Objective : To construct a molecular classification system for head and neck squamous cell carcinoma (HNSCC) utilizing hypoxia-related gene (HAG) expression profiles, and to comprehensively examine the clinicopathological significance and biological functions of the hypoxia gene stanniocalcin 2 (STC2) in HNSCC. Methods : Transcriptomic data and clinical information of 546 HNSCC samples were obtained from The Cancer Genome Atlas (TCGA) database, and based on the expression profiles of 200 HRGs, HNSCC was classified subclasses using non-negative matrix factorization (NMF). HNSCC was classified into three subclasses (C1, C2, and C3), and the molecular characteristics and prognostic differences of the subclasses were assessed by comparing the tumor mutation load, functional enrichment analysis, drug sensitivity, and clinical features among the subclasses. LASSO-Cox regression was used to screen prognosis-related genes and construct prognostic models. Using oral squamous cell carcinoma (OSCC)-related data in the TCGA database, we analyzed the expression differences of STC2 in OSCC and control samples, and detected the mRNA and protein expression of STC2 in oral squamous carcinoma samples using qRT-PCR and immunohistochemistry. We knocked down STC2 in CAL-27 cells and verified the knockdown efficiency by qRT-PCR and Western blot. CCK-8 assay and cell scratch assay were used to assess the effect of STC2 on cell proliferation and migration ability. Results: Based on HRGs expression profiles, HNSCC was categorized into three subclasses (C1, C2, and C3). Subclass C1 had moderate hypoxic activity and good prognosis; subclass C2 had the highest hypoxic activity, poor prognosis, and poor sensitivity to CTLA-4 inhibitors (P<0.05); subclass C3 had the lowest hypoxic activity and moderate prognosis, and STC2 belonged to subclass C3. The frequency of cyclin-dependent kinase inhibitor 2A (CDKN2A), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and tumor protein p53 (TP 53) mutations was higher in HNSCC. C1 genomic gain and deletion burden were significantly higher than C3 subclass (P<0.05) and C2 genomic gain than C3 subclass (P<0.05). The C2 subclass was significantly enriched in hypoxia-associated pathways, such as glycine metabolism and base excision repair (P<0.05). The C1, C2, and C3 subclasses were significantly positively correlated in terms of sex (male) (Cramer’s V=0.15), radiation exposure (Cramer’s V=0.12), medication (Cramer’s V=0.18), and pathological grading (G1/G2) (Cramer’s V=0.25) (P<0.05). Nine prognosis-related genes were screened by LASSO-Cox regression, among which high expression of STC2 was positively correlated with poorer overall survival (OS) in HNSCC patients (P<0.01). Bioinformatics analysis showed that STC2 mRNA expression was higher in OSCC than in normal controls (P<0.05). qRT-PCR and immunohistochemistry confirmed that both mRNA and protein expression of STC2 were significantly upregulated in OSCC tissues and cells (P<0.01). In vitro experiments showed that STC2 expression was knocked down to approximately 80% in CAL-27 cells (P<0.001), and the STC2 knockdown group had a reduced value-added rate (P<0.001) and a reduced percentage of scratch closure (P<0.05) compared with the control group. Conclusion We successfully constructed a molecular typing system for HNSCC based on the expression profiles of HRGs and categorized HNSCC into three subclasses with significant prognostic differences, among which the C2 subclass had the highest hypoxic activity and the poorest prognosis. STC2 was highly expressed in HNSCC and suggested a poor prognosis, demonstrating that it may be a potential target for HNSCC treatment.

Hepatic ischemia-reperfusion injury （HIRI） is an inevitable major complication during surgical procedures such as liver transplantation and partial hepatectomy， and its prevention and treatment are hotspots and difficulties in clinical practice. This article reviews the mechanism of injury caused by energy metabolism disorders during liver ischemia-reperfusion and related treatment strategies and summarizes the current advances in metabolism-related therapies， in order to provide new ideas for further clarifying the onset mechanism of HIRI and exploring effective clinical prevention and treatment strategies for HIRI.

