1.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.
2.Development and Synthesis of Activity-based and Affinity-based Ubiquitin Probes
Ling XU ; Cui-Na WEI ; Xian-Fu LU ; Yi-Ming LI
Progress in Biochemistry and Biophysics 2024;51(3):598-623
Ubiquitination, a diverse post-translational modification, is carried out by enzymes including E1-activating enzymes, E2-conjugating enzymes, E3 ligases, and deubiquitinating enzymes (DUBs). Ubiquitin itself possesses 7 lysine residues and N-terminal methionine, allowing for the formation of polyubiquitin chains with different lengths and linkages. These chains exhibit various topologies that can be recognized by proteins containing ubiquitin-binding domain, thereby transmitting distinct cellular signals. To unravel the physiological mechanisms associated with ubiquitin, numerous ubiquitin probes have been developed. This review provides an overview of recent advancements in the field of ubiquitin probes, focusing on activity-based and affinity-based probes. Activity-based probes are designed to covalently bind to DUBs, E1s, or E3s, enabling the identification and characterization of these enzymes. Affinity-based probes, on the other hand, selectively bind to ubiquitin-binding domains, facilitating the identification of proteins that interact with ubiquitin. Moreover, this review comprehensively discusses the synthetic methodologies employed for the acquisition of ubiquitin probes. These includes meticulous discussions on the synthesis of individual monomeric modules, the establishment of isopeptide linkages, as well as the incorporation of reactive functional groups. Additionally, the review explores the emerging area of cell-penetrating ubiquitin probes and highlights their latest applications in living cells. These probes incorporate cell-penetrating peptides to enable their internalization into cells, allowing for direct visualization and manipulation of ubiquitin-modified proteins within their native environment. Overall, this review offers insights into the design, synthesis, and applications of ubiquitin probes, highlighting their significance in elucidating ubiquitin-mediated cellular processes.
3.Analysis of potential categories of sexual behaviors among male students who have sex with men and the status of pre exposure prophylaxis use
Chinese Journal of School Health 2024;45(7):974-977
Objective:
To analyze the use of preexposure prophylaxis (PrEP) among male students who had sex with men (MSM) with different sexual behavior patterns using potential categories, so as to provide evidence for determining the use patterns of PrEP consistent with MSM.
Methods:
A questionnaire survey was conducted by proportional sampling method on MSM in 31 provincial administrative regions in mainland China from 20 October to 30 December 2021, a total of 1 040 students were selected for the study. Latent variable analyses were conducted on a total of seven sexual behavioral characteristics, including knowledge of sexual partner HIV infection, frequency of condom use, number of sexual partners, engaging in group sex, provision of commercial sex, use of sex aids, and history of sexually transmitted infections (STIs) in the past year. And demographic characteristics were analyzed by Logistic regression analysis. The rates of PrEP awareness, willingness to use and usage rate in different sexual behavior risk groups were investigated.
Results:
Student MSM could be divided into two potential category groups:a lowrisk behavior group (82.4%) and a highrisk behavior group (17.6%). The PrEP usage rate (15.8%) was higher in the highrisk behavior group, and the difference was statistically significant compared to the lowrisk behavior group (7.2%) (χ2=13.43, P<0.05). Student MSM residing in the northeast, south, and northwest of China, in the pilot city, and with a sex role of "0.5" (possible acceptance and insertion of sexual behavior) were more likely to be in the highrisk behavior group (OR=3.13, 3.07, 3.87, 2.22, 1.66, P<0.05).
Conclusion
Student MSM in highrisk and lowrisk sexual differs in the behavior of PrEP, and targeted interventions should be implemented to promote the use of PrEP and reduce HIV infection in this population.
