OBJECTIVE: To explore the improvement effect of CXC chemokine receptor 4 (Cxcr4) gene-modified bone marrow mesenchymal stem cell (BMSC)-derived exosomes on aplastic anemia (AA), and make a preliminary exploration of the mechanism. METHODS: Mouse BMSCs were isolated and cultured, then infected by recombinant lentivirus carrying Cxcr4 gene. The expression of green fluorescence was observed through fluorescence microscope, the expression of Cxcr4 mRNA was detected by real-time fluorescence quantitative PCR, and the BMSC-derived exosomes modified with Cxcr4 gene were extracted. Mouse models of AA were constructed, and control group, model group (AA), AA+BMSC group, AA+NC-BMSC group, AA+Cxcr4-BMSC group were set up. Except control group and model group, the other three groups of mice were injected 400 μl exosomes from different sources via the tail vein, after 2 weeks, the routine blood indices and the number of bone marrow nucleated cells were detected, the pathological changes of bone marrow were observed by HE staining, and the expression level of Treg cells was detected by flow cytometry. RESULTS: Mouse BMSCs were successfully isolated, and BMSCs with high expression of Cxcr4 and their exosomes were obtained. Compared with the control group, the number of red blood cell (RBC), white blood cell (WBC), and platelet (PLT), the hemoglobin (Hb) content and proportion of Treg cells in the peripheral blood of mice in the model group significantly decreased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). The proliferation level of nucleated cells was low, and the medullary cavity was filled with a large number of fat cells. Compared with the model group, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+BMSC group, AA+NC-BMSC group, and AA+Cxcr4-BMSC group significantly increased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01), and pathological changes of bone marrow were improved. In addition, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+Cxcr4-BMSC group were significantly higher than those in the AA+BMSC group (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). CONCLUSION Injection of Cxcr4 gene-modified BMSC-derived exosomes has a certain improvement effect on AA mice, and the mechanism may be related to an increase of the proportion of Treg cells.
Anemia, Aplastic/metabolism* ; Animals ; Bone Marrow Cells ; Exosomes/metabolism* ; Humans ; Mesenchymal Stem Cells ; Mice ; Receptors, CXCR4

OBJECTIVE: To explore the effect of CXCR4 on the treatment response and prognosis of Carfilzomib (CFZ) in multiple myeloma. METHODS: Dataset GSE69078 based on microarray data from two CFZ-resistant MM cell lines and their corresponding parental cell lines (KMS11-KMS11/CFZ and KMS34-KMS34/CFZ) were downloaded from Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were identified, and Protein-protein interaction (PPI) network was established to identify the key genes involved in CFZ resistance acquisition. Finally, the prognostic roles of the CFZ risistance key genes in MM using MMRF-CoMMpass data study was verified. RESULTS: 44 up-regulated and 46 down-regulated DEGs were identified. Top 10 hub genes (CCND1, CXCR4, HGF, PECAM1, ID1, HEY1, TCF4, HIST1H4J, HIST1H2BD and HIST1H2BH) were identified via Protein-protein interaction (PPI) network analysis. The CoMMpass data showed that high CXCR4 expression showed correlation to relative higher relapse and progress rates and the overall survival was significant decreased in high CXCR4 patients (P=0.013). CONCLUSION CXCR4 perhaps plays a crucial role in CFZ acquired resistance, which might help identifying potential CFZ-sensitive patients before treatment and providing a new therapeutic target in CFZ-resistant MM.
Histones ; Humans ; Multiple Myeloma/genetics* ; Neoplasm Recurrence, Local ; Oligopeptides/therapeutic use* ; Prognosis ; Receptors, CXCR4

