BACKGROUND: Hepatic inflammatory cell accumulation and the subsequent systematic inflammation drive acute-on-chronic liver failure (ACLF) development. Previous studies showed that the vagus nerve exerts anti-inflammatory activity in many inflammatory diseases. Here, we aimed to identify the key molecule mediating the inflammatory process in ACLF and reveal the neuroimmune communication arising from the vagus nerve and immunological disorders of ACLF. METHODS: Proteomic analysis was performed and validated in ACLF model mice or patients, and intervention animal experiments were conducted using neutralizing antibodies. PNU-282987 (acetylcholine receptor agonist) and vagotomy were applied for perturbing vagus nerve activity. Single-cell RNA sequencing (scRNA-seq), flow cytometry, immunohistochemical and immunofluorescence staining, and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) technology were used for in vivo or in vitro mechanistic studies. RESULTS: The unbiased proteomics identified C-X-C motif chemokine ligand 9 (CXCL9) as the greatest differential protein in the livers of mice with ACLF and its relation to the systematic inflammation and mortality were confirmed in patients with ACLF. Interventions on CXCL9 and its receptor C-X-C chemokine receptor 3 (CXCR3) improved liver injury and decreased mortality of ACLF mice, which were related to the suppressing of hepatic immune cells' accumulation and activation. Vagus nerve stimulation attenuated while vagotomy aggravated the expression of CXCL9 and the severity of ACLF. Blocking CXCL9 and CXCR3 ameliorated liver inflammation and increased ACLF-associated mortality in ACLF mice with vagotomy. scRNA-seq revealed that hepatic macrophages served as the major source of CXCL9 in ACLF and were validated by immunofluorescence staining and flow cytometry analysis. Notably, the expression of CXCL9 in macrophages was modulated by vagus nerve-mediated cholinergic signaling. CONCLUSIONS Our novel findings highlighted that the neuroimmune communication of the vagus nerve-macrophage-CXCL9 axis contributed to ACLF development. These results provided evidence for neuromodulation as a promising approach for preventing and treating ACLF.
Animals ; Mice ; Chemokine CXCL9/metabolism* ; Vagus Nerve/physiology* ; Acute-On-Chronic Liver Failure/metabolism* ; Humans ; Male ; Mice, Inbred C57BL ; Proteomics ; Flow Cytometry ; Receptors, CXCR3/metabolism*

This study aims to explore the role and mechanism of CXC chemokine receptor 3 (CXCR3) in cisplatin-induced skeletal muscle atrophy. Wild-type mice were divided into two groups: cisplatin group and control group (treated by normal saline). The results showed that, compared to the control group, the expression levels of CXCR3 mRNA and protein were significantly up-regulated in the skeletal muscle of the cisplatin group, suggesting that CXCR3 may play an important role in the model of cisplatin-induced skeletal muscle atrophy. To further investigate its role and potential mechanisms, CXCR3 knockout mice and wild-type mice were treated with cisplatin to induce skeletal muscle atrophy. The results revealed that CXCR3 knockout not only failed to alleviate cisplatin-induced skeletal muscle atrophy, but also further reduced body weight, skeletal muscle mass, and muscle fiber cross-sectional area. Further analysis showed that, in the cisplatin-induced muscle atrophy model, CXCR3 knockout significantly up-regulated the expression levels of E3 ubiquitin ligases in skeletal muscle and down-regulated the expression levels of myogenic regulatory factors. To explore the molecular mechanism by which CXCR3 gene deletion exacerbated cisplatin-induced skeletal muscle atrophy, transcriptomic sequencing was performed on the atrophied skeletal muscles of wild-type and CXCR3 knockout mice. The results showed that, compared to wild-type mice, 14 genes were significantly up-regulated and 12 genes were significantly down-regulated in the skeletal muscle of CXCR3 knockout mice. Gene set enrichment analysis (GSEA) revealed a significant enrichment of genes related to fatty acid β-oxidation. Quantitative real-time PCR validation results were consistent with the transcriptomic sequencing results. These findings suggest that CXCR3 may counteract cisplatin-induced skeletal muscle atrophy by up-regulating E3 ubiquitin ligases, down-regulating myogenic regulatory factors, and enhancing the recruitment of fatty acid β-oxidation-related genes.
