Muscle cell-derived Ccl8 is a negative regulator of skeletal muscle regeneration.

Skeletal muscles undergo robust regeneration upon injury, and infiltrating immune cells play a major role in not only clearing damaged tissues but also regulating the myogenic process through secreted cytokines. Chemokine C-C motif ligand 8 (Ccl8), along with Ccl2 and Ccl7, has been reported to mediate inflammatory responses to suppress muscle regeneration. Ccl8 is also expressed by muscle cells, but a role of the muscle cell-derived Ccl8 in myogenesis has not been reported. In this study, we found that knockdown of Ccl8, but not Ccl2 or Ccl7, led to increased differentiation of C2C12 myoblasts. Analysis of existing single-cell transcriptomic datasets revealed that both immune cells and muscle stem cells (MuSCs) in regenerating muscles express Ccl8, with the expression by MuSCs at a much lower level, and that the temporal patterns of Ccl8 expression were different in MuSCs and macrophages. To probe a function of muscle cell-derived Ccl8 in vivo, we utilized a mouse system in which Cas9 was expressed in Pax7+ myogenic progenitor cells (MPCs) and Ccl8 gene editing was induced by AAV9-delivered sgRNA. Depletion of Ccl8 in Pax7+ MPCs resulted in accelerated muscle regeneration after barium chloride-induced injury in both young and middle-aged mice, and intramuscular administration of a recombinant Ccl8 reversed the phenotype. Accelerated regeneration was also observed when Ccl8 was depleted in Myf5+ or MyoD+ MPCs by similar approaches. Our results suggest that muscle cell-derived Ccl8 plays a unique role in regulating the initiation of myogenic differentiation during injury-induced muscle regeneration.

Chemokine profiling of melanoma-macrophage crosstalk identifies CCL8 and CCL15 as prognostic factors in cutaneous melanoma.

During cancer evolution, tumor cells attract and dynamically interact with monocytes/macrophages. To find biomarkers of disease progression in human melanoma, we used unbiased RNA sequencing and secretome analyses of tumor-macrophage co-cultures. Pathway analysis of genes differentially modulated in human macrophages exposed to melanoma cells revealed a general upregulation of inflammatory hallmark gene sets, particularly chemokines. A selective group of chemokines, including CCL8, CCL15, and CCL20, was actively secreted upon melanoma-macrophage co-culture. Because we previously described the role of CCL20 in melanoma, we focused our study on CCL8 and CCL15 and confirmed that in vitro both chemokines contributed to melanoma survival, proliferation, and 3D invasion through CCR1 signaling. In vivo, both chemokines enhanced primary tumor growth, spontaneous lung metastasis, and circulating tumor cell survival and lung colonization in mouse xenograft models. Finally, we explored the clinical significance of CCL8 and CCL15 expression in human skin melanoma, screening a collection of 67 primary melanoma samples, using multicolor fluorescence and quantitative image analysis of chemokine-chemokine receptor content at the single-cell level. Primary skin melanomas displayed high CCR1 expression, but there was no difference in its level of expression between metastatic and nonmetastatic cases. By contrast, comparative analysis of these two clinically divergent groups showed a highly significant difference in the cancer cell content of CCL8 (p = 0.025) and CCL15 (p < 0.0001). Kaplan-Meier curves showed that a high content of CCL8 or CCL15 in cancer cells correlated with shorter disease-free and overall survival (log-rank test, p < 0.001). Our results highlight the role of CCL8 and CCL15, which are highly induced by melanoma-macrophage interactions in biologically aggressive primary melanomas and could be clinically applicable biomarkers for patient profiling. © 2024 The Pathological Society of Great Britain and Ireland.

Pathogenic Th2 Cytokine Profile Skewing by IFN-γ-Responding Vitiligo Fibroblasts via CCL2/CCL8.

PURPOSE: Vitiligo is a T cell-mediated skin depigmentation disease. Though treatments arresting disease progression and inducing repigmentation are available, the efficacy of these options is often limited and poorly sustained. How stromal signals contribute to the interferon-γ-dominant skin niches is unclear. This study aims to determine how fibroblasts participate in the IFN-γ-dominant vitiligo niche. PATIENTS AND METHODS: Mouse vitiligo models were established. Fibroblasts from control and vitiligo mice were extracted for RNA sequencing. In vitro IFN-γ stimulation was performed to verify the JAK-STAT pathway by qPCR and Western blot. T cell polarization with chemokines was measured by flow cytometry. Protein levels in tissues were also examined by IHC. RESULTS: The vitiligo mouse model recapitulates the human CD8-IFN-γ pathway. RNA sequencing revealed elevated chemokine CCL2 and CCL8 in vitiligo fibroblast, which may be regulated by the JAK-STAT signaling. Such phenomenon is verified by JAK inhibitor peficitinib in vitro. Moreover, CCL2 addition into the naïve T polarization system promoted type 2 cytokines secretion, which represents a hallmark of vitiligo lesions. CONCLUSION: Dermal fibroblasts, a principal constituent of skin structure, respond to IFN-γ by skewing T cells towards a type 2 cytokine profile via CCL2 and CCL8, which can be abrogated by JAK inhibitor peficitinib.

