1.Effects of Quorum Sensing Molecules on The Immune System
Wen-Min MA ; Xuan-Qi CHEN ; Hong-Xia MA ; Wen-Hui ZHANG ; Ling-Cong KONG ; Yu-Jia ZHOU ; Yuan-Yuan HU ; Yu JIA
Progress in Biochemistry and Biophysics 2024;51(11):2853-2867
In recent years, the development of host-acting antibacterial compounds has gradually become a hotspot in the field of anti-infection. Through research on the interaction mechanism between hosts and pathogenic bacteria, it has been found that the immune system is one of the key targets of host-acting antibacterial compounds. There is a communication system called the quorum sensing system in microorganisms, which mainly adjusts the structure of multi-microbial community and coordinates the group behavior. When the quorum sensing molecules secreted by microorganisms reach a threshold concentration, the quorum sensing system is activated and the overall gene expression of the microorganism is changed. In addition to regulating the density of microorganisms, quorum sensing molecules can also act as a link between pathogenic microorganisms and hosts, entering the host immune system and playing a role in affecting the morphological structure of immune cells, secreting cytokines, and inducing apoptosis, leading to host immune injury and causing host immune dysfunction.The key mechanism of 3-oxo-C12-HSL and other acyl-homoserine lactone (AHL) molecules in the innate immune system has been extensively studied. The lipid solubility allows AHLs to pass through the plasma membrane of host immune cells easily and induce dissolution of lipid domains. Then, it acts through signaling pathways such as p38MAPK and JAK-STAT, further influencing the immune cell’s defense response to bacteria and potentially leading to cell apoptosis. Additionally, the human lactonase paraoxonase 2, which can degrade3-oxo-C12-HSL, has been found in macrophage. It acts as an immune regulator that promotes macrophage phagocytosis of pathogens and is hypothesized to have the ability to reduce bacterial resistance. The mechanism of quorum sensing molecules in the adaptive immune system is less studied, the current results suggest that 3-oxo-C12-HSL is closely related to the mitochondrial pathway in host immune cells. For example, 3-oxo-C12-HSL induces apoptosis of Jurkat cells by inhibiting the expression of three mitochondrial electron transport chain proteins; it can also trigger mitochondrial dysfunction and induce mast cell apoptosis through Ca2+ signaling.Among the quorum sensing molecules, the AHLs have the greatest impact on plant immune system. The different effects on plant resistance depends on the chain lengths of acyl groups in bacterial-produced AHLs. Short-chain AHLs (C4-HSL and C8-HSL) induce plant resistance to pathogenic bacteria mainly through the auxin pathway and jasmonic acid pathway. Long-chain AHL (3-oxo-C14-HSL) is commonly used in hosts against fungal pathogens by inducing stomata defense responses, and the reaction process is related to salicylic acid. Diffusible signal factor molecules also interfere with the stomatal immunity caused by pathogens. It may act through the formin nanoclustering-mediated actin assembly and MPK3 pathway to inhibit the innate immunity of Arabidopsis. In summary, AHLs induced different plant pathways and affects the plant-bacteria interactions to trigger plant immunity. As a quorum sensing molecule of fungi, farnesol has similar effects on host immunity as AHLs, such as stimulating cytokine secretion and activating an inflammatory response. It also plays a unique role on dendritic cell differentiation and maturation. In addition, studies have found that farnesol has a protective effect on autoimmune encephalomyelitis, which may be related to its effect on the composition of intestinal microorganisms of the host.Therefore, targeting the host immune system and quorum sensing molecules to develop antibacterial compounds can effectively inhibit the invasion of pathogens and subserve the host to resist the influence of pathogenic bacteria. This article will review the mechanism of host immune responses triggered by important quorum sensing molecules, aiming to explore the targets of host-acting antibacterial compounds and provide new directions for the prevention or treatment of causative infectious sources and the development of related drugs.