4.Downregulation of MUC1 Inhibits Proliferation and Promotes Apoptosis by Inactivating NF-κB Signaling Pathway in Human Nasopharyngeal Carcinoma
Shou-Wu WU ; Shao-Kun LIN ; Zhong-Zhu NIAN ; Xin-Wen WANG ; Wei-Nian LIN ; Li-Ming ZHUANG ; Zhi-Sheng WU ; Zhi-Wei HUANG ; A-Min WANG ; Ni-Li GAO ; Jia-Wen CHEN ; Wen-Ting YUAN ; Kai-Xian LU ; Jun LIAO
Progress in Biochemistry and Biophysics 2024;51(9):2182-2193
ObjectiveTo investigate the effect of mucin 1 (MUC1) on the proliferation and apoptosis of nasopharyngeal carcinoma (NPC) and its regulatory mechanism. MethodsThe 60 NPC and paired para-cancer normal tissues were collected from October 2020 to July 2021 in Quanzhou First Hospital. The expression of MUC1 was measured by real-time quantitative PCR (qPCR) in the patients with PNC. The 5-8F and HNE1 cells were transfected with siRNA control (si-control) or siRNA targeting MUC1 (si-MUC1). Cell proliferation was analyzed by cell counting kit-8 and colony formation assay, and apoptosis was analyzed by flow cytometry analysis in the 5-8F and HNE1 cells. The qPCR and ELISA were executed to analyze the levels of TNF-α and IL-6. Western blot was performed to measure the expression of MUC1, NF-кB and apoptosis-related proteins (Bax and Bcl-2). ResultsThe expression of MUC1 was up-regulated in the NPC tissues, and NPC patients with the high MUC1 expression were inclined to EBV infection, growth and metastasis of NPC. Loss of MUC1 restrained malignant features, including the proliferation and apoptosis, downregulated the expression of p-IкB、p-P65 and Bcl-2 and upregulated the expression of Bax in the NPC cells. ConclusionDownregulation of MUC1 restrained biological characteristics of malignancy, including cell proliferation and apoptosis, by inactivating NF-κB signaling pathway in NPC.
5.The Exquisite Intrinsic Mechanisms of Adverse Health Effects Caused by Overtraining
Shuai-Wei QIAN ; Xian-Juan KOU ; Chun-Yan LI
Progress in Biochemistry and Biophysics 2024;51(8):1750-1770
Overtraining is a condition characterized by various functional disorders or pathological states caused by continuous fatigue, which occurs after a persisting imbalance between training-related load and physical function and recovery. Generally speaking, it’s a state of imbalance between training and recovery, exercise and exercise performance, and stress and stress tolerance. Overtraining can cause various phenotypic changes or pathological remodeling, such as decreased skeletal muscle strength and exhaustive exercise endurance, skeletal muscle fatigue damage and dysfunction, skeletal muscle atrophy and loss, skeletal muscle glycogen depletion, skeletal muscle soreness and stiffness, skeletal muscle glucose intolerance, inattention, memory decline, anxiety, depression, abnormal emotions and behaviors, sleep disorders, cognitive function impairment, poor appetite, weight loss, liver/heart fat deposition, compensatory increase of liver/heart insulin signaling and glycogen storage, cardiac pathological hypertrophy, exercise-induced arrhythmias, myocardial fibrosis, ectopic and visceral fat deposition, and increased risk of injury. Unfortunately, its underlying mechanism is largely unclear. Recently, the enrichment of molecular and cellular signal pathway theory offers us a new explanatory paradigm for revealing its internal mechanisms. Based on the traditional explanation mechanisms and molecular and cellular signal pathway theory, we thoroughly analyzed the key mechanisms of health damage caused by overtraining from the perspective of oxidative stress, mitochondrial quality control disorder, inflammatory response, endoplasmic reticulum stress, cell apoptosis, and so forth. Specifically, overtraining-induced excessive reactive oxygen species (ROS) leads to serious oxidative stress damage in organisms at least via depressing Kelch like ECH associated protein 1(Keap1)/nuclear factor erythroid-2-related factor (Nrf2)/antioxidant response element (ARE) antioxidant pathway and activating p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway. Overtraining induces mitochondrial quality control disorder and mitochondrial dysfunction, and thus triggers health impairment through inhibiting mitochondrial biogenesis and fusion, stimulating mitochondrial fission, and over-activating autophagy/mitophagy. Overtraining can also produce muscle, skeletal and joint trauma, then circulating monocytes are abundantly activated by injury-related cytokines, and in turn generate large quantities of proinflammatory IL-1β, IL-6, TNF‑α, causing systemic inflammation and inflammatory health injury. Overtraining induces excessive pathological endoplasmic reticulum stress (ERS) and severe health damage via PERK-eIF2α, IRE1α-XBP1 and ATF6 pathways which activated by proinflammatory signals. Overtraining also induces excessive apoptosis and harmful health consequences via Bax/Bcl2-Caspase 3-mediated mitoptosis which activated by oxidative stress and inflammation or even CHOP and Caspase 12-dependent ERS apoptosis. Nonetheless, it should be importantly emphasized that oxidative stress and inflammation are the central and pre-emptive mechanisms of overtraining and its health damage. Although the efficient strategies for preventing and controlling overtraining are scientifically and reasonably arranging and planning training intensity, training volume, and recovery period, as well as accurately assessing and monitoring physical function status in the early stage, yet various anti-inflammatory, anti-oxidant, anti-apoptotic, or anti-aging drugs such as curcumin, astaxanthin, oligomeric proanthocyanidins, silibinin, hibiscus sabdariffa, dasatinib, quercetin, hydroxytyrosol, complex probiotics, astragalus polysaccharides, semaglutide and fasudil also have an irreplaceable positive effect on preventing overtraining and its relevant health damage via depressing oxidative stress, mitochondrial quality control disorder, proinflammatory signals, endoplasmic reticulum stress, apoptosis and so on. We hope that this review can help us further grasp the features, mechanisms and regularity of overtraining, and provide an important reference for athletes and sports fan to conduct scientific training, improve training effectiveness, extend exercise lifespan, and promote physical and mental health.
