Expression Of CC Chemokine Ligand 2 Research Articles

Interventional effect and inflammatory regulation mechanism of dihydroartemisinin combined with pregabalin on neuropathic pain mice

This study aims to clarify the effects of dihydroartemisinin(DHA) combined with pregabalin(PGB) on neuropathic pain(NP) in mice and explore the neuroinflammatory regulatory mechanism. NP mice model was established using spinal nerve ligation, whereas the sham group exposed the spinal nerve without ligation. The mice were randomly divided into sham group, model group, PGB groups of low, medium, and high doses(PGB-L, PGB-M, and PGB-H, with 22, 45, and 91 mg·kg~(-1)), DHA group(16 mg·kg~(-1)), and DHA combined with PGB groups of low, medium, and high doses(DHA + PGB-L, DHA + PGB-M, and DHA + PGB-H). Administration by gavage 18 days after modeling. Von Frey and cold plate were used to detect mechanical pain threshold and cold pain sensitivity in mice. The tail suspension test and forced swimming test were used to investigate depressive behavior, and the open field test was used to estimate anxiety behavior. The Morris water maze was used to evaluate cognitive function. Liquid suspension chip technology was used to quantitatively analyze immune inflammation-related factors. Immunofluorescence was used to detect the expression of CC chemokine ligand 3(CCL3) and transmembrane protein 119(TMEM119). The results showed that compared with the sham group, the mechanical pain and cold pain sensitivity thresholds of the model group were significantly reduced, and the struggle time was significantly increased in the tail suspension test and forced swimming test. The activity time in the central area was significantly reduced in the open field test. The residence time in the second/fourth quadrant was significantly longer than that in other quadrants, and the latency time of platform climbing significantly increased after platform withdrawal in the Morris water maze experiment. The expression of CCL3 was significantly increased; the number of TMEM119 positive cells and the cell body area were significantly increased. Compared with the model group, the DHA + PGB-M group showed a significant increase in mechanical pain and cold pain sensitivity thresholds, as well as a significant increase in struggle time in the tail suspension test and forced swimming test. The activity time in the central area of the open field test was significantly reduced. The residence time in the second/fourth quadrant was significantly shorter than that in other quadrants, and the latency time of platform climbing after platform withdrawal was significantly reduced. Compared with the PGB-M group, the mechanical pain threshold of D14-17 in the DHA + PGB-M group was significantly increased, and the struggle time during forced swimming was significantly increased. The residence time in the second/fourth quadrant of the Morris water maze was significantly shorter than that in other quadrants. Compared with the model group, the expression of CCL3, the number of TMEM119 positive cells, and the cell body area in the DHA + PGB-M group were significantly decreased. This study indicates that DHA + PGB can enhance the analgesic effect of PGB on NP mice, break through the limitations of PGB tolerance, and make up for the shortcomings of PGB in antidepressant and cognitive improvement. Its mechanism may be related to regulating neuroinflammation by inhibiting the activation of microglial cells and expression of CCL3.

The Role of Nuclear Factor-Kappa B in Fibrinogen-Induced Inflammatory Responses in Cultured Primary Neurons.

Traumatic brain injury (TBI) is an inflammatory disease associated with a compromised blood-brain barrier (BBB) and neurodegeneration. One of the consequences of inflammation is an elevated blood level of fibrinogen (Fg), a protein that is mainly produced in the liver. The inflammation-induced changes in the BBB result in Fg extravasation into the brain parenchyma, creating the possibility of its contact with neurons. We have previously shown that interactions of Fg with the neuronal intercellular adhesion molecule-1 and cellular prion protein induced the upregulation of pro-inflammatory cytokines, oxidative damage, increased apoptosis, and cell death. However, the transcription pathway involved in this process was not defined. The association of Fg with the activation of the nuclear factor-κB (NF-κB) and the resultant expression of interleukin-6 (IL-6) and C-C chemokine ligand-2 (CCL2) were studied in cultured primary mouse brain cortex neurons. Fg-induced gene expression of CCL2 and IL-6 and the expression of NF-κB protein were increased in response to a specific interaction of Fg with neurons. These data suggest that TBI-induced neurodegeneration can involve the direct interaction of extravasated Fg with neurons, resulting in the overexpression of pro-inflammatory cytokines through the activation of transcription factor NF-κB. This may be a mechanism involved in vascular cognitive impairment during neuroinflammatory diseases.

