Objective To explore the construction of heart preservation model of empty beating donor based on extracorporeal membrane oxygenation (ECMO). Methods From January 2022 to August 2023, 20 Guangxi Bama miniature pigs weighing 25-30 kg were selected, half male and half female. Under general anesthesia and heparinization, a midline thoracotomy was performed. The pericardium was cut after freeing the anterior and posterior vena cavae, and a perfusion needle was inserted near the brachiocephalic artery in the ascending aorta, connected to a blood collection bag to collect 500-600 mL of blood. The anterior and posterior vena cavae were ligated, the aorta was blocked and perfused with HTK solution to stop the heart beating. The superior and inferior vena cavae were cut off, the right pulmonary vein was decompressed, the aorta and left and right pulmonary arteries and veins were cut off, and the whole heart was removed. An ECMO device was used to continuously perfuse a cardioprotective solution mainly composed of oxygenated warm blood, maintaining the isolated pig heart beating for 8 hours, monitoring (once/hour) ECMO perfusion parameters, blood gas indicators, perfusate electrolytes, inflammatory factors, myocardial enzymes, myoglobin, and troponin levels. Myocardial tissue was taken for hematoxylin-eosin (HE) staining to observe myocardial cell damage and evaluate the quality of heart preservation. Results Among the 20 isolated beating pig hearts, 17 successfully resumed beating, 3 experienced ventricular fibrillation, resuscitated after intracardiac electrical defibrillation, and all 20 pig hearts successfully beat for 8 hours. There was no statistical difference in ECMO perfusion parameters, blood gas indicators, perfusate electrolytes, and inflammatory factors at each time point (P>0.05). There were statistical increases in myocardial enzymes, myoglobin, and troponin levels (P<0.05). HE staining results suggested that there was no severe myocardial damage. Conclusion ECMO technology can be used for pig heart preservation with good results, and this study provides experimental evidence for improving heart preservation research in clinical heart transplantation.

Objective To investigate the expression characteristics of c-MET protein in colorectal cancer (CRC) and its associations with clinicopathological parameters, MET gene amplification status, and prognosis, and to evaluate the concordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) detection strategies, thereby providing evidence for patient selection for MET-targeted therapy. Methods A total of 193 formalin-fixed paraffin-embedded (FFPE) tissue samples from CRC patients were collected. Immunohistochemistry (IHC) was used to detect c-MET protein expression, and fluorescence in situ hybridization (FISH) was performed to evaluate MET gene amplification status. The associations between c-MET protein expression and clinicopathological characteristics, including KRAS, NRAS, and BRAF mutation status, as well as progression-free survival (PFS), were analyzed. The concordance between IHC and FISH detection results was also evaluated. Results c-MET protein expression was significantly higher in tumor tissues than in adjacent normal tissues (P<0.05). Significant differences in c-MET expression were observed between primary tumors and liver or peritoneal/pelvic metastatic lesions (P<0.05). The proportion of high c-MET expression was significantly higher in KRAS-mutant patients than in KRAS wild-type patients (41.38% vs. 16.92%, P<0.05). The MET gene amplification rate was 8.29% (16/193), including clustered or diffuse amplification in 1.55% (3/193) and heterogeneous amplification in 6.74% (13/193). No MET exon 14 skipping mutation or amplification was detected by next-generation sequencing (NGS). Using an IHC H-Score≥150 as the threshold, the positive percent agreement (PPA) between IHC-detected c-MET protein expression and FISH-detected MET gene amplification was 100%. All clustered MET amplification regions exhibited diffuse strong c-MET expression (IHC 3+). No statistically significant association was observed between c-MET expression level and PFS (P>0.05). Conclusion High c-MET expression may represent a potential therapeutic target for KRAS-mutant CRC patients. An H-Score ≥150 is recommended as the initial screening threshold to rapidly identify patients suitable for MET-targeted therapy, with FISH testing when necessary. Diffuse strong c-MET expression (IHC 3+) shows high concordance with clustered MET gene amplification.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

