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 and aims The mechanism of cholestatic liver injury (CLI) is unclear, and effective therapies are lacking. While peroxisome proliferator-activated receptor alpha (PPARα) agonists show potential hepatoprotective effect and pyroptosis is implicated in hepatocellular damage, how PPARα activation mitigates lithocholic acid (LCA)-induced pyroptosis remains unknown. Methods The hepatoprotective effect of PPARα agonists was evaluated in a mouse model of intrahepatic cholestasis induced by LCA. Liver injury was assessed via serum biochemistry, hematoxylin and eosin and TUNEL staining, and electron microscopy. Pyroptosis pathways were analyzed using real-time quantitative polymerase chain reaction, Western blot, and co-immunoprecipitation. Results Combined morphological, histopathological, and biochemical analyses confirmed that PPARα activation protects against CLI. Compared with LCA treatment alone, PPARα activation significantly attenuated the elevation of serum lactate dehydrogenase (LDH), the increased TUNEL-positive cells, and the formation of hepatocyte membrane pores. Mechanistically, PPARα activation suppressed both NOD-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis and apoptosis protease-activating factor-1 (APAF-1)/CASPASE-3/GSDME-mediated pyroptosis. Furthermore, PPARα agonist pretreatment inhibited activation of the nuclear factor-kappa B (NF-κB) and forkhead box O1 (FOXO1) signaling pathways. Conclusions PPARα protects against LCA-induced CLI by inhibiting both NLRP3 inflammasome-mediated pyroptosis associated with NF-κB and APAF-1/CASPASE-3/GSDME-mediated pyroptosis associated with the FOXO1 signaling pathway.

Objective:In order to clarify the ABO phenotype and genotype,and explore the molecular biological mechanism,serological detection,genotyping and gene sequencing were performed on an upper gastrointestinal hemorrhage patient with inconsistent forward and reverse ABO blood typing.Methods:ABO forward and reverse blood typing,H antigen identification,capillary centrifugation test and salivary substance detection were performed by classical serological method,moreover,polymerase chain reaction-sequence specific primer(PCR-SSP)was used for ABO genotyping,ABO gene 1-7 exons were sequenced by Sanger analysis in order to identify mutation.Results:Mixed field agglutination with anti-A,anti-AB and no agglutination with anti-A1 were appeared in the forward typing tests,agglutination with B cells but no agglutination with A1 cells and O cells were appeared in the reverse typing tests.3+agglutination strength was showed with anti-H.In capillary centrifugation experiment,erythrocyte after isolation in proximal part and distal end had same strength of agglutination with anti-A.Substances A and H were detected in saliva.The patient was assigned an A3 phenotype according to serological characteristics.Sequencing results of ABO gene 1-7 exons showed c.261delG,c.467C＞T,c.865A＞G,in which,865A＞G was the first discovered mutation,and this new mutation had been submitted to GenBank with accession number PP187306.Conclusion:A novel site mutation c.865A＞G is reported in this study,and this new mutation can result in a replacement of Met with Val at residue 289(p.Met289Val)and lead to an A3 phenotype.