Bacillus is a class of spore-producing Gram-positive bacteria that produce a variety of antimicrobial substances with different structures and functions. The application of the antimicrobial substances produced by Bacillus can effectively inhibit the activity of harmful bacteria and fungi and promote the sustainable development of green agriculture. The antimicrobial substances produced by Bacillus mainly include proteins, lipopeptides, polyketones, and polypeptides. This paper reviews the synthesis gene clusters, synthesis pathways, structures, and mechanisms of various antimicrobial substances produced by Bacillus and discusses the challenges in the industrial application of these antimicrobial substances. Furthermore, this paper clarifies the future research and development focuses and prospects the application prospects, and provides comprehensive theoretical support for the in-depth research and wide application of the antimicrobial substances produced by Bacillus.
Bacillus/genetics* ; Anti-Infective Agents/metabolism* ; Bacterial Proteins/genetics* ; Antimicrobial Peptides/biosynthesis* ; Lipopeptides/biosynthesis*

Objective Using the weighted gene co-expression network analysis(WGCNA)to explore the key genes of aging associated with Alzheimer's disease(AD).Methods GSE132903 was selected from GEO database as the analysis dataset.The differential expressed genes(DEGs)of AD were screened,and visualized with volcano and heat map.Aging and senescence-associated genes(ASAGs)were downloaded from MsigDB,Aging Altas and CellAge databases.WGCNA screened the gene modules with the highest correlation with AD,and genes of key modules subsequently performed with gene ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis.AD age-related differential expressed genes(ARDEGs)were obtained by taking intersection genes of DEGs,key module genes of WGCNA and ASAGs.Protein-protein interaction(PPI)network analysis was performed using the STRING database to find key node genes.The co-expression networks and associated functions of key genes were analyzed using the GeneMANIA database.The key genes were validated in Alzdata database.Results 226 DEGs,606 ASAGs and 8 ARDEGs were obtained.The top 5 key genes selected by PPI were SYP,STXBP1,VAMP2,CPLX1 and STX1A.Alzdata database verified that the expressions of 5 key genes in other brain regions of AD were down-regulated,except for no significant changes of VAMP2 in hippocampus and STXBP1 in frontal cortex,as well as no expression of CPLX1 in frontal cortex.The differential expression of VAMP2,STXBP1 and STX1A appeared in the early stage of AD,and CPLX1 was related to the pathological process of Tau.SYP and STXBP1 were related to the pathological processes of amyloid β-protein and Tau.Conclusion SYP,STXBP1,VAMP2,CPLX1 and STX1A are ARDEGs,which are expected to be potential diagnostic and therapeutic targets for AD.

Objective:To study the distribution of drug resistance genes and virulence genes in multidrug-resistant Salmonella typhimurium strains.Methods:A total of 96 strains of Salmonella typhimurium were collected，and drug sensitivity tests were performed to evaluate the drug resistance and multidrug-resistance of Salmonella typhimurium.Multidrug-resistant Salmonella typhimurium strains were selected to conducted whole genome sequencing，and the distribution of drug resistance genes and virulence genes in the strain were analyzed.Results:Salmonella typhimurium strains had the highest resistance rates to ampicillin and ampicillin/sulbactam，with 89.58% and 76.04%，respectively.Followed by trimethoprim/sulfamethoxazole，ceftriaxone，and aztreonam，with 47.92%，38.54% and 33.33%，respectively，and low resistance rates to ciprofloxacin and levofloxacin，with 8.33% and 4.17%，respectively.Ninety-six strains were all sensitive to carbapenem antibiotics and piperacillin/tazobactam.Fifty-seven strains（59.38%）of Salmonella typhimurium showed multidrug-resistance.Resistance genes were detected in all 57 multidrug-resistant Salmonella typhimurium strains,with higher carrier rates of 98.25%,77.19%,and 59.65% for aac(6')-Iaa,aadA22,and blaTEM-1B,respectively.The multidrug-resistant Salmonella typhimurium strains had the highest carrier rates for invA，sipA，sseL，and sopB.Conclusion:Multidrug-resistant Salmonella typhimurium strains have a high incidence and a high carrier rate for multiple drug resistance genes and virulence genes.The monitoring and prevention of Salmonella typhimurium should be strengthened in the clinic in order to reduce the spreading epidemic of multidrug-resistant strains.

