CXC Chemokine Receptor 4 Expression Research Articles

SDF-1 Improves Renal Fibrosis in Type 2 Diabetes Mellitus Involving TGF-beta-mediated ECM via PI3K/AKT Signaling

The present study investigated the role of stromal cell-derived factor-1 in the progression of renal injury in type 2 diabetic nephropathy. The 8-week old male db/db mice were used as the model of diabetic nephropathy and aged-matched male C57BL/6 mice constituted the control group. Fasting blood glucose, 24 hour urinary albumin and the creatinine clearance rate were measured. The expressions of stromal cell-derived factor-1, CXC chemokine receptor 4 and F4/80 were detected. Normal rat kidney epithelial cells were exposed to stromal cell-derived factor-1α, high glucose, tumor growth factor-β1, valsartan and LY294002, respectively. The extracellular matrix expression was evaluated. It was found that creatinine clearance rate was significantly decreased in 28-week db/db mice compared to the age-matched C57BL/6 mice and valsartan could significantly increase creatinine clearance rate. The expression of stromal cell-derived factor-1, CXC chemokine receptor 4 and F4/80 was significantly increased in the kidney of db/db mice but not in C57BL/6 mice, which was improved with valsartan treatment. In vitro, the expression of CXC chemokine receptor 4 was detected in the rat kidney epithelial cells. Tumor growth factor-β1 increased the expressions of type IV collagen and fibronectin in rat kidney epithelial cells under low glucose and high glucose condition. Stromal cell-derived factor-1α inhibited the harmful effect of tumor growth factor-β1 on extracellular matrix expression, and valsartan exerted synergistic effect on stromal cell-derived factor-1α. Stromal cell-derived factor-1α decreased tumor growth factor-β1expression and increased p-AKT expression, which were inhibited by LY294002 treatment. Stromal cell-derived factor-1 improved renal fibrosis which might partly involve TGF-β-mediated extracellular matrix via PI3K/AKT pathway.

Correlation analysis between CXC chemokine receptor 6 and prognosis of renal clear cell carcinoma

Objective To investigate the correlation between CXC chemokine receptor 6 (CXCR6) and prognosis of renal clear cell carcinoma. Methods A total of 100 patients with renal clear cell carcinoma who underwent surgery in the First People's Hospital of Ziyang from January 2013 to October 2014 were selected. Immunohistochemistry was used to detect the expression of CXCR6 in 100 cases of renal clear cell carcinoma and adjacent normal tissues. The patients were followed up to observe the positive rate of CXCR6 expression and the factors affecting overall survival (OS) and progression-free survival (PFS) of renal clear cell carcinoma and adjacent normal tissues. Results The positive rate of CXCR6 expression in renal clear cell carcinoma tissues was higher than that in adjacent tissues, and the difference was statistically significant [46.0% (46/100) vs. 20.0% (20/100), χ2 = 15.287, P < 0.01]. The positive expression rate of CXCR6 in patients with clinical stage Ⅲ-Ⅳ, lymph node metastasis and pathological grade Ⅲ-Ⅳ was higher than that in patients with clinical stage Ⅰ- Ⅱ, pathological grade Ⅰ- Ⅱ and without lymph node metastasis, and the difference was statistically significant (all P < 0.05). A total of 92 patients were followed up and 40 died. The follow-up time reached to (35-60) months and the median follow-up time was 48.9 months. Kaplan-Meier and log-rank test showed that patients with positive CXCR6 expression had lower 3-year OS and PFS rate compared with patients with negative CXCR6 expression, and the difference was statistically significant (3-year OS rate: 52.1% vs. 78.6%, χ2 = 10.027, P = 0.001; 3-year PFS rate: 48.3% vs. 67.8%, χ2 = 4.344, P = 0.037). Cox regression multivariate analysis showed pathological grade (OS: OR = 2.154, 95% CI 1.547-9.517, P = 0.023; PFS: OR = 1.235, 95% CI 1.109-5.917, P = 0.042), lymph node metastasis (OS: OR = 1.412, 95% CI 1.109-5.917, P = 0.041; PFS: OR = 1.841, 95% CI 1.354-8.994, P = 0.010), CXCR6 expression (OS: OR = 1.864, 95% CI 1.358-6.813, P = 0.031; PFS: OR = 1.457, 95% CI 1.127-6.884,P = 0.025) were independent risk factors of OS and PFS for renal clear cell carcinoma patients treated by the surgery. Conclusions The positive expression of CXCR6 is an independent risk factor for OS and PFS of renal clear cell carcinoma. The prognosis of patients with positive CXCR6 expression is poor. Key words: Carcinoma, renal cell; Receptors, chemokine; Prognosis