2.Finite element analysis of femoral neck fracture treated by internal fixation of femoral neck system under nonanatomical reduction
Jizhai JIA ; Guikun YIN ; Hui XIE ; Weimin FU ; Shun HAN ; Yingjie MA ; Zhun WEN ; Benjie WANG
Chinese Journal of Tissue Engineering Research 2024;28(21):3319-3325
BACKGROUND:Irreducible femoral neck fracture was difficult to obtain anatomic reduction.As a new type of internal fixation,the femoral neck system is still blank for the treatment of non-anatomical reduced femoral neck fractures. OBJECTIVE:To explore the biomechanical stability of femoral neck system internal fixation under nonanatomical reduction in the treatment of femoral neck fractures based on finite element analysis. METHODS:CT data of the hip joint of a healthy female adult were obtained.Anatomical reduction of femoral neck fracture models with Pauwels angles of 30°,50°,and 70° were established using Mimics 21.0,Geomagic Wrap 2021,and SolidWorks 2020.The fracture proximal ends of the three anatomical reduction models were shifted upward by 2 mm along the fracture line,and three positive buttress models with different Pauwels angles were obtained.In the same way,three negative buttress models were acquired by shifting downward by 2 mm.SolidWorks 2020 was used to make the femoral neck system internal fixation,and the nine femoral neck fracture models were assembled with the femoral neck system.Then Ansys 19.0 was used for finite element analysis.The displacement distribution and maximum displacement,stress distribution and maximum stress of the femur and femoral neck system were recorded under 2100 N stress. RESULTS AND CONCLUSION:(1)When Pauwels angles were 30°,50°,and 70°,the maximum stresses of the femoral neck system appeared to be concentrated at the junction of the sliding hip screw and anti-rotation screw.The maximum femur stresses appeared to be concentrated in the medial cortex of the femur.The maximum displacement was concentrated at the upper of the femoral head and femoral neck system.(2)When Pauwels angles were 30° and 50°,the maximum displacement and maximum stress of the femoral neck system and femur were:negative buttress>anatomical reduction>positive buttress.(3)When Pauwels angle was 70°,the maximum displacement and maximum stress of the femoral neck system were:negative buttress>anatomical reduction>positive buttress;the maximum displacement and maximum stress of the femur were:negative buttress>positive buttress>anatomical reduction.(4)With the increase of Pauwels angle,the biomechanical advantage of the positive buttress was weakening.However,it was better than a negative buttress.When Pauwels angle was 30°,positive buttress was more stable than anatomical reduction.When Pauwels angle was 50°,the biomechanical difference between positive buttress and anatomical reduction became smaller.When Pauwels angle was 70°,the stability of anatomical reduction was slightly better than positive buttress.(5)If it was difficult to achieve anatomical reduction of femoral neck fracture during operation,but the positive buttress had been displaced within 2 mm,the femoral neck system could be used to offer stable mechanical fixation.It is necessary to avoid negative buttress reduction.
