1,5-AG suppresses pro-inflammatory polarization of macrophages and promotes the survival of B-ALL in vitro by upregulating CXCL14.

B-lineage acute lymphoblastic leukemia (B-ALL) is one of the most common malignancies in children. Despite advances in treatment, the role of the tumor microenvironment in B-ALL remains poorly understood. Among the key components of the immune microenvironment, macrophages play a critical role in the progression of the disease. However, recent research has suggested that abnormal metabolites may influence the function of macrophages, altering the immune microenvironment and promoting tumor growth. Our previous non-targeted metabolomic detection revealed that the metabolite 1,5-anhydroglucitol (1,5-AG) level in the peripheral blood of children newly diagnosed with B-ALL was significantly elevated. Except for its direct influence on leukemia cells, the effect of 1,5-AG on macrophages is still unclear. Herein, we demonstrated new potential therapeutic targets by focusing on the effect of 1,5-AG on macrophages. We used polarization-induced macrophages to determine how 1,5-AG acted on M1-like polarization and screened out the target gene CXCL14 via transcriptome sequencing. Furthermore, we constructed CXCL14 knocked-down macrophages and a macrophage-leukemia cell coculture model to validate the interaction between macrophages and leukemia cells. We discovered that 1,5-AG upregulated the CXCL14 expression, thereby inhibiting M1-like polarization. CXCL14 knockdown restored the M1-like polarization of macrophages and induced leukemia cells apoptosis in the coculture model. Our findings offer new possibilities for the genetic engineering of human macrophages to rehabilitate their immune activity against B-ALL in cancer immunotherapy.

Blocking CXC Motif Chemokine Ligand 2 Ameliorates Diabetic Peripheral Neuropathy via Inhibiting Apoptosis and NLRP3 Inflammasome Activation.

Evidence suggests that CXC motif chemokines are involved in neuronal injury and inflammatory processes. Bioinformatics analysis by using data from the Gene Expression Omnibus (GEO) database was performed and identified CXC motif chemokine ligands (CXCLs) as associated with diabetic peripheral neuropathy (DPN). The present study focused on CXC motif chemokine ligand 2 (CXCL2), and the role and potential mechanisms of CXCL2 in DPN were investigated. The DPN rat model was generated by streptozotocin (STZ) injection in vivo, and high-glucose (HG)-stimulated Schwann cell RSC96 was considered a cell model of DPN in vitro. Neuropathic symptoms of DPN were explored by neurological tests and histological examinations. DPN rats showed a decreased level of motor nerve conduction velocity (MNCV) along with typical histological changes. CXCL2 expression was significantly increased in STZ-induced DPN rat sciatic nerve and HG-induced RSC96 cells. Functionally, CXCL2 knockdown inhibited cell apoptosis and inflammation activation under diabetic conditions in vitro and in vivo. CXCL2 knockdown increased cell viability in HG-treated RSC96 cells and reduced apoptosis concerning the decreased expression of cleaved Caspase 3/9. In addition, CXCL2 knockdown protected against NOD-like receptor protein 3 (NLRP3) inflammasome activation and reduced levels of pro-inflammatory cytokines, interleukin (IL)-1ß and IL-18. The repressive effects of CXCL2 knockdown on inflammasome activation under HG conditions were significantly abolished by treatment of the NLRP3 activator nigericin. In conclusion, these results indicated that CXCL2 knockdown exhibited amelioration of hyperglycemia-induced DPN by inhibiting cell apoptosis and NLRP3 inflammasome activation, suggesting that targeting CXCL2 might be a potential strategy for DPN treatment.

Characterization of the bone marrow niche in patients with chronic myeloid leukemia identifies CXCL14 as a new therapeutic option.

