Wei GUI ; Zhong-Yan LIANG ; Feng-Bin ZHANG ; Ying-Ge FU ; Rui LI ; Fang WU ; Xi-Hua LIN
Asian Journal of Andrology 2025;27(2):204-210
Insulin-like growth factor 2 (IGF2) is a critical endocrine mediator implicated in male reproductive physiology. To investigate the correlation between IGF2 protein levels and various aspects of male infertility, specifically focusing on sperm quality, inflammation, and DNA damage, a cohort of 320 male participants was recruited from the Women's Hospital, Zhejiang University School of Medicine (Hangzhou, China) between 1 st January 2024 and 1 st March 2024. The relationship between IGF2 protein concentrations and sperm parameters was assessed, and Spearman correlation and linear regression analysis were employed to evaluate the independent associations between IGF2 protein levels and risk factors for infertility. Enzyme-linked immunosorbent assay (ELISA) was used to measure IGF2 protein levels in seminal plasma, alongside markers of inflammation (tumor necrosis factor-alpha [TNF-α] and interleukin-1β [IL-1β]). The relationship between seminal plasma IGF2 protein levels and DNA damage marker phosphorylated histone H2AX (γ-H2AX) was also explored. Our findings reveal that IGF2 protein expression decreased notably in patients with asthenospermia and teratospermia. Correlation analysis revealed nuanced associations between IGF2 protein levels and specific sperm parameters, and low IGF2 protein concentrations correlated with increased inflammation and DNA damage in sperm. The observed correlations between IGF2 protein levels and specific sperm parameters, along with its connection to inflammation and DNA damage, underscore the importance of IGF2 in the broader context of male reproductive health. These findings lay the groundwork for future research and potential therapeutic interventions targeting IGF2-related pathways to enhance male fertility.
Humans
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Male
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Insulin-Like Growth Factor II/metabolism*
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Infertility, Male/genetics*
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DNA Damage
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Adult
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Inflammation/metabolism*
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Spermatozoa/metabolism*
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Semen Analysis
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Semen/metabolism*
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Tumor Necrosis Factor-alpha/metabolism*
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Histones/metabolism*
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Interleukin-1beta/metabolism*
5.Association of angiotensin Ⅱ type 1 receptor autoantibody and sperm motility in human semen.
Dao-Qin TU ; Yu-Huan YANG ; Gui-Fang YANG ; Yi-Nan ZHANG ; Yao CHEN ; Xue-Ming LI ; Yu-Hui SHI ; Xiao-Li YANG ; Feng WANG
National Journal of Andrology 2025;31(5):387-394
OBJECTIVE:
To investigate the relationship between angiotensin Ⅱ type 1 receptor autoantibody (AT1-AA) and semen parameters. Methods: The semen samples of 820 male patients who were treated in the Reproductive Medicine Center of Taiyuan Central Hospital from August 2022 to August 2023 were retrospectively analyzed. The levels of AT1-AA and Ang Ⅱ of semen were detected by ELISA, and the function of AT1-AA was detected by cardiomyocyte beating assay in suckling rats. The patients were divided into low group, median group and high group according to the OD values of AT1-AA. The differences in general data and semen parameters between different groups were analyzed. And the correlation between AT1-AA level and semen parameters in semen of all study subjects was analyzed by the method of Spearman analysis. And the relationships between AT1-AA OD value, Ang Ⅱ level and semen parameters in the AT1-AA high value group were analyzed as well.
RESULTS:
AT1-AA was present in semen with good function. There was no significant difference in the general data of patients in different AT1-AA levels (P>0.05). In the comparison of semen parameters among the groups with different levels of AT1-AA, there were differences in sperm concentration, PR concentration, NP%, and ALH among the three groups (P<0.05). And AT1-AA OD value was positively correlated with total sperm count, sperm concentration, PR concentration, and NP%, and negatively correlated with semen volume (P<0.05). In the AT1-AA high value group, the OD value of AT1-AA in semen was negatively correlated with inactive sperm, and positively correlated with total motility ([PR+NP]%), curve rate, mean path rate, and ALH. However, there was no correlation between the level of Ang Ⅱ in semen and semen parameters (P>0.05).
CONCLUSION
The presence of AT1-AA in semen may be associated with the promotion of sperm motility.