3.Finite element analysis of absorbable screws in Bernese periacetabular osteotomy
Hui CHENG ; Xiaoying MA ; Ningtao REN ; Zhendong ZHANG ; Haigang JIA ; Yong LI ; Jianli ZHANG ; Dianzhong LUO ; Hong ZHANG ; Wei CHAI
Chinese Journal of Orthopaedics 2024;44(6):419-426
Objective:To investigate the stability and feasibility of using absorbable screws during Bernese periacetabular osteotomy.Methods:A retrospective analysis was conducted on a 36 year-old woman diagnosed with developmental dysplasia of the hip, who had undergone Bernese periacetabular osteotomy. Finite element analysis was used to simulate the stability of the acetabulum under loads of 10%, 20%, 50%, and 100% of the patient's weight. The structural stiffness of the pelvis and the maximum equivalent stress on the absorbable screws were observed under different conditions, including whether the acetabular bone block and the ilium were in contact, whether 3 or 4 screws were used, and whether a graft (including fibular cortical bone and PEEK grafts) was used.Results:The structural stiffness of the pelvis fixed with four screws increased by 67%-94% compared to that with three screws. After using a graft, the structural stiffness of the pelvis increased by 50%-83%. As the load increased, the maximum equivalent stress on the screws also increased. When the acetabular bone block and the ilium had no contact, no graft was used, and only three screws were used for fixation, the maximum equivalent stress could reach 518.9 MPa, while this value dropped to 61% when four screws were used (318.7 MPa). When the acetabular bone block and the ilium were in contact, the maximum equivalent stress was about 12% of that when there was no contact, regardless of the number of screws used. When a cortical bone graft or a PEEK graft was used, the maximum equivalent stress could drop to 21%-26% of that without a graft. When the screw strength was 130 MPa, a load of 20% of body weight was applied, and only three screws were used without a graft, the equivalent stress could exceed the strength of the screw; if four screws were used, the equivalent stress was slightly higher than the strength of the screw when a load of 50% of body weight was applied. However, when a graft was used (either cortical bone or PEEK), even when a load of 100% of body weight was applied, the equivalent stress was slightly lower than the strength of the screw.Conclusion:Absorbable screws can provide sufficient stability for Bernese periacetabular osteotomy. The contact between the acetabular bone block and the ilium, an increase in the number of screws, and the use of grafts (cortical bone and PEEK grafts) can further improve stability. Therefore, absorbable screws have broad application prospects in Bernese periacetabular osteotomy.
4. Lycium barbarian seed oil activates Nrf2/ARE pathway to reduce oxidative damage in testis of subacute aging rats
Rui-Ying TIAN ; Wen-Xin MA ; Zi-Yu LIU ; Hui-Ming MA ; Sha-Sha XING ; Na HU ; Chang LIU ; Biao MA ; Jia-Yang LI ; Hu-Jun LIU ; Chang-Cai BAI ; Dong-Mei CHEN
Chinese Pharmacological Bulletin 2024;40(3):490-498
Aim To explore the effects of Lycium berry seed oil on Nrf2/ARE pathway and oxidative damage in testis of subacute aging rats. Methods Fifty out of 60 male SD rats, aged 8 weeks, were subcutaneously injected with 125 mg • kg"D-galactosidase in the neck for 8 weeks to establish a subacute senescent rat model. The presence of senescent cells was observed using P-galactosidase ((3-gal), while testicular morphology was examined using HE staining. Serum levels of testosterone (testosterone, T), follicle-stimulating hormone ( follicle stimulating hormone, FSH ) , luteinizing hormone ( luteinizing hormone, LH ) , superoxide dis-mutase ( superoxide dismutase, SOD ) , glutathione ( glutathione, GSH) and malondialdehyde ( malondial-dehyde, MDA) were measured through ELISA, and the expressions of factors related to aging, oxidative damage, and the Nrf2/ARE pathway were assessed via immunohistochemical analysis and Western blotting. Results After successfully identifying the model, the morphology of the testis was improved and the intervention of Lycium seed oil led to a down-regulation in the expression of [3-gal and -yH2AX. The serum levels of SOD, GSH, T, and FSH increased while MDA and LH decreased (P 0. 05) . Additionally, there was an up-regulated expression of Nrf2, GCLC, NQOl, and SOD2 proteins in testicular tissue ( P 0. 05 ) and nuclear expression of Nrf2 in sertoli cells. Conclusion Lycium barbarum seed oil may reduce oxidative damage in testes of subacute senescent rats by activating the Nrf2/ARE signaling pathway.
