ObjectiveHepatocellular carcinoma (HCC) represents 90% of all primary liver cancers. The main risk factors associated with HCC include viral hepatitis (B and/or C), alcohol abuse, and metabolic dysfunction-associated steatotic liver disease (MASLD), which progressively advance to liver fibrosis, cirrhosis, and ultimately evolve into HCC. Surgical resection represents the most effective treatment for HCC, while recent advances in immunotherapy, including immune checkpoint inhibitors and adoptive cell therapies, have provided improved treatment prospects for patients with unresectable HCC. However, the complex metabolic heterogeneity of HCC limits the therapeutic efficacy. Metabolic intermediates acyl-CoA not only provide energy and substrates for numerous biochemical reactions but also serve as donors for protein lysine acylation, a major class of post-translational modification (PTM). Therefore, a deeper understanding of the molecular mechanisms underlying protein lysine acylation and hepatocarcinogenesis is urgently needed. MethodsThe levels of protein lysine acylation and silence information regulator 5 (SIRT5) expression levels in clinical HCC samples were analyzed by Western blot. Quantitative malonylome and succinylome of HCC samples were analyzed by antibody-based affinity enrichment coupled with tandem mass spectrometry. The proliferation of HCC cells was analyzed with Cell Counting Kit-8 (CCK-8) assays, the apoptosis was quantified by Annexin V-FITC/propidium iodide (PI) staining coupled with flow cytometry, and the ability of cells to migrate was assayed by Transwell assays. The enzymatic activity of glutathione S-transferase Mu 1 (GSTM1) was quantified. Transgenic mice with hepatic overexpression of SIRT5 were constructed using CRISPR-Cas9, and primary hepatocarcinogenesis was induced by administration of diethylnitrosamine. ResultsWestern blot analysis indicated that the expression level of SIRT5 was elevated in clinical samples from HCC patients, and the levels of lysine malonylation, glutarylation, and succinylation were significantly reduced in HCC tissues. Knockout of SIRT5 in MHCC-97H and MHCC-97L hepatoma cells suppressed cell proliferation, and increased the percentage of apoptotic cells significantly. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the differentially malonylome and succinylome of HCC samples revealed significant enrichment in two major classes of biological processes: core energy metabolism (e.g., glycolysis/gluconeogenesis, tricarboxylic acid metabolic process, fatty acid beta oxidation) and detoxification and oxidative stress response (e.g., response to toxic substance, chemical carcinogenesis, reactive oxygen species (ROS)). SIRT5 removes malonylation from lysine residues in GSTM1 and restores its detoxification activity, which is crucial for the survival of hepatocytes under stressed conditions. More importantly, in vivo experiment indicated that hepatic-specific overexpression of SIRT5 in mice accelerated diethylnitrosamine-induced liver fibrosis and hepatocarcinogenesis, indicating the critical role of SIRT5 in HCC progression. ConclusionThis study highlights the previously unrecognized SIRT5-GSTM1 axis as a key regulator in hepatocarcinogenesis, and suggests a potential target for the treatment of patients with HCC.