Objective To investigate the effect of transcranial direct current stimulation(tDCS)in the left posterior sylvia temporal-parietal association area on language function in patients with post-stroke conductive aphasia.Methods The post-stroke aphasia patients admitted to the Department of Rehabilitation Medicine,Xuanwu Hospital,Capital Medical University were prospectively included from June 2021 to April 2024.A self-cross randomized controlled trial was performed in this study.The patients enrolled were assessed as conductive aphasia by Western aphasia test kit diagnostic criteria.Twelve patients with post-stroke conductive aphasia were completely randomly divided into group A(treatment sequence:stage A—washout period—stage B)and group B(treatment sequence:stage B—washout period—stage A),with 6 cases in each group.Stage A performed true tDCS therapy combined with speech and language training,and stage B performed sham tDCS therapy combined with speech and language training.During washout period,only speech and language training was performed,and each stage was trained for 5 days.The tDCS anode is the stimulation electrode and is placed at the stimulation target.The cathode is the reference electrode and is placed on the right shoulder.The intensity of tDCS was 1.4 mA,the true stimulation was 20 min/time,and the sham stimulation stopped automatically after only 30 s/time,both twice/d,and a total of 10 times treatment were performed.Speech and language training was performed 30 min/time,2 times/d,a total of 10 times treatment.The function of rehearsal and picture naming(training item and non-training item)were examined before and after treatment of stage A and B immediately,and the difference of function scores of rehearsal and picture naming(training item and non-training item)before and after treatment of stage A and B were compared.Results(1)There were no significant differences in gender,age,course of disease and educational level between group A and group B(all P＞0.05).(2)Before and after washout period,there were no statistical significance in functional scores of rehearsal and picture naming(training items and non-training items)in both group A and group B(all P＞0.05).(3)There were no significant differences in functional scores of rehearsal and picture naming(training items and non-training items)between group A and group B before and after washout treatment(all P＞0.05).(4)Compared with the difference before and after treatment of stage B,the function scores difference before and after treatment of stage A in rehearsal function,picture naming(training item)and picture naming(non-training item)were higher([6.9±1.4]scores vs.[2.2±1.0]scores,t=9.604;[6.2±1.2]scores vs.[1.8±1.1]scores,t=9.277;[6.5±1.0]scores vs.[1.5±1.0]scores,t=12.247;all P＜0.01).Conclusions Preliminary analysis suggested that tDCS intervention in the brain tissue of the temporoparietal association area of the left posterior lateral cleft may help improve the rehearsal and picture naming(training and non-training items)ability in conductive aphasia patients after stroke.The sample size of this study is small,and the results need to be further explored.

Pulmonary fibrosis is a progressive interstitial fibrotic lung disease with high mortality.Its pathogenesis is complex and involves the reprogramming of fatty acid metabolism.This reprogramming includes changes in de novo fatty acid synthesis,uptake,oxidation,and derivatives.It crucially influences alveolar epithelial cell survival,macrophage polarization,and fibroblast activation,thereby playing a significant role in either exacerbating or miti-gating the disease.Understanding and intervening in the reprogramming of fatty acid metabolism offers potential strategies for prevention,diagnosing and treatment of pulmonary fibrosis.

Background Quartz dust cannot be degraded in the lungs, and inhalation of a large amount of quartz dust in the occupational production process will lead to the occurrence of pulmonary fibrosis, and then develop into silicosis. In recent years, studies have found that exosomes may be involved in the pathogenesis of fibrotic diseases by carrying microribonucleic acid (miRNA), but the mechanism of their actions in silicosis still needs to be studied. Objective To investigate the role of exosome-derived miRNA-21-5p/mothers against decapentaplegic homolog 7 (Smad7) in quartz dust-induced pulmonary fibrosis in rats. Methods Twenty-four healthy male SD rats were randomly divided into four groups (six rats in each group): control 4-week group, control 16-week group, quartz 4-week group, and quartz 16-week group. At the beginning of the experiment, 1 mL of quartz suspension (50 mg·mL⁻¹) and 1 mL of normal saline were injected into the trachea of rats in the quartz group and the control group, respectively, by means of one-time non-exposure intratracheal dust staining. Alveolar lavage was performed at the 4th and 16th weeks after dust staining, the exosomes in lavage solution were extracted by polyethylene glycol (PEG) precipitation, morphological identification was conducted by transmission electron microscopy (TEM), particle size of exosomes was detected by nano-tracking analysis (NTA), and the marker proteins CD9 and CD63 of exosomes were detected by Western blotting (WB). The expression of miRNA-21-5p in exosomes was determined by reverse transcription polymerase chain reaction (RT-PCR). The degree of lung tissue injury and fibrosis was observed by hematoxylin-eosin staining (HE) and Masson staining. The collagen content of lung tissue was detected by hydroxyproline (HYP) method. The expression of Smad7 protein in lung tissue was detected by WB. Results The results of pathological staining showed that compared with the control group, lung inflammatory cell infiltration, alveolar wall thickening, and collagen increase were observed after 4 weeks of dusting, and collagen deposition and silicon nodules appeared after 16 weeks of dusting. Compared with the control group, the expression level of HYP in the lung tissue of the quartz group was increased after 4 weeks and 16 weeks of dust staining (P<0.05). Transmission electron microscopy showed that exosomes were saucer-shaped, and the average particle size of exosomes was 95.8 nm by NTA. Positive expression of exosome marker proteins CD9 and CD81 was found by WB. Compared with the control group, the expression of exosome-derived miRNA-21-5p in alveolar lavage fluid in the quartz group increased in the 4th week and the 16th week (P<0.05), and the expression of Smad7 protein in lung tissue decreased (P<0.05). Conclusion Exosome-derived miRNA-21-5p and Smad7 may be involved in the mechanism of quartz dust-induced pulmonary fibrosis in rats.