5.Early experience with mechanical hemodynamic support for catheter ablation of malignant ventricular tachycardia
Mengmeng LI ; Yang YANG ; Deyong LONG ; Chenxi JIANG ; Ribo TANG ; Caihua SANG ; Wei WANG ; Xin ZHAO ; Xueyuan GUO ; Songnan LI ; Changyi LI ; Man NING ; Changqi JIA ; Li FENG ; Dan WEN ; Hui ZHU ; Yuexin JIANG ; Fang LIU ; Tong LIU ; Jianzeng DONG ; Changsheng MA
Chinese Journal of Cardiology 2024;52(7):768-776
Objective:To explore the role of mechanical hemodynamic support (MHS) in mapping and catheter ablation of patients with hemodynamically unstable ventricular tachycardia (VT), report single-center experience in a cohort of consecutive patients receiving VT ablation during MHS therapy, and provide evidence-based medical evidence for clinical practice.Methods:This was a retrospective cohort study. Patients with hemodynamically unstable VT who underwent catheter ablation with MHS at Beijing Anzhen Hospital, Capital Medical University between August 2021 and December 2023 were included. Patients were divided into rescue group and preventive group according to the purpose of treatment. Their demographic data, periprocedural details, and clinical outcomes were collected and analyzed.Results:A total of 15 patients with hemodynamically unstable VT were included (8 patients in the rescue group and 7 patients in the preventive group). The acute procedure was successful in all patients. One patient in the rescue group had surgical left ventricular assist device (LVAD) implantation, remaining 14 patients received extracorporeal membrane oxygenation (ECMO) for circulation support. ECMO decannulation was performed in 12 patients due to clinical and hemodynamic stability, of which 6 patients were decannulation immediately after surgery and the remaining patients were decannulation at 2.0 (2.5) d after surgery. Two patients in the rescue group died during the index admission due to refractory heart failure and cerebral hemorrhage. During a median follow-up of 30 d (1 d to 12 months), one patient with LVAD had one episode of ventricular fibrillation at 6 months after discharge, and no further episodes of ventricular fibrillation and/or VT occurred after treatment with antiarrhythmic drugs. No malignant ventricular arrhythmia occurred in the remaining 12 patients who were followed up.Conclusions:MHS contributes to the successful completion of mapping and catheter ablation in patients with hemodynamically unstable VT, providing desirable hemodynamic status for emergency and elective conditions.
6.Hypericin inhibits the expression of NLRP3 in microglia of Parkinson's disease mice and alleviates the damage of DA-ergic neurons
Li-Shan FAN ; Jia ZHANG ; Si-Xiang NIU ; Qi XIAO ; Hui-Jie FAN ; Lei XU ; Li-Xia YANG ; Lu JIA ; Shao-Chen QIN ; Bao-Guo XIAO ; Cun-Gen MA ; Zhi CHAI
The Chinese Journal of Clinical Pharmacology 2024;40(17):2523-2527
Objective To observe the intervention effect of hypericin(HYP)on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson's disease(PD)mice model and its mechanism.Methods Thirty C57BL/6 mice were randomly divided into normal,model and experimental groups with 10 mice per group.PD mouse model was established after 7 days of intraperitoneal injection of MPTP,and drug intervention was carried out from the first day of modeling.Normal group and model group were intraperitoneally injected with 500 μL·kg·d-1 0.9%NaCl.The experimental group was intraperitoneally injected with 25 mg·kg·d-1 HYP.The three groups of rats were given the drug once each time for 14 days.The expression levels of tyrosine hydroxylase(TH),Nod-like receptor thermal protein domain protein 3(NLRP3)and ionized calcium binding adapter molecule 1(Iba1)in the striatum of nigra were detected by Western blot.Results The climbing time of normal,model and experimental groups was(5.35±0.43),(9.71±1.19)and(8.07±0.34)s;suspension scores were(2.92±0.15),(1.38±0.28)and(1.96±0.28)points;the relative expression levels of TH protein were 1.04±0.06,0.51±0.09 and 0.75±0.07;the relative expression levels of NLRP3 protein were 0.51±0.03,1.00±0.04 and 0.77±0.06;the relative expression levels of Iba1 protein were 0.68±0.10,1.30±0.28 and 0.89±0.05,respectively.The above indexes in the model group were statistically significant compared with the experimental group and the normal group(all P<0.01).Conclusion HYP plays a therapeutic role in PD by inhibiting the expression of NLRP3 inflammasome in PD mice.
