Drug addiction,also referred to as drug dependence or substance use disorder,is a chronic and recurrent brain disease.Its main characteristics are compulsive drug-seeking behavior,continued use of drugs,and a loss of control over intake.Prolonged use of addictive substances can result in both physiological and psychological dependence.When usage is ceased,individuals may experience intense discomfort,including anxiety,insomnia,nausea,vomiting,and a strong craving for the substances.Drug dependence is classified into two types:physical dependence and psychological dependence.Physical dependence describes a pathological state of adaptation that results from the repeated use of addictive substances,leading to severe withdrawal syndrome upon cessation.Psychological dependence involves a mental craving for addictive substances,which is needed to experience the specific euphoria that follows consumption.Regular or continuous use is required to sustain these euphoric effects.The mechanisms of addiction are complex and influenced by genetic,environmental,and various other factors.They involve higher-level neurological activities,such as memory,reward,and decision-making.Currently,effective treatment methods for drug addiction are insufficient.Due to the complexity of drug addiction,laboratory animal research is essential.Using animal behavioral models to simulate human drug addiction can enhance our understanding of the mechanisms of addiction.This research offers a comprehensive overview of various animal experimental models that explore both physical and psychological dependence.It includes detailed descriptions of the methods and procedures used to assess physical dependence,behavioral sensitization,conditioned place preference,drug discrimination,and self-administration experiments.Additionally,the characteristics of each experimental model are compared,and the relevance of these models is discussed,aiming to provide support for the research on addiction mechanisms and the development of therapeutic methods.

The placenta is a crucial organ at the maternal-fetal interface, primarily composed of trophoblast cells. Its principal functions include facilitating embryo implantation into the uterus and establishing requisite vascular connections for nutrient exchange. The evolution of the trophoblast cell lineage undergoes a dynamic developmental process, wherein trophectoderm cells differentiate into cytotrophoblast cells, syncytiotrophoblast cells, and extravillous trophoblast cells. Perturbations in this process impair placental morphogenesis, thereby leading to adverse pregnancy outcomes. Post-translational modification (PTM) is an essential cellular regulatory mechanism, with 50%-90% of proteins in humans requiring such modifications to become functionally active. Proteins expressed in trophoblast cells can regulate cell growth, proliferation, and differentiation after undergoing various PTM, which are of great significance for embryo implantation and development. This review synthesizes current studies on the regulation of PTMs on trophoblast cell development and highlights recent progress, offering a foundation for future investigations on placental development and clinical applications.

Drug addiction,also referred to as drug dependence or substance use disorder,is a chronic and recurrent brain disease.Its main characteristics are compulsive drug-seeking behavior,continued use of drugs,and a loss of control over intake.Prolonged use of addictive substances can result in both physiological and psychological dependence.When usage is ceased,individuals may experience intense discomfort,including anxiety,insomnia,nausea,vomiting,and a strong craving for the substances.Drug dependence is classified into two types:physical dependence and psychological dependence.Physical dependence describes a pathological state of adaptation that results from the repeated use of addictive substances,leading to severe withdrawal syndrome upon cessation.Psychological dependence involves a mental craving for addictive substances,which is needed to experience the specific euphoria that follows consumption.Regular or continuous use is required to sustain these euphoric effects.The mechanisms of addiction are complex and influenced by genetic,environmental,and various other factors.They involve higher-level neurological activities,such as memory,reward,and decision-making.Currently,effective treatment methods for drug addiction are insufficient.Due to the complexity of drug addiction,laboratory animal research is essential.Using animal behavioral models to simulate human drug addiction can enhance our understanding of the mechanisms of addiction.This research offers a comprehensive overview of various animal experimental models that explore both physical and psychological dependence.It includes detailed descriptions of the methods and procedures used to assess physical dependence,behavioral sensitization,conditioned place preference,drug discrimination,and self-administration experiments.Additionally,the characteristics of each experimental model are compared,and the relevance of these models is discussed,aiming to provide support for the research on addiction mechanisms and the development of therapeutic methods.