6.A study of the rehabilitation effects of a multi-factor intervention based on the Finnish model of prevention of cognitive impairment in the elderly on patients with cognitive impairment after first-episode stroke
Qianwen CHAI ; Minghui LU ; Shuyan LI ; Anna WU ; Xian LIU ; Meng MENG ; Nan ZHANG ; Li WEI
Chinese Journal of Practical Nursing 2024;40(10):721-729
Objective:To explore the rehabilitation effect of multi-factor intervention based on the Finnish model of prevention of cognitive impairment in the elderly on patients with cognitive impairment after first-episode stroke, and to provide reference for rehabilitation nursing of cognitive impairment after stroke.Methods:The quasi-experiment research scheme was adopted and convenience sampling method was used to select participants with first-episode stroke cognitive impairment hospitalized in the General Hospital of Tianjin Medical University Airport Site. The 50 patients admitted from January to June 2022 were selected as the control group, and 50 patients admitted from July to December 2022 were selected as the intervention group. The control group received routine rehabilitation nursing and health education, and the intervention group received the Finnish model of prevention of cognitive impairment in the elderly on patients before discharge on the basis of the control group. The Mini-Mental State Examination (MMSE) and Health Education Compliance Assessment Scale for Stroke Patients were used to evaluate the changes of overall cognitive function and rehabilitation compliance before intervention, 3 and 6 months after intervention.Results:The final control group included 49 cases, including 35 males and 14 females, aged (64.67 ± 7.47) years old; the intervention group included 50 cases, 32 males and 18 females, aged (66.68 ± 8.75) years old. Before intervention, there were no significant differences in overall cognitive function and compliance of rehabilitation score ( P>0.05). At 3 and 6 months after intervention, the overall cognitive function score, the total score on compliance of rehabilitation, dimension scores of diet compliance, exercise rehabilitation compliance and health behavior compliance of the intervention group were (26.36±2.36) , (125.96 ± 13.80) , (23.30 ± 5.26) , (27.72 ± 4.46) , (43.66 ± 6.80) and (27.26 ± 3.71) , (152.44 ± 9.06) , (30.12 ± 6.42) , (33.32 ± 3.02) , (52.36 ± 4.70) , respectively. They were higher than the control group (24.04 ± 4.50) , (116.67 ± 10.26) , (19.31 ± 3.95) , (25.29 ± 3.45) , (40.59 ± 4.33) and (24.27 ± 4.33) , (138.92 ± 16.71) , (24.20 ± 4.48) , (30.00 ± 5.53) , (47.65 ± 8.03) , and the differences had statistical significance ( t values were -5.31- -2.67, all P<0.05). According to the variance analysis of repeated measurement, intergroup and time factor, the interaction between groups and time had significant impact on general cognitive function score, the total score of rehabilitation compliance, the dimension scores of diet, exercise rehabilitation and health behavior compliance ( Fgroup values were 8.33-18.08, Ftime values were 135.71-944.69, Finteraction values were 5.46-27.30, all P<0.05) . Time factor had significant impact on patient medication adherence score ( Ftime=206.23, P<0.05) . Conclusions:Multi-factor intervention based on the Finnish model of prevention of cognitive impairment in the elderly can improve the overall cognitive function and rehabilitation compliance of patients with cognitive impairment after first-episode stroke.
7.Research progress on the role of glutamine metabolism-related proteins in tumor metastasis
Xuerou LIU ; Yumei YANG ; Qian ZHAO ; Xiangyu RONG ; Wei LIU ; Ruijie ZHENG ; Jinlong PANG ; Xian LI ; Shanshan LI
China Oncology 2024;34(1):97-103
Tumor metastasis is closely related to high mortality rate of cancer.It is well known that glutamine plays an important role in the malignant progression of cancer.Notably,as an important carbon and nitrogen donor,glutamine has been found to be closely related to tumor metastasis in recent years.Glutamine is not only involved in regulating the proliferation of tumor cells,but is also closely related to the migration and invasion of tumor cells.Furthermore,various enzymes along with transporters in the metabolism of glutamine are involved in the process of tumor metastasis through different signaling pathways.This review provided a summary of the role of glutamine in tumor metastasis in recent years and proposed therapeutic targets to provide new strategies for the clinical treatment of tumor metastases.