Dexamethasone attenuated thoracic aortic aneurysm and dissection in vascular smooth muscle cell Tgfbr2-disrupted mice with CCL8 suppression.

NEW FINDINGS: What is the central question of this study? What is the relationship of chemokine (C-C motif) ligand 8 (CCL8) to thoracic aortic aneurysm and dissection (TAAD) formation in postnatal mice with vascular smooth muscle cell (VSMC) Tgfbr2 disruption, and is dexamethasone a potential treatment? What is the main finding and its importance? CCL8 was associated with the formation of TAAD in VSMC Tgfbr2-disrupted mice. Dexamethasone reduced TAAD formation and inhibited mitogen-activated protein kinase (p-p38) and nuclear factor-κB (p-p65) signalling pathways. CCL8 might be an important promoter of aortic inflammation. Dexamethasone provided potential therapeutic effects in TAAD treatment. ABSTRACT: Aortic inflammation plays a vital role in initiation and progression of thoracic aortic aneurysm and dissection (TAAD). Disturbance of the transforming growth factor-ß (TGF-ß) signalling pathway is believed to be one of the pathogenic mechanisms of TAAD. Initially, Myh11-CreERT2 .Tgfbr2f/f male mice were used to build a TAAD mouse model, and bioinformatic analyses revealed enriched inflammatory signal pathways and upregulated chemokine (C-C motif) ligand 8 (CCL8). So we hypothesized that vascular smooth muscle cell (VSMC) Tgfbr2 disruption in postnatal mice results in aortic inflammation associated with CCL8 secretion. Real-time quantitative PCR and serum enzyme-linked immunosorbent assay (ELISA) results confirmed that CCL8 expression began to increase after VSMC Tgfbr2 disruption. Next, we cultured mouse thoracic aortas ex vivo, and observed that the protein expression of CCL8 in culture supernatants was increased by ELISA. Subsequently, the co-localization of CCL8 with α-smooth muscle actin or CD68 was found to be significantly increased by immunofluorescence. Then, dexamethasone (DEX) was used to treat TAAD in VSMC Tgfbr2-disrupted mice; the results of histochemical, immunofluorescence and immunohistochemical staining indicated that DEX therapy reduced CCL8 secretion, inflammatory cell recruitment, aortic medial thickening, elastic fibre fragmentation, extracellular matrix degradation and contractile apparatus impairment, and thereby ameliorated TAAD formation. Western blotting showed that mitogen-activated protein kinase and nuclear factor-κB signalling pathways in aorta were overactivated after VSMC Tgfbr2 disruption, but inhibited by DEX therapy. Altogether, CCL8 might be an important promoter in TAAD formation of VSMC Tgfbr2-disrupted mice, and DEX provided potential therapeutic effects in TAAD treatment.

Altered Secretome of Diabetic Monocytes Could Negatively Influence Fracture Healing-An In Vitro Study.

Diabetes mellitus is a main risk factor for delayed fracture healing and fracture non-unions. Successful fracture healing requires stimuli from different immune cells, known to be affected in diabetics. Especially, application of mononuclear cells has been proposed to promote wound and fracture healing. Thus, aim was to investigate the effect of pre-/diabetic conditions on mononuclear cell functions essential to promote osteoprogenitor cell function. We here show that pre-/diabetic conditions suppress the expression of chemokines, e.g., CCL2 and CCL8 in osteoprogenitor cells. The associated MCP-1 and MCP-2 were significantly reduced in serum of diabetics. Both MCPs chemoattract mononuclear THP-1 cells. Migration of these cells is suppressed under hyperglycemic conditions, proposing that less mononuclear cells invade the site of fracture in diabetics. Further, we show that the composition of cytokines secreted by mononuclear cells strongly differ between diabetics and controls. Similar is seen in THP-1 cells cultured under hyperinsulinemia or hyperglycemia. The altered secretome reduces the positive effect of the THP-1 cell conditioned medium on migration of osteoprogenitor cells. In summary, our data support that factors secreted by mononuclear cells may support fracture healing by promoting migration of osteoprogenitor cells but suggest that this effect might be reduced in diabetics.

