Olfactory receptors (ORs) form the largest superfamily of G protein-coupled receptors (GPCRs). Traditionally recognized for their role in the nasal olfactory epithelium, where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidneys. The intestine, as the primary site for nutrient digestion and absorption, harbors a highly complex chemical environment. To adapt to this environment, the gut employs a sophisticated network of “chemosensors” to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as crucial functional components, serving as a molecular bridge that connects environmental chemical signals—such as food-derived odorants—to specific physiological responses. This discovery has significantly deepened our understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Studies indicate that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a wide variety of ligands, including exogenous dietary components, gut microbiota metabolites such as short-chain fatty acids, and endogenous small molecules like azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to elucidate the molecular mechanisms by which these receptors regulate the secretion of gut hormones. Activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility. Furthermore, the review addresses the critical roles of ORs in immune regulation and pathology. Evidence suggests that specific ORs contribute to the maintenance of intestinal immune homeostasis and may offer protection against inflammation. Beyond their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation by remodeling the gut microbiome and metabolome. These findings collectively suggest that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and maintaining gut homeostasis. Additionally, the review explores the emerging role of ORs in cancer. Although OR expression is often downregulated in tumor tissues compared to normal mucosa, activation of specific ORs by certain ligands can inhibit tumor cell proliferation and migration and induce apoptosis via pathways such as MEK/ERK and p38 MAPK. Conversely, other receptors, such as OR7C1, may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut’s sensory network. The review also discusses the translational potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may thus emerge as promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases, and malignancies.

Elemene is widely recognized as an effective anti-cancer compound and is routinely administered in Chinese clinical settings for the management of several solid tumors, including non-small cell lung cancer (NSCLC). However, its detailed molecular mechanism has not been adequately demonstrated. In this research, it was demonstrated that elemene effectively curtailed NSCLC growth in the patient-derived xenograft (PDX) model. Mechanistically, employing high-throughput screening techniques and subsequent biochemical validations such as microscale thermophoresis (MST), microRNA-145-5p (miR-145-5p) was pinpointed as a critical target through which elemene exerts its anti-tumor effects. Interestingly, elemene serves as a binding stabilizer for miR-145-5p, demonstrating a strong binding affinity (dissociation constant (K _D) = 0.39 ± 0.17 μg/mL) and preventing its degradation both in vitro and in vivo, while not interfering with the synthesis of the primary microRNA transcripts (pri-miRNAs) and precursor miRNAs (pre-miRNAs). The stabilization of miR-145-5p by elemene resulted in an increased level of this miRNA, subsequently suppressing NSCLC progression through the miR-145-5p/mitogen-activated protein kinase kinase kinase 3 (MAP3K3)/nuclear factor kappaB (NF-κB) pathway. Our findings provide a new perspective on revealing the interaction patterns between clinical anti-tumor drugs and miRNAs.