CCL2 overexpression is associated with paclitaxel resistance in ovarian cancer cells via autocrine signaling and macrophage recruitment

Tumor cells can secret various cytokines and chemokines, which affect the tumor cells themselves and the neighboring cells. Here, we observed that human ovarian cancer (OC) cells developed resistance to paclitaxel treatment following culture with the conditioned medium (CM) derived from paclitaxel-resistant OC (OCTR) cells. A cytokine array revealed that both OCTR cells secreted large amounts of CC chemokine ligand 2 (CCL2). CCL2 and its receptor, CCR2, were overexpressed in OCTR cells. CCL2 expression was associated with worse progression-free survival in patients with ovarian cancer. The inhibition of the CCL2/CCR2 axis suppressed the chemoresistance induced by OCTR-CM. The enhanced expression and production of CCL2 in OC cells were mediated via the NF-κB pathway, and stimulated the activation of the PI3K/Akt pathway, which resulted in the development of paclitaxel resistance in OC cells. Additionally, the OCTR cells significantly increased the migration of macrophages, which was also associated with the overproduction of CCL2 in chemoresistant cancer cells. The macrophages stimulated by OCTR cells expressed high levels of markers of M2 phenotype, and their CM significantly decreased the paclitaxel responsiveness of OC cells. The administration of a CCR2 inhibitor to a murine model significantly improved the paclitaxel sensitivity. These data suggested that apart from inducing chemoresistance in OC cells by acting as an autocrine factor, CCL2 also functions as a chemokine that induces the chemotaxis of macrophages, which may contribute to chemoresistance. Therefore, targeting the CCL2/CCR2 signaling axis may improve the therapeutic response of patients with ovarian cancer to paclitaxel.

Three key genes expression profiling in Egyptian rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a multi-system autoimmune disease with synovial joints involvement. The triad of autoimmunity, genetics, and environment is the key player in RA pathogenesis. We intended to investigate gene expression of C-C Chemokine Ligand 2 (CCL2), protein tyrosine phosphatase non-receptor type 22 (PTPN22), and Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) in RA patients versus controls, and its correlation with the activity of the disease. The relative expression of PTPN22, CTLA-4, and CCL2 in the peripheral blood of 59 RA patients and 50 controls was determined using RT-PCR. There was a significantly higher median (inter-quartile range) expression of CTLA-4 and CCL2 in RA patients in comparison to controls (P < 0.05). However, in RA patients, PTPN22 expression was significantly lower than in controls (P=0.0001). A weak significant correlation was detected between PTPN22 and either CTLA-4 or CCL2. Also, on comparing RA patients with moderate to severe disease activity versus those who have a mild disease activity, CCL2 was significantly over-expressed (P > 0.05). Thus, in Egyptian RA patients, there was a significant PTPN22 down-expression and greater expression of CTLA-4 and CCL2. Moreover, over-expression of CCL2 in RA patients with moderate-to-severe disease activity was significant. We conclude that these three key genes could become useful diagnostic markers for RA and CCL2 expression as a good prognostic tool for RA disease activity.

CC chemokine ligand 2 (CCL2) stimulates aromatase gene expression in mammary adipose tissue.

Obesity is a risk factor for postmenopausal breast cancer. Obesity-related inflammation upregulates aromatase expression, the rate-limiting enzyme for estrogen synthesis, in breast adipose tissue (BAT), increasing estrogen production and cancer risk. The regulation of aromatase gene (CYP19A1) in BAT is complex, and the mechanisms linking obesity and aromatase dysregulation are not fully understood. An obesity-associated factor that could regulate aromatase is the CC chemokine ligand (CCL) 2, a pro-inflammatory factor that also activates signaling pathways implicated in CYP19A1 transcription. By using human primary breast adipose stromal cells (ASCs) and aromatase reporter (hARO-Luc) mouse mammary adipose explants, we demonstrated that CCL2 enhances the glucocorticoid-mediated CYP19A1 transcription. The potential mechanism involves the activation of PI.4 via ERK1/2 pathway. We also showed that CCL2 contributes to the pro-inflammatory milieu and aromatase expression in obesity, evidenced by increased expression of CCL2 and CYP19A1 in mammary tissues from obese hARO-Luc mice, and subcutaneous adipose tissue from obese women. In summary, our results indicate that postmenopausal obesity may promote CCL2 production in BAT, leading to exacerbation of the menopause-related inflammatory state and further stimulation of local aromatase and estrogens. These results provide new insights into the regulation of aromatase and may aid in finding approaches to prevent breast cancer.