Pathogenic roles and therapeutic potential of the CCL8-CCR8 axis in a murine model of IgG4-related sialadenitis.

BACKGROUND: Our previous studies reveal that CCL18-CCR8 chemokine axis is upregulated in patients of immunoglobulin G4-related disease (IgG4-RD), suggesting that the CCL18-CCR8 axis is implicated in the etiology of IgG4-RD, although whether this axis has a potential as a therapeutic target remains unclear. Our purpose was to clarify the pathogenic roles and therapeutic potential of the murine CCL8 (analog of human CCL18)-CCR8 axis by using an animal model of IgG4-RD (LAT Y136F knockin mice; LAT mice). METHODS: We compared the infiltration of inflammatory cells and the fibrosis of the salivary glands of 6-week-old LAT mice and littermate mice. The expressions of Ccl8 and Ccr8 were also compared. Next, we investigated the therapeutic effects of intravenous administration of anti-CCL8 neutralizing antibody in LAT mice against inflammation and fibrosis of the salivary glands. We also investigated the effects of stimulation with recombinant mouse CCL8 on the collagen production in a mouse fibroblast cell line (NIH/3 T3) in vitro. RESULTS: When compared with the littermates, the LAT mice showed apparent infiltration of inflammatory cells and fibrosis in the salivary glands. The focus and fibrosis score in the salivary glands were significantly higher in the LAT mice than in the littermates. The expression levels of Ccl8 in the spleen and of Ccr8 in the salivary glands were significantly higher in the LAT mice than in the littermates. Anti-CCL8 antibody significantly improved the focus and fibrosis score in the salivary glands of the LAT mice. In vitro, stimulation with recombinant mouse CCL8 significantly increased the expression of collagen and ERK1/2 phosphorylation in NIH/3 T3. CONCLUSION: We clarified the overexpression and therapeutic potential of the mouse CCL8-CCR8 axis in LAT mice, which could play a crucial role in fibrosis via ERK1/2 phosphorylation, as well as the chemotaxis of inflammatory cells. The human CCL18-CCR8 axis might be a novel therapeutic target for IgG4-RD.

Biological characterization of ligands targeting the human CC chemokine receptor 8 (CCR8) reveals the biased signaling properties of small molecule agonists.

The human CC chemokine receptor 8 (CCR8) is a promising drug target for cancer immunotherapy and autoimmune disease. Besides human and viral chemokines, previous studies revealed diverse classes of CCR8-targeting small molecules. We characterized a selection of these CCR8 ligands (hCCL1, vCCL1, ZK756326, AZ6; CCR8 agonists and a naphthalene-sulfonamide-based CCR8 antagonist), in in vitro cell-based assays (hCCL1AF647 binding, calcium mobilization, cellular impedance, cell migration, ß-arrestin 1/2 recruitment), and used pharmacological tools to determine G protein-dependent and -independent signaling pathways elicited by these ligands. Our data reveal differences in CCR8-mediated signaling induced by chemokines versus small molecules, which was most pronounced in cell migration studies. Human CCL1 most efficiently induced cell migration whereby Gßγ signaling was indispensable. In contrast, Gßγ signaling did not contribute to cell migration induced by other CCR8 ligands (vCCL1, ZK756326, AZ6). Although all tested CCR8 agonists were full agonists for calcium mobilization, a significant contribution for Gßγ signaling herein was only apparent for human and viral CCL1. Despite both Gαi- and Gαq-signaling regulate intracellular Ca2+-release, cellular impedance experiments showed that CCR8 agonists predominantly induce Gαi-dependent signaling. Finally, small molecule agonists displayed higher efficacy in ß-arrestin 1 recruitment, which occurred independently of Gαi signaling. Also in this latter assay, only hCCL1-induced activity was dependent on Gßγ-signaling. Our study provides insight into CCR8 signaling and function and demonstrates differential CCR8 activation by different classes of ligands. This reflects the ability of CCR8 small molecules to evoke different subsets of the receptor's signaling repertoire, which categorizes them as biased agonists.

A Glucuronic Acid-Palmitoylethanolamide Conjugate (GLUPEA) Is an Innovative Drug Delivery System and a Potential Bioregulator.