OBJECTIVE: To explore the mechanism by which the extract of Semen Ziziphi Spinosae extract promotes bone growth in mice by modulation of the expression of miR-34a-5p in brain tissue. METHODS: Mice were assigned to four experimental groups:a normal control group, a drug administration group (receiving 0.320 mg·g^-1 body weight of Semen Ziziphi Spinosae extract via intragastric administration), a positive control group (receiving 0.013 mg·g^-1 body weight of jujube seed saponin via intragastric administration), and a combination group administration with Semen Ziziphi Spinosae extract plus a 5-hydroxytryptamine 2A receptor (5-HT2AR) agonist (intragastric administration of Semen Ziziphi Spinosae extract combined with intracerebroventricular injection of 8 μg P-MPPF per mice for the final three days of the experiment). Following a 20-day administration period, the effects of the interventions on bone growth, serum growth hormone (GH) levels, and 5-HT2AR expression in brain tissue were evaluated. MicroRNAs (miRNAs) that were differentially expressed in the brain tissues of mice exhibiting bone growth induced by Semen Ziziphi Spinosae extract, as compared to those in normal mice, were identified using a gene chip approach. The interaction between miR-34a-5p and 5-HT2AR was subsequently validated through quantitative reverse transcription polymerase chainreaction (RT-qPCR) and dual-luciferase reporter gene assays. Subsequently, by utilizing the miR-34a-5p inhibitor group and mimics group, along with the normal control group, the drug administration group, the positive control group, and the drug administration combined with miR-34a-5p inhibitor group, the variations in 5-HT2AR expression in mouse brain tissue across all groups were examined, and the binding activity of 5-hydroxytryptamine (5-HT) to the 5-hydroxytryptamine 1A receptor (5-HT1AR) in mice was assessed. RESULTS: The body lengths of the normal control group and the drug administration group were(8.9±0.3) and(10.4±0.4) cm;femur lengths were (8.5±0.3) and (9.1±0.5) mm;tibia lengths were (10.7±0.3) and (11.2±0.4) mm, respectively. The contents of GH levels were (58.6±8.2) and (72.9±6.1) ng·ml-1;and the contents of 5-HT2AR were (32.0±5.0) and (21.9± 5.5) ng·ml-1, respectively. Compared with the normal control group, the drug administration group promoted the growth of body length, femur, and tibia in mice, and increased GH secretion, showing statistically significant differences (P<0.05). Additionally, it significantly reduced the content of 5-HT2AR in brain tissue, with statistical significance (P<0.01). The gene chip analysis identified a total of 16 differentially expressed miRNAs, of which 13 were up-regulated and 3 were down-regulated. Bioinformatics analysis predicted that the up-regulated miR-34a-5p could regulate the expression of 5-HT2AR, a prediction that was confirmed through a dual-luciferase reporter gene assay, demonstrating a direct regulatory interaction between the two. Furthermore, in vivo experiments in mice revealed that overexpression and silencing of miR-34a-5p resulted in corresponding changes in the expression levels of 5-HT2AR in brain tissues/cells, as well as in the binding activity between 5-HT and 5-HT1AR. CONCLUSION The Semen Ziziphi Spinosae extract promotes animal bone growth by enhancing miR-34a-5p expression in brain tissue, downregulating the expression level of 5-HT2AR, improving the binding activity between 5-HT and 5-HT1AR, and extending slow-wave sleep duration, thereby stimulating GH secretion.
Animals ; MicroRNAs/metabolism* ; Mice ; Male ; Brain/metabolism* ; Ziziphus/chemistry* ; Bone Development/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Plant Extracts/pharmacology*

Aim To investigate the effect of metformin on epithelial-mesenchymal transition(EMT)of lung cancer A549 cells and its underlying mechanism.Methods Lung cancer A549 cells were cultured in vitro and treated with metformin.Cell morphology was observed by fluorescence staining.The mRNA expres-sion levels of E-cadherin,N-cadherin,SMA and Vimen-tin were detected by RT-PCR.The regulatory effects of metformin on EMT in A549 cellswere examined by high-throughput sequencing.An EMT model was estab-lished through TGF-β1 induction.Following metformin treatment,the morphology of A549 cells was observed.Western blot was employed to determine the expression levels of NGF,E-cadherin,N-cadherin,SMA and Vim-entin.Additionally,si-NGF transfection was performed to evaluate the protein expressions of E-cadherin,N-cadherin,SMA and Vimentin in A549 cells,and a cell scratch assay was conducted to assess cell migration.Results After metformin treatment,A549 cells exhibi-ted a loss of mesenchymal-like morphology,character-ized by a transition to a round shape,a reduction in colony formation,and decreased adherence.RT-PCR and high-throughput sequencing revealed a down-regu-lation in the expression of genes associated with mesen-chymal transition,including N-cadherin,SMA,and Vim-entin,and an up-regulation in the expression of genes associated with epithelial transformation,such as ZO-1 and E-cadherin.Additionally,the expression of nerve growth factor(NGF)was significantly up-regulated.Following transfection with si-NGF,A549 cells treated with metformin exhibited a down-regulation in the ex-pression of the epithelial marker E-cadherin,concomi-tant with an up-regulation in the expression of stromal markers N-cadherin,Vimentin,and SMA.Conclusions Metformin can up-regulate the expression of E-cad-herin and down-regulate the expression of N-cadherin,Vimentin and SMA in lung cancer A549 cells,thereby inhibiting EMT.Additionally,NGF signaling molecules may play a significant role in this process.

