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.

BACKGROUND:Age-related macular degeneration and deep vein thrombosis may share common pathophysiological mechanisms,but there is a lack of direct evidence regarding their relationship.Traditional studies are confounded by confounding factors and reverse causation.OBJECTIVE:To investigate the causal relationship between age-related macular degeneration and deep vein thrombosis based on Mendelian randomization design.METHODS:Through a two-way Mendelian randomization analysis,single nucleotide polymorphisms of exposure and outcomes were obtained from publicly available genome-wide association studies,with deep vein thrombosis data from the FinnGen database in a European population with a sample size of 363 612 and 1 048 575 single nucleotide polymorphisms.In addition,we obtained data on age-related macular degeneration from the IEUOpenGWAS project,also from a European population sample of 105 248 cases covering 11 304 110 single nucleotide polymorphisms.In R4.4.1,we used the TwoSampleMR package(version 0.6.8)to explore the causal effects of exposure factors on outcomes.At the same time,we also conducted a sensitivity analysis via MR-Egger regression,weighted median,weighted model and simple model methods to ensure that the assessment results were robust and reliable.In addition,we used the"heterogeneity"function to test for heterogeneity,and the"horizontal pleiotropy"function and the MR-PRESSO test to further assess horizontal pleotropy.The Cochran's Q test was used to determine whether there was statistical heterogeneity between single nucleotide polymorphisms,and the leave-one-out method was used to assess whether single nucleotide polymorphisms would significantly interfere with Mendelian randomization analysis.Funnel plots were drawn to assess the potential bias of single nucleotide polymorphisms.Forest plots were plotted to show the effect estimates of single nucleotide polymorphisms on exposure and outcomes,and their confidence intervals were plotted.Scatter plots were plotted to evaluate the relationship between the potency of single nucleotide polymorphisms and their causal effect size on outcome estimates.RESULTS AND CONCLUSION:Both forward and reverse studies showed that there was no causal association between age-related macular degeneration and the occurrence of deep vein thrombosis(P＞0.05).Sensitivity analysis showed that the main analysis results were reliable and robust,with no outliers,heterogeneity,and horizontal pleiotropy,and no single nucleotide polymorphism significantly affected the overall effect estimate.Although it is based on European population data,it has methodological reference value for Chinese biomedical research on complex disease associations.In this field,China can carry out multi-center large-sample studies,accurately analyze the internal links between Chinese population-related diseases,and provide a basis for prevention and treatment strategies and clinical practice.

BACKGROUND:Age-related macular degeneration and deep vein thrombosis may share common pathophysiological mechanisms,but there is a lack of direct evidence regarding their relationship.Traditional studies are confounded by confounding factors and reverse causation.OBJECTIVE:To investigate the causal relationship between age-related macular degeneration and deep vein thrombosis based on Mendelian randomization design.METHODS:Through a two-way Mendelian randomization analysis,single nucleotide polymorphisms of exposure and outcomes were obtained from publicly available genome-wide association studies,with deep vein thrombosis data from the FinnGen database in a European population with a sample size of 363 612 and 1 048 575 single nucleotide polymorphisms.In addition,we obtained data on age-related macular degeneration from the IEUOpenGWAS project,also from a European population sample of 105 248 cases covering 11 304 110 single nucleotide polymorphisms.In R4.4.1,we used the TwoSampleMR package(version 0.6.8)to explore the causal effects of exposure factors on outcomes.At the same time,we also conducted a sensitivity analysis via MR-Egger regression,weighted median,weighted model and simple model methods to ensure that the assessment results were robust and reliable.In addition,we used the"heterogeneity"function to test for heterogeneity,and the"horizontal pleiotropy"function and the MR-PRESSO test to further assess horizontal pleotropy.The Cochran's Q test was used to determine whether there was statistical heterogeneity between single nucleotide polymorphisms,and the leave-one-out method was used to assess whether single nucleotide polymorphisms would significantly interfere with Mendelian randomization analysis.Funnel plots were drawn to assess the potential bias of single nucleotide polymorphisms.Forest plots were plotted to show the effect estimates of single nucleotide polymorphisms on exposure and outcomes,and their confidence intervals were plotted.Scatter plots were plotted to evaluate the relationship between the potency of single nucleotide polymorphisms and their causal effect size on outcome estimates.RESULTS AND CONCLUSION:Both forward and reverse studies showed that there was no causal association between age-related macular degeneration and the occurrence of deep vein thrombosis(P＞0.05).Sensitivity analysis showed that the main analysis results were reliable and robust,with no outliers,heterogeneity,and horizontal pleiotropy,and no single nucleotide polymorphism significantly affected the overall effect estimate.Although it is based on European population data,it has methodological reference value for Chinese biomedical research on complex disease associations.In this field,China can carry out multi-center large-sample studies,accurately analyze the internal links between Chinese population-related diseases,and provide a basis for prevention and treatment strategies and clinical practice.