Although tyrosine kinase inhibitors (TKIs) are effective in treating chronic myeloid leukemia (CML), they often fail to eradicate the leukemia-initiating stem cells (LSCs), causing disease persistence and relapse. Evidence indicates that LSC persistence may be because of bone marrow (BM) niche protection; however, little is known about the underlying mechanisms. Herein, we molecularly and functionally characterize BM niches in patients with CML at diagnosis and reveal the altered niche composition and function in these patients. Long-term culture initiating cell assay showed that the mesenchymal stem cells from patients with CML displayed an enhanced supporting capacity for normal and CML BM CD34+CD38- cells. Molecularly, RNA sequencing detected dysregulated cytokine and growth factor expression in the BM cellular niches of patients with CML. Among them, CXCL14 was lost in the BM cellular niches in contrast to its expression in healthy BM. Restoring CXCL14 significantly inhibited CML LSC maintenance and enhanced their response to imatinib in vitro, and CML engraftment in vivo in NSG-SGM3 mice. Importantly, CXCL14 treatment dramatically inhibited CML engraftment in patient-derived xenografted NSG-SGM3 mice, even to a greater degree than imatinib, and this inhibition persisted in patients with suboptimal TKI response. Mechanistically, CXCL14 upregulated inflammatory cytokine signaling but downregulated mTOR signaling and oxidative phosphorylation in CML LSCs. Together, we have discovered a suppressive role of CXCL14 in CML LSC growth. CXCL14 might offer a treatment option targeting CML LSCs.

[Hypoxia promotes lipopolysaccharide-induced CXCL10 expression in microglia].

This study was aimed to investigate the effect of hypoxia on lipopolysaccharide (LPS)-induced CXC-chemokine ligand-10 (CXCL10) expression and the underlying mechanism. C57BL/6J mice were randomly divided into control, hypoxia, LPS, and hypoxia combined with LPS groups. The LPS group was intraperitoneally injected with 0.5 mg/kg LPS, and the hypoxia group was placed in a hypobaric hypoxia chamber (simulated altitude of 6 000 m). The serum and hippocampal tissue samples were collected after 6 h of the treatment. The levels of CXCL10 in the serum and hippocampal tissue of mice were detected by ELISA. The microglia cell line BV2 and primary microglia were stimulated with hypoxia (1% O2) and/or LPS (100 ng/mL) for 6 h. The mRNA expression level of CXCL10 and its content in culture supernatant were detected by real-time quantitative PCR and ELISA, respectively. The phosphorylation levels of nuclear factor κB (NF-κB) signaling pathway-related proteins, p65 and IκBα, were detected by Western blot. Moreover, after NF-κB signaling pathway being blocked with a small molecular compound, PDTC, CXCL10 mRNA expression level was detected in the BV2 cells. The results showed that in the LPS-induced mouse inflammatory model, hypoxia treatment could promote LPS-induced up-regulation of CXCL10 in both serum and hippocampus. Compared with the cells treated with LPS alone, the expression of CXCL10 mRNA and the content of CXCL10 in the culture supernatant of BV2 cells treated with hypoxia combined with LPS were significantly increased. The CXCL10 mRNA level of primary microglial cells treated with hypoxia combined with LPS was significantly up-regulated. Compared with the cells treated with hypoxia or LPS alone, the phosphorylation levels of p65 and IκBα in the BV2 cells treated with hypoxia combined with LPS were significantly increased. PDTC blocked the induction of CXCL10 gene expression by LPS in the BV2 cells. These results suggest that hypoxia promotes LPS-induced expression of CXCL10 in both animal and cell models, and NF-κB signaling pathway plays an important role in this process.

Potential role of the hydroxyl carboxylic acid receptor type 2 (HCAR2) in microglia pathophysiology: A possible cross-talk with C-X-C chemokine receptor 1 (CXCR1).

Following insults or injury, microglia cells are activated contributing to the cytotoxic response or by promoting an immune-mediated damage resolution. Microglia cells express HCA2R, a hydroxy carboxylic acid (HCA) receptor, which has been shown to mediate neuroprotective and anti-inflammatory effects. In this study we found that HCAR2 expression levels were increased in cultured rat microglia cells after Lipopolysaccharide (LPS) exposure. In a similar fashion, the treatment with MK 1903, a potent full agonist of HCAR2, increased the receptor protein levels. Moreover, HCAR2 stimulation prevented i) cells viability ii) morphological activation iii) pro/anti-inflammatory mediators production in LPS-treated cells. Likewise, HCAR2 stimulation reduced the proinflammatory mediators mRNA expression induced by neuronal chemokine fractalkine (FKN), a neuronal derived chemokine activating its unique receptor, chemokine receptor 1 (CX3CR1) on microglia surface. Interestingly, electrophysiological recordings in vivo revealed that MK1903 was able to prevent the increase of the nociceptive neurons (NS) firing activity mediated by the spinal FKN application in healthy rats. Collectively, our data demonstrate that HCAR2 is functionally expressed in microglia, by showing its capability to shift microglia toward an anti-inflammatory phenotype. Moreover, we indicated the contribute of HCAR2 in the FKN signaling and suggested a possible HCAR2/CX3CR1 functional interaction. This study paves the way for further investigations aimed at understanding the role HCAR2 as potential target in neuroinflammation-based CNS disorders. This article is part of the Special Issue on "The receptor-receptor interaction as a new target for therapy".