Animals ; Cisplatin/adverse effects* ; Muscular Atrophy/physiopathology* ; Mice ; Receptors, CXCR3/metabolism* ; Ubiquitin-Protein Ligases/metabolism* ; Mice, Knockout ; Oxidation-Reduction ; Fatty Acids/metabolism* ; Muscle, Skeletal/metabolism* ; Mice, Inbred C57BL ; Male

Objective To explore the effect of Evodiamine (Evo) on the immune function of allergic rhinitis (AR) rats and the regulatory mechanism on C-C motif chemokine ligand 2 (CCL2)/ C-C motif chemokine receptor 2 (CCR2) pathway. Methods The related targets of Evo-AR-immune function were screened by network pharmacology, and the protein interaction network diagram of intersecting targets was constructed. The AR rat model was established by ovalbumin (OVA) combined with aluminium hydroxide, and the rats were divided into six groups: a normal control (NC) group, a model group, a Loratadine (LOR) group, an Evodiamine low dose (Evo-L) group, a Evodiamine high dose (Evo-H) groups, and an Evo-H combined with CCL2 group. After the last administration, the symptoms of rats in each group were scored; ELISA was applied to detect the levels of histamine, immunoglobulin E (IgE), interleukin 4 (IL-4), IL-13 and interferon γ (IFN-γ); Diff-Quick staining solution was applied to detecte the number of cells in the nasal lavage fluid (NALF); hematoxylin eosin (HE) staining was applied to observe the pathological changes of nasal mucosa tissue; real-time quantitative PCR was applied to detect the levels of CCL2 and CCR2 mRNA in tissue; Western blot was applied to detect the expression levels of CCL2, CCR2 and CXC motif chemokine ligand 8 (CXCL8) proteins in nasal mucosa. Results There were eight intersection targets of EVo-AR-immune function, and protein interaction network diagram showed that CXCL8 was the core target. Compared with the NC group, the score of nasal symptoms, the levels of histamine, IgE, IL-4 and IL-13, the numbers of eosinophil, macrophages, neutrophils, lymphocytes and total cells, the mRNA and protein expression levels of CCL2 and CCR2, and the expression of CXCL8 protein in the model group were increased, while the level of IFN-γ was decreased. Compared with the model group, the score of nasal symptoms, the levels of histamine, IgE, IL-4 and IL-13, the numbers of eosinophil, macrophages, neutrophils, lymphocytes and total cells, the mRNA and protein expression levels of CCL2 and CCR2, and the expression of CXCL8 protein in LOR and Evo groups were decreased, while the level of IFN-γ was increased. Further use of CCL2 recombinant protein for compensatory experiments revealed that the improvement effect of Evo on immune function in AR rats was reversed by CCL2. Conclusion Evo can improve the immune function of AR rats, and its mechanism may be related to the inhibition of the CCL2/CCR2 pathway.
Animals ; Receptors, CCR2/immunology* ; Signal Transduction/drug effects* ; Chemokine CCL2/immunology* ; Rats ; Rhinitis, Allergic/metabolism* ; Immunoglobulin E/blood* ; Quinazolines/pharmacology* ; Male ; Interferon-gamma ; Rats, Sprague-Dawley ; Interleukin-13 ; Histamine ; Interleukin-4/immunology* ; Disease Models, Animal

Objective To investigate the effect of gentiopicroside on osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs), and to determine whether its mechanism involves the stromal cell-derived factor 1(SDF-1)/C-X-C chemokine receptor 4 (CXCR4) pathway. Methods BMSCs were divided into six groups: normal culture control group, osteogenic induction model group, low-dose gentiopicroside (L-gentiopicroside, 10 μmol/L) group, medium-dose gentiopicroside (M-gentiopicroside, 20 μmol/L) group, high-dose gentiopicroside (H-gentiopicroside, 40 μmol/L) group, and H-gentiopicroside+SDF-1/CXCR4 pathway inhibitor (AMD3100) group (H-gentiopicroside+AMD3100, 40 μmol/L gentiopicroside+10 μg/mL AMD3100). Cell viability, apoptosis, ALP activity, mineralized nodule formation, and protein levels of the SDF-1/CXCR4 pathway were assessed using the CCK-8 assay, flow cytometry, ALP staining, Alizarin Red S staining, and Western blotting, respectively. Results No mineralized nodules were observed in either the control and model group, although the color of the model group deepened. Compared with the control group, the model group showed significantly increased A value, ALP activity, expression levels of Runt related transcription factor 2 (RUNX2), osteopontin (OPN), SDF-1, CXCR4 proteins, along with a lower apoptosis rate. Compared with the model group, the L-gentiopicroside, M-gentiopicroside and H-gentiopicroside groups showed dose-dependently (LCXCR4, along with correspondingly decreased apoptosis rates. However, compared with the H-gentiopicroside group, the H-gentiopicroside+AMD3100 group showed reduced A value, ALP activity, expression levels of RUNX2, OPN, SDF-1, and CXCR4, along with a higher apoptosis rate. Conclusion The promoting effect of gentiopicroside on osteogenic differentiation of BMSCs may be achieved by activating the SDF-1/CXCR4 signaling pathway.