Expression and function of the stromal cell-derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) in the swine ovarian follicle

The most characterized stromal cell-derived factor-1 (SDF-1) variants are the isoform α, which is the predominant one but undergoes rapid proteolysis, and the β isoform, which is more resistant. Through the interaction with a specific chemokine receptor called CXCR4, SDF-1 is able to regulate different physiological processes. The aim of this study was to verify the expression and potential functional role of SDF-1 and CXCR4 in the porcine ovary. Firstly, the expression of SDF-1 and its receptor in different ovarian districts was verified for the first time. Thereafter, the effect of SDF-1 β isoform (51–72) fragment on functional parameters, such as proliferation, metabolic activity, redox status, nitric oxide production, and steroidogenic activity, was assessed on granulosa cells collected from follicles. In addition, the potential effect of this protein in vascular events was verified through investigations on porcine aortic (AOC) endothelial cells, such as the production of nitric oxide and viability tests. The proliferation and metabolic activity were not affected by treatment with the cytokine. As regard to steroidogenesis, the peptide stimulated both estrogen (P = 0.049) and progesterone production (P = 0.039). Redox status was affected by the examined substance since superoxide anion was inhibited (P = 0.001), while antioxidant power (P = 0.034), as well as nitric oxide generation, were stimulated (P = 0.034). Tests performed on AOCs showed significant stimulation of nitric oxide production (P = 0.004) by the examined peptide, while cell viability was unaffected. Therefore, the potential role of cytokine in the mechanisms involved in the regulation of follicular function can be hypothesized.

Mesenchymal Stem Cell-Platelet Aggregates Increased in the Peripheral Blood of Patients with Acute Myocardial Infarction and Might Depend on the Stromal Cell-Derived Factor 1/CXCR4 Axis.

Bone marrow mesenchymal stem cells (MSCs) are a rare subset of nonhematopoietic progenitor cells and are appealing biomaterial for multiple tissue damage repairs. Transplantation of MSCs is proved to improve heart function after myocardial ischemia. However, the limitations of MSC injection approaches are equally obvious. As a multiple-function cell, platelets (PLTs) are also known playing important roles in cardiac recovery after myocardial infarction. In this study, we analyzed circulating MSC-PLT aggregate numbers in acute myocardial infarction (AMI) patients by flow cytometry. We found more MSC-PLT aggregates in patients with AMI than in healthy controls, and the patients with higher MSC-PLT aggregates had better prognosis. When stromal cell-derived factor 1 (SDF-1) binds to its receptor CXC chemokine receptor 4 (CXCR4), they play an important role in MSC migration and engraftment. We explored SDF-1 and CXCR4 expression on PLT surface by flow cytometry and found relative mean fluorescence intensity of PLT CXCR4 and the number of MSC-PLT aggregates showed a significant correlation. Meanwhile, in vitro experiments demonstrated that SDF-1/CXCR4 was crucial in MSC-PLT aggregate formation, which might suggest a novel mechanism that SDF-1/CXCR4 is involved in MSCs homing and myocardial repair after AMI. There may be another strategy to encourage myocardial repair in AMI patients by increasing the expression of SDF-1 on MSCs and promoting the formation of MSC-PLT aggregates.

C-X-C chemokine receptor 2 correlates with unfavorable prognosis and facilitates malignant cell activities via activating JAK2/STAT3 pathway in non-small cell lung cancer

ABSTRACT This study aimed to investigate the correlation of C-X-C chemokine receptor 2 (CXCR2) with clinicopathological characteristics and survival in non-small cell lung cancer (NSCLC) patients and further explore its effect on proliferation, apoptosis, invasion, stemness, chemosensitivity as well as JAK2/STAT3 pathway in NSCLC cells. The expression of CXCR2 in tumor tissues and adjacent tissues from 340 NSCLC patients received surgery was detected by immunohistochemistry. CXCR2 overexpression and knockdown were constructed through plasmid transfection and the effect of CXCR2 dysregulation on cell proliferation, apoptosis, invasion, stemness, chemosensitivity as well as its regulatory effect on JAK2/STAT signaling pathway was assessed in NCI-H1437 cells and NCI-H1299 cells. CXCR2 expression was higher in tumor tissues than that in paired adjacent tissues, and it was correlated with poor pathological differentiation, greater tumor size, lymph node metastasis, higher TNM stage and poor survival in NSCLC patients. In vitro, CXCR2 expression was increased in human NSCLC cell lines compared with human normal lung bronchus epithelial cells. CXCR2 promoted cell proliferation and invasion, while suppressed cell apoptosis in NCI-H1437/NCI-H1299 cells. Additionally, CXCR2 increased CD133+ cell rate and cell sphere-forming ability, while reduced chemosensitivity to cisplatin and gemcitabine in NCI-H1437/NCI-H1299 cells. Besides, CXCR2 activated the JAK2/STAT3 signaling pathway in NCI-H1437/NCI-H1299 cells. In conclusion, the clinical implication and the molecular function of CXCR2 discovered in our study reveal the potential of CXCR2 as a future target for disease monitoring and treatment of NSCLC.

