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

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

BACKGROUND: The epidermal growth factor receptor (EFGR) mutation was closely related to the invasion and metastasis of lung adenocarcinoma and the biological axis of CXCR4/CXCL12 (chemokine receptor 4/chemokine ligand 12) played an important role in the organ-specific metastasis of the tumor. It was a question surrounding whether there is interaction between them in the process of lung adenocarcinoma metastasis. To investigate the potential molecular mechanisms of EGFR over-expression and EFGR-mutations effects on cell proliferation, migration and invasion, we constructed EGFR over-expression and three EFGR-mutant human lung adenocarcinoma H1299 cell sublines. METHODS: EGFR over-expression and three EFGR-mutant (EGFR-E746-A750del, EGFR-T790M and EGFR-L858R) plasmid were designed and transfected H1299 cells with Lipofectamine 2000. H1299 cells transfected with empty vector were negative control (NC), and H1299 cells without transfection were set as blank control (BC). The effects of EGFR over-expression and mutations on the proliferation, migration and invasion of H1299 cells were detected by cell cloning assay, wound healing assay and Transwell assay. The mRNA and protein expression levels of MMP-2, MMP-9, CXCR4 and CXCL12 were detected by RT-PCR and Western blot. RESULTS: Compared with negative control group and blank control group, EGFR over-expression and EGFR-E746-A750 deletion have significantly higher colony formation (28±2, 28.33±4.16; respectively) (P<0.05) and the cell migration and invasion ability were significantly increased (P<0.05). RT-PCR and Western blot assay showed that the mRNA and protein expression of MMP-2, MMP-9, CXCR4 and CXCL12 in EGFR over-expression and EGFR-E746-A750 deletion group were remarkably higher than that in negative control and blank control group (P<0.05). CONCLUSIONS EGFR over-expression and 19 exon deletion can promote the expression of MMP-2 and MMP-9 by up-regulating CXCR4/CXCL12 signaling pathway, leading to the change of tumor biological characteristics such as higher proliferation, migration and invasion ability.
Adenocarcinoma ; pathology ; Adenocarcinoma of Lung ; Cell Line, Tumor ; Cell Movement ; genetics ; Chemokine CXCL12 ; metabolism ; ErbB Receptors ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; pathology ; Mutation ; Neoplasm Invasiveness ; Receptors, CXCR4 ; metabolism ; Signal Transduction ; genetics

Chemokine 12 (CXCL12), also known as stromal cell derived factor-1 (SDF-1) and a member of the CXC chemokine subfamily, is ubiquitously expressed in many tissues and cell types. It interacts specifically with the ligand for the transmembrane G protein-coupled receptors CXCR4 and CXCR7. The CXCL12/CXCR4 axis takes part in a series of physiological, biochemical, and pathological process, such as inflammation and leukocyte trafficking, cancer-induced bone pain, and postsurgical pain, and also is a key factor in the cross-talking between tumor cells and their microenvironment. Aberrant overexpression of CXCR4 is critical for tumor survival, proliferation, angiogenesis, homing and metastasis. In this review, we summarized the role of CXCL12/CXCR4 in cancer, CXCR4 inhibitors under clinical study, and natural product CXCR4 antagonists. In conclusion, the CXCL12/CXCR4 signaling is important for tumor development and targeting the pathway might represent an effective approach to developing novel therapy in cancer treatment.
Animals ; Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Biological Products ; chemistry ; pharmacology ; Chemokine CXCL12 ; genetics ; metabolism ; Humans ; Molecular Targeted Therapy ; Neoplasms ; drug therapy ; genetics ; metabolism ; Receptors, CXCR4 ; antagonists & inhibitors ; genetics ; metabolism

Objective: To investigate the effect of icaritin on maturation and mineralization of mouse osteoblast MC3T3-E1 cells and its mechanism. Methods: The cultured MC3T3-E1 cells were divided into blank control group, CXC chemokine receptor type 4 (CXCR4) inhibitor (AMD3100) group, icaritin group, and icaritin plus AMD3100 group. The expression of CXCR4, stromal cell-derived factor 1 (SDF-1) and osteogenesis-related genes and proteins were detected by real-time RT-PCR and Western blotting after drug treatment for 24 h. The alkaline phosphatase (ALP) activity was determined with ALP kit on d3 and d6; calcium nodules were detected by alizarin red staining after drug treatment for 14 d. Results: Real time RT-PCR showed that compared with the blank control group, relative expressions of CXCR4, SDF-1 and osteogenesis-related genes in icaritin group were significantly increased (P<0.05 or P<0.01); After AMD3100 treatment, the relative expression of CXCR4 gene was decreased (P<0.05). Western blot showed that compared with the blank control group, relative expressions of CXCR4, SDF-1 and osteogenesis-related proteins in the icaritin group were significantly increased (all P<0.01), but were decreased after AMD3100 was added (all P<0.01). The ALP activity of icaritin group was significantly higher than that of blank control group (all P<0.01) on d3 and d6 after drug treatment, while the activity of ALP was significantly decreased after AMD3100 treatment (all P<0.01). At d14 after drug treatment, compared with the blank control group, the area of alizarin red staining was increased in the icaritin group, while it was significantly reduced after the addition of AMD3100. Conclusion: Icaritin may promote maturation and mineralization of mouse osteoblast MC3T3-E1 cells through CXCR4/SDF-1 signaling pathway.
3T3 Cells ; Animals ; Calcification, Physiologic ; drug effects ; Chemokine CXCL12 ; metabolism ; Flavonoids ; pharmacology ; Gene Expression Regulation, Developmental ; drug effects ; Mice ; Osteoblasts ; cytology ; drug effects ; Receptors, CXCR4 ; metabolism ; Signal Transduction ; drug effects