8.Analysis of pre-exposure prophylaxis awareness, willingness, uptake patterns, barriers and needs among MSM students and its influencing factors
Chinese Journal of School Health 2024;45(1):55-59
Objective:
To explore the pre-exposure prophylaxis (PrEP) awareness, willingness, uptake patterns, barriers and needs among Chinese student men who have sex with men (MSM), so as to provide relevant evidence for targeted interventions with PrEP.
Methods:
A proportional sampling method was used to conduct a cross sectional survey of MSM aged 16 years and older residing in 21 provinces, municipalities, and autonomous regions in mainland China between October 20 and December 20, 2021, to collect information on demographic and sexual behavioral characteristics, and 923 students of them were selected as the subjects of this study. The chi-square test and Fisher s test were used for univariate analysis, followed by multivariate Logistic regression to analyze the influencing factors of PrEP awareness and uptake.
Results:
According to the cascade analysis method, the awareness, willingness, uptake and adherence rates of PrEP among the student MSM were obtained as 88.95%, 67.36%, 13.20% and 45.21 %, respectively. HIV testing more than once in the last 3 months, and all of them were aware of the HIV test results of their sexual partners, and those with high frequency of condom use had a higher rate of awareness ( OR =2.32, 1.79, 1.69, P <0.05). Willingness rates were higher for those from the pilot city, using substances, and HIV testing more than once in the last 3 months ( OR =2.13, 1.65, 1.69, P <0.05). Higher rates of uptake were found among those from high risk and pilot areas, presence of commercial sex, substance use, and high literacy ( OR =5.60, 3.54,2.81, 1.92, 4.54, P <0.05). Adherence rates were higher among those who used one pill per day or both ( OR =12.77, 13.26, P <0.05). The barriers and needs faced by student MSM were primarily personal concerns about medication side effects, preventative effects, and confidence in sexual behavioral styles, and the high cost of medication and related service costs.
Conclusions
The student MSM population in China is characterized by high awareness, low willingness, low uptake, and low adherence to PrEP. Targeted interventions should be considered and tailored by the departments to facilitate PrEP promotion among student MSM.
9.Current status and related factors of antiviral treatment among HIV infected men who have sex with men students
Chinese Journal of School Health 2024;45(12):1798-1801
Objective:
To investigate the current situation and related factors of antiretroviral therapy (ART) among HIV infected male students engaging in men who have sex with men (MSM), so as to provide the reference data for HIV prevention and treatment.
Methods:
In November 2021, 137 MSM students from 31 provincial administrative regions in China were recruited. An online survey was conducted to collect data on demographic characteristics, ART status, CD4 count, and HIV viral load before treatment. Logistic regression was used to analyze the factors related the effectiveness of ART in MSM.
Results:
Among the included research subjects, 14.6% had late detection of HIV,97.1% of participants were currently undergoing ART. Among those whose ART duration was less than 6 months, while 76.9% were undergoing ART. Logistic regression indicated that HIV infected students who received ART for more than 24 months ( OR =5.28, 95% CI =1.38-20.22) had a higher rate of successful HIV suppression. HIV infected students who reported physical sensory side effects ( OR =0.08, 95% CI =0.01-0.71) and cognitive side effects ( OR =0.28, 95% CI =0.09-0.90) were more likely to experience failure of ARI inhibition ( P <0.05).
Conclusions
There is still room for improvement in the efficacy of ART among MSM students. Strategies to improve treatment adherence must consider individual variances among HIV infected patients and the side effects of medications when designing treatment plans.
10.Expert Consensus on Standard Terminology for Hair Transplantation (2024 Edition)
Yong MIAO ; Wei WU ; Zhenyu GONG ; Wenjie JIANG ; Yufei LI ; Zhiqi HU ; Hua XIAN ; Xiang XIE ; Weiqi YANG ; Dongyi ZHANG ; Jufang ZHANG ; Jiaxian ZHANG ; Chunhua ZHANG ; HAIR TRANSPLANTATION EXPERT GROUP OF PLASTIC AND AESTHETIC NATIONAL MEDICAL QUALITY CONTROL CENTER
Medical Journal of Peking Union Medical College Hospital 2024;15(6):1301-1310
In order to promote the development of hair transplantation, particularly the establishment of standards, the Hair Transplantation Expert Group of Plastic and Aesthetic National Medical Quality Control Center invited experts in the field of hair transplantation across China and formed a draft of the


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