Palmitoylethanolamide (PEA) is an endogenous anti-inflammatory lipid mediator and a widely used nutraceutical. In this study, we designed, realized, and tested a drug-carrier conjugate between PEA (the active drug) and glucuronic acid (the carrier). The conjugate, named GLUPEA, was characterized for its capability of increasing PEA levels and exerting anti-inflammatory activity both in vitro and in vivo. GLUPEA treatment, compared to the same concentration of PEA, resulted in higher cellular amounts of PEA and the endocannabinoid 2-arachidonoyl glycerol (2-AG), and increased 2-AG-induced transient receptor potential vanilloid type 1 (TRPV1) channel desensitization to capsaicin. GLUPEA inhibited pro-inflammatory monocyte chemoattractant protein 2 (MCP-2) release from stimulated keratinocytes, and it was almost as efficacious as ultra-micronized PEA at reducing colitis in dinitrobenzene sulfonic acid (DNBS)-injected mice when using the same dose. GLUPEA is a novel pro-drug able to efficiently mimic the anti-inflammatory and endocannabinoid enhancing actions of PEA.

Chemokine C-C motif ligand 8 in periodontal ligament during orthodontic tooth movement.

OBJECTIVES: To investigate the roles of chemokine (C-C motif) ligand 8 (CCL8) in periodontal ligament during orthodontic tooth movement (OTM). METHODS: Bioinformatics analyzed 100 genes in human periodontal ligament cells that were most upregulated after 48 hours of mechanical stress, and these genes were classified through GO and KEGG databases. Nickel-titanium closed-coil springs were placed between right first molar and incisors to produce 20 cN of orthodontic force in eight-week-old male SD rats for 1 and 2 days, followed by immunohistochemical staining of CCL8. Human periodontal ligament fibroblasts (hPDLFs) were stimulated by 14% cyclic tension force (Flexcell FX-5000 T Tension System) or hypoxia conditions to mimic OTM for 1 and 2 days, then the resulting CCL8 were examined through ELISA. Scratching assay was performed by treating hPDLFs with different concentrations of CCL8 (1 ng/ml, 10 ng/ml, 100 ng/ml). The migration, proliferation, and adhesion abilities of 100 ng/ml CCL8-treated hPDLFs were also examined. qRT-PCR and western blot detected matrix metalloproteinase 3, periostin, and osteoprotegrin expressions of hPDLFs under 100 ng/ml CCL8. RESULTS: Bioinformatic analysis demonstrated that CCL8 was upregulated after applying mechanical stress for 48 hours. CCL8 secretion showed upregulation after 24 hours of OTM applicationsin vivo and in vitro. CCL8-treated hPDLFs showed significant positive effects on cell proliferation and matrix metalloproteinase 3. It also inhibited periostin and osteoprotegrin expressions. CONCLUSIONS: CCL8 was upregulated in periodontal ligament during initial stage of OTM. Although CCL8 in human periodontal ligaments showed no significant effects on cell migration ability, it did enhance cell proliferation and osteoclastogenesis.

C-C Motif Chemokine 8 promotes angiogenesis in vascular endothelial cells.

OBJECTIVES: Angiogenesis is an important progress associated with several pathological situations. Several chemokines have been reported to act as regulators of angiogenesis. The current study aimed to find whether C-C Motif Chemokine 8 is involved in angiogenesis regulation. METHODS: To verify whether C-C Motif Chemokine 8 is related to angiogenesis in plaques, carotid plaques were collected from patients with severe carotid stenosis and analysed using CD31 immunohistochemistry and real-time PCR. To further clarify the relation between C-C Motif Chemokine 8 and angiogenesis, human umbilical vein endothelium cells and human dermal microvascular endothelial cells were treated with C-C Motif Chemokine 8 in the presence or absence of C-C motif chemokine receptor 2-Ab and extracellular regulated MAP kinase 1/2 inhibition (FR180204). Proliferation and migration of human umbilical vein endothelium cells and human dermal microvascular endothelial cells were examined with Cell Counting Kit-8 and Transwell chamber assay, respectively. In vitro angiogenesis stimulated by C-C Motif Chemokine 8 was examined using tube formation assay. Ex vivo and in vivo angiogenesis were assessed by mice aortic ring assay and Matrigel plug assay, respectively. C-C motif chemokine receptors of human umbilical vein endothelium cells were examined with real-time PCR, and C-C motif chemokine receptor 1, C-C motif chemokine receptor 2, extracellular regulated MAP kinase 1/2 and phosphorylation-extracellular regulated MAP kinase 1/2 were examined with western blotting assay. RESULTS: C-C Motif Chemokine 8 was increased in carotid plaques with severe angiogenesis in both RNA and protein level. C-C Motif Chemokine 8 (5 ng/ml) weakly increased human umbilical vein endothelium cell proliferation, but not on human dermal microvascular endothelial cells. Migration and tube formation could be induced by C-C Motif Chemokine 8 in both human umbilical vein endothelium cells and human dermal microvascular endothelial cells. In mice aortic ring assay and Matrigel plug assay, C-C Motif Chemokine 8 could promote angiogenesis compared to vehicle groups. Phosphorylation of extracellular regulated MAP kinase 1/2 was increased with C-C Motif Chemokine 8 stimulation. The migration and tube formation promoted by C-C Motif Chemokine 8 could be largely blocked by C-C motif chemokine receptor 2-Ab or extracellular regulated MAP kinase 1/2 inhibition (FR180204). CONCLUSIONS: C-C Motif Chemokine 8 could promote both in vitro and in vivo angiogenesis. C-C motif chemokine receptor 2 played an important role in the activation of C-C Motif Chemokine 8 and extracellular regulated MAP kinase 1/2 signalling pathway was involved in this mechanism.