Disease modification and symptom relief in osteoarthritis using a mutated GCP-2/CXCL6 chemokine.

We showed that the chemokine receptor C-X-C Motif Chemokine Receptor 2 (CXCR2) is essential for cartilage homeostasis. Here, we reveal that the CXCR2 ligand granulocyte chemotactic protein 2 (GCP-2) was expressed, during embryonic development, within the prospective permanent articular cartilage, but not in the epiphyseal cartilage destined to be replaced by bone. GCP-2 expression was retained in adult articular cartilage. GCP-2 loss-of-function inhibited extracellular matrix production. GCP-2 treatment promoted chondrogenesis in vitro and in human cartilage organoids implanted in nude mice in vivo. To exploit the chondrogenic activity of GCP-2, we disrupted its chemotactic activity, by mutagenizing a glycosaminoglycan binding sequence, which we hypothesized to be required for the formation of a GCP-2 haptotactic gradient on endothelia. This mutated version (GCP-2-T) had reduced capacity to induce transendothelial migration in vitro and in vivo, without affecting downstream receptor signaling through AKT, and chondrogenic activity. Intra-articular adenoviral overexpression of GCP-2-T, but not wild-type GCP-2, reduced pain and cartilage loss in instability-induced osteoarthritis in mice. We suggest that GCP-2-T may be used for disease modification in osteoarthritis.

Hypoxia promotes lipopolysaccharide-induced CXCL10 expression in microglia / 生理学报

This study was aimed to investigate the effect of hypoxia on lipopolysaccharide (LPS)-induced CXC-chemokine ligand-10 (CXCL10) expression and the underlying mechanism. C57BL/6J mice were randomly divided into control, hypoxia, LPS, and hypoxia combined with LPS groups. The LPS group was intraperitoneally injected with 0.5 mg/kg LPS, and the hypoxia group was placed in a hypobaric hypoxia chamber (simulated altitude of 6 000 m). The serum and hippocampal tissue samples were collected after 6 h of the treatment. The levels of CXCL10 in the serum and hippocampal tissue of mice were detected by ELISA. The microglia cell line BV2 and primary microglia were stimulated with hypoxia (1% O2) and/or LPS (100 ng/mL) for 6 h. The mRNA expression level of CXCL10 and its content in culture supernatant were detected by real-time quantitative PCR and ELISA, respectively. The phosphorylation levels of nuclear factor κB (NF-κB) signaling pathway-related proteins, p65 and IκBα, were detected by Western blot. Moreover, after NF-κB signaling pathway being blocked with a small molecular compound, PDTC, CXCL10 mRNA expression level was detected in the BV2 cells. The results showed that in the LPS-induced mouse inflammatory model, hypoxia treatment could promote LPS-induced up-regulation of CXCL10 in both serum and hippocampus. Compared with the cells treated with LPS alone, the expression of CXCL10 mRNA and the content of CXCL10 in the culture supernatant of BV2 cells treated with hypoxia combined with LPS were significantly increased. The CXCL10 mRNA level of primary microglial cells treated with hypoxia combined with LPS was significantly up-regulated. Compared with the cells treated with hypoxia or LPS alone, the phosphorylation levels of p65 and IκBα in the BV2 cells treated with hypoxia combined with LPS were significantly increased. PDTC blocked the induction of CXCL10 gene expression by LPS in the BV2 cells. These results suggest that hypoxia promotes LPS-induced expression of CXCL10 in both animal and cell models, and NF-κB signaling pathway plays an important role in this process.

IRX1 ameliorates sepsis-induced acute kidney injury in mice by promoting CXCL14.

