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.

Protein as the allergens could lead to allergy. In addition, a widespread class of allergens were known as glycans of N-glycoprotein. N-glycoprotein contained oligosaccharide linked by covalent bonds with protein. Recently,studies implicated that allergy was associated with glycans of heterologous N-glycoprotein found in food, inhalants, insect toxins, etc. The N-glycan structure of N-glycoprotein allergen has exerted an influence on the binding between allergens and IgE, while the recognition and presentation of allergens by antigen-presenting cells (APCs) were also affected. Some researches showed thatN-glycan structure of allergen was remodeled by N-glycosidase, such as cFase I, gpcXylase, as binding of allergen and IgE partly decreased. Thus, allergic problems caused by N-glycoproteins could potentially be solved by modifying or altering the structure ofN-glycoprotein allergens, addressing the root of the issue. Mechanism of N-glycans associated allergy could also be elaborated through glycosylation enzymes, alterations of host glycosylation. This article hopes to provide a separate insight for glycoimmunology perspective, and an alternative strategy for clinical prevention or therapy of allergic diseases.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

Objective To establish an indirect enzyme-linked immunosorbent assay(ELISA)method for testing the concentration of a monoclonal antibody target tumor necrosis factor-α(TNF-α)in animal serum.Methods The critical parameters of the method including coating concentration of human TNF-α,source,concentration and stability of HRP-labeled goat anti-human immunoglobulin G(IgG)were investigated.The specificity,accuracy,precision,linearity and Limited of Determination of the method were investigated.Results The critical parameters of the method were confirmed as below:TNF-α was coated at 400 ng·mL-1;HRP labeled goat anti-human IgG antibody was diluted at 1:3.0 ×105;the diluted horseradish peroxidase labeled goat anti-human IgG antibody is well stored at 4 ℃ for 3 days.Meanwhile the method was confirmed to have good specificity,the recovery rate ranged from 84.00％to 106.82％,the coefficient of variation of different antibody concentration levels were no more than 10％;the method had a good linearity and the standard curve was y=(-8.37×103-2.37 × 106)/[1+(x/29.80)106]+2.37 × 106(R2=0.999);the limit of quantification was 1 ng·mL-1,all of which met the requirements.Conclusion A accurate and robust ELISA method was developed to test the concentration of anti-TNF-α monoclonal antibody in serum.

Monosodium urate (MSU)-induced the gouty arthritis (GA) model was used to investigate the effect of Nod-like receptor protein 3 (NLRP3) inhibitor N14 in alleviating GA. Firstly, the effect of NLRP3 inhibitor N14 on the viability of mouse monocyte macrophage J774A.1 was examined by the cell counting kit-8 (CCK-8) assay. The expression of mature interleukin 1β (IL-1β) and cysteinyl aspartate specific proteinase-1 (caspase-1) p20 in the cell supernatant and the expression of NLRP3, caspase-1 and pro-IL-1β proteins in the cell lysates was detected by Western blot for the inhibitory effect of N14 on the MSU-induced NLRP3 inflammasome activation in J774A.1 cells. Animal behavioral tests were used to detect redness, swelling, heat and pain in mice with gouty arthritis. Hematoxylin-eosin (H&E) staining revealed pathologic changes and inflammatory infiltration in foot sections. Protein expression of NLRP3, caspase-1, and pro-IL-1β in mouse hind paw tissues were assessed by Western blot. The effect of N14 on the plasma levels of alanine transaminase (ALT), aspartate transaminase (AST), creatinine (CRE), urea, and uric acid (UA) was investigated by the MSU-induced gouty arthritis model in mice. All animal experiments in this paper were approved by the Scientific Ethics Review Board of Qingdao Marine Biomedical Research Institute (grant No. E-MBWNL-2024-20). The experimental results showed that N14 did not exhibit cytotoxicity in mouse monocyte macrophage J774A.1 cells at concentrations up to 100 μmol·L^-1, and N14 effectively prevented MSU-induced activation of NLRP3 inflammasome. In the mouse gouty arthritis model, N14 significantly ameliorated the redness, swelling, heat and pain caused by GA, and down-regulated the levels of NLRP3 inflammasome-associated proteins in mouse hind paw tissues. Meanwhile, N14 appeared to be well tolerated, as it did not significantly affect various biochemical indices in mouse plasma. In conclusion, N14 effectively alleviated GA in mice by inhibiting the NLRP3 inflammasome pathway, which is important for both prevention and treatment of related diseases.