This study explored the effects and underlying mechanism of Raf kinase inhibitory protein(RKIP)on apoptosis in mast cells sensitized by Echinococcus granulosus cyst fluid.Bone marrow-derived mast cells(BMMCs)were isolated and cultured from RKIP knockout(KO)and wild-type(WT)C57BL/6 mice.Cells were divided into control and sensitized groups.The sensitized group was incubated for 24 h in RPMI1640 medium containing 10%serum from mice infected with E.granulosus,then activated for 3 h or 6 h with E.granulosus cyst fluid.The control group was incubated for 24 h in RPMI1640 medium,and then received an equal vol-ume of PBS.Cells and supernatants were collected for analysis.Flow cytometry was used to detect the expression of CD117 and FcεRⅠα on BMMCs.The levels of β-hexosaminidase,IL-4,and TNF-α in the supernatant were quantified with ELISA.Western blot analy-sis was used to assess expression changes in RKIP,apoptosis-related proteins,and pathway proteins in BMMC before and after sensi-tization.Flow cytometry analysis revealed that after 4 weeks of induction,the CD117 and FcεRⅠα double-positivity rates on both WT and KO BMMC exceeded 90%.ELISA indicated that the E.granulosus cyst fluid resulted in significantly greater β-hexosaminidase re-lease(F=16.88,P<0.05),and levels of IL-4(F=16.51,P<0.05)and TNF-α(F=9.78,P<0.05)in the KO sensitized group than the WT sensitized group.With respect to the WT control group,the WT sensitized group showed significantly down-regulated pro-tein expression levels of RKIP(F=8.20,P<0.05)and Bcl-2(F=101.40,P<0.01)after 3 h,but significantly up-regulated levels of p-PI3K(F=8.04,P<0.05),p-Akt(F=32.52,P<0.01),p-P65(F=13.29,P<0.05),and cleaved-caspase-3(F=46.34,P<0.01).With respect to the WT sensitized group,the KO sensitized group showed significantly up-regulated protein expression of p-PI3K(F=8.45,P<0.05),p-Akt(F=8.58,P<0.05),p-P65(F=11.02,P<0.05),and Bcl-2(F=84.50,P<0.001)after 3 h,but significantly down-regulated expression of cleaved-caspase-3(F=15.66,P<0.05).In conclusion,RKIP may inhibit the PI3K/Akt/NF-κB pathway,thereby inducing apoptosis in mast cells sensitized by E.granulosus cyst fluid.This process may help ease aller-gic reactions caused by mast cells in echinococcosis,thus offering a promising new approach for preventing and treating such reactions.

Aim To investigate the effects of sodium lactate(NALA)on right heart failure induced by monocrotaline(MCT)-induced pulmonary arterial hy-pertension in rats and to reveal the underlying mecha-nisms.Methods Forty male Sprague-Dawley(SD)rats were randomly allocated into four groups,with ten rats in each group,namely,MCT group,NALA group,and NALA+MCT group;the MCT and NALA+MCT groups were administered a single intraperito-neal injection of MCT at 60 mg·kg-1 to induce pul-monary hypertension,and one week later,the NALA and NALA+MCT groups received intraperitoneal in-jections of NALA at 0.1 g·kg-1(once a day,for 5 weeks),while the CON and MCT groups received e-qual volumes of physiological saline(once a day,for 5 weeks);right heart function was assessed using echo-cardiography,right ventricular and pulmonary artery remodeling were evaluated via histopathological sec-tions,and the expression levels of ANP,BNP,and in-flammatory factors were measured by ELISA,along with assessments of oxidative stress levels,Western blot detection of the expression levels of proteins in the TLR4/NF-κB signaling pathway.Results Compared to the CON group,the MCT group exhibited increased RVSP and RVHI,decreased right heart function,in-creased collagen fiber deposition,and elevated oxida-tive stress and inflammatory factor expression,and the expression levels of proteins in the TLR4/NF-κB signa-ling pathway increased(P＜0.05);compared to the MCT group,the NALA+MCT group showed reduced RVSP and RVHI,improved right heart function,atten-uated pulmonary vascular remodeling,decreased ex-pression of ANP,BNP,inflammatory factors,and H2O2,along with increased antioxidant enzyme expres-sion,and the expression levels of proteins in the TLR4/NF-κB signaling pathway decreased(P＜0.05).Conclusion NALA can inhibit right ventric-ular remodeling in rats with pulmonary hypertension,and the underlying mechanism may involve the allevia-tion of inflammatory responses and oxidative stress through the inhibition of the TLR4/NF-κB signaling pathway.

Objective:To investigate the related factors of cognitive impairment in middle-aged and old-aged patients with type 2 diabetes mellitus(T2DM).Methods:A total of 970 patients with T2DM(585 middle-aged group and 385 old-aged group)were selected from residents of a large community in Beijing from September to December 2018.The Mini-Mental State Examination(MMSE)was used to assess the cognitive func-tion.Multivariate logistic regression was used to analyze the related factors.Results:The detection rates of cognitive impairment were 12.0％and 13.5％in middle-aged and old-aged patients with T2DM,respectively.Among mid-dle-aged patients with T2DM,work(OR=0.22,95％CI:0.03-0.77)and education at the junior college or un-dergraduate level and above(OR=0.18,95％CI:0.04-0.55)were protective factors for cognitive impair-ment.Myocardial infarction(OR=4.13,95％CI:1.26-13.63)was a risk factor for cognitive impairment.Among old-aged patients with T2DM,drinking tea 1-2 times a week(OR=0.11,95％CI:0.01-0.58)and education at the junior college or undergraduate level and above(OR=0.19,95％CI:0.05-0.54)were protective factors for cognitive impairment.Stroke(OR=3.64,95％CI:1.55-8.39)and good sleep self-assessment(OR=2.75,95％CI:1.13-7.35)were risk factors for cognitive impairment.Conclusion:Cognitive impairment in middle-aged pa-tients with T2DM is related to work,education level and myocardial infarction,and cognitive impairment in old-aged patients with T2DM is related to lifestyle,education level and stroke.