BACKGROUND: Sepsis-induced acute kidney injury is a general critical complication having high relevance to kidney inflammation. In spite of advances in clinical and critical care, the specific and effective therapies for acute kidney injury are still insufficient. The present study aimed to investigate the protective effect of Iroquois homeobox genes (IRX) on sepsis-induced kidney dysfunction in mice. METHODS: In order to gain insight into sepsis-related actions in acute kidney injury, the cecal puncture-induced kidney injury animal model was established. The hematoxylin and eosin staining was used to measure the pathology of kidney tissues. The kidney function-related biomarkers, including neutrophil gelatinase-associated lipocalin, creatinine, kidney injury molecule-1, blood urea nitrogen, and inflammatory cytokines, which included tumor necrosis factor α, interleukin 1ß (IL-1ß), IL-6, and monocyte chemotactic protein 1, were detected by automated biochemical analyzer or their corresponding test kits. The protein expression was measured using Western blot analysis, and the apoptotic rate of kidney tissue was measured by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. RESULTS: The present study revealed the protective ability of IRX1 in sepsis-induced acute kidney injury. This study also determined the potential mechanism of IRX1 on sepsis-induced inflammatory response and cell apoptosis. Finally, it highlighted that IRX1 exerted a protective influence on CLP-induced acute kidney injury by suppressing the activation of chemokine (C-X-C motif) ligand 14 (CXCL14). CONCLUSION: To conclude, the results suggest that overexpression of IRX1 could promote survival rate and suppress the CLP-induced apoptosis, inflammatory response, and kidney dysfunction through the activation of CXCL14. IRX1 and CXCL14 are essential to elucidate the mechanism of acute kidney injury. These findings may help to identify the promising targets for clinical sepsis therapy.

IRX1 ameliorates sepsis-induced acute kidney injury in mice by promoting CXCL14

Background Sepsis-induced acute kidney injury is a general critical complication having high relevance to kidney inflammation. In spite of advances in clinical and critical care, the specific and effective therapies for acute kidney injury are still insufficient. The present study aimed to investigate the protective effect of Iroquois homeobox genes (IRX) on sepsis-induced kidney dysfunction in mice. Methods In order to gain insight into sepsis-related actions in acute kidney injury, the cecal puncture-induced kidney injury animal model was established. The hematoxylin and eosin staining was used to measure the pathology of kidney tissues. The kidney function-related biomarkers, including neutrophil gelatinase-associated lipocalin, creatinine, kidney injury molecule-1, blood urea nitrogen, and inflammatory cytokines, which included tumor necrosis factor α, interleukin 1β (IL-1β), IL-6, and monocyte chemotactic protein 1, were detected by automated biochemical analyzer or their corresponding test kits. The protein expression was measured using Western blot analysis, and the apoptotic rate of kidney tissue was measured by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results The present study revealed the protective ability of IRX1 in sepsis-induced acute kidney injury. This study also determined the potential mechanism of IRX1 on sepsis-induced inflammatory response and cell apoptosis. Finally, it highlighted that IRX1 exerted a protective influence on CLP-induced acute kidney injury by suppressing the activation of chemokine (C-X-C motif) ligand 14 (CXCL14). Conclusion To conclude, the results suggest that overexpression of IRX1 could promote survival rate and suppress the CLP-induced apoptosis, inflammatory response, and kidney dysfunction through the activation of CXCL14. IRX1 and CXCL14 are essential to elucidate the mechanism of acute kidney injury. These findings may help to identify the promising targets for clinical sepsis therapy (AU)

Oxytocin suppresses CXCL10 production in TNF-α-stimulated human dental pulp stem cells.

Oxytocin (OX) is a posterior pituitary hormone secreted into the blood from axon terminals projecting from the posterior pituitary. Recent reports indicate OX plays an important role in the progression of inflammatory diseases such as rheumatoid arthritis. Pulpitis is caused by the activation of the biological defense mechanism of the dental pulp against cariogenic bacteria. However, the role of OX in the pathogenesis of pulpitis remains unknown. The aim of this study was to examine the effect of OX on CXC chemokine ligand 10 (CXCL10) production in human dental pulp stem cells (HDPSCs). Expression of the oxytocin receptor (OXR) on HDPSCs was detected by Western blot analysis and immunofluorescence. CXCL10 production in HDPSCs was measured using an enzyme-linked immunosorbent assay kit. Western blot analysis was performed to determine the phosphorylation levels of signal transduction molecules, including nuclear factor kappa B, mitogen-activated protein kinases (MAPKs), and Akt in HDPSCs. HDPSCs expressed OXR. OX significantly decreased CXCL10 production in tumor necrosis factor (TNF)-α-stimulated HDPSCs. The p38 MAPK and Akt pathways were related to the OX-suppressed CXCL10 production in TNF-α-stimulated HDPSCs. These results indicate that OX appears to modulate the immune response in pulpitis via suppression of CXCL10 production by HDPSCs.