Humans ; Receptors, CXCR4/genetics* ; Mesenchymal Stem Cells/metabolism* ; Chemokine CXCL12/genetics* ; Iridoid Glucosides/pharmacology* ; Osteogenesis/drug effects* ; Cell Differentiation/drug effects* ; Signal Transduction/drug effects* ; Cells, Cultured ; Apoptosis/drug effects* ; Bone Marrow Cells/metabolism*

Objective To investigate the expression of blood basophil activation markers in patients with allergic rhinitis (AR) and the effects of allergens on their expression. Methods The blood samples were collected from the following four groups: healthy control (HC), AR patients with negative skin prick test (nAR), seasonal AR patients (sAR) and perennial AR patients (pAR). Flow cytometry was employed to analyze the expression of basophil activation markers Immunoglobulin E receptor I alpha(FcepsilonRIα), CD63 and CD203c in AR patients. Plasma levels of interleukin 4 (IL-4) and IL-8 were measured by liquid-phase chip technology, and their correlations with the percentages of activated basophils were further analyzed. An ovalbumin-induced AR mouse model was established, and the expression levels of FcepsilonRIα and CD63 on blood basophils were detected. Results The expression of FcepsilonRIα, CD203c and CD63 on basophils were increased in nAR, sAR and pAR patients. Allergens enhanced the mean florescence intensity expression of CD63 and CD203c on basophils of sAR and pAR patients. The plasma levels of IL-4 and IL-8 were elevated in nAR, sAR and pAR patients, showing moderate to high correlations with the expression levels of basophil activation markers. The FcepsilonRIαand CD63 expression on basophils of AR mice were increased. Conclusion Allergens may contribute to AR pathogenesis by upregulating the expression of FcepsilonRIα, CD63 and CD203c, as well as promoting the secretion of IL-4 and IL-8.
Basophils/metabolism* ; Humans ; Allergens/immunology* ; Animals ; Rhinitis, Allergic/blood* ; Female ; Male ; Adult ; Mice ; Biomarkers/blood* ; Tetraspanin 30/blood* ; Interleukin-4/blood* ; Interleukin-8/blood* ; Receptors, IgE/blood* ; Phosphoric Diester Hydrolases ; Young Adult ; Pyrophosphatases ; Middle Aged ; Mice, Inbred BALB C

OBJECTIVE: To explore the effects of hydroxychloroquine (HCQ) on immune mediators dysregulation in severe infection after chemotherapy in acute myeloid leukemia (AML) and its molecular mechanism. METHODS: Bone marrow or peripheral blood samples of 36 AML patients with severe infection (AML-SI) and 29 AML patients without infection (AML-NI) after chemotherapy were collected from the First Affiliated Hospital of Gannan Medical University from August 2022 to June 2023. In addition, the peripheral blood of 21 healthy subjects from the same period in our hospital was selected as the control group. The mRNA expressions of CXCL12, CXCR4 and CXCR7 were detected by RT-qPCR technology, and the levels of IL-6, IL-8 and TNF-α were detected by ELISA. Leukemia-derived THP-1 cells were selected and constructed as AML disease model. At the same time, bone marrow mesenchymal stem cells (BM-MSCs) from AML-SI patients were co-cultured with THP-1 cells and divided into Mono group and Co-culture group. THP-1 cells were treated with different concentration gradients of HCQ. The cell proliferation activity was subsequently detected by CCK-8 method and apoptosis was detected by Annexin V/PI double staining flow cytometry. ELISA was used to detect the changes of IL-6, IL-8 and TNF-α levels in the supernatant of the cell co-culture system, RT-qPCR was used to detect the mRNA expression changes of the core members