ObjectiveTo evaluate the effect of sex on phenotypic stability in mouse models of chemotherapy-induced alopecia (CIA) induced by cyclophosphamide (CYP) or paclitaxel (PTX), and to explore potential mechanisms underlying phenotypic heterogeneity in female mice. MethodsTwenty-eight wild-type specific pathogen-free (SPF) C57BL/6J mice (half male and half female) aged 6-8 weeks were selected for synchronous back hair removal. On the 9th day after hair removal (T0), the mice were randomly divided into a wild-type female CYP group, a wild-type male CYP group, a female negative control group and a male negative control group. Mice in the CYP groups were intraperitoneally injected with a single dose of 120 mg/kg CYP, and mice in the negative control groups were intraperitoneally injected with the same volume of normal saline. Subsequently, the phenotypic changes of the CIA model induced by CYP were continuously observed and photographed. Eleven 6-week-old SPF female C57BL/6J mice underwent bilateral ovariectomy (OVX group). Following successful surgery, these mice and five XY (Sry⁻) mice bred from Four Core Genotypes breeding stock were used to establish the chemotherapy-induced alopecia (CIA) model using the same protocol. Serum was collected from mice in the OVX group, wild-type female CYP group, and wild-type male CYP group on T7 after CYP administration for steroid hormone analysis by mass spectrometry to evaluate the effects of gonadal estrogen and sex chromosome background changes on the stability of the CYP-induced female alopecic phenotype. Finally, twenty SPF C57BL/6J mice aged 6-8 weeks (half male and half female) were randomly divided into a PTX low-dose group and a PTX high-dose group. On the 9th day after simultaneous hair removal, PTX was injected intraperitoneally at a single dose of 80 mg/kg or 120 mg/kg, respectively. Mice from the PTX low-dose group and the PTX high-dose group were continuously observed and photographed to compare the intra-group consistency of the phenotypes of female and male mice. Six SPF C57BL/6J mice (half male and half female) aged 6-8 weeks were used to repeat the construction method of the PTX low-dose group, and the hair follicle histological examination was performed at T0, T4, T7, T14 and T21, respectively, to observe the damage caused by PTX to hair follicle regeneration. ResultsThe phenotypes of CYP-induced male CIA mice are stable and reproducible. There are obvious individual differences in the alopecia phenotype in the CYP-induced female CIA model mice, which may be mainly caused by the differences in the relevant estrogens in the estrous cycle. The difference between OVX+CYP group and XY (Sry⁻) +CYP group disappeared, suggesting that ovarian-derived hormones and XY (Sry⁻) sex chromosome background may be involved in the formation of phenotypic heterogeneity of CYP-induced alopecia in female mice. The mice in the high-dose PTX group and the low-dose PTX group showed a relatively consistent alopecia and regrowth process, and there was no significant sex difference. ConclusionCYP-induced CIA is strongly influenced by sex, and ovariectomy or alteration of the sex chromosome background can improve the consistency of CYP-induced alopecic phenotypes in female mice. PTX-induced CIA shows good phenotypic consistency in both female and male mice, indicating broad applicability across sexes. Taken together, the choice of animal sex in CIA model construction, mechanistic studies, and evaluation of anti-alopecia interventions should take into account the type of chemotherapeutic agent, the study objective, and the required degree of phenotypic stability. Sex should therefore be considered an important variable in model standardization and interpretation of experimental findings.

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.

A microchannel-based electrochemiluminescence(ECL)sensor was developed for detection of tetracycline(TC)utilizing luminol/H2O2 as ECL reporting system.The low excitation potential of luminol/H2O2 effectively mitigated the impact of clamping voltage,thereby enhancing the detection performance of the microchannel-based ECL sensor.The microchannel modified with TC aptamer selectively recognized and captured target TC.The positively charged TC reduced the surface charge density within the microchannel,thereby increasing the ionic current in the microchannel,leading to change of ECL signal of system.The experimental conditions such as electrolyte concentration,TC-aptamer concentration,and reaction time between TC and TC-aptamer were optimized.Under optimal conditions,the difference of ECL signal in the absence and presence of TC(?ECL)exhibited a good linear relationship with TC concentration in the range from 1.00 ng/mL to 200 ng/mL,with a detection limit as low as 0.69 ng/mL.The sensor had good selectivity and was successfully used in detection of TC in milk samples.

In this work,a fluorescent probe PIN was synthesized using indole-3-carbohydrazide and pyrenecarboxaldehyde as raw materials.PIN showed weak fluorescence emission in aqueous solution with acetonitrile volume fraction of 70％.However,when Cu2+was added to this aqueous solution of PIN,a new fluorescence emission peak appeared at 495 nm,and the intensity of this peak gradually increased with the increase of concentration of Cu2+,and also caused a significant change in the fluorescence color of the solution.In contrast,the addition of 15 kinds of other common metal ions did not cause such change.The detection limit of PIN for Cu2+was 78.7 nmol/L,which was much lower than the maximum permitting level of Cu2+in drinking water in hygienic standard for drinking water in China.Therefore,PIN was a highly selective and sensitive fluorescence-enhanced probe for Cu2+.Meanwhile,the addition of Cu2+could also cause a new absorption peak at 440 nm in the ultraviolet-visible absorption spectrum of the aqueous solution of PIN,and meanwhile the colorless PIN solution changed into yellow,exhibiting the performance of PIN as a colorimetric probe for Cu2+.By fitting with the Levenberg-Marquardt algorithm equation,the binding ratio of PIN to Cu2+was 2:1,and the binding constant was 3.42×1012 L2/mol2.In addition,the binding mode of PIN with Cu2+was explored by using proton nuclear magnetic resonance(1H NMR)titration experiments and density functional theory simulations.The results showed that the addition of Cu2+could cause the aggregation of PIN molecules to form excimers,thus showing highly selective recognition.Finally,PIN was made into a simple test strip,which could achieve rapid and convenient fluorescence detection of Cu2+in actual water samples.