7.Development of a High-throughput Sequencing Platform for Detection of Viral Encephalitis Pathogens Based on Amplicon Sequencing
Li Ya ZHANG ; Zhe Wen SU ; Chen Rui WANG ; Yan LI ; Feng Jun ZHANG ; Hui Sheng LIU ; He Dan HU ; Xiao Chong XU ; Yu Jia YIN ; Kai Qi YIN ; Ying HE ; Fan LI ; Hong Shi FU ; Kai NIE ; Dong Guo LIANG ; Yong TAO ; Tao Song XU ; Feng Chao MA ; Yu Huan WANG
Biomedical and Environmental Sciences 2024;37(3):294-302
Objective Viral encephalitis is an infectious disease severely affecting human health.It is caused by a wide variety of viral pathogens,including herpes viruses,flaviviruses,enteroviruses,and other viruses.The laboratory diagnosis of viral encephalitis is a worldwide challenge.Recently,high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections.Thus,In this study,we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing. Methods We designed nine pairs of specific polymerase chain reaction(PCR)primers for the 12 viruses by reviewing the relevant literature.The detection ability of the primers was verified by software simulation and the detection of known positive samples.Amplicon sequencing was used to validate the samples,and consistency was compared with Sanger sequencing. Results The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×,and the sequence lengths were consistent with the sizes of the predicted amplicons.The sequences were verified using the National Center for Biotechnology Information BLAST,and all results were consistent with the results of Sanger sequencing. Conclusion Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis.It is also a useful tool for the high-volume screening of clinical samples.
8.REDH: A database of RNA editome in hematopoietic differentiation and malignancy
Jiayue XU ; Jiahuan HE ; Jiabin YANG ; Fengjiao WANG ; Yue HUO ; Yuehong GUO ; Yanmin SI ; Yufeng GAO ; Fang WANG ; Hui CHENG ; Tao CHENG ; Jia YU ; Xiaoshuang WANG ; Yanni MA
Chinese Medical Journal 2024;137(3):283-293
Background::The conversion of adenosine (A) to inosine (I) through deamination is the prevailing form of RNA editing, impacting numerous nuclear and cytoplasmic transcripts across various eukaryotic species. Millions of high-confidence RNA editing sites have been identified and integrated into various RNA databases, providing a convenient platform for the rapid identification of key drivers of cancer and potential therapeutic targets. However, the available database for integration of RNA editing in hematopoietic cells and hematopoietic malignancies is still lacking.Methods::We downloaded RNA sequencing (RNA-seq) data of 29 leukemia patients and 19 healthy donors from National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database, and RNA-seq data of 12 mouse hematopoietic cell populations obtained from our previous research were also used. We performed sequence alignment, identified RNA editing sites, and obtained characteristic editing sites related to normal hematopoietic development and abnormal editing sites associated with hematologic diseases.Results::We established a new database, "REDH", represents RNA editome in hematopoietic differentiation and malignancy. REDH is a curated database of associations between RNA editome and hematopoiesis. REDH integrates 30,796 editing sites from 12 murine adult hematopoietic cell populations and systematically characterizes more than 400,000 edited events in malignant hematopoietic samples from 48 cohorts (human). Through the Differentiation, Disease, Enrichment, and knowledge modules, each A-to-I editing site is systematically integrated, including its distribution throughout the genome, its clinical information (human sample), and functional editing sites under physiological and pathological conditions. Furthermore, REDH compares the similarities and differences of editing sites between different hematologic malignancies and healthy control.Conclusions::REDH is accessible at http://www.redhdatabase.com/. This user-friendly database would aid in understanding the mechanisms of RNA editing in hematopoietic differentiation and malignancies. It provides a set of data related to the maintenance of hematopoietic homeostasis and identifying potential therapeutic targets in malignancies.