Knockdown of CXCL3-inhibited apoptosis and inflammation in lipopolysaccharide-treated BEAS-2B and HPAEC through inactivating MAPKs pathway.

BACKGROUND: CXCL3 (C-X-C motif chemokine ligand 3) is a member of chemokines family, which binds to the receptor to recruit neutrophils to lungs, thus participating in the pathogenesis of asthmatic lung. The role of CXCL3 in sepsis-induced acute lung injury is investigated here. METHODS: Human lung epithelial cell line (BEAS-2B) and human pulmonary artery endothelial cell line (HPAEC) were treated with lipopolysaccharides (LPS). MTT and flow cytometry were performed to detect cell viability and apoptosis, respectively. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to assess the levels of inflammatory factors. RESULTS: Treatment with LPS resulted in the decrease of cell viability in BEAS-2B and HPAEC. CXCL3 was particularly upregulated in LPS-treated BEAS-2B and HPAE cells. Knockdown of CXCL3 enhanced viability and suppressed apoptosis i006E LPS-treated BEAS-2B and HPAE cells. Knockdown of CXCL3 also upregulated TNF-α, IL-1ß, and IL-18 in LPS-treated BEAS-2B and HPAE cells. Moreover, knockdown of CXCL3 suppressed the activation of mitogen-activated protein kinases (MAPKs) signaling in LPS-treated BEAS-2B and HPAE cells through downregulation of p-ERK1/2, p-p38, and p-JNK. On the other hand, overexpression of CXCL3 caused completely opposite results in LPS-treated BEAS-2B and HPAE cells. CONCLUSION: Knockdown of CXCL3 exerted antiapoptotic and anti-inflammatory effects against LPS-treated BEAS-2B and HPAE cells, at least partially, through inactivation of MAPKs signaling, suggesting a potential strategy for the intervention of sepsis-induced acute lung injury.

Novel role of CXCL14 in modulating STAR expression in luteinized granulosa cells: implication for progesterone synthesis in PCOS patients.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-age women. Reduced progesterone levels are associated with luteal phase deficiency in women with PCOS. The levels of C-X-C motif chemokine ligand-14 (CXCL14) were previously reported to be decreased in human-luteinized granulosa (hGL) cells derived from PCOS patients. However, the function of CXCL14 in hGL cells and whether CXCL14 affects the synthesis of progesterone in hGL cells remain unclear. In the present study, the levels of CXCL14 were reduced in follicular fluid and hGL cells in PCOS patients, accompanied by decreased progesterone levels in follicular fluid and decreased steroidogenic acute regulatory (STAR) expression in hGL cells. CXCL14 administration partially reversed the low progesterone production and STAR expression in hGL cells obtained from PCOS patients. In primary hGL cells, CXCL14 upregulated STAR expression and progesterone production. CXCL14 activated the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB) and CREB inhibitor attenuated the modulation of StAR expression by CXCL14. P38 and Jun N-terminal kinase (JNK) pathways were also activated by CXCL14 and inhibition of p38 and JNK attenuated the increase of phosphorylation of CREB, STAR expression and progesterone production caused by CXCL14. Our findings revealed the novel role of CXCL14 in upregulation of STAR expression and progesterone synthesis through CREB phosphorylation via activation of p38 and JNK pathways in hGL cells. This is likely contributing to the dysfunction in steroidogenesis in granulosa cells from PCOS patients.

C-X-C Motif Chemokine Ligand 14 is a Unique Multifunctional Regulator of Tumor Progression.

Cancer is a leading cause of death and disease worldwide, with a tremendous financial impact. Thus, the development of cost-effective novel approaches for suppressing tumor growth and progression is essential. In an attempt to identify the mechanisms responsible for tumor suppression, we screened for molecules downregulated in a cancer progression model and found that the chemokine CXCL14, also called BRAK, was the most significantly downregulated. Increasing the production of CXCL14 protein by transfecting tumor cells with a CXCL14 expression vector and transplanting the cells into the back skin of immunodeficient mice suppressed tumor cell growth compared with that of parental tumor cells, suggesting that CXCL14 suppressed tumor growth in vivo. However, some studies have reported that over-expression of CXCL14, especially in stromal cells, stimulated the progression of tumor formation. Transgenic mice expressing 10-fold more CXCL14 protein than wild-type C57BL/6 mice showed reduced rates of chemical carcinogenesis, transplanted tumor growth, and metastasis without apparent side effects. CXCL14 also acts as an antimicrobial molecule. In this review, we highlight recent studies involving the identification and characterization of CXCL14 in cancer progression and discuss the reasons for the context-dependent effects of CXCL14 on tumor formation.