Analysis on the expression and value of CCL2 and CCL3 in patients with osteoarthritis

In this study, we investigated the clinical value of CC chemokine ligand 2 (CCL2) and CC chemokine ligand 3 (CCL3) in osteoarthritis (OA). A prospective analysis was performed on 126 patients with rheumatoid arthritis of the knee (observation group (OG)) who admitted to Qilu hospital from August 2016 to August 2018 and 135 healthy controls (control group (CG)) who underwent physical examinations during the same period. The concentrations of CCL2 and CCL3 in peripheral blood were compared between the two groups, and the predictive value of the two on the occurrence, efficacy and prognosis of recurrence of OA were analyzed. In addition, an OA rat model was established to detect the relative protein levels of CCL2 and CCL3 in rat knee joint tissues. There were no statistically significant differences between the two groups in baseline data such as age, body mass index (BMI), gender, smoking, drinking, educational level, family medical history and living environment (P > 0.05). CCL2 and CCL3 increased in peripheral blood of patients in the OG (P < 0.05), both of which were positively correlated with rheumatoid factor (RF) (P < 0.001). CCL2 and CCL3 were of good predictive value for the occurrence, efficacy and prognosis of recurrence of OA (P < 0.001). The relative protein levels of CCL2 and CCL3 in bone and joint tissues of OA rats were significantly higher than those of normal rats (P < 0.001). CCL2 and CCL3 are elevated in peripheral blood of OA patients, which have good predictive value for the occurrence, efficacy and prognosis of recurrence of OA, indicating their potential roles as excellent markers for diagnosis and treatment of OA in the future.

CCL3–CCR5 axis contributes to progression of esophageal squamous cell carcinoma by promoting cell migration and invasion via Akt and ERK pathways

AbstractTumor-associated macrophages (TAMs) contribute to the progression and mortality of various malignancies. We reported that high numbers of infiltrating TAMs were significantly associated with tumor progression and poor prognosis in esophageal squamous cell carcinoma (ESCC). In our previous investigation of TAMs' actions in ESCC, we compared gene expression profiles between peripheral blood monocyte (PBMo)-derived macrophages and TAM-like macrophages stimulated with conditioned media of ESCC cell lines. Among the upregulated genes in the TAM-like macrophages, we focused on CC chemokine ligand 3 (CCL3), which was reported to contribute to tumor progression in several malignancies. Herein, we observed that not only TAMs but also ESCC cell lines expressed CCL3. A CCL3 receptor, CC chemokine receptor 5 (CCR5) was expressed in the ESCC cell lines. Treating the ESCC cell lines with recombinant human (rh)CCL3 induced the phosphorylations of Akt and ERK, which were suppressed by CCR5 knockdown. Migration and invasion of ESCC cells were promoted by treatment with rhCCL3 and co-culture with TAMs. TAMs/rhCCL3-promoted cell migration and invasion were suppressed by inhibition of the CCL3–CCR5 axis, PI3K/Akt, and MEK/ERK pathways. Treatment with rhCCL3 upregulated MMP2 and VEGFA expressions in ESCC cell lines. Our immunohistochemical analysis of 68 resected ESCC cases showed that high expression of CCL3 and/or CCR5 in ESCC tissues was associated with poor prognosis. High CCR5 expression was associated with deeper invasion, presence of vascular invasion, higher pathological stage, higher numbers of infiltrating CD204+ TAMs, and higher microvascular density. High expression of both CCL3 and CCR5 was an independent prognostic factor for disease-free survival. These results suggest that CCL3 derived from both TAMs and cancer cells contributes to the progression and poor prognosis of ESCC by promoting cell migration and invasion via the binding of CCR5 and the phosphorylations of Akt and ERK. The CCL3–CCR5 axis could become the target of new therapies against ESCC.The authors. show that CCL3 derived from both tumor-associated macrophages and esophageal squamous cell carcinoma (ESCC) cells promotes cell migration and invasion of ESCC cells via binding CCR5. High expression of CCL3 and/or CCR5 associates with poor prognosis in ESCC patients. CCL3–CCR5 axis could be a specific target of anti-cancer therapy.