AIM To study the chemical constituents from Tylophora ovata(Lindl.)Hook.ex Steud.and their antibacterial activities.METHODS Ethanol extract was isolated and purified by MCI,silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by spectral data.The inhibitory activities of each compound against Phomopsis sp.were determined by mycelial growth rate method.RESULTS Twenty-six compounds were identified as paeonol(1),stigmast-4-en-3-one(2),ergosta-4,6,8(14),22-tetraen-3-one(3),2,4-methoxyphenol(4),1,2,4-trimethoxybenzene(5),3-methoxyphenol(6),3,4-dimethoxyacetophenone(7),5α,8α-epidioxy-ergosta-6,22(E)-diene-3β-ol(8),kaempferol 3-O-β-D-galactopyranoside(9),glaucogenind C(10),glaucoge-nin A 3-O-β-D-cymaropyranoside(11),dibutyl phthalate(12),cynatratoside A(13),hirundigoside C(14),sublanceoside B2(15),cynanoside A(16),dipentyl phthalate(17),5-hydroxymethyl-2-furancarboxaldehyde(18),bis-(2-ethyl)hexylphthalate(19),p-hydroxybenzoic acid(20),syringic acid(21),β-hydroxypropiovanillone(22),3-hydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(23),(+)-syringare sinol(24),(-)-syringare sinol(25),(+)-medioresinol(26).IC50 value of compound 12 was 37.27 μg/mL.CONCLUSION Compounds 1-26 are isolated from this plant for the first time.Compound 12 has inhibitory activity against Phomopsis sp.

Aim To investigate the effects of rutae-carpine(RUT)on lung inflammation in septic mice and the underlying mechanisms.Methods The sepsis mouse model was generated by intraperitoneal injection of lipopolysaccharide(LPS)at 5 mg·kg-1.The mice were randomly divided into the Control group,Model group,Low-dose,Medium-dose,High-dose RUT(5,10,20 mg·kg-1)treatment group and dexamethasone(DEX,2 mg·kg-1),with 10 mice in each group.The mice were intraperitoneally injected with RUT 30 min before LPS injection.HE staining was used to observe the morphology of lung tissues,and activity of my-eloperoxidase was determined to assess the neutrophil infiltration.Wet/dry weight ratio and Evan's blue ex-travasation of lung tissues were examined to assess lung edema.Survival analysis was performed to determine the in vivo protective effects of RUT.ELISA and quan-titative RT-PCR analysis were employed to determine the contents and gene expression of pro-inflammatory mediators,including tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1 β),IL-6,and IL-18 in lung tis-sues.Western blot was used to detect the protein levels of p38 MAPK,NF-κB,Caspase-1,NOD-like receptor family pyrin domain containing 3(NLRP3)and IL-18.Results RUT at 10-20 mg·kg-1 could dose-de-pendently inhibit leukocyte infiltration,reduce pro-in-flammatory mediator production,vascular permeability and wet/dry weight ratio in lungs,similar to the effects induced by DEX.The mice treated with RUT exhibited increased survival,down-regulated expressions of p-p38 MAPK,p-NF-κB,Caspase-1,NLRP3,and IL-18 pro-teins in lungs,with decreased IL-18 mRNA level.Conclusions RUT exhibits protective effects on sep-sis-induced lung injury,manifested by reduced inflam-mation and edema,potentially via inhibition of p38 MAPK signaling pathway and inflammasome formation.

Objective To develop and validate a transgenic mouse model enabling specific and inducible optogenetic activation of oligodendrocyte precursor cells(OPCs).Methods A conditional allele for the photosensitive opsin chicken opsin 5(cOpn5)(Rosa26-LSL-cOpn5)was generated using CRISPR/Cas9 technology.These mice were subsequently crossed with NG2-CreERT transgenic mice to produce NG2-CreERT;cOpn5 animals.In this model,tamoxifen administration induces Cre-mediated recombination,leading to specific expression of cOpn5 in NG2-positive OPCs.The specificity and efficiency of cOpn5 expression in OPCs were confirmed by immunofluorescent staining.Functional validation of light-induced OPC activation was performed by using calcium imaging in acute brain slices after stimulation with 470 nm blue light.Results Immunofluorescence analysis confirmed robust and specific expression of cOpn5 within NG2-positive OPCs in the brains of tamoxifen-treated NG2-CreERT;cOpn5 mice.Crucially,calcium imaging of acute brain slices from these mice demonstrated a significant increase in intracellular calcium levels in cOpn5-expressing OPCs upon stimulation with 470 nm blue light,indicating successful optogenetic activation.Conclusion We have successfully generated and validated a novel transgenic mouse model(NG2-CreERT;cOpn5)that permits specific and inducible optogenetic activation of OPCs.This model provides a novel tool for subsequent in vivo studies of the role and regulating mechanisms of OPCs in the central nervous system.