CXC chemokine­7 inhibits growth and migration of oral tongue squamous cell carcinoma cells, mediated by the epithelial­mesenchymal transition signaling pathway.

Oral tongue squamous cell carcinoma (OTSCC) is the most common oral malignancy with different histopathological symptoms and etiology of tumorigenesis. Migration and invasion is the most important characteristics of OTSCC, and limits tumor therapy in clinics. The epithelial­to­mesenchymal transition (EMT) signaling pathway is an important process in the progress of tumor cell migration and invasion. Previous studies have indicated that C­X­C chemokine receptor­7 (CXCR­7) promotes the progression and metastasis of tumor cells, presenting a potential target molecule for cancer therapy. The present study investigated the inhibitory effects of C­X­C chemokine­7 (CXC­7) on human OTSCC cells both in vitro and in vivo. The results demonstrated that the Tca8113 human OTSCC cell line expressed higher levels of CXC­7 mRNA compared with the hNOE human normal oral epithelial cell line. MTT assays indicated that CXC­7 suppressed Tca8113 cell growth, and the cytotoxicity of CXC­7 was indicated as the cell survival of the negative control group was significantly decreased compared with the blank control and hNOE cells. Migration and invasion assays revealed that CXC­7 inhibited Tca8113 cell local expansion and distant metastasis. In addition, the results demonstrated that the extracellular signal­regulated kinase (ERK)/protein kinase B (AKT) signaling pathway was inhibited after CXC­7 treatment in Tca8113 cells. N­cadherin, E­Cadherin, Snail and Slug expression levels in the ERK/AKT signaling pathway were inhibited in Tca8113 cells after treatment with CXC­7. It was demonstrated that important extracellular matrix proteins involved in cell migration, including Slug, collagen type I and Vimentin, were significantly downregulated by CXC­7 treatment. In conclusion, CXC­7 inhibited growth and migration in OTSCC cells, mediated by the EMT signaling pathway. This suggests that CXC­7 serves an inhibitory role in OTSCC migration, implicating CXCR­7 as a promising biomarker for chemokine receptor­based drug development.

Overexpression of CXCL3 can enhance the oncogenic potential of prostate cancer.

PURPOSE: CXCL3 and its receptor CXCR2 were considered to play particularly important roles in the progression of malignancies. However, the investigations about CXCL3/CXCR2 axis in prostate cancer have been poorly involved. Herein we firstly reported our studies on the expression and biological roles of CXCL3 and CXCR2 in prostate cancer. METHODS: Expression levels of CXCL3 and CXCR2 in prostate cancer cell lines (PC-3, DU145 and LNCaP), immortalized prostate stromal cell line (WPMY-1) and immortalized prostate epithelial cell line (RWPE-1) were investigated by RT-PCR, ELISA and western blot, whereas expression levels of CXCL3 in a prostate tissue microarray were detected by immunohistochemistry. Cell counting kit-8 and transwell assays were, respectively, utilized to determine the effects of exogenous CXCL3 on the cell proliferation and migration. We further examined whether CXCL3 could regulate the expression of genes correlated with prostate tumorigenesis by RT- PCR. RESULTS: Elevated expression of CXCR2 was detected in DU145, LNCaP and RWPE-1. Moreover, high-level CXCL3 can be secreted by PC-3 and RWPE-1, and CXCL3 protein expression level in tissue microarray is concordant with prostate cancer metastasis. Exogenous CXCL3 does not contribute to proliferation, but has a significant effect on migration of prostate cancer cells and RWPE-1. Finally, our data showed that exogenous CXCL3 can regulate the expression of genes including ERK, TP73, NUMB, BAX and NDRG3. CONCLUSION: Our findings suggest that CXCL3 and its receptor CXCR2 are overexpressed in prostate cancer cells, prostate epithelial cells and prostate cancer tissues, which may play multiple roles in prostate cancer progression and metastasis.