Expression of monocyte chemotactic protein 2 and tumor necrosis factor alpha in human normal endometrium and endometriotic tissues.

Endometriosis is a gynocological disease characterized by the presence of the endometrial glands and stroma outside the uterine cavity. This disease affects % 6-10 of women with reproductive age and it causes serious problems such as pelvic pain, dysmenorrhea and infertility. Although endometriosis is one of the most investigated disease of gynecology, its pathogenesis is not clear completely. In recent years, many studies revealed the inflammatory nature of endometriosis. Many of the immune cells and their secretory products cytokines and chemokines has been detected in body fluids of women with endometriosis. Cytokines are protein or glycoprotein in structures and hormon-like molecules that act generally in a paracrine fashion to regulate immun responses. They involved in chemotaxis, cell proliferation, cell activation, motility, adhesion and morphogenesis. Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine secreted by the macrophages, monocytes, neutrophiles, T cells and natural killer cells. It stimulates increase in the level of the chemokines in body fluids. Monocyte chemotactic protein 2 (MCP-2) is a chemokine act to recruit and activate monocytes into sites of inflammation area. The aim of this study to investigate the ultrastructural properties and whether the expression and localization of TNF-α and MCP-2 in the eutopic endometrium (normal endometrium of women with endometriosis) and endometritic tissues of women with endometriosis. Eutopic endometrial and endometriotic tissue samples were obtained from women with endometriosis between 20-41 y and normal endometrial tissues were collected from 5 women without endometriosis as a control group. Tissues were processed for light and electron microscopy and examined. The epithelial cells of endometriotic tissues were revealed strongly cytoplasmic TNF-α and MCP-2 immunreactivities. Eutopic endometrial tissues were also stained prominently for both TNF-α and MCP-2. Furthermore, a significant increase in stromal macrophages were observed in endometriotic tissues. Moreover, the ultrastructural observations on the normal and endometriotic tissues were exhibited microvilli-rich cells and ciliated cells. These findings suggest that TNF-α and MCP-2 may be involved in normal endometrial biology and in the pathogenesis of endometriosis.

Loganin alleviates macrophage infiltration and activation by inhibiting the MCP-1/CCR2 axis in diabetic nephropathy.

BACKGROUND/AIMS: The theory of inflammation is one of the important theories in the pathogenesis of diabetic nephropathy (DN). We herein aimed to explore whether loganin affected macrophage infiltration and activation upon diabetic nephropathy (DN) by a spontaneous DN mice and a co-culture system of glomerular mesangial cells (GMCs) and macrophage cells (RAW264.7) which was induced by advanced glycation end products (AGEs). METHODS AND KEY FINDINGS: Loganin showed remarkable capacity on protecting renal from damage by mitigating diabetic symptoms, improving the histomorphology of the kidney, decreasing the expression of extracellular matrix such as FN, COL-IV and TGF-ß, reversing the production of IL-12 and IL-10 and decreasing the number of infiltrating macrophages in the kidney. Moreover, loganin showed markedly effects by suppressing iNOS and CD16/32 expressions (M1 markers), increasing Arg-1 and CD206 expressions (M2 markers), which were the phenotypic transformation of macrophage. These effects may be attributed to the inhibition of the receptor for AGEs (RAGE) /monocyte chemotactic protein-1 (MCP-1)/CC chemokine receptor 2 (CCR2) signaling pathway, with significantly down-regulated expressions of RAGE, MCP-1 and CCR2 by loganin. Loganin further decreased MCP-1 secretion when RAGE was silenced, which means other target was involved in regulating the MCP-1 expression. While loganin combinated with the inhibitor of CCR2 exerted stronger anti-inhibition effects of iNOS expression, suggesting that CCR2 was the target of loganin in regulating the activation of macrophages. SIGNIFICANCE: Loganin could ameliorate DN kidney damage by inhibiting macrophage infiltration and activation via the MCP-1/CCR2 signaling pathway in DN.