Systemic MCP-1 Levels Derive Mainly From Injured Liver and Are Associated With Complications in Cirrhosis

Background and Aims: Monocyte chemotactic protein-1 (MCP-1) is a potent chemoattractant for monocytes. It is involved in pathogenesis of several inflammatory diseases. Hepatic MCP-1 is a readout of macrophage activation. While inflammation is a major driver of liver disease progression, the origin and role of circulating MCP-1 as a biomarker remains unclear.Methods: Hepatic CC-chemokine ligand 2 (CCL2) expression and F4/80 staining for Kupffer cells were measured and correlated in a mouse model of chronic liver disease (inhalative CCl4 for 7 weeks). Next, hepatic RNA levels of CCL2 were measured in explanted livers of 39 patients after transplantation and correlated with severity of disease. Changes in MCP-1 were further evaluated in a rat model of experimental cirrhosis and acute-on-chronic liver failure (ACLF). Finally, we analyzed portal and hepatic vein levels of MCP-1 in patients receiving transjugular intrahepatic portosystemic shunt insertion for complications of portal hypertension.Results: In this mouse model of fibrotic hepatitis, hepatic expression of CCL2 (P = 0.009) and the amount of F4/80 positive cells in the liver (P < 0.001) significantly increased after induction of hepatitis by CCl4 compared to control animals. Moreover, strong correlation of hepatic CCL2 expression and F4/80 positive cells were seen (P = 0.023). Furthermore, in human liver explants, hepatic transcription levels of CCL2 correlated with the MELD score of the patients, and thus disease severity (P = 0.007). The experimental model of ACLF in rats revealed significantly higher levels of MCP-1 plasma (P = 0.028) and correlation of hepatic CCL2 expression (R = 0.69, P = 0.003). Particularly, plasma MCP-1 levels did not correlate with peripheral blood monocyte CCL2 expression. Finally, higher levels of MCP-1 were observed in the hepatic compared to the portal vein (P = 0.01) in patients receiving TIPS. Similarly, a positive correlation of MCP-1 with Child-Pugh score was observed (P = 0.018). Further, in the presence of ACLF, portal and hepatic vein levels of MCP-1 were significantly higher compared to patients without ACLF (both P = 0.039).Conclusion: Circulating levels of MCP-1 mainly derive from the injured liver and are associated with severity of liver disease. Therefore, liver macrophages contribute significantly to disease progression. Circulating MCP-1 may reflect the extent of hepatic macrophage activation.

Tumor-associated macrophages secrete CC-chemokine ligand 2 and induce tamoxifen resistance by activating PI3K/Akt/mTOR in breast cancer.

Breast cancer is the most prevalent malignancy among women. Although endocrine therapy is effective, the development of endocrine resistance is a major clinical challenge. The tumor microenvironment (TME) promotes tumor malignancy, and tumor‐associated macrophages (TAM) within the TME play a crucial role in endocrine resistance. Herein, we aimed to elucidate the relationship between TAM and the endocrine‐resistant phenotype of breast cancer. Macrophages were cultured with conditioned medium (CM) from tamoxifen‐sensitive (MCF7‐S) or ‐resistant (MCF7‐R) MCF7 breast cancer cells. M2 polarization was detected by CD163 immunofluorescence. To determine the effect on endocrine resistance, MCF7 cells were cultured in the supernatant of different TAM, and then treated with tamoxifen. CC‐chemokine ligand 2 (CCL2) immunohistochemistry was carried out on pathological sections from 100 patients with invasive estrogen receptor‐positive breast cancer. We found that macrophages cultured in the CM of MCF7‐S and MCF7‐R cells were induced into TAM, with a more obvious M2 polarization in the latter. Tamoxifen resistance was increased by culture in TAM medium. TAM secreted CCL2, which increased endocrine resistance in breast cancer cells through activation of the PI3K/Akt/mTOR signaling pathway. High expression of CCL2 was correlated with infiltration of CD163+macrophages (r = 0.548, P < .001), and patients with high CCL2 expression presented shorter progression‐free survival than those with low CCL2 expression (P < .05). We conclude that CCL2 secreted by TAM activates PI3K/Akt/mTOR signaling and promotes an endocrine resistance feedback loop in the TME, suggesting that CCL2 and TAM may be novel therapeutic targets for patients with endocrine‐resistant breast cancer.