Objective To investigate the role and mechanism of inflammatory marker C5a in regulating the polarization of M2 macro-phages as well as its clinical application value in the prognosis evaluation of lung cancer.Methods The phorbol 12-myristate 13-ace-tate(PMA)-pulsed human monocytic leukemia cell line THP-1 was stimulated with C5a for 0,6,12,24,and 48 h or 0,1,2,3,6,and 12 h,and then the expression levels of M2 markers CD163 and CD206 mRNA were determined by real-time fluorescence quantita-tive PCR(qRT-PCR).The expression level of general control non-repressed protein 5(GCN5)with histone acetyltransferase(HAT)activity was detected by Western blot.Co-immunoprecipitation(co-IP)was used to determine the acetylation of GATA binding protein 3(GATA3),a key transcription factor for macrophages,and its binding ability to GCN5 and E1A binding protein p300(Ep300/p300).After the macrophages pre-treated with GCN5 inhibitor butyrolactone 3(MB-3)were stimulated with C5a,the expression levels of CD163 and CD206,acetylation of GATA3,and its binding ability to GCN5 were determined by Western blot and co-IP.The clinical significance of the expression of C5a receptor 1(C5aR1)and GCN5 in lung cancer tissues in the prognosis of lung cancer patients was analyzed using the KM plotter database.Results C5a could significantly increase the expression levels of CD163 and CD206 mRNA,expression of GCN5,acetylation of GATA3,and its binding ability to GCN5 in PMA-induced adherent macrophages,but did not affect the binding of GATA3 to p300.Inhibiting the activity of GCN5 not only significantly reduced the acetylation of GATA3 and its binding ability to GCN5,but also down-regulated the expressions of CD163 and CD206.The overall survival rate of lung cancer patients with high expression of C5aR1 or GCN5 was significantly reduced.Conclusion C5a promotes the polarization of M2 macrophages by indu-cing GCN5 to acetylate GATA3.The expressions of C5aR1 and GCN5 in lung cancer tissues may have certain clinical application value for the prognosis of the patients.

Objective To conduct a bibliometric analysis of relevant literature on liver failure caused by viral hepatitis from the past five years,and to help researchers understand the current status and hotspots in this field,and to provide insights into future research trends.Methods Based on the Science Citation Index Expanded(SCI-Expanded)data from Web of Science Core Collection,visualization analysis and mapping were conducted through VOSviewer and CiteSpace software to generate visual representations of international research collaboration networks,keyword co-occurrence clustering,and keyword bursts.Results From 2019 to 2023,a total of 873 relevant literature were included,with a total citation frequency of 7 364 and an average citation frequency of 8.44.Among them,China had the highest number of publications(458 articles,52.46%)and had the most cooperation with the United States.The research hotspots of viral hepatitis induced liver failure were mainly divided into three categories:basic and clinical research on liver failure caused by non-hepatitis B virus(HBV),the pathogenesis of HBV related liver failure,and treatment and prediction models of liver failure.The keyword time overlay map and burst map showed that the research hotspots had gradually shifted from the prevention and control of new infections to the treatment and prognosis assessment of patients with chronic infection.Conclusion China is a major international research entity in liver failure caused by viral hepatitis and actively participates in international scientific collaborations.The research hotspots on liver failure caused by viral hepatitis have gradually shifted from preventing viral hepatitis infections and expanding treatment options to the treatment of chronic infection patients and prognostic prediction.