Objective To map the genome-wide distribution profile of histone H3K27me3 modification in diffuse gastric cancer tissues,identify target genes regulated by H3K27me3,and primarily explore the potential mechanism of its modification reprogramming in the occurrence and development of the tumor.Methods Normal gastric mucosal tissues and diffuse gastric cancer tissues were harvested from the patients who underwent examinations or treatments in the departments of gastroenterology and gastrointestinal surgery of our medical center between 2021 and 2023.There were 14 patients in the normal group(6 males and 8 females,average age of 46 years)and 14 patients in the gastric cancer group(8 males and 6 females,average age of 63 years).Cleavage under target and tagmentation(CUT&Tag)technology was employed to capture genomic regions modified by H3K27me3,and analyze the reprogramming characteristics of these modifications.RNA sequencing data,data from high-throughput chromosome conformation capture(Hi-C)technology,and publicly available single-cell data were integrated to investigate the target genes regulated by the reprogramming of H3K27me3 modifications in diffuse gastric cancer cells.Results The quality of the CUT&Tag and RNA sequencing data met the standards required for subsequent analysis.Histone H3K27me3 modifications in normal gastric mucosa and diffuse gastric cancer tissues were primarily distributed in distal intergenic regions and intronic regions.In gastric cancer tissues,compared to normal tissues,there was significant reprogramming of H3K27me3 modifications,characterized by a marked reduction in overall H3K27me3 signal intensity.The loss of 2 912 H3K27me3 signal peaks might lead to the up-regulation of 822 tumor-associated genes.Among them,56 genes displayed the most significant up-regulation(fold change in signal intensity≥2,P<0.05),with notable enrichment in the mammalian target of rapamycin complex 1(mTORC1)signaling pathway.Specifically,the methionine transporter SLC7A5 and the cystine transporter SLC7A11 were found to have the highest expression levels in gastric cancer tissues.Single-cell data revealed that the abnormal overexpression of SLC7A11 in diffuse gastric cancer was primarily observed in tumor epithelial cells.Further validation using public data and immunohistochemical experiments confirmed the elevated expression of SLC7A11 in diffuse gastric cancer,which is associated with poor prognosis in gastric cancer patients.Conclusion The reprogramming of histone H3K27me3 modification is an important epigenetic characteristic in diffuse gastric cancer.Loss of H3K27me3 signal peaks may up-regulate the expression of SLC7A11 in diffuse gastric cancer cells,and thereby promote tumor progression.

Objective To map the super-enhancers remodeling of intestinal gastric cancer and reveal the tumor biological functions of the super-enhancers and the downstream target genes that may be activated.Methods A total of 31 normal gastric mucosal tissues,23 intestinal gastric cancer tissues and 9 intestinal gastric cancer organoids were collected from the Department of Gastroenterology of Army Medical Center of PLA from January to December 2022.Chromatin targeting histone H3K27ac modified chromatin targeting cleavage under targets and tagmentation(CUT&Tag)sequencing was conducted on above tissues.The remodeling profiles of super-enhancers in intestinal gastric cancer were analyzed and the key target genes were identified based on bioinformation tools.CRISPRi technology was used to intervene with the super-enhancers,the expression of target genes was detected with Western blotting,and the proliferation,migration and invasion abilities were detected by CCK-8 assay and Transwell chambers in the control group and the intervention group.Results There was a significant difference in the signal of super-enhancers between intestinal gastric cancer tissues and normal gastric mucosal tissues(P<0.05),and the active super-enhancers in cancer tissues may be involved in biological processes such as negative regulation of the immune system and cell adhesion.The expression of up-regulated cell migration-inducing protein(CEMIP)in tumor cells was regulated by the super-enhancers,and intervening the super-enhancers down-regulated the expression of CEMIP(P<0.05),and inhibited the cell proliferation,invasion and migration abilities of tumor cells(P<0.05).Conclusion Super-enhancer remodeling is observed in intestinal gastric cancer,and they can up-regulate the expression of CEMIP gene and promote the growth,migration and invasion of cancer cells.