Elemene is widely recognized as an effective anti-cancer compound and is routinely administered in Chinese clinical settings for the management of several solid tumors,including non-small cell lung cancer(NSCLC).However,its detailed molecular mechanism has not been adequately demonstrated.In this research,it was demonstrated that elemene effectively curtailed NSCLC growth in the patient-derived xenograft(PDX)model.Mechanistically,employing high-throughput screening techniques and subsequent biochemical validations such as microscale thermophoresis(MST),microRNA-145-5p(miR-145-5p)was pinpointed as a critical target through which elemene exerts its anti-tumor effects.Inter-estingly,elemene serves as a binding stabilizer for miR-145-5p,demonstrating a strong binding affinity(dissociation constant(KD)=0.39±0.17 μg/mL)and preventing its degradation both in vitro and in vivo,while not interfering with the synthesis of the primary microRNA transcripts(pri-miRNAs)and precursor miRNAs(pre-miRNAs).The stabilization of miR-145-5p by elemene resulted in an increased level of this miRNA,subsequently suppressing NSCLC progression through the miR-145-5p/mitogen-activated pro-tein kinase kinase kinase 3(MAP3K3)/nuclear factor kappaB(NF-κB)pathway.Our findings provide a new perspective on revealing the interaction patterns between clinical anti-tumor drugs and miRNAs.

Objective To investigate the benefits and challenges of the reform in evidence-based obstetric nursing practice in clinical nursing,therefore to provide a reference for initiating and keeping the reform in evidence-based nursing practices.Methods A method of descriptive phenomenological research was conducted between January and February 2024 in our hospital on 10 selected clinical nurses by purposive sampling.An outline for interviews was developed based on literature review and expert interviews,followed by semi-structured interviews with the nurses.Core themes were extracted with Colaizzi's seven-step analysis.Results Three themes and 12 sub-themes were summarised in this study.The 3 core themes that were identified among the nurses included:acceptance of evidence-based nursing practice reform(with 3 domains regarding knowledge,decision-making and action),perception of the benefits of the reform in evidence-based nursing practice(with 5 domains regarding the professionalism and scientific nature of clinical nursing,improvement of patient experience and nursing outcomes,enhancement of nursing quality and safety,promotion of innovation in on-the-job training and education,and facilitation of collaboration within the nursing team),and perception in the challenges of reform in evidence-based nursing practice(with 4 domains regarding the stress and challenges,doubts and resistance,poor cooperation between doctors and nurses,and risks in clinical decision-making).Conclusion The acceptance regarding reform in evidence-based nursing practice varies among the nurses.It is necessary to promote the acceptance,provide the targeted guidance and intervene in the factors of benefits and challenges among the nurses,hence to facilitate a smooth implementation of the reform in evidence-based nursing practice.

Objective To investigate the benefits and challenges of the reform in evidence-based obstetric nursing practice in clinical nursing,therefore to provide a reference for initiating and keeping the reform in evidence-based nursing practices.Methods A method of descriptive phenomenological research was conducted between January and February 2024 in our hospital on 10 selected clinical nurses by purposive sampling.An outline for interviews was developed based on literature review and expert interviews,followed by semi-structured interviews with the nurses.Core themes were extracted with Colaizzi's seven-step analysis.Results Three themes and 12 sub-themes were summarised in this study.The 3 core themes that were identified among the nurses included:acceptance of evidence-based nursing practice reform(with 3 domains regarding knowledge,decision-making and action),perception of the benefits of the reform in evidence-based nursing practice(with 5 domains regarding the professionalism and scientific nature of clinical nursing,improvement of patient experience and nursing outcomes,enhancement of nursing quality and safety,promotion of innovation in on-the-job training and education,and facilitation of collaboration within the nursing team),and perception in the challenges of reform in evidence-based nursing practice(with 4 domains regarding the stress and challenges,doubts and resistance,poor cooperation between doctors and nurses,and risks in clinical decision-making).Conclusion The acceptance regarding reform in evidence-based nursing practice varies among the nurses.It is necessary to promote the acceptance,provide the targeted guidance and intervene in the factors of benefits and challenges among the nurses,hence to facilitate a smooth implementation of the reform in evidence-based nursing practice.