CXCR4-Targeted Positron Emission Tomography Imaging of Central Nervous System B-Cell Lymphoma

Introduction Central nervous system lymphoma (CNSL) is a rare neoplasia and arises as primary (PCNSL) or secondary CNSL (SCNSL) and most commonly occurs as diffuse large B-cell lymphoma. Although prognosis of this disease has significantly improved due to advantages in diagnostic procedures and intensification of treatment over the last decade there remain major challenges in the clinical management. Magnetic resonance imaging (MRI) - as the standard imaging modality - has difficulties to discriminate CNSL from other brain-derived tumors or metastasis. Moreover, prognostic scores in CNSL lack the ability to reliable define patients with high relapse risk 1. Therefore, novel strategies to facilitate diagnosis and to select patients that profit from intense treatment protocols are urgently needed. The C-X-C chemokine receptor 4 (CXCR4) is a transmembrane chemokine receptor with pivotal roles in cell homing and is often overexpressed in hematologic malignancies. CXCR4-directed positron emission tomography (PET) imaging with the tracer [68Ga]Pentixafor has been proven to be a suitable in vivo imaging modality for CXCR4 expression in lymphoid malignancies 2. To evaluate the feasibility of CXCR4-directed PET and the prognostic value of this imaging modality this retrospective proof-of-concept study evaluated [68Ga]Pentixafor PET imaging in patients with CNSL. Methods 11 patients with lymphoma of the CNS (n=8 PCNSL, n=3 SCNSL) were imaged with the CXCR4-directed PET tracer [68Ga]Pentixafor in this retrospective proof-of-concept study after signing inform consent. Lymphoma tissue was assessed for CXCR4 expression ex vivo by immunohistochemistry. The prognostic value of CXCR4-directed PET imaging was evaluated in a computed analysis in 7 patients with follow-up MRI. Treatment response calculated as treatment efficiency η by sequential MRI was correlated with [68Ga]Pentixafor PET derived parameters at diagnosis such as volume of PET positive lymphoma lesion V(PET), maximal PET uptake value within the lesion max(PET) or integrated uptake values over the lymphoma lesion ∫(PET). Analysis was performed in a lesion- and patient-based manner. Results [68Ga]Pentixafor PET imaging was positive in all patients with active disease (10/11 patients) with excellent contrast characteristics to the surrounding brain parenchyma. PET positive lesions correlated well with lymphoma lesions in MRI-T1c sequences. The surrounding edema depicted in MRI-FLAIR sequences was evaluated as PET negative (Figure 1). Semi-quantitative analysis revealed maximum standard uptake values of [68Ga]Pentixafor-derived PET from 4.2 to 23.3 within the lesions with a high tumor-to-background-ratio ranging from 13.2 to 83.0. The computed analysis revealed that CXCR4-directed PET parameters at diagnosis given by max(PET) and ∫(PET) significantly correlated with treatment response in the lesion-based as well as in the patient-based analysis. Specifically, ∫(PET) was the most significant prognostic factor in the present study (Figure 2 C, D, F). On the other hand tumor volume at diagnosis measured either by MRI or by [68Ga]Pentixafor PET did not denote a predictive marker for treatment response (Figure 2 A, B, E). Conclusion/Outlook CXCR4-directed PET imaging represents a novel imaging modality for CNSL. Due to its excellent contrast properties it might help to facilitate diagnosis and refine response assessment. Moreover, owing the predictive value for treatment response, CXCR4-directed PET could serve as a biomarker for the selection of patients profiting from intense treatment protocols. Furthermore, the feasibility of endoradiotherapeutic approaches targeting CXCR4 with Pentixather - the therapeutic twin of the imaging peptide Pentixafor - has been shown in hematologic malignancies and could be incorporated in the treatment of CNSL.

CXCR4 and CXCR3 are two distinct prognostic biomarkers in breast cancer: Database mining for CXCR family members.