To investigate the clinical features and peripheral blood immune cell subsets ofelderly (≥60 years old) onset rheumatoid arthritis (EORA) patients.

Objective To explore the clinical characteristics of patients with diffuse large B-cell lymphoma (DLBCL) accompanied with KMT2D gene mutation and the impact of its co-mutated genes on prognosis. Methods Clinical data of 155 newly diagnosed DLBCL patients were obtained. The second-generation sequencing method was used to detect 475 hotspot genes, including KMT2D mutation. Patients were divided into the KMT2D mutation group and KMT2D wild-type group based on the presence or absence of KMT2D gene mutation. Clinical characteristics, differences in co-mutated genes, and survival differences between the two groups were compared. Results The frequency of KMT2D mutation was 31%, which is predominantly observed in elderly patients (P=0.07) and less in the double-expressor phenotype (P=0.07). Compared with the KMT2D wild-type group, KMT2D gene mutation was associated with higher co-mutation rates of CDKN2A (OR=2.82, P=0.01) and BCL2 (OR=3.84, P=0.016), while being mutually exclusive with MYC gene mutation (OR=0.11, P=0.013). In univariate survival analysis, no statistically significant difference in overall survival (OS) was found between the KMT2D mutation group and the wild-type group (P=0.54). Further analysis of the prognostic significance of KMT2D with other gene mutations indicated that patients with KMT2D^mutBTG2^mut had poorer OS than those with KMT2D^wt BTG2^mut (P=0.07) and KMT2D^wt BTG2^wt (P=0.05). On the contrary, patients with KMT2D^mut CD79B^mut had better OS than those with KMT2D^mut CD79B^wt (P=0.09), with no prognostic impact observed for other co-mutated genes. Multivariate Cox regression analysis revealed that Ann Arbor stages Ⅲ and Ⅳ (HR=2.751, 95%CI: 1.169-6.472, P=0.02), elevated LDH levels (HR=2.461, 95%CI: 1.396-4.337, P=0.002), Ki-67 index>80% (HR=1.875, 95%CI: 1.066-3.299, P=0.029), and KMT2D^mutBTG2^mut(HR=4.566, 95%CI: 1.348-15.471, P=0.015) were independent risk factors for OS in patients with DLBCL (P<0.05). Conclusion DLBCL patients with KMT2D mutation often have multiple gene mutations, among which patients with a co-mutated BTG2 gene have poor prognosis.

Background/Aims: Metabolic dysfunction–associated steatotic liver disease (MASLD) is a chronic liver disease characterized by hepatic steatosis. Ubiquitin-specific protease 29 (USP29) plays pivotal roles in hepatic ischemiareperfusion injury and hepatocellular carcinoma, but its role in MASLD remains unexplored. Therefore, the aim of this study was to reveal the effects and underlying mechanisms of USP29 in MASLD progression. Methods: USP29 expression was assessed in liver samples from MASLD patients and mice. The role and molecular mechanism of USP29 in MASLD were assessed in high-fat diet-fed and high-fat/high-cholesterol diet-fed mice and palmitic acid and oleic acid treated hepatocytes. Results: USP29 protein levels were significantly reduced in mice and humans with MASLD. Hepatic steatosis, inflammation and fibrosis were significantly exacerbated by USP29 deletion and relieved by USP29 overexpression. Mechanistically, USP29 significantly activated the expression of genes related to fatty acid β-oxidation (FAO) under metabolic stimulation, directly interacted with long-chain acyl-CoA synthase 5 (ACSL5) and repressed ACSL5 degradation by increasing ACSL5 K48-linked deubiquitination. Moreover, the effect of USP29 on hepatocyte lipid accumulation and MASLD was dependent on ACSL5. Conclusions USP29 functions as a novel negative regulator of MASLD by stabilizing ACSL5 to promote FAO. The activation of the USP29-ACSL5 axis may represent a potential therapeutic strategy for MASLD.