Pulmonary fibrosis is an irreversible interstitial lung disease characterized by lung parenchyma remodeling and collagen deposition. In recent years, the incidence and mortality of pulmonary fibrosis caused by unknown causes have risen. However, its pathogenesis is still unclear. C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C chemokine receptor 4 (CXCR4)/CXCR7 signal axis plays a critical regulatory role in pulmonary fibrosis disease. In addition, the signal axis has been shown to regulate recruitment and migration of circulating fibrocytes, mesenchymal stem cells to the damage lung tissue, the migration of endothelial cells, the proliferation and differentiation of fibroblasts and endothelial cells, which further affects the occurrence and progression of pulmonary fibrosis. In this review, we summarized the pathogenesis and treatment research progress of CXCL12 and its receptor CXCR4/CXCR7 in the occurrence and progression of pulmonary fibrosis.
Chemokine CXCL12 ; Endothelial Cells/pathology* ; Humans ; Ligands ; Lung/pathology* ; Pulmonary Fibrosis/pathology* ; Receptors, CXCR4

BACKGROUND: There is growing evidence that 5-fluorouracil (5-FU) combined with therapeutic trauma can effectively induce skin repigmentation in vitiligo patients who are unresponsive to conventional treatments. Previous studies have mainly focused on identifying the antimitotic activity of 5-FU for the treatment of skin cancer, but few studies have investigated its extra-genotoxic actions favoring melanocyte recruitment. METHODS: We utilized the full thickness excisional skin wound model in Dct-LacZ transgenic mice to dynamically assess the migration of melanocytes in the margins of wounds treated with or without 5-FU. The in-situ expression of CXCL12 was examined in the wound beds using immunofluorescence staining. Quantitative real-time polymerase chain reaction and Western blotting analyses were performed to detect the expression levels of CXCL12 mRNA and protein in primary mouse dermal fibroblasts treated with or without 5-FU. Transwell assays and fluorescein isothiocyanate (FITC)-phalloidin staining were used to observe cell migration and filamentous actin (F-actin) changes of melan-a murine melanocytes. RESULTS: Whole mount and cryosection X-gal staining showed that the cell numbers of LacZ-positive melanocytes were much higher in the margins of dorsal and tail skin wounds treated with 5-FU compared with the controls. Meanwhile, CXCL12 immunostaining was significantly increased in the dermal compartment of wounds treated with 5-FU (control vs. 5-FU, 22.47 ± 8.85 vs. 44.69 ± 5.97, P < 0.05). Moreover, 5-FU significantly upregulated the expression levels of CXCL12 mRNA (control vs. 5-FU, 1.00 ± 0.08 vs. 1.54 ± 0.06, P < 0.05) and protein (control vs. 5-FU, 1.00 ± 0.06 vs. 2.93 ± 0.10, P < 0.05) in cultured fibroblasts. Inhibition of the CXCL12/CXCR4 axis suppressed melanocyte migration in vitro using a CXCL12 small interfering RNA (siRNA) or a CXCR4 antagonist (AMD3100). CONCLUSION 5-FU possesses a pro-pigmentary activity through activation of the CXCL12/CXCR4 axis to drive the chemotactic migration of melanocytes.
Animals ; Cell Movement ; Cell Proliferation ; Chemokine CXCL12/genetics* ; Fibroblasts ; Fluorouracil/therapeutic use* ; Humans ; Mice ; RNA, Messenger ; Receptors, CXCR4

CXCL12/CXCR4 axis composed of chemokine CXCL12 and its specific ligand CXCR4 can regulate and control the adhesion of leukemia cells to protective bone marrow niche, promote cell survival, and resist apoptosis induced by signal transduction inhibitors and chemotherapeutic drugs. Therefore, CXCL12 /CXCR4 axis has become a new target for the treatment of acute myeloid leukemia. At present, CXCR4 inhibitors that have been developed are in different clinical trials, showing good anti-leukemia effect. In this review, the research advance of CXCR4 inhibitors in the treatment of acute myeloid leukemia is summarized briefly.
Antineoplastic Agents/therapeutic use* ; Apoptosis ; Bone Marrow ; Chemokine CXCL12/pharmacology* ; Humans ; Leukemia, Myeloid, Acute/drug therapy* ; Receptors, CXCR4 ; Signal Transduction