OBJECTIVETo investigate the effect of exenatide on chemotactic migration of adipose-derived stem cells (ADSCs) and confirm that Rho GTPase is the downstream effector protein of SDF-1/CXCR-4 migration pathway.

METHODSADSCs were isolated, cultured, identified by flow cytometry, and induced to differentiate in vitro. RTCA xCELLigence system was used to analyze the effect of exenatide on ADSC proliferation. The effects of exenatide at different concentrations, AMD3100 (CXCR-4 antagonist), and CCG-1423 (Rho GTPase antagonist) on chemotactic migration of ADSCs were tested using Transwell assay. The expression of CXCR-4 in exenatide-treated ADSCs was measured by flow cytometry and Western blotting. Active Rho pull-down detection kit was used to detect the expression of Rho GTPase. Laser confocal microscopy was used to observe the formation of stress fibers in ADSCs with different treatments.

RESULTSExenatide treatment for 24 h had no significant effect on ADSC proliferation. Exenatide obviously promoted chemotactic migration of ADSCs in a concentration-dependent manner, and this effect was blocked by either AMD3100 or CCG-1423. Both flow cytometry and Western blotting showed that exenatide dose-dependently up-regulated CXCR-4 expression in ADSCs. Western blotting showed that the expression of Rho GTPase was related to SDF-1/CXCR-4 pathway, and laser confocal microscopy revealed that the formation of stress fibers in ADSCs was related to SDF-1/CXCR-4/ Rho GTPase pathway.

CONCLUSIONExenatide promotes chemotactic migration of ADSCs, and Rho GTPase is the downstream effector protein of SDF-1/CXCR-4 pathway.

Adipose Tissue ; cytology ; Anilides ; pharmacology ; Benzamides ; pharmacology ; Cells, Cultured ; Chemokine CXCL12 ; metabolism ; Chemotaxis ; Heterocyclic Compounds ; pharmacology ; Humans ; Peptides ; pharmacology ; Receptors, CXCR4 ; antagonists & inhibitors ; metabolism ; Signal Transduction ; Stem Cells ; cytology ; Venoms ; pharmacology ; rho GTP-Binding Proteins ; antagonists & inhibitors ; metabolism

OBJECTIVETo explore the role of CXCR4/STAT3 in mesenchymal stromal cell (MSC)-mediated drug resistance of AML cells.

METHODSAML cell lines U937 and KG1a and primary AML cells were co-cultured with MSC from bone marrow of healthy donors. The AML cell lines cultured alone were used as control. Apoptosis induced by mitoxantrone was measured by flow cytometry. Expression of CXCR4 and STAT3 protein were detected by Western blot. After incubated with STAT3 inhibitor Cucurbitacin I or CXCR4 antagonist AMD3100, the apoptosis of AML cells induced by mitoxantrone was evaluated.

RESULTSApoptosis of AML cells (U937 and KG1a) and primary AML cells induced by mitoxantrone significantly decreased in cocultured group than that of control group [U937 cells: (20.08±1.53)% vs (45.33 ± 1.03)% , P=0.004; KG1a cells: (25.60 ± 1.82)% vs (40.33 ± 3.29)% , P=0.020]. Expression of phosphorylated STAT3 and CXCR4 protein in AML cells were upregulated in cocultured group. After addition of Cucurbitacin I into the co-culture system, the apoptosis rate of primary AML cells significantly increased. Similar results of the apoptosis rates were also detected when the inhibitor of CXCR4 AMD3100 was added to overcome the stromal cell-mediated drug resistance. Besides, the expression of p-STAT3 in AML cells after incubated with AMD3100 decreased significantly.

CONCLUSIONSAML cells cocultured with MSC leads to the up-regulation of phosphorylated STAT3 and CXCR4 proteins, which resulted in AML cells resistance to chemotherapeutic drugs. Therefore targeting STAT3 or CXCR4 could be a new therapeutic strategy of AML.