Aim To investigate the effect of metformin on epithelial-mesenchymal transition(EMT)of lung cancer A549 cells and its underlying mechanism.Methods Lung cancer A549 cells were cultured in vitro and treated with metformin.Cell morphology was observed by fluorescence staining.The mRNA expres-sion levels of E-cadherin,N-cadherin,SMA and Vimen-tin were detected by RT-PCR.The regulatory effects of metformin on EMT in A549 cellswere examined by high-throughput sequencing.An EMT model was estab-lished through TGF-β1 induction.Following metformin treatment,the morphology of A549 cells was observed.Western blot was employed to determine the expression levels of NGF,E-cadherin,N-cadherin,SMA and Vim-entin.Additionally,si-NGF transfection was performed to evaluate the protein expressions of E-cadherin,N-cadherin,SMA and Vimentin in A549 cells,and a cell scratch assay was conducted to assess cell migration.Results After metformin treatment,A549 cells exhibi-ted a loss of mesenchymal-like morphology,character-ized by a transition to a round shape,a reduction in colony formation,and decreased adherence.RT-PCR and high-throughput sequencing revealed a down-regu-lation in the expression of genes associated with mesen-chymal transition,including N-cadherin,SMA,and Vim-entin,and an up-regulation in the expression of genes associated with epithelial transformation,such as ZO-1 and E-cadherin.Additionally,the expression of nerve growth factor(NGF)was significantly up-regulated.Following transfection with si-NGF,A549 cells treated with metformin exhibited a down-regulation in the ex-pression of the epithelial marker E-cadherin,concomi-tant with an up-regulation in the expression of stromal markers N-cadherin,Vimentin,and SMA.Conclusions Metformin can up-regulate the expression of E-cad-herin and down-regulate the expression of N-cadherin,Vimentin and SMA in lung cancer A549 cells,thereby inhibiting EMT.Additionally,NGF signaling molecules may play a significant role in this process.

Aim To investigate the molecular mechanism by which quercetin inhibits the malignant behavior of breast cancer cells. Methods Breast cancer cell lines MCF-7 and MB231 were used as the research models. Lentiviral transfection was employed to establish tumor cells with high expression of ERa and MAL-AT-1. The expression of MALAT-1 was assessed using RT-qPCR,and ERa expression was determined through Western blot. Subsequently, CCK-8 assay and colony formation assay were conducted to evaluate cell proliferation. PI staining and adenovirus transfection were performed to observe the inhibitory effects of quercetin on breast cancer cell proliferation. Results 17|3-es-tradiol ( E2 ) promoted the proliferation of MCF-7 breast cancer cells, while 5 jjunol L quercetin reversed the promoting effect of E2 on proliferation ( P 0. 05 ) . Quercetin had no effect on MB231 breast cancer cells. Overexpression of ERa significantly inhibited the pro-proliferative effect of E2 on MB231-ERa cells, and quercetin further suppressed this effect. Additionally , quercetin inhibited the expression of MALAT-1. However,this inhibitory effect was reversed by overexpression of MALAT-1, leading to enhanced cell proliferation , cell cycle progression, and clonal formation a-bility. Conclusions Quercetin exerts its anti-tumor effects on breast cancer cells by regulating MALAT-1, dependent on the presence of estrogen receptor. Quercetin shows potential as a therapeutic drug for breast cancer targeting the estrogen receptor.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.