Toll-like receptor 4 contributes to uterine activation by upregulating pro-inflammatory cytokine and CAP expression via the NF-κB/P38MAPK signaling pathway during pregnancy.

Evidence indicates that inflammatory response is significant during the physiological process of human parturition; however, the specific signaling pathway that triggers inflammation is undefined. Toll-like receptors (TLRs) are key upstream gatekeepers that control inflammatory activation before preterm delivery. Our previous study showed that TLR4 expression was significantly increased in human pregnancy tissue during preterm and term labor. Therefore, we explore whether TLR4 plays a role in term labor by initiating inflammatory responses, therefore promoting uterine activation. The results showed that expression of TLR4, interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), CC chemokine ligand 2 (CCL-2), and uterine contraction-associated proteins (CAPs) was upregulated in the human and mice term labor (TL) group compared with the not-in-labor (TNL) group, and the TLR4 level positively correlated with CAP expression. In pregnant TLR4-knockout (TLR4-/- ) mice, gestation length was extended by 8 hr compared with the wild-type group, and the expression of IL-1β, IL-6, TNF-α, CCL-2, and CAPs was decreased in TLR4-/- mice. Furthermore, nuclear factor-κB (NF-κB) and P38MAPK activation is involved in the initiation of labor but was inhibited in TLR4-/- mice. In uterine smooth muscle cells, the expression of inflammatory cytokines and CAPs decreased when the NF-κB and P38MAPK pathway was inhibited. Our data suggest that TLR4 is a key factor in regulating the inflammatory response that drives uterine activation and delivery initiation via activating the NF-κB/P38MAPK pathway.

Dahuang Zhechong Pill suppresses colorectal cancer liver metastasis via ameliorating exosomal CCL2 primed pre-metastatic niche

Ethnopharmacological relevanceDahuang Zhechong Pill (DZP) is a classical formula from “Synopsis of Prescriptions of the Golden Chamber”. It has been used for treatment of abdominal masses (including tumorous diseases) for thousands of years. Aim of the studyOur previous work showed that DZP suppresses CCl-4 induced hepatic fibrosis by downregulating the expression of interleukin-13. We aimed to test if DZP suppresses the metastasis of colorectal cancer (CRC) by ameliorating the fibrosis status of the future metastatic organ. Materials and methodsLiver metastasis was observed by injection of MC38-EGFP cells with stably expressing enhanced green fuorescence protein beneath the splenic capsule of C57BL/6J mice. MC38-EGFP-derived exosomes were analyzed by Label-free comparative proteomics. mRNA expression was determined by Quantitative PCR. Protein expression was determined by immunohistochemistry, immunofuorescence and Western blot. Collagen deposition was determined by Masson staining. All data were statistically analyzed using SPSS. ResultsDZP drastically reduced the metastatic tumor number and fluorescence intensity in a splenic liver metastasis model. It also lowered the expression of mature TGF-β1 and decreased the fibronectin contents & collagen deposition. Exosome proteomics showed that the upregualted CC chemokine ligand-2 (CCL2) was repressed by DZP treatment. Importantly, DZP markedly lowered the expression of CCL2 and its receptor CCR2 in the liver. Exosomal CCL2 activated macrophage recruitment and shifted the M1/M2 paradigm to a M2 phenotype. DZP reduced the macrophage infiltration and attenuated the M2 polarizaion in tumor-bearing mice liver. It decreased the F4/80 positive areas and specifically reduced the ratio of CCR2+ positive macrophage. Anti-fibrosis and inhibition of CCR2 suppress the growth and metastasis of CRC. ConclusionsDZP inhibits the liver metastasis of CRC by suppressing CCL2 mediated M2-skewing paradigm and ameliorating the pro-fibrotic microenvironment.

Bone marrow‑derived mesenchymal stem cell‑conditioned medium attenuates tubulointerstitial fibrosis by inhibiting monocyte mobilization in an irreversible model of unilateral ureteral obstruction.