OBJECTIVE: To investigate the effect of chronic emotional stimulation induced by empty bottle stimulation on CXCL12/CXCR4-mediated inflammatory response in rats with acute myocardial infarction (AMI). METHODS: Rat models of anxiety were established by a 21-day stimulation with uncertain empty bottle drinking water, and myocardial infarction was induced by ligating the left anterior descending branch of the coronary artery; compound models were established by performing myocardial infarction operation on the 15th day of anxiety modeling. The rats were randomly divided into 4 groups: shamoperated group (=6), myocardial infarction group (=6), compound model group (with myocardial infarcted and anxiety; = 6), and inhibitor group (compound models treated daily with 1 mg/kg AMD3100 for 6 days; =7). Echocardiography was used to examine the LVEF and LVFS to evaluate the cardiac function of the rats. Elevated maze test and open field test were used to evaluate the behaviors of the rats. The expressions of CXCL12, CXCR4, IL-1β, IL-18 and neutrophil active protease (NE) in the myocardial tissues and blood samples were detected with ELISA and immunohistochemistry. RESULTS: The LVEF and LVFS were lower in the compound model group than in the sham group and myocardial infarction group ( < 0.05), and were higher in inhibitor group than in the compound model group ( < 0.05). LVID; d and LVID; s were lower in the inhibitor group than in the compound model group ( < 0.05). Compared to those in the sham group and myocardial infarction group, the rats in the compound model group more obviously preferred to stay in the closed arm ( < 0.05) in EPM; the rats in the inhibitor group had more times of entering and staying in the open arm than the compound model rats ( < 0.05); the horizontal and vertical movements were less in the compound model rats than in those in the sham group and the myocardial infarction group ( < 0.05) in OFT, and the vertical movement of the rats in inhibitor group was higher than those in the compound model group ( < 0.05). The expression of CXCR4 in the marginal zone of myocardial infarction was significantly higher in the compound model group than in the sham-operated group, myocardial infarction group and inhibitor group ( < 0.05). The expressions of IL-1β, IL-18 and NE in the inhibitor group were significantly lower than those in the compound model group ( < 0.05). Compared with at in the sham-operated group, the number of Nissl bodies in the compound model group decreased significantly ( < 0.01). CONCLUSIONS Chronic emotional stress induced by empty bottle stimulation can lead to dysfunction of the CXCL12/CXCR4 axis, which causes inflammatory cascade after myocardial infarction to worsen myocardial cell necrosis, cardiac function and hippocampal neuronal damage after the infarction.
Animals ; Chemokine CXCL12 ; Coronary Vessels ; Emotions ; Myocardial Infarction ; Myocardium ; Psychological Distress ; Rats ; Receptors, CXCR4 ; Signal Transduction

OBJECTIVE: To investigate the expressions of stromal cell-derived factor (CXCL12), stromal cell-derived factor receptor (CXCR4), vascular endothelial growth factor (VEGF) and microvessel density (MVD) in bone marrow microsputum of patients with multiple myeloma (MM) and their correlation with the prognosis. METHODS: The expressions of CXCL12, CXCR4, VEGF and MVD in bone marrow microtubules of 57 newly diagnosed MM patients and 26 normal bone marrow samples were detected by immunohistochemistry. The rank sum test was used to compare the differences between the two groups. The clinical data of the patients were collected to analyze the correlation between the indicators of the MM group and the prognosis. RESULTS: The expressions of CXCL12, CXCR4, VEGF and MVD in the bone marrow biopsy of the patients in MM group were significantly higher than those in the normal control group (P＜0.05). The expressions levels of CXCL12, CXCR4, VEGF and MVD were in the bone marrow of the patients in MM group were correlated with the ISS stage, risk stratification and the proportion of plasma cells in the bone marrow (P＜0.05). Univariate analysis showed that age, ISS stage, risk stratification, plasma cell ratio, expressions of CXCL12, CXCR4, VEGF, and MVD associated with the prognosis of patients with MM (P＜0.05). Multivariate analysis found that expressions of CXCR4, VEGF, MVD, age, and plasma cell ratio were independent prognostic factors. CONCLUSION The expressions of CXCL12, CXCR4, VEGF and MVD are increase in the bone marrow of patients with multiple myeloma, and their expressions levels are associate with the occurrence and development of multiple myeloma, and their high expression may indicate a poor prognosis.
Chemokine CXCL12 ; Humans ; Multiple Myeloma ; Neovascularization, Pathologic ; Patients ; Prognosis ; Receptors, CXCR4 ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