Objective To draw the genome-wide distribution and remodeling characteristics of H3K27me3 silencers in signet-ring cell carcinoma of the stomach(SRCC)through epigenetic sequencing technology,and to investigate their roles in transcriptional regulation in order to elucidate the regulatory mechanism of SRCC malignant progression.Methods The study was conducted on 35 gastric samples obtained by gastroendoscopic biopsy(15 normal and 20 SRCC tissues)from Department of Gastroenterology of Army Medical Center of PLA between January 2021 and December 2023.Multi-omics analyses,including assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq),cleavage under targets and tagmentation(CUT&Tag)and transcriptome sequencing(RNA-seq),were performed to identify chromatin accessibility,H3K27me3 silencer regions,and transcriptional changes,with aid of Illumina NovaSeq 6000.H3K27me3 related differentially expressed genes(|Log2FC|>1,FDR<0.05)were screened using DESeq2.Gene Ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis were employed to analyze the enrichment function,and Homer was employed to identify transcription factor motifs.A regulatory network was constructed using Cytoscape,and then validated using immunohistochemistry to explore its regulatory mechanism.Results H3K27me3 silencers were primarily located in distal intergenic regions(37.06%)in SRCC.Compared with the normal tissues,SRCC showed a significant reduction in H3K27me3 silencer signals(95%CI:1.34～2.30,P=0.007)with 6 257 lost sites(FDR<0.01).Integrating CUT&Tag and RNA-seq revealed 380 up-regulated immune-related genes,particularly in T cell receptor signaling(OR=4.2,95%CI:2.8～6.3,P=0.002).Immunohistochemistry confirmed elevated expression of transcription factor EHF(P<0.05).Conclusion There is the remodeling of H3K27me3 silencers in SRCC,and EHF may potentially play a crucial role in the SRCC malignant progression.

The placenta is a crucial organ at the maternal-fetal interface, primarily composed of trophoblast cells. Its principal functions include facilitating embryo implantation into the uterus and establishing requisite vascular connections for nutrient exchange. The evolution of the trophoblast cell lineage undergoes a dynamic developmental process, wherein trophectoderm cells differentiate into cytotrophoblast cells, syncytiotrophoblast cells, and extravillous trophoblast cells. Perturbations in this process impair placental morphogenesis, thereby leading to adverse pregnancy outcomes. Post-translational modification (PTM) is an essential cellular regulatory mechanism, with 50%-90% of proteins in humans requiring such modifications to become functionally active. Proteins expressed in trophoblast cells can regulate cell growth, proliferation, and differentiation after undergoing various PTM, which are of great significance for embryo implantation and development. This review synthesizes current studies on the regulation of PTMs on trophoblast cell development and highlights recent progress, offering a foundation for future investigations on placental development and clinical applications.

Objective·To analyze the expression of mitochondrial related gene SFXN3(sideroflexin 3)in head and neck squamous cell carcinoma(HNSCC)and its effect on cell proliferation.Methods·Mitochondrial related genes and TCGA-HNSCC dataset were obtained from public databases to identify the target gene SFXN3 by using bioinformatic methods.The expression of SFXN3 in HNSCC patient samples was analysed by using the UALCAN database,and survival analyses of patients with different SFXN3 expression levels were performed according to TCGA-HNSCC cohort and GEO cohorts(GSE65858,GSE41613 and GSE27020).By using TCGA-HNSCC cohort and GEO cohorts(GSE40020,GSE210287),the differences in SFXN3 expression levels between therapeutic responders and non-responders were compared.Quantitative real-time PCR(qRT-PCR)was used to verify the expression of SFXN3 in the collected HNSCC tumor and para-tumor tissues,and the expression level of SFXN3 in human normal oral epithelial cells and HNSCC tumor cell lines was detected.With the construction of stable-SFXN3-knockdown HNSCC cell lines,the effect of SFXN3 on the proliferation ability of HNSCC cells was observed by using the Incucyte live-cell imaging analysis system and plate colony formation assay.Transcriptome sequencing was performed on the total RNA of stably-SFXN3-knockdown cells and control cells,and pathway enrichment analysis was performed on the genes with differentially down-regulated expression in knockdown group compared with control group.Results·SFXN3 was highly expressed in tumor tissues of HNSCC patients(P=0.000),and the prognosis of patients in the SFXN3-high-expression group was poor(all P＜0.05).The expression level of SFXN3 in the non-responders was higher than that in the responders(P=0.008),indicating an unfavorable prognosis.High expression of SFXN3 was verified in the collected HNSCC tumor tissues and HNSCC cell lines(all P＜0.05).After the knockdown of SFXN3 expression,the proliferation ability of HNSCC cells decreased,and the number of plate clones decreased(all P＜0.05).RNA sequencing showed that the differentially expressed down-regulated genes in HNSCC cells in the SFXN3-knockdown group were enriched in DNA replication,cell cycle,mitochondrial translation,mitochondrial RNA metabolic process and mitochondrial gene expression pathways.Conclusion·SFXN3 is highly expressed in HNSCC and it has negative correlation with the prognosis of patients.The proliferation ability and plate colony formation ability are inhibited in SFXN3-knockdown HNSCC cells,and these may work by affecting mitochondria function.