Expression of the Peptidase "Fibroblast Activation Protein" on Decidual Stromal Cells Facilitating Tissue Remodeling.

INTRODUCTION: Expression of fibroblast activation protein (FAP) has been detected in activated fibroblasts participating in injury response, fibrotic and inflammatory conditions, and tumorigenesis. Human endometrium is equally characterized by rapid tissue remodeling events due to the reproductive tasks comprising the activity of proteolytic enzymes. OBJECTIVE: We therefore hypothesized that FAP-positive fibroblasts could also be involved in physiological processes requiring tissue remodeling, such as decidualization during early pregnancy. METHODS/RESULTS: The expression of FAP was analyzed by immunohistochemistry in frozen sections of decidual tissue from early pregnancy (gestational weeks: 6-12). All tissue samples clearly displayed a strong expression of FAP on the surface of stromal fibroblasts. Additionally, the percentage of FAP-positive fibroblasts freshly isolated from the decidua of the corresponding gestational weeks was calculated by applying FACS analysis. Decidual fibroblasts of different gestational weeks showed a significant decrease in FAP expression between the 6th and 7th weeks of gestation, which was followed by a steady slow reconstitution. By analyzing the expression of cytokines, chemokines, and growth factors of isolated FAP-positive decidual fibroblasts, we detected high levels of monocyte-attracting chemokines (growth-related oncogene alpha and monocyte chemoattractant protein-1 and -2), granulocyte-attracting chemokines (e.g., IL-8), proinflammatory factors (IL-1α and tumor necrosis factor alpha), and angiogenic substances (e.g., vascular endothelial growth factor and IL-8), which all promote an optimal microenvironment for implantation and growth of the conceptus. CONCLUSIONS: Our data demonstrate that the healthy early pregnancy decidua is characterized by a general occurrence of FAP-positive fibroblasts possibly participating in active tissue remodeling during implantation.

Bioinformatics identification of CCL8/21 as potential prognostic biomarkers in breast cancer microenvironment.

BACKGROUND: Breast cancer (BC) is the most common malignancy among females worldwide. The tumor microenvironment usually prevents effective lymphocyte activation and infiltration, and suppresses infiltrating effector cells, leading to a failure of the host to reject the tumor. CC chemokines play a significant role in inflammation and infection. METHODS: In our study, we analyzed the expression and survival data of CC chemokines in patients with BC using several bioinformatics analyses tools. RESULTS: The mRNA expression of CCL2/3/4/5/7/8/11/17/19/20/22 was remarkably increased while CCL14/21/23/28 was significantly down-regulated in BC tissues compared with normal tissues. Methylation could down-regulate expression of CCL2/5/15/17/19/20/22/23/24/25/26/27 in BC. Low expression of CCL3/4/23 was found to be associated with drug resistance in BC. Results from Kaplan-Meier plotter and BC Gene-Expression Miner v4.2 (bcGenExMiner) v4.2 demonstrated that BC patients with high CCL8 and low CCL19/21/22 expression were more likely to have a worse prognosis. CCL8 expression was significantly up-regulated in BC tissues compared with normal tissues. High CCL8 expression was significantly correlated with negative PR, negative ER, positive nodal status, triple-negative BC subtype, basal-like BC subtype, triple-negative and basal-like BC subtype and high grades. CCL21 was down-regulated in BC, while high levels of CCL21 was associated with negative PR, triple-negative subtype, basal-like subtype and low tumor grade. Functional analysis demonstrated that CCL8 and CCL21 were involved in carcinogenesis, tumor immune escape and chemoresistance in BC. CONCLUSION: Integrative bioinformatics analysis demonstrated CCL8/21 as potential prognostic biomarkers in BC microenvironment.

IL6/sIL6R regulates TNFα-inflammatory response in synovial fibroblasts through modulation of transcriptional and post-transcriptional mechanisms.