of the CXCL12-CXCR4/7 regulatory axis, and Western blot was used to detect the expressions of apoptosis regulatory molecules and related signaling pathway proteins. RESULTS: CXCL12, CXCR4, CXCR7, as well as IL-6, IL-8, and TNF-α were all abnormally increased in AML patients, and the increases were more significant in AML-SI patients (P <0.01). Furthermore, there were statistically significant differences between AML-NI patients and AML-SI patients (all P <0.05). HCQ could inhibit the proliferation and induce the apoptosis of THP-1 cells, but the low concentration of HCQ had no significant effect on the killing of THP-1 cells. When THP-1 cells were co-cultured with BM-MSCs of AML patients, the levels of IL-6, IL-8 and TNF-α in the supernatance of Co-culture group were significantly higher than those of Mono group (all P <0.01). After HCQ intervention, the levels of IL-6, IL-8 and TNF-α in cell culture supernatant of Mono group were significantly decreased compared with those before intervention (all P <0.01). Similarly, those of Co-culture group were also significantly decreased (all P <0.001). However, the expression of the core members of the CXCL12-CXCR4/7 regulatory axis was weakly affected by HCQ. HCQ could up-regulate the expression of pro-apoptotic protein Bax, down-regulate the expression of anti-apoptotic protein Bcl-2, as well as simultaneously promote the hydrolytic activation of Caspase-3 when inhibiting the activation level of TLR4/NF-κB pathway, then induce the programmed death of THP-1 cells after intervention. CONCLUSION The core members of CXCL12-CXCR4/7 axis and related cytokines may be important mediators of severe infectious immune disorders in AML patients. HCQ can inhibit cytokine levels to reverse immune mediators dysregulation and suppress malignant biological characteristics of leukemia cells. The mechanisms may be related to regulating the expression of Bcl-2 family proteins, hydrolytically activating Caspase-3 and inhibiting the activation of TLR4/NF-κB signaling pathway.
Humans ; Leukemia, Myeloid, Acute/immunology* ; Hydroxychloroquine/pharmacology* ; Receptors, CXCR4/metabolism* ; Apoptosis/drug effects* ; Tumor Necrosis Factor-alpha/metabolism* ; Chemokine CXCL12/metabolism* ; Interleukin-8/metabolism* ; Interleukin-6/metabolism* ; Receptors, CXCR/metabolism* ; Mesenchymal Stem Cells ; THP-1 Cells

Chronic pain, frequently comorbid with neuropsychiatric disorders, significantly impairs patients' quality of life and functional capacity. Accumulating evidence implicates the chemokine CCL2 and its receptor CCR2 as key players in chronic pain pathogenesis. This review examines the regulatory mechanisms of the CCL2/CCR2 axis in chronic pain processing at three hierarchical levels: (1) Peripheral Sensitization: CCL2/CCR2 modulates TRPV1, Nav1.8, and HCN2 channels to increase neuronal excitability and CGRP signaling and calcium-dependent exocytosis in peripheral nociceptors to transmit pain. (2) Spinal Cord Central Sensitization: CCL2/CCR2 contributes to NMDAR-dependent plasticity, glial activation, GABAergic disinhibition, and opioid receptor desensitization. (3) Supraspinal Central Networks: CCL2/CCR2 signaling axis mediates the comorbidity mechanisms of pain with anxiety and cognitive impairment within brain regions, including the ACC, CeA, NAc, and hippocampus, and it also increases pain sensitization through the descending facilitation system. Current CCL2/CCR2-targeted therapeutic strategies and their development status are discussed, highlighting novel avenues for chronic pain management.