CXC chemokine receptors (CXCRs) and chemokines are involved in tissue development and homeostasis, including in cancer development and progression. To date, seven CXCRs have been identified. However, the expression of CXCRs and their influence on the occurrence and development of breast cancer (BC) requires further investigation. In the present study, mRNA expression levels of the seven CXCRs were compared between normal tissues and several cancer types using the Oncomine database. Highly expressed CXCRs were selected and the expression levels of these CXCRs were examined in different subtypes of BC using the Gene Expression-Based Outcome for Breast Cancer database. Finally, the prognostic value of these CXCRs was examined using Kaplan-Meier plotter. It was found that, compared with normal controls, transcripts of CXCR4 and CXCR3 were significantly overexpressed in BC samples compared with other CXCRs. Survival analysis showed that high expression of CXCR4 promoted the recurrence of BC but had no impact on overall survival (OS), while a high level of CXCR3 transcript expression was significantly associated with increased survival in patients with BC. With regards to different subtypes of BC, the present study revealed that high CXCR4 transcript expression was significantly associated with both longer relapse-free survival and OS only in basal-like BC. Furthermore, CXCR4 promoted chemosensitivity in patients with basal-like BC and induced resistance against endocrine therapy for patients with luminal A BC. Thus, CXCR4 and CXCR3 are two distinct prognostic biomarkers and further studies are required.

Houshiheisan promotes angiogenesis via HIF-1α/VEGF and SDF-1/CXCR4 pathways: in vivo and in vitro.

Rationale: Houshiheisan (HSHS), a classic prescription in traditional Chinese medicine (TCM), has remarkable efficacy in the treatment of ischemic stroke.Objective: To investigate the pro-angiogenic effect and molecular mechanism of HSHS for stroke recovery.Methods and results: The rat permanent middle cerebral artery occlusion (pMCAO) model was constructed by suture method, HSHS (5.25 or 10.5 g/kg) and Ginaton (28 mg/kg) treatment was intragastrically administrated at 6 h after modeling which remained for 7 consecutive days. Pathological evaluation conducted by Hematoxylin–Eosin (HE) staining and the results showed that HSHS alleviated blood vessel edema, reduced the damage to blood vessels and neurons in the ischemic areas. Immunostaining, quantitative real-time fluorescence PCR results showed that HSHS up-regulated pro-angiogenic factors including platelet endothelial cell adhesion molecule-1 (cluster of differentiation 31 (CD31)), vascular endothelial growth factor (VEGF), vascular endothelial growth factor A (VEGFA), VEGF receptor 2 (VEGFR2), angiopoietin-1 (Ang-1), while down-regulated angiopoietin-2 (Ang-2), stromal cell derived factor-1 (SDF-1), and cxc chemokine receptor 4 (CXCR4) expression in infarct rat cortex, and similar results were obtained in subsequent Western blot experiment. Furthermore, CCK8 assay and transwell migration assay were performed to assess cell proliferation, migration, and tube formation. The medicated serum (MS) of HSHS appeared to have beneficial effects for immortalized human umbilical vein cells (Im-HUVECs) on proliferation and migration after persistence hypoxia. Western blot analysis revealed that the expression of hypoxia inducible factor-1α (HIF-1α), VEGFA, Ang-1, Ang-2, and CXCR4 were significantly up-regulated while Ang-2 was down-regulated by HSHS MS treatment compared with vehicle group in vitro.Conclusion: The present study suggests a novel application of HSHS as an effective angiogenic formula for stroke recovery.

Stromal Cell-Derived Factor 1 Protects Brain Vascular Endothelial Cells from Radiation-Induced Brain Damage.

Stromal cell-derived factor 1 (SDF-1) and its main receptor, CXC chemokine receptor 4 (CXCR4), play a critical role in endothelial cell function regulation during cardiogenesis, angiogenesis, and reendothelialization after injury. The expression of CXCR4 and SDF-1 in brain endothelial cells decreases due to ionizing radiation treatment and aging. SDF-1 protein treatment in the senescent and radiation-damaged cells reduced several senescence phenotypes, such as decreased cell proliferation, upregulated p53 and p21 expression, and increased senescence-associated beta-galactosidase (SA-β-gal) activity, through CXCR4-dependent signaling. By inhibiting extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription protein 3 (STAT3), we confirmed that activation of both is important in recovery by SDF-1-related mechanisms. A CXCR4 agonist, ATI2341, protected brain endothelial cells from radiation-induced damage. In irradiation-damaged tissue, ATI2341 treatment inhibited cell death in the villi of the small intestine and decreased SA-β-gal activity in arterial tissue. An ischemic injury experiment revealed no decrease in blood flow by irradiation in ATI2341-administrated mice. ATI2341 treatment specifically affected CXCR4 action in mouse brain vessels and partially restored normal cognitive ability in irradiated mice. These results demonstrate that SDF-1 and ATI2341 may offer potential therapeutic approaches to recover tissues damaged during chemotherapy or radiotherapy, particularly by protecting vascular endothelial cells.