Endometriosis(EMs)is a common estrogen-depend-ent clinical disease with the pathological characteristics of malig-nant tumors,which has great impact on women's physical and mental health.In recent years,experimental exploration has re-vealed that ectopic foci are in a hypoxic environment outside the uterine cavity,and mitochondria,as the"functional factories"of the cells,play an important role in the process of planting and in-vasion,and the mitochondrial quality control system,which in-cludes mitochondrial oxidative stress,kinetics,autophagy,bio-genesis and calcium homeostasis,is a key mechanism for the e-quilibrium of the mitochondrial function.The mitochondrial quality control system,including mitochondrial oxidative stress kinetics,autophagy,biogenesis and calcium homeostasis,is a key mechanism for mitochondrial functional balance.Therefore,to clarify the role of the mitochondrial quality control system in the development of EMs with the help of rational and rigorous experi-mental and clinical studies can not only help to clarify the patho-genesis of the disease,but also explore the key targets in the prevention and treatment of the disease.Therefore,this article summarizes the research progress of mitochondrial quality control system in endometriosis,with a view to providing reference and theoretical basis for the etiology,pathogenesis and prevention strategies of EMs.

Objective:To investigate the anti-heart failure mechanism of N-acetylcysteine(NAC)in diabetic cardiomyop-athy independent from coronary artery factors.Methods:A total of 40 diabetic mice after heart failure model construction were randomly divided into two groups,NAC group(n=20,NAC 100mg·kg-1·d-1)and control group(n=20,Saline 100 mg·kg-1·d-1).Echocardiography was performed to detect left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular ejection fraction(LVEF),mitral left ventricular early-dias-tolic peak flow velocity/left ventricular late-diastolic peak flow velocity(E/A),isovolumic relaxation time(IVRT)and cardiac output(CO)after 4 weeks.Terminal uridine nick-end labeling(TUNEL)was performed to detect apoptosis in-dex,and Western Blot was performed to detect the expression of extracellular regulated protein kinases(ERK)1/2 after 6 weeks in two groups.Results:Compared to those in control group,mice in NAC group had significant higher LVEF[(40.5±3.4)％vs.(36.9±3.2)％],E/A[(1.5±0.1)vs.(1.4±0.1)]and CO[(10.3±0.6)ml/min vs.(9.9±0.5)ml/min](P＜0.05 or＜0.01);and significant lower LVESV[(23.1±1.3)μl vs.(24.7±1.5)μl],apoptosis index[(31.2±0.5)％vs.(45.1±0.9)％]and the expression of ERK1/2[(2.2±0.2)vs.(3.9±0.1)](P＜0.001 all).Conclusion:NAC exerts anti-heart failure effect by attenuating apoptosis of cardiomyocytes via regulating ERK1/2 pathway.

Aim To explore the mechanism of Jiawei Shaofu Zhuyu decoction in antagonizing endometriosis fibrosis by regulating mitophagy.Methods After the animal model was constructed,the syndrome was evalu-ated by general condition,organ water content and ther-mal imaging.The curative effect was evaluated by the weight of ectopic focus and the degree of adhesion.The pathological changes were compared using HE stai-ning,transmission electron microscopy,Masson and Sir-ius red staining.The expression of PINK1 and Parkin was detected by immunohistochemistry.The expression of mRNA and protein was determined by qPCR and Western blot,and the level of serum ROS was detected by ELISA.Results The autonomic activity of model mice was weakened,the water content of organs rose,and the temperature of limbs and lower abdomen was reduced by thermal imaging.HE staining showed obvi-ous hyperplasia of ectopic epithelium and glands.Transmission electron microscopy showed mitochondrial and endoplasmic reticulum structure damage,and nor-mal autophagy structure disappeared.Masson and Siri-us red staining showed increased collagen deposition;immunohistochemistry showed decreased expression of PINK1 and Parkin in ectopic foci.qPCR and Western blot showed that the expression of PINK1,Parkin,Bec-lin1,LC3 mRNA and protein in ectopic foci of model mice decreased,the expression of p62 mRNA and pro-tein increased,and serum ROS increased.The syn-drome performance of model mice was improved after the intervention of Jiawei Shaofu Zhuyu decoction;the inflammatory infiltration of ectopic foci was relieved,the morphology of mitochondria and endoplasmic retic-ulum was restored,and normal autophagy structure ap-peared.The degree of collagen deposition and fibrosis was reduced;the mRNA and protein expression of PINK1,Parkin,Beclin1 and LC3 increased.The ex-pression of p62 mRNA and protein decreased,and the level of ROS decreased.Conclusions Jiawei Shaofu Zhuyu decoction can improve the fibrosis of ectopic le-sions in mice with endometriosis of cold-dampness sta-sis syndrome,which may be related to the regulation of mitophagy.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.