Mesenchymal stem cell-conditioned medium (MSC-CM) contains various cytokines (osteopontin and macrophage colony stimulating factor 1) secreted by MSCs and may modulate the immune response in tubulointerstitial fibrosis. The aim of the present study was to investigate whether MSC-CM treatment may affect B cell-dependent immune responses, which have previously been reported to facilitate the renal fibrotic processes following unilateral ureteral obstruction (UUO). In the present study, histological analysis, flow cytometry, western blotting and reverse transcription-quantitative polymerase chain reaction were performed. MSC-CM treatment was observed to impede renal infiltration of B lymphocytes and the expression of CC chemokine ligand-2. Additionally, UUO suppressed the subsequent recruitment of monocytes/macrophages to the kidney, limited local inflammation and attenuated renal fibrosis. The findings of the present study identified a potential mechanism of MSC-CM in ameliorating the UUO-kidney.

Porphyromonas gingivalis lipopolysaccharide induces over production of CC chemokine ligand 2 via toll-like receptor-4 in oral lichen planus.

We recently reported that the CC chemokine ligand 2 (CCL2)-CC receptor 2 (CCR2) axis was involved in the pathogenesis of oral lichen planus (OLP). However, the exact mechanism for the high expression of CCL2 in OLP specimens is not clear. Therefore, this study was designed to investigate the potential role of the toll-like receptor 4 (TLR-4) pathway in overproduction of CCL2 in OLP lesions. Immunohistochemical staining and real-time RT-PCR were used to detect TLR-4, CCL2, and CCR2 expression in OLP lesions. Then, gingival epithelial cells from OLP lesions were established and treated with Porphyromonas gingivalis (P.gingivalis) lipopolysaccharide (LPS). CCL2 expression in epithelial cells was determined by Western blotting and real-time RT-PCR. In some experiments, TAK-242, a specific inhibitor of TLR-4, was used to block the TLR-4 pathway before cells were stimulated with LPS. We found that TLR-4 was significantly increased in the epithelium of OLP specimens, compared with controls. Moreover, LPS can induce the over production of CCL2 in epithelial cells of OLP, invitro. TAK-242 effectively eliminated the increase in CCL2 expression induced by LPS by blocking the TLR-4/NF-κB pathway. In addition, we again confirmed that expression of CCL2 and CCR2 was increased in OLP specimens. Increased TLR-4 expression contributes to the upregulated expression of CCL2 in the epithelium of OLP lesions, which suggests that oral bacteria participate in the pathogenesis of OLP via the TLR-4 pathway.

CCL2-driven inflammation increases mammary gland stromal density and cancer susceptibility in a transgenic mouse model

BackgroundMacrophages play diverse roles in mammary gland development and breast cancer. CC-chemokine ligand 2 (CCL2) is an inflammatory cytokine that recruits macrophages to sites of injury. Although CCL2 has been detected in human and mouse mammary epithelium, its role in regulating mammary gland development and cancer risk has not been explored.MethodsTransgenic mice were generated wherein CCL2 is driven by the mammary epithelial cell-specific mouse mammary tumour virus 206 (MMTV) promoter. Estrous cycles were tracked in adult transgenic and non-transgenic FVB mice, and mammary glands collected at the four different stages of the cycle. Dissected mammary glands were assessed for cyclical morphological changes, proliferation and apoptosis of epithelium, macrophage abundance and collagen deposition, and mRNA encoding matrix remodelling enzymes. Another cohort of control and transgenic mice received carcinogen 7,12-Dimethylbenz(a)anthracene (DMBA) and tumour development was monitored weekly. CCL2 protein was also quantified in paired samples of human breast tissue with high and low mammographic density.ResultsOverexpression of CCL2 in the mammary epithelium resulted in an increased number of macrophages, increased density of stroma and collagen and elevated mRNA encoding matrix remodelling enzymes lysyl oxidase (LOX) and tissue inhibitor of matrix metalloproteinases (TIMP)3 compared to non-transgenic controls. Transgenic mice also exhibited increased susceptibility to development of DMBA-induced mammary tumours. In a paired sample cohort of human breast tissue, abundance of epithelial-cell-associated CCL2 was higher in breast tissue of high mammographic density compared to tissue of low mammographic density.ConclusionsConstitutive expression of CCL2 by the mouse mammary epithelium induces a state of low level chronic inflammation that increases stromal density and elevates cancer risk. We propose that CCL2-driven inflammation contributes to the increased risk of breast cancer observed in women with high mammographic density.