CXCR4 upregulation is an indicator of sensitivity to B-cell receptor/PI3K blockade and a potential resistance mechanism in B-cell receptor-dependent diffuse large B-cell lymphomas.

B-cell receptor (BCR) signaling pathway components represent promising treatment targets in multiple B-cell malignancies including diffuse large B-cell lymphoma (DLBCL). In in vitro and in vivo model systems, a subset of DLBCLs depend upon BCR survival signals and respond to proximal BCR/phosphoinositide 3 kinase (PI3K) blockade. However, single-agent BCR pathway inhibitors have had more limited activity in patients with DLBCL, underscoring the need for indicators of sensitivity to BCR blockade and insights into potential resistance mechanisms. Here, we report highly significant transcriptional upregulation of C-X-C chemokine receptor 4 (CXCR4) in BCR-dependent DLBCL cell lines and primary tumors following chemical spleen tyrosine kinase (SYK) inhibition, molecular SYK depletion or chemical PI3K blockade. SYK or PI3K inhibition also selectively upregulated cell surface CXCR4 protein expression in BCR-dependent DLBCLs. CXCR4 expression was directly modulated by fork-head box O1 via the PI3K/protein kinase B/forkhead box O1 signaling axis. Following chemical SYK inhibition, all BCR-dependent DLBCLs exhibited significantly increased stromal cell-derived factor-1α (SDF-1α) induced chemotaxis, consistent with the role of CXCR4 signaling in B-cell migration. Select PI3K isoform inhibitors also augmented SDF-1α induced chemotaxis. These data define CXCR4 upregulation as an indicator of sensitivity to BCR/PI3K blockade and identify CXCR4 signaling as a potential resistance mechanism in BCR-dependent DLBCLs.

The Involvement of SDF-1α/CXCR4 Axis in Radiation-Induced Acute Injury and Fibrosis of Skin.

Radiation-induced acute skin injury and consequent fibrosis are common complications of cancer radiotherapy and radiation accidents. Stromal cell-derived factor-1α (SDF-1α) and its receptor, CXC chemokine receptor 4 (CXCR4) have been shown to be involved in multiple cellular events. However, the role of SDF-1α/CXCR4 axis in radiation-induced acute injury and fibrosis of skin has not been reported. In this study, we found that the expression of SDF-1α and CXCR4 was significantly increased in irradiated skin tissues of humans, monkeys and rats, compared to their nonirradiated counterparts. Mice with keratinocyte-specific ablation of CXCR4 showed less severe skin damage than wild-type mice after receiving a 35 Gy dose of radiation. Consistently, subcutaneous injection of AMD3100, an FDA approved SDF-1α/CXCR4 inhibitor, attenuated skin injury and fibrosis induced by exposure to radiation in a rat model. Mechanically, the SDF-1α/CXCR4 axis promotes pro-fibrotic TGF-b/Smad signaling through the PI3K-MAPK signaling cascade in human keratinocyte HaCaT cells and skin fibroblast WS1 cells. AMD3100 inhibited Smad2 nuclear translocation and transcriptional activity of Smad2/3 induced by radiation, which suppressed the pro-fibrotic TGF-b/Smad signaling pathway activated by exposure. Taken together, these findings demonstrate the involvement of SDF-1α/CXCR4 axis in radiation-induced acute injury and fibrosis of skin, and indicate that AMD3100 would be an effective countermeasure against these diseases.

Comparison for immunophysiological responses of Jeju and Thoroughbred horses after exercise.

ObjectiveThe study was conducted to investigate variations in the immunophysiological responses to exercise-induced stress in Jeju and Thoroughbred horses.MethodsBlood samples were collected from the jugular veins of adult Jeju (n = 5) and Thoroughbred (n = 5) horses before and after 30 min of exercise. The hematological, biochemical, and immunological profiles of the blood samples were analyzed. Blood smears were stained and observed under a microscope. The concentration of cell-free (cf) DNA in the plasma was determined using real time polymerase chain reaction (PCR). Peripheral blood mononuclear cells (PBMCs) and polymorphonuclear cells were separated using Polymorphprep, and the expression of various stress-related and chemokine receptor genes was measured using reverse transcriptase (RT) and real-time PCR.ResultsAfter exercise, Jeju and Thoroughbred horses displayed stress responses with significantly increased rectal temperatures, cortisol levels, and muscle catabolism-associated metabolites. Red blood cell indices were significantly higher in Thoroughbred horses than in Jeju horses after exercise. In addition, exercise-induced stress triggered the formation of neutrophil extracellular traps (NETs) and reduced platelet counts in Jeju horses but not in Thoroughbred horses. Heat shock protein 72 and heat shock protein family A (Hsp70) member 6 expression is rapidly modulated in response to exercise-induced stress in the PBMCs of Jeju horses. The expression of CXC chemokine receptor 4 in PBMCs was higher in Thoroughbred horses than in Jeju horses after exercise.ConclusionIn summary, the different immunophysiological responses of Jeju and Thoroughbred horses explain the differences in the physiological and anatomical properties of the two breeds. The physiology of Thoroughbred horses makes them suitable for racing as they are less sensitive to exercise-induced stress compared to that of Jeju horses. This study provides a basis for investigating the link between exercise-induced stresses and the physiological alteration of horses. Hence, our findings show that some of assessed parameters could be used to determine the endurance performance of horses.