Humans ; Chronic Pain/physiopathology* ; Animals ; Neuroglia/metabolism* ; Chemokine CCL2/metabolism* ; Receptors, CCR2/metabolism*

OBJECTIVE: To explore the effects and mechanisms of the C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4) signaling axis on apoptosis and autophagy in SH-SY5Y neuronal cells subjected to oxygen-glucose deprivation/reperfusion (OGD/R) model in vitro. METHODS: SH-SY5Y cells were divided into the following groups: OGD/R group and non-OGD/R group, with the OGD/R group subjected to OGD/R modeling and the non-OGD/R group receiving no treatment. Cells were also divided into CXCL12⁺ and CXCL12^- groups; the CXCL12⁺ group received 0.1 mg/L exogenous recombinant CXCL12 (rhCXCL12) at reoxygenation, while the CXCL12^- group did not. Another set of cells was divided into CXCL12+AMD3100 and CXCL12 groups; the CXCL12+AMD3100 group was pretreated with 2.5 mg/L AMD3100, a CXCR4 inhibitor, for 2 hours before OGD/R and received both 2.5 mg/L AMD3100 and 0.1 mg/L rhCXCL12 at reoxygenation, whereas the CXCL12 group received rhCXCL12 only. Additionally, cells were divided into small interfering RNA CXCR4 (siCXCR4) and small interfering RNA negative control (siNC) groups; the siCXCR4 group underwent CXCR4 knockdown before OGD/R modeling and received 0.1 mg/L rhCXCL12 at reoxygenation, while the siNC group, transfected with a negative control, received the same treatment. Protein expression of autophagy-related 16 (ATG16), microtubule-associated protein 1 light chain 3 (LC3), aquaporin-3 (AQP3), and CXCR4 was detected by Western blotting. Apoptosis rate and CXCR4 expression were measured by flow cytometry. RESULTS: Compared with the non-OGD/R group, the OGD/R group showed a significantly increased apoptosis rate and markedly decreased protein expression levels of ATG16, LC3, AQP3, and CXCR4 (all P < 0.05). CXCR4 fluorescent expression was also significantly reduced, suggesting that OGD/R simultaneously affects neuronal apoptosis and autophagy while inhibiting CXCR4 and AQP3 expression in SH-SY5Y cells. Compared with the CXCL12^- group, the CXCL12⁺ group exhibited no significant change in apoptosis rate but demonstrated significantly increased protein expression of ATG16, LC3, and AQP3 (ATG16/GAPDH: 1.21±0.10 vs. 1.00±0.00; LC3/β-actin: 1.22±0.10 vs. 1.00±0.00; AQP3/β-actin: 1.26±0.04 vs. 1.00±0.00; all P < 0.05). CXCR4 expression was also significantly enhanced (fluorescence intensity: 1.19±0.05 vs. 1.00±0.00, P < 0.05), indicating that CXCL12 may promote autophagy in OGD/R-injured SH-SY5Y cells via the CXCR4/AQP3 pathway. Compared with the CXCL12 group, the CXCL12+AMD3100 group showed no significant difference in apoptosis rate but significantly lower protein levels of ATG16 and LC3 (ATG16/GAPDH: 0.75±0.08 vs. 1.00±0.00; LC3/GAPDH: 0.86±0.07 vs. 1.00±0.00; both P < 0.05), suggesting that CXCL12 induces autophagy in OGD/R SH-SY5Y cells through CXCR4. Compared with the siNC group, the siCXCR4 group showed no significant change in apoptosis rate but significantly reduced protein expression of ATG16, LC3, AQP3, and CXCR4 (ATG16/GAPDH: 0.76±0.06 vs. 1.00±0.00; LC3/GAPDH: 0.79±0.11 vs. 1.00±0.00; AQP3/GAPDH: 0.81±0.05 vs. 1.00±0.00; CXCR4/GAPDH: 0.86±0.04 vs. 1.00±0.00; all P < 0.05), indicating that CXCR4 knockdown suppresses OGD/R-induced autophagy in SH-SY5Y cells likely via AQP3. CONCLUSIONS The CXCL12/CXCR4 signaling axis can regulate OGD/R-induced autophagy in SH-SY5Y cells through AQP3 without affecting apoptosis, indicating a role for this pathway in neuronal autophagy during cerebral ischemia/reperfusion injury.