TC-2559, an α4β2 nicotinic acetylcholine receptor agonist, suppresses the expression of CCL3 and IL-1β through STAT3 inhibition in cultured murine macrophages

The anti-inflammatory properties of TC-2559, an α4β2 nicotinic acetylcholine receptor (nAChR) agonist, on cultured murine macrophages was investigated. TC-2559 suppressed the upregulation of CC-chemokine ligand 3 (CCL3) and interleukin-1β (IL-1β) following lipopolysaccharide (LPS) treatment in J774A.1 cells. TC-2559 inhibited the phosphorylation of signal transducer and activator of transcription 3 (pSTAT3) but not nuclear factor-κB p65 after LPS. Blockade of pSTAT3 by AG490 inhibited the upregulation of CCL3 and IL-1β after LPS. In conclusion, TC-2559-driven α4β2 nAChR signaling suppressed the upregulation of CCL3 and IL-1β by inhibiting pSTAT3 in inflammatory macrophages, resulting in the suppression of neuropathic pain.

Changes in CCL3 and CCR5 expression in spinal cord during hyperalgesia induced by remifentanil in rats with incisional pain

Objective To evaluate the changes in the expression of CC-chemokine ligand 3(CCL3)and CC-chemokine receptor 5(CCR5)in the spinal cord during hyperalgesia induced by remifentanil in rats with incisional pain. Methods Thirty-two male Sprague-Dawley rats, aged 2-3 months, weighing 240-260 g, were randomly divided into 4 groups(n=8 each)using a random number table: control group(group C), incisional pain group(group I), remifentanil group(group R)and remifentanil+ incisional pain group(group R+ I). A 1-cm longitudinal incision was made in the plantar surface of the left hindpaw in anesthetized rats.While the model of incisional pain was established, remifentanil was infused for 60 min at 1 μg·kg-1·min-1.At 24 h before infusion of remifentanil(baseline)and 2, 6, 24 and 48 h after the end of infusion, the mechanical paw withdrawal threshold(MWT)and thermal paw withdrawal latency(TWL)were measured.The rats were sacrificed after the last measurement of pain threshold, the lumbar segment(L4-6)of the spinal cord was removed for determination of CL3 and CCR5 mRNA expression(by real-time PCR)and CL3 and CCR5 expression(by Western blot). Results Compared with group C, the MWT was significantly decreased, the TWL was shortened, and the expression of CCL3 and CCR5 mRNA and protein was up-regulated in I, R and R+ I groups.Compared with I and R groups, the MWT was significantly decreased, the TWL was shortened, and the expression of CCL3 and CCR5 mRNA and protein was up-regulated in group R+ I. Conclusion The mechanism by which remifentanil induces hyperalgesia is related to up-regulated expression of CCL3 and CCR5 in the spinal cord of rats with incisional pain. Key words: Piperidines; Hyperalgesia; Pain; Chemokine CCL3; Receptors, CCR5; Spinal cord

Chloroquine differentially modulates inflammatory cytokine expression in RAW 264.7 cells in response to inactivated Staphylococcus aureus.

The anti-inflammatory property of chloroquine (CQ) has long been recognized. This study aimed to investigate the effect of CQ on proinflammatory cytokine expression in RAW 264.7 macrophages stimulated with heat-inactivated Staphylococcus aureus cells (SAC). The results showed that CQ treatment reduced the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and CC chemokine ligand 2 (CCL2) in culture medium but increased intracellular protein expression of TNF-α and CCL2 in SAC-activated cells. However, CQ showed differential effects on their messenger RNA (mRNA) levels: it reduced IL-6 mRNA expression, increased CCL2 mRNA levels, but had no effect on TNF-α mRNA. The SAC-activated inflammatory signaling pathways were slightly or minimally affected by CQ treatment. Additionally, CQ increased the accumulation of pro-TNF-α proteins within cells, suggesting an inhibition of pro-TNF-α processing and secretion. Collectively, CQ differentially modulated proinflammatory cytokine expression in Gram-positive bacterium-activated macrophages at multiple regulatory layers in the course of their biosynthesis.