Abstract 1237: Down-regulation of chemokine receptor CXCR4 by gambogic acid suppresses metastasis of pancreatic cancer in an orthotopic mouse model

Abstract More than 90% of patients die of pancreatic cancer due to metastasis. Among the cytokines, CXCL12 and its CXC chemokine receptor 4 (CXCR4) are known to play a role in invasion and metastasis in many types of cancer. Thus, agents that can interrupt the CXCR4/CXCL12 signaling cascade have the potential to suppress cancer metastasis. In the present study, we demonstrate that gambogic acid (GA), a xanthone from Gamboge hanburyi, down-regulated CXCR4 expression in pancreatic cancer cells in a dose- and time-dependent manner. We found that the decrease in CXCR4 by GA was not specific to cell type since its expression was abrogated in multiple myeloma cell lines and in colorectal, head and neck, prostate, and breast cancer cell lines. Furthermore, down-regulation of CXCR4 was not due to proteolytic degradation since proteasome inhibitors had no effect. Instead, the down-regulation of CXCR4 was due to transcriptional regulation, as indicated by the corresponding down-regulation of mRNA expression. This xanthone also inhibited the invasion of pancreatic tumor cells in vitro. Down-regulation of CXCR4 and prevention of cell invasion by the xanthone were both found to be mediated through the reactive oxygen species (ROS) as N-acetylcysteine, a ROS quencher, abolished these effects. When examined in an orthotopic nude mouse model of human pancreatic cancer, intraperitoneal administration of GA suppressed both tumor growth and metastasis. Immunohistochemical analysis of tumor tissue showed that besides decreasing the level of CXCR4, GA also reduced the expression of VEGF and MMP-9, which are also linked to invasion and metastasis. Thus, our results demonstrate gambogic acid’s potential in suppressing tumor invasion and metastasis through down-modulation of CXCR4/CXCL12 signaling pathways. Citation Format: Sahdeo Prasad, Sanjay Srivastava. Down-regulation of chemokine receptor CXCR4 by gambogic acid suppresses metastasis of pancreatic cancer in an orthotopic mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1237.

Fingolimod reduces CXCR4-mediated B cell migration and induces regulatory B cells-mediated anti-inflammatory immune repertoire

BackgroundFingolimod, an oral therapy for patients with relapsing Multiple Sclerosis (MS), traps CC chemokine receptor type 7 (CCR7)-expresssing lymphocytes within lymphoid tissues in the periphery, thereby supposedly reducing the infiltration of pathogenic cells into the central nervous system. Additional immunomodulatory effects of Fingolimod, involving cell function, B and T cells interactions and cross-regulation, have scarcely been studied. The objective of this study was to assess how Fingolimod therapy affects B cells functions, namely cell migration, immunoglobullin production and T cell stimulation. MethodsB cells from 36 patients with relapsing MS were obtained before and after 3 months Fingolimod therapy, while CD4 T cells were collected pre-treatment. Clinical follow-up was performed for 1 year. For in-vitro validation, Lymphoblastoid cell-lines from 16 patients were cultured with Fingolimod. B cell migration towards C-X-C Motif Chemokine Ligand 12 (CXCL12) was assessed using a transwell system. C-X-C chemokine receptor 4 (CXCR4) expression was assessed by flow cytometry and western blot. Plasma immunoglobullins and Brain-derived Neurotrophic Factor (BDNF) were assessed by ELISA or RT-PCR. Drug effect on interacting co-cultured B and T cells on cytokine profiles and T cell proliferation was explored by flow cytometry. ResultsLymphocyte count reduction did not predict clinical response of patients. Fingolimod therapy reduced CXCR4 expression and B cell migration towards CXCL12. No effect was found on immunoglobulins and BDNF. B cells from Fingolimod-treated patients induced a reduction in pro-inflammatory cytokines in T cells, while increased transforming growth factor beta (TGFβ)+ B and T cells, and downregulated IL2-secretion from proliferative T cells. ConclusionsFingolimod promotes anti-inflammatory cytokine profiles of B and T cells, through induction of regulatory B cells. Reduced B cell migration capacity in Fingolimod-treated patients leading to decreased cerebral inflammatory infiltration, may be part of the mechanism by which Fingolimod reduces disease activity in MS.