The effect of triptolide( TP) on VEGFA,SDF-1,CXCR4 pathway were investigated in vitro to explore the mechanism in improving platelet activation in patients with ankylosing spondylitis( AS). Peripheral blood mononuclear cells( PBMC) were used for the experiment and divided into 4 groups: normal group( NC),model group( MC),triptolide group( TP),and AMD3100 group. The optimal concentration of TP was measured by the MTT method. The expressions of TNF-α,IL-1β,IL-4,IL-10,VEGFA and VEGFR were detected by ELISA. The expressions of SDF-1,CXCR4 and VEGFA were detected by real-time quantitative PCR( RT-qPCR).The expressions of SDF-1,CXCR4,VEGFA and VEGFR were detected by Western blot. The expression levels of CD62 p,CD40 L and PDGFA were detected by immunofluorescence. MTT results showed that medium-dose TP had the strongest inhibitory effect on cells at24 h. The results of ELISA and PCR showed that TP inhibited mRNA expressions of IL-1β,TNF-α,VEGFA,VEGFR and SDF-1,CXCR4 and VEGFA. The results of Western blot indicated that TP inhibited SDF-1,CXCR4 and VEGFA,VEGFR protein expressions; immunofluorescence results indicate that TP can inhibit the expressions of CD62 p,CD40 L,PDGFA. TP may regulate platelet activation by down-regulating SDF-1,CXCR4,VEGFA and VEGFR mRNA expressions,thereby down-regulating IL-1β and TNF-αexpressions,and up-regulating the expressions of IL-4 and IL-10 cytokines.
Cells, Cultured ; Chemokine CXCL12 ; metabolism ; Cytokines ; metabolism ; Diterpenes ; pharmacology ; Epoxy Compounds ; pharmacology ; Heterocyclic Compounds ; pharmacology ; Humans ; Leukocytes, Mononuclear ; drug effects ; Phenanthrenes ; pharmacology ; Platelet Activation ; Receptors, CXCR4 ; metabolism ; Spondylitis, Ankylosing ; Vascular Endothelial Growth Factor A ; metabolism