Acute Disease ; Apoptosis ; Coculture Techniques ; Drug Resistance, Neoplasm ; Flow Cytometry ; Gene Expression Regulation, Leukemic ; Heterocyclic Compounds ; Humans ; Leukemia ; metabolism ; Mesenchymal Stromal Cells ; cytology ; Receptors, CXCR4 ; metabolism ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; U937 Cells ; Up-Regulation

OBJECTIVETo investigate the expression of ALDH1, CXCR4 and E-cadherin in gastric carcinoma and their roles in lymphatic metastasis.

METHODSSurgical specimens from 127 cases of gastric carcinoma were examined for expressions of ALDH1, CXCR4 and E-cadherin immuohistochemistry with 60 adjacent tissues as control. The associations of ALDH1, CXCR4 and E-cadherin with the clinicopathological pfeatures, 5-year survival rate and lymph node metastasis of the patients were analyzed.

RESULTSALDH1, CXCR4 and E-cadherin were positive in 57.5% (73/127), 63.8% (81/127), and 36.2% (46/127) of the gastric carcinoma tissues, respectively, showing significant differences from the rates in the adjacent tissues (P<0.05). The expression of ALDH1 was significantly correlated with TNM stage and lymph node metastasis (P<0.05), CXCR4 was significantly correlated with the invasion depth, differentiation, TNM stage and lymph node metastasis of the tumor (P<0.05), and E-cadherin was significantly correlated with the invasion depth, differentiation and lymph node metastasis (P<0.05). The positivity rates of ALDH1, CXCR4 and E-cadherin were higher in cases with lymph node metastasis than in those without metastasis. E-cadherin expression was inversely correlated with ALDH1 and CXCR4 expression, and the latter two were positively correlated (P<0.001). Overexpressions of ALDH1 and CXCR4 and a decreased expression of E-cadherin were all related to a poor prognosis of the patients (P<0.05). The expressions ofALDH1, CXCR4 and E-cadherin were all independent prognostic factors of gastric carcinoma.

CONCLUSIONThe expressions of ALDH1, CXCR4 and E-cadherin are associated with the invasion, metastasis and prognosis of gastric carcinoma, and their combined detection provides important evidence for predicting the progression and prognosis of gastric carcinoma.

Cadherins ; genetics ; metabolism ; Carcinoma ; genetics ; metabolism ; Disease Progression ; Humans ; Isoenzymes ; genetics ; metabolism ; Lymphatic Metastasis ; Prognosis ; Receptors, CXCR4 ; genetics ; metabolism ; Retinal Dehydrogenase ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; metabolism ; Survival Rate

OBJECTIVETo investigate the expression of chemokine stromal cell-derived factor-1 (SDF-1) receptor CXCR4 in human gingival mesenchymal stem cells (GMSCs) and the migration potential of GMSCs stimulated with SDF-1.

METHODSHuman GMSCs were isolated by single-cell cloning method. Their cell surface markers were characterized by flow cytometry, and the rate of colony formation was evaluated. Differentiation assay was used to detect the differentiation potential of GMSCs. The expression of chemokine SDF-l receptor CXCR4 in GMSCs was detected by immunocytochemical staining. The chemotactic effect of SDF-1 on GMSCs was detected using a 24-multiwell Transwell cell culture chamber. The number of net migrated cells was counted in different microscope fields.

RESULTSHuman GMSCs possessed high self-renewal potential and formed single-cell colonies cultured in vitro. GMSCs expressed mesenchymal stem cells-associated markers CD44, CD73, CD90, CD105, and CD166, and the expression of hemopoietic stem cell surface markers CD14, CD34, and CD45 was negative. GMSCs differentiated into osteoblasts and adipocytes under defined culture conditions. The colony forming unit-fibroblastic for GMSCs was 21.4%/±2.8%. Immunocytochemical staining demonstrated that GMSCs expressed chemokine SDF-1 receptor CXCR4. The number of GMSCs migrating at concentrations of 100 ng.mL-1 and 200 ng.mL-1 of SDF-l in the Transwell cell culture chamber was significantly higher than that of the negative control (189.3±4.4, 164.6±4.9 cells/field vs. 47.8±2.5 cells/field, P<0.01). Treatment with the CXCR4 neutralizing antibody, an antagonist for CXCR4, significantly reduced the migratory effect compared with the negative controls (29.0±2.4 cells/field vs. 47.8±2.5 cells/field, P<0.01).

CONCLUSIONHuman GMSCs express chemokine SDF-l receptor CXCR4. SDF-1 may participate in regulating chemotaxis of human GMSCs. Results suggest that the migration induced by SDF-1 is mediated by CXCR4.

Adipocytes ; Cell Culture Techniques ; Cell Differentiation ; Chemokine CXCL12 ; metabolism ; Chemotaxis ; Flow Cytometry ; Gingiva ; physiology ; Humans ; Mesenchymal Stromal Cells ; physiology ; Osteoblasts ; Receptors, CXCR4 ; Signal Transduction