Relationship between CXC chemokine receptor 4 expression and prognostic significance in acute myeloid leukemia.

CXC chemokine receptor 4 (CXCR4) expression on acute myeloid leukemia (AML) cells correlated with stromal cell derived factor-1α (SDF-1α) and retained hematopoietic progenitors and leukemia cells within the bone marrow microenvironment. Here, we examined CXCR4 expression in 134 de novo AML and 21 controls by flow cytometry, evaluated the relationship between CXCR4 expression and clinical characteristics, and elucidated the prognostic significance of CXCR4 expression in AML prospectively. We found that the CXCR4 expression was significantly higher in AML patients than controls (P = .000). One hundred thirty four cases of de novo AML patients were divided into 2 groups according to the median of CXCR4 relative fluorescence intensity (RFI). CXCR4 high group (RFI >4.23) had markedly shorter overall survival (OS) and disease-free survival (DFS) than CXCR4 low group (RFI ≤4.23) in 106 AML patients who received chemotherapy (P = .002; .026, respectively). Furthermore, in the 87 non-M3 patients who received induction therapy, there was a significant decrease for OS but not for DFS in the CXCR4 high group (P = .047 and .178, respectively). Moreover, high levels of CXCR4 expression independently increased the risk of relapse in both all AML and non-M3 patients who achieved complete remission (CR) after chemotherapy (odds ratio = 1.090, P = .010; odds ratio = 1.068, P = .048, respectively). Collectively, our data suggest that CXCR4 overexpression was an independent prognostic factor for disease relapse and poorer OS in both all AML and non-M3 patients. CXCR4 expression levels can be determined at disease presentation by the flow rapidly and easily. As such, CXCR4 could be used as a potential therapeutic target in AML patients with poor prognosis.

Expression and clinical significance of SDF-1 and CXCR4 in peripheral blood of patients with hepatitis C cirrhosis

Objective To detect the expression and clinical significance of stro-mal cell derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) in peripheral blood of patients with hepatitis C cirrhosis. Methods From January 2015 to January 2018, 120 patients with hepatitis C cirrhosis in our hospital were selected as the subjects, including 60 patients with compensated hepatitis C cirrhosis and 60 patients with decompensated hepatitis C cirrhosis, and 60 hepatitis C patients without cirrhosis in the same period were selected as the control group. Enzyme linked immunosorbent assay (ELISA) was used to detect the expression levels of SDF-1 and CXCR4 in peripheral blood; the correlation between SDF-1 and CXCR4 expressions in compensated cirrhosis and decompensated cirrhosis patients was analyzed. Results The expression levels of SDF-1 and CXCR4 in peripheral blood samples of patients with decompensated cirrhosis of hepatitis C were significantly higher than those of patients with compensated cirrhosis of hepatitis C (P<0.05); the expression levels of SDF-1 and CXCR4 in peripheral blood samples of patients with compensated and decompensated cirrhosis of hepatitis C were significantly higher than those of control group (P<0.05); the expressions of SDF-1 and CXCR4 in peripheral blood of patients with compensated and decompensated cirrhosis of hepatitis C were positively correlated (r=0.684, P<0.05, r=0.765, P<0.05). Albumin (AlB) level in peripheral blood of cirrhosis group was significantly lower than that of control group (P<0.05); alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), while fasting insulin (FINs) and interleukin (IL)-6 in cirrhosis group were higher than those of control group (P<0.05); SDF-1 level and CXCR4 level were positively correlated with AlB, FINs and IL-6 (P<0.05); multiple regression analysis showed that FINs, IL-6, SDF-1 and CXCR4 were risk factors for hepatitis C cirrhosis. Conclusions The levels of SDF-1 and CXCR4 in peripheral blood of patients with hepatitis C cirrhosis increased, and the levels of SDF-1 and CXCR4 in peripheral blood were positively correlated, suggesting that they may be involved in the regulation of the occurrence and development of hepatitis C cirrhosis. Key words: Chemokine CXCL12; Receptors, CXCR4; Hepatitis C; Liver cirrhosis

Epoxyeicosatrienoic Acid Analog EET-A Blunts Development of Lupus Nephritis in Mice.