Objective To explore the genome-wide distribution of histone H3K27ac in intestinal type gastric cancer,analyze remodeling features of enhancers and regulome and construct a prediction model for prognosis.Methods H3K27ac CUT&Tag sequencing and RNA sequencing were performed in intestinal type gastric cancer tissues from 15 patients and normal gastric mucosa tissues from 18 healthy volunteers.Bioinformatics analysis was performed to identify the differences in genome distribution of H3K27ac modifications.Based on the distribution characteristics of H3K27ac,the enhancer elements were identified and the remodeling characteristics of enhancer and related regulome were explored.The prediction model for prognosis based on enhancer related target genes was constructed by univariate Cox and multivariate Cox regression analyses.Results The histone H3K27ac modification was mainly distributed in the enhancer region and displayed no significant differences in the genomic distribution patterns between normal and cancer tissues.Compared with normal gastric mucosa,the level of enhancer H3K27ac modification was higher in intestinal type gastric cancer.A total of 8847 enhancers with increased activity in intestinal type gastric cancer were identified,accounting for 8.3%of all enhancers,which might promote malignant behaviors such as proliferation and adhesion of gastric cancer cells.A prognosis-predicting model established based on a panel of 6 genes that upregulated by the acquired enhancer in cancers,which was able to predict the overall survival of patients.Conclusion Enhancer remodeling is one of the significant epigenetic features of intestinal type gastric cancer.These enhancers may drive malignant growth and adhesion of cancer cells by upregulating the expression of MYC,E2F3 and other genes.A prognosis model based on enhancer target genes is constructed.

The epitranscriptomic mark N⁶-methyladenosine (m⁶A), which is the predominant internal modification in RNA, is important for plant responses to diverse stresses. Multiple environmental stresses caused by the tea-withering process can greatly influence the accumulation of specialized metabolites and the formation of tea flavor. However, the effects of the m⁶A-mediated regulatory mechanism on flavor-related metabolic pathways in tea leaves remain relatively uncharacterized. We performed an integrated RNA methylome and transcriptome analysis to explore the m⁶A-mediated regulatory mechanism and its effects on flavonoid and terpenoid metabolism in tea (Camellia sinensis) leaves under solar-withering conditions. Dynamic changes in global m⁶A level in tea leaves were mainly controlled by two m⁶A erasers (CsALKBH4A and CsALKBH4B) during solar-withering treatments. Differentially methylated peak-associated genes following solar-withering treatments with different shading rates were assigned to terpenoid biosynthesis and spliceosome pathways. Further analyses indicated that CsALKBH4-driven RNA demethylation can directly affect the accumulation of volatile terpenoids by mediating the stability and abundance of terpenoid biosynthesis-related transcripts and also indirectly influence the flavonoid, catechin, and theaflavin contents by triggering alternative splicing-mediated regulation. Our findings revealed a novel layer of epitranscriptomic gene regulation in tea flavor-related metabolic pathways and established a link between the m⁶A-mediated regulatory mechanism and the formation of tea flavor under solar-withering conditions.
RNA/metabolism* ; Epigenome ; Plant Proteins/metabolism* ; Plant Leaves/metabolism* ; Camellia sinensis/metabolism* ; Flavonoids ; Terpenes/metabolism* ; Tea/metabolism* ; Gene Expression Regulation, Plant