ABSTRACT
OBJECTIVE: vMIP-II (viral macrophage inflammatory protein 2)/vCCL2 (viral chemotactic cytokine ligand 2) binds to multiple chemokine receptors, and vMIP-II-based positron emission tomography tracer (64Cu-DOTA-vMIP-II: vMIP-II tracer) accumulates at atherosclerotic lesions in mice. Given that it would be expected to react with multiple chemokine receptors on monocytes and macrophages, we wondered if its accumulation in atherosclerosis lesion-bearing mice might correlate with overall macrophage burden or, alternatively, the pace of monocyte recruitment. Approach and Results: We employed a mouse model of atherosclerosis regression involving adenoassociated virus 8 vector encoding murine Apoe (AAV-mApoE) treatment of Apoe-/- mice where the pace of monocyte recruitment slows before macrophage burden subsequently declines. Accumulation of 64Cu-DOTA-vMIP-II at Apoe-/- plaque sites was strong but declined with AAV-mApoE-induced decline in monocyte recruitment, before macrophage burden reduced. Monocyte depletion indicated that monocytes and macrophages themselves were not the only target of the 64Cu-DOTA-vMIP-II tracer. Using fluorescence-tagged vMIP-II tracer, competitive receptor blocking with CXCR4 antagonists, endothelial-specific Cre-mediated deletion of CXCR4, CXCR4-specific tracer 64Cu-DOTA-FC131, and CXCR4 staining during disease progression and regression, we show endothelial cell expression of CXCR4 is a key target of 64Cu-DOTA-vMIP-II imaging. Expression of CXCR4 was low in nonplaque areas but strongly detected on endothelium of progressing plaques, especially on proliferating endothelium, where vascular permeability was increased and monocyte recruitment was the strongest. CONCLUSIONS: Endothelial injury status of plaques is marked by CXCR4 expression and this injury correlates with the tendency of such plaques to recruit monocytes. Furthermore, our findings suggest positron emission tomography tracers that mark CXCR4 can be used translationally to monitor the state of plaque injury and monocyte recruitment.
Subject(s)
Aorta, Thoracic/diagnostic imaging , Atherosclerosis/diagnostic imaging , Chemokines/administration & dosage , Endothelium, Vascular/diagnostic imaging , Molecular Imaging , Monocytes/metabolism , Organometallic Compounds/administration & dosage , Positron-Emission Tomography , Radiopharmaceuticals/administration & dosage , Receptors, CXCR4/metabolism , Animals , Aorta, Thoracic/immunology , Aorta, Thoracic/metabolism , Aorta, Thoracic/pathology , Atherosclerosis/immunology , Atherosclerosis/metabolism , Atherosclerosis/pathology , Biomarkers/metabolism , Cell Line , Chemokines/pharmacokinetics , Disease Models, Animal , Endothelial Cells/immunology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Endothelium, Vascular/immunology , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Injections, Intravenous , Male , Mice, Inbred C57BL , Mice, Knockout , Mice, Knockout, ApoE , Monocytes/immunology , Monocytes/pathology , Organometallic Compounds/pharmacokinetics , Plaque, Atherosclerotic , Predictive Value of Tests , Radiopharmaceuticals/pharmacokinetics , Receptors, CXCR4/geneticsABSTRACT
Objective: To investigate the role of hypoxia inducible factor 1 α (HIF1α) in the invasion and metastasis of human colon cancer. Methods: Human colon cancer LoVo and HCT116 cells were cultured under hypoxia, then the cell invasiveness was detected by Transwell chamber assay, and the expression levels of HIF1α, C-X-C chemokine receptor 4 (CXCR4), SRC and phosphorylated SRC (p-SRC) were detected by Western blotting. The expressions of HIF1α and CXCR4 in 59 cases of colon cancer were detected by immunohistochemical method, and the correlation between the expression of HIF1α and the clinicopathological characteristics of colon cancer patients was analyzed. The relationship between CXCR4 transcription and hypoxia was revealed by realtime fluorescent quantitative PCR, and the interaction between HIF1α and nuclear receptor coactivator 1 (Ncoa1), a transcription regulation factor of CXCR4, was cofirmed by coimmunoprecipitation assay. Results: The invasiveness ability of colon cancer LoVo and HCT116 cells was significantly enhanced under hypoxia (both P 0.05). Conclusion: Under hypoxia, the expression level of HIF1α is upregulated in the colon cancer LoVo and HCT116 cells, and the invasiveness ability of these cells is enhanced. The positive expression of HIF1α is positively correlated with tumor stage and metastasis in colon cancer patients. HIF1α maybe upregulate the expression of CXCR4 by binding and activating a transcription factor Ncoa1, so as to promote the invasion and metastasis of colon cancer.