INTRODUCTION: The clinical efficacy of specific interleukin-6 inhibitors has confirmed the central role of IL6 in rheumatoid arthritis (RA). However the local role of IL6, in particular in synovial fibroblasts (SF) as a direct cellular target to IL6/sIL6R signal is not well characterized. The purpose of the study was to characterize the crosstalk between TNFα and IL6/sIL6R signaling to the effector pro-inflammatory response of SF. METHODS: SF lines were stimulated with either TNFα, IL6/sIL6R, or both together, for the time and dose indicated for each experiment, and where indicated, cells were treated with inhibitors actinomycin D, adalimumab, ruxolitinib and cycloheximide. mRNA expression of cytokines, chemokines and matrix metalloproteases (MMPs) were analyzed by quantitative RT-PCR. Level of IL8/CXCL8 and CCL8 in culture supernatants was measured by ELISA. Mononuclear and polymorphonuclear cells migration assays were assessed by transwell using conditioned medium from SF cultures. Statistical analyses were performed as indicated in the corresponding figure legends and a p-value < 0.05 was considered statistically significant. RESULTS: The stimulation of SF with IL6/sIL6R and TNFα, cooperatively promotes the expression of mono- and lymphocytic chemokines such as IL6, CCL8 and CCL2, as well as matrix degrading enzymes such as MMP1, while inhibiting the induction of central neutrophil chemokines such as IL8/CXCL8. These changes in the pattern of chemokines expression resulted in reduced polymorphonuclear (PMN) and increased mononuclear cells (MNC) chemoattraction by SF. Mechanistic analyses of the temporal expression of genes demonstrated that the cooperative regulation mediated by these two factors is mostly induced through de novo transcriptional mechanisms activated by IL6/sIL6R. Furthermore, we also demonstrate that TNFα and IL6/sIL6R cooperation is partially mediated by the expression of secondary factors signaling through JAK/STAT pathways. CONCLUSIONS: These results point out to a highly orchestrated response to IL6 in TNFα-induced SF and provide additional insights into the role of IL6/sIL6R in the context of RA, highlighting the contribution of IL6/sIL6R to the interplay of SF with other inflammatory cells.

Possible involvement of crosstalk between endometrial cells and mast cells in the development of endometriosis via CCL8/CCR1.

BACKGROUND: The density and the activity of mast cells are associated with endometriosis. However, the role of mast cells on the pathogenesis of endometriosis remains unclear. Our study aims to investigate whether endometrial cells interact with mast cells and the involvement of their crosstalk in the development of endometriosis. METHODS: The transwell assay was applied to investigate the effect of mast cells on the migratory ability of human primary endometrial cells. Mast cells were cocultured with endometrial epithelial and stromal cells respectively and total RNAs were isolated and subjected to mRNA sequencing. Next, the transwell assay, CCK-8, and tube formation were applied to study the role of CCL8 on the endometrial and endothelial cells in vitro. The mouse model was also established to confirm the role of CCL8 in the development and angiogenesis of endometriosis. RESULTS: CCL8 was up-regulated in mast cells when cocultured with endometrial cells. CCL8 was highly expressed in the ectopic endometrium and the serum of patients with endometriosis. CCL8 promoted the migratory ability of endometrial epithelial and stromal cells and increased the proliferation, migration, and tube formation of endothelial cells. CCR1, the receptor of CCL8, was over-expressed in the ectopic endometrium and colocalized with blood vessels in ovarian endometriomas. The inhibition of CCR1 suppressed the development and angiogenesis of endometriosis in vivo. CONCLUSION: The crosstalk between endometrial cells and mast cells in the development of endometriosis via CCL8/CCR1 was demonstrated, thereby providing a new treatment strategy for endometriosis.

Inhibition of inflammatory CCR2 signaling promotes aged muscle regeneration and strength recovery after injury.

Muscle regeneration depends on a robust albeit transient inflammatory response. Persistent inflammation is a feature of age-related regenerative deficits, yet the underlying mechanisms are poorly understood. Here, we find inflammatory-related CC-chemokine-receptor 2 (Ccr2) expression in non-hematopoietic myogenic progenitors (MPs) during regeneration. After injury, the expression of Ccr2 in MPs corresponds to the levels of its ligands, the chemokines Ccl2, 7, and 8. We find stimulation of Ccr2-activity inhibits MP fusion and contribution to myofibers. This occurs in association with increases in MAPKp38δ/γ signaling, MyoD phosphorylation, and repression of the terminal myogenic commitment factor Myogenin. High levels of Ccr2-chemokines are a feature of regenerating aged muscle. Correspondingly, deletion of Ccr2 in MPs is necessary for proper fusion into regenerating aged muscle. Finally, opportune Ccr2 inhibition after injury enhances aged regeneration and functional recovery. These results demonstrate that inflammatory-induced activation of Ccr2 signaling in myogenic cells contributes to aged muscle regenerative decline.

Type I IFN signaling in T regulatory cells modulates chemokine production and myeloid derived suppressor cells trafficking during EAE.