Objective: To explore the effects of subchronic aluminum exposure on the level of N6-methyladenosine (m6A) methylation and the expression of N6-methyladenosine RNA binding protein 1 (YTHDF1) in the hippocampus of rats. Methods: Twenty-four healthy male SD rats were randomly divided into the control group (normal saline), the low dose group [10 μmol/kg Al(mal)3], the medium dose group [20 μmol/kg Al(mal)3] and the high dose group [40 μmol/kg Al(mal)3], with 6 rats in each group. The Al(mal)3 solution was administered via intraperitoneal injection on alternate days for 90 days. Escape latency, target quadrant dwell time and platform crossing times were tested to evaluate the learning and memory ability of the rats by the Morris water maze test after exposure. The brain tissue was weighted and the brain-to-body weight ratio was calculated after euthanasia. The level of m6A methylation and the expression of YTHDF1 were determined by enzyme-linked immunosorbent assay and western blot assay, respectively. Results: All rats survived during aluminum exposure period. The brain-to-body weight ratios of the control group and the low, medium and high dose groups were (0.46±0.06)%, (0.44±0.04)%, (0.49±0.06)% and (0.51±0.07)%, respectively, with no statistically significant differences (P>0.05). The escape latency of rats in the high dose group was longer than that in control and low group during the third to fifth day (both P>0.05). The escape latency of rats in all groups was shortened with the increase of training days (P<0.05). The target quadrant dwell time of rats in low, medium and high dose groups were lower than that in control group, and the platform crossing times of rats in high dose group were lower than that in control group (all P<0.05). The methylation level of m6A and expression level of YTHDF1 in hippocampus of rats in medium and high dose groups was higher than that in control group (both P<0.05). Conclusion The learning and memory impairment caused by subchronic aluminum exposure may be related to the increase of m6A methylation level and the decrease of YTHDF1 expression.

A colon-specific drug delivery system has great potential for the oral administration of colorectal cancer. However, the uncontrollable in vivo fate of liposomes makes their effectiveness for colonic location, and intratumoral accumulation remains unsatisfactory. Here, an oral colon-specific drug delivery system (CBS-CS@Lipo/Oxp/MTZ) was constructed by covalently conjugating Clostridium butyricum spores (CBS) with drugs loaded chitosan (CS)-coated liposomes, where the model chemotherapy drug oxaliplatin (Oxp) and anti-anaerobic bacteria agent metronidazole (MTZ) were loaded. Following oral administration, CBS germinated into Clostridium butyricum (CB) and colonized in the colon. Combined with colonic specifically β-glucosidase responsive degrading of CS, dual colon-specific release of liposomes was achieved. And the accumulation of liposomes at the CRC site furtherly increased by 2.68-fold. Simultaneously, the released liposomes penetrated deep tumor tissue via the permeation enhancement effect of CS to kill localized intratumoral bacteria. Collaborating with blocking the translocation of intestinal pathogenic bacteria from lumen to tumor with the gut microbiota modulation of CB, the intratumoral pathogenic bacteria were eliminated fundamentally, blocking their recruitment to immunosuppressive cells. Furtherly, synchronized with lipopolysaccharide (LPS) released from MTZ-induced dead Fusobacterium nucleatum and the tumor-associated antigens produced by Oxp-caused immunogenic dead cells, they jointly enhanced tumor infiltration of CD8⁺ T cells and reactivated robust antitumor immunity.