Male
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Humans
;
Autoantibodies
;
Sperm Motility
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Semen
;
Retrospective Studies
;
Receptor, Angiotensin, Type 1/immunology*
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Animals
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Rats
;
Angiotensin II
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Adult
;
Sperm Count
;
Semen Analysis
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Receptor, Angiotensin, Type 2/immunology*
6.Shexiang Tongxin Dropping Pill Improves Stable Angina Patients with Phlegm-Heat and Blood-Stasis Syndrome: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial.
Ying-Qiang ZHAO ; Yong-Fa XING ; Ke-Yong ZOU ; Wei-Dong JIANG ; Ting-Hai DU ; Bo CHEN ; Bao-Ping YANG ; Bai-Ming QU ; Li-Yue WANG ; Gui-Hong GONG ; Yan-Ling SUN ; Li-Qi WANG ; Gao-Feng ZHOU ; Yu-Gang DONG ; Min CHEN ; Xue-Juan ZHANG ; Tian-Lun YANG ; Min-Zhou ZHANG ; Ming-Jun ZHAO ; Yue DENG ; Chang-Jiang XIAO ; Lin WANG ; Bao-He WANG
Chinese journal of integrative medicine 2025;31(8):685-693
OBJECTIVE:
To evaluate the efficacy and safety of Shexiang Tongxin Dropping Pill (STDP) in treating stable angina patients with phlegm-heat and blood-stasis syndrome by exercise duration and metabolic equivalents.
METHODS:
This multicenter, randomized, double-blind, placebo-controlled clinical trial enrolled stable angina patients with phlegm-heat and blood-stasis syndrome from 22 hospitals. They were randomized 1:1 to STDP (35 mg/pill, 6 pills per day) or placebo for 56 days. The primary outcome was the exercise duration and metabolic equivalents (METs) assessed by the standard Bruce exercise treadmill test after 56 days of treatment. The secondary outcomes included the total angina symptom score, Chinese medicine (CM) symptom scores, Seattle Angina Questionnaire (SAQ) scores, changes in ST-T on electrocardiogram and adverse events (AEs).
RESULTS:
This trial enrolled 309 patients, including 155 and 154 in the STDP and placebo groups, respectively. STDP significantly prolonged exercise duration with an increase of 51.0 s, compared to a decrease of 12.0 s with placebo (change rate: -11.1% vs. 3.2%, P<0.01). The increase in METs was significantly greater in the STDP group than in the placebo group (change: -0.4 vs. 0.0, change rate: -5.0% vs. 0.0%, P<0.01). The improvement of total angina symptom scores (25.0% vs. 0.0%), CM symptom scores (38.7% vs. 11.8%), reduction of nitroglycerin consumption (100.0% vs. 11.3%), and all domains of SAQ, were significantly greater with STDP than placebo (all P<0.01). The changes in Q-T intervals at 28 and 56 days from baseline were similar between the two groups (both P>0.05). Twenty-five participants (16.3%) with STDP and 16 (10.5%) with placebo experienced AEs (P=0.131), with no serious AEs observed.
CONCLUSION
STDP could improve exercise tolerance in patients with stable angina and phlegm-heat and blood stasis syndrome, with a favorable safety profile. (Registration No. ChiCTR-IPR-15006020).
Humans
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Double-Blind Method
;
Drugs, Chinese Herbal/adverse effects*
;
Male
;
Female
;
Middle Aged
;
Angina, Stable/physiopathology*
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Aged
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Syndrome
;
Treatment Outcome
;
Placebos
;
Tablets
7.Investigation on a suspected outbreak of carbapenem-resistant Acinetobacter baumannii nosocomial infection in an intensive care unit
Mei HUANG ; Xiaobo GUI ; Ya YANG ; Feng LU ; Juanxiu QIN ; Yan LI ; Shuyi ZHANG ; Wenqin ZHOU ; Xiaofang FU ; Haiqun BAN
Shanghai Journal of Preventive Medicine 2024;36(5):435-438
ObjectiveTo investigate a suspected outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) nosocomial infection in an intensive care unit (ICU) and provide scientific evidence for prevention and control of multi-drug resistant nosocomial infection. MethodsClinical and epidemiological data of 4 patients with CRAB infection were retrospectively investigated in the ICU of Renji Hospital in November 2021. Environmental hygiene monitoring and multilocus sequence typing (MLST) were conducted and intervention measures were taken. ResultsA total of 4 cases with CRAB infection were identified, among which 1 case was determined to be community-acquired and3 cases were hospital-acquired. The isolated strains shared the same drug resistance, and were all classified into ST368 type. In the surface and hand samples (n=40), 2 CRAB strains were detected in the air filter beside the bed of the first case, with a detection rate of 5%. After adopting comprehensive prevention and control strategies, including environmental cleaning and disinfection, hand hygiene, staff management and training, and supervision, no similar case with CRAB infection was found. ConclusionThis suspected outbreak of CRAB nosocomial infection may be induced by inadequate environmental cleaning and disinfection, and inadequate implementation of hand hygiene. Timely identification, investigation, and targeted measures remain crucial to effective control of possible nosocomial infection.