Interferon-ß has therapeutic efficacy in Multiple Sclerosis by reducing disease exacerbations and delaying relapses. Previous studies have suggested that the effects of type I IFN in Experimental Autoimmune Encephalomyelitis (EAE) in mice were targeted to myeloid cells. We used mice with a conditional deletion (cKO) of the type I IFN receptor (IFNAR) in T regulatory (Treg) cells to dissect the role of IFN signaling on Tregs. cKO mice developed severe EAE with an earlier onset than control mice. Although Treg cells from cKO mice were more activated, the activation status and effector cytokine production of CD4+Foxp3- T cells in the draining lymph nodes (dLN) was similar in WT and cKO mice during the priming phase. Production of chemokines (CCL8, CCL9, CCL22) by CD4+Foxp3- T cells and LN resident cells from cKO mice was suppressed. Suppression of chemokine production was accompanied by a substantial reduction of myeloid derived suppressor cells (MDSCs) in the dLN of cKO mice, while generation of MDSCs and recruitment to peripheral organs was comparable. This study demonstrates that signaling by type I IFNs in Tregs reduces their capacity to suppress chemokine production, with resultant alteration of the entire microenvironment of draining lymph nodes leading to enhancement of MDSC homing, and beneficial effects on disease outcome.

CaSR Antagonist (Calcilytic) NPS 2143 Hinders the Release of Neuroinflammatory IL-6, Soluble ICAM-1, RANTES, and MCP-2 from Aß-Exposed Human Cortical Astrocytes.

Available evidence shows that human cortical neurons' and astrocytes' calcium-sensing receptors (CaSRs) bind Amyloid-beta (Aß) oligomers triggering the overproduction/oversecretion of several Alzheimer's disease (AD) neurotoxinseffects calcilytics suppress. We asked whether AßCaSR signaling might also play a direct pro-neuroinflammatory role in AD. Cortical nontumorigenic adult human astrocytes (NAHAs) in vitro were untreated (controls) or treated with Aß25-35±ï€ NPS 2143 (a calcilytic) and any proinflammatory agent in their protein lysates and growth media assayed via antibody arrays, enzyme-linked immunosorbent assays (ELISAs), and immunoblots. Results show Aß•CaSR signaling upregulated the synthesis and release/shedding of proinflammatory interleukin (IL)-6, intercellular adhesion molecule-1 (ICAM-1) (holoprotein and soluble [s] fragment), Regulated upon Activation, normal T cell Expressed and presumably Secreted (RANTES), and monocyte chemotactic protein (MCP)-2. Adding NPS 2143 (i) totally suppressed IL-6's oversecretion while remarkably reducing the other agents' over-release; and (ii) more effectively than Aß alone increased over controls the four agents' distinctive intracellular accumulation. Conversely, NPS 2143 did not alter Aß-induced surges in IL-1ß, IL-3, IL-8, and IL-16 secretion, consequently revealing their Aß•CaSR signaling-independence. Finally, Aß25-35±ï€ NPS 2143 treatments left unchanged MCP-1's and TIMP-2's basal expression. Thus, NAHAs Aß•CaSR signaling drove four proinflammatory agents' over-release that NPS 2143 curtailed. Therefore, calcilytics would also abate NAHAs' Aß•CaSR signaling direct impact on AD's neuroinflammation.

Silencing CCL8 inhibited the proliferation and migration of PDGF-BB-stimulated human aortic smooth muscle cells.

C-C motif Chemokine ligand 8 (CCL8) has been found in diseases' pathogenesis. But its molecular mechanism in atherosclerosis (AS) remains to be elucidated. Human aortic smooth muscle cells (HASMCs) were stimulated by PDGF-BB to establish cell model. α-SMA in PDGF-BB-stimulated HASMCs was measured by immunofluorescence staining. Relative gene expressions in PDGF-BB-stimulated HASMCs were detected by quantitative real-time polymerase chain reaction and western blot. HASMCs proliferation, migration, and cell cycle were assessed by cell counting kit-8, wound-healing assay, and flow cytometry. HASMCs viability was increased after PDGF-BB stimulation, with α-SMA downregulation yet CCL8 upregulation. Silencing CCL8 inhibited PDGF-BB-stimulated HASMCs proliferation and migration, and increased cells percentage in G1 phases but decreased those in S phase. Also, silencing CCL8 decreased OPN and cyclinD1 expressions and AKT and ERK1/2 phosphorylation while increased those of α-SMA and Sm22α. However, upregulating CCL8 led to opposite effects, suggesting CCL8 could be an atherosclerosis therapeutic target.