Objective To investigate the role and mechanism of inflammatory marker C5a in regulating the polarization of M2 macro-phages as well as its clinical application value in the prognosis evaluation of lung cancer.Methods The phorbol 12-myristate 13-ace-tate(PMA)-pulsed human monocytic leukemia cell line THP-1 was stimulated with C5a for 0,6,12,24,and 48 h or 0,1,2,3,6,and 12 h,and then the expression levels of M2 markers CD163 and CD206 mRNA were determined by real-time fluorescence quantita-tive PCR(qRT-PCR).The expression level of general control non-repressed protein 5(GCN5)with histone acetyltransferase(HAT)activity was detected by Western blot.Co-immunoprecipitation(co-IP)was used to determine the acetylation of GATA binding protein 3(GATA3),a key transcription factor for macrophages,and its binding ability to GCN5 and E1A binding protein p300(Ep300/p300).After the macrophages pre-treated with GCN5 inhibitor butyrolactone 3(MB-3)were stimulated with C5a,the expression levels of CD163 and CD206,acetylation of GATA3,and its binding ability to GCN5 were determined by Western blot and co-IP.The clinical significance of the expression of C5a receptor 1(C5aR1)and GCN5 in lung cancer tissues in the prognosis of lung cancer patients was analyzed using the KM plotter database.Results C5a could significantly increase the expression levels of CD163 and CD206 mRNA,expression of GCN5,acetylation of GATA3,and its binding ability to GCN5 in PMA-induced adherent macrophages,but did not affect the binding of GATA3 to p300.Inhibiting the activity of GCN5 not only significantly reduced the acetylation of GATA3 and its binding ability to GCN5,but also down-regulated the expressions of CD163 and CD206.The overall survival rate of lung cancer patients with high expression of C5aR1 or GCN5 was significantly reduced.Conclusion C5a promotes the polarization of M2 macrophages by indu-cing GCN5 to acetylate GATA3.The expressions of C5aR1 and GCN5 in lung cancer tissues may have certain clinical application value for the prognosis of the patients.

This study explored the effects and underlying mechanism of Raf kinase inhibitory protein(RKIP)on apoptosis in mast cells sensitized by Echinococcus granulosus cyst fluid.Bone marrow-derived mast cells(BMMCs)were isolated and cultured from RKIP knockout(KO)and wild-type(WT)C57BL/6 mice.Cells were divided into control and sensitized groups.The sensitized group was incubated for 24 h in RPMI1640 medium containing 10%serum from mice infected with E.granulosus,then activated for 3 h or 6 h with E.granulosus cyst fluid.The control group was incubated for 24 h in RPMI1640 medium,and then received an equal vol-ume of PBS.Cells and supernatants were collected for analysis.Flow cytometry was used to detect the expression of CD117 and FcεRⅠα on BMMCs.The levels of β-hexosaminidase,IL-4,and TNF-α in the supernatant were quantified with ELISA.Western blot analy-sis was used to assess expression changes in RKIP,apoptosis-related proteins,and pathway proteins in BMMC before and after sensi-tization.Flow cytometry analysis revealed that after 4 weeks of induction,the CD117 and FcεRⅠα double-positivity rates on both WT and KO BMMC exceeded 90%.ELISA indicated that the E.granulosus cyst fluid resulted in significantly greater β-hexosaminidase re-lease(F=16.88,P<0.05),and levels of IL-4(F=16.51,P<0.05)and TNF-α(F=9.78,P<0.05)in the KO sensitized group than the WT sensitized group.With respect to the WT control group,the WT sensitized group showed significantly down-regulated pro-tein expression levels of RKIP(F=8.20,P<0.05)and Bcl-2(F=101.40,P<0.01)after 3 h,but significantly up-regulated levels of p-PI3K(F=8.04,P<0.05),p-Akt(F=32.52,P<0.01),p-P65(F=13.29,P<0.05),and cleaved-caspase-3(F=46.34,P<0.01).With respect to the WT sensitized group,the KO sensitized group showed significantly up-regulated protein expression of p-PI3K(F=8.45,P<0.05),p-Akt(F=8.58,P<0.05),p-P65(F=11.02,P<0.05),and Bcl-2(F=84.50,P<0.001)after 3 h,but significantly down-regulated expression of cleaved-caspase-3(F=15.66,P<0.05).In conclusion,RKIP may inhibit the PI3K/Akt/NF-κB pathway,thereby inducing apoptosis in mast cells sensitized by E.granulosus cyst fluid.This process may help ease aller-gic reactions caused by mast cells in echinococcosis,thus offering a promising new approach for preventing and treating such reactions.