Objective To establish a rapid screening and analysis method for etomidate and its ana-logues using a portable mass spectrometer equipped with a thermal desorption-atmospheric pressure chemical ionization source-linear ion trap.Methods A 10 μL aliquot of a standard solution at a con-centration of 1 μg/mL was taken,and after the solvent evaporated,the sample was inserted into the in-let of the portable mass spectrometer for detection.By adjusting the collision-induced dissociation pa-rameters,the molecular ion peak and fragment ion peak information of the standard were obtained and used to establish a reference database.In addition,the method was applied to 29 seized liquid and plant samples.Results A screening system for etomidate and its analogues was established based on the portable mass spectrometer and the corresponding mass spectrometry library.The system enables qualitative screening analysis by identifying primary protonated molecular ions and secondary product ions of etomidate and its analogues.The limits of detection for etomidate and its 12 analogues ranged from 0.1 to 10 μg/mL.Etomidate and its analogues were detected in all 29 liquid and plant samples.However,this method could not distinguish between isomeric imidazole esters,such as isopropoxate and propoxate.Additionally,when testing 2-SH-etomidate,there was a false positive for the detection of etomidate.Conclusion This study established a rapid screening method for etomidate and its ana-logues using a portable mass spectrometer.The method combines the high sensitivity of mass spectrome-try with the on-site applicability of portable devices,significantly improving detection efficiency and meeting the on-site detection needs of etomidate and its analogues.

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.

Objective To explore the feasibility and safety of ultrasound-guided percutaneous microwave ablation for unresectable pancreatic cancer.Methods Totally 84 patients who underwent ultrasound-guided percutaneous microwave ablation for unresectable pancreatic cancer were enrolled,and the technical success rate,complete ablation rate,complication rate,pain relief rate and survival time,etc.were observed.Results The median age of 84 cases was 61.5 years.Totally 86 tumors,including 44.19％(38/86)at the head/neck and 55.81％(48/86)at the body/tail of pancreas were detected,and a total of 85 ablation sessions were performed with the median ablation energy applied per tumor of 9.90(1.08,21.60)kJ and the complete ablation rate of 42.86％(36/84).The technical success rate was 100％(85/85).Thirty-nine complication events occurred in 25 cases,no ablation-related death.Among 34 patients underwent ablation mainly for pain symptoms,the pain score decreased from(6.22±1.12)points before treatment to(1.94±1.64)points after treatment(P＜0.001).During 6.8(3.3,12.9)months' follow-up,the mean survival time was(8.5±6.7)months,and all 47 patients died due to tumor progression.Conclusion Ultrasound-guided percutaneous microwave ablation was safe and feasible for unresectable pancreatic cancer.

This study was aimed at evaluating the characteristics of H9N2 subtype avian influenza viruses(AIVs)origina-ting from wild birds in major wetlands in Fujian.Five H9N2 subtype AIVs isolated from fecal samples from wild birds in wet-lands of the Minjiang River,Jiulong River,Sandu Bay,Xinghua Bay,and Quanzhou Bay in Fujian were sequenced.Sequence a-nalysis of the HA genes of the five H9N2 subtype AIVs indicated that the five isolates shared 89.8％-99.4％nucleotide se-quence identity.All five isolates belonged to the same h9.4.2.5c evolutionary branch.The cleavage site motifs of HA were all PSRSSR ↓ GLF,thus indicating molecular characteristics of AIVs with low pathogenicity.The HA proteins of the viruses orig-inating from wild birds bore eight identical potential glycosylation sites,among which the glycosylation site at position 313 was located near the HA protein cleavage site.The 226th amino acid of HA in the receptor binding site was leucine in each virus,thus indicating that HAs of the five H9N2 subtype AIVs had mammalian sialic acid α-2,6 receptor binding affinity.In conclu-sion,the five H9N2 subtype AIVs originating from wild birds in Fujian had low pathogenicity,and the HAs had mammalian sialic acid α-2,6 receptor binding affinity.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder affecting multiple systems, characterized by the development of harmful autoantibodies and immune complexes that lead to damage in organs and tissues. Chinese medicine (CM) plays a role in mitigating complications, enhancing treatment effectiveness, and reducing toxicity of concurrent medications, and ensuring a safe pregnancy. However, CM mainly solves the disease comprehensively through multi-target and multi-channel regulation process, therefore, its treatment mechanism is often complicated, involving many molecular links. This review introduces the research progress of pathogenesis of SLE from the aspects of genetics, epigenetics, innate immunity and acquired immunity, and then discusses the molecular mechanism and target of single Chinese herbal medicine and prescription that are commonly used and effective in clinic to treat SLE.
Lupus Erythematosus, Systemic/immunology* ; Humans ; Medicine, Chinese Traditional ; Drugs, Chinese Herbal/pharmacology* ; Animals