9.Effect and possible mechanism of Wuzi Yanzong Pill on motor function of neurons in Parkinson's disease mice
Tao PAN ; Qi XIAO ; Hui-Jie FAN ; Lei XU ; Lu JIA ; Shao-Chen QIN ; Li-Ran WANG ; Cun-Gen MA ; Bo ZHANG ; Zhi CHAI
Medical Journal of Chinese People's Liberation Army 2024;49(5):550-556
Objective To observe the effects of Wuzi Yanzong Pill(WYP)on motor function in a mouse model of Parkinson's disease(PD)and to explore its potential mechanisms.Methods Twenty-four male C57BL/6 mice were randomly divided into control group,model group and WYP group,with 8 mice in each group.Mice in model and WYP group were intraperitoneally injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine for 7 consecutive days to establish a PD model.From the 1st day of model preparation,mice in WYP group were gavaged with WYP solution[16 g/(kg·d)]twice daily for 14 consecutive days.At the same time,mice in control group and model group were gavaged with 0.9%NaCl solution[50 ml/(kg·d)]twice a day.Gait experiment was utilized to assess the behavioral performance of mice in each group.Immunofluorescence staining was conducted to detect the number of tyrosine hydroxylase(TH)-positive cells in the substantia nigra region,the fluorescence intensity of nuclear factor E2-related factor 2(Nrf2),and the number of NeuN neurons co-labeled with Nrf2 in each group.Western blotting was employed to determine the expression levels of TH,Kelch-like ECH-associated protein 1(Keap-1),Nrf2,and heme oxygenase-1(HO-1)in the brain tissue of mice in each group.Results The gait experiment results showed that,compared with control group,standing time of the left front paw,right front paw,left hind paw,and right hind paw of the mice in model group was significantly shortened(P<0.01),while swinging time of the left front paw,right front paw,left hind paw,and right hind paw was significantly prolonged(P<0.05).Compared with model group,standing time of the left front paw and right hind paw of the mice in WYP group was significantly prolonged(P<0.05),while swing time of the left front paw and right front paw was significantly shortened(P<0.05).Immunofluorescence staining and Western blotting results showed that,compared with control group,in model group the number of TH-positive cells,average fluorescence intensity of Nrf2,and HO-1 levels decreased(P<0.01),while the Keap-1 protein level increased(P<0.01),and the number of Nrf2 expression on NeuN neurons decreased(P<0.001).Compared with model group,the number of TH-positive cells,average fluorescence intensity of Nrf2,HO-1 level,and the number of Nrf2 expression on NeuN neurons in the brain tissue of mice in WYP group increased(P<0.05),while Keap-1 protein level decreased(P<0.05).Conclusions WYP could alleviate the motor dysfunction and protect dopaminergic neurons in PD mice.The underlying mechanism may be related to the regulation of Keap-1/Nrf2/HO-1 pathway to inhibit oxidative stress response.
10.Research progress on the impact of lipid metabolism on endometrial receptivity and embryo implantation
Li-Na MA ; Ying QIN ; Ke-Hua WANG ; Cong-Hui PANG ; Li-Ge LU ; Wen-Xian YUAN ; Duo-Jia ZHANG ; Xiao-Ke WU
Medical Journal of Chinese People's Liberation Army 2024;49(9):1088-1093
Lipids,including fats(triglycerides)and lipoids(phospholipids and sterols),not only serve as an energy source for the body but also play a pivotal role throughout the reproductive process,particularly in the establishment and maintenance of early pregnancy.This encompasses the regulate of early embryonic development and uterine tolerance,and the facilitation of embryo implantation.Given the diversity of lipids,this review focuses on extensively studied lipid mediators such as polyunsaturated fatty acids,endocannabinoids,prostaglandins,lysophosphatidic acid,sphingolipids and steroid hormones.It systematically elaborates on the regulatory effects of fatty acid,phospholipid,and cholesterol metabolism on the formation of endometrial receptivity and embryo implantation,as well as the potential underlying mechanisms.The review aims to provide new insights and feasible intervention approaches for predicting and improving the outcomes of natural pregnancy and/or assisted reproductive technology.

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