BACKGROUND: Spinal cord injury (SCI) is a worldwide medical concern. This study aimed to elucidate the mechanism underlying the protective effect of hyperbaric oxygen (HBO) against SCI-induced neurologic defects in rats via exploring the stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) axis and expression of brain-derived neurotrophic factor (BDNF). METHODS: An acute SCI rat model was established in Sprague-Dawley rats using the Allen method. Sixty rats were divided into four groups (n = 15 in each group): sham-operated, SCI, SCI treated with HBO (SCI + HBO), and SCI treated with both HBO and AMD3100 (an antagonist of CXCR4; SCI + HBO + AMD) groups. The rats were treated with HBO twice a day for 3 days and thereafter once a day after the surgery for up to 28 days. Following the surgery, neurologic assessments were performed with the Basso-Bettie-Bresnahan (BBB) scoring system on postoperative day (POD) 7, 14, 21, and 28. Spinal cord tissues were harvested to assess the expression of SDF-1, CXCR4, and BDNF at mRNA and protein levels, using quantitative real-time polymerase chain reaction, Western blot analysis, and histopathologic analysis. RESULTS: HBO treatment recovered SCI-induced descent of BBB scores on POD 14, (1.25 ± 0.75 vs. 1.03 ± 0.66, P < 0.05), 21 (5.27 ± 0.89 vs. 2.56 ± 1.24, P < 0.05), and 28 (11.35 ± 0.56 vs. 4.23 ± 1.20, P < 0.05) compared with the SCI group. Significant differences were found in the mRNA levels of SDF-1 (mRNA: day 21, SCI + HBO vs. SCI + HBO + AMD, 2.89 ± 1.60 vs. 1.56 ± 0.98, P < 0.05), CXCR4 (mRNA: day 7, SCI + HBO vs. SCI, 2.99 ± 1.60 vs.1.31 ± 0.98, P < 0.05; day 14, SCI + HBO vs. SCI + HBO + AMD, 4.18 ± 1.60 vs. 0.80 ± 0.34, P < 0.05; day 21, SCI + HBO vs. SCI, 2.10 ± 1.01 vs.1.15 ± 0.03, P < 0.05), and BDNF (mRNA: day 7, SCI + HBO vs. SCI, 3.04 ± 0.41 vs. 2.75 ± 0.31, P < 0.05; day 14, SCI + HBO vs. SCI, 3.88 ± 1.59 vs. 1.11 ± 0.40, P < 0.05), indicating the involvement of SDF-1/CXCR4 axis in the protective effect of HBO. CONCLUSIONS HBO might promote the recovery of neurologic function after SCI in rats via activating the SDF-1/CXCR4 axis and promoting BDNF expression.
Animals ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; metabolism ; Disease Models, Animal ; Hyperbaric Oxygenation ; methods ; Male ; Rats ; Rats, Sprague-Dawley ; Receptors, CXCR4 ; metabolism ; Receptors, Interleukin-8A ; metabolism ; Spinal Cord Injuries ; metabolism ; therapy

OBJECTIVE: To evaluate the change of cell surface CXC chemokine receptor 4 (CXCR4) expression of stem cells from apical papilla (SCAP) after the inhibition of endocytotic pathway, thus to provide experimental basis for the mechanism of SCAP migration. METHODS: The immunofluorescence analysis was conducted to examine the co-expression of CXCR4 and endocytotic compartments, including early endosomes, recycling endosomes and lysosomes in SCAP. Several Rab proteins were applied as markers of organelles in the endocytotic pathway, including Rab5 for early endosomes, Rab11A for recycling endosomes, and Lamp1 for lysosomes. The co-localization of CXCR4 with these endodontic compartments was further observed by proximity ligation assay (PLA). SCAP was treated with two kinds of endocytotic inhibitors, Blebbistatin and Dynasore, at a concentration of 80 μmol/L, respectively. The conditioning time was 1 hour. Flow cytometry was carried out to evaluate the proportion of SCAP that expressed CXCR4 on cell surface. The data were analysed by analysis of variance (ANOVA). RESULTS: The red staining of CXCR4 on immunofluorescence confocal microscopy predominantly overlapped with the green staining of Rab5 and Rab11A, and partly overlapped with Lamp1. It indicated that most CXCR4 molecules were located in early endosomes and recycling endosomes, and some were located in lysosomes. The PLA results revealed that the co-localizaiton of CXCR4 with endocytotic compartments could be observed in early endosomes, recycling endosomes and lysosomes. According to the results of flow cytometry, the proportion of SCAP that expressed CXCR4 on cell surface was as low as 0.13%±0.10%. After the inhibition of endocytosis by pretreating the cells with the following two inhibitors, Blebbistatin and Dynasore, the percentage of SCAP that positively expressed CXCR4 on cell surface was significantly increased to 13.34%±1.31% in Blebbistatin group and 4.03%±0.92% in Dynasore group (F=16.721, P<0.001). Moreover, the number of SCAP that expressed CXCR4 on cell surface in Blebbistatin group was significantly higher than that in Dynasore group (P<0.001). CONCLUSION The inhibition of endocytotic pathway could increase the number of SCAP that expressed CXCR4 on cell surface, and provide potency for the migration of SCAP.
Endocytosis ; Endosomes ; Lysosomes ; Receptors, CXCR4 ; Stem Cells