ABSTRACT
Objective To detect the expression of chemokine receptors CXCR3 mRNA in the peripheral blood mononuclear cells (PBNCs) of patients with Rheumatoid Arthritis (RA) and to analyze the relationship between the expression and the disease activity. Methods mRNA was extracted from PBNCs and the expression of CXCR3 mRNA was detected by real-time fluorescence quantitative PCR (RFQ-PCR) in 51 RA patients and 32 controls. T-test, x2-test, ANOVA were used for statistial analysis. Results Comparison between the two groups had shown that the expression levels of CXCR3 mRNA in clinical active RA group were higher than those of the RA patients in remission and healthy controls (P<0.05). The expression levels of CXCR3 mRNA were positively correlated with serum levels of ESR and CRP in clinical active RA group (r=0.824, r=0.765, P<0.05). In addition, RF titer, APF, AKA, and anti-CCP had no significant correlation with the expression levels of CXCR3 mRNA in RA patients (P>0.05). Conclusion RFQ-PCR is a sensitive,reproducible and practical test. The mRNA expressions of CXCR3 are significantly elevated in RA patients,which suggest that CXCR3 may be involved in the pathogenesis of RA. The mRNA expressions of CXCR3 in active RA patients are higher than those of RA patients in remission. These results indicate that CXCR3 may play an important role in the pathogenesis and progression of RA, and CXCR3 may be considered as an indicator for disease activity, therapeutic efficacy and prognosis of RA.
ABSTRACT
Objective:To observe the expression of chemokine receptor CCR7 and CXCR4 in human colorectal carcinoma and its significance,so as to assess their expression with the metastasis and prognosis of colorectal carcinoma. Methods:Immunohistochemistry was used to detect the expression of chemokine receptor CCR7 and CXCR4 in 110 patients with colon cancer.The relationship between the CCR7 and CXCR4 expression and the clinic pathological characters was statistically analyzed. Results:CCR7 and CXCR4 expression were positively expressed in 59.1% and 45.5%of the patients. The high expression rate of CCR7 and CXCR4 in lymph node metastasis positive cases was 81. 5% and 60.0% respectively,but the without lymph node metastasis positive cases were 26.7% and 24.4% respectively. The positive expression was significantely higher in the patients with lymph node metastasis than those non-lymph node metastasis(P
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Objective To construct the recombinant plasmid carrying small interfering RNA(siRNA) to CXCR4 and observe dumbness effect of chemokine receptor gene CXCR4 suppression by RNA interference(RNAi),and explore the new method of more efficacious therapeutic possibilities for HIV-1.Methods Small interfering RNAs targeting CXCR4 gene were designed by using software.The complement form was obtained by annealing and interted into vector Psilencer3.1-H1neo.After sequencing,MT4 cells were transfected using the plasmid vector.RT-PCR and flow cytometry detection were used to evaluate the suppression of CXCX4 expression in different groups.Results The recombinant plasmid had the correct special fragments and DNA sequence detected by PCR,electrophoresis and DNA sequencing;The siRNA obviously suppressed the expression of CXCR4.When transfected with plasmid vector for 48 h,the inhibitory rate was 70%,compared with control and negative groups,there were significant differences(P
ABSTRACT
Objective To investigate the expression of chemokine receptors CXCR1and CXCR2in progressive plaque psoriasis and their clinical significance.Methods Reverse transcription-polymerase chain reaction(RT-PCR)technique was applied to semi-quantatatively analyze CXCR1and CXCR2mRNA expression in peripheral blood polymorphonuclears(PMNs)from30cases of psoriatic patients,14of the30patients which were treated until the70%of skin lesions resolved,and30healthy controls.The correlation between CXCR1/2and psoriatic area and severity index(PASI)was evaluated.Results CXCR1and CX-CR2mRNA levels in PMNs from psoriatic patients were1.30?1.18和1.62?0.97,respectively,which were markedly higher than those in normal controls(0.56?0.36,0.74?0.58,respectively)and treated patients(0.49?0.34,0.51?0.51,respectively.)(P