CC chemokine ligand 3 and receptors 1 and 5 gene expression in recurrent aphthous stomatitis

The aim of this study was to investigate the local and systemic expression of CC-chemokine ligand 3 (CCL3) and its receptors (CCR1 and CCR5) in tissue samples and peripheral blood mononuclear cells of recurrent aphthous stomatitis (RAS) patients. This case-control study enrolled 29 patients presenting severe RAS manifestations and 20 non-RAS patients proportionally matched by sex and age. Total RNA was extracted from biopsy specimens and peripheral blood mononuclear cells for quatitative reverse-transcription polymerase chain reaction. The data obtained by relative quantification were evaluated by the 2(-ΔΔCt) method, normalized by the expression of an endogenous control, and analyzed by Student t test. The results demonstrated overexpression in RAS tissue samples of all of the chemokines evaluated compared with healthy oral mucosa, whereas the blood samples showed only CCR1 overexpression in RAS patients. These findings suggest that the increased expression of CCL3, CCR1, and CCR5 may influence the immune response in RAS by T(H)1 cytokine polarization.

Lack of CC chemokine ligand 2 differentially affects inflammation and fibrosis according to the genetic background in a murine model of steatohepatitis

Expression of CCL2 (CC chemokine ligand 2) (or monocyte chemoattractant protein-1) regulates inflammatory cell infiltration in the liver and adipose tissue, favouring steatosis. However, its role in the pathogenesis of steatohepatitis is still uncertain. In the present study, we investigated the development of non-alcoholic steatohepatitis induced by an MCD diet (methionine/choline-deficient diet) in mice lacking the CCL2 gene on two different genetic backgrounds, namely Balb/C and C57/Bl6J. WT (wild-type) and CCL2-KO (knockout) mice were fed on a lipid-enriched MCD diet or a control diet for 8 weeks. In Balb/C mice fed on the MCD diet, a lack of CCL2 was associated with lower ALT (alanine transaminase) levels and reduced infiltration of inflammatory cells, together with a lower generation of oxidative-stress-related products. Sirius Red staining demonstrated pericellular fibrosis in zone 3, and image analysis showed a significantly lower matrix accumulation in CCL2-KO mice. This was associated with reduced hepatic expression of TGF-β (transforming growth factor-β), type I procollagen, TIMP-1 (tissue inhibitor of metalloproteinases-1) and α-smooth muscle actin. In contrast, in mice on a C57Bl/6 background, neither ALT levels nor inflammation or fibrosis were significantly different comparing WT and CCL2-KO animals fed on an MCD diet. In agreement, genes related to fibrogenesis were expressed to comparable levels in the two groups of animals. Comparison of the expression of several genes involved in inflammation and repair demonstrated that IL (interleukin)-4 and the M2 marker MGL-1 (macrophage galactose-type C-type lectin 1) were differentially expressed in Balb/C and C57Bl/6 mice. No significant differences in the degree of steatosis were observed in all groups of mice fed on the MCD diet. We conclude that, in experimental murine steatohepatitis, the effects of CCL2 deficiency are markedly dependent on the genetic background.

Analysis of gene expression profiles in human periodontal ligament cells under hypoxia: The protective effect of CC chemokine ligand 2 to oxygen shortage

Periodontal ligament (PDL) cells appear to play important functional roles in response to mechanical stress. We hypothesized that hypoxia caused by a deformation of blood vessels and the following ischaemia may play a crucial role in differential gene expression in PDL cells affected by mechanical stress. Gene induction in cultured human PDL cells by hypoxia was analyzed using cDNA array, followed by RT-PCR analysis. Eleven hypoxia-responsive genes were found differentially expressed under low-oxygen conditions in PDL cells. Among them, CCR2, CC chemokine ligand 2 (CCL2) receptor was studied in more detail since little information is available on the role of chemokines in adaptive responses of PDL cells under hypoxia. Here we investigate whether CCR2 mediates the signalling to maintain the homeostasis of PDL cells. We found that cell death of PDL cells was induced under hypoxia with down-regulation of CCL2 mRNA expression. However, the exogenous CCL2 prevented PDL cell death under oxygen shortage with the increment of cellular inhibitor of apoptosis (cIAP) mRNA expression. The present study demonstrated substantial effects of hypoxia on gene expression of CCL2 and CCR2 in PDL cells, indicating that mechanical loading accompanied with mild hypoxia allows PDL cells to elicit adaptive responses with up-regulation of CCR2.