CXCL16 signaling mediated macrophage effects on tumor invasion of papillary thyroid carcinoma.

Macrophages in tumor microenvironment have pivotal roles in tumor growth, metastasis, and angiogenesis. We investigated the interacting mechanism of macrophage actions in human papillary thyroid cancer (PTC). Co-cultures of macrophage/PTC significantly increased the cancer cell migration potentials, compared with the PTC culture alone. Treatment of conditioned medium (CM) of macrophage/PTC co-cultures enhanced cell invasions in 3D invasion assay. Cytokine array analysis demonstrated that CM of macrophage/PTC co-cultures contained a high level of CXCL16, while it was not found in CM of PTC culture alone. Treatment with CXCL16 enhanced the cell migration potentials in PTC cells, and blocking CXCL16 signaling using anti-CXCL16 antibody or metalloproteinase inhibitor (TAPI2) attenuated macrophage-mediated enhancement of PTC cell migration potentials. In PTC cells, CXCL16 treatment or co-cultures with macrophages increased Akt phosphorylation, and these macrophage-dependent increases of Akt phosphorylation was inhibited by anti-CXCL16 antibody. Moreover, Akt inhibitor attenuated macrophage-mediated increases of PTC cell migration potential. In macrophages, treatment of macrophage/PTC co-cultured CMs up-regulated CD163, Il10, and CD206, which were attenuated by anti-CXCL16 antibody treatment. Finally, CXCR6 and CXCL16 expressions were evaluated by immunohistochemical staining with a thyroid tissue microarray including 136 PTC. CXCR6 expressions showed positive correlation with the density of CD163(+) macrophages and associated with lymph node metastasis. In conclusion, CXCL16 signaling partly mediated macrophage actions on PTC tumor cell invasion and also changed the macrophage phenotypes into M2-macrophages in PTC tumor microenvironment. These data suggested that CXCL16 signaling, a bidirectional player in macrophage-associated tumor microenvironment, might be a potential therapeutic target of human PTC.

CXCL14 displays antimicrobial activity against respiratory tract bacteria and contributes to clearance of Streptococcus pneumoniae pulmonary infection.

CXCL14 is a chemokine with an atypical, yet highly conserved, primary structure characterized by a short N terminus and high sequence identity between human and mouse. Although it induces chemotaxis of monocytic cells at high concentrations, its physiological role in leukocyte trafficking remains elusive. In contrast, several studies have demonstrated that CXCL14 is a broad-spectrum antimicrobial peptide that is expressed abundantly and constitutively in epithelial tissues. In this study, we further explored the antimicrobial properties of CXCL14 against respiratory pathogens in vitro and in vivo. We found that CXCL14 potently killed Pseudomonas aeruginosa, Streptococcus mitis, and Streptococcus pneumoniae in a dose-dependent manner in part through membrane depolarization and rupture. By performing structure-activity studies, we found that the activity against Gram-negative bacteria was largely associated with the N-terminal peptide CXCL141-13. Interestingly, the central part of the molecule representing the ß-sheet also maintained ∼62% killing activity and was sufficient to induce chemotaxis of THP-1 cells. The C-terminal α-helix of CXCL14 had neither antimicrobial nor chemotactic effect. To investigate a physiological function for CXCL14 in innate immunity in vivo, we infected CXCL14-deficient mice with lung pathogens and we found that CXCL14 contributed to enhanced clearance of Streptococcus pneumoniae, but not Pseudomonas aeruginosa. Our comprehensive studies reflect the complex bactericidal mechanisms of CXCL14, and we propose that different structural features are relevant for the killing of Gram-negative and Gram-positive bacteria. Taken together, our studies show that evolutionary-conserved features of CXCL14 are important for constitutive antimicrobial defenses against pneumonia.

Snake (Walterinnesia aegyptia) venom-loaded silica nanoparticles induce apoptosis and growth arrest in human prostate cancer cells.