Humans ; Receptors, CXCR4/metabolism* ; Chemokine CXCL12/metabolism* ; Autophagy ; Glucose/metabolism* ; Apoptosis ; Neurons/cytology* ; Oxygen/metabolism* ; Signal Transduction ; Cell Line, Tumor ; Cell Hypoxia ; Benzylamines ; Cyclams

OBJECTIVES: To observe the role of miR-139-5p and Notch1 signaling pathway in regulation of homing of bone mesenchymal stem cells (BMSCs) of asthmatic rats. METHODS: Normal rat BMSCs were co-cultured with bronchial epithelial cells from normal or asthmatic rats, followed by transfection with miR-139-5p mimics or a negative control sequence. The changes in cell viability and cell cycle were analyzed, and the cellular expressions of CXCR4 and SDF-1 were detected using immunofluorescence staining. The changes of BMSC homing after the transfection were observed, and the expressions of Notch1, RBP-J, and Hes1 mRNAs and proteins and Th1/Th2 cytokines were detected with RT-qPCR, Western blotting or ELISA. RESULTS: The co-cultures of BMSCs and asthmatic bronchial epithelial cells showed significantly decreased expressions of miR-139-5p, IL-2 and IL-12 and increased expressions of CXCR4, SDF-1, IL-5, IL-9, Notch1, RBP-J, and Hes1. Transfection with miR-139-5p mimics significantly increased the expressions of miR-139-5p, IL-2, CXCR4 and SDF-1 and lowered the expression levels of IL-5, IL-9, Notch1, activated Notch1, and Hes1 in the co-cultured cells. Correlation analysis showed that BMSC homing was positively correlated with miR-139-5p and IL-12 and negatively correlated with IL-5 expression. The expression of CXCR4 was negatively correlated with activated Notch1, and SDF-1 was positively correlated with miR-139-5p but negatively correlated with Notch1 expression. CONCLUSIONS High expression of miR-139-5p promotes homing of BMSCs in asthma by targeting the Notch1 signaling pathway to regulate the expressions of Th1/Th2 cytokines, thereby alleviating airway inflammation.
Asthma/genetics* ; Animals ; Mesenchymal Stem Cells/cytology* ; MicroRNAs/metabolism* ; Rats ; Transcription Factor HES-1/genetics* ; Signal Transduction ; Receptor, Notch1/genetics* ; Immunoglobulin J Recombination Signal Sequence-Binding Protein/genetics* ; Receptors, CXCR4/genetics* ; Coculture Techniques ; Rats, Sprague-Dawley ; Chemokine CXCL12/genetics* ; Epithelial Cells/metabolism*

The CC chemokine ligand 2 (CCL2, also known as MCP-1) and its cognate receptor CCR2 have well-characterized roles in chemotaxis. CCL2 has been previously shown to promote excitatory synaptic transmission and neuronal excitability. However, the detailed molecular mechanism underlying this process remains largely unclear. In cultured hippocampal neurons, CCL2 application rapidly upregulated surface expression of GluA1, in a CCR2-dependent manner, assayed using SEP-GluA1 live imaging, surface GluA1 antibody staining, and electrophysiology. Using pharmacology and reporter assays, we further showed that CCL2 upregulated surface GluA1 expression primarily via Gα_q- and CaMKII-dependent signaling. Consistently, using i.p. injection of lipopolysaccharide to induce neuroinflammation, we found upregulated phosphorylation of S831 and S845 sites on AMPA receptor subunit GluA1 in the hippocampus, an effect blocked in Ccr2^-/- mice. Together, these results provide a mechanism through which CCL2, and other secreted molecules that signal through G-protein coupled receptors, can directly regulate synaptic transmission.
Animals ; Receptors, AMPA/metabolism* ; Chemokine CCL2/metabolism* ; Hippocampus/drug effects* ; Neurons/drug effects* ; Synaptic Transmission/drug effects* ; Mice ; Receptors, CCR2/metabolism* ; Protein Transport/drug effects* ; Mice, Inbred C57BL ; Cells, Cultured ; Mice, Knockout ; Excitatory Postsynaptic Potentials/drug effects* ; Rats