Objective To study the in vitro expression of three phenylalanine hydroxylase(PAH)mutants(p.R243Q,p.R241C,and p.Y356X)and determine their pathogenicity.Methods Bioinformatics techniques were used to predict the impact of PAH mutants on the structure and function of PAH protein.Corresponding mutant plasmids of PAH were constructed and expressed in HEK293T cells.Quantitative reverse transcription polymerase chain reaction was used to measure the mRNA expression levels of the three PAH mutants,and their protein levels were assessed using Western blot and enzyme-linked immunosorbent assay.Results Bioinformatics analysis predicted that all three mutants were pathogenic.The mRNA expression levels of the p.R243Q and p.R241C mutants in HEK293T cells were similar to the mRNA expression level of the wild-type control(P>0.05),while the mRNA expression level of the p.Y356X mutant significantly decreased(P<0.05).The PAH protein expression levels of all three mutants were significantly reduced compared to the wild-type control(P<0.05).The extracellular concentration of PAH protein was reduced in the p.R241C and p.Y356X mutants compared to the wild-type control(P<0.05),while there was no significant difference between the p.R243Q mutant and the wild type control(P>0.05).Conclusions p.R243Q,p.R241C and p.Y356X mutants lead to reduced expression levels of PAH protein in eukaryotic cells,with p.R241C and p.Y356X mutants also affecting the function of PAH protein.These three PAH mutants are to be pathogenic.[Chinese Journal of Contemporary Pediatrics,2024,26(2):188-193]

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

The present study aimed to investigate the inhibitory effect and mechanism of Isodon terricolous-medicated serum on lipopolysaccharide(LPS)-induced hepatic stellate cell(HSC) activation. LPS-induced HSCs were divided into a blank control group, an LPS model group, a colchicine-medicated serum group, an LPS + blank serum group, an I. terricolous-medicated serum group, a Toll-like receptor 4(TLR4) blocker group, and a TLR4 blocker + I. terricolous-medicated serum group. HSC proliferation was detected by methyl thiazolyl tetrazolium(MTT) assay. Enzyme-linked immunosorbent assay(ELISA) was used to measure type Ⅰ collagen(COL Ⅰ), COL Ⅲ, transforming growth factor-β1(TGF-β1), intercellular adhesion molecule-1(ICAM-1), α-smooth muscle actin(α-SMA), vascular cell adhesion molecule-1(VCAM-1), cysteinyl aspartate-specific proteinase-1(caspase-1), and monocyte chemotactic protein-1(MCP-1). Real-time PCR(RT-PCR) was used to detect mRNA expression of TLR4, IκBα, and NOD-like receptor thermal protein domain associated protein 3(NLRP3), nuclear factor-κB(NF-κB) p65, gasdermin D(GSDMD), and apoptosis-associated speck-like protein containing a CARD(ASC) in HSCs. Western blot(WB) was used to detect the protein levels of TLR4, p-IκBα, NF-κB p65, NLRP3, ASC, and GSDMD in HSCs. The results showed that I. terricolous-medicated serum could inhibit the proliferation activity of HSCs and inhibit the secretion of COL Ⅰ, COL Ⅲ, α-SMA, TGF-β1, caspase-1, MCP-1, VCAM-1, and ICAM-1 in HSCs. Compared with the LPS model group, the I. terricolous-medicated serum group, the colchicine-medicated serum group, and the TLR4 blocker group showed down-regulated expression of p-IκBα, NLRP3, NF-κB p65, GSDMD, and ASC, and up-regulated expression of IκBα. Compared with the TLR4 blocker group, the TLR4 blocker + I. terricolous-medicated serum group showed decreased expression of TLR4, p-IκBα, NLRP3, NF-κB p65, GSDMD, and ASC, and increased expression of IκBα. In conclusion, I. terricolous-medicated serum down-regulates HSC activation by inhibiting the TLR4/NF-κB/NLRP3 signaling pathway.
NF-kappa B/metabolism* ; Hepatic Stellate Cells ; Transforming Growth Factor beta1/metabolism* ; NF-KappaB Inhibitor alpha/metabolism* ; Intercellular Adhesion Molecule-1/metabolism* ; Isodon ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Toll-Like Receptor 4/metabolism* ; Vascular Cell Adhesion Molecule-1/metabolism* ; Lipopolysaccharides/pharmacology* ; Signal Transduction ; Colchicine/pharmacology* ; Caspases

ObjectiveTo investigate the effects of epidural analgesia plus dexmedetomidine infusion on postpartum depression in parturients with natural childbirth. MethodsWe selected 70 parturients aged between 22 and 36， with singleton， term， cephalic presentation， natural delivery and ASA class I or Ⅱ. The cases undergoing epidural analgesia with ropivacaine and sufentanil were randomly divided into two groups by using a random number table （n=35 for each group）. The control group （Group C） used intravenous infusion of normal saline， while the experimental group （Group D） used equivalent volumes of intravenous infusion of dexmedetomidine. Participants were followed up at 1， 6， 12 weeks after childbirth to assess the severity of postpartum depression. Blood samples were collected at 12 h and 48 h after childbirth to measure the serum prolactin levels. The hemodynamic （HR and MAP） changes， VAS scores， and Ramsay scores were recorded at five time points： before analgesia （T1）， 10 min after analgesia （T2）， 30 min after analgesia （T3）， 12 h （T4） and 24 h （T5） after delivery. The number of analgesia pump presses and adverse events were also documented. ResultsCompared with Group C， Group D showed significantly lower EPDS scores at 1 week after childbirth， significantly higher prolactin concentrations at 12 h and 48 h after childbirth， significantly lower VAS scores at T2， T3 and T4， significantly higher Ramsay score at T3 and significantly reduced number of analgesia pump presses （P < 0.05）. ConclusionEpidural analgesia plus intravenous infusion of dexmedetomidine can alleviate early postpartum depression in women undergoing natural delivery， promote early prolactin secretion and provide a safe and effective adjunctive analgesic and sedative effect.