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.

Osteoporosis is a systemic disease, and epidemiological projections indicate that by 2050, approximately 23.43% of the Chinese population over 50 years of age will be affected. Given the poor prognosis associated with osteoporosis, the exploration of safe and effective natural products is of considerable significance. Studies investigating the chemical constituents of traditional Chinese medicine in cellular and/or animal models have demonstrated bone-protective effects. Although most of these compounds lack clinical data, they hold considerable potential as lead candidates for drug development. In-depth study of the structure-activity relationship of these natural products not only contributes to elucidating the mechanisms of action but also provides a theoretical basis for the development of novel antiosteoporosis therapies. This review summarizes natural products with potential antiosteoporotic effects reported between 2020 and 2024. Overall, plant-derived natural compounds exhibit antiosteoporotic effects by regulating bone remodeling, inflammation, and oxidative stress, highlighting their promise as multitarget therapeutic candidates.

OBJECTIVE: To investigate the relationship between physical activity and genetic risk and their combined effects on the risk of developing chronic obstructive pulmonary disease. METHODS: This prospective cohort study included 318,085 biobank participants from the UK. Physical activity was assessed using the short form of the International Physical Activity Questionnaire. The participants were stratified into low-, intermediate-, and high-genetic-risk groups based on their polygenic risk scores. Multivariate Cox regression models and multiplicative interaction analyses were used. RESULTS: During a median follow-up period of 13 years, 9,209 participants were diagnosed with chronic obstructive pulmonary disease. For low genetic risk, compared to low physical activity, the hazard ratios ( HRs) for moderate and high physical activity were 0.853 (95% confidence interval [ CI]: 0.748-0.972) and 0.831 (95% CI: 0.727-0.950), respectively. For intermediate genetic risk, the HRs were 0.829 (95% CI: 0.758-0.905) and 0.835 (95% CI: 0.764-0.914), respectively. For participants with high genetic risk, the HRs were 0.809 (95% CI: 0.746-0.877) and 0.818 (95% CI: 0.754-0.888), respectively. A significant interaction was observed between genetic risk and physical activity. CONCLUSION Moderate or high levels of physical activity were associated with a lower risk of developing chronic obstructive pulmonary disease across all genetic risk groups, highlighting the need to tailor activity interventions for genetically susceptible individuals.
Humans ; Pulmonary Disease, Chronic Obstructive/epidemiology* ; Exercise ; Male ; Female ; Middle Aged ; Prospective Studies ; Aged ; Genetic Predisposition to Disease ; Risk Factors ; United Kingdom/epidemiology* ; Incidence ; Adult

Vertebral refracture following percutaneous vertebral augmentation (PVA) is commonly seen in elderly patients with osteoporotic thoracolumbar compression fractures (OTLCF). It can lead to recurrent pain, loss of vertebral height, progression of kyphosis, and even neurological dysfunction, significantly impairing patients′ quality of life. Current diagnosis and treatment face multiple challenges, including high misdiagnosis rate, difficulty in choosing between surgical and non-surgical treatment options, lack of standardized surgical protocols, interference from intralesional bone cement during procedures, inadequate stability of internal fixation in osteoporotic bone, and suboptimal compliance of anti-osteoporotic therapy. Establishing a standardized diagnostic and therapeutic framework is urgently needed. To standardize the management process and improve outcomes for vertebral refractures after PVA in elderly OTLCF patients, Spinal Trauma Group of the Orthopedic Branch of Chinese Medical Doctor Association organized experts in the field to develop Guideline for the diagnosis and treatment of vertebral refracture after percutaneous vertebral augmentation in elderly patients with osteoporotic thoracolumbar compression fractures ( version 2025), based on current literature and clinical experience, and adhering to principles of scientific rigor and clinical applicability. A total of 11 recommendations were proposed, encompassing diagnosis, treatment, and rehabilitation of vertebral refracture after PVA in elderly patients with OTLCF, aiming to provide a foundation for a standardized management.