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disorder that causes life threatening renal disease and current therapies are limited with serious side-effects. CYP epoxygenase metabolites of arachidonic acid epoxyeicosatrienoic acids (EETs) demonstrate strong anti-inflammatory and kidney protective actions. We investigated the ability of an orally active EET analog, EET-A to prevent kidney injury in a mouse SLE model. Twenty-weeks old female NZBWF1 (SLE) and age-matched NZW/LacJ (Non SLE) were treated with vehicle or EET-A (10 mg/kg/d, p.o.) for 14 weeks and urine and kidney tissues were collected at the end of the protocol. SLE mice demonstrated marked renal chemotaxis with 30–60% higher renal mRNA expression of CXC chemokine receptors (CXCR) and CXC chemokines (CXCL) compared to Non SLE mice. In SLE mice, the elevated chemotaxis is associated with 5-15-fold increase in cytokine mRNA expression and elevated inflammatory cell infiltration in the kidney. SLE mice also had elevated BUN, serum creatinine, proteinuria, and renal fibrosis. Interestingly, EET-A treatment markedly diminished renal CXCR and CXCL renal mRNA expression in SLE mice. EET-A treatment also reduced renal TNF-α, IL-6, IL-1β, and IFN-γ mRNA expression by 70–80% in SLE mice. Along with reductions in renal chemokine and cytokine mRNA expression, EET-A reduced renal immune cell infiltration, BUN, serum creatinine, proteinuria and renal fibrosis in SLE mice. Overall, we demonstrate that an orally active EET analog, EET-A prevents renal injury in a mouse model of SLE by reducing inflammation.

Stromal-derived Factor-1α signaling is involved in bone morphogenetic protein-2-induced odontogenic differentiation of stem cells from apical papilla via the Smad and Erk signaling pathways

Stromal-derived factor-1α (SDF-1α) is a chemokine signaling molecule that binds to the transmembrane receptor CXC chemokine receptor-4 (CXCR4) and carries out important functions in development tissue homeostasis. SDF-1α signaling via CXCR4 regulates the recruitment of stem and precursor cells to support tissue-specific repair or regeneration. In this study, we examined the contribution of SDF-1α signaling to the odontogenic differentiation of stem cells from the apical papilla (SCAP) induced by bone morphogenic protein 2 (BMP-2). CXCR4 expression was detected in cultured SCAP and SDF-1α promoted the migration of SCAP in Transwell assays. Blocking SDF-1α signaling by treatment with siRNA significantly affected BMP-2-induced mineralized nodule formation and alkaline phosphatase (ALP) activity. Moreover, blocking SDF-1α signaling inhibited the BMP-2-induced early expression of runt-related factor-2 (Runx-2) and strongly suppressed the induction of dentin matrix protein 1 (DMP-1) and dentin sialophosphoprotein (DSPP) expression by BMP-2. Furthermore, the interaction between SDF-1α and BMP-2 signaling was mediated via intracellular Smads and Erk activation. In conclusion, our results demonstrated that SDF-1α can significantly promote the migration of SCAP. Moreover, we revealed corequirement of the SDF-1α/CXCR4 signaling pathways in the BMP-2-induced odontogenic differentiation of SCAP, and these findings may be applied in new strategies for dental pulp regeneration.

Hyperbaric oxygen improves functional recovery of rats after spinal cord injury via activating stromal cell-derived factor-1/CXC chemokine receptor 4 axis and promoting brain-derived neurothrophic factor expression.

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.

Circulating tumour cells and their association with bone metastases in patients with neuroendocrine tumours

BackgroundBone metastases are associated with a worse outcome in patients with neuroendocrine tumours (NETs). Tumour overexpression of C-X-C chemokine receptor 4 (CXCR4) appears predictive of skeletal involvement. We investigated the role of circulating tumour cells (CTCs) and CXCR4 expression on CTCs as potential predictors of skeleton invasion.MethodsBlood from patients with metastatic bronchial, midgut or pancreatic NET (pNET) was analysed by CellSearch. CXCR4 immunohistochemistry was performed on matched formalin-fixed paraffin-embedded (FFPE) samples.ResultsTwo hundred and fifty-four patients were recruited with 121 midgut and 119 pNETs, of which 51 and 36% had detectable CTCs, respectively. Bone metastases were reported in 30% of midgut and 23% of pNET patients and were significantly associated with CTC presence (p = 0.003 and p < 0.0001). In a subgroup of 40 patients, 85% patients with CTCs had CTCs positive for CXCR4 expression. The proportion of CXCR4-positive CTCs in patients with bone metastases was 56% compared to 35% in those without (p = 0.18) it. Staining for CXCR4 on matched FFPE tissue showed a trend towards a correlation with CXCR4 expression on CTCs (p = 0.08).ConclusionsCTC presence is associated with bone metastases in NETs. CXCR4 may be involved in CTC osteotropism and present a therapeutic target to reduce skeletal morbidity.