OBJECTIVE: Varied acupoint selections represent a potential cause of the uncertainty surrounding the efficacy of acupuncture for knee osteoarthritis (OA). Skin temperature, a guiding factor for acupoint selection, may help to address this issue. This study explored thermal sensitization of acupoints used for the treatment of knee OA. METHODS: This cross-sectional case-control study enrolled cases aged 45-75 years with symptomatic knee OA and age- and gender-matched non-knee OA controls in a 1:1 ratio. All participants underwent infrared thermographic imaging. The primary outcome was the relative skin temperature of acupoint (STA), and the secondary outcome was the absolute STA of 11 acupoints. The Z test was used to compare the relative and absolute STAs between the groups. Principal component analysis was used to extract the common factors (CFs, acupoint cluster) in the STAs. A general linear model was used to identify factors affecting the STA in the knee OA cases. For the group comparisons of relative STA, P < 0.0045 (adjusted for 11 acupoints through Bonferroni correction) was considered to indicate statistical significance. For other analyses, P < 0.05 was used as the threshold for statistical significance. RESULTS: The analysis included 308 participants, consisting of 151 cases (mean age: [64.58 ± 6.67] years; male: 25.83%; mean body mass index: [25.70 ± 3.16] kg/m²) and 157 controls (mean age: [63.37 ± 5.96] years; male: 26.11%; mean body mass index: [24.47 ± 2.84] kg/m²). The relative STAs of ST34 (P = 0.0001), EX-LE2 (P < 0.0001), EX-LE5 (P = 0.0006), SP10 (P < 0.0001), BL40 (P = 0.0012) and GB39 (P = 0.0037) were higher in the knee OA group. No difference was found in the STAs of ST35, ST36, SP9, GB33 and GB34. Four CFs were identified for relative STA in both groups. The acupoints within each CF were consistent between the groups. The mean values of the relative STAs across each CF were higher in the knee OA group. In the knee OA cases, no factors were observed to affect the relative STA, while age and gender were found to affect the absolute STA. CONCLUSION Among patients with knee OA, thermal sensitization occurs in the acupoints of the lower extremity, exhibiting localized and regional thermal consistencies. The thermally sensitized acupoints that we identified in this study, ST34, SP10, EX-LE2, EX-LE5, GB39 and BL40, may be good choices for the acupuncture treatment of knee OA. Please cite this article as: Tu JF, Wang XZ, Yan SY, Wang YR, Yang JW, Shi GX, Zhang WZ, Jing LN, Yang LS, Liu DH, Wang LQ, Mi BH. Thermal sensitization of acupoints in patients with knee osteoarthritis: A cross-sectional case-control study. J Integr Med. 2025; 23(3): 289-296.
Humans ; Osteoarthritis, Knee/physiopathology* ; Male ; Cross-Sectional Studies ; Middle Aged ; Female ; Acupuncture Points ; Case-Control Studies ; Aged ; Skin Temperature ; Acupuncture Therapy

OBJECTIVE: Observational studies have found associations between inflammatory bowel disease (IBD) and the risk of dementia, including Alzheimer's dementia (AD) and vascular dementia (VD); however, these findings are inconsistent. It remains unclear whether these associations are causal. METHODS: We conducted a meta-analysis by systematically searching for observational studies on the association between IBD and dementia. Mendelian randomization (MR) analysis based on summary genome-wide association studies (GWASs) was performed. Genetic correlation and Bayesian co-localization analyses were used to provide robust genetic evidence. RESULTS: Ten observational studies involving 80,565,688 participants were included in this meta-analysis. IBD was significantly associated with dementia (risk ratio [ RR] =1.36, 95% CI = 1.04-1.78; I ² = 84.8%) and VD ( RR = 2.60, 95% CI = 1.18-5.70; only one study), but not with AD ( RR = 2.00, 95% CI = 0.96-4.13; I ² = 99.8%). MR analyses did not supported significant causal associations of IBD with dementia (dementia: odds ratio [ OR] = 1.01, 95% CI = 0.98-1.03; AD: OR = 0.98, 95% CI = 0.95-1.01; VD: OR = 1.02, 95% CI = 0.97-1.07). In addition, genetic correlation and co-localization analyses did not reveal any genetic associations between IBD and dementia. CONCLUSION Our study did not provide genetic evidence for a causal association between IBD and dementia risk. The increased risk of dementia observed in observational studies may be attributed to unobserved confounding factors or detection bias.
Humans ; Mendelian Randomization Analysis ; Inflammatory Bowel Diseases/complications* ; Dementia/etiology* ; Observational Studies as Topic ; Genome-Wide Association Study