Vertebral refracture following percutaneous vertebral augmentation (PVA) is commonly seen in elderly patients with osteoporotic thoracolumbar compression fractures (OTLCF). It can lead to recurrent pain, loss of vertebral height, progression of kyphosis, and even neurological dysfunction, significantly impairing patients′ quality of life. Current diagnosis and treatment face multiple challenges, including high misdiagnosis rate, difficulty in choosing between surgical and non-surgical treatment options, lack of standardized surgical protocols, interference from intralesional bone cement during procedures, inadequate stability of internal fixation in osteoporotic bone, and suboptimal compliance of anti-osteoporotic therapy. Establishing a standardized diagnostic and therapeutic framework is urgently needed. To standardize the management process and improve outcomes for vertebral refractures after PVA in elderly OTLCF patients, Spinal Trauma Group of the Orthopedic Branch of Chinese Medical Doctor Association organized experts in the field to develop Guideline for the diagnosis and treatment of vertebral refracture after percutaneous vertebral augmentation in elderly patients with osteoporotic thoracolumbar compression fractures ( version 2025), based on current literature and clinical experience, and adhering to principles of scientific rigor and clinical applicability. A total of 11 recommendations were proposed, encompassing diagnosis, treatment, and rehabilitation of vertebral refracture after PVA in elderly patients with OTLCF, aiming to provide a foundation for a standardized management.

A prokaryotic expression vector for the mutant diphtheria toxin CRM197 was constructed and expressed in Esch-erichia coli cells.Anti-CRM197 antibody concentrations were detected in serum samples of healthy volunteers.The crm 197 gene was codon-optimized in E.coli and cloned into the plasmid pET28a(+)under optimized expression conditions.CRM197 was purified using Ni-NTA spin columns and ion exchange chromatography,and confirmed by western blot analysis.The puri-fied CRM197 was used to detect specific anti-CRM197 antibody levels in serum samples of different age groups.The results showed that soluble codon-optimized CRM197 was successfully expressed under optimized expression conditions.The purity of CRM197 was more than 95％,as determined with Ni-NTA spin columns and ion exchange chromatography,consistent with the single specific bands obtained by western blot analysis and detection of serum levels of the anti-CRM197 antibody.Collec-tively,these results confirmed that the proposed expression strategy achieved high-yield production of soluble CRM197,al-though high levels in human serum may affect evaluation of immune interactions with glycan-CRM197 conjugates for applica-tion as a diagnostic antigen.The diphtheria mutant toxin CRM197 is used in many conjugate vaccines.The synthetic crm 197 gene with codon optimization in pET28a was transformed into E.coli Origami B(DE3)cells.CRM197 was induced by isopro-pyl β-d-1-thiogalactopyranoside and high level accumulation of soluble CRM197 was purified using Ni-NTA spin columns and ion exchange chromatography.The purity of the final prepara-tion reached 95％.CRM197 was used to detect the concentra-tions of the anti-CRM197 antibody in serum samples of healthy volunteers of different ages.The proposed expression strategy yielded high production of CRM197,which could interfere with evaluations of induced immune interactions by glycan-CRM197 conjugates and prohibit application as a diagnostic antigen.

Objective:To explore the relationship between blood urea nitrogen to creatinine ratio and frailty in the elderly aged ≥65 years in 8 longevity areas in China.Methods:Participants were recruited from the Healthy Aging and Biomarkers Cohort Study. Based on baseline information about blood urea nitrogen and risk for frailty obtained at follow-up of the participants, blood urea nitrogen to creatinine ratio was classified according to quintiles, Cox proportional hazard regression models were used to analyze the association between blood urea nitrogen to creatinine ratio and frailty.Results:A total of 1 562 participants aged (81.0±17.0) years were included, in whom 814 (52.1%) were men, and 258 frailty events occurred during a mean follow-up of (3.73±1.43) years. Cox proportional hazards model showed that after adjusting for relevant confounders, compared with the participants in the lowest quintile group ( Q1), the risk for frailty decreased by 36%, 44%, and 40% in the participants in the third quintile group ( Q3), the fourth quintile group ( Q4) and the highest quintile group ( Q5) respectively [hazard ratio ( HR)=0.64, 95% CI: 0.43-0.94; HR=0.56, 95% CI: 0.38-0.84; HR=0.60, 95% CI: 0.41-0.88]. The risk for frailty decreased by 20% for every unit standard deviation increase in blood urea nitrogen to creatinine ratio ( HR=0.80, 95% CI: 0.70-0.91). Moreover, blood urea nitrogen to creatinine ratio and the risk for frailty showed a nearly linear dose-response relationship. Conclusions:The increase in blood urea nitrogen to creatinine ratio was associated with higher risk for frailty. Maintaining high blood urea nitrogen to creatinine ratio is important for the prevention of frailty in the elderly.