8.Correlation analysis of miR-4500,NGF expressions with preoperative magnetic resonance signs in breast cancer
Fan YANG ; Jing CHEN ; Bin ZHENG ; Jiao-Jiao LI ; Li ZHANG ; Gui-Feng BIAN ; Ya-Jing BIAN ; Xiao-Yan LANG
Journal of Regional Anatomy and Operative Surgery 2024;33(1):47-50
Objective To analyze the correlations of the expressions of miR-4500 and nerve growth factor(NGF)in breast cancer patients with preoperative magnetic resonance(MR)signs.Methods A total of 105 patients with breast cancer admitted to our hospital were selected,the mRNA expression levels of miR-4500 and NGF in breast cancer tissues and adjacent tissues of patients were detected by qRT-PCR,and the positive expression rates of NGF in breast cancer tissues and adjacent tissues were determined by immunohistochemistry method.The correlations of the expressions of miR-4500 and NGF in breast cancer tissues with clinicopathological features and MR signs of patients were analyzed.The targeting relationship between miR-4500 and NGF was predicted by the bioinformatics website,and the correla-tion between the expressions of the two was analyzed.Results Compared with the adjacent tissues,the expression level of miR-4500 in breast cancer tissue decreased(P<0.05),while the level of NGF mRNA and the positive expression rate of NGF increased(P<0.05).There was no significant difference in age,pathological type,tumor classification,parenchymal background,apparent diffusion coefficient or enhancement curve among different expressions of miR-4500 and NGF(P>0.05).The histological grade,lymph node metastasis,tumor diameter,tumor morphology,ring-like enhancement,and peritu-moral brain edema were related to the expressions of miR-4500 and NGF(P<0.05).The bioinformatics website prediction showed that miR-4500 and NGF had binding sites,and the expressions of miR-4500 and NGF mRNA in breast cancer tissues were negatively correlated(r=-0.576,P<0.05).Conclusion The expression of miR-4500 in breast cancer tissue is low,and the expression of NGF is high,which are correlated with the preoperative MR signs in patients,providing a molecu-lar basis for MR signs.
9.Endo-beta-N-acetylglucosaminidase: Possible Functions and Mechanisms
Xin-Rong LU ; Yong-Liang TONG ; Wei-Li KONG ; Lin ZOU ; Dan-Feng SHEN ; Shao-Xian LÜ ; Rui-Jie LIU ; Shao-Xing ZHANG ; Yu-Xin ZHANG ; Lin-Lin HOU ; Gui-Qin SUN ; Li CHEN
Progress in Biochemistry and Biophysics 2024;51(5):985-999
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.
10.Pollution status and distribution characteristics of indoor air bacteria in subway stations and compartments in a city of Central South China
Shuyan CHENG ; Zhuojia GUI ; Liqin SU ; Guozhong TIAN ; Tanxi GE ; Jiao LUO ; Ranqi SHAO ; Feng LI ; Weihao XI ; Chunliang ZHOU ; Wei PENG ; Minlan PENG ; Min YANG ; Bike ZHANG ; Xianliang WANG ; Xiaoyuan YAO
Journal of Environmental and Occupational Medicine 2024;41(7):801-806
Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO2), fine particulate matter (PM2.5), and inhalable particulate matter (PM10) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min−1, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO2 concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM2.5, and PM10 in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO2, but 0% for humidity. The overall median (P25, P75) total bacteria count was 177 (138,262) CFU·m−3. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

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