Prostate cancer (PCa) is the most commonly diagnosed cancer in men. The progression and invasion of PCa are normally mediated by the overexpression of chemokine receptors (CKRs) and the interaction between CKRs and their cognate ligands. We recently demonstrated that venom extracted from Walterinnesia aegyptia (WEV) either alone or in combination with silica nanoparticles (WEV+NP) mediated the growth arrest and apoptosis of breast cancer cells. In the present study, we evaluated the impact of WEV alone and WEV+NP on the migration, invasion, proliferation and apoptosis of prostate cancer cells. We found that WEV alone and WEV+NP decreased the viability of all cell types tested (PCa cells isolated from patient samples, PC3 cells and LNCaP cells) using an MTT assay. The IC(50) values were determined to be 10 and 5 µg/mL for WEV alone and WEV+NP, respectively. WEV+NP decreased the surface expression of the CKRs CXCR3, CXCR4, CXCR5 and CXCR6 to a greater extent than WEV alone and subsequently reduced migration and the invasion response of the cells to the cognate ligands of the CKRs (CXCL10, CXCL12, CXCL13 and CXCL16, respectively). Using a CFSE proliferation assay, we found that WEV+NP strongly inhibited epidermal growth factor-mediated PCa cell proliferation. Furthermore, analysis of the cell cycle indicated that WEV+NP strongly altered the cell cycle of PCa cells and enhanced the induction of apoptosis. Finally, we demonstrated that WEV+NP robustly decreased the expression of anti-apoptotic effectors, such as B cell Lymphoma-2 (Bcl-2), B cell Lymphoma-extra large (Bcl-(XL)) and myeloid cell leukemia sequence-1 (Mcl-1), and increased the expression of pro-apoptotic effectors, such as Bcl-2 homologous antagonist/killer (Bak), Bcl-2-associated X protein (Bax) and Bcl-2-interacting mediator of cell death (Bim). WEV+NP also altered the membrane potential of mitochondria in the PCa cells. Our data reveal the potential of nanoparticle-sustained delivery of snake venom as effective treatments for prostate cancer.

CXCL17, an orphan chemokine, acts as a novel angiogenic and anti-inflammatory factor.

Chemokines play pivotal roles in the recruitment of various immune cells to diverse tissues in both physiological and pathological conditions. CXCL17 is an orphan chemokine preliminarily found to be involved in tumor angiogenesis. However, its protein nature, as well as its endogenous bioactivity, has not been well clarified. Using real-time PCR, immunohistochemical staining, and Western blotting, we found that CXCL17 is highly expressed in both a constitutive and inducible manner in the rat gastric mucosa, where it undergoes endoproteolysis during protein maturation. The mature CXCL17 exhibited strong chemoattractant abilities targeting monocytes and macrophages, potentially through ERK1/2 and p38 but not JNK signaling. CXCL17 also induced the production of proangiogenic factors such as vascular endothelial growth factor A from treated monocytes. Furthermore, in contrast to other CXC chemokines that accelerate inflammatory responses, CXCL17 showed novel anti-inflammatory effects on LPS-activated macrophages. Therefore, our data suggest that CXCL17 in the gastric lamina propria may play an important role in tissue repair and anti-inflammation, both of which help to maintain the integrity of the gastric mucosa.

CXCL14 enhances proliferation and migration of NCI-H460 human lung cancer cells overexpressing the glycoproteins containing heparan sulfate or sialic acid.

CXCL14 is a chemokine family member that is involved in various cellular responses in addition to immune cell activation. Although constitutive CXCL14 expression in normal epithelial cells may help protect against infection by activating immune systems, its expression in cancer cells has raised controversy regarding its possible role in tumorigenesis. However, the underlying mechanisms for this disparity remain unknown. Investigation of cellular CXCL14 binding properties might increase our understanding of the peptide's roles in tumorigenesis. In the present study, we found that CXCL14 binds to various cell types. Interestingly, binding to NCI-H460 cells was prevented by heparan sulfate and N-acetyl neuraminic acid. Next, we examined effect of CXCL14 binding in NCI-H460 and NCI-H23. CXCL14 enhanced proliferation and migration in NCI-H460 but had no effect on NCI-H23. A reporter gene assay with various transcription factor response elements revealed that only nuclear factor-κB (NF-κB) signaling was activated by CXCL14 in NCI-H460 cells, which was blocked by BAPTA-AM, TPCA-1, and brefeldin A. Exogenous expression of some glycoproteins such as syndecan-4, podoplanin, and CD43 in these cells enhanced CXCL14 binding and NF-κB activity. Collectively, these results demonstrate that CXCL14 binding to glycoproteins harboring heparan sulfate proteoglycans and sialic acids leads proliferation and migration of some cancer cells.