Humans ; Asthma/drug therapy* ; Biological Therapy

ObjectiveTo investigate the therapeutic effect of rhubarb decoction （RD） retention enema on a rat model of minimal hepatic encephalopathy （MHE） and its mechanism of action based on bile acid （BA） metabolomics. MethodsA total of 55 male Sprague－Dawley rats were randomly divided into blank group （NC group with 10 rats）， hepatic encephalopathy group （HE group with 15 rats）， MHE group with 15 rats， and MHE+rhubarb decoction treatment group （MHEY group with 15 rats）. Intraperitoneal injection of carbon tetrachloride （CCl₄） and thioacetamide （TAA） was performed to establish a rat model of MHE or HE， and the rats were sacrificed after 2 weeks of administration. The serum levels of aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， alkaline phosphatase （ALP）， total bilirubin （TBil）， and total bile acid （TBA） and the concentration of blood ammonia were measured； the colonic contents were collected to measure pH value； liver and brain tissue samples were collected， and HE staining was used to observe the histopathological changes of the liver； the bile was collected， and liquid chromatography－mass spectrometry was used to perform BA－targeted metabolomics analysis. Continuous data were expressed as mean±standard deviation； a one－way analysis of variance was used for comparison between multiple groups， and the least significant difference t－test was used for further comparison between two groups. ResultsCompared with the NC group， the HE group and the MHE group had a significant increase in searching platform latency （after modelling and after administration） and a significant reduction in the number of platform crossings （all P<0.05）； compared with the MHE group， the MHEY group had a significant reduction in searching platform latency （after administration） and a significant increase in the number of platform crossings， and the HE group had a significant increase in searching platform latency and a significant reduction in the number of platform crossings （all P<0.05）. Compared with the NC group， the HE group and the MHE group had significant increases in AST， ALT， ALP， TBil， TBA， blood ammonia， and colon pH value （all P<0.05）； compared with the MHE group， the MHEY group had significant reductions in AST， ALT， ALP， TBil， TBA， blood ammonia， and colon pH value （all P<0.05）， and the HE group had significant increases in AST， ALT， ALP， TBil， TBA， blood ammonia， and colon pH value （all P<0.05）. The MHE group had significantly lower TBA， primary BA， and secondary BA than the NC group （all P<0.05）； compared with the MHE group， the HE group had significantly lower TBA and primary BA （all P<0.05）， and the MHEY group had significantly higher TBA and primary BA （all P<0.05）. Compared with the NC group， the MHE group had significant reductions in GCDCA， GUDCA， GHDCA， TCDCA， TUDCA， GLCA， and TLCA （all P<0.05） and significant increases in γ－MCA， THCA， 7－KDCA， AlloLCA， and α－MCA （all P<0.05）， and compared with the MHE group， the MHEY group had significant increases in THDCA， TMCA， TCDCA， TUDCA， and TLCA （all P<0.05）. ConclusionRD retention enema can improve liver injury and cognitive function in a rat model of MHE induced by CCl₄ and TAA by regulating the enterohepatic circulation of BA， possibly by increasing the synthesis of taurine－binding BA.

Humans ; Diabetes Mellitus, Type 2/epidemiology* ; Air Pollution/adverse effects* ; Air Pollutants/toxicity* ; Risk Assessment ; Particulate Matter ; Environmental Exposure